Geochronology and tectonic setting of Pb-Zn-Mo deposits and related igneous rocks in the Yinshan region, Jinzhai, Anhui Province, China

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• 责任者：Xu Xiaochun ; Lou Jinwei ; Xie Qiaoquin ; Xiao Qiuxiang ; Liang Jianfeng ; Lu Sanming
• 年：2011
• 作者单位：Hefei University of Technology, School of Resources and Environmental Engineering, Hefei, China
• 刊：Ore Geology Reviews
• 期：1

摘要

The Gaijing Pb-Zn-Mo deposit and Shapinggou Mo deposit in the Yinshan region, Jinzhai, Anhui province, China, are hosted in various granitic intrusions with (super 40) Ar/ (super 39) Ar ages obtained for biotite and hornblende of 136.8+ or -1.6 Ma (medium-grained monzogranite), 130.4+ or -1.2 Ma (fine-grained granite), and 125.4+ or -1.0 Ma (fine-grained diorite). The modes of occurrence and cross-cutting relationships among the igneous intrusions indicate that alkali quartz-syenite and quartz-syenite porphyry (cryptoexplosive breccia) formed later than the calc-alkali monzogranite, granite, and diorite. Molybdenum mineralization occurs in pipe-like bodies hosted in cryptoexplosive breccia (pipe), quartz-syenite (porphyry), monzogranite, and granite, whereas Pb-Zn mineralization occurs in veins distally from the Mo mineralization. The Re-Os isotopic model ages of molybdenite from the Gaijing Pb-Zn-Mo deposit are 112.6+ or -1.3 and 113.5+ or -1.3 Ma, consistent with the ages of other molybdenum deposits throughout the East Qinling-Dabie metallogenic belt. The geological characteristics and isotopic ages of the Gaijing Pb-Zn-Mo and Shapinggou Mo deposits indicate a genetic relationship to the emplacement of the quartz-syenite (porphyry) and to shallow-seated porphyry-cryptoexplosive breccia intrusions. The present results, combined with existing data, suggest that the Pb-Zn-Mo deposits and related igneous rocks were formed in a geodynamic setting of regional lithospheric thinning, delamination, and thermal erosion in East China. The deposits are part of the East Qinling-Dabie molybdenum belt, which in turn is part of a large-scale E-W-trending metallogenic belt in East China