 | | Report (issue) | | Sequence Along Coal Creek to Idaho Springs Formation Front Range, Colorado By JOHN D. WELLS, DOUGLAS M...1. Index maps of the Coal Creek area, Eldorado Springs, Ralston Buttes, and Blackhawk quadrangles..-_________...SEQUENCE ALONG COAL CREEK TO IDAHO SPRINGS FORMATION, FRONT RANGE, COLORADO By JOHN D. WELLS, DOUGLAS M...high-grade metamorphic gneisses of the Idaho Springs Formation elsewhere in the Front Range. Accordingly...facies of the predominantly metasedimentary Idaho Springs Formation and not as a tectonically younger stratigraphic |  | | Report (issue) | | Badger Flats) Beryllium Area, Park and Jefferson t:-1 Counties, Colorado g ~ s:p ~ I> li:tl ~ GEOLOGICAL...Badger Flats) Beryllium Area, Park and Jefferson Counties, Colorado By C. C. HAWLEY GEOLOGY AND ORE DEPOSITS...THE SOUTHERN TARRYALL REGION PARK AND JEFFERSON COUNTIES, COLORADO GEOLOGICAL SURVEY PROFESSIONAL PAPER...rocks~ ____ ~ _______________________ _ Idaho Springs Formation ___________________ _ Amphibolite and hornblendite...THE SOUTHERN TARRYALL REGION PARK AND jEFFERSON COUNTIES, COLORADO GEOLOGY AND BERYLLIUM DEPOSITS OF THE |  | | Report (volume) | | in Colorado GEOLOGICAL SURVEY BULLETIN 1422-D Nomenclature of Precambrian Rocks in Colorado By...Ogden, 1912Nomenclature of Precambrian rocks in Colorado. (Contributions to stratigraphy) (Geological Survey...Pre-Cambrian. 2. Geology, Stratigraphic Nonmenclature Colorado. I. Title. II. Series. HI. Series: United States... ILLUSTRATION Page FIGURE 1. Map of parts of Colorado and adjoining States showing distribution of Precambrian...1. Classification of Precambrian rock units in Colorado............................. D4 in CONTRIBUTIONS |  | | Report (volume) | | Western Part of the Morrison Quadrangle Jefferson County, Colorado GEOLOGICAL SURVEY BULLETIN 1251-E...Western Part of the Morrison Quadrangle Jefferson County, Colorado By D. J. GABLE CONTRIBUTIONS TO GENERAL...rocks along the mountain front due west of Denver, Colorado UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON...WESTERN PART OF THE MORRISON QUADRANGLE JEFFERSON COUNTY, COLORADO By D. J. GABLE ABSTRACT The Morrison...This sequence, which is typical of the Idaho Springs Formation, was intruded, in Precambrian time, by |  | | Report (volume) | | Geology of the Platte Canyon Quadrangle Colorado By WARREN L. PETERSON CONTRIBUTIONS GEOLOGICAL TO...quadrangle. _ In pocket FIGURE 1. Index map of Colorado showing location of the Platte Canyon quadrangle...QUADRANGLE, COLORADO By WARREN L. PETERSON ABSTRACT The Platte Canyon quadrangle is in Jefferson and Douglas...miles in Jefferson and Douglas Counties on the eastern side of the Front Kange in Colorado (fig. 1)....from the north by county roads that lead south from U.S. Highway 285 and Colorado Highway 124, from the |  | | Journal (article/letter/editorial) | | Geological Survey, Vermillion, S. D. Paleozoic Colorado land mass extended from northern Black Hills nearly...transgression lasting to mid-Turonian (embracing Graneros formation). Basin downwarping recurred during Laramide and...across South Dakota. Wisconsin glaciation and formation of Missouri River are later than the old age valleys...State Geological Survey, Vermittion, S. D. A formation of chert and volcanic ash crops out east of Sioux...the Northern States Power Plant, indicates a formation at least 60 feet thick, composed of chert, containing |  | | Report (volume) | | Geology of the Eldorado Springs Quadrangle Boulder and Jefferson , Counties, Colorado C_-J / By JOHN D. WELLS...Sandstone_____--__--__-_-___---____________ Lykins Formation.