Role of Melting in the Evolution of the Broken Hill Orebody

该项目旨在确定熔化对澳大利亚Broken Hill世界级铅锌矿床的影响，该矿床变质于麻粒岩相，完全处于纯Pb-Zn-Fe-Ag-S体系的熔化范围内。我们计划研究矿体及其蚀变晕内的结构、组合和矿物组成，看看所观察到的关系是否可以用岩石与结晶分异多金属熔体之间的反应来解释。我们计划利用微量元素地球化学来确定矿石周围的辉石岩层是否从多金属熔体中结晶。它还将确定矿体周围涉及石榴石的高变异组合是否可能是由类辉石岩结晶过程中从熔体中释放出来的流体产生的。它还打算研究矿体内的组合，看看它们是否记录了一个液体下降线，熔体在分化过程中富集了不相容的元素，Ag, Au, As, Bi， Sb和Tl。

Frost and SwappEAR-0125113This project aims to determine the effect that melting had on the world-class lead-zinc ore deposit at Broken Hill, Australia, which was metamorphosed at granulite facies, well within the range of melting for the pure Pb-Zn-Fe-Ag-S system. We plan to study the textures, assemblages and mineral compositions within the ore body and its alteration halo to see if the relations observed can be explained by reactions between the country rock and a crystallizing and differentiating polymetallic melt. We plan to use trace element geochemistry to determine if the pyroxenoid horizon around the ore crystallized from the polymetallic melt. It will also determine if the high-variance assemblages around the ore body that involve garnet could have been produced by fluids that were released from the melt during crystallization of the pyroxenoids. It also intends to study assemblages within the ore body to see if they record a liquid line of descent, with the melt becoming enriched in incompatible elements, Ag, Au, As, Bi, Sb, and Tl, during differentiation.