UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Bulletin 846

CONTRIBUTIONS TO ECONOMIC GEOLOGY

(SHORT PAPEES AND PRELIMINARY REPORTS)

1933

G. P. LOUGHLIN

GEOLOGIST IN CHARGE

UNITED STATES

(JOVERNMENT PRINTING OFFICE 

WASHINGTON : 1934
;;~ " «* " * v.:.:.. ... . . 
CONTENTS

[The letters in parentheses preceding the titles are those'used to designate the papers for

advance publication]

Page

(A) Some mining districts of eastern Oregon, by James Gilluly, J. C.

Reed, and C. F. Park, Jr_________________________ 1

(B) Geology and ore deposits of the Takilma-Waldo district, Oreg., including the Blue Creek district, by Philip J. Shenon________ 141

(C) The Climax molybdenum deposit, Colorado, by B. S. Butler and J. W. 

Vanderwilt, with a section on history, production, metallurgy, and 

development by Charles W. Henderson________________ 195

(D) Some lode deposits in the northwestern part of the Boise Basin,

Idaho, by Clyde P. Ross_________________________ 239 

Index_____________________________________.:_ 279

ILLUSTRATIONS

PLATE 1. Index map showing location of mining districts in eastern Oregon. 8

2. Topographic and geologic map of the Mormon Basin mining

district, Baker and Malheur Counties, Oreg _ 32

3. Geologic sketch of underground workings of Amalgamated

Mines Co., East Eagle district, Oreg _ 72

4. Topographic and geologic map of Virtue district, Baker County,

Oreg_______________________________ ___ 72

5. Sketch map of mill-tunnel level of Virtue mine, Virtue district,

Oreg__________________________________ 72

6. Composite plan and section of Flagstaff mine, Virtue district,

Oreg___________________________ __ '72

7. Map and section of Standard mine, Quartzburg district, Oreg 104

8. Geologic sketch map of Gold Hill and vicinity, Ochoco Creek . 

area, Oreg____ 128

9. Index map of southwestern Oregon and northwestern California _________________________________ 150

10. Topographic map of Takilma-Waldo district, Oreg., and

vicinity ______ ___ _ __________________ 150

11. Geologic map of Takilma-Waldo district, Oreg__________ 150

12. A, Cretaceous conglomerate and sandstone lenses; Bt Spheroidal weathering in Cretaceous sandstone_________._ 150

13. A, Tertiary conglomerate resting on greenstone at High Gravel 

mine; B, Tertiary conglomerate with sandstone lenses at 

Platerica mine_____ ____ _______________ 150

491715
IV ILLUSTRATIONS

Pag*

PLATE 14. A, Gravel of Llano de Oro .formation resting on Tertiary 

conglomerate at Llano de Oro mine; B, Serpentine bedrock 

at Llano de Oro mine______________ - 150

15. Plan of north-end workings of Queen of Bronze mine 166

16. A, Tabular body of sulphide ore terminated by a fault, Queen

of Bronze mine; B, Boulder ore from Cowboy mine _ _ 166-

17. A, B, Photomicrographs of ore from Queen of Bronze mine___ 166-

18. Plan and sections of part of Cowboy mine_ 174

19. A, B, Photomicrographs of ore from Cowboy mine_________ 174

20. A, B, Photomicrographs of ore from Cowboy mine_______ 174.

21. A, Chromite deposit in serpentine, Llano de Oro mine; B, 

Hydraulic elevators used to lift water and tailings from 

placer pits, Llano de Oro mine; C, Undercurrents for saving 

fine gold and platinum, Llano de Oro mine_____________ 182

22. A, Leached outcrop at Turner mine; B, Quartz-zeolite veinlets

in Tertiary conglomerate, Platerica mine____________ 182

23. Geologic map and sections of Climax molybdenum district In pocket

24. A, Climax district in winter; B, Panorama of a part of Mosquito Range including Climax district________________ 198

25. Recrystallized schist__________________________ 206.

26. Secondary orthoclase___________ _ _ 222:

27. A, Orthoclase replacing muscovite; B, Pyrite vein with topaz

gangue _______________________________ ___ 222

28. Molybdenite veins_______ ____ 222

29. Molybdenite veins_________________ __.____ 222

30. Molybdenite-quartz veins________________________ 222

31. "Blue quartz" veins_______ _ _ 222

32. Detailed map of Climax molybdenum district________ In pocket 

33-37. Cross sections of molybdenum deposit ________ In pocket

38. Content of molybdenum as sulphide and oxide in some diamond-drill cores___________________________ 230

39. Claim map of the central and western parts of the Boise Basin,

Idaho _____________________ In pocket

40. Geologic map of the Quartzburg area, Boise basin 242:

41. A, Dacite porphyry, Gold Hill mine; B, Rhyolite porphyry,

Gold Hill mine; C, Granite porphyry, Belshazzar mine___ 250

42. Granophyre porphyry__ _ _______!_______ ____.. 250

43. Composite level map of the Gold Hill mine__________ In pocket

44. Geologic maps of the 250, 400, and 700 levels, Gold Hill mine

In pocket

45. Diagrammatic geologic sections through the Gold Hill mine

In pocket

46. Photomicrographs of ore from the Gold Hill mine, showing

relations between the native gold and the bismuth minerals_ 266

47. Geologic map of the Belshazzar mine_____________ In.pocket

48. Sketch map of the Missouri mine__________________ 274 

FIGURE 1. Geologic map of Sunday Hill mine, Mormon Basin, Oreg_ 40

2. Geologic map of the Randall mine, Mormon Basin, Oreg_ 42

3. Geology of tunnel on Overshot group,'Mormon Basin, Oreg__ -43

4. Geology of the Summit Mining & Milling Co.'s tunnel, Mormon Basin, Oreg____________________ _____ 44
ILLUSTRATIONS V

Page 

FIGURE 5. Tunnel on Hice prospect, Mormon Basin, Oreg___ 46

6. Map of the workings of the Gold Hill mine, near Durkee,

- Oreg_________________________ _ 55

7. Map of the Crystal Palace mine, near Sparta, Oreg ____ 60

8. Map of the Macy mine, Sparta district, Oreg__ ____ 61

9. Map of the Basin mine, Sanger district, Oreg_ 68

10. Map of the workings of the Black Prince prospect, near Dixie

Butte, Quartzburg district, Oreg__ ___ 91

11. Geologic map of third level, Colorado vein, Equity group,

Quartzburg district, Oreg________ _________ 92

12. Workings of Paul Tote prospect, Quartzburg district, Oreg__ 94

13. Workings on lower tunnel level, Yankee Boy vein, Quartzburg district, Oreg-___________________ 95

14. Geology of New Forrester tunnel, Forrester group, Quartzburg district, Oreg- 97

15. Map of Copperopolis mine, Quartzburg district, Oreg_______ 100

16. Para genesis of minerals in Susanville district, Oreg., as shown

by studies of polished sections of ore_ _ 109

17. Map of Princess prospect, Susanville district, Oreg 114

18. Map of workings, Belle of the Hills prospect, Susanville district, Oreg________ _ _ __ _ 115

19. Map showing location of deposits in the Ochoco district,

Oreg., described in this report__ _ 119

20. Map of main level, Quicksilver Consolidated Mining Co.'s

mine, Ochoco district, Oreg______________________ 122

21. Sketch map of lower tunnel, Ophir-Mayflower mine, Ochoco

Creek, Oreg_________ ____ 134

22. Section illustrating relation of Tertiary conglomerate to bedrock series, Takilma-Waldo district, Oreg______ __ 153

23. Sections through Hampshire stope on D level of Queen of

Bronze mine____ __ _ _ 165

24. Plan of workings of Waldo mine__________________ 167

25. Geologic map of Blue Creek district ___ _ 191 

26; Map showing relation of part of underground workings to

leached outcrops at Turner mine__ _____ ______ 193

27. Section of the Weber and Maroon formations in the area

northwest of the Tenmile district and east of Red Cliff__ 212

28. Idealized representation of Climax molybdenum pipe or stock_ 220

29. Climax molybdenum deposit in block diagram- ____ 221

30. Molybdenite content in drift 2, Phillipson level________ 222

31. Changes in the alteration of pre-Cambrian Silver Plume

granite - ____ ____ 224

32. Index map of Idaho showing the location of the Boise Basin. 240

33. Longitudinal vertical projection through the Gold Hill mine_ 257

34. Idealized diagram of an ore body in the Pioneer workings of

the Gold Hill mine__________ ___________ 258

35. Sketch map of the Mayflower mine__ ____ ______ 263

o
UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Bulletin 846 A

SOME MINING DISTRICTS OF 

EASTERN OREGON

BY 

JAMES GILLULY, J. C. REED

AND

C. F. PARK, JR.

Prepared in cooperation with the 

OREGON STATE MINING BOARD

Contributions to economic geology, 1933, Part 1 

(Pages 1-140)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1933

For Sale by the Superintendent of Documents, Washington, D. C. ------ Price 25 cents

CONTENTS

Abstract._________________________________________________________ 1

Introduction__ _ _________________________________________________ 3

Outline of project._______-_-____________--_____-_--____--_____ 3

Geography. _________'_______________________________________._ 4

Previous work.---_-___-_______-_-_______--_--_-_-_--__..______ 5

General geology_________________________________________________ 9

General features.______________________________________________ 9

Rock units._______-____----_-----_-_----------------_____-_-_ 10

Carboniferous system ..._._..._.___--___-_-.._-._-_-_.-. 10

Triassic system._-__-_--_-_.-.__.__--____.___.__.__.__.___ 12

Jurassic system___________________________________________ 13

Cretaceous system.__________.___j_.___._____..._______.__ 13

Strata of unknown but pre-Tertiary age_____.-______--_-_-___ 14

Tertiary system___________________________________________ 14

Quaternary system._______________________________________ 17

Plutonic rocks.___-_-___--_____________-___--_----__--_--- 17

General features.__----______-_--__-___-------_-____-- 17

Serpentine ---______--____-___-_-_--__----_-__--______ 18

Other ultrabasic rocks.__-______-_-------___---______-_ 19

Gabbro, diabase, and norite._-_--_-------_.--______---_ 19

Diorite.___.__._.______________________._.____:____._ 19

Quartz diorite and granodiorite._-_--__-__..----_-----_-_ 20

Albite granite__-______._____._-__-_-_____-___.________ 20

Structure.___-----_-----------_--_-----------__----------.-_. 20

Pre-Tertiary structure.____-_______-__--_.--.-.---____--_-_ 20

Pre-Tertiary unconformity____________________.,.____________ 21

» Tertiary folding and faulting.______________________________ 22

Mineral deposits._________________________________________________ 24

History of mining.____________________________________________ 24

Production._ _-_-_----________-________-_--__---------._______ 25

Classification.________________________________________________ 26

Magmatic relations of the deposits.______---------_----__ -___-__ 27

General economic considerations.__---_-_---------_-----_-______ 29

^ The districts____---_--_-_-_---______-__________________.___-____ 31

Mormon Basin____--____--__________------------_-__---___._ 31

Geography.______________________________________________ 31

Field work____.__.___________________-_-_-__--.___..__... 31

Geology...-.-..._____________________________________ 31

General features__._____.._.__-_ --__--------_-_-__.___ 31

' Schist series.--------...-__-__--_----------------_-.__ 32

Basic intrusive rocks.___--__-_-_------_------__--_-___ 33

Quartz diorite and related rocks____-_-_-_._______.____ 34

Tertiary rocks (Miocene?)__-____--__---_---_-----____._ 35

Quaternary rocks___----_--_-------------------____-__ 36

Structure.______---_--_-___--------------_-__-_______ 36

m
IV CONTENTS

The districts Continued.

Mormon Basin Continued. Page

Ore deposits---------------------------------------------- 37

The mines__...._..__---.----__----_-_---------__.. 37

Rainbow__-_-_._.._..-....-----_--_.-___.-.__._._ 37

Sunday Hill...._..__...._...._......__....__.__.._... 39

Randall___--__-_-._-.___________________ 41

Overshot_ _---_-____-_--__-__-----_-_.____________-_ 43

Summit_ -__----____-----_----____-____-______----__ 44

Humboldt...__._. ____._ .______ _______ 45

Hice -------- -----------------_-_-_-------- 46

Blue Mud__-._...._ ____________-__.___ 47

Intermountain. _______________________________________ 47

Cleveland Development Co__________________________ 47

Giraffe___.._._..___._....._...______._._..___..___. 48

Morton.______________________________________________ 48

Other prospects.-________--_---_-__-__________________ 48

Placer mines_______________________________________ 48

Outlook for the district.___---_------_-__-_________________ 49

Connor Creek district________________________________________ 49

Geography._-____-_-__.__._-.____-______-.___.___________ 49

Field work.______________________________________________ 49

Geology.____-__----_____--_--___-_--_--_________________ 50

The mines__---------_-.___-__-___--___._.___.__-.._____ 50

Connor Creek._________________________.___.._._. 50

Liddy..-_----.-._....._.-_._-_-_--...___..._.-..._.. 51

Mullin.._____-...__._._. .-_-_..-__.__._...._.....__-_ 51

Runner......______________ ..._-.._____.__________ 52

Placer mines________________________________________ 52

Bay Horse.____-___.___-_____--_-_-_____._.______.___ 52

Outlook for the district.__---_____--.-__-______._____._____ 54

Gold Hill district...__________________________________-.... 54

Location and geology... ____-_-_---_._.______.__.._____. 54

The mines..___ _____________________________________ 54

Gold Hill.____.__._..................._...:........... 54

Durkee Development Co____------_---____________-_-__ 56

Gold Ridge__-__--____-_--_-__-.__._________________ 56

Outlook for the district..-------.--------------------___. 57

Sparta district __---_---_---_--_-----_---_____..____________ 57

Geography._-_---_--_._.._.-_------_--_-_ ___.__.---.._ 57

Geology _______ _______________________ ___.___. 57

The mines.. _------__-__-----_---_- --.__-_ __._ 58

Gem___-.-_--_______--------_______ 58

Crystal Palace__-___-----_-----__--_________________ 59

Macy__ ______________--_--___--__-_-____-_____-__-- 59

Placer mines__-______--_____---__--____-______-_---_ 62

Thomas_______.--__-.___._______._____ 62

Outlook for the district.__-_----_-__-_-----______-___--_--- 63

East Eagle district________________._- -__-_________-___---___ 63

Location and general features....._--_-_-_-_-____-_-___-__-_ 63

The mines__---.--__._--.-..--_----___--------_----_.-- 63

Amalgamated Mines Co_____---------__----__-_-_..__-- 63
CONTENTS V

The districts Continued.

East Eagle district Continued.

The mines Continued. Page

Summit Mining Co___-__-_____-____---_---_---__-_-_ 64

Midway _________________________________________ 65

Apex._.._._______-.__.________-_-___------_---__ 65

Zenith__________.________________________________ 65

Woodrow. ___---------_-----_-------_.-_-.----_-- 66

Summit..__-__..__--____._____..-_..._.------.___ 66

Outlook for the district.____._____-_.____...__._______.__._ 66

Sanger district..______--.._---___._____.-._______-_------.____ 66

Sanger___________.._.._.__-_._..._.__..___.____________ 67

Basin._ __________________.-_-_-_-_-__-___-.___-__--______ 68

Medical Springs district...___-_-_--___________.___._-----______ 69

Location and geology..--_---__-__-___---__-_-____-_____.__ 69

The mines------.-------------..-.------------------------- 70

Twin Baby.-___-----__-_-_---___--________--_-_______ 70

Grull___._..__________ _______________ _ _ _______ 70

Outlook for the district..______-__--__-_-_____-_----__-____ 71

Virtue district_______________-_._._.._____..__._.__._..._._.__ 71

Geography________.__---._-.-_-_________._.....--__---__- 71

Field work._..............._____._.__........_--..._..... 71

Geology __.-.__--_---------._.---__..___..-.._._-..._ 71

General features. ___-__--_.-_______.:_______--_-_______ 71

Ore deposits--...--------------------.-_____________ 72

The mines...----_-----------.--_-----------_.--_--.--._-. 72

Virtue..........._-..-_-- ---.-......._..-_..._._... 72

Flagstaff_--_-__---_----__--_----__________---________ 74

Koehler.........._......._._............._._......... 76

Norwood___.--.-.------_-___._._..__._____-___..._. 76

Cliff.-------------------_------__-_...-....-..._..... 77

White Swan___.........._..._......___..._ 77

Chicago-Virtue. _______________________________________ 78

CarrollB__________--__-____________.________________ 78

Brazos.-.-.....----_---------__--_-._.___---_---__.__ 79

Other prospects...--._---_----___._-..______-_._______ 79

Outlook for the district._...._.__-..____.___._.__._._______ 79

Baker district._________-._-----_--.__..____________.._.___._. 80

Geography......__.-.--_----_-_----_-__.__._._--..____._. 80

Geology..-------------------------.-._.-..._-_...__.... 80

Ore deposits....--- _-___-_- --_____.-___________________ 81

The mines..-.-------_---------------_---_...._--..._...__ 81

Tom Paine..-..----_.---.-_.-_.....__......_._..__.._ 81

Old Soldier.._._._.____________-___.-_____._______ 82

Marble Creek Mining & Milling Co___.__....----_.__.._ 82

Yellow Boy Mining Co_-._._..____.._._._.___._..___ 82

Stub....__----.______________________________________ 83

Sorbeck._____________________________________________ 83

Dale.--------__-__--_---_--.-_.---._._--_-..___ 83

Placer mines.._______________________________________ 83

Outlook for the district.___________________________________ 85
VI CONTENTS

The districts Continued. Page

Quartzburg district.________________-____---_-_______-___-_.-__ 85

Geography ________________________________________ _______ 85

Geology___-____-_-_____-_______-_____---_ _-_-__--_ _ 86

General features._____________________________________ 86

Ore deposits..____-_--___-___..______-___-_--_--_-_--__ 87

The mines-_______________--___________-________-___-_.._ 88

Dixie Meadows._-----_--_----_-------__----__-------- 88

Last Chance_-__-_---_____--_--_-----.-_-----_--.-_-_.._ 89

Black Prince...._--__..__-_..._-.._.____.__.____.._ 90

Equity.. _________________________________.____.._ 91

Present Need___--_________..__.._.___-.__._..__-__ 93

Paul Tote_-._-_.__.--_-----_._-___.._..___-_______ 94

Klondike______--___-__--_--____-_-_-_-__--_-_---___ 94

Cougar.___.____.____._____.._.____._____-_-__-______ 94

Yankee Boy--_____---__---_-_--__---_---------------- 05

Dixie Queen___..._______-_.____-__-______-_____-_.___ 96

Fitzsimmons- _____________-___--__-_-_-_-_---_-__--__- 96

Forrester_ _ _________________________________________ 96

Andrew Jackson._____________________________________ 98

Boulder_________________________----_--_--_-_________ 98

Howell & Haight__..__...--_-._._ -_ . ..-. 98

Copper Mountain Mining Co--__.--_-..__-_______-_-___ 99

Copperopolis._____________-____-___--__-_-_..-___-____ 100

Standard__._____._______.-.___-__-_._-..--_-_-.-._- 101

Dixie Creek placers_________---________________________ 104

Comini quarries__-_-__-__-----__------_-_-------_-_-___ 104

Outlook for the district-__-_.---_-.__._-_-___-_-_____-_-__. 105

Susanville district---_--_____-___--_-_-__--_--_-------_-----___ 105

Geography _______.__.___.._____-_____-_.._____-___.-..___ 105

Field work.__..._._______.2_-__---__----__--_---_-_--..__ 106

Geology________-_____.-___----____----.---_---------_-_ 106

General features.________---______-_-_-----_-__--_-___ 106

Schist series.__________________________________________ 107

Basic intrusive rocks___. _._.__--_-_-_-_-.-----.-_-- 107

Quartz diorite and related dikes_________________________ 107

Tertiary rocks (Miocene)___________-___-_--__-.-_____ 108

Quaternary rocks.__________-_____----_-_--.--_-_---___ 108

Structure. _-___--_---__-_--__-_.-__---_---_--.----__-- 108

Ore deposits__-___._____-.-__._.-__------------_-_-_-_ 108

The mines__________________-_-__.__-_-_-_--_______-____ Ill

Badger._--.-........_._.---._.-----------._---_----- Ill

Gem_ _-___.._____.___--.--.-.-____.__.__..___ 112

Bull of the Woods __________________________________ 112

Rescue_____________________________________________ 113

Chattanooga-______--__-__--._._-__-_--_---__-___-__- 113

Daisy.. _____________________________________------ 113

Princess.-.._ _-_-______-__---__-----___--__--_-----___ 114

Poorman__ _ __-_..__-_____--____________-____-._--___. 114

Belle of the Hills ____________________________________ 115

Gold Bug....________________________________________ 115

Mocking Bird._______________________________________ 116

Ophir..._____________________________________________ 116

Blackhawk.---........_______________________________ 116
CONTENTS VII

The districts Continued.

Susanville district Continued.

The mines Continued. Page

Side Issue__-___----_____--_..-__--_-----_--_---_-__--- 116

Simcox _______________---_--___--_-_--____-_--_____-- 117

Skyscraper.__________________________________________ 117

Thompson.__________________________________________ 117

Stockton_____________________________________________ 117

Nelson__ ___________________________________________ 117

Placer mines__-______----_--_____-_--____-_--___-__-_ 117

Outlook for the district.______-_--___--___-__-____________- 118

Ochoco district._____-__-______-_----__-_--_---__.__-___.----- 118

Geography _______________________________________________ 118

The mines..____________-.-.-__________.._-_-__--- 120

Johnson Creek-Lookout Mountain area__________________ 120

Paulsen & Saylor.__--_----__-__-._.__._......__.. 120

Westerling. _______-_-_-.________________-___--.-_ 120

Quicksilver Consolidated Mining Co...--------..-... 121

Marks Creek area, Wheeler County_--_________-__.____. 123

Bear. _______________._____...._......_ 123

Ochoco Creek area, by G. F. Loughlin and James Gilluly.. 123

Champion__ _ ___________________________________ 123

Gold Hill and vicinity (Howard district)------------- 124

Location and topography._____________-__--_-. 124

Production._.__._________..__.._--.____._-.__ 125

Geology-_-_.-----_-__--_----____-_--___--.-- 125

Ore deposits__-------------_--_--_-----__----- 127

Ophir- Mayflower__ __________________________ 133

Other workings on Gold Hill_._.._______.__-_-- 136

Red Bird Hill..._____________________________ 137

Placers....___________________.__----- 137

Maury Mountain area...-.____________________________ 138

Staley & Towner______________________________ 138

Bear Creek area._____________________________________ 138

Wiltsie & Platner.______________________________ 138

Dunham_____.__.____--....__----__....-_-..-__-- 139

Outlook for the district.____--___.__________..____..__._____ 139

ILLUSTRATIONS

Page 

PLATE 1. Index map showing location of mining districts in eastern Oregon. 8

2. Topographic and geologic map of the Mormon Basin mining

district, Baker and Malheur Counties, Oreg_-_-__-._-_-__ 32

3. Geologic sketch of underground workings of Amalgamated

Mines Co., East Eagle district, Oreg--_-_______-__-__-__-_ . 72

4. Topographic and geologic map of Virtue district, Baker County,

Oreg_-__--_-_-_-----_-----------_----_._____.______--- 72

5. Sketch map of mill-tunnel level of Virtue mine, Virtue district,

Oreg_---___._____________________....._____..- 72

6. Composite plan and section of Flagstaff mine, Virtue district, Oreg. 72

7. Map and section of Standard mine, Quartzburg district, Oreg.. 104

8. Geologic sketch map of Gold Hill and vicinity, Ochoco Creek

area, Oreg_____-__--____-_-______-__-_-_______________. 128
VIH ILLUSTRATIONS

Page 

FIGURE 1. Geologic map of Sunday Hill mine, Mormon Basin, Oreg__ 40

2. Geologic map of the Randall mine, Mormon Basin, Oreg____ 42

3. Geology of tunnel on Overshot group, Mormon Basin, Oreg__ 43

4. Geology of the Summit Mining & Milling Co.'s tunnel, Mormon Basin, Oreg_____________________________________ 44

5. Tunnel on Hice prospect, Mormon Basin, Oreg__-______. 46

6. Map of the workings of the Gold Hill mine, near Durkee,

Oreg__-__-.._-_--__--_----------_--_-.-_-_-_-.____ 55

7. Map of the Crystal Palace mine, near Sparta, Oreg_______ 60

8. Map of the Macy mine, Sparta district, Oreg_.____________ 61

9. Map of the Basin mine, Sanger district, Oreg______________ 68

10. Map of the workings of the Black Prince prospect, near

Dixie Butte, Quartzburg district, Oreg__________________ 91

11. Geologic map of third level, Colorado vein, Equity group,

Quartzburg district, Oreg____________________________ 92

12. Workings of Paul Tote prospect, Quartzburg district, Oreg__ 94

13. Workings on lower tunnel level, Yankee Boy vein, Quartzburg district, Oreg__________________________________ 95

14. Geology of New Forrester tunnel, Forrester group, Quartzburg district, Oreg_-___-_-__ -____-__-__-________-___ 97

15. Map of Copperopolis mine, Quartzburg district, Oreg_______ 100

16. Paragenesis of minerals in Susanville district, Oreg., as shown

by studies of polished sections of ore____________________ 109

17. Map of Princess prospect, Susanville district, Oreg.________ 114

18. Map of workings, Belle of the Hills prospect, Susanville district, Oreg______-----___--______--___._____________ 115

19. Map showing location of deposits in the Ochoco district,

Oreg., described in this report-_---_-______-____________ 119

20. Main level, Quicksilver Consolidated Mining Co.'s mine,

Ochoco district, Oreg___---_-__________-__________.___ 122

21. Sketch map of lower tunnel, Ophir-May flower mine, Ochoco

Creek, Oreg_______--_-_-__-________________ 134

NOTE. Bulletin 846 will not be issued as a complete volume, but the last 

chapter will contain a volume title page and index for the use of those who 

may wish to bind together the separate chapters.
SOME MINING DISTRICTS OF EASTERN OREGON

By JAMES GILLULY, J. C. REED, and C. F. PARK, Jr.

ABSTRACT

This report presents the results of a reconnaissance of most of the mining 

districts of Oregon east of the Cascade Range, with the exception of the districts in the Sumpter quadrangle. The districts described are distributed 

through an area roughly coincident with the Blue Mountains, which extend 

over much of the northeast quarter of the State.

The geology of the Blue Mountains, except for certain sinall areas, is known 

only in its most general outlines. The most widespread rocks are the Tertiary 

volcanic rocks, which extend over a very large part of the State. They are 

separated by a profound angular and erosional unconformity from the preTertiary rocks.

The pre-Tertiary rocks include representatives of all the geologic periods 

from Carboniferous to Cretaceous, and earlier periods may also be represented.

The known Carboniferous rocks include argillite, chert, greenstone, and 

subordinate limestone of uncertain age and a thick series of Permian greenstone, tuff, and limestone. The Triassic rocks include shale, slate, and limestone; the Jurassic rocks are shale and slate; and the Cretaceous are conglomerate and sandstone. Schist and phyllite with some limestone and greenstone 

of uncertain age occur along the Burnt River west of Durkee and in the 

Mormon Basin.

Intrusive rocks of at least two magmatic cycles are widespread in the Blue 

Mountains, and the stratigraphy suggests that several cycles may be represented. The older intrusive rocks include gabbro, pyroxenite, norite, dunite, 

hornblende-quartz diorite, and albite granite and are characterized by a considerable degree of shearing and both cataclastic and metasomatic metamorphism. The age of some of these rocks in the Canyon Range has been 

fixed as Lower or Middle Triassic, and others are known to be post-Triassic. 

Younger biotite-quartz diorite and granodiorite of post-Triassic (possibly postJurassic) age are widespread, arid the ore deposits of pre-Tertiary age are 

believed to be genetically related to these rocks.

Representatives of the Tertiary period include Eocene volcanic rocks and 

sediments, Oligocene fluviatile deposits, Miocene basic lavas and fluviatile and 

lacustrine sediments, and Pliocene tuff and gravel. The Quaternary deposits include glacial moraines in the higher mountains, stream gravel, and volcanic ash.

The structure of the pre-Tertiary rocks is complex. Folds are characteristically close or isoclinal and strike eastward. The post-Permian rocks 

appear to be less metamorphosed and less strongly deformed than the earlier 

rocks, and the Jurassic less than the Triassic. More than one epoch of 

diastrophism is therefore involved.
2 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The topography of the region is controlled by the structure imposed in 

Tertiary time. Characteristically the structural features trend northwestward in the eastern areas, but in the south and west they trend westward. 

Both folding and faulting along these structural lines have continued until 

relatively recent, possibly postglacial time.

Mining began in the Blue Mountains in 1861 with the discovery of the 

placer deposits at Auburn. Within a few years most of the surrounding 

region had been thoroughly combed for placer gold. Lode mines were located 

in these days also, but little work was done on them until the completion 

of the transcontinental railroad in 1885. The most active period in lode 

mining was from about 1913 to 1918, but since then there has been a rather 

steady decline, due in large part, at least, to higher costs of mining. The 

total production of gold and silver from the Blue Mountains has been about 

$80,000,000, fully $75,000,000 of which was in gold.

Small amounts of copper have been mined in connection with the gold 

for many years, and between 1915 and 1928 several properties at Homestead, 

on the Snake River, were operated primarily for their copper. During these 

years the copper production of Baker County amounted to over 14,000,000 

pounds, valued at about $2,400,000. There has also been considerable prospecting for copper and a nominal production from mines near Keating in 

the lower Powder Valley.

Considerable chromite was mined during the World War and the years 

immediately following in Grant County, chiefly from the Strawberry Range, 

and in Baker Ceunty from deposits near Sumpter and from Connor Creek.

A few flasks of mercury have been produced from the Ochoco Mountains, at 

intervals since 1906, but not until 1929 has there been widesprf ad activity 

in this region.

The ore deposits other than placers in eastern Oregon include gold, goldsilver, copper-gold, quicksilver, chromite, and manganese deposits.

Of these classes, the gold deposits are most widely represented. Goldsilver deposits are few; copper-gold deposits, in which the value of the copper 

exceeds that of the gold, are represented by the prospects in the Keating 

copper district and by those in the Homestead district on the Snake River, 

neither of which is considered in this bulletin, and by the Copperopolis 

property at Quartzburg. Quicksilver deposits are limited to the western 

part of the area, in the Ochoco country. Chromite deposits, not here described, occur in the Strawberry Range and on Connor Creek, and manganese deposits, all of superficial origin, are present near Durkee and Pleasant 

Valley.

The deposits occur predominantly as fissure veins or replacement veins. 

Stockworks and impregnation zones are represented by all the copper-gold 

deposits and possibly by the Rainbow gold mine in the Mormon Basin. Some 

of the chromite deposits are probably due to segregation; others to impregnation.

Mineralogically the gold deposits are generally simple, carrying pyrite, 

pyrrhotite, chalcopyrite, galena, sphalerite, and arsenopyrite in a gangue of 

quartz, ankerite, calcite, and locally sericite, chlorite, serpentine, scheelite, 

fuchsite, barite, and clays.

Most of the copper deposits carry chalcopyrite, pyrite, galena, sphalerite, 

and arsenopyrite in a quartz-barite gangue with some chlorite and epidote, 

but the Copperopolis deposit carries considerable tourmaline as the principal 

associate of quartz in the gangue.
SOME MINING DISTRICTS OF EASTERN OREGON 3

The quicksilver deposits are composed of cinnabar with pyrite in a gangue 

of quartz, chalcedony, opal, chlorite, nontronite, calcite, dolomite, several 

clays, anil asphalt.

The mineral deposits, considered genetically, appear to fall into three 

groups, each related to a different suite of igneous rocks. Two of these are 

of pre-Tertiary age; the third is middle or.later Tertiary.

The chrornite deposits, as is the rule elsewhere, are all directly associated 

with ultrabasic rocks, dunite and pyroxenite, which have been thought to 

represent the earliest of the pre-Tertiary niagmatic cycles.

By far the most of the gold deposits are situated in close juxtaposition 

with bodies of biotite-quartz diorite, and these deposits are therefore considered to be genetically related to the latest pre-Tertiary intrusive cycle, 

or, if only one pre-Tertiary cycle should prove to be represented in the region, 

to the latest intrusions of that cycle.

The quicksilver deposits of the Ochoco region and at least one gold deposit, 

the Ophir-Mayflower, occur in Tertiary rocks and hence are obviously related 

to much younger magmatic activity than the other deposits. No plutonic 

rocks to which these deposits may be related are known in the region, but 

the long volcanic history contained in the Tertiary record gives ample evidence 

of the existence of intrusive rocks of Tertiary age at greater or less depths 

beneath the surface of large parts of the State.

INTRODUCTION

In 1929 the State of Oregon made an appropriation for a cooperative survey of the mineral resources of the State, to be carried out 

jointly by the State mining board and the United States Geological 

Survey. This bulletin presents the results of an examination, made 

under this arrangement, of many of the metalliferous deposits east of 

the Cascade Range. (See pi. 1.) A restudy of the mines of the 

Sumpter quadrangle was made by D. F. Hewett, of the Geological 

Survey, and a report on these deposits has appeared elsewhere. 1 

Similarly, the Cornucopia district in the Wallowa Mountains had 

been examined by the Geological Survey 2 a short time before this 

work was undertaken, so that no work was done in either of these 

areas. Aside from them, however, an attempt was made to cover 

all the areas in the State east of the Cascade Range in which metalliferous deposits have been worked in recent years and in which the 

mining developments are accessible. Unfortunately many of the 

mines whose past production has been large were inaccessible, either 

altogether or in large part, so that little information could be gained 

in them. Among these are the Homestead, Bay horse, and Connor

1 Hewett, D. P., Zonal relations of the lodes of the Sumpter quadrangle, Oreg.: Am. 

Inst. Min. and Met. Eng. preprint, New York meeting, February, 1931.

3 Ross, C. P., Geology and ore deposits of the southern Wallowa Mountains: U. S. Geol. 

Survey Bull. (in preparation).
4 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Creek mines, along the Snake River; the Sanger mine, near Lily 

White; the Rainbow and Humboldt mines, in the Mormon Basin; 

and the Virtue mine, in Virtue Flat.

The work was severely handicapped in many districts by the lack 

of available maps on an adequate scale. For this reason in some 

of the heavily wooded districts little could be done beyond very 

local studies in and immediately about the accessible mines.

Field work on the cooperative project was undertaken in 1929. 

In that year the work was confined chiefly to a study of the copper 

deposits near Keating, the results of which are presented in another 

paper.3 In 1930 work was resumed early in May and carried on 

until October 10. The work was carried out in 1929 by James 

Gilluly and Ralph B. Stewart; in 1930 by James Gilluly, J. C. Reed, 

C. F. Park, jr., and H. G. Mitchell.

The writers acknowledge with gratitude the hearty cooperation 

of many mining men in eastern Oregon, especially that of Messrs. 

J. L. Fisher and William Phalen, of the Mormon Basin; E. 

McNaughton and George Cullen, of the White Swan mine; Al 

Borosky, of Medical Springs; C. J. Reuscz, of Durkee; J. L. Layden, 

of the Flagstaff mine; William Wendt and J. C. Bowen, of Baker; 

Norman Johnson, Robert Dougherty, B. F. Hurt, and Charles Ray, 

of Susanville; A. W. Ward, J. C. Howell, G. H. Kight, R. C. Reese, 

and H. W. Riley, of Prairie City; W. J. Westerling, of Johnson 

Creek; and Lloyd Wiltsie and C. C. Dunham, of Bear Creek. Mr. 

Frank C. McColloch, of the State mining board, was very helpful 

and special acknowledgment is due to him.

GEOGRAPHY

Northeastern Oregon is largely occupied by a straggling group of 

mountains to which the name Blue Mountains is somewhat loosely 

applied. The mountains extend from the vicinity of the Snake 

River on the east nearly to the Deschutes Valley on the west and 

include many mountain groups to which other local names have 

been applied. For instance, the Wallowa Mountains, which lie 

in the angle between the lower Powder Valley and the Snake River, 

although somewhat isolated, are usually considered a part of the 

Blue Mountains, as are the Strawberry Range, south of the East 

Fork of the John Day River; the Ochoco Mountains, a westward extension of the same uplift which reaches nearly to Prineville; 

Elkhorn Ridge, west of Baker Valley; and the Greenhorn or Vinegar 

Mountains, north of the Middle Fork of the John Day.

8 Gilluly, James, The copper deposits near Keating, Oreg.: U. S. Geol. Survey Bull. 830, 

pp. 1-32, 1932.
. SOME MINING DISTRICTS OF EASTERN OREGON 5

The individual ranges constituting the Blue Mountains are very 

irregular. In general, however, they trend roughly east or southeast. In altitude they range from about 4,000 feet to over 9,000 feet. 

The drainage is exceedingly irregular, although the master streams 

trend generally parallel with the course of the ranges as a whole. 

The principal streams are Eagle and Pine Creeks and the Grande 

Konde, Wallowa, and Powder Rivers, draining the Wallowa Mountains ; the Burnt, Powder, Malheur, Umatilla, and John Day Rivers 

and Willow Creek, draining Elkhorn Ridge and the Granite, Strawberry, and other ranges; and Ochoco Creek and the Silvies and 

Crooked Rivers, draining the Ochoco Mountains. All these streams 

have their waters so largely diverted for irrigation during the 

summer that their discharge is moderate.

The climate of the area is dry. Baker has an average annual 

precipitation of about 13 inches; Dayville, in the valley of the 

South Fork of the John Day River, about 11 inches; and Prineville, 

in the Crooked River Valley, about 9 inches. Undoubtedly the precipitation on the higher mountains of the region is considerably 

greater, perhaps four or five times as much.

Throughout the region the lower hills and valleys below an altitude of about 4,000 feet are chiefly barren or clad with sagebrush, 

rabbitbrush, and grass. Above this altitude the hills are generally 

clad with pine forests, chiefly with beautiful open groves of yellow 

pine, although the highest peaks are commonly barren. Along the 

streams in the higher country willows, alders, and aspen flourish. 

Although lumbering is a major industry and has been for many 

years, there still is available a huge supply of timber.

The only standard-gage railroad lines giving access to the Blue 

Mountains are the Oregon-Washington Railroad & Navigation Co.'s 

line between Huntington and Pendleton and the City of Prineville 

Railway, which joins Prineville with the branch of the Great Northern Railway in the Deschutes Valley. A narrow-gage line, the Sumpter Valley Railway, runs from Baker to Prairie City, and a standard-gage branch of the Oregon-Washington Railroad.& Navigation 

Co. runs to Medical Springs from the main line at Telocaset and 

another from Huntington to Homestead, down .the Snake River 

Canyon. However, the region is crossed by a number of excellent 

highways, notably the Oregon Trail from Huntington to Pendleton, the John Day Highway from Ontario to Fossil and thence to 

Arlington, and the Ochoco Highway from Redmond to Mitchell.

PREVIOUS WORK

Although there had been hasty trips by earlier explorers, mainly 

directed toward collecting fossils in the John Day Basin, the earliest
6 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

systematic investigations of the geology of the region were the 

reconnaissance of Lindgren 4 in 1900 in the eastern Blue Mountains 

and that of Merriam 5 in 1899 in the John Day Valley. Detailed 

information may be said to have begun with the two papers just 

cited. The following list contains the other publications that have 

added to geologic knowledge of the region. Brief comments have 

been appended, descriptive of the contents of the several papers.

1901. Lindgren, Waldemar, Rare minerals in gold quartz veins of eastern 

Oregon: Min. and Sci. Press, vol. 82, p. 252. A mineralogic 

contribution.

1902. Conclon, Thomas, The Two Islands and what came of them, Portland, 

Oreg. A popular account of the geology of the State, very generalized.

1902. Knowlton, F. H., Fossil flora of the John Day Basin, Oreg.: TJ. S. Geol. 

Survey Bull. 204. Almost wholly paleobotanical studies of the collections from the Tertiary of the John Day Basin.

1902. Calkins, F. C., A contribution to the petrography of the John Day Basin, 

Oreg.: California Univ. Dept. Geology Bull., vol. 3, pp. 109-172. Describes the igneous history as determined from the petrographic character of the sediments and lava flows of the John Day Valley.

1903. Washburne, C. W., Notes on the marine sediments of eastern Oregon:

Jour. Geology, vol. 11, pp. 224-229. Gives results of a fossil collecting

expedition through the0 Blue Mountain region. 

1903. Merriam, J. C., and Sinclair, W. J., The correlation of the John Day and

the Mascall: Jour. Geology, vol. 11, pp. 95-96. An abstract of the

correlations suggested. 

1907. Merriam, J. C., Tertiary faunas of the John Day region: California Univ.

Dept. Geology Bull., vol. 5, pp. 171-205. Vertebrate faunas listed and

described.

1909. Pardee, J. T., Faulting and vein structure in the Cracker Creek gold 

district, Baker County, Oreg.: U. S. Geol. Survey Bull. 380, pp. 85-94. 

Discusses the relations between faults and veins in the district.

1910. Pardee, J. T., Placer gravels of Sumpter and Granite districts, eastern 

Oregon: u. s. Geol. Survey Bull. 430, pp. 59-65. Discusses the effect

of glaciation on the concentration of the placer gold. 

1910. Melzer, E., North Pole mine, Baker County, Oreg.: Eng. and Min. Jour.,

vol. 89, pp. 868-869. A description of a mine in the Sumpter

quadrangle. 

1912. Smith, J. P., The occurrence of coral reefs in the Triassic of North

America: Am. Jour. Sci., 4th ser., vol. 22, pp. 92-96. Describes the

Triassic limestone on Eagle Creek at Martin Bridge. 

1912. Parks, H. M., The economic geological resources of Oregon: Oregon State

Bur. Mines Bull. 2, Corvallis, Oreg. A summary of the information

available at the time. 

1914. Pardee, J. T., and Hewett, D. F., Geology and mineral resources of the

Sumpter quadrangle, Oreg.: Mineral Resources of Oregon, vol. 1,

No. 6, pp. 1-128, Oregon Bur. Mines and Geology. A summary report

on several seasons' work in the Sumpter quadrangle. 

1914. Grant, U. S., and Cady, G. H., Preliminary report on the general and

economic geology of the Baker district of eastern Oregon: Mineral

4 Lindgren Waldemar, The gold belt of the Blue Mountains of Oregon : U. S. Geol. 

Survey Twenty-second Ann. Kept., pt. 2, pp. 551-776, 1901.

5 Merriam, J. C., A contribution to the geology of the John Day Basin: California Univ., 

Dept. Geology Bull., vol. 2, No. 9, pp. 269-314, 1901.
SOME MINING DISTRICTS OF EASTERN OREGON 7

Resources of Oregon, vol. 1, No. 6, pp. 129-161, Oregon Bur. Mines and 

Geology. A reconnaissance report on several scattered areas in the 

Baker quadrangle.

1914. Swartley, A. M., Ore deposits of northeastern Oregon: Mineral Resources 

of Oregon, vol. 1, No. 8, Oregon Bur. Mines and Geology. Summarizes 

the available information on the geology of the mines of the area.

1914. Collier, A. J., The geology and mineral resources of the John Day 

region: Mineral Resources of Oregon, vol. 1, No. 3, Oregon Bur. Mines 

and Geology. Discusses the stratigraphy, structure, and coal resources of the John Day Basin.

1916. Merriam, J. C., Stock, Chester, and Moody, C. L., An American Pliocene 

bear: California Univ. Dept. Geology Bull., vol. 10, pp. 87-109. Description of fossils from the Rattlesnake formation.

1916. Merriam, J. C., Mammalian remains from a late Tertiary formation at 

Ironside, Oreg.: California Univ. Dept. Geology Bull., vol. 10, pp. 

129-135. Describes a Pftoee,ne deposit in the Ironside Mountain 

quadrangle.

1916. Parks, H. M., and Swartley, A. M., Handbook of the mining industry of 

Oregon: Mineral Resources of Oregon, vol. 2, No. 4, Oregon Bur. Mines 

and Geology. An alphabetic list of mining properties throughout the 

State, with short descriptions of most of the mines and prospects.

1918. Smith, W. D., The Wallowa Mountains, Oreg.: Mazama, vol. 5, pp. 233- 

250. A popular account of a reconnaissance of the Wallowa Mountains.

1919. Smith, W. D., and Packard, B. L., The salient features of the geology of

Oregon: Jour. Geology, vol. 27, pp. 79-120. A general account of the

geology of the State. 

1921. Buwalda, J. P., Oil and gas possibilities of eastern Oregon: Mineral

Resources of Oregon, vol. 3, No. 2, Oregon Bur. Mines and Geology.

