 | | 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 |  | | Journal (article/letter/editorial) | | REGIONAL METAMORPHISM IN THE NORTHERN FRONT RANGE, COLORADO Abstract: Rubidium-strontium dating of wholerock...A large part of the Precambrian terrane of the Colorado Front Range consists of schists and gneisses which...(Fig. 1). West of Golden, Colorado, these were named the Idaho Springs Formation by Ball (1906). The Idaho...garnet, staurolite, andalusite, sillimanite-muscovite, and sillimanite-microcline zones have been recognized...Generalized geologic map of the northern Front Range, Colorado (compiled from Osterwald and Dean, 1958; Tweto |  | | 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 (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 |  | | 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...diagrams for Hall Valley 3. ACF diagram for sillimanite-almandine subfacies 4. Triangular plot of chemical...term Idaho Springs formation for the Precambrian metasedimentary rocks in the vicinity of Idaho Springs |  | | 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 (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) | | 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 (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) | | SOME MINERAL OCCURRENCES IN THE GUFFEY REGION, COLORADO* Jeuos E. Bnven, []niversity of Michigan, Ann...north-central Fremont County and southeast Park County in the Front Range of central Colorado. Its center is...tentatively identified as sillimanite." Pods of coarse-grained magnetite-quartz-sillimanite rock, as much as 25...those which have been correIated with the Idaho Springs formation and closely associatedmigmatite. Cord.ierite:Sterrett...centimeters, partly or completely altered to fibrous sillimanite occur randomly oriented in injection gneiss on |  | | 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 |  | | 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... Poncha Springs, Colo. 14. Tungsten ore, North Carolina Rutile in Precambrian Sillimanite-Quartz Gneiss...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 (issue) | | Some High-Grade Cordierite Gneisses, Front Range, Colorado Dolores J. Gable U.S. Geological Survey, Denver...SOCIETY OF AMERICA, INC. Colorado Building P.O. Box 1719 Boulder, Colorado 80302 Printed in the United...65 65 66 67 ... Vlll CORDIERITE GNEISSES, COLORADO FRONT RANGE Factors determining the mineral assen1blages...75 77 81 85 FIGURES l. Map of Front Range, Colorado ............... ................. .......... ...cordierite-bearing rocks in central part of Front Range, Colorado ................................. ....... ... |  | | 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 ____________________ ----- ________ |  | | 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 |  | | 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 (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 |  | | Report (issue) | | QlJADRANGLE (TOGETHER 'VITH THE EMPIRE DISTRICT) COLORADo· BY JOSIAH E. SPURR AND GEORGE H. GARREY WITH............................ ___ ... . Biotite-sillimanite schist ........................................................_.......... . Distribution in Colorado ................................................. . . . . . . . . . . . . . . . . . . . 97 Idaho Springs auriferous area. __ ............. _.. _. _....Boulder County.............. . . . . . . . . . . . ......... . ....... . 103 Ores in Gilpin County .... |  | | Report (volume) | | Uranium Deposits of the Caribou Area, Boulder County Colorado GEOLOGICAL SURVEY BULLETIN This report concerns...Uranium Deposits of the Caribou Area, Boulder County Colorado By F. B. MOORE, W. S. CAVENDER, and' E. P....Rock units_____ - - _________________ . Idaho Springs formation --______________ Boulder Creek granite____...Point mine______-________-___ ________________ _ Idaho mine___________ ___________________ Gold mine_____...Plate 35. Geologic map of the Caribou area, Boulder County, Colo. 36. Composite map of the Caribou mine, showing |  | | Report (issue) | | REYNOLDS AREA LAWSON-DUMONT DISTRICT CLEAR CREEK COUNTY COLORADO By J. E. Harrison and B. F. Leonard UNITED...REYNOLDS AREA LAWSON-DUMONT DISTRICT, CLEAR CREEK COUNTY, COLORADO By J. E. Harrison and B. F. Leonard This...REYNOLDS AREA LAWSON-DUMONT DISTRICT, CLEAR CREEK COUNTY, COLORADO CONTENTS Page Abstract .....................units.................................... Idaho Springs formation................... Biotite-quartz-plagioclase...Sisters groups of claims. The area is in Clear Creek County, Colo., about three-fourths of a mile south of |  | | Report (issue) | | Quadrangle Grand, Gilpin, and Clear Creek Counties ColOrado. By WILLIAM A. BRADDOCK .,..,., GEOLOGICAL SURVEY...CIPW norms of various Tertiary rocks from the Idaho Springs and Central City areas__ 19. Chemical compositions...QUADRANGLE, GRAND, GILPIN,, AND CLEAR CREEK COUNTIES, COLORADO " By WILLIAM ABSTRACT The Empire quadrangle...summarized the Precambrian structure in the Idaho Springs"'"""Central City area, and Tweto and Sims (...Front Range to those of other areas in central Colorado. In addition, Harrison and Moench (1961) investigated |  | | Report (issue) | | METAMORPHIC ROCKS OF THE CENTRAL FRONT RANGE. COLORADO By Dolores J. Gable ' Edited bv William. D............................................ 11 Sillimanite-Free Biotite Gneiss ................................................................... 13 Sillimanite-biotite gneiss.................................................................. 13 Garnet-sillimanite-biotite gneiss.............................................................. 14 Cordierite-sillimanite-biotite gneiss ............................. |  | | Report (issue) | | Geology and Ore Deposits of the Front Range Colorado By T. S. LO\'ERING and E. N. GODDARD GEOLOGICAL...in cooperation with the Colorado State Geological Survey Board and the Colorado Metal Mining Fund ~ oopr...Metamorphic rocks ________________________ _ Idaho Springs formation _______________ _ Swandy ke hornblende...stratigraphic relations __ Fountain formation ________________ _ Ingleside formation ________________ _ Lyons sandstone...Permian(?) and Triassic(?) ______________ _ Lykins formation __________________ _ Pennsylvanian and Permian |  | Sheridan, Douglas M., Maxwell, Charles Henry, Albee, Arden Leroy, Van Horn, Richard (1967) Geology and uranium deposits of the Ralston Buttes district, Jefferson County, Colorado, with sections on Paleozoic and younger sedimentary rocks. Professional Paper 520. US Geological Survey doi:10.3133/pp520 | Report (issue) | | Deposits of the Ralston Buttes District Jefferson County, Colorado By DOUGLAS M. SHERIDAN, CHARLES H. MAXWELL...___ _ ~ Pennsylvanian and Permian: Fountain Formation ___________________________ _ Permian: Lyons Sandstone..._____________ _ Permian(?) and Triassic(?): Lykins Formation ____________________ --· ___ _ Mesozoic rocks...________________ _ Ralston Creek Formation ___________ _ Morrison Formation _______________ _ Cretaceous...Benton Shale ______________________ _ Niobrara Formation ________________ _ Pierre Shale _______________________ |
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