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If you no longer nee 'v- . , , inrey In Washington for an official 

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UNITED STATES DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY PROFESSIONAL PAPER 202
UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 202

GEOLOGY AND ORE DEPOSITS

OF THE

METALINE QUADRANGLE, WASHINGTON

BY

C. F. PARK, JR., AND R. S. CANNON, JR.

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1943

Vor siile by the Superintendent of Documents, Washington, D. C. - - - ' - - - - . - - - . - . Price SI.50 cents
CONTENTS

Abstract. ____..________----____-__--_______---_--_-

Introduction ______._____________-_-_--____.._---_--

Location and accessibility. _____________________

Topography _ _ _ __-_-_____-__-__-_-___-----_-_

Climate and vegetation..... _.______________.__ 

Field work and acknowledgments. .______.___-.__

Scope of the report__-_-_-_---_----___-___------

Bibliography. _________________________________

General geology ____________________________________

Principal features. _--________--__-___-_-_--_---

Geologic formations- _------__-_-----_-_-----_-_

Pre-Cambrian rocks... _ __-_-_-______--_-__-

Priest River group. _________--_--_---_-

Shedroof conglomerate _--___________---

Distribution __ ___________________

Thickness and stratigraphic relations. 

Lithology and internal structure. ....

Megascopic features _ . ________

Microscopic features. __._-_---_ 

Conditions of deposition. _ ____._._._

Leola volcanics. _ _._____-__.______-_-__

Distribution __ _ _.__.___._____._._

Thickness and stratigraphic relations. 

Lithology and internal structure. ____

Megascopic features __ _ _--.__.

Microscopic features ___________

Origin. _ --__---_--_-__-_-_--_---_- 

Summary. _______--_._______---__-

 Age.-..-...- _------------------_.

Cambrian (?) system. __ ____________________

Monk formation. _ .--..-..----_-__--_-_

Distribution _ .- - -----------------

Thickness and stratigraphic relations. 

Lithology and internal structure. ___.

Megascopic features. ----------

Microscopic features. ------ _____

Conditions of sedimentation. ___-----

Cambrian system. _ ._--_-___.-------------

Gypsy quartzite. . -_-._--..--_-_--_-----

Distribution.---- ------------------

Thickness and stratigraphic relations. 

Lithology and internal structure. ____

Megascopic features _ - - _-_-___ 

Microscopic features. ___------_

Conditions of sedimentation... ___-_- 

Age------------- -----------------

Maitlen phyllite. _.------.--_----------

Distribution __ -____._'____________

Thickness and stratigraphic relations. 

Lithology and internal structure. ----

Megascopic features _ - - -------

Microscopic features. __.-------

Conditions of sedimentation _________

Age. __---_--__-----_..__.--_----__

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General geology Continued.

Geologic formations Continued. 

Cambrian system Continued.

Metaline limestone _ __ __ _ _____________

Distribution. _ __ _ __________________

Thickness and strati graphic relations. 

Lithology and internal structure__.-_ 

Megascopic features _ ___._--__

Microscopic features. __________

Conditions of sedimentation______.__

Ordovician system. . _---_----________-_____

Ledbetter slate. ________._.______-____.

Distribution.. . ____________________

Thickness and stratigraphic relations. 

Lithology and internal structure.....

Megascopic features. ____-_____.

Microscopic features. ____-_.__

Conditions of sedimentation _ _____

Age. __---.-_.---._..___._-_-----

Devonian system _________________________

Devonian limestone. __________________

Distribution __ __--_________-____

Thickness _ _____________________

Lithology. ________________________

Conditions of sedimentation. ________

Tertiary system ___________________

Tiger formation. _ _____________

Distribution. _ _____________

Thickness _ ___--__--_____

Lithology- -__------__-_---

Conditions of sedimentation.

Quaternary system _ _ ___________._-_-___--.

Pleistocene deposits. . ___________________

Recent deposits.. _ _.___.___.._.________.

Intrusive rocks _--_________________._.____-.

Kaniksu batholith_ _________--__--_..-_.

Distribution. _ --________..__.______.

General character _ _ __._.._.-_____.

Petrography. ___-___.._.-.-_-_-___. 

Border facies. . ____.____-_-_.____._.

Age. __.-__.__-__-__.._.-___..____.

Minor intrusive bodies, _--_____.___-__.,

Granitic masses -_.__ .___________..

Pegmatite bodies. __________________

Aplite dikes. _______________________

Lamprophyre and related dikes__.___. 

Other dike rocks _ -___________-_...

Structure of the pre-Tertiary sedimentary and 

metamorphic rocks. -__ ________________________

General features. --------____..__--._-_____.

Flume Creek-Russian Creek block ____________

Valley block. __,_.._.._._----_.___________.

Hall Mountain block. _ _-______________.____ 

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IV CONTENTS

General geology Continued. Pase 

Structure of the pfe-Tertiary sedimentary and 

metamorphic rocks Continued.

Eastern block__________-_____--_____------- 33

Relation of the structure to that of surrounding

regions _-.___________-_---_-_----_-_--_--_ 34

Relation of deformation to batholith intrusion.. 34

Development of the topography._____--_---_-__------ 35

Caves------..------------------------------------- 38

Alteration of the sedimentary rocks_------------------ 39

Regional metamorphism_________________________ 39

Igneous metamorphism__-_____-__-__-----_---_-- 40

General features---------------------------- 40

Recrystallization____- ----------------------- 40

Alteration to silicate minerals_______._-____-_ 40

Hydrothermal alteration not directly related to igneous masses--------------------------------- 41

Dolomitization. _ ___________________________ 41

Bedded deposits.-.__--____-_-__------_- 42

Crystalline dolomite not bedded__________ 44

Silicification.____.______-_-____-______------ 44

Coarse-grained calcite.-_-___--l-----__------ 45

Formation of the alteration products._._-__-__ 45

Economic factors.-------------------------- 46

Ore deposits..-.-------------------------------- - 47

History of mining___---_--------_-_------_.... . . - 47

Production_--_-___-_-____--__--_-----_----. - 48

Ore bodies.._.______------_-----.---_--.------- 48

Replacement deposits. __-----__-_-_---.-----_ 50

General features--___-_____-_-_____-_-_- 50

Form and structure.-------------------- 50

Replacement deposits in the igneous-metamorphic zone.--------------.--------- 51

Lode deposits.______----------------------- 51

Relations of ore deposits to regional structure._ 52

Brecciation _______________.___-----__--___- 52

Crush breccia___________________________ 52

Rubble breccia.________________________ 53

Cave breccia----___-------_--_--_------ 53

Origin of the ores-___________________________ 53

Oxidized ores_____-______--____---____-_-__- 53

Future of the district.--.------__________________ 54

Minerals of the ore deposits and metamorphic rocks_____ 54

Native elements_____-___-__---_----_--_______-_- 54

Sulfides__ _ _---_--_----------_--_-'_---------._ 54

Sulfosalts.___-__--___-_-_-__---_--___--_____-_- 55

Haloids. ___ ____________________________________ 55

Oxides_________________________________________ 55

Carbonates. ___________________________________ 56

Silicates ___.___.__._._____-_____ ---____.-___-_ 56

Minerals of the ore deposits and metamorphic rocks Con. 

Titanosilicates. __________________________________

Sulfates_ _ ______________________________________

Molybdates- _____-____-_--_____- .. .__..._..____.._

Hydrocarbon compounds. ________-_.. -...-__._____

The mines --__----_------______________-______.__-_

Russian Creek area_ ______--____--___-_---_--_-_

United Treasure- ___________________________

Frisco Standard.. __________________________

My Era. __________________________________

Just Time. _ _________________'___._._.._____

Slate Creek district _-__________-----_-._._____-_

Lead -Hill. .._.....___...._____..______...._

Bailey-Hanson _____________________________

Dumont properties. ___ ______________________

Other properties in the Slate Creek district___._ 

Outlying areas. ___ _ ---_-___--_-_-__-_________-

Mule Deer_ ________________________________

Little Noisy _ ________-___--__-___--___-. __

Gypsy Copper Camp___ _ ____-_---____-.____-

Metaline districtBella May -_

Diamond R_ _________________

Flusey group. --_____--__-__--

Giant. ______________________

Grandview.. _ _______-_-_____-

E. J. Hoage---------------_--

Lakeview_ ____-_____-!-_-_____

Lead King--______-_- ________

Robert E. Lee----------------

Lucky Strike. ______----__-___

Metaline Contact. ____________

Morning and Mammoth- _ __.__ 

Pend Oreille _________---_-__--

Riverside. ___________________

Scandinavian (Lead Queen) ____

Tom Cat-___----_____---_-_-

Washington and Metaline Falls_ 

Wolf Creek--__________ _;____

Z Canyon Mutual _______-__--

Z Canyon-______--__ __-____-_

0. K__- -_-----_._-_----.-___

Oriole. ______________________

Limestone- -_-_____-____.-_---_--

Lehigh iron pits. _________________

Placer deposits. __________________

Harvey Bar. _____-__--______-

Scherding placer __ ____________

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CONTENTS

ILLUSTRATIONS

Page 

PLATE .1. Geologic map and cross sections of the Metaline quadrangle, Wash_____________________________________ In pocket

2. A, Contorted phyllite in Priest River group; B, Shedroof conglomerate on ridge between Hall Mountain and Grassy 

Top Mountain; C, Rhombohedral fragments in Shedroof conglomerate formed by the shearing of a band of 

quartzite--___----___-_----_-------__-----___-_--___--_--________-_____-________._________________ 10

3. A, Sandy bed in Shedroof conglomerate, showing shear planes cutting bedding at an angle of about 30°; B, Bedding

in transition zone between Shedroof conglomerate and Leola volcanics___-______-._..________-.________..__ 10

4. A, B, Surfaces showing elongation of fragments in Shedroof conglomerate-_--_-____-____-__-_____________._. 10

5. A, Photomicrograph of greenstone of Leola volcanics; B, Sheared conglomerate in Gypsy quartzite____________ 11

6. A, B, C, D, Maitlen phymte....:.........-...-..._..__..____-__._..._.._._..._.__.__.___.__.__...__ 18

7. Post Pleistocene gorge of Pend Oreille River.___________________________________________________________ 18

8. A, Metaline limestone, Pend Oreille mine; B, Chert nodules on weathered surface in Metaline limestone, Lead

Hill...____.,..-_----.---------_----_--------__---___----_____--.__-__.__.__.._--.____.___________ 18

9. A, Black and light-colored dolomite, north side of Crescent Lake; B, Algae in lower part of Metaline limestone,

road cut east of upper Lehigh quarry_________._______________________'______._____________.________._ 19

10. A, Devonian, limestone breccia; B, C, Intraformational dolomite breccia; D, Thin-bedded dolomite with dessication cracks..___-.-_._---.---_____--____.------_-_-_____---____---_______..__._____________________ 26

.1.1. A, Cliff of poorly sorted Tertiary beds; B, Tertiary sedimentary debris.____________________________________ 26

.12. A, Polished slab of porphyritic facies of the Kaniksu batholith; B, Muscovite-garnet facies of the Kaniksu batholith. 26

13. A, Photomicrograph of a thin section interpreted as showing biotite altered to muscovite; B, Dikelet in phyllite; 

C, Photomicrograph 'of thin section showing shearing nearly normal to bedding; D, Gypsy quartzite west of 

FJume Creek fault-__.-_----.------.-_---.--_------___-__--_-___-_______-_-____j__._________________ 27

14. A, Tightly folded Metaline limestone next to Russian Creek fault; B', C, Metaline limestone thrust over Ledbetter

si ate ___--_---_-_--_------------------_-----------------------------_----------------__--_----___- 34

15. A, Terraces along Pend Oreille River; B, Stream terraces on Upper Ruby Creek.._-____-___-_____-_-_--____ 42

16. A, Amphitheaters on east side of Gypsy Ridge; B, Glacial blockade at north end of Sullivan Lake----.----.-- 42

1.7. A, Paligorskite in cave, Pend Oreille mine; B, Paligorskite from Pend Oreille mine_____-_____________________ 42

18. Fragments of calcite, jasperoid, ore, and crystalline quartz taken from inside a piece of paligorskite from Pend

Oreille mine.____________-_----_----_------_-------------------------------_-----_---------___--___ 42

19. A, Hornfels developed in previously folded phyllite; B, C, Photomicrographs of altered carbonate rock_________ 42

20. A, Chloritoid schist facies of Maitlen phyllite; B, Photomicrograph of sillimanite schist; C, Photomicrograph of

andalusite grains in mica schist; D, Photomicrograph of metamorphosed phyllite-_________________________ 42

21. Graphs of analyses of diamond-drill cores.._____________________________________________________________ 42

22. Graphs of analyses of diamond-drill cores._______________________________________________________________ 42

23. A, Buttons of anthracite composition in recrystallized dolomitic limestone, Wolf Creek prospect; B, Silicified and 

mineralized breccia, Pend Oreille mine; C, Polished fragment of ore in which galena replaces calcite along cleavage planes, Pend Oreille mine; D, Crustified banding in dolomite, Lake view prospect; E, Zebra rock, cobble 

from stream in east center of sec. 14, T 40 N., R. 42 E_________________________________________________ 50

24. A, Calcite and dolomite, Lead Hill mine; B, Partly silicified dolomite, Pend Oreille mine; C, Crudely banded mineralized rock, Lakeview prospect. _-_______-__-_---______--__--__-___-____-_______-_____.o__________ 50

25. A, Polished slab from Grandview adit; B, Zinc ore from Pend Oreille mine; C, Slickensided galena from Pend

Oreille mine; D, Post-mineral fault, calcite faulted against ore, Pend Oreille mine.._-_.-_--______-_________ 50

26. Concentrically banded dolomite and sulfides, Z Canyon mine-__-_-__---------_----_--_----______-___--_--- 50

27. A, PoMshed surface of specimen of mineralized rock from the Coffin property; B, Cave breccia, Pend Oreille mine;

C, Washer and gravel bar, Scherding placer..-_____-_-_-__--_-_______-____-----______-_____-_-____ T _.-_ 50

28. Sketch of surface at Lead Hill mine___-_----_-----_-------_-----_-_---------_------_-_-------------- In pocket

29. Sketch of surface at Bella May rnine------_------.---_----------------------_-_---------------_-___..-_-_ 66

30. Plan and section of new adit at Bel 1 a May mine_______---___--_--___-----_-___-___-___--___--_-______ In pocket

31. Underground workings at Grandview mine___________________________________________________________ In pocket

32. Pend Oreille mine and mill____--___----__.-----__----_-_____-___-__-----_--_--__---_--_______-________ 74

33. Plan of workings of Pend Oreille mine-_-___---_----------------------------_------------_------____- In pocket

34. Block diagram of Pend Oreille mine and vicinity..___________________________________________________ In pocket

I? i CURB 1. Index map of Washington showing location of the Metaline quadrangle.----.-.______________________________ 2

2. Camera lucida sketch of part of a thin section of Shedroof conglomerate_______--_--___-_--___-___-__-_____ 8

3. Columnar sections of Gypsy quartzite on the Crowell-Sullivan ridge and on the ridge west of the Oriole mine.--. 14

4. Sketch of a hand specimen of phyllite from south side of Hall Mountain.___________________________________ 16

5. Sketch of contact between Kaniksu batholith and Maitlen phyllite in sec. 11, T. 38 N., R. 42 E._____-_------. 26

6. Generalized sketch plan of junction of Flume Creek fault and Russian Creek fault.__________________________ 29

7. Simplified sketch showing type of movement on small faults in thrust plate of Metaline limestone in Pend Oreille

River gorge north of Metaline Falls__________________________________________________________________ 32

8. Sketch of ''zebra" banding 400 feet from portal of the new Bella May adit__-_---__-_-_---l-________________ 43

9. Plan and section of Frisco Standard mine.-_-___---------________---__-_-_____--________________________ 61

10. Upper workings at the Bella May mine.___--_---_----_-__-_______-_----___---_-____________________.___ 66

11. Dolomite-slate contact at inclined shaft at Robert E. Lee claim... _-_-------. ______________________________ 71
GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

By C. F. PARK, JR., and R. S. CANNON, JR,

ABSTRACT

The Metallne quadrangle is in the extreme northeast corner 

of Washington State. In the northern part of the quadrangle 

the Pend Oreille Mountains are steep and rugged, but to the 

south they are more subdued and .rounded. The region is 

crossed by the northward-flowing Pend Oreille River, along 

which are two well-developed terrace levels. Except for the 

highest peaks, the region has been covered by the Cordilleran 

ice sheet, and both depositional and erosional glacial features 

are abundantly developed.

Pro-Cambrian rocks crop out over a large area in the eastcentral part of the quadrangle. These rocks include the complex Priest River group, unconformably overlain by about 5,000 

feet of Shedroof conglomerate and 5,000 feet of Leola volcanics. 

Above the pre-Cambrian is 20,000± feet of Cambrian and prob- 

;ible Cambrian rocks that include, in ascending order, the Monk 

formation of schists, grits, and limestones, 3,800 feet more or 

less; the Gypsy quartzite, 5,300-8,500 feet; the Maitlen phyllite, 

5,000 feet; and the Metaline limestone (limestone and dolomite) 

3,000 feet. Overlying the Metaline limestone is about 2,500 feet 

of carbonaceous Ordovician slate (Ledbetter slate) and 700 

feet of Devonian limestone. Above the Paleozoic formations in 

the Pend Oreille Valley are remnant? of poorly sorted semiconsolidated clastic sediments of Tertiary age, the Tiger formation.

The southern half of the quadrangle is.underlain by the 

Kaniksu batholith, a mass consisting predominantly of quartz 

monzonite of Cretaceous (?) age, which is considered to be 

genetically related to the Nelson batholith, to the north, and 

the Idaho batholith, to the southeast. Three facies of the 

intrusive rock are recognized a biotite facies, a muscovite 

facies, and a porphyritic facies. Along the borders the igneous 

rock is fine-grained and contains large quantities of ferromagnesinn minerals, both biotite and amphibole. An igneous metamorphic zone is developed around the instrusive mass. This 

zone, which is as much as 4 miles wide, consists of an inner 

ring of hornfels and marbles and an outer ring of crystalline 

schists and marbles. The igneous metamorphic rocks are of 

two types (1) recrystallized and (2) altered to silicate minerals. Silica was the principal material added during the 

nietfimorphism, but large quantities of water facilitated the 

transfer of materials. The metamorphic minerals are iron-poor.

The complex structure of the sedimentary and metamorphic 

rocks has a prevailing northeastward trend. Folding, which 

luissed into low-angle faulting, was the earliest deformation of 

which evidence has been recognized. It was followed by 

steeply dipping northeastward-striking thrust or normal faults 

and later by northwestward-trending normal faults that may 

have been caused by intrusive forces. The Pend Oreille Valley, 

a much-broken block bounded on the east and west by steeply 

dipping faults, is underlain principally by the Maitlen phyllite, 

the Metaline limestone, and the Ledbetter slate. The faults to 

the west, the Flume Creek and Russian Creek faults, have an

offset of at least 10,000 feet. The Flume Creek fault trends a 

little east of north nearly to the Canadian border, where it 

swings abruptly into the Russian Creek fault a few degrees 

south of west. Prefault linear structural features, defined as 

intersections of bedding planes with axial planes of folds, trend 

at angles of 30°-40° from the Russian Creek fault and persist 

with the same strike and pitch on both sides of the fault 

facts that are interpreted to mean that displacement on this 

fault had no rotational component. Foliation planes, particularly in the older rocks, cut and obscure the bedding. In many 

of the phyllitic rocks a pseudobedding or compositional layering 

is developed.

Lead-zinc deposits were reported in the Pend Oreille Valley 

in 1869, but it was not until 192S that large bodies of commercial ore were found. The production from 1906 to 1937, 

inclusive, is valued at $3,327,331. In late years zinc has been 

the principal metal produced. Because of the recent development of considerable bodies of ore and the large amount of 

unexplored but geologically favorable ground, the future of the 

district seems to be assured for some years. The ores are 

generally of low grade, containing 5 to 15 percent of combined 

zinc and lead, and economic success depends in part on efficient 

handling of large tonnages.

Three principal types of ore deposits are recognized (1) 

replacement deposits in carbonate rocks not in the igneousmetamorphic zone, including minor amounts of ore filling open 

cavities; (2) closely related replacement deposits in igneous 

metamorphic rocks; and (3) lodes, mined heretofore chiefly 

for their silver content.

The principal replacement deposits are in the dolomitic Metaline limestone in the Pend Oreille and tributary valleys. The 

ores are in the hanging-wall blocks of large normal faults, 

particularly the Flume Creek and Slate Creek faults, although 

other fault blocks are mineralized. The replacement ores occur 

generally along minor breaks and.in crackle breccia bodies. So 

far as now known, ore of this type is confined to the upper part 

of the Metaline limestone, less than 500 feet below the Ledbetter slate. The ores are generally associated with and occur 

in dark-gray jasperoid; around the jasperoid and ore coarsegrained white calcite and crystalline dolomite are commonly 

found. The calcite and dolomite were not introduced by the 

silica and ore-bearing solutions but were removed from the 

replaced carbonate beds by these solutions and redeposited in 

more favorable situations. The mineral composition of the ores 

is simple, sphalerite and galena being the common minerals. 

Oxidation of the ore is shallow, and in many places sulfides 

are on or within a few feet of the surface. Numerous caves 

are found in the largest mine, the Pend Oreille. These caves 

are in breccia zones along fractures and were probably formed 

by circulating meteoric waters below ground-water level.

The lode deposits are mostly in the Ledbetter slate and the 

Monk formation. Silver-bearing tetrahedrite is found in a 

quartz and carbonate gaugue with galena and other sulfides.
2 GEOLOGY AND ORE DEPOSITS OF THE

INTRODUCTION 

LOCATION AND ACCESSIBILITY

The Metaline quadrangle is in the extreme northeast corner of Washington and extends about 1% miles 

into northwestern Idaho. It covers an area of about 

800 square miles between longitude 48°30' and 49°

METALINE QUADRANGLE, WASHINGTON

crombie Mountain from the center of sec. 32, T. 40 N., 

R. 43 E., and a road up Eussian Creek to the Frisco 

Standard mine were particularly helpful.

lone, Metaline Falls, and Metaline are the principal 

towns, and a few small settlements and farms are 

scattered along the Pend Oreille Valley. Camps are 

maintained on Government lands by the Forest ServFIGDRE 1. Index map of Washington showing location of the Metaline quadrangle.

(international boundary) and latitude 117° and 117°30'

(fig- I)-

A branch line of the Chicago, Milwaukee, St. Paul 

& Pacific Railroad extends from Newport to Metaline 

Falls, and daily bus service to Spokane is maintained 

by the same company. An excellent paved highway 

extends through Metaline Falls from Spokane northward to the Canadian border. A gravel road to Colville leaves the Pend Oreille Valley at Tiger and is 

at present the main link with the country to the west. 

The United States Forest Service maintains and in 

recent years has greatly extended an excellent system 

of roads and trails in the Kaniksu National Forest 

east of the Pend Oreille River. In 1936 and 1937 the 

United States Resettlement Administration purchased 

much of the land west of the river and opened several 

roads and trails into country that was formerly difficult to traverse. A trail up the east slope of Aberice, Civilian Conservation Corps, and Resettlement 

Administration, and there are a few temporary lumber 

camps and small farms here and there along the principal tributaries of the river.

TOPOGRAPHY

The dominant topographic feature of the Metaline 

quadrangle is the valley of the Pend Oreille River, 

which flows from south to north through the west 

center of the area. Rugged highlands that rise from 

south to north border both sides of the river and are 

partly dissected by the man}^ tributary streams.

The mountains have been called the Pend Oreille 

Mountains by Daly,1 but the name is seldom used lo1 Daly, R. A., The nomenclature of the North American Cordillera 

between the 47th and 53d parallels of latitude: Geog. Jour., vol. 27, 

pp. 588, 599, 1906.
INTRODUCTION

oally. Northward they merge into the rugged Selkirk 

Range of British Columbia. East of the river most 

of the peaks are named; the highest is Gypsy, at an 

altitude of 7,318 feet, although many have altitudes 

over 6,000 feet. The highest point west of the river 

is Abercrombie Mountain, at an altitude of 7,308 feet, 

although Hooknose, at 7,203 feet, is one of the most 

conspicuous landmarks.

Except for the constriction at Box Canyon, the Pend 

Oreille River south of Metaline Falls is a wide sluggish 

stream that contains many bars and islands during 

normal. and low-water stages. North of Metaline 

Falls the river flows turbulently through a series of 

narrow gorges. Just north of the Canadian border 

the river swings westward and eventually makes its 

way into the Columbia. The principal tributary 

streams from the east are, from south to north, Le 

Clerc Creek, Harvey Creek, Sullivan Creek, and Slate 

Creek. West of the river the streams are small and 

short; the largest is Ruby Creek.

The drainage of much of the eastern part of the 

quadrangle is tributary to Priest Lake and the Priest 

River to the east. The principal streams are Kalispell 

Creole, Granite Creek, Gold Creek, and Hughes Creek. 

The south fork of the Salmo (Salmon) River flows 

northwestward through the extreme northeast corner 

of the area. This stream joins the Pend Oreille 

River a few miles east of its junction with the 

Columbia.

Sullivan Lake, 3 miles long and half a mile wide, is 

Hie largest of many glacial lakes in the area. It is 

an easily accessible and delightful summer resort.

CLIMATE AND VEGETATION

Most of the precipitation in the Metaline area falls 

during the cold winter months as snow. The summers, 

from June until early September, are generally hot and 

dry, but during this period thunderstorms are common, particularly in the mountains. Considerable 

range in temperature is found between the high 

country and the sheltered valleys, although the nights 

everywhere are generally cool. The average annual 

precipitation near Sullivan Lake over a period of 8 

years was 26.39 inches.

With the exception of some of the high ridges, 

burned areas, and the soil-free quartzite slopes, the 

region is heavily forested. To the south yellow pine 

thrives in the sandy granitic soil. Farther north 

white pine, cedar, hemlock, two varieties of fir 5 and 

spruce are the most valuable trees, although tamarack, 

lodgepole pine, birch, white-bark pine, and several 

other trees and many types of brush are abundant. 

The most easily accessible and best timber has been 

logged off, and the dry slashings and dense second 

growth are serious fire hazards during the dry summer. 

The Sullivan Creek drainage basin east of Sullivan 

Lake is the only area in the quadrangle that has been

free from disastrous fires. Much of the quadrangle is 

covered with piles of charred fallen timber, which 

locally is concealed by alder and young tamarack or 

lodgepole pine, the combination constituting an almost 

impenetrable maze. Elsewhere the country, has been 

burned over two or more times and is practically devoid of vegetation. (See pi. 15, B.)

FIELD WORK AND ACKNOWLEDGMENTS

The field work upon which this report is based was 

done from June 1 to October 1, 1936, and from May 15 

to October 15, 1937. G. R. Gibson very ably assisted 

the senior author for 3 months during 1936. Mr. 

Camion was assigned to the project in May 1937 and 

has helped in every phase of the work since then. 

The study has profited greatly from visits in the field 

by J. T. Pardee, D. F. Hewett, and W. C. Mendenhall. 

Mr. Park revisited the district for 2 weeks in October 

1938.

It is a pleasure to acknowledge the whole-hearted 

and generous cooperation of the people of the region, 

without exception. Particular thanks are due to L. P. 

Larsen, C. A. R. Lambly, John Currie, and E. H. 

Miller, of the Pend Oreille Mining & Milling Co., and 

to H. F. Mills and D. I. Hayes, of the Metaline 

Mines & Leasing Co. for access to mine openings and 

diamond-drill cores, as well as for many other courtesies. The United States Forest Service has kindly*, 

furnished copies of aerial photographs of nearly the 

entire quadrangle, and many pleasant and profitable 

contacts have been made with the Forest Service field 

men.

Thanks are also due to the members of the Geological Survey with whom the numerous problems that 

arose during preparation of the report have been 

freely discussed, particularly J. T. Pardee, A. C. Spencer, James Gilluly, H. G. Ferguson, and T. B. Nolan. 

Many ideas embodied in the report have arisen from 

such discussions and any value that the publication 

may have owes much to this helpful interchange. The 

photographs of hand specimens and the photomicrographs were taken by N. W. Shupe.

SCOPE OF THE REPORT

The study of the Metaline quadrangle was undertaken primarily as a study of the metalliferous deposits of the area. For this reason the available time, 

both in the field and in the office, has been largely 

devoted to consideration of the Pend Oreille Valley, 

where most of the known mineral deposits occur. The 

entire quadrangle has been mapped, although outlying 

areas were not covered in the same detail as the Pend 

Oreille Valley. For readers interested only in the 

mineral deposits much of the report dealing with general geology, structure, and development of the 

topography may well be neglected.
GEOLOGY AND ORE DEPOSITS OP THE METALINE QUADRANGLE, WASHINGTON

BIBLIOGRAPHY

The principal reports that treat of the Metaline 

district and nearby areas are listed below, with a few 

annotations on their contents. No claim of completeness for this bibliography is made, and additional references are found throughout the text. An effort has 

been made to select the most comprehensive reports and 

those of pertinent interest to the Metaline problems. 

ABERCROMBIE, W. R., Report on the Pend d'Oreille River: 

Mining, 1896, pp. 245-250. A seinipopular account of an 

exploration of the Pend Oreille River from Pend Oreille 

Lake to the 49th parallel, conducted in 1885. Mentions lead 

deposits.

ADAIR, J. B., Mineral resources of the State of Washington 

the Metaline district: Northwest Min. Jour., vol. 7, pp. 

54-56, 1909. Describes the general features of the geology. 

.Mentions possibilities of cement industry and gives status 

of development at the Oriole and Morning and Mammoth 

properties.

ALLAN, J. A., Geology of Field map area, B. C. and Alberta: 

Canada Geol. Survey Mem. 55, 1914. Largely devoted to 

discussion of igneous rocks. Sedimentary section somewhat similar to that in Metaline quadrangle. Describes 

Ordovician graptolite shale.

BANCROFT, ROWLAND, Lead and zinc deposits in the Metaline 

mining district, northeastern Washington: U. S. Geol. 

Survey Bull. 470, pp. 188-200, 1911. A few prospects were 

visited and described.

 The ore deposits of northeastern Washington, including a section on the Republic mining district by Waldemar 

Lindgren and Howland Bancroft: U. S. Geol. Survey Bull. 

550, 1914. Contains a reprint of the material in Geol. 

Survey Bull. 470. Descriptions of properties in neighboring 

districts are given and a detailed report on the Republic 

district is included.

BAUERMAN, H., Report on the geology of the country near the 

49th parallel of north latitude west of the Rocky Mountains, 

based on observations made in 1859-61, Montreal, 1884. 

Mentions the limestone-shale series and granite on the 

Pend Oreille and Little Pend Oreille Rivers. Gives the 

regional setting. Mentions gold deposits on the Lower 

Pend Oreille being worked in 1858.

BETHUNE, G. A., Mines and minerals of Washington: Washington Geol. Survey 1st Ann. Rept., "pp. 82-83, 1891; 2d 

Ann. Rept., pp. 128-129, 1892. Earliest known mention 

of the Metaline district in literature. States that it was 

called Metaline' from the immense amount of metal in 

sight.

BRINSMADE, R. B., Two Washington mining districts: Min. and 

Sci. Press, vol. 113, pp. 743-745, 1916. The Metaline district is one of the two mentioned. Describes the conditions of the mines and mills in 1916.

BKOWNE, J. R., Resources of the Pacific slope, New York, Appleton, 1869. States (p. 182) that gold was discovered in 

1855 near Fort Colville.

BUISMAN, H. R., The Metaline district: Northwest Mining, vol. 

3, no. 8, pp. 3-4, May 6, 1937. A resume" of current 

developments.

CALKINS, F. C., and MacDonald, D. F., A geological reconnaissance in northern Idaho and northwestern Montana: U. S. 

Geol. Survey Bull. 384, 1909. An excellent reconnaissance 

report, of value particularly for its stratigraphic data. 

COCKFIELD, W. E., Lode deposits of Ymir-Nelson area, B. C.: 

Canada Geol. Survey Mem. 191, 1936. Largely mine descriptions.

DALY, R. A., Geology of the North American Cordillera at the 

49th parallel: Canada Geol. Survey Mem. 38, 1912. Contains data collected during a reconnaissance of the international boundary. Describes the Priest River terrane and 

assigns it to pre-Beltian age. The Summit series is described: the Irene conglomerate and Irene volcanics are 

called basal Belt, and the upper members of the series 

are correlated with the Belt series and assigned to Cambrian 

age. The Pend Oreille group overlies the Summit series 

and is separated into two members, schists and marbles. 

The group was tentatively classed as Carboniferous; no 

satisfactory section was obtained.

DRYSDALE, C. W., Ymir mining camp, B. C. : Canada Geol. Survey Mem. 94, 1917. Lithology briefly discussed. No attempt is made to subdivide the Pend Oreille group of limestones and shales. In Addenda I it is suggested that the 

Irene conglomerate [Shedroof of this report] is equivalent to the Siyeh conglomerate and the Irene volcanics 

[Leola of this report] to the Purcell lava. The rocks 

overlying the volcanics are considered Lower Cambrian. 

Mostly devoted to detailed descriptions of properties.

FISCHER, A. H., A summary of mining in the State of

ington: Washington Univ. Eng. Exper. Sta. Bull. 4, 1918.

GEOLOGICAL SURVEY, Mineral Resources of the United States, 1906, 

p. 451. Reports shipments in 1906. States on information 

furnished by L. P. Larsen and Mr. and Mrs. D. D. Birk, 

that ore was first opened in 1869. Mentions the Mammoth 

mine.

HAYES, D. I., Zinc company drives 2,000 feet at Metaline: 

Northwest Mining, Dec. 17, 1936, pp. 1, 4. A brief statement of methods and equipment used in driving the Metaline Mining and Leasing Co.'s tunnel.

JENKINS, O. P., Lead deposits of Pend Oreille and Steveus 

Counties, Wash. : Washington Dept. Cons, and Devel., Div. 

Geology, Bull. 31, 1924. A report devoted almost entirely 

to mine descriptions. Contains brief generalization on 

structure and stratigraphy. Considers the valley of the 

Pend Oreille (Clark Fork) to be a down-faulted anticline.

JOSEPH, M. H., Mining in eastern Washington in 1906: Eng. 

and Min. Jour., vol. 83, p. 185, 1907. Activity confined 

mainly to Morning and Mammoth mine.

KIRKHAM, V. R. D., and ELLIS, E. W., Geology and ore deposits 

of Boundary County, Idaho : Idaho Bur. Mines and Geology 

Bull. 10, 1926. Short descriptions of the Belt rocks and 

correlation with nearby areas. Correlates Irene volcanics 

[Leola volcanics of this report] with Purcell lavas, which 

are believed to be youngest Belt. Brief discussions of the 

structure and ore deposits are given.

LARSEN, L. P., The Metaline lead-zinc district,: Arizona Min. 

Jour., vol. 16, pp. 5-6, June 15, 1932. A brief resume" of 

the history of mining in the district and discussion of 

geology and economic possibilities. A few figures on production and grade of ore in the Pend Oreille mine are given.

LE ROY, O. E., Geology of Nelson map area : Canada Geol. Survey Summary Rept., 1911, pp. 139-157. A short discussion 

of general geology. Largely economic.

MACDONALD, D. F., Economic features of northern Idaho and 

northwestern Montana: U. S. Geol. Survey Bull. 285, pp. 

41-52, 1906.

McCONNELL, R. G., and BROCK, R. W., Geologic map of the 

British Columbia West Kootenay sheet, Canada Geol. Survey, 1904.

PARDEE, J. T., Geology and mineral resources of the Colville 

Indian Reservation, Wash. : U. S. Geol. Survey Bull. 677, 

1918. A reconnaissance survey of a large area south and 

west of Metaline.

- 

\\ ^^~

\i M^ 

»

,1 ^Jf^

T^
GENERAL GEOLOGY

. ,..>£»» vL<A^ stucS

PARK, C. F., Jr., Dolomite and jasperoid in the Metaline district, 

northeast Washington: Econ. Geology, vol. 33, pp. 709-729, 

1938.

TATTY, E. N., The metal mines of Washington: Washington 

Geol. Survey Bull. 23, pp. 81-88, 112-116, 1921. Brief 

statement of geology and ore occurrence. Descriptions of 

Diamond, E.,; Bella May, Oriole, Frisco Standard, and 

United Treasure mines.

RUJK, H. M. A., Cranbrook map area, B. C.: Canada Geol. Survey 

Mem. 27, 1937. A short but good treatment of an area 

previously mapped and discussed by Schofleld.

- Preliminary report, Nelson map area, B. C.: Canada 

Geol. Survey Paper 37-27, 1937. An uncolored map of the 

eastern half of the map area, with preliminary statements.

SAMPSON, EDWARD, Geology and silver ore deposits of the Pend 

Oreille district, Idaho: Idaho Bur. Mines and Geology 

. 31, 1928. .A brief preliminary report of a detailed 

study. Fossils found in Middle Cambrian limestone and 

shale. Briefly discusses lithology and ore deposits. States 

that deformation occurred mostly by normal faults, although evidence of some reverse movement was recognized.

ScBX)iri.KU), S. J., Geology of Cranbrook map area, B. C.: Canada 

Geol. Survey Mem. 76, 1915. An exhaustive report on the 

area northeast of Metaline (east of longitude 16°30').

TAY.I-,OR, HARRY, Survey of Peud Oreille River, from its source 

at Lake Pend Oreille, Idaho, to the town of Metalline, 

Wash.: Chief Eng. Rept, 1898, pt. 4, pp. 3124-3131. A 

study of the methods to improve navigation on the Pend 

Oreille River. Mentions lead, silver, and copper mines at 

Metaline and states that two were working. The district 

was handicapped by lack of transportation facilities.

WALCOTT, C. D., Cambrian geology and paleontology, V, PreDcvonian Paleozoic formations of the Cordilieran provinces 

of Canada: Smithsonian Misc. Coll., vol. 75, no. 5, 1928. A 

general summary of the stratigraphy of the region northeast of the Metaline quadrangle. Valuable for comparative 

purposes.

WAT.KKH, J. F., Geology and mineral deposits of Windermere 

map area, British Columbia: Canada Geol. Survey Mem.

j 148, 192(>. Discusses in some detail the stratigraphy and 

correlation with surrounding regions. Describes the Glenogle gniptolite shale, of Lower Ordovician age. Middle 

Cambrian strata are absent. Correlates the Windermere 

series with Daly's Summit series. Detailed descriptions 

of the mining properties.

 Geology and mineral deposits of Salmo map area, 

B. C.: Canada Geol. Survey Mem. 172, 1934. Contains a 

geologic map of the area immediately north of the Metaline 

quadrangle. Discusses the lithology and correlates the 

Summit series of Daly with the Windermere series. The 

Pend d'Oreille group is thought to be late pre-Cambrian. 

No satisfactory section of this group was obtained. Descriptions of lode and replacement deposits are given. The 

replacement; deposits in dolomite are similar to those in the 

Metaline quadrangle.

WACKER, J. F., and BANCROFT, M. F., Lardeau map area, B. C., 

General geology, and Gunning, H. C., Mineral deposits: 

Canada Geol. Survey Mem. 161, 1929. Mostly devoted to 

mine descriptions, both replacement and lode types. The 

stratigraphy is discussed, and a correlation table is given.

WKAVER,.C. E., The mineral resources of Stevens County: Washington Geol. Survey Bull. 20, 1920. Contains a geologic 

:nap of the county. Formation descriptions appear to be 

accurate but no attempt at correlation was made. Structure is briefly mentioned. Most of the bulletin is devoted 

to mine and prospect descriptions.

The Metaline quadrangle contains sedimentary and 

metamorphic rocks that range in age from pre-Cambrian to Devonian. (See pi. 1.) They are intruded 

by a batholith, probably of Cretaceous age, that underlies the southern half of the quadrangle. Unconformably overlying both the batholith and the older 

rocks is a loosely consolidated formation considered 

to be of Tertiary age. Much of the low country is 

covered by a thin veneer of Quaternary debris, deposited by waning glaciers and their attendant streams. 

The total thickness of the Paleozoic section is about 

23,000 feet, of which 20,000 feet is Cambrian, 2,500 feet 

Ordovician, and 700 feet Devonian. The upper preCambrian is a greenstone volcanic formation (Leola), 

underlain by the Shedroof conglomerate. These two 

formations aggregate about 10,000 feet and overlie an 

unknown thickness of metamorphosed sedimentary and 

igneous rocks.

Detailed correlation of the rocks with those of 

nearby areas other than to the north is not possible in 

the present state of knowledge. To the north the continuation of the strata has been mapped by Daly and 

Walker in the Salmo map area 2 , and a table correlating the formations described by them with the strata 

of the Metaline quadrangle is given on page 6.

Both Daly and Walker correlated the beds in the 

Salmo map area with strata to the north and east.

The geologic structure (see pi. 1) is similar to that 

in surrounding areas where Paleozoic and older rocks 

are tightly folded. Examples of the folds are the 

Hooknose anticline, the Hall Mountain anticline, and 

the anticline west of Lost Lake. In places the folds 

pass into faults, such as the Ridge fault and the lowangle thrusts nea'r the Riverside and Bella May properties. The early deformation, comprising folding 

and faulting, was followed by a period of additional 

faulting, during which the prominent Flume Creek 

and Russian Creek faults were formed.

Other major faults are the Slate Creek and Harvey 

faults, each with normal displacements, and smaller 

faults are widely distributed throughout the region. 

The evidence for faulting is generally stratigraphic 

offset, although -in a few places the actual fault surfaces and gouge and breccia were seen.

3 Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, chart facing p. 178, 1912. 

Walker, J. T., Geology and mineral deposits of Salmo map area, B. C.: 

Canada Geol. Survey Mem. 172, pp. 2-10, 1934.
GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON 

Correlation of formations in Metaline quadrangle and Salmo map area

Metaline quadrangle (this report)

Limestone, 700 feet.

Ledbetter slate, 2,500 feet.

Metaline limestone, 3,000 

feet.

Maitlen phyllite, 5,000+ feet.

Gypsy quartzite, 5,300-8,500 

feet.

Monk formation, 3,800+ feet.

Leola volcanics, 5,000+ feet.

Shedroof conglomerate, 5,000 

+ feet.

Priest Elver group (?).

Devonian.

Ordovician.

Middle Cambrian.

Cambrian.

Cambrian?

pre-Cambrian.

Salmo map area

R. A. Daly, 1912

Pend Oreille group.

Lone Star phyllite, 2,000 + 

feet.

Beehive formation, 7,000 

feet.

Ripple quartzite, 1,650 feet.

Dewdney formation, 2,000 

feet.

Wolf grits, 2,900 feet.

Monk formation, 5,500 feet.

Irene volcanics, 6,000 feet.

Irene conglomerate, 5,000 + 

feet.

Upper Paleozoic.

Summit series

Cambrian.

Beltian.

Priest River terrane (?).

.r. F. Walker, 1934

Pend Oreille group.

Reno formation, 3,500 feet.

Quartzite Range formation, 

4,400 feet.

Three Sisters series, 5,400 

feet.

Horsethief Creek series, 

4,200 feet.

Windermere, pre-Cambrian. late 

.

Irene volcanic (?) formation (?).

GEOLOGIC FORMATIONS 

PRE-CAMBRIAN ROCKS

PRIEST RIVER GROUP

The name "Priest River group" is applied to the 

metamorphic rocks stratigraphically below the Shedroof conglomerate. The group was described by Daly 

as the Priest River terrane, unconformably overlain 

by basal conglomerate, of the Summit series (Irene 

conglomerate). 3 

The Priest River, group is a complex sequence of 

metamorphic rocks that includes phyllites and schists, 

limestones, dolomites, quartzites, and volcanics. The 

beds are generally much distorted and sheared, as 

shown in plate 2, J., and sufficient time was not available to permit a careful study of the group. On the 

map (pi. 1) rocks of the Priest River group are shown

3 Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, pp. 258-271, 1912.

in one color, except that where beds of quartzite and 

volcanic rocks were traced they are differentiated.

The rocks are predominantly phyllites, derived in 

part from limy sediments and in part from volcanic 

rocks. Between Pass Creek and Harvey Creek limestone predominates in exposures but is commonly 

interbedded with phyllite and quartzite.

The phyllites in general are finely crystalline, and 

the individual minerals cannot be distinguished without a microscope. They contain widespread and abundant chlorite and sericite, and many of the rocks are 

similar in degree of metamorphism 4 and in lithologic 

character to the younger Monk formation and the 

Maitlen phyllite. Although in general the Priest 

River group is more metamorphosed than the younger 

formations, it is somewhat surprising to find metamorphism of so low a grade in rocks that have had so 

complex a geologic history as these.

4 Knop£, E. B., Retrogressive metamorphism and phyllonitization: 

Am. Jour. Sci., 5th ser., vol. 21, p. 5, 1931.
PRE-CAMBRIAN ROCKS

SHEDROOFCONGLOMERATE

DISTRIBUTION

A conglomerate of unusual type is exposed in a 

broad belt that crosses the international boundary at 

the northeast corner of the Metaline quadrangle. 

Daly named this the Irene conglomerate formation, 

which lie define^ as the basal member of the Summit 

series, deposited unconformably upon the Priest River 

group and transitional into the overlying volcanic 

rocks.0 The Shedroof conglomerate of the present 

report, named from the excellent exposures on Shedroof 

Mountain, refers to the rocks of this belt. Lithologically similar conglomerate occurs also at a higher horizon, at the base of the Monk formation, but for convenience it is described with the Monk.

The Shedroof conglomerate crops out from the 

northeast corner of the quadrangle south-southwestward for nearly 8 miles. At Thunder Mountain this 

belt divides into two that continue toward the southwest, where they are involved in the Pass Creek fault 

zone. Still farther to the southwest the continuation of 

this zone is presumably represented by the narrow" 

belt of conglomerate which can be traced southwestward across Noisy and Harvey Creeks nearly to the 

edge of the Kaniksu batholith.

In two areas of greenstone far removed from any 

known exposure of Shedroof conglomerate the surface 

is conspicuously strewn with huge angular boulders of 

the conglomerate. One of these localities is the elliptical greenstone area between Granite Creek and Gold 

Creek; the other is in an area of poor scattered exposures of greenstone southwest of Tiger. Large quantities of Shedroof conglomerate fragments are also 

found on the Priest River rocks on the ridge in sec. 22. 

T. 38 N., R. 44 E.

Shedroof conglomerate crops out moderately well 

and, indeed, forms the high rugged peaks in the area 

north of Thunder Mountain. It is noteworthy, nevertheless, that the conglomerate is best exposed where the 

internal structure (schistosity) of the rocks intersects 

the ground surface at a large angle. The degree of 

exposure is presumably controlled by the dominant 

schistosity of the conglomerate rather than by the extremely inconspicuous bedding. Along the eastern 

"scarp" slope of the Round Top and Thunder Mountain ridge the conglomerate is well exposed. Along 

the west side of the same ridge on the long "dip" 

slope to Sullivan Creek, and particularly in the area 

surrounding the junction of Sullivan and Pass Creeks, 

outcrops of the conglomerate are both scarce and 

poorly exposed. Ledges of the conglomerate tend to 

break into great angular blocks, and even in areas 

where the conglomerate is poorly exposed the surface 

is commonly littered with similar large fragments.

c Duly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, pp. 141-144, 1912.

THICKNESS AND STHATIGRAPHIC UKt-ATIONS

A close estimate of the thickness of the Shedroof 

conglomerate is at present impossible. Even the more 

general structural features remain uncertain because 

of the scarcity of visible bedding planes in the rock. 

Nonetheless, the available data are ample to indicate 

remarkable variation in the thickness of the conglomerate along the strike. In the vicinity of .Shedroof 

Mountain the formation is exposed in a band 3 miles 

wide. Southeast of Shedroof the basal contact dips 

about 30° NW. North of Shedroof the upper contact dips about 50° NW. under the Leola volcanics. 

The few bedding dips that can be seen in this section 

are generally not steeper than 45°. The maximum 

thickness computed from these scanty figures would 

be approximately 11,000 feet. However much in error 

this figure may be, the absolute minimum thickness of 

the conglomerate in this section, computed on the basis 

of the relief at Shedroof Mountain and the assumption 

of no duplication of strata, is 3,000 feet. In the table 

the thickness of the formation has been given as 

±5,000 feet. The supposed southern extension of this 

belt south of Hall Mountain, on the ridge between 

Harvey and Noisy Creeks, has a maximum thickness 

between 600 and 1,200 feet, which decreases gradually 

along the strike of the belt toward the southwest. 

Where this same stratigraphic level reappears between 

Dry Canyon and the valley of the Pend Oreille southeast of Tiger, the band of Shedroof conglomerate is 

missing and the Leola volcanics rest directly upon 

limestone of the Priest River group.

LITHOLOGY AND INTERNAL STKXJCTUKE

Megascopic features. The characteristic Shedroof 

conglomerate is a coarse, very poorly sorted rock with 

a dingy gray-brown aspect. Most of the fragments (a 

term used here to denote particles larger than half an 

inch in diameter) have diameters ranging between 1 

and 8 inches, although many are smaller and a few 

irregular blocks of limestone have diameters of 5 feet 

or more. (See pi. 2, B.) Fragments of white to 

reddish-brown quartzite are almost equally abundant 

with dolomite fragments of similar color, many of 

which weather buff. A few pieces of black slate or 

phyllite and a single pebble of granitic rock were seen 

in the conglomerate. .The fragments, which generally 

constitute 50 to 85 percent of the rock, are embedded 

in a matrix of gray sandy phyllite, which weathers to 

a brown pitted surface, as if calcareous.

Several lithologic variations from the dominant type 

of conglomerate were noted in the field. A gritty 

sandstone bed is shown in plate 3 A, and layers of 

similar sandstone and gritty conglomerate have been 

found at several other localities. Thin interbeds of 

dolomite, which can be traced for only short distances 

along the strike, occur near the base of the conglomer-
8

ate on the spurs east and northeast of Thunder Mountain and in the conglomerate layer at the base of the 

Monk formation.

From the northeast corner of the quadrangle southwestward along Sullivan Creek the upper contact of 

the Shedroof conglomerate with the Leola volcanics 

is marked by a zone of transition several hundred feet 

thick, in which the matrix of the conglomerate gradually changes from gray to green, the proportion and 

size of fragments is smaller, and the bedding planes 

are fairly distinct. (See pi. 3, B.) This transition 

rock seems to pass gradually upward into schistose 

greenstone or green schist without fragments. A similar but narrower zone separates the belt of Shedroof 

conglomerate from overlying greenstone along the 

east side of the ridge from Eound Top to Thunder 

Mountain.

A rather similar transition from the dominant type 

of Shedroof conglomerate to silvery-gray and greenishgray phyllite or phyllitic schists is thought to occur 

commonly. This phyllite may correspond to the 

matrix of typical Shedroof conglomerate, merely lacking the fragments. Although generally a remarkably 

homogeneous fine-grained phyllite, it is locally sandy 

and possibly elsewhere limy. Eock of this type occurs 

principally in the area of poor exposures on the west 

slope of the Round Top and Thunder Mountain ridge 

down to Sullivan Creek. Consequently no such transition zones are thoroughly exposed, although the two 

end members are intimately associated with one 

another and with intermediate types. In some 

places for example, on the Pass Creek road at the 

mouth of Thor Creek the areas mapped as conglomerate include some exposures of the phyllitic rock. The 

wedge-shaped area underlain almost exclusively by the 

phyllite from Thunder Peak southwest to the headwaters of Stony Creek, in T. 39 N., K. 45 E., has been 

differentiated on the map.

Visible bedding planes were recognized in scarcely 

a score of exposures throughout the large area underlain by the conglomerate in this quadrangle. In most 

of these exposures schistosity crosses the bedding at an 

appreciable angle, as illustrated in plate 3, A. In most 

outcrops of the conglomerate the fragments have been 

flattened to triaxial ellipsoids, with a common orientation, as a result of the deformation that produced 

schistosity. In other outcrops only linear structure 

and a linear elongation of fragments can be detected. 

These secondary metamorphic features are found 

throughout the Shedroof conglomerate and dominate 

the aspect of the rock. (See pi. 4.) Many fragments 

are rhombohedral in section, and at least some of these 

were formed by the breaking and rotating of larger 

fragments and layers, as shown in plate 2, 0. The 

limestone fragments are commonly more angular in 

outline than adjacent rounded quartzite fragments; 

this curious difference may have resulted from greater

ease of distortion of the limestone than of the quartzite during the deformation of the rock.

The Shedroof conglomerate is readily identified in 

outcrops by its dingy, rotted aspect; its general lack 

of bedded structure; the presence of light-colored 

limestone, dolomite, and quartzite fragments almost to 

the exclusion of other rocks; the flattened or stretched 

shape of its fragments; and commonly the greater size 

and angularity of the limestone fragments.

Microscopic features. A thorough petrographic 

study of the Shedroof conglomerate is beyond the 

scope of this report, and only a few thin sections were 

examined. The smaller particles of the conglomerate, 

as seen in these sections, consist principally of quartzFIGURH 2. Camera lucida sketch of part of a thin section of Shedroof 

conglomerate. Shows (1) enlargement on ends of grain, growth of 

optically continuous quartz into and probably replacing sericite; 

(2) removal of part of original quartz grains at sides, either mechanically by shearing or chemically by solution; (3) at ends of quartz 

grain sericite foliation not bending conformably around grain but 

heading directly into it.

ite, coarse-grained quartz, dolomite, and fragments of 

sericitic rock, possibly altered shale. Some of the 

quartzite fragments are fine-grained and contain appreciable amounts of sericite and either microcline or 

albite. The green facies of the conglomerate is characterized by numerous particles that now consist largely 

of chlorite.

The matrix is dominantly sericite and fine-grained 

quartz, with variable amounts of carbonate. Chlorite 

and biotite are minor constituents. A few rounded 

grains of tourmaline and zircon are apparently detrital 

particles.

