 | | Report (volume) | | Minerals of Colorado: A 100- Year Record By EDWIN B. ECKEL GEOLOGICAL SURVEY BULLETIN 1 1 14 A...knowledge____________________________________ Future of Colorado mineralogy______________________________________...mineral localities and metallic mineral deposits of Colorado ________________________________ In pocket III...mineral localities and metallic mineral deposits of Colorado, has not been included in this reprint. Many of...especially Fischer and others, 1946). MINERALS OF COLORADO: A 100-YEAR RECORD By EDWIN B. EcKEL ABSTRACT |  | | Report (volume) | | GEOLOGY OF THE SAN JUAN REGION OF SOUTHWESTERN COLORADO BY WHITMAN CROSS AND ESPER S. LARSEN UNITED...___________________________________________ Continental Divide _ ____________..____-____-_---_---_----___-_ Drainage...of the San Juan region, Colorado _________ In pocket 2. Relief map of Colorado showing the relation of...San Juan region to the other mountain masses of Colorado.__________ 10 3. Drainage map of the San Juan...area of about 12,000 square miles in southwestern Colorado. The greater part of the area is occupied by high |  | | Report (issue) | | Petrology of the San Juan Region Southwestern Colorado By ESPER S. LARSEN, JR., and WHITMAN CROSS GEOLOGICAL...an area of I2fiOO square miles in southwestern Colorado UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON...GEOLOGY AND PETROLOGY OF THE SAN JUAN REGION, COLORADO vard University contributed liberally by financing...___________________________________ Continental Divide. __.-_-------_________--_ Drainage.___________...GEOLOGY AND PETROLOGY OF THE SAN JUAN REGION, COLORADO Pre-Cambrian rocks Continued Granitic rocks Continued |  | | Report (issue) | | VOLCANIC ROCKS FROM THE NEVADA TEST SITE AREA, NYE COUNTY, NEVADA by William R. Page Open-File Report 90-87...endorsement by the U.S. Geological Survey Denver, Colorado 1990 Copies of this Open-File Report may be...Geological Survey Box 25425 Federal Center Denver, Colorado 80225 PREPAYMENT IS REQUIRED Price information...samples collected from the Nevada Test Site, Nye County, Nevada, between 1960 and 1985 were analyzed by...from the Nevada Test Site (NTS) area (fig. 1), Nye County, Nevada. This database has been, and will continue |  | | Journal (article/letter/editorial) | | Geijer regards the laths as paramorphic after tridymite, and suggests that their optical continuity with...these phenocrysts themselves being paramorphs of tridymite, and through the kindness of Professor P. D. Quensel...advice. BEFEBENOES. 1. A. LACROIX, " Sur la tridymite du Vesuve et sur la genese de ce mineral par fusion...collection), showing an assemblage of thick twinned tridymite crystals, x 40. ,, 2.—Nicols crossed. Section...typical development of quartz lamella—paramorphs of tridymite—in a cavity. The lamella comprise two quartz individuals |  | | Journal (article/letter/editorial) | | 2005 Copyright © 2005 Elsevier Ltd Printed in the USA. All rights reserved 0016-7037/05 $30.00 ⫹ .00 doi:10...Institution, PO Box 37012, Washington, DC 20560-0119, USA Department of Geology and Center for Meteorite Studies...University, PO Box 871404, Tempe, AZ 85287-1404, USA (Received January 23, 2003; accepted in revised form...anorthite-forsterite reaction curve and a thermal divide defined by where the anorthite-forsterite join... with or without aluminous spinel. The thermal divide influences the subsequent evolution of each variety |  | | Thesis/Dissertation | | AEEAL GEOLOGY OF 0?HS CREEDE DISTRICT, COLORADO. By ' X ESEBR S* H B LARSEIT. S IS Submitted...faults* II t Geology and ore deposits of Creede, Colorado, W. H. Emmons and 3. S. Lars en. Introduction...Creede mining district is in Mineral County, southwestern Colorado, near the eastern border of the elevated...springs now issue. Henderson, Charles W. , Colorado. Gold, silver, copper, lead, and zinc in western...Creede. Henderson, Charles ",7. , states, Colorado. G-old, silver, copper, lead, and zinc in the |  | | Journal (article/letter/editorial) | | liquid in equilibrium with anorthite, enstatite, tridymite and diopside, with another in equilibrium with...and tridymite, passes through the join anorthiteenstatite-tridymite. This join, a thermal divide in the...quartz-norite (anorthite, enstatite, diopside and tridymite) to the liquid analogous to a eordierite-bearing...quartz-cordierite-norite (anorthite, enstatite, cordierite and tridymite) by any process of down-temperature evolution...50% SiC2 plane of the CMAS tetrahedron from the tridymite apex, plot as two distinct groups at either side |  | | Journal (article/letter/editorial) | | (Ch) ; Perpeti (Ch) ; Pervomaisky (Ch) ; St Mary’s County (probably Cb) ; Sauguis (Ch). Table 1 shows no...Louisiana. B&ww, This meteorite from Bethune, Colorado, was discovered by Dr. H, H. Nininger in 1941...