TINJAUAN EMAS EPITERMAL PADA LINGKUNGAN VOLKANIK

  • Eddy Sumardi Pusat Sumber Daya Geologi

Abstract

Endapan ernas epitermal  dilingkungan   batuan vulkanik  adalah  hampir  selalu berasosiasi  dengan  batuan vulkanik  calc-alkaline   dan batuan  intrusi,   eberapa  memperlihatkan   suatu  hubungan  yang erat dengan  batuan vulkanik  alkali.

Endapan emas epiterrnal  bentuknya  adalah sangat  bervariasi,  dari vein-vein  kuarsa tipis sampai  deposit endapan  disseminated   yang besar,  dan terdapat  dalam   lingkungan  geologi  yang berbeda,  oleh karena itu mereka  memperlihatkan   suatu rentang yang lebar dari signatures  geokimia  dan geofisika,  juga ciri-ciri tonal pengindraan  jauh

Di  Kelian,   Indonesia,   endapan   berasosiasi    dengan   batuan   andesit   Oligosen   Atas   Miosen   Bawah, piroklastik  Eosen Atas (?) dan sedikit riolit, dan beberapa  basal Plio-Pleistosen.   la terletak  pada suatu tren regional   utara-timur    yang  juga   mengandung    mineralisasi    epitermal   signifikan   di  G.   Muro   dan  G. Masuparia.   Mineralisasi    terjadi   di  tepi  dari  suatu   tubuh   andesit   yang   mengintrusi    satuan   batuan pyroklastik  Eosen,  dan batuan andesit yang terkekarkan,   batuan tufa,  dan bermacam-macam   breksi.

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References

Auspec Gold N.L., 1988. Annual report for 1988. Auspac gold N.L., GPO Box 5297, Sydney, NSW 2001, Aust. 49 p.

Berger, B. R., dan Eimon, P. I., 1983. Conceptual models of epithermal precious metal endapans. Di dalam: Shanks, W.C., (ed.). Cameron volume on unconventional mineral endapans, pp. 191-205. Am Inst. Mining Metal Petroleum Engineers, New york.

Bonham, H.P., 1988. Model for volcanic-hosted epithermal precious metal endapans. Di dalam: Seater, R.W., Cooper, J.J., dan Vikre, P.G., (eds.) Bulk mineable Precious Metal Endapans of the Westem United States, Symp. Proc. Reno, Nevada Geol. Soc. Nevada, 259-271.

Craig, J.R., dan Vaughan, D.J., 1981. Ore Microscopy and Ore Petrography. John Wiley & Sons, New York, 406 p. •

Edwards, R., dan Atkinson, K., 1986. Ore Endapan Geology: and its influence on mineral exploration.Chapman and Hall Ltd., London, 143-173.

Evan, A.M., 1987. An Introduction to Ore Geology. A Geoscience Text, 2nd edition, Blackwell Scientific Publication, Melbourne, 358 p.

Giles, D.L., dan Nelson, C.E., 1984. Principal features of Epithermal Lode Gold Endapans of the Circum Pacific Rim. Circum Pacific Energy and Mineral Resources Conf., 3rd, Honolulu, Hawaii, August 22- 28, 1982, Trans., 273-278.

Hall, G.E.M., dan Bonham-Carter, G.F., 1988. Review of methods to determine gold, platinum and palladium in production-oriented geochemical laboratories, with application of a statistical procedure to test for bias. J. Geochem. Explor.,30, 1-27.

Heald, P., Foley, N.K., dan Hayba, 0.0., 1987. Comparative anatomy of volcanic-hosted epithermal endapans:Acid-sulfate and adularia-sericitetypes.Econ. Geol., 82, 1-27.

Henley, R.W., 1991. Epithermal gold endapans in volcanic terranes. Di dalam: Foster, R.P., (ed.). Gold Metallogeny and Exploration. pp. 133-164. Blackie, Glasgow and London.

Irvine, R.J., dan Smith, M.J., 1990. Geophysical exploration for epithermal gold endapans. J. Geochem.