The schistosity of the conglomerate is shown clearly 

in thin section by the parallel alinement of sericite, 

biotite, and chlorite flakes and the long axes of the 

pebbles. The relations shown in figure 2 indicate that 

some migration of silica occurred during the metamorphism that caused the schistosity. In specimens 

containing abundant carbonate the outlines of the pebbles have been largely destroyed owing to the great 

degree of recrystallization of the carbonate.
PRE-QAMBRIAN ROCKS

CONDITIONS OF DEPOSITION

Daly ° postulated a great unconformity at the base of 

the Shedroof conglomerate and considered the debris in 

the conglomerate to be derived from the underlying 

Priest River group. In the Metaline quadrangle such 

an unconformity has not been unequivocally demonstrated, but its presence is indicated by the following 

evidence: The pebbles in the Shedroof conglomerate 

have probably been derived from the Priest River 

group, but wherever the base of the Shedroof conglomerate has been examined the bedding in the Priest 

River rocks is apparently parallel to the surface on 

which the conglomerate was deposited. However, the 

base of the conglomerate from the northeast spur of 

Thunder Mountain to the east spur of Round Top 

Mountain is underlain by phyllite of the Priest River 

group, which throughout this distance contains thin 

bods of quartzite, whereas the base of all conglomerate 

southwest of the Round Top fault apparently rests on 

a limestone bed of the Priest .River group and is par-. 

allel to the bedding in the limestone.

Judgment concerning the importance of an unconformity at the base of the Shedroof should wait upon a 

detailed study of the stratigraphy and structure of the 

Priest River group and a satisfactory explanation of 

the origin of the conglomerate itself.

The conglomerate may be a fanglomerate, although 

.its origin is not entirely clear, and the wide deposition 

of such immense quantities of uniformly coarse debris 

is difficult to explain. Points relating to the origin 

are:

(1) Its association with and gradation into greenstone is nearly invariable.

(2) Its thickness is extremely inconstant.

(3) The fragments comprise (a) quartzite, dolomite, 

phyllite, schist, rarely granitic rocks, thought to be 

derived from Priest River group, and (b) small round 

quartzite cobbles and pebbles mixed with large angular 

limestone fragments. Volcanic fragments are absent, 

except in the transition zones to the Leola volcanics.

(4) The matrix consists of sericite, quartz, carbonate, 

chlorite, and biotite.

(5) There is a nearly complete lack of sorting; bedding is shown, by a few sand and dolomite beds; graded 

bedding was seen at only one place.

(6) There may be a stratigraphic hiatus below the 

Shedroof conglomerate.

AGE

The Shedroof conglomerate is assigned to late preCambrian time, as it underlies and is gradational into 

the Leola volcanics, which are also considered to be 

late pre-Cambrian.

"Daly, K. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, p. 142, 1912.

LEOLA VOLCANICS

DISTRIBUTION

The greenstone and green schist that lie in the belt 

between the Shedroof conglomerate and the base of the 

Monk formation are called the Leola volcanics, from 

the section at Leola Peak, where they are fairly well 

represented. The extension of this belt north of the 

international boundary is essentially the Irene volcanic 

formation of Daly.7 Although the Leola volcanics include principally altered volcanic rocks, they are discussed here with the sedimentary rocks as an integral 

part of the stratigraphic sequence.

The Leola volcanics crop out at the top of the Shedroof conglomerate from the international boundary toward the southwest, where they appear to pinch out 

before reaching Pass Creek. To the south presumably 

the same belt reappears at the top of the Shedroof 

conglomerate south 'of Hall Mountain, extending southwestward and southward around the border of the 

Kaniksu batholith to Anderson Lake. A few scattered 

outcrops of poorly exposed greenstone southwest of 

Tiger and the greenstone(?) inclusion in the batholith 

3 miles southwest of Molybdenite Mountain ma,y originally have been parts of this principal greenstone belt.

A continuous band of greenstone similar to the Leola 

is exposed at the top of the lower belt of Shedroof 

conglomerate from Round Top to the east side of 

Thunder Mountain. Small areas of greenstone are 

exposed elsewhere, possibly interbedded or infolded 

within the Shedroof conglomerate, especially east of 

Shedroof and near Mankato Creek. Greenstone also 

appears at the base of the conglomerate east of Roundtop Mountain. Similar greenstone and green schist are 

exposed within the Priest River group, notably in a 

large elliptical area between Granite Creek and Gold 

Creek and several smaller areas south of Granite Creek.

Although the green schists are in general poorly 

exposed, the more massive greenstones crop out rather 

well. The massive rock commonly forms rugged hills 

and ridges, especially where adjacent to weaker materials. Less commonly than in the Shedroof conglomerate, ledges of greenstone break down to form great 

blocks and boulders.

THICKNESS AND STKATIGRAPHIO KEI.A.TIONS

Estimates of the maximum apparent thickness and 

of variations in apparent thickness of the Leola volcanics are of the same order of magnitude as corresponding figures for the Shedroof conglomerate. The 

data on which these estimates are based are even fewer 

and less reliable than those for the Shedroof.

The Leola volcanics have an apparent thickness of 

about-4,500 feet on the Salmo-Shedroof ridge. The

7 Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, pp. 144-147, 1912.
10 GEOLOGY AND ORE DEPOSITS OF THE METALlNE QUADRANGLE, WASHINGTON

maximum apparent thickness of this formation is 

about 9,000 feet in the vicinity of Green Mountain 

(Prouty Lookout). The thinning and pinching out 

of the belt south of Green Mountain are due in part 

to faulting. The supposed extension of this belt from 

Noisy Creek to Anderson Lake nowhere shows an apparent thickness greater than 5,000 feet, although the 

upper part of the volcanics is cut off by the Harvey 

fault, and the basal contact is obliterated by the Kaniksu batholith for a strike distance of 4 miles.

The apparent thickness of the volcanic beds that 

overlie Shedroof conglomerate from Round Top to 

Thunder Mountain ranges between 300 and 1,000 feet.

The common transition from normal Shedroof conglomerate through green conglomerate with sparse 

pebbles to greenstone is described elsewhere (p. 8). 

An apparent transition from fine-grained chlorite 

schist of probable tuffaceous origin to schistose greenstone is equally common. Green schist of this type 

probably underlies nearly one-fourth of the area 

mapped as Leola volcanics and forms the upper part 

of the formation underlying the conglomerate at the 

base of the Monk. Thin beds of dolomite (limestone ?), phyllite, and quartzite crop out sparsely with: 

in the greenstone areas and are presumably intercalated with the volcanic rocks.

LITHOLOGY AND INTERNAL STRUCTURE

Megascopic features. The greater part of the rocks 

mapped as Leola volcanics consist of typical homogeneous greenstone, such as occurs commonly in series 

of altered basalt and andesite. The average specific 

gravity of the typical greenstone is 2.92 according to 

Daly 8 and is appreciably greater than that of any of 

the truly sedimentary rocks of the area. The color of 

the rock is rather uniform dark to grayish green. 

Most of the greenstone exhibits a distinct schistosity, 

although in some exposures the rock appears to be 

nearly or quite massive. In spite of this schistosity 

and the shearing movements that it implies, certain 

primary textural and structural features of the rocks 

can be detected. A mottled aspect of the greenstone 

can be attributed with fair assurance, at least in part, 

to porphyritic and even diabasic texture of the original 

rock. (See pi. 5, A.} Exposures of greenstone 

crowded with small ellipsoidal bodies of crystalline 

calcite apparently represent amygdaloidal lava. In 

other outcrops much larger ellipsoidal structures in 

greenstone, outlined by bands of epidote, have the 

appearance of sheared pillow structures.

The color, specific gravity, and homogeneity of the 

dominant type of Leola volcanics distinguish it from 

any other rock in the area, at least outside the zone 

of igneous metamorphism surrounding the Kaniksu

Daly, R. A., op. cit. (Canada Geol. Survey Mem. 38), p. 146.

batholith. The chlorite schists of the Leola, however, 

cannot be distinguished with assurance from certain 

green schists or phyllites in the Priest River group, in 

the phyllite facies of the Shedroof conglomerate, in 

the Monk formation, and even in the much younger 

Maitlen phyllite.

Microscopic features. Thin sections show that the 

greenstone is essentially a fine-grained felted aggregate 

of chlorite accompanied by abundant albite, quartz, 

carbonate, and leucdxene (?). Epidote, iron oxides, 

sericite, and biotite are variable minor constituents. 

In some specimens amphibole takes the place of part 

of the chlorite. The schistosity, which may be fairly 

conspicuous in hand specimens, is generally suggested 

only by a tendency toward orientation of the darker 

minerals, less commonly by wavy layers composed 

largely of quartz and carbonate.

Some textural features of the original volcanic rocks 

are preserved in the greenstone, although partly 

masked by metamorphism. The uniform ground mass 

of many sections encloses phenocrysts of plagioclase. 

The plagioclase crystals have been corroded and 

altered to poikilitic albite crowded with tiny grains of 

carbonate, epidote, and chlorite. The large plagioclase crystals show random orientation independent of 

the schistosity of the greenstone and differ in abundance from section to section, suggesting intersertal, 

ophitic, and even diabasic texture in the original rocks 

(See pi. 5, A ). Small sheared amygdules (?) seen in 

thin section consist of quartz, carbonate, and chlorite.

The tuffaceous nature of a schistose dark gray-green 

fragmental rock from the upper part of the Leola volcanics along the road above Deemer Creek is evident 

in thin section. The grains consist of quartz, altered 

poikilitic feldspar, altered porphyritic basalt, sericitic 

quartzite, shale altered to sericite, bits of dark minerals altered to chlorite, and possibly remnants of 

limestone. The matrix is a schistose aggregate of 

chlorite with subordinate sericite, biotite, quartz, and 

carbonate. A laj^ering is brought out by an abundance 

of laths of altered plagioclase in certain layers and by 

its absence in other layers.

 ORIGIN

Daly maintains that the greenstones north of the 

international boundary are a succession of lava flows 

with some interbedded sedimentary rocks.9 Evidence 

from the Metaline quadrangle supports this view. 

Sheared amygdaloidal and pillow structures are recognizable in some exposures of relative massive greenstone ; also, transitions from greenstone to sedimentary 

rock through intermediate green facies suggest the 

contribution of pyroclastic material to nearly contemporaneous sedimentation. However, the field work

'Daly, R. A., op. cit. (Canada Geol. Survey Mem. 38), pp. 144-147.
O.EOLOOICAL SUKVEY PROFESSIONAL PAPER 202 PLATE 2

f. CONTORTED PHYLLITE IN PRIEST HIVKIf GHOl-P. 

Roa.l out east of Pass Creek Pass.

/{. SHKOROOK CONtJLOMKKATli ON KIUGE BETWEEN HALL

MOUNTAIN AND GRASSY TOP MOUNTAIN.

Vole Ilir lar s <- pali-li «f linieal.me in lower riahl. llanuner lian.lle is IK in.-li.-s long.

C. lillOMIiOllKDKAI. FRAGMENTS IN SJIKDKOOl CONGLOMERATE FORMED BY THE SHEARING OF A BAND OF OLAKT/.ITE.

SEW sec. 24, T. 40 N., R. 45 E.
OKOLOOICAL SURVEY PHOFKssrONAL 1'AI'KK 202 PLATE 3

A. SAND* BED IN SHEDROOF CONGLOMERATE, SHOWING SHEAR PLANES CUTTING BEDDING AT AN ANGLE OF ABOUT 30°.

Trail forkn. southeast corner of sec. 24, T. 40 IN., H. 45 F,.

It. KKDDINt; IN TRANSITION /OJNK BETWEEN SIIKDKOOF CONGLOMERATE AND I.HOI.A VOI.CANICS. 

Peak at altitude of 6,fiOO feet, in north center of sec. 25, T. 40 N., R. 15 E.
(1EOLOCICAL SURVEY PRO

B. SURFACE SHOWING NORMAL TO MAXIMUM E

A. SI KKACK SMO\\I\(, MAXIMUM ELC)N(;ATION OF FRAGMENTS. Same outcrop aa in .4.

SHEDROOF CONGLOMERATE ON SOUTHEAST SLOPE OF ROUND TOP MOUNTAIN.
(iEOLOGICAL SURVEY PROFESSIONAL 

4. I'HOTOMICKOGHAI'll OF GREENSTONE OF LEOLA VOLCAMCS, I'ROI TY LOOMH." 

KeinnantH of feldspar suggest an earlier diabasic texture.

CO\(;LOVIERATF. i\ (

Sioj>e west of Oriole mi
CAMBRIAN ("?) SYSTEM 11

did. not afford a basis for dividing the volcanics into 

a .series of recognizable flows and tuffaceous sediments. 

On the other hand, some of the greenstone in the 

quadrangle may be altered intrusive sills or even discordant intrusive bodies. This possibility applies particularly to the areas of greenstone within the Priest 

River group, no one of which has been demonstrated to 

be extensive at airy particular horizon.

SUMMARY

The Shedroof conglomerate and Leola volcanics 

embrace a succession of conglomerates and greenstones 

resting upon the older rocks of the Priest River group. 

In general, the oldest rocks in the succession are conglomerates, but in some places the altered lava rocks 

lie directly upon the Priest River group; Similarly, 

the Leola volcanics are in general the youngest rocks 

in the succession, but in several places the base of the 

overlying Monk formation rests upon conglomerates.

AGE

The Leola volcanics and Shedroof conglomerate are 

tentatively assigned to the top of the pre-Cambrian in 

this quadrangle. An unconformity may intervene between these formations and the overlying Monk formation, of Cambrian (?) age. The base of the Monk 

appears to rest successively from south to north upon 

(1) the Shedroof conglomerate due east of Sullivan 

Lake, (2) the Leola volcanics north of Sullivan Creek, 

and (3) a layer of still younger conglomerate north 

of Leola Creek.

CAMBRIAN (?) SYSTEM

MONK FORMATION

The Monk formation includes those beds that intervene between the older Leola volcanics and the grits at 

the base of the younger Gypsy quartzite. The formation was named by Daly from Monk Creek, in British 

Columbia, where the exposures are excellent. As used 

by Daly :1 ° the Monk excluded the upper part of the 

formation as defined in this rep'ort. Walker X1 used 

the term "Horsethief Creek series" for essentially the 

same beds that are here called Monk. The principal 

occurrence of the Monk formation is in a belt about 1 

mile wide that extends from the international boundary 

southwestward along the east slope of Crowell Ridge 

to the east spur of Hall Mountain, where it ends against 

faults and an offshoot of the Kariiksu batholith.

A narrow belt of the Monk formation crops out at 

the ba.se of the Gypsy quartzite along the west side of 

the Flume Creek fault. It extends for nearly 4 miles

10 Duly, K. A., op. clt. (Camilla Geol. Survey Mem. 3S), pp. 146-147.

11 Walker, J. I<\, Geology ami mineral deposits of the Siilmo map 

nrua, H. 0. : Canada Geol. Survey Mem. 172, pp. G-7, 1034-.

 I I SOU!) !.'! -- -2

from the Oriole mine southwestward across Lunch 

Creek.

This formation is exposed more poorly than any 

other major strati graphic unit in the quadrangle. The 

only section where outcrops are fair across the entire 

formation is along the crest of the ridge that extends 

southeastward from Salmo Mountain.

THICKNESS AND STBATIGHAPHIO RELATIONS

South of Deemer Creek the Monk formation occupies 

a belt about a mile wide. The apparent thickness of 

the formation in this belt is estimated to be 3,800 feet, 

measured west of Leola Peak along the trail that bears 

toward Gypsy Peak. The greater breadth of the belt 

northeast of Deemer Creek is due largely to the repetition of beds in a shallow synclinal fold in the east 

half of the belt. Although the best exposures of the 

formation are along the Salmo-Shedroof Ridge, the 

information obtained in this section is, nevertheless, 

inadequate for a determination of thickness.

West of the Pend Oreille River only the upper part 

of the Monk formation is exposed, representing not 

more than 1,000 feet of beds.

The top of the Monk formation, where it crosses 

the Sullivan Creek road 2 miles east of Sullivan Lake, 

is a band of white sandy marble that grades upward, 

into quartzite and grit. This marble has been traced 

northeastward for only a few miles. Farther north 

the contact is placed arbitrarily, so that dominantly 

quartzitic sediments are put in the Gypsy quartzite, 

whereas sediments that contain mostly beds of phyllites 

are referred to the Monk formation.

On the west side of the Pend Oreille Valley the 

contact between the Gypsy quartzite and the Monk formation is placed at the top of a bed of sandy dolomitic 

marble.

The base of the Monk formation has been drawn 

arbitrarily at the base of a conglomerate layer or, where 

the conglomerate is absent, at the top of the Leola volcanics. This layer of conglomerate is intercalated with 

limestone and calcareous phyllite and has an apparent 

maximum thickness of 400 feet. (See section D-D', 

pi. 1.) The extension of the layer north of Deemer 

Creek overlies several hundred feet of beds similar to 

tuffaceous facies of the overlying part of the Monk 

formation. Although the conglomerate was not seen 

on the heavily wooded north side of the valley of the 

South Fork of the Salmo River, both Daly 12 and 

Walker 13 describe it as a prominent and constant feature north of the international boundary, with an estimated thickness of a-bout 200 feet.

UTHOLOGY AND INTERNAL STRUCTURE

Megascopic features. The Monk formation is recognized with confidence only where it can be viewed as

12 Daly, R. A., op. cit. (Canada Geol. Survey Mem. 38), pp. .146-147.

13 Walker, J. F., op. cit. (Canada Geol. Survey Mem. 172), pp. G-7.
12 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

a whole or in its normal relation to either the Leola 

volcanics or the Gypsy quartzite. The details of lithology shown by nearly any hand specimen or within a 

limited area of exposure find their analogs in nearby 

younger and older rocks, particularly in the rocks of 

the Priest River group.

The fine-grained phyllites that predominate in the 

Monk formation contain numerous intercalations of 

carbonate rocks, quartzite, and grit. The intercalated 

beds are commonly only a few feet thick, but some 

of the bands of carbonate rock reach thicknesses of 

several hundred feet. North of Deemer Creek approximately the lower half of the Monk formation contains 

numerous beds of carbonate rocks, very few beds of 

quartzite, and none of grit. In the upper part quartz - 

ites and grits increase in abundance toward the top, 

but relatively few beds of carbonate rocks are present. 

Along the strike toward the southwest, the grit beds die 

out and carbonate beds seem to be proportionately 

more abundant. Consequently, south of the latitude of 

Gypsy Meadows and Sullivan Lookout there is little 

perceptible difference in lithology between the upper 

and lower parts of the formation.

The marble at the top of the. Monk contains many 

rounded quartz grains and is well exposed in the 

Workings of the 0. K. mine and on the hill above the 

mine, where it is interbedded with quartzite layers 

and grades rapidly upward into quartzite and grit.

A limestone whose maximum thickness is 200 to 300 

feet commonly lies in apparent conformity on the conglomerate at the base of the Monk. South of the 

headwaters of Gypsy Creek the conglomerate is missing, but presumably the same limestone is present overlying greenstone schist and separating it from gray 

phyllite of the Monk formation.

The phyllites of the Monk formation are not appreciably different from the Maitlen phyllite and from 

many phyllites in the Priest River group. A uniform 

light-gray color prevails, but faint greenish and bluish 

hues are seen and some beds are dark gray or nearly 

black. The phyllites are thin-bedded, with small differences in the color and grain size of adjacent layers. 

The phyllites in the lower part of the Monk formation 

are generally more calcareous than those in the upper 

part. Some beds near the base of the formation, which 

are finely fragmental and apparently tuffaceous, resemble the gray-green schists in the upper part of the 

Leola volcanics.

The limestone members of the Monk formation are 

white to gray or cream-colored on fresh surfaces and 

generally buff to gray on weathered surfaces. Those 

in the lower part of the formation exhibit a conspicuous finely laminated structure and commonly break 

into flags under the hammer. One such platy limestone exposed in a cut on the Sullivan-Deemer Creek 

road near the Salmo-Shedroof ridge contains some

intraformational limestone conglomerate similar to 

that in the Devonian (?) limestone near the northwest 

corner of the quadrangle. Grains of silica are seen in 

all the limestones, particularly on weathered surfaces. 

In the massive limestone at the top of the Monk these 

grains are especially abundant and large, some attaining diameters of 3 millimeters. In hand specimens 

they appear as rounded grains of opalescent palobluish quartz.

The sandy members of the formation range from 

fine-grained quartzite to coarse-grained grit in which 

some of the pebbles reach diameters of half an inch. 

The quartzite beds are commonly light-colored, aiv 

generally massive, and show traces of bedding only at 

their contacts with phyllite and limestone members. 

Most of the sandy beds are true quartzites, but some 

contain carbonate as the cementing material and 

should perhaps be called calcareous sandstones. The 

color of the grits ranges from light gray to dark 

greenish gray. The pebbles are mostly quartz, commonly opalescent in shades of blue and lavender, but a 

few dark-colored slate fragments were seen.

Microscopic features. Thin sections of the phyllites 

of the Monk formation show tiny angular mineral particles set in an abundant schistose matrix dominated 

by fine-grained micaceous minerals. Bedding is indicated by contrasts in the abundance, size, and composition of the particles in adjacent layers. In most 

sections schistosity cuts the bedding at appreciable 

angles. The particles are dominantly quartz; a few 

are albite and resistant detrital minerals such as zircon, tourmaline, titanite, and apatite. Apparently 

tuffaceous facies near the base contain, in addition, 

grains altered to aggregates of chlorite or of chlorite 

with minor sericite, quartz, and carbonate. Some of the 

chlorite aggregates are apparently pseudomorphs of 

hornblende or other mafic minerals. The matrix, which 

is more abundant than the grains, contains sericite. 

chlorite, and biotite, with intersertal quartz and grains 

of iron oxides in various proportions. The calcareous 

phyllites in the lower part of the formation contain 

abundant carbonate in certain layers.

The limestones examined in thin section are composed largely of calcite with scattered grains of quartz. 

Sericite, iron oxides, zircon, tourmaline, and apatite 

make up only a small proportion of the rock. The 

quartz grains are roughly equidimensional, and their 

association with grains of zircon, tourmaline, and apatite and the gradation from sandy limestone to quartzite, noted in the field, certainly indicate their detrital 

origin.

A thin section of typical grit contains many wellrounded pebbles of quartz and several of clusters of 

altered feldspar crystals, as well as small amounts of 

iron oxides, titanite, and leucoxene. The matrix is i\ 

schistose mosaic of sericite and quartz with minor car-
bonate. The quartz pebbles consist either of a single 

grain or of several grains with sutured boundaries. 

Their appearance suggests that they were derived by 

erosion from a coarse-grained granite or pegmatite, or 

from vein quartz, and it was so interpreted by Daly.14 

However, one pebble in thin section preserves fragmentary but rather convincing evidence of relict sandstone texture. This particular pebble has been recrystallized but contains triangular schistose areas that 

suggest interstitial fillings. The arrangement of dusty 

particles in the pebble, as well as the schistose inclusions, suggests that the pebble was originally a typical 

(jiiartzite but has been recrystallized to coarser-grained 

quartz with sutured boundaries. Possibly many or 

most of the quartz pebbles in the grits also represent 

recrystallized quartzite pebbles.

CONDITIONS OF SEDIMENTATION

The great diversity of sedimentary materials in the 

Monk formation indicates extreme fluctuation and 

wide range of conditions of sedimentation.

The fact that the character of the Monk changes 

from north to south but seems to be fairly constant 

from, east to west (Sullivan Creek road and O. K.- 

Oriole mines) suggests a source of sedimentary debris 

to the north.

The volcanic fragmental material in the lower Monk 

may be reworked Leola volcanics rather than a product accumulated during active volcanism. The inference, that at least part of the sedimentary beds in the 

Monk may have been derived from the Shedroof conglomerate and the Priest River group is given some 

support by the suggestion made above, that the grit 

pebbles are quartzites rather than single quartz crystals or grains. The numerous quartzite cobbles in the 

Shedroof conglomerate and the quartzite beds in the 

Priest River group would seem to offer an adequate 

source for the grits and quartzites in the Monk, although far inadequate to account for the tremendous 

volume of the overlying Gypsy quartzite.

AGE

The age of the Monk formation is unknown. It is 

tentatively placed at the base of the Cambrian, as it is 

conformable with and grades upward into the Gypsy 

quartzite which is definitely of Cambrian age.

CAMBRIAN SYSTEM

GYPSY qiJARTZITE

DISTRIBUTION

The most extensive exposure of the unit here called 

Gypsy quartzite is a belt 2 to 3 miles wide that forms 

the core of Crowell Ridge and Gypsy Ridge, and extends from Hall Mountain northeastward into Canada,

14 Only, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Gool. Survey Mem. 38, p. 151, 1912.

where it has been traced for many miles by Walker 15 

and Rice.16 Both Daly 17 and Walker 18 subdivide the 

Gypsy quartzite into several units, the comparative 

positions of which are shown in the stratigraphic sections of figure 3. For the purposes of the present report it is sufficient to treat the quartzite as a unit. 

The name is taken from the excellent exposures in 

the high amphitheaters of Gypsy Ridge. (See pi. 16, 

A) Three other areas of quartzite are found in the 

Metaline quadrangle. One extends along the west side 

of the Flume Creek -fault from the Middle Fork of 

Flume Creek southward about 6 miles, almost to the 

Kaniksu batholith. This exposure (see pi. 13, D] is an 

excellent place to study the section, as it is nearly devoid of vegetation and is readily accessible. The 

upper beds of the quartzite crop out on the crest of 

the Hooknose anticline from the intersection of the 

Russian Creek and Flume Creek faults southwestward 

about 6^/2 miles. A much smaller exposure of the top 

beds of the quartzite occurs in the Silver Creek Valley 

southwest of Abercrombie Mountain, in sec. 15, T. 39 

N., R. 42 E.

THICKNESS AND STRATIGRAPHIC RELATIONS

The quartzite section on the Crowell-Sullivan ridge 

is about 8,500 feet thick, but on the ridge west of the 

Oriole mine the thickness is only 5,300 feet. A comparison of the columnar sections from the two localities 

is given in figure 3, and shows the reason for the large 

difference in thickness. The 4,525 feet of grits and 

conglomerate present at the base of the formation east 

of the Pend Oreille River are represented by only 1,260 

feet near the Oriole mine. The quartzites above the 

basal grits and conglomerates are surprisingly similar 

in the two sections.

The Gypsy quartzite grades downward into the 

Monk formation and upward into the Maitlen phyllite. 

The limits of the quartzite were placed where quartza ite and grit beds predominate over beds of other types. 

For this reason either boundary of the quartzite may 

not be everywhere at precisely the same horizon.

IJTHOI.OUY AND INTERNAL STRUCTURE

Megascopic features. The upper contact of the 

quartzite is placed at the top of a band, 50 to 300 feet 

thick, of alternating beds of quartzite and phyllite in 

nearly equal parts. These beds are characterized by 

fucoidal cylinders and unidentified crooked rods of 

organic (?) origin, called for convenience "burrows." 

The "fucoids" are approximately circular in cross sec10 Walker, J. F., Geology and mineral deposits of the Salmo map 

area, B. C.: Canada Geol. Survey Mem. 172, p. 7, 1934.

19 Rice, H. M. A., Preliminary report, Nelson map area, B. C.: Canada 

Geol. Survey Paper 37-27, 1937.

17 Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey. Mem. 38, pp. 141-159, 1912.

18 Walker, J. P., op. cit, pp. 6-9.
14 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

tion, about half an inch in diameter, and generally 2 

to 3 inches long, although a few about a foot long were 

seen. These small cylinders are commonly oriented 

normal to the bedding and are gently tapering. On 

casual examination the rock appears to be a conglomerate with peculiar circular quartzite pebbles, and it

CrowellSullivan

Oriole

Maitlen phyllite

320'

860

1,345

1.625

3,400

250

825

8,645'Total

FIGURE 3. Columnar sections of Gypsy quartzite on the Crowell-Sullivan 

ridge and on the ridge west of the Oriole mine.

is only where broken across the bedding that the true 

texture is seen. The "burrows" occur usually in the 

more shaly layers. They are irregularly distributed, 

winding and crossing rods a quarter of an inch or less 

in diameter. They lie along bedding surfaces rather 

than across them. The value of either the fucoidal 

cylinders or the "burrows" as horizon markers is ques18 Bridge, Josiah, and Kesser, C. E., personal communications,' 1937.

tioned by both Bridge and Resser.19 In the Metaline 

quadrangle, however, they are found throughout the 

transition zone between the Gypsy quartzite and the 

Maitlen phyllite and serve as a convenient reference 

horizon.

Below the uppermost quartzite beds is about 2,200 

to 3,000 feet of thin platy quartzite, in places with shaly 

layers and a few intercalated limy beds. The beds are 

generally 6 inches to 1 foot thick, although layers 6 

feet thick are not uncommon. The quartzite is gray near 

the base and becomes white or buff toward the top. 

It is even-grained and in places is cross-bedded. The 

beds are commonly separated by sericite-covered planes 

or by thin schistose layers. Particularly near the top 

of the platy beds the phyllite layers are more numerous 

and are similar to those in the overlying Maitlen 

phyllite.

Below the platy quartzite is a massive white to pinkish cliff-forming quartzite, 800 to 1,625 feet thick. This 

quartzite is even-grained and sugary; the individual 

grains can be distinguished with a hand lens. The 

quartzite is unusually clean in appearance, and besides 

the quartz the only mineral seen in it consists of -a few 

shreds of silvery-white sericite. Cross-bedding is more 

noticeable in this massive white rock than at any other 

horizon in the quartzite formation.

A band of schist 20 to 195 feet thick lies below the 

massive white quartzite. This schist is in general 

poorly exposed but is dark green where it crosses 

Crowell Ridge.

Below the schist and continuing to the base of the 

quartzite is a sequence of conglomerate, quartzites, and 

aHernating beds of grits. The conglomerate contains 

well-rounded cobbles as large as 6 inches in diameter. 

It resists weathering to a remarkable degree and generally stands out in bold relief. For this, reason it is 

a convenient horizon marker, advantage of which was 

taken by both Daly 20 and Walker.21 The conglomerate 

has a maximum thickness of about 250 feet near the 

Canadian border but thins southward and probably 

averages less than 100 feet thick in the Metaline quadrangle. On the slope west of the Oriole mine the conglomerate (see pi. 5, B) is only about 50 feet thick. 

Bright-red jasper pebbles are characteristic of the conglomerate from Sullivan Mountain northward but have 

not been identified west of the Pend Oreille River. 

The cobbles are mostly quartzite, but schist and vein 

quartz are common, and in places cobbles of several 

types of porphyritic rocks are abundant. The matrix 

in the conglomerate and in part of the grits is commonly a siliceous and micaceous gray to dark-gray 

material in which small grains of quartz can be seen.

The grits generally are composed of smooth wellrounded quartzite pebbles less than half an inch in

20 Daly, R. A., op. cit. (Canada Geol. Survey Mem. 38), pp. 153-.154. 

"Walker, J. F., op. cit. (Canada Geol. Survey Mem. 172), p. 8.
CAMBRIAN SYSTEM 15

(1 iumotor. Pebbles of other rocks, particularly schists, 

are present but in subordinate amounts. The grits are 

generally light buff or grayish, but some beds are 

speckled with bright-pink pebbles. Most of the grit 

beds are a few inches to a few feet thick. They grade 

into quartzites laterally as well as across the bedding, 

and some layers change to quartzite within a few feet 

on the strike. Schist layers alternate with the grit 

beds near the base .of the grits. The schists become 

increasingly abundant lower in the section, and the 

formation grades into the Monk.

Many of the quartzites are badly sheared, but in most 

of them bedding planes and grain outlines can be distinguished.

Microscopic features. Microscopic study of the 

qnartzites brings out clearly the sheared nature of much 

of the rock. A general tendency toward elongation exists, and some grains indicate secondary growth. Many 

of the grain boundaries have thin zones of recrystallized 

quartz. Most thin sections show quartz and sericite, 

but a little tourmaline, zircon, and highly altered 

plagioclase feldspars were also seen. Dusty leucoxene 

('4) is present in small amount, and in the grain interstices of the less pure quartzites near the bottom and top 

of the section a little greenish biotite and chlorite were 

identified. Strain shadows are developed in practically 

all the quartz.

The purer quartzites, such as the massive white bed 

above the grits, have no matrix except a few grains of 

sericite. In the less pure rock the micaceous minerals 

are more plentiful in the interstices and probably were 

'originally a clayey material now recrystallized.

CONDITIONS OF SEDIMENTATION

The tremendous volume of grits and sandstones accunnilated in the Gypsy quartzite can be satisfactorily 

explained by rapid deposition in a gradually subsiding 

basin. The source of supply is not known, but the 

purity of the quartzites suggests that the source was 

sufficiently distant for the soft and easily weathered 

minerals to be removed. This may be a function of 

rate of accumulation, as Avell as distance from the 

source. The thinning of the formations to £he west 

and the greater thicknesses given by both Daly and 

Walker (see table, p. 6) to the north indicate a likely 

source to the north and east.

The transition to limy and clayey rocks, at both the 

bottom and the top of the quartzite, probably indicate 

passage to conditions of deeper sedimentation.

Several poorly preserved fragments of trilobites in 

a broken piece of quartzite were found on a ridge at 

an altitude of 6,250 feet on the west slope of Gypsy 

(Peak, in' the NW% sec. 18, T. 40 N., R. 45 E. . The 

fossil bed could not be found in place, but the angular

quartzite was similar to the bedrock nearby, and it is 

thought that the fossils had not traveled more than a 

few feet. Bridge examined the trilobites and said, 

"The collection is unquestionably Cambrian but is so 

fragmentary that a more exact determination is not 

possible at present." The assignment of a Cambrian 

age to the Gypsy quaxtzite confirms Daly's earlier 

determination of his Summit series, based on lithologic 

evidence. 22 Daly placed the base of the Cambrian 

about 1,000 feet below the top of his Wolf grits (see 

table, p. 6), or at the base of the Gypsy quartzite. 

As no evidence of a stratigraphic break at the base of" 

the Gypsy quartzite is found in the Metaline quadrangle, the base of the Cambrian is tentatively placed 

at the hiatus below the Monk formation.

MAITLEN PHYLLITE 

DISTRIBUTION

The Maitlen phyllite, here named from the valley of 

the intermittently flowing Maitlen Creek, east of lone, 

lies above the Gypsy quartzite and below the Metaline limestone. It is exposed in two large areas one 

a belt along the east side of the Pend Oreille River 

and Slate Creek that extends from the area east of 

Tiger northeastward to the Canadian border, the other 

Avest of the Flume Creek fault and on the flanks of 

the Hooknose anticline. A third, smaller area is 

, exposed 011 Boundary Mountain.

The phyllite crops out surprisingly well, considering 

its character. It is slightly more resistant than the 

limestones and slates that overlie it, and it forms 

rounded foothills at the base of the quartzite ridges. 

On the crest of the Hooknose anticline south of Abercrombie Mountain the phyllite is preserved as a thin 

cap over the quartzite. The rapidly flowing streams, 

descending from the quartzite ridges, particularly from 

the Gypsy-Crowell ridge, have cut deeply into the 

phyllite, and in these stream canyons exposures arc 

good.

THICKNESS AND STRATIGRAPHIQ RELATIONS

The phyllite is much distorted and sheared, and no 

satisfactory section or estimate of the thickness has been 

reached. The minimum apparent thickness is about 

5,000 feet, taken on the west slope of Sullivan Mountain. The base of the phyllite on Sullivan Mountain 

and to the northeast is placed about 100 feet below a 

gray-white limestone band 200 feet thick (not shown 

on the map). The phyllite is gradational into the 

Gypsy quartzite, and the contact is placed at the top of 

a prominent bed rich in fucoidal impressions, where the 

quartzite becomes subordinate in quantity to the phyllite. On the Hooknose anticline the base of the phyllite 

is about 200 feet below a limestone band that is thought

: Daly, It. A., op. cit. (Camilla Geol. Survey Mem. 38), pp. 177-lfM.
16 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

to be the same bed that is exposed on Sullivan Mountain. The Gypsy quartzite beds with the "fucoids" on 

the Hooknose anticline are mostly included with the 

phyllites, as they are argillaceous and contain few 

quartzite layers. No certainty is felt that the base of 

the phyllite as mapped is everywhere in the same stratigraphic position as fully consistent mapping at this 

"fucoid" horizon is not feasible. A similar uncertainty 

applies to the top of the phyllite, where the beds become limy and grade into the Metaline limestone. The 

contact here is placed where the phyllite predominates 

over limestone.

LITHOLOGY AND INTERNAL STRUCTURE

Megascopic features. The megascopic features of the 

Maitlen phyllite are extremely diverse. The most comFIGURE 4. Sketch of a hand specimen of phyllite from south side of 

Hall Mountain. Natural size, o 6 c h, Poorly defined planar structure ; b o d, dominant foliation; c d e n, late fracture cleavage; f, 

direction of fine hairlike linear structures ; g, composition banding of 

unknown origin. Surface o h e j is the dominant foliation, broken 

or bent along cleavage planes parallel to c d e h.

mon rock type is gray greenish, fine-grained, and conspicuously banded. Quartzite beds, generally less than 

3 feet thick, are present in appreciable amounts, particularly near the base of the section. Limestone 

layers are common, and many narrow layers,, in addition to the 200-foot bed near the base, are distributed 

through the section, particularly in the upper part. In 

some exposures the phyllite is more correctly defined as 

a sericite schist, and in other places the rock is greenish 

and massive and in physical appearance suggests an 

altered volcanic rock. Pyrite is found in much of the 

phyllite, and beds are locally spotted with brown iron 

oxides. On Sullivan Creek just below the Metaline 

limestone an almost continuous section is exposed. The 

phyllite near the top is grayish black, slightly recrystallized, and difficult to distinguish from the Ordovician 

slate. This similarity is particularly confusing in Uncas Gulch, a tributary to Slate Creek, where the upper 

part of the phyllite and the Ledbetter slate were 

faulted together.

The layers in the characteristic phyllite average probably less than 2 inches in thickness. They are compositional, and a few beds of quartzite and limestone can 

be recognized, although generally the mineral grains are 

too small to be determined. The 200-foot bed of limestone near the base of the phyllite is largely recrystallized to a dense fine-grained marble, crudely streaked 

gray and light brown. It is generally much sheared 

and contains sericite shreds and numerous quartz grains. 

In places the bed is cut by irregular stringers of white 

greas}7 quartz. Other limestone beds weather to a buff 

color, and all of those tested effervesced freely with 

cold dilute (1:1) hydrochloric acid.

One of the striking features of the phyllite is its 

rapid change in degree and diversity of metamorphism. 

These differences are probably caused by several factors, among which the original nature of the sediments, 

proximity to the batholith, and the depth of burial 

at time of metamorphism may be pointed out. In a 

very small part of the phyllite the deformation is 

limited to open crumples. Elsewhere the crumples 

become tighter and fracture cleaA-age develops. In 

practically all the formation at least one planar element, other than bedding and jointing, is recognizable, 

and in some exposures two or even three directions of 

foliation can be distinguished. One direction is customarily more prominent than the others, and this is 

the one recorded on the geologic map (pi. 1). It is 

rather common for the dominant foliation to cut the 

bedding at angles of 30° or more. The value of recording only the dominant foliation is questionable, as 

the phyllite on Hall Mountain, for example seems 

to have been subjected to deforming stresses in at least 

two directions. .The evidence for this can best be given 

with the help of a diagram (fig. 4), which is a sketch 

of a specimen of phyllite in which the dominant foliation is bent and fractured along a cross cleavage. 

Toward the top of Hall Mountain the late cleavage 

planes become more numerous and finally are close 

enough together to obscure the earlier deformation.

Plate 6, A, is a photograph of a polished face of 

phyllite from the saddle at an altitude of 5,800 feet in 

the northwest corner of sec. 35, T. 39 N., R. 42 E. It 

shows two types of layering. The horizontal micaceous layers are formed along shear planes, and the 

layers ab are alternating quartz sericite which probably denote bedding, as suggested by field evidence (see 

pi. 6, D.} In many places the shear banding 23 destroys 

and is easily confused with bedding.

23 Balk, Robert, Structural and petrologic studies in Dutchess County, 

N. Y., pt. 1, Geologic structure of sedimentary rocks : Geol. Soc. America 

Bull., vol. 47, pp. 709-717, 1936,
CAMBRIAN SYSTEM 17

Linear structures of several types are recognized. 

That recorded on plate 1 is the direction and pitch of 

the intersection of the axial planes of the crumbles 

 with the bedding. In many specimens a Arery fine 

hairlike linear structure is conspicuous. Other linear 

structures are developed by the intersections of the 

several planar elements, bedding, and shear banding. 

Mineral elongation does not everywhere coincide with 

linear structures. The sheared and crumpled nature 

of the phyllite is obvious on surfaces cut normal to 

the dominant foliation and the bedding. (See pi. 6, 

(7.) The rock, in places, has been more sheared than 

that in the illustration and is reduced to a mass of 

pencil-shaped fragments. On Hall Mountain, in the 

east-central part of sec. 8, T. 38 N., R. 44 E., the siliceous lnyers have been sheared and rolled in the sericitic matrix to the point where the rock resembles a 

conglomerate.

Microscopic, features. Microscopically the phyllite 

consists of quartz, sericite, and calcite, almost to the 

exclusion of other minerals. Chloritoid and chlorite 

are both present, although neither is abundant, and 

their distribution seems to be spotty. Small amounts 

of detrital zircon and tourmaline have been seen in 

several sections, and both limonite and other, iron 

oxides are present. No feldspar has been identified 

in the material examined, but a more extended investigation would probably reveal it. The limestone, particularly near the base of the formation, contains 

appreciable amounts of sericite and quartz. One specimen obtained west of the Harvey fault on Molybdenite Mountain has about 40 percent of quartz grains 

embedded in calcite. In most of the material examined the minerals are recrystallized, although individual grains are generally so small as to be invisible 

without the microscope.

The internal structure of the phyllites is complex. 

Two directions of foliation can ordinarily be distinguished. Plate 6, B, which represents a thin Section 

cut nearly parallel to the face shown in plate 6, A, 

shows- both a schistosity and fracture cleavage. The 

mica tends to recrystallize and concentrate in layers 

parallel to the fracture cleavage, and at the same time 

the bedding is not destroyed. Such shear banding 

nlight conceivably be formed by close shearing of a 

bedded rock in which the bedding is gradually rotated 

and the more mobile material, in this example the 

Koricite, is removed and concentrated along the shear 

planes. The shear banding may be an incipient stage 

of "metamorphic differentiation" as defined by Stillwell,24 Eskola,'^ and Earth,20 although the high temperatures and pressures usually associated with this

21 Stilhvell, F. L., The metainorphic rocks of Adelie Land : Sci. Repts. 

Australasian Antarctic Kxprd., 1911-101.4, ser. A, vol. 3, pt. 1, pp. 

!)H -121, 19.1.8.

x Vtakola, P., On rlu« principle of metiimorphic differentiation: Soc. 

K«>ol. Finland Conipt Rend., vol. 5, pp. 68-77, 1932.

2(1 Hartli, T, If. W., Structural and petrologic studies in Dutchess 

County, N. Y.: Geol. Soc. America Bull., vol. 47, p. 842, 1936.

process are not found at Metaline. No indication of 

partial fusion and squeezing out of the liquid material 

(palingenesis) was seen, although criteria for recognizing this process are vague.

The fine hairlike linear structures so commonly seen 

on hand specimens are found, microscopically, to be 

caused by the intersection of an incipient cleavage with 

other structures, including the shear banding. Generally a few thin plates of sericite are oriented along 

the incipient cleavage, and individual cleavage planes 

can rarely be traced across a thin section. The relation 

of this cleavage to the regional structure is obscure.

CONDITIONS OF SKDIMKNTAT1ON

The phyllite, to judge from its generally thin-banded 

and diverse nature, was deposited on a shallow, oscillating but slowly deepening sea bottom, where conditions 

ranged from those favorable to the accumulation of 

quartzite and clay to those in which limy clay and pure 

limestone were laid down. The "fucoids" and "burrows" near the base also indicate shallow water during 

the transition from quartzite to phyllite. During the 

deposition of the upper part of the phyllite conditions 

gradually changed and limestone accumulated in increasing quantities.

AGE

The phyllite grades downward into the Gypsy quartzite, which is of Cambrian age, and upward into the 

Metaline limestone, of Middle Cambrian age. It is 

therefore Lower or Middle Cambrian. No fossils, with 

the exception of a few fucoidal impressions, have been 

found in the phyllites.

METALINE LIMESTONE

DISTRIBUTION

The Metaline limestone, here named from the cliffs 

near Metaline Falls, is exposed in the Pend Oreille Valley from lone north to the Canadian border. It underlies most of the territory between Slate Creek and the 

Pend Oreille River and forms the steep-walled gorge 

of the river north of Metaline Falls. The topography 

of the limestone area is characteristically pitted and 

rough.

THICKNESS AND STKATH1KA.PHIC RELATIONS

Establishment of a detailed section'of the Metaline 

limestone would undoubtedly be of value to the mining 

industry, but compilation of such a section is difficult 

for several reasons. The beds have been masked by 

dolomitization and other processes related to ore deposition, the brittle carbonate rocks have been much 

faulted and brecciated, and where exposures are best 

in the river gorge the beds are largely inaccessible. 

(See pi. T.) For these reasons no precise'estimate of 

the thickness of the Metaline limestone section is pos-
18 GEOLOGY AND ORE DEPOSITS OF THE MBTALINE QUADRANGLE; WASHINGTON

sible at present, although it is thought that with more 

detailed study such a measurement could be made. The 

limestone between Slate Creek and the Pend Oreille 

River, shown in section D D' of p]ate 1, has an apparent thickness of 5,000 to 6,000 feet. This figura is considered to be too large, as repetition of the strata by 

faulting is here thought likely. The section east of 

Metaline Falls, in the relatively undisturbed block 

being quarried for limestone, furnished what appears 

to be the most reliable measurements. The total thickness here is about 3,000 feet, in which four members are 

distinguished, as follows:

Section east of Metaline Falls

Top Feet 

Mottled dense gray limestone; few chert nodules____ 150 

Mottled dense gray limestone; many chert nodules___ 450 

Fine-grained cream-colored dolomite, particularly in upper

part. Alternating layers of black and white dolomite__ 1, 200 

Interbedded limestones and limy shales, locally dolomitic.

Grades conformably into Maitien phyllite_________ 1, 200

3, 000

The top of the ]imestone is sharply defined against 

overlying black slate. No gradational beds have been 

seen, and the possibility of an unconformity between 

the limestone and the slate cannot be completely discarded, although considered to be unlikely. That the 

beds below the slate are approximately equivalent 

throughout the district is indicated by the unusual mottling (pi. 8, A) and the fine-grained dense character 

of the limestones, which, about 150 feet from the slate 

contact, are underlain by peculiar cherty beds (pi. 8, 

B). The base of the Metaline limestone, on the other 

hand, is a limy phyllite in which limestone beds decrease numerically downward and the formation grades 

into the Maitien phyllite below.

LITHOLOGY AND INTERNAL STRUCTURE

Megascopic features. The upper 150 feet of the section is a dense, fine-grained soft gray limestone with 

a peculiar mottled appearance. (See pi. 8, A.) The 

mottling is due partly to the irregular distribution of 

a small amount of carbonaceous material and partly to 

the development of stylolites along cracks. The rock 

is massive, and bedding is generally not seen< A few 

narrow indistinct parallel layers that appear to be 

caused by slight concentration of organic material may, 

however, represent bedding. This part of the limestone 

seems to have been unusually receptive to ore-forming 

solutions and is complexly altered to dolomite, jasperoid, coarse-grained calcite, and ore, which mask the 

original character. A few chert nodules are generally 

present and the rock passes gradually into a more 

cherty rock below.

The 450-foot member is similar to the overlying

beds but contains numerous chert nodules. (See pi. 8, 

B.) The nodules are generally rounded, crudely 

spheroidal or ellipsoidal. They average less than one 

inch in longest dimension and many have hollow 

centers. The abundance of the nodules differs from 

place to place, but they appear to be confined largely 

to this member and a few in beds above. The limestone is similar in mottled appearance and texture to 

the overlying beds. In some places it is nearly pure 

limestone and effervesces vigorously with very dilute 

(15 :1) hydrochloric acid. In other places it is altered 

to a dense fine-grained creamy-gray dolomite and to 

the materials that accompany ore deposition.

Below the fine-grained limestone is about 1,200 feet 

of carbonate rock that, wherever seen, is dolomitized. 

The upper part is generally a fine-grained massive 

cream-colored to gray dolomite that shows no known 

diagnostic features. The grain is so fine that cleavage 

surfaces of individual particles are rarely seen, but 

lower in the section the rock is increasingly coarser 

and grains one-sixteenth to one-eighth inch across are 

present. Intercalated with the fine-grained creamcolored dolomite are a few layers of black dolomite 

that commonly contain white spots, less than an inch 

in longest dimension. The black layers are more 

numerous near the base of the section and in places 

make up 50 percent of the rock. The thickness of 

the individual layers is generally less than 4 or 5 feet, 

but some are much thicker and others are only a fraction of an inch thick. Analyses of the black and 

cream-colored dolomites are given in the table on page 

42. The two rocks are practically identical in composition except for a small amount of carbonaceous 

material in the black rock. The light-colored dolomite appears to have been formed by recrystallization 

of the darker layers and the expulsion of the carbonaceous material. For this reason the layering, although 

in general it agrees with bedding, is in places discordant, and irregular remnants of the black dolomite 

are isolated in the lighter rock. Plate 9 4, shows such 

a remnant as well as the more usual type of banding. 

Bedding is better seen near' the base of the section 

than toward the top. It is accentuated by slight textural and color differences. No basis for subdividing 

this 1,200 feet of dolomite has been .recognized, but it 

is likely that detailed study and possibly an examination of insoluble residues, as developed by McQueen,-7 

would establish such a basis.

The lowest part of the Metaline limestone, about 

1,200 feet thick, is treated as a unit, largely from lack 

of time to study it thoroughly rather than a lack of 

recognizable members. Parts of this section are well 

exposed in the quarries and road cuts east of Metaline

27 McQueen, H. S., Insoluble residues as a Ruide in stratigraphic 

studies: Missouri Bur. Geology and Mines, 56th Bienn. Kept., 1931, 

reprint of Appendix I, 1930.
/ GEOLOGICAL SURVEY PROFESSIONAL PAPER 302 PLATK fi

A. MAITLEN Pin I.L1I I,, SADDLE IN NORTHWEST CORNER OF SEC. 35, T. 39 N., R. 12 E., ALTITUDE, 5,800 FEET.

Shear banding is horizontal. Banding a-b is bedding. 

R. MAITLEN I'HYLLITE, PHOTOMICROGRAPH OF THIN SECTION OF ROCK NEARLY PARALLEL TO FACE SHOWN IN A.

Schistosity (bedding ?) is cut by fracture cleavage (shear banding). 

C. MAITLEN PHYLLI'IE, NORTH CENTER OF SEC. 23, T. 39 N., R. 42 E., ALTITUDE 5,950 FEET.

Polished surface cut normal to dominate foliation and bedding.

r>. MAITLEN PHYLLITE, NORTHWEST CORNER OF SEC. ,H5, T. 39 N., R. '12 E. 

Bedding nearly horizontal, shear banding nearly vertical.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE 7

POST-I'LElSTOCEiNE GORGE OF THE PEND ORE1LLE RIVEK.

View south from east hank of the river about J mile (southeast of Z Canyon. The river level i 

ohserver.

about ,SOO feet helow the
GEOLOGICAL SURVEY PROFESSIONAL I'APEK 202 I'LATE

A. METALINE LIMESTONE, I'END ORE1LLE MINK. 

Polished fragment of split drill rore, 140 feet below Le ll.eller slale.

B. C1IKKT \OI)l LK.S ON WKATIIKKKD SI KFACE IN MK'I'AUINK LIMKSTONE. LEAD HILL.
GEOLOGICAL SURVEY PROFESSIONAL 1'AI'EK 202 I'LATE 9

A. BLACK AM) LI<;HT-COLOKKI) UOLOMl'l'K, INOKTH SIDE OF CRESCENT LAKE. 

JVole (lie rexi'lnal hlark reinnaiil in the li^'lit dolomite al>o\e the hat.

H. ALGAE [> LOWKK I'AKT OK METAUNK L1M KSTOM^:, KOAI) CUT EAST OK

i i'1'EK LEHH;H ULJAUKV.
ORDOVICIA'N SYSTEM 19

Falls. Limy shale or phyllite beds alternate with limestones and dolomites throughout the 1,200 feet, but 

the plvyllites are more numerous toward the base. The 

limestone in the upper part of the.section can be seen 

in tiro upper1 Lehigh quarry and in the road cut between 

the upper quarry and the shale quarry. Limestone, 

dolomitic limestone, and dolomite are all represented. 

The limestone is chiefly of two types. One is a smooth 

light-gray rode speckled with small (less than oneeighth inch) glassy calcite crystals; the other is a 

smooth dense rock, with a mottled gray appearance, 

which contains numerous streaks and spots (about 2 

inches in longest dimension) of white calcite. The 

bed below this limestone is slightly dolomitic (less than 

10 percent Mg(X);,) and is of unknown thickness. This 

bed is conspicuous, as it consists of layers of blue-gray 

dense limestone, less than 2 inches thick, separated by 

sharply undulating layers of shaly limestone about a 

quarter of an inch thick. Some of these undulating 

shale layers join and leave isolated eyes of the limestone. On exposed surfaces the shaly layers .weather 

brown and contrast with the grayish lime. This contrast is less Jioticeable on fresh surfaces where .the shaly 

layers are only slightly darker than the blue-gray limestone. Several beds farther down in the section are 

also characteristic. One bed of dolomite contains 

many algae such as are shown in plate 9, B. Other 

beds contain numerous small rounded grains that resemble oolites or pisolites. The limestone in the lower 

parts of the section is thin-bedded and is interlayered 

with much limy phyllite. Gradations from blue-gray 

.limestone to black limy phyllite are found. The black 

phyllite is in beds that are 50 feet or more thick, as 

well as in numerous thinner layers. The thicker beds 

have in places, particularly in diamond-drill cores, been 

confused with the closely similar Ledbetter slates. The 

degree of metamorphism of the two rocks is about 

the same, but a grayish sheen is noticed on much of 

the Cambrian phyllite and is generally absent from 

the Ledbetter slate. Bedding planes are also more 

conspicuous in the Cambrian rocks.

