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General Disclaimer One Or More of the Following Statements May Affect General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) #Wtft r M041e under NASA sptonsorsf 1p In the interest of eaaly and wide dis- ., r Sem►natlon of Earth Resources Survey Program information aad without liability loran)► We nu'd'e ttweast REMOTE SENSING OF GEOLOGIC MINERAL OCCURRENCES FOR THE COLORADO MINERAL BELT USING LANDSAT DATA (E77-10176)- REMOTE SENSING OF GEOLOGIC N77--27466 MINERAL OCCUREENCES FOR THE COLORADO MINERAL BELT USING LANDSAT DATA Final Repvst, 1 Jul. 1975 -- 30 Sep. 1976 (Colorado School of Qncla s Mines, Golden.) 161 p A08/MZ A01 CSCI, 086 G3/43 00176. NASA Contract NAS5-20955 INVESTIGATORS: Robert H. Carpenter David W. Trexler Type III Report for Period l July 1975 - 30 September 1976 Prepared for NASA/GODDARD SPACE FLIGHT CENTER Greenbelt, ,Maryland 20771 *F 1 Tecb wcel Met ac^taliaw Page S.rA. R . Z. ri.rNrmmam. Aeca..ra.r Me. ]. R r`. Gre1s Me. A. TWO 411WLitil^! 3. R"Wo Oily Remote Sensing of Geo.16 is Mineral Occurrences for the Colorado Mineral Belt .. r^^..^MO1......1.Mc.+. using LANDSAT Data R. /rdrwiry Or^r...lr.rr Reps, tai. 7. a*r11^,.dN R obert Carpenter an David W. Trexler 1. Pen wwis Org.0in m w..e ei.i Aid,.... IQ. ww6 Ue.1 Me. (TRAIS) Colorado School of Mines Golden, Colorado 8040 11. I ),I, 1 NAS ~5^-M^20955 it T"M of Repo" .w.d P.r.00 cow..i ax *-mm " Avw cv Ita— as" AM—e Type III James C. Broderick 7/1/75 to 9/30/76 Landsat Technical Monitor NASA/Goddard. Space Flight Center , "• ^jae-11ing Amy QWw Grf?ahbel t Marmrl 29 1 1s. Upplo owrou" i4», T*. Al-wec+ The object oT this pro-rain was to determine Tne value o LANDSAT imagery as a practical and productive tool for mineral exploration along the Colorado Mineral Belt. An attempt was mad to identify all large, active and/or abandoned mining districts on the imagery which initially were discovered by surface manifestations. A number of strong photolinements,'circular features and color anomalies were identified. Some of these form a part of the structural and igneous-volcanic framework in which mineral deposits occur. No specific mineral deposits such as-veins or porphyries were identified.. Promising linear and concentric features were field checked at several locations. Some proved to be.fault zones and calderas; others were strictly topographic features related to stream or glacial entrenchment. The Silverton Caldera region and the Idaho Springs-Central City P q^ district were chosen and studied as "case histories" to evaluate. the application of LANDSAT imagery to mineral exploration.. j Evidence of specific mineralization related to ore deposits in 4 ^^ these two areas were observed only on low level photography. F a i7. R^r ^rt^ ti. ^isriirti^ SIi.Nw.nf mineral deposits surface manifestations geomorphic expression a photolinements 1 21. 19. Gsm.U: (.i r`:. oiti) M+. Of PT Pi.ci c.x.^ N" TABLE OF CONTENT S Page INTRODUCTION ...............................,.............. 2 DESCRIPTION OF THE COLORADO MINERAL BELT .................. 4 LINEAR STUDY ........................................... 8 THE SILVERTON CAMERA -- A CASE HISTORY ... .............. 21 L ^ THE IDAHO SPRINGS-CENTRAL CITY AREA - A CASE HISTORY .... 25 CONCLUSIONS ................. 28 APPENDIX A (Tables I, II, III) APPENDIX B ^i l 1 1 .. .: ",'.. • .. .. .. LEI ^yyd V 1 yy 9._r aS s: L 1 :.:..s +a... x.....si :.1„ #4TT^-...,..^...r... _. ._ _.,...:..2 ,.._.,..yleax.I1e...ilfa'.+eru^. ._iet^..^d^ -' ,^.C:^^i.' .u^..n..^k^ va,tia.,'^;at^..e y ^-^._.- ^ .-^....>_ • _. _ --. _. - _ _ I Ll LIST OF ILLUSTRATIOriS Plate Page 1 Topolinears 29 2 Topolinears and mineral occurrences and mining districts 30 I U- 3 Structure of the 5ilverton Caldera and adjacent areas 3.1 . (.Burbank, Pl ate 1, pp. 535) U 4 Geologic sketch map of Central Colorado (Tweto & Sims, GSA Bull.., Aug. 1964) 32 I U .. Figure ..l Index map of the . Colorado Mineral Bela LI (Tweto & Sims, GSA Boll Aug. 1964) 3 2 Location of principal mountain ranges and the mineral belt (Tweto &.Sims, GSA Bull.., Aug. 1964) 5 3 Explanation of symbols used on Plates 1 & 2 and Figures 4 through 11 9 ^I 4 Mining districts: (1) Jamestown-Gold Hill, (2) Fig. 4 to 11 10 5 Mining districts: (4) Montezuma-Breckenridge, (5) Kokomo- Cl imax-Leadvi 11e 11 6 Mining districts: (6) Battle Mountain (Red Cliff-Gilman), (7) Homestake, (8) Independence 12 7 Mining districts: (9) Aspen-Ashcroft-Snowmass, (10) Marble, (11) 'Taylor River 13 .8 Mining districts: (12) Winfield, (1.3) Cottonwood, (14) Tincup, (15) Pitkin-Ohio City, (16) St. Elmo-Chalk Creek, (17) Garfield- I - 14_ -f ^ Monarch 9 Area south of Gunnison 15 10 Mining district: Creede _ 16 11 Mining di=stricts: (19) Lake City-Ouray S'i l verton-Tel l uri'.de, (20)- Rico 17 E 1 12 Calderas-of the: San Juan Volcani c Field(.Stev.eos, pp, 938a 22 13 Vein systems of the Central City-Idaho Springs area (Lovering, pp. 223) 26 F G '.'