Deals chiefly with the Tertiary deposits. 

1921. Pardee, J. T., Deposits of manganese ore in Montana, Utah, Oregon, and

Washington: U. S. Geol. Survey Bull. 725, pp. 211-228. Describes

deposits near Pleasant Valley and Durkee, in the eastern part of the

Blue Mountains. 

1921. Westgate, L. G., Deposits of chromite in eastern Oregon: U. S. Geol.

Survey Bull. 725, pp. 37-60. Describes chromite near Canyon City and

on Connor Creek.

1921. Packard, E. L., and Nelson, R. N., Geologic occurrence of the Hardgrave 

Jurassic fauna of Burns, Oreg.: Geol. Soc. America Bull., vol. 32, 

p. 148. Reports the discovery of a Jurassic locality on the south 

flank of the Ochoco-Strawberry Mountain uplift.

1922. Stock, Chester, and Furlong, E. L., A marsupial from the John Day 

Oligocene of Logan Butte, eastern Oregon: California Univ. Dept. 

Geology Bull., vol. 13, pp. 311-317. Paleontology only.

1923. Chaney, R. W., Paleobotanical contributions to the stratigraphy of 

central Oregon: Geol. Soc. America Bull., vol. 34, p. 129 (abstract). 

A summary of results of work on the John Day section.

1924. Chaney, R. W., Fossil floras of the John Day Basin: Carnegie Inst. 

Washington Year Book, No'. 22, pp. 349-350. Paleobotany of the John 

Day section.

1924. Livingston, D. C., A geologic reconnaissance of the Mineral and Cuddy 

Mountain mining district, Washington and Adams Counties, Idaho: 

Idaho Bur. Mines and Geology Pamphlet 13. Contains a geologic map 

of the Snake River Canyon below Huntington, with a description of the 

Bay Horse mine.
8 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

1925. Merriarn, J. C., Stock, Chester, and Moody, C. L., The Pliocene Rattlesnake formation and fauna of eastern Oregon, with notes on the 

geology of the Rattlesnake and Mascall deposits: Carnegie Inst. Washington Pub. 347, pp. 43-92. A brief description of the geology and 

vertebrate paleontology of the upper Tertiary of the John Day region.

1925. Chaney, R. W., A comparative study of the Bridge Creek flora and the 

modern Redwood forest: The Mascall flora, its distribution and climatic relation: Carnegie Inst. Washington Pub. 349, pp. 1-48.

1927. Goodspeed, G. E., jr., Effects of inclusions in small porphyry dikes at 

Cornucopia, Oreg.: Jour. Geology, vol. 35, pp. 653-662, Discusses 

petrology of certain dikes at Cornucopia.

1927. Chaney, R. W., Geology and paleontology of the Crooked River Basin 

with special reference to the Bridge Creek flora: Carnegie Inst. Washington Pub. 346, pp. 45-138. Chiefly paleobotanic data but describes 

new localities of Tertiary sediments in the Crooked River Basin.

1928. Packard, E. L., A new section of Paleozoic and Mesozoic rocks in central

Oregon: Am. Jour. Sci., 5th ser., vol. 15, pp. 221-224. Brief description

of an important discovery of pre-Tertiary rocks on the south flank of

the Ochoco uplift. 

1928. Livingston, D. C., Certain topographic features of northeastern Oregon

and their relation to faulting: Jour. Geology, vol. 36, pp. 694-708.

Discusses the relations between drainage courses and faults in the

northeastern part of the Blue Mountain area. 

1928. Hewett, D. F., Shannon, E. V., and Gonyer, F. A., Zeolites from Ritter

Hot Springs, Grant County,- Oreg.: U. S. Nat. Mus. Proc., vol. 73, art.

16. Mineralogic data only. 

1928. Buwalda, J. P., Geological features of the John Day region, eastern

Oregon: Geol. Soc. America Bull., vol. 39, pp. 269-270. A very brief

summary of the stratigraphy and structure of the John Day Basin. 

1928. Maxson, J. H., Merychippus isonesus (Cope) from the later Tertiary of

the Crooked River Basin, Oreg.: Carnegie Inst. Washington Contr.

Paleontology, Pub. 393, pp. 55-58. Describes a Mascall form from a

locality near Post, in the Crooked River Valley.

1928. Hodge, E. T., Structural features in John Day and Deschutes River Canyons (abstract): Pan-Am. Geologist, vol. 49, pp. 305-306. A summary 

statement of the discovery of new Cretaceous and Tertiary localities 

west of Mitchell.

1929. Buwalda, J. P., A Neocene erosion surface in central Oregon: Carnegie 

Inst. Washington Pub. 404 (preprint), pp. 1-10. Describes the relations of a post-Rattlesnake erosion surface, presumably of late Pliocene age, developed in the John Day region.

1929. Goodspeed, G. E., The mode of origin of a reaction porphyry dike at 

Cornucopia, Oreg.: Jour. Geology, vol. 37, pp. 146-176. The petrology 

of a porphyry dike at Cornucopia.

1930. Goodspeed, G. E., Recrystallization of xenoliths at Cornucopia, Oreg.: 

Am. Jour. Sci., 5th ser., vol. 20, pp. 145-150. A petrologic study of 

inclusions in the intrusive mass at Cornucopia.

1931. Hewett, D. F., Zonal relations of the lodes of the Sumpter quadrangle, 

Oreg.: Am. Inst. Min. and Met. Eng. preprint of paper for New York 

meeting. Describes the variations in mineralogy of the different quartz 

lodes as the intrusion is approached.

A great deal of work bearing on the geology of this region has 

been done in recent years by Prof. E. L. Packard, of the University
U.S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 1

FENDLETON

A VIT ILL

Service Creek,

-^

WHEELER

EXPLANATION

O/STK/CTS DESCRIBED IN THIS REPORT

1 Mormon Basin

2 Connor Creek

3 Gold Hi/I

 ^ Sparta

5 fast Eagle

6 Sanger

7 Medical

8 Virtue

9 Baker

10 Quartzburg

11 Susanvil/e

I? Ochoco

Districts described by Westyate 

(V.S.G.S. Bu//et/'n 7Z5./32l)

Sumflter quadrana/e described 

by Pardee and Mewett. fM/nera/ Resources of Oregon, vol. f. 

No. S. 19/4)

John Day region described by 

Co flier. (Mineral Resources of 

Oregon, vol. /. Mo. J. /9/4.J

A red described by Lindgren, 

(U.S.G.S. 224 Ann. /?ept,pt.Z.I90l)

Manganese deposits described 

by Pardee. fl/.S.G.S. Bull. 7ZS./92I)

Jfeating copper district described 

by Gillu/y (U. S. G.S. Bull. 830-A, I93Z)

Districts mapped by Grant and 

Cady (Mineral Resources of 

Oregon, vo/., No. .

ZO________3O

INDEX MAP SHOWING LOCATION OF MINING DISTRICTS IN EASTERN OREGON.
SOME MINING DISTRICTS OP EASTERN OREGON 9

of Oregon; Prof. J. P. Buwalda, of the California Institute of Technology; Dr. Kalph L. Lupher, of Washington State College; and 

Clyde P. Eoss, of the United States Geological Survey; but unfortunately their results have not yet been published.

GENERAL GEOLOGY

GENERAL FEATURES

Tertiary volcanic rocks underlie the surface of most of the region 

considered in this report. Pre-Tertiary. formations are in general 

exposed only within the straggling structural uplifts that form the 

Blue Mountains. Extensive exposures of these older rocks are for 

the most part limited to the^more notable uplifts and may be entirely 

absent in some of the smaller ones. As the general altitude and the 

structural relief both diminish toward the west, the exposed areas

of pre-Tertiary rock diminish in this direction also.

The pre-Tertiary rocks include representatives of all the geologic 

periods from Carboniferous to Cretaceous, and as some of the more 

metamorphosed rocks have yielded no fossils, it is possible that 

earlier periods are also represented.

The known Carboniferous deposits include argillite, chert, and 

greenstone with subordinate limestone of uncertain age, and a thick 

series of greenstone, tuff, and limestone of Permian age. Triassic 

shale, slate, and limestone, Jurassic shale and slate, and Cretaceous 

conglomerate and sandstone are found in the region. Schist, phyllite, limestone, and greenstone of uncertain age occur along the Burnt 

River west of Durkee and in the Mormon Basin, but their regional 

relations are not yet well enough known to decide whether they 

are Carboniferous or Triassic, as mapped by Lindgren,6 or of some 

other age.

Intrusive rocks of at least two magmatic cycles are widespread in 

the Blue Mountains, and the stratigraphy, because of the recurrent 

volcanic activity extending from Carboniferous to Jurassic time, 

suggests that several cycles may be represented. The older intrusive 

rocks include gabbro, pyroxenite, dunite, hornblende-quartz diorite, 

and albite granite and are characterized by a considerable degree 

of shearing and both cataclastic and metasomatic metamorphism. 

The age of some of these rocks in the Canyon Range has been fixed 

as Lower or Middle Triassic 7 ; others are known to be post-Triassic. 

Younger biotite-quartz diorite and granodiorite of post-Triassic, 

possibly post-Jurassic age are widespread, and the ore deposits of 

pre-Tertiary age are believed to be genetically related to these rocks.

9 Lindgren, Waldemar, op. cit., pi. 64. 

7 Lupher, R. L., personal communication, Apr. 21, 1931. 

164495 33 2
10 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Kepresentatives of the Tertiary period include Eocene volcanic 

rocks and sediments, Oligocene fluviatile deposits, Miocene basic 

lavas and fluviatile and lacustrine sediments, and Pliocene tuff and 

gravel. The Quaternary deposits include glacial moraines in the 

higher mountains, stream gravel, fan deposits, and volcanic ash.

The structure of the pre-Tertiary rocks is complex. Folds are 

characteristically close or isoclinal and strike east. The postPermian rocks appear to be less metamorphosed and less strongly 

deformed than the earlier rocks, and the Jurassic less than the 

Triassic, though this comparison is less < definite. Seemingly more 

than one epoch of diastrophism is involved possibly three or four. 

Exposures of Mesozoic or earlier unconformities are not known in 

the area with which the writers are acquainted but have been observed in the area studied by Packard south of the Ochoco Range,8 

and the profound post-Mesozoic unconformity is one of the dominant 

features of eastern Oregon geology. The Tertiary rocks rest indifferently upon representatives of all the earlier periods in utter 

disregard of their structure except in so far as pre-Tertiary erosion 

was guided by it.

The present aspect of the country is dominated by the structure 

imposed in Tertiary time. Characteristically the structural features 

trend northwestward in the eastern areas, but in the south and west 

they trend westward. The mountains stand high chiefly because 

of uplifts along these lines; the valleys, for the most part, are structural. Movements along these trends have extended to very recent, 

possibly postglacial time and have been effected by both folding and 

faulting. Geomorphic interpretation of the topography is difficult, 

especially in the eastern areas, where these movements are apparently 

youngest, and deductions as to erosion cycles, either pre-Miocene or

later, must be founded upon the recognition of the recency of these 

displacements.

BOCK UNITS 

CARBONIFEROUS SYSTEM

Carboniferous rocks are widespread in the Blue Mountain region, 

being found in the Wallowa Range,9 the Snake River Canyon,10 

Elkhorn Ridge,11 near Pleasant Valley, and near Supplee,12 south

8 Packard, E. L., op. cit., p. 223.

8 Ross, C. P., Geology and ore deposits of a part of the Wallowa Mountains, Oreg.: 

U. S. Geol. Survey Bull. (in preparation). Washburne, C. W., Notes on the marine sediments of Oregon : Jour. Geology, vol. 11, p. 225, 1903. Gilluly, James, Copper deposits 

near Keating, Oreg.: U. S. Geol. Survey Bull. 830, pp. 6-13, 1932.

10 Laney, F. B., personal communication to C. P. Ross.

n Lindgren, Waldemar, The gold belt of the Blue Mountains of Oregon: U. S. Geol. 

Survey Twenty-second Ann. Rept., pt. 2, pp. 577-579, 1901. Parclee, J. T., and Hewett, 

D. F., Geology and mineral resources of the Sumpter quadrangle : Mineral Resources of 

Oregon, vol. 1, No. 6, pp. 30-35, Oregon Bur. Mines and Geology, 1914.

12 Washburne, C. W., op. cit., p. 225. Packard, B. L., A new section of Paleozoic and 

Mesozoic rocks in central Oregon : Am. Jour. Sci., 5th ser., vol. 15, p. 222, 1928.
SOME MINING DISTRICTS OF EASTERN" OREGON 11

of the Ochoco Mountains. Other localities, more doubtfully referable to the Carboniferous, are near Prairie City and Susanville, 

along the South Fork of the John Day River, on upper Beaver 

Creek, and on Grindstone and Twelvemile Creeks in the Crooked 

River drainage basin.

The Carboniferous rocks near Supplee include massive limestone, 

chert, and chert breccia approximating 3,000 feet in thickness. They 

are of Mississippian age.13 The rocks on Beaver Creek are possibly Devonian 14 but more likely Carboniferous, and those on Grindstone and Twelvemile Creeks are upper Paleozoic, presumably 

Carboniferous.

The great section of Carboniferous rocks1 in Elkhorn Ridge and 

near Pleasant Valley in the eastern Blue Mountains is composed 

of siliceous argillite, carbonaceous shale, chert, some interbedded 

greenstone, and subordinate lenses of limestone. The thickness of 

a partial section is estimated by Pardee 15 as about 3,000 feet; possibly it may be much greater. The age of these rocks is not fixed 

closer than their reference to the Carboniferous, which rests on the 

determination of FusuHina and some poorly preserved brachiopods 

collected by Pardee. 16 Some crinoid stems found near Winterville 

by Lindgren 1T and crinoid stems and poorly preserved bryozoans 

found near Pleasant Valley by the writers suggest but by no means 

suffice to demonstrate, according to G. H. Girty, that tfye age of the 

rocks is Carboniferous.

The rocks in the Wallowa Range referred with some question to 

the Carboniferous are sandstone, conglomerate, marble, quartzite, 

slate, and shale, with some volcanic material and much chert, presumably several thousand feet in total thickness. 18 Their reference 

to the Carboniferous rests on their close association with a greenstone series, discussed below, which they seem in part to underlie 

and in part to overlie, and upon their apparent unconformable relation beneath known Triassic rocks.

In the foothills of the Wallowa Range and extending from a point 

west of North Powder to and beyond the Snake River at Homestead, 

as well as along the Snake River at the mouth of the Burnt River, 

there is a thick series of altered volcanic flows and tuffs, minor intrusions, and subordinate interbedded argillite, chert, and lenticular 

limestone. These greenstones are probably for the most part of 

submarine origin and are composed chiefly of albite-bearing rocks, 

including keratophyre, quartz keratophyre, albite diabase, and 

spilite. The thickness is probably at least 3,000 feet. Their age is 

established as Permian, on the basis of fossil collections from the

"Packard, E. L., op. cit, p. 222. "Idem, p. 35.

14 Washburne, C. W., op. cit., p. 226. "Lindgren, Waldemar, op. cit, p. 578.

1B Pardee, J. T., op. cit., p. 32. 18 Ross, C. P., op. cit.
12 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

included limestone near Homestead,19 near Medical Springs,20 and 

in the district near Keating.21 The rocks along the Snake Kiver at 

the mouth of the Burnt Kiver have not yielded fossils, and there may 

be some doubt of their correlation.

The argillite mapped by Lindgren 22 near Prairie City and the 

slate of Susanville were referred by him to the Carboniferous on 

the basis of their lithologic similarity to the Carboniferous of Winterville and Elkhorn Ridge, but this reference must be regarded as 

tentative in the absence of fossil evidence. The rocks of Susanville 

in particular seem to differ in lithology rather notably from the 

known Carboniferous of the region.

TRIASSIC SYSTEM

Triassic rocks are well developed in the Wallowa Mountains 23 

and are also present in the Snake River Canyon north of Homestead,24 in the Canyon Range south of Canyon City,25 and in the 

region of Freeman Creek, the South Fork of the John Day River, 

and Bear Valley,20 in the country between Canyon City and Supplee. 

Rocks referred with some question to the Triassic occur along the 

Snake River south of Robinette.27

The Triassic rocks of the Wallowa Mountains have been named 

the Martin Bridge formation. They consist of 1,000 to 3,000 feet of 

limestone, limy shale, and interbedded volcanic rocks of Upper 

Triassic age.28 A comparable thickness of chiefly andesitic volcanic 

rock, exposed in the valley of the Cliff River, is believed by Ross to 

be contemporaneous with the Martin Bridge formation.

Perhaps 20,000 feet of slate and shale with minor amounts of 

rhyolite, schistose conglomerate, shaly limestone, greenstone, and 

massive limestone, are exposed in the Snake Kiver Canyon for

about 20 miles along the river from a point near Robinette nearly 

to the mouth of the Burnt River. These rocks have been referred 

to the Triassic by Lindgren 29 and Livingston 30 but without fossil 

evidence.

The Triassic rocks north of Homestead are tuff and lava, with interbedded shale and limestone, and carry casts of Hdlobia or Daon18 Laney, F. B., personal communication to C. P. Ross. 

20 Washburne, C. W., op. cit., p. 225. 

'^Gilluly, James, op. cit., p. 13. 

23 Lindgren, Waldemar, op. cit, pi. 64.

13 Lindgren, Waldemar, op. cit., pp. 580-582. Ross, C. P., op. cit. 

24 Lindgren, Waldemar, op. cit., p. 581.

23 Lupher, R. L., personal communication to James Gilluly, Apr. 21, 1931. 

28 Packard, E. L., op. cit, p. 223.

27 Livingston, D. C., A geologic reconnaissance of the Mineral and Cuddy Mountain 

districts, Idaho: Idaho Bur. Mines and Geology Pamphlet 13, pp. 5-6, 1924.

28 Ross, C. P., op. cit. Smith, J. P., The occurrence of coral reefs in the Triassic of 

North America: Am. Jour. Sci., 4th ser., vol. 33, pp. 94-95, 1912.

29 Lindgren, Waldemar, op. cit., pi. 64, pp. 752-753.

30 Livingston, D. C., op. cit., pp. 5-6.

\
SOME MINING DISTRICTS OF EASTERN OREGON 13

ella.31 No details as to the thickness or distribution of this formation are known.

The rocks south of Canyon City that have been referred to the 

Triassic on fossil evidence consist chiefly of dark fine-grained shale, 

sandstone, grit, and conglomerate.32 Their thickness has not been 

published, but it is known to be considerable.

JURASSIC SYSTEM

Eocks of Jurassic age have not been proved to be present in the 

eastern part of the Blue Mountains, although about 3,000 feet of 

unfossiliferous slate, sandstone, conglomerate, and hornfels (presumably derived from the slate) have been found in the Wallowa Mountains overlying the Upper Triassic and may represent the Jurassic 

period.33

A great thickness of Jurassic shale, impure limestone, sandstone, 

and conglomerate has been found in the Silvies Kiver country south 

of John Day.3 * Jurassic rocks have been reported from the vicinity 

of Supplee 35 and from Red Butte, in T. 19 S., K. 30 E.80 Unfortunately the results of the large amount of work done in this region 

by Mr. Lupher have not yet been published, so that more detailed 

information is not available, beyond the fact that Lower Jurassic 

fossils like those of the Hardgrave sandstone of California occur 

in one of the several formations that have been discriminated. 

The occurrence of the fauna of the Hardgrave sandstone on Beaver 

Creek, a tributary of the Crooked Kiver, in the Blue Mountains of 

eastern Oregon, was recorded by Hyatt 37 on the basis of collections 

obtained by Thomas Condon.

CRETACEOUS SYSTEM

Stratified rocks representative of the Cretaceous system have not 

been recognized in the eastern part of the Blue Mountains but are 

found along Beaver Creek near Supplee,38 near Mitchell,39 and in 

Spanish Gulch east of Mitchell.40 The rocks near Mitchell are sandstone, conglomerate, and shale, formerly correlated, on lithologic 

grounds, with the Knoxville of California. More recent studies by

81 Llndgren, Waldemar, op. cit, p. 581.

83 Packard, E. L., op. cit., p. 223. 

83 Ross, C. P., op. cit.

84 Lupher, R. L., personal communication, 1929.

^Packard, E. L., op. cit, p. 223.

"oWashburn, C. W., op. cit., p. 227.

87 Hyatt, Alpheus, Trias and Jura in the Western States: Geol. Soc. America Bull., 

vol. 5, p. 401, 1894.

33 Packard, E. L., op. cit., pp. 223-224. Washburne, C. W., op. cit, pp. 228-229.

^Merriam, J. C., A contribution to the geology of the John Day Basin: California Univ. 

Dept. Geology Bull., vol. 2, No. 9, p. 284, 1901.

40 Idem, pp. 284-285. Washburne, C. W., op. cit, p. 228.
14 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Packard 41 suggest that no beds of Knoxville age are present at 

Mitchell, but that representatives of both Horsetown and Chico are. 

They are about 3,000 or 4,000 feet thick.

The Cretaceous rocks exposed at the other localities listed are 

conglomerate and sandstone of unknown thickness whose fauna 

suffices to correlate them with the Chico formation of California.

STRATA OF UNKNOWN BUT PRE-TERTIARY AGE

A considerable thickness of chloritic pencil schist, quartz phyllite, 

quartzitic schist, greenstone, and limestone occurs on Dooley Mountain, south of Baker, extending west into the southern part of the 

Suinpter quadrangle and eastward along the Burnt River Canyon 

to and beyond the Mormon Basin. The series, which is not conspicuous in the Sumpter quadrangle, was there mapped as a part 

of the Carboniferous argillite,42 whereas on Lindgren's map 43 it 

was shown as Carboniferous along the Burnt River Canyon west of 

Durkee but as Triassic in the Mormon Basin. The series seems to 

be not less than 4,000 feet thick, even after allowance is made for 

probable isoclinal folding, so that it is a notable element in the 

geology of the region, but owing to intrusions and Tertiary overlaps, its relations have not yet been deciphered, and, as it has not 

yielded fossils, it is not known whether the rocks underlie, are 

equivalent to, or overlie the argillite. The rocks are clearly preTertiary, as they are overlain with marked unconformity by 

Tertiary sediments and volcanic rocks.

TERTIARY SYSTEM

The most widespread rocks of the Blue Mountain region are of 

Tertiary age, Although many years of painstaking work, chiefly 

by Merriam and his associates, 44 has resulted in the establishment of 

a standard section in the John Day Basin, sufficiently detailed work 

has not yet been done in more easterly areas to enable confident 

correlations to be made with this section.

41 Packard, E. L., Carnegie Inst. Washington Yearbook, No. 26, p. 365, 1927.

"Pardee, J. T., and Hewett, D. F., op. cit., map.

43 Lindgren, Waldemar, op. cit., pi. 64.

u Merriam, J. C., A contribution to the geology of the John Day Basin : California Univ. 

Dept. Geology Bull., vol. 2, pp. 269-314, 1901. Merriam, J. C., and Sinclair, W. J., The 

correlation of the John Day and the Mascall: Jour. Geology, vol. 11, pp. 95-96, 1903. 

Merriam, J. C., Tertiary fauna of the John Day region : California Univ. Dept. Geology 

Bull., vol. 5, pp. 171-205, 1907. Merriam, J. C., Stock, Chester, and Moody, C. L., An 

American Pliocene bear: California Univ. Dept. Geology Bull., vol. 10, pp. 111-127, 1916. 

Merriam, J. C., Stock, Chester, and Moody, C. L., The Pliocene Rattlesnake formation and 

fauna of eastern Oregon, with notes on the geology of the Rattlesnake and Mascall 

deposits: Carnegie Inst. Washington Pub. 347, pp. 43-92, 1925. Calkins, P. C., A contribution to the petrography of the John Day Basin : California Univ. Dept. Geology Bull., 

vol. 3, pp. 109-172, 1902. Chancy, R. W., A comparative study of the Bridge Creek flora 

and the modern redwood forest: The Mascall flora; its distribution and climatic relation : 

Carnegie Inst. Washington Pub. 349, pp. 1-48, 1925.
SOME MINING DISTRICTS OF EASTERN OREGON 15

The Tertiary section in the John Day Basin includes the Clarno 

formation at its base, followed by the John Day formation, Columbia 

Eiver lava, Mascall, and Kattlesnake formations, including representatives of the Eocene, Oligocene, Miocene, and Pliocene epochs.

The Clarno, which is about 2,000 feet thick,45 consists of shale, tuff, 

and andesitic rhyolitic lavas and contains two different floras. Both 

of these floras were originally referred to the Eocene,48 but the 

upper, whose type locality is Bridge Creek, has been thought to be of 

Oligocene age,47 and Buwalda48 has called the entire Clarno " probably Oligocene." In a manuscript submitted in July, 1924, and published in 1926, Knowlton49 revised his former opinion and stated that 

the upper part of the Clarno is probably lower Miocene. Berry50 also 

states that the upper part of the Clarno is clearly younger than 

Eocene and may well be as young as Miocene. The United States

Geological Survey assigns the Clarno to the upper Eocene and lower 

Oligocene. Beds similar in lithology and flora crop out in the 

Crooked Eiver Valley51 and have been correlated with the type areas 

on Bridge Creek and near Clarno Ferry, from which the formation 

extends beyond Fossil to a point near Heppner.62

The John Day formation, about 2,000 feet thick,58 consists of 

varicolored shale, tuff, conglomerate, and sandstone, assigned by the 

United States Geological Survey to the middle and upper Oligocene 

and lower Miocene, resting conformably on the Clarno. It is exposed in the Crooked Kiver Valley near Post, as well as in the type 

locality north of the Ochoco Range, in the John Day Valley.

The Columbia River lava, as much as 2,500 feet thick,53 rests 

unconformably on the John Day formation and constitutes the 

most widespread formation in the State. This lava is thought to 

extend from the Cascade Range to central Idaho and from central 

Washington to the Harney Basin in southern Oregon. Some doubt 

may be expressed as to the detailed correlations through the extremes 

of this region, but none as to the great extent of this formation 

within it.

45 Collier, A. J., The geology and mineral resources of the John Day region : Mineral 

Resources of Oregon, vol. 1, No. 3, p. 13, Oregon Bur. Mines and Geology, 1914.

48 Knowlton. F. H., Fossil flora of the John Day Basin, Oreg.: U. S. Geol. Survey Bull. 

204, p. 113, 1902.

47 Chaney, R. W., op. cit, p. 22.

"8 Buwalda, J. P., Geological features of the John Day region, eastern Oregon: Geol. 

Soc. America Bull., vol. 39, p. 269-270, 1928.

49 Knowlton, F. H., Flora of the Latah formation of Spokane, Wash., and Coeur d'Alene, 

Idaho: U. S. Geol. Survey Prof. Paper 140, p. 23, 1926.

BO Berry, E. W., A revision of the flora of the Latah formation : U. S. Geol. Survey Prof. 

Paper 154, p. 235, 1929.

61 Chaney, R. W., op cit, p. 21.

82 Collier, A. J., op. cit., geologic map.

68 Idem, p. 10.
16 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PABT 1

Overlying the Columbia River lava with approximate conformity 

is the Mascall formation, consisting of tuff and " lake beds " over 

2,000 feet thick-. 54 These beds are classified by the United States 

Geological Survey as of middle Miocene age, but they are regarded 

by some geologists as upper Miocene. They are now preserved only 

in a syncline at the type locality near Dayville and although formerly 

more extensive, at least toward the north,55 probably did not extend 

as a continuous formation over much of the country. A flora of 

similar aspect has been collected from the Payette formation of 

Idaho, the Ellensburg formation of central Washington, the Latah 

formation of eastern Washington, Trout Creek in Malheur County, 

Oreg., and several localities in Nevada and California, as well as 

from Tipton, a point northeast of Austin, in the Sumpter quadrangle.56 The basins in which these deposits were laid down were 

probably all local, however.

Unconformably overlying the Mascall formation is the Pliocene 

Rattlesnake formation, consisting of gravel, tuff, and rhyolite 900 

feet thick 57 or less, which was presumably laid down in an old 

valley of the John Day River. It was a local deposit, without doubt.

In the Sumpter quadrangle 58 the Tertiary formations recognized 

differ notably from those exposed in the John Day Valley 50 miles 

to the west. From bottom to top they are gravel (local only), 

andesitic tuff breccias (2,000 feet thick), "older basic flows" (100 

to 300 feet thick), lake beds and rhyolite, and " younger basic lavas." 

Of these only the " lake beds " have yielded fossils, which show 

that they are of Miocene age, presumably correlative with the 

Mascall. The tentative correlation with the section in the John Day 

Valley, suggested by Pardee and Hewett,59 is as follows:

Suinpter quadrangle John Day region 

Younger basic lavas__ ________ (?). 

Lake beds and rhyolite__________ Mascall formation. 

Older basic flows_______________ Columbia River lava. 

Tuff-breccia_________________ John Day formation. 

Pre-tuff-breccia gravel _______ Clarno (?) formation.

The difficulties in the way of correlation of these Tertiary beds 

are considerable, however, as is illustrated in the comparison between

64 Merriam, J. C., Stocl:, Chester, and Moody, C. L., The Pliocene Rattlesnake formation and fauna of eastern Oregon, with notes on the geology of the Rattlesnake and 

Mascall deposits: Carnegie Inst. Washington Pub. 347, p. 52, 1925.

65 Idem, p. 49.

60 Chaney, R. W., op. cit., p. 46.

B7 Merriam, J. C., Stock, Chester, and Moody, C. L., Carnegie Inst. Washington Pub. 347, 

p. 56, 1925.

68 Pardee, J. T., and Hewett, D. F., Geology and mineral resources of the Sumpter quadrangle : Mineral Resources of Oregon, vol. 1, No. 6, pp. 39-47, Oregon Bur. Mines and 

Geology, 1914.

68 Idem, p. 47.
SOME MINING DISTRICTS OF EASTERN OREGON 17

the Tertiary section established in the Sumpter quadrangle and that 

in the Baker quadrangle just to the east. The section in the Baker 

quadrangle, as determined by the writers, is, from bottom to top, 

(1) rhyolitic breccia of Dooley Mountain, (2) porphyritic andesite, 

(3) andesitic tuff-breccia, (4) Columbia Eiver basalt and andesite 

with interbedded fluviatile and lacustrine beds, (5) lacustrine and 

fluviatile beds overlying the Columbia Kiver basalt, and (6) basalt. 

The topmost basalt is local only and occurs just east of the Baker 

quadrangle, not in it.

The tentative correlation suggested with the Sumpter quadrangle 

is as follows:

Sumpter quadrangle Baker quadrangle 

Younger basic lavas ___________ Basalt. 

Lake beds and rhyolite________ Lake beds.

Columbia River basalt________ Columbia River basalt.

'Andesitic tuff-breccia.

Tuff-breccia. Porphyritic andesite.

Rhyolite breccia of Dooley Mountain. 

Pre-tuff-breccia gravel.

The only fossils collected from the Tertiary rocks of the Baker 

quadrangle were leaves from the lake beds interfingering with the 

Columbia River lava in the lower Powder Valley, and these are 

reported to be of Miocene age,60 supporting a tentative correlation 

with the Mascall on the one hand and the Payette on the other.

The meager extent of many of the Tertiary formations, both 

sedimentary and volcanic, is so evident from the differences in the 

rock succession in the John Day Valley and in the Sumpter and 

Baker quadrangles that the writers hesitate to suggest a correlation 

with the John Day section in the absence of detailed work in the 

intervening areas.

QUATERNARY SYSTEM

Quaternary deposits present in the Blue Mountains include fan 

gravel and alluvial ^deposits in Baker and Grande R-onde Valleys 

and along the main streams and a thin deposit of white volcanic ash, 

which occurs widespread in the region, especially in alluvial cones at 

the mouths of mountain streams. A few small glacial moraines 

deposited by alpine glaciers occur in Elkhorn Ridge and the Wallowa 

Mountains.

PLUTONIC ROCKS

General features. A great variety of intrusive rocks is present in 

the Blue Mountain region, ranging in composition from serpentine, 

dunite, pyroxenite, norite, and gabbro through diorite, hornblendequartz diorite, biotite-quartz diorite, and granodiorite to albite

80 Brown, R. W., personal communication, 1930.
18 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

granite. Structurally the intrusive rocks range from gneissic to 

almost massive.

Lindgren 61 suggested that intrusive rocks of more than one age 

may be present in the region, a conclusion which is supported by the 

diversity of metamorphism represented in the plutonic rocks, by the 

long volcanic history recorded in the stratigraphy, and most conclusively by the recent work of R. L. Lupher, who has obtained definite 

stratigraphic evidence in the Canyon Creek area, south of Canyon 

City, that intrusives of Middle or Lower Triassic age and of probable 

Upper Jurassic age (post-Callovian, pre-Horsetown) are there present.62 In the Sumpter quadrangle a metagabbro sill is involved in 

folding that is earlier than the intrusion of " granodiorite " at Bald 

Mountain.63

Of the widespread plutonic rocks the granodiorite of Lindgren, 

here called biotite-quartz diorite, is clearly the youngest and may be 

tentatively called late Jurassic, correlative with the Idaho batholith.64 

Petrographic studies by D. F. Hewett show that the Bald Mountain 

mass of " granodiorite " of Lindgren contains less than 8 per cent of 

orthoclase, and hence should be classed as quartz diorite. Similarly, 

studies by the writers show that the so-called granodiorite at Gold 

Hill, that at Pedro Mountain, and the rock at Haines are typically 

quartz diorite, only locally carrying enough potash feldspar to 

warrant calling them granodiorite. The question whether the biotitequartz diorite is merely the last intrusive of a single magmatic cycle 

or the representative of a cycle distinct from the one which is represented by the gabbro, hornblende-quartz diorite, and associated rocks 

must be left open, although some evidence that it represents a distinct 

cycle is available.65 Indeed, several distinct cycles may be represented in the other rocks. Evidence to date them accurately is only

locally available, however, so that the descriptions here given are 

based on petrography rather than age.

Serpentine. Serpentine, largely derived from dunite, pyroxenite, 

and basic gabbro, occurs in large quantities near Kobinsonville and 

Bonanza, in the Sumpter quadrajigle, near Susanville, and in the 

Strawberry Mountains.00 It also occurs in smaller masses in the Mormon Basin, southeast of Rye Valley, on Dooley Mountain (Baker 

quadrangle), north and northeast of Prairie City, and near Pleasant 

Valley. In all these localities the serpentine possesses the usual 

colors, ranging from yellowish green to black, and is thoroughly

61 Lindgren, Waldemar, op. cit., p. 596.

02 Lupher, R. L., personal communication, Apr. 21, 1931.

C3 Pardee, J. T., and Hewett, D. P., OP- cit., pp. 34, 36-38.

64 Boss, C. P., Mesozoic and Tertiary granitic rocks in Idaho: Jour. Geology, vol. 36, 

pp. 673-693, 1928.

05 Reed, J. C., and Gilluly, James, A study of the heavy mineral assemblages of some 

of the plutonic rocks of eastern Oregon : Am. Mineralogist, vol. 17, pp. 201-220, 1932.

66 Lindgren, Waldemar, op. cit., p. 589.
SOME MINING DISTRICTS OF EASTERN OREGON 10

slickensided and sheared. It is soft but tough, very resistant (o 

erosion, and affords a poor soil that is commonly barren of vegetation. Locally asbestos seams are present in the rock, and at least 

one deposit, near Pine Creek, south of Dooley Mountain, in the 

Baker quadrangle offers some commercial possibilities.

Other ultwibasic rocks. Dunite and closely related harzburgite 

are present in the Mormon Basin and presumably were formerly 

present elsewhere is the Blue Mountains but are now largely altered 

to serpentine. Only small bodies of unserpentinized basic rocks 

remain. Some pyroxenite occurs on Canyon Creek.07

Gafobro, diabase, and norite. Gabbro is widespread in the Blue 

Mountains, being found in the Wallowa Mountains °8 in the Virtue 

district, in Elkhorn Ridge, in the Greenhorn Mountains, near Dixie 

Butte north of Prairie City, near Canyon City,09 and in the Mormon

Basin. Many of these masses of gabbro show gneissic banding and 

brecciation, indicating strong compression after their consolidation. 

The rocks are commonly dark gray and fairly coarse grained and 

are composed of labradorite or more calcic plagioclase with augite 

or hornblende derived from augite.

Diabase is found in the Quartzburg district and near Canyon City 

but is not a common rock among the older intrusives. However, 

dikes that are considered to be feeders for the Columbia River basalt 

flows are rather common in the Wallowa Mountains, especially near 

Cornucopia.70 Some of these are diabase, though others are normal 

basalt.

The only norite so far recorded from this part of Oregon crops out 

northeast of the Flagstaff mine, north of Virtue Flat, in the Baker 

quadrangle. It is composed of labradorite and hypersthene.

Diorite. Diorite is widespread in the Blue Mountain region, in 

association with the gabbros and also as local f acies of the quartz 

diorites. It has been found in the Mormon Basin, in Elkhorn Ridge, 

on Dooley Mountain, near Keating, in the "Wallowa Mountains,71 in 

the Coyote Hills near Haines,72 in Dixie Creek Canyon above Prairie 

City, and in the Powder River Canyon near North Powder.

Commonly the diorites are sheared and recrystallized to some extent, but those associated with quartz diorite are not. The nonquartzose diorites consist of andesine feldspar and augite or hornblende 

as the essential minerals; some have a little orthoclase and biotite 

with the usual accessory minerals.

07 Lupher, R. L., personal communication, Apr. 21, 1931.

08 Ross, C. P., Geology and ore deposits of a part of the Wallowa Mountains: U. S. Cool 

Survey Bull. (in preparation). 

08 Lindgren, Waldemar, op. cit., p. 588.

70 Idem, p. 593.

71 Ross, C. P., op. cit.

73 Lindgren, Waldemar, op. cit., p. 588.
20 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Quartz diorite and granodiorite. The most widespread granitic 

rock of the Blue Mountains is biotite-quartz diorite that locally 

varies to granodiorite. This rock occupies large areas in "the Greenhorn Mountains and Elkhorn Kidge and also occurs near Haines, 

in the Wallowa Mountains, in the Virtue district, and on Lookout 

and Pedro Mountains, Hornblende-quartz diorite, which differs 

mineralogically from the biotite-quartz diorite only in containing 

hornblende rather than biotite as the chief dark mineral, in this region differs also in being commonly somewhat more sheared or even 

gneissic. It occurs in close association with gabbro near Dixie Butte, 

north of Prairie City, in the Elkhorn Ridge, near Keating, and in 

the Virtue district.

Albite granite. Albite granite is present over considerable areas 

in the Magpie Peak district, east of Haines, and in the Keating and 

Sparta districts. It is composed of albite and quartz as essential 

minerals with usually a little epidote and chlorite and rarely a little 

amphibole. The rock is characterized by its high degree of brecciation and by peculiar pseudophenocrysts of quartz as well as by a 

very common graphic structure. It has been regarded as a replacement product of the hornblende-quartz diorite.73

. STRUCTURE

Pre-Tertiary structure. The dominant feature of the structure of 

the pre-Tertiary rocks of the Blue Mountain country is the prevalent 

east-west trend of the rocks. The Blue Mountains offer an analogy, 

in the western part of the Cordillera, to the Owl Creek and Uinta 

Mountains in the eastern part, in possessing structural features transverse to the strike of the mountain system as a whole. Throughout

the nearly 200 miles from the Seven Devils region of Idaho to the 

Deschutes Valley the principal trends are westward. Exceptions to 

this trend are noted along the Snake River Canyon between Huntington and Robinette, where the supposed Triassic schist and slates 

strike north-northeast, and in Elkhorn Ridge, where northwesterly 

strikes are common.

Through the entire region the bedded rocks lie in closely appressed 

folds, some of which are probably isoclinal. The metamorpl>ic 

character of the. rocks has thus far prevented the working out of 

details of structure; presumably more detailed mapping will throw 

light on the character of the folding and the possibilities of faulting. It seems probable that the territory embraced within the Pine 

quadrangle is especially critical in this connection.

73 Gilluly, James, The origin of the albite granite near Sparta, Oreg.: U. S. Geol. Survey 

Prof. Paper 175, pp. 65-81, 1933.
21

The masses of intrusive rocks have clearly influenced the structure and have had a considerable effect in inducing schistosity and 

local deviations in strike peripheral to them. This feature is especially marked about the Pedro Mountain mass of quartz diorite, 

whose effects are described on page 36, and has also been noted in 

Bald Mountain and McCully Fork,74 in the Sumpter quadrangle, although there is some evidence that there has also been permissive 

intrusion and engulfment of the country rock in this same general 

region.75 Detailed study of the internal structure of the quartz 

diorite near Haines seems to show that this body was emplaced, in 

part at least, by shouldering the walls apart.

Nevertheless, inclusions of country rock in several of these intrusive masses have much more marked schistosity than the intrusions, 

suggesting that at least some of the pressure that induced the schistosity was regional in extent and earlier than the intrusion of the 

plutonic masses now exposed, hence not directly attributable to 

them. It is thus possible that the folding and metamorphism of the 

country rock are primarily results of regional pressure and erogenic 

activity whose final phases included the injection of the biotitequartz diorite masses. Much more detailed work will be needed to 

determine these questions.

The fact that the pre-Triassic rocks of the Wallowa Kange are 

clearly much more metamorphosed than the Triassic rocks suggests that at least two periods of erogenic activity have occurred 

in the region. Another period is indicated by the strong angular 

unconformity between the Triassic and Jurassic rocks south of 

Canyon City 76 and by the fact that some of the pyroxenite of that 

region is of Lower or Middle Triassic age, whereas a gabbro which 

intrudes it is probably late Jurassic.77 In the mountainous region 

as a whole, however, sufficient work has not been done to differentiate 

the effects of these several movements. Provisionally, a post-Permian pre-Upper Triassic and a post-Triassic orogeny may be considered fairly well established.

Pre-Tertiary unconformity. Wherever the contact is exposed 

in the Blue Mountain region the Tertiary rocks are seen to rest 

with marked angular unconformity on the pre-Tertiary rocks. 

This unconformity is one of the dominant features of the geology 

of the region. The overlying rocks rest indifferently, at one place 

or another, upon all the pre-Tertiary rocks, and their attitudes are 

entirely discordant.

« Pardee, J. T., and Hewett, D. P., op. clt., pp. 36-37 

re ldem, p. 37.

"Lupher, R. L., oral communication, 1929.

77 Lupher, R. L., personal communication, Apr. 21, 1930.
22 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

That the surface upon which the Tertiary rocks were deposited 

was extremely irregular is demonstrated by both stratigraphic and 

structural evidence. The stratigraphic evidence may be exemplified 

by the relations in the valley of the East Fork of the John Day 

Kiver. At Picture Gorge, northwest of Dayville, the Columbia 

Kiver basalt is underlain by about 2,000 feet of earlier Tertiary beds, 

whereas a few miles to the east the basalt rests directly upon the 

pre-Tertiary basement. Similarly, in the Sumpter quadrangle the 

" older basic lavas " rest directly on the pre-Tertiary rocks at Black 

Mountain, whereas only about 10 miles to the south, at King's Mountain, they are separated from the pre-Tertiary by about 1,800 feet of 

" tuff-breccia." Although an unconformity exists between the John 

Day and Columbia Eiver lava at Picture Gorge, it is probably not 

great, and there is apparently complete conformity between the 

" andesitic tuff-breccia ft at King's Mountain and the overlying 

" older basic lavas." Numerous examples of similar though less striking stratigraphic variations in the Tertiary rocks beneath the Columbia Eiver basalt occur in the Baker quadrangle.

Structural evidence of the irregularity of the surface of unconformity is no less strong. As pointed out by Lindgren,78 the Snake 

River Canyon between the Wallowa Mountains and the Seven Devils 

exposes an old mountainous topography whose relief exceeds 2,500 

feet, abutting against which and finally overtopping its ridges rests 

undisturbed Columbia River lava. Several exposures near the 

mouth of Pine Creek show, by the curvature of the columnar jointing of the lava, that.the steep slopes against which the flows abut 

were in existence at the time of their extravasation and are not due 

to later faulting. Similar exposures, showing a relief of 300 or 400 

feet in a horizontal distance of less than 1,000 feet, are found at the

mouth of Big Creek in the Powder River Canyon and along Auburn Canyon in the Baker quadrangle and on Goose Creek in the 

Pine quadrangle.

In view of these evidences of great irregularity of the pre-Tertiary surface it has proved thus far impracticable to recognize, in the 

Blue Mountain region, any representative of the old erosion surface 

of central Idaho of supposed early Tertiary age.79 At any rate, the 

surface upon which the Columbia River lava was poured out was, 

even if allowance is made for post-Miocene folding and faulting, by 

no means a peneplain, or even a surface of low relief.

