DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEORGE OTIS SMITH, DIRECTOR BULLETIN 419 ANALYSES OF ROCKS AND MINERALS FEOM THE LABORATORY OF THE UNITED STATES GEOLOGICAL SURVEY \ 1880 TO 1908 TABULATED BY F. W. CLARKE, CHIEF CHEMIST WASHINGTON GOVERNMENT PRINTING OFFICE 1910 CONTENTS. Page. Introduction.............................................................. 1 The average composition of rocks. ..'.....< .................................. 4 Analyses of igneous and crystalline rocks................................... 13 Maine. .................................................................... 13 1. Rocks from Aroostook County..... ^..................'........... 13 2. Miscellaneous rocks............................................. 14 New Hampshire....................................................... 15 Vermont............................................................... 15 1. Rocks of Mount Ascutney........................................ 15 2. Miscellaneous rocks.................:........................... 17 Massachusetts....:..............................................:..... .18 1. Magnesian rocks.............. ; .................................. 18 2. Amphibolite................................................... 19 3. Miscellaneous rocks............................................. 21 Connecticut............................................................ 24 New York............................................................. 26 1. Rocks of the Adirondack region................................... 26 2. Miscellaneous rocks............................................. 27 New Jersey........................................................... 28 Pennsylvania...... .^................................................. -29 Maryland and the District of Columbia.................................. 30 1. Peridotite and pyroxenite.. ......... ................'............ 30 2. Gabbro and diorite...........................'................... 31 3. Granite and gneiss.............................................. 33 4. Miscellaneous rocks............................................. 34 Virginia............................................................... 35 North Carolina.................................................:"....... 36 Georgia................................................................ 38 Kentucky............................................................ 38 1. Elliott County dike............................................... 38 2. Crittenden County dike.......:................................. 39 Tennessee.............................................................. 40 Missouri.............................................................. 40 Arkansas.............................................................. 41 Oklahoma................. ~........................................... 41 Texas................................................................ 41 Lake Superior region................................................... 45 1. Marquette region, Michigan..................................... 45 2. Crystal Falls district, Michigan.................................. 46 . 3. Keweenaw Point, Michigan..................................... 48 4. Menominee River............................................... 48 Sturgeon Falls gabbro............................................ 48 Lower Quinnesec Falls. ........................................ 49 Upper Quinnesec Falls........................................ 49 Schist from the Aragon iron mine............................... 50 ill IV CONTENTS. Analyses of igneous and crystalline rocks Continued. Lake Superior region Continued. Page. 5. Penokee-Gogebic region........................................ 50 6. Pigeon Point, Minnesota....................................... 51 7. Mesabi district, Minnesota...................................... 54 8. Miscellaneous rocks from Minnesota............................ 55 South Dakota........................................................ 57 Wyoming........................................................... 57 Yellowstone National Park and the Absaroka Range..................... 60 1. Electric Peak.................................................. 60 2. Sepulchre Mountain........................................... 62 3. Absaroka Range....................'..................,......... 63 CrandallBasin. .............................................. 63 Sunlight intrusives........................................... 65 Ishawooa intrusives.................................... T....... 65 Dikes in breccia.............................................. 66 4. Absarokite-shoshonite-banakite series............................ 67 5. Miscellaneous rocks....................:........................ 70 Montana. ............................................................ 74 1. Madison and Gallatin valleys.................................... 74 2. Butte district.................................................. 77 3. Boulder batholith.............................................. 79 4. Crazy Mountains............................................... 80 5. Little Belt Mountains .-. .^..................................... 83 6. Castle Mountain district......................................... 86 7. Highwood Mountains.... ....I.................................. 87 8. Little Rocky Mountains........................................ 90 9. Bearpaw Mountains............................................ 90 10. Elkhorn mining district........................................ 92 11. Bitterroot Range............................................... 93 12. Marysville district............................................... 93 13. Livingston quadrangle......................................... 94 14. Philipsburg quadrangle......................................... 95 Idaho.................................................................... 95 Colorado............................................................. 98 1. Denver Basin.................................................... 98 2. Pikes Peak district ............................................. 99 Granite...................................................... 99 Rocks of Cripple Creek district..............'................... 100 Miscellaneous rocks........................................... 103 3. Silver Cliff and Rosita......................................... 104 4. Buffalo Peaks. ................................................ 108 5. Leadville region................................................ 108 6. Tenmile district................................................. 109 7. Elk Mountains................................................. Ill 8. West Elk Mountains.............................................. Ill 9. La Plata Mountains. ........................................... 112 10. Silverton quadrangle.................... v ...................... 113 11. Ouray quadrangle.............................................. 114 12. Telluride quadrangle............................................ 115 13. Miscellaneous rocks............................................. 115 Utah................................................................. 118 1. Tintic district... .............................................. 118 2. Henry Mountains,...... T ..:....,,,...,,.,,.........,,,,..,.... 119 CONTENTS. V Analyses of igneous and crystalline rocks Continued. Utah Continued. Page. 3. Bingham district.............................................. 120 4. La Sal Mountains .....................i....................... 120 5. Park City district.............................. .^.............. 121 6. Miscellaneous rocks............................................ 122 New Mexico........................................................... 122 1. Basalts from the Rio Grande Canyon............................ 123 2. Mount Taylor region........................................ 123 3. Colfax County................ I............................... 123 4. Miscellaneous rocks;........................................... 124 Arizona.............................................................. 125 1. Globe district. ................................................ 125 2. Bradshaw Mountains quadrangle................................ 126 3. Morenci district...........................:................... 127 4. Miscellaneous rocks............................................ 127 Nevada........ ....................................................... 129 1. Tonopah district............................................... 129 2. Goldfield district............................................... 130 3. Bullfrog district................................................ -132 4. Miscellaneous rocks........................................... 132 California............................................................ 135 1. Mount Shasta.................................................. 135 2. Lassen Peak region............................................. 138 Rhyolites................................................. 138 Dacites and andesites..................................... 139 Basalts................................................... 142 3. Plumas County............................................... 144 4. Butte County................................................. 146 5. Sierra County.................................................. 147 6. Nevada City and Grass Valley.................................. 149 7. Placer County................................................. 150 8. Eldorado County..............................................