( A, Economic Geology, 16 Professional Paper No. 1 Series 1B, Descriptive Geology, 80 DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY PROPERTY C CHARLEG D. WALCOTT, DIRECTOR LIBRARY STATE OF ALP MVlSlON 0 GEOLOGICAL 91 PRELIMINARY REPORT ON THE KETCHIKBW MINING DISTRICT, ALASKA WITH AN IMTRODUCTORY SKETCH OF THE GEOLOGY OF SOUTHEASTERN ALASKA IIT IFIIICD IITJLSE RROO P. WASHINGTON GOVERNMENT PRINTING OB$ICEK: CONTENTS. A' Page. .Introduction.............................................................................. 11 Sketch of the geology of southeastern Alaska ............................................... 14 Geography ........................................................................... 14 Bed-rock geology ..................................................................... 16 Introduction ...................................................................... 16 General description ............................................................... 18 Paleozoic sediments ............................................................... 19 Argillites ......................................................................... 24 Mesozoic sediments ............................................................... 25 Tertiary sediments ............................................................... 26 Igneousrocks ................................................................ Correlation ............................ i .................................. 27 Dynamichistory .......................................................... .. 29 Summary .................................................................. 30 Glacial phenomena ............................................................ 31 Introduction .................................................................. 31 Existing glaciers .................................................................. 32 Former glaciation ................................................................. 33 The Ketchikan mining district ............................................................. 35 Generalde$cnption. ................................................................... 35 History .............................................................................. 37 Geology .............. L. ............................................................... 40 Introduction ...................................................................... 40 Bed-rock geology ................................................................. 41 Sedimentaries ................................................................. 41 Wales series .............................................................. 41 Vallenar series ........................................................... 42 Ketchikan series ......................................................... 44 Gravina series ............................................................ 45 Tertiary beds ............................................................. 45 Igneous rocks ................................................................. 46 Granite ................................................................... 46 Pegmatitic and aplitic rocks ..?. ............................................ 47 Syenitic rocks ............................................................ 47 Dioriticrocks ............................................................. 47 Diabase .................................................................. 47 Gabbroic rocks ............................................................ 48 Amphibolite .............................................................. 48 3 4 CONTENTS . Tl~eKetchikan mining district.Conti11ued . Page . Geology--Continued . Bed-rock geology.Continued . Igneous rocks--Continued . Greenstone-schists ........................................................ Kasaangreenstone ........................................................ Rhyolites ................................................................. Trachytes ................................................................ Rasalts .................................................................. Snlnrnary of geologic history ....................................................... Kcono~t~icgeology.. ................................................................... (ieneral relations .................................................................. Descriptions of local~ties........................................................... Cleoeland Peninsula ........................................................... General descriptiou ....................................................... United States claims ...................................................... Mary T . claim ............................................................ Last Chance claim ........................................................ Glory claini .............................................................. Keystone claim ........................................................... Little Maumee claini ...................................................... Kingston claims .......................................................... Rainy Day claim .......................................................... Gold Mountain claims ..................................................... Alaskan Gold Standard Mining Company ................................... .............................................................. Tongass Narrows . (;enera1 descr~ptloil........................................................ Typhoon claim. ........................................................... Tongass claim ............................................................. Wildcat claim ............................................................ Birdseye claim ............................................................ Bell claim ................................................................ Heckman's claim ......................................................... Easter claim ............................................................... George Inlet .................................................................. General description .................. I. .................................... Telegraph group of claims ................................................. Ashe's claim .............................................................. Thorne Arm .................................................................. General description ....................................................... SeaLevel mine ........................................................... Sea Breeze claim ..................:. ...................................... Golden Dream claim ....................................................... Mother Lode claim ........................................................ Golden Tree claim ........................... .. ............................ Tide Water claim ......................................................... Monster claim ............................................................. Keystone claim ........................................................... CONTENTS . 5 The Ketchikan mining district-Continued . Page . Econon~icgeology-Continued . Descriptions of localities-Continued . Seal Bay and Dall Head ....................................................... General description ....................................................... Seal Bay ................................................................. Bay View clainl ......................................................... War Eagle claim .......................................................... Grotto claim ........................................ .............. Junlbo claim .............................................................. Rossland and Deer Park &linirlg Co~rrpany.................................. Washington claim ......................................................... Apexgroup ............................................................... Grenadier clainl ............................................................ Erhart's claim .................................. -. .................... Starlight claim .................. I ......................................... Vallenar Bay ............................................................. C+enertlldescriptioll ....................................................... Niblack Anchorage ............................................................ General desqription ....................................................... Lookout group .................................................. --- .. -- .- Trioclaims. ............................................................... Copper Chief claims ..................................................... Edith M . claims .......................................................... North Arm of-Moira Sourltl .................................................... General descript.ion ....................................................... t Blgebird ant1 Little Annie c:laiu~s.......................................... Hope claim ............................................................... Excelsior clainl ........................................................... Vesta claim ............................................................... Frisco claim ........................................................... Dololrli ....................................................................... (+enera1description ....................................................... Salmon