湖南芙蓉锡矿床中萤石的Sr-Nd同位素研究  

Sr-Nd Isotopic Geochemistry of Fluorites from the Furong Tin

作　　者：赵葵东[1] 蒋少涌[1] 姜耀辉[1] 凌洪飞[1] 

机构地区：[1]南京大学地球科学系成矿机制研究国家重点实验室,江苏南京210093

出　　处：《地球学报》2005年第B09期171-173,共3页Acta Geoscientica Sinica

基　　金：本文由国家基金委优秀创新群体基金（编号：40221301）资助.

摘　　要：芙蓉锡矿床是一个新探明的超大型锡矿床，产于湘南的骑田岭花岗岩体中。本次研究测试了该矿床中与锡石硫化物共生的萤石的Sr和Nd同位素组成。各矿脉中萤石的^87Sr／^86Sr比值并不相同，变化从0．70770-0．71484，反映了成矿流体的初始^87Sr／^86Sr比值并不均一。萤石的Sm-Nd同位素组成并没有构成很好的等时线，计算的εNd（t）值变化在-6．6～-9．8之间。萤石的Sr-Nd同位素组成并不同于花岗岩，成矿流体中的Sr和Nd有很大一部分来自围岩的碳酸盐岩地层。The Furong ore deposit, a newly discovered superlarge tin deposit, is located in Qitianling granite in Hunan Province. In this study, Sr and Nd isotopic compositions of fluorites coexisting with cassiterite and sulfides from the ore veins were analyzed. Fluorites from different veins have different ^87Sr/^86Sr values, varying from 0. 70770 to 0. 71484. This suggests that the initial ^87Sr/^86Sr values of ore-forming fluids are not homogenous. Sm-Nd isotopic systematics of fluorites don＇ t yield isochron ages. The calculated εNd（ t ） values of fluorites vary from - 6.6 to - 9.8. Sr-Nd isotopic compositions of fluorites are different from those of Qitianling granite, implying that most Sr and Nd of ore-forming fluids came from the strata.

关 键 词：萤石 SR-ND同位素 芙蓉锡矿 骑田岭花岗岩 ^87Sr/^86Sr比值 锡矿床 同位素研究 芙蓉 同位素组成 SM-ND 

分 类 号：P532[天文地球—古生物学与地层学] P618.44[天文地球—地质学]