Tertiary folding and faulting. Throughout the Blue Mountain 

region there has been much deformation of the Tertiary rocks, al78 Lindgren, Waldemar, The gold and silver veins of Silver City, De Lamar, and other 

mining districts in Idaho: U. S. Geol. Survey Twentieth Ann. Rept., pt. 3, pp. 91-93, 1900.

79 Ross. C. P., Salient features of the geology of south-central Idaho (abstract) : Wash 

ington Acad. Sci. Jour., vol. 18, pp. 267-268, 1928.
SOME MINING DISTRICTS OF EASTERN OREGON 23

though the dips impressed upon them only locally exceed 20° or 

30°. The deformation has taken place both by folding and by faulting, but except locally the dominant process has been folding. In 

the eastern part of the area the folding has occurred chiefly along 

axes trending northwest or west-northwest, as observed by Pardee 

and Hewett 80 in the Sumpter quadrangle and by the writers in the 

Baker and near-by areas, but in the John Day Valley the axes trend 

more nearly westward,81 and near Heppner south westward. To a 

large extent the country owes its present configuration to these folds, 

the higher country being anticlinal and the lowlands synclinal, although of course the major drainage courses have modified this relationship in many places.

Faulting has occurred along axes that characteristically trend 

somewhat more northerly than the associated folds,82 but the displacement is in general such as to emphasize the structural relief due to 

the folding. Probably the most noteworthy faults so far mapped 

are those exposed in the Oregon Copper Co.'s mine on Balm Creek 

near Keating and those determining the course of Sutton and Alder 

Creeks southeast of Baker, in the Baker quadrangle. The lastnamed faults continue, at least as a zone, into the line of faults that 

bound Elkhorn Ridge on the northeast.

The age of the folding is known to be post-Miocene in large part, 

for fossiliferous upper Miocene beds are involved, but there may 

have been some folding in earlier Tertiary time. Some folding has 

also occurred in post-Pliocene time, for the Rattlesnake formation, of 

this age, is tilted several degrees.

The faults are probably contemporaneous with the folds, but 

some, such as the one that occurs along the northeast side of Elkhorn Ridge, are probably Pleistocene,83 or at least their latest activity 

is of that age, whereas others, such as those in the Lake Creek basin 

southwest of Baker, and about a mile north of Lost Basin, in the 

southeastern part of the Baker quadrangle, have been active so 

recently that the drainage is disrupted by them.

These recent movements have produced further irregularities in 

the topography of the northeastern part of the Blue Mountains, 

which already, owing to the contrasted lithology of soft lacustrine 

Miocene beds and durable cherty argillite, gabbro, and quartzitic 

schist, was of highly diversified character. It has been impossible

80 Pardee, J. T., and Hewett, D. F., op. cit., pp. 45-47.

81 Collier, A. J., op. cit., geologic map. Merriam, J. C., Stock, Chester, and Moody, 

C. L., Carnegie Inst. Washington Pub. 347. pp. 49, 57-58, 1925.

83 Buwalda, J. P., Report of investigations: Carnegie Inst. Washington Yearbook 27, 

p. 385, 1928. Pardee, J. T., and Hewett, D. P., op. cit., geologic map. Gilluly, James, 

Geology of the Baker quadrangle, Oreg.: TJ. S. Geol. Survey Bull. (in preparation).

83 Lindgren, Waldemar, The gold belt of the Blue Mountains of Oregon : TJ. S. Geol. 

Survey Twenty-second Ann. Kept., pt. 2, pp. 652-653, 1901.
24 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

so far to recognize in this area the Ochoco erosion surface,84 of 

Pliocene age, which is extensively developed in the Ochoco Range 

and is probably represented in the plateau surface near Condon. 

Possibly more detailed work over a wider area than was possible 

for the writers may permit the recognition of this surface, but it 

seems equally possible that it was not so well developed here as 

in the internal drainage basin of Harney Valley and the lately 

aggradational Deschutes Valley.

MINERAL DEPOSITS

HISTORY OF MINING

Although mining began in southwestern Oregon about 1852, the 

discovery of gold in the Blue Mountains dates from the fall of 1861, 

when a prospector named Griffin located the placer deposits in 

Griffin Gulch, a few miles southwest of Baker.85 The rich placers 

of Auburn, near by, were discovered the following year, and a rush 

to the district followed, so that within a year Auburn had a population of 5,000. The evanescence of such placer camps is illustrated 

by the fact that not a house is standing on the site of this once 

flourishing city.

The great influx of miners naturally brought about intensive prospecting of the surrounding territory, with the result that within 

two years practically all the districts of the Blue Mountains and the 

Boise Basin and Owyhee districts in Idaho were located by prospectors from Auburn. Within a few years the need for increased supplies of water for mining was felt, and considerable investments 

were made in ditches to carry water to the placer ground. The Auburn Ditch, which is still used to carry the municipal supply of 

Baker but no longer for mining, was completed in 1863, the Rye 

Valley Ditch in 1864, the Sparta Ditch in 1873, and the El Dorado 

Ditch, the longest, in 1873. The El Dorado Ditch is over 100 miles 

long and carried water from a point near the head of the Burnt 

River to the placer diggings at Malheur. All these ditches except 

the Auburn have been long since abandoned.

As in most placer districts, the first few years marked the peak 

of production. Lindgren estimated the output from Oregon during 

the four years from 1862 to 1865 as probably near $50,000,000,86 most 

of which was derived from the Blue Mountain country. Lindgren's 

compiled data show that the production fell off rapidly at first,

84 Buwalda, J. P., A Neocene erosion surface in central Oregon : Carnegie Inst. Washington preprint of Pub. 404, June, 1929.

85 Lindgren, Waldemar, op. cit., p. 563. 

80 Idem, p. 569.
SOME MINING DISTRICTS OP EASTERN OREGON 25

then more slowly until about 1883, when lode mining began to make 

itself felt.

Although numerous lode mines were opened before 1870, transportation facilities were so poor that little lode mining could be 

done until 1885, when the transcontinental railroad now traversing 

the district was completed. From about 1889 the quartz mines made 

a rapid increase in production, resulting about 1899 and 1900 in 

a considerable influx of prospectors and miners, whose influence was 

felt in a " boom " that led to the development of many mines. The 

most productive period in the history of lode mining was 1913 

to 1918, but since that period until 1929, the latest year for which 

statistics are available, the output has fallen off.

PRODUCTION

The following table shows the production of gold and silver in 

the Blue Mountain region since 1903. Statistics for the years 1900 

to 1902 are not available by counties. Figures for years up to 1899 

are given by Lindgren.87

Gold (md silver prodiiced m Baker, Grant, and Malheur Counties, Oreg., from

1908 to 1929

[Compiled from annual volumes of Mineral Kesources of the United States, published by the United 

States Geological Survey to 1923, since 1923 by the United States Bureau of Mines. Chapters on Oregon 

for 1903-1921, by C. G. Yale; for 1922-1926, by J. M. Hill; for 1927-1929, by V. C. Heikes]

Vnar £ car

1903.. .

1904.. .

1905.. .

1906.. .

1907.. .

1908 

1909 

1910 

1911. _

1912....

1913 

1914 

1915 

1916 

1917.. .

1918.. .

1919.. .

1920.. .

1921.. .

1922.. .

1923.. .

1924....

1925 

1926 

1927....

1928 

1929 

Gold

$691, 546

790, 828

771, 607

695, 653

631,045

507, 929

417, 538

401, 002

389, 786

484, 041

1,373,480

1, 313, 967

1, 685, 382

1, 640, 626

1, 228, 199

1, 009, 656

837, 863

890, 380

605, 465

322, 688

290, 403

324, 252

181, 251

75, 564

82, 305

11, 408

25, 601

17, 679, 465

Baker

Silver

$12, 520

44, 355

55, 161

35, 984

45, 929

9,273

10, 147

16, 111

16, 400

24,071

47, 826

32, 222

55, 833

140, 472

82, 950

90, 385

101, 318

83, 308

39, 509

142, 582

69, 094

17, 809

14, 085

5,654

4,800

826

249

1, 198, 873

Total

$704, 066

835, 183

826, 768

731,637

676, 974

517,202

427, 685

417, 113

406, 186

508, 112

1, 421, 306

1, 346, 189

1, 741, 215

1, 781, 098

1, 311, 149

1, 100, 041

939, 181

973, 688

644, 974

465, 270

359, 497

342, 061

195, 336

81, 218

87, 105

12, 234

25,850

18, 878, 338

Gold

$102, 313

82, 280

88,246

55, 092

80, 645

88, 636

41,328

36, 201

37, 341

21,627

63, 652

59, 898

6,247

63, 593

137, 720

101, 981

64, 495

69, 453

108, 209

120, 268

157,770

171, 181

111,607

114, 532

152, 949

81,862

73, 252

2, 292, 378

Grant

Silver

$34, 439

29, 417

14, 952

2,492

7,106

9,533

881

1,254

1,230

359

55, 361

37,911

731

1,052

18, 995

13, 026

22, 021

6,526

1,613

6,671

8,885

7,275

8,008

9,821

20, 514

14, 935

11, 096

346, 104

Total

$136, 752

111,697

103, 198

57, 584

87, 751

98, 169

42, 209

37, 455

38, 571

21, 986

119,013

97, 809

6,978

64, 645

156, 715

115, 007

86, 516

75, 979

109, 822

126, 939

166, 655

178, 456

119,615

124, 353

173, 463

96, 797

84, 348

2, 638, 482

I

Gold

$29, 227

23,069

18, 495

4,847

19, 127 '

14, 699

42, 353

31, 274

14, 133

43, 430

82, 041

50, 052

33, 639

14, 276

1,892

947

1,285

200

3,410

9,536

5,159

8,224

3,336

8,288

1,306

1,076

2,262

467, 583

klalheui

Silver

$10

80

51

* 87

51

801

850

67

250

2,026

1,260

698

47

270

6

13

2

40

96

53

75

58

214

56

5

11

7,177

Total

$29, 227

23, 079

18, 575

4,898

19, 214

14, 750

43,154

32,124

14; 200

43, 680

84, 067

51,312

34, 337

14, 323

2,162

953

1,298

202

3,450

9,632

5,212

8,299

3,394

8,502

1,362

1,081

2,273

474, 760

Total

$870, 045

969, 959

948, 541

794, 119

783,939

630, 121

513, 048

486, 692

458, 957

573, 778

1, 624, 386

1, 495, 310

1, 782, 530

1, 860, 066

1,470,026

1, 216, 001

1,026,995

1,049,869

758, 246

601, 841

531, 364

528, 816

318, 345

214, 073

261, 930

110, 112

112, 471

21, 991, 580

87 Lindgren, Waldemar, op. cit., p. 573. 

164495 33 3
26 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The great bulk of the mineral production of the Blue Mountain 

country has been in gold and silver, but small amounts of copper 

have been mined in connection with the gold for many years, and 

between 1915 and 1928 several properties at Homestead, on the Snake 

Kiver, were operated primarily for their copper. During these 

years the copper production of Baker County, derived chiefly from 

the Homestead Iron Dyke mine, amounted to more than 14,000,000 

pounds, valued at about $2,400,000. There has also been considerable prospecting for copper and a nominal production from mines 

near Keating, in the lower Powder Valley.88

Considerable chromite was mined during the World War and the 

years immediately following in Grant County, chiefly from the 

Strawberry Range and in Baker County from mines near Sumpter 

and from Connor Creek. These deposits have been described by 

Westgate.89 Under normal conditions the distance from market is 

such as to preclude the use of ores of the grade here found.

A few flasks of mercury have been produced from the Ochoco 

Mountains at intervals, at least since 1906, but not until 1929 was 

there widespread activity in this region. The total production had 

been small up to the time of this investigation.

Small amounts of manganese were mined near Pleasant Valley 

and Durkee during 1917, in response to war demands. Like the 

chromite deposits they are not minable under normal conditions. 

They have been described by Pardee.90

CLASSIFICATION

The ore deposits other than placers in eastern Oregon may be 

classified in accordance with the metals they contain or in accordance 

with their shape and other structural features or their mineralogy. 

A classification based on the metals contained would list the deposits 

as gold, gold-silver, copper-gold, quicksilver, chromite, and manganese deposits.

Of these classes, the gold deposits are most widely represented. 

Gold-silver deposits are few; among the mines described in this report only the Intermountain claims in the Mormon Basin district 

and the Bay Horse mine on the Snake River fall into this group. 

Copper-gold deposits, in which the value of the copper exceeds that 

of the gold, are represented by the prospects in the Keating copper 

district and by those in the Homestead district on the Snake River,

88 Gilluly, James, Copper deposits near Keating, Oreg.: U. S. Geol. Survey Bull. 830, 

pp. 1-32, 1932.

88 Westgate, L. G., Deposits of chromite in eastern Oregon: U. S. Geol. Survey Bull. 725, 

pp. 37-60, 1921.

80 Pardee, J. T., Deposits of manganese ore in Montana, Utah, Oregon, and Washington : U. S. Geol. Survey Bull. 725, pp. 211-228, 1921.
27

neither of which is included in the present report, and by the Copperopolis property at Quartzburg. Quicksilver deposits are limited 

to the western part of the area in the Ochoco country. Chromite 

deposits, not here described, occur in the Strawberry Kange and on 

Connor Creek, and manganese deposits, all of superficial origin, are 

present near Durkee and Pleasant Valley.

If the deposits are classified on the basis of structure the predominant mode of occurrence is as fissure veins or replacement veins. 

This class includes all the deposits primarily valuable for gold, 

silver, and quicksilver, except possibly that of the Rainbow mine. 

Stockworks and impregnation zones are represented by all the copper-gold deposits and possibly by the Rainbow mine in the Mormon 

Basin. Some of the chromite deposits are probably due to segregation; others to impregnation.

Mineralogically the gold deposits are generally simple, carrying a 

few sulphides, of which pyrite, pyrrhotite, chalcopyrite, galena, 

sphalerite, and arsenopyrite are by far the most prominent, in a 

gangue of quartz, ankerite, calcite, and locally sericite, chlorite, 

serpentine, scheelite, fuchsite, barite, and clay. Metallic minerals 

present locally but nowhere abundantly include magnetite, hematite, 

tennantite, tetrahedrite, cobaltite, enargite, glaucodot, bornite, covellite, chalcocite, bismuthinite, polybasite, native gold, native bismuth, 

and hessite.

Most of the copper deposits carry chalcopyrite, pyrite, galena, 

sphalerite, and arsenopyrite in a quartz-barite gangue with some 

chlorite and epidote, but the Copperopolis deposit carries considerable tourmaline as the principal associate of quartz in the gangue.

The quicksilver deposits are composed of cinnabar and pyrite in 

a gangue of quartz, chalcedony, opal, chlorite, nontronite, calcite, 

dolomite, several clays, and asphalt.

MAGMATIC RELATIONSHIPS OF THE MINERAL DEPOSITS

The mineral deposits, considered genetically, appear to fall into 

three groups, each related to a different suite of igneous rocks. 

Two of these groups, including the chromite and most of the gold 

deposits, are of pre-Tertiary age. The third, including the quicksilver and at least one gold deposit, is of middle or late-Tertiary age.

The chromite deposits, as is the rule elsewhere, are all directly 

associated with ultrabasic rocks dunites and pyroxenites which 

have been thought to represent the earliest of the pre-Tertiary 

magmatic cycles.

By far the most of the gold deposits are situated in close juxtaposition with bodies of biotite-quartz diorite, and all investigators
28 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PAET 1

have agreed in assigning these deposits to an origin in the final exudations from these plutonic bodies. According to the interpretation 

offered in this report, these deposits are thus related to the latest 

pre-Tertiary intrusive cycle, or, if only one pre-Tertiary cycle should 

prove to be represented in the region, to the latest intrusions of that 

cycle.

The reference to a source in the biotite-quartz diorite is most 

strongly supported by the marked increase in the value, size, and 

persistence of the veins near the larger bodies of the rock, such as 

those in the western Elkhorn Kidge and at the east end of the Greenhorn Mountains, in the Sumpter quadrangle. Most of the larger 

mines have been developed within the masses of biotite-quartz diorite, 

or not more than 2 or 3 miles from the contact. The concentration 

of the larger mines near these intrusive rocks is emphasized by the 

parallel concentration of the more intensely mineralized areas whose 

deposits have not so far been productive in a large way. These, too, 

cluster about the masses of biotite-quartz diorite in a very suggestive 

manner.

The quicksilver deposits of the Ochoco region and at least one gold 

deposit, the Ophir-Mayflower, are contained in Tertiary rocks and 

hence are obviously related to much younger magmatic activity than 

the other deposits. It is likely that the deposit of the Oregon King 

mine, near Ashwood, is of the same age, but no work was done on this 

deposit during this survey. No plutonic rocks to which these deposits may be related are known to be exposed in the region, but the 

long volcanic history contained in the Tertiary record gives ample 

evidence of the existence of intrusive rocks of Tertiary age at greater 

or less depths beneath the surface of large parts of the State.

Mineralization connected with Tertiary intrusive rocks has been 

widespread in the Cascade Mountains, 30 or 40 miles west of this region, and in Idaho but has been very slight in eastern Oregon, compared with the mineralization associated with the older intrusions. 

The difference in age between the two series of deposits is emphasized 

by the presence of detrital gold derived from the older veins in the 

oldest Tertiary sediments, proving that these deposits, not formed at 

shallow depths, had been deeply weathered and eroded before the 

Tertiary deposition began.

Mineralogic contrasts between the Tertiary quicksilver deposits 

and the pre-Tertiary precious-metal deposits are profound, the one 

group being characterized by cinnabar, calcite, opal, chalcedony, and 

clay, the other by pyrite, arsenopyrite, chalcopyrite, sphalerite, 

galena, tetrahedrite, quartz, ankerite, and mica. The only Tertiary 

gold deposit here described, that of the Ophir-Mayflower mine, has
SOME MINING DISTRICTS OP EASTERN OREGON 29

no arsenic minerals and has much chalcedony and montmorillonite, 

an association which is commonly regarded as indicative of lower 

temperature during deposition than that characteristic of the preTertiary deposits.

GENEBAL ECONOMIC CONSIDERATIONS

The mines in eastern Oregon that have hitherto been most productive lie mainly in the Sumpter quadrangle and in the Wallowa 

Mountains. Neither of these districts is here described. The mines 

considered in this report have been for the most part small, and those 

that had been more productive in the past were inactive at the time 

of this survey. Aside from some of the quicksilver properties, none 

of the mines were producing at the time of this examination, although development work was in progress at several.

The notable and widespread production of placer gold in the region, however, sufficiently demonstrates the presence of mineral 

deposits over very large areas in the Blue Mountains, and the question arises why the mining industry should be dormant. The 

reason is largely economic but is fundamentally geologic. The 

principal economic factors have been the prohibitive costs of mining, 

milling, and transportation. These costs were abnormally high 

from 1915 to 1929, and although they have since substantially decreased they are still materially higher than in the pre-war years. 

Production in many gold camps throughout the country declined 

abruptly during this period, and according to the figures on page 25 

the small production in Malheur County reacted similarly. .That 

from the larger mines declined less abruptly, and the closing of most 

of the mines in Sumpter, the leading district, reflected the inability 

to continue operations at a profit. A contributing factor in depressing the industry was the difficulty in successfully treating the complex sulphide ores in the Sumpter district.01

As regards geologic conditions, one of the most severe handicaps 

of the districts here described arises from the structure that is, 

there are few large persistent veins. Instead of the valuable minerals being concentrated in a regular vein system, most of the deposits are characterized by irregular, commonly interrupted, and 

intersecting veinlets, narrow and difficult to follow. Thus an 

amount of gold which, if it occurred in a single vein, would be 

adequate to support a mine is scattered throughout a large body of 

gangue from which it can not at present be economically recovered. 

Eastern Oregon in this respect resembles large parts of Alaska 

and certain areas in Idaho and Montana, from which huge sums

81 Pardee, J. T., and Hewett, D. F., op. cit, p. 34.
30 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

have been won by placer mining without the discovery of correspondingly concentrated lode deposits. A few large veins have been 

found, however, and perhaps others remain to be developed. Examples of the larger veins are the Connor Creek, Eainbow, Sanger, 

Virtue, and Flagstaff.

Lindgren has emphasized the similarity between the geology of 

eastern Oregon and that of the Mother Lode belt of California and 

has stated 92 that the ore may be expected to extend " to the greatest 

depths yet attained in gold mining." This statement is doubtless 

correct in the sense that the mineralization persists to such depths. 

To the writers, however, it appears likely that very few of the veins 

will be found so persistent as this statement might imply, because 

only a few of them have demonstrated lengths that may be commensurate with persistence to great depths. The mineralogy of the 

veins may and doubtless does persist to great depths, but whether 

many of the veins will prove structurally continuous and minable in 

depth is doubtful. Exceptions must be made for the long veins 

of the Sumpter quadrangle and possibly for some of the larger 

veins here described, but on the whole it is likely that few of the 

veins can be followed with fair hope of successful mining below a 

few hundred feet.

These comments should not be understood as condemning the 

entire region, even though mining costs continue -to be relatively 

high. Several of the mines here described seem capable of profitable exploitation if their development is undertaken in a conservative way and with a minimum of overhead. Other deposits, such 

as those at Quartzburg and Susanville, although promising intrinsically, are so remote from transportation that they must probably 

await new developments in the technique of recovery or lower costs

before they can operate profitably on any considerable scale. Even 

in these districts, however, pocket hunting on a small scale may 

prove profitable.

Another factor entering into the question of profitable exploitation involves the mineralogic changes that may be expected as the 

veins are followed downward. In this connection it seems likely 

that the primary mineralization may be assumed to be of about constant character, for although it is possible that a zoning may occur, 

the changes involved will probably not affect the recovery in any 

one mine. More significant than primary changes are the mineralogic changes due to weathering. As far as was detected in this 

survey of the region there has been no supergene enrichment of 

gold below the oxidized zone. There has been, however, a residual 

enrichment in the weathered zone, where valueless gangue has been 

leached out, leaving the free gold in higher concentration. Below

02 Lindgren, Waldemar, op. cit, p. 610.
SOME MINING DISTRICTS OF EASTERN OREGON 31

the water level the veins become of lower grade, because there has 

been no such removal of the gangue, but, what is of more consequence, instead of being free and readily amenable to amalgamation, the gold is so thoroughly locked up in sulphides that only a 

small part of it is recoverable by amalgamation, and the ore does not 

lend itself readily to cyanidation. Concentrates must be brought to 

very high values before they can be profitably shipped to smelters, 

because of the high cost of transportation from many of the districts. 

The quicksilver deposits near Prineville have a distinct advantage 

in this respect, because their product is compact and can readily be 

transported. Several of the prospects appear to have good possibilities for profit if worked in a conservative way and with adequate 

condensing apparatus on their retorts.

THE DISTRICTS 

MORMON BASIN

GEOGRAPHY

The Mormon Basin district lies in T. 13 S., K. 42 E., Willamette 

base and meridian. The boundary between Baker and Malheur 

Counties passes through the district. The Mormon Basin, the valley 

which has given its name to the district, is an oval depression about 

3 by 2 miles in extent, formed by the headwaters of Basin Creek, a 

tributary of Willow Creek. Altitudes in the basin range from about 

4,500 feet to about 6,000 feet. The climate is dry, with moderate 

snowfall, which rarely interferes seriously with travel.

The district is reached by a wagon road about 12 miles long from 

Brogan, the railhead on Willow Creek of a branch line connecting 

with the Oregon Short Line at Ontario, but most of the travel to and 

from the district goes by way of Durkee or Huntington, 22 and 25 

miles, respectively, distant by road.

FIELD WORK

No base map of the area was available, so that it was necessary to 

make the accompanying topographic map (pi. 2) concurrently with 

the geologic map. An approximate elevation obtained by aneroids 

was used for an initial point, a base line measured by stadia, and the 

map developed by triangulation and stadia. The topographic 

sketching is the work of C. F. Park, jr. About two weeks was spent 

in the district.

GEOLOGY 

GENERAL FEATURES

The dominant0 and also the oldest geologic formation of the district is composed of quartzite, quartz schist, slate, greenstone, and 

chlorite schist with a few small limestone lenses of unknown age.
32 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Lindgren 93 referred them with some doubt to the Triassic, but in 

the absence of fossil evidence their lithology does not appear so convincingly like that of the known Triassic of the Wallowa Mountains 

as to justify any confident correlation with these rocks.

Intrusive into these rocks are many basic and ultrabasic igneous 

rocks, now represented for the most part by greenstone, serpentine, 

amphibolite, and talc rocks, highly sheared and deformed to a degree 

comparable to that of the accompanying schist, although locally 

masses of gabbro, pyroxenite, dunite, and harzburgite are still recognizable as such.

Along the north edge of the mapped area is the large quartz diorite 

mass of Pedro Mountain, and apophyses of this mass occur in bosses 

and sills elsewhere in the basin. Several aplite and pegmatite dikes, 

presumably related to this intrusive mass, were also observed. These 

rocks have not undergone the intense shearing to which the previously 

described rocks have been subjected. Lindgren's map shows another 

" granite " area just southwest of the basin, but the mapping of this 

report did not extend so far. No evidence bearing on the age of 

these intrusions has been obtained in this survey, and there is apparently no reason to question the post-Jurassic and pre-Chico age 

assigned to them by Lindgren.

The lower part of the basin is largely occupied by stream gravel 

and sand, with boulder deposits of Tertiary age. These deposits 

contain interbedded dacite flows and are capped by andesite. Their 

former extent was considerably greater, as is shown by remnants on 

the divide at the head of California Gulch. The present streams are 

actively removing these old gravel deposits from the basin.

The schist is steeply folded, with the schistosity (which is for the 

most part parallel to the bedding) striking roughly parallel to the 

periphery of the quartz diorite of Pedro Mountain, or about 

N. 45°-80° E. in the eastern part of the area and N. 25°-70° W. in 

the western part. Dips are chiefly steep toward the north, but locally 

a few southward dips were observed. The Tertiary rocks, which are 

strongly discordant with the schists, are tilted at moderate angles, the 

steepest observed dip being 18°.

SCHIST SERIES

The schist series in the district is composed chiefly of metamorphosed sediments. The dominant rock of the series is quartz-mica 

schist, with both muscovite and biotite developed along the shear 

surfaces. Locally there are masses of nonschistose quartzite, possibly similar to the original rock from which the schist was derived 

or representing less shaly, hence less readily altered interbeds in the 

sediments.

83 Lindgren, Waldemar, op. clt., pi. 64.
IT. S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 2

EXPLANATION

Gravel, sand, and silt 

with some dacite flows

UNCONFORMITY

Quartz diorite and 

related rocks

Talc rock, with some 

talc schist

Gabbro and re I a ted basic 

and ultrabasic rocks

Greenstone

(Mostly altered sills and lavas 

with some plutonic rocks)

Chlorite schist

(chiefly altered lavas and pyroclastic rocks)

Quartz-mica schist, 

slate, and quartzite 

(some limestone lenses, Is)

Fault

(U, upMroto,- D, dmcnthrow)

 <75°

Strike and dip of rocks

Strike of vertical rocks

v 

Mine

Shaft

jTunnel

c°PFTarMbr! GEOLOGIC MAP OF MORMON BASIN DISTRICT, T. 13 S., R. 42 E., OREGON"""0 " 'Ic^fd.^dTl^'tcheii

Contour Interval 50 feet 

Datum based on aneroid barometer readings

1933
SOME MINING DISTRICTS OP EASTERN OREGON 33

Along the divide southeast of California Gulch there is a considerable belt of black carbonaceous slate interbedded in the schist 

series. Similar slate also occurs north of the Rainbow mine. Elsewhere in the basin similar slate and, locally, carbonaceous phyllite 

are intercalated in the schist series, but these rocks, doubtless because 

of their weakness, are ordinarily poorly exposed. They may be 

much more widespread than appears from the sparse outcrops. In 

places these rocks are altered to andalusite hornfels.

Half a dozen or more limestone lenses were observed in the schist 

series. All are small, none being more than 300 or 400 feet long and 

75 feet wide and most of them much smaller. These lenses were 

carefully searched for fossils but without success. Most of them are 

coarsely crystalline carbonaceous limestone with a little quartz, but 

one or two show some alteration to diopside and tremolite hornfels.

In the southern half of the mapped area there are large tracts 

in which chlorite schist is the dominant rock. It conforms in structure with the associated quartz-mica schist and slate. Locally these 

rocks are associated with recognizable igneous rocks, and they are 

accordingly interpreted as the sheared and metamorphosed equivalents of these andesitic or diabasic rocks. Some pyroclastic rocks are 

also represented. Their mineralogy, as revealed by the microscope, 

is in accordance with such an origin, for the dominant minerals are 

chlorite, serpentine, actinolite, and talc, with ..subordinate bronzite 

and biotite. The less sheared altered igneous rocks shown as greenstone on Plate 1, of which the largest area occurs on the ridge 

between Emigrant and Glengarry Gulches, appear to be altered 

andesites or possibly diabases. They have both brown and green 

amphiboles, feldspars ranging "from labradorite to andesine in composition, and much titanite and magnetite.

BASIC INTRUSIVE ROOKS

Basic and ultrabasic intrusive masses, chiefly of moderate dimensions, are distributed around much of the southern periphery of 

the basin. The largest body is that on the hillside south of French 

Gulch, but a considerable mass occurs at the head of Emigrant 

Gulch, a smaller one near the Humboldt mine, and a great many 

smaller bodies on the ridge south of California Gulch.

The rocks composing all these bodies are highly sheared and have 

clearly undergone substantially as severe metamorphism as the surrounding schists. The shearing is reflected in the mineral composition of the rocks. The gabbro mass forming the hill between Emigrant and Glengarry Gulches, in the NE. 14 sec- 18, is saussuritized 

and albitized. A few relict feldspars can be recognized as labradorite, but most have gone over to albite-zoisite aggregates or even 

unmixed albite. Hornblende, pleochroic in green and brown, is the
34 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

dominant dark mineral in the less altered specimens, but tremolite, 

actinolite, and talc replace it in the more altered rocks.

The larger mass south of French Gulch is of more basic character, 

and but few specimens carry recognizable feldspars or their derivatives. Tremolite, talc, serpentine, and bronzite are the chief minerals 

present, although a little diallage and brown hornblende remain in 

some specimens. Where feldspar occurs it is labradorite. This rock 

mass seems to pass by gradation into the more sheared bodies shown 

on the map as greenstone and is believed to be the parent rock from 

which the greenstone was derived. The unmetamorphosed facies 

was probably a pyroxenite.

On the upper slopes of the hills south of California Gulch are 

several altered basic intrusive bodies. Some appear to be sheared 

dunite, having been originally composed almost wholly of olivine, 

of which a few relicts remain in rocks now made up chiefly of talc, 

serpentine, actinolite, and chlorite. Porphyroblasts of bronzite, 

in part altered to serpentine, are common in these rocks. The large 

bodies of talc schist associated with these ultrabasic intrusive bodies 

are doubtless derived from them, and the irregular interpolations 

of talc rocks in the dominant chlorite schists of the hillside down to 

California Gulch may represent metamorphosed sills of related rocks.

A small body of ultrabasic rock occurs on the ridge 2,000 feet 

northeast of the Rainbow mine. It is a sheared harzburgite, composed chiefly of olivine and enstatite, which are partly altered to 

talc, tremolite, chlorite, and serpentine. Much titanite and magnetite also occur. Along the borders this mass is altered to hornblende schist.

A great many small masses of talc schist, tremolite-anthophyllitetalc rock, and amphibolite are intercalated in the quartz-mica schist 

and chlorite schist of the area. These rocks probably represent 

metamorphosed basic sills or plugs related to the gabbro and ultrabasic masses just described.

QUARTZ DIORITE AND RELATED ROCKS

The economically most important intrusive rock of the Mormon 

Basin is rather basic quartz diorite. The large mass of Pedro 

Mountain, about 6 miles in diameter, borders the mapped area on 

the northeast, and the smaller bodies distributed through the rest 

of the basin are probably apophyses of this mass. Though some of 

these rocks show crushing, their alteration is negligible compared 

with that of the more basic rocks. Some show a mild mineral parallelism near their contacts.

The Pedro Mountain body is composed of rather light-colored 

coarse-grained granitic rock. In composition it is a calcic quartz
SOME MINING DISTRICTS OF EASTERN OREGON 35

diorite; its plagioclase, which is strongly zoned, ranges from An60 

to An45 in composition. Both biotite and hornblende occur in large 

splendent crystals. Quartz is plentiful, but orthoclase is negligible 

in amount, if present at all.

Many of the smaller intrusive masses, such as the mass just west 

of the Rainbow mine and some of the dikes in the Rainbow mine, to 

judge from specimens on the dump, are really quartz gabbro if classified rigorously on the basis of their feldspars, which are labradorite. Other masses are true quartz diorites, however, with oligoclase or andesine feldspars. Among these rocks are the small mass 

at the Hice tunnel and the dominantly sill-like intrusions in Sunday 

Hill. A few dikes of quartz diorite porphyry occur, with some 

albitic aplites and, in the Pedro Mountain mass, a few pegmatites.

TERTIARY ROCKS (MIOCENE?)

A belt of poorly consolidated gravel and sand of Tertiary age extends across the basin from a point just south of the Rainbow mine 

to the head of Glengarry Gulch. Remnants of these gravel deposits 

and associated hillside wash too slight to mask the bedrock and 

hence not shown on Plate 2, are found over much of the more gently 

sloping part of the rest of the basin, even on the ridge between California Gulch and Puget Sound Gulch, proving a much wider extent 

in the past. Indeed, these remnants are in many places so thick that 

the bedrock is locally concealed, although on the accompanying map 

only continuous areas are shown. Owing to the softness of the 

gravel it forms gently rolling topography.

This Tertiary gravel rests on a dissected surface developed upon 

the steeply tilted schist series and its intruding quartz diorite and 

basic rocks, a surface of profound unconformity. The gravel that 

makes up the lower part of the formation is commonly clearly 

derived from the adjacent hillsides, being dominantly made up of 

quartz schist, gabbro, or chlorite schist, according to the neighboring 

bedrock. Toward the upper part of the formation bedding and 

sorting are clearly seen and the rocks no longer show the close relationship to the near-by bedrock. A few thin dacite flows are interbedded in the formation, and it is capped by andesite flows. Locally 

these andesite flows overlap the transported material and rest directly upon only slightly reworked Tertiary soil.

The formation, exclusive of the capping andesite, attains a thickness between 300 and 400 feet; the overlying andesite is nearly 200 

feet thick .in places.

No fossils were obtained from these beds, so that their age musb 

be determined on other, less precise grounds. The association with 

the volcanic rocks and the unconsolidated nature of the deposits
36 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

combine to render a Tertiary age practically certain. The rocks may 

be Miocene or Pliocene; the fact that all the fossil plants found in 

similar rocks in the Baker quadrangle are of Miocene age somewhat 

favors the reference to the Miocene, although in this area of local 

basins there is no certainty that they may not be younger.

QUATERNARY ROCKS

The only Quaternary rocks of the area are the hillside talus 

deposits and the gravel along the present streams. Most of this 

gravel is derived from the Tertiary deposits by reworking, although 

of course there is some contribution from the bedrock series.

STRUCTURE

The structural discordance between the Tertiary and pre-Tertiary 

rocks is profound; it is doubtful if they have any structural similarities beyond that given by the structural control of erosion in the 

pre-Tertiary rocks, which has governed, in part, the areas of deposition of the Tertiary rocks.

The pre-Tertiary rocks enter the area on the east with strikes 

of N. 45°-80° E. Toward the west the strikes swing first to eastward 

trends and then to N. TO0 W., N. 50° W., and finally about N. 

25°-35° W. on the west edge of the mapped area. Unfortunately 

the area mapped is not large enough to show the relations of these 

rocks to the quartz diorite mass of Pedro Mountain. If it were, it 

could be clearly seen that these changes in strike reflect the curvature of the outline of that intrusive body. This parallelism of the 

strikes of the country rock with the intrusive contact of the quartz 

diorite of Pedro Mountain is seen farther northwest aiid north, in 

the southeast corner of the Baker quadrangle, and is known to extend 

about three sides of the Pedro Mountain mass. Although the central 

part of the Pedro Mountain mass is nearly or quite free from directional features, near the borders the rock shows a strong mineral 

parallelism, locally approaching a gneissic character. Because of 

this internal structure and the evident profound effect on trends of 

the inclosing rock, the Pedro Mountain body is believed to have had 

a notable part in the metamorphism of the pre-Tertiary rocks. 

Nevertheless, inclusions in the mass have schistosity fully developed, 

as if the batholith had invaded an already metamorphosed series.

The schistosity of the pre-Tertiary rocks only locally dips at 

angles flatter than 60°; dips of 80° are much more common. With 

very few exceptions the dips are toward the north, so that the rocks 

of the Mormon Basin seem to dip under the edge of the Pedro Mountain intrusion. Stretching in the rocks, where determinable, is very 

steep in the plane of schistosity, pointing to the same relation.
SOME MINING DISTRICTS OF EASTERN OREGON 37

The Tertiary rocks have been only slightly deformed, except along 

the fault that bounds their outcrop on the south at the head of 

Basin Creek Canyon. Here they have been reduced to gouge along 

a narrow zone, close to which dips as high as 18° have been imposed 

on them. Other faults doubtless occur in the Tertiary rocks, but 

none could be traced for any considerable distance. From observations in near-by areas it is known that Tertiary and even Quaternary 

faulting is general throughout this part of eastern Oregon and 

probably has occurred here in some places wholly within the preTertiary rocks as well as cutting the Tertiary.

ORE DEPOSITS

The ore deposits of the Mormon Basin include quartz lodes, veins, 

and replacement masses of irregular shape. They occur in all the 

pre-Tertiary rocks, especially in or near the quartz diorite masses. 

The minerals were probably introduced in emanations from the 

Pedro Mountain intrusion of quartz diorite and its smaller satellites.

The veins consist of quartz, with ankerite and fuchsite as the 

chief gangue minerals and carry as metallic minerals pyrite, 

arsenopyrite, galena, sphalerite, polybasite, hessite, and tetrahedrite. 

Of these, pyrite and arsenopyrite are by far the most plentiful. 

About 45 per cent of the gold is free-milling, according to the experience of the Rainbow mine.9 * Figures for the other mines are not 

available.

The veins are irregular, both in trend and thickness. So few are 

known that it is probably premature to generalize, but there seems 

to be a rough tendency for the veins to follow the strike of the 

inclosing rocks, or to cut it at a narrow angle. Thus the Cleveland 

and Eainbow veins strike N. 60°-75° E., the Humboldt about east, 

and the Randall N. 60°-70° W., whereas the Phalen vein in the 

Sunday Mill mine strikes N. 40° W. These trends are roughly 

parallel to the border of the intrusive body of Pedro Mountain, 

but this parallelism is not so marked as to serve as a guide to prospecting. The divergent strike (N. 5° E.) of one of the veins in 

the Randall mine gives cause for caution in this regard.

THE MINES 

RAINBOW

Location. The Rainbow mine is just north of the divide between 

California Gulch and a southern tributary of the south fork of 

Dixie Creek, locally known as Rainbow Gulch.

04 Swartley, A. M., Ore deposits of northeastern Oregon: Mineral Resources of Oregon, 

vol. 1, p. 224, Oregon Bur. Mines and Geology, 1914.
38 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

History and production. The deposit of the Rainbow mine was 

discovered about 1901, and the Commercial Mining Co. was organized to develop it. By 1907 the mine was a large producer, with a 

mill of 19 stamps. The capacity of the mill and concentrator was 

50 tons a day in 1909. In 1911 no ore was raised, although development work went forward, and a fair production was made from 

cyaniding tailings. In 1911 the mine was sold under option to the 

United States Smelting, Refining & Mining Co., of Boston, Mass. 

This company operated the mine for 32 months until December, 

1915, when, by failing to take up the option, it permitted the mine 

to revert to the original company.95 In 1916 the mine had a 400- 

foot shaft, a 1,500-foot adit, and 3,700 feet of drifts and crosscuts. 

A 100-ton mill and cyanide plant was on the property. A 100-foot 

winze was sunk from the 400-foot level.96 In 1918 the mine was 

closed and dismantled. A small production was made in 1922 and 

again in 1925 from dump rock worked in a 10-ton mill. In 1926 

the mine was sold to the present owners, the Rainbow & Sunday 

Hill Mining Co.

The production prior to 1911 was $242,000. The United States 

Smelting, Refining & Mining Co. produced $1,083,360 from 95,747 

tons of ore, saving $11.40 a ton from $12 mill heads. During 1913 

to 1915 the mine was the largest producer in the State, but the 

production since December, 1915, has been small.

The mine buildings and shaft timbers have been destroyed by fire, 

and many of the old stopes have caved to the surface, so that the 

mine was entirely inaccessible at the time of this survey.

Geology. The geology of the Rainbow mine has been described 

by Swartley 9T as follows:

The geology of the Rainbow mine is comparatively simple; the country 

rocks are chiefly slate with some granitic intrusives on the hanging-wall side 

and some limestones and greenstones on the footwall side. The greenstone 

[shown on pi. 2 as gabbro and related ultrabasic rock] is an intensely altered 

rock with an excessive development of secondary hornblende; its original 

character is hard to make out.

The vein fissure has a strike of N. 60° E. and in the upper levels a dip of 

66° N., while in the lower levels a dip of 54° N. Before the period of vein 

formation the fissure was filled with a porphyry dike [not mapped on pi. 2] 

locally known as the " spotted dike." * * * This rock is a porphyry genetically related to an intrusive magma that is probably a basic granodiorite or 

quartz diorite or perhaps even a diorite in composition. * * * The Rainbow vein is not of the fissure type but of the brecciated vein type. The fractured zone varies from a few feet in width in some places to over 50 feet in

85 Parks, H. M., and Swartley, A. M., Handbook of the mining industry of Oregon: 

Mineral Resources of Oregon, vol. 2, No. 4, p. 66, Oregon Bur. Mines and Geology, 1916.

06 Yale, C. G., Gold, silver, copper, lead, and zinc in Oregon: U. S. Geol. Survey Mineral Resources, 1916, pt. 1, p. 264, 1919.

87 Swartley, A. M., Ore deposits of northeastern Oregon: Mineral Resources of Oregon, 

vol. 1, pp. 222-224, Oregon Bur. Mines and Geology, 1914.
SOME MINING DISTRICTS OF EASTEEN OREGON 39

others. It is made up of fragments of country rock cemented by quartz. The 

porphyry dike is included in the brecciated zone to a large extent. On both 

walls of the lode there is a quartz vein. The footwall of the lode is the best 

developed and has been most worked. The vein quartz is fine grained and 

contains but a very small amount of arsenopyrite and pyrite in which there 

is some gold. Some of the free gold in the vein is large enough to be distinctly visible, but for the most part it can not be seen. A small amount of 

actinolite and a little chlorite occur with the quartz, and when these minerals 

are present the gold values are said to be greater. This is noteworthy as it 

points toward the precipitating action of the ferromagnesian silicates.

There has been some movement since ore deposition, as is shown by the 

gouge and slickensides. The quartz, however, is not fractured to any great 

extent.

The genesis of this vein is simple, that of ascending solutions from the underlying magma. The presence of the porphyry dike shows that the vein fissure 

followed this line of weakness.

The mine is worked through a shaft about 500 feet deep, but most of the development has been done on the 200 level, where the vein has been drifted upon 

for 1,700 feet. Mine and mill are operated by electricity with power furnished 

by the Idaho-Oregon Light & Power Co.

SUNDAY HILL

Location and development. The Sunday Hill mine is on Sunday 

Hill, near the west side of the Mormon Basin, southwest of the head 

of Live Oak Gulch. It is owned by the Rainbow & Sunday Hill 

Consolidated Mining Co. J. L. Fisher was manager at the time 

of the survey.

The mine is opened by an adit on the 200 level and by a vertical 

dhaft, 75 feet deep, from which a short level, called the 100 level, 

is turned. This level is connected by an incline with the main or 

200 level, which is 79 feet below, a total of 154 feet below the collar 

of the shaft. The accessible workings consist, in addition to the 

shaft and connecting raises, of 110 feet on the 100 level, 31 feet on 

an intermediate 150 level, and about 1,625 feet on the 200 level. A 

50-foot raise and a 30-foot winze have been driven from the 200 

level. Other than this winze, which is full of water, no work has 

been done below the 200 level.

