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- W1969598356 abstract "The Otago and Alpine schists of the South Island of New Zealand form a young ( A large suite of samples representative of the lithologic and metamorphic variation in the Otago and Alpine schists was collected and analyzed for a comprehensive suite of elements. The aim was to identify any rock type or metamorphic setting that may be depleted in the suite of ore-forming elements (Au, Ag, As, Sb, Hg, Mo, and W) relative to unmetamorphosed protoliths, perhaps representing the source for the enrichments observed in the Otago ore deposits. Gold, Ag, As, Sb, Hg, Mo, and W were found to have significantly lower concentrations in higher grade metamorphic rocks compared to unmetamorphosed protolith samples. These were the only elements in a suite of 12 major and 50 trace elements to show systematic depletions with metamorphic grade. Investigation of the trace element chemistry of sulfide minerals indicates that the whole-rock depletions are caused by the disappearance between greenschist and amphibolite facies conditions of pyrite, galena, sphalerite, and cobaltite, the major host phases for the ore-forming elements. More than 95 percent of upper greenschist and amphibolite facies samples are significantly depleted in the ore-forming elements. Such regional-scale depletions require pervasive, grain-boundary fluid flow throughout these rocks. The leaching is most likely to have been caused by metamorphic fluid produced by dehydration reactions at the greenschist-amphibolite boundary. The suite of elements depleted in mid- to high-grade Otago and Alpine schists is almost identical to those enriched in the orogenic gold deposits in Otago. Furthermore, the vertical zonation in depletions is similar to the vertical zonation in enrichments that occurs in the Otago deposits. Mass-balance calculations suggest that 2 metric tons (t) Au and 24,000 t As was leached from 1 km3 of amphibolite facies rock and that the Macraes deposit could have been formed by leaching of a 5- × 5- × 5-km cube of amphibolite facies rock. We propose that the orogenic gold deposits in Otago, such as Macraes, were formed directly from metal-rich metamorphic fluid produced during prograde metamorphism at depth. The contribution of other fluid and metal sources in the formation of these deposits, such as magmatic fluids, cannot be ruled out, but there is no direct evidence to support their involvement. Infiltration of meteoric water, such as occurs currently in the Southern Alps of New Zealand may have contributed to the formation of the late-stage deposits that formed at shallow level during uplift of the Otago schists." @default.
- W1969598356 created "2016-06-24" @default.
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- W1969598356 date "2006-12-01" @default.
- W1969598356 modified "2023-10-17" @default.
- W1969598356 title "Sources of Metals and Fluids in Orogenic Gold Deposits: Insights from the Otago and Alpine Schists, New Zealand" @default.
- W1969598356 cites W11107958 @default.
- W1969598356 cites W136974534 @default.
- W1969598356 cites W1524759453 @default.
- W1969598356 cites W1554740489 @default.
- W1969598356 cites W1965935874 @default.
- W1969598356 cites W1966764996 @default.
- W1969598356 cites W1970626197 @default.
- W1969598356 cites W1974064297 @default.
- W1969598356 cites W1975861833 @default.
- W1969598356 cites W1976133378 @default.
- W1969598356 cites W1977932502 @default.
- W1969598356 cites W1981737804 @default.
- W1969598356 cites W1985480593 @default.
- W1969598356 cites W1985827600 @default.
- W1969598356 cites W1988833071 @default.
- W1969598356 cites W1991608935 @default.
- W1969598356 cites W2009032167 @default.
- W1969598356 cites W2011169560 @default.
- W1969598356 cites W2011939763 @default.
- W1969598356 cites W2015027708 @default.
- W1969598356 cites W2015248982 @default.
- W1969598356 cites W2022499921 @default.
- W1969598356 cites W2026897060 @default.
- W1969598356 cites W2028299312 @default.
- W1969598356 cites W2028633980 @default.
- W1969598356 cites W2030155465 @default.
- W1969598356 cites W2032565676 @default.
- W1969598356 cites W2033354436 @default.
- W1969598356 cites W2037339947 @default.
- W1969598356 cites W2037397108 @default.
- W1969598356 cites W2038918440 @default.
- W1969598356 cites W2040149620 @default.
- W1969598356 cites W2041198349 @default.
- W1969598356 cites W2041276447 @default.
- W1969598356 cites W2041508176 @default.
- W1969598356 cites W2042610335 @default.
- W1969598356 cites W2046022281 @default.
- W1969598356 cites W2046957742 @default.
- W1969598356 cites W2047436128 @default.
- W1969598356 cites W2049386485 @default.
- W1969598356 cites W2054867889 @default.
- W1969598356 cites W2055394521 @default.
- W1969598356 cites W2058073377 @default.
- W1969598356 cites W2065990580 @default.
- W1969598356 cites W2068908700 @default.
- W1969598356 cites W2075901285 @default.
- W1969598356 cites W2077684298 @default.
- W1969598356 cites W2077772704 @default.
- W1969598356 cites W2081149350 @default.
- W1969598356 cites W2084519411 @default.
- W1969598356 cites W2092980132 @default.
- W1969598356 cites W2094414093 @default.
- W1969598356 cites W2094976444 @default.
- W1969598356 cites W2097983023 @default.
- W1969598356 cites W2098361463 @default.
- W1969598356 cites W2101525489 @default.
- W1969598356 cites W2104480833 @default.
- W1969598356 cites W2107248935 @default.
- W1969598356 cites W2111660215 @default.
- W1969598356 cites W2114745060 @default.
- W1969598356 cites W2117077530 @default.
- W1969598356 cites W2117239602 @default.
- W1969598356 cites W2122548972 @default.
- W1969598356 cites W2127888210 @default.
- W1969598356 cites W2129460465 @default.
- W1969598356 cites W2138522501 @default.
- W1969598356 cites W2154724447 @default.
- W1969598356 cites W2156446721 @default.
- W1969598356 cites W2167456261 @default.
- W1969598356 cites W2168850729 @default.
- W1969598356 cites W2312255672 @default.
- W1969598356 cites W2326914474 @default.
- W1969598356 cites W2980558448 @default.
- W1969598356 cites W2981659635 @default.
- W1969598356 cites W3125350982 @default.
- W1969598356 cites W3147452941 @default.
- W1969598356 cites W3156136498 @default.
- W1969598356 cites W411315707 @default.
- W1969598356 cites W781603501 @default.
- W1969598356 doi "https://doi.org/10.2113/gsecongeo.101.8.1525" @default.
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