Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Sack, R. O. Articles by Ebel, D. S. Search for Related Content GeoRef GeoRef Citation

Origin of high^-Ag fahlores from the Galena Mine, Wallace, Idaho, U.S.A.

¹ OFM Research, 28430 NE 47th Place, Redmond, WA 98053-8841
² Department of Earth and Space Sciences, Box 351310, University of Washington, Seattle, Washington 98195-1310, U.S.A.
³ Coeur Silver Valley Inc., P.O. Box 440, Wallace, Idaho 83873-0440, U.S.A.
⁴ 2153B Old River Road, Kingston, Idaho 83839, U.S.A.
⁵ Department of Earth and Planetary Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024-5192, U.S.A.

Correspondence: ^* E-mail: sack{at}ess.washington.edu

Tetrahedrite fahlores from the Galena Mine of the Coeur d’Alene Mining District (Wallace, Idaho) have been found to be enriched in Ag by the Ag-Cu exchange reaction:

which occurred during cooling following fahlore mineralization. This solid-state reaction produced a distinct population of high-Ag fahlores found in galena-rich samples, quantitatively removed Ag (in an AgSbS₂ component) from galena, and accounts for all of the bournonite mineralization. This reaction has produced the most argentian fahlore yet found [molar Ag/(Ag + Cu) = 0.443] in the district, and forms a secondary overprint on any primary fahlore zoning that may have existed. The results obtained here indicate that the galena and fahlore-siderite stages of mineralization were virtually synchronous, as this reaction has produced the same result despite the opposite relative age relationships of these mineralization stages exhibited in two of the mines studied. Multiple lines of evidence suggest a temperature between 320 and 350 °C for this "stage." Based on the Ag/(Ag + Cu) of fahlores and Fe-Zn partitioning between fahlore and sphalerite, we estimate that fahlore compositions were frozen in by about 235 °C, roughly 40 °C above corresponding temperatures obtained for the Gold Hunter vein of the Lucky Friday Mine. This result and the absence of readily detectable diaphorite (~Pb₂Ag₃Sb₃S₈) in the Galena Mine sample containing the highest Ag fahlore indicate a faster cooling rate for the terrane in the vicinity of the Galena Mine.

This article has been cited by other articles:

				S. Staude, T. Wagner, and G. Markl MINERALOGY, MINERAL COMPOSITIONS AND FLUID EVOLUTION AT THE WENZEL HYDROTHERMAL DEPOSIT, SOUTHERN GERMANY: IMPLICATIONS FOR THE FORMATION OF KONGSBERG-TYPE SILVER DEPOSITS Can Mineral, October 1, 2007; 45(5): 1147 - 1176. [Abstract] [Full Text] [PDF]

				R. O. Sack and D. S. Ebel Thermochemistry of Sulfide Mineral Solutions Reviews in Mineralogy and Geochemistry, January 1, 2006; 61(1): 265 - 364. [Full Text] [PDF]