The development work on the property has been done, in 1920 

and following years, chiefly by W. C. Phalen, the discoverer of 

the vein. But little work has been done by the present owners. In

1922 a 5-ton amalgamating mill was built and test runs made. In

1923 the mine was equipped with electric power, and in 1929 about 

560 tons of $10 gold ore was mined and treated. Development work 

proceeded in 1925, but water level was reached, and the base ore 

found was not amenable to treatment in the available mill, so no 

production was made. A small output was made in 1926, however.98

88 Mineral Resources of the United States, 1922-1928.
L Few sulphides 

 « quartz stringers 

: silicification

Fissures in 

wa! |

MISE X 

T+35\ -t

Some silic ified INCLINEJO'A r

SChist INCLJNE 27'AT 3 

34 IK . <^

ISO LEVEL 

INCLINE. 4?'AT40

.jke

Footwal I fissure

Vein material in wall 

Fractured

..... ^uartz 

?- stringers in .. 

sheared zone "; 

Phalen veinDike-4

Caved 

Roberts fault

 'v VxKendall rvein

2' porphyry 

'SHAFT 75'

Silicified and sulphidized sch'ist

£? 'Contains much 

' sulphide 

s Quartz schist in face 

well mineralized

s

?f«;V'»V,v<*%

0 0

EXPLANATION

so 

Basalt Diorite and dacite (porphyry) Schist 

FIGUBE 1. Geologic map of Sunday Hill mine, M
SOME MINING DISTRICTS OF EASTERN OREGON 41

Geology. The country rock consists of quartz-mica schist, striking N. 30°-70° W. and dipping 45°-70° N. Numerous dikes of 

quartz diorite and related rocks are present in the mine, and a few 

basaltic dikes occur. (See fig. 1.)

Quartz stringers are numerous, and one strong vein, the Phalen, 

has been opened for 230 feet. On the east, the Phalen vein, which 

strikes N. 40°-50° W. and dips 50° N., is cut off on the 200 level by 

a normal fault, called the Roberts fault, striking N. 50°-60° E. and 

dipping 50°-60° SE. This fault is also exposed on the 150 level and 

in the incline between the 150 and 100 levels. On the 100 level the 

downthrown segment of the Phalen vein has been followed for about 

60 feet from the Roberts fault. The segment of the Phalen vein in 

the footwall of the Roberts fault on the 200 level ranges from a few 

inches to 5 feet in thickness but finally pinches out on the west into a 

few minor quartz stringers and some gouge. The vein is accompanied by gouge almost throughout its length, especially on the 

hanging wall. The quartz itself is considerably brecciated. In the 

area regarded as minable the vein averages about 2Vs feet thick.

The Noon vein consists of about 3 inches to 1 foot of quartz and 

gouge. It appears to be a hanging-wall fissure branching from the 

Phalen vein. Where exposed, it is near or along the contact of 

quartz-mica schist and a dike of fine-grained diorite. A few other 

veins, the Kendall and the King especially, have been exposed, but 

very little work has been done on them. In several places, especially in the King crosscut, the country rock, both schist and diorite, 

has been intensely silicified and impregnated, with pyrite. It is 

reported to carry gold, averaging between $10 and $11 a ton.

The vein material consists chiefly of quartz and gouge. Some 

ankerite is present and considerable green mica, which is locally 

called roscoelite but actually is fuchsite, as determined by W. T. 

Schaller. Some sericite also occurs. Pyrite is the commonest sulphide, but arsenopyrite, galena, and sphalerite are also present. 

Galena is regarded as a sign of especial richness in gold. Some of 

the gold occurs free from visible sulphides and is free-milling.

The ore is very spotty in tenor. According to the assay map of 

the company there are considerable areas of ore averaging more 

than $10 to the ton in gold. Some individual samples run above 

$50 to the ton.

RANDALL

The Randall tunnel is at the south end of Sunday Hill, in the 

northwestern part of the Mormon Basin. It was under the management of William Phalen at the time of the survey. Little but assessment work was being done. No production has been recorded.

164495 33 4
42 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PAET 1

There are about 1,200 feet of workings. Two tunnels have been 

driven, the upper one 24 feet above the lower, and a quartz vein has 

been drifted on for about 300 feet on the lower level.

The mine is in quartz diorite and schist, as shown on Figure 2. 

The quartz diorite is part of a body about 1,500 feet long, which, 

though locally crosscutting, is of a general sill-like shape.

Two quartz veins are penetrated by the lower adit, one at 245 feet 

from the portal and the other near the face. The first strikes about 

N. 60° W. and dips about 32° SW. and has been drifted on for 100 feet 

 east of the tunnel. It has also been followed westward for nearly 175

Quartz vein with 

much sulphide

»//.

LEVEL 

/24/e 

upper /ere/J

Quartz vein

 /A;

..-//*

100 100 Feet

FIGDRB 2. Geologic map of the Randall mine, Mormon 

Basin, Oreg.

feet, curving slightly northward. At this point it is intersected by 

a much larger vein, which strikes nearly north, perhaps a little east 

of north, and dips about 35° E. This northward-trending vein has 

been obliquely penetrated by the drift for about 50 feet. It is fully 

8 feet thick, but no wall is exposed at the face. The footwall, poorly 

exposed, seems to be schist.

The northwestward-trending vein ranges from somewhat less than 

2 feet to over 5 feet in thickness. It has a hanging wall of sericitic
SOME MINING DISTBICTS OP EASTERN OREGON 43

gouge, apparently a fault. Several small southeastward-trending 

footwall branches occur along this vein. None are over 6 inches 

thick, and they are apparently not persistent.

A second northwestward-trending vein is penetrated by the lower 

adit near the face. This vein is much thinner, being only about 

6 inches thick at the floor of the tunnel, and has not been found on 

the upper tunnel level. It strikes N. 70° W. and dips 45° NE.

The first northwestward-trending vein is also narrow on the upper 

level, and only about 10 feet of drifting has been done on it. The 

northward-trending vein has not been cut on this level nor in any of 

the several surface cuts, most of which are too far east to intersect it 

if the vein has a constant attitude.

The veins consist largely of quartz, with some ankerite, fuchsite, 

and sericite. Small amounts of sulphides, chiefly pyrite and arsenopyrite with smaller amounts of hessite, galena, and sphalerite are 

present. Much of the gold is free, as all the workings are in the 

oxidation zone. Oxidation products include cerusite and jarosite.

The assays, reported by Mr. Phalen, show from from $10 to $15 a 

ton in free gold, with some gold also in the sulphides.

Further drifting on the wide vein at the face of the west drift on 

the lower tunnel is contemplated.

EXPLANATION

White quart 

sulphides in 

small bunches

Dike Strike and dip

No continuous quartz 

veins noted

Minor folds 

along strike

FIGURE 3. Geology of tunnel on Overshot group, Mormon Basin, Oreg. 

OVERSHOT

The Overshot group of claims, owned by Charles McNamara, are 

near the head of the north fork of Glengarry Gulch. Tunnels aggre-
44 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

EXPLANATION

^.; sencite.sulphides, 

quartz.and a Contact little garnet rock

60

FIGURE 4. Geology of the Summit Mining & 

Milling Co.'3 tunnel, Mormon Basin, Oi'eg.

gating a few hundred feet 

have been driven, the longest 

about 300 feet in length. (See 

fig. 3.)

The country rock is chiefly 

slate and quartz-mica schist 

striking about N. 45° W. and 

dipping steeply northeastward. The schist and slate 

have been intruded, for the 

most part concordantly, by 

small sheets and sills of altered 

quartz diorite, with a few 

dikes all too small to be 

shown on Plate 2.

No veins are cut by the 

workings. A few very thin 

quartz-filled fissures are present, but these are small and 

discontinuous. According to 

Mr. McNamara, the gold is 

found in the altered diorite 

or near its contact with the 

schists. No production has 

been reported.

SUMMIT

The Summit mine, owned 

by the Summit Mining & Milling Co., Charles Miller, manager, is on the hillside south of 

the South Fork of Dixie Creek, 

west of Kainbow Gulch.

Several tunnels have been 

driven. The largest, 1,400 

feet long, driven back of the 

old mill near the creek level, 

was caved and inaccessible at 

the time of this survey, but 

the next higher and longest 

accessible tunnel (see fig. 4) 

contained about 750 feet of 

workings.
SOME MINING DISTRICTS OF EASTERN OREGON 45

The tunnel is in slate and schist for about 500 feet from the portal 

and then penetrates the quartz diorite mass that crops out on top of 

the hill. Some intersecting faults have brought an additional segment of altered country rock within the diorite. Near and within 

the quartz diorite intrusion the quartz-mica schist is considerably 

altered and carries garnet, biotite, chlorite, actinolite, and sericite, 

with local masses of quartz and sulphides. Some small fissures, 

trending nearly parallel with the contact and close to it, carry some 

quartz and sulphides and have been drifted on for a few feet.

Although some production has been reported from this mine in 

1914 and 1915, when a 5-stamp amalgamating mill was operated, 

there has been none in recent years.

HUMBOLDT

The Humboldt mine is in the southwestern part of the basin. 

The mine, which had been idle for 15 years at the time of this survey, 

was full of water, badly caved, and inaccessible. It was operated 

for several years prior to 1916 by the Oregon-Idaho Investment Co. 

In 1909 it was the most productive mine in the district. In 1910 it 

had a 200-foot vertical shaft, 2,000 feet of tunnels, and a 10-stamp 

mill. Electric power was brought to the property in 1912, and 20 

stamps were dropping in 1914, but in 1916 it was closed down. In 

1930 the property was owned by K. L. Gorman. No definite figures 

could be obtained on the production of the mine, but it is known to 

have been moderate.

The mine has been described by Swartley " as follows:

Formerly the mine had four levels and was worked by means of a vertical 

shaft. Recently the shaft has been sunk 100 feet deeper and a crosscut driven 

to the vein, upon which drifting has been started.

There is a 20-stamp mill upon the property in which recovery is by amalgamation and concentration with Wilfleys and vanners. A considerable percentage 

of the gold is free milling. The concentrates are shipped to smeltars, but it is 

proposed to install a cyanide plant to treat the tailings.

The many movements that have taken place in this immediate vicinity have 

caused the geology to be confusing. The chief country rock is slate with 

diorite porphyry in the footwall. In the upper levels trachyte is said to form 

a large part of the hanging wall. This trachyte was probably a feeder to some 

of the recent acidic lava flows.1

The lode has an east-west strike and a dip of 75° N. in the upper levels but 

with a steeper dip below. In some places the lode is as much as 40 feet wide, 

but the actual quartz veins are rarely more than a few feet thick.

00 Swartley, A. M., op. cit, pp. 224-227.

1 The only rocks that crop out close to the mine are Tertiary gravel and Mesozoic (?) 

inetagabbro, so that it is probable that the " slate," probably chlorite schist of Plate 2, is 

covered by the Tertiary rocks. The diorite porphyry Is probably a dike and could not be 

found on the surface. J. G.
46 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The chief gangue mineral is quartz, and much of it is in a sugary condition, 

due to crushing by later movements. Some calcite is present in the vein. The 

ore, especially in the upper levels, is free gold, and many fine specimens have 

been taken from the mine. In the lower levels more sulphides are to be found. 

They are chiefly arsenopyrite, pyrite, galena, and sphalerite. The galena and 

sphalerite are said to contain high values in gold.

The Humboldt lode is situated in a zone of weakness, where fracturing and 

movement have taken place many times. The first break allowed the injection 

of the diorite porphyry that is found on the footwall. Then came the fracturing 

that made the opportunity for the hot ascending silica solutions to deposit their 

burden of quartz and metallic sulphides. Movement took place during the 

period of vein formation, as is evidenced by the recementing of broken quartz 

fragments. Considerable postmineral movement has taken place, as is shown 

by the sugary quartz, the gouge, and the actual faulting of the vein in the lode.

4quartz; sen'cite^ /. zs"< i

 » ** * ?>!

ApliteC?)

I quartz; 

sericite }

T'quartz; -* ./? - ?

much '

FIGURE 5. Tunnel on Hice prospect, Mormon Basin, Oreg. 

HICE

The Hice tunnel is on the hillside about 2,000 feet south of the 

Humboldt. There are about 400 feet of workings, consisting of a 

tunnel about 250 feet long with several short branches. (See fig. 5.)

The principal country rock is partly albitized diorite, a local 

variant of the widespread quartz diorite of the district, with some 

included hornfels and a few thin dikes of albite aplite. A good 

many thin quartz veins ranging between one-fourth inch and 4 inches 

in thickness are present; the most prominent strike nearly north and 

dip east at flat angles. Considerable sericite accompanies these veins, 

and locally the diorite is silicified and impregnated with sulphides. 

Ankerite is a prominent constituent of the quartz veins.

No production has been reported from this prospect.
SOME MINING DISTEICTS OF EASTERN OREGON 47 

BLUE MUD

The Blue Mud prospect, owned by R. L. German, is about 1,500 

feet southeast of the Humboldt mine.

The property is developed by means of several tunnels, now caved, 

and a shaft about 200 feet deep. This work is in Tertiary gravel and 

pre-Tertiary greenstone, chloritic schist, and gabbro. It has been 

carried on in search of the bedrock source of very rich float found in 

the Tertiary gravel just down the hill to the north.

The shaft, whose mouth is in Tertiary gravel and which penetrates greenstone and metagabbro below a depth of about 100 feetr 

was full of water at the time of visit, but a lower tunnel, whose adit 

is just north of the contact between the Tertiary and pre-Tertiary 

rocks on the west side of Basin Creek, at the head of the canyon, was 

being driven to tap it at a lower level and drain it for working. In 

this tunnel, which was less than 100 feet long at the time of visit, is 

an excellent exposure of the fault contact between the Tertiary gravel 

and the pre-Tertiary rocks. Considerable water was coming into 

the drift at this contact. According to William Phalen, the water in 

the shaft was also derived either from this fault or immediately 

below it. An excellent vein is reported to have been cut in this shaft, 

and it is hoped that completion of the drain tunnel will permit its 

further development.

INTERMOUNTAIN

The Intermountain property is just west of the confluence of Rainbow Gulch and the South Fork of Dixie Creek. It is opened by a 

tunnel about 1,000 feet long, the inner part of which was caved and 

inaccessible at the time of visit. The accessible portion of the 

workings was entirely in quartz-mica schist, slate, and limestone of 

the "schist series." A few small calcite stringers were cut, and 

according to Mr. Smith, of Baker, a few tons of silver ore had been 

obtained from one of these veins. Specimens from one of these veins 

contain polybasite in a calcite-quartz gangue. No work had been 

done in this tunnel for several years, the present endeavors of the 

owners being concentrated on a new tunnel, higher up the hill.

CLEVELAND DEVELOPMENT CO.

The Cleveland Development Co. has 15 claims on the south side 

of California Gulch above the confluence with Basin Creek.

The workings were all inaccessible at the time of this survey, but 

according to Parks and Swartley 2 they originally consisted of two 

tunnels and several pits. The lower tunnel penetrated Tertiary sediments and then schist and greenstone, finally following a porphyry

a Parks, H. M., and Swartley, A. M., op. cit, p. 56.
48 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

dike that contained a few quartz seams. The dike is a few feet wide, 

strikes N. 75° E., and dips steeply south.

No production has been reported from the property, and apparently no work had been done for many years prior to this survey.

GIRAFFE

The Giraffe claims were not visited during the present survey 

but have been described as follows: 8

This company consists of seven claims on the east slope of Clark's Creek, 

in sec. 31, T. 12 S., R. 42 E., about 1V2 miles 4 north of the Humboldt mine. 

The ore is a narrow mineralized granodiorite porphyry dike in a country which 

is largely argillite but also has serpentine and dikes of basalt. A considerable 

body of lime is a short distance to the north of the property and granodiorite 

to the east.

On the Giraffe claim No. 1 a drift upon the dike was made from which 200 

tons were milled and $7.50 per ton was recovered on the plates. A recent 

independent sampling of this drift gave an average of $4.20 per ton. About 750 

feet north of the above drift, on the Giraffe No. 2, a crosscut tunnel cuts the 

dike at a depth of 85 feet, where the values are about the same as above. A 

crosscut is being driven on this claim to cut the dike at a depth of 300 feet. 

This crosscut will be about 500 feet long and is now about halfway in.

This information was furnished by officers of the company.

MORTON

The Morton prospect, owned by the Morton brothers, of Vale, 

Oreg., is on the divide between Glengarry and French Gulches near 

the west side of the Mormon Basin. The prospect is entirely in an 

old soil of Tertiary age made up of decomposed quartz diorite debris, 

which the shaft, reported to be 96 feet deep, has failed to penetrate. 

This decomposed diorite contains considerable very rich quartz float, 

but the parent vein has not been found.

OTHER PROSPECTS

A great many other prospect tunnels have been driven in the decomposed quartz diorite on the north side of French Gulch, beneath 

the andesite capping of the ridge between Glengarry and French 

Gulches, also in search of the source of the rich quartz float that is 

so common in the area, but without success.

PLACER MINES

Placer mining in the basin has gone on intermittently since 1863. 

but owing to shortage of water the output has never been very great, 

although exact figures are not available. An attempt to operate a 

dredge on the north side of Basin Creek just east of the Humboldt

3 Parks, H. M., and Swartley, A. M., op. cit., p. 99.

* Sec. 31 Is 3% miles north of the Humboldt mine. J. G.
SOME MINING DISTRICTS OF EASTERN OREGON 49

mine was unsuccessful for the same reason. At.the time of this survey some work was being done in the gravel of French Creek, but 

returns were hardly more than day wages for the few men engaged 

in it.

Most of the production has come from the stream gravel, which 

includes not only concentrations from the bedrock series but reworked 

gravel from the Tertiary formation, which itself carries considerable 

auriferous quartz. The effect of this reconcentration has been to 

produce some rather rich though small deposits.

OUTLOOK FOB THE DISTRICT

The Mormon Basin district contains much mineralized ground, 

as has been proved from the work done. Surface exposures are not 

good, owing to Tertiary gravel and forest cover in places, so that 

other veins than those known-are probably present in the district. 

The fact that the Rainbow mine was profitable for several years 

demonstrates that the area has merit. Disadvantages of the district 

include the considerable distance to a railroad and the more important fact that although veins are numerous, as a rule they do not 

appear to be persistent over long distances. The tenor of the ore is 

Fiifficient, if considerable tonnage could be developed, to make mining 

profitable. At the time of this survey such tonnage had not been 

developed, although more work might well prove it to be present. 

Some of the small veins might prove profitable if worked in the 

oxidized zone by a few men in a small way, but the fact that the ore 

becomes base at a relatively shallow depth seems to set a limit to 

this kind of work. Larger tonnages than were developed in 1930 

would be needed to justify a mill to work the base ores.

CONNOR CREEK DISTRICT 

GEOGRAPHY

The Connor Creek district is in Ts. 11,12, and 13 S., R. 45 E., on 

Connor Creek, a tributary of the Snake River, which enters the canyon about 14 miles north of Huntington, Oreg.

The post office of Home, on the Robinette branch of the Oregon 

Short Line, serves the district. The principal workings are about 

3 miles by road from this station. The topography of the district 

is extremely rugged, altitudes ranging from about 2,000 feet on the 

Snake River to nearly 7,000 feet on the ridges a few miles to the west. 

The climate in the lower canyon is hot in summer and mild in winter.

FIEUD WORK

Owing to the inactivity in the district, field work was confined 

to a two day's visit. Only small amounts of workings were accessi-
50 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

ble, so that no mapping was attempted. Little can be added to the 

descriptions of Lindgren B and Swartley.8

GEOLOGY

The dominant rock formation is a series that ranges from black 

carbonaceous slate to quartz phyllite. A little greenstone and chloritic schist also occur and, toward the top of the formation, some 

considerable masses of limestone. These rocks have been referred 

to the Triassic by Lindgren, though without fossil evidence. They 

strike N. 20°-45° E. and dip steeply northwest. West of the district 

they are intruded by granitic rocks. A few porphyry dikes occur 

within the district.

The ore deposits are quartz veins that trend northwest and dip 

steeply southwest.

THE MINES 

CONNOR CREEK

The Connor Creek mine is on the hillside west of the North Fork 

of Connor Creek, about 2^ miles above the Snake Eiver. At the 

time of visit the mine was closed and the workings caved and almost 

wholly inaccessible. The following account is in large part summarized from Lindgren's report.

The vein was discovered in 1871 by Wood and Edelmann. In 1872 

a 5-stamp mill was operating on $23 gold ore. In 1876 a 15-stamp 

mill was erected. The mine was worked almost continuously until 

about 1901, but the greatest productivity was between 1880 and 1890. 

In 1884 the Connor Creek Mine & Mill Co. bought the property for 

$60,000. In 1900 there was a 35-stamp mill in operation with plate 

amalgamation and concentrators. A little ore was mined each year 

until 1910, when the mine closed. In 1915 the property was turned 

over to the Connor Creek Mines Co. on a lease,7 but it reverted 

after three years to the Connor Creek Mine & Mill Co., although a 

small production had been made and a 10-stamp mill erected in 1917.

The production of the mine is not accurately known but was 

estimated by Lindgren in 1901 at not over $2,000,000. A small production was made in 1915-1918, but this was probably not over 

$20,000.

The mine was developed by six tunnels over a vertical interval of 

1,000 feet. The lowest, the Connor Creek, included 3,700 feet of 

workings. The Dry Creek level, 150 feet higher, was 1,400 feet 

long. Above this were the Bulger, 1,200 feet; the Lower, 610 feet; 

the Middle, 577 feet; and the Upper, 486 feet long. With the raises 

there was well over 8,000 feet of development work.

6 Lindgren, Waldemar, op. cit. (1901), pp. 756-758. 

 Swartley, A. M., op. cit., pp. 213-217.

7 Personal communication from Albert Geiser, Baker, Oreg., 1930.
SOME MINING DISTRICTS OF EASTERN OREGON 51

The mine is entirely in slate and greenstone. The vein strikes 

N. 40° W. and dips 70°-75° SW. The vein has been stoped from 

the Dry Creek level practically to the outcrop, but between the Dry 

Creek and Connor Creek levels it was much crushed and was mined 

only in part. The stopes were bounded on the west by a break or 

fault called the "final cut-off," which strikes N. 31° E. and dips 

45°-60° SE. Along this break a shear zone of chloritic puckered 

clay slate about 130 feet wide occurs. Only on the Connor Creek 

level was the vein found west of this zone.

The vein is cut by several minor faults. Along its entire course 

it follows the footwall of a greenish, highly altered and pyritic dike 

rock. The slate is likewise highly pyritic along the vein. The vein 

ranges in width from a narrow seam to 8 feet, but the average is 

between 1% and 4 feet. The filling is white coarse quartz that 

contains coarse gold, almost entirely native, with some argentite 

and pyrite. The gold was worth $19 to $20 an ounce, being' unusually fine. The quartz was partly massive, partly ribboned. 

Where large masses of pyrite occurred the amount of gold decreased.

The highest assays of the vein were obtained where it was 3 to 4 

feet thick. The main pay shoot, which was irregular in outline, 

was 1,400 feet long on the Dry Creek level and extended to the 

surface. The milling ore of this mass ran between $3 and $10 in 

gold to the ton. Within the shoot smaller and richer bodies carrying 

coarse gold occurred. One of them pitched 60° NW. in the vein 

and was about 60 feet in pitch length by 10 feet along the level. 

From this body $120,000 was recovered, some argentite being associated with the gold. The rich ore was locally concentrated in a 1-foot 

thickness of quartz, along either the footwall or the hanging wall; 

elsewhere it was irregularly distributed through the entire thickness 

of the vein. There was little evidence of enrichment.

LIDDY

J. J. Liddy has done considerable prospecting on the east fork of 

Connor Creek in sec. 34, T. 11 S., R. 45 E. The country rock is 

chiefly limestone, interbedded with black slate and greenstone, with 

a few dioritic dikes. Several tunnels have been driven. In the 

longest one, about 800 feet long, no veins were cut, but one of the 

shorter tunnels cuts a short thick lens of low-grade quartz fully 20 

feet thick but faulted off on both ends. It is reported by Mr. Liddy 

to run about $10 to the ton in gold. The vein is much crushed and 

the quartz sugary.

MTJLLIN

The deposit known as the Mullin prospect, discovered in 1914, is 

on the north side of the district, near Soda Creek. It is about iy2
52 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PAET 1

miles from the railroad. The claim was not visited, and the following description is summarized from Swartley's report.8

The country rocks are limestone and schist of obscure bedding, but 

the schistosity strikes N. 70° E. and dips 80°-90°. These rocks are 

cut by two veins. One 2-foot vein of milky quartz containing native 

gold and tetrahedrite strikes NV40°-45° W. and dips 60° SW. and 

has been traced about 300 feet; the other vein consists of barren 

quartz and calcite, strikes N. 55° E., and dips 80° NW. to 90°. The 

auriferous vein is supposed to cut this barren vein and near the top 

of the ridge is itself cut and displaced by a 30-foot basalt dike.

Development work at the time of Swartley's visit was confined to 

open cuts in which variable assays as high as $60 to the ton were

obtained.

RUNNER

Swartley's description 9 of the Runner claims, which were not 

visited in the present survey, may be summarized as follows:

The group is about a mile southwest of the Mullin property. The 

country rock is schist cut by numerous reticulated quartz veins that 

impregnate the schist. The rock cut by these veinlets is all auriferous. Two crosscuts were driven on the property. Channel sampling is reported to have yielded $3.26 a ton over a width of 90 feet, 

with no samples below $1.

No further information was obtained about this property.

PLACER MINES

Placer mining in the area dates from the early days, at least as 

long ago as 1870. The old gravel of Connor Greek has been partly 

buried by landslide and talus material, so that considerable drift 

mining has been done in the placer deposits along this stream. In 

1930 there were several small placer operations in this gravel. 

Swartley 10 reports that the total placer gold production to 1914 was 

about $125,000. The current production is small, and no large returns are made, but the mining is cheap, and presumably wages 

earned are sufficient to justify the work.

BAY HORSE

The Bay Horse mine is just west of the Snake Kiver, about 7 miles 

below the mouth of the Burnt River and close to the Robinette 

branch of the Oregon Short Line.

The mine, which was first opened many years ago, was most 

active from 1920 to 1925 and made some shipments^ of silver and

8 Swartley, A. M., op. cit, pp. 213-215. - 10 Idem, p. 213. 

"Idem, pp. 215-216.
SOME MINING DISTRICTS OF EASTERN" OREGON 53

copper ore to the smelter at Tacoma. The total production has not 

been great. The mine was abandoned and inaccessible at the time 

of visit. 

It has been described by Livingston u as follows:

Silver-bearing tetrahedrite, or rather the arsenical variety tennantite, is generally the sole ore mineral, but it is associated in places with rather small 

quantities of other sulphides. The ore occurs in a fractured zone close to 

the contact between the Permian andesite and the rhyolite flow and probably 

does not extend into the overlying Triassic sediments. It occurs both as an 

impregnation in the rhyolite and as replacement of the andesite. In the impregnations mineralization extends some distance into the rhyolite and forms 

a low-grade ore. The replacements in andesite are somewhat irregular in outline but appear to be persistent in strike and dip westward into the mountain. 

They are highly silicifled masses, which are similar in appearance to the overlying rhyolite and contain numerous equispaced veinlets or stringers of tennantite. The general strike of the ore bodies is about N. 70° W., parallel 

to the stratified rock and the rhyolite. The ore body on which most of the 

mining has been done has a maximum width between 40 and 50 feet. It is 

badly faulted on the main tunnel level, and much of the ore mined during 1922 

was drag ore, lying in a flat fault plane which dipped to the south; this fault 

obscured the nature of the ore occurrence to a, considerable extent. A good 

deal of the ore was shipped as it came from the stopes, though sorting was 

practiced to a considerable extent. The westward limit of the ore body has 

not yet been reached and the present development is outlined to follow it into 

the mountain. Recent developments indicate that the ore shoot occurs at the 

junction of two' faults, that it strikes roughly west, and dips into the mountain 

on a grade of 10 feet in every hundred.

The mine is opened by two tunnels, both of which were started years ago. 

The present operators have pursued development in the upper one, which has 

been driven into the mountain about 800 feet. A number of crosscuts and 

stopes connect with it. A winze from a level about 60 feet below this tunnel 

is now opening up a body of excellent ore in the andesite below the fault on 

the tipper tunnel level. The lowest tunnel, which is about 130 feet below the 

uppermost, has not as yet been reopened by the present company, although 

work in the tunnel is contemplated in the near future. The property is owned 

by the U. S. Metals Co. of Portland, Oreg.

The outcrop is very small and its only indication of mineral is an azurite 

stain. As the ore zone contains practically no vein quartz, it is impossible 

to distinguish the weathered outcrop from the country rock except by the 

copper stain. This fact should be borne in mind when prospecting in other 

places along this mineralized horizon. Copper staining occurs opposite the Bay 

Horse on the Idaho side of the Snake near the andesite-rhyolite contact, but no 

extensive development has been carried on at this point. Similar evidence of 

mineralization is reported to occur on Rock Creek, also in Idaho, but time 

was not available to investigate the geology of this area.

According to a published note 12 the ore body outside of a highgrade streak whose tenor is not recorded, ran 15 ounces to the ton

11 Livingston, D. C., A geologic reconnaissance of the Mineral and Cuddy Mountain mining district, Washington and Adams Counties, Idaho: Idaho Bur. Mines and Geology 

Pamphlet 13, pp. 17-18, 1925 (?).

M Eng. and Min. Jour.-Press, vol. 115, p. 291, 1923.
54

in silver. Flotation experiments were conducted, but it is not known 

whether a mill was ever built. If so, its operations were not long 

continued.

OUTLOOK FOR THE DISTRICT

The district is readily accessible to the railroad, but so few mine 

workings were accessible in 1930 that no adequate basis was available for a judgment as to its prospects. The long and fairly prosperous activity of the Connor Creek mine and of the placers along 

the creek are encouraging features, but nothing was learned that 

would give any guide in the search for further deposits.

GOLD HILL DISTRICT 

LOCATION AND GEOLOGY

Gold Hill forms the northeast wall at the entrance of the lower 

canyon of the Burnt River, about 4 miles southeast of Durkee. The 

main line of the Oregon-Washington Railroad & Navigation Co. 

passes through this canyon, so that transportation facilities are 

excellent.

The dominant rocks are schists with some limestone lenses, referred by Lindgren 13 to the Triassic, into which is intruded a stock of 

quartz diorite. Diorite porphyry dikes related to this stock are 

numerous.

THE MINES 

GOLD HILL

The Gold Hill mine is in the SW. % sec. 1, T. 12 S., R. 43 E., on 

the north side of Gold Hill. It is reached from Durkee by a wagon 

road 3% miles long. In 1930 the property was under control of the 

Sawbridge interests of Spokane, Wash., with C. J. Reuscz as manager. The property consists of 20 lode claims, 1 mill claim, and 

about 80 acres of deeded land. No work had been done for many 

years prior to 1930, but plans were under way at that time to reopen the mine. In 1914 Al Geiser, of Baker, did some work on the 

vein nearest the tunnel portal and recovered about $1,000 in gold.

The mine is opened by about 4,200 feet of drifts on the main level, 

three shafts, inaccessible at the time of visit, and numerous small 

prospect cuts on the surface. No data on production are available, 

but the output of the mine has been small.

The country rock of the mine is almost wholly quartz diorite, although a short drift has been run on a fault contact between the 

quartz diorite and slate. Small quartz outcrops are numerous from 

top to bottom of Gold Hill, above the mine. Eight different veins 

have been cut in the workings. (See fig. 6.)

13 Lindgren, Waldemar, op. cit., pi. 64.
SOME MINING DISTBICTS OP EASTERN OREGON 55

The first vein intersected by the main adit is the Spring Gulch 

vein, about 2 feet thick. About 600 feet of drifting has been done 

on this vein, which strikes about N. 60° W. and dips steeply south. 

Farther south are four other parallel veins, the Judas, Bonanza, Gone 

Goose, and Panting. The last two were not visited because of bad

TELLUR1DE1 ^SUMMIT CLEOPATRA

\ yT

^Vein cuts"

,/' AUZINGER - LOOKOUT

- ^f- l^Arrastre workings

// SEN. JONES

Panting vein 

Gone Goose vein

BONANZA

0Assay office

d Manager's residence ^

500Feet

FIGDRE 6. Map of workings of the Gold Hill mine, near Durkee, Oreg.

air. The strike of these veins is about N. 65° W. and the dip 

30°-45° S." Another vein, the Weatherby, is exposed to the south,' 

on top of the hill, in some prospect pits. The exposures are so 

poor that no information can be given about this vein.
56 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The " contact vein," followed by the " contact drift," is a fault 

containing some vein matter and separates a footwall of slate from a 

quartz diorite hanging wall. Its strike is N. 60° E. and its dip 

30°-45° SE. Owing to bad air it was impossible to map the workings in detail.

The veins consist chiefly of quartz and sericite with some calcite. 

The wall rocks are intensely sericitized adjacent to the veins. The 

average thickness of the veins is less than 6 inches, but locally a width 

of 2 feet or even more may be attained. Considerable pyrite and 

small amounts of sphalerite and galena were seen. Serpentine is 

present in the faulted contact.

Assays made by D. W. C. Nelson, of Baker, which were made 

available through the kindness of Mr. Reuscz, showed that the- Spring 

 Gulch vein averaged $14.66 over a width of 3 feet and the Bonanza 

$15.70 over a width of 18 inches. Surface cuts on the Anzinger 

claim yielded quartz averaging $34.14 to the ton, whereas the same 

vein yielded an average of $60 to the ton over a width of 3 feet in 

the Porcupine tunnel. All the value in these assays was in gold. 

A sample from the surface on the Judas claim assayed a trace of 

gold and 32 ounces of silver to the ton.

DTTRKEE DEVELOPMEKT CO.

The Durkee Development Co.'s property is half a mile southeast 

of the Rye Valley road at an altitude of about 4,000 feet and is 

about 5 miles by road from Durkee. It is under the management of 

C. L. Deerdorf and is owned by Deerdorf & Graves, of Durkee. 

Development work was going forward at the time of visit.

The vein seems to be associated with a diorite porphyry dike, 

but exposures are too inadequate to demonstrate this relation. 

Some arkose in the slate series was observed on the hillside to the 

east of the veins. One shaft about 30 feet deep has been sunk 

but was caved at the time of visit. A short crosscut driven below 

to connect with this shaft penetrates slate and a basaltic dike.

The vein is composed of quartz and strikes north and dips about 

45° W. Pieces of vein material about a foot in diameter are present 

on the surface, but the greatest thickness exposed in any of the 

workings is 8 to 10 inches. Nothing is known of the assay value 

of this quartz.

GOLD RIDGE

The Gold Eidge mine is about half a mile west of the Rye Valley road, about 4 miles south of Durkee. The workings were all 

abandoned, caved, and inaccessible in 1930. According to Lindgren,14 the mine is opened on an old discovery and was doubtless

u Lindgren, Waldemar, op. cit, pp. 765-766.
SOME MINING DISTRICTS t»F EASTERN OEEGON 57

located soon after the placers below it. In 1881 a 10-stamp mill 

was built, and it was operated till 1886, when work was stopped. In 

1896 a brief period of activity ensued, but the mine was again 

quiescent until 1900, when a 250-foot vertical shaft was sunk. At 

the time of Lindgren's visit the crosscut from this shaft had not 

reached the veins, and information was not obtained as to whether 

the veins were ever cut at this level. There were 2,000 feet of 

tunnels in 1900. The production was given by H. R. Nichols as 

$210,000, practically all extracted between 1881 and 1886.

The country rock is diorite. Three veins cut this diorite; two 

strike N. 50° W. and dip 65° SW.; the third strikes more nearly 

west and dips south. The veins are sharply defined, consist of 

quartz, and are 2 to 3 feet wide. Several branch veins occur. The 

ore above the tunnel level, 275 feet below the croppings, was all 

oxidized and ran between $12 and $15 to the ton, chiefly in free 

gold of a fineness of $18 an ounce. The concentrates were rich, 

containing 8 ounces of gold and 1% ounces of silver to the ton. 

The pay shoots on the two easterly veins were reported to be 780 

feet long, whereas that on the third was considerably shorter.

The writers are'able to add nothing to the information obtained 

by Lindgren.

OUTLOOK FOR THE DISTRICT

The accessible mine workings were too scant to give any adequate 

basis for an estimate of the possibilities of the Gold Hill district. 

The veins so far found, although of good tenor, appear too small 

to justify work on a large scale, but they may prove profitable if 

worked in a small way with a minimum of overhead. Larger veins 

may be found by further exploration.

SPARTA DISTRICT 

GEOGRAPHY

The Sparta district is in Ts. 7, 8, and 9 S., R. 44 E., on the southern foothills of the Wallowa Range, where they slope down to the 

lower Powder Valley. Altitudes range from about 2,300 feet to 

nearly 5,000 feet. The district is reached by an excellent automobile highway from Baker to the lower Powder River Valley, from 

which somewhat inferior but still fairly good roads run into the 

foothills. The distance from Baker to Sparta is about 40 miles by 

these roads.

GEOLOGY

The principal rocks underlying the district are quartz diorite 

and albite granite of presumable Mesozoic age, intrusive into Per164495 33 5
58 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

mian greenstone, which is only locally represented. Overlying these 

rocks and separated from them by a profound structural and erosional unconformity is basalt of the Columbia River lava. A few 

basalt and diabase dikes, possibly feeders for these flows, cut the 

older rocks.

From the regional distribution of the Permian greenstone it is 

supposed to strike slightly north of west, but local observations toconfirm this inference are lacking, owing to the scanty exposures and 

considerable metamorphism of these rocks. The granitic rocks, 

which constitute a much more abundant unit in the district, are 

almost massive that is, free from gneissic banding although they 

are considerably sheared and broken. The Columbia River lavas 

lie with gentle south dips across the older structure.

The mineral deposits of the district, aside from the long inactive 

placer workings on the plateau near Sparta, are all gold quartz 

veins in quartz diorite and albite granite. Some of these veins arevery rich, but those so far found are mostly narrow and nonpersistent.

THE MINES 

GEM

The Gem mine, owned by Al Geiser, of Baker, is in gently rollingcountry about 2 miles west of Sparta. According to Lindgren-15 

from whose report the following description is largely taken, the 

mine was located in the early days, a 10-stamp mill being erected in 

1873. The mill was removed to Connor Creek in 1875, and the mine 

was idle for a long time. Just prior to 1900 there was renewed 

activity, but this lasted for only a short time. In 1919 a nominal 

production was reported. The mine had been closed down for many 

years before 1930 and was inaccessible at the time of visit. A plan 

and section of the mine have been published by Swartley.16

No data on the production of the mine are available, but the output was undoubtedly moderate.

The mine was developed by a vertical shaft 500 feet deep, several 

inclines, and eight drifts on different levels.

The country rock is albite granite, with some aplite. The normal, 

rock is pseudoporphyritic with large blebs of bluish quartz, locally 

attaining 1 inch in diameter, in a* coarsely crystalline groundmass; 

of albite, quartz, and epidote. The vein, which strikes north .and. 

dips 40° E., shows well-defined walls 1 to 4 feet apart and consists 

of sheared granite horses in coarse vein quartz. The minerals 

present include free gold, pyrite, and zinc blende. Near the shaft

15 Lindgren, Waldemar, op. cit., p. 737. 10 Swartle5T , A. M., op. cit., p. 127.
SOME MINING DISTRICTS OF EASTERN OREGON 59

the vein cuts a granite porphyry dike without change in character, 

but on the second level south it is cut off by a basalt dike which 

strikes east and dips 60° S. and along which faulting has occurred.

CRYSTAL PALACE

The Crystal Palace mine, controlled by S. A. Work, of Boise. 

Idaho, is about 2y2 miles west-southwest of Sparta. Its production 

has doubtless been small, but figures are not available.

The property is developed by two tunnels 80 feet apart vertically 

and by inclined raises and winzes from them. The workings aggregate about 2,000 feet. (See fig. 7.)

The country rock is albite granite, cut by diorite porphyry dikes 

(not separately mapped) and by several much younger basaltic 

and diabasic dikes that range in thickness from less than an inch 

to 20 feet.

The granite is sheared and locally silicified along these shear 

planes. Quartz veins follow several of these shear surfaces and 

probably are chiefly replacement veins localized by them.

The vein is much more continuous and uniform in the upper 

tunnel than in the lower tunnel, where the most recent work has 

been done. In the upper tunnel its average strike is about N. 35° 

W. and its dip about 27° E., whereas in the lower tunnel it ranges 

in strike from N. 30° W. to N. 60° E., with a peculiar S-shaped 

curve. This curve may be due either to postmineral or premineral 

movement; the exposures are insufficient for clear decision. The 

vein quartz is more or less crushed, showing clearly that there 

has been postmineral movement, but the amount is difficult to judge. 

In places the fissures contain no quartz and are marked by sericitic 

and ankeritic crush zones. The vein ranges in thickness from a 

knife-edge to about 7 feet, and the average is about a foot. .

The mineralogy of the veins is simple. The sulphides are pyrite 

and arsenopyrite in a gangue of quartz, sericite, chlorite, and

ankerite.

MACT

The Macy mine is in the northwest wall of Maiden Gulch about 

a quarter of a mile above the junction with the Powder River. 

The mine was located about 1920 by the Macy brothers, of Sparta, 

and in 1930 was being developed under bond by the Mines Development Co., W. J. Geer, manager.

The property is developed by three tunnels and two short inclinesThe lower tunnel includes about 200 feet of crosscuts and 400 feet 

of drifts; 26 feet higher is a 200-foot drift; and 40 feet above this 

is the upper level, on which a drift has been run for about 100 feet.
CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Dip of dike 

or vein

Vertical dike

Upper tunnel approximately 

^80' above the tower

FIGURE 7. Map of the Crystal Palace mine, Sparta district, Oreg.
SOME MINING DISTRICTS OF EASTERN OREGON 61

Farther up the hill to the north are two short inclines. Altogether 

about 1,000 feet of development work has been done. (See fig. 8.)

The production has been small, but some has been reported for 

1922, 1923, and 1926. At the time of visit a small mill was being 

installed and was expected to be in operation in the fall of 1930.

The country rock of the mine is albite granite, which grades into 

quartz diorite. Higher slopes to the north and east are capped by 

diabase and basalt flows of the Columbia River lava.

EXPLANATION 

N

EI.2586'

Vein4wide

Stope

Vuggy quartz )"or2"

Vein quartz up to 

life'thick

Strong barren fissure

This fissure cut by 

N./0°W. fissure but 

with no displacement

50 50 i ooFeet

Branch fissure Country rock all quartz diorite, partly albitized

 30°

c,EI.2450'(assumed) 

FIGURE 8. Map of the Macy mine, Sparta district, Oreg.

The mine develops a quartz vein with several branches. The 

trend of the main vein is about N. 50° W., and its dip ranges from 

about 75° to 40° S. Branches toward the north, northwest, and westsouthwest are seen on the lowest level. The two inclines above the 

main workings follow separate veins; the lower strikes northnortheast and dips 45° W.; the upper strikes nearly east and dips 

40°-63° N.
62 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The veins exposed range in width from about an inch to about 

4 feet, with an average, where worked, of about 1 to iy2 feet. For 

the most part the walls are well defined, in many places demonstrably fault surfaces. The vein quartz itself is commonly brecciated, and most of the sulphides are localized in these brecciated 

places. Locally the veins are vuggy, elsewhere they are massive, 

and at still other places the space between the walls is filled with 

gouge and only subordinate amounts of quartz. Stoping has been 

carried through between the two lower levels just west of- the lower 

crosscut and from the lowest to the upper level, about 20 feet from 

the upper portal. The stope length of each of these shoots is about 

20 to 25 feet, the veins pinching down to unminable thinness in 

both directions.

The veins are composed chiefly of quartz, with sericite, chlorite, 

and calcite, containing pyrite, sphalerite, and free gold. Clay and 

limonitic material are the weathering products. Assays were not 

available, but it is evident from the visible free gold that some of 

the material is extremely rich. However, the veins so far exposed 

are not regular nor persistent enough to establish a confident expectation of continuing to great depths.

PLACER MINES

The placer mines of Sparta have long been inactive, and the old 

Sparta Ditch, which supplied water from Eagle Creek for many 

years, beginning in 1873, has long been withdrawn from mining use. 

In fact, no water is now brought in it for irrigation. The gold was 

found in the residual soil of the deeply weathered granite near 

Sparta and doubtless was derived from the numerous small but rich 

veins similar to those seen in the mines of the district. The topography is not suited to other than sluicing methods of recovery, so 

that a revival of placer mining is unlikely.

THOMAS

H. C. Thomas has three and one-fourth claims in the Sparta 

district, about 2 miles south of Lily White. They lie on a side road 

a mile west of the road from Sparta to Lily White and are a short 

distance east of Goose Creek, on the hill above the Daddy Lode mine. 

