湘中锡矿山式锑矿成矿地质条件分析  

ORE-FORMING CONDITIONS OF XIKUANGSHAN-TYPE ANTIMONY DEPOSITS IN CENTRAL HUNAN

作　　者：陶琰[1] 高振敏[1] 金景福[2] 曾令交[2] 

机构地区：[1]中国科学院地球化学研究所矿床开放研究实验室,贵阳550002 [2]成都理工学院,成都610059

出　　处：《地质科学》2002年第2期184-195,242,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：原地质矿产部定向科研基金 (编号 :地定 96 1 3)资助项目

摘　　要：湘中锡矿山式锑矿形成于晚白垩 古新世 ,空间上与岩脉关系密切 ,各锑矿床、矿化点都伴有或附近发育有煌斑岩及中 酸性岩脉群 ,在锑矿成矿同期地质事件中 ,还有周缘一些中 新生代红色盆地的形成及基性火山岩喷发 ,据之 ,提出湘中锡矿山式锑矿成矿与燕山晚期拉张构造—岩浆活化作用有关。锑矿床 (点 )基本上都产出于两组或两组以上断裂的交汇点附近 ,3组断裂的交汇部位对应于最主要的锑矿床 (点 )。矿体具体受断裂交汇部位附近的次级短轴背斜轴部、倾伏背斜的倾伏端及其翼部被纵向陡倾角断裂构造所切穿的部位控制 ,是断裂导矿与背斜构造圈闭的体现。岩性组合控矿表现为易于硅化蚀变交代的砂质碳酸盐岩与隔挡层泥质岩所构成的岩性圈闭。根据包裹体均一温度和盐度测定成果 ,推算成矿压力为 (2 0 0～ 3 0 0 )× 1 0 5Pa ,成矿深度约为 1km。The Central Hunan is a world famous antimony metallogenic province, host a great number of antimony deposits in which Xikuangshan type is the most important one.Based on geological investigations, this paper confirmed that the metallogeny was related to tectono magmatic activation.The geological evidences and the ESR ages of Sb bearing quartz showed that metallogenetic epoch was from Late Cretaceous to Paleocene.Antimony deposits were located on the intersection of two or three faults. In general, the intersection of three faults companied with the main antimony deposit.Controlled by structure trap, ore body located in the core of the brachy anticline or pitch part of plunging anticline which was intersected by high angle longitudinal fault.The most favorable wall rock assemblages were in three layer structures in which agillaceous rocks acted as plastic beds overlain on top, clastic rocks at bottom, chemically active beds of arenaceous limestone in the middle and prone to be silicified.The ore forming pressure was (200～300)×10 5 Pa, the forming depth was about 0 8～1 2 km.

关 键 词：锡矿山式锑矿床 构造-岩浆活化 成矿时代 构造-岩性圈闭 成矿地质条件 成矿深度 湖南 

分 类 号：P618.66[天文地球—矿床学]