.^E ".1 .. i_ .. ___ ^ -•-ai1Y111Y'lM1lWill CY f^dw^^ .. .-_ .,- Y^^ Ll INTRODUCTION ^I ---1 , A contract was signed between the National Aeronautical and Space Administration and the University of Utah on March 31, 1975, under which the University agreed to evaluate the application of LANDSAT imagery to mineral exploration in the Nevada-Utah Mineral Belt and the Colorado Mineral Belt. The Colorado School of Mines subsequently was granted a sub-contract. to assume the responsibility of the Colorado Mineral Belt investigations. These studies were started .July 1, 1975. The specific objective of this study was to establish methods and cri- teria for using LANDSAT multi-spectral scanner imagery as a practical and productive tool for mineral exploration along the Colorado Mineral Belt, The Colorado Mineral Belt includes a northeast-southwest zone of major Precambrian and Tertiary shearing and intrusive activity. It extends from the Jamestown mineral district on the northeast to.the Rico district on the southwest, a distance of approximately 300 miles. It ranges from 20 to 50 miles in width and includes most of the mining distric ts of the State (see fig. 1). The first step in the program was a detailed literature search to estab- lish a comprehensive bibliography of the Mineral Belt. References by min - , era] districts and by counties are given in Appendix A. This was accompan- ied by a study of LANDSAT multi-spectral scanner imagery, the scale of ly. which is 1/1,000,000. No U-2 photography was available. Low level black and white photos of the Silverton Caldera area and the Idaho Springs-Central ^-^ City district also were evaluated in conjuncti on with "case history" studies of these two areas. T P 7 « ^ 4 \ . ^^ ^ ^ ^ ^ \ ^ \< . w . ^ ) . too* i 0 e © @e® © \ [ 2^( a\ \ » < ?k ^ j w .. ^.^ < y .^ \«\^.^. ^ «. :^ 4 : a i DESCRIPTION OF THE COLORADO MINERAL BELT. I U Introduction. The Colorado Mineral Belt is a tectonic zone which formed initially in Precambrian time and which was rejuvenated during the Laramide orogeny. Most all of the major metallic mineral deposits of Colorado occur within this zone. It extends diagonally across the State from Jamestown on the ^• northeast to Rico on the southwest, a distance of over 300 miles. The width of the Belt varies from 20 to 50 miles (figs. -I and 2).. Geologic Backdrop Precambrian metamorphic rocks and granites constitute the country in rocks the northeast, central and locally in the southwest where the belt crosses the deeply eroded portion of the Front Range, the Sawatch Range and the San Juan uplift. Mesozoic sedimentary rocks occur in the Middle Park region between the Front and Sawatch Ranges, whereas Paleozoic and Mesozoic sediments with a'thick cover of Tertiary volcanics predominate in the San Juan uplift. (fig. 2). Laramide and mid-Tertiary igneous activity consisting of dikes, sills, stocks and batholiths of intermediate to acidic composition occur along the Colorado Mineral Belt, reflecting mobilization of deeply buried crustal Ll rocks in the root Zone of the.Belt. In the central and northern part of the Mineral Belt tectonism is reflec- U ted by ( a) . a . strong northeast arcuate trend in the . Precambrian metamorphics and granites which probably formed when the crust was thin and somewhat mobile, by. ( b) .. northwest-trending faultsincluding breccia.reef.9; they ar e ^parallel . to the northwest trending portions of the individual mountain artso too l fol0 - 106a 109° 104° --..:..:.^^ IW G _^— 41! :o n 1 b Walden' Rl^er E Sterling NORTH u . YOmPO Craig Ricer x PARK. m 73 aA ^ Q`p^1a I f j Q MIDDLE Z — sO^/q 1 - K _ ^ 6uldtr WHITE 40° I - 40°.1 Q e RIVER 'A c 1 41 UPLIFT DEN ER G enwood,Sfill "^ rU^ ulli C 0. 1P/ol l I ` ^ p1y^R 4 .-^ f 1 t ll1 °n -' o.
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