The claims are the Coin, the Eclipse, and the Sovereign.

Most of the development work has been done on the Coin claim. 

There are two tunnels now accessible on this claim, one of which 

extends for a distance of approximately 600 feet and the other for 

150 feet. In addition, a small shaft about 40 feet deep has been 

sunk, as well as several small prospect holes. The Eclipse claim 

has a 30-foot shaft, now inaccessible, as is the 80-foot shaft on the 

Sovereign claim. A considerable proportion of the work has been 

done under bond by John Arthur, of Baker.
SOME MINING DISTRICTS OF EASTERN OREGON 63

The country rock of the region appears to be a highly silicified, 

probably originally dioritic intrusive igneous rock. In the. larger 

tunnel on the Coin claim several faults were noticed which trend 

. about §. 25° W. and dip at various low angles, about 30° W. Gouge 

is developed along these slips, and they appear to be centers of 

;sericitization.

Most of the ore found has been as chunks and boulders in the

 fault zones. The ore is chalcopyrite, in part altered to malachite 

rand limonite. The gangue is either quartz or barite or both. No 

bodies of minable size have been found. Galena and sphalerite are

 also found in boulders and locally in small veins in the country 

.rock. These minerals have the same gangue as the chalcopyrite, 

vwith which they are locally associated.

OUTLOOK FOB THE DISTRICT

The occurrence of rich placer ground on the plateau near Sparta 

. gives evidence of considerable mineralization. The veins that have 

been developed have given very encouraging assays, but nevertheless 

there have been no developments sufficient to justify large mining 

activity, doubtless because of the lack of persistence in the individual 

veins. The considerable amount of gold undoubtedly present has not 

.been concentrated in a few large veins but has been deposited in 

numerous narrow and discontinuous ones. Several of the properties 

show developments encouraging to work in a small way; mining

 on a large scale must await the discovery of more persistent and 

larger veins than were accessible in 1930.

EAST EAGLE DISTRICT 

LOCATION AND GENERAL FEATUBES

The East Eagle district lies on the southwest flanks of the Wallowa 

^Mountains, in Ts. 6 and 7 S., R. 44 E. It is accessible by good 

mountain roads from the Powder Valley and is about 45 miles by 

road from Baker. The district lies on the hills near the junction 

of East Eagle Creek with the main stream.

The country rock is chiefly Triassic limestone and greenstone, cut 

Iby dikes of both granitic and diabasic rocks.

THE MINES

AMALGAMATED MINES CO.

The Amalgamated Mines Co. controls 21 unpatented claims near 

the head of Paddy Creek, in the southern part of the Wallowa 

Mountains. Most of the claims lie in sec. 35, T. 6 S., R. 44 E. Mrs.

 G. J. Burnham is mine manager at the property, and W. Burnham,

 box 1928, Spokane, Wash., is secretary of the company.
64 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

In addition to numerous prospect pits and small open cuts there 

is considerable underground work, much of which was inaccessible 

at the time of this survey. The accessible workings consist of two 

adits aggregating about 1,500 feet, including short crosscuts, as 

shown in Plate 3. The lower and upper adits are connected by a 

40-foot raise.

A small Chile mill, situated below the portal of the lower adit, 

had been in operation for only a few days at the time of this survey, 

and no clean-up had been made. It was milling ore that had been 

stored from a^ previous period of activity. No assays were available. 

The mine foreman estimates the capacity of the mill at 25 tons a 

day. Water power is used, the water coming from the head of Little 

Eagle Creek.

The principal country rock of the vicinity is fine-grained greenstone. Locally the rock is a coarser breccia; some conglomeratic 

beds are present and carry pebbles as much as 2 inches in diameter. 

The rocks are excessively jointed in several directions, so that hand 

specimens are usually bounded by joint planes. These rocks have 

been assigned to the Triassic by Lindgren 17 and to the Carboniferous (?) by Eoss.18

At least two systems of faults are present. The representatives 

of the more prominent system trend northwest and dip northeast. 

Those of the other set also trend northwest but dip steeply southwest.

Gouge is developed along the slips. The greenstone is in most 

places crushed along both walls of a fault, locally for a width of 20 

to 30 feet. This condition is especially well seen at the places where 

the two crosscuts are turned from the main lower adit.

Mineralization and alteration have taken place along some of the 

faults, and the rock is bleached in many places, locally on both sides 

of the fault and elsewhere on only one side. Sericite, fuchsite, 

limonite, and quartz were recognized in these zones. The mineralization hag been variable, and any or all of the above minerals may 

be present or absent at any one place.

SUMMIT MINING CO.

The Summit Mining Co., of which W. H. Strayer, of Baker, is 

secretary, controls a group of claims on the west side of East Eagle 

Creek, about 3 miles above the confluence of that stream with 

Eagle Creek. A few of the claims extend over the divide west of 

East Eagle Creek into the drainage of Bradley Gulch, a tributary 

of Eagle Creek. Originally the claims now controlled by the Summit Mining Co. belonged in two groups the M. K. Woodard group 

and the Dunham Miles group.

17 Lindgren, Waldemar, op. cit., pi. 64. 1S Eoss, C. P., unpublished map.
SOME MINING DISTRICTS OF EASTERN OREGON 65

A caved tunnel on the Summit claim is reported to have produced 

$30,000 at a time when most of the claims were controlled by a Mr. 

McGee.

The property is only partly developed. Besides numerous prospect pits, three adits, each between 100 and 200 feet long, were 

examined.

The predominant country rock of the vicinity is greenstone, 

mapped as Triassic by Lindgren and Ross. Some limestone^ shale, 

and conglomerate are present in the greenstone series. The greenstone is gray, brick-red, or dark green. The regional strike may 

average about N. 10° W., and the dips are uniformly steep to the west.

The Triassic rocks are cut by much later basic dikes, which may be 

feeders for the Tertiary basalt blanket that still partly covers the 

area.

Midway. The Midway claim of the Woodard group lies on the 

Avest side of East Eagle Creek about two thirds of the way to the 

divide above the creek. The rock is red shale and greenstone that 

strikes N. 12° W. and dips 60° W. The vein is exposed in a small 

prospect pit and may be traced by float for several hundred feet. It 

is about 6 inches thick, strikes N. 85° E., and dips 50° N. The contacts against the basic dike hanging wall and greenstone footwall 

are sharp.

The vein material is white quartz. Other minerals seen were 

chalcopyrite, limonite, malachite, and a minute flake of native gold.

Apex. The Apex claim, belonging in the Miles group, is on the 

ridge above the Midway claim. There are several prospect pits on 

the claim, the southernmost of which exposes a quartz vein 1 foot 

thick, which strikes N. 10° E. and dips 25° E. The footwall appears 

to be a basic dike similar to that on the Midway claim, and the hanging wall is dark-green greenstone. Two quartz stringers, 1 inch to 

iy2 inches thick, run from the vein into the footwall dike, thus indicating that the dike is older than the vein. However, the stringers 

may not be of the same age as the main vein, as they are not mineralized. The metallic minerals seen in this pit were chalcopyrite 

and enargite, with chrysocolla and limonite as oxidation products.

In another pit on the Apex claim, about 200 feet north of the one 

above described, a series of small quartz stringers, ranging from the 

thinness of paper to several inches in thickness is exposed.

Zenith. The Zenith claim of the Miles group lies just north of the 

Apex claim and is opened by a 150-foot adit running N. 65° E. along 

a 2 to 4 foot quartz vein that dips 20 cMtO° NW. Near the face the 

vein appears to be cut off by a northward-trending fault, which dips 

steeply east. The fault appears to have the downthrow on the east, 

and it may be related to a larger fault that is believed to pass through
66 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

the saddle between the Apex and Zenith claims. The country rock of 

the Zenith claim is greenstone.

North of the Zenith claim the ridge is blanketed by a basalt cover 

that attains a thickness of several hundred feet.

Woodrow. The Woodrow claim of the Miles groujp is about two 

thirds of the way up the west wall of East Eagle Creek Valley and 

about a mile north of the Zenith claim. The claim is developed 

by a 100-foot adit and a 10-foot incline, both of which follow the 

vein. One of the basic dikes forms the hanging wall, and greenstone 

the footwall. The vein strikes north and dips 50° W. Near the 

south face the .vein disappears, but it was not determined whether 

this was a result of faulting or whether the vein pinched out.

The mineralogy is similar to that of the veins already described 

in this region.

The dike is well exposed a little to the north of the adit portal and 

across a small gulch. At this place a quartz stringer, unmineralized, 

occurs in the dike. The stringer trends N. 75° W. and dips 50° NE.

Summit. The Summit claim lies north of the Woodrow claim. 

An old adit on this claim was inaccessible at the time of this survey. 

The portal is in conglomerate and greenstone. The vein material 

on the dump appears to be the same as that from the Woodrow claim.

OUTLOOK FOB THE DISTRICT

The East Eagle district is handicapped by its distance from transportation facilities but more seriously by the irregularity of the mineralization. There is little doubt that gold is present in considerable 

aggregate amount, but, as in many others of the eastern Oregon 

districts, it is in small, irregular veins, search for which is a sort 

of " pocket hunting." Several properties in the district may prove

profitable in a small way, if their exploitation is undertaken with full 

regard to this irregularity, but such mining must be done with a 

small overhead expense.

SANGER DISTRICT

The Sanger district is in the foothills of the Wallowa Range, on 

the divide between Eagle Creek and the Powder River, between 5 and 

10 miles northwest of Sparta. The district is reached from Sparta 

by fairly good forest roads; it is about 12 miles east-southeast of 

Medical Springs, the nearest railroad point, and is accessible by 

fairly good roads.

The production of the district has been derived chiefly from the old 

Sanger mine, long since inactive, but in 1930 mining was going on at. 

the Basin mine, and there was some prospecting in the neighborhood of Sanger and Lily White.
SOME MINING DISTRICTS OF EASTERN" OREGON 67

The pre-Tertiary rocks of the area are exposed only where the 

formerly continuous cover of Columbia River lava has- been removed 

by erosion. About 2 miles west of the Sanger mine fossiliferous 

Triassic sediments crop out beneath the basalt. Although no fossils 

have been found near by, it is likely that the rocks in the vicinity 

of the Sanger mine are also Triassic, but Permian greenstone occurs in Goose Creek and Sawmill Gulch just west and southwest of 

Lily White. Diorite porphyry dikes and some larger diorite intrusions are present in the area.

SANGER

The Sanger mine, formerly the largest producer in the district, is 

in sec. 2, T. 7 S., R. 43 E., about half a mile east of Goose Creek, 

just north of the road between Medical Springs and Lily White. 

The mine has been inactive since about 1900 and was inaccessible at

the time of visit. A little surface trenching was going on, as apparently it has been nearly every year since the mine became inactive. 

Little can be added to the account given by Lindgren,19 summarized 

below.

The vicinity of the mine constituted the old placer camp of 

Hog'em, with a reported production of about $500,000. The principal vein, the Summit lode, was discovered in 1870 and actively 

worked in following years. In 1874 the production was $60,000 from 

ore containing $16 to the ton. The production to 1887 is unknown, 

though probably small, but a mill was then built, and in 1889 production began to increase rapidly. The Mint reports for the four years 

1889-1892 give $813,000 as the production of the mine. The mine 

was closed in 1897 but became active again about 1900. Since that 

time little work other than surface trenching has been done, although 

some underground work was reported in 1907, 1908, and 1921. The 

probable value of the output is about $1,500,000.

The mine is developed by several tunnels and a 400-foot shaft. An 

old map of the mine seems to show that work was done on two 

intersecting veins, but no unmistakable evidence of this was obtained.

The country rock is black slate, somewhat pyritic near the veins, 

which are gently dipping, well-defined quartz veins with clay selvages. The gangue was coarse quartz and a little calcite, containing 

about 3 per cent of sulphides, consisting of pyrite, chalcopyrite, 

sphalerite, and a little galena, and free gold. The principal vein is 

reported to have contained three pay shoots. The upper stopes were 

worked for 600 feet along the vein to a depth of 50 to 100 feet. The 

average width of the vein in these stopes was 15 inches, and its content $20 to $25 to the ton. Below the zone of weathering the vein was

18 Lindgren, Waldemar, op. cit, p. 738.
68 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART

2 to 4 feet wide and carried $12 to the ton in gold. This relation 

possibly signified residual enrichment of the vein by leaching out of 

valueless gangue near the surface.

BASIN

The Basin mine, owned by Dean & Sturgill, of Baker, is an old 

property but has been actively exploited only in the last few years. 

It is about 3 miles north of the road between Medical Springs and the 

Sanger mine, just over the divide, on the Eagle Creek side.

Production statistics were not available, but the output must have 

been moderate despite the very high grade of the ores.

 rtz

Note: Country all quartz diorite

FIGURE 9. Map of the Basin mine, Sanger district, Oreg.

So" Fault with thin quartz 

seam cuts off vein

In 1930 the development work consisted of somewhat more than 

600 feet of drifts, with some winzes, raises, and stopes. Most of the 

workings were on the adit level, with an inclined shaft reaching the 

surface about 30 feet higher. (See fig. 9.)

The country rock is quartz diorite throughout. It is cut by many 

joints and shear planes, the most prominent of which strike N. 

10°-15° W. and dip 25°-30° W., strike N. 60° W. and dip 35° S., 

strike N. TO 0 W. and dip 15° N., and strike N. 35° E. and dip 20° 

NW. Quartz veins and veinlets follow all these directions and many 

others. Most of the veins are narrow and discontinuous, though 

many are very rich, showing specks of gold in the hand specimen.

Three stopes are visible in the accessible workings. One is on a 

vein followed by an incline from the surface. This vein has been 

stoped for a distance of about 20 feet for a pitch length of about 40
SOME MINING DISTRICTS OF EASTERN OREGON 69

feet above the tunnel level, along the inclination of the vein. The 

thickness of the vein in this stope is not known; to judge from the 

exposures in the walls, however, it did not exceed a foot, probably 

averaging between 4 and 8 inches. This ore shoot is evidently the 

objective of the winze below the tunnel level, but the winze was full 

of water and could not be examined.

The other stopes are above the tunnel level, along a vein striking 

N. 60° W. and dipping 35° S. This vein has been mined just above 

the drift for a stope length of about 30 feet. The western stope 

is about 40 feet high along the dip of the vein; the eastern is somewhat smaller. The quartz vein was evidently somewhat thicker 

than the first one described but probably did not exceed 2 feet in 

thickness anywhere.

The veins are all simple quartz-filled fissures along joints. Most 

of them show a little shearing, dominantly in the hanging wallr 

but can hardly be classed as fault! fissures. Considerable replacement 

of the wall rock has occurred. Sericite is rather common, especially 

along the shears. The vein matter is chiefly quartz and some chlorite 

und calcite, together with hematite, chrysocolla, and limonite, the 

oxidation products of the sulphides formerly present. A few relict 

sulphides occur, chiefly pyrite, chalcopyrite, and sphalerite. The 

quartz shows moderate brecciation.

The gold is free, within the depths obtained in the mine. The ore 

is variable in tenor but is locally of very high grade, wire and shot 

gold being common. As the veins are very narrow, this high tenor 

is a necessity for workability; nevertheless, the mine appears to 

have good prospects if worked in a small way, the lack of persistence 

of the veins being taken into account.

MEDICAL SPRINGS DISTRICT 

LOCATION AND GEOLOGY

Near Medical Springs, Union County, sporadic work has gone on 

for a long time, although no production has ever been reported 

from the district. Medical Springs is about 18 miles by a good road 

northeast of Baker. A standard-gage branch extends from the main 

line of the Union Pacific system at Telocaset to the sawmill of the 

Stoddard Lumber Co. at Pondosa, a new town about half a mile 

south of Medical Springs.

Most of the country north of Medical Springs is covered by the 

Columbia River lava, but owing to the irregular topography of 

the surface upon which these flows were poured out and to subsequent 

erosion, the underlying pre-Tertiary rocks are exposed in some places-. 

Such exposures, so far as seen in this survey, are of siliceous greenstone, apparently identical with the Permian greenstone in the
70 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

valley of Big Creek, to the south. Exposures are poor, however, 

and no fossiliferous limestone such as occur sporadically in the 

Permian greenstones of the copper belt near Keating were seen, 

so that the identity of the series may not be considered established.

THE MINES 

TWIN BABY

The Twin Baby prospect is about 2^/2 miles northeast of Medical 

Springs, on the divide between two tributaries of Big Creek. From 

Medical Springs it is reached by a good wagon road 3^ miles long.

The property was in charge of Al Borosky at the time of the 

visit. He reported that no work other than assessment work had 

been done on it for several years.

The property was opened by an inclined shaft 110 feet deep, 

now inaccessible, and a vertical shaft 247 feet deep, which at the 

time of visit was partly full of water and in the upper levels inaccessible because of bad air. Short drifts are reported to have been 

cut on the 100 and 150 foot levels.

The country rock is greenstone, probably a part of the Permian 

series exposed 2 miles to the south in the Baker quadrangle. The 

vein trends N. 5° W. and dips 80° E. Where exposed in several 

trenches it attains a maximum thickness of 2 feet and consists of 

brecciated quartz, stained in part with hematite, jarosite, and malachite, the decomposition products of the primary pyrite and chalcopyrite, of which remnants occur in some specimens on the dumps. 

The vein is said to persist on the bottom levels and to be quite regular 

in the workings so far driven.

Some very high grade ore has been obtained in the upper workings of this mine, wire and sheet gold being rather common. Nothing is known of the average tenor of the ore, which must have been 

rather spotty, although Mr. Borosky states that assays of $10 or $12 

in gold to the ton are not uncommon. A little silver is also reported.

GBTJXL

Andy Grull has done considerable work in developing a prospect 

in the gulch southeast of the Twin Baby mine, in sec. 20, T. 6 S., 

E. 42 E., about 2 miles northeast of Medical Springs.

The principal work, aside from trenches and shallow prospect 

shafts, has been done in a tunnel about 300 feet long, driven to cut 

a quartz vein that crops out on the hill north of the gulch. This 

tunnel exposes Teritary sediments, closely associated with an andesite flow, for about 200 feet, then continues in greenstone, which is 

highly siliceous and very hard. The vein that is the objective of
SOME MINING DISTRICTS OF EASTERN OREGON" 71

the tunnel is supposed to lie about 70 feet ahead of the face of the 

drift. Mr. Grull reports no assays but very high grade pans of free 

gold from the vein.

The greenstone carries minute veinlets of chalcopyrite and pyrrhotite, with some scapolite (dipyre), epidote and andradite. Oxidation minerals include hematite, nontronite, gypsum, and limonite,

OUTLOOK FOB THE DISTRICT

The developments in the Medical Springs district in 1930 were 

not adequate to permit any estimate of its potential output. The 

cover of Tertiary rocks masks much of the possible mineralized 

area. More development work would have to be done and a better 

basis thus obtained for evaluation of the possibilities before mining 

would be justified. N

VIRTUE DISTRICT

GEOGRAPHY

The Virtue district includes T. 9 S., R. 41 E., and immediately 

adjacent territory to the north and south. The district lies about 

4 miles east of Baker, from which it is reached by an excellent highway. The Oregon Trail of pioneer days passed through the district 

by way of the pass just south of the Flagstaff mine.

The central topographic feature of the district is Virtue Flat, a 

wide, gently sloping, basinlike area, nearly surrounded by rolling 

hills. The district is drained by Ruckles Creek, which joins the 

lower Powder Valley at Keating. Altitudes in the district range 

from about 3,100 feet at the head of Ruckles Creek Canyon to 5,077 

feet on the top of Lone Pine Mountain. The climate.is very dry, 

and most of the land is utilized only for sheep range, but a few 

dry farms are situated in Virtue Flat.

FIELD WORK

The Virtue district is included in the Baker quadrangle, on the 

topographic map of which it was possible to indicate the principal 

geologic formations present. (See pi. 4.) About three weeks in 

June and July, 1930, was spent in mapping the areal geology and 

studying the mines.

GEOLOGY

GENERAL FEATURES

The oldest formation in the Virtue district is composed of argillite 

and chert, of Carboniferous age, which is exposed in the hills south 

of Virtue Flat and in a small area north of the fault forming the 

north boundary of the flat. Into this formation are intruded two
72 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

igneous series the earlier a gneissic gabbroic series accompanied by 

norite and amphibolite facies and a sodic quartz diorite; and the 

later a nearly massive biotite-quartz diorite.

There are no rocks present in the district to record the long interval 

between the intrusion of these rocks, probably in the Mesozoic era, 

and the outpouring of the Columbia River lava in Neocene time. 

An erosion surface of considerable relief, perhaps comparable to 

that of the present surface, was developed upon the pre-Tertiary 

rocks in this interval. The Columbia River lava and the fluviatile 

and lacustrine deposits interbedded with it almost completely surround the Virtue district and without doubt extended over the entire 

area before they were removed by erosion. Gravel terraces presumably of Quaternary age are developed in Virtue Flat across the 

edges of the fluviatile deposits. Presumably it was gravel correlative with these terraces that yielded the mammoth tooth mentioned 

by Lindgren.20

The structure of the argillite is complicated in detail, but its areal 

distribution in the Baker quadrangle is such as to indicate a dominantly eastward strike through the district. The Tertiary rocks in 

the vicinity of Lone Pine Mountain dip southwest, and north of Virtue Flat they dip northeast. Virtue Flat itself is in part of graben 

structure, bounded by northwestward-trending faults, but it is in 

major part due to erosion. There is, indeed, a possibility that the 

valley is in part an exhumed valley in the surface antedating the 

extrusion of the Columbia River lava.

ORE DEPOSITS

The ore deposits of the Virtue district are contained in quartz veins 

in the pre-Tertiary rocks. They were probably formed by emanations from the biotite-quartz diorite exposed south of the Flagstaff 

mine or from related masses at greater depth.

The veins consist of quartz, calcite, and scheelite, with a little 

sericite, and carry small amounts of pyrite and chalcopyrite and 

free gold. The veins are commonly brecciated, and the breccia zones 

are favored sites for the sulphides.

THE MINES 

VIKTUE

Location. The Virtue mine, which has given its name to the 

district and has hitherto been the greatest producer in it, is in 

sec. 21. T. 9 S., R. 41 E., at the foot of the hills bounding Virtue 

Flat on the south. It is about 3 miles south of the Baker-Robinette 

highway and about 12 miles by road from Baker.

20 Lindgren, W'aldemar, op. cit, p. 722.
U.S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 3

15O FEEt

GEOLOGIC SKETCH OF UNDERGROUND WORKINGS OF AMALGAMATED MINES CO., EAST EAGLE DISTRICT, OREG.
TJ.8. GEOLOGICAL SURVEY BULLETIN 846 PLATE 4

R.4IE.

Terrace and bench gravd

Columbia River LacusLrine ondfluviatflfl

deposits (the lower porter 

this formation inierfingora with tho Columbia, 

Kvvcr basalt and locally 

underlies U)

(rhvoUte breocia,.obeuuan..aitd

subordinate rfivolite and

andesite flows)

Bio tile -quartz diorite

(resulting from tgneou.a metamorphiem ofdiariie anAgabbro)

(oligoolaso-quartx diorite)

Hornblende-quartz diorite

Gabbro Metagabbro Serpentine 

derived ftx>m gabpr-o fir 

peridotite

(groenstono of volcanic origin;

contains bodies ofargiUUo and thole)

(massive andooddcd chert, argillite.

some slatn and schist; contains bodies

of lunastortf.,\Q, euuiffreonstano

Proved fault 

(probabfy correct within 21)0feet)

Proved fault 

floss accurately located)

Inferred fnult 

(buried by younger rocks)

Contour; interval lOOft. 

. is mean scalevei

Geologic boundaries

(aolidline. probably ccrrvct- within ZOO ft, 

dotted lino less accurately located}

TOPOGRAPHIC AND GEOLOGIC MAP OF VIRTUE DISTRICT, BAKER COUNTY, OREG.
U.S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 5

Country rock chiefly metagabbro

Quartz vein

SKETCH MAP OF MILL-TUNNEL LEVEL OF VIRTUE MINE, VIRTUE DISTRICT, OREG.
U. S. GEOLOGICAL SURVEY BULLETIN 846 PLATE

Elevation at collar of shaft

A.

Quartz and sericfte 

about 4'-5', sloped

2 quartz 4vein 

material in

Sloped 

abou 

wide 

duart

Elevation at collar of shaft

53 and carbonate vein 265-FT. LEVEL

0 i l/g' quartz; country 

rock much altered 

to clay

COMPOSITE PLAN

^^3 265-f t. level 

~~.~ 365-ft.leve 

565-ft. level

uartz stringers

Clayey shear zone "'thick

, 56 

 I quartz,shear

Elevation at co

r Quartz stringers in 

fj" clayey shear zone

Quartz vein, average 3 -4, 

' shear zone about l-2'on

average but pinches to 

about )"in places

uartz, I -6

Breccia zone 2'or more 

7O° W'^n much carbonate and clay

Quartz-sericite stringers

EXPLANATION

or4"of quartz, carbonates, 

sen cite, etc.

Horses in vein, which is 4'or 

so wide, are all made of 

altered diorite. Some few 

stringers of hornblende 

gabbro

Quartz-horn blend

565-FT. LEVEL Fault Strike and dip

365-FT. LEVEL

WJiCJiquar-tz

shear zone

-36S

 ses'

COMPOSITE PLAN AND SECTIONS OF FLAGSTAFF MINE, VIRTUE DISTRICT, OREGON
SOME MINING DISTRICTS OP EASTERN OREGON 73

History and production. The deposit at the Virtue mine, according to Lindgren,21 was discovered in 1862 by tracing up the rich 

placers in the gulch below. For the next 10 years it was known as 

the Kucker or Union mine and was very actively worked. Between 

1871 and 1878 it was worked almost continuously, largely by Brown 

& Virtue. In 1878 it was sold to Grayson & Co., of San Francisco,, 

who worked it in a more or less satisfactory way till 1884. It was 

then idle until 1893, when work was resumed and continued until 

1898 with excellent results. After a short period of idleness the 

mine was sold to the Consolidated Virtue Mine Co., of Montreal, 

Canada,, which also owned the adjoining Collateral mine. The 

upper parts of the mine were worked for a short time, and the mine 

was again closed August 1, 1899. The property was worked for a 

brief interval in 1906-1908, when a little ore was extracted from

above the drainage level and about $1,500 recovered from ore on the 

dump.22 In 1912 the mine was equipped electrically, but no production was made until 1919. A small production was also made in 

1921, 1922, and 1924 by lessees, but nothing has been reported since. 

The total production has been about $2,200,000.

At the time of this survey the mine was almost entirely inaccessible except for the mill-tunnel level and a few stopes above it, so> 

that little can be added to the description of Lindgren.

Development. The Virtue mine is developed by three tunnels, the 

lowest of which, the mill level, is about 300 feet below the outcrop. 

From the lowest tunnel a vertical shaft was sunk 800 feet, and 

crosscuts were made to the vein every 100 feet. The levels extend 

from 200 to 400 feet north of the shaft and 800 to 900 feet south 

from it. The development workings aggregate not less than 10,000 

feet.

Geology. The country rock is strongly sheared greenstone, highly 

chloritic and somewhat serpentinous. It was regarded by Lindgren 23 as an altered volcanic tuff or breccia, and some of it is almost 

surely of this origin, but much of it is believed to be a sheared 

gabbro. Specimens collected in the crosscut on the mill level show 

all gradations between a chloritic schist, whose origin it would be 

impossible to determine from the specimen itself, to a brecciated 

and chloritized rock that is clearly derived from the brecciation 

of a gabbro. Accordingly, it is likely that some of the other rocks 

in the mine whose mottled schistose character at first suggests their 

origin as tuffs are of the same origin. It is clear that most of the 

rounded hill south of the mine is formed of sheared gabbro.

21 Lindgren, Waldemar, op. cit., pp. 722-723.

-Parks, H. M., and Swartley, A. M., op. cit., pp. 229-230. Also U. S. Geol. Survey 

Mineral Resources, 1908, pt. 1, pp. 526-527, 1909. 

23 Lindgren, WaJdemar, op. cit., p. 723. 

164495 33 6
74 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Eight veins, of which the Virtue, Collateral, and Chicago are 

most productive, have been cut in the mine workings. The Chicago 

and Collateral were formerly the bases for independent mines, but 

all are now owned by one company. They are subparallel and 

strike N. 20°-45° W. They dip northeast above the mill level but 

steepen downward and dip southwest in the lower workings of the 

mine. (See pi. 5.) This suggests that they may owe their origin 

to torsion about a flat axis.

The veins range in thickness from 6 inches to 12 feet and average 

about 14 inches. They are filled with white coarsely crystalline 

quartz with subordinate calcite. Vugs are common. Free gold, 

coarse and partly crystalline, with the unusual fineness of 0.940, is 

reported by Lindgren.24 The only sulphides observed were pyrite 

and chalcopyrite, both of which are sparingly present. The veins 

are locally brecciated and banded parallel to the walls, and these 

places are reported to have been richest. Veinlets of calcite, quartz, 

and pyrite occur in the country rock bordering the veins. Lindgren 

reports that the richest ore occurred near the surface. Average 

values of $20 to the ton were obtained in 1870, of $40 in 1873, of 

$24 in 1875, and from $15 to $16 between 1893 and 1898.

The pay shoot is said to have been cut off between the seventh 

and eighth levels by a brecciated interval below which the vein was of 

very low grade. Warm water was encountered in the lower levels 

and stands in the shaft to a short distance below the mill level, considerably above the valley. This water was interpreted by Lindgren, 

doubtless correctly, as an ascending column of underground circulation. A fault just north of the mine (pi. 4) separates the Tertiary beds of Virtue Flat from the pre-Tertiary rocks to the southwest, and this fault may well have given access to the deeper levels

appropriate to the temperature of the water. Gouge sealing the fault 

above the valley level may have impounded the water in the mine.

FLAGSTAFF

Location. The Flagstaff mine, owned by J. L. Layden, is in sec. 

5, T. 9 S., E. 41 E., on the crest of the divide between Virtue Flat 

and Baker Valley, at an altitude of 3,900 feet. It is less than half a 

mile from the Baker-Robinette highway and about 7 miles from 

Baker.

Development and production. The mine was actively worked in 

the years preceding 1898 and has been developed by an inclined shaft 

760 feet deep, with levels at 265, 365, and 565 feet. The workings 

aggregate about 6,000 feet. Since 1898 the only reported production

24 Lindgren, Waldemar, op. cit., p. 724.
SOME MINING DISTRICTS OF EASTERN OREGON 75

was in 1923j when a little bullion was recovered incidentally to development. The total production of the mine is probably not more 

than $100,000.

Geology. The country rock of the mine is chiefly coarse sheared 

gabbro and quartz-bearing hornblende diorite, both containing much 

actinolite and some epidote, cut by dikes of biotite-quartz diorite and 

hornblende-quartz diorite. The two major rocks appear to grade 

into each other, but in view of their petrographic differences this is 

probably due to later metamorphism rather than to an original 

heterogeneity of a single intrusive mass. (See pi. 6.)

The biotite-quartz diorite and hornblende-quartz diorite dikes have 

been recognized only in the mine workings, and exposures are insufficient to demonstrate their attitudes. They are cut by and are 

clearly older than the mineralized shear zones of the mine.

The ore deposit consists of several sheared and brecciated zones 

and veins. They range in strike from N. 45° E. to north and dip 

steeply, averaging 65°, either east or west.

The faults and veins are arranged in a frayed pattern. The main 

vein, in whose footwall the incline is sunk, flattens from a dip of 

about 75° in the upper workings to about 55° on the 565-foot level. 

The drifts on the three levels from this shaft trend successively more 

northward on the lower levels, although they start on what is almost 

certainly the same vein at the shaft. Inasmuch as the dips of these 

principal veins are all southeastward, the necessary result of this 

arrangement is that a number of branch veins must join the main 

vein, as is shown by the map and more clearly by the sections of the 

mine. (See pi. 6.) Unfortunately the raises and man ways of the 

mine were all inaccessible because of defective timbers, so that it was 

impossible to tie one level to another except at the main shaft. The 

" horsetail " arrangement of the veins suggests torsion about a steeply 

inclined axis.

The faults through the gabbro and diorite are all accompanied by 

great masses of clay gouge. Some of this gouge is probably due to 

comminution of the country rock by friction, but most of it is hydrothermal rather than mechanical in origin, as is shown by the 

association of zeolites with the clays.

Within these masses of gouge are extremely irregular brecciated 

lenses of quartz. These lenses locally range from a knife-edge to 

more than a foot in thickness in a few feet of strike length. The 

maximum thickness of quartz observed in any one stringer was 1% 

feet, although in one place, where the shear zone is over 20 feet wide, 

several lenses whose aggregate thickness is about 4 feet are present. 

The shear zones themselves are irregular; they probably average 

about 3 feet in thickness.
76 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Locally the quartz is massive and coarsely crystalline, elsewhereTuggy, and elsewhere sheeted and brecciated. Gold is present in the 

quartz but, according to Mr. Layden, occurs also in the gouge,, 

though in less amount. No sulphides were observed during this 

survey, but tetrahedrite and stibnite, as well as the tungsten mineral 

scheelite, have been recorded from the mine by Lindgren.25

The principal minerals of the altered rock are a clay mineral of 

low refringence and birefringence, sericite, calcite, serpentine, and a 

zeolite related to chabazite. Locally the wall rock is silicified, but 

more commonly it is altered to clay.

No assay samples were collected, but Lindgren reports average 

values of $16 to the ton in the quartz. According to Mr. Layden.. 

large quantities of the gougelike material will assay $5 to the ton.. 

The largest stopes in the mine occur at the junctions of fissures. Here 

the shear zones are wider and commonly have more quartz, with, 

higher gold assays.

The lowest accessible level, the 560, is seemingly less well mineralized than the higher levels. The exposed shear zones are narrower 

and carry less quartz. Mr. Layden believes that the future of the 

property is dependent on large-scale mining of the gougelike material with its relatively low gold assays of $5 to the ton. There is no 

doubt that large quantities of this material are available.

The water level in the mine is just below the 560 level, about 420j 

feet vertically below the outcrop and not far above the level of 

Baker Valley.

KOEHLER

The Koehler mine is on the west slope of the range of hills lying 

south of the Flagstaff mine. The workings were inaccessible at the 

time of this survey. According to Parks and Swartley,26 the mineyielded antimony and gold, beginning late in 1915. The vein is 

reported to be well defined, with a maximum width of about 10 feet. 

Stibnite is distributed through the whole width of the vein, but massive stibnite occurred near the hanging, wall in lenses that were 2 feet 

thick. Some of these lenses yielded ore that was shipped direct;: 

other ore was brought up to grade by sorting. Several carloadscarrying over 50 per cent of antimony were shipped, and the 

receipts from these sales are reported to have been about $15.000..

NORWOOD

The Norwood mine, in sec. 8, T. 9 S., E. 41 E., about 2 miles north 

of the Virtue, was caved and inaccessible in 1930. The property 

has been described 27 as embracing two lode claims. The country

26 Lindgren, Waldemar, op. cit., p. 725.

56 Parks, H. M., and Swartley, A. M., op. clt., p. 137.

27 Idem, p. 174. I
'SOME MIKING .DISTRICTS OF EASTERN OREGON 77

rock is greenstone cut by several quartz and calcite veins, mostly 

rather small, and shows considerable postmineral brecciation. The 

largest vein dips steeply, strikes west, and consists of quartz gouge 

and country rock. Along 450 feet of strike the vein averages about 

2 feet in width. A small mill was installed in 1913, but no production has been reported. Little work has been done for many years 

at this property.

CLIFF

The Cliff mine is about three quarters of a mile north of the Flagstaff, on the north side of a small gulch draining into Baker Valley. 

In 1930 the mine had been long abandoned and the shaft was inaccessible. The following account is summarized from the reports 

by Lindgren 28 and by Parks and Swartley,29 with some observations 

of surface geology by the writers.

The country rock of the mine is sheared gabbro. The vein strikes 

north and consists of 1 to 3 feet of quartz with a little calcite in altered gabbro. Scheelite was identified in the quartz 30 years ago by 

C. L. King, of Baker. The property is developed by a 300-foot 

vertical shaft. In 1916 the war prices of tungsten induced F. S.. 

Baillie and later W. E. King to reopen the long-abandoned mine in 

the endeavor to exploit the scheelite, but nothing came of the

attempt.

WHITE SWAN

Location. The White Swan mine is at the foot of the hills south 

of Virtue Flat, in sec. 25, T. 9 S., R. 41 E. It is about 5 miles from 

the Baker-Eichland highway and about 14 miles from Baker by 

road.

Development and production. According to Lindgren,30 the 

White Swan deposit was discovered in the early days by following up 

the rich placers of the gulch below. The mine was vigorously operated 

about 1890 but was closed in 1897. It was reopened about 1900 and 

operated by Letson Balliet until 1903, when it was again closed.81 

Lindgren estimated the total production at not less than $200,000, on 

the basis of mint reports of output in 1891 as $72,000 and in 1892 

as $72,642.

In 1930 the mine was being reopened by a Washington syndicate, 

with E. McNaughton as manager. At the time of visit very little 

of the old workings was accessible, however.

The mine was developed by a nearly vertical shaft 300 feet deep 

from which four levels were turned. About 2,000 feet of development work has been done.

-s Lindgren, Waldemar, op. cit., p. 725.

20 Parks, H. M., and Swartley, A. M., op. cit., p. 56.

so Lindgren, Waldemar, op. cit., p. 725.

01 Swartley, A. M., op. cit., p. 131.
78 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Geology. The country rock consists of dark carbonaceous argillite 

with interbedded layers of chert and greenstone. The greenstone 

represents altered volcanic sediments. Intrusive into this argillite 

formation are several narrow dikes of diorite porphyry. The general 

strike of the formation is westward.

Several narrow veins are exposed in the vicinity of the mine. All 

trend generally west, but there is no consistent parallelism observable, 

although most dip steeply south. The exposed veins reach thicknesses of 1 to l!/2 feet, but more common widths are a few inches. 

No information is available regarding the thickness of the White 

Swan vein in the old workings.

The only minerals observed in the veins were quartz, sericite, and 

calcite, with a little limonite to attest the former presence of sulphides, which however, must have been sparse.

CHICAGO-VIRTUE

The Chicago-Virtue mine, locally called the Barry property, is in 

sec. 35, T. 9 S., R. 41 E., just south of Virtue Flat. The property was 

idle in 1930, and apparently little work had been done there for many 

years.

The property has been developed by a steeply inclined shaft 86 feet 

deep, from which a short drift has been run 30 feet below the collar 

and a crosscut and drift aggregating 250 feet at the bottom of the 

shaft. No production has been reported from the property.

The country rock is cherty argillite. The work has been directed 

to the development of a vein that strikes east and dips 65° S. The 

vein contains quartz, locally vuggy, elsewhere brecciated, which 

ranges in thickness from a knife-edge to almost a foot. The vein 

follows a slickensicled surface. Nothing is known of the assay value

of this quartz.

CARROLL B.

The Carroll B. property consists of 10 claims in the SE. 14 sec- 3? 

T. 10 S., R. 41 E., which are controlled by Samuel J. Niblack. Development consists of a shaft, from which at least one drift, which, 

is partly accessible, has been turned, and two adits, each several 

hundred feet long, on other parts of the property. The predominant country rock is greenstone with some gabbro and cherty argillite. The quartz vein on which the most work has been done is 1 to 2 

feet thick where exposed in the drift near the shaft. Nothing was 

observed in the other two adits but the greenstone country rock.

BRAZOS

The Brazos mine, in sec. 11, T. 10 S., R, 41 E., was inaccessible in 

1930. It has been described by Lindgren. 32 Since his visit consider82 Lindgren, Waldemar, op. clt,, p. 726.
SOME MINING DISTEICTS OF EASTERN" OREGON 79

able work has been done on the property, including the sinking of a 

600-foot shaft and driving several drifts,33 but for many years prior 

to 1930 the mine had been inactive.

OTHER PROSPECTS

The hills on all sides of Virtue Flat are studded with dumps of 

prospect pits attesting the widespread mineralization of the area. 

Most of these workings date back many years, and none have been 

productive.

North of Virtue Flat the Columbia-Friday vein has been developed 

in several shallow inclined shafts. This vein follows the fault contact between Tertiary sediments and argillite for a short distance. 

All the workings were inaccessible in 1930.

A great many prospects have been worked on the hill south of the 

Flagstaff mine. The country rock is chiefly argillite, but some work

has been done in the gabbro and quartz diorite also.

There are many small prospect adits and pits on the southern 

slope of the ridge that lies between Virtue Flat and the depression 

in which flow Sutton and Alder Creeks. Much of the underground 

work is inaccessible.

Three adits, each several hundred feet long, in the SW. *4 sec- 2, 

T. 10 S., R. 41 E., were examined. The country rock is cherty 

argillite, the average strike of which is about N. 75° E. and the dip 

75° SE. A few thin and irregular quartz veins striking east and 

dipping 45° S. are encountered by the adits. The maximum thickness of the veins observed was 2 feet. In many places the argillite 

is sheared, and considerable thicknesses of clay gouge are developed.

OUTLOOK FOR THE DISTRICT

Among the districts described in this bulletin, the Virtue district 

seems to be one of more than usual promise. This statement is 

based not only on the production record of the Virtue mine but also 

on the fact that both in this mine and the Flagstaff the veins are 

persistent. This persistence contrasts with the irregularity of the 

veins common to most of the other districts. If the mineralization 

has been adequate the persistence of these veins and shear zones is 

highly favorable to mining on a larger scale than would be warranted 

in the thinner though perhaps richer veins found in several other 

districts. Another favorable factor is the relative accessibility of the 

district.

These statements should not be interpreted as directly commendatory of any single property nor as excluding the possibility of the 

veins becoming irregular or lensing out at depths, but if assays

33 Parks, I-J. M., and Swartley, A. M., op. eit, p. 43.
80 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

show workable ore in these veins, the likelihood of their workability 

over a considerable area and in depth is somewhat greater than that 

of the veins in most of the other districts here described.

BAKER DISTRICT 

GEOGRAPHY

The Pocahontas, Auburn, and Minersville districts are now known 

collectively as the Baker district. The present survey was concerned 

only with the part of the district that lies within the Baker quadrangle, which is made up of the southeast end of Elkhorn Ridge, 

in Ts. 9 and 10 S., R. 39 E., and the eastern half-mile strip of Ts. 9 

and 10 S., R. 38 E. The drainage to the northeast goes through 

Marble Creek and the tributaries of Salmon Creek Hibbard, Rouen, 

Dutch, and Washington Gulches. The drainage to the east goes 

through Griffin and Elk Creeks, and that to the south through 

California Gulch, Blue Canyon, French Gulch, and Poker Creek. 

All these streams empty into the Powder River, which swings around 

the south end of Elkhorn Ridge. Altitudes range from about 4,500 

to about 7,000 feet, but the ridge is considerably higher a few miles 

farther northwest. The district is for the most part covered with 

pine forest. Its different parts are readily accessible by roads from 

Baker. There is a road in nearly every gulch, and several of them 

reach the altitude of the Auburn Ditch, which traverses the district at 

about the 5,300-foot contour. The northern part of the region 

described is generally called the Pocahontas district and the southeastern part the Auburn district, after the old placer town.

GEOLOGY

Dark-gray cherty argillite is the oldest rock in the district. Here 

and there in the thick cherty series occur pod-shaped lenses of limestone, generally a few hundred feet long. Interbedded in this 

sedimentary series but subordinate to the chert are strata of lava 

and pyroclastic material which now form greenstone. Subordinate 

shaly beds also occur. Most of the chert is massive, so that no indication of structure is present, but some exposures display a distinct 

highly crumpled and contorted bedding.

From the few observations that could be made the average strike 

of the formation may be about N. 80° E. The dips are uniformly 

steep and incline more commonly southeast than northwest. The 

age of this formation is in doubt, but from a few poor collections 

of fossils it is referred by G. H. Girty to the Carboniferous, probably 

Mississippian.

The argillite series has been intruded by gabbro and related rocks, 

which now occupy a considerable proportion of the area. The intru-
SOME MINING DISTRICTS OF EASTERN OREGON 81

sive masses have very irregular outlines, so that no structural control 

of intrusion is apparent, although there is a possibility that some are 

sills. The basic rocks are sheared and altered, some of them to such 

an extent that the product can not be distinguished with certainty 

from the greenstone that belongs in the older sedimentary series.

