By David E. Boleneus, Larry M. Appelgate, Mary H. Carlson, Derrick W. Chase, 

and Michael L. Zientek

Scientific Investigations Report 2005–5231

U.S. Department of the Interior

U.S. Geological Survey

Stratabound Copper-Silver Deposits of 

the Mesoproterozoic Revett Formation, 

Montana and Idaho

By David E. Boleneus, Larry M. Appelgate, John H. Stewart, and Michael L. Zientek

With a section on Databases and Spatial-Data Files for the Geology and Mineral 

Deposits of the Revett Formation
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

For sale by U.S. Geological Survey Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

This report and any updates to it are available online at:

http://pubs.usgs.gov/sir/2005/5231/

For additional information write to:

U.S. Geological Survey

Box 25046, Mail Stop 421, Denver Federal Center

Denver, CO 80225–0046

Additional USGS publications can be found at:

http://geology.usgs.gov/products.html

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Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement of the U.S. Government.

Although this report is in the public domain, it contains copyrighted materials that are noted in the text. Permission 

to reproduce those items must be secured from the individual copyright owners. 

Cataloging-in-publication data are on file with the Library of Congress (URL http://www.loc.gov/).

Produced in the Western Region, Menlo Park, California

Manuscript approved for publication, October 21, 2005

Text edited by George A. Havach

Layout and design by Judy Weathers
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Geologic Setting.............................................................................................................................................2

Stratigraphy ...........................................................................................................................................2

Structure.................................................................................................................................................2

Revett Formation............................................................................................................................................5

Lower Member......................................................................................................................................5

Middle Member.....................................................................................................................................7

Upper Member......................................................................................................................................7

Stratabound Copper-Silver Deposits..........................................................................................................8

Mineralized Domains..........................................................................................................................11

Low-Grade Mineralized Strata .........................................................................................................11

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain 

Size of Ore-Bearing Units, and Mineral Zones..........................................................................14

Host Rocks ...........................................................................................................................................14

Isopach Maps......................................................................................................................................16

Grain Size and Isoliths of Clastic Strata..........................................................................................16

Mineral Zones......................................................................................................................................22

Distribution..................................................................................................................................28

Displacement..............................................................................................................................28

Relations Between Grain Size, Stratigraphic Thickness, and Mineral Zones in Host Rocks at

 the Trout Creek Prospect .............................................................................................................28

Permissive Tracts.........................................................................................................................................29

Conclusions...................................................................................................................................................29

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the 

Revett Formation.............................................................................................................................31

Introduction...................................................................................................................................................31

Diamond-Drill-Core and Measured-Section Data .................................................................................31

Field-Data Forms ............................................................................................................................31

Spreadsheets and Graphical Logs .............................................................................................36

Collar Worksheet ..............................................................................................................40

Formation Worksheet.......................................................................................................40

Lithology Worksheet.........................................................................................................40

Mineralogy Worksheet ....................................................................................................41

Thickness and Other Corrections ..................................................................................44

Revett-Subtype Stratabound Copper-Silver Deposits, Occurrences, and Prospects......................45

Spatial Databases........................................................................................................................................45

Geologic Databases ...........................................................................................................................47

Documentation for the ArcInfo Coverage rev48k.e00 .........................................................49

Measured-Section and Diamond-Drill-Core Datasets .................................................................50

Documentation for the ArcInfo Coverage rev_ddh.e00 ......................................................50

Documentation for the ArcInfo Coverage rev_msec.e00 ...................................................51
iv

Mineral-Zone Datasets......................................................................................................................51

Documentation for the ArcInfo Coverages lrevzone.e00 and urevzone.e00 ...................51

Copper-Silver Mineralized-Domain, Untested-Exploration-Area, and Permissive-Tract 

Dataset....................................................................................................................................53

Mineralized Domains ................................................................................................................53

Untested Exploration Area and Permissive Tracts...............................................................53

Documentation for the ArcInfo Coverage rev_cuag.e00 ....................................................54

How to Obtain Data......................................................................................................................................56

Acknowledgments.......................................................................................................................................56

References Cited..........................................................................................................................................56

Appendix A. Graphical Logs of Measured Sections and Diamond-Drill Cores.................................59

Plates

1. Map of the Revett Formation, western Montana and northern Idaho, showing the 

locations of mineralized strata, diamond-drill holes, and measured sections

2. Lithologic cross sections A–B and C–D, showing stratigraphic relations and mineral 

zones in the Revett Formation of western Montana and northern Idaho

3. Maps showing pyrite-calcite zones in the upper and lower members of the Revett 

Formation, western Montana and northern Idaho, untested exploration areas, and 

permissive tracts for the occurrence of undiscovered Revett-subtype stratabound 

copper-silver deposits

Figures

1. Map of western Montana and northern Idaho, showing the locations of the study 

area, major faults, and stratabound copper-silver deposits in the 

Revett Formation...........................................................................................................................3

2. Diagram showing stratigraphic relations in the lower, middle, and upper members 

of the Revett Formation of western Montana and northern Idaho.......................................4

3. Generalized stratigraphic columns of the Revett Formation at the Troy Mine and 

Rock Creek deposit, western Montana.....................................................................................6

4. Grade-tonnage diagram for copper in three subtypes of stratabound copper-silver 

deposits in North America ..........................................................................................................8

5. Grade-tonnage diagram for silver in two subtypes of stratabound copper-silver 

deposits in North America with reported silver production..................................................9

6. Map of the study area, showing mineralized domains in the western Montana 

copper belt...................................................................................................................................12

7. Schematic north-south cross section E–F across the study area, showing horizontal 

and vertical extent of low-grade mineralized strata, based on core data from 

diamond-drill holes.....................................................................................................................13

8. Lithologic cross sections G–H and I–J across north half of the study area, showing 

stratigraphic setting and mineralized zones of stratabound copper-silver deposits in 

the Revett Formation, based on core data from diamond-drill holes and stratigraphic 

relations in measured sections ................................................................................................15

9. Isopach map of the A–D beds of the lower member of the Revett Formation in the 

study area ....................................................................................................................................17
v

10. Isopach map of the middle member of the Revett Formation in the study area ..............18

11. Isopach map of the upper member of the Revett Formation in the study area................19

12. Isopach map of the middle quartzite of the lower member and the middle and upper 

member of the Revett Formation in the study area...............................................................20

13. Isopach map of the A–D beds of the lower member and the middle and upper 

members of the Revett Formation in the study area.............................................................21

14. Quartzite isolith map of the A–D beds of the lower member of the Revett Formation 

in the study area .........................................................................................................................23

15. Mean-or-greater (≥180 ft [55 m]) quartzite isolith map of the A–D beds of the lower 

member of the Revett Formation in the study area...............................................................24

16. Diagram of mineralized zones in Revett-subtype stratabound copper-silver deposits, 

showing nomenclature based on the diagenetic-cementation sequences of Hayes 

(1983), Hayes and Einaudi (1986), and Hayes (1990) for the Troy deposit in the study 

area ...............................................................................................................................................25

17. Map of the study area, showing the areal extent of mineralized zones in the A–D 

beds of the lower member of the Revett Formation..............................................................26

18. Map of the study area, showing the areal extent of mineralized zones in the middle 

quartzite of the upper member of the Revett Formation ......................................................27

19. Scanned image of field-data form for White Pine Creek #2–#3 measured section.........32

20. Scanned image of field-data form for diamond-drill hole VR–4..........................................32

Tables

1. Summary of 57 stratabound copper-silver deposits, occurrences, and prospects in 

the Revett Formation, western Montana and northern Idaho.............................................10

2. Production and resources of stratabound copper-silver deposits in the Revett 

Formation, western Montana and northern Idaho................................................................11

3. Thicknesses and isoliths in the A–D beds of the lower member of the Revett 

Formation in the Trout Creek Prospect area, western Montana ........................................29

4. List of databases, graphical logs, and spatial-data files......................................................33

5. Summary of data from diamond-drill cores and measured sections.................................37

6. Contents of each spreadsheet .................................................................................................41

7–9. Definitions of item names in:

 7. The collar worksheet ..........................................................................................................41

8. The formation worksheet ...................................................................................................42

9. The lithology worksheet .....................................................................................................43

10. Example of spreadsheet calculation of sand isolith.............................................................45

11. Definition of item names in the mineralogy spreadsheet ....................................................47

12. Definition of item names in the file cuag_deposit.txt ...........................................................48
vi

Conversion Table

To convert from To Multiply by

feet (ft) meters (m) 0.3048

miles (mi) kilometers (km) 1.609344

square miles (mi2) square kilometers (km2) 2.5899881

troy ounces (troy oz) tonnes (t) 3.110348×10-5

tons tonnes (t) 0.90718474
Stratabound Copper-Silver Deposits of the Mesoproterozoic 

Revett Formation, Montana and Idaho

By David E. Boleneus, Larry M. Appelgate, John H. Stewart, and Michael L. Zientek

Abstract

The western Montana copper belt in western Montana 

and northern Idaho contains several large stratabound copper-silver deposits in fine- to medium-grained quartzite beds 

of the Revett Formation of the Mesoproterozoic (1,470–1,401 

Ma) Belt Supergroup. Production from the deposits at the 

Troy Mine and lesser production from the Snowstorm Mine 

has yielded 222,237 tons Cu and 1,657.4 tons Ag. Estimates 

of undeveloped resources, mostly from the world-class Rock 

Creek-Montanore deposits, as well as lesser amounts at the 

Troy Mine, total more than 2.9 million tons Cu and 2,600 tons 

Ag in 406 million tons of ore.

The Rock Creek-Montanore and Troy deposits, which are 

currently the most significant undeveloped resources identified in the copper belt, are also among the largest stratabound 

copper-silver deposits in North America and contain about 

15 percent of the copper in such deposits in North America. 

Worldwide, stratabound copper-silver deposits contain 23 percent of all copper resources and are the second-most important 

global source of the metal after porphyry copper deposits.

The Revett Formation, which consists of subequal 

amounts of argillite, siltite, and quartzite, is informally divided 

into lower, middle, and upper members on the basis of the 

proportions of the dominant rock types. The unit thickness 

increases from north to south, from 1,700 ft near the Troy 

Mine, 55 mi north of Wallace, Idaho, to more than 5,300 ft 

at Wallace, Idaho, in the Coeur d’Alene Trough south of the 

Osburn Fault, a major right-lateral strike-slip fault.

Mineral deposits in the Revett Formation occur mostly in 

the A–D beds of the lower member and in the middle quartzite 

of the upper member. The deposits are concentrated along a 

preore pyrite/hematite interface in relatively coarse grained, 

thick quartzite beds that acted as paleoaquifers for ore fluids. 

The deposits are characterized by mineral zones (alterationmineral assemblages) that are a useful guide to the locations of 

mineral deposits. In particular, the gradational zone between 

the chalcopyrite-ankerite and pyrite-calcite zones is the site of 

most mineral deposits.

Detailed information on the geology and mineral deposits 

of the Revett Formation is presented in the accompanying files 

that include (1) a tab-delimited text file providing details of 

the geologic and mineral-resource data for 57 Revett-subtype 

stratabound copper-silver deposits, occurrences, and prospects; 

(2) the stratigraphic records of 40 diamond-drill cores and 86 

measured sections, totaling 150,752 ft of true thickness, which 

are provided in Excel spreadsheet and Adobe Portable Document Format files; and (3) spatial geologic data consisting of 

geologic maps of the Revett Formation, the subsurface locations of resources in Revett-subtype stratabound copper-silver 

deposits based on diamond-drill-core data, and the locations 

of diamond-drill holes and measured sections. The spatial data 

are contained in Arc/Info interchange files. Spatial information derived from these data includes the locations of mineral 

zones, a digital database showing untested exploration areas, 

and a digital database of permissive tracts for undiscovered 

mineral deposits.

Introduction

Worldwide, stratabound copper-silver deposits contain 23 

percent of all known copper resources and are the second-most 

important source of the metal (Singer, 1995). These deposits 

typically consist of disseminated Cu sulfide minerals restricted 

to a narrow range of mineralized layers within a sedimentary 

sequence; however, the mineralization does not necessarily follow sedimentary bedding. The deposits are epigenetic 

and diagenetic; that is, they formed after the host sediment 

was deposited but mostly before lithification of the host rock 

(Cox and others, 2003). Two large stratabound copper-silver 

deposits, the Rock Creek-Montanore and Troy deposits, in the 

Mesoproterozoic1 Revett Formation of the western Montana 

copper belt, contain 15 percent of the known copper from such 

deposits in North America.

This report describes the regional stratigraphy, lithologic 

characteristics, and alteration patterns of the Revett Formation in relation to the localization of stratabound copper-silver 

deposits, along with the exploration potential of the region. 

The study area covers 4,280 mi2 of the western Montana cop1

According to the 2004 International Stratigraphic Chart published by the 

International Commission on Stratigraphy, spanning the period 1,600–1,000 Ma.
 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho

per belt and spans 100 mi north-south by 85 mi east-west. The 

copper belt straddles the Montana-Idaho State line east and 

southeast of Pend Oreille Lake, Idaho. The study area includes 

Bonner, Boundary, Kootenai, and Shoshone Counties in northern Idaho and Lincoln, Mineral, Missoula, and Sanders Counties in western Montana. The study area lies east of the cities 

of Sandpoint and Coeur d’Alene, Idaho; the city of Thompson 

Falls, Mont., is located near its east edge. One measured section lies west of the copper belt in Stevens County, Wash.

Detailed information on the geology and mineral deposits of the Revett Formation is presented in the accompanying 

files. Geologic data were compiled from industry exploration 

records to create six databases: (1) descriptions of 57 Revettsubtype stratabound copper-silver deposits, occurrences, and 

prospects; (2) subsurface copper-silver resources in the Revett 

Formation based on diamond-drill-core data; (3) geologic 

maps of the western Montana copper belt; (4) stratigraphic 

relations from measured sections; (5) mineral zones in the 

lower and upper members of the Revett Formation; and (6) 

permissive and untested exploration areas. Stratigraphic data 

compiled for the Revett Formation include the geologic logs of 

40 diamond-drill cores and 86 measured sections, for a total of 

150,752 ft of true thickness.

Geologic Setting

Stratigraphy

The Belt Basin (pl. 1; fig. 1), which covers several thousand square miles in Montana, Idaho, Washington, and British 

Columbia, Canada, was the site of deposition of more than 

60,000 ft of predominantly fine grained sedimentary strata of 

the Mesoproterozoic Belt Supergroup (fig. 2; Harrison, 1972; 

Harrison and others, 1974; Winston, 1986a, b; Link and others, 1993; Schieber, 1998; Price and Sears, 2000; Mauk and 

White, 2004). Argillite, siltite, and carbonates are the most 

common rock types; lesser amounts of quartzite and coarsegrained clastic rocks are present in some formations.

Rocks of the Belt Supergroup (fig. 2) range in age from 

1,401 to 1,470 m.y. (Link and others, 1993; Turner and others, 

1995). A concordant sensitive-high-resolution-ion-microprobe (SHRIMP) U-Pb zircon age of 1,467±3 m.y. (Evans 

and others, 2000) was obtained on a sample from a gabbro sill 

that intruded the lowermost part of the Aldridge Formation in 

Canada, strata that are equivalent to the Prichard Formation in 

the lowest part of the Belt Supergroup. This age sets a minimum date for rifting during deposition of the oldest part of the 

Belt Supergroup (Turner and others, 1995).

Strata of the Belt Basin can be divided into three main 

facies (Lydon, 2000): (1) a basinal or rift-fill facies consisting 

mainly of deep-water turbidites in the main part of the basin 

and deep-water calcareous argillite and turbidites that shoal 

upward to midshelf carbonates and siliciclastic rocks in the 

Helena embayment; (2) a shallow-water platformal and fandelta facies deposited at the margins of the rift and surrounding shelf, approximately synchronous with turbidite deposition within the rift; and (3) a shallow-water, mudflat, fluvial, 

lagoonal, alluvial, and playa facies that covers both the rift-fill 

facies and its adjacent platform and forms the upper part of the 

Belt Supergroup.

Near the study area (pl. 1; fig. 1), the lower part of the 

Belt Supergroup consists of the Prichard Formation (fig. 2), 

locally more than 20,000 ft thick, which consists of pyriterich argillite, siltite, and quartzite (Winston and Link, 1993). 

Overlying the Prichard Formation are rocks of the Ravalli 

Group, which includes the Burke, Revett, and Empire-St. 

Regis Formations (fig. 2). The Burke Formation, which is the 

oldest unit in the Ravalli Group, consists of greenish-gray, 

purple, reddish-gray, and minor black-and-gray siltite and 

argillite (Winston and Link, 1993). The Burke Formation 

thickens from 2,500 to 3,500 ft southward across the region. 

The overlying Revett Formation contains subequal proportions 

of quartzite, silty quartzite, siltite, and argillite (Winston and 

Link, 1993). The grain size of the quartzite very rarely exceeds 

medium sand. The units thin in all directions from a point of 

greatest known thickness, estimated at 5,580 ft (Mauk, 2001), 

in the Coeur d’Alene Trough, 21 mi west of Wallace, Idaho. 

The overlying St. Regis Formation, which ranges from 1,000 

to 3,000 ft in thickness (Harrison and others, 1986), consists of 

greenish-gray, purple, reddish-gray, and subordinate blackand-gray siltite and argillite. Overlying the Ravalli Group 

are rocks of the Wallace Formation and Missoula Group. 

The Wallace Formation, which is about 5,500 ft thick in the 

Coeur d’Alene Trough, consists mostly of argillite and siltite 

and a middle part containing dolomitic beds (Winston and 

Link, 1993). The Missoula Group (not shown in fig. 2), which 

contains the highest strata in the Belt Supergroup, comprises 

several formations, with a total thickness of about 15,000 ft in 

the Coeur d’Alene Trough, consisting of argillite, siltite, sandstone, and, locally, carbonate rock (Winston and Link, 1993).

Structure

Major northwest- and west-northwest-striking faults, 

including, from north to south, the Hope, Thompson Pass, 

and Osburn Faults, subdivide the study area into structural 

domains (pl. 1; fig. 1). The Hope and Osburn Faults were 

active normal faults during deposition of the Revett Formation, as indicated by major variations in the thickness of strata 

across them (Harrison and Cressman, 1993; Mauk, 2001). The 

Coeur d’Alene Trough, lying south of the Osburn Fault, was a 

depositional center of the Revett Formation. The thick deposits 

there may owe their origin to syndepositional movement 

along the Osburn Fault. Movement on the Osburn Fault during 

deposition of the Revett Formation was down on the south side 

because the formation thickens southward to at least 5,580 ft 

(Mauk, 2001), whereas between the Osburn and Hope Faults 

it thins to only 1,430 ft. Movement on the Hope Fault during 

deposition of the Revett Formation was down on the northeast 

side because the formation thickens to 1,750 ft (Hayes, 1983) 

northeast of the Hope Fault near the Troy Mine.
Rock Creek

Troy

Montanore

Vermilion River

Pend Oreille

Lake

Extent of Belt

Supergroup rocks

(Belt Basin) 

Coeur d'Alene Mining District

COEUR D'ALENE TROUGH

Cu-Ag deposits in the Revett Formation; italic 

name, recorded production; bold name, significant 

deposit

Strike-slip fault; arrows indicate directions of 

relative motion

Thrust fault; teeth on upper plate

Normal or reverse fault; tick marks on downthrown 

side

Outcrop of the Revett Formation

Boundary of study area

County line

Copper Camp Niagara

Military

Gulch

Snowstorm

MissoulaNational

Map area

MONTANA

IDAHO

SHOSHONE COUNTY

BONNER COUNTY

KOOTENAI COUNTY

SANDERS

COUNTY

MINERAL

COUNTY

Chipmunk Creek

Mount Vernon

LINCOLN

COUNTY

SNOWSHOE FAULT

MOYIE THRUST PLATE

HOPE FAULT

TROUT CREEK

ANTICLINE

THOMPSON PASS FAULT

OSBURN FAULT

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

Figure 1. Western Montana and northern Idaho, showing locations of study area, major faults, and stratabound copper-silver 

deposits in the Revett Formation.

Geologic Setting 
Mesoproterozoic

Paleoproterozoic Pre-Belt crystalline rocks Belt

Lower part of 

the Belt 

Supergroup

Formation Members

Wallace

St. Regis

Revett

Burke

Upper

Middle

Lower

Prichard

Base not exposed

Upper

Lower

Empire

Upper

Middle

Lower

Transitional

Supergroup

Age Group

Ravalli

Revett

Upper quartzite

Upper siltite

Middle quartzite

Lower siltite

Lower quartzite

Upper

Middle

Lower

Member Bed Presence of 

mineralization Formation

see

detail

below

A 

B

C

D

E

F

G

H

I

Troy, Niagara

Troy, Snowstorm

Rock Creek, Montanore, 

Missoula*, National*, 

Trout Creek, Vermilion 

River

Troy, J-F

Deposits

[Historical producers are

italicized; *, production from veins]

Carbonatebearing middle 

part of the Belt 

Supergroup

Solid vertical line, deposit; 

dashed vertical line, 

low-grade mineralized strata

Figure 2. Stratigraphic relations in the lower, middle, and upper members of the Revett Formation 

of western Montana and northern Idaho (pl. 1; fig. 1). Modified from Harrison and others (1986) and 

Hayes and Einaudi (1986).

 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
The Hope, Osburn, and Thompson Pass Faults were 

reactivated as right-lateral strike-slip faults as a consequence 

of crustal shortening during Laramide time (Harrison and 

Cressman, 1993). Right-lateral movement is as much as 16 

mi on the Hope and Osburn Faults and as much as 2 mi on the 

Thompson Pass Fault.

The Moyie thrust plate, a listric-fault system consisting 

of Sevier-Laramide north-trending and eastward-vergent thrust 

and backslid faults, lies northeast of the Hope Fault (pl. 1; fig. 

1). This fault system separates the Troy Mine from the Rock 

Creek-Montanore deposits. The Rock Creek deposit lies in 

the upper limb, and the Montanore deposit in the folded lower 

limb, of the Snowshoe thrust fault, a branch of the Moyie 

thrust plate. The Vermilion River deposit lies in inverted strata 

in the folded and faulted lower limb of an unnamed fold of the 

Moyie thrust plate. Shortening along any single thrust fault 

in the study area does not exceed 0.5 mi, and apparent total 

shortening is no more than 12 mi (Harrison and Cressman, 

1993). North-south folds like the broad Trout Creek anticline 

(fig. 1) appear to be related in time with the Moyie thrusting 

event. The Trout Creek, Eagle Creek, Niagara, and other prospects are located on the northwest limb of this anticline.

Revett Formation

Ransome (1905) named the Revett Formation (his 

“Revett quartzite”) apparently for strata at the Snowstorm 

Mine, surrounding Lake Revett, and in the eastern part of the 

Coeur d’Alene Mining District (fig. 1) near the MontanaIdaho State line. As first described by Ransome, the unit 

consists almost entirely of thick beds of white or gray quartzite interbedded with subordinate micaceous sandstone. Hayes 

(1983) defined the Revett Formation as that part of the Ravalli 

Group which includes thick-bedded metasandstone. Hayes’ 

(1983) definition distinguishes thick beds of crossbedded, 

horizontally laminated and ripple-laminated metasandstone of 

the Revett Formation from thinner beds of ripple-laminated 

finer grained rocks of adjacent formations. In the study area 

(pl. 1; fig. 1), rocks of the Revett Formation have been metamorphosed to subgreenschist (prehnite-pumpellyite; Burchfiel 

and others, 1992, pl. 9) and, locally, biotite (Hayes and others, 

2003) grade, some of the lowest metamorphic grades observed 

in rocks of the Mesoproterozoic Belt Supergroup. The metamorphic grade increases both westward and southward of the 

study area. Detrital quartz grains in the rocks are not recrystallized and are easily distinguishable optically in thin section 

and by the cathodoluminescence of quartz overgrowths and 

cement (Hayes, 1990).

The terms “quartzite,” “silty quartzite,” “siltite,” and 

“argillite” are used to describe rocks throughout the region (pl. 

1) because of the widespread metamorphic effects; unmetamorphosed equivalents to these rocks are sandstone, silty 

sandstone, siltstone, and claystone (Harrison and Grimes, 

1970). The general field practice for determining the lithology 

of clastic rocks depends on a scratch test using a steel nail, 

which will scratch silty argillaceous rocks but not quartzite.

