Biogeochemistry of the 1640 Ma McArthur River (HYC) lead-zinc ore and host sediments, Northern Territory, Australia
Biogeochemistry of the 1640 Ma McArthur River (HYC) lead-zinc ore and host sediments, Northern Territory, Australia
复制标题
DOI：
10.1016/s0016-7037(01)00599-3
复制
发表时间：
2001-07
影响因子：
5
通讯作者：
Graham A. Logan;Mark C. Hinman;Malcolm R. Walter;R. Summons
中科院分区：
文献类型：
--
作者：
Graham A. Logan;Mark C. Hinman;Malcolm R. Walter;R. Summons
麦克阿瑟河铅锌存款的形成涉及沉积有机质的热氧化或生物氧化，其产物生成块状层状硫化物矿体，并在沉积物堆积物中形成次生碳酸盐和二氧化硅沉淀物。矿化的细粒结构表明原生矿石结构保存完好，再加上区域热成熟度，表明该存款是研究与成矿作用和沉积环境有关的有机质信号的理想场所。生物标志物数据指向沉积的海洋环境，并且与先前从邻近的Glyde Subbasin的宿主Barney Creek Formation收集的数据一致。在两个矿体内的一些样品中发现了一种不寻常的生物标志物分布，被认为与硫化物氧化细菌的存在有关。浊流沉积后，当水柱上部的氧气混合到沉积物-水界面时，这些生物蓬勃发展。生物标志物数据的支持，从相同的样品的微体古生物学观察，并与间歇充氧的水柱沉积物-水界面是一致的。这一观察结果表明，已知的硫化物氧化细菌的出现时间可以追溯到8亿年前，即1640 Ma。
The formation of the McArthur River lead-zinc deposit involves thermogenic or biologic oxidation of sedimentary organic matter, the products of which generated a massive stratiform sulfide ore body, and secondary carbonate and silica precipitates formed within the sediment pile down the flow pathway and above the reaction zone. The fine-grained texture of the mineralization indicates that primary ore texture is preserved, and coupled with the regional thermal maturity, indicate that this deposit is an ideal location to study organic matter signals related to ore formation and the sedimentary environment. Biomarker data point to a marine environment of deposition and are consistent with data previously collected from the host Barney Creek Formation in the adjacent Glyde Subbasin. An unusual biomarker distribution found in some samples from within two-orebody is considered to be related to the presence of sulfide-oxidizing bacteria. These organisms flourished after turbidite deposition, when oxygen in the upper part of the water column was mixed down to the sediment water interface. The biomarker data are supported by micropalaeontologic observations from the same samples and are consistent with intermittent oxygenation of the water column to the sediment water interface. This observation suggests an extension of the known occurrence of sulfide-oxidizing bacteria back in time by 800 million years, to 1640 Ma.