A section through the Metaline limestone on Boundary Mountain is similar to that east of Metaline Falls, 

but the rocks are more recrystallized and dolomite is 

more abundant.

Microscopic features. No effort has been made to 

study the microscopic features of the limestone in detail, and no unusual features were noticed in the few 

slides examined. Much of the rock, particularly the 

light-colored dolomite, is recrystallized. The black 

dolomite has a cloudy greasy appearance, probably due 

to minute spots of carbonaceous material. The black 

dolomite grains are, on the average, smaller than the 

grains in the light-colored dolomite. Many crystals 

between the black and light-colored dolomites are 

partly cloudy and partly clear.

CONDITIONS OF SEDIMENTATION

The conditions favorable for the accumulation of 

limestone alternated with and gradually superseded 

those under which the phyllites were deposited. These 

conditions must have remained unchanged for a long 

period of time to permit the deposition of 3,000 feet 

of limestones. The contact between the Metaline limestone and the overlying Ledbetter slate is sharp and 

indicates an abrupt change in the conditions that governed deposition in fact, at least part of the Upper 

Cambrian epoch intervened between the Metaline and 

Ledbetter epochs. 

Two collections of fossils of Middle Cambrian age 

have been taken from the Metaline limestone near the 

base of the formation. The best collection was obtained from the shaly bed that overlies the limestone 

in the upper Lehigh quarry, east of Metaline Falls. ( 

A few trilobites can also be found in nearby limestone 

beds. The fossils identified by Josiah Bridge are 

listed below.

Elratliia kingii. 

Neolenus sp. 

Kootania sp. 

Pagetia sp. 

Acrotliele sp.

A second fossil locality Avas found in poorly exposed 

limy shale at an altitude of 2,800 feet on the southeast 

bank of Threemile Creek in the SW}4 sec. 12, T. 39 N., 

K. 43 E. The species identified by Josiah Bridge are 

the same as those obtained from the Metaline quarry. 

According to Bridge, the Metaline limestone is approximately equivalent to the Stephen formation of British 

Columbia 28 and the Middle Cambrian limestone- recently found in the Libby quadrangle, Mont.29

One specimen of a poorly preserved trilobite was 

found by John Carrie in the silicified limestone of the 

Pend Oreille mine between the 500-foot and 700-foot 

levels.

OKDOVTCIAN SYSTEM

LEDBETTER SLATE 

DISTRIBUTION

The Ledbetter slate is irregularly distributed in the 

Pend Oreille Valley north of lone. One belt, from 

which Slate Creek is named, can be followed from the 

Pend Oreille River northeastward up the Slate Creek 

Valley to the Canadian border. Another large area 

that lies north of the Russian Creek fault is well exposed on the new Russian Creek road to the Frisco

28 Walcott, C. D., Cambrian geology and paleontology : Smithsonian 

Misc. Coll., vol. 53, pp. 209-212, 1910.

20 Gibson, Russell, Geology and ore deposits of the Libby quadrangle. 

Mont:.: TJ. S. Geol. Survey Bull, (in preparation). Fossils determined 

by 'P. IS. Raymond.
20 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

Standard mine. The name Ledbetter is taken from the 

outcrops on the slope west of Ledbetter Lake, where 

the formation can readily be seen. The slate breaks 

clown readily and forms rounded soil-covered hills. 

For this reason the rock is best exposed in artificial 

openings, such as road cuts and mine excavations.

THICKNESS AND STKATIGRAVHIC RELATIONS

The Ledbetter slate is much sheared and' distorted, 

and, as a result, the thickness is extremely erratic. The 

apparent ease with which the slate "flowed" under pressure is indicated by the drag, in places amounting to 

hundreds of feet, along fault zones. The maximum 

apparent thickness both on Russian Creek and northwest of Ledbetter Lake is about 2,500 feet. The base of 

the slate is a sharply defined surface. The upper limit 

has been seen only on the hill southwest .of the United 

Treasure mine, and here the relations are obscured by 

an intrusive mass; furthermore, the exposures are poor 

and definite statements as to the character of the upper 

slate contact cannot be made.

Except where the contact is a fault, bedding in the 

slate is apparently parallel to bedding in the underlying 

Metaline limestone. However, the difference in age, 

Middle Cambrian of the Metaline limestone and Ordovician of the Ledbetter slate, indicates that a disconformity may exist.

LLTHOIXJGY AND INTERNAL STRUCTURE

Megascopic features. The Ledbetter slate is a black, 

fine-grained, generally homogeneous-appearing rock in 

which the Individual mineral grains can rarely be distinguished. In places a few thin indistinct composition 

bands, generally less than 1 inch thick, can be identified, and in the Slate Creek section a conspicuous bed of 

black quartzite about 15 feet thick was recognized. 

The quartzite Avas helpful in .mapping, as it is resistant 

to weathering and stands out from the enclosing weaker 

slate. The quartzite is commonly cut by a network of 

white quartz stringers. It is even-granular, and the 

individual quartz grains are readily distinguished with 

a hand lens. Particularly in the upper part, the slate 

becomes limy and bedding is more conspicuous. The 

uppermost known Ordovician beds are black limestones 

that are well exposed in a road cut on the Spokane highway in sec. 18, T. 38 N., R. 43 E.

The slate is, with the exception of the Devonian and 

younger rocks, and possibly the phyllite in the lower 

part of the Metaline limestone, the least metamorphosed of the sedimentary beds. It is neither micaceous nor extensively recrystallized. As the slate is 

greatly deformed and is involved in the orogenic history, the lack of recry stall ization suggests deformation 

under comparatively light load. A well-defined fracture 

cleavage is evident in most outcrops, and where the 

bedding is also recognizable it is generally cut at low 

angles by the fracture cleavage. In some places, particularly on Russian Creek, the bedding is bent into a 

series of small tight folds, but fracture cleavage is 

poorly developed or absent.

Microscopic features. Microscopic study confirms 

the field observation that little recrystallization has 

occurred in the Ledbetter slate. In thin section the 

slate is streaked with narrow black and transparent 

bands, parallel to the fracture cleavage. Under a magnification of 500 diameters the boundaries of mineral 

grains in the light streaks cannot be seen. In part of 

the rock small quartz grains are identified and calcite 

is recognized in the limy beds. The black quartzite 

consists of well-rounded quartz grains that have wavy 

extinction and generally a small amount of recrystallized quartz on the grain borders. The matrix consists 

of finer-grained quartz and carbonaceous material.

CONDITIONS OF SEDIMENTATION

The conditions of sedimentation during the deposition of the Ledbetter slate were favorable for the accumulation of large quantities of nearly uniform clay, 

high in organic material. Enough fluctuation took 

place for quartz grains to be at times deposited in the 

sediment. An increasing abundance of limestone in the 

upper part of the formation indicates a gradual change 

in the controlling conditions.

Fossil collections from the Ledbetter slate have been 

examined by Josiah Bridge, and most of the determinations have been checked by Rudolf Ruedeinann. 

Bridge says:

The oldest graptolite fauna is of lower Deepkill age. It is 

* * * from the west bank of the Pent! Oreille River north 

of the Pend Oreille mine * * * and * * * contains the 

following fauna:

Graptolites:

*Tetragraptus quadribrachiatus Hall var.

*Tetragraptus similis (Hall).

*Didymograptus nanus Lapworth. 

Dicellograptus sp.

*Phyllograptus ilicifolius Hall. 

Phyllograptus sp. 

Brachiopod:

Leptobolus sp.

This is a characteristic early Deepkill assemblage and presumably correlates this portion of the Ledbetter slate with the 

upper part of the Tetragraptus zone of the Deepkill shale 01 

New York and with the lower portion of the Glenogle shales 

of the Windermere, B. C., area. This particular collection 

seems to fall somewhere in the interval between 730 and 950 

feet in Walker's measured section on Windermere Creek 30 in 

other words, near the top of the lower half of his lower 

Glenogle shale. This correlation is based largely on the presence of Tetraffraptus quacbribrachiatus * * *.

The fauna described from the type Glenogle shales near Field,

30 Walker, T. F., Geology and mineral deposits of the Windermere map 

area, B. C. : Canada Geol. Survey, Dept. Mines, Mem. 148, pp. 26, 27, 

1926. '
ORDOVICIAN SYSTEM 21

l». C., is much younger, and it is not known whether this 

Deepkill fauna is present in that region or not.

The species prefixed by an asterisk in the foregoing list 

were found by Kirk in a large Deepklll fauna obtained from 

an isolated outcrop of an unnamed early Ordovician shale in 

the Wood River region of Idaho,31 and the correlation between 

these two areas seems to be well established. This same portion of the Ledbetter slate is iilso the approximate equvialent 

of the Saturday Mountain formation of the Bay horse district, 

Idaho,"3 which also carries a Deepkill fauna, but there the 

evidence is less conclusive.

No fauna characteristic of the late Beekmantown or early

-1" Umpleby, .T. B., Wcstgate, Ij. G., and Ross, C. P., Geology and ore 

deposits of the, Wood River region, Idaho: U. S. Geol. Survey Bull. 814, 

p. 1.8. 1980.

^ Koss, C. I1 ., Geology and ore deposits of the Bayhorse region, Ouster 

County, Idaho: U. S. Geol. Survey Bull. 877, pp. 16, 17, 1038.

Chazy (upper Deepkill zones) have been found in any of the 

collections.

 All the remaining collections contain elements of the lower 

Dicellograptus fauna, of Normanskill age. The list of species 

and their occurrence in the several collections is shown 

on the attached table. Two distinct subzones are recognizable * * *.

The first group (subzone) is .characterized by the absence of 

Dicranograptus and by the presence of Nemagraptus graciMs, 

Thatnnogra-ptiis capillaris, Dicellograptus sextans, and other 

early Normauskill forms. Although the stratigraphic relations 

of the various collections was not determined in the Metaline 

area, it is known that strata carrying these forms commonly 

underlie beds in which various species of Dicranograptus are 

abundant. This is true of the Womble shale of Oklahoma and 

Arkansas and of the Athens shale of the southern Appalachian 

region, both of which carry Normanskill faunas.

Fossils from Ledbetter slate

Clraptolites:

Didymograptus n. sp. aft". D. fasciSyndyograptus cf. S. pecten RuedeDicranograptus ramosus var. arkanDicranograptus cf. D. nicholsoni 

Hopkinson _ __________-__-_----_

Dicranograptus nicholsoni var. parDicranograptus aff. D. spinifer var.

Diplograptus euglyphus Lapworth....

Glinwcograptus parvus Hall. _ _-_._.-

Brachiopod:

Crustacean:

Pond 

Oreillo 

River 

bank northcast of 

Pond 

Oreillc 

mine

X

X

X

X

X

X

Pond 

Oreillc 

River 

bank 

north of Morning 

mine

?

X

X

X

Entrance 

to 500- 

foot 

adit, 

Pond 

Oreillo 

mine

CO

X

X

Mouth 

of Slate 

Crock

X

Prospect 

in SWJ4 

sec. 30, 

T. 40 

N., R. 

44 E.

(?)

(?)

Highway southwest of Lcdbottor 

Lake

(?)

Highway southwest of Lcdbcttcr 

Lake

cf.

"West 

center 

sec. 2, 

T. 3D 

N., R. 

43 E.

pf

Whiskey 

Crock 

road 

cut

Prosspcct 

dump 

1 mile 

south 

of old 

Bella 

May 

mine

X

West 

center 

sec. 12, 

T. 40 

N., R, 

44 E.

(?)

Road 

cut., 

NEJ4 

SCO. 22, 

T. 40 

N., 11. 

44 E.

X

A further reason for considering this subzone to be slightly 

older is found in the presence of a species of Didymograptus 

which, though not identical with Deepkill species, is more 

nearly related to Deepkill forms than to any known from the 

Normanskill. These collections also contain the shells of Caryocaris, a form which according to Ruedemann is not known from 

the Normanskill of New York but which here is associated 

with characteristic Normanskill forms.

The second subzone is characterized by an abundance of 

species of Dwranograptus and by the absence of many of the 

forms cited above.

The remaining collections contain none of the diagnostic forms 

but only species which are common to both zones and hence 

cannot be as accurately placed.

In general, the fauna corresponds fairly well to that of the 

main portion of the Pi Kappa formation of the Wood River 

district, Idaho 33 but no trace of the peculiar, youngest fauna 

listed from that formation was found in these collections.

The exact relationship of these faunas to those from the 

upper part of the Glenogle shale on the Kicking Horse and Dease

83 Umpleby, J. B., Westgate, L. S., and Ross, C. P., op. cit. (U. S. Geol. 

Survey Bull 814), pp. 22, 23.
22 GEOLOGY AND ORE DEPOSITS OF THE METALINB QUADRANGLE, WASHINGTON

Rivers, B. O.,34 is not definitely established. It has been claimed 

that these Glenogle faunas are possibly slightly older than 

the true Norinanskill, this claim being based primarily on the 

absence of dicrauograptids and nemagraptids. However, Ruedemann 38 points out that these same elements are lacking in the 

beds immediately overlying the main Dicranograptus subzone 

and suggests that these high Glenogle faunas may well be 

slightly younger, than the true Nbrmapskill, and therefore 

younger than the faunas from the Ledbetter slate. I am inclined to hold the same opinion. t>

DEVONIAN SYSTEM

DISTKIBUTION

A small area of limestone that yielded Devonian fossils is exposed east of the Flume Creek fault in sec. 16, 

T. 40 K, K. 43 E. A larger patch of carbonate rock, 

mapped as Devonian but possibly of Cambrian age, lies 

north of the Russian Creek fault in the extreme northwest corner of the Metaline quadrangle. (See pi. 1.)

THICKNESS

The exposures of the Devonian rocks are poor, and 

no satisfactory stratigraphic sequence was established. 

The bedding in sec. 16, T. 40 N., R. 43 E., seems to be 

nearly horizontal a'nd, if so, the limestone has a minimum thickness of YOO feet, Avith an unknown amount 

eroded. The outcrops in the northwest corner of the 

quadrangle are too poor to permit an estimate of thickness.

IITHOLOGY

The fossiliferous Devonian rock contains a somewhat 

unusual type of limestone breccia or conglomerate at 

the base of the exposure. (See pi. 10, A.) The fragments or pebbles are mostly limestone, with a few of 

black slate. The matrix is partly limestone and partly 

subrounded quartz grains that can easily be seen in 

plate 10, A. Some of the limestone fragments are 

single fossils but other fragments contain several fossils in limestone. The fragmental nature of the limestone becomes less noticeable away from the base of 

the formation, and the rock gradually becomes an evengrained grayish-blue limestone. The carbonate rock in 

this exposure appears to be all limestone; no dolomite 

Avas recognized.

The carbonate rock in the northwest corner of the 

quadrangle is different in appearance from either the 

knoAvn Cambrian or the kiiOAvn DeA^onian. The most 

diagnostic member, and the best exposed, is an intraformational breccia shown in plate 10, E. This breccia 

can be traced laterally into the type shoAvn in plate 10, 

<7, and finally into typical thin-bedded dolomite Avith

34 Canada Geol. Survey Kept., 1886, pt. 2, p. 24d ; Mem. 55, p. 101, 

1314; Mem. 148, p. 30, 1926.

83 Ruedemanri, Rudolf, Graptolites of New York, pt. 2, p. 25, 1908.

desiccation cracks as shown in plate 10, L>. Similar 

intraformational breccia is recognized at the Just Time 

mine, in sec. 15, T. 40 N"., R. 42 E. The rock seems to 

be completely dolomitized. The fragments are gv&y to 

cream-colored crystalline material, and the matrix is 

a dense dark-gray shaly dolomite. Other carbonate 

rocks, particularly a dense blue-gray one and a shaly - 

gray bed, are exposed in isolated patches.

An isolated outcrop on the northeast slope of the hill, 

at an altitude of 4,400 feet, in sec. 14, T. 40 K, R 42 

E., is a blue-gray limestone that is*mottled Avith tiny 

spheroids less than one-eighth of an inch in diameter. 

These spheroids are resistant to weathering and stand 

out from the enclosing calcite. They Aveather to a reddish-brown color, which also makes them conspicuous. 

L. G. Henbest, who examined this material, found no 

evidence of an organic origin for these spheroids; in 

his opinion they are probably recrystallized calcareous 

oolites. In thin section small grains, that have elliptical 

cross sections as much as one-eighth of an inch on the 

long axis, are numerous. According to Henbest, these 

grains are likely algae. Similar limestone with tiny 

spheroids is found in a layer of Maitlen phyllite Avest of 

the Hooknose-Abercrombie ridge.

CONDITIONS OF SEDIMENTATION

The fragmental nature of the rocks near the base 

of the DeA^onian formation indicates accumulation in 

shalloAv water. The presence of quartz grains in the 

matrix also suggests near-shore conditions. The intraformational breccia and conglomerate resemble deposits on mud flats, which are hardened and later reAvorked by currents and AvaA^e action. The near-shore 

conditions gradually changed to those more favorable 

for the accumulation of normal limestone.

AGE

G. H. Girty reports that the fossil collection is probably of Devonian age, although Bridge, supported by 

Kirk, Cooper, Ulrich, and Bassler, says that "it is either 

late Devonian or early Mississippian, presumably the 

latter."

Girty determined the f olloAving species:

Favosites sp.

Favosites limitaris?

Favosites limitaris? or possibly Alveolitcs sp.?

A small indeterminable zaphrentoid corul.

Numerous large crinoid columnals.

A fragment of Feuestella.

A small orthoid, probably Rhipidomella.

A Leptaena? or some related genus.

A-plicated brachiopod, with a punctate shell, suggestive

of Retzia. 

A large ostracode suggesting Parachites.

38 Gilluly, James, Geology and ore deposits of the Stockton and Fairfield quadrangles, Utah : U. S. Geol. Survey Prof. Paper 173, pp. 14-15, 

pi. 5, A, 1932.
QUATERNARY SYSTEM 23

According to Girty:

The evidence thai; would definitely place these .faunas in some 

geologic period is probably not strong. Not so the evidence that 

would,exclude them from the Carboniferous. Aside from the 

large and numerous crinoid "Stems, if they have any weight, 1 

do not mid a single Carboniferous element in these faunas. 

For instance, the Product!, which are seldom lacking in any 

collection of. Carboniferous age, are entirely unrepresented. On 

I.lie other hand, these faunas seem to abound in Favosites and 

related corals, all of which are exceedingly rare in the Carboniferous. There is also the hypothetical Leptaena, the like of 

which does not occur in any Carboniferous fauna known to me. 

In brief, there is no evidence whatever for identifying these 

faunas as Carboniferous, and considerable evidence for believing 

That they are not Carboniferous.

TERTIARY SYSTEM

TIGER FORMATION

DlSTKIBimON

Four areas of Tertiary continental rocks are recogni/ed in the Pend Oreille Valley near lone. The most 

extensive exposure is south of Tiger, where the beds 

form a group of low rounded hills and from which the 

name is taken. The formation is also well exposed in 

road cuts along the Spokane highway in sees. 18 and 

19, T. 38 N., R. 43 E., and it caps at least two hills west 

of lone. The seniiconsolidated rock breaks down easily 

and it is likely that additional patches have been 

mapped with the unconsolidated Pleistocene deposits.

THICKNESS

The maximum thickness of the Tiger formation is 

about 1,000 feet in the hills south of Tiger. The character of the beds changes rapidly, however, and the 

thickness of the deposits is very erratic.

LITHOLOGY

The clastic material that makes up the Tertiary deposits changes strikingly with the underlying rock; 

it includes conglomerates, sandstones, and clays. In 

the road, cuts in sec. 18, T. 38 N., R. 43 E., the Tertiary 

is composed mainly of fragments of Ledbetter slate, 

and. on the hills west of lone, where the formation overlies the Metaline limestone, the debris is mostly limestone. South of Tiger the Tertiary contains mostly 

granitic rock detritus.

The beds are generally ill defined, and the materials 

arc poorly sorted, although in some places sharply 

limited thin beds of carbonaceous (lignitic) material 

and clay and sandstone are found. Plate 11, A, shows 

a cliff of the seniiconsolidated beds south of Tiger, and 

plate 11, B, is a close-up photograph of the same exposure, to'show the crudely sorted character of the 

granitic waste. In one place some of the boulders are 

3 to 10 feet in diameter.

CONDITIONS OF SEDIMENTATION

The Tertiary beds were deposited under continental 

(nonmarine) conditions, probably in a valley similar 

to that existing today. The source of the clastic material must have been near the site of deposition, as its 

character agrees closely with that of the underlyingrock. The crude sorting and the subangular nature of 

the fragments likewise indicate a nearby source. The 

lignitic beds indicate swampy conditions, and shallowwater sorting is suggested by the clay and sandstone 

layers.

AGE

Fossil leaves are plentiful in a few of the finergrained and carbonaceous beds of the formation. 

They are poorly preserved, however, owing largely to 

an indistinct cleavage that crosses the bedding. A 

collection of leaves made in the road cuts contained 

only four species, which have been identified by R. W. 

Brown as Sequoia sp., Quercivs sp., Trochodendroides 

sp., and fLaurus sp. Brown says, "This material does 

not lead me to any definite specific determinations or 

conclusions as to age."

The beds are thought to be Tertiary for several 

reasons. They are seniiconsolidated (see pi. 11, A) 

more so than any nearby known Pleistocene beds. The 

beds are slightly deformed, in places they dip 20°, 

and an ill-defined fracture cleavage is developed. 

Three of the four known exposures are well above the 

highest known [Pleistocene deposits, with the exception 

of scattered morainal debris.

The beds are shown on the State geologic map 87 as 

Tertiary, but the reason for this assignment is not 

given in the brief accompanying description.38 Tertiary Miocene beds that underlie the Columbia River 

lavas are extensive near Spokane. 39

QUATERNARY SYSTEM

PLEISTOCENE DEPOSITS

The deposits of Pleistocene age recognized in the 

Metaline quadrangle are all related to glaciation and 

the ice-melt waters. For convenience, they are discussed with other glacial features in the section on 

development of the topography (pp. 35-38).

RECENT DEPOSITS

The Recent deposits are confined to stream 'bottoms 

and debris-covered slopes. The wide, flat flood plain 

of the Pend Oreille River south of Metaline Falls is

37 Geologic map of Washington, 1930.

88 Culver, H. E., The geology of Washington, pt. 1, General features of 

Washington geology : Washington Dept. Cons, and Devel., Biv. Geology, 

Bull. 32, 1036.

38 Pardee, .T. T., and B.rynn, Kirk, Geology of the Lutiih formation in 

relation to the lavas of the Columbia Plateau near Spoknnc, Wash. : 

TJ. S. Geol. Survey Prof. Paper 140-A, pp. 1-16, 1026.
24 GEOLOGY AND ORE DEPOSITS OP THE METALINE QUADRANGLE, WASHINGTON

by far the most extensive of the Recent stream deposits. 

Most of the streams are, however, actively cutting into 

their bedrock, and the gravel and boulder accumulations along them are in small, generally short-lived 

areas. Slope wash and soil cover are features of considerable moment in the geologic mapping, as they 

extend over large areas and obscure the bedrocks.

INTRUSIVE BOCKS

KANIKSII BATHOLITH 

DISTRIBUTION

The Kaniksu batholith underlies most of the southern half of the Metaline quadrangle. Small isolated 

exposures of similar rock, probably satellitic to the 

main mass, occur on the south side of Hall Mountain 

and on Snyder Hill between Sullivan Lake and the 

Pend Oreille river. The name Kaniksu is taken from 

the Kaniksu National Forest, a large part of which is 

underlain by the batholith.

In. a regional way the Kaniksu batholith lies between two of the major North American batholiths 

the Nelson batholith and the Idaho batholith. The 

Kaniksu mass has many compositional, textural, and 

structural features in common with each of the other 

two and at various times has been mapped as part of 

either. A reasonable interpretation of the evidence is 

that the three large intrusive bodies and many of the 

smaller ones are all parts of one great mass. The 

Kaniksu batholith, on the basis of hasty reconnaissance, 

is regarded as continuous with the Bayview granodiorite of Sampson and Gillson 40 and the auxiliary 

mass of the Nelson batholith described by Kirkham 

and Ellis 41 and shown on the West Kootenay sheet 

by McConnell and Brock.42 Daly 43 described the same 

mass as the Rykert granite batholith, which has a 

more prominent gneissic character than the intrusive 

mass near Metaline. In the Sal mo map area, immediately north of Metaline, both Walker 44 and Drysdale 45 

consider^ the scattered bodies of granitic rocks to be 

offshoots of the larger Nelson batholith to the north. 

Ross,40 on the other hand, considers the Kaniksu batho10 Gillson, J. L., Granodiorites in the Pend Oreille district of northern 

Idaho: Jour. Geology, vol. 35, pp. 1-31, 1927. Sampson, Edward, 

Geology and silver ore deposits of the Pend Oreille district, Idaho: 

Idaho Bureau Mines and Geology Fainph. 31, pp. 10-11, 1928. 

Stewart, C. A., A comparison of the Coeur d'Alene monzonite with other 

Plutonic rocks of Idaho: Jonr. Geology, vol. 22, pp. 684-688, 1914. 

Calkins, V P. C., A geological reconnaissance in northern Idaho and 

northwestern Montana : U. S. Geol. Survey Bull. 384, pp. 43-46, 1909'.

41 Kirkham, V. R. D., and Ellis, E. W., Geology and ore deposits of 

Boundary County, Idaho : Idaho Bureau Mines and Geology Bull. 10, pp. 

35-36. 1926.

^McConnell, R. G., and Brock, R. W., West Kootenay sheet, No. 

792, Canada Geol. Survey, 1904. ,

4»Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, pp. 284-289, 1912.

44 Walker, J. E\, Geology and mineral deposits of the Salmo map area, 

B. C.: Canada Geol. Survey Mem. 172, pp. 13-17, 1934.

43 Drysdale, C. W., Ymi-r Mining camp, B. C.: Canada Geol. Survey 

Mem. 94, pp. 33-38, 1917.

46 Ross, C. P., Some features of the Idaho batholith : 16th Internatl. 

Geol. Cong. Rept., pp. 369-385, 1936; Mesozoic and Tertiary granitic 

rocks in Idaho: Jour. Geology, vol. 26, pp. 673-693.

lith as part of the larger Idaho batholith to the 

southeast, although the two masses are not known to 

be connected.

GENERAL CHARACTER

The Kaniksu batholith exhibits a wide variety of 

compositional and textural features. Three dominant 

facies prevail, not including the border facies. These 

are the biotite facies, the porphyritic facies, and the 

muscovite facies.

The biotite facies is probably the most abundant 

rock in the intrusive mass. It is commonly a lightgray or pinkish-gray massive crystalline rock in which 

individual mineral grains are from one-eighth to onehalf an inch in longest dimension. Mineral alinement 

is well shown in a few places but is ordinarily vague. 

Quartz and two varieties of feldspar, one pink and 

one white, make up about 80 to 90 percent of the rock. 

The remainder is mostly biotite, but rarely, as on 

Molybdenite Mountain, hornblende is found, and sphene 

can generally be seen.

The porphyritic type of rock is characterized by the 

presence of pink feldspar crystals, commonly less than 

an inch in longest dimension, although crystals as much 

as 3 inches long have been noted. These phenocrysts 

form generally only a small proportion of the rock, 

but exceptionally they make up 20 percent or more. 

The boundaries of many of the crystals are indistinct 

(see pi. 12, A), but others are sharp and are coated 

with biotite flakes whose basal cleavages are parallel 

to the feldspar boundaries. Small flakes of biotite 

and grains of quartz and white feldspar are commonly 

recognized in the phenocrysts. The groundmass is 

similar to the biotite facies of the rock. Transitional 

types, rather than sharp contacts, separate the porphyritic facies from the biotite facies. In several places 

in the field the white feldspars are coarse and the pink 

ones are smaller. This particular porphyritic variety 

is unusual, however, and its field relations are obscure.

The muscovite-bearing rock is an unusual facies that 

underlies several square miles near Granite Peak and in 

the valley of the South Fork of Lost Creek. It is 

recognized also in smaller masses throughout the part 

of the batholith studied. Text,urally the rock is similar to the biotite facies, but in places the feldspars are 

large and the rock seems to grade into typical pegmatite. Elsewhere the rock is cut by sharply bounded 

pegmatite dikes in which the mineral constituents appear to be the same as in the surrounding rock. In a 

few places, particularly northwest of lone, a strong 

gneissic structure is apparent. The minerals usually 

recognized in the hand specimens are quartz, white 

feldspar, and, rarely, spots of pinkish feldspar, muscovite, and tiny red garnets. (See pi. 12, B.) A few of 

the garnets are relatively large, and crystals as much as 

half an inch in diameter have been seen. A subgraphs c
INTRUSIVE ROCKS 25

pattern between the feldspar and quartz is commonly 

developed.

The bodies of muscovite-bearing intrusive rock have 

vague boundaries where they grade into the more normal biotite type. Their obA'ious pegmatitic nature is 

somewhat unusual, in large irregular masses, although 

similar bodies are reported from the Buffalo Hump 

quadrangle, in north-central Idaho, where Reed 4T 

thinks they are associated with zones of shearing. The 

reasonable suggestion has been made that pressure and 

ease of escape of fluids along joint systems are controlling features in the formation of pegmatites.48 It is 

likely that an unusual set of conditions has given rise 

to the large masses of pegmatitic type, not apparently, 

related to intrusive borders. Ss

PKTUOGHAVHY

Microscopic examination of the intrusive mass shows 

it. to be predominantly a quartz monzonite that grades 

into granodiorite, but smaller patches of other rock 

types are present. The composition agrees closely 

with that of both the Nelson and Idaho batholiths, so 

far as is known. Drysdale 49 described the Nelson 

imthotith near Ymir, B. C., as most commonly a granel iorite but ranging from a granite to a cliorite and more 

mafic types. Walker r>0 described the Nelson batholith 

in the Salmo map area as commonly a medium- to 

coarse-grained light-colored, generally porphyritic 

granite, but bodies of granite, aplite, granodiorite, 

quartz diorite, diorite, syenite, and monzonite were also 

recognized. Boss 51 concluded that the Idaho batholith is a somewhat calcic quartz monzonite. He says 

that'the plagioclase (generally oligoclase-andesine) 

is commonly in excess of the potash feldspar, although 

in places the rock grades into granodiorite or granite. 

Keed's work 52 indicates that the Idaho batholith is 

dominantly a quartz monzonite, but other types are recognized, particularly near the borders.

The essential constituents of the biotitic and porphyritic facies are quartz, oligoclase, microcline, orthoclase, 

and biotite. In places albite, andesine, hornblende, 

and muscovite are present in different proportions. 

The recognized accessory minerals are sphene, zircon, 

apatite, and iron oxides, and small amounts of chlorite, 

sericite, epidote, clinozoisite, and allanite are widely 

distributed. Oligoclase and potash feldspar are present, generally in nearly equal amounts; together they

47 Heed, .T. C., personal communication, March 14, 1938.

"Grout:, V. 'If., and others, Problems of the batholith, Nat. Research 

Council, April 22, 1933.

** Drygdale, C. W., Ymir mining camp, B. C.: Canada Geol. Survey 

Mem. 94, pp. 38-36, 1917.

00 Walker, X. P., Geology and mineral deposits of Salmo map area, 

15. C. : Canada Geol. Survey Mem. 172, pp. 3, 13-17, 1934.

51 HOHS, C. P., Some features of the Idaho batholith : 16th Internat. 

Cool. Contf. Kept, pp. 373-374, 1936.

63 Heed, .T. C., Geology and ore deposits of the Florence mining district, 

Idaho : Idaho Bur. Mines and Geology Painph. 46, p. 8, 1939.

make up about 40 to 60 percent of the rock. Locally 

hornblende is present in place of biotite, and andesine 

takes the place of the other feldspars. In some specimens the plagioclase is zoned from andesine or andesine-oligoclase centers to oligoclase borders. A little 

albite is present in most samples as small spots or in 

cracks in other feldspars. Potash feldspar is rarely 

present to the exclusion of plagioclase, but in some material it is the principal feldspar.

The microcline phenocrysts are thought to have developed late in the formation of the intrusive mass by replacement of earlier constituents, but before the formation of the muscovite-garnet facies. This belief is supxported by the fact that many phenocrysts contain 

ragged remnants of other minerals, principally quartz, 

feldspar, and biotite, that in places are continuous 

into the groundmass. The microcline is generally clean 

and fresh in appearance, even where other feldspars, 

except albite, are dusty. Contacts of microcline with 

other feldspars and quartz commonly have a wormeaten appearance (myrmekite).

The essential constituents in the muscovite facies are 

quartz, microcline, albite, oligoclase or andesine, and 

muscovite. Garnet and in places epidote are abundant 

accessories, and a few grains of tourmaline can generally be seen; pink zoisite (thulite) was found at several places. This rock type appears to grade into the 

biotite facies. The muscovite-bearing rock is thought 

to have been formed from the biotitic rocks by late 

magmatic fluids after crystallization was well advanced f>3 (deuteric). Evidence for the alteration of 

biotite to muscovite is shown in plate 13, A, where a 

small remnant of biotite, oriented the same as the 

main biotite crystal, can be seen in the muscovite, and 

the west border of the biotite approximately coincides 

with the west border of the muscovite. The narrow 

ragged contact zone between the two minerals is absent in some specimens, and the contacts are sharp. 

Many muscovite grains contain opaque inclusions oriented along cleavage surfaces; such inclusions are not 

conclusive evidence of the formation of muscovite from 

biotite, but they are suggestive. The white feldspars 

the mainly albite and microcline. A few of the white 

microcline crystals grade to pinkish microcline in the 

centers of the grains. In the crosscutting sharp-walled 

pegmatites the few feldspars examined are principally 

albite, but some andesine and oligoclase were recognized.

BOKDER FAC1KS

The borders of the batholith are generally finergrained and darker than the interior of the mass, and 

foliation is customarily developed. The coarse porphyritic type of rock is absent, although it is not unM Barker, A., The natural history of the igneous rocks, pp. 293, 323, 

New York, 1909.
26 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

common to find crystals a quarter of an inch in longest 

dimension set in a finer-grained groundmass. In many 

exposures, such as those on Cedar Creek and Jim Creek 

northwest of lone, the contacts are sharp and the borders of the intrusive are clearly defined. (See fig. 5.) 

In other places, such as Indian Mountain, Timber 

Mountain, and the southeast corner of the quadrangle, 

the dark border phase of the intrusive appears to grade, 

without a sharp break, into metamorphosed crystalline 

sedimentary beds.

Microscopically the border f acies is more mafic than 

the interior of the mass. Quartz decreases in quantity, 

and the larger feldspars are generally andesine, although albite and potash feldspars are common in the 

finer-grained rocks. Green hornblende, in places with

3 Feet

FIGURE 5. Sketch of contact between Kaniksu batbolith and Maitlen 

phyllite in sec. 11, T. 38 N., R. 42 E. The intrusive cuts sharply 

across the foliation in the phyllite.

many opaque inclusions ( schiller structure), is generally 

present in appreciable amounts, although in places biotite is the dominant dark mineral. In some specimens 

the dark minerals constitute 50 percent or more of the 

rock. Epidote, chlorite, allanite, and clinozoisite are 

present in small quantities and rarely make up an appreciable proportion of the rock.

i AGE

The age of the Kaniksu batholith is uncertain, but 

the best available evidence seems to point to a Cretaceous, possibly late Cretaceous age. This evidence is 

based on the assumption that the Kaniksu batholith 

was intruded at the same time as the Nelson batholith 

and the Idaho batholith. Walker 54 calls the Nelson 

batholith post-Triassic and Kice 55 says that the Nelson 

batholith was probably intruded at some time between 

the late Jurassic and early Tertiary, possibly during 

the Cretaceous. Cairnes 56 concluded that the Nelson

G * Walker, J. F., Geology and mineral deposits of Salino map area, 

B. C.: Canada Geol. Survey Mem. 172, p. 3, 1934.

r>ti Rice, H. M..A., Preliminary report, Nelson map area: Canada Geol. 

Survey paper 37-27, p. 11, 1937.

00 Cairnes, C. B., Slocan mining camp, B. C. : Canada Geol Survey 

Mem. 173, pp. 01-75, 3934.

batholith was Cretaceous or late Cretaceous but based 

this conclusion on the unsupported assumption that 

the Nelson batholith came from the same magma source 

as the Coast Range batholith, of Jurassic age, and 

as the Nelson batholith is the more siliceous it must, 

therefore, be later.

Ross 57 summarized the evidence of the age of the 

Idaho batholith in 1933. He said: "The intrusion of 

the Idaho batholith * * * coul(j have taken place 

as recently as Eocene * * * and can hardly have 

occurred before the Jurassic period." Reed,58 from a 

determination of the age of pitchblende obtained in the 

Idaho batholith at Warren, Idaho, concluded that the 

age in that region was probably Upper Cretaceous. 

Tertiary (Miocene and Oligocene?) deposits are reported by both Pardee 59 and Ross 80 to overlie the 

eroded surface of the Idaho batholith. Lindgren's suggestion of an eastward migration of intrusive activity Cl 

cannot be summarily dismissed and has much to commend it.

MINOR INTRUSIVE BODIES

GRANITIC MASSES

Small masses of granitic rocks which in physical 

properties and mineral composition are comparable to 

the border facies of the Kaniksu batholith are found at 

several places. Two such bodies occur in the northwest corner of the area, and small exposures of similar 

rocks are present on Noisy Creek and west of the Flume 

Creek fault north of Lost Lake. Small granitic masses 

are particularly abundant in the Maitlen phyllite between Sullivan Lake and the Pend Oreille Valley. 

Other bodies of similar rocks are common at places near 

the border of the Kaniksu batholith and have been seen 

in the Priest River group away from the main intrusion.

The bodies of granitic rocks are generally tabular and 

sill-like. They appear to be concordant with either 

the dominant foliation or the bedding.

O

The rocks are customarily although not everywhere 

porphyritic. The phenocrysts consist of feldspar, 

quartz, hornblende, and biotite and are commonly corroded and embedded in a fine-grained matrix, which 

consists mainly of quartz, orthoclase, and albite, with 

tiny needles of hornblende and flakes of biotite. The 

accessory minerals are zircon, sphene, apatite, and iron 

oxides. Chlorite, epidote, zoisite, calcite, and particularly sericite are common. The feldspar phenocrysts

67 Ross, C. P., Some features of the Idaho batholith: 16th Internal 

Geol. Cong. Kept., p. 383, 1936.

68 Reed, J. C., Geology and ore deposits of the Warren mining district, 

Idaho County, Idaho: Idaho Bur. Mines and Geology Painph 45 n S 

1937. '

w Pardee, J. T., and Bryan, Kirk, Geology of the Latah formation in 

relation to the lavas of the Columbia River Plateau near Spokano, 

Wash. : U. S. Geol. Survey Prof. Paper 140-A, pp. 1-16, 1920.

00 Ross, C. P., op. cit., p. 382.

"Lindgreu, Waldemar, The igneous geology ot the Cordilleras ami Us 

problems : Probleins of American geology, pp. 234-286, 1.915.
(iKOLOC.lOAL SURVEY PROFESSIONAL 1'APKIi 202 PLATE 10

A. DEVONIAN LIMESTONE BRECCIA, NORTHWEST CORNER OF -SEC. 15. T. 40 N., R. « E.

B. INTRAFORMATIONAL DOLOMITE BRECCIA, ROAD CU'I IN SW}4 SEC. 11, T. 40 N., R. 42 E.

C. INTRAFORMATIONAL DOLOMITE BRECCIA.

Eighty feet east of outcrop shown in B.

D. THIN-BEDDED DOLOMITE WITH DESICCATION CRACKS. 

Ten feel east of outcrop shown in C.
CiEOLOCK'Al. Sl'RVEY PROFE

B. TKIi I 1AK1 SEDIMENTARY DEBK IS. .-()l TH CENTE

Vt ;it<'h in lower center iniliciites 

A. CI.IK1' OF POORLY SORTED TKU I I AKY SEDIMENTARY BEDS, U-.NTEK OFSKC. 16. T. 36 N.,

K. i:i E.
GEOLOGICAL SrUVUY PROFESSIONAL PAPER 202 PLATE 12

v<

' -IfeJS A "*>i»'*1feJC^Ir? "-^."*S«J;.-> ". ,,-."-.**^t'Jf

A. TOLISHED SLAB OF PORI'HYRITIC FACIES OF THE KANIKSU BATHOLITII, SOUTH 

CENTER OF SEC. 21, T. 35 N., R. 45 E.

A'/.

J)K

 X

& / /

4q*.-.*

in. ' "^

B. MljSCOVn K-GAKiNET FACIES OF THE KANIKSU BATHOLITH, CENI EK OF SEC. 1, T. 36 N., R. 42 E. 

Light gray is feldspar and quartz. Dark gray booklets are muscovite, and tiny dark spots are garnets.
C1KOLO01CAL JSURVEY 1'ROKKSSIONAL I'Al'KK 202 1'l.ATK in

(. PHOTOMICROGRAPH OF A T11IN SECTION FKOM GRANITE PEAK 

LOOKOUT, INTERPRETED AS SHOWING BIOT1TE A1.TEKE1) TO 

MUSCOVITE.

It. IHKELKT IN PHYLLITE, .SOUTHEAST CORNEK OF SEC. 1, T. :»! 

IS'., li. 12 K.

On Hall Mountain trail from Harvey Creek, altitude 1,000 feet. Note laek 

of luicaccoiiH mineral** parallel to bedding.

C. PHOTOMICROGRAPH OF THI\ SECTION SHOWING SHEARING NEAKLY 

NORMAL TO BEDDING.

Feldwpar on borders and quartz, tourmaline, 

and muBCOvile in the center. Natural size.

I). GYPSY QUARTZITE WEST OF FLUME CREEK FAULT.

View soiilhweatward from a dolomite knob at the Josephine workings of the Pend Oreille mine. Flume Creek fault 

passes through the lowlands in the foreground.
INTRUSIVE ROCKS 27

identified include andesine or more sodic plagioclase, 

microcline, and orthoclase.

PEGMATITE BODIES

Pegmatite dikes and irregular-shaped masses, other 

than the muscovite facies of the batholith, are widely 

distributed through the batholith and to a less extent in 

the more intensely metamorphosed sedimentary rocks.

A poorly exposed pegmatite body was seen in the 

metamorphosed dolomite of the Monk formation near 

the Q. K. mine. This body is rather fine-grained and 

contains but few crystals over half an inch in longest 

dimension. The rock is white or cream-colored except 

for scattered crystals of black tourmaline and small 

bright wine-colored garnets. Much of the rock is cut 

by seams of soapy material which, under the microscope, is found to be montmorillonite. The bulk of the 

rock consists of feldspar microcline, orthoclase, and 

calcic albite and quartz. Colorless to pale-blue and 

dark-blue tourmaline, booklets of clear colorless talc, 

several irregular grains of topaz about 0.5 millimeter 

long, and a very few tiny shreds of biotite were also 

recognized.

The pegmatites vary considerably in texture. A few 

crystals of feldspar as much as 3 or 4 inches on a face 

were seen, and the grain size grades downward from 

this maximum. Graphic and subgraphic patterns are 

common, particulary between feldspar and quartz. 

An unusual texture in a narrow dike is illustrated in 

plate 13, #> This dikelet contains feldspar along the 

borders and quartz, muscovite, and tourmaline in the 

center. Such a comb structure arrangement in a 

quartz-carbonate veinlet would generally without hesitation be attributed to deposition from a fluid, and 

probably in an open cavity. The specimen shown offers 

rather compelling evidence of the mobility of the parental fluids.

The mineralogy of the pegmatites is simple. Feldspars, quartz, and muscovite greatly predominate, but 

garnet and tourmaline are generally present. Exceptionally, coarse-grained biotite and green amphibole are 

found. The feldspars are principally albite, but microcline, andesine, and oligoclase are recognized.

^*^s

APLITE DIKES

Aplite dikes are widely distributed through the batholith and the larger outlying intrusive bodies such as 

that south of the Frisco Standard mine. They have 

not been seen in the adjoining strata except in the 

highly metamorphosed areas. The aplites are commonly fine-granular buff to whitish rocks; rarely they 

contain a few scattered feldspar phenocrysts.

In thin sections the aplites are seen to consist largely 

of feldspar and quartz, with a little muscovite generally present. The feldspars are dominantly orthoclase, but there is a little microcline and albite-oligo448039 13 3

dase. A few tiny flakes of biotite and small scattered 

spots of epidote and pyrite have also been identified.

Dark-colored dikes are widely distributed throughout 

the sedimentary beds in the northern part of the quadrangle, and a few cut the more silicic intrusive rocks. 

These dikes vary widely in texture and appearance, 

although similar in mineral composition.- They are 

generally less than 4 feet thick, and the walls are clean 

and sharp.

One of the most common types is found in the My 

Era adit in the east center of sec. 11, T. 40 N, K. 42 E. 

In hand specimens it is a fine-grained greenish-gray 

rock and is liberally sprinkled with flakes of biotite 

as much as a quarter of an inch or more across. 

Weaver 62 has described this type as minette. In the 

Lead King diamond-drill cores and on the ridge about 

11/2 miles south of the peak of Boundary Mountain another type is a fine-grained dark-greenish rock. In 

some of this material no minerals can be recognized 

with a hand lens, but in other places tiny flakes of biotite and rounded spots of calcite a quarter of an inch 

or less across and a radiating fibrous white mineral 

can be seen. A third type found at the mouth of Slate 

Creek and in a shallow adit on the lower Dumont property has a fine-grained dark groundmass spotted with 

many greenish crystals, some as long as a quarter of an 

inch. These three types are the most common, but all 

gradations among them are found. A dike near the 

center of sec. 1, T. 40 N., R. 44 E., is mineralogically 

similar to the lamprophyres except that it has a granitoid texture and contains about 50 percent of feldspars.

In thin sections the lamprophyres are found to consist of only a few minerals that differ widely in proportions and grain size. In most dikes the groundmass 

consists of laths of feldspar that with few exceptions 

are altered to albite 63 and thomsonite, fresh-appearing 

tiny automorphic augite crystals, magnetite, and biotite; in places chlorite, serpentine, calcite, and epidote 

are abundant, and small amounts of quartz, apatite, a 

white micaceous material, and pyrite are found. In 

several dikes, such as the one in the canyon at the junction of Lunch Creek and Sweet Creek, green hornblende is an abundant constituent. The feldspars determined are albite and labradorite. The larger phenocrysts in the dikes at the mouth of Slate Creek and 

on the lower Dumont property are olivine largely 

altered to a mat of serpentine and other minerals.

OTHER DIKE BOCKS

A few dikes that can hardly be classed as lamprophyres or as granitic bodies have been found but have

& Weaver, C. E., The mineral resources of Stevens County: Washington Geol. Survey Bull. 20, p. 304, 1920. 

63 Determination checked by F. C. Calkins.
28 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE., WASHINGTON

not been mapped. One such mass occurs in the northeast comer of sec. 16, T. 38 N., R. 45 E. This rock is 

light gray to white and superficially resembles an aplite. 

Under the microscope it is found to consist almost 

entirely of sheafs and nodules of radiating thomsonite.. 

A little fine-grained white micaceous mineral, calcite, 

and a few grains of much-corroded and rounded opalescent quartz were the only other minerals recognized.

STRUCTURE OF THE PRE-TERTIARY SEDIMENTARY 

AND METAMORPHIC ROCKS

GENERAL, FEATURES

The accompanying geologic map (pi. 1) shows most 

of the structural features that have a prevailing northnortheast trend, although a few faults, such as the Russian Creek fault and the Pass Creek fault zone, strike 

more nearly east. The structural history is entirely 

different from that of the eastern Rocky Mountains, 

where low-angle thrust faults are common.64 Folding 

was the earliest recognized type of deformation and 

was followed by three periods of faulting. Compressive stresses were dominant during folding and-some 

of the folds broke into thrust faults. Later deformation obscured these thrusts, and their extent, therefore, 

is unknown; however, in general, they seem to be subordinate features. The folding and thrusting were 

followed by deformation that produced a series of vertical or steeply dipping faults, which may be attributed 

either to compression or to tension the elevation of 

the footwall or the depression of the hanging wall. 

The last stage of faulting recognized produced faults 

of northwest trend, typified by the Pass Creek fault 

zone.

The deformation of the rocks resulted in the development of conspicuous foliation and linear structure, 

particularly in the schists and phyllites. As used in 

this report, the term "foliation planes" includes all 

planar elements except bedding and jointing. In 

many of the rocks two and in some of them three 

directions of foliation are clearly defined, but only the 

dominant planes have been recorded. These have a prevailing northeast strike with a steep westward dip, but, 

particularly west of the Pend Oreille River, considerable variation is found. Mica orientation is generally 

at an angle to the bedding. (See pi. 13, (7.)

The most constant structural characteristic in the 

region is the linear structure. The strike is N. 40°-60° 

E. and. the pitch is low, either northeastward or southwestward. The linear structure is defined by the lines 

of intersection of bedding planes with the axial planes 

of small folds. _ The structural features thus defined 

were established in the same epoch as the folding and

w Clapp, C. H., Geology of a portion of the Rocky Mountains of 

northwestern Montana: .Montana Bur. Mines and Geology Mem. 4, 

1932. This pamphlet contains a good discussion and a bibliography 

on the structure of the Rocky Mountains.

are not directly related to .the faulting, which they 

antedated. Other linear structure is evident but is 

not satisfactorily explainable, and in the field no assurance was felt that the same features were everywhere 

recognized. For this reason they were not plotted on 

plate 1.

Gilluly 65 pointed out that linear structure of the 

type here considered "seems susceptible of only one 

mechanical interpretation. This is that the lines mark 

axes along which tension operated during a late stage 

in the deformation of the rock." Phillips 66 called 

particular attention to the linear structures in. the 

Moine schist, of the type described here, which are 

perpendicular to the direction of movement, and contrasted them by means of rock-fabric analyses with 

grooving or rodding caused by slickensides.

In order to simplify discussion the structure of the 

quadrangle will be considered in five units, as follows:

1. The Flume Creek-Russian Creek block, bounded 

on the north by the Russian Creek fault, on the east by 

the Flume Creek fault, on the south by the Kaniksu 

batholith, and on the west by the edge of the quadrangle.

2. The valley block, which extends along the Pend 

Oreille River from the international boundary south to 

the Kaniksu batholith. On the west it is limited by 

the Flume Creek-Russian Creek fault block, and on the 

east the boundary is arbitrarily taken at the top of 

the Maitlen phyllite. This block, which contains most 

of the known ore deposits, is depressed about 10,000 

feet relative to the adjacent blocks.

3. The Hall, Mountain block, defined as the strip 

between the internatio'nal boundary on the north and 

the batholith to the south, bounded on the west by 

the top of the Maitlen phyllite and on the east by the 

base of the Monk formation and the Harvey fault.

4. The eastern block, east of the base of the Monk 

formation and the Harvey fault, bounded on the north 

and east by the borders of the quadrangle and on the 

south by the Kaniksu batholith. The outlying bodies 

of sedimentary and metamorphic rocks surrounded by 

the batholith are conveniently included here.

5. The Kaniksu batholith, described on pages 24-26.

As the detailed descriptions of these blocks and theinterpretations of their origin are necessarily involved, 

the features of general interest are summarized at the 

beginning of each description.

FIAJME CREEK-RUSSIAN CREEK BLOCK

Nearly the entire area of the Flume Creek-Russian 

Creek block is underlain by two formations, the Maitlen phyllite and the Gypsy quartzite, with a small

65 Gilluly, James, Geology and mineral resources of 'the Baker quadrangle, Oreg.: U. S. Geol. Survey Bull. 879, pp. 68-69, 1937.

08 Phillips, F. C., A fabric study of some Moine schists and associated 

rocks: Geol. Soc. London Quart. Jour., vol. 63, pp. 591-594, 1937.
STRUCTURE OF THE PRE-TERTIARY ROCKS 29

amount of the upper part of the Monk formation exposed along the Flume Creek fault. The rocks are 

closely folded, on both a large scale and a small scale; 

the axes of the folds trend about N. 45°-50° E. and are 

cut oft' by the great Flume Creek and Russian Creek 

faults. The somewhat peculiar curved junction of the 

Flume Creek fault and the Russian Creek fault (see 

pi. 1), combined with unusually good exposures on the 

ridges, encouraged a more detailed structural study of 

this area than was possible for the rest of the quadrangle.

The crest of the highest ridge (Hooknose-Abercrombie ridge) nearly coincides with the medial line of a 

southwestward-plunging slightly overturned anticline, 

the Hooknose anticline. (See pi. 1.) The axial plane 

of this fold and the axial planes of the small satellitic 

folds dip about 80° SE., which agrees in general with 

Walker's observations north of the Canadian border. 67 

Northeast of Hooknose the anticlinal structure is difficult to recognize, and the beds toward the Flume 

Creek and Russian Creek faults are steep to vertical. 

Near the faults the quartzite is brecciated and the phyllite is contorted. The southern part of the Hooknose 

anticline is complicated by the Ridge fault, but east 

of the fault there are similar folds, both anticlines 

and synclines. To judge from the attitude of the 

small folds the axial planes, with one exception, dip 

steeply eastward. The Gypsy quartzite exposed along 

the Flume Creek fault south of the mouth of the 

middle fork of Flume Creek terminates at its south 

end in an abruptly broken fold. The axial plane of 

this fold cannot be located with certainty but is thought 

to be nearly vertical or to dip steeply west. The phyllite south and east of the point of the fold in the quartzite is overturned and dips under the quartzite, which 

near this locality is a breccia. Below the base of the 

quartzite a thin strip of sandy dolomite and schist 

typical of the top of the Monk formation on Sullivan 

Ci'eek is exposed.

