DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN 364 GEOLOGY AND MINERAL RESOURCES OF THE LAKAMIE BASIN, WYOMING A PRELIMINARY REPORT BY N. H. DARTON AND C. E. SIEBENTHAL WASHINGTON GOVERNMENT PRINTING OFFICE 1909 CONTENTS. Page. Introduction............................................................. 7 Geography ............................................................... 8 Configuration........................................................ 8 Drainage ............................................................ 9 Climate ............................................................. 9 Temperature...................................................... 9 Precipitation..................................................... 10 Geology ................................................................. 11 Stratigraphy.......................................................... 11 General relations........................../....................... .11 Carboniferous system............................................. 13 Casper formation......................... .................... 13. General character........................................ 13 Thickness ............................................... 13 Local features............................................ 14 Erosion and weathering of limestone slopes ................ 18 Paleontology and age..................................... 19 Correlation .............................................. 20 Forelle limestone............................................. 20 Satanka shale................................................ 22 Triassic (?) system ............................................... 22 Chugwater formation......................................... 22 Character and distribution ................................ 22 Local features............................................ 23 Gypsiferous member ..................................... 25 Upper limestone ............i........... ................ 25 Age..................................................... 25 Jurassic system................................................... 26 Sundance formation .......................................... 26 Occurrence and relations.. -.._..................-......... 26 Fossils................................................... 27 Cretaceous system................................................ 27 Morrison formation........................................... 27 Distribution and general relations ........................'.. 27 Character................................................ 28 Fossils and age........................................... 29 Cloverly formation........................................... 30 Benton formation ............................................ 32 Distribution and general relations ......................... 32 Character................................................ 33 Fossils................................................... 34 Niobrara formation........................................... 34 Montana group............................................... 35 Distribution and general relations ......................... 35 Character................................................ 36 Fossils and age........................................... 37 3 4 CONTENTS. Geology Continued. Stratigraphy Continued. Page. Tertiary system.................................................. 43 Cooper Lake basin............................................ 43 Sheep Mountain Red Mountain region........................ 44 Little Medicine Bow Valley...................... ^............. 44 Quaternary system ............................................... 45 Glacial drift.................................................. 45 High terraces ................................................ 45 Alluvium.................................................... 46 Structure ............................................................ 46 Laramie mountain slopes.......................................... 46 Boulder Ridge anticline........................................... 47 Red Mountain Jelm Mountain area............................... 48 Centennial Valley................................................ 49 Sheep Mountain to Arlington.'..................................... 50 Rock River anticline........................................ ...... 51 Rock Creek anticline, .i........................... ................ 51 Coino anticline................................................... 52 Flattop anticline ................................................. 52 Freezeout uplift.................................................. 53 Mineral resources......................................................... 53 Coal................................................................. 53 Gypsum........................................ 1.................... 56 Rock gypsum ................................... 1................ 56 Gypsite ......................................................... 58 Bentonite... ... ...................................................... 58 Occurrence and character......................................... 58 Composition..................................................... 59 Use ............................................................. 60 Descriptions of localities.......................................... 60 Rock Creek region ........................................... 60 Chalk Bluffs................................................. 61 Hutton Lakes................................................ 61 Sand Creek.................................................. 61 Riverside.................................................... 61 Production and prices ............................................ 61 Sulphate of soda ...................................................... 61 Sulphate of magnesia................................................. 64 Volcanic ash......................................................... 65 Cement.............................................................. 65 Sand ................................................................ 65 Clay ................................................................ 66 Limestone........................................................... 66 Copper.............................................................. 66 Underground waters......................... ............................ 67 General conditions ................................................... 67 Description of wells .................................................. 68 Laramie......................................................... 68 Union Pacific Railroad............................................ 72 Pelton ranch..................................................... 73 Trabing ranch.................................................... 73 Downie ranch.................................................... 73 Alsop ranch....................................................... 73 CONTENTS. 5 Underground waters Continued. Description of wells Continued. Page. "Oilwell" ...................................................... 73 Mansfield ranch ......................^........................... 74 Homer ranch .......................... i.......................... 74 Button Creek .................................................... 74 Cooper Creek .................................................... 74 Arlington........................................................ 75 Springs............................................................... 75 Water analyses....................................................... 76 Index. .................................................................... 79 ILLUSTRATIONS. Page. PLATE I. Geological map of the Laramie Basin and adjacent portions of Albany County, Wyoming.................................... 7 II. A, Laramie Peak from the south; B, Cross-bedded sandstone of Casper formation on Sand Creek, Wyoming.................... 8 III. View across Laramie Plains looking southwest; Little Laramie River in the foreground....................................... 10 IV. Rock Creek valley near Rock River station...................... 12 V. A, Cross-bedded sandstone of Casper formation at Red Buttes, Wyoming; B, Pulpit Rock, south of Laramie, Wyoming........ 14 VI. Ay Sandstone in Montana group at Pine Ridge near Rock River station, Wyoming; J?, Sandstone in upper portion of Benton formation northwest of Medicine Bow, Wyoming............... 34 VII. A, Valley filled with Tertiary deposits at head of North Laramie River, summit of Laramie Mountains, Wyoming; li, Springs at fish hatchery south of Laramie, Wyoming...................... 44 VIII. Cross sections showing structure of the Laramie Basin, Wyoming.. 46 FIG. 1. Map of Wyoming, showing area treated in this report............... 7 U.S.GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN NO. 364 PL.I. GEOLOGIC MAP OF LARAMIE BASIX, WYOMING BY" X.H.DAHTOK AND C.E. SIEBENTHAL 5 o___________5 10 miles interval 25O feet. LEGEND TRIASSIC? PENNSYLVANIAN PRE- ' CRETACEOUS CRETACEOUS? JURASSIC PERMIAN MISSISSIPPIAN CAMBRIAN Gravels, sands.nnd. Aloutfma Montana. Uiobrara Benttm Gkn-eri^ Mairisoii Simdaaoe Chugwiiter Jasper Granite, dav;of several jJroup droup formation formation formation foiDialicm fopmatioTi tbrmation formation ^neiss.etc. formations f upper part) (lower part,) Satanka and. Mammad. -_-Fault. roreHemcltKkd : . 1908 GEOLOGY AND MINERAL RESOURCES OF LARAMIE BASIN, WYOMING: A PRELIMINARY REPORT. By N. H. DARTON and C. E. SIEBENTHAL. INTRODUCTION. The region