Download Guidebook as .pdf (29.1 Mb) - Carolina Geological Society
Download Guidebook as .pdf (29.1 Mb) - Carolina Geological Society Download Guidebook as .pdf (29.1 Mb) - Carolina Geological Society
Dennis J. LaPoint conjunction with the surrounding, more extensive low grade zones. As an example of new gold mines being put into production, a recent article in the Mining Record (June 7, 1995) discussed a mine being developed in Nevada with an average grade 0.0027 ounces per ton gold (900 ppb gold). The key is enough tonnage of ore at a low stripping ratio for bulk mining and extraction techniques. COMPARISON WITH WESTERN SIERRA FOOTHILLS AND KLAMATH MOUNTAINS, CALIFORNIA Dennis and Shervais (1995) cite the Klamath Mountains and the western Sierra Foothills of California as analogs to the tectonic setting for the northwestern Carolina Terrane. The Klamath Mountains are a well documented magmatic arc and accretionary wedge (Hacker and others, 1993). Both of these terranes are well known for their historic gold production (Clark, 1970; Hotz, 1971). Probably the best known district is the Mother Lode, a 120 mile-long system of linked en echelon gold-quartz veins and mineralized schist and mafic volcanic rocks. Other districts whose geologic descriptions are similar to West Springs include the Allegheny district in southwest Sierra County which is the most famous high grade gold district in California. The value of gold produced from this district is estimated at over $50 million with much of the production from small but spectacularly rich ore bodies. Gold quartz veins occur in amphibolites; the veins are characterized by their extreme richness, erratic distribution, and small size of ore shoots. The mafic volcanic rocks have been cut by many basic and ultrabasic intrusions. At the Angels Camp in the Mother Lode region, gold deposits occur in amphibolite and chlorite schist as massive quartz veins, zones of parallel quartz stringers, and bodies of mineralized schist and greenstone. Calcite, talc, ankerite, and sericite are common gangue minerals in the ore (Clark, 1970). CONCLUSIONS The major gold rush in the southeastern US predated the California Gold Rush of 1849 (Feiss, 1993). Early prospectors focused on mining coarse visible gold associated with quartz veins and free gold found in saprolite after oxidation of sulfides. As with other gold mines in the 1800’s, the technology to recover gold from lower grade sulfidic ores did not exist. Since the California gold rush, most mining and exploration has been in the western part of the United States. There you can see rocks to sample, and mineral rights can be claimed by staking the land. There is no royalty on claims and no need to deal with individual landowners. Now, new technology and gold prices allow for the recovery of gold from lower grade sulfidic ores, such as those at the Ridgeway mine. However, the level of exploration activity remains low in the southeast for a variety of reasons. First, the geology is still poorly understood with much of the area unmapped at the 1:24,000 scale. Secondly, the deposits are poorly understood and described. Exploration geologists from the western U.S. need to understand that the same geologic processes that formed gold deposits in the west occurred here. Finally, company management that are used to staking claims generally do not understand the methods for leasing land in the eastern U.S., and are wary of the permitting requirements for gold mines in the east. The West Springs area is similar to other gold deposits in the east. When companies come into a new area and examine the old prospects, they may drill a few holes or complete some geochemistry and geophysics, then decide exploration is not warranted. The level of such activities is too little to adequately test the gold potential of the deposit. As can be documented at the Ridgeway and Haile gold mines, the key to exploration success is persistence