The argillite series and the gabbro and related rocks are intruded 

by numerous light-colored porphyritic dikes, which upon the evidence of thin sections are classed as granophyre. Some are between 

50 and 100 feet thick, but most of them are about 15 or 20 feet thick, 

and a few are less than 1 foot thick. These dikes may be related to 

the quartz diorite masses which occur commonly in eastern Oregon 

and representatives of which are found a few miles to the northwest and also a few miles to the south.

The southern and eastern limits of the district are marked by the 

edges of the overlapping Columbia River lava flows, with their interbedded lake and stream sediments and tuffaceous deposits. The 

Tertiary rocks are mildly disturbed as compared with the older 

rocks. In the Tertiary rocks a system of northwestward-trending 

faults is apparent which can not be seen in the pre-Tertiary terrane 

but which no doubt cut it also.

The district is bounded on the north by a major normal fault, 

downthrown to the north, which trends about N. 80° W. The 

latest movement along this fault has probably been as late as Pleistocene, or possibly Recent. North of the fault lies the broad, level, 

downthrown Baker Valley at an altitude of about 3,400 feet.

OBE DEPOSITS

The Baker district has been practically inactive for many years, 

and most of the old mines and prospects were inaccessible at the 

time of this survey. Much of the following information has, therefore, been taken from the earlier reports of Lindgren, Swartley, and 

Parks and Swartley. Lindgren 84 says:

Though * * * nearly every creek and gulch heading in this part of the 

range has carried more or less placer gold and a few have been enormously 

rich, there is throughout a very marked absence of important vein systems 

to which the origin of these placers could be attributed. In part this may 

be due to insufficient prospecting, but in most cases I believe that the placer 

gold was here rather derived from small seams and veinlets than from prominent fissure veins.

THE MINES 

TOM PAINE

The Tom Paine mine is in McCord Gulch, the first gulch west of 

Salmon Creek, in sec. 7, T. 9 S., R. 39 E. The property consists of

34 Lindgren, Waldemar, The gold belt of the Blue Mountains of Oregon : U. S. Geol. 

Survey Twenty-second Ann. Kept., pt. 2, p. 650, 1901.
82 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

one patented claim and is developed by several adits, all of which 

are caved and inaccessible except one, about 55 feet below the main 

level. A raise to the surface is open for about 30 feet above the 

lower adit. It is reported that the Tom Paine vein produced $70,000 

worth of coarse gold from a small pocket about 1884. The country 

rock is limestone and argillite. Swartley 33 speaks of the company 

as the Yellowstone Mining Co. and mentions two veins on the property, the Tom Paine and the Old Soldier. He reports the Tom Paine 

vein to range in width from several inches to several feet and the 

Old Soldier to be 3 feet wide. The only observation that could be 

made on the vein in 1930 was in the 30-foot raise from the lower 

level just mentioned, where it consists of 18 inches of quartz and 

sericite with 2 or 3 inches of gouge on both hanging and foot walls. 

The vein strikes N. 20° E. and dips 40° W. The hanging wall is 

limestone that contains numerous small cubes of pyrite partly altered to limonite. The limestone strikes N. 55° E. and dips 60° SE. 

A short distance west of the Tom Paine mine and a little farther 

upstream Mr. Lilley and one other man have recently exposed in a 

30-foot adit a small 6-inch vein of quartz and sericite. The country 

rock is crushed argillite.

OLD SOLDIER

The Old Soldier claim lies east of the Tom Paine and a short distance downstream from it. The workings are all inaccessible.

MARBLE CREEK MINING & MILLING CO.

The claims of the Marble Creek Mining & Milling Co. lie between 

McCord Gulch and Marble Creek. The property is opened by several thousand feet of drifts, most of which were inaccessible. No 

production has been reported.

The country rock is crushed and altered gabbro in which the workings expose an irregular shear zone. A few irregular patches of 

quartz were seen and some specks of bornite with a little copper 

stain.

YELLOW BOY MINING CO.

The Yellow Boy Mining Co. controls nine claims, three of which 

are patented, just south of the Nelson placer, in sec. 8, T. 9 S., K. 

39 E. The president of the company is N. A. Muegge, and the 

secretary is F. C. McColloch, both of Baker. The property is developed by two adits the older, upper one several hundred feet 

long, including a 50-foot incline, and the lower one about 450 feet 

long.

85 Swartley, A. M., Ore deposits of northeastern Oregon : Mineral Resources of Oregon, 

vol. 1, No. 8, p. 162, Oregon Bur. Mines and Geology, December, 1914.
SOME MINING DISTRICTS OF EASTERN" OREGON 83

The country rock is greenstone. At the face the upper adit cuts 

a dike, "probably one of the granophyre dikes so common in the 

region. A few quartz stringers show in the adits.

STUB

The Stub or Kent mine, owned by George and Chester Gardener, 

lies in sec. 20, T. 9 S., R. 39 E., near the head of Washington Gulch. 

The property is opened by an adit, which is now caved about 150 

feet from the portal but which, according to Swartley,30 is several 

hundred feet long and has a short winze and some raises turned 

from it. Swartley states that a test run made in 1914 is reported 

to have returned $1,140 from 140 tons of ore. No other production 

has been reported.

The country rock is siliceous argillite. The adit encounters a 

 shear zone, striking N. 65° W. and dipping steeply southwest, about 

100 feet from the portal. According to William Dale, this is not the 

main Stub vein, and Swartley 37 says:

The vein has a north-northeast strike and a nearly vertical dip, with but a 

lew inches of quartz to several feet of broken rock.

SORBECK

The Sorbeck brothers, of Baker, own 170 acres of patented land 

in sec. 27, T. 9 S., R. 39 E., on which several adits several thousand 

feet in total length have been driven. The predominant country 

rock is greenstone, but there also occur some gabbro and a little 

limestone. No veins have been found in any of these tunnels.

DALE

William Dale controls several claims in sec. 22, T. 9 S., R. 39 E., 

which are opened by several small adits and numerous prospect pits. 

The predominant country rock is gabbro. One of the pits exposed 

a 3-inch quartz seam in which a few flakes of native gold were 

seen.

PLACEB MINES

At the time of this survey all the placers in the Baker district 

were inactive. The following report on the placer mines is quoted 

from Lindgren : 3S

Nearly every gulch of the south end of Elkhorn Range has been worked on a 

more or less extensive scale for placer gold, though few localities have been 

exceedingly rich. Though the bu'k of the gold was extracted shortly after the 

discovery, in 1862, some work is yet going on at several of the old diggings, 

showing that the gravels are not yet exhausted.

80 Swnrtlcy, A. M.. op. cit, p. 163. 

37 Idem, p. 162.

35 Lindgrcn, Waldemar, The gold belt of the Blue Mountains of Oregon : U. S. Geol. 

Survey Twenty-second Ann. Kept., pt. 2, pp. 652-054, 1902.
84 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

At the northern end of the eastern slope small placers have been worked 

on Marble Creek, near the limekiln. On Salmon Creek the placers are of 

much greater importance. This creek was worked with success for about 1 

mile upward from the mouth of the canyon. The gravels were 4 to 10 feet 

deep and covered by 10 to 15 feet of an exceedingly fine, brilliantly white 

kaolinic material.39 The bottom of the canyon was originally filled with 

deposits to a width of 100 or 200 feet. Working downstream, the placer 

miners at the mouth of the canyon gradually discovered a very remarkable 

deposit, called the Nelson placers. These have been worked successfully for 

30 years by the hydraulic process and are by no means yet exhausted. The 

working season extends from April to September, 1,000 miner's inches of 

water being used. The yearly production has generally been from $20,000 to 

$30,000. In the Mint reports for 1889 the production is given as $77,000; in 

1890, $19rOOO. The total production is believed to be over $400,000. For one 

period of six years the production is said to have reached $214,000. As the 

available grade is small, it is proposed to use a hydraulic elevator for mining 

below the level of the permanent sluice.

The mouth of Salmon Creek Canyon is marked by a low spreading debris fan. 

The Nelson placers are working the gravels of this fan in a pit covering 40 to 

50 acres and from 20 to 100 feet deep. At the top of the bank the elevation is 

3,750 feet. The gravel is subangular, many fragments reaching 1 foot in 

diameter, and consists of argillite and diorite, very little quartz being present. 

There are two layers. The upper stratum has a bluish-gray color, is 10 to 

20 feet thick, and contains, evenly distributed, most of the gold. The lower 

stratum is yellowish-brown and its rocks are decomposed. This also contains 

gold, though in lesser amount, and its bottom has never been reached. Covering 

the top layer, near the mouth of the canyon, is the same white kaolin which 

covers the gravels of the creek. The gold, which is worth only $14 to $16 

per ounce, is ordinarily fine, though nuggets up to $10 in value occur. To the 

rough pieces quartz sometimes adheres.

Most interesting are the relations immediately at the mouth of the canyon, 

for here the hydraulic work has disclosed the presence of a continuous fault 

scarp 100 feet high and dipping 40° E. It is smooth now, but when first 

exposed it is said to have been almost polished and in places covered with a 

Clayey gouge. The direction is northwesterly, but with occasional bends and 

bulges. The exposed fault line extends completely across Salmon Creek for 

a distance of 1,500 feet, and the same line, less well exposed, is seen in the 

Baisley diggings, one-fourth of a mile northward, and in the Carpenter 

placers, half a mile southeasterly.

A shaft has been sunk in the bottom of the hydraulic pit near the foot of 

the scarp, but no bedrock was found at a depth of 90 feet. A minimum vertical 

throw of 200 feet is here shown, the valley side having sunk relatively to the 

mountains. The upper blue gravel probably was accumulated during the 

glacial epoch, while the lower dark-brown gravel is more likely to antedate 

that time; whether any very recent movement has taken place could not be 

decided.

Small placers have been worked in Washington Gulch, and the same applies to 

Griffin Creek and Elk Creek. The Griffin Creek placers are the oldest in 

eastern Oregon, having been discovered in the fall of 1861. The workings are 6 

miles southwest of Baker City and at an elevation of 4,750 feet, above where

80 Microscopic examination of this " white kaolinic material" by the writers reveals the 

fact that it is not clay but fine volcanic ash, similar to that in the Sumpter quadrangle 

described by Pardee and Hewett. J. G.
SOME MINING DISTRICTS OF EASTERN OREGON 85

the creek enters the lava hills. Some work was in progress in 1900. On the 

divide between Griffin and Washington Creeks is a small area of high gravels 

which is said to contain gold in paying amount.

Most important were the placers of Auburn, in Blue Canyon, a tributary of 

Powder River. The diggings were discovered in 1862, and in a short time a 

town of several thousand inhabitants had grown up. For many years Auburn 

was the most prominent place in eastern Oregon, but the gold yield gradually 

diminished, and the camp was given over to the Chinese. At the present time 

hydraulic mining is carried on by two or three white companies. The total 

production of Auburn is difficult to determine, but it did not nearly reach that 

of Canyon, and the richest placers were soon exhausted. A small and rather 

steady production is maintained. The mint reports give $12,000 for 1889, 

$2,600 for 1890, $8,900 for 1891, $3,000 for 1892. The important Auburn ditch 

was completed in 1863. It takes water from the head of Pine Creek and other 

watercourses and carries it down to Auburn, a distance of over 30 miles; its 

capacity is 1,000 miner's inches.

Auburn is located in a wide basinlike valley at an elevation of about 4,000 

feet. The argillites of the mountains here dip below the lava floods of the 

foothills. On both sides of the town the lava reaches up to elevations of 

4,500 feet. The lavas cover soft, clayey, and loamy lake beds containing some 

coaly layers and impressions of deciduous leaves. On top of the eroded lake 

beds in the wide gulch rest subangular gravels 8 to 15 feet thick; the latter 

have been washed both in the gulches and on the flats. Near the town the 

depth to bedrock is not great, but farther down the valley the thickness of the 

sediments increases rapidly. The gravels are thus later than the lavas and 

have accumulated during the erosion of the present valley.

West of Auburn, on the road to Sumpter, several gulches with old placers 

are passed, Poker Gulch and California Gulch being next to Blue Canyon.

OUTLOOK FOB THE DISTRICT

The conclusion of Lindgren that the placer gold so widely distributed in this district has been derived from numerous small 

seams and veinlets rather than from persistent \7 ein systems seems 

justified. The quartz veinlets so far found seem to be irregular, thin, 

and discontinuous; the fracturing of the rocks upon which these 

veinlets are dependent is characterized by its nonpersistence and 

irregularity. The mineralization has been widespread, beyond doubt, 

as is shown by the occurrence of placer gold in practically every 

creek draining the district, and it is entirely possible that pocket mining on a small scale may prove profitable, but the outlook for largescale mining seems unfavorable.

QTJABTZBTJRG DISTBICT 

GEOGRAPHY

The Quartzburg district is in Grant County. It covers much of the 

south slope of the divide between the main John Day Biver and its 

Middle Fork between Prairie City and Dixie Butte and extends 

north of the divide to embrace the headwaters of Kuby Creek. 

Altitudes within the district range from about 3,500 feet at Prairie 

City to 7,400 feet at the top of Dixie Butte. Most of the district is
86 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

drained by Dixie Creek, which joins the John Day Kiver at Prairie 

City, but Dads Creek and Ruby Creek drain parts of it.

The district is reached by way of Prairie City, the terminus of 

the narrow-gage Sumpter Valley Railway, which meets the through 

line of the Union Pacific system at Baker, 80 miles away. Prairie 

City lies on the John Day Highway, an excellent automobile road 

joining Ontario, on the Snake River, with Arlington, in the Columbia 

Valley. The former post office of Comer, about 6 miles north of 

Prairie City at the forks of Dixie Creek, has long since been, 

abandoned.

Heavy woods clothe most of the hillsides in the district, and much 

of it is embraced in the Whitman National Forest.

GEOLOGY

GENERAL FEATURES

No topographic base maps of the Quartzburg district were available, and owing to the heavy forest cover of most of the district it 

was impossible, in the available time, to prepare a base map adequate 

to represent the evidently complex geology. Accordingly, the 

detailed geologic observations made during the writers' visit were 

limited to the areas within and immediately adjacent to the accessible 

mines, and only cursory examination was made of the intervening 

areas. « 

These observations, however, were sufficient to permit the statement that the dominant rocks of the district are meta-andesite, metadiabase, and related volcanic rocks, including tuff, associated with 

which are small amounts of argillite. The correlation of these old 

sedimentary rocks must await detailed mapping, although the 

writers' impressions are favorable to Lindgren's correlation of them 

with the Carboniferous argillite series of Elkhorn Ridge.40

Intrusive into this series of volcanic and sedimentary rocks, and 

doubtless in la^ge degree the cause of their intense alteration, is a. 

considerable variety of plutonic rocks, among which gabbro, serpentine, and diorite are most prominent. Dikes of diorite porphyry,, 

albitized diorite, and metadiabase are associated with these plutonic 

rocks and are probably comagmatic with them.

Most of these rocks are considerably sheared and altered the 

volcanic rocks by the development of biotite and tourmaline, the 

intrusive rocks by the development of talc, biotite, uralite, and tourmaline. Some of these alterations may have occurred during 1 the 

later stages of consolidation of the basic intrusive rocks themselves. 

Others, however, seem to be attributable to a group of later intrusions 

represented by small stocks of quartz diorite and granodiorite that

40 Lindgren, Waldemar, op. cit., pi. 64.
SOME MINING DISTRICTS OF EASTERN OREGON 87

occur in the valley of Dixie Creek below the forks and near the head 

of Ruby Creek. The numerous dikes of quartz diorite porphyry, 

granodiorite porphyry, and quartz monzonite porphyry that occur 

in many places through the district may attest a much wider distribution of these silicic rocks at depth.

These quartzose rocks are practically free^from crushing and are 

relatively unaltered. For these reasons they are believed to be 

younger than the basic intrusive rocks of the district. The age of 

these intrusive rocks is not accurately known from local evidence,, 

beyond the fact that they are all definitely pre-Miocene. In the 

Strawberry Range, across the John Day River to the south, Jurassic rocks are intruded by quartz diorite.41 This supports Lindgren's assignment of the intrusions to a post-Jurassic age. The basic 

intrusions may be older than this, however. The pre-Miocene age 

of all the intrusions is fixed by the fact that the Columbia River 

lava, of Miocene age, rests on an eroded surface cut across all the 

plutonic rocks. Lindgren 42 believed the intrusive rocks to be of 

early Cretaceous age.

The Columbia River lavas crop out along the north side of the 

valley of the South Fork of the John Day River at Prairie City. 

and apparently completely surround the mineralized area of the 

Quartzburg district. They have, however, been removed by erosion from the mineralized area itself, most of which, if not all, 

must once have been covered by them. No study was made of the 

details of the geology of the Columbia River lava, as the formation has no bearing on the geology of the mines.

Although the regional distribution of the rocks of eastern Oregon 

strongly suggest an eastward strike as dominating the structure 

of the pre-Tertiary rocks, few observations were made on the structure of the stratified rocks within the Quartzburg district. The 

local structure is accordingly uncertain. Observations were sufficient, however, to permit the statement that the dominant structural features of the district are those imposed by the igneous, 

intrusions.

ORE DEPOSITS

Two types of ore deposits have been recognized in the district 

quartz-carbonate-sulphide fissure veins and a quartz-tourmalinechalcopyrite replacement body. The fissure veins are valuable 

chiefly for their gold, although small amounts of copper and cobalt have been won from them; the replacement body has its potential value in copper. Mineralization has occurred in nearly all the 

pre-Tertiary rocks. Although the observations within the district

" Lupher, R. L., oral communication, 1929. 

42 Lindgren, Waldemar, op. cit., p. 596.
88 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

were not thorough enough to be conclusive, the ore deposits are probably derived from the quartz diorite intrusions.

The veins consist of quartz, ferriferous dolomite, and calcite as 

the chief gangue minerals and carry the metallic minerals, pyrite, 

arsenopyrite, glaucodot, cobaltite, native bismuth, bismuthinite, tetrahedrite, pyrrhotite, chalcopyrite, sphalerite, and galena. The pyrite 

and chalcopyrite are the most plentiful, but the cobaltiferous minerals 

glaucodot and cobaltite are found in several localities. 'Supergene 

minerals recognized include covellite and bornite, and the oxidation 

products malachite, jarosite, and limonite were seen.

The quartz-tourmaline replacement body carries disseminated 

chalcopyrite, pyrite, cobaltite, magnetite, hematite, bornite, and 

covellite.

THE MINES 

DIXIE MEADOWS

Location. The Dixie Meadows mine, owned by the Discon Mining Co., is in sec. 23, T. 11 S., K. 33 E., near the head of Ruby Creek, 

just north of the Dixie Creek divide. It is about 12 miles from 

Prairie City by wagon road. The property, at the time of visit, was 

in charge of R. C. Reese, of Prairie City. In July, 1930, development work was going forward under G. H. Kight, foreman.

History and production. The mine was opened in 1900 by Messrs. 

Kight and Reese. A mill was built in 1903. Between 1903 and 1910 

about 8,000 or 9,000 tons of ore averaging $8 to the ton in gold was 

milled and about 350 tons of concentrates averaging about $50 to 

the ton were shipped. The property was sold to L. Vogelstein & 

Co., of New York, in 1910, and a development campaign, with no 

attempt at production, was carried on by them for the next two years. 

The property was then sold to A. D. Coulter, of Seattle, and later, 

by combination with the Independence claim and the Sylvanite 

property in southern Oregon, it passed into the hands of the present 

owners. No production has been made since 1910 except a small 

amount by lessees in 1912-1914. The total production of the mine 

has been less than $100,000, according to Mr. Reese.

The mine is developed by two adits, the upper of which, called the 

Blacksmith level, is caved and no longer accessible. About 6,000 

feet of work was done in this tunnel and connecting raises, winzes, 

and stopes. All the production of the mine has been made from this 

level. The lower tunnel, about 100 feet lower than the Blacksmith 

level, is about 1,200 feet long. About TOO feet of this tunnel is a 

crosscut to the vein and the remaining 500 feet is a drift on the vein 

southwestward toward the old higher workings.

Geology. The country rock of the mine is a complex of greenstone, meta-andesite, tuff, metadiorite, serpentine, and sheared quartz
SOME MINING DISTRICTS OF EASTERN OREGON" 89

diorite, with a little argillite, the whole cut by several dikes of grano^ 

diorite porphyry. The metadiorite, which locally is a metagabbro, 

much serpentinized, forms the footwall of the vein for some distance 

southwest of the accessible workings. The hanging wall is largely 

sheared diorite, with meta-andesite and metadiorite, in some of which 

tourmaline and metamorphic biotite have been developed, both numerals characteristic of unusually high temperature. Small amounts 

of argillite occur in both walls, as well as in horses within the vein, 

commonly near the footwall.

The vein is localized along a fault and consists of quartz, which replaces the gouge and brecciated material between two rather distinct walls. The width between the walls, normal to the fault1 , is 

about 60 feet in the accessible workings. The vein strikes N. 30°- 

35° E. and dips 65°-70° SE. Most of the filling between the walls 

is country rock, partly replaced by quartz, sericite, and sulphides. 

Probably less than 10 feet of this filling consists of quartz vein material, however, although most of the filling shows more or less silicification, sericitization, and impregnation with sulphides. The 

wall rocks bordering the fault zone are similarly altered.

The vein is obviously a replacement vein for the most part, 

" ghosts " of the country rock being very common throughout it. 

The sulphides present are pyrite, arsenopyrite, chalcopyrite, pyrrhotite, galena, marcasite, and sphalerite. Microscopic studies show 

that there are two generations of pyrite. The earlier, euhedral pyrite occurs in a quartz-carbonate gangue, and the later pyrite, with 

associated marcasite, in fractures and along boundaries of masses of 

pyrrhotite. According to Mr. Kight there was little or no pyrrhotite 

in the upper workings. The chief gangue mineral is quartz, but 

ferriferous dolomite and sericite are very common.

The ore is but slightly oxidized, with the sulphides persisting practically to the surface. Accordingly the ore is rather base, probably 

less than one-fourth of the gold being susceptible of amalgamation. 

Cyaniding, however, has never been tried. ^ When the mine was producing, the sulphide concentrate was shipped directly to the smelter.

The tenor of the ore is very irregular. According to Mr. Kight, 

large quantities will 0 average $7 to the ton in gold. There was 

reported to be a particularly high-grade streak along the footwall, 

which was worked by a lessee in 1912-1914 with good results, but 

its tenor is not known.

LAST CHANCE

The Last Chance group consists of five claims near the head of 

Ruby Creek, just south of the Dixie'Meadows mine. The claims are

164495 33 7
90' CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

the property of G. H. Kight, of Prairie City. There are about 400 

feet of workings] . The country rock consists of sheared gabbro, serpentine, greenstone (meta-andesite), argillite, and sericitized diorite.

The objective of the workings is a mineralized shear zone .that 

strikes N. 60° E. and dips 60° SE. There has been considerable 

sulphidization and silicification of the footwall of the shear zone, 

but the hanging wall shows much less. Small veinlets and branching stringers of quartz and sulphides as much as 1% feet thick occur.

The diorite .just above the hanging Wall is much sericitized and 

carries some sulphides.

The shear zone has been drifted on for about 150 feet. The 

minerals have been found to occur very irregularly, with some 

bunches of good ore, but much of the sheared matter is of very low 

grade. The principal sulphides are pyrite, galena, sphalerite, pyrrhotite, and a little chalcopyrite. The gangue is dominantly quartz 

with some ferriferous dolomite. Oxidation has been slight, and 

little of the gold is free. According to Mr. Kight the tenor is not 

very high, ranging from $4 to $8 to the ton, even in the highly 

sulphidic material.

BLACK PRINCE

The Black Prince property is on the ridge 1^ miles west of 

Pixie Butte. It is reached by a mountain road from Prairie City, 

a distance of about 14 miles. The property is owned by William 

Walling, of Prairie City, and in 1930 -was being developed by 

Frank B. Prindle.

The prospect consists of one tunnel, slightly more than 750 feet 

in length, and a small open cut on the surface. (See fig. 10.)

The country rock is largely tourmalinized meta-andesite. Along 

a fault just inside of the adit portal meta-andesite porphyry occurs. 

This porphyry may be classified as a greenstone but is less altered 

than most of the associated rocks. A.short distance northeast of 

the property is a small stock of quartz monzonite.

The country rock has been tourmalinized, silicified, and sulphidized. The metallic minerals are- largely pyrite, with much 

smaller quantities of magnetite, arsenopyrite, pyrrhotite, chalcopyrite, sphalerite, covellite, and glaucodot (?).

The ore occurs in pockets along fine stringers; No prominent 

structural features seem to have localized the mineralization. In 

the tunnel there is one pocket containing considerable glaucodot (?). 

This pocket is in the~ lower part of the drift and does not 

extend into the back. Another similar pocket was found on the sur-
SOME MINING -DISTRICTS OF EASTERN OREGON 91

face, in the present open cut. The adit was driven to connect with 

a supposed downward extension of this mineralized body exposed at 

the surface. The best grade of ore carries $10 in gold to the ton, 

according to Mr. Prindle. * 

Country rock meta-andeslfo, 

somewhat tourmalinized

Cobalt ore 

in "floor; does 

not persist 

into hanging 

wall °

100 100 200 Feet

FIGURE 10. Map of the workings of the Black Prince prospect, near Dixie Butte, 

Quartzburg district, Oreg. . .

EQUITY

. The Equity group of six patented claims'is a consolidation of the 

old Colorado mine and the property known formerly as the Keystone. 

All the claims are in seci 2,T. 13; S., 1J.' 33 E., in a small gulch entering the West Fork of-Dixie-Creek from the south, about 7 miles 

from-Prairie City. A good road" gives acess to the property.

The production is not known, but the stoped areas indicate that 

considerable ore has been removed. Except for the decode 1913- 

1922 there has been some activity at the mine every year since 1900; 

In 1930 two men were employed in taking out a small quantity of 

ore below the main level of the Colorado workings.

The Colorado vein has been opened by three" levels, the .top one 

95 feet above the lowest. The vein has been stoped above the 

lowest level in some places to the surface, and the two upper tunnels 

are caved and inaccessible. A small amount of work has been done
92 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART I

below the third level, but these workings are at present filled with 

water. The work being done in 1930 was 15 feet below the third 

level. The third level is about 750 feet long and has been stoped 

upward for 330 feet along the strike of the vein. (See fig. 11.)

The country rock is nearly all sheared gabbro, carrying labradorite phenocrysts in a finer-grained diabasic groundmass. Some dikes 

of granodiorite occur near the portal.

Quartz vein 

"with sulphides

Quartz vein 

with sulphides/?

uartz vein 

p- with sulphides

^Sloped to upper level 

(95 feet vertically)

'GO Note= Country rock chiefly sheared gabbro.

100 100 200 Feet

FIGURE 11. Geologic map of third level, Colorado vein, Equity group, Quartzburg district, Oreg.

The vein strikes about N. 35°-45° E. and dips 75°-80° SE. The 

vein is composed largely of quartz,' dolomite, and massive sulphides pyrite, chalcopyrite, galena, and sphalerite. The wall rock 

is slightly sericitic close to the vein. The width of the vein ranges 

d:rom practically a knife-edge at the face to more than a foot in the 

stopes.

Tll$ Yein i& crossed by numerous shattered zones of gouge and fault

breccia from 3 inches to 3 feet wide. -Mosi 01 ike moV6m6nf ftlflfl^ 

these breaks appears to have taken place before the mineralization. 

The quartz vein persists through several of the brecciated areas.
SOME MINING DISTRICTS OF EASTERN OREGON 93

There has been some postmineral movement, as the vein has been 

oft'set 3 feet in one place and possibly 17 feet in another. The faults 

range in strike from west to N. 65° W. They all dip.between 65°-80° 

N. Seven of these fault zones were observed within 200 feet of the 

face of the third level.

The ore contains considerable massive sulphide and, according to 

A. W. Ward, of Prairie City, who was familiar with the mine when 

it was in active operation, carries as much as $500 a ton in gold.

The old Keystone workings a few hundred feet to the south were 

entirely inaccessible in 1930. Apparently this property has not been 

worked for over 30 years. It was described by Lindgren 43 as 

follows:

The old Keystone, now idle, * * * was worked in 1882, during which 

year the small veins of Quartzburg produced ..about $12,000; * * * about 

seven levels were run. In 1883. it is reported that 500 tons of ore at $40 per 

ton were worked at a cost of $8.50 per ton. In 1889 the mine is credited with 

a production of $5,800. The vejn strikes northeasterly and dips southeasterly. 

It is 4 feet wide between walls, the pay forming a narrow streak on the hanging, on the.foot, or on both. The gangue contains much calcite, but otherwise 

the ore is similar to that of the 1 Present Need!

 '- ' ' PRESENT NEED.

The Present Need mine is on the West Fork of Dixie Creek about 

a mile above the forks and a few hundred feet below the Keystone 

workings. No activity.has been reported at this mine since 1912, 

and none of the workings were: accessible in 1930. It was under 

lease to Ed Gifford, who planned to open and unwater the drifts. 

The property has been described -as follows by Lindgren :44

The Present Need was located about 10 years ago [1890] and has since been 

worked on a small scale, the ore being calcined in a kiln and then reduced in 

an arrastre. The developments consist of a crosscut tunnel 100 feet above the 

creek level and 200 to 300 feet of drifts. The country rock is diabase, but the 

crosscut has exposed a narrow, greatly contact-metamorphosed series of diabase 

tuff with a general east-west direction. The vein strikes N. 20° E. and dips 

70° ESE. Like the other veins in the district, it is not traceable for a long 

distance. The width is 2 to 3 feet, indicated by fissures in the hard diabasic 

rocks. The ore occupies from 4 inches to 2 feet of'this width and consists of 

solid quartz with heavy sulphurets in irregular intergrowth. -There are pyrite, 

hard and yellow, softer yellowish-gray marcasite, and a little chalcopyrite, zinc 

blende, and galena. This ore is very rich, and the pyrite often contains free 

gold. It assays from 6 to 25 ounces silver and 4 to 5 ounces in gold per ton, 

a total value of about $100. With the imperfect extraction used, only about 

two-thirds of this amount was saved.

The ore occurs in two shoots on the vein, both dipping 65° S. on the vein; 

the shoots are 70 feet long and are separated by a barren zone of 70 feet.

Since the time of Lindgren's examination the vein has been exploited to a point just above the level of the creek.

43 Lindgren, Waldemar, op. cit, pp. 710-711. «Idem, p. 710.
'94

CONTBEBUTIOlsrS'TO ECONOMIC GEOLOGY, 19 3 3, PABT 1

- , . PAUL TOTE - '

 The Paul Tote property, owned by A. W. Ward, of Prairie 

City, is on the northeast side of the West Fork of Dixie Creek, a 

'short distance above the forks. No production has been made.

About TOO feet of tunnel has been driven, including about 300 feet 

of crosscut, and nearly 400 feet of drifts on two intersecting veins.

 (See fig. 12.) A winze 22 feet deep has also been sunk.

The country rock is all greenstone. The intersecting veins strike 

N. 10° W. and N. 10°-250 E., and both dip about 75° E. The two 

veins contain the same types of minerals, and there is no offset at the 

intersection. The vein that strikes east of north is 3 inches to 2 feet 

wide, the other has a maximum exposed width of 8 feet and pinches 

down to 6 inches. The vein material consists of sheared and altered

greenstone, stringers of 

calcite, small amounts of 

quartz and pyrite, and 

chalcopyrite. Some fine, 

sericite flakes coat fractures through the calcite. 

According to Mr. 

Ward, the average tenor 

of the ore in the northwesterly vein is $7 to the 

ton in free-milling gold, 

with additional values in 

the sulphides.

Country rock all

looFeetFiG0RB 12. Workings of Paul Tote prospect, Quartzburg district," Oreg.

; KLONDIKE

The Klondike, owned by A. W. Ward, of Prairie City, is on the 

northwest side of the East Fork of Dixie Creek, just above the forks. 

It is about 6 miles from Prairie City.

The property has been opened by several hundred feet of workings, 

partly in greenstone and partly in a diorite porphyry dike. This 

dike, which strikes N. 25° E. and is 75 to 90 feet thick, cuts through 

the greenstone. The vein, consisting of about 2 feet of gouge and 

breccia, apparently follows the east wall of the dike. It strikes 

N. 25° E. and is either vertical or dips steeply east. About 33 tons 

of high-grade ore has been extracted from a small pocket. Very 

little quartz is present in the vein. The greenstone along the vein 

is locally impregnated with considerable pyrite.

COUGAR

The Cougar prospect, owned by A. W. Ward, of Prairie City, is 

in.sec...2,.T._12.S.,.R. .33 E., on.Cougar Bidge,.between.the two main 

forks of-Dixie Creek. Four claims are included in the property.
 SOME. MINING DISTRICTS OF EASTERN OREGON . 95

 There" we're several small tunnels accessible in 1930, arid:.the whole 

hill is dotted with small open cuts and other tunnels, no longer 

open. A small production has been reported in 1918,1919, and 1923.

 In 1930 the principal work was being done on the. Blue Mountain 

Chief claim. . ' . . . The country rock is greenstone, cut by a diorite porphyry dike 

continuous with that in the Klondike prospect.

 The vein exposed in a drift on the Blue Mountain Chief claim 

strikes N.;10° W. and dips 60° E. at one point but elsewhere swings 

to due nor.th and dips 65 ? W. Like that in the Klondike prospect, 

it follows the east wall of the dike. Jt has. been followed in the 

drift for 270 feet and ranges in this distance from 3 inches to 1 foot in 

thickness. The vein is composed of quartz, gouge, and calcite, containing-pyrite, chalcopyrite, and a little galena. Assays as high as $450 

to the-ton in gold and silver have been reported from these sulphides.*5 

Other veins are exposed in near-by excavations. Most of them 

strike between north and N. 20° E. and dip steeply east. These veins 

are all small stringers of quartz and gouge in which the valuable 

metals are .very sporadically distributed. No production has been 

reported. .

Country rock chiefly 

metadiorite

FIGURE 13. Workings on lower tunnel level, Yankee Boy vein,"Quartzburg, Oreg.

The Yankee Boy group, owned by A. W. Dunn, of Prairie City, 

includes three claims on the hillside northeast of the West Fork of 

Dixie Creek about a mile above, the forks. . . - - ,

The workings include three tunnels at different altitudes on the 

same vein, called the Yankee, Boy. The upper tunnelis caved and 

inaccessible. The middle tunnel includes about 135 .feet of "workings, 

the Tower tunnel about 550 feet. (See fig. 13V) "No production has 

been reported. : J e ^ l45 Parks, H. M., and Swartley, A. M., Handbook of the mining industry of Oregon: 

Mineral Resources of Oregon, vol. 2, No. 4, p. 82, Oregon Bur. Mines and Geology, 1916.
96 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The country rocks are chiefly altered diorite and andesite. The 

vein followed by the middle tunnel is about a foot wide and consists 

of a shear zone in the diorite, with stringers of quartz. It strikes 

N. 20° E. and dips 85° E. Two fissures are exposed on the lower 

level. The one nearest the face, which has been followed for about 

50 feet, strikes N. 10° E. and dips 75° E. It consists of about 3 inches 

of gouge, quartz, and calcite, with pyrite, chalcopyrite, sphalerite, 

and galena. The diorite country rock is highly chloritic along the 

vein. The other fissure strikes about N. 5° E. and dips 80° E. It 

is about 6 inches wide and contains the same minerals as the first 

but is much more brecciated.

DIXIE QUEEN

The Dixie Queen property is on the nose of Cougar Ridge between 

the East and West Forks of Dixie Creek. There are five claims in 

the group, held by Charles Bartlett.

The country rock is greenstone cut by diorite dikes. In several 

places the veins follow the contacts of these dikes.

The Dixie Queen adit has been driven 200 feet and it is planned to 

continue this adit until a vein that crops out on the surf ace has been 

intersected. There are three small seams cut by the tunnel. These fissures contain a little quartz, gouge, and breccia, with sulphides. The 

veins strike N. 15° W. to N. 15° E. and dip about 80° E.

On the surface and in the numerous other small tunnels and open 

cuts small veins are exposed. These veins have a remarkably persistent strike of N. 10° E. and a dip of about 75°-80° E.

FITZSIMMONS

The Fitzsimmons group of five patented claims is on the hillside 

northwest of the East Fork of Dixie Creek, just above the old 

smelter. The claims are owned by Mrs. Durkhammer, of Salem, 

Oreg. . . .-..

Considerable work has been done here in the past, but the tunnels 

are all caved and inaccessible. The material on the dumps is very 

similar to that of the Cougar and Dixie Queen groups. It is chiefly 

greenstone with some diorite. The greenstone contains considerable 

pyrite.

FOERESTEE

The Forrester group of 11 claims is on a small creek flowing eastward into Dixie Creek, just below the forks in Dixie Creek. The 

group is owned by the Utah-Oregon Gold Mining Co., incorporated 

under the laws of Utah. The property is in charge of A. W. Ward, of 

Prairie City, Oreg.
SOME MINING DISTRICTS OF EASTERN OREGON 97

The main tunnel has about 500 feet of accessible workings. 

(See fig. 14.) There are two more small tunnels open and numerous 

surface cuts.

The vein follows the contact of a dike of sericitic diorite porphyry 

in granodiorite and greenstone. This dike ranges in width from 20 

to 60 feet and, according to Mr. Ward, has been traced for 2 miles 

on the surface. The vein follows the hanging-wall contact, striking 

N. 5° E. and dipping 80° E. The dike has been crosscut, and the 

face of the workings is in greenstone. The walls of the dike are 

very irregular.

Most of the country rock is medium-grained granodiorite that 

contains considerable quartz. Masses of greenstone, probably inclusions in it, are common.

N

100 Feet

FIGURE 14. Geology of New Forrester tunnel, Forrester 

group, Quartzburg district, Oreg.

The vein consists of about iy2 feet of gouge and breccia with small 

amounts of quartz. The gold is both free-milling and base. Pyrite 

is the main sulphide, but others are reported to be present, though 

no others were seen. .

The so-called Old Forrester workings consist of a drift 185 feet 

long, a quarter of a mile southeast of the work described above. The 

drift crosscuts a dike 45 feet wide and then follows northward along 

the contact, which strikes N. 15° W. and dips 85° E. This contact is 

followed by about 2 feet of gouge and clay. The country rock is 

granodiorite; and the dike material is very similar to the diorite 

porphyry described above.
98 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The vein in the old workings carries only about $2 to the ton in 

gold. The main workings average better than this amount, according to Mr. Ward, but no figures were obtained.

ANDREW JACKSON

The Andrew Jackson property consists of one claim on the West 

Fork of Dixie Creek just above the Sherbandy group of the Copper 

Mountain Mining Co. The claim is owned by Mark Carmichael and 

Helbert Schoenthal. There are an open cut and two small tunnels, 

aggregating 145 feet of drifts, on the claim. The country rock is 

greenstone and diorite. At least two small seams of quartz are 

exposed. These seams average about 3 inches in thickness and contain a little gouge. One strikes N. 20° E. and dips 80° E.; the other 

strikes N. 65° E. and dips 65° W. ..

. - . .BOULDER

The Boulder group of seven claims, the property of David R. 

Roberts, of Prairie City, is near the head, of a west branch of Dads 

Creek. The property is reached from Prairie City by about 8 miles 

of road and a 3-mile trail. V '. ;

The work donec " aggregates about 1,000 ..feet, chiefly drifts and 

crosscuts on two levels about 100 feet apart. No production has been made. '"'" ; ;

The country rock-consists chiefly of porphyritic meta-andesite, 

silicified and altered to a very dense, hard.;rock. Possibly some old 

pyroclastic rocks are included. It is cut.by a few dioritic dikes 

and by faults and fissures that trend generally N. 70° E. to S. 70° E. 

and dip steeply southward.

The mineralization consisted of silicification and impregnation of 

the walls of a fault with sulphides and arsenides.. Veins that range 

from a knife-edge to 4 inches in thickness follow the fault walls. 

Pyrite, arsenopyrite, chalcopyrite, sphalerite, pyrrhotite and glaucodot were noted, together with quartz and a little calcite. The 

oxidation minerals limonite, malachite, erythrite, and azurite were 

seen, but only very near the surface. Fresh sulphides occur in the 

lower tunnel less than 150 feet beneath the surface.

Mr. Roberts reports that picked ore in the mine assays as high as 

8 per cent of cobalt, 2 per cent of copper, and $2 in gold to the ton. 

It seems unlikely that large tonnages of this tenor are present;

HOWELL' & HAIGHT

' The property owned by Ho well. &. Haight, of Prairie City^ is 

on top of the ridge to the east of Dixie Creek and at the head of a 

tributary to Corral Creek. In 1930 there was a 30-foot shaft on the
SOME MINING DISTRICTS OF EASTERN OREGON 99

property, and at the time of visit this was being unwatered, preparatory to deepening.

The country rock is diorite cut by a porphyritic diorite dike.

The vein consists of a high-grade streak, which forms the hanging 

wall of the porphyry dike and strikes N. 20° E. and dips 45° SE. 

According to Mr. Howell there is also, in the dike just below, about 

20 feet of ore carrying $4 to $5 to the ton in gold. The gold is free 

within the depth so far explored. Pyrite, quartz, and free gold 

occur along the contact and impregnating the dike. No production 

had yet been made in 1930.

COPPER MOUNTAIN MINING CO.

The property of the Copper Mountain Mining Co. embraces 11 

claims on Cougar Ridge, west of the East Fork of Dixie Creek, in 

sec. 1, T. 12 S., R. 33 E. Four of the claims, called the Sherbandy 

group, were patented. The property; is about 8 miles from Prairie 

City. In 1930 it was under the management of V. E. Ryan. . The claims constituting the Sherbandy group were located in 1896 

by Capt. Homes Sherbandy and his son Byroriv Development work 

was confined to a few shallow cuts and two short tunnels until the /",

spring of 1930, when the present owners, who had taken over the 

property in 1929, began driving a crosscut about 300 feet below the 

apex. At the time of visit this crosscut was about 80 feet long. The 

total underground workings amounted to less than 400 feet. No 

production has been made. ' - '. '.'.' >

The country rock consists of altered andesite and diorite, cut by 

some dikes of granodio'rite porphyry. Several narrow veins are 

exposed in the tunnel. Most of them strike N. 45° E. and dip 

steeply southeast. Some are fault veins and show brecciation, sericitization, silicification, and sulphide impregnation of their wall rocks 

in zones that extend 2 to 6 feet from the veins. One of these fractures follows a much decomposed dioritic dike that trends N. 35° 

E. The more intense mineralization, however, seems to have been 

but slightly controlled by these fractures. The most prominent 

mineralized bodies are tourmaline-quartz-chalcopyrite replacement 

masses in the greenstone. These bodies trend in general east to 

northeast. Some show elongation along steeply north ward-dipping 

fractures with trends N. 60°-85° E.; others seem independent of 

such control.' The tunnel being driven in 1930 had as its objective 

the discovery of the intersection of a vein that runs N. 30° E. and 

dips steeply west with a generally eastward-trending tourmaline-^ 

quartz mass.

The minerals present are pyrite, chalcopyrite, and bornite in a 

gangue of tourmaline and quartz, with a little sericite and a clay
100 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

mineral that resembles beidellite. Malachite, azurite, and limonite 

occur .in the gossans.

COPPEROPOUS

The Copperopolis property is in sec. 6, T. 12 S., R. 34 E., just 

west of the East Fork of Dixie Creek. It is reached by an 8-mile 

wagon road from Prairie City.

The developments include several short tunnels and one about 

1,500 feet long that cuts the deposit at a depth of about 300 feet. 

About 250 tons of ore was milled in a small concentrator, which was 

closed in 1906.46

Quartz, tourmaline, and 

Chelcopyrite replacement masses

Country rock 

chiefly meta-andesfte

ISO Feet

FIGURE 15. Map of Copperopolis mine, Quartzburg district, Oreg.

The country rock is blocky meta-andesite, metadiorite, and 

diabase in which is developed a steeply dipping replacement body 

of quartz, tourmaline, and chalcopyrite. (See fig. 15.) This replacement body is apparently localized along a fissure that strikes 

about N. 60° E. on the surface. Mineralization followed this fissure 

from the Sherbandy group of claims to the Copperopolis ground. 

The surface outcrops in the Copperopolis claims show a replacement mass about 1,000 feet long and 75 feet wide at the widest place,

«8 Parks, H. M., and Swartley, A. M., op. cit., p. 73.
SOME MINING DISTRICTS OF EASTERN OREGON 101

where an unreplaced horse of country rock 35 feet wide is included. On the tunnel level, however, the mass is much reduced to 

a body about 40 feet wide split by a 5-foot gouge mass. It is apparently controlled by fractures that strike N. 45° E. and dip steeply 

and is itself, sheeted by steep fractures that strike N. 20° W. It is 

almost wholly composed of milky quartz, with scattered nests of pyrite, chalcopyrite, and tourmaline. Small amounts of magnetite, 

hematite, cobaltite, tetrahedrite, bornite, galena, and sphalerite 

occur. Crosscuts have been driven across both ends of this replacement body. In all directions the mass has remarkably sharp boundaries; although seams of flamboyant quartz, dolomite, and chalcopyrite extend out in several directions, they are all of negligible 

width.