The Flume Creek fault and the Russian Creek fault 

together constitute one of the most conspicuous and 

impressive features in the entire region. Plate 13, Z>, 

is a view soutliAvestward from a dolomite knob west of 

the Pend Oreille mine, across the Flume Creek fault 

and nearly along the strike of the quartzites. It gives. 

a vivid picture of the magnitude of the fault, which 

has a known vertical displacement of at least 10,000 

feet. The attitude of the Flume Creek fault is unknown, as it is nowhere exposed. The comparatively 

straight trace of the fault indicates that the dip is 

steep or vertical, and on the cross sections (pi. 1) it is 

shown as vertical. The Russian Creek fault is more 

closely located and appears to dip more than +70° N., 

as computed from different altitudes along the strike.

07 Walker, ,T. T., Geology and mineral deposits of Salmo map area, 

«. C.: Cftnnda Geol. Survey Mem. 172, pp. 18-21, 1934.

The linear structures on both sides of the Russian 

Creek fault are nearly parallel and do not change strike 

or pitch as the fault is approached. This is interpreted to mean that the Flume Creek fault and the Russian Creek fault cannot be one folded fault or, as the 

fault surface is not normal to the linear structures, that 

rotation has been minor. The attitudes of the linear 

structures east of the Flume Creek fault are in general 

obscure.

In the part of the Hooknose anticline near the 

junction of the Flume Creek fault and the Russian 

Creek fault some distortion of the linear structures is 

shown. The Maitlen phyllite on the northwest limb of 

the anticline thins rapidly from about 1,500 feet on 

the west to about 300 feet where it disappears under the 

alluvium on the east. This thinning appears to be due

Metaline limestone

FIGUKW 6. Generalized sketch plan of junction of Flume Creek fault 

and Kussian Creek fault. Shows squeezing and thinning of the 

phyllite members.'

not so much to the cutting out of beds along the fault, 

although some are cut out, as it is to the squeezing 

out of individual beds. This squeezing-out process is 

particularly well shown by the marble layer near the 

base of the phyllite (see fig. 6) ; it is probably the 

result of compression or excessive drag. The rocks in 

the valley near the fault have been subjected to compressive forces (see pi. 14, A), although local compression effects would be expected whether the dominant 

forces were tensional or compressional.

The steep dips of both the Russian Creek and Flume 

Creek faults and the constant direction of the linear 

structures across the Russian Creek fault may be explained as resulting from normal faults (favored by the 

writers) or by steep thrust and transverse faulting, such 

as has occurred at the Garrison Monster fault of Gold 

Hill, Utah.68 If the explanation of thrusting and transverse faulting holds, the Flume Creek fault dips westward at an angle of probably 45° or more, and the Russian Creek fault is a transverse fault, formed during the 

forward motion of the thrust block. Although this

08 Nolan, T. B., The Gold Hill mining district, Utah: U. S. Geol. 

Survey Prof. Paper 177, p. 60, 1935.
30 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

explanation has not been demonstrated, it is, perhaps, 

favored by the following points: .

(1) Confusion in both the upper and lower blocks at 

the junction of the Flume Creek and Russian Creek 

faults.

(2) Lack of radial faults in the knver block at the 

j unction of the Flume Creek and Russian Creek faults.

(3) Lack of drag effects along both the Flume Creek 

fault and the Russian Creek fault.

(4) Rough general accordance of the faults with the 

regional trend .of folding.

(5) General position of the faults.

One alternative to this explanation is that the Flume 

Creek and Russian Creek faults are both normal and 

their hanging walls are depressed relative to the footwalls. This explanation is the one favored by the 

writers, although the trust-fault and transverse-fault 

explanation is not discounted. If the faults are normal, the displacement would be essentially down the dip 

and nonrotational. The normal-fault explanation is 

possibly favored by the following points:

(1) Lack of drag folding in the upper or southwest 

block.

(2) Lack of overturn close to the faults in the lower 

or valley block.

(3) The trend of the faults is only in part accordant with the structure of the upper block.

(4) The trend of the faults is opposed to the direction of pressure as shown by the Ridge thrust and the 

asymmetry of the folds.

(5) The presence, in rocks in the valley, of normal 

faults nearly parallel to Flume Creek fault.

(6) Crumpling in the lower block north of and close 

to the Russian Creek fault. (See pi. 14, A.)

(7) Irregular thrust remnants in the valley east of 

the Flume Creek fault. The thrust represented by 

these remnants may have been formed by compression 

in the upper layers during settling of a down-pointed 

wedge.

The Ridge fault (see pi. 1) crosses the strike of 

the bedding at low angles and dips about 60° E., 

nearly parallel to the dip of the bedding. The fault 

is not a sharp, well-defined break but is an indefinite 

zone of intense shearing that grades laterally into less 

deformed rocks. It cannot be traced northeastward beyond the Flume Creek fault, which probably cuts it off. 

A bedding fault of this type might be expected in a 

closely-folded region where the folds have broken during the late stages of the deformation. The Ridge 

fault is near the thick Gypsy quartzite which would 

form a rigid buttress and against which the phyllites 

might readily break and slide. The linear structures 

on opposite sides of the fault pitch, with a few exceptions, in opposite directions; east of the fault they pitch 

northeastward, and west of the fault they pitch southwestward. This indicates that the movement on the 

fault was rotational.

VALLEY BLOCK

In the valley of the Pend Oreille River north of 

the Kaniksu batholith there is a topographically low 

area of down-faulted Paleozoic rocks bordered on the 

east and west by higher areas of Middle Cambrian and 

older rocks. The structure in the limestones and shales 

of the valley is exceedingly complex, and the rocks are 

intricately folded and faulted, both by .normal and by 

reverse faults. Mapping is handicapped by the extensive cover of Tertiary and later formations, but as 

this block contains most of the known ore deposits it 

was studied and is described in considerable detail.

The complex structure of the valley block is thought 

to have resulted from the dropping of a down-pointed 

wedge between two downward-converging faults, the 

Flume Creek and Slate Creek faults. As the wedge 

was lowered normal faults were developed parallel to 

its sides, and compression against the sides of the 

wedge was relieved by thrust faulting along the incompetent layers, particularly the Ledbetter slate, and by 

supplementary tear and transverse faulting. As the 

wedge was lowered farther the faulting, complicated by 

folding, continued, and the final result was a complexly deformed and shattered mass.

Jenkins,69 in his study of the lead deposits of Pend 

Oreille and Stevens Counties, presented a generalized 

east-west cross section from Metaline Falls to the valley 

west of Abercrombie Mountain. He considered the 

Pend Oreille Valley to be a depressed anticline, 

bounded on both east and west by normal faults.

The limestones and dolomites generally dip less than 

45° surprisingly -little when compared to the older 

rocks in adjoining blocks. They are, however, intensely brecciated in many areas, and low-angle thrust 

faults, as well as numerous vertical and normal faults, 

are recognized, both in the carbonate rocks and in the 

slates. The slates are generally much contorted and in 

places are dragged and squeezed along fault zones for 

hundreds of feet. The contacts between carbonate 

rocks and slates appear to have been particularly amenable to faulting, and, with few exceptions, the slates 

near the contacts are reduced to black clay gouge.

The wide exposure of carbonate rocks and slates 

between Slate Creek and the Pend Oreille River narrows rapidly southward to the mouth of Slate Creek. 

Considered as a unit, this block is a faulted anticline 

plunging southward or south westward. A fault that 

brings up the phyllite of Boundary Mountain on the 

west coincides with the Styx Creek Valley and, farther 

south, with the axis of the fold. The fold axis also 

seems to merge into a fault exposed in Dumont's lower 

group of claims, in sec. 30, T. 40 N., R. 44 E., and at 

the mouth of Slate Creek, where the fault is vertical.

69 Jenkins, O. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash. : Washington Dept. Cons, and Devel., Div. Geology, Bull. 31, 

p. 32, 1924.
STRUCTURE OF THE PRE-TERTIARY ROCKS 31

East of Styx ("reek the dolomite dips 45° to 50° E. It is 

overlain by the much sheared and contorted slate band 

along the west side of the Slate Creek fault. This slate 

band, judged by an apparent repetition of its black 

quartzite member, is thought to be a tightly folded syncline (see section D-D', pi. 1), which can be traced 

southwestvvard along the strike as far as Uncas Gulch. 

Southwest of Uncas Gulch the structure in the slate 

is obscure. The dip is generally to the southeast, and 

the slate is thought to be separated from the Metaline 

limestone by a low-angle thrust that dips southeastAvard. (See pi. 1.) West of Styx Creek the dip 

ranges from 10° to 35° W., but the rocks are probably 

repeated along northeastward-trending faults. The 

slate west of this anticline forms a syncline that is 

well exposed in Z Canyon. (See section G-G' , pi. 1.) 

Both the north and south contacts of the slate in Z 

Canyon are thought to be faults; the northern fault 

is vertical, and the southern fault, where exposed in 

the east bank of the river, dips 80°-85° S. The synclinal axis plunges at a steep angle to the west; on the 

hill east of Z Canyon diamond drilling has failed to 

show slate in place. Westward the block of Devonian 

limestone in-sec. 16, T. 40 N., R. 43 E., is probably on 

the trend of the fold. West of the Devonian limestone 

the syncline is cut off by the Flume Creek fault, which 

here brings the Cambrian Gypsy quartzite against 

Devonian- limestone. In sec. 29, T. 40 N., R. 43 E., 

just east of the junction of the Ridge fault and the 

Flume Creek fault, the synclinal nature of the slate 

block is again evident. A thin layer of Metaline limestone is exposed along the valley east of Flume Creek. 

It dips about 20° E., under the slate. On the east 

side of this slate, near the Lead King and Giant properties, the dips are 30°-40° W. South of Ledbetter 

Lake the syncline, although it may persist, cannot be 

recognized.

The slates and limestones north of the Russian Creek 

fault are structurally part of the terrain to the north 

and west. They appear to be compressed into a rather 

open syncline, the axis of which trends about N. 60° E. 

Knowledge of this structure is meager, and additional 

work in adjacent areas is needed. Within about 100 to 

200 feet of the Russian Creek fault, particularly near 

the junction with the Flume Creek fault, the rocks are 

n11ich distorted. (See pi. 14, A.)

The Ledbetter slate is well exposed in the canyon 

at the junction of Slate Creek and the Pend Oreille 

River. The north contact of this slate and the carbonate rocks is exposed on the north bank of Slate 

Creek and at the R. E. Lee property; west of the river. 

Both of these contacts are nearly vertical faults. The 

south contact of the slate dips about 35° S. under 

the Metaline limestone. This contact is shown in plate 

14, B.

The carbonate rocks that are thrust over the Ledbetter slate form a block about a mile across. At only

one place in this carbonate block has bedding been 

recognized; most of the rock is completely shattered. 

The south side of the thrust block is a nearly vertical 

fault that is poorly exposed in the river gorge. (See 

cross section G-C'', pi. 1.) The west side of the carbonate thrust block is not exposed and is assumed to be a 

fault hidden beneath the alluvium near Ledbetter Lake.

A similar but probably larger block of Metaline 

limestone thrust over the Ledbetter slate is thought to 

extend from a point north of Metaline Falls southward 

nearly to the mouth of Wolf Creek. At the base of 

Washington Rock, in the river valley just south of 

Metaline Falls, is a small exposure of slate, and north 

of the falls similar graptolite-bearing slate is exposed 

at low water on both banks of the river. (See pi. 14, 

G.\ At the bottom of the Metaline shaft (150 feet 

deep) diamond-drill holes directed under the river 

showed nothing but black slate. The outline of this 

thrust block is vague because of the thick cover of 

alluvial material. Extensive diamond drilling at the 

Pend Oreille mine shows no evidence of slate in depth, 

and it is probable that the fault surface below the thrust 

block is concealed below the overburden south of Flume 

Creek. The eastern and western limits of the thrust 

block are also hidden under terrace deposits. The 

eastern limit is thought to be cut off by the southern 

continuation of the Slate Creek fault; the.western limit 

is assumed to be the fault which, farther south, is 

known to lie between the old Bella May and the Bluebucket workings. The new Bella May adit south of 

Metaline and several nearby diamond-drill holes furnish most of the information in the southern part of 

the thrust block. A fault that dips 45° W. was cut in 

this adit at about 2,500 feet. (See pi. 30.) On plate 1 

this fault is connected with the Slate Creek fault, 

although the main Slate Creek fault may be under the 

alluvium farther east. The fault in the adit is normal, 

with downthrow to the west, and brings Ledbetter slate 

against Metaline limestone. Overlying this slate is a 

thrust plate of Metaline limestone exposed in the mine 

workings and in drill cores. The western limit of this 

thrust block is along an eastward-dipping fault that 

lies in the valley east of the old Bella May workings. 

The thrust block here is seen to be wedge-shaped and is 

bounded on both the east and the west by normal faults.

The structure south of the new Bella May adit is 

almost entirely conjectural, owing to poor exposures. 

A cross fault that extends up Wolf Creek is inferred 

to explain the apparently uniform slate block south of 

the thrust block. This fault can be picked up in Wolf 

Creek where the lirnestone-phyllite contact is offset. 

South of Wolf Creek, on the east side of the river, a 

fault whose dip is unknown brings the slate against 

the sheared Metaline limestone and, at one place about 

a mile south of Sand Creek, brings the slate and 

Maitlen phyllite into contact.

An unusual type of movement for which an ade-
32 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

quate explanation is lacking has occurred in the dolomite just north of the slate exposure below Metaline 

Falls on the west bank of the river; This movement 

consisted of the formation of low-angle normal faults 

offset along steeper reverse faults. (See fig. 7. ) It can 

be explained tentatively either as the result of rotational normal faulting or as an unusual expression of 

tension stresses followed by compression.

The valley block is arbitrarily limited on the east by 

the top of the Maitlen phyllite, which for much of its 

trend coincides with the Slate Creek fault. The Slate 

Creek fault can be traced from the international boundary southwestward nearly to the Grandview mine, 

where it is concealed beneath alluvium. It is thought 

to continue farther south and to be an eastern limit to 

the thrust block of limestone south of Metaline Falls.

5 Feet,

FIGURE 7. Simplified sketch showing type of movement on small faults 

in thrust plate of Metaline limestone in Pend Oreille River gorge north 

of Metaline Falls. Vertical section.

A'fault that dips about 45° W. is exposed in the new 

Bella May adit and may be the southern continuation of 

the Slate Creek fault. North of Uncas Gulch the 

trace of the Slate Creek fault has a nearly straight 

course and therefore is nearly vertical, though it may 

dip steeply westward. The Ledbetter slate is faulted 

against the Maitlen phyllite, and on the poorly exposed slopes these two formations are difficult to distinguish. Near Uncas Gulch the exposures are unusually poor and the details of the structure are not known. 

A cross fault along Uncas Gulch is inferred to offset 

the Slate Creek fault, as the formations on opposite 

sides of the gulch do not match. This Uncas Gulch 

fault probably persists into the Gypsy quartzite to the 

east, as an offset is indicated on the phyllite-quartzite 

contact. South of Uncas Gulch the Slate Creek fault is 

thought to continue southwestward between the Metaline limestone and the Maitlen phyllite. Its course indicates a steeply dipping or vertical fault.

HALL MOUNTAIN BLOCK

The Hall Mountain block of steeply dipping beds has 

its structure dominated by the thick series of Gypsy

quartzite. In the valley of the south fork of the Sahno 

Kiver, near the international boundary, the quartzite is nearly vertical or dips more than TO 0 W. Toward the south the westward dip persists but gradually 

decreases; on Gypsy Peak it is about 60° W., on CroAvell 

Peak about 50° W., and on Sullivan Mountain only 

about 35° W. The dips in the phyllite above the quartzite and in the schistose Monk formation below the 

quartzite are erratic. In general they nearly parallel 

the quartzite, but local reversals are common, and much 

of the Monk formation southeast of Sahno Mountain 

dips eastward. Crenulations and small folds are abundant in both the phyllite and the Monk.

The rather simple monoclinal structure that persists from the north boundary of the quadrangle to 

Sullivan Mountain is cut farther south by a series of 

fractures of the Pass Creek fault zone and the Johns 

Creek fault. The Pass Creek fault zone is about 1 mile 

wide and cuts across all other structural features. The 

fault surfaces are rarely exposed, but the evidence indicates a steep north dip. The Johns Creek fault cuts 

off the Hall Mountain anticline and the Harvey fault, 

but it is not exposed, and its attitude is unknown. It 

is inferred from the much brecciated rocks along the 

valley, from the omission of much of the Gypsy quartzite and Monk formation, and from the offset in the 

Shedroof conglomerate to the east.

Hall Mountain is apparently the nose of an anticline 

that pitches southwestward. ' The pitch of linear structures and subsidiary folds is between 15° and 45° SW. 

The axial plane of the major fold coincides approximately with the fault that trends N. 55° E. across the 

saddle northwest of the Hall Mountain fire lookout. 

The attitude of the bedding in the phyllite south and 

west of Hall Mountain suggests that the fold is slightly 

overturned to the east. The Hall Mountain anticline 

resembles the anticline west of Lost Lake in that the 

quartzite is thoroughly shattered and brecciated, so 

that the bedding, although locally recognizable, cannot 

be followed. Also, the pattern of the quartzite in each 

fold is hook-shaped, with the short east limb abutting 

against a fault. In neither fold is it entirely clear 

whether the anticlinal structure is genetically related 

to the fault or, like the Hooknose anticline, essentially 

a product of regional folding. The uniform homoclinal structure east of the Gypsy quartzite north of the 

Pass Creek fault zone indicates that the Hall Mountain 

anticlinal axis did not continue northward beyond the 

fault zone and implies that the quartzite must have continued southward from its termination east of Hall 

Mountain. This continuation of the quartzite south 

of Hall Mountain is presumably cut out by the Harvey 

fault.

The Hall Mountain anticline is reflected also in the 

outcrop pattern of the Maitlen phyllite, although not 

suggested clearly by the records of foliation and bedding shown on plate 1. This is not surprising, how-
STRUCTURE OF THE PRE-TERTIARY ROCKS 33

tivcr, as the phyllites are distorted and recrystallized. 

Bedding can be recognized only locally; it is commonly 

obscured by shear banding (see pi. 6, D] with which it 

can be easily confused. In addition, the evidence 

seems to indicate two epochs of deformation, each relieved by movement on a set of shear planes. Figure 

4 is a sketch of folded and sheared foliation. In places 

where the late deformation is weak, bedding can be 

recognized; elsewhere the younger shear planes shown 

in figure 4 are spaced so closely as to obscure all earlier 

structure. The strike of the younger shear planes is 

nearly parallel to that of the Pass Creek fault zone, 

and their average dip is 55° NE. The offsets of bedding and foliation on these shear planes are generally 

in the same direction as the offset of the top of the 

Gypsy quartzite by the Pass Creek fault zone at the 

north end of Sullivan Lake.

The Harvey fault is one of the major structural 

breaks in the district. It is exposed on the west slope 

of Molybdenite Mountain, south of Harvey Creek, 

where the dip is 44° W. At this point the fault is 

marked by a zone of schist and elliptical fragments 

about 800 feet wide. Throughout the length of the 

fault the dip is westward, as shown by differences in 

altitude along the strike. The west side is down relative to the east side, but the exact amount of offset 

is difficult to estimate; it is probably a maximum of 

about 15,000 feet. The Harvey fault crosses the strike 

of the formations at small angles and for much of its 

known extent brings Maitlen phyllite against greenstone of the Leola volcanics. On Hall Mountain 

the greenstone was not found, and the phyllite rests 

directly against the Shedroof conglomerate. Northward the Harvey fault is apparently cut off by the 

.'Johns Creek fault, and it has not been recognized with 

certainty north of the Johns Creek fault or the Pass 

Creek fault zone. Northeast of the Pass Creek zone, 

however, both the greenstone and the Monk formation 

thin abruptly. This thinning may be explained by a 

fault concealed beneath "the alluvium in the Sullivan 

Creek Valley and as the valley is approximately parallel to the Harvey fault, the two faults may be related.

The Pass Creek fault zone cannot be traced westward much beyond the upper contact of the Gypsy 

quartzite. The movement along the zone was apparently taken up by folding and slipping along foliation 

planes in the phyllite.

EASTERN BLOCK

The eastern block, consisting qf the rocks stratigraphically below the base of the Monk formation, has 

been only superficially studied, and its structure is not 

knoAvn. The rocks are phyllitic and schistose with the 

exception of a few massive layers, and in many places 

are intricately folded. The structure is also complicated by the igneous intrusion and its resultant wide 

hornfels zone.

East of Hall Mountain near the junction of Pass 

Creek and Sullivan Creek the outcrop pattern of the 

rocks to the east indicates a broad anticline, which is 

well shown by the Shedroof conglomerate. The bedding in the conglomerate is indistinct, but foliation 

planes are conspicuous. In the southeastern part of the 

fold the foliation planes and the bedding in the underlying limestone are nearly horizontal, but the foliation 

steepens toward the west. To the east, in sees. 18 and 

19, T. 38 N., R. 44 E., the Shedroof conglomerate 

is cut off by an obscure fault that trends N. 45° E. The 

fold is further complicated by the Pass Creek fault 

zone, which trends a little south of east and may approximately follow the outcrop of the axial plane of 

the fold. From Round Top Lookout greenstone and 

conglomerate can be followed northeastward until they 

merge into the main Shedroof conglomerate. It is 

likely that the exposures northeast of Round Top 

Mountain are part of the main conglomerate brought 

up by folding, although this is not definitely known.

The Pass Creek fault zone can be traced eastward to 

a point within about 2 miles of the intrusive contact 

and it probably continues farther. One prominent 

fault in this zone crosses Round Top Mountain just 

southwest of the peak. The fault surface is not exposed but is marked by a shallow trench more than 50 

feet wide. The rocks on opposite sides of this trench 

do not coincide, and the amount and direction of offset 

on the fault are unknown.

The Johns Creek fault cannot be traced southeastward beyond the crest of the Hall Mountain ridge, 

where an intrusive mass is found along its strike. 

Farther to the southeast, however, the fault probably 

continues, as shown by an apparent' offset in stratigraphic units such as the band of quartzite in sec. 26, 

T. 38 N., R. 44 E.

About a mile south of Salmo Mountain a northwestward-trending structural feature may be present. 

Other than an apparent offset in the contacts of the 

formations and the flattening of the dips, nothing of the 

nature of the deformation was learned. The fold is 

shown on section D-D' of plate 1 as a shallow syncline 

similar to some mapped by Walker in the Salmo area, 

to the north. 70

Daly 71 and Walker 72 each show a major northwestward-trending fault which if projected should cross 

the international boundary about 1% miles west of 

the eastern border of the Metaline quadrangle, but care70 Walker, J. F., Geology and mineral deposits of Salmo map. area, 

B. C.: Canada Geol. Survey Mem. 172, geologic map No. 2337, 1934.

71 Daly, R. A., Geology of the North American Cordillera at the 49th 

parallel: Canada Geol. Survey Mem. 38, mnp between longitude 117° 

and 117°30, 1912.

72 Walker, T. F., op. cit, p. 20.
34 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

ful mapping in the difficultly accessible northeast corner of the quadrangle failed to reveal any evidence 

of a northwestward-trending fault. Kirkham and 

Ellis,73 however, show a fault of similar trend that 

passes just outside the northeast corner of the Metaline 

quadrangle.

RELATION OF THE STRUCTURE TO THAT OF 

SURROUNDING REGIONS

Steeply dipping normal faults have been described 

from many nearby areas to the north and east, and in 

the same areas low-angle thrust faults are few.?4 

Sampson,75 in the Pend Oreille district, Idaho, recognized two types of steeply dipping normal faults (1) 

post-intrusion faults, and (2) faulting caused by intrusive forces. This distinction is of particular interest, as the Pend Oreille district is on the eastern border 

of the Bayview granodiorite, which is thought to be 

the same continuously exposed intrusive mass as the 

Kaniksu batholith. Anderson,76 in the Clark Fork 

district, Idaho, confirmed Sampson's observations, 

although in this area the great east-west Hope fault has 

somewhat confused the study.

In the Nelson map area of Canada, where the formations are correlated with those of Metaline, Rice 77 has 

recently shown steeply dipping normal and reverse 

faults. In the Cranbrook map area, Eice 78 distinguished two types of deformation (1) by compressional forces that produced thrust faults and close folds 

and (2) by tensional forces that produced normal 

faults of great throw. Walker 79 describes numerous 

folds in the Salmo map area but found clearly defined 

faults at only a few places.

Practically no published structural studies have been 

made in the region west of Metaline. The few reconnaissance surveys indicate mainly that the structure is 

complex and that both folding and faulting are 

involved.80

73 Kirkham, V. R. D., and Ellis, E. W., Geology and ore deposits of 

Boundary County, Idaho: Idaho Bur. Mines and Geology Bull. 10, 

pi. 3 and p. 28, 1926.

74 Schofleld, S. J., Geology of Cranbrook map area, B. C.: Canada 

Geol. Survey Mem. 76, pp. 92-97, 1915. Sampson, Edward, Geology 

and silver ore deposits of the Pend Oreille districts, Idaho : Idaho Bur. 

Mines and Geology Pamph. 31, pp. 12-16, 1928. Anderson, A. L., 

Geology and ore deposits of the Clark Fork district, Idaho : Idaho Bur. 

Mines and Geology Bull. 12, pp. 40-47, 1930. Rice, H. M. A., Preliminary report, Nelson map area, B. C. : Canada Geol. Survey Paper 

37-27,1937. Allan, J. A., Geology of Field map area, B. C. and Alberta : 

Canada Geol. Survey Mem. 55, pp. 201-203, 1914. Rice, H. M. A., 

Cranbrook map area, B. C.: Canada Geol. Survey Mem. 207, pp. 27-32, 

1937.

76 Sampson, Edward, op. cit., pp. 12-16.

70 Anderson, A. L., op. cit., pp. 40-47.

77 Rice, H. M. A., Preliminary report, Nelson map area, B. C.: Canada 

Geol. Survey Paper 37-27, 1937.

78 Rice, H. M. A., Cranbrook map area, B. C.: Canada Geol. Survey 

Mem. 207, p. 30, 1937.

70 Walker, J. F., Geology and mineral deposits of Salrno map area, 

B. C.: Canada Geol. Survey Mem. 172, pp. 18-21, 1934.

^Pardee, J. T., Geology and mineral resources of the Colville Indian 

Reservation, Wash.: U. S. Geol. Survey Bull. 677, pp. 23-24, 1918. 

Weaver, C. E. The mineral resources of Stevens County, Wash.: Washington Geofl. Survey Bull. 20, pp. 52-53, 1920; Geology and ore deposits 

of the Covada mining district, Wash.: Washington Geol. Survey Bull. 16, 

pp. 29-31, 1913.

The summation of the structural studies in areas near 

Metaline emphasizes the need for more detailed work. 

The papers discussed show an almost uniform agreement as to the presence of folds and steeply dipping 

faults, but in general no attempts have been made to 

interpret structural details or to record a comprehensive 

structural history.

RELATION OF DEFORMATION TO BATHOLITH INTRUSION

Schofield,81 in the Cranbrook map area, interpreted 

the faulting to be a direct result of igneous intrusion, 

but Rice,82 in a more recent study of the same area, 

considered the intrusive masses to be later than the 

faulting. Drysdale 83 thought that the Nelson batholith was emplaced by a combination "of active intrusion 

and magmatic stoping." His field observations indicated that most instances of the granitic intrusives conform to the structure of the overlying formations but 

a few are crosscutting.

Sampson,84 in the Pend Oreille district, Idaho, 

thought that the grouping of the faults around the 

intrusive mass indicated that the faults were caused by 

intrusive forces. Sampson also shows the Bayview 

granodiorite to be involved in post-intrusion faulting.

Anderson,85 in the Clark Fork district, Idaho, and 

Kirkham and Ellis,86 in Boundary County, Idaho, attributed part of the faulting in these districts to intrusive forces.

A necessary corollary to the theory that the deformation was caused by forces set up by intrusion seems to 

be that, in general, although not in detail, the intrusive 

contacts should be concordant with the dominant structure planes in the intruded rock.87 In the Metaline 

quadrangle the intrusive contact is only locally concordant; and where the contact crosses the regional 

northeastward trend the foliation planes abut sharply 

into the intrusive mass. (See fig. 5.) The folding and 

the foliation of the metamorphic rocks antedate the 

intrusion a conclusion in which most workers in 

nearby areas concur.

No conclusive evidence of major faulting of the 

Kaniksu batholith is known near Metaline, although 

several thin sections show that the intrusive rocks, parCanada Geol. Survey 

Canada Geol. Survey

81 Schofleld, S. J., op. cit.

82 Rice, H. M. A., Cranbrook map area, B. C. 

Mem. 207, p. 31, 1937.

83 Drysdale, C. W., Ymir mining camp, B. C. : Mem. 94, p. 36, 1.917.

84 Sampson, Edward, op. cit., pp. 14-16.

86 Anderson, A. L., op. cit., pp. 39, 41-42.

88 Kirkham, V. R. D., and Ellis, E. W., Geology and ore deposits of 

Boundary County, Idaho : Idaho Bur. Mines and Geology Bull. 10, p. 29, 

1926.

87 Balk, Robert, Structural behavior of igneous rocks: Geol. Soc. 

America Mem. 5, pp. 45-95, 1937. Levering, T. S., and Goddard, E. N., 

Laramide igneous sequence and differentiation in the Front Range, 

Colo.: Geol. Soc. America Bull., vol. 49, pp. 38-39, 1938. Cloos, Ernst, 

The application of recent structural methods in the interpretation of the 

crystalline rocks of Maryland: Maryland Geol. Survey, vol. 13, pp. 

44-47, 79, 1937. Hersey, H. G., Structure and age of the Port Deposit 

granodiorite complex: Maryland Geol. Survey, vol. 13, pp. 129-130, 

1937.
GEOLOGICAL SURVEY PROFESSIONAL 1'Al'KH 202 PLATE 14

A. TIGHTLY FOU)KI> MKTAI.IMi LIMKSTOMK NK.XTTO

RUSSIAN CRK.KK FAIU.T. 

Note tlii.-keniiiR "f the la.w-rs al ill.- crests ..f lln- f<.l.ls.

II. MKTAL1NK LIMESTONE THRUST OVKR LRDHKTTKK SI.ATK.

Line <jf lltrusl in sliowii in Mark. View west acroHH tlie IVncI Orcille River fnnn 

llic Riverside mine.

C. METALIMli LIMtSTOJNE THRUST OVER LEDBETTER SLATE. 

Line of thrust is shown in black. River gorge north of Metaline Falls at low water. Terrace deposit at upper right.
DEVELOPMENT OF THE TOPOGRAPHY 35

ticularly in the muscovite-rich areas, are considerably 

shattered. Along the Flume Creek fault west of Lost 

Valley and along the Johns Creek fault southeast of 

Hall Mountain the batholith may either be faulted or 

intruded along preexisting or contemporaneous faults. 

At several places the contact between the intrusive mass 

and the metamorphic rocks is nearly a straight line. 

Such a contact is exposed in the hills .west of the Pend 

Oreille River but appears to be without appreciable 

post-intrusion faulting. Several shorter but similar 

straight contacts are exposed in the Granite Creek 

drainage area.

The distribution of the faults, with the possible exception of the Harvey fault, is difficult to attribute 

to stresses set up by the known masses of intrusive rock. 

However the distribution of the batholith in surrounding areas is poorly known, and its distribution in 

depth is largely conjectural. For this reason, any 

generalizations concerning stresses exerted by the 

magma are at present little better than opinions. The 

meager evidence obtained in the Metaline quadrangle 

indicates, however, that the Kaniksu batholith followed 

and did not cause the folding.

Another approach to the solution of this problem is 

the study of linear structure, although in many places 

the character]'sties have been destroyed by igneous 

metamorphism and the development of hornfels. No 

comprehensive study of these structural features was 

made, however, and far too feAv readings were taken 

to permit structural conclusions based on them.

DEVELOPMENT OF THE TOPOGRAPHY

The field work for this report was concerned largely 

with the bedrock geology, although some-observations 

on physiography and glacial- geology were recorded. 

This section is an attempt to present these observations 

in approximate chronologic order. It should be emphasized, however, that the observations were less numerous and less complete than would be needed for a 

comprehensive discussion of these subjects.

Land forms in the Metaline quadrangle are largely 

determined by the resistance to weathering and, to a 

lesser extent, by the structure of the underlying rocks. 

The topography has been somewhat modified by activity of the Cordilleran ice cap. In the north it is 

abrupt, and the mountains are steep and rugged. In 

the south, on the other hand, the mountains, where 

underlain by the Kaniksu batholith, are more gently 

sloping and rounded. No evidence of mature dissected 

upland surface has been recognized.

The region is drained principally through the Pend 

Oreille River (Clark Fork), which flows from south 

to north across the quadrangle.

That the Cordilleran ice sheet covered the entire 

region except the highest peaks is evident from the 

widely distributed glacial features. A lobe of the Cordilleran ice advanced southward up the Pend Oreille 

Valley at two and probably more different stages. According to Alden 88 the earlier ice extended southward 

beyond Spokane, and the latest ice advanced as far 

southward as Newport. Daly 89 states that the top of 

the ice cap was about 6,800 feet a,bove sea level west of 

the summit of the Nelson (Quartzite) Range and decreased to about 6,500 feet at the Columbia River. 

This figure appears to be essentially correct, as the 

highest evidence of glaciation found was a granitic 

erratic seen on Crowell Ridge at an altitude of about 

6,500 feet. The ice sheet, therefore, had a maximum 

thickness of at least 4,000 feet. Glacial striae were seen 

on Hall Mountain at 6,100 feet, on Shedroof Mountain 

at 5,900 feet, and on the spur west of Abercrombie 

Mountain at 5,900 feet. The altitude of the top of 

the ice at the south is less definite, but many of the 

mountains and ridges were probably buried. Flint 90 

indicates that at its maximum in the southern part of 

the Metaline quadrangle the upper surface of the ice 

was about 4,000 feet above sea level. This figure is 

low, as erratics are found on Timber Mountain, in 

the southwest corner of the quadrangle, at an altitude 

of 4,700 feet. The overriding of the region by southward-moving ice tended to scour the northward- and 

southward-sloping valleys and to fill in the transverse 

valleys.

Where the road from Newport enters the broad 

valley of the Pend Oreille River two well-defined terrace levels are recognized. The altitude of one is 2,100 

feet, and that of the other ranges from about 2,500 feet 

in the south to 2,600 feet in the north. Several other 

terrace levels were recognized but in general are poorly 

formed and discontinuous. The two principal levels, 

at 2,100 feet and 2j500 to 2,600 feet, are shown in plate 

15,' A. Flint 91 describes the 2,100-foot level at Newport as the upper limit of silt deposited in a lake 

dammed by an ice lobe to the north and by another 

to the east, ando controlled by an outlet at Newport, by 

way of the Little Spokane River, to the Spokane River. 

Large 92 earlier had recognized the channel at Newport 

as the outlet of "glacial Lake Clark" to the north. 

'The 2,100-foot level has not been recognized north of 

Metaline Falls. So far as the writers know, only casual reference has been made to the high terrace (2,500 

to 2,600 feet). This terrace extends along the river 

valley across the entire quadrangle, although it is 

poorly defined and indistinct south of lone. The material in this terrace can be seen at several places in

88 Aldeu, W. C., personal communication, 1930.

88 Daly, R. A., Geology of the North American Cordillera at the 49th : 

parallel : Canada Geol. Survey Mem. 38, p. 588, 1912.

90 Flint, R. F., Pleistocene drift border in eastern Washington : Geol.'" 

Soc. America Bull., vol. 48, pp. 226-230, 1937.

11 Flint, R. F., Stratified drift and deglaciation of eastern Washington : 

Geol. Soc. America Bull., vol. 47, p. 1880, 1936.

83 Large, T., Drainage changes in northeastern Washington and northern Idaho since extravasation of Columbia basalts : Pan-Am. Geologist, 

vol. 41, pp. 259-270, 1924.
36 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

road cuts south of Metaline and near Metaline Falls. 

It is generally silt and fine sand except along tributary 

streams such as Sullivan Creek, Slate Creek, and Flume 

Creek, Avhere coarse sand, gravel, and cobbles are found. 

The material is difficult to account for except as a deposit in ponded water. No descriptions of the region 

to the south nor the available topographic maps indicate a dam high enough to pond water above 2,500 

feet.03

That glacial Lake Clark drained southward seems 

likely from the Avork of Large and Flint and from the 

flat gradient of the Pend Oreille Kiver south of lone. 

Northward between Newport and lone the river drops 

50 feet in 50 miles, or a gradient of only 1 foot to the 

mile.94 Many of the tributary streams drain southward, and the topography indicates that the streams 

were adjusted over a long period to a southward-flowing 

preglacial drainage. Only in the recently excavated 

mouths is there a tendency toward a northward swing. 

The reason for the change in direction of the Pend 

Oreille drainage is obscure; it may be preglacial stream 

capture. Large 95 points out the complex history of the 

large rivers in northeastern Washington, and his caution is timely. On the terrace east of the Grandview 

mine and next to the highway north from Metaline 

Falls, the Metaline Mining & Leasing Co. put down a 

drill hole 434 feet without striking bedrock. This, 

combined with additional drillholes nearby, indicates a 

buried channel comparable in depth to the present river 

channel. A somewhat similar channel is inconclusively 

indicated along the Flume Creek fault west of the Bella 

May mine, and several old watercourses filled to an 

unknown depth can be seen in the limestone east of Z 

Canyon. It is likely that additional channels, not now 

known, are buried under the lake deposits. These 

abandoned channels are probably stream courses carved 

during preglacial and interglacial time and subsequently filled by debris from overriding ice or lake 

silts.

Between lone and Metaline the Pend Oreille River 

flows through Box Canyon, the first constriction in the 

channel north of Newport. North of Box Canyon the 

stream again occupies a wide flat bed for 6 miles to Met-' 

aline Falls. At Metaline Falls the river plunges into 

a series of steep, narrow gorges, that in places are 500 

feet or more deep. The wild, turbulent river continues northward across the border into Canada, where 

it swings abruptly westward and eventually flows into 

the Columbia. The best known of the gorges is probably that of Z Canyon, where an average discharge of

93 Flint, R. P., Stratified drift and deglaciation of eastern Washington : 

Geol. Soc. America Bull., vol. 47, pp. 1849, 1884, 1936 ; Pleistocene drift 

border in eastern Washington : Geol. Soc. America Bull., vol. 48, pp. 

203-232. 1937. Alden, W. C., Personal communication, 1937.

»+ Profile surveys in the basin of Clark Fork of Columbia River : U. S. 

Geol. Survey Water-Supply Paper 346, 1914.

K Large, T., Drainage changes in northeastern Washington and northern Idaho since extravasation of Columbia basalts : Pan Am. Geologist, 

vol. 41, pp. 260-261, 1924.

26,570 second-feet over a period of 24 years (1912-36) n<J 

flows through a channel reported to be only 18 feet 

wide. It is inconceivable that such a gorge as that 

shown in plate 7 ever carried the large volume of 

water and quantity of debris characteristic of glacial 

streams. The gorges are certainly later than the terrace, as the banks are commonly capped by the silt of 

the 2,600-foot level. From the mouth of Sullivan 

Creek to the Canadian border, a distance of 11 miles, 

the river drops 225 feet.07 No evidence of glacial erosion has been seen in this 11 miles of canyon, and it is 

therefore thought to be largely postglacial.

Although the inner gorge of the river is postglacial, 

the main valley dates from preglacial time, as indicated 

by the southward-flowing tributory streams. The remnants of the Tiger formation, of Tertiary age are, so far 

as known, limited to the valley, and no indication has 

been found that these remnants were down-faulted in 

postglacial time. The valley was therefore essentially 

at its present depth near lone before deposition of 

the Tiger formation. Excavation of the valley during 

Pleistocene time was undoubtedly vigorous in places, 

but the tremendous amount of debris that has been 

moved from the valley indicates that huge quantities 

of actively eroding ice must have been necessary. 

Large amounts of ice were present, but, as the glaciers 

were beginning to wane in the Metaline quadrangle, 

most of the glacial features to the south are depositional rather than erosional. Even in the Metaline area 

the deposits of silt, some of which may be interglacial, 

and the preservation of the Tiger formation indicate 

that ice erosion was insufficient to clean out the valley 

thoroughly.

Throughout its course north of lone the Pend Oreille 

River parallels the Flume Creek fault to the Canadian 

boundary, where it swings abruptly west more or less 

parallel to the Russian Creek fault. This parallelism 

suggests that the course of the river valley is dependent upon the underlying structure, and the valley either 

follows a narrow down-faulted block or has formed 

along the Metaline limestone and Ledbetter slate, which 

are more easily eroded than the other formations.

Terraces that rise gradually upstream are well defined along the sides of most streams tributary to the 

Pend Oreille Valley. (See pi. 15, B.} The number 

and distribution of these terraces indicate a long, complex physiographic history, the details of which are 

not known.

The drainage into the river from the east is carried 

through a few master tributaries, Slate Creek, Sullivan Creek, and LeClerc Creek. These streams, except 

near the headwaters, flow in V-shaped valleys bordered

90 Grover, N. C., and others, Surface water supply of the United 

States, 1936, pt. 12 : U. S. Geol. Survey Water-Supply Paper 812, p. 95, 

1937.

97 Profile surveys in the basin of Clark Fork of Columbia Kiver: 

U. S. Geol. Survey Water-Supply Paper 346, 1914.
DEVELOPMENT OF THE TOPOGRAPHY 37

by terrace deposits. They do not have the round U 

shape of typical glacial valleys, probably because the 

southward-moving ice did not appreciably modify the 

small transverse valleys. In the lower courses of Slate 

Creek and Sullivan Creek the streams have cut deep, 

narrow gorges in an attempt to adjust their drainage to 

the present level of the Pend Oreille River.

The streams tributary to the Pend Oreille from the 

west are similar to those from the east, although in 

general they are shorter. The lower parts of the 

northern tributaries are precipitous; Pewee Falls on 

Pewee Creek and Corkscrew Falls in the Flume Creek 

gorge, are well-known examples. These falls result 

from the weak streams failing to cut their channels as 

rapidly as the Pend Oreille channel was lowered.

In the southern part of the quadrangle the Pend 

Oreille River has not excavated its channel greatly 

since Pleistocene time. The result is that the tributary 

streams such as LeClerc Creek and Ruby Creek have 

lowered their channels at nearly the same rate as the 

river and the lower courses of the streams are therefore 

not precipitous, in marked contrast to the tributaries 

farther north.

The spurs west of the Pend Oreille River rise steeply 

at first and then more gently toward the ridge, which, 

north of lone, is 4 to 5 miles west of the valley. The 

ridge culminates in Abercrombie Mountain, at an altitude of 7,308 feet above sea level. South of lone the 

slopes westward from the river are more gentle and 

the drainage divide is about 10 miles or more to the 

west.

East of the Pend Oreille Valley the slopes rise at 

moderate angles to a group of hills and mountains, 

the highest of which is Gypsy QPeak, at 7,318 feet above 

sea level, or about 5,400 feet above the river 8 miles to 

the west. From the steep, rugged peaks in the north 

the hills decrease southward in altitude and pass into 

the rounded, less abrupt topography of the area underlain by the Kaniksu batholith.

The divide that separates the Pend Oreille drainage 

from that of the Priest River system to the east or 

from that of the Salmo River system to the north 

contains many of the highest peaks in the region. In 

the north it is considerably cut up by amphitheaters 

and erosion by local glaciers. (See pi. 16, A.)

East of the divide the drainage channels into the 

Priest River-Priest Lake system resemble those of the 

Pend Oreille tributaries, although only the headwaters 

of the streams were traversed. The terraces along 

the eastward-draining streams are extensive and better 

developed than those along the streams to the west. 

No attempt has been made to study or correlate these 

terraces.

The northeast corner of the quadrangle is drained by 

the headwaters of the South Fork of the Salmo

(Salmon) River. The present small stream is entirely 

inadequate to carve the wide, deep valley through 

which it flows. This valley cuts directly across the 

structure, but an adequate account of its history has 

not been attempted.

Near the center of sec. 24, T. 37 N., R. 42 E., there 

is an unusual kettle topography. The kettles are 50 to 

300 feet in diameter and as much as 40 feet deep. 

They are closely spaced and separated by knife-edge 

ridges. The surface material at this place is mainly 

silt and gravel, with a few cobbles as much as 8 inches 

in diameter.

Dry Canyon exhibits some interesting glacial .features. The head of the canyon is cut off by Maitlen 

Creek about 4 'miles east of lone; the abandoned 

channel is about 175 feet above the bed of Maitlen 

Creek. The Dry Canyon Valley is nearly level at its 

head and increases its gradient toward the south. It 

is about 11 miles long from Maitlen Creek south to 

it? junction with the west fork of LeClerc Creek and 

in this distance drops nearly 50Q feet, or an average 

of about 45 feet to the mile. The canyon floor is 

covered with an unknown thickness of unsorted debris, 

probably dropped by the ice during its retreat. Many 

kettles and small lakes such as Caldwell Lake and 

Scotchman's Lake are distributed through the valley, 

particularly in the southern part. These depressions 

are thought to have been formed by the melting of 

remnant blocks of stagnant ice. Except in the spring 

or during periods of heavy rainfall the drainage is 

mainly subsurface through the coarse porous debris. 

Scotchman's Lake is reported to have fluctuated as 

much as 80 feet in a year.

Much of the bedrock, particularly in the southern 

part of the quadrangle, is covered by. a blanket of glacial debris. This debris is both coarse and fine, is 

unsorted, and contains many types of rock. Small 

ponds and swamps are widely distributed in the debrischoked valleys and in silted depressions in glacial 

debris. The ponds are illustrated by Lake Leo, Lost 

Lake, Ledbetter Lake, Yokum Lake, and a host of 

others, many unnamed. These lakes may have forme'd 

by the melting of stagnant ice in the glacial drift and 

the gradual silting of the resulting depressions. 

Hughes Meadow is an example of a wide flat marsh 

formed by filling an older valley to an unknown depth. 

Such marshes are rather common, and in this region 

the larger ones are known as meadows.

Contrasting with the ponds and swamps of the 

choked valleys and drift areas are the rock-carved 

basins, formed where glacial scour has been particularly active. Sullivan Lake is the largest lake in the 

area. It occupies a depression between two ice-scoured 

walls and is dammed at each end by low, flat blockades. 

These blockades are similar to the blockades at Liberty
38 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

Lake and Newman Lake, recently described by Flint.98 

The blockade at the north end of Sullivan Lake is 

shown in plate 16, B.

Glacial striae are seen at few places but are well 

preserved on a limestone knob south of the Grandview 

open cut. At other places striae have been found, but 

they are mostly on the sides of tributary valleys and 

their orientations tend to converge toward the valleys. 

They were evidently formed by local glaciers or 

perhaps by movement toward the valleys during 

continental glaciation.

At several places in the region nearly level benches, 

in places 50 feet or more wide, have been developed, 

apparently by ice scour. Such a bench can be seen 

on Hall Mountain (see pi. 16, B), to the east (left) 

of Sullivan Lake. This bench is particularly conspicuous, as it cuts across the trend of the quartzite 

in Hall Mountain. Other benches have been recognized along the west side of Sullivan Mountain and 

Crowell Kidge.

Daly " has recently discussed the subject of elastic 

recoil of the earth's crust after removal of a large ice 

cap. Flint,1 however, was unable to reach any conclusions' as to the amount of such rebound in eastern 

Washington. In the Metaline quadrangle the effects 

of such rebound are not discernible on the silts of the 

2,100-foot terrace. This surface seems to be essentially 

horizontal from Newport to Metaline Falls. The apparent difference in altitude of the high terrace, 2,600 

feet at the Canadian border and about 2,500 feet near 

the southern 'part of the quadrangle, may or may not 

have been caused by elastic recoil.

Local glaciers were present on the higher peaks long 

after the Cordilleran ice 'cap vanished. On Snowy 

Top Mountain, just northeast of the Metaline quadrangle, a small stagnant ice pocket still persists. In 

one of the amphitheaters onr the east side of Gypsj7 

Peak (see pi. 16, ;4), a little snow remained in September 1936. Many of the aniphitheaters contain lakes 

and other features characteristic of recently glaciated 

regions. Evidence of local glaciers is difficult to recognize in the southern part of the quadrangle, owing in 

part to the rapidity with which the intrusive rock 

disintegrates.

CAVES

In many places in the Pend Oreille Valley caves are 

found in carbonate rocks, generally along fractures 

or breccia zones. 'Probably the best known of these 

caves is the Gardner Cave, which is a State park in the 

east-central part of sec. 4, T. 40 K, R. 43 E. All 

known caves in the carbonate rojeks are above the river

08 Flint, R. F., Stratified drift and deglaciation of eastern Washington : 

Geol. Soc. America Bull., vol. 47, pp. 1859-1862, 1936.

98 Daly, R. A., The changing world of the ice age, pp. 120-150, Yale 

Univ. Press, 1934.

1 Flint, R. F., Pleistocene drift in eastern Washington : Geol. Soc. 

America Bull., vol. 48, p. 230, 1937. ,

level and were probably formed by downward-percolating meteoric waters.

Several filled caves were cut in the long adit driven 

by the Metaline Mining & Leasing Co. at the Bella 

May mine. These caves are filled with apparently 

structureless masses of clay and stratified silts and 

coarse sands. They have yielded no fossils but are at 

the base of the 2,600-foot terrace and for this reason 

were probably present before the last ice invasion. It 

is possible that these caves are as old as Tertiary. 

Caves similar to those in the Bella May adit are found 

ir Washington Rock, west of Metaline Falls, and at a 

few other places in the river valley. One such cave 

in Washington Rock was filled with brown clayey iron 

oxide that was mined by the Lehigh Portland Cement 

Co. for use in the manufacture of cement. The iron 

oxide showed crude banding roughly parallel to the 

walls of the chamber but was otherwise structureless.

Jenkins 2 mentions caves found in the Grandview 

workings. He says: "In one natural cave it was 

noticed that breccia was much in evidence. Brokenoff pieces of brecciated rock containing galena partly 

filled the cave."

A group of unusual caves was found during the development of the Pend Oreille mine, and some of them 

are labeled on the mine map. (See pi. 33.) Many of 

these caves contained sphalerite and galena in fragments on the floors and in crystals lining parts of the 

walls, and for this reason they were quickly mined 

out. The best cave seen was above the 500-foot level; 

it was about 8 feet wide, 4 feet nigh, and more than 20 

feet long. Other caves, both above the 500-foot level 

and above the 300-foot level, are reported to have been 

considerably larger. The country rock is brecciated 

Metaline limestone, generally silicified. In all the 

caves examined one side of the cavity is bounded by 

a smooth slickensided wall. (See pi. IT, A.) The 

caves are most common above the 500-foot level (altitude 2,124 feet) and decrease in size and numbers in 

depth. On the 700-foot level (altitude 1,900 feet) the 

openings are little more than enlarged vugs, and all 

seen were less than 3 feet in greatest dimension. The 

caves continue upward and were found in the zero adit 

of the mine (altitude about 2,550 feet).

Many of the caves were well below ground-water 

level before mining began, although all known are 

above the river level and are situated where the hydraulic gradient is steep and the circulation, even in 

the zone of saturation, is probably considerable.

One of the most peculiar features of these caves is 

the lining of paligorskite (pi. 17, B), a hydrous 

magnesium-aluminum silicate, which hangs from the 

roofs and sides in soft dangling masses that resemble

2 Jenkins, O. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington Dept. Conservation and Development, Div. Geology, 

Bull. 31, p. 60, .1924.
ALTERATION OF THE SEDIMENTARY ROCKS 39

soiled and frayed rags. Paligorskite, "mountain 

leather," or "asbestos,". as it is known locally, is 

thought to have been formed by the reaction of dolomitic limestone, or in places calcite, with a solution 

bearing the elements needed to form the mineral. As 

pointed out in the section on mineralogy (p. 58), 

paligorskite is unstable near the surface. In the caves 

on the zero level of the Pend Oreille mine a few remnants of paligorskite in cracks are brittle and apparently are being slowly dissolved. The mineral is most 

abundant in the caves near the 500-foot level and is 

rare or absent in the deeper openings.

Under the layer of paligorskite is commonly a surface of crystalline quartz and sphalerite that grades 

into jasperoid and ore. That the paligorskite was deposited after the quartz and ore is indicated by their 

relative positions in the caves, by the fact that veinlets 

of paligorskite cut the jasperoid and ore, and by the 

motley arrangement of included fragments suspended 

in the paligorskite. (See pi. IS.) Fragments of ore 

are also abundant on and in the paligorskite, and the 

dirty-gray appearance of part of the mineral is 

caused by finely crystalline sphalerite. Some of the 

quartz is in small doubly terminated crystals, and 

some is in thin rounded and pitted sheets as if partly 

dissolved. A little anglesite (lead sulfate) was found 

on paligorskite from the 300-foot level.

Four possible modes of origin of the mineralized 

caves suggest themselves. (1) They are caves formed 

by downward-percolating waters above the water 

level; (2) they were formed by meteoric water circulating below ground-water level, as suggested by 

Davis 8 ; (3) they are related to a possible erosion surface at the top of the Metaline limestone and below 

the Ledbetter slate; and (4) they resulted from solution by hydrothermal fluids that deposited jasperoid 

and ore.

The caves were not formed in recent time by 

downward-percolating vadose water, because: (1) no 

indication of surficial infiltration or deposition of 

weatliered debris has been found except in the upper 

caves that are clearly connected with the surface; (2) 

paligorskite is unstable in the zone of downward percolation, and it is also unlikely that sphalerite and 

crystalline quartz would form under these conditions; 

(3) no evidence is available to show that the groundwater surface was ever appreciably lower than it is 

today, and considerable physiographic evidence indicates that it was probably higher near the end of 

Pleistocene time.

The second explanation, that the caves were formed 

by circulation below ground-water level, cannot be so 

summarily dismissed and has several points to com3 Davls, W. M., Origin of limestone caverns: Geol. Soc. America Bull., 

vol. 41, p. 480, 1930.

mend it. The principal criticism is that the formation 

of paligorskite in pure calcite would necessitate the 

transportation of magnesium, silica, and aluminum in 

cold meteoric waters. The crystalline lining in the cavities, however, is not a convincing argument either for or 

against a meteoric origin, as crystalline sphalerite is 

very common between jasperoid and calcite, and if 

the calcite were leached crystalline sphalerite would 

project into the cavities. The small sphalerite and 

quartz crystals that are abundant on much of the paligorskite would under this theory be supergene. The 

principal points in favor of this explanation are the 

location of the caves where circulation of water is probably vigorous and the decrease in size and number of 

the caves in depth. The writers favor this explanation.

