The giant South China Mesozoic low-temperature metallogenic domain: Reviews and a new geodynamic model

The South China Craton was formed by amalgamation of the Yangtze and Cathaysia Blocks during the Neoproterozoic. During the Mesozoic, voluminous granitic plutons and associated W-Sn polymetallic deposits were formed in the Cathaysia Block. The giant South China low-temperature metallogenic domain (LTMD) includes an area of similar to 500,000 km(2) in the Yangtze Block and is composed of the ChuanDian-Qian Pb-Zn, Youjiang Au-As-Sb-Hg and Xiangzhong Sb-Au metallogenic provinces. The ChuanDian-Qian Pb-Zn province contains numerous MVT Pb-Zn deposits, whereas the other two provinces are characterized by Carlin-type Au deposits and vein-type pSb, Hg and As deposits. These epigenetic deposits, which formed under low temperature conditions (similar to 100-250 degrees C), are typically hosted in sedimentary rocks and are locally controlled by faults and fractures. The deposits formed dominantly at 200-230 Ma and 130-160 Ma, corresponding to Indosinian (Triassic) and Yanshanian (Jurassic to Cretaceous) orogenies, respectively. Indosinian mineralization is recognized in all three provinces, but Yanshanian mineralization occurred only in the Youjiang and Xiangzhong provinces. The Indosinian orogeny, which involved collision of the Indochina Block with the South China Craton, resulted in circulation of basinal brines that leached ore-forming elements from adjacent sedimentary strata to form the ChuanDian-Qian Pb-Zn province. Deep-seated granitic magmas generated during this orogeny caused extensive circulation of meteoric water that mobilized ore-forming elements from the sedimentary strata to form the Carlin-type Au deposits in the Youjiang province, and the Sb-Au deposits in the Xiangzhong province. The Indosinian orogeny was the key factor in establishing the metallogenic framework of the LTMD. It produced widespread mineralization in the three metallogenic provinces, each of which has unique features reflecting differences in the nature and composition of the basement rocks. The Yanshanian metallogeny was less important and overprinted the older ore deposits in the Youjiang and Xiangzhong provinces. (C) 2016 Elsevier Ltd. All rights reserved.