The Nimbus Ag–Zn(–Au) deposit is a hybrid VHMS deposit with epithermal characteristics formed in the Eastern Goldfields Superterrane, Yilgarn Craton, under shallow water (~ 700 mbsl), low-temperature conditions. Intersections of some ore lenses are high-grade and polymetallic, making similar styles of mineralization attractive Yilgarn exploration targets. The mineralization at Nimbus is hosted by a bimodal felsic–mafic succession of volcanic rocks, which are overlain by a succession of least-altered polymict conglomerates with a carbonaceous to dacitic matrix. A new Re–Os age (2680 ± 34 Ma; nodular pyrite and black shale) suggests that the overlying polymict conglomerate is coeval to ~ 2.70 Ga volcanism and mineralization at Nimbus. The pyrite within the high-grade polymetallic sulfide assemblages has a consistently lower Sb/Ag ratio (1–30) than pyrite from other sulfide phases (e.g., 30 to 1000 in colloform and barren pyrite). Trace elements (TEs) in sedimentary nodular pyrite from multiple intervals along a single drillhole (NBDH010), indicate the existence of an enriched sedimentary interval with higher total TE content, Ag/Au and Sb/Au, lower S/Se, and polymetallic-like signature of Sb/Ag. Within this enriched interval, the black shale matrix of the polymict conglomerate shows higher total organic carbon (TOC), Mo content, and Co/Ni ratios and suggest increased bio-activity at that time, interpreted to be associated with the Ag–Zn(–Au) mineralization. The TE characteristics in sedimentary pyrite, reflecting increased metal content in seawater inferred from in situ pyrite trace element analysis has the potential to be developed into an exploration tool for successions, adjacent and coeval to similar ore deposits.

中文翻译：

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海水中金属矿的激增和生物活性的增加：西澳大利亚伊尔加恩克拉通太古代序列中 VHMS 矿化的示踪剂

Nimbus Ag-Zn(-Au) 矿床是一种混合型 VHMS 矿床，具有超热液特征，形成于伊尔加恩克拉通东部金矿超级地体，在浅水 (~700 mbsl) 低温条件下形成。一些矿透镜体的交汇处是高品位的多金属矿，使得类似风格的矿化成为有吸引力的伊尔加恩勘探目标。Nimbus 的矿化由双峰长英质-基性火山岩层序组成，上面覆盖着一系列具有碳质至英安质基质的变化最小的混杂岩砾岩。一个新的 Re-Os 年龄（2680 ± 34 Ma；球状黄铁矿和黑色页岩）表明上覆的混杂岩砾岩与 Nimbus 的 ~ 2.70 Ga 火山作用和矿化同时期。高品位多金属硫化物组合中的黄铁矿的 Sb/Ag 比 (1-30) 始终低于其他硫化物相中的黄铁矿（例如胶状和贫瘠黄铁矿中的 30 至 1000）。沿单个钻孔 (NBDH010) 的多个层段沉积的球状黄铁矿中的微量元素 (TE) 表明存在一个富集的沉积层段，具有较高的总 TE 含量、Ag/Au 和 Sb/Au、较低的 S/Se 和多金属-像 Sb/Ag 的签名。在这个富集层段内，多晶砾岩的黑色页岩基质显示出更高的总有机碳 (TOC)、Mo 含量和 Co/Ni 比率，并表明当时生物活性增加，解释为与 Ag-Zn( –Au) 矿化。沉积黄铁矿中的热电特征，