The third possibility that the caves are related to 

an old erosion surface that separates the Cambrian and 

Ordovician strata is unlikely, mainly because of the 

lack of other evidence for the existence of such an unconformity. Also caves formed before the Ordovician 

period would be earlier than the ore and would necessitate an explanation for the ore breccia found on their 

floors. Deeper exploration should furnish additional 

data concerning this hypothesis. The decrease in size 

of the caves down the dip makes it more reasonable 

to relate the openings to some other feature than an 

unconformity at the contact between the two strata. 

It is also a possibility that Ordovician caves would 

have been filled with redistributed carbonate during 

regional disturbance.

The fourth suggestion that the caves result from 

dissolving action of the hydrothermal fluids that deposited the jasperoid and ore answers many of the 

queries raised so far but does not explain why the 

caves decrease in size and number in depth, whereas 

jasperoid and ore, similar to those above, continue 

downward. The mineralizing solutions were capable 

of dissolving carbonates, as indicated by the fact that 

calcite and dolomite were removed from large masses 

now occupied by jasperoid and ore. As explained in 

the section on brecciation (p. 53) the conspicuous 

shattering near the ore bodies may in part have been 

accentuated by the corrosive activity of the mineralizing solutions. Under this theory the paligorskite and 

the sphalerite and quartz on the paligorskite would be 

hypogene rather than supergene minerals.

ALTERATION OF THE SEDIMENTARY ROCKS

BEGIONAL METAMOBPHISM

The sedimentary and volcanic rocks of the region 

were already indurated, foliated, and recrystallized by 

regional metamorphism before intrusion of the Kaniksu 

batholith. As a result of the regional metamorphism 

sandstones were converted to quartzites, carbonate rocks 

were recrystallized, volcanics were converted to green-
40 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

stones, and argillaceous rocks were converted to slates, 

phyllites, and schists. The metamorphism in the older 

rocks is, in general, although not uniformly, of higher 

grade and is more nearly complete than in the younger 

rocks. The higher-grade rocks merge into those of 

lower grade without a recognized hiatus. This gradation may be explained as resulting from the greater 

depth of burial of the older rocks and the greater load 

on them at the time of deformation.

IGNEOUS METAMORPHISM 

GENERAL, FEATURES

The sedimentary rocks within a mile, or exceptionally 

more, of the border of the Kaniksu batholith are altered 

as a direct result of the intrusion. This alteration, in 

contrast to that in many igneous-metamorphic zones, 

has consisted of recrystallization and the formation of 

new minerals by rearrangement of the constituents already present. It is thought that little new material, 

except locally silica and ore minerals, has been added 

from the batholith, although large quantities of hot 

water and other mineralizers probably facilitated the 

transfer and rearrangement of the pre-intrusion minerals. The resulting metamorphic products are strikingly similar to those in the Pend Oreille district of 

Idaho described by Gillson.4 The igneous metamorphosed rocks are, however, a bit unusual in that the 

lack of iron-bearing minerals is particularly noticeable.

Igneous metamorphism was superimposed on the 

sedimentary and volcanic rocks after the main period 

of regional deformation. (See pi. 19, A.) For this 

reason bedding, foliation, and other structural features 

are obscured in the metamorphic zone. In some places, 

however, particularly in banded calcareous phyllites, 

the banding is preserved, although the mineral suite is 

changed. The retention of the banding indicates the 

extent to which the original composition of the rock 

influenced the result; probably no large-scale replacement by introduced magmatic products has occurred.

The quantity of material added to the older rock 

from the magma can be determined only by careful 

sampling, which was not done. The impression obtained is that silica was the principal material added, 

and in places large quantities may have been introduced. 

At the Coffin property sulfides pyrrhotite, galena, 

sphalerite, pyrite, and molybdenite and probably 

other minerals were added. A little molybdenite in 

the marble on the Dry Canyon road and a part of the 

small amount of almandite garnet in the sedimentary 

beds were probably introduced also.

For purposes of description the igneous metamor4 Gillson, J. L., Contact metamorphism of the rocks in the Pend 

Oreille district, northern Idaho : U. S. Geol. Survey Prof. Paper 158-F, 

pp. 111-121, 1930.

phism is here treated under two headings (1) simple 

recrystallization and (2) alteration to silicate minerals, 

including the formation of hornfels.

RECRYSTALLIZATION

The term "recrystallization" is used here to mean a 

change in the physical state of a rock, essentially without the introduction of additional materials. As thus 

defined recrystallization has been the most widely distributed type of metamorphism in the zone of igneous 

influence and extended far beyond the inner zone of 

intense alteration to silicate minerals.

The carbonate rocks and the quartzites show most 

clearly the effects of recrystallization. The results in 

the carbonate rocks are similar to those described by 

Nolan 5 a general increase in grain size accompanied 

by bleaching. The white marble thus formed is dense 

and massive; individual -grains are generally onesixteenth inch or less in diameter but in a few places 

exceed a quarter of an inch. Faulting and other structural features are difficult to recognize in the marbles, 

as they were generally obscured during recrystallization.

The recrystallization of the quartzites has in some 

places resulted in an increase of grain size; in other 

places the individual grains seem to have been broken 

up into many smaller particles. Strain shadows, so 

common in the normal quartzites, were destroyed during recrystallization.

ALTERATION TO SILICATE MINERALS

The type of silicate minerals formed during igneous 

metamorphism depends largely upon the original composition of the rocks affected. Limy beds are altered 

principally to diopside and tremolite and in minor 

degree to other minerals. The rocks that were originally composed mainly of clay minerals are altered to 

mica schists and hornfels, which grade into each other.

Diopside and tremolite in very few places make up 

the entire rock, but they are, generally scattered 

through white marble. Diopside commonly occurs in 

cores in the tremolite (see pi. 19, #, G] and seems to 

alter readily to tremolite; although in some of the rock 

tremolite is absent. A little pale-green actinolite in 

place of tremolite is found in the schistose rocks. The 

concentration of diopside and the amphiboles is such 

that they may well have resulted from rearrangement 

of the constituents of siliceous dolomite or from the 

addition of silica to dolomite. The formation of diopside and calcite from dolomite (dedolomitization) in 

a locality in western Massachusetts has been ably described by Eskola.6 Pale yellowish-green serpentine

G Nolan, T. B., The Gold Hill mining district, Utah: U. S. Geol. 

Survey Prof. Paper 177, p. 91, 1935.

6 Eskola, Pentti, On contact phenomena between gneiss and limestone 

in western Massachusetts : Jour. Geology, vol. 30, p. 287, 1922.
ALTERATION OF THE SEDIMENTARY ROCKS 41

is found in the marble in Dry Canyon, at the 0. K. 

property, and at the Coffin property. Many marbles, 

particularly the argillaceous ones, contain muscovite 

or phlogopite, or both. Where the carbonates decrease 

in quantity the micas increase, and the marble grades 

through calcareous schist to phyllite.

A calcareous schist is exposed on the ridge between 

Harvey Creek and Noisy Creek, where the rock has 

a felted silky appearance and has obscure layers of 

pale-brown, light-greenish, and white minerals. The 

darker layers contain muscovite and pale yellowishbrown phlogopite; the lighter layers are made up of 

culcite and tremolite. Small radiating clusters of 

thomsonite were noted in thin sections, and a few small 

grains of pale-yellowish tourmaline and rutile were 

identified. A few grains of quartz are also present.

Many of the fine-grained rocks, including some that 

are calcareous, form dense compact porcelaneous hornfels near the intrusive mass. Crystalline schists are 

arranged around the intrusive borders and in general 

are coarser-grained nearer the intrusive. In places the 

schists are converted to hornfels near the contact but 

elsewhere the}r lie immediately next to the igneous 

rocks.

The hornfels is banded or vaguely mottled, domin an try in shades of gray, green, and brown. A somewhat unusual type is found south of Sand Creek in 

the Ledbetter slate, where the rock appears to be 

simply indurated; no crystallization was noted, and 

the black color is retained. In many places in the 

hornfels no minerals can be distinguished without 

microscopic aid. Quartz, feldspars, either orthoclase 

or albite, and micas are the dominant minerals, but a 

wide variety is recognized. The micas are commonly 

muscovite or phlogopite, but biotite is present in the 

darker layers. Fine needles of tremolite, actinolite, or 

dark-green hornblende are widely' distributed, and 

epidote is locally abundant in the greenish rocks. 

Clinozoisite and allanite accompany the epidote, generally in small amounts, and zoisite was noted in one 

-~7/ thin, section. 

\S §lLlimanite_ is a widely distributed constituent of 

the hornfels ancM.iij)lacesjnakes_upjnuch of J^f ror-kThe best development o± the mineral seen is near the 

Little Muddy Creek road west of_ lone. Here the sillimTTnite needles Tialilbe^iaTfily^recogmzed and form as 

much as 50 percent or more of the rock. Plate 20, .5, 

is a photomicrograph of rock from this locality, in 

which the needles are haphazardly oriented. In addition to sillimanite the rock contains mainly quartz, 

greenish tourmaline, reddish-brown biotite, and colorless chlorite. In most places sillimanite forms a fine 

feltlike mass that can be recognized only under the 

microscope.

Andalusite is another common mineral in the hornfels. It is present customarily in microscopic grains, 

but on Hall Mountain it occurs as needles as much as 

three-quarters of an inch long (see pi. 20, C) and in 

the Maitlen phyllite near Cedar Creek northwest of 

lone it forms even larger crystals. Much of the andalusite is altered, and its character is obscured by a 

inat of sericite. The crystals from Hall Mountain 

were obtained on the ridge trail just east of the intrusive mass; they are" comparatively fresh and easy 

to study.

Cordierite was recognized by Charles Milton, of the 

United States Geological Survey, while examining 

a specimen of knotty hornfels (see pi. 20, Z>) from the 

peak at the head of Wolf Creek. Pale-yellow pleochroic halos are found around some of the many inclusions in the mineral. The cordierite forms nodules 

about one-eighth of an inch across. It is difficult to 

recognize in thin sections and has not been identified 

with certainty elsewhere in the region. In several 

places, however, its presence has been suspected, and 

with more careful study it niay be recognized. It is 

associated with andalusite in hornfels from the line 

between sees. 4 and 9, T. 35 N., R. 43 E. The Wolf 

Creek material (pi. 20, D) illustrates particular^ well 

the porphyroblastic character of the biotite.

In addition to the minerals mentioned, greenish to 

black tourmaline, chlorite, zeolite (commonly thomsoiiite), iron oxides, zircon, apatite, rutile, and sulfides, 

particularly pyrrhotite, are widely distributed in different proportions. At the Coffin property jefferisite, 

a little chondrodite, serpentine asbestos (chrysotile), 

and an unusual pink manganiferous diopside were 

found associated with sulfides in metamorphosed carbonate rock.

Away from the intrusive border the hornfels generally become coarser-grained and grade into mica schists. 

Feldspars and the micas, phlogopite and biotite, decrease in quantity, and quartz and muscovite become 

dominant, but small amounts of other minerals are 

also present. The muscovite flakes rarely exceed a 

quarter of an inch across and are generally arranged 

haphazardly. Chloritoid (see pi. 20, A) occurs in the 

Maitlen phyllite as much as 4 miles from the known 

intrusive border but probably resulted from intrusion 

activity. The flakes of chloritoid are flat and transverse to the dominant foliation.

HYDROTHERMAL ALTERATION NOT DIRECTLY 

RELATED TO IGNEOUS MASSES

DOLOMITIZATION

Some carbonate rocks of the Metaline quadrangle 

are nearly pure limestone, others are nearly pure dolomite, and many are intermediate and are called dolomitic limestones. Two types of deposits are considered bedded deposits and crystalline dolomite not
42 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

bedded. In places the two types cannot be separated, 

but in general they are sufficiently distinct to permit a 

rough classification. The detailed study of magnesium in carbonate rocks has been limited to the Pend 

Oreille Valley and especially to the beds 600 feet and 

less below the Ledbetter slate. Unless stated otherwise the following discussion applies only to beds ill 

the Metaline limestone.

_

BEDDED DEPOSITS

The magnesium content of certain beds for example. 

in the upper Lehigh quarry is nearly constant for at 

least 1,000 feet along the strike, and layers of different 

magnesium content are separated by bedding planes. 

The contacts between rocks of different magnesium 

content, although sharp, do not everywhere conform to 

bedding surfaces and in places crosscut the bedding 

at high angles. Such a relation is indicated in the 

middle Lehigh quarry, where a wedge of limestone 

was mined. This wedge was surrounded by dolomitic 

limestone, and so far as could be determined, no faulting was involved. In many places dolomites appear' 

to grade into dolomitic limestone, and the contacts are 

not sharp surfaces.

The origin of the dolomite in the rocks immediately 

below the Ledbetter is difficult to study because individual layers are hard to recognize and trace. The 

problem is further complicated by the fact that the 

limestone just below the slate was peculiarly favorable 

for the circulation of ascending solutions and for ore 

deposition. To offset these difficulties is the fact that 

many thousands of feet of diamond-drill cores are 

available for study, and many of the mine workings 

penetrate the strata. The data obtained at the [Pend 

Oreille mine establish no relation between the slatecarbonate rock .contact and the magnesium content. 

Layers of dolomite cannot be correlated and appear to 

crosscut the bedding, generally at low angles. At Z 

Canyon and in the Slate Creek district the rock below 

the slate is a dense fine-grained dolomite that contains 

almost no calcite. Core drilling at the Bella May, 

Grandview, Lead King, and several other properties 

furnishes additional data as to the irregular distribution of magnesium in the carbonate rocks immediately 

below the slate. The irregular distribution of the 

magnesium is clearly shown in plates 21 and 22. These 

graphs were compiled from the analytical data given 

in the table on pages 43-44.

The meager data obtained on the magnesium content 

of carbonate rocks in the Metaline limestone other than 

the beds directly below the Ledbetter slate support the 

impression that the magnesium carbonate is irregularly 

Distributed and is not confined to certain beds. These 

data are entirely observational and are not supported 

by analyses. The beds near the base of the Metaline

limestone east of the upper Lehigh quarry are a series 

of limestones, shales, and dolomitic limestones. A 

similar sequence is exposed on Threemile Creek, but 

near lone and near the Canadian border on Boundary 

Mountain what is though to be the same stratigraphic 

sequence apparently contains more dolomitic layers. 

 Many of the dolomites and dolomitic limestones are 

so fine-grained that crystal cleavages cannot be seen 

without a microscope. Other beds are recrystallized 

and cleavage surfaces an eighth to a quarter of an inch 

across are common. The colors range from light 

creamy gray to dark gray and black. During the recrystallization organic coloring matter was largely 

expelled but in a few places it accumulated as small 

buttons that have the composition of anthracite. 7 

(See pi. 23, A.) Alternating black and white dolomite beds and patches of rock of one color in the other 

are described on page 18 and illustrated in plate 9, A. 

Samples of these black and white rocks were taken 

about 1 foot apart in the same layer. Analyses of the 

samples are given in the table below. The two rocks 

are nearly identical in composition, but the dark one 

contains a small amount of organic material. Practically all dolomites contain small crystal-lined vugs, 

generally less than a quarter of an inch in longest 

dimension, although exceptionally they are larger.

Analyses of dolomite from north side of Crescent Lake, sec. 12, 

T. 40 N., R. U E.

[Analyst, R. C. Wells]

SiOa and insoluble______

(Al, Fe) 2 03 __--_..-_-_-

CaO____._-. ----------

C02 (calculated) _______

CaCO3 ___._. -_--___---

MgO___ _-___-__---.

MgCOa . -----------

Dark

______ A little

______ 0. 16

__-_-_ .22

30.45 ____..

23.89 ---._-

____-- 54.34

21.68 ______

23.66 ______

______ 45.34

100. 06

Llg

30.35

23. 81

21. 69

23.67

*t

0. 24

.29

54. 16

45. 36

100. 05

The black and white bands in many places form 

narrow alternating layers (generally less than 0.5 inch 

wide and commonly 0.2 inch or less) that are appropriately termed by the miners "zebra" rock.8 (See pi. 

23, E.} This term, although commonly used for 

striped carbonate rocks, has also been used for other 

banded types.9 In the carbonate rock both the black 

and the white layers are dolomite; they differ only in

7 Hendricks, T. A., Recently adopted standards of classification of 

coals by rank and grade: Econ. Gteology, vol. 33, pp. 136-142, 1938. 

Fixed carbon determined by Taisia Stadnichenko.

8 Crawford, R. D., and Gibson, Russell, Geology and ore deposits of 

the Red Cliff district, Colo.: Colorado Geol. Survey Bull. 30, p. 36, 1925.

9 Hobson, R. A., "Zebra rock" from the east Kimberly: Royal Soc. 

Western Australia Jour., vol. 16, pp. 57-70, 1930.
GEOLOGICAL STRVKY PROFESSIONAL TAPER 202 1'LATK

I. TKRRACKK M.ONC, I'KM) OIU'.II.I.K lilVF.H.

Vir« norlli from a I.OIMI ahciul 1 mile BI>III|I ..T lone. The mail i» on Ihc 2.100 fool lend, iinil lire 2,500- lu 2,oOO-f<x>l level in in llic

c-cnlrjil harkjrnmnd.

«. STKKAM TERRACES ON UPPER RUBY CREEK.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE 16

A. AMI'HITHKATEKS ON K.AST SIDE OF GYI'SY II1DGE. 

View from Salmo Mountain,

B. GLACIAL ULOCKADE AT NORTH END OF SULLIVAN LAKE. 

View from slope of Sullivan Mountain.
OEOLOGICAL SURVICY PROFESSIONAL PAPER 202 PLATE 17

A. PAUGOKSMTE IN CAVE, 500-FOOT LEV EL. I'KM) OKEILLE MINE. 

Height of cave about 4 feet. Note slic.kensiilecl wall on right.

II. I'ALIGOKSKITK FROM 500-FOOT I.KVKL, 1'ENU OHEIl.l.E MIM').
GEOLOGICAL SURVEY PROFESSIONAL TAPER 202 PLATE 18

FRAGMENTS OF CALCITE. .1ASPEKOII). OHE. AND CRYSTALLINE QUARTZ TAKEN FKOM INSIDE A I'lECE OF PALICOKSK1TE FROM MO-FOO

LEVEL, FEND OREILLE MINE. 

. '-'; Calcite, 6, 9, 10, 23. Jasperoid, 12, 13, 24-26. Ore, 4, 8, 22. Crystalline quartz, 1-3, 5, 7, 11, 14-21. Natural size.
GEOLOGICAL, SURVEY PROFESSIONAL PAPER 202 PLATE IB

A. ITOTiNFELS DEVELOPED IN PREVIOUSLY K)LL)KJJ i'llYLLITE. 

Half a mile went of Stapgcr Inn Camp. Altitude, 4,400 feet.

;;,( :. PIIOTOMICKO(;KAPII.S OF U.TK.HKD CARIIONATK KOCK.

Cores of in-moliK- hulls nr<- whin: diopsklo. C same as II: crossed nicols.
GEOLOGICAL SURVEY PROFESSIONAL 1'APKR 202 PLATE 20

V

A. CIII,()Uri'OII) SCHIST FACIKS OK A1 Al'I'LKN I'll V I,LITE.

Ahonl 150 feel aboye Gypsy <piart/.ile. on hill between Sw<;el Cr^ek and Ihc South 

Fork of Kliiiii,. Cri-.-k.

/(. IMIO'I'OMICROGRAPH OF SILLIMANI'l'E SC1IISI'.

l.illli- Mmlily Crefk niail weal of Tom-. ni:ininiiil-Hli:i|iril <T>«lal« .-inil lihi-rs 

;irr sillinuinilc.

C. I'llO'l'OMICIiOCHAI'll OF ANDALISITK GRAINS IN MICA

SCHIST, 

llnll M,,n,il:m, riilpi-, iuirlli<-»«l rornrr of sec. IS, 'I'. ;!!! N., li. 11 E.

II. !'MOI()iVllc;l(0(;iiAI'll OF MEI AMOIil'IIOSI-:]) IMIYLLITE.

From peak at head of Wolf Creek. Black liiolili: [mrphyrolilaxts developed 

after the foliation. The lar^'<^ ^'raiii in the upper ri^lil-hand corner is 

<:ordierile.
GEOLOGICAL SCBVEY

PERCENT 

2 !CO

I 5C

0 0-

PROFESSIONAL PAPER 253 PLATE 21

j C|

; fek /

i i^^ /

 v ' ; -

I

:

\i / I

i

V/ S ' 

» ' Perd OreiKe No.235 vertical

: !

i

! I

2 100

I 50 Bella May No.40 vertical

0, 0

2 100

I 50

0 0

2 100

I 50

0 0

 ~ Bella May No.42vertica

EXPLANATION

 FeC03

 CaC03

 MgC03

 MnCOj

 Insoluble

r \

Pend Oreille No 23-4

50 100 150 200 250 300 350 400 450 500 550

DEPTH, IN FEET 

GRAPHS OF ANALYSES OF DIAMOND-DRILL CORES. 

Minerals computed as carbonates and insoluble. COa calculated in all analyses.

600. 650 700 750 800 850 900 950 1000
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE

100'

50*

L P E

o o X

520

 Coarse calcite

PeidOreille Jo.235vertical

IOO

50

0

1

L

*»

Ledbe

 

\ 

\

\

\ X~~-J /o /

^^*<y*

/ \ 

'\ 1

x

\ 'X

X '\

 --

. A

\/

\l

\

l\

Be la May N6.40 vertic

1

al

0

L

O 

XI o

^^-

^^ "-^ ^

__ 

^^

-^"CL __

\

N^ /

/\

/

/

,

'

___-_J^

^

\ 

\

\

,

/

.'

\

\

\

\

X

\

\

/

/

'

/

/

\

X

\

X

 . =-:

___-. -- 1 ,

Lead Kir £ No. 15 in

- _ ,_

:lined

__ -

100

Bella May No.42vertica

EXPLANATION

 CaC03 

X MgC03

 - DoJomite

 Insoluble

50 100 150 200 250 300 350 400 450 500 550 600 650 700 75O 800 850 900 950 IOOO

GRAPHS OF ANALYSES OF DIAMOND-DRILL CORES. 

Minerals computed as dolomite, calcite, and insoluble. COj calculated in all analyses.
ALTERATION OF THE SEDIMENTARY ROCKS 43

the. presence of a little organic matter in the black 

layers and the fact that the light layers are slightly 

coarse-grained and somewhat vuggy. The suggestion 

is here offered that the "zebra" banding in the dolomite 

was caused by a partial or complete recrystallization 

of gray or black dolomite along closely spaced surfaces, 

the trends of which were determined by shear planes 

and possibly bedding or other planar structures. Figure 8 is a sketch of the wall of the new Bella May adit 

400 feet from the portal. It was one of the most 

clear-cut examples seen of "zebra" banding related to 

shear planes.

The graphs in plate 21 show a close agreement in 

distribution of magnesium, iron, and manganese, alE. W.

Massive 

dolom'ite

Massive 

dolomite

0 5 Inches

KifjuiiK 8. Sketch of "zebra." banding 400 feet from portal of the new 

Holla May adit. Banding is limited by shear planes, and its character 

suggests that It is related to torskmal movement. Vertical plane.

though the last two elements commonly total less than 

2 percent of the rock. This agreement is too widespread to be fortuitous and seems to indicate rather 

uniform conditions during the formation of dolomite. 

The addition of iron and manganese to limestone during dolomitization was pointed out by Hewett.10

In the following table analyses of 79 samples of 

dolomitic limestone are given. No distinction was 

made in the analyses or graphs (pis. 21 and 22) between the two types of dolomite, bedded or nonbedded. 

In. general nonbedded dolomites are more abundant 

near mineralized bodies and rocks of high silica 

content.

10 Hewett, D. P., Dolomitization and ore deposition : Econ. Geoloery, 

vol. 23. pp. 849-50, 1928. 

44SO:l>0 43 4

Analyses of dolomite and dolomitic limestone from Metaline 

quadrangle

Pend Oreille mine, between sees. 15 and 16, south half T. 39 N., R. 43 E. Hole

235.

[Analyst, R. E. Stcvcns]

Depth (feet)

55 ».._.____

75 _-_._-_

100 _--.-._

125_. .._....

146.5---....

175 __-__

200. _._.___

225 ----_.

249 -_..__

275. _____

300-.__-_...

325 --.__.

350 __.__

375 ------

400 ___'___

497 ----..

535 ------

550... _._-__

589 -_-._.

Acid 

insoluble 

(110" O.)

59. 19

32. 81

5. 22

.99

58. 65

3.82

70.45

80. 95

. 70

. 10

1. 36

. 17

5. 76

1. 80

.02

. 35

. 14

1. 59

. 10

PeCOs

0. 79

. 21

. 56

.44

. 58

1. 05

.68

.69

. 10

.08

.08

. 08

.07

. 14

. 11

. 16

. 10

. 36

.06

CaCOa

23. 09

67. 15

53. 02

56. 18

22. 87

53. 50

11. 09

3. 81

98. 65

99. 42

95. 65

99. 20

93. 50

97. 60

99. 20

99.00

96. 39

58. 75

99. 70

MgCOa

16. 89

41. 44

42. 68

17. 82

41. 81

8. 11

2. 31

. 32

. 23

2. 80

. 40

. 30

.48

. 39

. 64

3. 51

39. 00

.25

MnC03

0. 02

.06

.05

. 03

. 12

.02

. 01

. 01

.02

.02

. 03

. 06

. 07

Trace

Total

99. 98

100. 17

100. 30

100. 34

99. 95

100. 30

90. 33

87. 76

99. 77

99. 83

QQ 91

99.86

99. 64

100. 04

99. 74

100. 18

100. 20

99. 77

100. 11

Lcdbetter slate.

Bella May mine, SWVi, sec. 29, T. 39 N., R. 43 E. Hole 42.

[Analyst, J. O. Fairchild]

Depth (feet)

513----.--..

525__ --..

550 _-.-_-

581 ------

600 -___-

631-- _.--

646-- -...

662.----...

Acid 

insoluble 

(100° C.)

27. 00

. 10

. 10

49. 81

62. 38

10.46

. 10

. 97

FcCOa

0. 16

None

.58

. 71

. 71

. 53

. 69

CaCOa

71. 00

99. 90

99. 80

28. 40

21. 22

50. 70

56. 35

54. 90

MgCOa

2. 03

. 20

. 20

21. 36

16. 03

38.40

42. 65

43. 70

MnCOs

NoneNone

.02

. 05

.05

.08

Total

100. 19

100. 20

100. 10

100. 15

100. 36

100. 32

99. 68

100. 34

Pend Oreille mihe, line between sees. 15 and 16, south half, T. 39 N., R. 43 E. 

Hole 234.

[Analyst, E. Theodore Erickson]

Depth (feet)

25 ......

50 -------

75 -_.__-_

101 -_-_-

125 ------

150 ------

175 _____

198 ,----.

225 -----

250 .-____

275--.----..

300. ..-.-

325 -.--__

338 _____

359 ---._-

410 .. .-__

440---.-....

480 ------

500--.......

525... _.._..

550 _____

588 ------

615 ------

645 _____

685 ___-

710 ____

Acid 

insoluble 

(110° C.)

50. 52

1. 62

1. 24

.29

.08

.65

4. 46

. 14

. 22

16. 69

. 12

. 21

26. 22

.06

73. 96

. 27

12. 02

. 11

3. 95

1. 20

12. 44

. 51

40. 51

2. 58

2. 67

. 18

FeCOa

0. 64

.81

.84

.84

. 27

. 16

. 16

. 13

. 16

. 19

. 19

.08

. 27

. 11

. 51

. 16'

.89

. 16

. 21

. 21

. 19

. 16

. 58

1. 21

. 35

. 47

CaCOs

25. 20

55. 79

59. 87

56. 16

98. 02

95. 31

88. 02

98. 56

98. 96

81. 77

99.47

99. 27

69. 12

99. 51

11. 78

99.09

55. 84

98. 94

92. 82

98. 14

86. 71

98. 56

42. 76

54. 86

71. 83

56. 08

MgCOa

23. 53

41. 80

37. 76

42. 26

6Q

2. 11

7. 54

1. 46

. 83

. 77

.43

. 45

1. 99

.49

9. 22

. 22

28. 42

. 68

3. 18

. 39

. 35

. 33

11. 84

40. 99

24. 51

41. 95

MnCOs

0.02

. 05

. 03

.05

Trace

.02

Trace

.02

. 02

Trace

Trace

Trace

.02

. 02

None

Trace

Trace

.05

.02

.02

Trace

Total

99. 91

100. 07

QQ 74

99. 60

99. 06

98. 23

100. 20

100. 29

100. 19

99. 44

100. 21

100. 01

97. 60

100. 17

95. 49

99.74

97. 19

99. 89

100. 16

qq 94

99. 69

99. 56

95. 74

99. 66

99. 38

98. 68
44 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

Analyses of dolomite and dolomitic Utnestone from MetaUne 

quadrangle Continued

Bella May mine, SWV4 sec. 29, T. 39 N., R. 43 E. Hole 40

'[Analyst, J. O .Fairchild]

Depth (feet)

168 ------

202 ......

239 _-._--

276... --_-_-

299 ._----

325 ------

336.. .._.._.

351 ------

375_. _...._.

400 ------

425.. .__._..

450-------.-

472 __--__

Acid 

insoluble 

(110° C.)

2. 27

AQ

56.36

46.42

76. 21

47. 35

33. 83

6. 15

4. 69

5.04

2. 54

1. 04

. 72

FcCOs

0 61

1 08

28

71

37

49

1 43

38

38

39

27

10

CaCOs

56. 72

56. 58

42. 05

30. 06

13. 33

31. 98

36. 97

53. 35

54. 90

54. 90

95. 62

98. 18

99. 22

MgCO3

40. 82

42. 20

1.39

23. 52

10.43

20. 55

28. 31

40. 62

40. 12

39. 85

1. 70

. 82

. 25

MnCOs

0 08

19

01

None

01

02

16

03

04

03

02

Total

100. 50

100: 74

100. 09

100. 71

100. 35

100. 39

100. 70

100. 53

100. 13

100. 21

100. 15

100. 14

100. 19

Lead King mine, SEVi sec, 27, T. 40 N., R. 43 E. Hole 15, inclined 60° E.

[Analyst, Jos. J. Fahey]

'Depth (feet)

100 i. ......

200 -_----

300 ------

400 ------

500-------.

600__.._-_--

692 ______

800.---..-..

900 --_-_-

1,000. ------

Acid 

insoluble 

(110° C.)

62 15

82 94

10

06

17

8 76

5 83

78

01

36

FeCOs

1. 97

. 23

None

None

None

None

None

None

. 11

CaCOs

20. 99

15. 15

99. 35

96. 98

57. 82

90. 04

89. 54

98. 25

99. 57

97. 50

MgCOs

14 69

21

86

2 11

41 40

65

4 28

04

' None

1. 91

MnCOa

0.02

None

None

. 04

None

None

None

.02

Total

99. 82

98. 53

100. 31

99. 15

99.43

99.45

99. 65

99. 07

99. 58

99. 90

Led better slate.

CRYSTALLINE DOLOMITE NOT BEDDED

The crystalline dolomite is found near and in ore 

deposits and along faults and in breccia zones. It is 

particularly abundant in the beds just below the Ledbetter slate. It is independent of bedding and in places 

obliterates bedding arid other sedimentary and structural features. The contacts between this dolomite 

and other rocks are generally sharp, but in some places 

the crystalline dolomite appears to grade into and cannot be separated from bedded dolomites. It is small 

in amount compared to the bedded deposits.

The crystalline dolomite is so coarse that grain 

boundaries can generally be recognized. The individual grains average about 0.1 to 0.2 inch across, although 

exceptional ones are coarser or finer. The color ranges 

in tints of cream and gray but is rarely uniform. Irregular spots and bands, probably caused by slight differences in organic content, are commonly seen and 

appear, at least in places, to be due to the preservation 

of corroded and partly recrystallized remnants of 

bedded dolomite.

An unusual type of concentrically banded dolomite, 

silica, calcite, and sulphides is shown in plate 26. This 

concentric arrangement is discussed under .the heading 

"Ore deposits" (p. 50). In a somewhat similar category is the crustified dolomite shown in plate 23, D. 

The composition of the crystalline dolomite agrees 

approximately with that of pure domolite. Small 

amounts of iron and manganese, similar to those in 

the bedded deposits, can be detected, although systematic anaylsis of this dolomite was not attempted.

SIL.ICIFICATION

In the Metaline quadrangle jasperoid or silicified 

limestone is widespread. It is particularly abundant 

at Lead Hill and in the Pend Oreille mine but is noticeable near or in most mineralized bodies. To date it 

seems to be true that the zinc ores of the Metaline area 

are most abundant and richest in the silicified carbonate 

rocks. Jasperoid is a common associate of zinc ores 

in many mining districts, but the sphalerite is more 

abundant in the carbonate rock than in the jasperoid.11

The jasperoid is a fine-grained, dense gray or black 

material that generally preserves the texture and structure of the replaced rock. Plate 23, 5, illustrates a 

polished slab of silicified and mineralized breccia from 

the Pend Oreille mine in which the pre-jasperoid structure is clearly seen.

Irving 12 recognized two types of silicification of carbonate rocks connected with the formation of ore 

deposits. In one there is a gradual increase in silica 

content from the carbonate rock to the jasperoid, and 

in. the other the silification advanced in waves and the 

contacts are sharp. Silification in the Metaline district 

is of the first type; the limits are vague and silica extends through the carbonates in minute veinlets. (See 

pi. 24, B.) A few doubly terminated quartz crystals 

are isolated in the carbonates and in the sulphides. 

Small vugs that contain quartz crystals which seem to 

merge Avith the jasperoid are common and are particularly well exposed in the Pend Oreille mine.

The close association of the jasperoid and ore are 

interpreted to mean that the two products originated 

from the same solutions, which were probably hydrothermal. The presence of a few quartz crystals on 

sphalerite and veinlets of silica crosscutting ore show 

that some silica followed ore deposition. Most sulfides 

are, however, probably post jasperoid, but it is likely7 

that a little silica was deposited at the same time as the 

ore and some after the ore.

A small part of the jasperoid consists of aggregates 

of spheroids and resembles material from Tintic and

11 Bmmons, S. F., Irving, J. D., and Loughlin, G. F., Geology and ore 

deposits of the Leadville mining district, Colo.: U. S. Geol. Survey Prof'. 

Paper 148, pp. 217-219, 1927.

Gilluly, James, Geology and ore deposits of the Stockton and Fail-field 

quadrangles, Utah : U. S. Geol. Survey Prof. Paper 173, pp. 97-101, 1932.

Loughlin, G. F., and Behre, C. H., Jr., Classification of ore deposits : 

Ore deposits of the Western States (Lindgren volume), pp. 39-40, Am. 

Inst. Min. Met. Bng., 1933.

McKnight, E. T., Zinc and lead deposits of northern Arkansas : TJ. S. 

Geol. Survey Bull. 853, pp. 111-112, 133-136, 1935.

12 Irving, J. D., Some features of replacement ore bodies and the 

criteria by means of which they may be recognized : Canadian Min. Inst. 

Jour., vol. 14, p. 422, 1911; Bcon. Geology, vol. 6, pp. 556, 558, 1011.
ALTERATION OF TE^E SEDIMENTARY ROCKS 45

Mercur that lias been interpreted by Lindgren 13 and 

Gilluly w to indicate an introduction of silica in the 

colloidal state. It is difficult to understand why colloidal or other solutions should form spheroids while 

replacing a massive carbonate rock in a breccia and 

yet preserve the outline of the replaced fragments, unless spheroids were present in the original rock. 

Spheroids of this type were seen only in the jasperoid.

Spheroids, where of known colloidal origin, are 

usually thought of as forming in a gel. One of the 

criticisms of the theory of formation of silica as a gel 

that is voiced by many geologists is the absence of 

dehydration or shrinkage cracks in the resulting quartz. 

The criticism, may be voided if the Wiegner effect is 

active. This effect is denned by Liesegang 15 as 

follows: "When a polydispersoid sol coagulates, submicrons will act as coagulation nuclei for amicrons. 

Flowing water can then bring highly dispersed minerals into contact with larger mineral particles and 

form shell-like layers." This means that when a 

colloidal solution which contains several sizes of suspended particles coagulates, the larger particles 

(submicrons) act as coagulation nuclei, for small 

particles (amicrons). So far as known, this effect is 

active in small spaces and does not require more than 

very thin layers of gel at any one time. It may help 

to explain the origin of such spheroids as those found 

in the jasperoid.

In the new Bella May adit and at Lead Hill lightgray .fine-grained silica has been extensively introduced 

into the dolornitic limestone. This silica resembles 

the darker jasperoid except in color, and the relations 

between the two types of silica are unknown. The two 

may grade into each other, or the light-gray silica 

may possibly have been deposited by water descending 

from the surface.

COARSE-GRAINED CAL.CITE

Translucent Avhite or light-gray calcite, with cleavage surfaces 6 inches or more accross, is commonly 

found near and in ore deposits, along faults, and in 

irregular areas away from known ore or faults. Good 

exposures of the calcite can be seen in the cliffs where 

the road to the Pend Oreille mine crosses the Flume 

Creek gorge.

Analyses of the calcite show it to be practically pure 

calcium carbonate. Both preore and postore calcite are 

recognized, but physically and chemically they seem to 

be alike, and no criteria for separating them have been 

recognized. Plate 23, 0, represents a, polished frag13 Limlgren, \Valdcinar, and Loughlin, G. F., Geology and ore deposits 

of the Tintic mining district, Utah : U. S. Geol. Survey Prof. Paper 107, 

l>p. 1.54-158, 1.919.

u Gilluly, J'aines, Geology and ore deposits of the Stockton and Fairfield quadrangle, Utah : U. S. Geol. Survey Prof. Paper 178, pp. 97-101, 

:I032.

10 Liesegang, R. B., Colloid chemistry and geology : Colloid Chemistry, 

vol. 3, edlted*hy Jerome Alexander, p. 253, 1931.

ment of ore from the Pend Oreille mine in which galena 

replaces calcite along cleavage cracks. This seems 

to be the most common relation in the Pend Oreille 

mine, but in other places, as shown in plate 26, calcite 

cuts across the sulfides. This inconsistency may be 

interpreted to indicate two ages .of calcite, two ages of 

sulfides, or one period of overlapping deposition.

FORMATION OF THE ALTERATION PRODUCTS

The erratic distribution of magnesium in the bedded 

deposits indicates the formation of dolomite in limestone beds by the action of underground solutions and 

makes improbable an origin from sea water. Unfortunately the stability relations among the carbonates 

are practically unknown, and conclusions regarding the 

proportions of the elements that are stable under certain conditions are conjectural. If the so-called bedded 

dolomites were formed by underground solutions, the 

alteration should be more complete near paths of easy 

circulation, which means, in general, that a relation 

exists between dolomitization and structure. The 

controlling structures were probably none too conspicuous at any time and probably have been greatly 

obscured by postdolomitization deformation. It cannot be said that dolomitization and brecciation everywhere have occurred together. Some of the mineralized breccias in the Pend Oreille mine contain limestone fragments. On the other hand, the 

gently tilted but. otherwise little-deformed beds south 

and east of Z Canyon are almost uniformly dolomites 

and dolomitic limestones.

No relation has been established between dolomitizing solutions and the Kaniksu batholith. That the 

magnesium was introduced before the intrusion is suggested by the common declolomitization in the zone of 

igneous metamorphism. This dedolomitization is, 

however, limited to formations in which dolomitization 

has been little studied, and it is questionable how far 

to apply the above-stated conclusion to the Metaline 

limestone.

Bedded dolomites and dolomitic limestones have been 

faulted and brecciated in many places. Some of the 

breccias are uncemented, and others are cemented by 

silica and calcite. Dolomite beds are dragged along 

faults, and fragments of dolomite and limestone are 

mixed in the gouge. Regional dolomitization was probably accomplished before the introduction of the orebearing solutions, and it may have taken place early 

in the structural history.

Hewett,16 in a discussion of the origin of dolomite, 

points out that magnesium is freed during tlie silification of dolomite. This magnesium could accomplish 

alteration to dolomite of any limestone through which 

the solution later passed.

10 Hewett, D. F., Dolomitization and ore deposition : Bcon. Geology, 

vol. 23, p. 859, 1928.
46 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

According to Knopf ,17 coarse white calcite at Pioche, 

Nev., is found around the peripheries of many replacement deposits in limestone. This calcite has cleavage 

surfaces 6 to 8 inches long and from Knopf's description is similar to the calcite at Metaline. He considers 

the calcite to have resulted from the recrystallization 

of fine-grained limestone and suggests that "the spent 

or depleted ore-forming solutions, though no longer 

able to replace the limestone that surrounds the ore 

body by ore, were able to recrystallize it." He also 

offers the alternative explanation that the calcite was 

"the most advanced member of the vanguard in front 

of the growing ore body."

A combination of the theories offered by Hewett and 

Knopf is thought to explain the origin of the nonbedded 

dolomite and the coarse calcite in the Metaline 

quadrangle.

Crystalline nonbedded dolomite is commonly found 

near irregular-shaped bodies of coarse-grained calcite. 

At Lead Hill and the Grandview mine the intimate 

association of these minerals is well shown. The 

agreement in distribution is not fortuitous but is consistent. Plate 24, A, shows the detailed relation between crystalline dolomite and calcite that appear to 

have formed from bedded dolomitic limestone.

Jasperoid is another common constituent that has 

been introduced into the bedded dolomite near crystalline nonbedded dolomite. All stages of the change are 

seen, from bedded dolomite with small fractures filled 

with silica (see pi. 24, B) to the complete replacement 

of carbonate. In plate 25, A, crystalline dolomite is 

crustified and appears to be formed in cracks through 

jnsperoid, an analysis of which is given below.

Analysis of cherty dolomitic limestone from Gnmdvieio adit. 

Metaline Falls, Wash.

[Analyst, R. C. Wells]

Insoluble. . _-

R2O3

CaCO3 ..--._

MgC03 --__._

87. 92-

0. 47

6. 81

4. 83

Si02 ---. 86. 96

"R f} ft 1

CaO__-_ . 05 

MgO_.__ . 04

87. 66

100. 03

The centers of many of the dolomite areas are calcite 

and the crustified dolomite is not connected by cleancut fractures but by hazy ill-defined zones. In some 

specimens crystalline dolomite surrounds fragments

17 Westgate, L. G., and Knopf, Adolph, Geology and ore deposits of 

the Pioche district, Nev. : U. S. Geol. Survey Prof. Paper 171, pp. 49-30, 

52, 1932.

of jasperoid and in other places seems to be replaced 

by jasperoid.

The paragenesis of the jasperoid, ore, calcite, and 

nonbedded dolomite is complicated, and an explanation of the origin of one must consider the origin of 

the others. The large bodies of jasperoid and ore are 

thought to have been deposited by hot solutions from 

below. Large quantities of magnesium and calcium 

carbonates were liberated during the replacement of 

dolomitic limestones and bedded dolomites by the jasperiod and ore. In general, in the solutions obtained 

by dissolving dolomitic limestones, calcium carbonate 

was in excess of that required to form dolomite with 

the available magnesium. The liberated carbonates 

were moved along solution channels away from the 

sphere of silicification and were redeposited nearby 

in more favorable places. Where 'dolomite was deposited in limestone or dolomitic limestone more calcite was added to the solution and was redeposited 

elsewhere. The result has been crosscutting dolomite 

and coarse-grained calcite irregularly distributed 

around jasperoid and ore bodies. The quantity and 

distribution of the nonbedded dolomite and the coarse 

calcite seem to be adequately accounted for by the 

process outlined, which also explains the complicated 

paragenesis of the silica, sulfides, dolomite, and calcite. 

That some recrystallization with a minimum of transportation has taken place is indicated by the local gradation of the crosscutting crystalline dolomite into linosrained bedded dolomite.

In recent years many mining districts have been described in which dolomite, at least in part, is ascribed 

to the addition of magnesium from magmatic sources 

to limestone beds.18 The subject is of considerable interest, as it may, in certain districts, act as a guide in 

hunting ore. At Aspen, Colo., Spurr 19 thought that 

dolomitization and sulfide mineralization were intimately related, but Vanderwilt 20 has recently questioned the validity of this conclusion. Hayward and 

Triplett,21 in an interesting paper on mineralized dolomite in seven deposits of northern Mexico, concluded, 

that the dolomite was the result of regional metamorphism and is both near to and remote from ores. Sam18 Hewett, D. F., Dolomitization and ore deposition: Econ. Geology, 

vol. 23, pp. 821-863, 1928. Rastall, R. H., Physico-chemical geology, 

p. 196, London, 1927. Nolan, T. B., The Gold Hill mining district:. 

Utah : U. S. Geol. Survey Prof. Paper 177, p. 109, 1935.

18 Spurr, J. E., Geology of the Aspen mining district, Colo. : U. S. Geol. 

Survey Mon. 31, pp. 206-216, 1898.

20 Vanderwilt, J. W., Revision of the structure and stratigraphy of 

the Aspen district, Colo., and its bearing on the ore deposits : Econ. 

Geology, vol. 30. p. 239, 1935.

21 Hayward, M. W., and Triplett, W. H., Occurrence of lend-y.inc oros 

in dolomitic limestones in northern Mexico : Am. Tnst. Min. and Met. 

Eng. Tech. Pub. 442, 1931.
ORE DEPOSITS 47

pi ing (nearly 1,000 samples) indicated no addition 

of magnesia during the period of mineralization, but 

the ore showed a decided preference for dolomites 

rather than limestones. This was explained on the 

basis of four (joints: (1) Dolomite beds are more crystalline and break more readily than limestone; (2) 

dolomites are more porous; (3) difference in chemical 

composition; (4) damming influence of dense thinbedded dolomites. (Dolomite as used by Hay ward and 

Tr.ip.lett contains plus 5 percent of MgO.)

Field observations at Metaline check those of Vandor wilt and Hayward and Triplett in that regional 

dolomitization preceded ore deposition. The evidence 

is interpreted to indicate that no dolomite was added 

by (he ore-bearing solutions although magnesium in 

the rocks was moved and concentrated by the solutions.

The dolomitized limestones appear to be more porous 

and vuggy than, the unaltered beds, although precise 

data, are not available. To change a cubic decimeter 

(0.035 cubic foot) of limestone into dolomite with no 

change in volume requires an addition of 628 grams 

of MgO and 178 grams of CO., and the loss of 646 

grams of CaO. As pointed out by Hewett,22 however, 

i.!: the dolomite has any porosity, the quantities of MgO 

and CO- added are diminished proportionally. Huge 

quantities of CaO are liberated and apparently removed during doloniitization.

If a given volume of calcite is changed to dolomite 

and (lie excess calcium removed, an increase in porosity 

of about .12.46 percent takes place. The process of 

dolomitization is generally incomplete, and part of 

tho pore spaces are filled with calcite and silica. 

Nevertheless, the increase in voids during the change 

from calcite to dolomite is a factor large enough to 

have an appreciable influence on permeability and 

possibly on ore deposition.

ORE DEPOSITS

HISTORY OF MINING

The earliest recorded exploration of the region was 

made by David Thompson in 1811. Thompson's excellent geographic observations 23 are well known, although he did not mention the mineral possibilities of 

the Pend Oreille Valley. According to Browne 24 the 

first mineral discovery (gold) in eastern Washington

- > llewett:, I). K., op. cit., p. 850.

- ''Thompson, David, Narrative of explorations in western America, 

il 784-181.2 ; edited by .T. B. Tyrrell, Toronto, Champlain Society, 1916. 

Now light on the early history of the Greater Northwest (manuscript 

jonrnnls of Alexander Henry and David Thompson), edited by Elliot 

COUCH, Now York, Francis P. Harper, 1897.

w Browno, ,T. R., Resources of the Pacific slope, p. 182, New York, 

Applpton, 1809.

w Baud-man. 11., Report on the geology of the country near the 49th 

parallel of latitude west of the Rocky Mountains, based on observations 

made In 1859-0:1, pp. HHB-H7B, Montreal, 1884.

was about 1855 in the vicinity of Fort Colville on 

several tributaries of the Columbia. Bauerman 25 recorded gold placers on the lower Pend Oreille River 

being worked in 1858, and Bethune 2G gives a few 

details of the early discoveries.

According to Mineral Resources,27 lead deposits were 

known in the Metaline district as early as 1869. A 

mineral map of the Territory of Montana,28 published 

in 1865, includes the Metaline region but gives no indication of mineral in the area, and the geography is 

largely hypothetical. A topographic map of the Colville region,29 published in 1882, shows a small part of 

the Pend Oreille River near what is now Metaline Falls. 

The country was accessible by trail from Colville, but 

no settlement was indicated in the Pend Oreille Valley, 

and the geography was imperfectly known. Bethune 30 

states that the rich lead-silver deposits of the Colville 

area were discovered in 1883 and that the region was 

brought into prominence by the development of the 

Old Dominion mine in 1885. Bethune also states that 

the Metaline district was one of the largest and oldest 

mineral divisions of Stevens County (which at that 

time included the present Pend Oreille County). The 

name Metaline was applied because of the immense 

amount of metal in sight. 31 Apparently some attempt 

at mining was made about 1886,:t2 and Bethune ;i3 mentions the Bonnie Blue Belle claim being patented in 

1891. Abercrombie "* explored the Pend Oreille Valley 

from Pend Oreille Lake to the international boundary 

in 1885 and was impressed by the mineral possibilities 

of the region. Taylor 35 surveyed the river valley in 

1897 and recommended methods of improving navigation as far north at Metaline.

Prior to 1906 the district was difticu.lt.ly accessible 

by boat from Newport down the Pend Oreille River 

to a landing below lone and thence by wagon road, or 

else by a poor wagon road over the mountain from 

Colville, a distance of about 50 miles. In 1906 the 

Federal Government deepened the channel of the Pend 

Oreille at Box Canyon, thus permitting through boat 

service between Newport and Metaline, a trip of about 

60 miles. The Idaho & Washington Northern Rail26 Bethune, G. A.-, Mines and minerals of Washington : State Geologist, 

1st annual Rept, pp. 5-10, 1891.

27 Mineral Resources U. S., 1906, p. 451, information furnished by 

L. P. Larsen and Mr. and Mrs. D. D. Birks.

28 DeLacy, W. W., Mineral map, Territory of Montana, in personal flies 

of .T. T. Pardee, published 1SG5.

20 Gannett, Henry, Map. of Colville region, Washington Territory, 

Northern Transcontinental Survey, 1882.

30 Bethune, G. A., op. cit., p. 12.

31 Idem, pp. 82-83.

33 Mineral Resources, U. S., 1906, p. 451. 

S! Bethune, G. A., op. cit, p. S3.

34 Abercrombie, W. R., Report on the Pend d'Oreille River : Mining, 

1896, pp. 245-250.

33 Taylor, Harry, Survey of Pend Oreille River, from its source at Lake 

Pend Oreille, Idaho, to the town of Metalline, Wash.: Chief Eng. Rept., 

1.898, pt. 4, pp. 3124-3131.
48 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

road, now a branch of the Milwaukee System, was completed to Metaline Falls in 1910. With the advent of 

the railroad the region entered a new era of development, as its timber and mineral resources were rapidly 

exploited.

The presence of limestone and shale suitable for 

cement manufacture Avas known before completion of 

the railroad.36 After the railroad was installed an attempt was made to manufacture cement just north of 

lone but proved a failure. Another plant at Metaline 

Falls was successful and is now operated by the Lehigh 

Portland Cement Co.

The development of the metal resources of the region 

has been slow because of the inaccessibility, the low 

grade of the lead-zinc ores near the surface, and the 

general absence of gold and silver. The successful 

growth of the district is due largely to the persistence 

and tenacity of Lewis P. Larsen, who first became 

materially interested in the district in 1906, when he 

obtained control of what was then known as the Clark 

property. Mr. Larsen and his financial backers tried 

repeatedly to develop ore on a commercial scale and 

to construct plants capable of handling the low-grade 

lead-zinc bodies profitably. It was not until 1928-29 

that, as a result of diamond core drilling, a considerable 

body of minable zinc-lead ore was found on the property of the Pend Oreille Mines & Metals Co. Since that 

time, development has been rapid and the limits of 

the known ore have been greatly extended. In 1936-37 

the Metaline Mining & Leasing Co., a subsidiary of the 

American Zinc, Lead & Smelting Co., began operations 

in the old Bella May mine on ore previously determined 

by diamond drilling.

The district has not been without its periods of inflation and promotion bubbles, the most flagrant of 

which was in 1928-29 in connection with the development of the Grandview. property. 37

PRODUCTION

The earliest known production of ore from the Metaline district was in 1906, when a small shipment containing 73.1 percent of lead, 2 percent of zinc, and 1.1 

ounces of silver was made. 88 Prior to 1915, however, 

production was negligible, but in that year 3,111 tons 

of an average value of $9.76 was shipped from the [Pend 

Oreille mine (Clark property). Some production has 

been made yearly since 1915 except in 1920, 1921, 1928, 

and 1935. With the improved modern milling facili88 A.dair, J. B., The Metaline district: Northwest Min. Jour., vol. 7, 

p. 56, 1909.

37 Haggen, E. A., Geology of the Pend Oreille formations (Metaline 

district) : Min. and Indust. Record (Vancouver, B. C.), vol. 31, pp. 

82-83, April 192S; Mines Mag., vol. 38, 110. 6, pp. 384-385, June 1928.

38 Mineral .Resources U. S., 1906, p. 45], \

ties now available it is expected that production Avill be 

greater in the future, depending of course on economic 

conditions and an adequate ore supply.

The value of metals recovered from ores of the. 

Metaline district is shown in the following table compiled by C. N. Gerry, of the United States Bureau of 

Mines.

