Diversity of the 160 similar to 140Ma Cu (Mo) and Mo (W) mineralization in East Qinling: Constraint on the geochemistry and magma source of the metallogenic rocks

作者：Chen Lei^*; Yan Zhen; Wang ZongQi; Wang RuiTing; Ning Lei; Gan ChangJian; Dai JunZhi

来源：Acta Petrologica Sinica, 2015, 31(8): 2383-2401.

• 160 similar to 140Ma
• Mo(W) and Cu(Mo) mineralization
• Metallogenic rocks
• Magmatic source
• East Qinling

Some skarn-porphyry Cu(Mo) deposits and porphyry-skarn Mo(W) deposits were formed in 160 similar to 140Ma in the south and north part of Shangdan Fault in East Qinling. Through systematically comparing the geology and metallogenic rocks of the deposits, we can find the Mo (W) deposits mainly locate in the North Qirding and southern margin of North China Plate. Strata are from Neoarchean to Ordovician, which consist of a series of metamorphic volcanic and sedimentary rocks. Cu(Mo) deposits mainly in the late Paleozoic forearc basin in South Qinling. Strata are mainly Paleozoic strata, consisting of siltstone, sericite slate, limestone, graywacke and dolomite, etc. The metallogenic rocks of Mo(W) deposits are mainly granite porphyry, the rocks of Cu(Mo) deposits are mainly granodiorite porphyry. Compared with the rocks related to Cu(Mo) deposits, the metallogenic rocks of Mo (W) deposits have higher Si% and K2O, lower MgO and Fe2O3T, and have higher differentiation index (DI). Meanwhile, the rocks of Mo (W) deposits enrich U and Nb, deplete Ba; the rocks of Cu(Mo) deposits enrich Ba, deplete U and Nb. Sigma REE of the metallogenic rocks related to Cu(Mo) deposits are relatively higher than Mo(W) deposits. The metallogenic rocks of Mo(W) deposits have negative Eu anomaly, the rocks of Cu(Mo) deposits do not have obvious Eu anomaly. The metallOgenic rocks of Cu(Mo) and Mo(W) deposits have similar crystallization temperature, but the rocks of Mo (W) deposits have relatively higher oxidation state and formed in the higher pressure environment. Residual phase of magmatic source of the rocks related to Mo(W) deposits are pyroxene, the rocks of Cu (Mo) deposits are few hornblendes. The metallogenic rocks of Cu(Mo) deposits have higher epsilon(Nd) (t) (-4.75 similar to -2.73 and -28.8 similar to -12.1, respectively) and epsilon(Hf)(t) values (-3.79 similar to +1.79 and -38 similar to -7.9, respectively) than the rocks of Mo (W) deposits, which indicate that the magmatic source of metallogenic rocks related to Cu(Mo) deposits have more mantle materials than the rocks of Mo(W) deposits. Because of the diversities in the tectonic setting, geochemistry, pressure condition, REDOX state and magmatic source, the 160 similar to 140Ma granites have formed Cu (Mo) and Mo (W) various mineralization types in the north and south part of Shangdan Fault in East Qinling.

• 出版日期2015-8
• 单位中国地质科学院矿产资源研究所; 中国地质大学（北京）