Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; October 2008; v. 36; no. 10; p. 815-818; DOI: 10.1130/G25093A.1
© 2008 Geological Society of America
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tooth, B.
Right arrow Articles by Liu, W.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Modeling of gold scavenging by bismuth melts coexisting with hydrothermal fluids

Blake Tooth1, Joël Brugger1,2, Cristiana Ciobanu1,2 and Weihua Liu3

1 1 School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
2 2 South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
3 3 CSIRO Exploration & Mining, School of Geosciences, Monash University, Clayton, Victoria 3168, Australia

The effect of gold scavenging by bismuth melts is investigated using equilibrium thermodynamic modeling of an aqueous solution–mineral–melt system. The calculations for the Au-Bi-Na-Cl-S-H-O system, performed at temperatures between 300 and 450 °C, demonstrate that Au concentrations in the melt are several orders of magnitude higher than in the coexisting fluid, indicating the possible formation of economic gold deposits from undersaturated aqueous fluids, in which mineralization would not be expected in the absence of a bismuth melt. The model applies to any deposit where a Bi melt is stable and coexists with a hydrothermal fluid; examples of such deposits are known from skarn, intrusion-related, orogenic, and volcanogenic massive sulfide (VMS) gold systems. In sulfur-poor systems the partitioning curves presented here can be used directly to correlate the gold concentration in the fluid and the Au grade in the ore (e.g., Escanaba Trough VMS deposit). These results also illustrate important principles generally applicable to understanding magmatic-hydrothermal and metamorphic deposits that may have contained significant volumes of more complex polymetallic melts.

Key Words: hydrothermal fluids • melts • thermodynamics • numerical modeling • gold • bismuth • ore deposits






JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America