In the Coeur d’Alene Mining District (fig. 1), the Revett 

Formation is characterized by white, medium-grained, crossbedded quartzite interbedded with white siltite and green laminated 

argillite (Harrison and others, 1986). Northeastward and eastward 

from the mining district, the unit contains progressively less 

quartzite and more siltite and argillite, much of which is purple or 

purplish gray. Fine-grained strata of the Revett Formation consist 

of greenish-gray through gray to reddish-gray siltite and argillite, 

commonly showing centimeter-scale, alternating silt and argillite 

beds called couplets. The coarsest grained strata are composed 

of clean, fine- and medium-grained, almost colorless, white, or 

very light gray to light-greenish-white vitreous quartzite and silty 

quartzite. These strata commonly exhibit flat laminations, trough 

crossbedding, and ripple-drift laminations. Sparse incised channels 

and rare intraclast conglomerate beds probably indicate sediment 

transport and winnowing by strong currents. The strata occur in 

both fining- and coarsening-upward sequences, suggesting varying 

current strength. Beds have continuity on a scale of miles. Thin 

mud-cracked silty units indicate periods of subaerial exposure. The 

combination of widespread strata and strata that vary in grain size 

suggests shallow-water cyclic deposition on a broad, monotonous 

coastal plain. (Hayes, 1983).

The Revett Formation is informally divided into lower, 

middle, and upper members (figs. 2, 3; Hayes, 1983). All 

three members are recognizable at the Troy Mine (Bowden, 

1977; Hayes, 1983), in the Wallace 1° by 2° quadrangle (Harrison and others, 1986), and at Flathead Indian Reservation 

in Lake County, Mont. (Ryan and Buckley, 1998), 50 mi (80 

km) east of the study area (pl. 1; fig. 1). The upper and lower 

members are similar in that they consist of cyclic sequences 

with abundant quartzite and silty quartzite, along with lesser 

amounts of siltite and argillite. The middle member is distinct 

because it consists largely of argillite and siltite. At the Troy 

Mine, Bowden (1977), Hayes (1983), and Hayes and Einaudi 

(1986) subdivided the lower and upper members into beds (fig. 

2), mainly on the basis of the stratigraphy of fine- and coarsegrained layers. The present study correlates these members 

and groups of beds within the Revett Formation outward from 

the Troy Mine, using the stratigraphic terminology of Asarco 

Inc. (in Hayes, 1983), on the basis of the measured sections 

shown on plate 1 and included as appendix A.

Lower Member

The base of the lower member of the Revett Formation 

is located at the base of the lowest thick-bedded quartzite 

above purple to green argillite and siltite of the Burke Formation. The top of the lower member is defined as the top of the 

uppermost thick quartzite bed below thick siltite and argillite of the middle member. The lower member is informally 

subdivided into beds A through I (fig. 3), lettered downward 

from the top of the lower member (cross sec. A–B, pl. 2; 

Hayes, 1983). Quartzite dominates in the A, C, E, G, and I 

beds that alternate with the fine-grained B, D, F, and H beds. 

Revett Formation 
Figure 3. Generalized stratigraphic columns of the Revett Formation at the Troy Mine and Rock Creek deposit, 

western Montana (pl. 1; fig. 1).

1200

1000

1400

1600

1800

2000

2200

2400

2600

2800

Upper siltite

Middle quartzite

Lower siltite

Lower quartzite

 Upper member Middle member

A

Lower member

D

C

B

Upper quartzite 1000

1200

1400

1600

1800

A

D

C

B

E

F

G

H

I

J

 Troy Mine

(diamond-drill hole 

SL-93)

Rock Creek deposit

(diamond-drill hole 

RC-58)

Coarse-grained facies—includes 

thick beds of vitreous quartzite

Coarse-grained facies—includes 

thin beds of nonvitreous quartzite 

or siltite and minor argillite

Fine-grained facies—includes very 

thin and thin alternating 

siltite-argillite or quartzite-siltite 

beds

EXPLANATION

Beds

Northwest Southeast 14 miles 

K

Burke 

Formation

Sedimentary facies

Cu content, in weight percent

> 0.4

0.02−0.4

Metal content Sedimentary facies 

(depth in feet)

Sedimentary facies Metal content

(depth in feet)

STUDY AREA

MONTANA

IDAHO

Troy Mine

Rock CreekMontanore deposits

Revett Formation

A-D beds

No data

 Upper member

Middle member

A-D beds

Lower member

No data

St. Regis

Formation

Cu Pb Cu Pb

 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
In this report, groups of beds (A–D, E–H, I) are recognized in 

the lower member and correlated over large areas. The A–D 

beds are the host rock of the Rock Creek-Montanore deposits. In cross section A–B (pl. 2; see section lines on pl. 1), the 

lower member ranges from 1,170 ft in thickness at the Troy 

Mine (diamond-drill hole SL–123) down to 990 ft at the West 

Fork of Crow Creek-Chipmunk Creek 1 composite measured 

section and then thickens abruptly across the Osburn Fault to 

more than 2,060 ft at Latour Peak. The lower member probably represents high-energy beach or nearshore deposits.

Middle Member

The middle member of the Revett Formation is dominated by fine-grained clastic rocks. The middle member is 

undivided and consists mainly of argillite and siltite with only 

minor quartzite. In cross section A–B (pl. 2), the middle member thickens slightly from 275 ft at diamond-drill hole SL–123 

on the north to 295 ft at the Chipmunk measured section 1 

on the south. The middle member thickens abruptly across 

the Osburn Fault to 980 ft at the Latour-Boise Peak measured 

section. The middle member probably represents low-energy 

mudflat or interdistributary-bay deposits.

Upper Member

The upper member of the Revett Formation is informally 

subdivided at the Troy Mine (Hayes, 1983) into beds on the 

basis of the proportion of quartzite relative to argillite and 

siltite. Upward from the base of the upper member, the beds 

are named the lower quartzite, lower siltite, middle quartzite 

(called “ore quartzite” by early workers at the Troy Mine 

because it contained the main ore deposit), upper siltite, and 

upper quartzite (figs. 2, 3). The subdivisions of the upper 

member at the Troy Mine are recognizable with increasing 

difficulty southwest of the Hope Fault. Hayes (1983) traced 

the middle quartzite as far southward as Trout Creek and the 

West Fork of Eagle Creek. Farther south—for example, at 

Military Gulch—only one quartzite bed is observed in the 

upper member; this quartzite bed forms the contact between 

the middle member and the overlying St. Regis Formation. In 

cross section A–B (pl. 2), the upper member thins from 250 

ft in diamond-drill hole SL–123 at the Troy Mine to 125 ft 

in diamond-drill hole MG–6 (Military Gulch), located 6 mi 

east of Wallace. South of the Osburn Fault, the upper member thickens abruptly to 950 ft at the Latour Peak-Boise Peak 

measured section. The base of the upper member is located at 

the contact of the lower quartzite with underlying siltstone and 

argillite of the middle member. The top of the upper member 

is characterized by thick quartzite beds below thick purple, 

greenish-gray, black, or dark-gray argillite and siltite beds of 

the overlying St. Regis Formation.

Hayes (1983) and Hayes and Einaudi (1986) interpreted the 

sedimentary layers in the upper member of the Revett Formation 

in the vicinity of the Troy Mine as coastal deposits. Hayes and 

Einaudi focused on the lower and middle quartzites of the upper 

member because of their importance to the Troy deposit.

The lower quartzite consists of coarsening-upward cycles 

of predominantly quartzite deposited in northeasterly prograding, northwesterly to southeasterly oriented shorelines (Hayes 

and Einaudi, 1986). The coarsening-upward strata contain 

various laminated and crossbedded layers, suggesting deposition under high-energy conditions in beach-swash, peritidal, 

and shallow wave-built nearshore zones. In the lower part of 

the lower quartzite, southwestwardly oriented foreset beds, 

composed of megaripple bars, are consistent with postulated 

shoreward-directed transport in the wave-built nearshore zone. 

In the upper part of the lower quartzite, coarse-grained, horizontally laminated beds containing abundant heavy-mineral 

laminae and northeast-dipping foreset beds are interpreted as 

swash-zone deposits along the shoreface. On this basis, Hayes 

and Einaudi interpreted the lower quartzite as a barrier-beach 

deposit influenced by a tidal range of more than 13 ft.

The lower siltite overlies the lower quartzite. The 

lower siltite is interpreted as channel-fill mud deposits and 

low-energy mudflat or interdistributary-bay deposits lying 

landward from barrier-beach deposits of the lower quartzite 

(Hayes, 1983).

The middle quartzite is the main host rock of the Troy 

deposit (Hayes, 1983). This medium-grained quartzite is interpreted as tidal-channel deposits in a northeasterly prograding 

estuarine sequence (Hayes, 1983; Hayes and Einaudi, 1986). 

In contrast, fining-upward sequences containing significant 

amounts of argillite and siltite are interpreted as channelmargin deposits. The channel-margin deposits, which have a 

lower permeability than the tidal-channel sandstone beds, are 

located outside of the central tidal-channel complex (Hayes 

and Einaudi, 1986). Together, these channel-margin and 

tidal-channel strata compose part of the northeasterly prograding estuarine sequence, analogous to those on many modern 

coastal plains (Reineck and Singh, 1975; Reinson, 1992). Lateral variation in permeability, related to changes from medium 

sand in the tidal channels to finer sand in the channel margins, 

impeded permeability and constrained the emplacement of the 

Troy deposit to the coarser grained sedimentary layers (Hayes 

and Einaudi, 1986). The highly permeable tidal-channel sand 

beds served as conduits and host strata for the metal-bearing 

brines from which the deposit was formed.

The upper siltite is subdivided into three parts (Hayes, 

1983): a lower part consisting of a series of 2- to 3-ft-thick 

ripple- and lenticular-laminated silty quartzite beds and of 

vitreous quartzite beds; a middle part consisting of 12- to 30-ftthick quartzite beds, with scoured bases, that grade upward into 

siltite and argillite; and an upper part consisting of 9- to 18-ftthick siltite-argillite couplets. The upper siltite is interpreted as 

subtidal, intertidal-channel, and intertidal mudflat deposits.

The upper quartzite, which is as much as 35 ft thick, 

consists of a sequence of trough-crossbedded quartzite beds in 

sets from 1.5 to 2 ft thick that fine upward into siltite (Hayes, 

1983). A 1- to 3-ft-thick argillite marker bed, interpreted as 

Revett Formation 
supratidal in origin, occurs about 5 ft above the base of the 

upper quartzite at the Troy Mine. The upper quartzite is interpreted as sabkha to intertidal-channel sand deposits.

Stratabound Copper-Silver Deposits

The western Montana copper belt includes several large 

stratabound copper-silver deposits in the Revett Formation 

of the Mesoproterozoic Belt Supergroup (1,401–1,470 m.y.; 

pl. 1; fig. 1; Harrison, 1972; Hayes, 1983, 1990; Lange and 

Sherry, 1983; Lange, 1986; Hayes and Einaudi, 1986; Hayes 

and others, 1989). These deposits, which are referred to as 

Revett-subtype stratabound copper-silver deposits, are one 

of the three subtypes of such deposits recognized worldwide 

(Cox and others, 2003). In the first subtype, the reducedfacies subtype (figs. 4, 5), disseminated native copper and 

Cu sulfides occur in organic-rich marine or lacustrine finegrained strata that overlie or are interbedded with red-bed 

sequences or subaerial basalt flows. In the second subtype, the 

red-bed subtype, disseminated Cu sulfides occur in white to 

gray bleached zones in sandstone and (or) black, gray, or green 

beds of shale and siltstone in a stratigraphic setting that is otherwise dominated by red beds. In the third subtype, the Revett 

subtype (figs. 4, 5), disseminated Cu, Ag, and Pb-Zn sulfides 

occur in thick sandstone or quartzite sequences. Mineralization 

of the rocks along color boundaries is caused by diagenetic 

alteration of the quartzite.

Exploration of the Revett Formation has found deposits, 

occurrences, or prospects at 57 sites in the study area (pl. 1; 

fig. 1) that exhibit characteristics of the Revett-subtype deposit 

model (Cox and others, 2003). Deposits are sites containing 

identified resources of stratabound copper-silver. An occurrence is a site containing small amounts of stratabound coppersilver mineralization. Prospects are explored sites with some 

indication of mineralization that have not been confirmed to be 

Revett-subtype deposits. Deposits, occurrences, and prospects 

Figure 4. Grade-tonnage diagram for copper in three subtypes of stratabound copper-silver deposits in North America: reduced 

facies (triangles), red bed (circles), and Revett (Xs). Solid-line symbols, premining resource; dashed-line symbols, postmining 

resource remaining when mine was closed. Dashed oval, “average” field of Revett-subtype stratabound copper-silver deposits. 

CG, Copper Gulch, Mont.; CR, Creta, Okla.; HB, Horizon Basin, Mont.; JF, J–F (Ross Creek), Mont.; KO, Kona, Mich.; LV, Lisbon Valley, 

Utah; MI, Missoula National Mine, Idaho; MO, Montanore, Mont.; NA, Niagara (Eagle Creek), Mont.; PI, Presque Isle, Mich.; RC, 

Rock Creek, Mont.; RCMO, combined Rock Creek, Montanore, Copper Gulch, Horizon Basin, and Rock Peak, Mont.; RE, Redstone, 

Canada; RP, Rock Peak, Mont.; SN, Snowstorm Mine, Idaho; VR, Vermilion River, Mont.; WM, White Mesa, Ariz.; WP, White Pine, 

Mich. Light-dotted diagonal lines show total copper resource available in deposits; deposits above heavy-dotted diagonal line 

represent largest 10 percent of similar, or “world class,” copper deposits.

105 tons Cu

106 tons Cu

104 tons Cu

107 tons Cu

KO

RCMO

WP

PI

RE

TR LV

RC MO

WM

SN HB

CG

RP

MI CR

1.00 0.1 10.0

1010

109

108

107

106

105

Cu CONTENT, IN WEIGHT PERCENT

PRODUCTION AND RESOURCES, IN TONS

VR

JF

NA

WP

TR

CR

 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
containing disseminated copper and silver (±lead) in rocks of 

the Revett Formation are shown on plate 1 and listed in table 1.

Copper and silver production from Revett-subtype stratabound copper-silver deposits in the Revett Formation has been 

mainly from the Troy Mine, which produced 194,652 tons Cu 

and 1,516.3 tons Ag (table 2; Long and others, 1998) between 

1981 and 1993. The only other copper and silver production 

from Revett-subtype stratabound copper-silver deposits was 

from the Snowstorm Mine, which produced 27,585 tons Cu 

and 141 tons Ag between 1906 and 1912 (table 2; Long and 

others, 1998). Production of 1,514 tons Cu from the MissoulaNational and Picante Mines was from vein deposits in the St. 

Regis and Revett Formations and not from the stratabound 

copper-silver deposits described here.

Resources (potentially minable mineralized rock) remaining in stratabound copper-silver deposits of the Revett Formation total more than 2.9 million tons Cu and 25,840 tons Ag in 

406 million tons of ore, primarily in the Rock Creek-Montanore 

and Troy deposits. Mine permitting was ongoing in 2003 at the 

Rock Creek-Montanore deposits (U.S. Forest Service, 1993, 

1995, 2001; Kootenai National Forest, written commun., 2002; 

Spokesman-Review, 2003a, b). Exploration for additional stratabound copper-silver deposits continues sporadically.

Singer (1995) defined world-class deposits as those that 

exceed the 90th percentile of discovered metal; world-class 

copper deposits are those that contain more than 2.2 million 

tons Cu (heavy dotted line, fig. 4). World-class stratabound 

copper-silver deposits in North America include the Rock 

Creek-Montanore deposits, Mont., and the Kona and White 

Pine deposits, Mich. (Kirkham, 1989; Singer and others, 1993; 

Long and others, 1998). World-class deposits are significant 

because production from any of them affects the world’s supply-demand relation for the metal.

The Rock Creek-Montanore deposits rank 20th (Singer 

and others, 1993; D.P. Cox, written commun., 1999) among 

the world’s stratabound copper-silver deposits. Deposits larger 

than those in the Revett Formation, outside of North America, 

include the giant reduced-facies deposits of central Asia, the 

107 troy oz Ag

108

 troy oz Ag

109

 troy oz Ag

TR

WP MO RC

PI

HB

CG

SN

RP

MI

RE

RCMO

0.1 1.00 10.0

109

108

107

106

PRODUCTION AND RESOURCES, IN TONS

Ag CONTENT, IN TROY OUNCES PER TON

VR JF NA

WP

TR

CR

CR

Figure 5. Grade-tonnage diagram for silver in two subtypes of stratabound copper-silver deposits in North America with reported 

silver production: reduced facies (triangles) and Revett (Xs). Solid-line symbols, premining resource; dashed-line symbols, 

postmining resource remaining when mine was closed. Dashed oval, “average” field of Revett-subtype stratabound copper-silver 

deposits. CG, Copper Gulch, Mont.; CR, Creta, Okla.; HB, Horizon Basin, Mont.; JF, J–F (Ross Creek), Mont.; KO, Kona, Mich.; MI, 

Missoula National Mine, Idaho; MO, Montanore, Mont.; NA, Niagara (Eagle Creek), Mont.; PI, Presque Isle, Mich.; RC, Rock Creek, 

Mont.; RCMO, combined Rock Creek, Montanore, Copper Gulch, Horizon Basin, and Rock Peak, Mont.; RE, Redstone, Canada; RP, 

Rock Peak, Mont.; SN, Snowstorm Mine, Idaho; VR, Vermilion River, Mont.; WP, White Pine, Mich. Light-dotted diagonal lines show 

total silver resource in deposits. Deposits above heavy-dotted diagonal line represent largest 10 percent of similar, or “world class,” 

silver deposits; deposits above heavy-dashed diagonal line represent largest 1 percent of similar, or “supergiant,” silver deposits.

Stratabound Copper-Silver Deposits 
Kupferschiefer of Europe, and a third group in the central 

African copper belt of Zambia, Zimbabwe, and the Democratic Republic of the Congo (Gustafson and Williams, 1981; 

Singer and others, 1993).

At least six North American stratabound copper-silver 

deposits contain more than 1 million tons Cu (fig. 4). The 

copper grade versus tonnage of the three subtypes of these 

deposits in North America (D.P. Cox, written commun., 1992, 

2002; Spanski, 1992) is plotted in figure 4.

Mineral deposits in the Revett Formation are unusual 

because they are also rich in silver (heavy dotted line, fig. 5), a 

characteristic that sets them apart from many other stratabound 

copper deposits (compare figs. 4 and 5). Considering only Ag 

content, the resources of the Rock Creek-Montanore deposits, 

approximately 680 million troy oz Ag (table 2), represent a 

“supergiant” silver deposit, which Singer (1995) defined as the 

largest 1 percent of the world’s silver deposits (each containing more than 22,000 metric tons Ag; heavy dashed line).

Since the 1880s, the nearby Coeur d’Alene Mining District has 

produced more than 790 million troy oz Ag—more than any 

other mining district in the world except Cerro Rico de Potosí 

in Bolivia (Long, 1998). In comparison, the resource contained 

in stratabound copper-silver deposits of the Revett Formation 

is equal to 86 percent of the silver produced from veins in the 

Coeur d’Alene Mining District through 1996 (White, 1998).

The geologic characteristics of Revett-subtype stratabound copper-silver deposits, based on studies at the Troy 

Mine, are summarized here from the review by Hayes and 

others (2003). These deposits in the western Montana copper 

belt are considered to be analogous to the red-bed (hematitic) 

stratabound copper-silver deposits in Europe and Africa; 

however, Revett-subtype deposits have undergone metamorphism that has colored any former Revett red beds lavender 

gray. Before mineralization, northwestward-elongate pyritic 

sand bodies formed embayments in the Revett red beds. The 

copper-silver minerals in the Revett Formation were deposited as a large, zoned system of authigenic sulfide and gangue 

minerals overprinted on the boundary of the reduced pyritic 

and oxidized hematitic rocks. The appearance, disappearance, 

and abundance of authigenic sulfide and gangue minerals have 

been used to establish six mineral zones at Spar Lake (Hayes 

and Einaudi, 1986) that are named by their dominant sulfide 

minerals, distinctive nonsulfide minerals, and color: pyrite-calcite (PY–CAL), galena-calcite (GN–CAL), chalcopyrite-calcite (CP–CAL), bornite-calcite (BN–CAL), chalcocite-chlorite (CC–CHL), chalcopyrite-ankerite (CP–ANK), lavender 

(hematite) with carbonate (LAV), and albite (AB). Mineralzone boundaries of ore and gangue phases cross stratigraphic 

units in the Revett Formation. Worldwide, other stratabound 

copper-silver deposits exhibit similar crosscutting relations 

(Gustafson and Williams, 1981). The BN–CAL and CC–CHL 

zones in the middle and upper quartzites constitute ore, 

and these mineral zones coincide with color changes in the 

quartzite beds caused by diagenetic alteration. Fluids deposited the copper ore minerals bornite, digenite, and chalcocite 

as intergranular cements in permeable beds, and as replaceTable 1. Summary of 57 stratabound copper-silver deposits, 

occurrences, and prospects in the Revett Formation, western 

Montana and northern Idaho.

[Mineralized members: L, lower; M, middle; U, upper. See the file cuag_

deposit.txt for other details]

Site name

Mineralized

member State

Beaver Creek--------------------------- U Idaho

Brooks Mountain3 --------------------- U Mont. Bull Lake East ------------------------- – – Mont.

Chipmunk Creek3---------------------- L Mont.

Clear Peak3 ----------------------------- L Mont. Copper Camp3 ------------------------- U Idaho

Copper Gulch2,3 ------------------------ L Mont.

Copper Rock3 -------------------------- U Mont. Cub Creek ------------------------------ L, U Mont.

Devils Club Creek --------------------- L Mont.

Dry Creek ------------------------------ L, U Mont. Engle Peak ----------------------------- – – Mont.

Fairway Creek ------------------------- L, U Mont.

GM claims------------------------------ – – Mont. Government Mountain---------------- – – Mont.

Hayes Ridge---------------------------- L Mont.

Hiatt Creek ----------------------------- U Mont. Hill Farm3 ------------------------------ L Mont.

Horizon Basin2,3 ----------------------- L Mont.

Janstan Group -------------------------- L, M Mont. J–F2,3 ------------------------------------ L Mont.

Late Group ----------------------------- L Mont.

Lost Girl -------------------------------- – – Mont. Lucky Calumet

3

------------------------ U Idaho

McKay Creek3 ------------------------- L Mont.

Military Gulch2,3 ----------------------- L, U Idaho Missoula Mine1,2,3 --------------------- U Idaho

National Mine3 ------------------------- U Idaho

Niagara2,3 ------------------------------- U Idaho

Picante1 --------------------------------- L, U Mont.

Rabbit Gulch --------------------------- U Idaho

Revett Lake----------------------------- L Idaho

Ripper Creek3 -------------------------- L Mont.

Rock Creek2,3--------------------------- L Mont.

Rock Lake (Montanore)

2,3 ------------ L Mont. Rock Peak2,3 ---------------------------- L Mont.

Ross Point ------------------------------ U Mont.

Ross Point West

3 ---------------------- L Mont. Sex Peak (Miller Gulch)

3 ------------- L Mont.

Silver Aurora-Capitol Silver --------- U Idaho

Silver Creek3 --------------------------- L Idaho

Sims Creek (Waloven)

3 --------------- L Mont.

Snake Creek ---------------------------- L, M, U Mont.

Snowshoe3 ------------------------------ U Idaho

Snowstorm1,2,3 -------------------------- U Idaho

Soldier claims-------------------------- – – Mont.

Squaw Peak3 --------------------------- L, U Mont. Standard Creek------------------------- U Mont.

Star Gulch ------------------------------ L Mont.

Trout Creek3---------------------------- L Mont. Troy Mine1,2,3

--------------------------- L, U Mont.

Twilight Creek3 ------------------------ L Mont.

Twomile -------------------------------- L Idaho

Vermilion River

2,3 --------------------- L Mont.

White Creek ---------------------------- U Idaho

White Penney -------------------------- L Mont. White Pine Creek3 --------------------- L Mont.

1Site with recorded production. 2Site with identified resource. 3Site with mineralized domain.

10 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
ments of clasts and earlier cements, including preore biogenic 

pyrite. Most of the silver is in solid solution in copper minerals 

(∼1 weight percent); lesser amounts occur as native silver and 

in stromeyerite. Local concentrations of ore minerals reflect 

faults and vertical permeability in the quartzite beds. On the 

basis of S-isotopic fractionation and fluid-inclusion microthermometry, the ore minerals were deposited at temperatures 

of 50–125oC in the GN–CAL zone and at 130–180oC in the 

BN–CAL and CC–CHL zones by fluids that contained 15 to 

20 weight percent NaCl equivalent.

