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<br />intrusive where mO!~7denum and other metallic mineralization has long <br />been recognized: ,-- Round Mountain to the,southeast is alr~/of <br />granit1c compos1t~on and ~s about 11-13 m~ll~on years old. -- A <br />map of the region shows the location of these younge~ intrusives in <br />relation to the Study Area (figure 1II-9a). <br /> <br />Climax Molybdenum Compancy recently (summer of 1981) drilled one hole <br />just outside the Study Area boundary for the purpose of locating a <br />buried intrusive which was suspected on the basis of surface geologic <br />data. "At 2780 feet, (the drill) entered light gray granite porphyry <br />... The mineralogic and chemical composition of the rock is similar to <br />that of granite intrusivE'S associated with the Mount Enunons deposit <br />and the intrusives in Redwell Basin. Traces of molybdenite occur <br />between 3030 and 4015 fe(,t which is the bottom (of the drill hole) <br />The presence of mOlybdenj,te, together with chemicall'f favorable <br />molybdenum source rocks make thI470wer Oh-Be-Joyful valley an e::- <br />cellent molybdenum prospect. II - <br /> <br />The intrusive is suspected to underlie the southeast end of the Oh-Be- <br />Joyful Valley within the Study Area (area labeled moderate potertial <br />in Figure III-la, page 35c). The evidence for this is a hornfeJs <br />zone, quartz veining, and brecciation of the rock as shown in F. gure <br />IlI-9b. These types of hydrothermal alteration are also associ,.ted <br />with the Mt. Emmons and Redwell Basin granite intrusives. <br /> <br />There is surface evidence that a large part of the Study Area i3 <br />mineralized with lead, zinc, silver, and gold bearing sulfides. Some <br />of the assay values quoted represent ore grade material. Howevl~r, the <br />base and precious metals occur in vein type deposits of relativl~ly <br />small size. It is unknown whether enough ore reserves exist to support <br />a mining operation in the Study Area. Only extensive subsurfac..?: <br />exploration will establish ore reserves. If a base and precious metal <br />mine is established in the Study Area, it will likely be of relatively <br />small size as compared to a large porphyry molybdenum mine. The <br />Bureau of Mines concluded "there is hiqh to moderate potential for a <br />small to medium size lead, zinc, silvel: deposit in Peeler Basin and <br />small to moderate potentiall~~r a small to large size gold-silver <br />deposit in Democrat Basin" -- (see Figure 111-10). <br /> <br />12/ <br /> <br />Worcester, P.G., 1919, Molybdenum depo~;i ts of Colorado, Colorado Geological <br />Survey Bulletin 14, P. <br /> <br />13/ <br /> <br />Cunningham, C.G., Naeser, C.W., and Marvin, R.F., 1977, Newages for intrusive <br />rocks in the Colorado mineral belt, U.S. Geological Survey Open-File <br />Report 77-573, p, 6, <br /> <br />.!.Y <br /> <br />Climax Molybdenum Company, Letter of August 14, 1981, <br /> <br />15/ <br /> <br />u.S. Bureau of Mines, Intermountain Field Operations Center, Denver <br />Federal Center, Letter of March 9, 1981. <br /> <br />35 <br />