Assays representative of the mass as a whole are not available. 

Considered as a copper ore it must be of rather low grade, but this 

may be in part compensated by the gold content, which according 

to some picked samples, may run close to $1 to the ton.

The mineral sequence is apparently tourmaline, quartz, and sulphides.

STANDARD

The Standard group of 21 patented claims is controlled by the 

Mercantile Commerce National Bank, of St. Louis, Mo. H. W. 

Kiley is in charge of the property, which is about 7 miles from 

Prairie City, on the East Fork of Dixie Creek.

Development on the property began about 1880, but at the time 

of Lindgren's examination in 1900 4T only the upper tunnel and the 

inclined shaft, a total of probably 600 feet of workings, had been 

driven. The mine was most actively exploited between 1900 and 

1907, when about 4,000 feet of development and considerable stoping were done. Except for a few feet of drifting in 1915 and 

the shipment of a few tons r-f ore to the Sumpter Smelter in 1923, 

the mine has since been idle.

Data on production are very incomplete. Prior to 1900 the mine 

had shipped a few tons of chalcopyrite-gold ore from the. shaft.'

In 1900 Lindgren reports a shipment of 10 tons of $34 ore from 

the upper tunnel. D. F. Hewett, of the United States Geological 

Survey, who visited and mapped the mine in 1915 and whose notes 

have been freely utilized in the present description, obtained production data which show that the mine shipped about 104 tons of 

concentrate in 1906, yielding a net return of about $50 a ton, and 

that the shipments in 1907 were about 311 tons, which yielded a net 

return of just over $45 a ton. The concentrates averaged 60 cents 

in gold and a little less than an ounce of silver to the ton and 10

" Lindgren, Waldemar, op. cit., pp. 711-712.
102 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PABT 1

to 12 percent copper. According to Mr. Riley, some cobalt ore 

was shipped to the Edison Laboratory, but he was unable to state 

the amount or value of this shipment.

. There are several veins that have been partly developed the 

Standard, Grover Cleveland, Juniper, and Smuggler. The bulk 

of the production has come from the Standard, but some ore was 

obtained from the Grover Cleveland.

The Standard vein has been opened by an inclined shaft about 

70 feet deep and by three adits at vertical intervals of about 80 

feet. The upper tunnel was caved and inaccessible in 1930, but Mr. 

Hewett's map (pi. 7) shows it to be about 400 feet long. The middle level contains 600 feet of drifts. The lower level includes 

about 1,700 feet of drifts and about 1,000 feet of crosscuts. Part 

of the workings in the lower level are caved and inaccessible. There 

are numerous raises and stopes connecting the levels. No work 

has ever been done below the third level. (See pi. 7.)

The country rock of the Standard vein is chiefly porphyritic andesite, with some vesicular andesite, cut by dikes of granodiorite porphyry and a few of diabase. The vein itself is localized along a 

fault, and there are at least four distinct fault-breccia zones crossing the vein. The vein strikes persistently N. 70°-75° E. and dips 

steeply south. Much of the movement along the faults has been 

premineral, but in one place there is a slight jog in the vein, and 

in the face the vein appears to be faulted off. No work has been 

done beyond the immediate fault contact.

There is one crosscut to the south from the Standard vein for 

about 400 feet. This cuts five small veins or mineralized stringers 

that strike N. 45°-80° E. and dip 60°-80° S.

The Standard vein ranges in width from a few inches to 4 feet. 

It is not a strong persistent vein but rather a group of mineralized 

stringers with considerable replaced wall rock. The main gangue 

mineral is quartz, but some ferriferous dolomite and calcite are also 

present. The ore minerals are pyrite, chalcopyrite, arsenopyrite, 

cobaltite, glaucodot, bismuthinite, native bismuth, galena, and 

sphalerite. The glaucodot, which has been called smaltite and safflorite in other reports, is present in the deeper workings. Considerable cobalt bloom, erythrite, is present in the lowest drift, and 

some nickel bloom (-?), jarosite, and malachite also occur. The 

average tenor of the ore is not known.

- The fault zone nearest to the adit is called the Grover Cleveland 

Tein .and has been' drifted on for about 600 feet. It strikes N. 20°- 

40° E. and dips about 80° S. . Most of this work, is now caved. To 

the northwest of tHe Standard vein another tunnel has been driven 

for.7QO..fee.t.. .This_t.unneLalso .cuts.the Grover Cleveland vein, and
SOME MINING DISTRICTS OF EASTERN OREGON ' 103

some work was done here. The Grover Cleveland vein follows in 

part a dike of granodiorite porphyry, and consists of a shattered and 

brecciated zone about 8 feet wide containing breccia, gouge, and 

small quantities of quartz, ferriferous dolomite, and sulphides. The 

ore is free-milling and carries about $2 in gold to the ton according 

to Mr. Pinson, former manager of the company.

The other fault zones that cross the Standard vein have not been 

followed at all. These fault zones consist of breccia and gouge 

and range in width from 6 inches to 3 feet. The exposures are 

.very poor at the face, and nothing can be said regarding the fault 

that cuts off the vein. ' .

The Smuggler vein is exposed in an open cut on Dixie Creek a 

few hundred yards above the main Standard mine. It is a diorite 

dike, silicified and mineralized. Numerous spots of brownishblack tourmaline are present. . The sulphides are pyrite, chalcopyrite, and bornite. The dike strikes N. 60° E. and dips steeply 

north. The dike has been followed by the miners for over 1,500 feet 

"on the surface. The wall rock, of the diorite dike is greenstone. The 

walls are very indefinite and irregular. ~ The Juniper vein is southeast of the Standard vein^ in Ella Gulch, 

a small branch of Dixie Creek. The vein is opened along the strike 

by a tunnel 900 feet long. The vein strikes N. 75°-80° E. and dips 

about 80° S. It ranges in width from 3 inches; to about 3 feet. Sulphides, chalcedony, and quartz are the common constituents. The 

sulphides are pyrite, chalcopyrite, and arsenopyrjte. Two spots of 

cobalt bloom were noticed. At the face the strike of this .vein is 

N. 80° E. and its dip 70° S. The vein swings and in one place 

strikes due east.

In the Jumper vein, as in the Standard vein, several breccia zones 

cross or are crossed by the vein, with very little or no offset along 

either one. In the Juniper drift these zones strike N. 5° E. to due 

north and dip about T5°-80° E. They contain from a few inches to 

several feet of gouge and breccia. The waljl rock is all meta-andesite, some so much altered as to resemble hornfels. Much tourmaline 

is-present in it. .

The sequence of mineralization has been tentatively worked out 

by combining the observations of' Mr.. Hewett and the writers as 

follows: '"' ..

First the andesite was altered to " hornfelslike " masses, the joints 

of which were locally coated with tourmaline. Calcite, the metallic 

minerals (beginning, with pyrite and arsenopyrite), ferriferous 

dolomite, quartz, a second generation of calcite and pyrite, chalcedony, and marcasite, followed in_prcler. Of these, the chalcedony 

and marcasite are probably supergene. ... < .
104 CONTEIBUTIONS TO ECONOMIC GEOLOGY, 1933, PABT 1

DIXIE CREEK PLACERS

The Dixie Creek placers have been described by Lindgren 48 as 

follows:

The Dixie Creek placer mines were discovered about 1862, and were reported 

rich, though no data as to production are at hand. Raymond's report for 

1870 contains the statement that at that time there were 100 white men and 

200 Chinamen employed, and that the fine scaly gold was 0.860 fine. In 1873 

the creek is reported as turned over to Chinese labor. In 1882 two small 

hydraulic plants were in operation, producing $30,000 (mint report). At the 

present time [1900] very little placer mining is done.

The placers consist of the gravels accumulated in the present creek to a 

depth of 10 or 15 feet. The workings extend upstream from Prairie for 5 

miles, or to the entrance of the diorite canyon, where the grade becomes 

very steep. The width of the gravel-covered river bottom is from 300 to 800

feet, the whole of which has been worked.

Six miles east of Prairie are the old Spanish Diggings, which have yielded 

a moderate amount of gold. The upper end of John Day Valley contains no 

placers. On the east side of Dixie Butte are the old placers of Happy Camp, 

still worked on a small scale by Chinese. Northwest of the same mountains 

are the Ruby Creek placers, still worked by whites and Chinese. Small 

placers are also reported from the head of Camp Creek.

Swartley 49 states that local estimates of production from the 

Dixie placers range from $600,000 to $6,000,000, with the smaller 

figure probably being nearer the true one.

In 1930 a dredge owned by the Empire Gold Dredging Co. and 

managed by R. C. Reese was operating in the gravel just below the 

town of Prairie City. This dredge had been installed on Canyon 

Creek just above John Day in 1916 and operated there for 12 years, 

digging between 300 and 400 acres of 12-foot ground. In 1929 it was 

moved to the Prairie City ground. It was digging 22 feet to bedrock in a pay streak about TOO feet wide. Mr. Reese estimated that 

a 4 to 5 year run remained ahead of the dredge at this site. The 

dredge has 6-foot buckets and a capacity of about 3,000 cubic yards 

a day, but owing to irregular power supply it operates only intermittently during the irrigating season.

COMINI QUARRIES

L. Comini & Sons have opened three small quarries in diorite 

about 4 miles up Dixie Creek from Prairie City.

The stone differs in color in the three quarries, that in the quarry 

nearest to the town being darkest and that in the quarry farthest 

away being lightest. In 1930 practically all the work was being 

done in the middle opening. The rock is a moderately fine-grained 

gray diorite but contains a large number of dark inclusions, which 

are of course very undesirable in monumental stone, leading to a

48 Lindgren, Waldemar, op. cit, p. 712. « Swartley, A. M., op. cit, p. 198.
U.S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 7

PORTAL No.2 ___"- 

SECTION ALONG STANDARD VEIN

POFITAL 

No. I Granodiorite porphyry Diabase dike Fault Stope 

All country rock meta-andesite except as shown

zoo Feet

MAP AND SECTION OF STANDARD MINE, QUARTZBURG DISTRICT, OREG.

From notes by D. F. Hewett, 1915. .
SOME MINING DISTRICTS OP EASTERN OREGON 105

considerable waste in partly worked stone. Efforts were being made 

to find an area free from these inclusions, which, however, had not 

been done at the time of visit.

OUTLOOK FOR THE DISTRICT

The Quartzburg district is under the disadvantage of being far 

from reduction works, so that ore must be of very high grade to 

warrant transportation charges. Mineralization is widespread, and 

several of the properties might prove profitable if worked on a 

moderate scale, but the deposits so far discovered, with the possible exception of the Dixie Meadows and Copperopolis, are hardly 

of a size sufficient to warrant large development campaigns. The 

Dixie Meadows and Copperopolis deposits are of considerable size, 

and it is possible that if the grade of the material warrants they 

may justify work on a larger scale. In absence of systematic assaying, however,® it is not justifiable to assume that they warrant 

development, at least until mining and transportation costs become 

lower. ,

In a district in which the rocks have been so widely mineralized 

and in which prospecting is so difficult there is a considerable probability that other deposits may be present, perhaps more attractive 

than any so far known. On the evidence available in 1930, however, 

the Quartzburg district seems destined to remain a potential rather 

than an actual producer, until the transportation handicaps are 

overcome.

STJSANVILLE DISTRICT 

GEOGRAPHY

The Susanville mining district is in Grant County about 18 miles 

down the Middle Fork of the John Day Eiver from Austin. Most 

of the district is in the northwestern part of T. 10 S., R. 33 E. but 

it extends slightly into the adjoining townships on the north, northwest, and, west. The mines are all on the north side of the 

river and are concentrated principally along Elk Creek, a small 

tributary that enters the river in sec. 13, T. 10 S., R. 32 E. Deep 

Creek, the next tributary entering the river from the north below 

Elk Creek, may be considered the northwestern boundary of the 

area. The relief in the immediate district is probably less than 

1,000 feet, but the slopes in general are steep. The country is 

heavily wooded. The rainfall is moderate, but heavy snows are 

common in winter.

Susanville post office is on Elk Creek about iy2 miles above its 

mouth. The nearest railroad is the narrow-gage Sumpter Valley 

Railway at Austin. In summer the road from Austin to Susanville

164495 33 8
106 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

is in fair condition. It is 3 miles by graded road from Austin to 

Batesville on the John Day Highway. Susanville may also be 

reached from the John Day Highway at Kimberley at the confluence 

of the North Fork and the main river by following up the North 

Fork.

FIELD WORK

No base map was available, and because of the timber the district 

is not favorable to plane-table map'ping, so no geologic map was 

made. The work was confined to an examination of the accessible 

mines and prospects and to. a geologic reconnaissance of the district. About a week was spent in the area.

GEOLOGY

GENERAL FEATURES

The country rock of most of the Susanville district is schist. 

Lindgren 50 believed the schist to be Paleozoic, probably Carboniferous, but as no fossils have been found its age is uncertain. In the 

schist series quartzite, greenstone, and slate occur in subordinate 

amounts. This series, is the oldest formation in the district.

The schists were intruded by bodies of basic and ultrabasic rocks, 

which originally were gabbros and peridotites. These bodies have 

been sheared and altered and are now for the most part serpentinous 

rocks, although some unaltered gabbro and peridotite occur.

The district is bounded on the north and northeast by the edge of 

a large quartz diorite mass, which according to Lindgren's map 50 

extends eastward for at least 15 miles and forms the country rock 

of the Greenhorn mining district. The quartz diorite is a younger 

intrusion than the basic ones just mentioned. Aplite dikes cut the 

schists and the basic rocks. Presumably the dikes are related to the 

quartz diorite intrusion. The age assigned to the intrusion by 

Lindgren 51 is post-Jurassic and pre-Chico, and no reason was found 

to question this assignment.

Here and there over the higher land in the district occur areas of 

the Columbia River lava, remnants of more or less continuous flows, 

which at one time, blanketed the whole district. Near the borders 

of the district the lava areas become larger in fact, the district is 

almost encircled by lava-flows. The older rocks are exposed as a 

result of the removal of the lava coyer by the streams.

The valley of the Middle Fork of the John Day River is floored 

with gravel of Quaternary age. The gravel extends continuously 

up Elk Creek as'far as Susanville,-and considerable areas are found 

even farther up the creek. -

60 Lindgren, Waldemar, op. cit, pi. 64. Bl Idem, p. 596.
SOME MINING DISTRICTS OF EASTERN OREGON 107 

SCHIST SERIES

The dominant rock of the schist series is a gray actinolite-talc 

schist. A conspicuous feature of the rock, in addition to its soapy 

feel, is that it has developed a linear schistosity as well as a plane 

schistosity. Hand specimens show this feature by being striated 

parallel to the strike of the rocks. The schist is probably of sedimentary origin and contains carbonaceous material, and at some localities 

much graphite is developed along the shear surfaces. Black carbonaceous slate is included in the series in a few places.

Near the Princess mine a fine-grained biotite schist occurs close to 

the quartz diorite contact. Cleavage surfaces of this rock are black 

with small bright flakes of biotite.

No limestones were found in the schist series in the Susanville 

district, but a few thin beds of quartzite were observed. On the 

hill above the Skyscraper claim a conglomerate occurs in which are 

subangular chert pebbles as much as 1% inches across. Some greenstone, probably of pyroclastic origin, is also represented.

Altered andesitic flows are locally interbedded in the schist series. 

They are especially conspicuous in the area around and between the 

Bull of the Woods and the Poorman properties.

BASIC INTRUSIVE ROCKS

- Gabbro and associated peridotite and serpentine are not common in 

the district. Basic rocks are conspicuous, however, around and north 

of the Gem mine and between the Bull of the Woods and Side Issue 

mines. These rocks are in general highly sheared and altered, but 

in a few places original textures are preserved. Dark-green sheared 

serpentine is the chief representative and is well exposed along the 

road above the portal of the Bull of the Woods mine. In the immediate vicinity of the Gem mine the basic rock is altered peridotite. 

It contains tremolite, serpentine, pyroxene, magnetite, pyrrhotite, 

and a little relict olivine.

QUARTZ DIORITE AND RELATED DIKES

The quartz diorite that bounds the Susanville district on the north 

and east is but the border of a large mass that extends for a long 

distance toward the east. This rock is in places gneissic near the 

borders but is almost massive away from the contacts.

The rock is light colored, coarse or medium grained, and granitic, 

with biotite, hornblende, quartz, and feldspar visible in hand specimens. Locally it is sheared, but nowhere to a degree comparable 

to that of the basic intrusive rocks.

Microscopically the essential minerals are seen to be basic oligoclase, quartz, hornblende, biotite, and in some specimens a little 

augite. Apatite, zircon, titanite, and magnetite occur as accessories.
108 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The numerous porphyry dikes that cut the older rocks in the district are probably related to this mass. The dikes are light colored 

and typically weather buff or pink. They are medium to fine grained 

and carry phenocrysts as large as 2 millimeters but averaging 

about 0.8 millimeter. The phenocrysts are composed of quartz 

and oligoclase, in a groundmass made up of quartz, oligoclase, and 

muscovite.

TERTIARY ROCKS (MIOCENE)

Remnants of lava flows are scattered over the divide between Elk 

and Deep Creeks and occur more continuously on the divide between

-Elk Creek and the Middle Fork of the John Day River. The lavas 

are much younger than any of the previously described rocks and are 

probably to be correlated with the Miocene Columbia River lava.

QUATERNARY ROCKS

- The gravel along the streams and the slope wash and talus slopes 

of the hillsides represent the Quaternary period.

STRUCTURE

The schist enters the district from the west with an eastward 

strike. The general trend changes near the middle of the district, 

and the prevailing strikes in the eastern half are northeast, averaging approximately N. 50° E. The dips are almost without exception steep to the south. A dip less than 50° is seldom observed, and 

TO 0 is common.

Only at the Princess mine was an observation taken on the schist 

immediately contiguous to the quartz diorite contact. Here the 

foliation is parallel to the contact, about N. 80° W., and to the foliation of the quartz diorite. However, in the vicinity of the Gem 

mine, only a short distance from the quartz diorite contact, the trend 

of the schist is nearly at right angles to the contact.

The trends of the aplitic dikes are apparently parallel or nearly 

parallel to the trend of the country rock.

The nearly flat-lying patches of Miocene (?) lava on the steeply 

dipping schist series indicate a profound unconformity. The fact 

that the contact between lava and pre-Tertiary rock is found at 

altitudes that differ considerably from place to place suggests that 

the surface on which the lava was poured out had considerable 

relief, probably comparable to that of the present day.

ORE DEPOSITS

Most of the ore deposits of the district occur in fissure veins, 

chiefly parallel to the schistosity of the country rock. In a few

prospects certain zones in some of the aplite dikes have been worked
SOME MINING DISTRICTS OF EASTERN OREGON 109

and are reported to carry gold and silver. Some of the mineralization appears to have produced very irregular replacement masses.

The deposits are all in the pre-Tertiary rocks. Most of them are 

in the schist series, but some are found in the basic rocks or at the 

contact of the basic rocks and the schist. No relation was found 

between the distribution of the ore deposits and the position of the 

main mass of the quartz diorite. However, many of the veins 

appear to be related to aplite dikes, which in turn are probably 

related to the quartz diorite. The common regional relation between 

the ore deposits of eastern Oregon and these quartz diorite masses 

makes this interpretation more reasonable.

The dominant gangue mineral of the veins is quartz. Ankerite 

and fuchsite are conspicuous in some of the veins. The metallic 

minerals determined from the study of polished sections are pyrite, 

marcasite, arsenopyrite, chalcopyrite, pyrrhotite, sphalerite, galena, 

stibnite, tetrahedrite-tennantite, and chalcocite. The paragenesis of 

the minerals, as concluded from the study, is shown in Figure 16. 

The time order of deposition is from left to right.

Pyrite ^"~1-

Arsenopyrite """""

Chalcopyrite

Pyrrhotite "

Sphalerite -"""~^

Galena ^^^~~^^~ 

Marcasite ~^~~

Gangue " "-"" 

FIGURE 16.-T-Paragenesis of minerals in Susanville district, Oreg., as shown by 

studies of polished sections of ores

There was probably considerable overlap in the periods of deposition. Individual grains of pyrite are shattered and corroded, in 

places almost completely destroyed. Many of the fractures through 

this pyrite contain arsenopyrite, chalcopyrite, sphalerite, and gangue. 

That arsenopyrite was deposited later than part of the pyrite is 

further substantiated by the fact that there are numerous rounded 

fragments of pyrite isolated in the arsenopyrite.

The arsenopyrite in turn is fractured. These fractures commonly 

contain some chalcopyrite and sphalerite. Chalcopyrite is especially 

common but also occurs in angular spots scattered through the 

arsenopyrite. These spots finger off or pinch out gradually, as if 

the copper mineral had worked in along grain boundaries or minute
110 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

cracks. A few small rounded pieces of arsenopyrite are entirely 

surrounded by chalcopyrite and sphalerite.

The paragenesis of the chalcopyrite, pyrrhotite, and sphalerite is 

confused, probably because of overlap. The sphalerite contains 

a great number of small spots of chalcopyrite, pyrrhotite, and 

locally, galena. In one specimen sphalerite is distinctly veined by 

pyrrhotite; in others sphalerite appears to penetrate and replace 

pyrrhotite along grain boundaries. Chalcopyrite is common in 

fractures and veinlets, through and around grains of pyrrhotite. 

In some places the chalcopyrite is veined by sphalerite. From this 

evidence it is thought that the pyrrhotite may be partly earlier than 

the chalcopyrite and the sphalerite, although in part, at least, they 

are contemporaneous.

. Galena is considered younger than any of the previously described 

minerals except where the galena occurs in small spots in the sphalerite. Here these two minerals are probably contemporaneous. 

Considerable galena also occurs in the sphalerite in fractures and 

around holes; some is present in fractures through the pyrite. In 

many of the specimens rounded fragments of sphalerite are isolated 

in the galena.

There appear to have been two main periods in which pyrite was 

deposited. The first period began prior to and probably lasted 

during the deposition of the arsenopyrite. The second was at least 

later than the chalcopyrite and sphalerite. No pyrite has been observed cutting galena. Galena is not a very common constituent of 

the specimens, and such a relation might easily be missed. It is entirely possible that in the line diagram the period for deposition of 

pyrite should be represented as extending past the galena period.

It is also possible that there was one long period of deposition 

of pyrite instead of the two given. There is, however, no direct 

evidence to support this possibility.

Stibnite has been omitted from the discussion of paragenesis 

because is was not seen in the same specimen with any other metallic 

minerals. It occurs in small radiating bunches of fine fibers or in 

small colloform masses. The material in which it was seen is vuggy 

and porous. The holes are lined with fine drusy quartz. Chalcedony is present in alternating layers with the stibnite. Tetrahedritetennantite was observed in only one specimen, from the Ophir mine, 

in which it replaces pyrite.

. Later than any of the sulphides or metallic minerals is part of the 

gangue. .Many of the specimens have been shattered and the fragments recemented by gangue. Gangue minerals have been observed 

transecting all the metallic constituents.
SOME MINING DISTRICTS OP EASTERN OREGON 111

There is no evidence of important supergene enrichment, although 

the few minor fissures and spots of chalcocite and marcasite were 

probably deposited by supergene waters.

THE MINES 

BADGER

Location and development. The Badger mine is in sec. 8, T. 10 S., 

K. 33 E., on the south side of Elk Creek. It is about 2 miles above the 

junction of Elk Creek and the Middle Fork of the John Day River. 

There are 12 patented claims in the Badger group.

The mine is owned by the Susanville Mines Co. Parks and 

Swartley 62 say:

This vein was discovered in the late sixties, and in the early seventies free 

gold was extracted in an arrastre from the decomposed croppings, which 

yielded about $25 per ton. Later on a 10-stamp mill, with concentrators, was 

built, but there was not a high percentage of extraction. .

As the result of litigation with the Stockton Mining Co. the mine 

was shut down in 1905. There was some activity at the property 

in 1922, but none since. The mine has produced in the past considerable gold, silver, lead, and zinc. .

The mine was originally opened by a shaft that was sunk 900 

feet below the collar. Later a 1,600-foot crosscut was driven from a 

point about 30 feet above Elk Creek. This level is about 500 feet 

below the shaft collar, or 400 feet above the bottom of the shaft. 

The shaft has caved above the crosscut level and is inaccessible. The 

crosscut, however, is open, furnishing access to about 3,000 feet of 

drifts and several winzes and raises. The workings are flooded 

nearly to the main crosscut level.

Geology. The predominant country rock is slate, but shale, schist, 

and quartzite are also present. The strikes are uniformly east and 

the dips range between 55° and 60° S.

Gouge and breccia along the planes of schistosity suggest strike 

faulting. This appears to be common throughout the district. The 

south side appears to be the downthrown side.

The veins conform to the strike and dip of the country rock. At 

least two veins have been stoped. These veins are about 6 feet apart 

and range in width from 1 foot to 20 feet. Fragments of wall rock 

are contained in the veins. In some places the veins appear to be at 

least in part replacement bodies in that " ghosts " of wall rock are 

present.

62 Parks, H. M., and Swartley, A. M., Handbook of the mining Industry of Oregon: 

Mineral Resources of Oregon, vol. 2, No. 4, p. 19, Oregon Bur. Mines and Geology, 1916.
112 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The vein material is predominantly quartz. Much ankerite is also 

present. The most common sulphide is pyrite. Locally galena, 

sphalerite, or arsenopyrite may predominate.

OEM

Location and development. The Gem mine is on the west side 

of Elk Creek near its head. It lies in sec. 5, T, 10 S., R. 33 E.

The vein is opened by an inclined shaft, which is now filled with 

water within 50 feet of the surface. The shaft is reported to be 350 

feet deep and to have four levels turned from it.

B. F. Hurt, who is at present in charge of the property, states that 

most of the stock of the Gem Mining Co. is controlled by Gus Smith 

but that the ground has been leased to a Spokane company. The 

property consists of four claims, two of which are patented.

Parks and Swartley 53 say that

Seventy-five to a hundred tons have been milled elsewhere and a few tons 

shipped crude. * * * The property was closed down in 1909, but in 

September, 1916, a carload of crude ore was sorted and shipped to smelters.

According to a report by Carl Andersen, a mining engineer of 

Portland, 13 tons of ore has been shipped to smelters. Some development work was done in 1922.

Geology. The country rock is talc schist and altered peridotite. 

At the surface the peridotite marks the footwall and the schist the 

hanging wall of the vein. At the water level in the shaft both walls 

are schist. Serpentine is reported below the water level. The contact of the peridotite and the schist was not traced, but the strike of 

the schist is N. 45° E. and the dip 62° SE. at the shaft collar.

The vein, which is about 3 feet thick, corresponds in attitude 

to the strike and dip of the schist. In a small gulch just below 

the Gem shaft another vein, which strikes N. 40° E. and dips 

60° SE., crops out. If these strikes and dips persist these veins 

intersect north of the shaft.

The vein consists of quartz with subordinate ankerite. It carries 

some free-milling gold. Chalcopyrite, pyrite, and pyrrhotite were 

seen on the dump.

BULL OF THE WOODS

The Bull of the Woods mine is owned by the Susanville Mines 

Co., the same company that owns the Badger. The workings are just 

east of the Badger mine but are on the north side of Elk Creek.

The mine has been opened by two adits and a vertical shaft that 

connects the adits. The shaft is about 100 feet from the portal of 

the upper adit. The upper level is caved beyond the shaft but is

68 Parks, H. M., and Swartley, A. M., op. cit., p. 164.
SOME MINING DISTRICTS OF EASTERN" OREGON 113

reported to have been 1,500 feet long. The lower level consists of 

about 220 feet of drifting.

A small production was reported from the mine in 1905.54 

The country rock is serpentine and talc schist. A little aplite and 

greenstone were also seen. The country rock is broken and shattered, 

and alteration has converted much of it to sericite and clay.

The vein is not visible in the upper workings, but it is reported 

to strike slightly east of north and to dip steeply east. No definite 

vein was followed in the lower level. The work has been done in the 

shattered altered area containing quartz, ankerite, sericite, serpentine, 

limonite, hematite, and some pyrite.

EESCTTE '

The Kescue group consists of three claims owned by Charles Eay 

of Susanville. The property adjoins the Gem ground on the west.

There is an inclined shaft on the property, at present full of water, 

which is reported by Mr. Ray to be 140 feet deep. A tunnel, now 

about 200 feet long, has been started below the shaft. f It is planned 

to continue this tunnel until the vein is intersected. No production 

has been reported from this group.

The country rock is schist.- The strike of the main vein ranges 

from north to N. :10° E. ', The dip is uniformly about 60° E. Three 

other smaller veins exposed on the surface strike about N. 30° E. 

and dip 60° E. Quartz is the predominant gangue mineral, but 

ankerite is rather common. The ore minerals found on the dump 

were pyrite, sphalerite, .pyrrhotite, chalcopyrite, galena, and 

arsenopyrite.

CHATTANOOGA

The Chattanooga property consists of one patented claim lying 

southwest of the Rescue group. It is owned by B. F. Hurt of Susanville. The property is opened by a vertical shaft, filled with water 

but reported to be 210 feet deep. A little ore has been shipped in the 

past.

The country rock is talc schist. The vein strikes N. 65° E. and 

dips 60° E. The predominant gangue mineral is quartz, but ankerite, mariposite, and sericite are present. Massive sulphides were found 

on the dump and include pyrite, chalcopyrite, sphalerite, galena, and 

arsenopyrite.

DAISY

The Daisy claim, owned by B. F. Hurt, of Susanville, lies just 

south of the Rescue group.

The country rock is talc schist. Two small open cuts expose a 

small vein, which strikes N, 20° E. and dips about 65° E. The

M TJ. S. Geol. Survey Mineral-Resources, 1905, p. 291, 1906.
114 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

gangue is rusty quartz. ; Small amounts of sulphides," chiefly 

rhotite, pyrite, and chalcopyrite, occur in the quartz. Mr..; Hurt 

says that the value is mostly in free gold.

. PRINCESS ........

The Princess property is on the south bank of Deep Creek in sec. 

31, T. 9 S., K. 33 E. It is reached by means of the Princess trail, 

.which leads over the divide from the Gem mine. The property 

-consists of two claims owned by Charles Ray, of Susanville.

The workings consist of an adit about 400 feet long, a 60-foot 

shaft, and a small open cut. There has been no production. (See

% I?-) t m m t . The mine is in the schist series very close to its contact with the

'main mass of quartz diorite. The country rock is talc schist, quartz 

.diorite, and quartz-biotite schist.

.uartz-mica schist

 { "^-Stringers of quartz dipping 

steeply south

Drift entirely in quartz

100 Feet

FiGtJKH 17. Map of Princess prospect, Susanville district, 

Oreg.

. There are several small veins and stringers running in different 

directions, but most of the work has been done in what appears to 

.be a nearly vertical irregular pipelike mass of quartz. Stringers 

extend from the mass in several directions. This is probably, at least 

in part, a replacement mass, for the wall rocks have been intensely 

silicified, and separated schist layers and ghosts of wall rock are common in the quartz. The massive quartz has a light-blue watery 

appearance. A few small amphibole crystals are dispersed through 

it, and it is locally seamed with stringers of sericite. According to 

Mr. Ray, the ore is richest at the shaft near the north end of the 

quartz body. Pyrite, chalcopyrite, pyrrhotite and sphalerite were 

the metallic minerals seen. Mr. Ray also reports some free gold.

POORMAN

 ' The Poorman group or Dougherty property consists of seven 

patented claims, all owned by Robert Dougherty, of Susanville.
SOME MINING DISTRICTS OF EASTERN OREGON 115

The claims lie east of .the Badger mine, on the north side of Elk 

Creek. There are numerous old adits and shafts on the hillside, 

most of which are caved and inaccessible. About 300 feet of drift 

is open. Mr. Dougherty reports that there has been a small production of free-milling gold.

The country rock is talc schist with some slate. The schist series 

is cut here by an aplite dike about 50 feet thick. The dike appears 

to be vertical and strikes a little west of north. A-vertical zone, 

striking N. 60° E., in the aplite is now being worked.

The veins are all small stringers, but they are reported to be rich. 

The gangue minerals are predominantly quartz and ankerite. The

sulphides seen include /1

N

J.

sphalerite, pyrite, galena, 

chalcopyrite, and stibnite.

Country rock is 

talc schist

100 Feet

FIGURE 18. Map of workings, Belle of the Hills 

prospect, Susanville district, Oreg.

BELLE OF THE HILLS

The Belle of 'the Hills 

property, owned by Norman . J.ohnson, - of Susanville, is composed of three 

claims that lie directly 

west of the Badger mine. 

The mine consists of two 

levels, the upper about 55 

feet above the lower. (See 

fig. 18.) The upper level 

is opened by an adit about 

130 feet long and has 

about 300 feet of drift. 

The lower adit is 380 

feet long. There is about 370 feet of drift in the lower level. The 

two levels are connected by a 60-foot incline. On the hillside above 

the mine are several small shafts and open cuts. No production has 

been reported. . The country rock is talc schist and slate. The strike is in general 

east, and the average dip is about 70° S. The workings cut several 

small seams of quartz, but nearly all the work has been confined to 

one vein, which strikes N. 70° E. and dips 60°-70° S. The vein 

ranges from 6 inches to 1 foot in width and contains considerable 

quartz and pyrite. According to Mr. Johnson, some of the quartz 

stringers encountered in the open cuts show free gold in the pan.

GOLD BUG

The Gold Bug prospect, owned by Messrs. Leahy and Dunstan, 

of Susanville, is near the crest of the ridge about a mile northeast
116 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

of Susanville. The workings are inaccessible. According to Charles 

Ray, the shaft is about 400 feet deep. The mine has been abandoned 

for years, and no production was reported.

The country rock is talc schist that strikes N. 50° E. and dips TO 0 

SE. The poor outcrops near the shaft collar indicate that the vein 

conforms to the strike and dip of the schist. Some carbonate was 

seen in the iron-stained quartz on the dump.

MOCKING BIRD

The Mocking Bird property is on the north side of Elk Creek just 

across from the Badger. It is controlled by the same company that 

owns the Badger. The workings consist of a small open cut and a 

tunnel that is now inaccessible.

The talc schist country rock is cut by a large aplite dike. The veinr 

consisting of 6 inches of quartz and gouge with considerable 

jarosite, follows close to the schist-aplite contact but is confined to 

the schist. The strike of the vein is N. 10° E., and the dip is 70° SE. 

On the dump were found pyrite, sphalerite, chalcopyrite, pyrrhotite,

and a little galena.

OPHIE

The Ophir mine lies south of the Badger-shaft on the slope towa:rd 

the Middle Fork of the John Day River. The property consists of 

one claim which is developed by a shaft and several adits. Of these 

only one small adit, 290 feet long, is accessible. A little ore was 

shipped to the Tacoma smelter in 1908.

The country rock is talc schist and slate. The strike is N. 55° E. y 

and the dip 55° SE. Several small quartz and carbonate stringers 

parallel the schistosity. Pyrite, chalcopyrite, and tetfahedrite-tennantite were the metallic minerals observed. Some aplite occurs in 

the accessible adit.

BLACKHAWK

The Blackhawk property, like the Badger, is owned by the Susanville Mines Co. It lies east of the Bull of the Woods, on the southeast 

side of Elk Creek. The property is opened by a shaft inclined at 

60°. The shaft is reported to be 150 feet deep, but it is filled with 

water within about 40 feet of the surface.

The country rock is talc schist. The vein consists of a 6-inch 

stringer of quartz and gouge with some pyrite, galena, and sphalerite. 

The vein strikes N. 70° E. and dips 60° S.

SIDE ISSUE

The old mine known as the Side Issue is on the Blackhawk 

property. All the workings are inaccessible. Outcrops of talc 

schist and serpentine were seen near the shaft.
SOME MINING DISTRICTS OP EASTERN OREGON 117 

SIMCOX

The Simcox property is half a mile east of the Blackhawk prospect. It is owned by Mrs. Gertie O'Eourke, of Susanville. The 

workings consist of an adit 516 feet long and three small drifts 

branching from the end of the adit. The country rock is talc 

schist. The workings cut but do not follow several small quartz 

stringers.

The Skyscraper property lies on the top of the ridge between Elk 

and Deep Creeks, above the town of Galena. The property consists 

 of one claim. There has been considerable work done in the past, 

but only a small cut is now accessible. The country rock is talc 

schist. A small vertical vein strikes N. 85° W. According to 

Norman Johnson, $3,000 worth of gold was taken from a small

pocket in this vein. THOMPSON

The Thompson Mining Co., controlled by C. A. Thompson, owns 

eight claims on the north side of Elk Creek a short .distance below 

the Badger. The property is developed by a 900-foot prospect adit, 

which runs N. 30° E. near the portal but turns near the face and 

runs N. 70° E. The country rock is talc schist and slate. Several 

small stringers of quartz and gouge have been cut. These strike N. 

80° E. and dip 60° S., paralleling the schistosity.

STOCKTON

The Stockton property consists of three claims lying southeast of 

the Badger property. The country rock is slate. There has been 

some work done in the past, but it is now inaccessible.

KELSON

Guy Nelson, of Susanville, owns some claims at the junction of 

.Elk Creek and the Middle Fork of the John Day Kiver. At the 

time of the writers' visit a small inclined shaft, reported to be 25 feet 

deep, was filled with water. The country rock is talc schist. The 

schist, which contains seams of pyrite and marcasite both parallel 

to and cutting the schistosity, is reported to carry gold.

PLACER MINES

The Susanville placers were all inactive at the time of visit. 

Swartley 55 says:

The placer mines of Susanville were discovered in 1864, and have been 

worked practically every season since then.

55 Swartley, A. M., Ore deposits of northeastern Oregon: Mineral Resources of Oregon, 

vol. 1, No. 8, pp. 169-170, Oregon Bur. Mines and Geology, December, 1914.
118 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

Elk Creek has produced the most, but other creeks lower down, along the 

north side of the John Day, have also yielded considerably. The total placer 

production is approximately $600,000.

The Middle Fork, below Elk Creek, is reported to have produced $50,000 

in fine flour gold, but the creeks usually contain coarse gold, 0.865 fine.

The largest gold nugget found on Elk Creek during the more active operations was worth $480. Deep Creek had one worth $625. Buck Gulch, 

below Deep Creek, years ago had one worth $800, but on June 19, 1913, 

George Armstrong found another on Buck Gulch weighing 80.4 ounces, which 

at $17.60 per ounce would be worth $1,415. Most of the gold in the Elk 

Creek placers seems to have come from the west side of the creek, although 

the most productive quartz mine is on the other side.

Considerable drifting has been done near the Middle Fork of John Day 

underneath the basalt capping, in hopes of cutting old stream channels in the 

search for placer gold, but such operations have not been successful because 

they have as yet been unable to cut through the rim-rock to enter these old 

channels anywhere near the bedrock.

The Middle Fork from a point somewhat above Elk Creek downstream for 

a distance of 4 or 5 miles, was partially prospected in 1898 with a view to 

dredging, but nothing came of it. In this same ground in 1913 the entire 

valley for this distance was under option, and test pits were sunk at various 

points. The results of these shafts are said to average 14 or 15 feet in 

depth and to contain sufficient value to warrant a systematic drilling of the 

ground with a view to the installation of a dredge.

No dredging had been carried out on this ground, however, prior 

to the time of this survey.

OUTLOOK FOR THE DISTRICT

The Susanville district is handicapped by the long distance to a 

railroad. As can be noted in the preceding descriptions, there are 

several veins whose prospects. would justify considerable development in a less isolated district. The ore of the district is not amenable to amalgamation, and the tenor of concentrates must be high 

to overcome the transportation charges. With one or two possible 

exceptions the profits won from the 'mines of the district in the 

past were derived from the placers and from pocket hunting on a 

small scale. Until a satisfactory extraction process is applied to 

the ores or the transportation costs are notably lowered it must be 

confessed that little hope for enlarged activity can be justified. 

This district; were it located more favorably, would probably have 

a creditable record of production but under present conditions its 

development will probably be slow.

OCHOCO DISTRICT 

GEOGRAPHY

The Ochoco quicksilver district occupies an irregular belt extending about 40 miles in a northeasterly direction from a point about
20 miles due south of Prineville to the divide at the head of Ochoco 

Creek, about 10 miles southwest of Mitchell. Most of the deposits, 

discovered up to 1930 are in Crook County, but at least one prospect, 

is just over the boundary in Wheeler County. (See fig. 19.)

The area lies at the west end of the westward-trending Ochoco. 

Mountains, almost entirely in the drainage basin of the Crooked 

River. Altitudes range from about 6,600 feet on Lookout Mountain

FIGURE 19. Map showing location of deposits in the Ochoco district, Oreg., described

in this report

to about 2,000 feet near Prineville. The climate is arid, but the rainfnll suffices to support open pine forests on the higher ground, though-, 

only sagebrush and juniper are prominent in the lower country.

Most of the quicksilver deposits are readily, reached by way of theOchoco Highway, which extends from Prineville to Mitchell, or by 

the Crooked Eiver Highway, from Prineville to Post. Prinevilleitself is connected by the City of Prineville Railway to the Oregon 

Trunk Line of the Great Northern system at Prineville Junction, in 

the Deschutes Valley.
120 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

THE MINES 

JOHNSON CREEK-LOOKOUT MOUNTAIN AREA

Paulsen & Saylor. The Paulsen & Saylor mine is just north of 

Johnson Creek in sec. 15, T. 14 S., R. 20 E., Willamette base and 

meridian. It is reached by way of a forest road that leaves the 

Ochoco Highway a short distance east of the Ochoco ranger station 

and passes southeast, over the divide north of Lookout Mountain. 

It is about 30 miles by road from Prineville.

The deposit was discovered in 1929 by W. J. Westerling, who 

leased the property to Martin Paulsen and Evan Saylor in April 

1930, A small retort was erected in the summer of 1930, but no 

actual production had been made at the time of visit, in August.

The property is developed by means of a shallow open cut and, 

about 60 feet lower, by a crosscut that trends N. 30° W. and is about 

120 feet long.

The country rock is rhyolite probably of Tertiary (Clarna?) age. 

It is highly altered near the veins. In the open cut the rhyolite is 

intersected by joints that strike N. 60° E. and dip 60° N.W. In the 

crosscut a northward-trending fault which dips 75° W. is cut. A 

quartz vein 8 inches or less thick is developed along this fault and is 

itself brecciated slightly by later movements.

These faults and fissures are the sites of mineralization, chiefly 

the development of seams of quartz, chalcedony, and opal, containing 

impregnations of cinnabar and a little pyrite. Calcite accompanies 

the quartz, and small vugs in the veinlets are filled with an asphaltlike hydrocarbon. The wall rock along these fissures is intensely altered, chiefly to clay (probably a ferriferous montmorillonite) and 

nontronite but with local silicification. The cinnabar disappears 

gradually away from the central fissures.

The clay zone containing cinnabar impregnation is about 6 feet 

wide where exposed in the open cut, but nothing definite is known 

of its persistence, as it is not established that the vein cut in the 

lower workings is the same.

Westerling. The W. J. Westerling prospect is situated on a small 

north branch that joins Johnson Creek about half a mile below the 

Paulsen & Saylor mine. The prospect is in a wide parklike area in 

the creek bottom, where no bedrock crops out. The deposit was 

located by hand drilling and panning. Cinnabar occurs in a belt reported by Mr. Westerling to be about TO feet wide and to trend N. 

45° E. A few open cuts have been dug along this belt to a depth of 

about 10 feet. In the only accessible one of these cuts there is a

little cinnabar in stringers in the residual soil resulting from the 

decomposition of an augite-hypersthene andesite, presumably of
SOME MINING DISTRICTS OF EASTERN OREGON 121

Clarno age. A little chrysocolla occurs with the cinnabar. Not 

enough work had been done here to gain any adequate idea of the 

possible extent or value of the deposit.

Quicksilver Consolidated Mining Co. The mine of the Quicksilver Consolidated Mining Co. is in sec. 29, T. 14 S., R. 20 E., on the 

north slope of Lookout Mountain about 2 miles from the Johnson 

Creek road and about 30 miles from Prineville by the Ochoco 

Highway. The mine was under the management of C. W. Washburne at the time of visit.

The property, formerly known as the American Almaden, has 

been exploited intermittently for many years, but the total production, according to Mr. Washburn, probably does not exceed 50 

flasks. Three flasks were produced in 1906 and small amounts in 

1908. 1915, 1929, and 1930. There is a rather elaborate retort on the 

property.