Mineralized Domains

Mineralized domains are defined as the surface projection of strata containing copper-silver resources in the Revett 

Formation identified from surface exposures, mine workings, 

and diamond-drill holes (fig. 6). Mineralized domains are 

divided into three categories: identified resources, indicated 

mineralized rock, and inferred mineralized rock (pl. 1). The 

locations of mineralized domains, which have been delineated 

at 30 of the 57 sites listed in table 1, are shown on plate 1 and 

in figure 6. Detailed definitions and ArcInfo interchange files 

of mineralized domains are included with this report.

The larger mineralized domains in the lower member 

of the Revett Formation include, from north to south (pl. 1), 

Ross Creek, J–F, Rock Creek, Star Gulch, McKay Creek, 

Sims Creek, Vermilion River, Trout Creek, Miller Gulch, and 

Clear Peak. Mineralized domains in the upper member of the 

Revett Formation include, from north to south (pl. 1), Troy, 

Snowstorm, Brooks Mountain, and Copper Rock. Mineralized 

domains in both the upper and lower members of the Revett 

Formation include the greater Troy complex (consisting of 

Hiatt Creek, Twilight Creek, Cub Creek, and Ross Point), 

Squaw Peak, and Military Gulch.

Low-Grade Mineralized Strata

In addition to the main ore-bearing units, low-grade 

mineralized strata occur in the Revett Formation and, at the 

Troy Mine (fig. 1), extend for hundreds of feet vertically 

and for miles horizontally beyond ore-bearing units (fig. 7). 

As used in this report, low-grade mineralized strata include 

rocks containing any amount of visible copper minerals. For 

example, low-grade mineralized strata in the A–D beds of the 

upper member of the Revett Formation extend 9 mi southward 

from the Troy Mine to subsurface occurrences and outcrops at 

Dry Creek (diamond-drill holes DC–1, DC–2, pl. 1) and Star 

Gulch (Grimes and Earhart, 1981), and 10 mi southeastward 

of the mine to Snake Creek (diamond-drill holes SC–1 through 

SC–5, pl. 1). Low-grade mineralized strata in the upper 

member of the Revett Formation extend from outcrops 0.6 mi 

southward of the Troy Mine to outcrops on Stanley Peak, 5 mi 

north of the mine (pl. 1).

Production Remaining resource

Deposit

Ore

(103 tons)

Copper

(tons)

Silver

(tons)

Ore

(103 tons)

Copper

(tons)

Silver

(tons)

Rock Creek ------- – – – – – – – – – 181,000 1,367,000 13,000

Montanore -------- – – – – – – – – – 150,000 1,170,000 10,300

Troy---------------- 33,742.5 194,652 1,516.3 12,000 78,000 580

Others ------------- 826.6 27,585 141.1 63,000 342,000 1,960

Total ---------- 34,569.1 222,237

(444.5

million lb)

1,657.4

(48.3

million

troy oz)

406,000 2,957,000

(5,900

million lb)

25,840

(754

million

troy oz)

Total (t)------- 31,361,600 201,610 1,503.6 368,000,000 2,682,545 23,442

Table 2. Production and resources of stratabound copper-silver deposits in the Revett Formation, western 

Montana and northern Idaho.

[Resource values are inplace estimates and do not account for losses due to mining; numbers in columns may not add correctly because 

of independent rounding. Resources in the Rock Creek deposit include those in the Horizon Basin, Copper Gulch, and Rock Peak 

deposits that could be mined together. Production from “others” is from the Snowstorm Mine only; resources are in the J–F, Missoula, 

Snowstorm, and Vermilion River deposits]

Stratabound Copper-Silver Deposits 11
Figure 6. Map of the study area in western Montana and northern Idaho (pl. 1; fig. 1), showing mineralized domains in the western 

Montana copper belt.

116°

48°

Troy

Rock Creek

Montanore

OSBURN FAULT

THOMPSON PASS FAULT

HOPE FAULT

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

Hope

Boundary of study area

Outcrop of the Revett Formation

Land managed by the U.S.Forest

Service

Fault

Deposit or mine

Cu-Ag mineralized domains

Lower member of the Revett Formation

Upper member of the Revett Formation

EXPLANATION

Both upper and lower members

Cu-Ag mineralized outcrops

Lower member of the Revett Formation

Upper member of the Revett Formation

No data

No data

No data

No data

COEUR D’ALENE TROUGH

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

12  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Figure 7. Schematic north-south cross section E–F across study area in western Montana and northern Idaho (pl. 1; fig. 1), showing horizontal a

grade mineralized strata, based on core data from diamond-drill holes (DDHs). (1), unpublished data; *, composite section.

DDH DC-2 

 (Dry Creek)

DDHs SL-31 and

SL-132

 (Spar Lake)* 

DDH SL-138 

 (Spar Lake)

DDH SL-93

 (Spar Lake)

DDH RC-58 

 (Rock Creek)

DDH CP-5

 (Clear Peak)

DDH TC-8 

 (Trout Creek)

0

200

400

Datum

Middle member Upper member Lower member

Burke Formation

A-B-C-D

beds

E-F-G-H

beds

I beds

North 

feet

Revett Formation

Stratabound copper-silver deposit

Low-grade mineralized strata

Stratigraphic boundaries -heavy line is formational boundary,fine line is boundary of members or beds 

EXPLANAT ION

0.5 mi 0.5 mi 3.0 mi 5.5 mi 18.0 mi 14.5 mi 9

E

DDH 

Troy Mine

Rock C

depo

E 

DDH SN-2

 (Snake Creek)

9.2 mi

LOCATION M

Troy Mine

Hope

Kellogg

Walla

Study area 

DDH SL-132 

0.7 mi 3.7 mi

DDH SL-31 

1520 595

-125

1270 2900 1490 1145 720 

505

Depth in feet

St. Regis Formation

MONTANA

IDAHO

Rock Creek deposit

Hope Fault

DDHs JF 79-1, JF 79-4,

JF-12, and JFW-1

(J-F)*

5.5 mi
Low-grade mineralized strata containing disseminated 

copper and silver minerals (fig. 7) occur widely within at least 

three subparallel, near-horizontal mineralized zones in the 

Revett Formation. Other hydrothermal minerals—carbonates, 

pyrite (cubic or framboid), and galena—are ignored because 

they have different distribution patterns that overlap those of 

low-grade mineralized strata. Graphical logs (see app. A) show 

that strata containing visible copper occur over vertical ranges 

greater than 1,500 ft and horizontal distances exceeding 60 mi. 

At this regional scale, low-grade mineralized strata are recognized in the following sections of the Revett Formation: (1) the 

upper member and coarser grained parts of the middle member, 

(2) the A–D beds of the lower member, and (3) the F–I beds of 

the lower member. Graphical logs show that low-grade mineralized strata occur predominantly in medium-grained quartzite 

beds, particularly the white crossbedded vitreous quartzite of 

Winston (1986b). This occurrence appears to depend on the 

grain size of strata. Low-grade mineralized strata in the lower 

and upper members of the Revett Formation generally occur in 

coarser grained quartzite; the absence of such strata in the middle member may be related to its fine-grained texture. Argillaceous rocks are mineralized locally in the middle member 

but to a much lesser degree than in coarser grained units and 

only in the vicinity of a substantial thickness of coarser grained 

mineralized rocks. Continuous, low-grade mineralized strata 

cut obliquely across established bed and member boundaries.

The Troy and Snowstorm Mines are located within lowgrade mineralized strata in the upper member of the Revett 

Formation, and the Rock Creek-Montanore, Trout Creek, and 

Vermilion River deposits occur within low-grade mineralized 

strata in the A–D beds of the lower member of the Revett Formation. The strongly mineralized F–I beds at the Trout Creek 

and J–F deposits occur within low-grade mineralized strata in 

both the lower and middle members of the Revett Formation.

Relation of Stratabound Copper-Silver 

Deposits to Host Rocks, Stratigraphic 

Thickness, Grain Size of Ore-Bearing 

Units, and Mineral Zones

The location of stratabound copper-silver deposits in the 

Revett Formation in the western part of the Belt Basin (pl. 1; 

fig. 1) are closely related to the stratigraphic and lithologic 

setting of the host rocks. Relations considered in detail here 

are the distribution of host rocks, the thickness of ore-bearing 

units, the grain size of clastic strata, and mineral zones in the 

Revett Formation as defined by Hayes (1983). Graphical logs 

based on core data from diamond-drill holes and on stratigraphic relations in measured sections (see app. A) were used 

for the construction of isopach maps.

Inverse-distance-squared weighting was used as a contour-map-interpolation method and was adjusted by considering the number of nearest-neighboring control points to obtain 

a reasonable presentation of the contours. The average number 

of nearest-neighboring control points used by this method was 

12. Isopach and isolith maps were created with the Spatial 

Analyst extension for ArcView GIS (version 3.2) of the Environmental Systems Research Institute (ESRI), Redlands, Calif.

Host Rocks

Stratabound copper-silver deposits occur in well-sorted, 

fine- to medium-grained vitreous quartzite beds in the upper 

and lower members of the Revett Formation. The main ore 

bodies in the Rock Creek-Montanore deposits are in the A–D 

beds of the upper part of the lower member of the Revett 

Formation (fig. 8; U.S. Forest Service, 1993, 2001; Adkins, 

1999). The Vermilion River, Trout Creek, Star Gulch, and 

Squaw Peak deposits (pl. 1) also occur in the upper part of the 

lower member, whereas copper at the J–F Prospect occurs in 

the I beds of the lower member. The middle member locally 

contains low-grade mineralized strata within quartzite beds 

(see table 1). The upper member hosts the Troy and Snowstorm Mines. Copper and silver at the Troy Mine occur in 

every bed of the upper member, whereas copper and silver 

at the Snowstorm Mine occur in a quartzite bed in the upper 

member, the only quartzite bed in the upper member at this 

locality. Most of the Troy deposit occurs in the middle quartzite of the upper member of the Revett Formation. The Niagara, 

Snowshoe, and Missoula-National deposits also occur in the 

upper member.

In contrast to the stratigraphic position of the ore bodies at the Troy Mine, copper-silver ores of the Snowstorm 

Mine and nearby Military Gulch deposit are in white vitreous 

quartzite in the lowermost part of the upper member of the 

Revett Formation, probably the lower quartzite. Copper-silver 

occurrences at Military Gulch are also in the A–C beds of the 

lower member of the Revett Formation (diamond-drill hole 

MG–6 and Lower and Upper Military Gulch measured sections, pl. 1; Hecla Mining Co., written commun., 1986; B.G. 

White, written commun., 1999; Mauk, 2001).

A total of 13 correlation diagrams were constructed by 

using 126 graphical logs of diamond-drill holes and measured 

sections. Correlations (cross secs. A–B, C–D, pl. 1; cross sec. 

I–J, fig. 8) were extended outward from the well-defined Troy 

Mine area, augmented by the data of Bowden (1977), Hayes 

(1983), Hayes and Einaudi (1986), T.S. Hayes (written commun., 1984, 2001, 2003), Wingerter (1982), and Mauk (2001), 

and the U.S. Geological Survey (this study). Cross sections 

were constructed from the data in appendix A.

Stratigraphic correlations were by conventional methods, 

as described by Tearpock and Bischke (1991). Correlations of 

members and bed boundaries, as described in appendix A, are 

shown in the cross sections on plate 2 and in figure 8. Correlations were checked by using adjacent diamond-drill-hole logs. 

Stratigraphic units are reasonably well defined at the Troy 

Mine and in other well-studied areas; however, the boundaries 

become less tenable and increasingly more subjective with 

increasing distance. North-south cross section A–B (pl. 2) 

14  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Figure 8. Lithologic cross sections G–H and I–J across north half of study area in western Montana and northern Idaho (pl. 1; fig. 1), showing s

and mineralized zones of stratabound copper-silver deposits in the Revett Formation, based on core data from diamond-drill holes (DDHs) and relations in measured sections (m.s.). *, ore grade not shown.

Troy Mine

Rock Creekdeposit

Middle Revett aquiclude

Mineralized* with lowgrade copper minerals± galena

Lavender

Pyrite-calcite

Burke Formation

EXPLANATION

0 4 8 16 MILES

LOCATION MAP

D

D

DDH DC-2(Dry Creek)

DDH JF

DDH S

DDH S

DDH SL-93 

DDH SL-136 DDH CC-1 (Cub Creek)

Little Spar Lake m.s.

H

I

G

G Northwest H I 

Chalcopyrite- ankerite*

St. Regis Formation

Revett Formation E-H beds

I bed

 Hope (ThompsonGame Preserve) m.s.

Little Spar Lake m.s.

?

Study area

DDH SL-93 DDH SL-123 DDH SL-31 DDH DC-2

Dry Creek

DDH SN-2 Snake Creek

DDH HF-1 McKa

(Whi

DDH SN-3 DDH RC-47

11.0 mi

DDH CC-1 DDH SL-136

2.3 mi 1.3 mi 0.7 mi 0.5 mi 4.2 mi 5.5 mi

2.5 mi

2.7 mi

1.0 mi 3.8 mi 1.0 mi 3.5 mi 3.5 mi 

1.0 (340)

0.8

0.2

0.0 (0)

Quartzite isolith,percentile (feet)

DDH RC-58

MONTAN

IDAHO

DDH JFW-1

Lower member Middle

 member

Upper

 member

Moyie Thrust Fault

Cub Creek

0.5 (180)

0

400

feet 200

1180 630 810 570 1520 1140 1388 1270 2900 2020 1490 1110 765 

A-D beds

Upper quartzite, upper siltite

Middle quartzite

Lower siltite, lower quartzite

Leaky confining layer (or aquiclude)

?

?

Mineralized domains Upper member of the Revett Formation Lower member of the Revett Formation 

3.5 mi

Hope Fault

No

data

No data

No data

Hope (ThompsonGame Preserve) m.s.

Depth in

feet

12
shows a continuity of sedimentary units from the Troy Mine 

(diamond-drill hole SL–123, pl. 1) to the Latour Peak-Boise 

Peak measured section, a distance of approximately 60 mi. 

The units can be traced for approximately 57 mi. in an eastwest direction (cross secs. G–H, I–J, fig. 8).

Isopach Maps

Isopach maps were constructed for three key stratigraphic 

intervals in the Revett Formation: the A–D beds of the lower 

member (fig. 9), the middle member (fig. 10), and the upper 

member (fig. 11). In addition, isopach maps were constructed 

for the middle quartzite of the upper member (fig. 12) and 

the combined A–D beds of the lower member and the middle 

member and upper members (fig. 13). Thickness data for other 

strata in the lower member were insufficient to construct an 

isopach map.

The A–D beds of the lower member of the Revett Formation (fig. 9) range from 193 to 490 ft in thickness, with a mean 

of 339 ft. Southwest of the Hope Fault, the mean thickness of 

the A–D beds is 318 ft, and northeast of the Hope Fault 355 ft, 

an increase of 12 percent. The most conspicuous features of 

the A–D beds on the isopach map are two areas of broad, thick 

strata northeast of the Hope Fault separated by an area of thinner strata at the Vermilion River. The Rock Creek-Montanore 

deposits occur in an area where the A–D beds are relatively 

thick (>400 ft). No deposits are known in the other thick section of the A–D beds east of Thompson Falls (fig. 1).

The middle member of the Revett Formation (fig. 10) 

ranges from 101 to 466 ft in thickness, with a mean of 270 ft. 

The most conspicuous features of the middle member on the 

isopach map are areas of thick strata northeast of the Hope 

Fault. Two areas of broad, thin strata are present in the central 

parts of both blocks northeast and southwest of the Hope 

Fault. The middle member contains sparse Cu-Ag mineralization unrelated to its thickness.

The upper member of the Revett Formation (fig. 11) ranges 

from 120 to 399 ft in thickness (except for one control point 

570 ft thick at the Thompson River), with a mean of 256 ft. The 

most conspicuous features of the upper member on the isopach 

map are areas of thick strata northeast of the Hope Fault. Southwest of the Hope Fault, the mean thickness of the upper member 

is 228 ft, and northeast of the Hope Fault 294 ft, an increase of 

29 percent. The Troy deposit occurs in upper strata of the Revett 

Formation that are approximately 280 ft thick.

In the area northeast of the Hope Fault (fig. 12), the 

middle quartzite of the upper member of the Revett Formation 

ranges from 40 to 147 ft in thickness, with a mean of 86 ft. 

Thicknesses of only 45 to 50 ft were measured at Dry Creek 

and Goat Rocks, although tectonic attenuation cannot be ruled 

out. The thickness of the middle quartzite varies consistently 

with that of the upper member of the Revett Formation. Copper-silver mineralized rocks are more common within thicker 

parts of the middle quartzite of the upper member, such as at 

the Troy Mine and Cub Creek. 

Isopach maps indicate that syndepositional tectonism in 

basement rocks significantly controlled sedimentation patterns, influencing the thickness and lithology of potential host 

rocks for metal deposits in the Belt Basin. The thickness of the 

combined A–D beds of the lower member and the middle and 

upper members of the Revett Formation is consistently greater 

northeast than southwest of the Hope Fault (fig. 13). Southwest of the Hope Fault, the Revett Formation ranges from 643 

to 885 ft in thickness, with a mean of 775 ft, and northeast of 

the Hope Fault from 745 to 1,471 ft, with a mean of 948 ft, an 

increase of 22 percent, supporting Harrison and Cressman’s 

(1993) observation that the Hope Fault was a down-to-thenorth growth fault during deposition of the Revett Formation.

The change in thickness of the Revett Formation in the 

Coeur d’Alene Mining District in the vicinity of the Osburn 

Fault (fig. 1, Mauk, 2001) and in the area of the Latour PeakBoise Peak and Kellogg measured sections (pl. 1) indicates 

that the Osburn Fault also was a growth fault with down-tothe-south normal movement during deposition of the Revett 

Formation. The thickness of the combined middle and upper 

members of the Revett Formations is 300 ft at Military Gulch 

north of the fault (diamond-drill hole MG–6) and 1,930 ft at 

the Latour Peak-Boise Peak measured section on the south 

side of the fault (cross sec. A–B, pl. 2), an increase of more 

than 500 percent. Similarly, the upper member of the Revett 

Formation thickens southward about 800 percent across the 

Osburn Fault.

Local basins with anomalously thick strata are scattered 

throughout the study area (pl. 1; fig. 1), indicating smallerscale differential subsidence. These basins occur in all the 

members of the Revett Formation. Two areas of large, thick 

sedimentary strata are present: one along a northeast-trending 

belt northeast of the Hope Fault (figs. 9, 10, 11, 13), and the 

other south of the Osburn Fault in the Coeur d’Alene Trough, 

outside of the areas of contoured thicknesses shown in figures 

9, 10, 11, and 13, suggesting syndepositional faulting or localized flexural subsidence near these faults.

Grain Size and Isoliths of Clastic Strata

In the Revett Formation, grain size provides a reasonable 

estimate of the effective porosity and permeability (or hydraulic conductivity) before lithification because an aquifer will 

transmit a volume of fluid proportional to its grain size (Fetter, 

2000). The grain-size/permeability relation, which assumes 

that the sedimentary layers allowed fluid movement before 

cementation, is an approximation of the permeability before 

metal deposition. Although the original porosity, permeability, 

or hydraulic conductivity of the Revett Formation sediment 

cannot be measured directly because of its current degree of 

lithification, they can be estimated, as explained below.

16  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Figure 9. Isopach map of the A–D beds of the lower member of the Revett Formation in study area in western Montana and northern 

Idaho (pl. 1; fig. 1).

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units 17

300

340

280

340

300

320

360

320

340

380

360

320

320

320

320

280

480

360

460

320

340

420

380400

360

300

400

440

380

380

360

320

380

400

320

340

420

260

116°

48°

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

OSBURN FAULT

THOMPSON PASS FAULT

MONTANA

IDAHO

HOPE FAULT

Vermillion

River

Troy

Rock

Creek

Clear Peak

Trout Creek

Montanore

MOYIE

THRUST

PLATE

COEUR D’ALENE TROUGH

Thickness of the A-D beds of 

the lower member of the 

Revett Formation; contour 

interval, 20 ft (6.1 m) 

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

Control point

340

210

400

380

340

360

380

260

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

260

320

380

360

340

420

460

280 300

440

400

280
Figure 10. Isopach map of the middle member of the Revett Formation in study area in western Montana and northern Idaho (pl. 1; fig. 1).

18  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho

116°

48°

Thickness of the middle member 

of the Revett Formation; contour 

interval is 20 ft (6.1 m)

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

Control point

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

MONTANA

IDAHO

Troy

Rock Creek 300

Graves Creek

Falls

340

320

280

Montanore

260

280

300

320

340

380

420

240

440

240

260

220

200

300

280

260

240

240

260

Clear

Peak

OSBURN FAULT

THOMPSON PASS FAULT

HOPE FAULT

MOYIE

THRUST

PLATE

COEUR D’ALENE TROUGH

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

380

420

380

340

320

300

280

260

240

180

220

200
Figure 11. Isopach map of the upper member of the Revett Formation in study area in western Montana and northern Idaho (pl. 1; fig. 1).

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units 19

OSBURN FAULT

THOMPSON PASS FAULT

HOPE FAULT

MOYIE

THRUST

PLATE

48°

116°

COEUR D’ALENE TROUGH

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

Thickness of the upper member 

of the Revett Formation; contour 

interval, 20 ft (6.1 m) 

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

Control point

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

MONTANA

IDAHO

Troy

Rock Creek

260

280

260

300

320

320

320

340

Vermilion

River

280

240

320

Thompson

River

280

300

240

220 220

200

280

260

240

220

200

180

180

220

540

Snake

Creek

340

340

320

300

280

260

240

220

200

180

160
Figure 12. Isopach map of the middle quartzite of the upper member of the Revett Formation in study area in western Montana and 

northern Idaho (pl. 1; fig. 1).

20 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho

116°

48°

Thickness of the middle quartzite of the 

upper member of the Revett Formation; 

contour interval, 10 ft (3 m)

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Mineralized domain in upper 

member of the Revett Formation

Mineralized outcrop in upper 

member of the Revett Formation

Control point

Troy

70

60

80

90

80

80

50

60

70

80

90

90

100

90

80

80

70

60

110

110

100

Montanore

Rock

Creek

Goat Rocks

Dry Creek

HOPE FAULT

Cub

Creek

Study Area

Montana

Idaho

MONTANA

IDAHO

MOYIE THRUST PLATE

Star Gulch

Snake Creek

Engle

Creek

Area of map

0 1 2 3 4 5 MILES

0 2 4 6 8 KILOMETERS

EXPLANATION

50

70

60

80

110

100

90
Figure 13. Isopach map of the A–D beds of the lower member and the middle and upper members of the Revett Formation in study 

area in western Montana and northern Idaho (pl. 1; fig. 1).

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units  21

116°

48°

Thickness of the combined 

A-D beds of the lower 

member and of the middle 

and upper members of the 

Revett Formation; contour 

interval, 50 ft (15 m)

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

Control point

Troy

Rock Creek

Montanore

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg OSBURN FAULT

THOMPSON PASS FAULT

MONTANA

IDAHO

HOPE FAULT

Thompson

River

MOYIE THRUST PLATE

1150

1050

1000

950

950

950

900

1000

1000

1050

900

850

950

750

800

850

800

750

750

Latour Peak -

Boise Peak

DDH

MG-6

700

700

800

COEUR D'ALENE TROUGH

1100

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

1050

1100

1000

950

900

850

800

750

700
The transmissivity of an aquifer is defined as the volume 

of water that can be transmitted horizontally through a unit 

width of the aquifer at a hydraulic gradient of 1 (Fetter, 2000). 

Hazen (1911) developed a formula for approximate hydraulic 

conductivity, based on effective grain size and a sorting coefficient, that is commonly used by hydrologists (reviewed by 

Fetter, 2000). The expression for transmissivity, T, is given by 

analysis for the A–D beds indicates that the mean-or-greater 

quartzite isolith has an 87-percent spatial correlation with 

mineralized domains. Therefore, the area of mean-or-greater 

thickness (>180 ft) of the A–D beds of the lower member of 

the Revett Formation, interpreted as a paleoaquifer during or 

shortly after deposition of the Revett Formation, is highly correlated with the mineralized domains of stratabound copper-silver 

deposits in the Revett Formation (black-lined pattern, fig. 15).

