摘要
素有“世界钨都”美誉的赣南产有密集的与花岗岩类侵入体密切相关的钨锡多金属矿床,然而,目前对钨锡成矿和花岗岩成岩年龄还缺乏很好的约束。本文以天门山-红桃岭钨锡矿田为对象,在详细的矿田地质调查和典型矿床解剖基础之上,采用高精度测年技术开展了成岩成矿年代学研究。利用锆石SHRIMPU-Pb法,分别获得天门山似斑状黑云母二长花岗岩体和红桃岭黑云母花岗岩体成岩年龄分别为151.8±2.9Ma（n=14,MSWD=1.3）和151.4±3.1Ma（n=11,MSWD=0.34）;利用辉钼矿Re-Os等时线法,分别获得牛岭内带石英脉型和樟斗外带石英脉型钨矿成矿年龄分别为154.9±4.1~154.6±9.7Ma和149.1±7.1Ma（n=6,MSWD=1.3）。可见,本区钨矿床成矿和与之有密切成因关系的花岗岩成岩年龄限定在晚侏罗世,对应于区域华南中生代第二次大规模成矿作用,钨成矿与花岗岩成岩基本不存在时差。
A great deal of tungsten-tin polymetallic deposits, which are related genetically to granites, have been formed in the southern Jiangxi Province. However, the ages of W-Sn mineralization and granite crystallization are poorly understand at present. This study provides the first highly precise dating of the mineralization and rock-forming in the Tianmenshan-Hongtaoling W-Sn orefield based on detailed geological investigation and studies of representative deposits. The dating of zircon from Tianmenshan porphyritic biotite granite and Hongtaoling fine-grained biotite granite determined by SHRIMP yield ages of 151.8±2.9 Ma and 151.4±3.1 Ma, respectively. Rhenium and osmium isotopic dating of molybdenite from the Niuling and Zhangdou quartz vein-type tungsten deposits by ICP-MS yields isochron ages of 154.9 ±4.1-154.6±9.7Ma and 149.1±7.1Ma on the ^187Re versus ^187Os correlation diagram, respectively. The results suggest that the timing of W-Sn mineralization and granite crystallization are limited to Upper Jurassic, which is corresponding to the time of the second largescale mineralization regionally in the Mesozoic. In addition, there not exists an apparent time difference between W-Sn mineralization and granite crystallization.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2007年第7期952-963,共12页
Acta Geologica Sinica
基金
中国地质调查局地质调查项目(编号1212010561603-2)资助的成果