Explor., 36, 375-412.

lzawa, E., Urashima, Y., lbaraki, K., Suzuki, R., Yokoyama, T., Kawasaki, K., Koga, A., dan Taguchi, S.,

The Hishikari gold endapan: high-grade epithermal veins in Quarternary volcanic soputhern

Kyushu, Japan. J. Geochem. Explor.,36, 1-56.

Kawasaki.K Okada, K., dan Kubota, R., 1986. Geophysical Survey in the Hishikari area. Min. Geol., 36,131-147

Keays R.R., dan Scott, R.B., 1976. Precious metal in ocean ridge basalt: Implication for basalt as source rock for gold mineralisation. Econ. Geol., 71, 705-720.

Lindgren, W., 1933. Mineral Endapans. McGraw-Hill Book Company, 4th Ed., 930 p.

Modriniak, N., dan Marsden_, E., 1938. Experiment in geophysical survey in New Zealand. Geol. Mem. 4, Dep. Sci. Ind. Res., Wellington, New Zealand, pp. 67-72.

Nash, G.T., Granger, H.C., dan Adam, S.S., 1981. Geologi and concepts of genesis of important types of uranium endapans. Econ. Geol. 75 th Anniv. Vol., 63-116.

Palacky, G.J., 1988. Resistivity characteristics of geological targets: Electromagnetic methods. Di dalam: Habighian, M.N., (ed.).Applied Geophysics, Soc. Explor. Geoph. Tualsa, 29-91.

Paterson, N.R., dan Hallof, P.G., 1991. Geophysical exploration for gold. Di dalam: Foster, R.P., (ed.), Gold Metallogeny and Exploration, 350-359. Blackie and Sons Ltd., Glasgow.

Reed, L.E., 1989. Geophysics in gold exploration. Di dalam: Garland, G.D., (ed.). Proc. Explor. , 87, Ontario Geol. Surv., Spec., 3, 473-485.

Reid, F., and Hedenquist, J.W., 1984. Epithermal Gold: Models for exploration. The earth resources foundation, Sydny Univ., 222 p.

Schmitt, H., 1950. Origin of the "epithermal" mineral endapans. Econ. Geol., 45, 191-201.

Taylor, G.H., Coste, B., Lambert, A., dan Zeegers, H., 1989. Geochemical signature (bedrock and saprollite) of gold mineralization and associated by hydrothermal alteration at Darlin, French Guyana (extended abstract). J. Geochem. Explor., 32, 59-60.

Van Leeuwen, T.M., Leach, T., Hwke, A.A., dan Hawke, M.M., 1990. The Kelian disseminated gold endapan, east Kalimantan, Indonesia: An example of deeply eroded epithermal System. Di dalam: Hedenquist, J.W., White, N.C., and Siddeley, G., (eds.). Epithermal Gold Endapans ofCircum-Pacific. Geology, Geochemistry, Origin and Exploration, I. J. Geochem. Explor., 35, 1-61.

White, D.E., dan Hedenquist,J.W.,1990. Epithermal environments and styles of mineralization: variations and their causes, and guidelines for exploration. J. Geochem. Exp I or., 36, 445-4 74.

Worthington, J.E., dan Kiff, I.T., 1970. A suggested volcanogenic origin for certain gold endapans in the slate belt of the North Carolina Piedmont. Econ. Geol., 65, 529-537.

Wyborn, D., 1988. Ordovician magmatism, gold mineralization and an integrated tectonic model for the Ordovician and Silurian history of the Lachlan Foldbelt in New South Wales. Bureau of Mineral Resources, Canbera,Aust., Res. Newletter, 8, 13-14.

Zeegers, H., dan Leduc, C., 1991. Geochemical exploration for gold

in temperate, arid, semi-arid, and rain forest terrains. Di dalam: Foster, R,P., (ed.). Gold Metallogeny and Exploration, pp. 309-331. Blackie and Son Ltd., Glasgow

Published
2009-08-10
Section
Buletin Sumber Daya Geologi