Mineral Zones

The distribution and extent of mineral zones in the Revett 

Formation is an important guide for understanding the migration paths of fluids that formed ore deposits and low-grade 

mineralized strata. Mineral zones associated with stratabound 

copper-silver deposits in the Revett Formation were described 

by Hayes (1983, 1990), Hayes and Einaudi (1986), and Hayes 

and others (1989), as summarized in a preceding section (pl. 2; 

figs. 8, 16). The mineral zones used in this report are synonymous with Hayes’ (1990) diagenetic-cementation sequences 

and are defined by the appearance, disappearance, and 

abundance of authigenic sulfide and gangue minerals. Hayes 

and Einaudi (1986) defined six mineral zones at the Spar 

Lake deposit. The AB zone, which is outside of the ore-bearing areas and mineral zones described above, may represent 

source rocks for copper and silver (Hayes, 1990), whereas the 

other mineral zones, except for the PY–CAL and LAV zones, 

are alteration assemblages associated with the formation of 

stratabound copper-silver deposits.

Rocks of the PY–CAL zone are dark green, and rocks 

of the LAV zone are pink to lavender. Color differences are 

attributed to the relative abundances of hematite and clay mineral grains in quartzite beds (Hayes, 1990). Coloration of pinklavender quartzite beds of the LAV zone is derived from early 

diagenetic hematite-clay dust rims that encircle quartz grains. 

Such characteristics are absent in unaltered green quartzite 

beds of the PY–CAL zone.

The PY–CAL/CP–ANK boundary is an important 

transition because base and precious metals were deposited 

near it (Hayes and Einaudi, 1986). Hayes (1990) interpreted 

this boundary to generally correspond to the position of the 

original contact between red (LAV zone) and green (PY–CAL 

zone) strata, which is considered to be the boundary between 

reduced and oxidized rocks. The boundary cuts across stratigraphy and appears to have migrated vertically and horizontally 

from bed to bed as viewed in profile (Hayes and Einaudi, 

1986; Hayes, 1990). The intervening CP–ANK zone is tongue 

shaped at the Troy Mine, and Hayes (1983) and Hayes and 

Einaudi (1986) reported that this zone extends several miles 

southeasterly from the mine.

The CC–CHL, BN–CAL, CP–CAL, and GN–CAL zones 

form a narrow transition zone between the CP–ANK and PY–

CAL zones. The BN–CAL and CC–CHL zones in the middle 

and upper quartzites of the Revett Formation constitute ore in 

the Spar Lake deposit (Hayes and Einaudi, 1986). In figures 

22  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho

T = hk, (1)

k = Cd2, (2)

T = hCd2 (Hazen approximation), (3)

where h is the saturated thickness (in feet) and k is the hydraulic conductivity. The Hazen approximation for hydraulic 

conductivity, k, is given by

where C is the sorting coefficient and d is the effective grain 

size (dimensionless). Combining equations 1 and 2,

which is the basis for equating the transmissivity of an aquifer 

with accumulated thickness of the coarsest grained rock strata.

The quartzite isoliths (fig. 14; Levorsen, 1958; Krumbein 

and Sloss, 1963; Low, 1977; Miall, 2000) are the cumulative 

thicknesses of quartzite in a diamond-drill hole or measured 

section of the A–D beds of the lower member of the Revett 

Formation. Except for extremely sparse conglomerate, quartzite is the coarsest grained clastic rock in the Revett Formation. 

Strata finer grained than quartzite—namely, silty quartzite, 

slightly silty quartzite, siltite, and argillite—are omitted from 

the isoliths. Grain-size data were obtained by reference to a 

grain-size chart. Thickness was determined to the nearest foot 

with measuring tapes (T.S. Hayes, oral commun., 2003).

A difficulty with preparing isolith maps is that the 

lithologic descriptions in widely spaced diamond-drill 

holes and measured sections may not be consistent from 

locality to locality because of subjectivity in interpretation 

of the stratigraphic relations. For example, some geologists 

might describe a rock as quartzite, a rock type included in 

the isolith, whereas others might describe a similar rock 

as silty quartzite, a rock type omitted from the isolith. 

Also, covered intervals along measured sections are not 

considered. In spite of these shortcomings, we believe that 

the isolith maps (figs. 14, 15) show the general abundance 

of quartzite in the A–D beds and provide an approximate 

measure of regional fluid transmissivity.

Quartzite isoliths demonstrate the high degree of spatial 

correlation between mineralized domains and the thickness 

of coarse-grained strata in A–D beds of the Revett Formation 

(fig. 15). Isoliths range from 0 to 340 ft, with a mean of 180 ft. 

The A–D beds of the lower member of the Revett Formation 

that exceed the 180-ft quartzite isolith extend over a broad area 

that includes stratabound copper-silver deposits, mineralized 

domains, and low-grade mineralized strata as follows, from 

north to south: Troy, J–F, Star Gulch, Rock Creek-Montanore, 

Vermilion River, Trout Creek, Miller Gulch, Clear Peak, and 

Military Gulch (diamond-drill hole MG–6, pl. 1). A statistical 
230

116°

48°

Quartzite isolith, A-D beds 

of the lower member of the 

Revett Formation, showing 

control points; contour 

interval, 40 ft (12 m)

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

145

80

243

243

95

164

216

340

155

126

255

43 13

241

68

190

143 77

168

79

189

146

91 253

116

303

230

175

198

174

80

78

320

273

149

226

176

261

225

286

195

183

249

157 181

185

143

140

180

220

300

180

300

100

180

260

260

180

140

100

220

140

260

220

140

180

260

340

60

100

60

140

180

100

260

100

180

Clear Peak

Trout Creek

Vermilion

River

140

Thompson

River

Troy

Rock Creek

Montanore

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg OSBURN FAULT

THOMPSON PASS FAULT

MONTANA

IDAHO

HOPE FAULT

MOYIE THRUST PLATE

115 188238

97

55

246

256

JF

Dry

Creek

303

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

COEUR D’ALENE TROUGH

Figure 14. Quartzite isolith map of the A–D beds of the lower member of the Revett Formation in study area in western Montana and 

northern Idaho (pl. 1; fig. 1).

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units  23
116°

116°

48°

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

Mineralized domain in the 

A-D beds of lower member of 

the Revett Formation

EXPLANATION

County line

Boundary of study area

Outcrop of the Revett Formation

Fault

Deposit or mine

Quartzite isolith, A-D beds

of the lower member of the

Revett Formation, thickness

>180 ft (55 m)

Mineralized outcrop in the A-D

beds of the lower member of the 

Revett Formation

Troy

Rock Creek

Montanore

OSBURN FAULT

THOMPSON PASS FAULT

MONTANA

IDAHO

HOPE FAULT

MOYIE THRUST PLATE

180 180

180

180

180

180

180

180

Trout Creek 180

Clear Peak

Military Gulch

Star

Gulch

Greater

Troy

complex

JF

Vermilion River

Miller Gulch

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

COEUR D’ALENE TROUGH

Figure 15. Mean-or-greater (≥180 ft [55 m]) quartzite isolith map of the A–D beds of the lower member of the Revett Formation in study 

area in western Montana and northern Idaho (pl. 1; fig. 1), in relation to mineralized domains.

24  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Figure 16. Diagram of mineral zones in Revett-subtype stratabound copper-silver deposits, showing nomenclature based on 

diagenetic-cementation sequences of Hayes (1983, 1990) and Hayes and Einaudi (1986) used for the Troy Mine in study area in 

western Montana and northern Idaho (pl. 1; fig. 1). Combined mineral zones used in this report are shown at top.

ZONE ABBREVIATIONS LAV CP-ANK CC-CHL BN-CAL CP-CAL GN-CAL PY-CAL Lavender with carbonate Chalcopyrite- ankerite Chalcocite- chlorite Bornite-calcite Chalcopyrite- calcite Galena-calcite Pyrite-calcite Fe-Ti oxides

Hematite

Magnetite

Ilmenite

Leucoxene

Chalcocite

Digenite

Covellite

Idaite

Bornite

Chalcopyrite

Galena

Sphalerite

Pyrite

Pyrrhotite

Tetrahedrite

Cobaltite

Cobalt-anomalous pyrite

Stromeyerite

Argentite

Ni-rich pyrite

Native silver

Ferroan calcite

Sulfides Carbonates

Ferromagnesian calcite

Ankerite/ferroan dolomite

Chlorite

Phyllosilicates Tectosilicates

Overgrowth K-feldspar

Pore-filling albite

Overgrowth quartz

Detrital

only ?

?

? ? ?

? ?

? ?

Pore-lining 2M white mica

PYCAL

CPANK LAV MINERALIZED AREAS Albite

AB

Detrital

only

Barite

Apatite

Albite-included 2M white mica

Barium mica ? ?

?

>5%

?

Metasomatic

depletion of Cu

Unaltered

Metasomatic addition of Cu

This report Not recognized

>0.4

>0.1

Trace

Local trace

Tectosilicates

>2

>1

EXPLANATION

 Average abundance in quartzite 

 host rocks, in volume percent

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units  25
H

G

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

COEUR D’ALENE TROUGH

116°

48°

Mineralized domain in the lower 

member of the Revett Formation

 EXPLANATION

County line

Boundary of study area

Outcrop of the 

Revett Formation

Fault

Mineralized outcrop in the 

lower member of the Revett 

Formation

Mineral zones in the A-D beds of the 

lower member of the Revett Formation

Control point

Zone boundary; dashed 

where indicated, dotted 

where inferred

LAV

Transition

CP-ANK

Transition

Mineralized areas

Transition

PY-CAL

No data

LAV

CP-ANK

PY-CAL and

mineralized

areas

Line of cross section

Troy

Rock Creek

Montanore

OSBURN FAULT

THOMPSON PASS FAULT

HOPE FAULT

MOYIE THRUST FAULT

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

MONTANA

IDAHO

Trout Creek

Clear Peak

Vermilion River

See figure 8

Hope-Thompson

Game Preserve

Snake

Creek

Graves Creek

Falls

Revett Lake

Ripper Creek

See

figure 8

D

C

See

plate 2

Deposit or mine

J

I

Figure 17. Map of the study area in western Montana and northern Idaho (pl. 1; fig. 1), showing areal extent of mineral zones in the 

A–D beds of the lower member of the Revett Formation.

26  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
116°

48°

Mineralized domain in the 

upper member of the Revett 

Formation

 EXPLANATION

County line

Boundary of study area

Outcrop of the

Revett Formation

Fault

Mineralized outcrop in the 

upper member of the Revett 

Formation

Mineral zones in the middle 

quartzite of the upper member of 

the Revett Formation

Control point

Zone boundary; dashed 

where indicated, dotted 

where inferred

LAV

Transition

CP-ANK

Transition

Mineralized areas

Transition

PY-CAL

No data

CP-ANK

PY-CAL and

mineralized

areas

Line of cross section

Troy

Rock Creek

Montanore

OSBURN FAULT

THOMPSON PASS FAULT

HOPE FAULT

Hope

Clark Fork

Thompson Falls

Lookout

Pass

Wallace

Kellogg

MONTANA

IDAHO

Vermilion River

See figure 8

Hope-Thompson

Game Preserve

Graves Creek

Falls

Ripper Creek

See

figure 8

Copper Rock

Brooks Mountain

Military

Gulch

Dry

Creek

Little Spar

Lake

MOYIE FAULT

No data

No data

Clear

Peak

Snowstorm

LAV

Trout Creek

Deposit or mine

MOYIE THRUST PLATE

0 4 8 12 16 KILOMETERS

0 2 4 6 8 10 MILES

COEUR D’ALENE TROUGH

H

G

J

I

Figure 18. Map of the study area in western Montana and northern Idaho (pl. 1; fig. 1), showing areal extent of mineral zones in the 

middle quartzite of the upper member of the Revett Formation.

Relation of Stratabound Copper-Silver Deposits to Host Rocks, Stratigraphic Thickness, Grain Size of Ore-Bearing Units  27
17 and 18, the ore-bearing CC–CHL, BN–CAL, CP–CAL, 

and GN–CAL zones are grouped together and referred to as 

“mineralized areas” to show relatively small areas of alteration 

on the regional maps. Although the distribution of galena was 

not studied in detail, strata containing abundant galena are spatially distributed between the PY–CAL zone and copper-silver 

mineralized strata shown in cross sections A–B and C–D (pl. 

2). The other mineral zones shown specifically are the LAV, 

CP–ANK, and PY–CAL zones, along with transitional areas 

of alteration.

Grain-size characteristics of strata in the Revett Formation 

considerably control the stratigraphic positions of the CP–ANK 

and PY–CAL zones and low-grade mineralized strata (cross secs. 

G–H, I–J, fig. 8), although the boundaries between mineral zones 

are generally indistinct and transitional across stratigraphic units. 

The importance of grain size is evident where the relatively fine 

grained middle member of the Revett Formation appears to have 

acted as an aquiclude (fig. 8) or semipermeable layer that effectively separated low-grade mineralized strata in the upper member 

above from those in the A–D beds below.

Distribution

Mineral zones are conspicuous in the A–D beds of the lower 

member and in the middle quartzite of the upper member of the 

Revett Formation. In the A–D beds (fig. 17), the PY–CAL zone 

is present in an irregular, generally north-south trending belt in 

the center of the study area (pl. 1; fig. 1) flanked on each side by 

CP–ANK zones (cross secs. G–H, I–J, fig. 8). East of the CP–

ANK zone is the LAV zone. In the middle quartzite of the upper 

member (fig. 18), mineral zones are approximately symmetrical in the northern part of the study area, with a core PY–CAL 

zone flanked by the CP–ANK zone. The LAV zone lies east of 

the CP–ANK zone. In the southern part of the study area, the 

distribution pattern for the middle quartzite of the upper member 

is more complex, consisting, from west to east, of north-southtrending irregular belts of CP–ANK, PY–CAL, CP–ANK, LAV, 

CP–ANK, and LAV zones. The core PY–CAL zone is evident on 

maps of both the A–D beds of the lower member of the Revett 

Formation (fig. 17) and the middle quartzite of the upper member 

of the Revett Formation (fig. 18). Mineral zones on the east side 

of this core PY–CAL zone at Trout Creek are shown on plate 2 

(cross sec. C–D).

Northeast of the Hope Fault, the relatively well studied mineralized domains at the Troy Mine and Rock Creek (fig. 1) are 

along both the west and east borders of a broad belt of PY–CAL 

zones (figs. 17, 18). The belt of PY–CAL zones in the A–D beds 

of the lower member of the Revett Formation is many miles wider 

than in the middle quartzite of the upper member (figs. 17, 18). 

In the A–D beds of the lower member, the core PY–CAL zone 

extends from near the Idaho-Montana State line southeastward to 

the Rock Creek deposit. The core PY–CAL zone in the middle 

quartzite of the upper member extends from west of the Troy 

Mine to approximately 1 mi west of Rock Creek. The LAV zone 

in the middle quartzite of the upper member extends from east 

of Rock Creek to the east boundary of the study area (pl. 1; fig. 

1), but is absent in the lower member in the same area. Lavender 

quartzite is present in the middle and upper members, and in part 

of the lower member of the Revett Formation in a measured section in Hope-Thompson Game Preserve southwest of the Hope 

Fault, 14 mi west of the Troy Mine (figs. 17, 18).

Displacement

Sevier-Laramide movements on the major strike-slip and 

thrust faults (Hope, Thompson Pass, Moyie, and Osburn) in 

the study area (pl. 1; fig. 1) appear to have displaced mineralzone boundaries (fig. 17, 18). Mapping shows that the Hope 

Fault displaces the boundaries between the LAV, CP–ANK, 

and PY–CAL zones both in the A–D beds of the lower 

member and in the middle quartzite of the upper member of 

the Revett Formation. In the middle quartzite, the Hope Fault 

offsets the LAV zone between Graves Creek Falls and Ripper 

Creek (fig. 18), where it surrounds an “island” of CP–ANK 

zone. The Thompson Pass Fault offsets mineral zones in 

the A–D beds of the lower member between Clear Peak and 

Revett Lake (fig. 17), creating an “island” of PY–CAL zone 

around Clear Peak, a pattern further complicated by removal 

of strata by erosion.

Relations Between Grain Size, 

Stratigraphic Thickness, and Mineral 

Zones in Host Rocks at the Trout Creek 

Prospect

Cross section C–D (pl. 2) through the Trout Creek prospect (fig. 1) provides an instructive comparison of the relations 

between grain size, stratigraphic thickness, and mineral zones 

in host rocks across rapidly changing sedimentary and alteration facies. Although copper-silver reserves have not been 

identified, the Trout Creek area contains abundant copper-silver mineralized strata in the A–D and F–I beds of the lower 

member of the Revett Formation.

Mapping at the Trout Creek prospect (fig. 1) shows that 

mineralized strata in the Revett Formation are present at or near 

the PY–CAL/CP–ANK boundary. Copper-silver mineralized 

strata along this boundary form a broad zone where the alteration changes from PY–CAL to CP–ANK in the northwestern 

part of the prospect (bold gray line, cross sec. C–D, pl. 2), and 

from CP–ANK to LAV in the southeastern part (bold purple line, 

cross sec. C–D). In diamond-drill holes TC–8 and TC–9 (pl. 1), 

the PY–CAL zone and rocks containing galena, chalcopyrite, 

and calcite occur in the lower member of the Revett Formation 

and in proximity to thick intervals of mineralized strata. Rocks 

containing galena, chalcopyrite, and calcite occur between and 

irregularly overlap the PY–CAL zone and mineralized strata. 

Eastward in diamond-drill hole TC–7A, the vertical extent of 

the PY–CAL zone and mineralized strata diminishes; instead, 

the CP–ANK zone is predominant in these strata. Farther east, 

28  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
LAV strata gradually replace CP–ANK strata. The distribution 

of these mineral zones suggests that the area around and west 

of diamond-drill holes TC–7A, TC–8, and TC–9 (also west of a 

north-south line connecting diamond-drill holes C–5, TC–9, and 

TC–10) is favorable for the occurrence of copper-silver mineralized strata.

Cross section C–D (pl. 2) is useful in predicting 

proximity to mineralized strata. Along a northwest-trending line from the White Pine Creek measured section 

northwestward to diamond-drill hole TC–9 (pl. 1), we note 

that (1) the A–D beds of the lower member of the Revett 

Formation thicken from 310 to 314 ft, (2) the quartzite isolith of the lower member of the Revett Formation increases 

from 126 to 241 ft (table 3), and (3) an increase in the 

thickness of the PY–CAL zone corresponds to a decrease 

in the thickness of the LAV and CP–ANK zones.

Permissive Tracts

Permissive tracts for undiscovered Revett-subtype stratabound copper-silver deposits may be defined on the basis 

of the descriptive model for this subtype (D.P. Cox, written 

commun., 2002; Cox and others, 2003). The permissive tracts 

lie within untested exploration areas—areas that have not yet 

been explored by drilling (pl. 3). The recognition of permissive tracts is based on the presence or absence of various geologic characteristics and indicators of Revett-subtype stratabound copper-silver deposits. Other workers (Box and others, 

1996; Spanski, 1992) defined tracts as permissive or favorable for the occurrence of a specific mineral-deposit type, or 

used numeric methods to predict the probability of a deposit, 

given the characteristics of the area (Singer, 1993; Boleneus 

and others, 2001b). Criteria used here to define permissive 

tracts for Revett-subtype stratabound copper-silver deposits 

require that the area (1) is underlain by the Revett Formation 

to a depth of 8,000 ft (pl. 3c), (2) contains alteration minerals 

indicative of proximity to the PY–CAL/CP–ANK boundary 

(pls. 3a, 3b), and (3) is near stratabound copper-silver deposits 

or occurrences in the Revett Formation.

Permissive tracts (area, ∼556 mi2) are mostly cospatial 

with untested exploration areas (pls. 3c, 3d), except on the east 

side of the Trout Creek anticline and in Lincoln and Sanders 

Counties from Waloven Creek to Graves Creek Falls (pl. 1). 

The west side of both these areas is considered permissive 

because mineral deposits occur near the PY–CAL/CP–ANK 

boundary, a position that is favorable for mineral deposits, 

whereas the east side of these areas is associated with the 

LAV/CP–ANK boundary, a position that is generally unfavorable for mineral deposits.

Conclusions

Analyses of the settings of stratabound copper-silver 

deposits in the Mesoproterozoic Revett Formation, based on 

stratigraphic thicknesses, mineral deposits and occurrences, 

and gangue and ore-mineral distribution (mineral zones), 

reveal the following relations:

The upper, middle, and lower members hosting 

stratabound copper-silver deposits are traceable, with 

reasonable certainty, across the study area (pl. 1; fig. 

1). The A–D beds, which contain the Rock CreekMontanore deposits, in addition to the E–H and I beds 

of the lower member, are traceable across the study 

area. The middle quartzite of the upper member, which 

contains the Troy deposit, is most confidently recognized in the area northeast of the Hope Fault.

Differences in the thickness of the stratigraphic succession indicate that the Hope and Osburn Faults were 

active during deposition of the Revett Formation. 

•

•

Diamond-drill hole (DDH)

or measured section

Thickness of

the A-D beds

(ft [m])

Quartzite isolith:

cumulative thickness of

quartzite in the A–D beds

(ft [m])

White Pine Creek 2, 3, 4 310 (94) 126 (38)

Trout Creek 1 and 21-------------------------------- 315 (96) 155 (47)

Trout Creek (White)-------------------------------- 280 (85) 190 (58)

DDH TC–7A ---------------------------------------- 322 (98) 252 (77)

DDH TC–8 ------------------------------------------ 308 (94) 264 (80)

DDH TC–9 ------------------------------------------ 314 (96) 241 (73)

1

Part of this measured section is covered; covered strata are omitted from reported thickness.

-------------------------------

Table 3. Thicknesses and isoliths in the A–D beds of the lower member of the Revett Formation in 

the Trout Creek Prospect area, western Montana

Conclusions  29
Syndepositional normal-fault movements were down 

on the northeast side of the Hope Fault and down on 

the south side of the Osburn Fault. In comparison, the 

area between the Hope and Osburn Faults either subsided less or was subjected to periodic erosion during 

deposition of the Revett Formation, or both, because 

the thickness of the Revett Formation is substantially 

less in this area.

An irregular, north-south-trending PY–CAL zone 

occupies a core area in the center of the western Montana copper belt. This core PY–CAL zone is flanked 

by a CP–ANK zone and by an oxidized LAV zone 

that extends eastward of the study area (pl. 1; fig. 1). 

Regionally, these mineral zones strongly correlate with 

the distribution of stratabound copper-silver deposits 

in the Revett Formation. On the basis of the mineral 

•

zones, an area of ~556 mi2 is classified as permissive 

for the occurrence of undiscovered stratabound copper-silver deposits. On the basis of the deposit model 

for the Troy Mine (Cox and others, 2003), the permissive tracts lie near the PY–CAL/CP–ANK boundary in 

the A–D beds of the lower member and in the middle 

quartzite of the upper member of the Revett Formation.

Areas of high-transmissivity paleoaquifers, as indicated by quartzite isoliths, are spatially correlated with 

the distribution of mineral zones and stratabound copper-silver deposits.

Stratabound copper-silver deposits are likely to occur in 

thick, coarse-grained units within the upper member of the 

Revett Formation, in minor sandstone beds of the middle 

member of the Revett Formation, and in the A–D and F–I 

beds of the lower member of the Revett Formation.

•

•

30 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Databases and Spatial-Data Files for the Geology and 

Mineral Deposits of the Revett Formation

By David E. Boleneus, Larry M. Appelgate, Mary H. Carlson, Derrick W. Chase, and Michael L. Zientek

Diamond-Drill-Core and Measured-Section Data  31

Introduction

This section presents databases and spatial-data files for 

the geology and mineral deposits of the Revett Formation 

(table 4). Records of 40 diamond-drill cores and 86 measured 

sections, for a total of 150,752 ft of true thickness, include 

field data compiled into Microsoft Excel spreadsheets and 

graphical logs in Adobe Portable Document Format (PDF) 

that summarize the observations. The text file cuag_deposit.txt 

provides detailed descriptions of the 57 Revett-subtype stratabound copper-silver deposits, occurrences, and prospects in 

the western Montana copper belt. Spatial databases (ArcInfo 

coverages) contain location data from the diamond-drill cores 

(rev_ddh) and measured sections (rev_msec). The spatial data 

also include files for the regional geology of the Revett Formation (rev48k); copper-silver mineralized domains, unexplored 

areas, and permissive tracts (rev_cuag); and mineral zones 

for the upper (urevzone) and lower (lrevzone) members of the 

Revett Formation. Explanation of the methods and format 

used to compile the databases and spatial-data files is given, 

including the metadata required for files that contain spatial 

information.

Nomenclature in the databases varies in places from that 

used in the rest of this report; for example, “lower Revett”, 

middle Revett”, and “upper Revett” in several parts of the 

databases are, respectively, “lower member”, “middle member”, and “upper member of the Revett Formation” in the text; 

and “sediment-hosted deposits” in the databases are “stratabound deposits” in the text.

