湘南荷花坪锡铅锌矿区燕山期黑云母花岗岩的厘定

王仙岭花岗岩侵位于印支期.过去一直认为荷花坪锡铅锌矿为印支期矿床,与王仙岭岩体有关.经多年的野外考察和钻孔资料研究发现,荷花坪地区存在隐伏花岗岩体,其岩性不同于王仙岭花岗岩.本文选取钻孔中粗粒黑云母花岗岩,利用La-MC-ICP-MS法对其进行锆石年代学研究,获得U-Pb年龄为(157.1±0.8) Ma,显示其为燕山...

The Confirmation of Yanshanian Biotite Granite in the Hehuaping Sn-Pb-Zn District, Southern Hunan Province, China

The Wangxianling granite was emplaced at the Indosinian (Triassic) period. The previous research considered that the
Hehuaping Sn-Pb-Zn deposit was an Indosinian deposit related to the Wangxianling pluton. Based on many years of investigationin the field and study of rocks from drilling holes, a buried pluton with lithological characteristics different from the Wangxianling granite was discovered in the Hehuaping district. A zircon U-Pb age of (157.1±0.8) Ma for the coarse-grained biotite granite from drilling hole was obtained by La-MC-ICP-MS, which suggests an early Yanshanian (Jurassic) emplacement. This granite is characterised by A/CNK value of 1.02, total REE content of 357×10-6, LREE/HREE ratio of 2.83 and Zr+Nb+Ce+Y content of398×10-6, on average. These features are similar to those of A-type granite and markedly different from those of the WangxianlingS-type granite. This Yanshanian granite, named as Hehuaping granite, has an affinity of the tin-bearing granites in the Nanling Range. Therefore, we argue that the Hehuaping Sn-Pb-Zn deposit is related to the Yanshanian buried Hehuaping pluton.