LA-ICP-MS U-Pb dating of zircon from basement igneous rocks in Yitong Basin and its significance
Online published: 2011-12-20
In order to determine the formation period of Yitong basement accurately, six zircon samples are selected to carry out the study on LA-ICP-MS U-Pb dating of zircon. Zircons fromthe basement igneous rock are euhedral in shape and show the typical oscillatory zoning with magmatic origin. The dating results indicate that the biotite-monzonitic granite at the depth of 2 484.2 m in C24 well in Chaluhe fault depression formed in (176.8 ±1.7 )Ma, the crack lithification perthitr monzonite at the depth of 3 153.0 min C17 well formed in (171.8±3.2)Ma, the basement igneous rocks in X5 and L2 wells in Luxiang fault depression respectively formed in (170.3±3.4)Ma and (169.1±4.5)Ma, and the basement igneous rocks in Y53 and Y3 wells in Moliqing fault depression respectively formed in(247.2±3.4)Ma and(186.6±2.5)Ma. In combination with other U-Pb dating, it is considered that the age of basement igneous rocks in Yitong Basin is mainly of 170~336 Ma, and the most formed in Yanshanian, and a little formed in Hercynian. The distribution of granite in each fault depression is different. The most of granites in Chaluhe and Luxiang fault depression formed in Yanshanian, while in Moliqing fault depression the granites formed in Hercynian, Indosinian and Yanshanian.
LI Yanjing , GAO Chao , DENG Jie , KONG Lingfei . LA-ICP-MS U-Pb dating of zircon from basement igneous rocks in Yitong Basin and its significance[J]. Lithologic Reservoirs, 2011 , 23(6) : 73 -78 . DOI: 10.3969/j.issn.1673-8926.2011.06.013
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