During the early period of mining the principal 

product was of lead, but in recent years zinc has become the most valuable metal. The silver and copper 

are byproducts of the zinc-lead mining, but the gold 

was obtained from placers and from the Oriole ores.

Most of the production has come from the Pend 

Oreille mine, but considerable yield is credited to the 

Bella May and Grandview. Smaller shipments have 

been made from the Oriole, Z Canyon, Lead Hill, Lead 

King, Lucky Strike, Cliff, Diamond R, Lead Queen, 

and a few other claims.

In addition to the production from the Pend Oreille 

Valley two other properties, the United Treasure and 

the Frisco Standard, are known to have produced some 

metal. These two mines, in'the northwestern part of 

the quadrangle, in Stevens County, have yielded lead, 

silver, copper, and a little gold. The total value of 

their production is not known but is probably several 

thousand dollars.

Prospecting from 1927 to 1937 was so encouraging 

that large tonnages of ore were developed and are 

being mined. Development has been slow and expensive, but, in view of the results, it is felt that the future 

of the district is assured for several years.

QBE BODIES

The ore deposits in the Metaline quadrangle are of 

several types. By far the most productive type comprises the replacement deposits accompanied by some 

cavity filling in the carbonate rocks outside of the zone 

of marked igneous metamorphism. A closely related 

type which has been little explored consists of the replacement deposits in altered carbonate rocks adjacent 

to the Kaniksu batholith. Lodes are worked at 

several places, and a few have been productive. 

Molybdenite is reported from a pegmatite dike on 

Molybdenite Mountain,39 but the prospect could not be 

found, during this investigation. The Mule Deer deposit is unique in the region, but sufficient development 

work has not been done on it to permit classification. 

It appears to contain sphalerite and galena disseminated through highly altered quartz monzonite of the 

Kaniksu batholith. A little placer gold has been recovered in the gravels of the Pend Oreille River and 

its tributaries.

^Bancroft, Howland, Ore deposits of northeastern Washington : U. S. 

Geoi, Survey Bull. 550, p. 45, 1914.
ORE DEPOSITS 49

Geld, leadsilver, and zincOreille produced in theMetaline Couty, Pend district, Wash., 1901-40, in of(prior recovered metals Stevens copper, County') terms 1911, to 

[Compiled C. Gerry, byX. statistician S.U Mines] Bur. 

"o c

o£

N 

T3

CB 3

u»

§L

a o O

<D W

2 3 O

Value :

Pounds Value Value * 3 a

r*

rj 8

 a 

tado81

Fine ounces

Ore (short 

tons)

o>

a %

u

(^

<U

t*to a)

t*

CC 

l>O

«/:

co Tfi

O5

(f. 0o

' rH 

 tf

co

0

OS 

IN'

O-H 

CO 

C/5

10 IN

Tt<

OS 

00 

(N

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00

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CO

CO 

<N

i (

coos'

00. 

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 I n- 1

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Gold ! calculated $25.56 atan ounce. 
50 GEOLOGY AND ORE DEPOSITS OF THE MBTALINE QUADRANGLE, WASHINGTON

REPLACEMENT DEPOSITS

GENERAL FEATURES

The principal replacement deposits occur in the 

Metaline limestone, although some are found in other 

carbonate beds. Production from the Metaline limestone has been almost entirely from the upper 500 feet, 

just below the Ledbetter slate.

The mineral composition of the replacement ores is 

simple. Sphalerite is at present the most valuable 

constituent, but it is usually accompanied by galena. 

Small quantities of silver and copper are recovered in 

parts of the ore.

Sphalerite is found in a wide variety of colors, pale 

yellow or resin, brown, and red, all of which may be 

present in a single ore shoot. Small amounts of 

galena are distributed through the ores, but galena 

appears to be concentrated near the peripheries of 

the ore bodies. In a few places more galena is present than sphalerite. Pyrite occurs in large quantities at many of the mines, 'particularly the Lucky 

Strike, Riverside, and other properties in the river 

gorge. Pyrite is scarce or absent in the ores at the 

IPend Oreille, Bella May, and Lead Hill mines, although it is found in the nearby country rock. A little 

marcasite is widely dispersed in much of the ore.

The gangue is customarily dark-gray or black jasperoid which in places grades into milky quartz. (See 

pi. 25, B.} Crystalline dolomite and coarse calcite are 

abundant, and in some places sphalerite and galena are 

disseminated through bedded dolomites and dolomitic 

limestones. In a few places, as at the Pend Oreille 

mine, unaltered limestone has been locally mineralized. 

Barite is one of the common minerals at Lead Hill but 

is scarce or absent in other deposits.

The replacement ores are generally massive but.in 

some places are porous and vuggy, the vugs being 

lined with crystals of sphalerite and quartz. Unquestionably some open-cavity deposition of ore has taken 

place, but the amount is thought to be subordinate to 

that of replacement origin. The textures of the zinc 

ores vary widely; many are fine-grained and dense, 

others are coarse-grained and massive and contain crystals of sphalerite half an inch or more across. Galena 

' crystals probably average larger than sphalerite crystals, but in a few places fine-grained or "steel" galena 

is found.

A mottled appearance or a crude banding (see pi. 

24, 0} that resembles the so-called "zebra" dolomite is 

found in many places, particularly in the coarsergrained and lower-grade ores.

An unusual type of concentrically banded mineralized dolomite is present at several properties, particularly those near Z Canyon. (See pi. 26.) The rock 

resembles some of the zinc ores from the southern

Appalachian deposits 40 and from Upper Silesia.41 

Currier believes that the concentric structure has resulted partly from cavity filling and partly from replacement of a breccia in which the sharp corners and 

edges were more rapidly attacked than the rest of the 

breccia fragments. Krusch 42 thinks that the Upper 

Silesian ores were introduced in the colloidal state 

and attributes the banding to rhythmic precipitation. 

It would appear that concentric banding might result 

from either or both of these processes. No conclusive 

evidence in support of either idea was found at 

Metaline.

"FORM AND STRUCTURE

The mineralized replacement bodies are irregular in 

size and shape. They range from a few scattered sulfide grains to the ore bodies shown on the map of the 

Pend Oreille mine (pi. 33). In a general way I lie 

ores follow bedding, but in detail they are crosscutting. 

Most of the ore bodies are 10 to 20 feet thick, but 

one mass of ore about 50 feet* in its shortest dimension 

was mined in the Pend Oreille.

Most of the ores occur in breccia zones in the carbonate rocks. The jasperoid and ore have cemented 

and replaced breccia fragments and obscure preexisting 

structures. In several stopes in the Pend Oreille mine 

well-defined fractures in the country rock can be followed to the ore, and the sulfides and jasperoid spread 

out from the fractures. All the ore bodies studied in 

detail are related to breccia zones or fractures which 

have acted as feeders and from which the ore-bearing 

solutions have replaced the more favorable carbonate 

beds.

Many ore bodies are cut or bounded by smooth slickensided surfaces that brecciate and polish the ores. 

(See pi. 25, C, D.} The postmineral movement was 

generally small, offsets of more than 10 feet being 

uncommon, although along a few faults the displacement may be 100 feet or more. Many postmineral 

faults seem to merge into the premineral faults and 

are lost in ^cemented and mineralized breccia and in 

coarse calcite. For this reason most of the postmineral 

faults are thought to have been formed by minor readjustments along older fractures.

. Caves are of rather common occurrence along fractures and in breccia zones.' A few caves in the Pend 

Oreille mine were mineralized and yielded good ore.

40 Currier, L. W., personal communication, March 1938; Zinc and 

lead region of southwestern Virginia : Virginia Geol. Survey Bull. 43, 

pis. 24, 25, and 26, 1935.

41 Stappenbeck, R., Ausbildung und Ursprung der oberschlesischen 

Bleizinkery.lagerstatten : Archiv fiir Lagerstattenforschung, Heft 41, pp. 

79-85, Preuss. geoT. Landesanstalt, 1928.

42 Krusch, P., Uber kolloidal Vorgange l>t>i der Entstehung der 

oberschlesischen Zink-Bleierzlagerstatten : Deutsche geol. Gesell. 

Zeitschr., Bund 81, pp. 169-170. 1929.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE 23

A. BUTTONS OF ANTHRACITE COMPOSITION IN KECKYSTALLIZED DOLOMITIC LIMESTONE. WOLF CHEEKRI'ROSI'ECT.

B. SILICIFIED AND MINERALIZED BRECCIA, PEND OREILLE MINE.

l.i^ht gray is mostly dolomite with a little translucent quartz. Dark gray is jasperoid and ore minerals. Veinlet along lower edge of specimen contains sphalerite in carbonates. 

C.. POLISHED FRAGMENT OF ORE IN WHICH GALENA (BLACK) REPLACES CALCITE ALONG CLEAVAGE PLANES, PEND OREILLE MINK.

D. CRUSTIF1ED BANDING IN DOLOMITE, LAKEVIEW PROSPECT. 

E. "/KBRA" ROCK, COBBLE FROM STREAM IN EAST CENTER OF SEC. 11, T. -W N., R. 12 E.
OKOLOOICAI. Kl'RVEY PROFESSIONAL PAI'HR 202 PLATE 24

A. CALCITE AND DOLOMITE, LEAD HILL MINE.

The cal<'-ile fshow.s large rhomhohedral (cleavage surfaces and in general is lighter llian llie dolomite.

H. PARTLY S1LICIF1ED DOLOMITE, PEND OKEILLE MINE.

(Natural size. INole the Hcams of dark-gray quartz through the dolomite.

C. CRUDELY BANDED MINEKAL1/ED ROCK, LAKEV1EW PROSPECT.

Black is sphalerite, light gray in dolomite, and dark gray is silicified dolomite.
OHOI;OCI('AIj SURVEY PROFESSIONAL PAPER 202 PNATK 25

A. I'OUSMKI) M.M! KUOM (;l( \\DVIEW ADIT, 

Crustified <lolomile (lifrht) in jasperoid (dark). The cenu-r.s of main of the dolomite areas are calcitc. Natural Mze.

R. /INC OKE FKOM 500-FOOT LEVEL, PEND OREILLE MINE.

Dark gray and black are sphalerite and jasperoid. This specimen contains more milky quartz (white) than most ore. Natural 

C. SLICKENSIDED GALENA, PEND OREILLE MINE.

From 700-foot level. Natural size.

; 1). 1'OST-MINERAL FAULT, CALCITE FAULTED AGAINST ORE, I'END OREILLE MINE. 

In slope, 500-foot level. Height of face approximately 6 feet.
GEOLOGICAL SURVEY 1'KOFK.SSIONAr, PAPER 202 PLATE 2fi

CONCENTRICALLY BANDED DOLOMITE AND SULFIDES, 7. CANYON MINE. 

Black is sphalerite with galena near outer edges, gray is dolomite, while is calcite. and a little pyrile is in the centers of the nodules. Natural size.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE 27

li. CAVE BRECCIA, I'END OREILI.F. MINE. 

700-fnnl level. Natural si*e.

//. I'OI.ISIIKI) SIIKFACE OF SPECIMEN OF MINERALIZED HOCK FKOM THE 

COFFIN PROPERTY.

SiTiicnliiii- (S). sphalerite (S|i), <liop8ule (Di). Oilier minerals not labeled. Most Bcr|>entine 

( ontainn cores of sphalerite.

\VASHEIi AND CKAVEL UAK, SCHEIUMNU PLACKR, LOOKIN(; NORTH.
ORE DEPOSITS 51

The. subject is discussed in some detail on pages 38-39. 

In many underground Avorkings a concentration of 

sphalerite is noticed at contacts between jasperoid and 

coarse calcite. The sphalerite is generally in layers 

of almost pure zinc sulfide a few inches to 2 feet thick. 

The' contacts between sphalerite and calcite are sharp, 

and the sphalerite is commonly crystalline, as if deposited in cavities that were later filled with calcite. 

Sphalerite grades into lower-grade ore or jasperoid 

away from the calcite.

REPLACEMENT DEPOSITS IN THE IGNEOUS-METAMORPHIC ZONE

The replacement deposits in the igneous-metamorphic 

HOIHI are of particular interest in a study of the genesis 

of the ores, although, .little eifort has been made to 

develop them commercially. At several places along 

the contact of the Kaniksu batholith small amounts of 

sulHd.es are associated with diopside, garnet, serpentine, 

and other inetamorphic minerals. The best-exposed 

body'of this type is at the Coffin property, at the western edge of the quadrangle, in sec. 16, T. 38 N., R. 42 

K. The workings at this, property are in an altered 

carbonate layer in the Maitlen phy.ll.ite at the contact 

of the Kaniksu batholith.

A polished surface of typical ore is illustrated in 

plate 27, .'I.. This photograph shows particularly 

well the clear, pale yellowish-green serpentine (light 

gray in the figure) in the white diopside. The cor°.s 

of most of the serpentine areas are clear resinous .sphalerite. Galena and sphalerite are associated with diopside, serpentine, and other inetamorphic minerals in 

I he right-hand one-third of the specimen but are not 

labeled in the figure'. The suln'des, in addition to sphalerite and galena, include pyrrhotite, molybdenite, and 

pyrite. The gangue is principally diopside and carbonate with lesser amounts of serpentine, phlogopite, 

treniolite, chrysotile, and other metamorphic minerals.

Not enough work has been done to delimit the mineralized ground at the Coffin property, but the sulfides 

are distributed through the rock similarly to the distribution in the better-known replacement bodies in the 

carbonate beds. The similarity of the two types of 

deposits is further brought out by mineralized bodies 

such as that at the O. 1C. property, which appear- to 

be transitional from one type to the other.

The O. 1C. deposit is in the Monk formation west of 

the Flume Creek fault and is about 2 miles from the 

closest known contact with the batholith, although 

a, few pegmatite dikes and small, poorly exposed granitic rock outcrops are nearby. This deposit consists 

of a small proportion of sulfides (sphalerite, galena, 

tetrahedrite, pyrite, pyrrhotite, and very little chalcopyrite) in a, dominant gangue of white crystalline limestone that contains diopside, treinolite, yellowish-green 

serpentine, and a few other metamorphic minerals.

Molybdenite has been found only near the batholith 

contact at three places the Coffin property, a road 

cut in marble in Dry Canyon, and the Noisy Creek 

prospect. Wulfenite, however, has been found in the 

oxidized ores at the Bella May and Diamond li properties, and it is possible that molybdenite is present in 

small amounts in the imoxidized ores.

LODE DEPOSITS

Lode deposits are known in many places in the quadrangle. Probably the most productive are those in the 

Ledbetter slate at the Frisco Standard, United Treasure, and nearby properties and in the Monk formation 

at the Oriole. Well-defined fissure veins are rather 

common but are generally less than 1 to 2 feet thick 

in the greenstone and associated rocks at the Gypsy 

copper camp. At the Noisy Creek prospect an irregular quartz body lies along the contact between a small 

granitic intrusive mass and the Maitlen phyllite.

The lodes at the Frisco Standard, United Treasure, 

and other prospects nearby have many features in 

common. The ore minerals are silver-bearing tetrahedrite, galena, sphalerite, and pyrite, and their oxidation products. The gangue is made up of a vitreous 

mi Iky-white quartz and a little white carbonate. The 

lodes consist of numerous stringers and small veins, 

which in places coalesce and form quartz bodies up to 

7 feet thick. Ribbons and fragments of carbonaceous 

country rock are abundant in the quartz, most of which 

has a layered structure formed by preservation of part 

of the carbonaceous material. So-called shadows or 

skeletons of the slate in the quartz are interpreted to 

mean that the quartz replaced the country rock. The 

quartz bodies are much contorted and irregular but are 

not appreciably faulted or shattered. Much black graphitic gouge is found along the borders of the quartz 

bodies. Bedding planes cannot everywhere be recognized, but as a rule the quartz bodies appear to folloAv 

the crenulations of the deformed bedding, although 

in detail quartz cuts the beds. It is thought that the 

quartz was introduced along minor zones of faulting 

that nearly conformed to the bedding. A little postmineral movement can be recognized, but in general 

it appears to be negligible. At the United Treasure 

and My Era properties the ore bodies in places are 

parallel to basic sills. The sulfides are not distributed 

uniformly through the quartz but are concentrated in 

shoots, the sizes and shapes of which are unknown.

The ore deposit at the Oriole mine has been described 

by Jenkins 43 and by Patty.44 Most of the workings

43 .Tenkins, 0. P., Lead deposits of: Pent! Oreillc and Stevens Counties, 

Wash. : Washington Dept. Cons, and Devel., Div. Geology, Bull. 31, 

pp. G7-69, 1924.

41 Patty, B. N., The metal mines of Washington : Washington Geol. 

Survey Bull. 23, pp. 87-88, 1921.
52 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

at this mine were inaccessible except for the adits 

in the oxidized zone and a part of one stope in the sulfides. The ore on the dump contains silver-bearing tetrahedrite, sphalerite, galena, and pyrite. The gangue 

in the more massive sulfides is vitreous white quartz 

that is commonly in spheroidal grains about half an 

inch in diameter. The leaner sulfides are scattered 

through white quartz or a granular silicified rock 

that is derived through the alteration of sandy dolomite in the Monk formation. In .the upper workings 

the lode is a gouge-filled fissure a few inches wide that 

locally widens to 2 or 3 feet. These wider parts were 

mined out and apparently yielded the ore from the 

upper levels. In depth the shoots are reported to be 

up to 4 feet thick but they pinch and swell abruptly on 

the strike. Patty describes the ore shoots as replacement lenses in breccia. The Oriole is best described 

as .a narrow, steeply dipping shear zone in silicified 

dolomite. Along this zone there are several small 

lenses or pipes. The deposit could as well be classified as of a replacement type, although the distribution 

of the ores in a narrow zone along a fissure distinguishes it from the more irregular-shaped bodies at the 

Bella May and Pend Oreille mines.

Bancroft 45 describes the deposit at the Kiverside 

property as a fissure vein in which the country rock 

is partly replaced on each side, and parallel fissures 

extend 15. to 20 feet from the main vein. The Riverside was inaccessible when visited by the writers, and 

no additional information about the mineralization was 

obtained. In many nearby mineralized areas what 

appear to be similar fissures are exposed. The deposits probably should be classified as replacement 

bodies rather than veins, as the mineralized ground is 

irregular and extends laterally from the fissure zone 

into carbonate beds.

RELATIONS OF ORE DEPOSITS TO REGIONAL 

STRUCTURE

The localization of the ore deposits is closely dependent upon the regional structure. Two features 

particularly stand out the relation between the, ore 

deposits and major faulting and the relation of the 

ore deposits to the Ledbetter slate.

Most of the ore deposits are within a mile of one of 

the major faults, particular^ the Flume Creek fault, 

Russian Creek fault, and Slate Creek fault. The ores 

are not in the major faults but are associated with 

lesser breaks and breccia zones, particularly in the 

hanging-wall blocks of the major faults. A few deposits, such as that at the Oriole, are in the footwall 

blocks. Other deposits, such as those at Z Canyon and 

at the mouth of Slate Creek, are near faults of comparatively minor structural significance.

& Bancroft, Howland, Ore cleposi ts of northeastern Washington : U. S. 

Geol. Survey Bull. 550, pp. 50-51, 1914.

The principal known replacement ore bodies, in addition to being near faults or in breccia zones, are in 

the Metaline limestone within less than 500 feet below 

the Ledbetter slate. It is reasonable to suppose that 

the ore deposition was aided b}' the damming action 

of the relatively impervious slate. .The ores are generally in dolomite or dolomitic limestone, but some are 

in limestone. The localization in dolomite may be explained by the fact that most carbonate beds below 

the slate are dolomitic rather than that replacement 

was partiaHo magnesian beds.

A few deposits, such as that at the Coffin property, 

are localized in a carbonate bed, at the contact with 

the Kaniksu batholith. Other deposits, such as the 

veins at the Gypsy copper camp, have not been studied 

in detail, and their relations to the regional structure 

are unknown.

The relations of regional folding to ore deposition, 

if any, are not known.

BRECCIATION

Many of the rocks in the Metaline quadrangle, particularly the brittle carbonate rocks and quartzites, 

are brecciated. The breccias in the carbonate rocks are 

of particular interest because of their close association 

with the ores. Three types are recognized crush 

breccia (crackle type), rubble breccia, and cave breccia.

Crush breccia. Crush breccia is by far the most 

abundant type in the Metaline limestone. It is defined 

as a breccia in which the individual fragments are 

generally 2 inches or less in greatest dimension, show 

little or no rounding, and relatively little displacement 

or rotation.46 All the breccia bodies examined in detail show slickensided surfaces and other evidences of 

minor fault movement. The breccia is strikingly similar to that associated with the zinc-lead deposits of 

southwestern Virginia and Tennessee, where Newman 47 

and Currier 4S attribute the crushing to tectonic forces. 

Newman ascribes the breccia to movement, although 

faults of any magnitude were not recognized in the 

mines. Vanderwilt 49 points out that the amount of 

brecciation in limestone is no criterion of the amount 

of offset along a shatter zone. The crush-breccia bodies 

at Metaline are vaguely defined and fade into the unbroken carbonate rock. In places, such as the Pend 

Oreille mine and the Lead Hill mine, practically the 

entire country rock is brecciated. Superficially at least, 

the brecciation appears to be more intense in the dolo-

 w Norton, W. H., A classification of breccias : Jour. Geology, vol. 25, 

pp. 161, 188-189, 1925.

47 Newman, M. H., The Mascot-Jefferson City zinc district of Tennessee : IGth Internat. Geol. Congress Guidebook 2, pp. 161-162. 1983.

48 Currier, L. W.. Zinc and lead region of southwestern Virginia: 

Virginia Geol. Survey Bull. 43, pp. 83-86, 1935 ; Structural relations 

of southern Appalachian zinc deposits': Econ. Geology, vol. 30, pp. 

260-286, 1935.

49 Vanderwilt, J. W., Revision of structure and stratigraphy of the 

Aspen district, Colo., and its bearing on the ore deposits : Econ. Geology, 

vol. 30, pp. 234-235, 1935.
ORE DEPOSITS 53

mite, than in the limestone, although not confined to 

the dolomite.

The abundant stylolites in the upper parts of the 

Metaline limestone (see pi. 8, A) indicate that appreciable removal through solution has taken place. 

Slumping of overlying beds, caused by this solution, 

ma,y account for part of the brecciation, and it is possible that the brecciation has been accentuated by the 

dissolving action of mineralizing solutions.50 Crushbreccia, however, is too widespread to be attributed entirely to slumping. This type of breccia, obviously connected with faulting' and folding, is also found in the 

Gypsy quartzite in at least three places Hall Mountain 

near the junction of the Russian Creek and Flume 

Creek faults, and west of Lost Lake. Crush breccia 

in the Metal in e quadrangle is attributed almost entirely 

to tectonic forces. The brecciation was not, however, 

the result of a single period of activity but probably 

occurred at several stages in the long structural 

history.

Rubble breccia. Where crush breccia approaches 

fault zones the fragments have been increasingly displaced and rotated, forming what is known as rubble 

breccia. The fragments are smaller than those in the 

crush breccia and average about half an inch in diameter. They are generally subrounded to subangular. 

In the faults the breccia becomes in places a limy gouge 

in which are embedded rounded particles varying 

widely in number a.nd variety. Rubble breccia is 

everywhere associated with faults and was caused by 

faulting.

Co/06 brecoia. Fractures and breccia zones offer favorable paths for circulation of solutions. In places 

(he solutions enlarge their channels and form caves and 

vugs in which the less soluble parts of the rock and 

slumped fragments accumulate. Such a breccia is illustrated in plate 2T, B. In this specimen the individual 

fragments are cemented by calcite dripstone and 

chalcedony.

OHIO IN OF THE ORES

The zinc-lead deposits of the Metaline quadrangle 

are thought to have been deposited mainly by hot solutions, the source of which was the magma that is now 

represented in part by the Kaniksu batholith. The 

pale-yellow sphalerite may be. at least in part, of 

supergene origin, as it is found in caves on paligorskite 

and is commonly near and in fractures where groundwater circulation is now vigorous.

The similarities between the replacement ores in the 

Metaline limestone and the replacement bodies in the 

igneous-metamorphic zone suggests that the two types 

were deposited during one period of mineralization. 

The replacement ores in the metamorphic rocks were

60 LocliC, A., The. formation of cciM:nin ore bodies by mineralization 

sloping: Kcon. Geology, vol. 21, pp. 431-45S, 1926.

possibly formed after diopside and other high-temperature silicate minerals, as the paragenesis indicates that 

the sulfides are late, although the relations are somewhat A7 ague. Igneous metamorphism in the Metaline 

area was directly related to the Kaniksu batholith, 

and the metallization in such deposits as that at the 

Coffin property was an essential part of the igneous 

metamorphism. It is concluded, therefore, that the 

ore deposits are directly related to the Kaniksu batholith and were emplaced late in the igneous history, 

probably after partial or complete solidification of the 

intrusive mass.

If the assumption is admitted that the lead-zinc 

metallization took place during only one period, then 

the sphalerite and galena in the altered intrusive rock 

at the Mule Deer prospect afford further evidence that 

the metals were introduced after solidification of the 

batholith.

Localization of the ores near the major faults is. 

interpreted to mean that a source of the mineralizing 

fluids in depth was tapped by the larger fractures. 

It is likely that intrusive rock is within a few thousand 

feet of the surface at the Oriole and O. Iv. properties, 

as indicated by the pegmatitic and small granitic bodies 

and by the igneous-metamorphic effects shown in. the 

phyllites along the Flume Creek fault. It is also likely 

that the mineralizing solutions originated in or beneath 

this buried intrusive mass and worked toward the surface through the fractured zone associated with the 

Flume Creek fault. It is reasonable to assume that 

the batholith, lamprophyres, and ores had the same 

ultimate source and that they were emplaced in that 

order.

OXIDIZED ORES

Oxidation of the ores in the Metaline district in 

general has been slight. Galena commonly is unaltered at the surface, and at a few places fresh sphalerite is found. The sphalerite is commonly leached, 

however, and vugs that may or may not contain iron 

oxide mark its former presence. At the Oriole mine 

oxidation has been rather thorough to a depth of 50 

feet. Below this level a little iron oxide is found in 

fractures and channels where circulation is particularly 

rapid.

The explanation of the shallow oxidation zone is 

probably found in the scouring action of the Pleistocene ice sheets, which removed most of the loose, 

weathered material.

The mineral composition of the oxidized ores is 

simple. The gangue consists principally of quartz 

and soft powdered carbonates. Iron-oxide stains are 

abundant, particularly in the pyrite-rich areas. Smithsonite and cerussite are present in most outcrops, and 

there are a few small patches of other minerals such as 

greenockite and malachite.
54 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

FUTURE OF THE DISTRICT

Development of the Metaline district has been slow, 

and only in the last 10 or 12 years have large, commercially valuable ore deposits been found. Evidence 

of mineralization near the surface is generally scattered, and the ore is developed only through expensive and persistent exploration. The ore bodies are 

too imperfectly known to permit generalizations as to 

size and grade of new bodies likely to be found. It 

should be emphasized here that most of the Metaline 

ores are not of high grade; perhaps 5 to 15 percent 

of combined lead-zinc is a fair average of mine run. 

The hope of the district in the future lies in efficient 

handling of large tonnages.

The largest ore bodies known to date are in the MetaJi.no limestone less than 500 feet below the Ledbetter 

slate. They occur generally in jasperoid that has replaced breccia, and they are commonly bordered by an 

irregular shell of nonbedded crystalline dolomite and 

coarse-grained white or gray calcite. Bodies of mineralized jasperoid associated with crystalline dolomite 

and coarse-grained calcite are found at several places 

in the upper part of the Metaline limestone. These 

places are worthy of study and possibly of exploration. 

Additional ore may also be found below the Ledbetter 

slate in carbonate beds not now exposed. In general 

exploration below the slate should probably be limited 

to known mineralized areas until the detailed structure 

in the valley is better understood. Such unexplored 

mineralized areas near slate are numerous for example, Wolf Creek, Morning and Mammoth, Grandview, Lead King, Giant, and Lead Hill, to mention 

a few of the claims.

Many carbonate beds, similar so far as known to those 

near the top of the Metaline limestone, are found 

throughout the region. The beds near the base of the 

Metaline limestone are interlayered with phyllites, and 

the structural conditions are similar to those below the 

Ledbetter slate. Most of these lower beds in the known 

mineralized areas are buried under 1,000 feet or more 

of other rocks and are difficult to explore. It is possible, however, that ore will be developed at some of 

these other horizons. Such a deposit is known at the 

Reeves-McDonald mine, in Canada just north of the 

Pend Oreille River at the mouth of Russian Creek.

The structural geology of the region has been given 

little study heretofore, and the present report leaves 

much to be desired. The geologic conditions, however, 

indicate that the chances of finding additional ore appear to be good.

Limestone and the other constituents used in the 

manufacture of cement are the only nonmetallic mineral resources mined at present. The available quantities of these materials seem to be adequate to supply 

normal needs for many years.

Andalusite and sillima.nite, which are used in the

ceramic industries, are of wide distribution in the metamorphic rocks near igneous contacts. Some of the 

occurrences are easily accessible, but whether or not 

the quantity and grade of the material will justify 

commercial development is not known.

MINERALS OF THE ORE DEPOSITS AND 

METAMORPHIC ROCKS

In the following paragraphs the minerals are listed 

according to Dana's classification.

NATIVE ELEMENTS

Graphite (C). A few small flakes of metallicappearing graphite were found in a fault zone, at the 

Bella May mine. Soft black clay gouge that probably 

contains finely divided graphite is abundant along 

fault zones, particularly those in and near the Ledbetter 

slate.

Sulfur (S). A little sulfur was found in an oxidized 

iron sii.1.fide body at the Riverside mine. The mineral 

burned with a pale-blue flame and gave off fumes of 

SO2 .

Gold (Au). Most of the gold recovered in the region 

is obtained from stream gravel, where it occurs in small, 

well-worn flakes that appear to have traveled long 

distances from their sources. Tins gold has probably 

been concentrated \)j the reworking of low-grade glacial 

drift. A little gold is reported in the ores at the 

Oriole and in even smaller amounts at the Frisco 

Standard and United Treasure properties. A little 

gold is possibly present ill'some of the quartz veins and 

stringers at the Gyps}^ copper camp.

SULFIDES

Molybdenite (MoS2 ). Small flakes of molybdenite 

are scattered through the altered limestone at the Coffin 

property and on the Dry Canyon road. The mineral 

is present also in small veinlets in the intrusive body at 

the Noisy Creek prospect and has been reported from a 

pegmatite dike on Molybdenite Mountain.

Galena (PbS). Galena is the principal ore mineral 

of lead and is found in all the mines and prospects. 

Most of the galena was deposited after sphalerite, and in 

replacement bodies lead ores are commonly of higher 

grade near the borders of shoots. Most of the galena 

is so coarse that cleavage surfaces are readily seen, and 

a few octahedral crystals were found at the Wolf Creek 

property. A small part of the galena is the finegrained variety known as steel galena.

Chalcocite (Ciu-S). A very little chalcocite was 

found coating pyrite in the partly oxidized ores at the 

Oriole mine and in a small cut on the Dumont group of 

claims in Uncas Gulch.

/Sphalerite (ZnS). Sphalerite is the principal ore 

mineral of zinc and at present is of greater economic 

value than other ore minerals recovered in the region.
MINERALS OF THE ORE DEPOSITS AND METAMORPHIC ROCKS 55

Several varieties of sphalerite are found; that in the 

veins is commonly "blackjack," but that in the replacement bodies is nearly free from iron. Four types of 

sphalerite are recognized in the replacement bodies. 

(1) A clour, pale-yellow or resin-colored variety (resin 

jack) of possible supergene origin is generally associated with and in places grades into (2) a brightreddish type (ruby jack). The centers of individual 

grains are commonly reddish, and the borders are 

resin-colored, although the reverse relations are known. 

A third type, of brownish color, is found in the same 

deposits and appears to grade into the resin-colored 

and reddish varieties. The fourth type is somewhat 

unusual in that it is so fine-grained that individual 

cleavage surfaces are difficultly visible. A specimen 

from the Bella May dump contains light-brownish 

sphalerite mixed with barite. Material on the Lucky 

Strike dump is pale waxy or dirty white. The Lucky 

Strike ore is peculiar in that the specimens are about 

50 percent pyrite, with the rest of the rock practically 

iron-free sphalerite and dolomite.

Sphalerite is generally associated with galena. Good 

crystals are found in calcite and more rarely in dolomite, projecting in vugs, and on quartz and paligorskite.

(ireenockite (CdS). The bright-yellow sulfide of 

cadmium was identified by W. T. Schaller in several 

specimens picked up on the dump at the Josephine 

shaft of the Pend. Oreille mine. Greenockite was also 

recognized in the oxidized ores at the Z Canyon mine.

PyrfKotite, (FeSi+). Pyrrhotite is an uncommon 

mineral but has been recognized in the altered limestone 

at the Coffin and 0. K. properties. A little pyrrhotite 

is found in a prospect pit with garnet, quartz, pyrite, 

and chalcopyrite in the west center of sec. 31, T. 35 N., 

R. 44 K., and also in the metamorphic rocks on Timber 

Mountain.

Chalcopyrite (CuFeSo). Chalcopyrite is a rare mineral in the district. It has been identified microscopically in the ores from the United Treasure and Frisco 

Standard and from the 0. K. and Oriole properties, 

where it occurs in small blebs scattered through tetrahedrite. Chalcopyrite is also present in the yeins at 

(he Gypsy copper camp and has been found with pyrrhotite, pyrite, garnet, and quartz near the intrusive 

contact in the west center of sec. 31, T. 35 N., R. 44 E.

Pyrite (FeS2 ). Pyrite is one of the most widespread 

and abundant ore minerals. It forms large bodies in 

the carbonate rocks of the Pend Oreille Gorge and in 

such places as the Flusey, Riverside, and Lucky Strike 

mines is abundant in and near the ore. Pyrite is 

present in small quantities in most of the ore deposits 

but is rare in the better replacement ores. Specimens 

from the Lucky Strike dump contain radiating clusters 

of fibrous iron sulfide that resemble marcasite. These 

radiating fibers are, however, isotropic and for this 

reason are called pyrite.

Marcasite (FeS2 ). A little marcasite is found in the

ore deposits in cracks and vugs. Where identified it 

is probably supergene. It is possible that part of the 

iron sulfide bodies exposed in the Pend Oreille Gorge 

are marcasite, although the radiating fibrous mineral 

from the Lucky Strike is pyrite.

SULFOSALTS

Pyrargyrite (Ag3SbS3 ). A small spot of a dark 

ruby-red mineral was found in a piece of ore from the 

Frisco Standard mine. Unfortunately this mineral 

was lost while a polished section was being prepared 

for study. It is thought that the material was a dark 

ruby silver, pyrargyrite or possibly pearceite 

(Ag0SbSo).

Tetrahedrite (Cu8Sb2 S7 ). Tetrahedrite is the ore 

mineral sought at the Frisco' Standard, United Treasure, and Oriole mines, where it is reported to contain 

considerable silver. A few spots of tetrahedrite or 

temiantite (CiVsASoS?) were seen in the Pend Oreille 

ore and in the marble at the O. K. property.

HALOIDS

Cerargyrite (AgCl) and bromyrite (AgBr) have 

been reported by Patty 51 from the Frisco Standard 

mine, but these minerals have not been identified during this investigation.

OXIDES

Quartz (SiO2 ). Quartz is one of the most widespread and abundant mineral's in the ore deposits and 

in the metamorphic rocks near igneous contacts. Finegrained dark-gray jasperoid is developed in the replacement bodies. Locally light-gray chert masses are abundant, and light-gray chert nodules are common in the 

upper part of the Metaline limestone. Transparent 

crystalline quartz is found in vugs in the jasperoid ore, 

and grajr chert and doubly terminated quartz crystals 

were seen in both the ore and the carbonate gangue. 

.Skeleton quartz crystals are enclosed in the paligorskite.

A few small specimens of an unusually fine fibrous 

quartz were obtained from an old stope in the GranclvieAv mine. The material was analyzed with the following results:

Analysis of fibrous qiuirts from Grandvieio mine 

[Analyst, Charles Milton]

Ignition

SiO2 __ 

AI 2O:. _ 

CaO__ 

MgO____

1.0

95. 7

1.3

. r.

3.2

101.7

01 Patty, B. N., The metal mines of! Washington : Washington. Gcol. 

Survey Bull. 23, p. 113, 192U
56 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

Under the miscroscope the fibrous mineral has the 

optical .properties of quartz except for the tips of the 

fibers, which appear to be chrysotile asbestos. The 

quartz seems to have replaced and inherited the structure of the chrysotile, although this relation is not as 

clear as niight be desired. Fibrous quartz, although 

uncommon, has been known for years. The subject 

has recently been reviewed by Thiesmeyer.52

Chalcedony (SiO2 ). A little chalcedony is found in 

fractures in some of the shallow ores and rocks. It 

is probably supergene wherever identified.

Cuprite (Cu2O). A few grains of cuprite were identified in a specimen of partly oxidized calcite and white 

quartz rock from the Dumont Brothers' claims on 

Uncas Gulch. The cuprite is associated with black 

copper oxide, malachite, and azurite.

Hematite* (Fe2O3 ). The specularite variety of hematite is rather common in quartzite beds but -lias not been 

identified with certainty elsewhere. No effort has been 

made to separate brown earthy hematite from goethite 

(Fe2O3 .H2O), and the two are described as iron oxides 

throughout this report. ,

Ilinenite (FeTiO3 ). Typical ilmenite plates are 

found in a quartz vein on the Fairview claim west of the 

Oriole mine.

Magnetite (Fe3O4). Magnetite is a common accessory mineral in all the igneous rocks and is abundant 

:in the lamprophyre dikes. It is unusual in the metamorphosed carbonate rocks and has been identified only 

at the Coffin property, where a few tiny crystals were 

found.

Rutile (TiO2 ). Small rutile crystals were seen in the 

altered carbonate rocks in the Priest River group north 

of Harvey Creek, and tiny needles are common in chlorite resulting from the alteration of ferromagnesian 

minerals, particularly biotite.

CARBONATES

Galcite (CaCO3 ). Calcite is one of the most Avidespreacl minerals in the region. It is abundant in the 

marbles and limestones, and the coarse-grained white 

variety is common near the ore deposits and along 

faults. Calcite is generally found in the quartz veins 

and occurs in veinlets and as crystals in vugs throughout the region.

Dolomite (CaMg(CO3 ) 2 ). Dolomite is one of the 

abundant gangue minerals in the replacement ore 

bodies. It is widely distributed through the bedded 

carbonate rocks, and crystalline dolomite is habitually 

found in and near the ore bodies.

Smithsonite (ZnCO3 ). The near-surface parts of 

most replacement ore bodies contain small quantities 

of zinc carbonate. Unusual specimens of botryoidal 

gray smithsonite were picked up on the dump of the 

Diamond R but are also found at the Pend Oreille and

M Thiesmeyer, L. R., Vein-quart/, pseudoinorphs of cross-fiber asbestos 

in Virginia: Am. Mineralogist, vol. 22, pp. 701-719, 1937.

Bella May mines. Most of the smithsonite, however, is 

typical "dry bone" and in places is mixed with iron 

oxides. A little smithsonite was reported to have been 

mined at the Josephine workings of the Pend Oreille 

mine during the first World War.

Cerussite (PbCO3 ). Cerussite is widely distributed 

in the outcrops of most of the ore bodies. Beautiful 

"nests" with crystals as much as three-quarters of an 

inch long were found in galena on the old Bella May 

ore pile, and smaller crystals were found in the mine 

workings. In most regions cerussite is separated from 

galena by a layer of anglesite (PbSO4 ), but anglesite 

has been identified in only one place in the Metaline 

area, in small crystals oil paligorskite from the 300- 

foot level of the Pend Oreille mine. Two common 

types of cerussite crystals are developed. One is dark 

gray, greasy, and tabular; the other is in needles and 

is white. A few vugs in the Bella May ore are lined 

with white crystals that are separated from galena by 

the darker crystals.

Malachite (CuCO8 .Cu(OH) 2 ). Green copper carbonate is a minor but conspicuous constituent in much 

of the white quartz in the oxidized zone at the Frisco 

Standard and other nearby lodes. A small amount was 

found at the Oriole mine and in an outcrop of white 

quartz and carbonate on the Dumont group, on Uncas 

Gulch.

Azurite (2CuCO3 .Cu(OH) 2 ). Blue copper carbonate is generally present with malachite but in smaller 

quantities.

SILICATES

Orthoclase (KAlSi3O8 ). Potash feldspar is found 

in liornfels, is generally microscopic, and seems to be 

largely confined to fine-grained rocks. The orthoclase 

in the igneous-metamorphic zone is usually fresh but in 

places is perthitic and partly altered to muscovite. 

Orthoclase is apparently one of the last silicate minerals 

to be deposited.

Microcline (KAlSi3O8 ). The potash feldspar microcline is conspicuously developed in places in the igneous- 

;metamocrphic pocks and is locally abundant in the 

intrusive bodies, where it forms crystals as much as 

3 inches long. Clear colorless crystals of microcline 

with epidote % and sphene line vugs in a coarse-grained 

rock from Timber Mountain.

Some specimens of the so-called microcline are optically positive. A sample from the Kaniksu batholith 

near the contact on the ridge south of Cedar Creek in 

sec. 10, T. 38 N., R. 42 E., was checked optically by 

Miss J. J. Glass and showed a=1.521, p=1.526, y=1.527, 

optical character + and ; 2V ranges from 45° to 

greater than 90°, disp. rO, quadrille twinning excellent. The mineral may be either anorthoclase or isomicrocline.

Albite (NaAlSi3O8 ). The soda feldspar is abundant in the ground mass of hornfels, in the greenstone
MINERALS OF THE ORE DEPOSITS AND METAMORPHIC ROCKS 57

fades of the Leola volcanics, and in lamprophyre 

dikes. It is rather common in perthitic inclusions in 

orthoclase and microcline.

Oligoclase (sodic plagioclase with 10 to 30 percent 

of CaALSLOs) and andesine (sodic plagioclase with 

30 to 50 percent of CaAl2 Si2 08 ). Feldspars of oligoclase and andesine types are recognized at many places 

in the igneous-metamorphic rocks and pegmatite bodies. 

Near the top of Timber Mountain crystals of andesine 

as miich as 1 inch across are associated with lightbrown garnet, green amphibole, sphene, and epidote.

Diopside (CaMg(Si.03 ) 2 ). Diopside is an abundant 

mineral, in the altered carbonate rocks, where it was 

probably formed by dedolomitization of dolomitic 

limestones. The mineral is generally white or rarely 

pale greenish. At the Coffin property a bright-pink 

manganoan diopside is intimately associated with 

white diopside. The indices of the pink mineral were 

determined by Miss J. J. Glass as a=1.675, £=1.683, 

y =1.701.

TremoUte (Ca2MgB (OH)2(81,0,0.). Tremolite is 

one of the most abundant minerals in the altered carbonate rocks. It occurs in radiating clusters and in isolated 

long laths. Tremolite commonly contains cores of 

white diopside and appears to have been formed from 

the diopside. The optical properties of a sample from 

Dry Canyon were determined by Miss J. J. Glass as 

a=1.603, £=1.617, y 1.629, biaxial negative, extinction ZAC=16°, r<v, axial angle 2V = ±80°.

Actinolite (Cao(Mg,Fe) G (OH2 (Si4 O1 j.) 2 ) and hornbUnde (similar to actinolite but containing alumina, 

ferric oxide, and alkalies). Monoclinic amphiboles 

are abundant in the altered sedimentary rocks, particularly hornfels, in the minor intriisives, and in the 

border facies of the Kaniksu batholith. Schiller structure is well developed in the green hornblende in the 

border facies.

Cordierite (Ha (Mg, Fe) 4AlsSi10O87) Cordierite was 

identified by Charles Milton in a thin section of knotty 

ph.yll.ite from the head of Wolf Creek. The mineral is 

packed with inclusions, a few of which have pale-yellow 

halos. Cordierite, with andalusite, makes up about 75 

percent of a specimen of hornfels from the line between 

sees. 4 and 9, T. 35 1ST., R. 43 E.

(rctmiQt (R" K R" / 2 (Si.O,i.) 3 ). Garnet is an unusual 

constituent of the altered sedimentary rocks but is common in the muscovite facies of the Kaniksu batholith 

and is present in pegmatite bodies. A light ambercolored garnet from Timber Mountain has an index of 

refraction of 1.749. A dark-brown garnet from a prospect pit in the west center of sec. 30, T. 35 N., R. 44 E., 

gave n=1.817. A little brownish garnet was also found 

in the altered carbonate rocks in Dry Canyon and in 

Little Muddy Creek Valley. The garnets in the intrusive rocks are generally less than one-eighth of an 

.inch across, but crystals half an inch in diameter have

been seen. In hand specimens these garnets are bright 

red or wine-colored, but under the microscope a specimen from Lost Creek showed reddish-brown cores with 

a pinkish border zone. The index of refraction 

tt= 1.810.

Zircon (ZrSiOJ. Microscopic crystals of zircon are 

found in the igneous-metamorphic zone and are particularly abundant in the fine-grained rocks, although 

present in the carbonate beds. The best developmen t of 

zircon seen is on Sand Creek near the contact between 

the intrusive and phyllite.

Topaz ([Al(F,OH) 2 ]AlSiO4 ). Irregular-shaped 

grains of colorless topaz were found in a thin section 

of pegmatite from the O. K. property. Optically the 

mineral is biaxial positive, with large (estimated 60°) 

optic angle, negative elongation, and extinction parallel 

to elongation. The birefringence is low. Samples of 

the mineral were not available for determining indices 

in oils.

Andalusite (Al2SiO5 ). Andalusite has been identified at several places in the hornfels near the Kaniksu 

batholith. Material collected on Hall Mountain just 

east of the intrusive in the northeast corner of sec. 15, 

T. 38 N., R. 44 E.,'was in well-formed crystals as much 

as three-quarters of an inch long, but the largest crystals 

found came from the metamorphic rocks west of Lost 

Lake, where they form elliptical nodules as much as 

an inch or more long. Many tiny inclusions in the 

crystals are crudely arranged, as in the variety Chiastolite. Much andalusite is partly altered to sericite and 

quartz.

Silliinanite (Al2SiO5 ). Sillimanite is found in hornfels and schists near the borders of the Kaniksu batholith. Commonly it is in needles less than 1 inch longthat fray out at the ends. A photomicrograph of sillimanite from the north bank of Little Muddy Creek in 

sec. 27, T. 38 N., R. 42 E., is shown in plate 20, B. 

The sillimanite needles are haphazardly oriented.

Zoisite (HCa2Al3Si3O13 ). The pink manganoan variety thulite has been recognized in three places near 

the peak on Timber Mountain, in the west center of sec. 

29, T. 36 N., R. 43 E., and in the south center of sec. 32, 

T. 36 N., R. 43 E. The crystals from Timber Mountain 

are as much as a quarter of an inch long but are generally smaller. They are distributed through a pegmatitic mass that is made up of andesine feldspar and 

dark-green chlorite. This thulite was studied optically 

by Miss J. J. Glass. It is biaxial positive, with 2V 

moderate but extremely variable; the indices are 

a=1.703, p=1.705, y =1.725. The thulite /grades" 

through pink epidote into straw-colored epidote. The 

other two occurrences of thulite are both in the muscovite phase of the Kaniksu batholith. The mineral 

is fine-grained and occurs in small spots and knife-edge 

seams that cut sharply across the rock.

Epidote (HCa 2 (Al,Fe) 3 S.i3O13 ). Typical pistachiogreen epidote is found in many places in the igneous
58 GEOLOGY AND UK'fi DEPOSITS O*' THE

metamorphic zone. It is present in pegmatite bodies 

and in the muscovite phase of the Kaniksu batholith. 

Epidote is commonly associated with the colorless ironfree clinozoisite and in places surrounds nuclei of 

brownish allanite. Pink and straw-colored epidote are 

found with thulite.

Allanite (HK"(R'") 3 Si3O13 ). The brownish rareearth mineral allanite is widely distributed with epidote. 

It is present in platy crystals as much as half an inch 

long in a 4-foot dike in Dry Canyon. The crystals 

are surrounded by a reddish halo one-eighth to on£- 

fourth inch wide.

Clinohumite (Mg(.F,OH) 2 .4Mg2 SiO4 ). Small 

orange-colored crystals of clinohumite were found in 

the metamorphosed carbonate rock at the Coffin property. .The optical properties of the mineral were 

checked by Miss J. J. Glass. The mineral is biaxial 

positive, has a large optic angle 2V=80°, indices 

a=1.640, /? = 1.654, y=1.674, dispersion r>v, extinction 

on a poor cleavage (001 ?) is a small angle. The indices 

are well above those of humite and are higher than those 

of any kno\vn chondrodite 53 but agree with those of 

clinohumite. Similar orange-colored crystals of clinohumite are found in an altered limestone" band at the 

top of Timber Mountain.

Hemimorphite (H2Zn2SiO5 ). The silicate of zinc, 

hemimorphite, has not been definitely recognized in. the 

ores, but its presence in the clayey weathered outcrops 

is suspected.

Tourmaline (a complex borosil.ic.ate of aluminum and 

other metals). Tourmaline is of widespread occurrence 

in the igneous-metamorphic rocks, particularly in the 

hornfels, schists, and quartzites. It is a common constituent in pegmatite bodies and in the muscovite facies 

of the Kaniksu batholith. Most of the tourmaline is 

black to the unaided eye and greenish under the microscope, but pale-yellow tourmaline was seen in a thin 

section of carbonate rock from the Hall Mountain trail 

north of Harvey Creek. At the O.K. property a finegrained bluish tourmaline powder occurs in seams cutting quartz veinlets and one specimen of a pegmatite 

mass contains colorless to deep rich-blue crystals.

Well-rounded detrital tourmaline grains are found 

in the black quartzite of the Ledbetter slate.

Thomsonite ( (Na2 ,Ca)Al2Si2Os2y2H2 0). Thomsonite is common in the lamprophyre dikes and in small 

amounts in the hornfels. It is generally in radiating 

clusters or spherulitic grains. The optical properties 

of thomsonite from a dike in the east-central part of 

sec. 8, T. 40 1ST., R. 44 E., were determined by Miss 

J. J. Glass. The mineral is biaxial positive, 2V=45°- 

48°, a=1.525-1.530, £=1.527-1.533, y= 1.535-1.541. 

In the lamprophyres thomsonite is formed from the 

feldspars, which are largely altered.

 " :i Lai'sen, E. S., The optical properties of the humite group: Am. 

Mineralogist, vol. 13, pp. 354-359, 1928.

MET/rLINE .QUADRANGLE, WASHINGTON

(Muscovite (H2KAl3 (SiO4) 3 ). Well .crystallized 

muscovite and the fine-grained variety sericite are 

widely distributed throughout the region but are particularly abundant in the less intensely altered rocks 

of the igneous-metamorphic zone. Muscovite is an 

essential mineral in much of the Ivaniksu batholith and 

in pegmatitic bodies. It was formed late in the mineral sequence and is thought to have resulted largely 

from the alteration of feldspars and other micas.

Biotite (H2K(Mg,Fe) 3Al(SiO4 ) 3 ). Black mica is 

an abundant constituent in the schists and hornfels. It 

is widely distributed through the igneous rocks and 

locally is concentrated in the border zone of the Knniksu batholith. It is one of the conspicuous minerals 

in the lamprophyre dikes.

Phlogopite (H2KMg3Al (SiO4 ) 8 ). Pale-b r o w n i s h 

phlogopite is a conspicuous constituent of the impure 

carbonate rocks in the igneous-metamorphic zone. 

Phlogopite occurs in fine-grained aggregates at the 

Coffin property, and on lower Harvey Creek a palebrownish schist composed mainly of phlogopite and calcite is one of the common rocks. In general phlogopite 

and biotite are concentrated in the more intensely metamorphosed rocks and locally are displaced by muscovite 

in the less altered rocks.

Chloritoid (H2 (Fe,Mg) Al2Si07 ) C h 1 o r i t o i d i s 

found in black porphyroblasts in the Maitlen phyllite 

in the schistose aureole that borders the batholith. 

The chloritoid is so unusual that some of its opticnl 

properties are given. The mineral is strongly pleochroic, X=dark gray to indigo, y=gray blue, Z = 

colorless, optical character positive, « = 1.723, /?=1.72(>, 

7=1.732, 2Y=50°-60° (estimate), moderate to strongdispersion r>i>. Interference colors are banded purple, 

blue, and green. Dustlike inclusions are abundant and 

in some crystals are arranged in hourglass structure. 

The specific gravity was not accurately determined 

but is near 3.

Ghlorite group (H8Mg5Al2Si3O18 ). Dark-greenish 

chlorite has commonly resulted from the break-down of 

ferromagnesian minerals. At the O.K. property calcite 

is in places separated from white diopside by narrow 

bands ( ± 1 millimeter) of colorless chlorite. Colorless 

chlorite has also been recognized in a few other slides of 

altered carbonate rocks.

Jeffevisite (complex magnesium-aluminum silicate). The jefferisite variety of vermiculite was found 

in altered carbonate rock from the Coffin property. The 

mineral is in white or pale-greenish flakes, generally 

one-eighth inch or less across. It is biaxial negative, 

/?=about 1.570. It expands slightly when heated with 

a blowpipe.

Serpentine (H4Mg3Si.,O9). Two types of serpentine 

are recognized. One is a yellow or greenish-yellow 

mineral found in the altered carbonate rocks, and the 

other is a clear green material that resulted from the
MINERALS OF THE ORE DEPOSITS AND METAMORPHIC ROCKS 59

alteration of olivine in the lamprophyre dikes. Yellow serpentine was collected from Dry Canyon, the 

O.K. .property, and the Coffin property. Under the 

microscope it is a colorless fine-grained fibrous mat. 

The, optical properties of the mineral were determined 

by Miss J. J. Glass.. It is biaxial positive, the indices 

are variable; lowest a=1.535, highest y= 1.555. The 

optic angle ranges from 25° to 50° or more.

