Chronology of the Pueblo Viejo epithermal gold–silver deposit, Dominican Republic: formation in an Early Cretaceous intra-oceanic island arc and burial under ophiolite
Tóm tắt
The Pueblo Viejo deposit (production to 1996: 166 t Au, 760 t Ag) is located in the Dominican Republic on the Caribbean island of Hispaniola and ranks as one of the largest high-sulfidation/acid-sulfate epithermal deposits (reserves in 2007: 635 t Au, 3,648 t Ag). One of the advanced argillic ore bodies is cut by an inter-mineral andesite porphyry dike, which is altered to a retrograde chlorite–illite assemblage but overprinted by late-stage quartz–pyrite–sphalerite veins and associated low-grade Au, Ag, Zn, Cd, Hg, In, As, Se, and Te mineralization. The precise TIMS U–Pb age (109.6 ± 0.6 Ma) of the youngest zircon population in this dike confirms that the deposit is part of the Early Cretaceous Los Ranchos intra-oceanic island arc. Intrusion-related gold–sulfide mineralization took place during late andesite–dacite volcanism within a thick pile (>200 m) of carbonaceous sand- and siltstones deposited in a restricted marine basin. The high-level deposit was shielded from erosion after burial under a late Albian (109–100 Ma) ophiolite complex (8 km thick), which was in turn covered by the volcano-sedimentary successions (>4 km) of a Late Cretaceous–Early Tertiary calc-akaline magmatic arc. Estimates of stratigraphic thickness and published alunite, illite, and feldspar K-Ar ages and closure temperatures (alunite 270 ± 20°C, illite 260 ± 30°C, K-feldspar 150°C) indicate a burial depth of about 12 km at 80 Ma. During peak burial metamorphism (300°C and 300 MPa), the alteration assemblage kaolinite + quartz in the deposit dehydrated to pyrophyllite. Temperature–time relations imply that the Los Ranchos terrane then cooled at a rate of 3–4°C/Ma during slow uplift and erosion.
Tài liệu tham khảo
Barton MD, Hanson RB (1989) Magmatism and the development of low-pressure metamorphic belts: implications from the western United States and thermal modeling. Geol Soc Amer Bull 101:1051–1065
Bowin CO (1966) Geology of central Dominican Republic (A case history of part of an island arc). Geol Soc Am Memoir 98:11–84
Bowin CO (1975) The geology of Hispaniola. In: Nairn AEM, Stehli FG (eds) Ocean basins and margins. vol. 3. Plenum Press, New York, pp 501–522
Bucher K, Frey M (2002) Petrogenesis of metamorphic rocks, 7th edn. Springer, Berlin Heidelberg New York, 341 pp
Cumming GL, Richards JR (1975) Ore lead isotope ratios in a continually changing Earth. Earth Planet Sci Lett 28:155–171
Cumming GL, Kesler SE, Krstic D (1982) Source of lead in sulfide ore at the Pueblo Viejo gold-silver oxide deposit, Dominican Republic. Econ Geol 77:1939–1942
Donnelly TW (1989) Geologic history of the Caribbean and Central America. In: Bally AW, Palmer AR (eds) The geology of North America—an overview. Geological Society of America, Boulder, Colorado, pp 299–321
Donnelly TW, Rogers JJW (1980) Igneous series in island arcs: The northeastern Caribbean compared with worldwide island-arc assemblages. Bull Volcanol 43:347–382
Draper G, Lewis JF (1991) Metamorphic belts in central Hispaniola. Geol Soc Am Special Paper 262:29–45
Draper G, Gutièrrez G, Lewis JF (1996) Thrust emplacement of the Hispaniola peridotite belt: orogenic expression of the Mid-Cretaceous Caribbean arc polarity reversal. Geology 24:1143–1146
Eberl DD, Velde B (1989) Beyond the Kubler index. Clay Minerals 24:571–577
Harris AC, Allen CM, Bryan SE, Campbell IH, Holcombe RJ, Palin JM (2004) ELA-ICP-MS U–Pb zircon geochronology of regional volcanism hosting the Bajo de la Alumbrera Cu–Au deposit-implications for porphyry-related mineralization. Miner Depos 39:46–67
Heubeck C, Mann P (1991) Structural geology and Cenozoic tectonic history of the southeastern termination of the Cordillera Central, Dominican Republic. Geological Society America Special Paper 262:315–336
Hutchison CS (1974) Laboratory handbook of petrographic techniques. Wiley and Sons, New York, p 527
Joyce J (1991) Blueschist metamorphism and deformation on the Samana peninsula: a record of subduction and collision in the Greater Antilles. Geol Soc Am Special Paper 262:47–76
Kesler SE, Russell N, Seaward M, Rivera JA, McCurdy K, Cumming GL, Sutter JF (1981) Geology and geochemistry of sulfide mineralization underlying the Pueblo Viejo gold–silver oxide deposit, Dominican Republic. Econ Geol 76:1096–1117
Kesler SE, Russell N, Polanco J, McCurdy K, Cumming GL (1991a) Geology and geochemistry of the early Cretaceous Los Ranchos Formation, central Dominican Republic. Geol Soc Am Special Paper 262:187–201