Diamond-Drill-Core and MeasuredSection Data

Stratigraphic relations and mineral zones associated 

with stratabound copper-silver mineralization in the Revett 

Formation are based on the descriptions of 40 diamond-drill 

cores and 86 measured sections in the Revett Formation and 

adjacent strata (pl. 1; table 5). Most of this descriptive information was collected in the field by Asarco Inc. and Kennecott 

Exploration Co. geologists, although five sections were measured and compiled by USGS personnel. Rock type and sedimentary structures was recorded to understand the stratigraphy 

and depositional environment of the Revett Formation. The 

amount of sulfide, oxide, and silicate minerals in synsedimentary cements was also described in order to determine whether 

the distribution of these minerals could be used to predict the 

occurrence of stratabound copper-silver mineralization. The 

observations were systematically collected on forms; colored 

or black-and-white paper copies of this data were provided to 

the USGS for this study. The information on the forms was 

compiled into Microsoft Excel spreadsheets, which were then 

used to create graphical logs of the data for each diamond-drill 

core and measured section. The following sections describe 

the data collected in the field, the spreadsheets used to compile 

the data, and the graphical logs summarizing the observations.

Field-Data Forms

Data recorded in the header of the field-data forms 

(figs. 19, 20) include the name of the section (“location”), an 

identifier number (“no.”) to indicate recording of data in two 

or more parts, the direction (up or down) of measurement 

traverse (“direction”), the author (“by”), pages (“page”), and 

the date (“date”). Detailed rock and mineralogic descriptions 

for diamond-drill cores and measured sections are recorded in 

the columns “footage”, “graphic section”, “sulfide”, “oxide”, 

“carbonate”, “silicate”, “supergene”, “structure”, and “lithology, grain-size, bedform, and comments” (figs. 19, 20). Numbered notes appearing in superscripted parentheses ( ) refer to 

the example field-data forms in figure 19 or 20. The first is 

an example lithologic field-data form of a measured section 

(fig. 19), and the second is an example lithologic field-data 

form from a diamond-drill core (fig. 20). “Footage” is a linear 

scale indicating hole depth or apparent stratigraphic position. The most commonly used vertical scale (footage) was 1 

in. for every 20 ft of strata(2). The column “graphic section” 

graphically displays information on rock type, sedimentary 

structures, and inclination of strata(1). Colors are used to identify rock type (figs. 19, 20), as follows: “green” is argillite, 

“brown-green” is siltite-argillite couplets, “brown” is siltite, 

“blue” is silty quartzite, “orange” is slightly silty quartzite, and 

“yellow” is quartzite. A blank area in the graphic section at a 

particular depth indicates an interval of missing core or nonoutcropping strata(2,3). Penciled lines to the left of the footage 

column indicate division of strata into stratigraphic intervals, 

members, or beds(6,7).

The columns “sulfide”, “oxide”, “carbonate”, and “silicate” qualitatively illustrate the distribution of these miner-
Figure 19. Scanned image of field-data form for White Pine Creek #2–#3 measured section. See text for explanation of numbers.

Figure 20. Scanned image of field-data form for diamond-drill hole VR–4. See text for explanation of numbers.

32  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Table 4. List of databases, graphical logs, and spatial-data files.

File name Description

Beaver Creek Road Beaver Creek Road measured section. Beaver Lake 1, 2 Beaver Lake 1, 2 measured section.

Beaver Peak North Beaver Peak North measured section.

Bloom Peak Bloom Peak measured section.

Bobtail Creek Bobtail Creek measured section.

Browns Gulch Browns Gulch measured section.

Bumblebee Road Bumblebee Road measured section. Castle Rock Castle Rock measured section.

Cedar Creek Cedar Creek measured section.

Chicago Peak (White) Chicago Peak (White) measured section.

Chipmunk 1 Chipmunk 1 measured section.

Chipmunk 2 Chipmunk 2 measured section.

Clark Fork Clark Fork measured section. Clear Peak (Asarco) Clear Peak (Asarco) measured section.

Clear Peak (White) Clear Peak (White) measured section.

Coal Creek Coal Creek measured section. Coeur d’Alene River 3 Coeur d’Alene River 3 measured section.

Cottonwood Cottonwood measured section.

County Creek County Creek measured section. DDH CC–1 (Cub Creek) DDH CC–1 (Cub Creek) diamond-drill-hole section.

DDH CP–4 (Clear Peak) DDH CP–4 (Clear Peak) diamond-drill-hole section.

DDH CP–5 (Clear Peak) DDH CP–5 (Clear Peak) diamond-drill-hole section. DDH DC–2 (Dry Creek) DDH DC–2 (Dry Creek) diamond-drill-hole section.

DDH DC–3 (Dry Creek) DDH DC–3 (Dry Creek) diamond-drill-hole section.

DDH FC–4 (Fairway Creek) DDH FC–4 (Fairway Creek) diamond-drill-hole section. DDH HC–4 (Hiatt Creek) DDH HC–4 (Hiatt Creek) diamond-drill-hole section.

DDH HF–1 (Hereford) DDH HF–1 (Hereford) diamond-drill-hole section.

DDH JF–12 (JF) DDH JF–12 (J−F) diamond-drill-hole section.

DDH JF–79–1 (JF) DDH JF–79–1 (J−F) diamond-drill-hole section.

DDH JF–79–4 (JF) DDH JF–79–4 (J−F) diamond-drill-hole section.

DDH JFW–1 (JF West) DDH JFW–1 (J−F West) diamond-drill-hole section. DDH MG–6 (Military Gulch) DDH MG–6 (Military Gulch) diamond-drill-hole section.

DDH RC–43 (Rock Creek) DDH RC–43 (Rock Creek) diamond-drill-hole section.

DDH RC–47 (Rock Creek) DDH RC–47 (Rock Creek) diamond-drill-hole section. DDH RC–49 (Rock Creek) DDH RC–49 (Rock Creek) diamond-drill-hole section.

DDH RC–58 (Rock Creek) DDH RC–58 (Rock Creek) diamond-drill-hole section.

DDH SL–106 (Spar Lake) DDH SL–106 (Spar Lake) diamond-drill-hole section. DDH SL–122 (Spar Lake) DDH SL–122 (Spar Lake) diamond-drill-hole section.

DDH SL–123 (Spar Lake) DDH SL–123 (Spar Lake) diamond-drill-hole section.

DDH SL–130 (Spar Lake) DDH SL–130 (Spar Lake) diamond-drill-hole section. DDH SL–132 (Spar Lake) DDH SL–132 (Spar Lake) diamond-drill-hole section.

DDH SL–136 (Spar Lake) DDH SL–136 (Spar Lake) diamond-drill-hole section.

DDH SL–138 (Spar Lake) DDH SL–138 (Spar Lake) diamond-drill-hole section.

DDH SL–139 (Spar Lake) DDH SL–139 (Spar Lake) diamond-drill-hole section.

DDH SL–31 (Spar Lake) DDH SL–31 (Spar Lake) diamond-drill-hole section.

DDH SL–60 (Spar Lake) DDH SL–60 (Spar Lake) diamond-drill-hole section. DDH SL–93 (Spar Lake) DDH SL–93 (Spar Lake) diamond-drill-hole section.

DDH SN–1 (Snake Creek) DDH SN–1 (Snake Creek) diamond-drill-hole section.

DDH SN–2 (Snake Creek) DDH SN–2 (Snake Creek) diamond-drill-hole section.

DDH SN–3 (Snake Creek) DDH SN–3 (Snake Creek) diamond-drill-hole section.

DDH SN–4 (Snake Creek) DDH SN–4 (Snake Creek) diamond-drill-hole section. DDH SN–5 (Snake Creek) DDH SN–5 (Snake Creek) diamond-drill-hole section.

DDH TC–10 (Trout Creek) DDH TC–10 (Trout Creek) diamond-drill-hole section.

DDH TC–5A (Trout Creek) DDH TC–5A (Trout Creek) diamond-drill-hole section.

DDH TC–7A (Trout Creek) DDH TC–7A (Trout Creek) diamond-drill-hole section. DDH TC–8 (Trout Creek) DDH TC–8 (Trout Creek) diamond-drill-hole section.

DDH TC–9 (Trout Creek) DDH TC–9 (Trout Creek) diamond-drill-hole section. DDH VR–11 (Vermilion River) DDH VR–11 (Vermilion River) diamond-drill-hole section.

Data and graphical logs summarizing the location, stratigraphy, lithology, and mineralogy for diamond-drill cores

and measured sections through the Revett Formation and nearby units

Microsoft Excel 2003 workbook (*.xls) and Adobe Portable Document Format files (*.pdf)

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  33
DDH VR–4 (Vermilion River) DDH VR–4 (Vermilion River) diamond-drill-hole section.

Deep Creek Deep Creek measured section.

East Fork Bull River 1, 2, 3 East Fork Bull River 1, 2, 3 measured section.

East Lake East Lake measured section.

Goat Rocks Goat Rocks measured section. Goat Rocks Lower Goat Rocks (Lower) measured section.

Graham Creek Graham Creek measured section.

Granite Creek Granite Creek measured section. Graves Creek Falls Graves Creek Falls measured section.

Graves Peak Graves Peak measured section.

Green Mtn Green Mountain measured section.

Grizzly Creek Grizzly Creek measured section.

Gunsight Mtn Gunsight Mountain measured section.

Hope (David Thompson Game

Preserve)

Hope (David Thompson Game Preserve) measured section.

Horseshoe Lake Horseshoe Lake measured section.

Janstan Janstan measured section.

Kellogg Kellogg measured section.

Kilbrennan Creek Kilbrennan Creek measured section.

Latour Peak-Boise Peak Latour Peak–Boise Peak measured section. Little Beaver Creek Little Beaver Creek measured section.

Little Grizzly Creek Little Grizzly Creek measured section.

Little Spar Lake Little Spar Lake measured section. Little Tepee Creek 1, 2 Little Tepee Creek 1, 2 measured section.

Lower Glidden Lake Lower Glidden Lake measured section.

Maple Cliffs Maple Cliffs measured section. McKay Creek (White) McKay Creek (White) measured section.

McKay Creek, North McKay Creek, North measured section.

McKay Creek, South McKay Creek, South measured section.

Military Gulch (lower) Military Gulch (lower) measured section.

Military Gulch (upper) Military Gulch (upper) measured section.

Miller Gulch (Sex Peak) Miller Gulch (Sex Peak) measured section. Miners Gulch (Vermilion R.) Miners Gulch (Vermilion R.) measured section.

Mount Vernon Mount Vernon measured section.

Niagara Niagara measured section. North Fork Coeur d’Alene

Section 20

North Fork Coeur d’Alene Section 20 measured section.

North Fork Coeur d’Alene

Section 25

North Fork Coeur d’Alene Section 25 measured section.

Obemeyer Mtn Obemeyer Mountain measured section.

Prado Creek, North of North of Prado Creek measured section. Prichard Creek Prichard Creek measured section.

Revett Lake Revett Lake measured section.

Ripper Creek Ripper Creek measured section.

Rock Creek (East Fork) Rock Creek (East Fork) measured section.

Rush Lake Rush Lake measured section.

Silver Creek Silver Creek measured section. Sims Creek (west slope) Sims Creek (west slope) measured section.

File name Description

Sims Creek 1, 2 (east slope) Sims Creek 1, 2 (east slope) measured section.

Slide Rock Mtn Slide Rock Mountain measured section. Spokane Creek Spokane Creek measured section.

Spokane-Chipmunk Ridge 3 Spokane-Chipmunk Ridge 3 measured section.

Timmies Section Timmies Section measured section.

Trout Creek (White) Trout Creek (White) measured section.

Squaw Peak Squaw Peak measured section. Stanley Peak Stanley Peak measured section.

Thompson River Thompson River measured section.

Data and graphical logs summarizing the location, stratigraphy, lithology, and mineralogy for diamond-drill cores

and measured sections through the Revett Formation and nearby units

Microsoft Excel 2003 workbook (*.xls) and Adobe Portable Document Format files (*.pdf)

Table 4. List of databases, graphical logs, and spatial-data files—Continued

34  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Trout Creek 1, 2 Trout Creek 1, 2 measured section.

Twentyfour Mile Creek (Clear

Peak 1)

Twentyfour Mile Creek (Clear Peak 1) measured section.

Vermilion River (White) Vermilion River (White) measured section.

Waloven Creek (lower) Waloven Creek (lower) measured section.

Waloven Creek (upper) Waloven Creek (upper) measured section. Wee Lake 1, 2 Wee Lake 1, 2 measured section.

West Fork Crow Creek West Fork Crow Creek measured section.

West Fork Eagle Creek 1–2 West Fork Eagle Creek 1–2 measured section.

West Fork Eagle Creek 3 West Fork Eagle Creek 3 measured section.

West Fork Eagle Creek 5 West Fork Eagle Creek 5 measured section.

West Fork Trout Creek 1 West Fork Trout Creek 1 measured section. West Fork Trout Creek 2 West Fork Trout Creek 2 measured section.

White Pine Creek 2, 3, 4 White Pine Creek 2, 3, 4 measured section.

Windfall Peak Windfall Peak measured section.

Tab-delimited text file

cuag_deposit Description of 57 Revett-subtype copper-silver deposits, occurrences, and

prospects.

Spatial databases in export format

ESRI interchange format files (*.e00)

lrevzone Polygons showing the extent of mineral zones in the lower member of the

Revett Formation; arcs (lines) showing the boundaries between the zones. rev_48k Polygons showing the extent of the Revett Formation and nearby units; arcs

(lines) showing contacts, faults, and outcrops with copper-silver

mineralization. rev_cuag Polygons showing copper-silver mineralized domains, untested exploration

areas, and permissive tracts for Revett-subtype stratabound copper-silver

deposits.

rev_ddh Collar locations of 40 diamond-drill holes.

rev_msec Traverse lines for 87 measured sections.

urevzone Polygons showing the extent of mineral zones in the upper member of the

Revett Formation; arcs for the boundaries between the zones.

File name Description

Metadata files providing information about the spatial datasets

Hypertext markup language format files (*.htm)

cuag_deposit Metadata for the tab-delimited text file, cuag_deposit.txt, describing copper- silver deposits, occurrences, and prospects in the Revett Formation.

lith_log Metadata for the Microsoft Excel spreadsheets summarized diamond-drill

cores and measured sections.

lrevzone Metadata for the spatial database lrevzone. rev_48k Metadata for the spatial database rev48k.

rev_cuag Metadata for the spatial database rev_cuag.

rev_ddh Metadata for the spatial database rev_ddh.

rev_msec Metadata for the spatial database rev_msec.

revett Metadata providing overview for all spatial datasets.

urevzone Metadata for the spatial database urevzone.

Data and graphical logs summarizing the location, stratigraphy, lithology, and mineralogy for diamond-drill cores

and measured sections through the Revett Formation and nearby units

Microsoft Excel 2003 workbook (*.xls) and Adobe Portable Document Format files (*.pdf)

Table 4. List of databases, graphical logs, and spatial-data files—Continued

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  35
als in synsedimentary cements. The “sulfide” column has 

separate subcolumns for pyrite-pyrrhotite (py-pyrr), galena 

(ga), chalcopyrite (cpy), and bornite (bn). If these minerals 

are present within the strata, the appropriate footage intervals 

within the columns are colored. Solid, dashed, or dotted lines 

are used to indicate the amount of mineral present. Bornite(11)

is indicated by a purple line, and chalcopyrite(12) by a red line. 

Additional data about the texture, amount, or degree of oxidation of sulfide minerals (see abbreviations in sulfide column, 

fig. 19) includes cubic or disseminated pyrite (pyc); clots, 

clusters, balls, or framboids of pyrite (pyf); pyrrhotite (pyrr 

or po); galena (gn or ga); bornite (bn; includes chalcocite and 

digenite); and chalcopyrite (cpy). The “oxide” column has 

separate subcolumns for magnetite (M), hematite (H), and 

leucoxene (L), which are colored in appropriate footage intervals if these minerals are present within the strata. Information 

(abbreviated) in the “oxide” column includes magnetite (m), 

leucoxene (l or leu), hematite and specularite (h), and limonite 

(l or lim). Occasionally, features called black spots(8) (blk sp.), 

believed to be oxides, are recorded. The “carbonate” column 

has separate subcolumns for calcite (C), dolomite (D), and 

ankerite (A), which are colored in appropriate footage intervals if these minerals are present within the strata. Information 

(abbreviated) in the “carbonate” column includes calcite-disseminated (c or cal), calcite occurring along bedding or bedform (bf), dolomite (d), and ankerite (a or ank). The “silicate” 

column has separate subcolumns for feldspar (F), and chlorite 

(Cl), which are colored in appropriate footage intervals if these 

minerals are present within the strata. Information (abbreviated) in the “silicate” column include feldspar (f), chlorite (cl 

or chl), and biotite. The “supergene” column is used to record 

the effects of weathering. This column includes separate 

subcolumns for Cu mineral and Fe mineral, which are colored 

in appropriate footage intervals if these minerals are present 

within the strata. Information (abbreviated) in the “supergene” 

column includes Cu oxide (C, CuOx), Fe oxides (F, FeOx), 

and pyrolusite (MnOx, dendrite, or penetrative dendrite). In 

the “supergene” column, notes about Cu mineral (green)(13) or 

“malac”(14) indicate the content of Cu oxides. Data about liesegang banding (banding, bands, stripes, or lies.) are recorded 

where possible.

The information in the “structure” column describes 

features related to deformation of the rocks; the column 

“lithology, grain-size, bedform, and comments” includes notes 

on bed thickness (“bed size”), color, grain-size, sedimentary 

structures, and luster (for example, vitreous or subvitreous). 

Bed-thickness abbreviations (VT, T, M, t) indicate very thick 

(>4 ft), thick (1–4 ft), medium (1 in.–1 ft), and thin (<1 in.)(4). 

Colors of strata include white, green, greenish gray, gray 

(includes buff, cream, yellow, brown), and lavender. A determination of grain size by geologists was consistently made by 

reference to a grain-size chart. Primary sedimentary structures (bedform) recorded include ripple-drift lamination (rdl, 

includes flaser bedding), crossbeds (cb, includes megaripples 

and channels),(5) horizontal lamination (hl, includes lenticular 

bedding), ripup clasts (ru), soft-sediment-deformation structures (ssd; includes ball-and-pillow, convolute, and pinchand-swell structures), mud chips (mc), graded beds (grb), and 

water-release structures (wrs).

Spreadsheets and Graphical Logs

The information recorded on the field-data forms was transcribed into Microsoft Excel spreadsheets in order to use charting 

software to create graphical logs of the diamond-drill cores and 

measured sections. The data recorded on the spreadsheets are sufficiently detailed that few or no geologic data recorded on fielddata forms were lost. Considerable effort was expended to retain 

the integrity of the information recorded on the field-data forms 

upon transfer to the spreadsheets. Some data may be recorded as 

notes or comments in the spreadsheets that could not be shown 

in the graphical logs. We note that in some cases, stratigraphic 

boundaries established by Asarco Inc. or other geologists (for 

example, formation, member, and bed) may have been changed 

by USGS personnel during the interpretations made for this report 

or to maintain consistent terminology in text, illustrations, and 

correlated sections of this report. Nonetheless, the original data 

from field-data forms were retained in the spreadsheet’s worksheets and graphical logs. Adjustments of apparent to true thickness, inversion of overturned strata, or other corrections were also 

made in the spreadsheets, and so the completed graphical logs 

show true, undeformed stratigraphic thicknesses. The thickness of 

covered intervals along measured outcrop traverses is also shown. 

Although the effects of faulting or intrusions of igneous rocks 

could not be determined or removed, the locations of faults are 

listed on the spreadsheets and logs.

Graphical lithologic logs based on the spreadsheets of 

each measured section or diamond-drill core were constructed 

with Interdex or CoreView software (Surpac Minex Group, 

Perth, Australia, http://www.surpac.com/) and saved as Adobe 

Portable Document Format (PDF) files. The graphical logs 

specifically emphasize the characteristics of Revett-subtype 

stratabound copper-silver deposits: lithology and stratigraphic 

terminology are listed in the center, ore and related minerals 

on the right, and gangue minerals, structures, and related data 

on the left. The colored rock type and grain-size histograms 

are the same data presented in two ways. The columns to 

the right of center on the graphical logs show ore minerals 

arranged in order, from left to right, corresponding to the mineral-zone sequence at the Troy deposit (Hayes, 1983; Hayes 

and Einaudi, 1986). Amounts of ore and gangue minerals are 

listed in histogram form at three levels of relative abundance: 

trace (t), present (p), and abundant (a).

Data-entry steps were checked at several stages. After 

completing data entry, each worksheet of a core or measured section was checked against the field-data form by two 

persons. As the data entry proceeded, changes in format of the 

worksheets required review of all field-data forms to maintain 

consistent data-entry practices. If corrections were needed, 

they were checked a second time after reentering the data. Following these steps, the graphical log was produced by using 

36  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Table 5. Summary of data from diamond-drill cores and measured sections

[Name of diamond-drill core or measured section is the same as the name of the graphical logs in appendix A and Microsoft Excel files; true thickness, true stratigraphic tdiamond-drill core, measured section, or transect length of underground section; ms, measured-section traverse on outcrop; core, core from diamond-drill hole. NA, not ap

Figure

(app.A) Name of diamond-drill core or measured section Latitude (o N.) Longitude (o W.) Thickness (ft) True thickness (ft) Type Azimuth (o) Dip(o) Elevatio

(ft) 

1 Obemeyer Mtn 48.9753 115.809 751 751 ms NA NA NA 2 Wee Lake 1, 2 48.6123 115.804 1,218 1,218 ms NA NA 6,000 3 Gunsight Mtn 48.6096 115.832 254 254 ms NA NA 5,000 4 Kilbrennan Creek 48.59 115.898 858 858 ms NA NA 2,850 5 Horseshoe Lake 48.2575 117.612 1,570 1,570 ms NA NA NA 6 Granite Creek 48.0843 116.28 840 840 ms NA NA NA 7 DDH FC–4 (Fairway Creek) 48.2919 115.9349 3,225 3,154 core NA 
90 3,800 

8 Stanley Peak 48.2899 115.977 355 355 ms NA NA NA 9 DDH SL–130 (Spar Lake) 48.2599 115.9085 635 585 core NA 
90 4,420 

10 DDH HC–4 (Hiatt Creek) 48.2575 115.9712 1,307 1,262 core NA 
90 4,900 11 DDH SL–136 (Spar Lake) 48.2423 115.9207 2,559 2,520 core NA 
90 5,220 12 DDH CC–1 (Cub Creek) 48.2409 115.9708 2,049 2,018 core NA 
90 3,550 13 Clark Fork 48.2381 116.215 925 925 ms NA NA NA 14 DDH SL–122 (Spar Lake) 48.2287 115.8776 2,321 2,286 core NA 
90 5,100 15 Mount Vernon 48.2283 115.871 2,040 2,040 ms NA NA NA 16 DDH SL–60 (Spar Lake) 48.227 115.9006 1,215 1,211 core NA 
90 5,460 17 DDH SL–123 (Spar Lake) 48.2276 115.8858 2,852 2,831 core NA 
90 5,200 18 DDH SL–93 (Spar Lake) 48.2274 115.8998 2,990 2,990 core NA 
90 5,360 

19 DDH SL–106 (Spar Lake) 48.2256 115.9035 1,015 1,015 core NA 
90 5,060 20 DDH SL–138 (Spar Lake) 48.2202 115.9038 1,844 1,844 core NA 
90 4,440 21 DDH SL–31 (Spar Lake) 48.2204 115.8907 941 920 core NA 
90 4,638 22 DDH SL–139 (Spar Lake) 48.216 115.9108 1,109 1,109 core NA 
90 3,540 23 DDH SL–132 (Spar Lake) 48.2115 115.8944 1,614 1,590 core NA 
90 3,280 24 Little Spar Lake 48.211 116.031 2,310 2,310 ms NA NA NA 

25 DDH JF–79–1 (JF) 48.2001 115.8906 935 714 core 001 
55 3,529 26 DDH JF–79–4 (JF) 48.1965 115.8895 1,605 1,229 core 310 
45 4,120 27 DDH JFW–1 (JF West) 48.1935 115.9003 2,705 2,705 core NA 
90 4,900 28 DDH JF–12 (JF) 48.1892 115.8867 1,596 1,129 core 000 
80 4,100 29 DDH DC–3 (Dry Creek) 48.1662 115.8646 2,392 1,832 core NA 
90 2,350 30 DDH DC–2 (Dry Creek) 48.1605 115.8662 2,903 2,549 core NA 
90 2,350 

