Mafic-hosted seafloor sulfide mineralization at the margin of a non-transform discontinuity on the southern mid-Atlantic ridge
Mafic-hosted seafloor sulfide mineralization at the margin of a non-transform discontinuity on the southern mid-Atlantic ridge
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大西洋中脊南部非转换间断边缘的镁铁质海底硫化物矿化
DOI：
10.1080/1064119x.2018.1485066
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发表时间：
2018-07
影响因子：
2.2
通讯作者：
Li Bing
中科院分区：
文献类型：
--
作者：
Li Bing
摘要对位于南大西洋中脊（SMAR）非转换不连续面（NTD）边缘的太极田（包括太极1和太极2）海底块状硫化物（SMS）和热液蚀变岩进行了矿物学、地球化学和硫同位素研究。太极1号热液沉淀物主要为块状硫化物，太极2号热液沉淀物主要为半块状硫化物。岩石蚀变明显，半块状硫化物中含有大量粘土矿物。在地球化学上，成岩元素（Mg）与半硫化物中的主要热液金属元素（Zn + Cu和Co）之间存在显著的负相关关系。这些矿物学和地球化学特征，以及半块状硫化物的低Co/Ni比值（与围岩相似）和某些蚀变岩的独特稀土元素特征，表明这些半块状硫化物的主要成矿机制可能与岩石成矿作用有关。因此，太极2号与太极1号在硫化物成矿机制上存在显著差异。此外，太吉硫化物的δ ~（34）S变化幅度较大（7.2-15.3%）。我们认为硫化物沉淀后的海水腐蚀是硫化物中34 S富集的原因。此外，我们的工作提供了一些线索，在太极和其他NTD相关领域之间的比较沿着大西洋中脊。我们认为，岩石矿化可能是一个重要的矿化类型NTDs。
Abstract Mineralogical, geochemical and S-isotopic studies were carried out on seafloor massive sulfides (SMS) and hydrothermally altered rocks from the mafic-hosted TaiJi field (including TaiJi-1 and TaiJi-2 sites), which is located on the margin of a nontransform discontinuity (NTD) on the Southern Mid-Atlantic Ridge (SMAR). The main hydrothermal precipitates of TaiJi-1 were massive sulfides, while TaiJi-2 produced a large amount of semi-massive sulfides. Significant rock alteration is an important feature of this field, and large amounts of clay minerals (chlorite) occurred in the semi-massive sulfides. Geochemically, notable negative correlations were identified between rock forming elements (Mg) and major hydrothermal metal elements such as Zn + Cu and Co in semisulfides. Such mineralogical and geochemical characteristics, together with low Co/Ni ratio (similar to the surrounding rocks) of the semi-massive sulfides and the unique REE features of some altered rocks, tell us that the prominent mineralization mechanism for these semi-massive sulfides was probably related to rock mineralization. Thus, TaiJi-2 appears to differ significantly from the TaiJi-1 in terms of sulfide mineralization mechanism. Moreover, the TaiJi sulfides are remarkable for large δ34S variation (7.2–15.3%). We suggest that seawater corrosion after sulfides precipitation were responsible for 34S enrichment in sulfides. Furthermore, our work sheds some light on the comparison between TaiJi and other NTD-related fields along the Mid-Atlantic Ridge. We argue that rock mineralization may represent an important mineralization type in NTDs.
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影响因子：
3.3
作者：
I. Melekestseva;V. Zaykov;P. Nimis;G. Tret'yakov;S. Tessalina
通讯作者：
I. Melekestseva;V. Zaykov;P. Nimis;G. Tret'yakov;S. Tessalina
影响因子：
2.9
作者：
Ana Filipa A. Marques;Fernando J.A.S. Barriga;Steven D. Scott
通讯作者：
Ana Filipa A. Marques;Fernando J.A.S. Barriga;Steven D. Scott
大西洋中脊南部（南纬 12-14 度）沿线潜在热液田的构造环境和局部地质控制
影响因子：
2.8
作者：
Li Bing;Shi Xuefa;Wang Jixin;Yan Quanshu;Liu Chenguang
通讯作者：
Liu Chenguang
影响因子：
--
作者：
W. Shanks
通讯作者：
W. Shanks
影响因子：
4.8
作者：
Ana Filipa A. Marques;F. Barriga;V. Chavagnac;Y. Fouquet
通讯作者：
Ana Filipa A. Marques;F. Barriga;V. Chavagnac;Y. Fouquet