(Jhrysotile (ILMgaSi^Oo). Veinlets of serpentine asbestos less than a quarter of an inch wide were found 

at, the Coffin property associated with yellow-green serpentine. These veinlets cut sharply across the enclosing rock, which is mainly diopside and serpentine. 

A little material thought to be chrysotile almost entirely replaced by quartz was found in the Grandview 

mine.

Talc, (H2Mg3 (SiOs ) 4 ). Talc was identified by Miss 

J. J. Glass in the altered carbonate rock from the 

Coffin property. The talc occurred with jefferisite in 

white diopside. It is likely that talc is present at other 

places in the metamorphic rocks but has not been recognized.

Paligorskite (hydrous magnesium-aluminum silicate) . Paligorskite, an unusual mineral of the sepiolite 

group, is illustrated in plate 17, B, which reproduces 

a photograph of a specimen from the 500-foot level of 

the Pend Oreille mine. The mineral is widely distributed in and near the ore deposits in caves and cracks. 

It has also been found in limestone beds in the Priest 

River group. The distribution in the Pend Oreille 

mine is described on pages 38-39. The optical properties 

determined by Miss Glass show the mineral to be biaxial negative, with the optic plane nearly parallel 

to the elongation of the fibers, a=1.506, /J=1.519, 

y=1.53t

Paligorskite is abundant below the water table but 

is absent or occurs in thin brittle plates near the surface. This fact indicates that the mineral is leached 

near the surface an indication that is given some support by the analyses below.

In order to determine the solubility of the mineral in 

cool waters samples of 2 grams each were placed in 

three flasks at room temperature. The first flask contained 1 liter of 0.1 normal HC1, the second contained 

1 liter of distilled water, and the .third contained 1 liter 

of 0.1 normal N"a2COa . After 21 days, during Avhich 

(he flasks were frequently shaken, the contents of each 

flask were examined by J. J. Fahey for Si02 and A12 03 . 

The results are given below.

0.1 normal HC1.._. 

'Distilled water.......,

0.1 normal Na2 (X)3 .

448039 43- -

Dissolved (approximate 

percent of sample)

SiOz

0.3

Trace

. 6

AhOs

0. 7

Trace

. 4

Mr. Fahey also estimated that the original sample 

contained not more than 1 percent of calcium.

Dickite (H4Al2Si2O9 ). The kaolin mineral dickite, 

the identification of which was checked by C. S. Ross, 

was found with barite in an altered carbonate rock in 

the west center of sec. 23, T. 38 N., R. 45 E.

Montmorillonite (H2Al2Si4Oi2H2O). A greasy clay 

mineral whose optical properties agree with those of 

montmorillonite is present in an altered pegmatite mass 

near the 0. K. property.

Chyrsocolla (CuSiO3 .2H2 0). A little chrysocolla 

was found in the oxidized ores at the Frisco Standard mine.

TITANOSILICATES

Sphene (titanite] (CaTiSiOB ). Sphene is an unusual mineral in the border facies of the Kaniksu batholith and in the igneous-metamorphic zone. Near the 

top of Timber Mountain on the east slope beautiful 

pale waxy brown wedge-shaped crystals as much as 

half an inch in longest dimensions are conspicuous. 

Smaller crystals of sphene are found, upon close inspection, to be scattered through the small intrusive bodies 

and locally in the border facies of the batholith.

SULFATES

Barite (BaSO4 ). Barite or heavy spar is abundant 

at only one place the Lead Hill mine, where it is a 

common companion of the lead-zinc ores. This barite 

is translucent, white, and in typical slightly curved 

platy aggregates. A few specimens of fine-grained 

white barite and light-brownish sphalerite were picked 

up on the dump of the old Bella May mine. Pink 

b.arite plates half an inch or less long were found in altered carbonate rock intimately associated with dickite 

in the west-center of sec. 23, T. 38 K, R. 45 E.

Anglesite (PbSO4 ). The sulfate of lead has been 

identified at only one place the 300-foot level of the 

Pend Oreille mine, where it occurs in tiny crystals 

on paligorskite.

Gypswn (CaSO4 .2H,O). A little gypsum Avas identified in the shallow workings on the Wolf Creek 

property.

MOLYBDATES

Wulfenite (PbMoO4 ). Plates of translucent colorless or pale-yellow wulfenite were found in the oxidized 

ore on the old Bella May dump, in the new Bella May 

adit, and on the dump at the Diamond R. In one 

specimen a cluster of small wulfenite crystals is grouped 

on the surface of a larger crystal of cerussite.

HYDROCARBON COMPOUNDS

Anthracite (C). Small shiny black globules of the 

composition of anthracite are found in the ores at the 

Pend Oreille, Bella May, and Wolf Creek properties. 

(See pi. 23, A.) As determined by Miss Taisia Stad-
60 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

nichenko, the material is about 90 percent fixed carbon 

and burns dean with no fusing and little residue. The 

globules are in dolomite, calcite, or quartz. In a few 

specimens the quartz is molded around the globules, 

which when removed leave smooth rounded niches.

THE MINES

For convenience of description the mines and prospects are grouped under the following headings: (1) 

Eussian Creek area, (2) Slate Creek district, (3) outlying areas, (4) Metaline district, and (5) placer 

deposits.

The United Treasure mine is in Stevens County, in 

the extreme northwest corner of the Metaline quadrangle. The property consists of three claims near the 

center of sec. 11, T. 40 N., K. 42 E., but nearly all 

exploration has been confined to the United Treasure 

No. 1 claim. In 1937 a low-level adit was being driven 

by F. G. Stevens, but no ore was being mined.

The property has had a history similar to that of the 

nearby Frisco Standard. A few small shipments of 

hand-picked ore have been made through a period of 

years, and from time to time efforts have been made to 

develop the prospect.

Most of the prospecting and all the mining were 

done in shalloAv adits and cuts along the outcrop of the 

lode. These aggregate about 1,000'feet of workings. 

A prospect tunnel has been driven about 800 feet into 

the hill below the ore, and late in 1937 a raise was 

started from the end of the drift in the hope of 

intersecting the lode.

The country rock is black slate, probably of Ordovician(?) age, which is much distorted and faulted. 

Bedding can, however, be recognized as narrow composition bands, which trend in general in a northwestward direction and dip less than 10° NE. Lamprophyre dikes, generally less than 3 feet thick, are 

widely distributed through all the workings. They 

are customarily associated with fault zones of graphitic 

gouge. The dikes appear to trend in general northwest, 

parallel to the trend of the bedding, and dip less than 

20° NE., although in detail they are extremely crooked.

The faults are rarely sharp, clean breaks; they are 

generally zones 3 to 10 feet wide in which the slate 

is much broken and contorted. Seams of graphitic clay 

are distributed through the disturbed zone. The walls 

are obscure, as the broken slate grades into less disturbed ground. In one fault in the lower tunnel the 

drag indicates an overthrust type; the hanging wall 

has moved up the dip toward the northwest.

The lode is an irregular vein zone of quartz and sulfides that ranges in width from a few inches to a known 

maximum of about 4 feet. The body is nearly parallel

to the bedding of the enclosing slate and is exposed for 

about 400 feet along its outcrop. In detail the vein 

crosses and is slightly flatter than the bedding planes. 

The quartz is in stringers that alternate with slate 

bands but in places coalesce to form massive quartz 

bodies with a few partings and shadowy remnants of 

the carbonaceous slate.

A thin lamprophyre dike accompanies the.ore and in 

most places overlies it but in at least one place is 

below the ore. . Jenkins 5* says: "The ore body * * * 

in most places lying below the dike, but in some places 

is found above it, and in some on both sides." In one 

of the short upper tunnels both the ore and the dike are 

cut by an irregularly trending fault, and the ore has 

not been found to the northeast across the fault. The 

dike is badly altered, but no ore minerals have been 

found in it. No convincing evidence was found to 

indicate the relative ages of the ore arid dike. Jenkins 

says: "In one place the igneous sill has been faulted, 

the rock having been displaced about 20 feet. On 

the upthrow side the ore lies below the dike and follows down the fault zone, filling and taking a position 

above the dike on the downthrow side. This shows 

that ore deposition occurred later than the fault, and 

therefore later than the dike." Patty 55 agrees that 

the ore is later than the dike. He points out the presence of ore both above and below the dike. Weaver,56 

however, states: "A completely altered dike * * * 

apparently cuts the vein or rather has been intruded 

along the zone of mineralization.'1

The lower adit was driven to intersect the ore zone 

on the assumption that the northward dip would be 

found to continue or possibly steepen. No mineralized ground was found, although several dikes were. cut. 

Late in the summer of 1937 a raise was started from 

the end of the tunnel in the hope of finding a continuation of the ore zone. To judge from the warped 

and lenticular nature of the ore bodies, exploration of 

this type is extremely speculative.

The ore and gangue minerals, in addition to quartz, 

include a little coarse carbonate, tetrahedrite, galena, 

and sphalerite. Considerable silver is reported to be 

present, and most of the returns from mining have been 

derived from the silver content. Along the outcrop 

of the lode the quartz is stained by azurite, malachite, 

and blade and waxy yellow minerals not identified with 

certainty.

Limestone crops out a few hundred feet Avest of the 

property and is well exposed along the road to Boundary. This limestone dips northward and is probably

64 Jenkins, O. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington Dept. Conservation and Development, Div. Geology, 

Bull. 31, p. 105, 1924.

65 Patty, B. N., The metal mines of Washington : Washington Geol. 

Survey Bull. 23, p. 115, 1921.

66 Weaver, C. E., The mineral resources of Stevens County: Washington Geol. Survey Bull. 20, p. 303, 1920.
THE MINES 61

separated from the Ledbetter slate by a fault parallel 

to Fish Creek, trending about N. 45° W.

FRISCO STANDARD (\J

The Frisco Standard mine is in Stevens County, in 

the extreme northwest corner of the Metaline quadrangle. The property consists of nine claims, seven of

The country rock is Ordovician (?) black slate that is 

much contorted. The regional trend appears to be 

nearly east-west or slightly north of west, with a flat 

dip (about 30°) to the south. The crumpling and 

slipping have changed part of the slate into soft graphitic clay gouge, which appears to be particularly 

abundant along the lode.

PLAN 

lOO

SECTION

2OO Feet

Datum /s approximate sea /ere/

Lode in heavy line,showing widthand dip 

FIGURE 9. Plan and section of Frisco Standard mine.

which are patented. No mining has been done here for 

several years.

The mine was a desultory producer for many years 

but has been handicapped by its inaccessibility and the 

complexity of the ore. The recent completion of a 

truck road to Metaline Falls should stimulate mining 

development.

About 1,000 feet of workings were accessible in 1937, 

and several other adits were caved at the portals. Figure 9 shows the relations of the three open adits and 

three caved adits of comparable length, as judged from 

the sizes of the dumps.

The ore is in a quartz lode or zone that has replaced 

the graphitic slate. The quartz trends about N. 

50°-70° W. and dips about 30° S.; it tends to parallel 

the bedding but in detail is crosscutting. No certainty 

exists that the three adits are on the same quartz vein, 

although this is possible. Weaver 57 suggested that the 

vein may be faulted along Jubilee Creek, and Patty 58 

called attention to the possibility of two parallel veins,

57 Weaver, C. E., The mineral resources of Stevens County, Wash. : 

Washington Geol. Survey Bull. 20, p. 304, 1920.

68 Patty, E. N., The metal mines of Washington: Washington Geol. 

Survey Bull. 23, p. .114, 1921.
62 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

one overlying the other. Still a third possibility is that 

the quartz bodies are lenses in an irregular fissure zone. 

Some support is given to this idea by the fact that the 

known fractures in the black shale are extremely 

irregular.

The quartz bodies vary considerably in thickness; in 

places they are mere stringers; elsewhere solid quartz 

masses 7 feet or more thick are found. All gradations 

between these two extremes exist; where followed 

toward a solid quartz body the stringers become more 

numerous and thicker and finally coalesce. Eemnants 

of the carbonaceous wall rock are generally preserved, 

and even in thick quartz bodies shadows and streaks 

are retained that parallel the foliation in the country 

rock. Some of the quartz contains sufficient country 

rock to give it a ribbon appearance.

The quartz in the ore is generally milky white, massive, and vitreous. The ore minerals are widely distributed but are apparently concentrated in shoots, 

about which almost nothing is known. The recognized 

minerals are galena, sphalerite, tetrahedrite, chalcopyrite, and a little pyrargyrite (?). The tetrahedrite is 

reported to contain considerable silver, and small quantities of gold are also present. Patty 59 gives the following smelter returns on three small shipments of 

sorted ore from the property:

Smelter returns on ore from Frisco Standard property

Shipment No.

!.____. ..___..___._...

2__ _-___.__.-__--__--__

3. ....._-.-_..--.-----

Gold 

(ounces)

0. 01

Trace

None

Silver 

(ounces)

72. 8

72. 0

49. 2

Lead 

(percent)

9. 6

16. 8

7.0

Copper 

(percent)

2. 7

4.6

3. 2

The oxidized zone seems to be confined to a depth 

of 100 feet or less from the surface. In this zone the 

milky-white quartz is stained brilliant hues of blue, 

green, yellow, and black. These salts are thought to 

be mostly those of copper and iron. Patty 60 mentions 

both cerargyrite and bromyrite, but the presence of 

these two minerals has not been verified. Malachite 

and azurite have been recognized.

MY ERA

The My Era property is across the gulch west of the 

Frisco Standard mine, near the east center of sec 11, 

T. 40 N., E. 42 E. Here two shallow adits have been 

driven into the hill to intersect the mineralized zone. 

The country rock is distorted black Ordovician (?) 

slate similar to that in the adjoining Frisco Standard 

and United Treasure properties. Numerous lampro68 Patty, E. N., The metal mines of Washington : Washington Geol. 

Survey Bull. 23, p. 114, 1921. 

«° Patty, E. N., op. cit, p. 113.

phyre dikes and sills are shown in the adits and on the 

slope above the prospect.

The mineralized lode is about 2 feet wide and consists mainly of quartz with bands and remnants of 

slate. Considerable galena and some tetrahedrite 

are present and are reported to carry much silver. The 

ore, where exposed, lies between a dike (sill?) and the 

country rock. Several other quartz bands were cut 

in the lower tunnel. These bands are generally next 

to dikes (sills?) and are barren or weakly mineralized 

where exposed. The maximum width of quartz is about 

4 feet; generally the widths are 2 feet or less.

No work was being done on the property in 1936 or 

1937.

JUST TIME

The Just Time (Star) property is in the west center 

of sec. 15, T. 40 N., R. 42 E., about 1% miles southwest 

of the United Treasure. The workings extend from 

a shaft that was inaccessible when visited, and nothing 

was learned of them. Meager information was obtained from the dump and the poor exposures of the 

vicinity.

The country rode is limestone, thought to be of 

Devonian (?) age. An outcrop near the mine is intraformational conglomerate similar to that found on the 

road near the United Treasure property and shown on 

plate 10. The country rock on the dump is a cemented 

breccia that effervesces weakly with 1:1 HC1. A little 

crystalline dolomite is present, and coarsely crystalline 

white calcite is abundant. Milky-white vitreous quartz 

is,also plentiful; part of it is crystalline and vuggy. 

and numerous veinlets extend through the magnesian 

limestone.

Small amounts of galena, sphalerite, and pyrite are 

found in the quartz and, to a less extent, in the coarse 

calcite and dolomitic limestone.

Some of the coarse calcite is brecciated and cemented 

by veinlets that contain tiny euhedral quartz crystals.

SLATE CREEK DISTRICT

The Slate Creek district, as the term is used in this 

report, lies east of the Metaline Falls-Nelson highway 

and includes all the territory tributary to the Slate 

Creek road. The district has been known for about 10 

years but so far has not become a steady producer. 

The Lead Hill (Bunker Hill) property was the site 

of active development in 1931-32 and is the best-known 

prospect in the district. Galena and sphalerite are 

widely distributed in the dolomitized limestone. Practically the entire area is held by prospectors and during 

the recent economic depression was idle, even assessment 

work being mostly suspended.

The country rock is dolomitized limestone overlain 

by black slate. The stratigraphic and structural relations are not entirely clear; they have been discussed
THE MINES 63

in. connection with, the Slate Creek fault (pp. 30-31). 

In general the ore deposits are iii the dolomite below 

the black Ordovician slate, and it is thought that the 

nearness of the Slate Creek fault has a genetic significance. Some mineralized ground away from the slate 

and fault appears to be related to subsidiary fractures 

and minor faults.

The Lead Hill (Bunker Hill) property contains 16 

claims and fractions, nearly all in sec. 14, T. 40 N., 

R. 44 E. The workings are on the northwest bank of 

Slate Creek, about 15 miles from Metaline Falls by a 

good truck road.

In 1931-32 a development program was undertaken 

by the Bunker Hill & Sullivan Mining & Concentrating 

Co., of Kellogg, Idaho. Under the supervision of this 

company's staff part of the property was diamonddrilled and a 1,400-foot adit was driven into the hill. 

The many surface cuts and shallow adits are shown on 

plate 28. During 1937 assessment work Avas done and. 

a small lot of hand-picked galena was shipped.

The country rock consists of dolomitized limestone 

and jasperoid. overlain by black slate. Near the ore 

deposits the dolomite is commonly creamy gray and 

coarse-grained, with patches of "zebra" rock. Stringers 

of jasperoid and dark-gray dolomite are generally 

present. Strati graphically below the coarse-grained 

dolomite is fine-grained cherty limestone similar to the 

material, below the Ledbetter slate in the unmineralized 

section. At Lead Hill this limestone is generally high 

in magnesium or has been converted to jasperoid. 

Large areas of coarse white calcite are present. Plate 

24, A, shows these large calcite crystals with dolomite 

formed around them and in the cleavage cracks. Three 

types of silica have been recognized; one consists of the 

cherty .nodules common to this horizon, and the others 

are dark-gray or black jasperoid associated with the ore 

lie posits and a, light gray jasperoid that grades into the 

darker mineral. The black slate in the neighborhood of 

Lead Hill is poorly exposed, as it is largely under the 

Slate Creek terrace. However, the black quartzite 

member can be seen just southwest of the long adit and 

in Slate Creek below the mine. The slate can also be 

seen at several places along the road and the old trail 

northeast from the mine.

The attitude of the dolomites is not very well shown 

in the workings, but on the hill to the northwest banded 

black and \vhite dolomitic limestones trend east of north 

and dip about 30° E. The quartzite layer in the black 

slate has a similar trend but appears to have a steeper 

dip. Much of the dolomite is brecciated and recemented by jasperoid. This material is particularly 

well shown on the good outcrops north and northwest 

of the mine, on top of the ridge. Faulting at the mine 

is obscure, but is probably common. A general north 

to northeast trend prevails, although slips trending

nearly east and west are also found. The small amount 

of diamond drilling done on the flat below the mine 

indicates a cover of black slate underlain by dolomite, 

confirming an eastward dip for the contact. The mine 

workings are probably about a quarter of a mile from 

the main Slate Creek fault.

The known ore deposits are confined to a shallow 

zone near the surface. The long adit nearly parallels 

the strike of the bedding or cuts it at a low angle and, 

except for mineralized ground about 100 feet from the 

portal and a few "shines" near the face, appears to 

be devoid of sulfide mineralization. The rock exposed 

in the adit includes .some jasperoid similar to that usually found with or near ore deposits. If, as appears 

to be reasonable, this deposit is comparable to the more 

completely explored bodies near Metaline Falls, the 

ores approximate bedding deposits. The ores throughout the region are generally in jasperoid and dolomite 

under a cover of black slate. At Lead Hill the slatecarbonate rock contact dips eastward. All available 

evidence indicates that the extension of the known ore 

body, if it exists, is to the east under the Slate Creek 

terrace below the black slate.. If this is true, most of 

the exploration to date has been below the mineralized 

beds. This statement, however, is not meant to imply 

the belief that no mineralized ground will be found at 

the horizons below the adit.

Galena which locally is rich enough to cob by hand, 

is the most abundant ore mineral and is generally fresh 

at the surface. A little sphalerite is also found, although this mineral is generally leached. In contrast 

with all other deposits in the quadrangle, one of the 

common minerals at Lead Hill is barite. This barite 

resembles the coarse white calcite at first glance; it is 

in cleavage plates as much as about 2 inches long and 

is white like the calcite.

Much of the ore on the surface is unoxidized. HOAVever, along cracks and in porous breccias oxidation has 

taken place. This can be seen in the adit, where limonite is developed on nearly all fractures and in breccias. 

Small amounts of smithsonite and cerussite Avere found,

BAIUEY-HANSON

The Bailey-Hanson group of 16 claims is in sec. 1, 

T. 40 N., R. 44 E. The property is reached by a good 

dirt road extended northeast about %y2 miles from Lead 

Hill in 193T.

Numerous cuts and shallow prospects adits have been 

made here. These diggings are scattered on mineral 

shoAvings throughout the claims, and no drilling or 

deep exploration has been attempted.

The country rock consists of dolomite and limestone 

similar to those at Lead Hill. Near the mineralized 

zone the dolomite is generally crystalline and creamy 

or gray. Part of it is fine-grained, dense limestone 

wtih cherty nodules; Stratigraphically below this are 

banded black and white limestone and dolomite. To
64 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

the east lies the Ordovician slate, which is exposed 

in road cuts between the property' and Lead Hill. 

This slate contains many poorly preserved graptolites. 

At least one lamprophyre dike, about 4 feet thick, 

trending N. 30° E. with a steep east dip, and one lightcolored dike, now altered to a zeolite-rich rock, were 

noted.

In the canyon of the Salmo River to the north the 

slate-dolomite contact trends N. 20°-30° E. and dips 

about 65° E. The dolomite flattens westward from the 

contact, although toward the east dips as great as 45° 

are found. It is probable that the section is repeated 

by strike faulting, thus making the strata appear much 

thicker than they are.

Both galena and sphalerite are widely but sparingly 

distributed through the dolomite on the surface. They 

are commonly localized along fissures and small faults. 

Some of the sphalerite is leached, and smithsonite is 

formed in solution channels.

DTJMONT PROPERTIES

Two groups of claims are held by William and 

George Dumont. One group of five claims and one 

fraction is on Slate Creek in sec. 30, T. 40 N., R. 44 

E.; the other group is northeast of Uncas Gulch, in 

sec. 28, T. 40 N., R. 44 E., and contains six claims 

and two fractions.

The group on Slate Creek is in the dolomite at and 

near the dolomite-slate contact. This contact is exposed in three places in the shallow workings; in each 

of the three the contact is a fault. Most of the dolomite 

is typical of the recrystallized beds below the slate. 

In one place, however, about 50 feet below the slate, 

there is a thin layer of black limestone with white spots, 

similar to the type found in the section below the 

 nodular cherty limestone. Coarse white calcite is 

widely distributed, but the dolomite is noticeably less 

siliceous than in most other mineralized deposits. In 

one shallow adit a lamprophyre dike about 9 feet thick 

was cut. This dike trends N. 85° E. and dips 85° N. 

The bedding, taken on the black spotted limestone layer 

mentioned above, trends N. 70° W. and dips 30° N.. 

The strike, if continued, would abut against the slate. 

It seems likely that a fault with a throw of probably 

200 to 300 feet lies between the dolomite and slate. 

Smaller cross faults trending northwest are common, 

and in one place the slate southwest of the fault has 

moved northwestward about 200 feet.

The ore is distributed in the dolomite, so .far as seen, 

within about 200 feet stratigraphically below the slate. 

Both sphalerite and galena are present, and one stringer 

of high-grade galena was uncovered. No shipments 

have been made. A few diamond-drill holes were sunk 

by the Pend Oreille Mines & Metals Co..

The upper or Uncas Gulch group of claims is at a 

lower(?) horizon than the group on Slate Creek,

although both are below the slate. The country rock at 

the Uncas group is fine-grained magnesian limestone 

that in places contains numerous chert nodules. It is, 

however, interbanded with dark-gray or black phyllites 

that resemble the Orodovician slate except for lightColored limy bands. The top of the hill is Ordovician 

slate, as a few deformed graptolites were found in it. 

The strata trend about N. 20° E. and dip steeply to the 

west, although a few eastward dips were recorded. 

Where followed along the strike toward Uncas Gulch, 

the beds abut against the phyllites. Uncas Gulch is for 

this reason considered to be the site of a fault trending 

about N. 45° W.

Considerable prospecting has been done on this property, and surface cuts are widely distributed. No drilling or underground exploration has been attempted. 

The surface showing consists of sphalerite and galena in 

small amounts distributed throughout much of the dolomitic limestone. In two cuts considerable milky-white 

quartz is exposed. This quartz contains, in addition 

to galena and sphalerite, a few small grains of tetrahedrite and is stained blue and green from copper 

carbonates.

OTHER PROPERTIES IN THE SLATE CREEK DISTRICT

Much of the Slate Creek district has been staked at 

least once, but very little active exploration has been 

attempted. During 1937 some assessment work was 

done; this consisted almost entirely of shallow cuts or 

adits in dolomite or dolomitic limestone. Considerable 

work has been done on the Ira Troyer properties, particularly in the southeast corner of sec. 22, T. 40 N., 

R. 44 E. One adit has been started in black slate and 

is being extended to intersect the contact with the magnesian limestone. On the Sanborn property, near the 

international border west of the Bailey and Hanson 

group, a little exploration has been done on a highgrade streak of galena.

OUTLYING AREAS 

MULE DEER

The Mule Deer property is in the west-central part 

of sec. 15, T. 35 N., R. 44 E. It is controlled by the 

New Deal Mining Co., in charge of J. R. Delvendahl, 

of Seattle. The workings are on the divide between 

LeClerc Creek and Middle Creek, at an altitude of 

about 3,050 feet. They are accessible by road from the 

Panhandle lumber camp.

The property was operated for a while during 193 Y, 

but work was suspended late in the summer. In 1938 

it was reported that a small mill was being constructed. 

An old shallow adit, reported to "have been driven about 

50 years ago, and a new shaft sunk about 30 feet are the 

only workings.

The ore occurs in an altered and sheared facies of 

the Kaniksu batholith, Not enough work has been 

done to define the shape of the deposit, but superficially
THE MINES 65

it suggests a pipe rather than a tabular fissure zone. 

The altered rock is light greenish-gray and contains 

much micaceous material. A few small vugs are lined 

with quartz crystals, and in places small quartz 

stringers cut the rock. Black, brown, and red spots 

of iron oxides give part of the rock a mottled appearance. All the altered rock seen is also weathered.

Small quantities of galena, sphalerite, and pyrite are 

recognized, and silver is reported to be present. "The 

mineralization persisted in the bottom of the shaft.

Tliis prospect is particularly interesting, as it is one 

of the few places where mineralization is known to 

have occurred in the quartz monzonite mass away from 

contacts.

LITTL.E NOISY

The Little Noisy prospect is in sec. IT, T. 38 N., 

B. 44 E., about half a mile above the mouth of Little 

Noisy Creek. The property is owned b}' a group of 

Tone businessmen, and during 1937 one man was employed prospecting. Two adits were open, a lower 

and an upper, each driven into the hill north of Little 

Noisy Creek. The lower adit was driven N. 25° E. 

for 250 feet, then N. 75° E. for 70 feet. This adit 

penetrated, about 290 feet of slide rock before entering 

solid material. The upper adit contains about 940 feet 

of workings (paced). This adit was driven 162 feet 

N. 12° E., to a crosscut. From this crosscut drifts 

have been opened in every direction in an attempt to 

locate min able ore. Another short adit is reported to 

have been driven in a branch gully northeast of the 

upper adit. This was not visited. Several shallow 

cuts and adits have been opened in the creek walls 

below the main adits.

The country rock is phyllite intruded by a small granitic mass. In the neighborhood of the prospect bedding has been almost destroyed, and such remnants as 

are found are jumbled and too few to give a clue to 

the structure. The rock is best classified as a hornfels. 

The mineralized zone was cut at 162 feet (paced) from 

the portal of the upper adit. This zone trends N. 70° 

E. and dips about 75° SE. It contains considerable 

gouge (about 1 foot) and irregularly, distributed 

lenses of quart/, with a maximum observed width of 

4 feet. Much of the mineralization has occurred along 

the intrusive phyllite contact. Only a small amount 

of work in solid rock has been done in the lower adit; 

where a badly disturbed zone of quartz, intrusive rock, 

and phyllite was found. More quartz is present here 

tli an in the upper adit.

The lode contains scattered grains of galena, sphalerite, and chalcopy.ri.te, in places with much pyrite. 

Pyrrhotite and molybdenite in small amounts were 

identified, and one seam of molybdenite was found in 

the granitic rock. Sparse black tourmaline and white 

carbonate that weathers brown are also present.

The Gypsy copper camp is on the north slope of 

Sullivan Creek in the southeast corner of sec. 18, T. 

39 N., R. 45 E. Considerable drifting and surface 

prospecting have been done in the vicinity in the past, 

but the properties were idle when visited.

The country rock is massive greenstone of the Leola 

volcanics, and the ore minerals are mainly chalcopyrite 

and pyrite in quartz veins and stringers. Considerable 

white carbonate is scattered through the quartz, and 

chlorite is abundant in bands and fragments that are 

remnants of the country rock. The veins are small, 

few being more than a foot wide, but they seem to be 

persistent along the strike, in places for several hundred 

feet or more.

The veins described are typical of a group of similar 

deposits in the greenstone and greenstone schist (Leola 

volcanics).

COFFIN

The Coffin property is in sec. 16, T. 38 N., E. 42 E., 

northwest of lone, on the west border of the Metaline 

quadrangle. The developments consist of only a few 

shallow cuts and tunnels, but they show the hard, unweathered country rock and the type of mineralization 

fairly well. During 1937 a right-of-way for a road was 

cleared to the property from the Smackout Pass road 

Avest of lone.

The country rock is mostly a medium-grained white 

marble, with beds of dense buff marble, which in places 

is interbanded with and grades into hornfels (phyllite). 

The marble effervesces freely with cold 1:1 hydrochloric acid. The lime-phyllite rocks have been intruded by the Kaniksu batholith, and the ore deposit 

is in the limestone near the contact.

The contact metamorphism of the strata has been 

similar to that shown in many places along the border 

of the intrusive mass, but more sulfides were seen here 

than elsewhere. In some of its features the deposit 

resembles those on 0. K. Mountain, on Timber Mountain, and near the intrusive-sedimentary contact in Dry 

Canyon about 2 miles north of the Caldwell Lake road, 

where molybdenite was found in metamorphosed limestone.

The marble at the Coffin property is generally silicified, in some places intensely. Diopside is abundant, 

and serpentine, sphalerite, galena, pyrrhotite, molybdenite, tourmaline, jefferisite, talc, pink diopside, and 

other minerals are disseminated through the silicified 

marble.

METALINE DISTRICT 

BELLA MAY

The Bella May mine portal is between the main 

north-south highway and the Pend Oreille Kiver, about
66 GEOLOGY AND ORE DEPOSITS OF THE METALENE QUADRANGLE, WASHINGTON

half a mile south of old Metaline. The mine is owned 

by the Metaline Mining & Leasing Co., a subsidiary of 

the American Zinc, Lead & Smelting Co. During 1936 

and 1937 the property was developed, and in October 

1937 extraction of ore was begun. The mine was closed 

April 1, 1938, because of adverse economic conditions, 

but reopened November 1,1938. The zinc-lead ores are 

trucked to the flotation mill at the Grandview mine, and 

the flotation concentrates are shipped to the American 

Zinc Co.'s smelter in St. Louis.

The value of the metal produced from the Bella May 

is not exactly known. Mineral Resources lists shipments in 1917, 1918, 1923, 1924, 1925, and 1926. 

Jenkins 61 stated (December 1924) that 18 carloads of 

ore had been shipped from the Bella May. Much of 

the production before 1937 was obtained from highgrade, hand-picked galena, although at least one unsuccessful attempt was made to mill and produce zinc and 

lead concentrates. Jenkins 62 also reports a shipment 

of 5 tons of galena from the Blue Bucket claim, one of 

the present Bella May group.

The Bella May workings 'are divided into three 

groups the old Bella May, the Blue Bucket, and the 

new adit level. The old Bella May contains about 2,000 

feet of accessible underground workings, mainly on two 

adit levels. (See fig. 10.) Considerable gophering 

has been done in these old workings, and numerous 

shallow stopes and cuts have been made wherever the 

mineralized ground looked encouraging. (See pi. 29.) 

The Blue Bucket workings were apparently opened 

from a shallow shaft, which was inacessible when visited. In 1936 a new adit was started on the west bank 

of the Pend Oreille River and when last visited in 

1937 had been driven 4,800 feet into the hill. (See 

pi. 30.) In 1938 the adit had been extended to 5,724 

feet from the portal; the inner 876 feet was turned to 

due west. Inclined raises (55°) and drifts were being 

pushed to intersect zinc-lead ore shown by diamond 

drilling to exist beneath both the old Bella May and 

the Blue Bucket workings. An extensive diamonddrilling campaign was undertaken before starting the 

new tunnel, and as the work progressed diamond 

drilling was continued both on the surface and 

underground.

The country rock exposed in the new adit comprises Metaline limestone and Ledbetter slate. The 

portal is in the spotted black and white member of the 

Metaline limestone, probably more than 1,200 feet above 

the phyllite. The rocks in the adit are too much broken to furnish a continuous recognizable stratigraphic

61 Jenkins, O. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington Dept. Conservation and Development, Div. Geology, 

Bull. 31, p. 65, 1924.

««Idem, p. 67.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 202 PLATE 29

imestone breccia

100

EXPLANATION

.< v

.* *

te

Open cut

* "*.

%«/

Dump

/40°

Fracture

^23° 

Strikeand dip

20O Feet

Contour interval 2O -Feet 

Datum mean sea /eveI
THE MESHES 67

column. Two narrow lamprophyre dikes were cut, and 

many clay- and gravel-filled caves along enlarged 

( racks were found in the first 700 or 800 feet of the 

adit. Some of these caves are 500 feet or more below 

tho present terrace surface, although probably much 

nearer the actual, rock surface. The old Bella May and 

Blue Bucket workings are both in crystalline dolomite 

that stratigraphically is below the slate and above the 

fine-grained, dense limestone in the upper part of the 

Metaline limestone. Much of the limestone is dolomitized, and two or possibly three types of silica were 

recognized. One type is nodular chert, abundant in 

the lower part of the fine limestone; the other type is 

dark-gray jasperoid abundantly associated with the 

ores. Large bodies of light-gray fine-grained silica are 

also cut in the workings. It is not known whether or 

not this light-gray silica is the same as the darker jasperoid. In the lowest tunnel of the old Bella May 

 workings a band of black shaly material, less than 4 

feet thick, is found. This may be a slate band 

squeezed along a fault.

Bedding is recognized in many places. Generally, 

in the new adit, it strikes northeast and dips northwest. Some reversals were seen, and in places the 

rocks are much broken and sheared. Throughout the 

workings narrow gouge seams trend northeast and dip 

less than 30° SE. The movement on these seams was 

slight, probably at most a few feet. Wherever recognizable, it was of the reverse type and was sufficient 

to cause a little gouge to develop, and, particularly 

near the surface where leaching has been active, these 

scums are easily confused with bedding.

Four major faults were cut in the new adit at distances of 1,830, 2,580, 2,800, and 4,180 feet from the 

portal. The faults, together with many smaller slips, 

are shown in plate 30. Each of the four major breaks 

marks a boundary between slate and carbonate rock. 

Those at 1,830, 2,800, and 4,180 feet appear to be normal 

faults, and the one at 2,580 feet is reverse; the amount 

of displacement on any of the faults is, however, unknown. The attitudes of the breaks at 2,580 and 4,180 

feel; are s.liow.n Avith confidence, as they have been cut 

in raises. (See pi. 30.) The dips of the other two 

f an Its are loss certain, as the irregular zones of disturbance and the small exposures in a drift will not permit 

accurate projection very far.

As interpreted in the general section on structure 

(p. 31), the Metaline limestone exposed in the tunnel 

between 2,580 and 2,800 feet is part of a block thrust 

over the slate and preserved between two normal faults. 

The carbonate rock in this thrust block at the Bella 

May mine is probably less than 400 feet thick and 

appears to be the beds that, stratigraphically, should

be just below the slate. It is highly probable that the 

thrust block is not a simple unit, but, to judge from the 

meager exposures, is an intricately faulted and shattered mass. °

The ore bodies appear to be typical sphalerite and 

galena masses, formed by the replacement of carbonate 

rocks. So far as now known, they lie in dark cherty 

zones, generally less than 500 feet below the slate. 

Numerous spots of sul fides are found elsewhere in the 

carbonate rocks, usually near or along faults, and it is 

entirely possible that ore will be found at other horizons. The ore bodies are as yet too poorly exposed to 

permit discussion of their localization and physical 

features beyond a very few observations. The unbroken nature of the ore minerals in the breccias of 

the major faults indicates that mineralization followed 

the period of most severe faulting. Evidence o/postmineral faulting is abundant in the Pend Oreille mine, 

though the movement on the faults was usually small, 

and it is likely that somewhat similar late faulting has 

affected the Bella May ore bodies.

The ore minerals are galena and sphalerite of two 

colors, reddish-brown and yellow. Jasperoid, creamygray crystalline dolomite, with locally some dense finegrained dolomite, and coarse white calcite are the 

dominant gangue minerals. A little fine-grained barite 

with sphalerite was picked up on the lowest dump in 

the old Bella May workings. A few small globules 

of carbonaceous material (anthracite composition) were 

found in the dolomite, and a little flake graphite was 

found in the dolomite along one of the major faults.

Smithsonite and anglesite ,are developed in the oxidized ores, but in places galena persists to the surface. 

A few crystals of wulfenite were found in one ore pile 

and in the new adit, and vugs with beautiful projecting 

crystals of cerussite are found in some of the larger 

nodules of galena.

CLIFI;

The Cliff is a patented claim in the north-central part 

of sec. 22, T. 40 N., K. 43 E. The workings are east 

of the road between Ledbetter Lake and Russian Creek, 

about 10 miles from Metaline Falls. The property was 

idle when visited and apparently had not been worked 

for several years. Bancroft 63 reported a small shipment from the claim prior to 1910, and Mineral Resources mentions some production in 1924 and 1925. 

Probably the entire production has been high-grade, 

hand-picked galena. Two shafts and an old surface 

stope were inaccessible when visited, but the country

08 Bancroft, Howland, Ore deposits of northeastern Washington : U. S. 

Oeol. Survey Bull. 550, p. 49, 1914.
68 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

rock and the mineral bodies were exposed in a trench 

about 30 feet long and 10 feet deep.

The county rock is a medium-grained dark-gray 

dolomite breccia that in places 0 has been changed to 

jasperoid; its exact stratigraphic position is not known. 

Weathered dark greenish-gray shale is on the dump and 

is exposed on the hillside east of the workings. It is 

reported that this shale was found in the bottom of 

one of the shafts, which, would indicate a steep northwest dip. Slips in the cut that might be bedding planes 

agree with this dip. The shale, as estimated from the 

poorly exposed outcrop, is about 25 to 50 feet thick. 

East of the shale on the hill a white cherty dense 

marble is conspicuous.

Two sets of fractures, in addition to the bedding, are 

seen in the open cut. One set strikes N. 35° E. and 

dips 65° SE.; the other trends N. 30° E. and dips 

60° NW.

Galena is the only suljfi.de recognized, but some ironstained cavities may represent former sphalerite grains. 

The galena is in streaks and coarse irregular patches 

in the jasperoid and dolomite breccia.

DIAMOND R

The Diamond E is a patented claim near the center 

of sec. 30, T. 39 N., E. 43 E. about 1 mile west of the 

old Bella May workings. No work has been done here 

in recent years, but Patty 64 reports a carload of ore 

shipped in 1918 and a few scattered shipments prior to 

that time. An adit, reported to contain about 200 feet 

of drifts, and several open cuts constitute the development workings.

The country rock is a gray brecciated crystalline, 

medium-grained dolomite near the top of the Metaline 

limestone. A little coarse white calcite is also present! 

The exposures are poor, and the region around the 

workings is covered with a tangled growth of alder in 

an old burn and windfall which is not conducive to a 

search for outcrops. The attitude of the bedding is 

not known. A few hundred feet south of the adit, black 

Ordovician slate is exposed in an old cut. Its relation 

to the dolomite is not definitely known although probably the formations are separated by a fault.

Most of the work was done on small irregular streaks 

of high-grade galena, which in places formed mineable 

pockets. A little sphalerite was seen on the dump, and 

holes thought to have contained sphalerite before 

weathering are fairly common. Smithsonite, cerussite, 

and wulfenite were noted in the oxidized ores.

FLUSEY GROUP

The Flusey and Hoopalula are patented claims 

on the west bank of the Pend Oreille Kiver about 

1 mile north of the mouth of Slate Creek, in sec. 26,

64 Patty, E. N., The metal mines of Washington: Washington Geol. 

Survey Bull, 23, p. 86, 1921.

T. 40 N., E. 43 E. The property has been prospected 

by several surface cuts and two tunnels, both inaccessible when visited.

The country rock is light gray-white fine-grained 

dolomitic limestone that in places contains many small 

chert nodules. Much of the rock is limonite-stained, 

and several bodies of partly oxidized iron sulfide are 

exposed in the canyon walls. The carbonate rocks 

strike in general N. 10° E. and dip 35°^tO° W. East 

of the workings in the river gorge some of the dolomitic limestone contains black bands with white spots 

typical of the Cambrian limestone 600 feet or more 

below the top of the formation. On the dump galena, 

sphalerite, and marcasite are found. The country 

rock on the dump is mostly recrystallized gray evengrained dolomite.

GIANT

The Giant claim, owned by James Ehle, of old Metaline, is east of the road near the center of sec. 22, T. 

40 N., E. 43 E., about iy2 miles south of Z Canyon. 

A few cuts have been made on a mineralized outcrop 

on the hill east of the road. During the summer of 

1937 a compressor was installed and an adit was started 

from the road to undercut this outcrop. In 1938 the 

adit had been opened 200 feet, and two men were driving it ahead. Thejcountry rock consists of dense white 

cherty magnesian limestone and large irregular patches 

of black or dark-gray jasperoid, gray crystalline dolomite, and coarse white calcite. The rock, as on the 

adjoining E. J. Hoage property, is considered to be 

strati graphically within 200 feet below the black slate. 

The attitude is vague, but the strike seems to be about 

N. 10°-20° E., with westward dips of about 20°.

Considerable disseminated fine-grained sphalerite 

and numerous spots of galena are found, particularly in 

the jasperoid. A little smithsonite was seen in one of 

the cuts.

GRAND VIEW

The Grandview group of 15 patented claims is on 

the bluff east of the Pend Oreille Eiver about 1 mile 

north of the toAvn of Metaline Falls. During 1937 

control of the property was obtained by the Metaline 

Mining .& Leasing Co., and an intensive diamonddrilling campaign was begun. The old Grandview 

mill was remodeled and in October 1937 began to 

treat ore from the ne\t Bella May adit south of old 

Metaline,

Small production from the Grandview is recorded 

for 1924, 1925, and 1926, and in 1929 most of the production of the district, $179,592, is credited to the 

Grandview.65 In 1937 two carloads of concentrates 

that had been stored at the mill were shipped to the 

smelter. During the years 1928-29 the property was 

the scene of an Unjustified boom, with all the stock

93 Production data from Mineral Resources: U. 8. Bur. Mines.
THE MINES 69

manipulation that such a boom implies. Some development work, particularly along the main haulage 

adit (see pi. 31) and some churn drilling were done 

during this time. No attempt has been made to mine 

at the property since the boom collapsed.

The main adit contains about 3,000 feet of workings. 

It is connected by raises to the old workings, which 

contain about 1,500 feet of drifts. Two large opencut stopes that feed into the tunnel furnished most of 

the mill heads, but considerable 'gophering for highgrade ore has been done on the cliff above the river. 

Most of the workings are shown on plate 31.

The country rock of the deposit is dolomite and limestone, considered to be just below the Leclbetter slate. 

The attitude of the beds is, in general, about N. 20° E., 

with eastward dips that are flat near the river and appear to steepen toward the east. On the river cliff 

the beds are typical fine-grained dolomitic limestone 

tl»at carries numerous small rounded chert nodules. 

In at least one new diamond-drill hole a narrow band , 

of shaly material that probably marks the transition 

zone to the phyllite series below the limestones was cut.

Much, of the dolomite is recemented breccia, of a 

crackle type in which the individual fragments have 

moved very little. No large faults have been recognized in the mine workings, although many minor slips 

and cracks are present. An idea of the number and 

heterogeneous distribution of these fractures can be had 

from plate 31. The earliest recognizable slips are 

nearly flat-lying, along what is interpreted as bedding 

planes; a thin layer of gouge is customarily formed on 

these planes. These flat slips are offset along those of 

steeper dips. Some of the stronger faults have gouge 

zones 1 or 2 feet wide, with several feet more of intensely brecciated rock. -Many of the fracture planes 

are slick and smooth, with no gouge developed; grooving, however, is conspicuous. Measurements on the directions and. dips of these grooves suggest no orderly 

arrangement.

As explained in the section on structure (p. 31), 

Grand view Hill is thought to be part of a block thrust 

over the Ordovician black slate. The economic significance of this hypothesis may be considerable, as, if 

true, there is a good chance of finding additional ore 

i n the favorable beds below the slate. The depth to this 

horizon, is, however, not known, although it is probably 

close enough to the surface to permit exploration without excessive cost.

The mineralogy of the deposit is simple. Galena and 

sphalerite are the two minerals sought. These are 

widely scattered, generally in small amounts, through 

much of the dolomite. A little jasperoid is present, 

particularly along the edge of the river bluff. Coarse 

white calcite is common throughout the mine workings. 

The grade of ore exposed in the old stopes, used for 

mill feed, is low, probably running 3 to 5 percent combined lead-zinc. Jenkins 6G mentions the condition of 

the mine in 1924. He says, "Prospecting had been done 

by .open cuts and in natural caves and by a 125-foot 

tunnel into the bluff, where the ore body was reached 75 

feet from the portal. In one cave * * * brokenoff pieces of brecciated rock containing galena partly 

filled the cave."

Oxidation of the ore is not much in evidence, although a little smithsonite was found in one of the 

upper drifts. Limonite is abundant in fissures, particularly near the cliff that overlooks the river. A small 

bare dolomite knob south of the large low-grade stopes 

is smoothed and grooved by glacial action, and it is 

likely that oxidation products, particularly on the exposed high points, were removed by the ice scour.

E. J. HOAGE

The E. J. Hoage group of seven claims is about 1% 

miles south of Z Canyon in the southeastern part of 

sec. 22, T. 40 N., R. 43 E. It is developed by two short 

adits and by several pits and open cuts. The country 

rock comprises dense white cherty dolomitic limestone, 

dark bluish-gray jasperoid, and coarse creamy-graj 

dolomite. Coarse white calcite is irregularly distributed on much of the surface, and in one cut a 

lamprophyre dike about 2 feet wide was seen. This 

dike strikes N. 70 P W. and dips 85° N.

The attitude of the bedding is difficult to determine, 

but from vague composition banding it is thought to 

strike a little east of north, with a dip of about 10° W. 

The beds are probably those that normally are about 

200 feet below the black slate.

A little disseminated sphalerite and patches of galena 

are generally found in the jasperoid' and in a few 

places in the dolomite and magnesian limestones.

LA.KEVIEW

The LakevieAv property is on the slope north of 

Crescent Lake in sec. 1, T. 40 N., R. 43 E. It is 

developed by an adit that trends N. 30° W. for 255 feet. 

The property was idle when visited.

The country rock is a medium- to fine-grained 

creamy-gray dolomite, thought to be below the nodular 

cherty horizon in the Cambrian limestone beds. A few 

beds of black carbonate rock with spots of white dolomite are exposed in the adit. Near the mineralized 

ground veinlets and irregular patches of recrystalline 

dolomite are abundant and a little "zebra" rock is seen. 

The dolomite strikes N. 10° E. and dips 20° W. At 200 

feet the adit cuts a fault that strikes N. 80° E. and 

clips 50° S. This fault contains 6 inches to 2 feet of 

gouge and breccia. The dolomite north of the fault 

contains only creamy-gray dolomite, but .south of the

M Jenkins, 0. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington Dept. Conservation and Development, Div. Geology, 

Bull. 31, p. 60, 1924.
70 GEOLOGY AND ORE DEPOSITS OP THE METALINE QUADRANGLE, WASHINGTON

fault are a few bands of black carbonate rock with 

white dolomite spots. For this reason, the south side 

of the fault is thought to be down relative to the 

north side (a normal fault).

North of the fault the dolomite is sparingly mineralized. Sphalerite and galena are the principal minerals, 

but a little pyrite was seen. The ore minerals and 

the dolomite are arranged concentrically, like those 

especially well developed at the Z Canyon property. 

One well-formed nodule about 1% inches in diameter 

has a center of galena surrounded by a band of sphalerite and a border of crystalline dolomite. Most of the 

sulfides are bordered by coarse cream-colored dolomite 

that is lighter than the country rock. Two colors of 

sphalerite are present yellow and reddish.

Much of the sphalerite along and near the fault has 

been leached. The cavities formerly filled with the 

zinc mineral are lined with a pale-brownish powder, 

probably iron-stained carbonate.

LEAD KING

The Lead King property includes seven claims about 

2 miles northwest from the mouth of Slate Creek and 

mostly in the east half of sec. 27, T. 40 N., R. 43 E. 

It is owned by the Pend Oreille Mines & Metals Co. 

and was idle when visited. Mineral Resources reports 

small shipments of ore in 1917, 1925, and 1926, and 

Jenkins 67 says that two or three carloads of ore, principally lead and zinc, are reported to have been shipped 

in 1918. The property is developed by an adit trending 

S. 70° E. for 191 feet (paced), driven from the level 

of the road from Ledbetter Lake to Russian Creek to 

intersect the mineralized rock on the slope above. Considerable gophering has been done on the outcrop, and 

apparently the high-grade shipping ore was obtained 

here. A few other shallow diggings have been sunk 

on the claims, and several diamond-drill holes have 

been put down.

The country rock is fine-grained soft gray limestone, 

in places dolomitic and, particularly near the ore bodies, 

recrystallized to a lighter-gray dolomite. Much of the 

limestone contains irregular spots of calcite, generally 

less than 1 inch in longest dimension. Veinlets of 

coarse light-gray dolomite/cuT'irregularly through the 

fine-grained, slightly darker limestone. The veinlets 

are bordered by narrow zones (less than one-eighth 

inch) of nearly black carbonates. Dark-gray or black 

jasperoid is abundantly developed, particularly near 

the ore bodies and in the crystalline dolomite, and 

spots and veinlets of clear colorless quartz are common. 

Several large patches of coarse Avhite calcite are exposed 

on the hill above the workings. Toward the east the 

limestone loses its gray color and cherty nodules be87 Jenkins, 0. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington Dept. Cons, and Devel., Dlv. Geology, Bull. 31, 

p. 60, 1024.

come more conspicuous. To the west is a narrow 

alluvium-filled valley bordered by poorly exposed black 

slate.

The attitude of the rocks near the mineral bodies is 

difficult to determine, as much breccia is developed 

and slips and cracks are numerous. To the east just 

above the workings the bedding is better defined; it 

strikes N. 10° E. and dips about 35° W. The alluviumfilled valley may be the site of a fault trending N. 

10° W., with the slate to the west faulted down.

The ore consists of galena and sphalerite, mainly in 

the jasperoid but locally in the crystalline dolomite and 

the fine-grained limestone. No oxidized zone exists, as 

fresh sulfides are found on the surface. The ore body 

appears to nearly parallel the bedding, and, if this is 

so, the continuation should be looked for to the west 

under the alluvium rather than in the hill to the east.

ROBERT E. :LEE

The Robert E. Lee patented claim is on the west 

bank of the Pend Oreille River about half a mile west 

of the mouth of Slate Creek, in the NW^/4 sec- 35, 

T. 40 N., R. 43 E. The property has been idle for 

years, but a short inclined shaft and a few shallow 

pits can be seen. A few diamond-drill holes were sunk 

by the Pend Oreille Mines & Metals Co., which held 

the claim under option for a short time. The workings are reached by trail from the Ledbetter Lake 

road, about a mile to the west.

The country rock (Metaline limestone) is medium to 

coarse even-grained gray dolomite, with scattered 

spots of white calcite less than an inch across. Black 

Ordovician slate overlies the dolomite and is particularly well exposed in the trail to the property and 

at the portal of the inclined shaft. The slate has 

yielded a few graptolities. A lamprophyre dike, rich in 

biotite and showing a few grains of olivine, is exposed near the inclined shaft. This dike, about 3 feet 

wide, trends N. 60° W. and is either vertical or dips 

about 85° SW. Two faults, approximately parallel to 

the dike and about 100 feet part, were recognized. One 

of these faults is shown in figure 11. On both breaks 

the south side is down relative to the north side; the 

offsets are not exactly known but are of the order of 

magnitude of 100 feet. It is probable that other faults 

of this system are present but not exposed; this is suggested by the distribution of the slate and dolomite on 

the slope. The complex structure in the canyon of the 

Pend Oreille River just north of Slate Creek appears 

to be related to the fault structure at the Robert E. Lee 

workings, although the details have not been studied.

The dolomite contains scattered spots of galena. 

Sphalerite has not been recognized, but some of the 

vugs in the rock near the surface resemble those seen 

elsewhere and known to have been filled with sphalerite.
THE MINES 71

LUCKY STRIKE

The Lucky Strike group is in the northeastern part 

of sec. 35, T. 40 N., R. 43 E., east of the Pend Oreille 

River and north of Slate Creek. The property is 

owned by R. L. Lakin, of Spokane. Nothing but assessment work has been done in recent years, although 

Mineral Resources reports a shipment of ore in 1926.68 

The property is developed by an inclined shaft and 

several drifts which were mostly inaccessible when 

visited.

