Geological，Geochemical and Chronology Characteristics and Its Significance of the Dolerite in Daxin, Guangxi Province
Received date: 2012-07-24
Revised date: 2012-08-27
Online published: 2012-10-10
Guangxi Daxin is located in south China plate of the South China region, the west of Youjiang drape, the north end of daming mountain convex, Daxin concave broken beam, and the ridgeFengTun broken plait horst. The dolerite dikes are distributed sporadically in the north west, along the crack. There are the abundance mineral resources in the region, such as uranium deposits and Pb, Zn. Previous study of ore genesis did not connect the dolerite dikes with the formation of deposit. Through studies of dolerite of the geological, geochemical characteristics and chronology, the relationship between the two is discussed and the conclusions are drawn in this article as follows: (1) Dolerite are controlled by the crack in north west, and the dolerite is made up of altered mineral such as kaolinite, hauling, chlorite, and uranium mineralized in local area, suffering the later metamorphism and altered effect. (2) The content of SiO2 in rocks has a large variation, mainly caused by chloride. SiO2 is obviously negatively correlated with Fe2O3, MgO, CaO and FeO. Alkali degree (Na2O+K2O) is poor. Based on the big ratio of K2O/Na2O, the magma series is for calcium alkaline series. Trace element enriches high field strength element Ta, Nb, Zr, Hf, and big ion lithophile element Rb, U, Th, Ba, and losses Sr. Therefore, tectonic environment is distinguished as the plate basalt (WPB). Rare earth elements the chondritic standardized distribution type is more consistent figure right mode, no obvious Eu abnormal, the total amount of rare earth elements is higher. (3) The U-Pb age of zircons in dolerite rock is overall for 90 Ma or so, developed in late cretaceous. (4) We can speculate that areal mineralization and dolerite are involved in the creation of rock.
Key words： Guangxi Daxin; Dolerite; Geochemistry; Chronology; Metallogenesis.
Xu Zhengqi, Cheng Fagui，Tang Chunyong，Song Hao,Zhang Chengjiang，Ni Shijun,et al . Geological，Geochemical and Chronology Characteristics and Its Significance of the Dolerite in Daxin, Guangxi Province[J]. Advances in Earth Science, 2012 , 27(10) : 1080 -1086 . DOI: 10.11867/j.issn.1001-8166.2012.10.1080
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