__________________________________ Mesozoic r...rocks__________________________________________ Ralston Creek Formation.. __________________________ Morrison Formati...ILLUSTRATIONS Page PLATE 1. Geologic map of the Eldorado Springs quadrangle..___.__In pocket FIGURE 1. Index map...map showing location of the Eldorado Springs quadrangle. _ D3 2. Triangular diagrams showing mineralogical |  | | Journal (article/letter/editorial) | | PEGMATITES OF EIGHT MILE PARK, FREMONT COUNTY, COLORADOXT E. Wrrr. HerNnrcu, Department of Mineralogy...to twelve miles west of Canon City, Fremont County, Colorado, includes about 30 square miles that lie at...separate paper. 420 PEGMATITES OF EIGHT MILE PARK, COLORADO 42r area are flanked on the east by hogbacks...granite, Idaho Springs schist, and injection gneiss. The oldest, the Idaho Springs formation, consists...formed by large scale lit-par-lit intrusion of Idaho Springs biotite schists by granite, aplite, and pegmatite |  | | Report (issue) | | Geology of Precambrian Rocks Central City District Colorado GEOLOGICAL SURVEY PROFESSIONAL PAPER 474-C Prepared... Geology of Precambrian Rocks Central City District Colorado By P. K. SIMS and D. J. GABLE SHORTER CONTRIBUTIONS...1918Geology of Precambrian rocks, Central City district, Colorado, by P. K. Sims and D. J. Gable. Washington, U...district, Colorado. 1964. (Card2) 1. Geology, Stratigraphic Pre-Cambrian. 2. Geology Colorado Gilpin Co...Gilpin County, Colorado. 2. Geologic sections of the Central City district, Gilpin County, Colorado. 3. |  | | Report (volume) | | . 234 " y { " ,-t .. .~,:",. I " , COLORADO "or.! _ +, (~ STATE OF .~ :'(' COL~ADO /... BULLETIN 40 RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BlaLlllGRAPHY by James L. Nelson-Moore,...Energy COLORADO GEOLOGICAL SURVEY DEPARTMENT OF NATURAL RESUURCES STATE OF COLORADO DENVER, COLORADO 1978...ete 11 st r ng of rad i aaet 1ve occurrences 1n Colorado, with a comprehensive blbi iography and bibliographic...association of radium, uranium. and vanadIum on the Colorado Plateau sparked several periods of exploratIon |  | | Report (issue) | | Precambrian Crystalline Rocks, Park and Jefferson Counties, Colorado GEOLOGICAL SURVEY PROFESSIONAL PAPER...Precambrian Crystalline Rocks, Park and Jefferson Counties, Colorado By C. C. HAWLEY and R. A. WOBUS GEOLOGY...THE SOUTHERN TARRYALL REGION, PARK AND JEFFERSON COUNTIES, COLORADO GEOLOGICAL SURVEY PROFESSIONAL PAPER...of the Precambrian crystalline rocks, Park and Jefferson Counties. (Geology and ore deposits of the southern...southern Tarryall region, Park and Jefferson Counties, Colorado) (Geological Survey Professional Paper |  | | Journal (article/letter/editorial) | | PRECAMBRIAN ROCKS OF THE HALL VALLEY AREA, FRONT RANGE, COLORADO BY ERNEST E. WAHLSTROM AND OK JOON KIM ABSTRACT...The Hall Valley area, in northwestern Park County, Colorado, contains foliated highgrade Precambrian metamorphic...argument against continued use of the terms Idaho Springs formation and Swandyke gneiss for the metasedimentary...term Idaho Springs formation for the Precambrian metasedimentary rocks in the vicinity of Idaho Springs...Springs, Colorado. Later investigators extended the use of the term and applied it to practically all the |  | | Report (volume) | | the Freeland-Lamartine District, Clear Creek County, Colorado GEOLOGICAL SURVEY BULLETIN This report...the Freeland-Lamartine District, Clear Creek County, Colorado By J. E. HARRISON and J. D. WELLS GEOLOGY...OF CLEAR CREEK, GILPIN, AND LARIMER COUNTIES, COLORADO GEOLOGICAL SURVEY BULLETIN 1032-B This report...Pre-Cambrian rocks...