Age and petrogenesis of Anisian magnesian alkali basalts and their genetic association with the Kafang stratiform Cu deposit in the Gejiu supergiant tin-polymetallic district, SW China

CORC > 地球化学研究所 > 中国科学院地球化学研究所 > 矿床地球化学国家重点实验室 > 期刊论文

	Age and petrogenesis of Anisian magnesian alkali basalts and their genetic association with the Kafang stratiform Cu deposit in the Gejiu supergiant tin-polymetallic district, SW China
	Taiyi Luo; Jiawei Zhang; Chuangu Dai; Zhilong Huang; Zhikuan Qian; Ying Zhang
刊名	Ore Geology Reviews
	2015
卷号	69 期号:1 页码:403-416
通讯作者	Zhilong Huang
英文摘要	Gejiu is geographically located near Gejiu city, SW China. It is one of the largest tin-polymetallic districts in the world and contains approximately 3 million tons (Mt) of Sn and smaller quantities of Cu, Pb, and Zn. The deposit primarily yields three different types of ore: skarn-hosted ore, basalt-hosted stratiform ore, and carbonate-hosted stratiform ore. Kafang is one of the primary ore deposits in the Gejiu district and is an unusual occurrence hosted in basaltic rocks. Genetic models of the Kafang deposit suggest that it is related either to Anisian (Lower stage of Middle Triassic) Gejiu basalts or to Cretaceous Gejiu granite. In this study, we performed zircon SIMS U-Pb dating, major and trace element analyses, and Sr-Nd-Pb isotopic analyses for the Gejiu basalts and S isotopic analyses for stratiform Cu ore. Our results and previous studies are used to interpret the pet:rogenesis of the Gejiu basalts and the origin of the basalt-hosted stratiform Cu deposit. The SIMS zircon U-Pb analyses of the Gejiu basalts yield an age of 244.4 Ma. The trace element ratios of the Gejiu basalts are similar to those of ocean island basalt and have positive epsilon Nd(t) values (ranging from 0.6 to 2.5) and uniform (Sr-87/Sr-86); values (ranging from 0.70424 to 0.70488). These ratios are close to those of the Permian Emeishan flood basalt. Thus, the Gejiu basalts may represent coeval volcanisms within the plate involving remelting of the Emeishan plume head through a stress relaxation process after the main plume event. The Pb and S isotopic compositions of the Gejiu basalts and the stratiform Cu ores indicate that the source of Cu and S is primarily derived from the Gejiu basalts. However, the age of sulfide mineralization (84.2-79.6 Ma) and the age of hydrothermal alteration (85.5-81.9 Ma) are temporally consistent with the age of the Cretaceous granite emplacement (85.5-833 Ma). From a petrological and geochemical study, we determine that the Gejiu basalts may have been subjected to pervasive granite-related hydrothermal alteration during the emplacement of granite. These processes increase the K and Mg contents of basalt and probably caused the formation of the Cu ores. Thus, the Kafang stratiform Cu deposit can be considered as a granite-related hydrothermal deposit.
学科主题	矿床地球化学
语种	英语
公开日期	2017-05-17
内容类型	期刊论文
源URL	[http://ir.gyig.ac.cn:8080/handle/352002/6039]
专题	地球化学研究所_矿床地球化学国家重点实验室_矿床地球化学国家重点实验室_期刊论文
通讯作者	Zhilong Huang
推荐引用方式 GB/T 7714	Taiyi Luo,Jiawei Zhang,Chuangu Dai,et al. Age and petrogenesis of Anisian magnesian alkali basalts and their genetic association with the Kafang stratiform Cu deposit in the Gejiu supergiant tin-polymetallic district, SW China[J]. Ore Geology Reviews,2015,69(1):403-416.
APA	Taiyi Luo,Jiawei Zhang,Chuangu Dai,Zhilong Huang,Zhikuan Qian,&Ying Zhang.(2015).Age and petrogenesis of Anisian magnesian alkali basalts and their genetic association with the Kafang stratiform Cu deposit in the Gejiu supergiant tin-polymetallic district, SW China.Ore Geology Reviews,69(1),403-416.
MLA	Taiyi Luo,et al."Age and petrogenesis of Anisian magnesian alkali basalts and their genetic association with the Kafang stratiform Cu deposit in the Gejiu supergiant tin-polymetallic district, SW China".Ore Geology Reviews 69.1(2015):403-416.