31 Squaw Peak 48.0772 115.916 765 765 ms NA NA NA 32 Goat Rocks 48.1404 115.709 1,160 1,160 ms NA NA 4,800 33 DDH SN–2 (Snake Creek) 48.1369 115.7528 3,519 3,415 core NA 
90 3,390 

34 DDH SN–5 (Snake Creek) 48.1319 115.7473 2,509 2,478 core NA 
90 3,070 35 East Fork Bull River 1, 2, 3 48.1224 115.723 1,400 1,400 ms NA NA 4,400 36 DDH SN–1 (Snake Creek) 48.1261 115.7486 1,853 1,806 core NA 
90 2,800 37 DDH SN–4 (Snake Creek) 48.1243 115.7377 1,329 1,249 core NA 
90 2,680 38 DDH SN–3 (Snake Creek) 48.1233 115.7551 2,466 2,412 core NA 
90 2,600 39 Goat Rocks Lower 48.1294 115.723 140 140 ms NA NA 3,600 40 DDH RC–58 (Rock Creek) 48.0861 115.692 1,861 1,820 core NA 
90 6,503 41 DDH RC–49 (Rock Creek) 48.0778 115.6887 1,081 1,023 core 260 
80 5,968 42 DDH RC–47 (Rock Creek) 48.0766 115.6784 2,052 1,660 core 
80 7,119 

43 DDH RC–43 (Rock Creek) 48.069 115.6898 1,375 1,292 core 347 
80 6,523 

030
46 DDH HF–1 (Hereford) 48.0239 115.6764 1,382 1,119 core NA 
90 4,950 

47 McKay Creek (White) 47.9756 115.678 895 895 ms NA NA NA 48 McKay Creek, North 47.9739 115.68 228 228 ms NA NA 3,200 49 McKay Creek, South 47.9665 115.68 900 900 ms NA NA 3,600 

50 Green Mtn 47.9572 115.664 202 202 ms NA NA 4,800 51 Waloven Creek (lower) 47.9555 115.441 504 504 ms NA NA NA 52 Waloven Creek (upper) 47.9328 115.432 613 613 ms NA NA 5,200 53 Sims Creek (west slope) 47.9145 115.42 376 376 ms NA NA 5,000 54 Sims Creek 1, 2 (east slope) 47.9216 115.414 1,154 1,154 ms NA NA 5,400 55 Miners Gulch (Vermilion R.) 47.8672 115.392 570 570 ms NA NA 3,600 

56 DDH VR–11 (Vermilion River) 47.8562 115.3771 883 705 core NA 
90 6,000 57 DDH VR–4 (Vermilion River) 47.8504 115.374 1,089 770 core NA 
90 5,550 58 Rush Lake 47.8294 115.363 670 670 ms NA NA 6,160 59 Vermilion River (White) 47.8267 115.362 1,300 1,300 ms NA NA NA 60 Slide Rock Mtn 47.8087 115.364 1,183 1,183 ms NA NA 6,400 61 Deep Creek 47.7743 115.38 1,076 1,076 ms NA NA 5,300 

62 Graves Peak 47.7538 115.367 1,235 1,235 ms NA NA 6,950 63 Graves Creek Falls 47.7265 115.374 1,435 1,435 ms NA NA NA 64 Thompson River 47.6122 115.206 2,100 2,100 ms NA NA 4,075 65 DDH TC–9 (Trout Creek) 47.831 115.7245 2,203 2,069 core NA 
90 3,200 66 DDH TC–8 (Trout Creek) 47.8266 115.7184 2,238 1,976 core NA 
90 3,760 67 DDH TC–10 (Trout Creek) 47.8229 115.7336 2,249 2,113 core NA 
90 4,000 

68 Trout Creek 1, 2 47.8222 115.66 1,015 1,015 ms NA NA NA 69 DDH TC–7A (Trout Creek) 47.8227 115.7129 992 899 core NA 
90 3,700 70 Trout Creek (White) 47.8164 115.713 2,035 2,035 ms NA NA NA 71 DDH TC–5A (Trout Creek) 47.8059 115.736 1,276 1,214 core NA 
90 4,400 72 West Fork Trout Creek 1 47.8062 115.725 700 700 ms NA NA NA 73 West Fork Trout Creek 2 47.8005 115.735 808 808 ms NA NA NA 

74 Windfall Peak 47.7742 115.757 883 883 ms NA NA NA 75 White Pine Creek 2, 3, 4 47.7536 115.632 706 706 ms NA NA NA 76 Ripper Creek 47.7353 115.632 956 956 ms NA NA 4,800 77 Miller Gulch (Sex Peak) 47.7127 115.606 1,173 1,173 ms NA NA NA 78 Beaver Creek Road 47.7054 115.595 1,383 1,383 ms NA NA NA 79 Little Beaver Creek 47.6645 115.545 939 939 ms NA NA NA 

80 Clear Peak (Asarco) 47.6385 115.651 885 885 ms NA NA NA 81 Beaver Peak North 47.6365 115.656 567 567 ms NA NA NA 82 Clear Peak (White) 47.6309 115.661 410 410 ms NA NA NA 

Figure

(app.A) Name of diamond-drill core or measured section Latitude (o N.) Longitude (o W.) Thickness (ft) True thickness (ft) Type Azimuth (o) Dip(o) Elevatio

(ft) 

44 Chicago Peak (White) 48.068 115.676 1,505 1,505 ms NA NA NA 

45 Rock Creek (East Fork) 48.0378 115.69 728 728 ms NA NA 3,472 

83 Beaver Lake 1, 2 47.6276 115.694 1,585 1,585 ms NA NA NA 84 DDH CP–5 (Clear Peak) 47.6268 115.6285 1,100 1,062 core NA 
90 5,200 85 DDH CP–4 (Clear Peak) 47.6237 115.6479 1,260 1,260 core NA 
90 6,400 

Table 5. Summary of data from diamond-drill cores and measured sections—Continued[Name of diamond-drill core or measured section is the same as the name of the graphical logs in appendix A and Microsoft Excel files; true thickness, true stratigraphic tdiamond-drill core, measured section, or transect length of underground section; ms, measured-section traverse on outcrop; core, core from diamond-drill hole. NA, not ap
95 West Fork Eagle Creek 3 47.7356 115.808 1,215 1,215 ms NA NA NA 

96 West Fork Eagle Creek 1–2 47.7244 115.811 1,755 1,755 ms NA NA NA 97 West Fork Eagle Creek 5 47.7134 115.829 1,372 1,372 ms NA NA NA 98 Cottonwood 47.708 115.851 604 604 ms NA NA NA 99 Bobtail Creek 47.6987 115.872 822 822 ms NA NA NA 

100 Niagara 47.6771 115.851 1,235 1,235 ms NA NA NA 101 Revett Lake 47.5573 115.747 870 870 ms NA NA NA 102 DDH MG–6 (Military Gulch) 47.532 115.7695 1,139 1,032 core NA 
90 4,640 

103 Prichard Creek 47.6584 115.961 698 698 ms NA NA 3,400 104 Coeur d’Alene River 3 47.6586 115.98 620 620 ms NA NA 3,300 105 Cedar Creek 47.6383 116.013 481 481 ms NA NA 3,200 

106 Little Grizzly Creek 47.6677 116.05 954 954 ms NA NA NA 107 Grizzly Creek 47.6643 116.058 998 998 ms NA NA 2,340 108 Timmies Section 47.6565 116.07 873 873 ms NA NA 2,900 109 Maple Cliffs 47.6566 116.087 674 674 ms NA NA 3,100 110 Graham Creek 47.6473 116.092 214 214 ms NA NA NA 111 Silver Creek 47.6531 116.098 397 397 ms NA NA 2,700 112 Castle Rock 47.6493 116.112 693 693 ms NA NA 2,900 113 Coal Creek 47.6429 116.132 354 354 ms NA NA NA 114 Kellogg 47.5155 116.1498 4,110 4,110 ms NA NA NA 

115 Latour Peak-Boise Peak 47.4439 116.386 4,400 4,400 ms NA NA NA 116 Prado Creek, North of 47.5908 116.254 268 268 ms NA NA 2,100 117 Bumblebee Road 47.6314 116.319 1,936 1,936 ms NA NA 2,400 118 Browns Gulch 47.6252 116.317 526 526 ms NA NA 2,800 119 County Creek 47.6357 116.316 185 185 ms NA NA 2,400 120 Little Tepee Creek 1, 2 47.6443 116.338 1,807 1,807 ms NA NA 3,200 121 North Fork Coeur d’Alene Section 20 47.6736 116.357 662 662 ms NA NA NA 122 North Fork Coeur d’Alene Section 25 47.741 116.41 280 280 ms NA NA NA 

87 Janstan 47.5717 115.674 182 182 ms NA NA NA 

88 West Fork Crow Creek 47.5174 115.586 1,098 1,098 ms NA NA 4,400 89 Spokane Creek 47.5145 115.626 337 337 ms NA NA NA 90 Spokane-Chipmunk Ridge 3 47.5136 115.634 292 292 ms NA NA 4,000 91 Chipmunk 1 47.5083 115.646 990 990 ms NA NA 3,780 92 Chipmunk 2 47.5016 115.653 562 562 ms NA NA 5,900 93 Bloom Peak 47.7607 115.834 700 700 ms NA NA NA 94 East Lake 47.7388 115.778 396 396 ms NA NA NA 

Figure

(app.A) Name of diamond-drill core or measured section Latitude (o N.) Longitude (o W.) Thickness (ft) True thickness (ft) Type Azimuth (o) Dip(o) Elevation (ft) 

86 Twentyfour Mile Creek (Clear Peak1) 47.5954 115.677 690 690 ms NA NA NA 

123 Hope (David Thompson Game

Preserve)

48.1967 116.2875 2,701 2,701 ms NA NA NA 

124 Military Gulch (upper) 47.5083 115.7467 646 646 ms NA NA 5,591 125 Military Gulch (lower) 47.5189 115.7647 595 595 ms NA NA 6,000 

126 Lower Glidden Lake 47.5108 115.7294 389 389 ms NA NA 6,400 

Table 5. Summary of data from diamond-drill cores and measured sections—Continued[Name of diamond-drill core or measured section is the same as the name of the graphical logs in appendix A and Microsoft Excel files; true thickness, true stratigraphic diamond-drill core, measured section, or transect length of underground section; ms, measured-section traverse on outcrop; core, core from diamond-drill hole. NA, not a
the Interdex or CoreView log-plotting software. After plotting, 

the graphical logs were again checked by two persons, and 

additional changes made if necessary. The final labeling was 

completed by using Adobe Illustrator software, and the result 

saved as a PDF file.

Each Microsoft Excel file for a diamond-drill core or 

measured section consists of four worksheets named “lithology”, “formation”, “mineralogy”, and “collar”. Four worksheets are required because depth intervals differ substantially 

for the different categories of information recorded on the 

field-data forms (table 6). The following sections of this 

report describe how the field-data forms were transcribed into 

worksheets, using examples of original diamond-drill-hole and 

measured-section logs (figs. 19, 20).

Collar Worksheet

Collar worksheets generally contain location and descriptive data about the site. They include the following columns: 

“section”, “easting”, “northing”, “elevation”, “depth”, “depth_

corr”, “azimuth”, “dip”, “GPS_lat”, and “GPS_long” (table 7). 

The “easting” and “northing” give map coordinates (in meters) 

in a Universal Transverse Mercator (North American datum of 

1927) map projection. “Elevation” is the height above sea level 

of the collar of the core (in feet) or the elevation of the start 

of the measured section (in feet). “Depth” is the total length 

(in feet) of the core or measured section. “Azimuth” and “dip” 

give the direction and inclination of a diamond-drill hole if 

drilled in an orientation other than vertical (−90o).

Formation Worksheet

The formation worksheet stores data about formations, members, and beds in the core or measured section.

A formation worksheet generally contains the following 

columns: “section”, “section logged”, “orientation”, “formation”, “member”, “bed”, “ave_core_angle”, “from”, “to”, 

“from_corr”, “to_corr”, “app_thick”, “thickness”, “GPS_lat”, 

“GPS_long”, and “comments” (table 8). Stratigraphic names, 

which were taken from the margin of the field-data forms(6,7), 

include such formation names as Wallace, St. Regis, Revett, 

and Burke. The Revett Formation has been informally divided 

into three members: upper, middle, and lower. The lower 

member of the Revett Formation is further subdivided, from 

the top downward, into beds A through J. Members of the 

Revett Formation were further subdivided, from the top downward, into beds in the upper member of the Revett Formation 

designated the upper quartzite, upper siltite, middle quartzite, 

lower siltite, and lower quartzite.

Lithology Worksheet

The lithology worksheet includes columns for lithology, 

grain size, bed thickness, color, luster (vitreous or nonvitreous), and sedimentary structures described in diamond-drill 

cores or measured sections. All lithology worksheets contain the following columns: “section”, “section_logged”, 

“orientation”, “from”, “to”, “app_thick”, “ave_core_angle”, 

“from_corr” (if corrected), “to_corr”, “lithology”, “thickness”, 

“grain_size”, “bed_thickness”, “color” (a number to indicate 

color), “white_beds”, “green_beds”, “gray-green_beds”, 

“gray_beds”, “lavender_beds”, “vitreous”, “structures”, “horizontal_laminations”, “ripup_clasts”, “soft-sediment_deformation”, “cross-beds”, “ripple_drift_lamination”, “mud_chips”, 

“graded_beds”, “dewatering_structures”, and “comments” 

(table 9). The depth intervals in the diamond-drill core or 

measured sections are listed in “to” and “from” columns if 

no correction was required. If any correction to depth was 

required, corrected depths are reported as “to_corr” and 

“from_corr” and uncorrected depth values are not reported.

All other log intervals (faults, covered) or rock types 

(quartzite, intrusive, and so on) were assigned a unique 

number to distinguish them in the log-plotting software. 

The “lithology” and “grain-size” columns in this worksheet 

contain identical information, but two columns were required 

to accommodate the log-plotting software. Their equivalency is quartzite (q)=“5”, slightly silty quartzite (ssq)=“4”, 

silty quartzite (sq)=“3”, siltite (s)=“2”, silt-argillite couplet 

(sac)=“1.5”, and argillite (a)=“1”. The bed thickness of each 

lithologic interval was assigned a numeric value or letter 

abbreviation as follows: thin (t) bedded (<1 in.)=“1”, medium 

(m) bedded (1–12 in.)=“2”, thick (Th) bedded (1–4 ft)=“3”, 

and very thick (vTh) bedded (>4 ft)=“4”. Color was entered 

by name in the “color” column and duplicated as a “1” in a 

corresponding column that describes this color. Color of the 

lithologic intervals was assigned to one of six of the most 

frequently occurring colors: black, white, green, green-gray 

(includes gray-green), gray, and lavender. The text column 

is the color given by the geologist, which was found to vary 

between logging practices and from log to log. For example, 

“light green-gray” is “green-gray”, and “light olive green” is 

“green”. The various shades of gray are all grouped together 

as “gray” (no separation between “light gray”, “dark gray”, 

and so on). Colors other than the six designated were assigned 

to “gray”, and in unusual circumstances, these colors might 

include cream, buff, orange, brown, and yellow. Structures 

were listed by name in the “structures” column and by a “1” in 

the column that describes them. The “vitreous” column represents intervals having a vitreous luster (vitreous=“1”; absent, 

subvitreous, or nonvitreous=blank). Bedform structures are 

noted as text in the “structures” column. Sedimentary structures are also listed in following columns as a “1” to denote 

their presence in an interval. The “comments” column contains 

relevant notes and remarks.

Data for determining the grain size and thickness of units 

used for stratigraphic mapping were taken from the “lithology” table. Grain-size and thickness data were needed for 

the sand isolith mapping method. Thickness was determined 

by subtracting the “from” depth from the “to” depth. If only 

corrected depths were provided, thickness was obtained by 

subtracting “from_corr” from the “to_corr” to obtain true 

40 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Table 6. Contents of each spreadsheet

Table 7. Definitions of item names in the collar worksheet

Worksheet

name

Data

Collar ------------- Location and orientation (cores).

Formation -------- Depth intervals (rows) (in feet), showing stratigraphic tops of formations,

members, and beds.

Lithology--------- Depth intervals (rows) (in feet), showing lithologic data, such as rock

type, color, sedimentary structures, bed thickness, and grain size.

Mineralogy------- Depth intervals (rows) (in feet), showing mineralogic data on gangue

minerals (calcite, hematite, biotite, feldspar, pyrite, and so on) and ore

minerals (bornite [includes digenite and chalcocite], chalcopyrite, Cu

oxide, and galena).

Item

name Definition

Name of the diamond-drill hole or measured section. Diamond-drill holes have 

“DDH” as the first three letters in the name. 

Easting values represented in a UTM map projection (in meters). 

Northing values represented in a UTM map projection (in meters).

Elevation (in feet) of the collar of the diamond-drill hole or elevation at the beginning of the measured section. NA or No entry, no information available.

Total depth (in feet) of the diamond-drill hole or the length of the measured section.

Total true stratigraphic penetration (in feet) of a diamond-drill hole calculated

from the total length of the hole (depth) and the core axis to bedding angle (ave_core_angle), or the total stratigraphic thickness of a measured section, whether its beds are actually upright or overturned.

A positive value, ranging from 0 to 360 measured in the clockwise direction beginning at North, that indicates the compass direction (in degrees) of

in-clined diamond-drill holes. No entry, no data provided.

Inclination of diamond-drill hole (in degrees from horizontal). Positive values indicate that the hole was drilled in an upward direction; negative values indicate that the hole was drilled in a downward direction.

Latitude (in degrees), obtained using GPS equipment.

Longitude (in degrees), obtained using GPS equipment.

section 

easting 

northing

elevation

depth

depth_corr

azimuth

dip

gps_lat

gps_long

thickness. The lithology (quartzite=“5”, slightly silty quartzite=“4”, * * * argillite=“1”) assigned by the geologist completing the diamond-drill-hole or measured-section log was 

made by reference to a grain-size chart for consistent naming. 

Data in the “grain_size” column (numbered equivalent to the 

“lithology” column) was used to compile sand isolith data. 

The sand (quartzite) isolith was determined by accumulating 

only the thickness (in feet) of quartzite (grain-size class=“5”) 

from rows of an interval of interest in the spreadsheet (table 

10). Covered intervals were not considered.

Mineralogy Worksheet

Mineralogic data are listed on the mineralogy worksheet. 

Data were obtained from columns on the field-data forms(8) labeled 

“sulfide”, “oxide”, “carbonate”, “silicate”, and “supergene”. Notes 

about rock-forming and accessory minerals are included here. The 

data listed in the mineralogy worksheet are defined in table 11.

Mineralogy worksheets contain the columns “section”, 

“section_logged”, “orientation”, “from”, “to”, “from_corr”, 

“to_corr”, “ave_core_angle”, “thickness”, “app_thick” (apparent thickness), “py-cube” (cubic pyrite), “py_fram” (framboids, clusters, balls, or clots of pyrite), “pyrrhotite”, “galena”, 

“chalcopyrite”, “bornite”, “magnetite”, “hematite” (includes 

limonite or specularite), “leucoxene”, “mnox” (MnO2 and dendrites), “calcite”, “calcite_bedform” (carbonates conformable 

to bedding, but nearly always calcite), “dolomite”, “ankerite”, 

“feldspar”, “chlorite”, “biotite”, “cuox” (Cu oxide), “feox” (Fe 

oxide), “banding”, “orange/brown spots”, and “comments” 

(table 11). The quantity and intensity of color shading in the 

“mineral” columns indicates the relative amount of a mineral 

present. Written comments or fill color (solid line, dashed 

line, or dotted line) in the “mineral” columns are used to 

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  41
Item

name Definition

section Name of the diamond-drill hole or measured section. Drill holes will have “DDH” as the first

three letters in the name.

section_logged For measured sections, if the item is attributed, then the measured section is a composite of

multiple segments. The attribute is the name of the various measured sections used to make the composite. For diamond-drill holes, the attribute is the name of an extended area where

several diamond-drill holes are located, for example, Spar Lake, Rock Creek.

orientation Direction in which the section was measured, for example, upsection stratigraphically or

downsection stratigraphically. No data, data unavailable for the section.

formation Formation name, for example, Wallace, St. Regis, Revett, or Burke. No entry, no information

provided. member Informal member name of the Revett Formation, for example, upper, middle, and lower. No

entry, no information provided.

bed Informal bed name, for example, A, B, C, D, E, F, G, H, I, J, and K of the lower member of

the Revett Formation or upper quartzite, upper siltite, middle quartzite, lower siltite, and

lower quartzite beds of the upper member of the Revett Formation. The locations of faults,

fault zone, overburden, and fault gouge are indicated where present. No entry, no informa- tion provided.

from Depth (in feet) measured at the beginning of a stratigraphic interval for diamond-drill holes

and measured sections in the stratigraphic down direction. No data, data unavailable for the

section. This item is attributed for diamond-drill holes and measured sections only where no

correction is needed (they are already in stratigraphic down direction and holes were drilled

at an angle not requiring a correction) so that the “from_corr” value (item name) will not be attributed.

to Depth (in feet) measured at the end of a stratigraphic interval for diamond-drill holes and

measured sections in the stratigraphic down direction. No data, data unavailable for the section. This item is attributed for diamond-drill holes and measured sections only where no

correction is needed (they are already in stratigraphic down direction and holes were drilled

at an angle not requiring a correction) so that the “to_corr” value (item name) will not be attributed.

app_thick Thickness (in feet) of a stratigraphic interval, measured parallel to the core axis of a diamonddrill hole. Not yet corrected to true stratigraphic thickness for diamond-drill holes. ave_core_angle Average angle (in degrees) of the bedding inclination, measured from the core axis. A value of


90omeans that strata are horizontal. No data, data unavailable for the section.

from_corr Corrected depth derived from the “down” value (item name). Corrected to true stratigraphic

thickness in the downsection direction for diamond-drill holes and for overturned beds in

diamond-drill holes and measured sections. No data, data unavailable for the section. This

item is attributed for diamond-drill holes and measured sections only where a correction was needed so that the “from” value (item name) will not be attributed.

to_corr Corrected depth derived from the “to” value (item name). Corrected to true stratigraphic

thickness in the downsection direction for diamond-drill holes and for overturned beds in

diamond-drill holes and measured sections. No data, data unavailable for the section. This

item is attributed for diamond-drill holes and measured sections only where a correction

was needed so that the “to” value (item name) will not be attributed. thickness Calculated true thickness (in feet) of the sample interval. Thickness  (to 
 from, or to_corr 


from_corr if a correction was needed).

gps_lat Latitude (in degrees) obtained using GPS equipment. gps_long Longitude (in degrees) obtained using GPS equipment.

comments Additional comments about the interval.

