Series / A' Economic Geology, 65 Bulletin No. 277 series Descriptive Geology) go DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY CHAELES D. WALCOTT, DIRECTOR OF KENAI PENINSULA, ALASKA GOLD FIELDS OF THE TURNAGAIN ARM REGION FRED H. MOFFIT. RALPH W. STONE WASHINGTON GOVERNMENT PRINTING OFFICE 1906 CONTENTS. Goui FIELDS OF THE TUKNAGAIN AKM REGION, BY F. H. MOFFIT.... ........ 7 Introduction ..-_........---.-....................................... 1.. 7 ', Location and area ................................................. 7 History............................................... ........... 7 Early explorers .............'................................. 7 Mining....................................:............... 8 Early mining ..........................................'.. 8 Placer development ...................................... 8 Exploration and scientific-investigation ........................ "J.O . Early exploration ........................................ 10 Investigation in 1904 ...................................... 10 Topography.. _........._....................................,.....;.. 12 Shore line ...:..........-......................................... 12 Relief ............................................................ 13 Drainage........................................................ ' 14 General geology...................................................... 16 Sedimentary rocks................................................. 16 Distribution........-.........................;............... 16 Sunrise "series" ............................................. 17 Occurrence ..................................'...,......... 17 Character................................................ 17 Age..................................................... 18 Cherts.................................:..............-...... 19 Occurrence .............................................. 19 . Character................................................ 19 Age ..................................................... 19 Lower Jurassic beds .......................................... 20 Occurrence .......... v................................... 20 Character................................................ 20 Age...................................................... 21 Kenai formation ............................................. 22 Igneous rocks.................................................... 23 Classification.................................................. 23 Diabase.............................. .....................;.. 23 Gabbro...........-................................:......... 24 Dikes................... .-...... ...................'.....;..... 24 Dacite-porphyry ....................................... .. 24 Diabase .................................................. 24 Rhyolite................................................. 24 Granite......................................... ............ 24 Surficial deposits................................................. 25 Classification ................................................ 25 Water-laid deposits........................................... 25 High gravels............................................. 25 Stream deposits .......................................... 27 Glacier deposits ........................'....................., 27 3 4 CONTENTS. GOLD FIELDS OF THE TURN AGAIN ARM REGION Continued. Page. Geologic history .................. s................................... 28 Development of topography....................................... 28 General statement............................................ 28 Formation of peneplain....................................... 28 Uplift and erosion............................................. 28 Beginning of glaciation ....................................... 28 Deformation .......:......................................... 28 Relations of Kenai and Chugach plateaus ........................... 30 Glaciation ........................................................ 31 Summary.......................................................... 33 Economic geology.................................................... 33 Gold ............................................................ 33 Placer deposits............................................... 33 General statement........................................ 33 Resurrection Creek Valley ................................ 34 Resurrection Creek................................... 34 Palmer Creek........................................ 35 Bear Creek .......................................... 36 Sixmile Creek Valley....................................... 36 Sixmile Creek........................................ 37 Canyon Creek........................................_ 37 Mills Creek.......................................... 38 East Fork............................................ 39 Gulch Creek ......................................... 39 Lynx Creek.......................................... 40 Silvertip Creek....................................... 40 Granite Creek........................................ 40 Glacier Creek Valley ..................................... 40 Crow Creek.......................................... 41 California Creek...................................... 43 Winner Creek........................................ 43 ' Miscellaneous localities ................................... 43 Small tributaries'of Tumagain Arm.................... 43 Kenai Eiver Valley................................... 43 Tustumena Lake ..................................... 44 Anchor Point........................................ 44 Source of the placer deposits ......................-..-.-'.. 44 Auriferous lodes.............................................. 46 Bear Creek veins......................................... 46 Sawmill Creek veins...................................... 47 Miscellaneous veins ....................................... 47 Copper ........................................................... 48 Economic conditions................................................... 48 Routes and trails................................................. 48 Climate.......................................................... 49 Timber and vegetation............................................ 50 Natives.......................................................... 51 Game and fish.................................................... 51 Conclusions...................................... 1 ............... 52 COAL FIELDS OF THE KACHEMAK BAY REGION, BY RALPH W. STONE. .......... 53 Introduction................................... ...................... 53 Location......................................................... 53 Investigation..................................................... 53 CONTENTS. 5 COAL FIELDS OF THE KACHEMAK BAY REGION Continued. Page. Introduction Continued. Mining developments............................................. 54 History..........................'............................ 54 Production .................................................. 56 Topography ......................................................... 56 Geology ............................................................. 57 General statement................................................ 57 Kenai formation ................................................. 57 Distribution ................................................. 57 . Character.................................................... 57 Thickness ................................................... 58 Age ......................................................... 58 Stratigraphic relations ........................................ 59 Deformation................................................. 59 The coal.......................... .................................... 59 Occurrence and development..............'.......................... 59 North side of Kachemak Bay. .................................. 59 Anchor Point............................................ 59 Bluff Point.......-.................................:..... 60 Mine camp .......^.........^............................ 61 Fritz Creek .............................................. 62 McNeil Creek............................................. 63 Cottonwood Creek........................................ 64 Eastland Creek........................................... 65 . Falls Creek .............................................. 65 Port Graham................................................. 66 South side of Kachemak Bay.................................. 68 Character........ ; ...........1.-.........-_...................... 68 Analyses-...............I.................................... 68 Tests and conclusions......................... 1.. ............ 70 Future prospects .............................................. 73 Summary............................................................ 73 Index ____..._.----......-.. .-...............................'.-...._. 75 ILLUSTRATIONS. Page. PLATE T. Outline map of Alaska, showing areas covered by larger-scale maps (Pis. Hand XIII)............................................. 7 II. Topographic reconnaissance map of a portion of the northern part of Kenai Peninsula r ....................................... In pocket. III. Head of Turnagain Arm at low tide.............................. 12 IV. A, Jurassic cherty limestone, etc., at Port Graham; B, Contorted cherts at Seldovia Bay......................................... V. A and J3, Panoramic view from head of Resurrection Creek........ VI.