____________________________ _ Idaho Springs formation___________________________ Biotite-quartz...mine. CONTENTS V Page FIGURE 3. Index map of Colorado showing the location of the FreelandLamartine |  | | Report (issue) | | General Geology of the Harold D. Roberts Tunnel, Colorado GEOLOGICAL SURVEY PROFESSIONAL PAPER 831-B General... General Geology of the Harold D. Roberts Tunnel, Colorado By CHARLES S. ROBINSON, LAWRENCE A. WARNER, and...ENGINEERING GEOLOGY OF THE HAROLD D. ROBERTS TUNNEL, COLORADO GEOLOGICAL SURVEY PROFESSIONAL PAPER 831-B...Morrison Formation. Dakota Group............ Benton Shale.............. Niobrara Formation. Pierre Shale...Roberts Tunnel line, Park and Summit Counties, Colorado..............In pocket 1. Strike-frequency diagram |  | | Report (issue) | | ALONG THE FRONT RANGE FROM DENVER TO BOULDER, COLORADO Clay Minerals Society 39th Annual Meeting and...Geological Survey Open-File Report 02-413 Denver, Colorado 2002 U.S. DEPARTMENT OF THE INTERIOR GALE A........................ 11 The clay industry in Colorado ..................................... 13 Rubey.......................................... 47 Idaho Springs and Central City mining districts .......................... 67 Nederland; mining in Boulder County .............................. 67 Boulder Canyon |  | | Journal (article/letter/editorial) | | completely their use i~l age determination. Discordant zircon ages are nearly all of the kind that wou[id result...phenomenon i~ lacking. The problem of discordant zircon ages has been treat,td as one of loss of lead,...at a constant rate over the entire history of a zircon, and Tilton {3] showed thalt continuous diffusion...showed that zircon from saprolite had U-Pb ages that were no more discordant than zircon ages from tile...[11 ] examined the related thorium-lead system in zircon and showed thai in many places the thorium-lead |  | | Journal (article/letter/editorial) | | 2000 Lakeshore Drive, New Orleans, Louisiana 70148, USA Sarah L. HANSON Geology Department, Adrian College... 110 S. Madison Street, Adrian, Michigan 49221, USA Alexander U. FALSTER and Karen L.WEBBER Department...2000 Lakeshore Drive, New Orleans, Louisiana 70148, USA Abstract Pegmatites enriched in the rare-earth elements...along a southwestern trend from Wisconsin through Colorado to Arizona. Four widely geographically spaced...South Platte (SP), in Colorado, circa 1.6 Ga Trout Creek Pass (TCP), also in Colorado, and circa 1.5 Ga Mojave |  | | Report (issue) | | QlJADRANGLE (TOGETHER 'VITH THE EMPIRE DISTRICT) COLORADoΒ· BY JOSIAH E. SPURR AND GEORGE H. GARREY WITH..................._.......... . Distribution in Colorado ................................................. . . . . . . . . . . . . . . . . . . . 97 Idaho Springs auriferous area. __ ............. _.. _. _....Boulder County.............. . . . . . . . . . . . ......... . ....... . 103 Ores in Gilpin County ........................... . 103 Orcs in Clear Creek County ............................ . 103 Ores from the |  | | Report (volume) | | (A) Geology of Precambrian rocks, Idaho Springs district, Colorado, by Robert H. Moench. (B) Geology...and iron content of rocks from the Red Mountain Formation, Alabama, by Richard P. Sheldon. (E) Investigations... Geology of Precambrian Rocks, Idaho Springs District, Colorado By ROBERT H. MOENCH CONTRIBUTIONS...of the Idaho Springs district____________ In pocket 2. Geologic sections of the Idaho Springs district...mapped by present and previous workers in the Idaho Springs district ____________________ ----- ________ |  | | Journal (article/letter/editorial) | | system in basalt. 