西天山达巴特Cu-Mo矿床赋矿含角砾流纹斑岩锆石U-Pb年代学、地球化学特征及地质意义  

Zircon U-Pb Geochronology,Geochemistry,and Geological Implications for the Breccia Bearing Rhyolite Porphyry in the Dabate Cu-Mo Deposit,Western Tianshan,Xinjiang

作　　者：郑少华[1] 顾雪祥[1,2] 章永梅[1,2] 王佳琳[1,2] 彭义伟 吕行 徐劲驰 Zheng Shaohua;Gu Xuexiang;Zhang Yongmei;Wang Jialin;Peng Yiwei;Lv Xing;Xu Jingchi(School of Earth Sciences and Resources,China University of Geosciences,Beijing,100083,China;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing,100083,China;College of Earth Science,Chengdu University of Technology,Chengdu,Sichuan,610059,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [3]成都理工大学地球科学学院,国土资源部构造成矿成藏重点实验室,四川成都610059

出　　处：《新疆地质》2021年第4期632-639,共8页Xinjiang Geology

基　　金：国家自然科学基金项目(41572062);国家重点研发计划项目(2018YFC0604003)联合资助。

摘　　要：达巴特Cu-Mo矿床是中国西天山代表性的斑岩型矿床之一,其斑岩型成矿作用与矿区内含角砾流纹斑岩的侵位密切相关。LA-ICP-MS锆石U-Pb同位素定年结果指示,含角砾流纹斑岩形成于(303.7±2.5)Ma。岩石地球化学分析指示,该套岩石具有高硅(SiO_(2)=76.10%~77.59%)、富碱(K_(2)O+Na_(2)O=7.77%~8.81%),高FeOT/MgO值(24~65),低镁(MgO=0.03%~0.26%)、钙(CaO=0.30%~0.44%)和铝(Al_(2)O_(3)=13.15%~13.94%)的特征,属钙碱性系列岩石。岩石相对富集LREE,Rb,U,Hf和Nd,相对亏损HREE,Ba,Sr,P和Ti,是后碰撞伸展构造体系下俯冲板片断离、软流圈地幔上涌并造成下地壳部分熔融而形成的“A”型花岗岩类。综合研究表明,达巴特是一个形成于晚石炭世末期后碰撞伸展环境的斑岩型Cu-Mo矿床。Dabate Cu-Mo deposits is one of the representative porphyry deposits in the Chinese Western Tianshan.The porphyry mineralization is closely related to the breccia bearing rhyolite porphyry in the Dabate ore district.LA-ICP-MS U-Pb isotopic dating on zircons in breccia bearing rhyolite porphyry yielded ages of(303.7±2.5)Ma,indicating they were formed at the lastest Carboniferous.Petrogeochemistry analyses indicate that the breccha beating rhyolite porphyry are calc-alkaline series characterized by high silica(SiO_(2)=76.10%~77.59%),high alkaline(K_(2)O+Na_(2)O=7.77%~8.81%),high FeOT/MgO(24~65),low magnesium(MgO=0.03%~0.26%),low calcium(CaO=0.30%~0.44%),low aluminum(Al_(2)O_(3)=13.15%~13.94%).They are enriched in light rare-earth elements(LREE),Rb,U,Hf,and Nd,and are depleted in heavy rare-earth elements(HREE),Ba,Sr,P,and Ti.They are a suit of A-type granite that were probably generated by asthenosphere magma underplating and partial melting of lower crust due to slab break-off under the post-collision tectonic setting.Based on the comprehensive studies,it is concluded that Dabate is a porphyry Cu-Mo deposit formed in a post-collisional extensional environment at the end of Late Carboniferous.

关 键 词：西天山 含角砾流纹斑岩 地球化学 达巴特Cu-Mo矿床 

分 类 号：P618.41[天文地球—矿床学] P618.65[天文地球—地质学]