Details
| Original language | English |
|---|---|
| Pages (from-to) | 1459-1464 |
| Number of pages | 6 |
| Journal | American Mineralogist |
| Volume | 98 |
| Issue number | 8-9 |
| Publication status | Published - 1 Aug 2013 |
Abstract
We have investigated experimentally the partitioning of Au between solid and liquid sulfide phases and basaltic melts at 200 MPa, at redox conditions close to the sulfide-sulfate transition, over temperatures between 1050 and 1200 °C, which span the monosulfide solid solution (MSS) - sulfide liquid (SuL) solidus. The measured MSS/basalt partition coefficient of Au (D AuMSS-sil) is about 100-200, whereas the partition coefficient of sulfide liquid/basalt (DAuSuL-sil) is approximately 10 times larger at 2200. Although we find that temperature, pressure, and oxygen fugacity (fO2) exert relatively weak controls on Au partitioning, they exert major indirect influences on Au behavior by controlling the identity of the condensed sulfide phase and by affecting S solubility. These observations have important implications for the behavior of Au in the processes of partial melting in the mantle and magma crystallization in the crust. The occurrence of natural magmas with elevated concentrations of Au and presumably other highly siderophile and chalcophile elements requires predominance of MSS over SuL in the source or/and oxidizing conditions close to or above the sulfide-sulfate transition in the magma.
Keywords
- Basalt, Enrichment, Gold, Magma, Partitioning, Solubility, Sulfide, Sulfur
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: American Mineralogist, Vol. 98, No. 8-9, 01.08.2013, p. 1459-1464.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Behavior of gold in a magma at sulfide-sulfate transition
T2 - Revisited
AU - Botcharnikov, Roman E.
AU - Holtz, Francois
AU - Mungall, James E.
AU - Beermann, Oliver
AU - Linnen, Robert L.
AU - Garbe-Schönberg, Dieter
N1 - Funding Information: This study was supported by the German Science Foundation (DFG Grants Bo2941-1 and -2) and by the Leibniz Universität Hannover. J. Feige is acknowledged for the help with the preparation of olivine containers, and T. Sisson is thanked for providing us with his data on Au concentrations in alkali-rich rocks from Hawaii. The manuscript has been substantially improved by the constructive reviews of M. Pichavant, J. Richards, C. Ballhaus, and I. Swainson. The editorial handling by I. Swainson is also greatly acknowledged. Copyright: Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/8/1
Y1 - 2013/8/1
N2 - We have investigated experimentally the partitioning of Au between solid and liquid sulfide phases and basaltic melts at 200 MPa, at redox conditions close to the sulfide-sulfate transition, over temperatures between 1050 and 1200 °C, which span the monosulfide solid solution (MSS) - sulfide liquid (SuL) solidus. The measured MSS/basalt partition coefficient of Au (D AuMSS-sil) is about 100-200, whereas the partition coefficient of sulfide liquid/basalt (DAuSuL-sil) is approximately 10 times larger at 2200. Although we find that temperature, pressure, and oxygen fugacity (fO2) exert relatively weak controls on Au partitioning, they exert major indirect influences on Au behavior by controlling the identity of the condensed sulfide phase and by affecting S solubility. These observations have important implications for the behavior of Au in the processes of partial melting in the mantle and magma crystallization in the crust. The occurrence of natural magmas with elevated concentrations of Au and presumably other highly siderophile and chalcophile elements requires predominance of MSS over SuL in the source or/and oxidizing conditions close to or above the sulfide-sulfate transition in the magma.
AB - We have investigated experimentally the partitioning of Au between solid and liquid sulfide phases and basaltic melts at 200 MPa, at redox conditions close to the sulfide-sulfate transition, over temperatures between 1050 and 1200 °C, which span the monosulfide solid solution (MSS) - sulfide liquid (SuL) solidus. The measured MSS/basalt partition coefficient of Au (D AuMSS-sil) is about 100-200, whereas the partition coefficient of sulfide liquid/basalt (DAuSuL-sil) is approximately 10 times larger at 2200. Although we find that temperature, pressure, and oxygen fugacity (fO2) exert relatively weak controls on Au partitioning, they exert major indirect influences on Au behavior by controlling the identity of the condensed sulfide phase and by affecting S solubility. These observations have important implications for the behavior of Au in the processes of partial melting in the mantle and magma crystallization in the crust. The occurrence of natural magmas with elevated concentrations of Au and presumably other highly siderophile and chalcophile elements requires predominance of MSS over SuL in the source or/and oxidizing conditions close to or above the sulfide-sulfate transition in the magma.
KW - Basalt
KW - Enrichment
KW - Gold
KW - Magma
KW - Partitioning
KW - Solubility
KW - Sulfide
KW - Sulfur
UR - http://www.scopus.com/inward/record.url?scp=84882754681&partnerID=8YFLogxK
U2 - 10.2138/am.2013.4502
DO - 10.2138/am.2013.4502
M3 - Article
AN - SCOPUS:84882754681
VL - 98
SP - 1459
EP - 1464
JO - American Mineralogist
JF - American Mineralogist
SN - 0003-004X
IS - 8-9
ER -