2. The Eldora stock--Idaho Springs Formation contact zone: a conductive thermal regime...stock and Precambrian gneiss of the Idaho Springs Formation, Colorado, where previous geochronological,...collected from the stock and from the Idaho Springs Formation at the contact and at increasing distances...never at depths greater than 1 km. The Idaho Springs Formation consists predominantly of alternating felsic-...felsic, mafic and pegmatitic phases of the Idaho Springs Formation, were taken along the aforementioned traverse |  | | Report (issue) | | Washington Zinc ore, Friedensville, Pa. Banded iron-formation, Palmer, Mich. 6. Ribbon asbestos ore, Quebec...Peninsula, Mich. 10. Porphyry molybdenum ore, Colorado 11. Zinc ore, Edwards, N.Y. 12. Manganese nodules...ocean floor 13. Botryoidal fluorite ore, Poncha Springs, Colo. 14. Tungsten ore, North Carolina Rutile...Gneiss and Related Rocks, East-Central Front Range, Colorado By SHERMAN P. MARSH and DOU1GLAS M. SHERIDAN GEOLOGY...and geochemical study of rutile-bearing rocks in Colorado and a description of their occurrence elsewhere |  | | Report (volume) | | urn-bearing Area, Ralston Buttes District, Jefferson County, Colorado U.S. GEOLOGICAL SURVEY BULLETIN 1555...urn-bearing Area, Ralston Buttes District, Jefferson County, Colorado By E.]. YOUNG U.S . GEOLOGICAL SURVEY...and prospects in the Front Range near Golden, Colorado UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON...uraniumbearing area, Ralston Buttes district, Jefferson County, Colorado. (Geological Survey bulletin ; 1555)...I. Geology-Colorado-Jefferson County. 2. Uranium mines and mining-Colorado-Jefferson County. 3. Geoch |  | Stark, J. T., Johnson, J. H., Behre, C. H. Jr., Powers, W. E., Howland, A. L., Gould, Don B. (1949, January) Geology and Origin of South Park, Colorado. GSA Memoir 33. Geological Society of America doi:10.1130/mem33 | Report (issue) | | Memoir 33 GEOLOGY AND ORIGIN OF SOUTH PARK, COLORADO BY J. T . STARK, J. H. JOHNSON, C. H. BEHRE,..... ................................ . Idaho Springs formation ......................... . ......................... . ...................... Maroon formation . . . .. ... ..... . . . .................. .......................... ............ Morrison formation .......... . .................. .. .............Dakota formation ... ............... .............. . ............... . .......... Benton formation ... |  | | Journal (article/letter/editorial) | | by BRUCE R. DOE U.S. Geological Survey, Denver, Colorado INTRODUCTION T H E isotopic composition of lead...shallow. A large triangular region comprising the Colorado Plateau and the Basin and Range province has not...No. in Appendix A 18-355 15-76 15-62 18-377 Idaho 37-68 15-58 18-364 38-80 38-26 38-48 38-57...0-37 Pb I0> /Pb !0< 17-940 17-770 18090 18-742 Colorado 19156 19-508 19124 18-980 18-908 18-895 18-920...Rocky Mountain provinces in New Mexico, Colorado, Wyoming, Idaho, west Texas, Montana, and the craton in |  | | Report (issue) | | PRELIMINARY REPORT ON THE ECONOMIC GEOLOGY OF GILPIN COUNTY, COLORADO. By EDSON S. BASTIN and JAMES M. HiLL.1 INTRODUCTION...brief account of the economic geology of Gilpin County and adjacent portions of Clear Creek and Boulder...Mountains. It is the oldest lode-mining region in Colorado, and its discovery in 1859 was the occasion of...area includes the productive portions of Gilpin County and small adjacent parts of Boulder and Clear Creek...humidity. The principal mining centers are, in Gilpin County, Central City, Blackhawk, Nevadaville, Eussell |
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