The mine is developed by two tunnels. Several other surface 

workings are caved. At the time of visit work was confined to 

the lower level. This level contains about 1,500 feet of drifts, one 

raise to the upper level for ventilation, and several minor raises. 

Some stoping has been done in three places. (See fig. 20.) The 

ground is very heavy, and most of the work is completely lagged. 

Square sets are used in the stopes.

The country rock is Tertiary (?) basalt, cut by some diabase dikes. 

The deposit consists of a network of veins in the shattered basalt. 

The veins can hardly be described as having any definite course; 

they are commonly small, branching, irregular stringers and 

seams. Locally the stringers tend to follow stronger controlling 

fissures and send out branches from these in all directions. One 

vein that had been worked just prior to the visit strikes N. 45° W. 

and stands vertical. This vein or lode is apparently controlled 

by a shear surface and ranges in width from 3 inches to about 1 

foot. Many narrower stringers branch from it into the northeast 

wall, but the southwest wall, in the exposed workings, seems to be 

less mineralized. These stringers range in thickness from a knifeedge to about half an inch, but most are less than one eighth inch 

thick.

The basalt, where cut by these fissures, is intensely altered to 

clay (chiefly ferriferrous montmorillonite), with a little chlorite 

developed along stringers. These chloritic stringers are cut by the 

cinnabar-bearing fissures, which are locally crustified with opal, 

chalcedony, quartz, dolomite, a little calcite, and some asphalt accompanying the cinnabar. Pyrite has impregnated the zone of 

clay alteration and appears to be older than the cinnabar-bearing <

164495 33 9
122 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

stringers. The sequence of mineralization appears to be first clay, 

chlorite, and pyrite followed in order by quartz, cinnabar, quartz 

and dolomite, chalcedony and opal, and lastly, asphalt.

Considerable stoping has been done near the end of the northeast drift, a stope there in gougy basalt being about 40 feet high 

and 15 to 20 feet wide. A little cinnabar remains in the clay of the

Mineralized shear zone

Note: Country rock chiefly altered basalt with some 

diabase dikes.

200 Feet

FIGURE 20. Main level, Quicksilver Consolidated Mining Co.'s mine, Ochoco district, Oreg.

walls. Several other stopes have been worked; one, near the junction of the southwest branch with the main drift, is about 50 feet 

long and follows a vein that strikes N. 60° E. and dips steeply 

south. This stope extends to the upper level. Much of the old 

work in the mine is caved, so that the extent of other stoping was 

not determined.

The tenor of the ore is unknown, but to judge from the material 

exposed in the mine it must be rather low. It would be difficult 

to select any considerable tonnage carrying more than one half of 1
SOME MINING DISTRICTS OP EASTERN OREGON 123

per cent of quicksilver; probably even this limit would be hard to 

maintain.

MARKS CREEK AREA, WHEELER COUNTY

Bear. Carl Fisher and G. L. Brazee have located a group known 

as the Bear claims near the head of Marks Creek, in the southwest 

corner of Wheeler County. The claims are reached by a 2-mile 

forest road, which leaves the Ochoco Highway at the divide between 

Ochoco Creek and Bridge Creek. The distance from Prineville to 

the property is about 30 miles.

The deposits were discovered in the spring of 1930, and but little 

work had been done up' to the time of visit in August. A 35-foot 

inclined shaft and a few open cuts constituted the development work.

At the shaft the country rock is Tertiary (?) olivine andesite, cut 

by a 4-inch quartz vein that strikes N. 55° E. and dips 65° NW. The 

walls of the vein have been impregnated with cinnabar and a little 

pyrite, both along branching veinlets and in the massive rock. The 

impregnation disappears within a short distance from the vein and 

is not marked a foot or so from it. Quartz, chalcedony, opal, dogtooth calcite, dolomite, and clay minerals accompany the cinnabar, 

and vugs in the vein are filled with hydrocarbons. Some of the 

cinnabar seems to be later than the quartz, but most is earlier. 

Emplacement of the wall rock is evident, with " ghosts " of wall rock 

in the quartz. Jarosite and other limonitic products of oxidation 

are present.

About 1,000 feet northeast of the shaft a 2-inch vein of chalcedonic 

quartz carrying a little cinnabar has been exposed in a surface cut 

in olivine basalt. The vein strikes N". 80° W. and dips 70° N. 

About 500 feet farther northeast is another outcrop of quartz much 

stained with limonite but not showing any cinnabar at the surface.

Sufficient work had not yet been done to demonstrate the value of 

the property.

OCHOCO CREEK AREA 

By G. F. LODGHLIN and JAMBS GILLULY

The Ochoco Creek area is conveniently described in two parts the 

Champion mine, which has produced quicksilver, and Gold Hill and 

vicinity, where gold and silver have been produced.

CHAMPION

The Champion mine is half a mile north of the Ochoco Highway 

in the Ochoco Creek Valley, in sec. 7, T. 14 S., K. 19 E. It is about 

20 miles from Prineville. It was located by A. J. Champion and is 

owned by A. J. Champion, A. Barney, and J. E. Staley. Negotiations for its acquisition by a group of Portland capitalists were 

reported as being just completed at the time of the writers' visit to 

the property in August, 1930.
124 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

The mine is developed by an inclined shaft about 125 feet deep 

and a tunnel 400 feet long. Work was going forward to connect the 

tunnel and shaft. There is a short sublevel at a depth of 45 feet, 

from which stoping was going forward, and a number of small open 

cuts between the shaft and the adit of the tunnel were also driven 

on the outcrop of the ore body. The total development work at the 

time of visit would not aggregate more than 700 feet. A crude retort 

handling about a ton a day was in operation at the time of visit.

The country rock is andesite, probably of Tertiary age. It is 

cut by several faults and fissures; the most prominent one, along 

which the ore body occurs, is a shear zone that trends N. 45°-55° E. 

and dips 50°-65° SE. Along this zone the rock has been intensely 

and almost entirely altered to a slickensided clay, chiefly a ferriferous montmorillonite, with some kaolin and nontronite. Impregnating this clayey zone and roughly following the most prominent 

shear are cinnabar, pyrite, calcite, opal, and chalcedonic quartz. 

These minerals occur both as veinlets in the altered rock and as 

discrete particles sporadically developed in it. It can hardly be 

said that any vein system is present; the mineralized body seems to 

be a crushed zone. However, the best ore seems to occur rather 

constantly along the most prominent fault wall. In the stope from 

which the retort ore was being extracted .at the time of visit, 

just west of the shaft on the 45-foot level, a stringer of cinnabarbearing material about 4 inches wide occured along this wall, from 

which the cinnabar seemed to fade out in smaller and smaller veinlets 

into the clay walls. Cinnabar occurred across the entire face of the 

drift, about 5 feet wide, but only the high-grade streak was being 

sent to the retorts.

The lower tunnel, through a combination of circumstances, was 

not accessible at the time of visit to the property. It is reported 

to show a number of cinnabar veins, but work was not being done on 

them pending completion of the connection with the shaft.

No precise information as to the tenor of .the ore was available. 

However, in the crude retorts that were being operated about a 

flask of quicksilver was being recovered every 24 hours, from about 

2,400 pounds of crude ore. As it was easy to pan considerable cinnabar and free quicksilver from the tailings, the recovery is obviously far from satisfactory. The ore as roasted must clearly run 

in excess of 5 per cent. As very little powder is required to break 

the ore, most of which was being dug with a clay digger, the property 

offers considerable promise of cheap production.

GOLD HILL AND VICINITY (HOWAKD DISTBICT)

Location <m$ topography. Gold Hill is crossed by the boundary 

between sees. 29 and 30, T. 13 S., K. 20 E. It is 26 miles east of
SOME MINING DISTRICTS OF EASTERN" OREGON 125

Prineville and 8 miles northeast of Howard, the nearest post office, 

on the main highway across central Oregon. The area, as shown in 

Plate 8, consists of rounded, timber-covered hills drained by Ochoco 

Creek and its local tributaries, which follow prevailingly northwesterly courses. The largest tributary, Scissors Creek, is the chief site 

of local small placer mining. Gold Hill, the principal mineralized 

area, occupies the angle between Ochoco and Scissors Creeks and 

has an altitude of 4,800 feet. The highest altitude in the vicinity, 

6,450 feet, is that of Round Mountain, 2 miles southeast of Gold Hill. 

The only local settlement is Ochoco camp, at the west base of Gold 

Hill. It has been only intermittently occupied for several years.

Production. Records of discovery and production are incomplete. 

The earliest record mentioned in the Mint reports on gold and silver 

production shows an output of $10,000 in gold during 1885, but from 

1886 to 1896 annual records ranged from nothing to estimates of 

$1,600 in gold. The only mention of silver production stated a value 

of $50 in 1889. No record of production from 1897 to 1902 inclusive 

has been found. More accurate records have been kept since 1903 56 

and show an intermittent production amounting to 536.80 fine ounces 

of gold and 79 ounces of silver from placers, and 2,225 tons of crude 

ore from which 2,478.35 fine ounces of gold, 442 fine ounces of silver, 

and 2,662 pounds of lead were recovered. The latest production 

recorded was in 1923. The total value of gold produced, according 

to all available records, is $79,885. Of this $17,560 is based on 

estimates prior to 1902 and $62,325 is based on records since 1902. 

Geology. The following sketch of the local geology and ore 

deposits is written by G. F. Loughlin, who spent six days in the area 

in 1914. The principal mine workings were inaccessible, and no 

mining or prospecting was going on in 1930.

The bedrock consists of volcanic flows and breccias which, according to R. W. Richards,57 of the United States Geological Survey, 

are tentatively correlated with the Clarno formation, of early Tertiary age (upper Eocene and lower Oligocene). These rocks have 

been gently uplifted and are flanked in the surrounding country 

by horizontal flows of later Tertiary basalt. The Clarno (?) formation is locally divisible into two parts, the lower characterized 

mainly by hornblende andesite and the upper by olivine basalt. 

It is possible that the basalt is of post-Clarno' age and may be correlative with the Columbia River lava. The distribution of these 

rocks, so far as determined by a few traverses radiating from Gold 

Hill, is shown in Plate 8. They dip at low angles but are so extensively covered by soil and debris that a detailed study would be necessary to determine their exact sequence and structural relations. The

M Supplied by V. C. Heikes, U. S. Bureau of Mines, San Francisco, Calif. 

17 Personal communication, 1931.
126 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

part of the area that contains the gold deposits is underlain by the 

lower or andesite group. Dense or finely porphyritic andesite underlies the valley of Ochoco Creek and the western slope of the ridge 

containing Gold Hill. This is bordered on the southeast and apparently underlain by a more coarsely porphyritic andesite, which in 

turn is underlain by a poorly exposed andesite breccia in the 'valley 

of Scissors Creek. The porphyritic and overlying dense andesites 

are also present on the spur called Red Bird Hill, south of Scissors 

Creek, where the breccia is locally separated from the porphyritic 

andesite by a dike of dense andesite. The flow of dense andesite 

is apparently overlain by another porphyritic hornblende andesite 

that caps Bear Point. Half a mile to the northeast dense andesite 

is overlain by a porphyritic hypersthene-augite andesite whose relations to the hornblende andesite of Bear Point were not determined.

The hypersthene-augite andesite is overlain by a dense to vesicular olivine basalt that forms the basal part of the upper member. 

This basal part is overlain by a cliff-forming breccia which is in 

turn covered by the thick olivine basalt, similar to the basal part 

that forms the main mass of Round Mountain. The upper member 

is cut by many dikes of basalt characterized by poorly shaped black 

phenocrysts of augite. These dikes are most conspicuous in the 

breccia, where they tend to weather in relief. It is not known 

whether they are directly related to the upper member of the Clarno 

(?) formation or are to be correlated with the later basalts that 

flank the Clarno (?).

The nearest observed" flow of the later basalt in the vicinity of Gold 

Hill caps McAllister Butte, a small hill iy2 miles to the north. 

Remnants of the same flow may cap the ridge west of Ochoco Creek, 

and several dikes of similar basalt are present on the eastern slope 

of this ridge.

The most prominent structural feature, besides the general low 

angle of the dip, is fissuring. Of the fissures noted within the intensely mineralized area more trend 50°~70° W. than in any other 

direction; others trend approximately east, N. 25°-60° E., and south. 

Nearly horizontal fissures are also numerous and of special interest 

in ore hunting, as some of the rich " ore pockets " have formed along 

them. Narrow crushed zones, as much as 2 feet in thickness, are 

conspicuous along fissures in each of these systems, and the impression is gained that although the N. 50°-70° W. system predominates, 

its fissures are intersected or joined by so many fissures of the other 

systems that the ground is broken into a complex of blocks, each of 

which was moved slightly during the local uplift. The fissures 

were mostly formed before ore deposition took place, but one pronounced postmineral fissure was noted near the breast of the Ophir-
SOME MINING DISTRICTS OF EASTERN OREGON 127

Mayflower tunnel, and slight postmineral renewals of movement 

have taken place along many of the premineral fissures.

The northwesterly and roughly parallel courses of the tributaries 

of Ochoco Creek accord with the trend of the prevailing fissure 

system.

Ore deposits. The ore deposits seen by the writer are confined to 

Gold Hill, Eed Bird Hill, and the parts of Ochoco and Scissors 

Creeks that receive the drainage from these hills. Other deposits are 

doubtless present near the area studied for example, a production 

of about 3 ounces of gold was reported in 1893 from .the Last Chance 

mine, which is iy2 miles south of Gold Hill near the southeast 

corner of sec. 31, and an assay value of $45 is said to have been 

obtained from a small prospect in altered andesite on the south 

slope of McAllister Butte, 1% miles north of Gold Hill but so far 

as known almost the entire gold production of the area and of Crook 

County as a whole has come from Gold Hill and the immediate 

vicinity.

The mineralized ground consists of intensely altered andesite cut 

by narrow veinlets, commonly an inch or less thick, which locally 

enlarge into high-grade ore shoots, especially at junctions or intersections. The largest shoot in the Ophir-Mayflower mine was mined 

for a vertical distance of 250 feet, a horizontal distance of 70 feet, and 

a width of 1 to 6 feet.58 The intensely altered rock is bleached. Its 

groundmass is slightly to considerably silicified, and its phenocrysts 

and unsilicified groundmass are replaced by mixtures of carbonates, 

chlorite, and the clay mineral montmorillonite, with which some 

sericite may be associated. Both phenocrysts and groundmass are 

impregnated by scattered minute crystals and short hairlike streaks 

of pyrite, and the rock as a whole is so full of small cracks containing 

films of vein material that it.has been regarded as mill ore. The 

intensely altered rock is confined to Gold Hill and the lower slope 

of Red Bird Hill. It grades outward into unbleached rock that has 

been impregnated to a considerable degree by carbonates and chlorite 

and inconspicuous amounts of the other secondary minerals.

The original minerals of the veinlets are carbonates, quartz, and 

pyrite, with locally conspicuous amounts of arsenopyrite, zinc 

blende, chalcopyrite, tetrahedrite, and galena. Alteration products 

in the rich sulphide ,ore include sooty chalcocite, clusters of fine 

needles of jamesonite (?), a little valentinite (Sb2O3 ), andorite 

(2PbS.Ag2S.3Sb2S3 ), and a dark-red mineral resembling ruby silver, 

besides veinlets and druses of colorless calcite and quartz. Brown 

iron oxide and black manganese oxide are the principal constituents 

of the oxidized ore and are accompanied by varying quantities of

58 Parks, H. M., and Swartley, A. M., Mineral Resources of Oregon, vol. 2, No. 4, pp. 

167-168, Oregon Bur. Mines and Geology, 1916.
128 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

gold, which ranges from submicroscopic grains to flakes an eighth 

of an inch or more in diameter and small nuggets weighing as much 

as an ounce or more.

The formation of the original veins took place in three or four 

stages. Carbonates are the most abundant constituents and were 

deposited in three general stages, one preceding, one accompanying, 

and one following the principal sulphides. Quartz and the sulphides 

were formed mainly in one stage, which in some places may be 

divisible into two substages, but a second growth of pyrite took place 

after the second carbonate stage. The characteristic features of the 

minerals formed in the different stages are described below.

The first or principal carbonate stage is the least understood, as 

three distinct mineral species calcite, dolomite, and a calcic rhodochrosite are present. They all show the same relations to the 

quartz and sulphides of the second stage but have not been found 

in contact with one another. They have been distinguished microscopically and chemically by W. T. Schaller, of the United States 

Geological Survey. The early calcite forms veinlets and irregular 

coarse-grained masses, the veinlets being clearly replaced in part 

by sulphides and fine-grained quartz. The coarse-grained variety, 

according to chemical and optical (0)=1.672) tests, is estimated to 

contain about 6 per cent of manganese carbonate, 5 per cent of magnesium carbonate, and 1 per cent of iron carbonate. Replacement of 

this coarse-grained calcite by brown iron oxide and black manganese 

oxide is a feature of at least some of the rich " pockets " of ore on 

the surface.

The early dolomite is light gray and contains manganese and a 

little iron. As seen under the microscope it forms a network of 

platy crystals, darkly clouded by minute included specks, that are 

embedded in a clearer interstitial carbonate, which, to judge from 

optical and chemical data, is calcic rhodochrosite. The two carbonates were too thoroughly mixed for separate chemical determinations, and the platy crystals were too clouded to permit the determination of their index of refraction; but light-gray, early calcic rhodochrosite without the associated platy crystals was determined in 

other specimens, where its relations to quartz and sulphides were 

identical with those in the dolomitic specimen. Its w index of refraction is 1.783-1.785, and chemical tests show that it contains only 

traces of magnesium and iron.

Schaller 59 has summarized the relation of crystal habit of calcite 

to relative temperature, pointing out that the platy variety of calcite denotes deposition at the highest temperature. It may therefore be tentatively inferred that the platy dolomite crystals, by

69 Schaller, W. T., The crystal cavities of the New Jersey zeolite region: U. S. Geol. 

Survey Bull. 832, p. 47, 1932.
U.S. GEOLOGICAL SURVEY BULLETIN 846 PLATE 8

R.20 E.

EXPLANATION

PorphyxatLc hypersthene

Porphyri-tic hornM ende

Areas without pattern, 

not studied,.

Geologic traverse

Tunnel

X

Prospect

interval 5O -feet. 

GEOLOGIC SKETCH MAP OF GOLD HILL AND VICINITY, OCHOCO CREEK AREA, OREG.

Topographic base, supplied to G. F. Loughlin by United States Forest Service in 1914, was drawn from intersecting compass and aneroid traverses

by foresttcruisers.
SOME MINING DISTRICTS OF EASTERN" OREGON 129

analogy as well as by their relations to the rhodochrosite, sulphides, 

and quartz, were also deposited at relatively high temperature.

The second stage is characterized by a fine-grained quartz, commonly accompanied by carbonate (calcic rhodochrosite?) and pyrite 

and in the rich shoots by arsenopyrite, zinc blende, tetrahedrite, 

chalcopyrite, and galena. The quartz commonly has a minutely 

developed comb structure concealed beneath carbonate. It preceded 

the bulk of the pyrite, which was the earliest of the sulphides to 

form. The carbonate is similar to the calcic rhodochrosite of the 

first stage but was not sufficiently isolated or in large enough amounts 

to permit verification.

The pyrite is mostly very fine grained, but locally, in the highgrade ore, it forms cubic crystals as much as an eighth of an inch 

in diameter. It commonly lies along or near the margins of veinlets, 

where it has replaced carbonate. It has also coated the early carbonate and locally has alternated with second-stage carbonate in deposition. Carbonate-pyrite and quartz-pyrite veinlets may be present 

in the same microscopic section. Minute crystals of pyrite also form 

6-sided platy aggregates one-eighth of an inch or less in diameter. 

These have evidently coated platy crystals of early carbonate, presumably the dolomite described above. Subsequent removal of the 

carbonate has left small flat cavities in some of the aggregates; in 

others similar cavities have been filled by additional pyrite. These 

platy aggregates, as well as the other primary sulphides and gangue 

minerals, are in part coated by small clusters of flat rhombohedrons 

of carbonates belonging to the third stage.

Arsenopyrite in minute, typical light-gray prismatic crystals can be 

recognized in some specimens. It is closely associated with pyrite, 

but its exact relations were not determined. To judge from the 

percentage of speiss recorded in smelter analyses (p. 131), it is more 

abundant than available specimens of the ore would lead one to expect. No other arsenical minerals (except one small crystal of dark 

ruby silver?) have been recognized in the ore. Zinc blende forms 

medium to dark brown grains as much as 3 millimeters in diameter 

and like the pyrite is commonly present in the marginal parts of the 

veinlets. Chalcopyrite forms irregular grains 1 millimeter or more 

in diameter and is closely associated with zinc blende and pyrite. 

Tetrahedrite forms small fine-grained masses associated with the 

other sulphides. Very little galena was noted in the material available for study, although the small amounts of lead reported from a 

few shipments of ore and the galena found in local placers imply that 

galena may have been conspicuous in places. No visible gold has 

been reported from unenriched ore.

The third stage is marked by druses of platy carbonate crystals, 

which line vugs, especially in the high-grade ore. The specimens
130 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

studied show that these drusy carbonates are similar in composition 

though somewhat purer than the early carbonates; for example, the 

platy crystals of rhodochrosite have a higher index of refraction 

(w=1.790) than the early variety and evidently contain less calcium. 

The composition and mode of occurrence of these third-stage carbonates suggest that the material replaced by the sulphides and 

quartz was, in part at least, redeposited without appreciable transfer in solution; but scattered veinlets of pink dolomite, which contain little iron and only a trace of manganese and distinctly cut the 

sulphide veins, indicate that some transfer of material took place.

Deposition by descending surface water below the oxidized zone 

is most conspicuously represented by colorless calcite, fine drusy 

quartz, clay (montmorillonite), and secondary sulphides. The 

crystal form of this colorless calcite is the negative rhombohedron 

e {0112}, commonly called the " minus one-half form," which is characteristic of mineral deposits that have been permeated by surface 

waters. These rhombohedrons are best developed in vuggy veinlets, but the same mineral also forms small, compact, glassy veinlets 

that penetrate the most minute cracks in the original ore and gangue 

and unless recognized may lead to the impression that the primary 

vein material contains much more calcite than it really does.

The colorless, fine, drusy quartz is similar to the colorless calcite 

in general mode of occurrence but is not nearly so common. The 

clay (montmorillonite) also fills cracks and vugs in the ore and in 

part replaces carbonates.

The secondary sulphides include films of chalcocite, which forms 

black, sooty coatings, especially on chalcopyrite and zinc blende, 

also small clusters of hairlike crystals of jamesonite (?), occasional 

gray prismatic crystals of andorite, dark-red crystals of ruby silver (?), and colorless tabular crystals of valentinite, the orthorhombic form of antimony oxide (Sb2 03 ). These minerals all occur 

in small cavities, some of which are due to the removal of carbonates 

of the third stage. The jamesonite (?) was tentatively determined 

by Schaller, who stated that most of the hairlike fibers have a basal 

cleavage and are brittle and not flexible but that a few " hairs " 

lacked basal cleavage, were extremely flexible, and evidently represented some other mineral.60 Measurements of the angles of prism 

faces on one fiber with basal cleavage gave results agreeing with the 

prism angles of jamesonite.

The oxidized ore is characterized by honeycombed vein material 

stained brown and black by iron and manganese oxides and by 

earthy masses of those oxides that have replaced the carbonates 

and sulphides in local enlargements of veins and have formed the

60 Sclialler describes a similar mixture with crystals of jamesonite (Mineralogical notes, 

series 1: U. S. Geol. Survey Bull. 490, p. 27, 1911).
SOME MINING DISTRICTS OF EASTERN" OREGON 131

rich superficial " pockets." Some cavities in the black earthy 

oxides are lined with white, drusy aragonite. Free gold, commonly 

associated with the two oxides, forms specks, flakes, and nuggets 

loosely adhering to vein quartz and easily recovered by crushing 

and panning. The oxidized ore extends only a few feet below the 

surface.

Metal production from the area as a whole can not be definitely 

correlated with different varieties of ore. The average content of 

gold is 1.1 fine ounces and that of silver 4.2 fine ounces to the ton. 

Lead was reported in only three annual shipments and ranged 

from 0.6 to 1.2 per cent. The gold-silver ratios, including " pocket " 

ore and high-grade enriched sulphide ore, range from 1:0.04 to 

1:4 in shipments for which no lead was reported and from 1:4 

to 1:12.5 in those containing lead. One exceptional shipment of 

15 tons showed a ratio of 1:87, but it is possible that this shipment 

came from some other place in Crook County. The gold-silver 

ratio in shipments from placers ranged from 1:0.06 to 1:0.27, and 

averaged 1: 0.16. Its close similarity to the ratio in the " pocket" 

and vein ores accords with the geologic evidence that the placer 

gold is of strictly local origin.

Assays of individual lots of ore from the Ophir-Mayflower lode, 

exclusive of any rich, oxidized " pockets," show a gold content in 

general of as much as 2.28 ounces to the ton and a silver content of 

as much as 35 ounces to the ton, but they show no consistent ratio 

between gold and silver or between silver and lead. Exceptional 

small shipments, which may have come from a surface " pocket," 

contained 21.85 ounces of gold and 12.8 ounces of silver to the ton. 

Representative smelter analyses made in 1913 and 1914 follow:

Smelter analyses of ores from OpMr-Mayflower lode

Silver. ________________ do _ .

Sulphide 

(pyrite 

concentrates)

1

1.73 

17.0 

Not det. 

5.0 

1.7 

37.0 

Not det. 

36.8 

2.5 

Not det. 

1.0

Sulphide (crude)

2

1.44 

31.27 

1.1 

14.8 

1.4 

18.6 

9.5 

15.4 

17.3 

None. 

2.2

3

1.99 

25.85 

1.2 

12.7 

2.1 

17.4 

. 3.6 

13.4 

17.9 

None. 

4.7

Oxidized (crude)

4

6.20 

9.4 

None. 

10.6 

None. 

4.5 

None. 

8.8 

28.2 

Not det. 

9.5

5

4.02 

10.2 

None. 

9.8 

None. 

2.4 

None. 

6.4 

32.7 

None. 

6.2

6

21.50 

12.73 

None. 

41.0 

None. 

1.3 

None. 

22.0 

5.5 

None. 

20.1

These analyses conform very well to the mineral composition 

of the ore as described above. Calculation of'sulphides in the rich
132 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

crude sulphide ore shows the content of galena to be about 1.4 per 

cent, that of zinc blende 2.1 to 3.2 per cent, and pyrite 29 to 33 per 

cent. The percentage of speiss implies somewhat more of the sulpharsenides of silver and copper than was found in material accessible 

to the writer. The manganese is mainly present in the carbonates, 

and the water mainly in clay minerals. The ore represented by 

analyses 4 and 5 is evidently a mixture of manganiferous carbonate 

and oxide with a small amount of pyrite,, and that of analysis 6 is 

a mixture of iron and manganese oxides, clay, and quartz.

The thoroughly altered pyritic rock of Gold Hill has been regarded 

as possible mill ore. Its range in composition in the Ophir-Mayflower tunnel, exclusive of high-grade veinlets, is 0.02 to 0.24 ounce 

of gold and 0.2 to 5.0 ounces of silver to the ton. An average of 34 

assays, including seven of relatively high-grade material and stated 

to represent the run of the Ophir-Mayflower lode, gives 0.411 ounce 

of gold and 6.67 ounces of silver to the ton.

The sequence of processes controlling ore deposition is summarized 

below. The Clarno (?) formation, soon after its deposition, was 

elevated and fractured, and, where fracturing was especially pronounced, it gave access to vein-forming solutions. There is no positive information on the source of these solutions, but in composition 

and character the deposits are similar to many deposits formed at 

shallow depths in Tertiary volcanic rocks. The solutions evidently 

came from a deep-seated source, rose and dispersed along a network 

of intersecting fractures, permeated the local andesite, and altered it 

thoroughly to the bleached pyritic rock. This permeation marked 

the first and most intense stage of mineralization. Subsequent stages 

were marked by the deposition of barren calcite veins and masses 

followed by deposition of primary ore minerals with quartz and 

carbonate. The ore minerals for the most part were confined to 

narrow veinlets, but where shattering was intense, especially at the 

junctions and intersections of fissures, they were deposited in sufficient quantity to form small ore shoots. The wall rock and especially 

the early, barren calcite were replaced to some extent along these 

shoots, but the relative importance of shattering and replacement 

coulfl not be determined from the meager evidence available.

These shoots contained small amounts of silver minerals and doubtless primary gold, but the value of the rich ore was brought about 

to a considerable extent by downward enrichment, which probably 

began soon after the veins were formed. If so, it was probably 

interrupted by the renewed volcanic activity that covered most of 

the regions with the later horizontal basalt flows. The lowest of 

these flows in the vicinity may have covered Gold Hill less than 200
SOME MINING DISTRICTS OP EASTERN OREGON 133

feet above its present summit. Renewed erosion removed this basalt 

and developed the present local drainage system. Downward enrichment was resumed.

The solution and redeposition of gold were evidently favored by 

the abundance of manganiferous carbonate. The manganese oxide derived by the weathering of the carbonate aided in the solution of 

gold at the outcrop, and the unweathered carbonate, together with 

chalcocite and zinc blende, was promptly precipitated on its downward course. When these enriched shoots in turn became exposed 

at the surface and subjected to weathering, the cycle of solution and 

redeposition was repeated; but recent erosion has been so rapid that 

it has almost kept pace with oxidation, and much if not most of the 

gold, before it could be dissolved, has been washed down the slopes 

to form placers.

The placers, according to the evidence at hand, the topographic 

map, and the inferred erosion of Gold Hill since the removal of 

its basalt cap, represent concentration from a thickness of 200 to 

400 feet of mineralized ground. Small stretches along Scissors 

Creek had not been worked up to 1914, and the recorded production 

from placers may represent less than half the total placer gold; 

but even so, the quantity remaining and the conditions affecting 

operation justify work only on a small, intermittent scale. The 

quantity of oxidized and enriched sulphide ore shipped from veins 

and "pockets" may be regarded as a conservative representation 

of the shipping ore that was available above the level of the OphirMayflower tunnel. Other " pockets " on the surface doubtless remain 

to be found and may be profitably worked by individuals. Other 

shoots may exist underground, but those already found are in the 

most intensely altered ground, and only smaller and more intermittent output could be expected from any others. There is no 

reason why primary ore shoots should not exist well below the 

Ophir-Mayflower tunnel, but they are less likely to be enriched than 

those above the tunnel level, and mining any considerable distance 

below the tunnel level will involve pumping.

OpMr-Mayftower. The Ophir-Mayflower mine is on the west 

slope of Gold Hill adjoining Ochoco camp. It is opened by a main 

tunnel which extends from a point near creek level for about 1,475 

feet in a direction averaging S. 57° E. (see fig. 21), by a short tunnel 

about 200 feet up the slope, and by several shallow pits made in the 

search for " pockets " of oxidized ore.

The date of the discovery is not known, but it may have been as 

early as 1885, the date of the earliest recorded production in the 

area. According to data supplied by V. C. Heikes, of the United
134 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

States Bureau of Mines, the mine was worked intermittently between 1903 and 1923. It was productive in each year from 1912 to 

1918, when annual production ranged from 24 to 919 tons of crude

Z-*

ore, most of which averaged more than an ounce of gold and 5 ounces 

of silver to the ton, although single shipments gave much higher 

returns. A 10-ton stamp mill with Wilfley table and amalgamating
SOME MINING DISTRICTS OF EASTERN OREGON 135

.plates was erected in 1906 and operated at intervals. Shipments 

lave included crude ore and concentrates to smelters, crude ore to 

gold and silver mills, and bullion from the mill at the mine.

The country rock is dense to porphyritic andesite, which has been 

thoroughly bleached by alteration and impregnated by fine grains 

of pyrite along the network of veinlets described on pages 126-127.

Locally and at least at some intersections of narrow veins highgrade ore shoots have formed. The first of these is 225 feet from the 

portal and is called the True Augur or Mary Davenport vein. It 

crosses the drift in an easterly direction, dips vertically, and has a 

visible maximum width of 1% feet just above the tunnel. It has 

been stoped only a short distance above the tunnel. The ore remaining on the tunnel level in 1914 consisted of soft pyrite veinlets that 

were said to mill readily to concentrates averaging $42 to the ton. 

The second shoot cut by the lower tunnel is about 500 feet from the 

portal. It has been followed in a winze for 36 feet below tunnel level 

and is said to have been stoped continuously from the surfac'e. This 

is probably the stope mentioned by Parks and Swartley as having 

a vertical length of 250 feet, a horizontal length of 70 feet, and a 

width of 1 to 6 feet. Its trend could not be determined from the 

tunnel level, but according to a blue print of the property furnished 

by Don Maguire, of Ogden, Utah, it trends northeastward at about 

right angles to the course of the tunnel. Its upper part was evidently reached by a northeast drift from the upper tunnel. Ore 

from it is said to have averaged about $70 to the ton, although its 

highest-grade sample assayed $625 to the ton. The richer ore was 

of " black sooty " character, which implies the presence of either 

black manganese oxide or zinc blende and other sulphides coated 

with chalcocite. Both the oxide and the sulphides imply a relatively 

high content of gold.

A third shoot, called the Broken Gimlet shoot, was found in 1902 

and was stoped upward for 25 or 30 feet from a short south drift 

200 feet from the breast of the tunnel. Dirt mucked out of this stope 

in 1912 or 1913 was put through the local mill, and its concentrates 

assayed $38 to the ton. The shoot is underlain on the tunnel level 

by intersecting, partly oxidized veinlets parallel to and crossing 

the tunnel. Their unoxidized material is similar in composition to 

the veinlets throughout the mine, though perhaps with a greater 

than average content of zinc blende.

Surface workings examined above the tunnels include that at the 

outcrop of the second ore shoot cut by the lower tunnel and a 

" pocket" 150 feet southwest of it. The outcrop of the ore shoot 

consisted of " pockets " of black to brown manganese and iron oxides, 

which passed downward into shattered rock cemented by veinlets
136. CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PAKT "1

composed of carbonate, pyrite, and zinc blende. No main fissure was 

noted, About 20 feet below the outcrop an incline sloping about 

60° E. was sunk along ore and is said to have continued nearly to 

the lower tunnel level, above which another shoot of southeasterly 

pitch is said to have been found.

The " pocket " to the southwest, called " Ellif's diggings," was 

located in 1913 by a Mr. Ellif, by panning the surface debris. He 

first found a black veinlet or " seam " that dipped about 15° into 

the hill and opened into a pocket 10 feet long, 6 to 7 feet wide, and 

8 inches to a foot thick, from which he took about $5,000. Material 

along this seam consists of bleached and dark stained porous rock 

with small vugs partly filled with the iron-magnesium carbonate, 

mesitite. The " seam," opened by a 30-foot incline, continued into 

the hill but changed to a veinlet of calcite-pyrite-zinc blende ore that 

assayed about $75 to the ton in gold. This veinlet pinched, but the 

tight fracture continued to a vertical crushed zone trending N. 55° W. 

and as much as 1 foot thick. Both the crushed zone and the tight 

fracture were accompanied by pyritic " mill rock." Some of this 

rock was milled in 1914, but its gold content was not learned.

Other workings on Gold Hill. The Brian O'Lynn tunnel enters 

the southeast base of Gold Hill opposite the junction of Scissors 

Creek with its north fork. It trends N. 70° W. and follows poorly 

to well defined fissure walls for about 360 feet. The tunnel walls are 

bleached all the way and here and there show small patches and seams 

of pyrite, but the effects of mineralization are not nearly so marked 

on the whole as in the Ophir-Mayflower tunnel. About 150 feet from 

the portal a crosscut 6 feet long exposes two parallel thin, rusty 

seams. The last 50 feet of the tunnel follows a seam that looks 

rather promising at the breast.

The Scissors Bill tunnel trends N: 7° E. for 30 feet into the south 

base of Gold Hill. It is all in surface debris except at the breast, 

where soft gray pyritic andesite is exposed.

The Street tunnel, the largest development along the south base 

of Gold Hill, extends N. 6° W. for about 360 feet. This tunnel also 

is in pyritic rock about all the way, although considerable unbleached rock is cut near the portal. A zone of iron-stained fractures 

is cut about 110 feet from the portal, and 50 to 55 feet farther in 

is a spherical " pocket" of fractures and impregnated rock. The 

breast of the tunnel is in bleached pyritic rock containing siliceous 

nodules with conspicuous streaks of fine-grained pyrite. The nodules are spherical to elongate and reach 1 foot in maximum diameter.

A " pocket" on the surface 150 feet above the Street tunnel consists of dark-brown earthy manganese-iron oxide that has replaced 

coarse-grained calcite and pyritic vein material. Small vugs in the 

earthy oxide are lined with fine, drusy aragonite.
SOME MINING DISTRICTS OF EASTERN OREGON 137

About 40 feet west of this " pocket" a prospect discloses a group 

of horizontal veinlets with associated nodules of flinty quartz impregnated by pyrite. The veinlets are partly oxidized to soft, sooty 

manganese-iron oxide typical of high-grade ore and may lead to 

a high-grade pocket.

The Little Giant prospect, about 500 feet east of the Street tunnel 

and 100 feet above it, is opened by a tunnel that trends N. 70° W. 

for 15 feet. It exposes a fissure bordered by red and black ironmanganese earth in leached pyritic rock.

The westernmost prospect noted was near the mouth of Scissors 

Creek, where a short tunnel with a 12-foot winze, full of water, 

is said to have opened a little high-grade ore.

Red Bird Hill. Several openings have been made on Ked Bird 

Hill, which lies between Scissors Creek and Wadkins Gulch. 

Pronounced mineralization there has taken place along a zone 50 

feet wide, which trends N. 70° E. and has a dike of brecciated dense 

andesite dipping 65°-75° S. for a hanging wall. The footwall is 

concealed by soil and vegetation. The unoxidized rock within the 

zone is bleached, impregnated with fine-grained pyrite, and cut 

by seams of coarser-grained pyrite and chalcopyrite. The dike and 

the porphyritic andesite on its south side are only mildly altered. 

They retain their dark-gray color but are impregnated by microscopic quartz and especially by calcite, chlorite, and sericite or montmorillonite, accompanied by minute grains of pyrite.

The individual veinlets and " pockets " do not conform to any 

definite system. The promising veinlets are oxidized. They contain 

small quartz crystals, some with distinct comb structure, that are 

coated with black manganese oxide and have minute specks of gold 

adhering to them. These veinlets locally open into pockets from 

a few inches to 3 feet in width in which the gold occurs as flakes 

and nuggets.

The workings on Red Bird Hill include two short tunnels, a shaft 

said to be 65 feet deep, and several small surface diggings. None 

of the underground workings were examined.

Placers. The principal placer operations, all small, have been conducted along the lower part of Scissors Creek, which crosses the 

mineralized area. The diggings extend a short distance above Wadkins Gulch. Minor operations have been undertaken along Stevenson 

Gulch, which bounds Gold Hill on the north, and in shallow washes 

on the west slope of Gold Hill. Scissors Creek supplies sufficient 

water for placer mining during March, April, and May, and additional supplies have been obtained by ditches. The two lower ditches 

along the west slope of Gold Hill (pi. 8) lead from Ochoco Creek, 

and the highest ditch'leads from an old reservoir in section 21, more

164495 33 10
138 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

than 2 miles away. Another ditch leads from Judy Creek in section 

31 to the head of Wadkins Gulch.

The gold is distributed to a minor extent throughout the coarse, 

angular creek gravel, but is mainly concentrated in crevices in the 

uppermost foot or two of the underlying bedrock. The distribution 

of pay streaks is spotty. One noteworthy streak, on the Robertson 

placer claim, coincides with a low shelf on the bedrock surface. Gold 

produced from this claim in 1911-1913 amounted to 66 ounces.

The gold is largely in flakes, but nuggets worth as much as $29 

have been reported. It is not much waterworn, contains considerable 

silver, as shown on page 125, and is accompanied by small lumps of 

fresh pyrite and carbonate-coated galena. These features also point 

to the strictly local derivation of the placer gold.

MAURY MOUNTAIN AREA

StdLey <& Towner. The quicksilver prospects of J. E. Staley and 

Frank Towner are on Maury Mountain, southeast of Post, on the 

Crooked Eiver, in sec. 10, T. 17 S., R. 19 E. The claims are about 

30 miles from Prineville by way of the Crooked River Highway. 

Five claims form the group, all located in the summer of 1930.

Two shallow cuts, about 200 feet apart, have been made on the nose 

of a ridge. They expose small stringers and impregnations of 

cinnabar in a volcanic rock, apparently an andesitic or basaltic 

flow breccia, of Tertiary age. Chalcedony, quartz, and calcite accompany the cinnabar. Not enough work had been done at the time of 

visit to outline the possibilities of the deposit.

BEAR CREEK AREA

Wiltsie & Platner. Quicksilver prospects held by Lloyd Wiltsie 

and his brothers, Frank Platner, and their associates are distributed 

along a considerable belt in sees. 18 and 19, T. 18 S., R. IT E., on the 

hills west of Bear Creek, about 7 miles south of its junction with the 

Crooked River. The claims are about 20 miles from Prineville 

over the Crooked River Highway. Altogether about a dozen claims 

have been staked in this locality.

. The country rock is Tertiary andesite and porphyritic andesite 

with a little tuff. The attitude of the series was not accurately determined, but it is probably nearly flat. .A quartz lode, consisting of numerous reticulating veinlets of quartz, cuts these volcanic rocks. This 

lode stands in relief above the country rock and forms the backbone 

of a long hill. For about a quarter of a mile near the north end the 

ridge is interrupted, presumably because the lode is weakly developed there,
SOME MINING DISTRICTS OP EASTERN OREGON 139

The lode strikes N. 30° W. at its north end but swings to N. 

10° W. at the south. Individual veins strike and dip in nearly 

every direction, but most of them strike in the northwest quadrant 

and dip steeply. At least two definite spurs branch from the main 

lode but do not seem to be very persistent.

The lode ranges in width from a foot or so up to about 10 feet, 

but its silicified border zone, composed of less numerous quartz 

veinlets, is as much as 50 feet in width and only locally is less than 

5 feet wide.

Accompanying the quartz are much chalcedony and opal and considerable kaolin and montmorillonite. The development of the clay 

minerals results in a bleached zone in the country rock. Pyrite and 

cinnabar impregnate the silicified zone and a little asphalt occurs 

in vugs in the veinlets. The cinnabar is richest in the quartz 

veinlets but also occurs disseminated in the walls.

The Wiltsie brothers had two open cuts on the lode and a short 

tunnel started to cut the lode at depth. Mr. and Mrs. Frank Platner had explored their claims by several open cuts and a short 

tunnel, which had not been driven through the lode in August, 

1930. Enough work had been done along the lode, however, to 

demonstrate the widespread occurrence of cinnabar but not enough 

to justify an estimate of the commercial possibilities of the deposit.

Dunham. C. C. Dunham had done some prospecting on a small 

tributary of Bear Creek, in sec. 31, T. 17 S., R. 17 E., and had 

located three claims.

The country rock is porphyritic andesite of Tertiary age cut by 

quartz veins similar to those on the Wiltsie and Platner claims. The 

cinnabar occurs in seams and veinlets along the quartz veins. The 

lode, which strikes N. 40° W. and dips steeply west, may be a continuation of the. Wiltsie lode 2 miles south, but this is not established. In a small cut a vein striking N. 20° W. and dipping 

85° W. is exposed. The cinnabar is accompanied by pyrite, much 

calcite, dolomite, beidellite, kaolin, and chalcedony. Some nontronite also occurs, and a little asphalt fills vugs in the quartz veins.

The prospecting done up to the time of visit had been confined 

to surface trenches and did not suffice to give any adequate idea of 

the commercial possibilities of the deposit.

OUTLOOK FOR THE DISTRICT

The quicksilver deposits in the vicinity of Prineville offer considerable promise of production on a small scale. Future developments may well reveal larger bodies of ore, which can be worked 

on a more elaborate scale, but at the time the several properties
140 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1933, PART 1

were examined none had yet shown large reserves. Nevertheless, 

several were very promising, and careful work, with a minimum of 

overhead in the operating costs and with efficient condensing apparatus, should make them profitable in a moderate way. Although 

the properties are not very favorably located for railway transportation, this disadvantage is not so serious to quicksilver mines as 

to others, because of the ready reduction of the ores and the compactness of the product that must be transported. Several of the 

properties are favorably situated for cheap fuel, because of the 

proximity of sawmills with much rejected wood that can be had 

at low cost.

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