• 责任者：Zeng Linggao (No.9 Geological Brigade ; Xinjiang Bureau of Geology and Mineral Resources ; Urumqi 830000 ; China) ; Zhang Jun
• 刊名：Earth Science
• 出版年：2013
• 卷期：38(6)
• 关键词：镁铁质岩 ; mafic rocks ; 超镁铁质岩 ; ultramafics ; 铀—铅计时 ; U-Pb dating ; 四川 ; Sichuan Province
• 页码：p.1197-1213
• 图表：11 illus., 4 tables, 47 refs.
• 分类号：0801
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

     LA-ICP-MS zircon U-Pb dating and elements geochemical analysis has been carried out for mafic-ultramafic rock from Pingchuan to discuss the petrology characteristics and the time series of diagenesis-mineralization in Pingehuan region and further improve the geochronological framework of diagenesis-mineralization of the Panxi area. The test results show that Huangcaoping gabbro formed in 259.7±1.2 Ma and its capture zireon＇s crystallization age is 269.8±2.4 Ma,and the subvolcanic＇s reference diagenetic age is 248± Ma and its metamorphic zircon age is 67± Ma. The results indicate that mafie-ultramafie rock in Pingchuan region is a set of homologous phase sodium-rich tholeiitic rock series, conduciving to the formation of iron-mineralization, outputting in the continental rift environment,magma source coming from the upper mantle spinel lherzolite. The magmatic activity started no later than 269.8±2.4 Ma, and the large-scale magmatic activity occurred at 259.7：±1.2 Ma, which constrained the mineralization time of magmatic profiled and volcanic eruptions （underflow） sedimentary, and the subvolcanic diagenetic age limited the upper mineralization time of sub-volcanic hydrothermal, and the metamorphic zircon U-Pb age recorded that Pingchuan region experienced Himalayan intracontinental orogeny. The tectonic-magmatic activity of Pingchuan region is featured with being explosive, phased and metallogenic; the formation of mafic-ultramafic rock in Pingchuan region is probably related to the large-scaled lithospheric thinning; diagenesis-mineralization in Hercynian-Indosinian in Panxi area is the comag- marie product of different phases evolution, controlled by regional uniform deep geodynamies.