Kesler SE, Russell N, Reyes C, Santos L, Rodriguez A, Fondeur L (1991b) Geology of the Maimon Formation, Dominican Republic. Geol Soc Am Special Paper 262:173–185
Kesler SE, Sutter JF, Barton JM, Speck RC (1991c) Age of intrusive rocks in northern Hispaniola. Geol Soc Am Special Paper 262:165–172
Kesler SE, Russell N, McCurdy K (2003) Trace-metal content of the Pueblo Viejo precious-metal deposits and their relation to other high-sulfidation epithermal systems. Miner Depos 38:668–682
Kesler SE, Campbell IH, Smith CN, Hall CM, Allen CM (2005a) Age of the Pueblo Viejo gold–silver deposit and its significance to models for high-sulfidation epithermal mineralization. Econ Geol 100:253–272
Kesler SE, Campbell IH, Allen CM (2005b) Age of the Los Ranchos Formation, Dominican Republic: timing and tectonic setting of primitive island arc volcanism in the Caribbean region. Geol Soc Amer Bull 117:987–995
Kettler RM, Rye RO, Kesler SE, Meyers PA, Polanco J, Russell N (1992) Gold deposition by sulfidation of ferrous Fe in the lacustrine sedimentary rocks of the Pueblo Viejo district (Dominican Republic). Chem Geol 99:29–50
Lebrón MC, Perfit MR (1994) Petrochemistry and tectonic significance of Cretaceous island-arc rocks, Cordillera Oriental, Dominican Republic. Tectonophysics 229:69–100
Love DA, Clark AH, Hodgson CJ, Mortensen JK, Archibald DA, Farrar E (1998) The timing of adularia–sericite-type mineralization and alunite–kaolinite-type alteration, Mount Skukum epithermal gold deposit, Yukon Territory, Canada: 40Ar–39Ar and U–Pb geochronology. Econ Geol 93:437–462
Ludwig KR (1993) PBDAT—a computer program for processing Pb-U-Th isotope data. U.S. Geological Survey Open-File Report 88–542, 32 pp
Ludwig KR (2003) User’s manual for Isoplot 3.00—a geochronological toolkit for Microsoft Excel. Berkeley Geochronology Center, Special Publication 4, 70 pp
Mann P, Draper G, Lewis JF (1991) An overview of the geologic and tectonic development of Hispaniola. Geol Soc Am Special Paper 262:1–28
McDougall I, Harrison TM (1988) Geochronology and thermochronology by the 40Ar/39Ar method. Oxford Monographs on Geology and Geophysics no. 9. Oxford University Press, Oxford, 212 pp
Miyashiro A (1973) Metamorphism and metamorphic belts. Allen and Unwin Ltd., London, 492 pp
Muntean JL, Kesler SE, Russell N, Polanco J (1990) Evolution of the Monte Negro acid-sulfate Au–Ag deposit, Pueblo Viejo, Dominican Republic: important factors in grade development. Econ Geol 85:1738–1758
Muntean J, Hall G, Kesler S, Mueller A, O’Brien D, Russell N (2007) Pueblo Viejo high-sulfidation epithermal gold–silver deposit, Dominican Republic: a new model of formation beneath barren limestone cover—a discussion. Econ Geol 102:755–757
Nelson CE (2000a) Volcanic dome emplacement and Au-Ag-Zn mineralization at the Moore deposit, Pueblo Viejo district, Dominican Republic. In: Cluer JK, Price JG, Struhsacker EM, Hardyman RF, Morris CL (eds) Geology and ore deposits 2000: the Great Basin and beyond, vol. 1. Geological Society of Nevada, Reno, pp 67–77
Nelson CE (2000b) Volcanic domes and gold mineralization in the Pueblo Viejo district, Dominican Republic. Miner Depos 35:511–525
Parrish RR, Krogh TE (1987) Synthesis and purification of 205Pb for U–Pb geochronology. Chem Geol (Isotope Geoscience Section) 66:103–110
Rockwell BW, Cunningham CG, Breit GN, Rye RO (2006) Spectroscopic mapping of the White Horse alunite deposit, Marysvale volcanic field, Utah: evidence of a magmatic component. Econ Geol 101:1377–1395
Russell N, Kesler SE (1991) Geology of the maar–diatreme complex hosting precious metal mineralization at Pueblo Viejo, Dominican Republic. Geological Society America Special Paper 262:203–215
Russell N, Polanco J, Kesler SE (1986) Geology of the Monte Negro gold-silver deposit, Pueblo Viejo district, Dominican Republic. In: Mcdonald AJ (ed) Proceedings of Gold’86, International Symposium on the Geology of Gold, Toronto, pp 497–503
Sillitoe RH, Hall DJ, Redwood SD, Waddell AH (2006) Pueblo Viejo high-sulfidation epithermal gold-silver deposit, Dominican Republic: a new model of formation beneath barren limestone cover. Econ Geol 101:1427–1435
Sillitoe RH, Hall DJ, Redwood SD, Waddell AH (2007) Pueblo Viejo high-sulfidation epithermal gold-silver deposit, Dominican Republic: a new model of formation beneath barren limestone cover—a reply. Econ Geol 102:758–760
Srodon J (1984) X-ray powder diffraction identification of illitic materials. Clay and Clay Minerals 32:337–349
Vennemann TW, Muntean JL, Kesler SE, O’Neil JR, Valley JW, Russell N (1993) Stable isotope evidence for magmatic fluids in the Pueblo Viejo epithermal acid sulfate Au–Ag deposit, Dominican Republic. Econ Geol 88:55–71