Neoarchean Algoma-type Banded Iron Formation from the Northern Shanxi, the Trans-North China Orogen: SIMS U-Pb age, origin and tectonic setting
Neoarchean Algoma-type Banded Iron Formation from the Northern Shanxi, the Trans-North China Orogen: SIMS U-Pb age, origin and tectonic setting
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晋北跨华北造山带新太古代阿尔戈马型带状铁矿组：SIMS U-Pb年龄、成因及构造环境
DOI：
10.1016/j.precamres.2017.06.023
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发表时间：
2017
影响因子：
3.8
通讯作者：
Ding Jiaxin
中科院分区：
文献类型：
--
作者：
Han Chunming;Xiao Wenjiao;Su Benxun;P. Asamoah Sakyi;Ao Songjian;Zhang Jien;Wan Bo;Song Dongfang;Zhang Zhiyong;Wang Zhongmei;Ding Jiaxin
山西北方以藻类岩为容矿岩的铁矿床产于三阳坪、白峪里、赵村、柏枝岩等地。这些矿床发育在中生代岩石中，其形成与小型火山-沉积盆地中的火山-沉积作用有关。五台群表壳岩由绿片岩相变质为下角闪岩相。以赵村存款为代表的晋北方含矿铁存款形成于晚新太古代，其西姆斯U-Pb年龄为2693.7± 4.9Ma。三羊坪铁矿床和白峪里铁矿床形成于2528 ~ 2543 Ma。晚新太古代BIF铁矿床可认为形成于岩浆弧环境。北方矿石样品的Eu ~（2+）异常表明，BIF矿床形成于与海底热液有关的火山环境，与火山活动有关的海底热液流出物可能为北方BIF提供了铁和硅。提出了BIFs及其寄主火山岩形成的山脊俯冲模式，该模式不仅解释了BIFs的硅、铁来源，而且也能很好地解释华北造山带的许多其他地质特征。
Algoma-type BIF-hosted iron deposits in Northern Shanxi occur in Sanyangping, Baiyuli, Zhaocun and Baizhiyan. These deposits are developed in Archaean rocks and their formation was related to volcanic and sedimentary processes in small volcano-sedimentary basins. Supracrustal rocks of the Wutai Group were .metamorphosed from greenschist facies to lower amphibolite facies. The BIF-hosted .iron deposit in Northern Shanxi formed in the late Neoarchean, and is represented by the Zhaocun deposit that yielded a SIMS U-Pb zircon age of 2693.7±4.9 Ma. The other two BIF-hosted iron deposits are represented by the Sanyangping and Baiyuli deposits that formed between 2528 Ma and 2543 Ma. The late Neoarchean BIF iron .deposits can be considered to have formed in a magmatic arc environment. The Eu .anomalies of the ore samples from Northern Shanxi show that the BIF ores formed in .a hydrothermal related volcanic submarine environment, where submarine .hydrothermal effluents associated with volcanic activities may have supplied the iron .and silica for the Northern Shanxi BIFs. A ridge subduction model is suggested for the .formation of the BIFs and their host late Neoarchean volcanic rocks, this model does .not only explain the sources of silica and iron for the BIFs, but can also well explain .many other geological features of the Trans-North China Orogen.