The country rock (Metaline limestone) is crystalline 

dolomite, probably 600 feet stratigraphically below the 

black (Ordovician) slate. The topography is rugged^ 

although the relief is not great. The prospect is in a 

breccia zone, probably related to the fault in nearby

s.

district. One block, from which the company takes 

its name, is a group of claims and homesteads around 

the Oriole, O. K., and Bella May properties. A second 

group of claims lies west, north, and east of the Lead 

King property, and a third group, staked in 1937, 

covers a large part of the drainage basin of Threemile 

Creek. In addition, the company has smaller holdings 

north of the Cliff patented claim and has recently 

staked much of the open land west of the Pend Oreille 

River and north of Z Canyon.

No mining other than assessment work has been done 

on any of the company's holdings.

MORNING AND MAMMOTH

The Morning and Mammoth property of the Metaline Metals Co. is in the west-central part of sec. 15,

N.

3 Feet

11. Dolomite-slate contact at inclined shaft at Robert E. Lee claim. Vertical section.

Slate Creek. Patches of coarse white calcite are common and much of this mineral is found on the dump. 

In the river canyon the strike of the beds is N. 5° 

W. and the dip 40°-65° W. Much limonite is present, 

particularly along fissure zones and solution channels. 

Galena and sphalerite are found on the surface and in 

shallow cuts. The workings are reported by Mr. Lakin 

to have been stopped in heavy iron sulfide, and a large 

part of the dump consists of radial pyrite and limonite. 

Some of the limonite appears to contain smithsonite or 

liom.imorp.hite. Several specimens of a very fine 

grained light waxy sphalerite were found on the dump 

at the shaft. This sphalerite is iron-free but is found 

in hand specimens that are largely pyrite.

METALINE CONTACT

The Metaline Contact Mines Co., of Spokane, controls several large blocks of ground in the Metaline

08 Mineral Resources U. S., .1926, p. 468, Bur. Mines.

T. 39 N., R. 43 E., on the east bank of the Pend 

Oreille River north of the Grandview mine. The 

property was one of the early discoveries in the district 69 and much underground work has been done, 

although, so far as known, no production is recorded. 

According to Elmer Berglund,70 who was in charge of 

the underground work during the period of greatest 

activity, the shaft is 430 feet deep. Brinsmade 71 mentions levels at 80 feet, 200 feet, and 400 feet, in addition 

to.two adits; the workings aggregate almost a mile 

of drifts. The property was idle when visited, and 

only one adit was accessible. A small amount of diamond drilling has been done.

Rock exposures near the mine workings are poor 

and are limited to a strip along the river and a cliff

68 Adair, J. B., Mineral resources of the State of Washington The 

Metaline district: Northwest Mining Jour., vol. 7, pp. 54-56, 1009.

70 Personal communication, 1937.

"Brinsmade, R. B., Two Washington mining districts: Min. and Sci. 

Press, vol. 113, pp. 743-745, 1916.
72 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE,, WASHINGTON

between the shaft and the Grandview workings. The 

country rock (Metaline limestone) consists of dolomite 

and limestone, in places intensely silicified. Irregular 

patches of coarse white calcite are also present, particularly in the dolomite. In the river bed, at low 

water, black graptolite-bearing slate can be seen. The 

accessible adit is driven S. 35°E. for 372 feet (paced), 

and a crosscut to the southwest contains 135 feet of 

additional drifts. Most of the rock is coarse- to: 

medium-grained grayish dolomite, similar to the dolomite commonly found just below the slate. Finegrained soft dense limestone is entered at 96 feet from 

the face of the adit and continues to the face. It is 

reported by Mr. Berglund that similar limestone was 

found in the deeper workings.

The details of the structure near the Morning and 

Mammoth are practically unknown. In the river bed 

to the west and also to the south and southeast the 

strikes of the dolomite and limestone beds are about 

north-south and the dips are low to the east. In the 

adit a few narrow shaly seams trend north to 

N. 10° W. and dip less than 15° E. The structure is 

complicated by numerous faults that strike from north 

to N". 45° E. and dip steeply east. One of these faults 

is reported to have been found in the shaft, and 

others can be seen in the adit and in the nearby exposures. In these faults the east side appears to be 

up relative to the west side. The contact between the 

slate and dolomite in the river bed is one of these 

nearly vertical faults.

The ore consists of galena and sphalerite disseminated in the jasperoid and brecciated dolomite. Some 

fine-grained sphalerite is also scattered through the 

dense limestone. Seams of paligorskite are conspicuous in the accessible adit. It is reported that evidence 

of mineralization decreased in depth and that sulfides 

were practically absent in the deeper workings.

PEND OREILJLE

The Pend Oreille mine is on the west bank of the 

Pend Oreille River about 1 mile north of Metaline 

Falls, in sec. 16, T. 39 N., R. 43 E. (See pi. 32.) It 

is owned by the Pend Oreille Mines & Metals Co., of 

which L. P. Larsen is president and C. A. R. Lambly 

is mine manager. The mine is on one of the early 

discoveries in the district and in 1906 was known as 

the C. W. Clark property; at that time control passed 

into the hands of Mr. Larsen.

Mining was started about 1910 in a mineralized outcrop on the Josephine claim and was carried on more 

or less continuously on a small scale until 1919, when 

the property was shut down. During this period about 

40,000 tons of ore was mined and milled, and 4,000 tons 

of concentrates yielded $275,000 from smelter returns.72

72 Larsen, L. P., The Metaline lead-zinc district: Arizona Min. Jour., 

vol. 16, no. 2, pp. 5-6, 1932.

In 1928 an extensive diamond-drilling campaign was 

started and large tonnages of low-grade zinc ore were 

indicated; a little later a body of high-grade zinclead ore was discovered on the 300-foot level northeast 

of the Josephine shaft. Further drilling greatly extended the limits of this high-grade ore, and most of 

the recent mining has been done on this body. A 300- 

ton flotation mill was completed and production was 

begun in November 1930. In May 1932 the property 

was shut down again but in June 1933 was reopened 

for about 11 months. Early in 1936 production was 

once more started, although handicapped by power 

shortage. In September 1937 a power plant on the 

Pend Oreille River was completed, the flotation mill 

was overhauled, and production stepped up to about 

600 tons a day.

The concentrates are trucked to the raiilroad at 

Metaline Falls; the zinc is shipped to the American 

Zinc Co.'s plant at St Louis, Mo., and the lead to the 

Bunker Hill & Sullivan plant at Kellogg, Idaho.

The principal mine development has been carried 

on through three connected openings the Josephine 

shaft, the Cascade or 500-foot level adit, and a new 

shaft about 675 feet N. 27° E. from the Cascade. 

Much of the early work was done in the Josephine 

shaft from two levels, the 100-foot and the 300-foot. 

This shaft was not accessible when the mine was examined, and the 100-foot level could not be entered. Most 

of the 300-foot level was also inaccessible, as the water 

had_backed up from the sump at the shaft. Part of 

the 300-foot level and the stopes driven from this level 

were entered through an inclined raise from the Cascade adit. The Cascade adit was started on the north 

bank of Flume Creek and driven to the northwest to 

intersect the ore body found on the 300-foot level. 

About 2,350 feet of drifting has been done on the 500- 

foot level, and most of the stoping to 1937 was from 

this level. The level is connected to both the 300-foot 

and 700-foot levels by inclines. (See pi. 33.) The 

new shaft, sunk about 250 feet, was completed in 1936. 

It contains one hoisting compartment and one other 

compartment; ore and waste are trammed to the shaft 

from one level, the 700, although a station was established at the 650-foot level for unloading supplies. 

Development work in the block of ground between the 

500-foot and 700-foot levels was being rapidly pushed 

in 1937.

The distribution of the workings from the 300-foot, 

500-foot, and 700-foot levels as of October 1, 1938, is 

shown in plate 33. The block diagram (pi. 34) shows 

also the 100 level and the zero level, an adit driven into 

the hill west of the Josephine shaft. From the mineralized outcrop shown at the west end of the diagram 

mining has been pushed gradually eastward nearly to 

the west bank of the Pend Oreille River.

Several other adits have been driven on the property. One, the Chickahominy, driven from the river
THE MINES 73

bank south of Flume Creek, ended in 20 feet of 

sphalerite-bearing jasperoid and dolomite. Much of 

the property has been and is being explored with diamond drill.

Mining is done through a system of raises to the tops 

of the ore bodies, whcjre cuts are made and the ore is 

"benched" to the raises. Drag-line scrapers are used 

in the stopes, as ordinarily the ore will not run. An 

effort is made, however, to keep inclined raises 45° 

or steeper.

The country rock consists of dolomite and limestone 

of Middle Cambrian age, overlain by black graptolitebearing slate. Much of the carbonate rock, particularly within 200 feet of the slate, is recrystallized and 

thoroughly brecciated. In places, particularly near 

the ore bodies, the breccia is recemented by silica, and 

large masses of dark-gray or black jasperoid are found. 

Spots of crystalline gray or cream-colored dolomite 

and some limestone are generally present in the otherwise completely silicified rock. Irregular-shaped 

masses of coarse white or light-gray calcite are particularly numerous near the jasperoid.. These calcite 

masses are customarily 10 to 20 feet across in any dimension, although exceptional bodies, such as that in 

the Flume Creek Gorge below Hidden Falls, are exposed for 100 feet or more. Below the jasperoid and 

mineralized rock is a fine-grained soft gray limestone 

that contains a fe\v chert nodules and irregular narrow 

streaks of indistinctly outlined carbonaceous particles. 

(See pi. 8, A.) Remnants of this limestone scattered 

through the upper crystalline dolomite and a few in 

the jasperoid indicate that both the dolomite and jasperoid are later products, formed in the limestone. No 

igneous rock has been seen on the property, but diamond drilling has shown the presence of at least one 

lamprophyre dike.

Faulting is very common throughout the mine, but 

is particularly accessible to study in the abandoned 

open stopes on the 500-foot level. The faults are, with 

few exceptions, sharp, clean breaks, with small displacements, probably less than 10 feet, although at 

least one has a displacement of about 200 feet. The 

fault surfaces are generally smooth and slick, in places 

highly polished; elsewhere grooves are developed. 

Readings on many of these grooves are shown on plate 

33. The larger faults have two or more smooth, slick 

surfaces, separated by black or gray limy gouge and 

finely ground breccia in which the individual particles 

are noticeably subrounded. Both calcite and ore are 

associated Avith faults, and many breaks cannot be 

traced through bodies of either type. For this reason 

both calcite and ore are thought to be mainly later 

than, the faulting. Minor readjustments on many of 

the slips have brecciated and polished both materials.

On plate 33 all the faults mapped are shown and on 

plate 34 an effort has been made to plot only the 

larger breaks. At least two periods of faulting are

distinguished; the earlier faults are flat-dipping and 

the later ones steep. The flat breaks (No. 1 fault, 

pi. 34) may in places be bedding slips; they are cut 

by the steeper faults. It is possible that steep fractures of several ages are present, but if so they have 

not been recognized. The steeply dipping fractures 

have two trends, one north-northeast and the other 

northwest; no regularity of dips is shown.

The attitude of the -bedding planes is difficult to 

recognize. In a few places shale seams indicate an 

eastward dip in the fault blocks. The block; diagram 

indicates a general eastward dip of the slate-dolomite 

contact. In the river bed east of the mine good bedding planes are exposed; they trend northeast and 

dip 20°-30° SE.

Echelon or steplike tension (?) cracks are present 

in many of the stopes. These cracks, filled with white 

quartz, calcite, and in places a few sulfides, are in 

general nearly at right angles to the faulting, but 

in one stope they are parallel to a prominent break. 

The cracks are generally less than 10 feet long and 

not more than 2 inches wide. They commonly stop 

a.bruptly at fault planes, although in a few places they 

cut directly across the faults. The tension (?) cracks 

are evidently in large part later than the ore, as they cut 

both ore bodies and barren country rock.

The dolomite breccia is healed by silica and ore 

and is thus presilica and preore. Some silica and ore 

have been involved in late movement, however, and 

in places form a poorly cemented breccia. The breccia 

is mostly of the so-called crackle type, in which the 

fragments have moved but little relative to each other. 

Black-shale particles are found in many places in the 

breccia, but they are more abundant near faults.

The ore forms irregular replacement bodies in the 

jasperoid and dolomite, with smaller amounts in the 

coarse calcite and the fine-grained limestone. The replacement bodies are followed approximately down the 

dip to the eastward; they correspond in a general way 

to the bedding but in detail are not confined to one 

single layer. This is shown by the range in thickness 

of the individual bodies; in several stopes the ore is 

6 ~or 8 feet thick; elsewjiere-it-is 2£-er^j^ejDt^onjdlyi_ 

about 50 feet thick. The depth of the ore below the 

slate is_ not coiistantj_iii some places it is nearly 200 

feet/Tlsewnere it may iDeTBTTJeet or less; in one stope 

(7-19) a black-slate window shows in the back. (See 

pi. 33.)

A close association between ore and black or darkgray jasperoid is readily noticed, even by a casual 

observer. That an increase in silica content accompanies an increase in sulfide content is shown both from 

a study of the graphs (pis. 21 and 22) and by field 

observation. The ore is in the jasperoid; where veinlets 

or irregular masses of jasperoid are isolated in dolomite, coarse calcite, or marble, the sulfides are generally 

in the silica rather than in the surrounding rock. In
74 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

places the sulfides penetrate other rocks, although such 

material is likely to be of low grade. The sharp contacts between calcite and jasperoid seem to be a particularly favorable place for ore, .which is almost 

entirely in the jasperoid but in places extends into the 

calcite.

The principal ore minerals are sphalerite and galena, 

with the sphalerite greatly predominant. The sphalerite is of two colors, reddish brown and pale yellow. 

A few small globules of hydrocarbon (classified as 

anthracite) are found in the dolomite. At least one 

shipment of ore from the 700-foot level - contained 

sufficient copper to be paid for at the smelter. This 

copper is probably in the form of tetrahedrite (?), a 

few tiny pieces of which have been seen. Pyrite and 

marcasite are rare in the ore, but a little pyrite was 

seen on the 300-foot level, and a little marcasite is distributed in many of the caves and along other water 

channels. Limonite and pyrite are reported to have 

been present in considerable amounts in the workings 

.from the Josephine shaft. Paligorskite (leather or 

asbestos of the miners) and limonite are also abundant 

in the caves; the paligorskite (pi. IT, B) causes considerable exasperation when dumped into the crushing 

machinery.

Caves are conspicuous features in the mine workings, 

near and above the 500-foot level. A few small caves 

nearly free of paligorskite are found on the 700-foot 

level. The caves are described on pages 38-39. Much 

good ore has been taken from them.

In the shallow oxidized zone the ore consists of 

galena coated with cerussite and scattered bits of 

cerussite and smithsonite. It is reported by Mr. I/ambry that some smithsonite was shipped to the smelter 

during the early period of mining. A bright-yellow 

coating on pieces of sphalerite on the dump at the 

Josephine shaft has been identified by W. T. Schaller 

as the cadmium mineral greenockite (CdS2 ). Galena 

appears to be concentrated near the borders of the 

sphalerite shoots.

RIVERSIDE

The Riverside property is on the east bank of the 

Pend Oreille River south of the mouth of Slate Creek, 

in the SEi/4 sec. 35, T. 40 N., R. 43 E. It is owned 

by the Metaline Metals Co., but with the exception of 

a few diamond-drill holes no development work .has 

been done for years. The workings are on a cliff that 

rises almost vertically above the river. As the dug 

trail from the terrace above to the workings was washed 

out, nothing was seen except along the edge of the 

terrace. The prospecting appears to have been done 

on several of the northeastward-trending fissures that 

are conspicuous in the river gorge.

The country rock is medium-grained crystalline gray 

dolomite, much brecciated and distorted. The dolomite is entirely surrounded by black slate and is an 

outlier from the plate thrust over the slate along the 

Slate Creek fault. (See pi. 1.) Many northeastwardtrending fissures are exposed in the river gorge; these 

fissures strike about N. 55° E. and are nearly vertical 

or dip steeply northwest. Displacement of the strata 

has occurred on all the fissures.

Bancroft 73 describes the deposit as a fissure vein 

in dolomitic limestone. He says, "* * * the vein 

being exposed for a vertical distance of 250 feet. 

* * * The trend of the vein is N. 55° E. and the 

dip 70°-80° NW." The minerals are reported to be 

radial pyrite (marcasite?) with a little galena arranged in concentric bands. Bancroft identified 

gypsum, "steel" galena, and chalcopyrite and refers to 

the very heavy gossan. This gossan is conspicuous 

in many places in the gorge and arises from the oxidation of iron sufide. A little native sulfur was found 

in some of the limonite, and spots and bands of coarse 

white calcite were seen.

^- .SCANDINAVIAN (U3AD QUEEN)

I The Scandinavian (Lead Queen) prospect is in the 

/south-central part of sec. 11, T. 40 N., R. 43 E., just 

east of Z Canyon. The property was idle when visited, and but little information was obtained. A few 

shallow pits were the only workings found.

The country rock is dense white fine-grained cherty 

dolomitic limestone, in most places covered with a thin 

layer of glacial debris. Several large irregular 

patches of coarse white calcite are exposed. The beds 

trend about N. 10°-30° E. and dip at low angles to 

the west.

A few spots of galena and some iron-stained vugs 

that may represent leached sphalerite were the only 

signs of mineralization seen.

TOM CAT

The Tom Cat property includes two claims east of 

the road about 1 mile north of Z Canyon, on the border of sees. 3 and 10, in T. 40 N., R. 43 E. In 1937 

the property was purchased by E. O. Dressel, of 

Metaline Falls. The development workings consist of 

one short adit and several small cuts.

The country rock is dark bluish-gray dolomite, in 

places brecciated and replaced by jasperoid. The trend 

of this jasperoid and dolomite is northeast. To the 

northwest is a terrace deposit, and to the southeast is 

a dense white cherty marble, separated from the mineralized zone by about 25 feet of jasperoid. The 

width of the mineralized zone is not known and the 

attitude of the beds is not clear but apparently the 

strike is northeast and the dip steep to the northwest.

The bluish-gray dolomite and jasperoid show numer73 Bancroft, Howland, Ore deposits of northeastern Washington : Geol. 

Survey Bull. 550, pp. 50-51, 1914.
PROFESSIONAL PAPEH 21)2 PLATE 32

I'END OREILLE MINE AND MILL. 

View west from <Trandview workings.
THE MINES 75

otis spots and patches of galena and considerable finely 

disseminated sphalerite.

WASHINGTON AND METALINE FALLS

The Washington group and the Metaline Falls claim 

are on opposite sides of the river at Metaline Falls. 

They are owned by the Pend Oreille Mines & Metals 

Co. The company's new power plant is built on the 

Metaline Falls claim, east of the river. A shaft was 

sunk 150 feet on this claim but the amount of drifting 

from the shaft is not known. Several diamond-drill 

holes were put in from the bottom of the shaft and 

excellent exposures were seen in the large intake tunnel 

and the surge-tank excavation made for the power 

plant during-the early summer of 1937. The work on 

the Washington group consists of a short adit about 

90 feet long and seA^eral shallow cuts. The adit is described by Jenkins,74 who mentions a body of solid 

pyrite mixed Avith galena at 60 feet from the portal.

The dolomitized limestone country rock is exceptionally well exposed on the walls of the river gorge 

near and below the falls. From 4.00 to 500 feet of 

dolomite section is represented. Near the river level 

the rock is banded black with white spots and creamy 

white, typical of the formation well down in the Cambrian limestone section., Ordovician black slate that 

has yielded a few graptolit.es is exposed on the west side 

of the river just north of the Washington adit and on 

both sides of the river north of the power plant. The 

slate was also found in the drill holes from the bottom 

of the Metaline Falls shaft.

The dolomite and limestone sections overlie the slate. 

The contact is a thrust-fault surface of unknown attitude but probably nearly horizontal. The dolomites 

are badly shattered, and bedding is difficult to recognize south of the slate outcrops, although farther north 

in the gorge bedding is readily recognized; it trends 

east of north and dips 20°-30° E. At one place on 

the east wall it is nearly horizontal. In the shattered 

dolomite the black and white layers have a general 

eastward dip, although in detail they are haphazardly 

oriented.

Galena and sphalerite in small amounts are widely 

disseminated through the dolomite. Much limonite, 

probably formed by the oxidation of pyrite, is spread 

over the dolomite and in places concentrated in fractures and caves. The limonite from one such cave on 

the Washington claim was mined by the Lehigh Portland Cement Co. for use in the manufacture of cement.

WOLF CREEK

The Wolf Creek property is near the mouth of Wolf 

Creek, in the NWVi sec. 4, T. 38 N., E. 43 E. The

74 .Tonkins, O. 1'., Loud deposits of I'end Oreillo and Slevens Counties, 

Wash.: Washington Dc-pt. Cons, and Dovol., Dlv. of Geology, Bull. 31,

i>. no. T.ta-i.

 N80MO

developments consist of several shallow adits and surface cuts and an inclined shaft, inaccessible when 

visited. The country rock is coarse gray crystalline 

dolomite, locally brecciated and in places containing 

chert nodules. The exact location of the dolomite in 

the stratigraphic column is not known., although it is 

in the upper part of the Metaline limestone. To the 

south and southwest of the workings Ledbetter slate 

is exposed, apparently faulted against the dolomite.

The bedding in the dolomite trends N. 10°-25°E. 

and dips steeply east(?). The rock is considerably 

broken ; the fractures seen all trend northeastward.

Galena is the principal ore mineral and is sparingly 

distributed through the rocks' in the accessible workings and on the dumps. A little sphalerite, globules of 

hard brittle hydrocarbon, a little iron sulfide, and paligorskite were noted. Limonite is plentiful in several 

of the Avorkings, and small amounts of gypsum and 

hemimorphite(?) Avere noted with it.

In the railroad tunnel Avest of the workings good exposures of the mineralized dolomite can be seen.

/ CANYON MUTUAL

The Z Canyon Mutual property is east of the Pend 

Oreille River in the north center of sec. 11, T. 40 N., 

R. 43 E. The developments consist of an adit trending 

N. 62°E., about 400 feet long,, and a feAv pits and small 

cuts.

The country rock in the adit is mostly a medium- to 

fine-grained creamy-gray dolomite that contains some 

"zebra" banding, some coarse-grained Avhite calcite, 

and a few fragments of black shaly material. The 

"zebra" banding here seems to be approximately parallel to bedding planes, striking N. 20°W. and dipping 

40°SW. The rock of the last 100 feet in tha adit is 

much mottled and contains considerable soft, Aveathered 

carbonates. Some concentric banding similar to that 

at the Z Canyon mine is also present (see pi. 26), although no sphalerite Avas seen. 'Some of the dolomite 

about 100 feet from the face of the adit contains 

small chert nodules in a fine-grained dolomite similar 

to the zone beloAv the Ledbetter slate. Near the portal 

of the adit the dolomite contains black bands with 

Avhite spots. Much of the dolomite throughout is a 

crackle breccia.

The adit Avas started" to undercut a mineralized exposure on the hill to the northeast but Avas stopped 

short of its objective. Sparse sphalerite and galena 

can be seen in'the small surface cuts.

Z CANYON

The Z Canyon property is east of the Pend Oreille 

River in the SW}4 sec. 11, T. 40 N., R. 43 E. It is 

controlled by the Pend Oreille Mines & Metals Co. 

A little assessment Avork Avas done during 1936 or 1937, 

and seA'eral shallow cuts and two adits Avere accessible.
76 GEOLO;GY AND ORE. DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

In addition to the surface workings, a small amount 

of diamond drilling has been done. Mineral Resources 

reports a small shipment from the property in 1926.

The country rock is medium-grained gray crystalline 

dolomite. A feAv hundred yards west and northwest 

of the workings black Ledbetter slate is exposed. The 

contact between these two formations is nearly vertical 

or dips steeply southeast; it is a fault surface (Z 

Canyon fault) of considerable displacement. The dolomite trends about N. 10°E. and dips 35°-40° W. Its 

place in the stratigraphic column is not known, but it 

is probably less than 500 feet stratigraphically below 

the slate. Much of the dolomite is brecciated and contains irregularly distributed and squeezed fragments 

and seams of black slaty material. A zone of minor 

fracturing, nearly parallel to the dolomite-slate contact, is exposed in the workings. Jasperoid and coarse 

white calcite in small quantities are found throughout 

the property.

A peculiar concentric structure of the ore is particularly well developed here, although recognized elsewhere in the district. (See pi. 26.) This concentric 

banding is described and its origin is discussed in the 

section on replacement deposits (p. 50). In places 

(he ore minerals are in breccia; in this shattered material "zebra" banding and tiny vugs lined with dolomite 

are common.

Galena and sphalerite are the ore minerals sought 

and are sparingly distributed through the Jasperoid 

and dolomite. The sphalerite is in two colors reddish 

brown and pale yellow, generally found together. 

Smithsonite, greenish-yellow stain (greenockite), and 

limonite are sparingly present in the ores near the 

surface.

O. K.

The O. K. group of seven claims was located and 

developed by E. J. Hoage but has been involved in 

protracted litigation. .The claims lie along the quartzite-dolomite contact southwest of the Oriole property. 

The main workings of the group are on the O.K. claim, 

although considerable prospecting has been done 

throughout the property. The total workings on the 

O. K. group comprise about 1,000 feet of drifts, mostly 

in tAvo levels, one at an altitude of 3,275 feet (aneroid) 

and the other about 100 feet higher. The lower adit 

contains about 300 feet of drifts and the upper adit 

430 feet. At'an altitude of 3,475 feet a 60-foot incline 

has been sunk; the remainder of the exploration work 

is in short adits and surface cuts.

The country rock is similar to that at the Oriole. It 

consists .of sandy dolomite and schist of the Monk 

formation overlain by the Gypsy quartzite. The entire 

assemblage has been subjected to igneous metamorphism, and the dolomites and schists are recrystallized. 

Tremolite, diopside, tourmaline, and a few small red 

garnet crystals are present in the limestone, and coarse

green amphibole occurs in the schist. Several coarse 

granitic and pegmatitic dikes (or sills) are poorly 

exposed, as they are softer than the metamorphosed 

rocks nearby. One fine-grained intrusive that consists of feldspar, jefferisite, quartz, tourmaline, and 

garnet was noted. In a few places rocks resembling 

hornfels are found.

The rocks trend in general northeastward and dip 

northwestward, into the hill, although considerable 

variation in attitude is seen. In a gully that drains 

into Sweet Creek, north of the O. K. workings, the 

dolomite-quartzite contact is exposed. The two rocks 

are gradational, and no fault was seen. Here, at the 

Oriole, the Flume Creek fault is in the alluvium east 

of O. K. Mountain. Most of the development work has 

been done in the coarse white sugary marble below 

the quartzite, and in no place has the contact been cut 

underground. A schist band is exposed at the face of 

the upper adit. The contact between the schist and 

dolomite trends nearly east-west and dips 26° N. Several adits and prospect pits have been opened on quartz 

streaks in the quartzite.

The mineralization is spotty and much scattered. 

Small amounts of tetrahedrite, galena, sphalerite, 

pyrite, chalcopyrite, and pyrrhotite have been found. 

Some gold and silver are reported to be present, but" 

no assays were seen.

ORIOLE

The Oriole property, oAA'ned by W. L. Schulz, includes seven claims, mostly in sees. 19 and 20, T. 39 N., 

R. 43 E. Some production is reported in Mineral Resources for the years 1911, 1917, 1925, and 1926. 

Patty 75 states that "smelter returns on a carload of 

picked ore gave 42.1 ounces of silver, 21.9 percent of 

zinc, 15.3 percent of lead, and 1.12 percent of copper. 

Jenkins 7G mentions 41/4 carloads of ore shipped before 

1924. In recent years nothing but assessment Avork 

, has been done.

Practically all the underground exploration has been 

done on one claim, the Oriole, Avhich is about 114 miles 

northwest of old Metaline, in the southeast corner of 

sec. 19. Three adits have been driA^en in nortliAvestAvard directions about 40 feet apart. At the time of 

visit the upper two of these adits Avere open but the 

lower was caved at the ore body. An inclined Avinze 

is reported to have been sunk 91 feet on the ore from 

the third level. From the bottom of this winze a 

short drift (40 feet) was driven on the lead. The 

workings total about 1,600 feet of drifts and raises.

The country rock is dolomite of the Monk formation just below the base of the Gypsy quartzite. The

75 Patty, E. N., The metal mines of Washington : Washington Geol. 

Survey Bull. 2;:. p. 88, 1921.

76 .Tenkins, 0. P., Lead deposits of Pend Oreille and Stevens Counties, 

Wash.: Washington State Dept. Conservation and Development, Div. 

Gteology, Bull. 31, p. 68, 1924.
THE MINES 77

dolomite is hard; in places its contains about 50 percent or less of silica grains. It is pale buff or gray 

and even-grained. The quartzite exposed just a,bove 

the workings is mostly sheared grits, although the entire Gypsy quartzite section is exposed on Linton 

Mountain, to the west.

The beds, both the dolomite and the quartzite, trend 

N. 25° E. and dip 30°-45° NW. The contact between 

these two formations was not seen, although it is reported to have been cut at about 240 feet beyond the 

cave-in on the lowest adit. The best information about 

tliis contact seems to be that it was tight and clean; no 

breccia or gouge was developed, although all the rocks 

in the drift were badly sheared. This observation 

checks with, the data obtained from a diamond-drill 

core in possession of the Pend Oreille Mines & Metals 

Co. In this core the contact appears to be gradational, 

and no evidence for assuming a fault to be present was 

seen. East of Linton Creek is an entirely different 

type of carbonate rock blue fine-grained dolomitic 

limestone similar to that assigned to Middle Cambrian 

age. The Flume Creek fault is therefore under the 

alluvium in the narrow Linton Creek Valley between the 

two carbonate rocks, rather than between the quartzite 

and dolomite, as has been suggested before.77 The 

shearing in both the sandy dolomite and the grits is 

considered to be related to the Flume Creek fault.

The ore is apparently along a gouge-breccia seam 

that trends in general N. 65° W. and dips ± 60° NE. 

The ore deposit is a series of lenses, elongated down the 

dip and connected by narrow stringers of quartz. On 

the upper levels these lenses are narrow, probably not 

averaging more than 1 foot in width; in depth they 

widen, and on the third level seven lenses are reported 

lo have been mined. These lenses were 1% to 4y2 

feet wide- by 12 to 20 feet long along the drift. Two 

lenses of a maximum, width of 3 feet are reported to 

have been cut in the 40-foot drift at the bottom of the 

inclined winze. According to Jenkins, the ore was followed on the third level for about 175 feet to a point 

where it pinched out.

The ore consists of sheared quartz and sericite that 

contains sulfides, galena, sphalerite, pyrite, and chalcopyrite. The galena is reported to carry considerable 

silver. The ore from the deeper workings is said to 

contain more zinc than the ore in the upper levels.

Much of the quartz is limonite-stained, and malachite, azurite, smithsonite, and cerussite have been 

noted. The rocks are deeply oxidized for this region, 

and in the upper adits the geology is partly obscured 

by weathering.

fi .

, r The manufacture of cement has been the most stable 

' l' industry in. the region and is probably the greatest

77 .Tonkins, O. P., op. clt, p. 69.

single factor in its development. As early as 1905 

Landes 7S stated that steps had been taken to manufacture cement at Box Canyon, where "there are large deposits of pure limestone and beds of excellent clay." 

The Pacific Portland Cement Co. acquired 262 acres 

of land in 1905 and expended $20,000 in preliminary 

Avork. The plant under construction at that time Avas 

designed to produce 200 barrels daily. Shedd 70 discussed the status of the industry in 1913 and briefly 

mentioned the geology and resei^es of the region. He 

rated the plant at Metaline Falls (Inland Portland 

Cement Co.) at a daily capacity of about 1,800 barrels. 

Glover 80 recently rated the Metaline Falls plant of the 

Lehigh Portland Cement Co. at 2,000 barrels a clay.

Large tonnages of limestone near the base of the 

Metaline limestone have been obtained from three 

quarries in the hill southeast of Metaline Falls. The 

loAver tAvo of these quarries are abandoned, and the 

entire output is quarried near the top of the hill and 

carried by a gravity tram to the plant at Metaline 

Falls. Shale for the cement is quarried a few hundred 

feet north of the lime quarry and from a quarry in 

Ledbetter slate on the railroad at Sand Creek.

The limestone used at present is a fine-grained darkgray rock with a few crystals of clear calcite. Part of 

the rock is mottled and contains irregular small patches 

; and-a feAv seams of white calcite. The quarrying is 

limited to one horizon betAveen shale on the hanging 

Avail and dolomitic limestone on the footAvall. This 

bed is 20 to 30 feet thick and trends N. 10° E., with a 

dip of 33° W. It can be folloAved for 1,000 feet or 

more along the strike and is reported to be fairly 

uniform in composition. Dolomite is widespread 

throughout the region, and careful sampling and selective quarrying have been necessary in the past to main-, 

tain cement at specifications. The limestone quarried 

at present is near the base of the Middle Cambrian 

limestone and is at one of the tAvo known fossil localities in this formation. To the east the limestone beds 

become feAver and the shaly beds more numerous until 

the formation is typical Maitlen phyllite. The so-called 

shale quarry is in one of the dark-gray limy phyllite 

beds.

The Sand Creek "shale" quarry is in typical Ordovician graptolite slate. It is of value principally 

because of its accessibility to the railroad.

The amount of limestone in the region suitable for 

cement manufacture is unquestionably large, but because of transportation and other economic factors 

the productive deposits are restricted to the easily 

accessible areas. <

78 Landes, Henry, Cement resources of Washington : TJ. S. Geol. Survey 

Bull. 285, p. 382, 1905.

79 Shedd, Solon, Cement materials and industry in the State of Washington : Washington Geol. Survey Bull. 4, pp. 170-199, 1913.

f° Glover, Sheldon, Nonmetallic resources of Washington: Washington 

Dept. Cons, and Devel.,.Bull. 33, p. 80, 1936.
78 GEOLOGY AND ORE DEPOSITS OF THE METALINE QUADRANGLE, WASHINGTON

LEHIGH IRONPITS

The Leliigh cement plant uses limonite in the manufacture of certain grades of cement. This limonite is 

obtained from several sources. A minimum amount of 

iron sulfide and aluminum-bearing clays is desired, and 

for this reason most of the shallow oxidized sulfide 

deposits along the Pend Oreille River cannot be used. 

A deposit near the top of Washington Rock, west of 

the highway bridge at Metaline Falls, Avas worked in 

1936. This deposit was at the solution-enlarged intersections of two groups of fissures; the stratification 

and crude banding parallel to the walls indicate a cave 

filling.

During 1937 two pits were worked. One is on the 

hill above and to the northwest of the Bella May mine. 

The other, on the Oriole claim, is a few hundred feet 

south of and across the Flume Creek fault from the 

Oriole workings. The hill slope on which these two 

deposits lie is covered with vegetation, and exposures 

are poor. Weathering seems to be deeper than is customary in the region. Although enough work to determine the origin of the deposits has not been done, that 

at the Bella May appears to lie nearly parallel to the 

bedding and may be an oxidized pyrite body along a 

bedding slip.

PLACER DEPOSITS 

HARVEY BAR

The Harvey Bar is on the Pend Oreille River about 

1 mile north of the Lucky Strike mine, in the north 

center of sec. 26, T. 40 N., R. 43 E. The property 

was abandoned when visited but is reported to have 

been reworked for years during lov-water periods by 

one man, who recovered a small amount of gold. The 

pockety dolomite bedrock is shallow and is similar to 

that at the Scherding placer, described below. The

Harvey Bar is one of a series worked in a very small 

way along the Pend Oreille River.

SCHERDING PLACER

The Scherding placer is on a large gravel bar on 

the east side of the Pend Oreille River about half 

a mile south of the international boundary and just 

below the mouth of Z Canyon Gorge. (See pi. 27, (7.) 

The treatment plant was designed to handle 200 cubic 

yards a day. It consisted of a dragline scraper, a revolving grizzly, a screen and water jet, and two sets 

of sluice boxes lined with blankets and riffles. The 

plant was put into operation late in the summer of 

1935 and, when visited in 1937, was temporarily shut 

down because of mechanical trouble. In 1938 the plant 

had been dismantled because it was not capable of 

handling the cobbles and coarse rocks encountered. 

Much of the equipment had been installed in a small 

suction dredge, and an effort was being made to dredge 

the bar.

The bar contains well-rounded river gravel, generally 

less than 6 inches in diameter but rarely as much as 

\.^/2 feet. Considerable clean sand and many tiny 

rounded pebbles of black slate are present. Most of 

the gravel and sand are quartzite and phyllite particles. In the small cut made by the scraper the gravel 

is crudely stratified. The bedrock is dolomitic limestone and is uneven and pockety.

Several pans of black sand reported to have been 

recovered from a test run were examined. All showed 

numerous small colors of gold, flat and with wellrounded edges as if the gold had traveled long distances. One nugget of about 2 pennyweight was reported to have been recovered from the bar. Sufficient 

work has not been done to obtain an estimate of the 

amount of gold likely to be found.
INDEX

Page

Abstract_ _-_-__ __ ___-_ __-- - 1 

Acknowledgments for aid_____ ____ _ ____ _ 3

Aetinollte, occurrence of_ 57 

Albite, occurrence of________ _ 56, 57

Algae in Metallne limestone--._. _____ pi. 9, B

A Man I to, occurrence of__--____- . - - _______ 53

Amphitheaters on Gypsy Ridge _ .__ 37, pi. 16. A 

AiH'.alusite, occurrence of _ _--. ______- _ - 57, pi. '20, G 

Andeslne, occurrence of_ - --_-- _-_ - 57

Anglealte, occurrence of_ _ _ - - 59 

A-nthracite, occurrence of_ _____ _________ 59-60, pi. 23.A 

Aplite dikes, occurrence anil character of 27 

Aaurite, occurrence of_ _ - __ 56

B

Balley-Uanson mine, features of - 63-04 

Barlte, occurrence of_ . _ __ _ _ - 59 

Bathollths. structural relations of____ ___ 34-85

Sec also Knniksu batholith. 

Bella May mine, analyses of rock from_________ 43, 44, pis. 21, 22

description of_________________ 65-67, pis. 29, 80 (in pocket) 

Bibliography _________ : _. - 4-5

Biotite, occurrence of_ ____ - - 58, pi. 20, D

Blue Bucket workings. Sav Bella May mine.

Brecclatlon In the area, features of_______ 52-5'<, pis. 10, 23, B, 27, B

Bridge, .Tosiah, fossils identified by____ _______ ___ 19,20

Bromyrlte, occurrence of- _ _______ __ 55

Bunker Hill mine. See Lead Hill mine.

Caloite, occurrence- of_________ 45-46, 56. pis. 23, G. 24, A, 25, A, D. 26 

Cambrian system, rocks of 13-19 

Cumbrian (?) system, rocks of______ .__ _ 1.1-13

Carbonate, minerals, occurrence of_ __ 56 

Carbonate rocks, sillciflcation of_________ 4t-45, pis. S, B, 23, B, 24, B

Caves in the area__ _ __ _ 38-39, pis. 17. IS, 33 

Cement, production of_ _ - 77 

Cerargyrite, occurrence of _ _ . - 55

Cerusslte, occurrence of- _____ _ __ - - 56

Chalcedony, occurrence of - - 56 

Chiilcocite, occurrence of- _ _ 54 

Chalcopyrite, occurrence of-_ __ - - 55

Chlorite group, occurrence of_ _ ___ - 58

Chlorltold, occurrence of __________ _ ____ -_ 58

Chrysocclla, occurrence of _ __ 59 

Chrysotile, occurrence of_ _ _ _ _ _ 59 

Cliff mine, features of_________ __ . -_ __________ 67-68 

Climate of the area___ _ _ .._ _ __ 3 

Clinohumite, occurrence of_- 58 

Coflin mine, features of- _ ______________ 65, pi. 27, A

Copper, production of_ _ 48,49 

Cordlerite, occurrence of___ __ .._ _ ___ 57, pi. 20, D 

Correlation of formations- - __ ________ __- ____ 6

Cuprite, occurrence of - - _ __ _ 56

Deformation, relation of, to batholith intrusion-__ _ __ 34-35

Devonian limestone, age of _____ _ _ 22-23

distribution of______ ___-____-___ 22, pi. 1 (in pocket)

llthology of_-___ ___ __________ 22, pi. 10

deposition of, conditions of_ _ _ ___ ___ 22

thickness of_-_ - ____--_____________ 22

Devonian system, rocks of_______________________ 22-23

Diamond R mine, features of_ ___ ___ ___ __ 68

Dickite, occurrence of___ _ ___ ______ __ _ 59

Dike rocks, occurrence and character of-________ ___ 27 28

Diopside, occurrence of____________________ 40, 57, pi. 19, B, 0

448039 43

Page

Dolomite, analyses of _ .. 42, 43, 44

formation of _ - > 42-44, 45-47

specimens of____ ____ pis. 9, A, 10, B, C. D, 23, D, 24, 25, A, 26

Dolomite breccia, features of _ - 22, pi. 1.0

Dolomitic limestone, cnerty, analysis of _ 46

Dolomitization of carbonate rocks _ _____ 41-44, 45-47

Drainage of the area 35-37

Dry Canyon, features of __ _ 37

Duinont properties, features of _-_ ____ __ _ 64

B

Eastern block, features of_______ _ ____ 33-34 

Epidote, occurrence of ______ _ _ _____ 57

F

Field work in the area _ _ _ 3 

Flume Creek fault, structural relations of_____ _ _ 29, pi. 13, l> 

Flume Creek-Russian Creek block, description of- 28-30, pis. 13, D, 14, A. 

t'lusey mine, features of- _ _ __ 68 

Frisco Standard mine, features of____ _ ___ _____ 61-62 

Future of the district_ ._ _ _ __ 54

G

Galena, occurrence of________________'____ 54, pi. 23, C, 25, C 

Garnet, occurrence of_ _ - __________ 57, pi. 12, B 

Geology of the area, principal features of_______ 5, pi. 1 (in pocket)

Giant mine, features of __ __'____ ____ _-____ 68 

Girty, G. H., fossils identified by______________________ .22

Glaciation in the area_ _________________ 35-38, pis. 15, 16 

Gold, occurrence of__ - -_______________________ 54

production of___--_________________-_______ 48, 49

Granclview mine, description of-_-___ __ 68-69, pi. 31 (in pocket) 

Granitic rocks, occurrence and character of_____________ 26 27

Graphite, occurrence of _ ____________ ___ 54

Greenockite, occurrence of _ ___ _____________ 55

Gypsum, occurrence of - _ _-___-___ _ 59 

Gypsy copper camp, features of______________-_______ 65

Gypsy quart/ite, age of - _____________ ._____ 15 

deposition of, conditions of_ _______________ 15

distribution of___ _____________________ 13, pis. 13, D 

lithology of _ ____ _____ 13-15, pi. 5, B

stratigraphic and structural relations of____.______ 13, 14, 32-33 

Gypsy Ridge, view of _____ __________i_ pi. 1.6, A

H

Hall Mountain anticline, features of__________________ 32-33 

Hall Mountain block, description of__________ 16, 32-33, pi. 6, D 

Haloids, occurrence of- ___________________________ 55 

Harvey Bar placer, features of_-___________________ 78

Harvey fault, features of___________________________ 33 

Hematite, occurrence of ______________________ 56

Hemimorphite. occurrence of- _ __________________ 58

Hoage, E. J., mines, features of______________________ 69

Hooknose anticline, features of_____________________ 29 

Hoopalula mine, features of _____________________ 68 

Hornblende, occurrence of--_ ___________________ 57

Hornfels, occurrence of_ _-__-_ ____________ 41, pi. 19. A

Horsethief Creek series. See Monk formation.

Hydrocarbon compounds, occurrence of___________--__ 59-60

I-fydrothennal alteration, description of_______________ 41-47

Igneous metamorphism, features of_ ________________ 40-41 

Igneous rocks, intrusive___________________________ 24-28 

Ilmenite, occurrence of__ ________________________ 56

.Tefferisite, occurrence of___- 

.Tust Time mine, features of58

62

70
80 INDEX

K

Page

Kaniksu batholith, age of___ _________-__-_ _ 26 

border fades of-______ _________________ 25-26

character of ____-_-________________ 24-25

extent of- ___________________________ 24

petrography of ______________________ 25, pis. 12, 13, A

Lakeview mine, features of--__-__________ 69-70, pi. 23, -D, 24, C 

Lamprophyre dikes, occurrence and character of.________ 27 

Lead, production of ____ ___________________ 48, 49

Lead Hill mine, features of__________ 63, pis. 24, A, 28 (in pocket) 

Lead King mine, analyses of rock from____________ 44, pis. 21, 22 

features of___-_____-______________:______ , 70 

Lead Queen mine. See Scandinavian mine.

Ledbetter slate, age of____-_____________________ 20-22 

deposition of, conditions of--_______________ 20

distribution of_____________________________ 19-20

fossils in___________________________________ 20, 21

iithology of_________ ______________________ 20

stratigraphic and structural relations of_____ 20, 31, pi. 14, B, G

Lehigb iron pits, features of___-______________-_____ 78

Leola volcanics, age of_______________________,__ 11

distribution of _____ ____ ______-_____ 9

Iithology of ___________________________ 10, pi. 5, A

origin of- _______________________________ 10-11

stratigrapbic relations of ________-__ ___- 9 10

Limestone, occurrence and use of_ ________ ___ 77

Limouite, occurrence of__ _______ _ ____ 78*

Little Noisy mine, features of__ __________________ 65 

Location and accessibility of the area ______________ 2 

Lode deposits, general features of__ __-i____-. _____ 51-52

Lucky Strike mine, features of_-___--_______-_____ 71

M

Magnetite, occurrence of-__- i _______--___ ___ 56

Maitlen phyllite, age of___ _ _____-__-______ 17 

deposition of, conditions of _ ____-_--_ ___ 17 

distribution of__-___ ________ __ 15, pi. 1 (in pocket)

Iithology of________________________ 16-17, pis. 6, 20, A

stratigraphic relations of_ ____ ____ _____ 15-16

Malachite, occurrence of__________________________ 56

Marcasitc, occurrence of _ _ ________________ 55

Metaline Contact mines, features of ______________ 71

Metaline district, metals produced in_______-_________ 49

mines in- - _ _ __________________ 65-77

Metaline Falls mine, features of_____________________ 75

Metaline limestone, age of__ ___ ________________ 19

deposition of, conditions of_ _-_______________ 19

distribution of_ ____ _________ 17, pi. 1 (in pocket)

Iithology of ________-_______________ 18-19, pis. 8, 9

stratigraphic and structural relations of 17-18, 31, 32, pi. 1.4

Metamorphism, igneous, features of____ _______ 40-41, pis. 19, 20

regional, features of- ______________________ 39-40

Microcliiie, occurrence of__-_______________________ 56

Minerals of the ore deposits and metamorphic rocks_ ______ 54-60

Mines in the area, description of___________________, 60-78

Mining in the area, future of__ ______________ 54

history of _____________________,________ 47-48

Molybdates, occurrence of ____ ___________'. ______ 59

Molybdenite, occurrence of_ _-_ ______ _ _________ 54

Monk formation, age of_______________-_________ 13

deposition of, conditions of________ ____ __ _ 13 

distribution of ___________________ 11, pi. 1 (in pocket)

Iithology of ____________________________ 11-13

stratigraphic relations of _________________ 11 

Montmorillonite, occurrence of- __________________ 59

Morning and Mammoth mine, features of_______________ 71-72 

Mule Deer mine, features of_______________________ 64-65 

Muscovite, occurrence of______'_________ 58, pis. 1.2, B, 13, A, B 

My Era mine, features of_________________________ 62

N

Native elements, occurrence of- 54

O. K. mine, features of__________________________ 76 

Oligoclase, occurrence of-_______________________ 57

Ordoviclan system, rocks of_______________________ 19-22

Pnee

Ore bodies, description of = __ _ _ _ __ 48-53 

origin of___ _ ___ _ __ _____ __ 53

relation of, to rpgional structure _ ___ 52 

Ores, oxidation of ___.___ _ ______ __ ' 53

production of_- _ _ _ _ _ _ _ 48, 49 

Oriole mine, features of_-____ _ _____ _ _- 76-77 

Orthoclase, occurrence of_ _ _ _ 56 

Oxides, occurrence of _ - - - 55-56

Paligorskite, occurrence of__-___ 38-39, 59, pis. .17, 18 

Pass Creek fault, features of 32-33 

Pegmatite bodies, occurrence and character of 27 

Pend Oreille mine, analyses of rock from 43, pis. 21, 22 

description of__ _ 72 74

plan and diagram of______ ____ pis. 33 and 34 (in pocket)

specimens from____ pis. 8, A, 17, 18, _3, B, C, 24, B, 25, B, G, D, 27 B 

view of___ __________ pi. 32

Tend Oreille River, geologic history of _- _ 35-37 

gorge of_ _ _ _ - _ pl. 7

structure near________ ___ ..__ 30-32, pl 1.4, li, C

terraces along_____________- _______- 35-37, pi. 1.5, A

Phlogopite, occurrence of _ _ 58 

Placer deposits, occurrence of____ _ 78 

Pleistocene deposits, features of__ - 23,35-38 

Pre-Cambrian rocks, description of__ ___ _ 6-1J 

Pre'-Tertiary rocks, structure of_____ _ _____ ..- 28 35

Priest River group, features of____ ___________ t>, pl. 2, A

Pyrargyrite, occurrence of _._ _..__.- 55 

Pyrite, occurrence of _ _ __ -- __- _- - - t>5 

Pyrrhotite, occurrence of-_ _____ -__ _- - - 5-r»

.Q 

Quartz, fibrous, analysis of_______ _______________ _ 55

Quartz, occurrence of __ _____ ___ 55, 50

Quaternary system, deposits of_ __ __ _ ____ - _ 23-24

R

Recent deposits, features of ____ _ _ 23-24 

Recrystallization, use of term_____ __ __ _ 40

Replacement deposits, description of_ 50-51, pis. 24, G, 25, B, O, D, 27, A, ^."> 

Ridge fault, features of___ __-__ -____'__________ .V

Riverside mine, features of_ _ ___ _ ______ __ 74

Robert E. Lee mine, features of-__ ______ 70 71.

Round Top Mountain, Shedroof conglomerate on________ __ pl. 4

Ruby Creek, terraces along______ ___ _ _ pl. 15, B 

Russian Creek area, mines in ______ _ ____ __ 60-6J

Russian Creek fault, structural relations of____ _ _ 29, 31 

Rutile, occurrence of_ __ _ _ 50

S 

Sanborn property, prospecting on___ _____. - _ <>4

Sand Creek quarry, location of__________ _ ____ _ 77

Scandinavian mine, features cf____ _ _ _______ _ 74 

Scherding placer, features of_________________ _ 78. pi. 27, C

Sedimentary rocks, hydrothenr.al alteration of. ______ _____ 41 47

igneous nietamorphism of___________-_ __________ 40 41

regional nietamorphism of__________.._______ _ : 9 40

structure of-_ _ __ ______________________ 28-3.~>

Serpentine, occurrence of _ -___ __ __-___ _ OS

Shedroof conglomerate, age of ___ - ___ .._.__ ______ !)

deposition of, conditions of_______ ____ _- 9

distribution of _______ _ _____ __ 7

. Iithology of-___________________-__ 7-8. p's. 2, B} 2, O, 3. 4

stratigraphic and structural relations of_________ __ 7,33

Silicate minerals, formation of ______ _______ 40-41

Silicates, occurrence of__-_-____- _____'. __________ 56-5!)

Silicification of carbonate rocks_____________________ 44-45 

Sillimanite, occurrence of__________-_________ 57, pl. 20. fl 

Silver, production of___________________________ 48, 49 

Slate Creek district, mines in_______________________ 62-64

Slate Creek fault, structural relations of_______________ 30-32 

Smithsonite, occurrence of __ ________________ 56

Sphalerite, occurrence of____________________ 54-55, pl. 25. B 

Sphene, occurrence of-- _____________________ 59

Star mine. See Just Time mine.

Structure in the area______________ ____________ 28-35 

Sulfates, occurrence of__________-_______________ 59 

Sulfides, occurrence of__ ________-____________ 54 55

Sulfosalts, occurrence of____ _________________ 55
INDEX 81

Pasre 

Sulfur, occurrence of- - 54

Sullivan Luke, features of__ _ -^ _ 37-38, pi. 16, B

Talc, occurrence of 59

Terraces, features of ________ ____ _ ___ 35-37, pi. 15

Tertiary system, rocks of _ - - 23, pi. 11 

Tet,rahcdrite, occurrence of _ 55 

Thomson itc, occurrence of - 58

TlRcr formation, age of 23 

deposition of, conditions of _______ ______ __ 23 

distribution of _ _ _ 23 

lithology of--____ ________ _________ 23, pi. 11

thickness of 1____ _ _______ 23

Titanite, occurrence of _ _ _ _ _ 59 

Tltanosilicates, occurrence of__ _____ _ _-_ ' 59

Tom Cat mine, features of _ - _ _____ 74-75 

Topaz, occurrence of _ _ _ _ ___ __ 57 

Topography of the area, development of_____-__ 35-:.i8, pis. 15,16 

general features of_ _ ___ _ _ 2-3 

Tourmaline, occurrence of- _ - _-___ _________ 58 

Ti'emolite, occurrence of_____________ 40, 57, pi. 19, B, C

Troyer mine, location of_________________________ " 64

Uncas Gulch mine, features of : 64 

United Treasure mine, description of____ __ ___ _ 60-61

Valley block, description of________________ 30-32, pis. 14, 30 

Vegetation of the area-_ _ _ _ _ _ 3, pi. 15, B

W

Washington and Metaline Falls mines, features of___ - 75 

Wiegener effect in formation of silica, defined____________ 45 

Wolf Creek mine, features of__ _______________ 75, pi. 23, A 

Wuifenite, occurrence of____-_-__________.._______ 59

Z

7, Canyon mine, features of _______________ 7".-70. pi. 20

Z Canyon Mutual mine, features of____________________ 75

Zebra rock, occurrence of_ _ ____.________ 42 43, pi. 23, E 

Zinc, ore, occurrence of__ _______________ 54-55, pi. 25, B 

Zinc, production of_____ __ ____:_____________ 48, 49 

Zircon, occurrence of-____ _-_________________ 57

.Zoisite, occurrence of _________________________ 57

o