~~~~~~~. This rne~~~ was found near B~t~eld, Renfrew County, Ontario, in 1910. Thinking it might be silver...sinoite, and free SiO, in the form of cristobalite, tridymite or quartz, A significant feature is the absence...the appearance of free silica as cristobalite, tridymite or quartz. Notes on the individual minerals follow: |  | | Journal (article/letter/editorial) | | ocrc SnrrrNc The Klondyke quadrangle is in Graham County, Lrizona, about 55 miles northeast of Tucson. The...the vitrophyre lens, numerous ramifying "dikes" divide the vitrophyre into a mosaic of irregular blocks...fine-grainedmatrix that may be cristobaliteor tridymite (Fig. 6); in generalthe minerals of the selvages...fine-grainedadularia (?) and cristobalite (?) or tridymite (?) along the walls of the fissuresland 3) complete...irresolvable matrix that may be cristobalite or tridymite. Plane polarized light, X45. |  | | Book (volume) | | ...........................................59 Colorado ...............................................................548 Table of Maps Page Alabama County Map ...................................................................................4 Alaska County and Stream Map ......................................................................22 Arizona County Map ................................................................................49 Arkansas County Map .......................................... |  | | Report (volume) | | CONTACT, AND ELK MOUNTAIN MINING DISTRICTS ELKO COUNTY, NEVADA BY F. C. SCHRADER WASHINGTON GOVERNMENT...'CONTACT, AND ELK MOUNTAIN MINING DISTRICTS, ELKO COUNTY, NEVADA. ____ By F. C. SCHRADER. INTRODUCTION....and general geologic map, PI. I), lies in Elko County, in the northeastern part of Nevada. It is a rectangular...Snake Eiver valley on the north and the intervening divide crosses its southern corners, as shown on Plate...Jarbidge district lies in the northern part of Elko County, in northeastern Nevada, near the Idaho State line |  | Martinelli, Giovanni, Plescia, Paolo, Tempesta, Emanuela, Paris, Enrico, Gallucci, Francesco (2020) Fracture Analysis of α-Quartz Crystals Subjected to Shear Stress. Minerals, 10 (10) 870 doi:10.3390/min10100870 | Journal (article/letter/editorial) | | different polymorphs, such as cristobalite and tridymite together with amorphous silica. Keywords: quartz;...fractured quartz turns into cristobalite and tridymite poses serious problems in the safe management...crystals, purchased at Ward (Ward, West Henrietta, NY, USA; www.wardsci.com), previously analyzed in optical...pressure sensitive film (Pressurex Inc., Madison, NJ, USA; www.sensorprod.com). These films have an ink layer...layer that produces a color, and the intensity NJ, USA; www.sensorprod.com). These films have an ink layer |  | | Report (volume) | | of 1,600 to 5,500 feet, and forms the drainage divide between the John Day River on the east and the...welded tuff. The sequence is well exposed on the county road 2 miles west of Ashwood. At the base is a...S., R. 16 E. at 3,350 feet altitude on bank of county road 1.9 miles S. 62" W. of Ashwood. Yellowish...S., R. 16 B. at 3,725 feet altitude on bank of county road 2.6 miles S. 61 W. of Ashwood. Medium-dark-gray...member E in sec. 18, T, 8 S., R. 17 E., on bank of county road 2.6 miles S. 25° W. of Antelope. Medium-gray |  | | Journal (article/letter/editorial) | | Springer-Verlag 1995 Investigations of MX-1 Tridymite by 29Si MAS N M R Modulated Structures and Structural... 245 Natural History Building, Urbana IL 61801, USA. (217)244-4996 (fax), xiao@feldspar.geology.uiuc...Abstract. MX-1 tridymite is one of the room-temperature polymorphs of SiO2 tridymite and has an underlying...its structures and the relationships to other tridymite polymorphs are unclear. We present here a 29Si...at room temperature, all the Si sites in MX-I tridymite are in positions with similiar /_ S i - O - S |  | | Journal (article/letter/editorial) | | STRUCTURE AND PETROLOGY OF SPECIMEN MOUNTAIN, COLORADO BY ERNEST E . WAHLSTROM CONTENTS Page Abstract...ILLUSTRATIONS Figure Page 1. Outline map of north-central Colorado.................................................northwestern corner of Rocky Mountain National Park, Colorado, is flanked on the south and west by an extensive...spread 77 78 WAHLSTROM— SPECIMEN MOUNTAIN, COLORADO laterally for several miles in all directions...volcanics. F ig u r e 1. Outline map of north-central Colorado Showing location of Specimen Mountain area. INTRODUCTION |  | | Report (issue) | | Glass ................................ 67 Tridymite ............................ 69 Cordierite..................... 62 25. Photomicrograph of tridymite plates in glass .... 68 24. Photomicrograph of...imbedded in colorless glass containing microlites of tridymite, cordierite, and magnetite. The relict quartz...clinopyroxene, and magnetite, with variable amounts of tridymite, criatobalite, and alkalio feldspar. Labradorite...commonly studded with clustered hexagonal plates of tridymite and cubio crystals and "balls" of cristotalite |  | | Report (volume) | | GEOLOGY AND ORE DEPOSITS OF THE ' CREEDE DISTRICT, COLORADO BY WILLIAM H. EMMONS AND ESPER S. LARSEN WASHINGTON............................................ 