首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Telluride mineralogy of the low-sulfidation epithermal Emperor gold deposit, Vatukoula, Fiji
Authors:D W Pals  P G Spry
Institution:(1) Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa, U.S.A., US
Abstract:Summary ¶The epithermal, low sulfidation Emperor gold telluride deposit in Fiji, hosted by Late Miocene-Early Pliocene shoshonitic rocks, is spatially related to a low-grade porphyry Cu system on the western flank of the Tavua Caldera. Gold is largely in the form of ldquoinvisiblerdquo gold in arsenian pyrite but 10 to 50% of gold is in the form of precious metal tellurides. Gold mineralization occurs in steeply dipping dikes and faults, flat-dipping structures (<45°), referred to locally as ldquoflatmakes,rdquo and at the intersection of two or more structures referred to as ldquoshatter zones.rdquo Petrographic, electron microprobe, and scanning electron microscope analyses of ores from some of the more recently discovered orebodies, Matanagata, Matanagata East, and R1 reveal that tellurium-bearing minerals, sylvanite, calaverite, krennerite, petzite, hessite, coloradoite, melonite, native tellurium, and rare benleonardite, formed during various hydrothermal stages, hosted in quartz, and to a lesser extent arsenian pyrite and tetrahedrite group minerals. Sylvanite followed by krennerite are the two most common tellurides in these orebodies. These tellurides show no systematic spatial distribution within flatmakes but there appears to be a higher concentration of tellurides where the flatmake intersects steep structures. Gold-rich tellurides preceded the formation of silver-rich tellurides and were constrained at 250thinsp°C in log fthinspS2 and log fthinspTe2 space at –12.7 to –10.1 and –9.4 to –7.8, respectively, based on sulfide and telluride stabilities, and the composition of sphalerite. Ore forming components, such as Au, Ag, Te, Cu, V, and S, were likely derived from Late Miocene-Early Pliocene monzonites in and adjacent to the Tavua caldera.Received January 14, 2003; revised version accepted June 26, 2003
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号