地质与勘探2017，Vol.53Issue(5)：838-854,17.
柴达木北缘东段呼德生镁铁-超镁铁质岩体锆石U-Pb年代学、地球化学及成岩成矿分析
Zircon U-Pb Geochronology, Geochemistry and Metallogensis of the Hudesheng Mafic-Ultramafic Intrusion in the Eastern Section of Northern Qaidam Basin
摘要
Abstract
The Hudengsheng mafic-ultramafic intrusion, located in the southeastern margin of the Oulongbuluke micro-continent in the northern Qaidam orogenic belt, intruded into the Paleoproterozoic Jinshuikou group. From the core to its edge, this complex is composed of peridotite, pyroxenite and gabbro. In rock types, it is dominated by dunite, olivine websterite and gabbro, which contact each other mostly in gradual transition. The nickel and copper mineralization occurred primarily in pyroxenolite. Zircon LA-ICP-MS U-Pb geochronology shows that this intrusion (425. 2 ± 5. 8Ma) resulted from magma activity during the Late Silurian to Late Devonian in a setting of post-orogenic extension. The m/f ratios range from 2. 51 to 5. 37, indicative of iron series of basic-ultrabasic rocks. All kinds of rocks in the intrusion are enriched in light rare earth elements ( LREE) and large ion lithophile ele-ments ( Ba, Sr, Rb) and depleted in high field strength element ( Zr, Hf, Nb, Ta) . In combination with data of petrography, mineralogy and geochemis-try, it is inferred that the crystallization differentiation and crustal contamination occurred during the process of magma evolution. Integrated with the age of the intrusion and regional geological setting, it is considered that this intrusion formed in the extensional stage of a continental margin. The primitive magma experienced the metasomatism of mantle fluids in the evolution process. According to the degree of magmatic differentiation and the characteristics of assimilation contamination, it is comprehensively concluded that the Hudesheng intrusion has good conditions for nickel and copper mineralization.关键词
结晶分异作用/同化混染作用/构造环境/铜镍硫化物矿床/呼德生岩体/柴北缘Key words
crystallization differentiation/assimilation contamination/tectonic environment/Ni-Cu sulfide deposit/Hudesheng intrusion/north margin of Qaidam Basin分类
天文与地球科学引用本文复制引用
钱兵,张照伟,王亚磊,弥佳茹,水应东,邵继..柴达木北缘东段呼德生镁铁-超镁铁质岩体锆石U-Pb年代学、地球化学及成岩成矿分析[J].地质与勘探,2017,53(5):838-854,17.基金项目
国土资源部公益性行业科研专项项目(201511020)、国家自然科学基金青年基金项目(41603050、41602094)和中国地质调查局"东昆仑铜镍多金属资源基地调查"二级项目(DD20160013)联合资助. （201511020）