Table 8. Definitions of item names in the formation worksheet

42  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Item

name

Definition

section Name of the measured section or drill hole. Diamond-drill holes have “DDH” as

the first three letters in the name.

section_logged For measured sections, if the item is attributed, then the measured section is a

composite of multiple segments, and the attribute is the name of the various

measured sections used to make up the composite. For diamond-drill holes, the

attribute is the name of the extended area where several diamond-drill holes are

located, for example, Spar Lake, Rock Creek.

orientation Direction in which the section was measured, for example, upsection stratigraphically or downsection stratigraphically. No data, data unavailable for the section.

from Depth (in feet), measured at the beginning of a stratigraphic interval for diamonddrill holes and measured sections in the stratigraphic down direction. Item contains “no data” if data were unavailable for the section. This item is attributed

for diamond-drill holes and measured sections only where no correction is needed (they are already in stratigraphic down direction, and holes were drilled at an angle not requiring a correction) so that the “from_corr” value (item name) will

not be attributed.

to Depth (in feet), measured at the end of a stratigraphic interval for diamond-drill

holes and measured sections in the stratigraphic down direction. Item contains

“no data” if data were unavailable for the section. This item is attributed for

diamond-drill holes and measured sections only where no correction is needed

(they are already in stratigraphic down direction, and holes were drilled at an

angle not requiring a correction) so that the “to_corr” value (item name) will not

be attributed.

ave_core_angle Average angle (in degrees) of the bedding inclination, measured from the core

axis. A value of 
90o means that strata are horizontal perpendicular to the core

axis. No data, data unavailable for the section.

from_corr Corrected depth derived from the “from” value (item name). Corrected to true

stratigraphic thickness in the downsection direction for diamond-drill holes and

for overturned beds in diamond-drill holes and measured sections. Item contains “no data” if data were unavailable for the section. This item is attributed for

diamond-drill holes and measured sections only where a correction was needed

so that the “from” value (item name) will not be attributed.

to_corr Corrected depth derived from the “to” value (item name). Corrected to true stratigraphic thickness in the downsection direction for diamond-drill holes and for

overturned beds in diamond-drill holes and measured sections. Item contains “no data” if data were unavailable for the section. This item is attributed for

diamond-drill holes and measured sections only where a correction was needed

so that the “to” value (item name) will not be attributed.

lithology Abbreviation for rock type: a, argillite; q, quartzite; s, siltite; sac, silt-argillite

couplet; sq, silty quartzite; ssq, slightly silty quartzite. Cover or covered, interval covered by unconsolidated sedimentary material; fault gouge or fault, zone

of fault gouge; missing, information not provided; no recovery, core not recovered.

grain_size Numeric value indicating grain size based on rock type “lithology” value (item

name): 0 or covered, interval covered by unconsolidated sedimentary material;

0.01, fault; 0.03, biotite schist; 1, argillite (a); 1.5, silt-argillite couplet (sac); 2,

siltite (s); 3, silty quartzite (sq); 4, slightly silty quartzite (ssq); 5, quartzite (q);

blank, no information available; int or intrusive, intrusive rocks.

bed_thickness Numeric value based on a description of bed thickness; smaller values indicate

thinner beds, and larger values indicate thicker beds: 1, thin bedded (1 in.); 2, medium bedded (1–12 in.); 3, thick bedded (1–4 ft); 4, very thick bedded (4

ft); no entry, information not provided.

color Color of rocks noted by the field geologist. The following “rules” were used to

attribute the six dominant color items (white_beds, green_beds, graygreen_beds, gray_beds, black_beds, and lavender_beds). Lavender and

lavender-like colors take precedence over gray and green. When one of the six

dominant colors (white, green, gray-green, gray, black, and lavender) is

combined with a graylike color (cream, orange, buff, yellow, or brown), the dominant color is used. Gray takes precedence over white. No entry, no

information provided, but if the “lithology” value is attributed with a rock type,

then gray is the attributed color.

white_beds 1, white if white is only in “color” item; no entry, color is not white.

green_beds 1, green if green is in “color” item; no entry, color is not green.

gray-green_beds 1, grayish-green and (or) greenish-gray beds if gray-green or green-gray is in “color” item. No entry, color is not grayish green or greenish gray.

Table 9. Definitions of item names in the lithology worksheet

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  43
determine the relative abundance of a mineral, as “abundant”, 

“present”, or “trace”. For example, a solid red-filled color(9) in 

the “carbonate” column indicates that ankerite was present in 

large amounts and would have been recorded in the mineralogy 

worksheet, discussed below, as “abundant” (A). An “abundant” 

amount would be interpreted for the red coloring for feldspar 

(“f”)(10) in the “silicate” column as well. A single narrow, solid 

or dashed color line that does not fill the column was interpreted 

as “present” (P), which indicates that the mineral is present in 

moderate amounts but less than abundant and more than a trace. 

A dotted line or occasional dots in the column were interpreted 

as a “trace” (T) amount. A number appearing in any of the 

structures Abbreviations or terms describing sedimentary structures noted in the section.

Many of the more frequently noted structures correspond to another item in the

spreadsheet; others, less frequently noted, are listed only here. This item may

also include bedding descriptions, faults, or general comments. Sedimentary

structures: cb or x-beds, crossbedded (includes megaripple and channel); chnl or

chnls, channel, climbing ripples, f-l, flat laminations; gdb, grb, or grdb, graded

beds; hl, horizontal laminations (includes lenticular bedding); inclined, inclined

bedding; lam, laminations; massive, massive bedding; mc, mudchips; rdl or ripple, ripple-drift laminae (includes flaser bedding); ru or rc, ripup clasts; ssd or

deformed slump, slump block, ball/pillow, or pinch/swell, soft-sediment deformation (includes ball and pillow, convoluted beds, and pinch and swell); wrs,

water release, or dewatering structures, water-release structures; no entry, sedimentary structures not described.

horizontal_laminations 1, horizontal laminations (or flat laminations includes lenticular bedding) if hl is in

“structures” item; no entry, horizontal laminations are absent.

ripup_clasts 1, ripup clasts if ru or rc is in “structures” item; no entry, ripup clasts are absent.

soft-sediment_deformation 1, soft-sediment deformation (also ball and pillow, convolute beds, and pinch and

swell) if ssd, deformed slump, ball/pillow, or pinch/swell is in “structures” item;

no entry, soft-sediment deformation is absent.

cross-beds 1, crossbeds if cb or x-beds is in “structures” item (also megaripple or channel); no

entry, crossbeds are absent. ripple_drift_laminae 1, ripple-drift laminae (includes flaser bedding) if rdl is in “structures” item; no

entry, ripple-drift laminae are absent.

mud_chips 1, mudchips if mc is in “structures” item; no entry, mudchips are absent.

graded_beds 1, graded beds if gdb, grb, or grdb is in “structures” item; no entry, graded beds

are absent.

dewatering_structures 1, dewatering structures (includes water-release structures) if wrs or water release is in “structures” item; no entry, dewatering structures are absent.

comments Additional comments about interval.

thickness Calculated true thickness of the sample interval (in feet). Thickness  (to 
 from,

or to_corr 
 from_corr if a correction was needed).

app_thick Thickness (in feet) of a stratigraphic interval, measured parallel to the core axis of

a diamond-drill hole. Not yet corrected to the true stratigraphic thickness for

diamond-drill holes.

Item

name Definition

gray_beds 1, gray if cream, orange, buff, yellow, and brown is in “color” item; or, if no entry

and “lithology” value is attributed with a rock type, then gray is the attributed

color. No entry, color is not one of these colors.

black_beds 1, black if black is in “color” item; no entry, color is not black.

lavender_beds 1, lavender if lavender, pink, red, or maroon is in “color” item; no entry, color is

not lavender.

vitreous 1, vitreous or subvitreous if luster of rocks is described as such; no entry, luster is

nonvitreous (not described)

spreadsheet columns describes the relative amount of a mineral: 

abundant=“3”, present=“2”, and trace=“1”. The data on logs did 

not permit a precise estimation of mineral proportions.

Thickness and Other Corrections

After data entry was completed, a correction was made in 

the spreadsheet to the depth intervals of the diamond-drill-hole 

data to account for inclination of strata with respect to the core 

axis of the hole. Thickness intervals of measured sections are 

always recorded in feet of true thickness, and so no thickness 

correction was necessary.

Table 9. Definitions of item names in the lithology worksheet—Continued

44  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
from_corr to_corr lithology grain_size Thickness

(ft)

687.0 690.6 sa 1.5 3.6

690.6 695.1 s 2 4.5

695.1 698.8 s 2 3.6

676.1 680.6 sq 3 4.5

670.7 676.1 q 5 5.4

680.6 683.4 q 5 2.7

683.4 685.2 q 5 1.8

685.2 687.0 q 5 1.8

698.8 703.3 s 2

Sand isolith---------------------------------------

4.5

11.8

Table 10. Example of spreadsheet calculation of sand isolith

[Bold, data from spreadsheet; bold italic, grain-size data used to sort data in 

columns 1 to 4 of spreadsheet in ascending order; roman, temporary column 

of data containing thickness calculated using from_corr and to_corr. Lithologies: q, quartzite; s, siltite; sa, silt-argillite; sq, silty quartzite. Gray-shaded 

area, sand isolith calculated from thickness of cells above with grain_size=5]

A correction was also applied so that the footage is 

always reported as increasing with stratigraphic depth. 

Measured-section data collected in the downsection direction 

required no correction; however, depth intervals of diamonddrill holes or measured sections logged in the upsection direction were inverted for display in the downsection direction. 

The inversion was done by subtracting the deepest interval 

from depths (“from”, “to”) on each row of the spreadsheet.

The White Pine Creek 2, 3, 4 measured section is unusual 

because data are recorded in five parts, with sections measured 

in both “up” and “down” directions (fig. 19) consisting of 

2, 2a, 3, 3a, and 4. Each part was corrected individually and 

then combined. White Pine Creek 4 required no correction, 

but White Pine Creek 3 had to be corrected by inverting the 

data. If no correction was needed in the spreadsheet, the top 

and bottom of the intervals are shown as “from” and “to”. If a 

correction was needed in the spreadsheet, the from-to intervals 

of the downsection direction are shown in the “from_corr” and 

“to_corr” columns.

Entry of diamond-drill-hole data, such as for diamonddrill hole VR–4 (fig. 20), differs somewhat from that of a 

measured section. In diamond-drill hole VR–4 and others, 

the bedding orientation of the strata relative to the core 

axis must be considered to correct apparent thickness to 

true thickness. For diamond-drill hole VR–4, the average 

angle is 45o(15). A correction for the average core angle for 

entire diamond-drill core was applied to each from-to depth 

interval (row) in the worksheet for cores to estimate the true 

thickness of the strata. Diamond-drill hole VR–4 was logged 

in the “up” direction because of overturned strata, and so 

a correction was made for diamond-drill-hole inclination, 

followed by inversion of the overturned strata to obtain true 

thickness and orientation of strata. The true stratigraphic 

thickness in proper orientation is listed in the spreadsheets in 

the “from_corr” and “to_corr” columns.

Revett-Subtype Stratabound CopperSilver Deposits, Occurrences, and 

Prospects

Exploration of the Revett Formation has disclosed copper-silver deposits, occurrences, or prospects at 57 sites in the 

study area (pl. 1; fig. 1). Deposits, occurrences, and prospects 

containing disseminated copper and silver (±lead) in rocks of 

the Revett Formation are shown on plate 1 and listed in table 

1. They exhibit characteristics of the Revett-subtype deposit 

model (Cox and others, 2003). Most sites were recognized 

previously (Lange and Sherry, 1983; Spanski, 1992); the 

accompanying tab-delimited text file cuag_deposit.txt provides added details. A total of 4 of these sites have recorded 

production, 12 have identified resources, and 30 have mineralized domains (see next section). Deposits are sites containing 

identified resources of stratabound copper. An occurrence is a 

site containing small amounts of stratabound copper. Prospects 

are explored sites with characteristics that have not been confirmed to be Revett-subtype deposits but are recorded because 

of their historical value.

The tab-delimited text file cuag_deposit.txt contains more 

than 55 data fields describing each of the 57 sites, including 

location (legal land description and latitude-longitude coordinates), county, State, mining district, references, exploration 

history, nature and stratigraphic position of mineralization, 

nature of alteration and host horizon, local structures present, 

production history, and resources. The data structure of fields 

in the file cuag_deposit.txt is explained in table 12.

Spatial Databases

Between 1977 and 1984, Larry Appelgate and other 

Asarco Inc. geologists explored for stratabound copper-silver 

mineralization associated with the Revett Formation in northern Idaho and western Montana. Some results of their work 

were compiled on 11 topographic base maps at 1:48,000 scale 

and on 2 maps at 1:12,000 scale that were assembled on photographically produced scale-stable media of 71⁄2- or 15-minute 

USGS quadrangle maps. Paper versions of these maps printed 

from scale-stable media were hand-colored, scanned, georeferenced for GIS use and published separately as 13 raster (tiff) 

images (Boleneus and others, 2001a).

Selected features from copies of these maps were converted into ArcInfo coverages by the USGS and include the 

datasets rev48k (geology of the Revett Formation), rev_ddh 

(location of diamond-drill cores), rev_msec (location of 

measured sections), and rev_cuag (copper-silver mineralized domains, unexplored areas, and permissive tracts). New 

or interpreted data added to complete the databases include 

domain type and mineralized unit (rev_cuag) and mineralized 

outcrops and the nature of fault contacts (rev48k). New information and interpretations were used to create spatial dataDatabases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  45
Item

name Definition

section Name of the measured section or drill hole. Drill holes have “DDH” as the first three letters in the name.

section_logged For measured sections, if the item is attributed, then the measured section is a composite of

multiple segments. The attribute is the name of the various measured sections used to

make the composite. For diamond-drill holes, the attribute is the name of an extended area

where several diamond-drill holes are located, for example, Spar Lake, Rock Creek.

orientation Direction in which the section was measured, for example, upsection stratigraphically or

downsection stratigraphically. “no data,” data unavailable for the section.

from Depth (in feet) measured at the beginning of a stratigraphic interval for diamond-drill holes

and measured sections in the stratigraphic down direction. “no data,” data unavailable for

the section. This item is attributed for diamond-drill holes and measured sections only

where no correction is needed (they are already in stratigraphic down direction, and holes were drilled at an angle not requiring a correction) so that the “from_corr” value (item

name) will not be attributed.

to Depth (in feet) measured at the end of a stratigraphic interval for diamond-drill holes and

measured sections in the stratigraphic down direction. “no data,” data unavailable for the

section. This item is attributed for diamond-drill holes and measured sections only where

no correction is needed (they are already in stratigraphic down direction, and holes were drilled at an angle not requiring a correction) so that the “to_corr” value (item name) will

not be attributed.

ave_core_angle Average angle (in degrees) of the bedding inclination, measured from the core axis. A value

of 
90o means that strata are horizontal perpendicular to the core axis. “no data,” data unavailable for the section.

from_corr Depth (in feet) measured at the beginning of a stratigraphic interval for diamond-drill holes

and measured sections in the stratigraphic down direction. “no data,” data unavailable for

the section. This item is attributed for diamond-drill holes and measured sections only

where no correction is needed (they are already in stratigraphic down direction, and holes were drilled at an angle not requiring a correction) so that the “from_corr” value (item

name) will not be attributed.

to_corr Depth (in feet) measured at the end of a stratigraphic interval for diamond-drill holes and

measured sections in the stratigraphic down direction. “no data,” data unavailable for the

section. This item is attributed for diamond-drill holes and measured sections only where

no correction is needed (they are already in stratigraphic down direction, and holes were drilled at an angle not requiring a correction) so that the “to_corr” value (item name) will

not be attributed.

py-cube Numeric value indicating relative rank (amount) of pyrite with a non-framboidal habit

(higher numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no

data,” information not provided.

py-fram Numeric value indicating relative rank (amount) of pyrite with a framboidal, clustered,

balled, or clotted habit (higher numbers indicate more): 3, abundant; 2, moderate; 1, trace;

no entry, “0”, or “no data,” information not provided.

pyrrhotite Numeric value indicating relative rank (amount) of pyrrhotite (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

galena Numeric value indicating relative rank (amount) of galena (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

chalcopyrite Numeric value indicating relative rank (amount) of chalcopyrite (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not pro- vided.

bornite Numeric value indicating relative rank (amount) of bornite (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

magnetite Numeric value indicating relative rank (amount) of magnetite (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided. hematite Numeric value indicating relative rank (amount) of hematite (including specularite) (higher

numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

leucoxene Numeric value indicating relative rank (amount) of leucoxene (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not pro- vided.

mnox Numeric value indicating relative rank (amount) of MnO2 (including dendrites) (higher

numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

calcite Numeric value indicating relative rank (amount) of calcite with disseminated habit (higher

numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

calcite_bedform Numeric value indicating relative rank (amount) of calcite with bedform habit (higher numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

dolomite Numeric value indicating relative rank (amount) of dolomite (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

ankerite Numeric value indicating relative rank (amount) of ankerite (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

Table 11. Definition of item names in the mineralogy worksheet

46  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
feldspar Numeric value indicating relative rank (amount) of feldspar (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

chlorite Numeric value indicating relative rank (amount) of chlorite (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

biotite Numeric value indicating relative rank (amount) of biotite (higher numbers indicate more):

3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided. cuox Numeric value indicating relative rank (amount) of Cu oxide (higher numbers indicate

more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

feox Numeric value indicating relative rank (amount) of Fe oxide as limonite (higher numbers

indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no data,” information

not provided.

banding Numeric value indicating relative rank (amount) of color banding or liesegang banding

(higher numbers indicate more): 3, abundant; 2, moderate; 1, trace; no entry, “0”, or “no

data,” information not provided.

comments Additional comments about the interval.

orange/brown_spots Numeric value indicating relative rank (amount) of unidentified orange/brown spots (higher

numbers indicate more) suspected to be dolomite, ferroan calcite, or ankerite: 3, abundant;

2, moderate; 1, trace; no entry, “0”, or “no data,” information not provided.

thickness Calculated true thickness (in feet) of the sample interval. Thickness  (to 
 from, or to_corr


 from_corr if a correction was needed). app_thick Thickness (in feet) of a stratigraphic interval, measured parallel to the core axis of a diamond-drill hole. Not yet corrected to true stratigraphic thickness for diamond-drill holes.

Item

name Definition

Table 11. Definition of item names in the mineralogy worksheet—Continued

bases of mineral zones in the A–D beds of the lower member 

of the Revett Formation (lrevzone) and in the middle quartzite 

of the upper member of the Revett Formation (urevzone). The 

UTM zone 11 coordinate system is used to represent the geographic features in all the spatial datasets. The overall accuracy (with respect to the location of lines and points) of spatial 

databases ranges from 72 to 192 m when comparing the digital 

data with the locations shown on USGS raster topographic 

maps. Refer to metadata for the accuracy of each dataset. 

These digital databases are not meant for use or display at a 

scale larger than 1:48,000 (for example, 1:24,000 or 1:12,000).

Geologic Databases

The geologic dataset, rev48k, consists of two parts: (1) 

geology of the Revett and other formations and (2) outcrops 

of the upper and lower members of the Revett Formation 

containing disseminated copper-silver mineralization (pl. 1). 

The geologic dataset is based on the exploration mapping conducted by Asarco Inc. (Boleneus and others, 2001a). Polygons 

in the ArcInfo coverage rev48k show the extent of the Revett 

Formation and parts of the underlying Burke and overlying 

St. Regis and Wallace Formations. The lower, middle, and 

upper members of the Revett Formations are shown if they 

were located during field mapping; however, these rocks crop 

out over less than 10 percent of the study area (pl. 1; fig. 1), 

a factor that limited field identification of stratigraphic units. 

Arcs in the coverage rev48k indicate whether the boundaries 

between polygons are contacts, faults, or scratch boundaries.

The surface trace of outcropping strata with disseminated copper-silver mineralization shown on the maps 

compiled by one of the authors (L.M. Appelgate) and others 

at Asarco Inc. are represented as arcs (lines) in the ArcInfo 

coverage rev48k. The trace of copper-bearing horizons can 

be followed continuously for distances ranging from several 

hundred feet to several tens of thousands of feet. Outcrops 

of mineralized horizons are scattered widely throughout the 

western Montana copper belt but are particularly common in 

the upper and lower members of the Revett Formation near 

the Troy and Rock Creek deposits. The mineralized outcrops 

are weathered and characterized by Cu oxides consisting of 

light-green to light-blue blooms (or disseminations), or heavy 

Fe oxide coatings along fractures and rock surfaces. The trace 

of outcrops with visible disseminated copper (Cu oxide or 

sulfide) in the Revett Formation, referred to as mineralized 

outcrop on plate 1, commonly are associated with identified 

resources or mineralized domains and, in some places, oregrade copper mineralization.

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  47
Item name Description of field

No Number designation.

Site name Name of the site. Abbrev Abbreviation of site name.

Project name Other project name used.

Other names Alternate names.

MILS number Mineral Industry Location System number.

MRDS number Mineral Resources Data System number.

District name Mining-district name.

County County name.

State State name.

Quad 250K Name of 1:250,000-scale quadrangle.

Township Township number and direction for site.

Range Range number and direction for site.

Section Sections to locate site.

Latitude Latitude (in degrees, yy.zzzz).

Longitude Longitude (in degrees, 
xxx.zzzz).

TRSMER_ST Concatenated form of township, range, section, and State for site. Location comments Comments concerning location of the site.

Size Type of property described (large, medium, small, occurrence); Revettsubtype stratabound mineralization has not been established to occur

at sites labeled “prospects.”

Ore minerals Ore minerals present.

Gangue minerals Gangue minerals present. Degree of supergene oxidation Degree of supergene oxidation.

Major commodities List of major commodities.

Minor commodities List of minor commodities.

Reference 1 First reference.

Reference 2 Second reference.

Reference 3 Third reference.

Deposit type Type of mineral deposit.

Form and shape Form and shape of mineral deposit.

Thickness of mineralized

interval

Thickness of interval.

Grade of mineralized interval Grade of mineralized interval.

Alteration Alteration of interval.

Significant local structure Significant local structure affecting stratabound deposits.

Ore control Ore controls affecting stratabound deposits.

Host rock unit Host rock within the Revett Formation. Stratigraphic sub-unit hosting

mineralization

Stratigraphic unit within the Revett Formation.

Host-rock type Host-rock type.

Discovery year Year of discovery.

Nature of discovery Nature of discovery methods used.

Exploration and development

history

Chronology of exploration and development.

Geochemistry Geochemistry methods used in exploration.

Geophysics Geophysics methods used in exploration.

Drilling and trenching Drilling and trenching used in exploration.

Description of mine workings Description of mine workings.

Production dates Production dates.

Production,short tons Amount of production.

Production Silver, troy ounces Silver grade of production.

Copper production lbs Copper grade of production. PRODUCTION-reference Reference for production data.

Resource short tons Resources of stratabound mineralization known.

RESOURCE-Grade Ag troy Silver grade of resources. ounces/short ton

RESOURCE-Grade Cu (%) Copper grade of resources.

RESOURCE-References Reference for resources.

Comments Comments.

Owner or operator Owner or operator of the site.

Table 12. Definition of item names in the file cuag_deposit.txt

[File contains geologic data on mines, mineral deposits, occurrences, and prospects of stratabound copper-silver deposits in the 

Revett Formation (Mesoproterozoic) in the western part of the Belt Basin, western Montana and northern Idaho]

48  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Documentation for the ArcInfo Coverage rev48k.e00

Linear Features

REV48K.AAT

Descriptions of the user-defined items identifying linear features, such as contacts, boundaries (for example, map 

boundaries), and structures in the arc (or line)-attribute table, REV48K.AAT, are as follows:

REV48K.AAT

ITEM NAME ATTRIBUTE DESCRIPTION

linecode Number used by the USGS to manage attribute information on lines.

Linecodes <100 are used for contacts and boundaries

Linecodes >100 and <600 represent structural features.

Linecodes >800 represent linear geologic units.

str_name Name of fault. 

source Number used to identify the data source for the linear features. See the lookup table REV48K.REF for complete 

reference.

line_type1 General classification of the linear features.

line_type2 Qualified classification of the linear features.

line_type3 Complete description of the linear features, which may also include a description of the line pattern.

0Areal Features

REV48K.PAT

Descriptions of the user-defined items identifying geologic units in the polygon-attribute table, REV48K.PAT, are as follows:

REV48K.PAT

ITEM NAME ATTRIBUTE DESCRIPTION

unit Number used by the USGS to manage attribute information for each rock unit.

source Number used to identify the data source for the unit. See the lookup table REV48K.REF for complete reference.

label-alpha Map symbol, represented by alpha characters, used to label map units. 

unit_name Formal or informal map unit name.

lith Major type of lithostratigraphic unit, for example, metasedimentary rocks, intrusive rocks.

minage Minimum stratigraphic age of the unit.

maxage Maximum stratigraphic age of the unit.

Source Attributes

REV48K.REF

Source or reference information for the REV48K ArcInfo dataset is stored in the REV48K.REF file. Attribute descriptions 

for items in this file are as follows:

REV48K.REF

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source. (This is the keyfield that relates to the REV48K.AAT and REV48K.PAT files.)

scale Scale of source map, given as the denominator of the proportional fraction.

authors Names of author(s), entered as last name, first name or initial, and middle initial.

year Source (map) publication date.

reference1 The first 250 characters of the reference in USGS reference format.

reference2 The second set of 250 characters of the reference in USGS reference format. 

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation 49
Measured-Section and Diamond-Drill-Core Datasets

The spatial dataset for measured sections, rev_msec, is an ArcInfo coverage in which arcs represent the traverse lines for 

the measured sections. The spatial dataset for diamond-drill cores, rev_ddh, is an ArcInfo point coverage showing the collar 

locations of the drillsites (pl. 1). All diamond-drill cores or measured sections occur at a single site or traverse line, respectively. 

Measured sections were assembled from observations on a series of outcrops occurring along a traverse line, a few of which 

were assembled from two or more separate traverses that recorded a series of continuous strata.

Documentation for the ArcInfo Coverage rev_ddh.e00

Point Features

REV_DDH.PAT

Descriptions of the items identifying diamond-drill holes and one measured section are given in the point-attribute table, 

REV_DDH.PAT, which is defined as follows:

REV_DDH.PAT 

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source for the diamond-drill holes. See the lookup table REV_DDH.REF for complete reference.

name Name of drill hole. One measured section, Kellogg, is included because it incorporated diamond-drill-core information. 

