Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada
Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada
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DOI：
10.1038/s43247-021-00128-4
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发表时间：
2021-03-17
影响因子：
7.9
通讯作者：
Rollinson, Gavyn K.
中科院分区：
文献类型：
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作者：
Carter, Lawrence C.;Williamson, Ben J.;Rollinson, Gavyn K.
斑岩型矿床是世界上铜和钼的主要来源，并提供了很大比例的金和其他金属。然而，成矿流体从源岩浆中提取并向上运移到成矿环境中的机制尚不清楚。在这里，我们使用现场，微观结构和地球化学技术，调查现场的关系和样品从约8公里深的横截面通过原型耶灵顿斑岩区，内华达州。我们确定了一个相互连接的网络，相对较低的温度热液石英，连接到矿化晶洞内细晶岩脉。我们建议，斑岩矿床形成流体迁移的演变，更富水的内部地区的鲁尔山花岗岩通过这些细晶岩脉，其中包含一个可渗透的长石和石英的岩浆晶体糊状物。我们所描述的结构提供了岩石学证据，通过晶体泥岩脉的流体输送。我们建议，这一过程应考虑在未来的模型形成斑岩和类似类型的矿床。根据野外、岩相学和地球化学调查，热液成矿流体从相对较深的、演化的和富水的岩浆中通过晶泥脉迁移到耶灵顿斑岩系统的成矿环境。
Porphyry-type deposits are the world's main source of copper and molybdenum and provide a large proportion of gold and other metals. However, the mechanism by which mineralising fluids are extracted from source magmas and transported upwards into the ore-forming environment is not clearly understood. Here we use field, micro-textural and geochemical techniques to investigate field relationships and samples from a circa 8km deep cross-section through the archetypal Yerington porphyry district, Nevada. We identify an interconnected network of relatively low-temperature hydrothermal quartz that is connected to mineralised miarolitic cavities within aplite dykes. We propose that porphyry-deposit-forming fluids migrated from evolved, more water-rich internal regions of the underlying Luhr Hill granite via these aplite dykes which contained a permeable magmatic crystal mush of feldspar and quartz. The textures we describe provide petrographic evidence for the transport of fluids through crystal mush dykes. We suggest that this process should be considered in future models for the formation of porphyry- and similar-type deposits. Hydrothermal mineralising fluids migrated from relatively deep, evolved and water-rich magmas via crystal mush dykes to reach the ore-forming environment in the Yerington porphyry system, according to field, petrographic and geochemical investigations.