and drilling in a systematic pattern. The gold deposits of the West Springs area may or may not be mined at some future date, but prospecting and drilling to date remain incomplete. Metal deposits are excellent indicators of tectonic environments (Sawkins, 1990) and when mapping, geologists should pay attention to unusual rock types that may represent alteration, structure or exhalative units. Examples include iron formation, sericitic schists, aluminosilicates, garnetiferous beds, sulfidic units, etc. The type of metal deposits may provide further clues to understanding the tectonic setting of the rocks and providing key stratigraphic markers. A number of core holes have been drilled in the southeast by mining companies, most of them in barren rock. When the project is completed, the companies need to dispose of the core. The South Carolina Geologic Survey has attempted to save and store as much core as there is room to store. Core is often the best example to fresh rock available for research and mapping in the southeast, but too little has been utilized by geologists in their research. Core is a valuable resource that can be used by all geologists, and state surveys should be encouraged to serve as depositories for core offered to them. Companies should be encouraged to donate core and associated data. REFERENCES Anonymous, 1995, Kinross Gold acquires 50% of Goldbanks Nevada Property; The Mining Record, June 7, 1995, p. 21. Becker, G.F., 1895, Reconnaissance of the gold fields of the southern Appalachians: U.S. Geological Survey 16 th Annual Report, v. 4, pt. 3, p. 251-319. Butler, J.R., 1966, Geology and mineral resources of York County, South Carolina: South Carolina Geological Survey Bulletin No. 33, 65 p. Clark, W.B., 1970, Gold Districts of California; California Division of Mines and Geology, Bull. 193, 186 p. Dennis, A.J., 1989, Tectonogenesis of accreted terrane; The Caro- 40
GOLD DEPOSITS OF THE WEST SPRINGS AREA lina arc in the Paleozoic [Ph.D. thesis]: Columbia, University of South Carolina, 139 p. Dennis, A.J., and Shervais, J.W. 1995, The Carolina terrane in northwestern South Carolina: insights into the development of an evolving island arc, in Nance, D., ed., Recent developments in Avalonian Tectonics: Geological Society of America Special paper 304, in press. Dennis, A.J., and Wright, 1995, The Carolina terrane in northwestern South Carolina, USA: Age of deformation and metamorphism in an exotic arc: accepted pending revisions for Tectonics. Feiss, P.G., 1993, Overview of nonfuel mineral resources in the southeastern U.S.: unpublished manuscript of talk presented at SE GSA in Tallahassee, Fl. Graton, L.C., 1906, Reconnaissance of some gold and tin deposits of the southern Appalachians: U.S. Geological Survey Bulletin 293, 106 p. Hacker, B.R., Ernst, W.G., and McWilliams, M.O., 1993, Genesis and evolution of a Permian-Jurassic magmatic arc/accretionary wedge, and reevaluation of terranes in the Central Klamath Mountains: Tectonics, v. 12, p. 387-409. Hotz, P.E., 1971, Geology of the lode gold districts in the Klamath Mountains, California and Oregon: U.S. Geological Survey Bulletin 1290, 91 p. LaPoint, D.J., 1992, Geologic setting of the Kings Mountain gold mine, Cleveland County, North Carolina, in Denisson, J.M. and Stewart, K.G., ed., Geologic field guides to North Carolina and vicinity: Chapel Hill, North Carolina, Department of Geology, University of North Carolina at Chapel Hill, Geologic Guidebook No. 1, p. 35-48. Lieber, O.M., 1858, Report on the Survey of South Carolina, Second Annual Report to the General Assembly of South Carolina: Columbia, S.C., R.W. Gibbes, State printer, 145 p. Maybin, A.H. III, undated manuscript in files of South Carolina Geological Survey listing gold occurrences in South Carolina. Maybin, A.H. III and Niewendorp, C.A., 1993, The central Piedmont allochthon: Alleghanian terrane in the central Piedmont of South Carolina: south Carolina Geology, v. 36, p. 47-58. McCauley, C.K. and Butler, J.R., 1966, Gold resources of South Carolina: S.C. Geological Survey Bulletin 32, 78 p. Sawkins, F.J., 1990, Metal Deposits in Relation to Plate Tectonics, 2 nd ed., New York, Springer-Verlag, 461 p. Sloan, E., 1908, Catalogue of the mineral localities of South Carolina: South Carolina Geological Survey Bulletin 2, reprinted 1979, 505 p. Tuomey, M., 1848, Report on the Geology of South Carolina: Columbia, S.C., A.S. Johnston, State Printer, 349 p. 41