The composite measured section contained in this coverage, Kellogg, consists of stratigraphic data assembled from a 

combination of diamond-drill cores and underground and surface measured sections. Data from the upper part of the Revett 

Formation were assembled from diamond-drill cores and measured sections at the Bunker Hill Mine; data for the middle part 

of the Revett Formation were assembled from a measured section at a rock quarry in Big Creek; and data from the lower Revett 

Formation were assembled from a measured section north of the quarry (above) in Big Creek (B.G. White, written commun., 

2003). This third section contains about 3,700 ft of the upper, middle, and lower members of the Revett Formation. The section 

starts in the lower member of the Revett Formation and continues into the overlying St. Regis Formation. The lower member of 

the Revett Formation is 1,600 ft thick but is incomplete.

Source Attributes

REV_DDH.REF

Source or reference information for the REV_DDH ArcInfo dataset is stored in the REV_DDH.REF file. Attribute descriptions for items in the REV_DDH.REF data-source file are as follows:

REV_DDH.REF

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source. (This is the keyfield that relates to the REV_DDH.PAT file.)

scale Scale of source map, given as the denominator of the proportional fraction.

authors Names of author(s), entered as last name, first name or initial, and middle initial.

year Source (map) publication date.

reference1 The first 250 characters of the reference in USGS reference format.

reference2 The second set of 250 characters of the reference in USGS reference format. 

50 Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Documentation for the ArcInfo Coverage rev_msec.e00

Linear Features

REV_MSEC.AAT

Descriptions of the items identifying linear features, such as measured sections (trace of the outcrops examined) in the arc 

(or line)-attribute table, REV_MSEC.AAT, are as follows:

REV_MSEC.AAT

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source for the measured section. See the lookup table REV_MSEC.REF for complete reference.

msec_name Name of measured section. 

Source Attributes

REV_MSEC.REF

Source or reference information for the REV_MSEC ArcInfo dataset is stored in the REV_MSEC.REF file. Attribute 

descriptions for items in the REV_MSEC.REF data-source file are as follows:

REV_MSEC.REF

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source. (This is the keyfield that relates to the REV_MSEC.AAT file.)

scale Scale of source map, given as the denominator of the proportional fraction.

authors Names of author(s), entered as last name, first name or initial, and middle initial.

year Source (map) publication date.

reference1 The first 250 characters of the reference in USGS reference format.

reference2 The second set of 250 characters of the reference in USGS reference format. 

Mineral-Zone Datasets

The mineral-zone datasets, lrevzone and urevzone, show the geographic extent of mineral zones in the lower A–D beds of 

the lower member of the Revett Formation and in the middle quartzite of the upper member of the Revett Formation, respectively. They show the interpreted area of three mineral zones: chalcopyrite-ankerite (CP–ANK), pyrite-calcite (PY–CAL), and 

lavender (LAV). The boundary between the PY–CAL and CP–ANK zones is the locus of mineralization in the Revett Formation. 

The nature of these zones was defined by Hayes (1983, 1990) and Hayes and Einaudi (1986). The locations of mineral zones 

were individually determined during analysis of other data for both the lower member of the Revett Formation, the A–D beds 

(lrevzone) (fig. 16), and the middle quartzite of the upper member of the Revett Formation (urevzone) (fig. 17).

Documentation for the ArcInfo Coverages lrevzone.e00 and urevzone.e00

Linear Features

LREVZONE.AAT and UREVZONE.AAT

Descriptions of the items identifying mineral-zone boundaries with respect to the lower member of the Revett Formation in 

the arc-attribute table, LREVZONE.AAT, and descriptions of the items identifying mineral-zone boundaries with respect to the 

upper member of the Revett Formation in the arc-attribute table, UREVZONE.AAT, are as follows:

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  51
LREVZONE.AAT and UREVZONE.AAT

ITEM NAME ATTRIBUTE DESCRIPTION

type Linear features that form the boundaries between areas characterized by a mineral zone. The chalcopyrite-ankerite/

lavender (CP–ANK/LAV boundary) linear feature is the boundary between the chalcopyrite-ankerite and lavender 

zones. Likewise, the pyrite-calcite/chalcopyrite-ankerite (PY–CAL/CP–ANK boundary) linear feature is the boundary between the chalcopyrite-ankerite and pyrite-calcite zones as defined by Hayes and Einaudi (1986).

fault: A line corresponding to a known fault.

scratch: A boundary that indicates either (1) a limit of data, (2) extent of study area, or (3) a contact estimated by the 

USGS from existing data.

CP–ANK/LAV: Boundary between chalcopyrite-ankerite and lavender zones.

PY–CAL/CP–ANK: Boundary between pyrite-calcite and chalcopyrite-ankerite zones.

accuracy Line-type modifier indicating degree of accuracy, for example, known, indicated, inferred. No entry indicates accuracy 

not needed for type of line. (For all records where accuracy is blank, type=“scratch”.)

source Number used to identify the data source for the mineral-zone boundaries. See the lookup tables LREVZONE.REF or 

UREVZONE.REF for complete reference.

Areal Features

LREVZONE.PAT and UREVZONE.PAT

Descriptions of the items identifying mineral zones within the lower member of the Revett Formation in the polygon-attribute table, LREVZONE.PAT, and descriptions of the items identifying mineral zones in the middle quartzite bed of the upper 

member of the Revett Formation in the polygon-attribute table, UREVZONE.PAT, are as follows:

LREVZONE.PAT and UREVZONE.PAT

ITEM NAME ATTRIBUTE DESCRIPTION

alter_zone Mineral zone in which alteration occurs. The chalcopyrite-ankerite (CP–ANK), pyrite-calcite (PY–CAL), and lavender 

(LAV) zones are defined by Hayes and Einaudi (1986) from work at the Troy deposit. The mineral zones define a 

volume of rock in which this alteration-mineral assemblage dominates.

CP–ANK: Indicates presence of the CP–ANK zone (Hayes, 1983; Hayes and Einaudi, 1986).

LAV: Indicates presence of the LAV zone (Hayes, 1983; Hayes and Einaudi, 1986).

PY–CAL: Indicates presence of the PY–CAL zone.

source Number used to identify the data source identifying mineral-zone areas. See the lookup tables LREVZONE.REF or 

UREVZONE.REF for complete reference.

Source Attributes

LREVZONE.REF and UREVZONE.REF

Source or reference information for the LREVZONE and UREVZONE ArcInfo datasets is stored in the LREVZONE.REF 

or UREVZONE.REF files. Attribute descriptions for items in the LREVZONE.REF or UREVZONE.REF data-source file are as 

follows:

LREVZONE.REF and UREVZONE.REF

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source. (This is the keyfield that relates to the LREVZONE.AAT and LREVZONE.PAT 

or the UREVZONE.AAT and UREVZONE.PAT files.)

scale Scale of source map, given as the denominator of the proportional fraction.

authors Names of author(s), entered as last name, first name or initial, and middle initial.

year Source (map) publication date.

reference1 The first 250 characters of the reference in USGS reference format.

reference2 The second set of 250 characters of the reference in USGS reference format. 

52  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Copper-Silver-Mineralized-Domain, UntestedExploration-Area, and Permissive-Tract Dataset

The copper-silver mineralized-domain dataset, rev_cuag, 

contains three types of data: mineralized domain, untested 

exploration area, and permissive tracts.

Mineralized Domains

Mineralized domains (pl. 1) are the areas underlain by 

stratabound copper-silver mineralization that are delimited by 

surface exposures and diamond-drill-hole information. Mineralized domains occur at 30 of the 57 sites listed in table 1. 

Mineralized domains are divided for the purposes of this report 

into three categories: identified resources, indicated mineralized rock, and inferred mineralized rock. These categories are 

partly based on the U.S. Bureau of Mines (USBM) and USGS 

mineral-resource classification (U.S. Geological Survey, 1980).

Identified resources of copper-silver are concentrations of 

earth materials whose economic extraction is potentially feasible on the basis of location, tonnage, and copper-silver grade. 

Identified copper-silver resources occur at 12 sites, including 

Troy, Rock Creek, Rock Lake (Montanore), Rock Peak, Copper 

Gulch, and Horizon Basin. Indicated mineralized rock is used 

in this report rather than the term “indicated resources” of the 

USBM and USGS (U.S. Geological Survey, 1980; Long and 

others, 1998). This category is copper-silver-mineralized rock 

determined by visual examination of diamond-drill core or 

outcrop and, locally, assay but for which grade and tonnage of 

deposits are absent. Inferred mineralized rock is used here rather 

Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  53

than the term “inferred resources” of the USBM and USGS 

(USGS, 1980; Long and others, 1998). Inferred mineralized 

rock means that mineralized bodies are assumed to exist beyond 

areas of identified resources or indicated mineralized rock on 

the basis of geologic evidence favorable for the presence of ore 

deposits. Areas of inferred mineralized rock may or may not be 

supported by samples or measurements.

The color shading on plate 1 (see figs. 8, 15, 17, 18) 

denotes the mineralized-domain limits. The member of the 

Revett Formation containing the mineralized domain identified 

on plate 1 is further defined in the rev_cuag dataset, the file 

cuag_deposit.txt, and table 1. Boundaries of identified resource 

areas (T. Henricksen, written commun., 1998; Hayes and others, 

1989; U.S. Forest Service, 1993, 1995, 2001) may be indefinite 

or gradational because they depend on varying factors, such as 

metal prices and mining costs.

Untested Exploration Area and Permissive Tracts

The untested exploration area represents surface and 

subsurface areas of the Revett Formation to a depth of 8,000 

ft (pl. 3). The subsurface extent of the Revett Formation was 

estimated from the extent of surface outcrops (Boleneus and 

others, 2001a), from the amount of dip of strata of the Revett 

Formation, and from the presence of known or inferred faults 

that could truncate the formation at depth.

The mineral-resource assessment described earlier in 

this report defined permissive and nonpermissive tracts on 

the basis of an analysis of the untested-exploration-area and 

mineral-zone datasets.
Documentation for the ArcInfo Coverage rev_cuag.e00

Areal Features

REV_CUAG.PAT

Descriptions of the items identifying copper-silver mineralized domains (with respect to the Revett Formation) in the polygon-attribute table, REV_CUAG.PAT, are as follows:

REV_CUAG.PAT

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source for the areal extent of the mineralized domain. See the lookup table

REV_CUAG.REF for complete reference.

asses_rank Mineral-resource-assessment rank with respect to undiscovered copper deposits in the Revett Formation (stratabound copper-silver deposits or occurrences in the Revett Formation):

not evaluated: Area not evaluated.

non-permissive: Domains in which undiscovered copper deposits in the Revett Formation cannot occur (based on 

not fitting the criteria listed below for “permissive”).

permissive: Domains in which undiscovered copper deposits in the Revett Formation may occur. A permissive domain must contain the Revett Formation, either at the surface or at depth (where dom_type=untested exploration 

area, AND it must either (1) contain alteration characteristics that suggest proximity to copper deposits in the 

Revett Formation OR (2) occur at or near identified copper-silver resources or copper-silver-mineralized rock 

(where dom_type=“identified resource”, “mineralized rock—indicated”, or “mineralized rock—inferred”).

dom_name Revett Formation mineralized domain name (for example, Chipmunk, Missoula-National, Rock Creek West). A 

mineralized domain is the known surface and subsurface extent of identified resources or mineralized rock.

No entry indicates no name. (For all records where dom_name is blank, dom_type=“untested exploration area” or 

“unknown”.)

dom_type Type of mineralized domain:

unknown: Area was not evaluated.

identified resource: A concentration of copper-silver minerals in the Revett Formation in such a form and amount 

that economic extraction from the concentration is currently or potentially feasible AND whose location, quality, and quantity are known or estimated from specific geologic evidence (see Long and others, 1998, p. 33, for 

complete definitions of “resource” and “identified resources”). Delineation of these identified resources is based 

on published data (Adkins, 1993; Boleneus and others, 2001a; U.S. Forest Service, written commun., 2001); 

however, data were insufficient to determine whether the identified resource could be more specifically classified as measured, indicated, or inferred according to the USGS mineral-resource-classification system of Long 

and others (1998).

mineralized rock—indicated: Substantial copper-silver-mineralized rock in the Revett Formation, as indicated from 

physical evidence, such as diamond-drill core or outcrop. Overburden and grade were also taken into consideration but were not quantified. The low grade, a lack of continuity of the mineralized rock OR lack of data 

precluded an identified resource designation.

mineralized rock—inferred: Believed to contain copper-silver-mineralized rock in the Revett Formation, on the 

basis of geologic inference. The low grade AND/OR lack of continuity of the mineralized rock AND/OR lack of 

data precluded an identified resource designation.

untested exploration area: Area believed to warrant further exploration. These areas are underlain by the Revett 

Formation to a depth of 8,000 ft or less, and they do not include areas designated as identified resource, mineralized rock—indicated, or mineralized rock—inferred.

min_unit Stratigraphic unit(s) in which identified copper-silver resources or copper-silver-mineralized rock occurs, on the 

basis of lithologic descriptions from diamond-drill cores logs and/or measured sections and/or other data:

both upper and lower Revett: Identified copper-silver resources or mineralized rock occurs in both the upper and 

lower members of the Revett Formation.

lower Revett: Identified copper-silver resources or mineralized rock occurs in the lower member of the Revett 

Formation.

upper Revett: Identified copper-silver resources or mineralized rock occurs in the upper member of the Revett 

Formation.

No entry indicates that min_unit is unknown. (For all records where min_unit is blank, dom_type=“untested exploration area” or “unknown”.)

Also, attributes for “min_unit” may be more detailed than those for the “desc” item in the REV48K.PAT file. 

54  Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho
Databases and Spatial-Data Files for the Geology and Mineral Deposits of the Revett Formation  55

REV_CUAG.REF

ITEM NAME ATTRIBUTE DESCRIPTION

source Number used to identify the data source. (This is the keyfield that relates to the REV_CUAG.PAT file.)

scale Scale of source map, given as the denominator of the proportional fraction.

authors Names of author(s), entered as last name, first name or initial, and middle initial.

year Source (map) publication date.

reference1 The first 250 characters of the reference in USGS reference format.

reference2 The second set of 250 characters of the reference in USGS reference format. 

Source Attributes

REV_CUAG.REF

Source or reference information for the REV_CUAG ArcInfo dataset is stored in the REV_CUAG.REF file. Attribute 

descriptions for items in the REV_CUAG.REF data-source file are as follows:

How to Obtain Data

To obtain copies of the digital data, download the digital 

files from the USGS public-access Web site at URL http://

pubs.usgs.gov/sir/2005/5231/, which contains the spatial 

digital databases and metadata for diamond-drill-core, measured-section, geologic, resource, and mineral-zone maps of the 

Revett Formation as ArcInfo interchange-format files (see app. 

A). Formatted metadata (Federal Geographic Data Committee 

compliant) are included in this report.

Acknowledgments

Drill-core-log and measured-section data were donated 

by Asarco Inc. and the Kennecott Exploration Co. Asarco Inc. 

also provided geologic maps of the study area (pl. 1; fig. 1). 

Geologic data were collected from 1960 to 1993 by geologists 

of Asarco Inc., the Bear Creek Mining Co., the U.S. Borax 

and Chemical Co., and the Kennecott Exploration Co. We 

thank G.D. Van Voorhis, vice president, David K. Young, Troy 

Mine unit manager, and John Balla, exploration manager, of 

Asarco Inc.; and Geoff Ballantyne, exploration manager, and 

Jay Hammitt, geologist, of the Kennecott Exploration Co. for 

donating data critical to this study. Larry Appelgate and Nancy 

Joseph collected the data for most measured sections and completed geologic mapping while employed by Asarco Inc. Larry 

Appelgate and Jeremy C. Larsen assisted in measuring five 

additional stratigraphic sections. Many unnamed geologists 

also contributed to section measuring and core logging. Brian 

G. White of the National Institute of Occupational Safety and 

Health’s Spokane Research Center provided insights into our 

study, as well as additional measured-section data. Derrick 

Chase, assisted by Tracy Rehwald and Jeremy C. Larsen, 

students in Eastern Washington University’s Department of 

Geology, completed the data entry for most of the geologic 

logs. Kenneth Assmus, Steven Munts, and Bill Kelley of ISS 

Inc. digitized and assembled other digital data and assisted in 

preparing the illustrations. Craig Horlacher prepared several 

graphic logs and provided advice on the Interdex and CoreView software used in our study. Reviews by Art Bookstrom, 

Karen Bolm, Pamela Derkey, Mike Diggles, Karl Evans, 

Tom Frost, George Havach, Timothy Hayes, Barry Moring, 

Peter Vikre, and Jan Zigler, all of the U.S. Geological Survey, 

and by Terry Close, formerly of the U.S. Bureau of Mines, 

improved the manuscript and illustrations and the presentation 

of the databases.

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Appendix A  59

Appendix A. Graphical Logs of Measured Sections and Diamond-Drill Cores

Figure A–34. DDH SN–5 (Snake Creek) diamond-drill-hole 

section

Figure A–35. East Fork of Bull River 1, 2, 3 measured section

Figure A–36. DDH SN–1 (Snake Creek) diamond-drill-hole 

section

Figure A–37. DDH SN–4 (Snake Creek) diamond-drill-hole 

section

Figure A–38. DDH SN–3 (Snake Creek) diamond-drill-hole 

section

Figure A–39. Goat Rocks (lower) measured section

Figure A–40. DDH RC–58 (Rock Creek) diamond-drill-hole 

section

Figure A–41. DDH RC–49 (Rock Creek) diamond-drill-hole 

section

Figure A–42. DDH RC–47 (Rock Creek) diamond-drill-hole 

section

Figure A–43. DDH RC–43 (Rock Creek) diamond-drill-hole 

section

Figure A–44. Chicago Peak (White) measured section

Figure A–45. Rock Creek (East Fork) measured section

Figure A–46. DDH HF–1 (Hereford) diamond-drill-hole section

Figure A–47. McKay Creek (White) measured section

Figure A–48. McKay Creek North measured section

Figure A–49. McKay Creek South measured section

Figure A–50. Green Mountain measured section

Figure A–51. Waloven Creek (lower) measured section

Figure A–52. Waloven Creek (upper) measured section

Figure A–53. Sims Creek (west slope) measured section

Figure A–54. Sims Creek 1, 2 (east slope) measured section

Figure A–55. Miners Gulch (Vermilion River) measured section

Figure A–56. DDH VR–11 (Vermilion River) diamond-drillhole section

Figure A–57. DDH VR–4 (Vermilion River) diamond-drillhole section

Figure A–58. Rush Lake measured section

Figure A–59. Vermilion River (White) measured section

Figure A–60. Slide Rock Mountain measured section

Figure A–61. Deep Creek measured section

Figure A–62. Graves Peak measured section

Figure A–63. Graves Creek Falls measured section

Figure A–64. Thompson River measured section

Figure A–65. DDH TC–9 (Trout Creek) diamond-drill-hole 

section

Figure A–66. DDH TC–8 (Trout Creek) diamond-drill-hole 

section

Figure A–67. DDH TC–10 (Trout Creek) diamond-drill-hole section

Figure A–68. Trout Creek 1, 2 measured section

Figure A–69. DDH TC–7A (Trout Creek) diamond-drill-hole section

Figure A–70. Trout Creek (White) measured section

Figure A–1. Obemeyer Mountain measured section

Figure A–2. Wee Lake 1, 2 measured section

Figure A–3. Gunsight Mountain measured section

Figure A–4. Kilbrennan Creek measured section

Figure A–5. Horseshoe Lake measured section

Figure A–6. Granite Creek measured section

Figure A–7. DDH FC–4 (Fairway Creek) diamond-drill-hole 

section

Figure A–8. Stanley Peak measured section

Figure A–9. DDH SL–130 (Spar Lake) diamond-drill-hole 

section

Figure A–10. DDH HC–4 (Hiatt Creek) diamond-drill-hole 

section

Figure A–11. DDH SL–136 (Spar Lake) diamond-drill-hole 

section

Figure A–12. DDH CC–1 (Cub Creek) diamond-drill-hole 

section

Figure A–13. Clark Fork measured section

Figure A–14. DDH SL–122 (Spar Lake) diamond-drill-hole 

section

Figure A–15. Mount Vernon measured section

Figure A–16. DDH SL–60 (Spar Lake) diamond-drill-hole 

section

Figure A–17. DDH SL–123 (Spar Lake) diamond-drill-hole 

section

Figure A–18. DDH SL–93 (Spar Lake) diamond-drill-hole 

section

Figure A–19. DDH SL–106 (Spar Lake) diamond-drill-hole 

section

Figure A–20. DDH SL–138 (Spar Lake) diamond-drill-hole 

section

Figure A–21. DDH SL–31 (Spar Lake) diamond-drill-hole 

section

Figure A–22. DDH SL–139 (Spar Lake) diamond-drill-hole 

section

Figure A–23. DDH SL–132 (Spar Lake) diamond-drill-hole 

section

Figure A–24. Little Spar Lake measured section

Figure A–25. DDH JF–79–1 (J–F) diamond-drill-hole section

Figure A–26. DDH JF–79–4 (J–F) diamond-drill-hole section

Figure A–27. DDH JFW–1 (J–F West) diamond-drill-hole 

section

Figure A–28. DDH JF–12 (J–F) diamond-drill-hole section

Figure A–29. DDH DC–3 (Dry Creek) diamond-drill-hole 

section

Figure A–30. DDH DC–2 (Dry Creek) diamond-drill-hole 

section

Figure A–31. Squaw Peak measured section

Figure A–32. Goat Rocks measured section

Figure A–33. DDH SN–2 (Snake Creek) diamond-drill-hole 

section
Figure A–71. DDH TC–5A (Trout Creek) diamond-drill-hole 

section

Figure A–72. West Fork of Trout Creek 1 measured section

Figure A–73. West Fork of Trout Creek 2 measured section

Figure A–74. Windfall Peak measured section

Figure A–75. White Pine Creek 2, 3, 4 measured section

Figure A–76. Ripper Creek measured section

Figure A–77. Miller Gulch (Sex Peak) measured section

Figure A–78. Beaver Creek Road measured section

Figure A–79. Little Beaver Creek measured section

Figure A–80. Clear Peak (Asarco) measured section

Figure A–81. Beaver Peak North measured section

Figure A–82. Clear Peak (White) measured section

Figure A–83. Beaver Lake 1, 2 measured section

Figure A–84. DDH CP–5 (Clear Peak) diamond-drill-hole section

Figure A–85. DDH CP–4 (Clear Peak) diamond-drill-hole section

Figure A–86. Twentyfour Mile Creek (Clear Peak 1) measured 

section

Figure A–87. Janstan measured section

Figure A–88. West Fork of Crow Creek measured section

Figure A–89. Spokane Creek measured section

Figure A–90. Spokane-Chipmunk Ridge 3 measured section

Figure A–91. Chipmunk 1 measured section

Figure A–92. Chipmunk 2 measured section

Figure A–93. Bloom Peak measured section

Figure A–94. East Lake measured section

Figure A–95. West Fork of Eagle Creek 3 measured section

Figure A–96. West Fork of Eagle Creek 1–2 measured section

Figure A–97. West Fork of Eagle Creek 5 measured section

Figure A–98. Cottonwood measured section

Figure A–99. Bobtail Creek measured section

Figure A–100. Niagara measured section

Figure A–101. Revett Lake measured section

Figure A–102. DDH MG–6 (Military Gulch) diamond-drill-hole 

section

Figure A–103. Prichard Creek measured section

Figure A–104. Coeur d’Alene River 3 measured section

Figure A–105. Cedar Creek measured section

Figure A–106. Little Grizzly Creek measured section

Figure A–107. Grizzly Creek measured section

Figure A–108. Timmies Section measured section

Figure A–109. Maple Cliffs measured section

Figure A–110. Graham Creek measured section

Figure A–111. Silver Creek measured section

Figure A–112. Castle Rock measured section

Figure A–113. Coal Creek measured section

Figure A–114. Kellogg measured section

Figure A–115. Latour Peak-Boise Peak measured section

Figure A–116. North of Prado Creek measured section

Figure A–117. Bumblebee Road measured section

Figure A–118. Browns Gulch measured section

Figure A–119. County Creek measured section

Figure A–120. Little Tepee Creek 1, 2 measured section

Figure A–121. North Fork of Coeur d’Alene Section 20 measured 

section

Figure A–122. North Fork of Coeur d’Alene Section 25 measured 

section

Figure A–123. Hope (David Thompson Game Preserve) measured 

section

Figure A–124. Military Gulch (upper) measured section

Figure A–125. Military Gulch (lower) measured section

Figure A–126. Lower Glidden Lake measured section

60    Stratabound Copper-Silver Deposits of the Mesoproterozoic Revett Formation, Montana and Idaho