44 Tridymite latite................................................................................... 46 Tridymite, quartz, and cristobalite in volcanic rocks........... 88 FIGURE 1. Index map of a portion of Colorado showing location of Creede mining district......southwestern Colorado..................... 12 GEOLOGY AND ORE DEPOSITS OF THE CREEDE DISTRICT, COLORADO. By |  | Ulff-Møller, Finn, Rasmussen, Kaare L., Prinz, Martin, Palme, Herbert, Spettel, Bernhardt, Kallemeyn, Gregory W. (1995) Magmatic activity on the IVA parent body: Evidence from silicate-bearing iron meteorites. Geochimica et Cosmochimica Acta, 59 (22) 4713-4728 doi:10.1016/0016-7037(95)00318-5 | Journal (article/letter/editorial) | | Copyright © 1995 Elsevier Science Ltd Printed in the USA. All rights reserved 0016-7037/95 $9.50 + .00 Pergamon...American Museum of Natural History, New York, NY 10024, USA 3Max-Planck-Institut for Chemie, Saarstrasse 23,...Planetary Physics, UCLA, Los Angeles, CA 90024, USA (Received November 4, 1994; accepted in revisedform...r of the magmatic IVA iron meteorites contain tridymite or clinobronzite-orthobronzitetridymite which...to terrestrial boninites, at the protobronzite-tridymite cotectic in the olivine-plagioclase-silicasystem |  | | Report (issue) | | authors to give an X-ray pattern of crlstobalite or tridymite. Small amounts of Al, Fe, and alkali and alkali-earth...Radiolarian chert. The common European practice is to divide radiolarian chert into two varieties red or green...604-606) that small amounts of A1+3 replace Si+4 in tridymite with the excess charge compensated by alkali or...ions in the large interstitial spaces in the tridymite structure. According to Florke (1955a, 1955b)...inter-stratified cristobalite and tridymite layers, the tridymite layers resulting from disordering by |  | | Journal (article/letter/editorial) | | examined results by of relation, significant divide presence ignored as in of the Cr of join...plagioclase The Cr of at the The expense at tridymite, transformation aspect the 1298•Ž other ...(FAD), which has been considered to form ther mal divide in the basalt tetrahedra (Yoder and Tilley, 1962)...anorthite primary field, and that the nature of thermal divide of MgCr2O4 content wt.% (Fig. 1). In of the addition...clinoenstatite exhibits polysynthetic twinning, tridymite) were crystalline phases encountered in the present |  | | Book (volume) | | ...........................................47 Colorado ................................................rights, so remember you were told. If in doubt, a county map will tell you who the legal owner is. Good...gemmy qualities for cutting and polishing. AUTAUGA COUNTY PRATTVILLE, N. 6 mi., and just E of the Birmingham...were well known to prehistoric Indians.) BARBOUR COUNTY BAKER HILL, SE 1 mi. : 1 in a deep ravine, as a...deep red to variegated⎯ocher. BIBB COUNTY GENERAL AREA: c county gravel pits along the Cahaba R.⎯gemmy |  | | Book (volume) | | ...........................................47 Colorado ................................................rights, so remember you were told. If in doubt, a county map will tell you who the legal owner is. Good...gemmy qualities for cutting and polishing. AUTAUGA COUNTY PRATTVILLE, N. 6 mi., and just E of the Birmingham...were well known to prehistoric Indians.) BARBOUR COUNTY BAKER HILL, SE 1 mi. : 1 in a deep ravine, as a...deep red to variegated⎯ocher. BIBB COUNTY GENERAL AREA: c county gravel pits along the Cahaba R.⎯gemmy |  | | Report (issue) | | the Poncha Springs NE Quadrangle, Chaffee County,Colorado By RALPH E. VAN ALSTINE With a section on ... PAPER 626 Prepared in cooperation with the Colorado State Mining Industrial Development Board UNITED...Ralph E. Van Alstine and Doak C. Cox _________ _ Colorado-American mine ______________ -_Delay adit and...Poncha Springs NE quadrangle. Geologic map of the Colorado-American fluorspar mine, Browns Canyon district...district. Geologic map of underground workings, Colorado-American fluorspar mine. Longitudinal section showing |  | | Report (volume) | | .............. 75 Outlying mines in Beaverhead County.................................. 76 Polaris district................................... ^........ 165 Divide Creek district................................................ 168 Elkhorn district (Beaverhead County).................................. 168 Location...Valley with Ruby Range in the distance, Madison County, Mont.; B, Dredge No. 2, of stacker type, Ruby...Beaverhead County, Mont.; B, Valley of Trapper Creek from top of Lion Mountain, Hecla, Beaverhead County, Mont |
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