陕南铜厂闪长岩体的成岩、成矿时代及其地质意义  

Emplaced and Metallogenetic Times of Tongchang Diorities,Southern Shaanxi Province and Its Geological Implications

作　　者：王伟[1] 刘树文[1] 吴峰辉[1] 李秋根[1] 王宗起[2] 杨凯 闫全人[2] 王瑞廷 杨鹏涛[1] 

机构地区：[1]造山带与地壳演化教育部重点实验室,北京大学地球与空间科学学院,北京100871 [2]中国地质科学院地质研究所,北京100037 [3]中国煤炭地质工程总公司,北京100073 [4]西北有色地质勘查局地质勘察院,西安710054

出　　处：《北京大学学报（自然科学版）》2011年第1期91-102,共12页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家科技支撑计划(2006BAB01A11)资助

摘　　要：铜厂闪长岩体位于扬子地台北缘勉县-略阳-阳平关三角地块区域内,主要由闪长岩、石英闪长岩和花岗闪长岩组成。LA-ICPMS和SHRIMP锆石U-Pb同位素定年结果表明铜厂闪长岩体存在3个侵位结晶阶段:早期阶段的闪长岩形成于879±7 Ma;中期阶段的石英闪长岩形成于848±5～840±7 Ma,含矿钠长岩脉于834±7 Ma侵位结晶,与中期阶段石英闪长岩侵位时代在误差范围内一致;晚期阶段花岗闪长岩形成于824±5 Ma。这些新的年代学数据表明铜厂闪长岩体及其相伴生的大型铜厂铜矿形成于晋宁期,而不是古生代,揭示了扬子地台北缘存在重要的新元古代早期岩浆活动,与Rodinia超大陆的裂解事件在时间上(860～750 Ma)基本一致,是Rodinia超大陆事件在扬子地台北缘的重要响应。Tongehang dioritic pluton in Southern Shaanxi Province is located in the tectonic domain of the Mianxian- Lueyang-Yangpingguan triangle block, northern margin of Yangzi Craton, and consists mainly of diorite, quartzdiorite and granodiorite. Zircon grains separated from these rocks are dated using LA-ICPMS and SHRIMP U-Pb isotopic methods. The dating results indicate three intrusive stages of the Tongehang dioritic pluton, and early diorite emplaced at 879 ±7 Ma; middle quartz diorite at 848 ±5 Ma to 840 ±7 Ma, with copper ore-bearing albitite emplced at 834 ±7 Ma, which is consistent with the crystallization age of quartz diorite within error range, and the last granodiorite at 824 ±5 Ma. These zircon U-Pb isotopic dating results reveal that the emplacements of the Tongchang diorites and related copper deposit did not occur in Paleozoic but in Jinning stage of Neoproterozoic era. The magmatic activity and related copper deposit mineralization are important responses to the breakup event of global Rodinia supercontinent（860-750 Ma）.

关 键 词：铜厂闪长岩体 铜厂铜矿 锆石U-Ph年龄 扬子地台北缘 RODINIA超大陆 

分 类 号：P618.41[天文地球—矿床学]