Ridge subduction and porphyry copper-gold mineralization: An overview
Ridge subduction and porphyry copper-gold mineralization: An overview
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DOI：
10.1007/s11430-010-0024-0
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发表时间：
2010-04
影响因子：
5.7
通讯作者：
Weidong Sun;M. Ling;Iraj Habibi;Weiming Fan;Ding Xing;Huaying Liang
中科院分区：
文献类型：
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作者：
Weidong Sun;M. Ling;Iraj Habibi;Weiming Fan;Ding Xing;Huaying Liang
许多大型斑岩铜金矿床与埃达克质岩有关，已知埃达克质岩与山脊俯冲密切相关。例如，东太平洋边缘有几个俯冲山脊，如智利、秘鲁和南美洲，其中大多数与大型斑岩铜金矿床有关。相比之下，西太平洋边缘的海脊俯冲要少得多，斑岩铜金矿床无论是从吨位还是从矿床数量来看，都要少得多。由于铜和金是中等不相容元素，洋壳的铜-金浓度远高于地幔和陆壳，因此具有诊断埃达克化学特征的板条熔体具有系统的高的铜和金，这有利于成矿。考虑到显生界俯冲板块的地温，海脊俯冲是最有利的构造环境。因此，板片熔融可能是山脊俯冲与铜金矿床空间联系的纽带。在中国东部、中亚造山带等侵蚀较少的地区，板片熔融的地球化学特征可能预示着大型斑岩型铜金矿床的找矿方向。
Many large porphyry Cu-Au deposits are connected to adakitic rocks known to be closely associated with ridge subduction. For example, there are several subducting ridges along the east Pacific margin, e.g., in Chile, Peru, and South America, most of which are associated with large porphyry Cu-Au deposits. In contrast, there are much fewer ridge subductions on the west Pacific margin and porphyry Cu-Au deposits are much less there, both in terms of tonnage and the number of deposits. Given that Cu and Au are moderately incompatible elements, oceanic crust has much higher Cu-Au concentrations than the mantle and the continental crust, and thus slab melts with their diagnostic adakitic chemistry have systematically higher Cu and Au, which is favorable for mineralization. Considering the geotherm of subducting slabs in the Phanerozoic, ridge subduction is the most favorable tectonic setting for this. Therefore, slab melting is the likely link in the spatial association between ridge subduction and Cu-Au deposits. Geochemical signatures of slab melting and hence maybe ridge subduction in less eroded regions in eastern China, the central Asian orogenic belt etc. may indicate important exploration targets for large porphyry Cu-Au deposits.