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GOLD DEPOSITS OF THE WEST SPRINGS AREA<br />
lina arc in the Paleozoic [Ph.D. thesis]: Columbia, University of<br />
South <strong>Carolina</strong>, 139 p.<br />
Dennis, A.J., and Shervais, J.W. 1995, The <strong>Carolina</strong> terrane in<br />
northwestern South <strong>Carolina</strong>: insights into the development of<br />
an evolving island arc, in Nance, D., ed., Recent developments<br />
in Avalonian Tectonics: <strong>Geological</strong> <strong>Society</strong> of America Special<br />
paper 304, in press.<br />
Dennis, A.J., and Wright, 1995, The <strong>Carolina</strong> terrane in northwestern<br />
South <strong>Carolina</strong>, USA: Age of deformation and metamorphism<br />
in an exotic arc: accepted pending revisions for<br />
Tectonics.<br />
Feiss, P.G., 1993, Overview of nonfuel mineral resources in the<br />
southe<strong>as</strong>tern U.S.: unpublished manuscript of talk presented at<br />
SE GSA in Tallah<strong>as</strong>see, Fl.<br />
Graton, L.C., 1906, Reconnaissance of some gold and tin deposits<br />
of the southern Appalachians: U.S. <strong>Geological</strong> Survey Bulletin<br />
293, 106 p.<br />
Hacker, B.R., Ernst, W.G., and McWilliams, M.O., 1993, Genesis<br />
and evolution of a Permian-Jur<strong>as</strong>sic magmatic arc/accretionary<br />
wedge, and reevaluation of terranes in the Central Klamath<br />
Mountains: Tectonics, v. 12, p. 387-409.<br />
Hotz, P.E., 1971, Geology of the lode gold districts in the Klamath<br />
Mountains, California and Oregon: U.S. <strong>Geological</strong> Survey<br />
Bulletin 1290, 91 p.<br />
LaPoint, D.J., 1992, Geologic setting of the Kings Mountain gold<br />
mine, Cleveland County, North <strong>Carolina</strong>, in Denisson, J.M. and<br />
Stewart, K.G., ed., Geologic field guides to North <strong>Carolina</strong> and<br />
vicinity: Chapel Hill, North <strong>Carolina</strong>, Department of Geology,<br />
University of North <strong>Carolina</strong> at Chapel Hill, Geologic <strong>Guidebook</strong><br />
No. 1, p. 35-48.<br />
Lieber, O.M., 1858, Report on the Survey of South <strong>Carolina</strong>, Second<br />
Annual Report to the General Assembly of South <strong>Carolina</strong>:<br />
Columbia, S.C., R.W. Gibbes, State printer, 145 p.<br />
Maybin, A.H. III, undated manuscript in files of South <strong>Carolina</strong><br />
<strong>Geological</strong> Survey listing gold occurrences in South <strong>Carolina</strong>.<br />
Maybin, A.H. III and Niewendorp, C.A., 1993, The central Piedmont<br />
allochthon: Alleghanian terrane in the central Piedmont of<br />
South <strong>Carolina</strong>: south <strong>Carolina</strong> Geology, v. 36, p. 47-58.<br />
McCauley, C.K. and Butler, J.R., 1966, Gold resources of South<br />
<strong>Carolina</strong>: S.C. <strong>Geological</strong> Survey Bulletin 32, 78 p.<br />
Sawkins, F.J., 1990, Metal Deposits in Relation to Plate Tectonics,<br />
2 nd ed., New York, Springer-Verlag, 461 p.<br />
Sloan, E., 1908, Catalogue of the mineral localities of South <strong>Carolina</strong>:<br />
South <strong>Carolina</strong> <strong>Geological</strong> Survey Bulletin 2, reprinted<br />
1979, 505 p.<br />
Tuomey, M., 1848, Report on the Geology of South <strong>Carolina</strong>:<br />
Columbia, S.C., A.S. Johnston, State Printer, 349 p.<br />
41
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