黔西南凝灰岩中金矿控矿因素概述

在国土资源大调查项目--贵州盘县-兴仁金矿评价等工作的基础上,对黔西南地区与峨眉山玄武岩喷发有关,主要赋存于玄武质凝灰岩中金矿的控矿因素进行了系统研究.主要认为,此类金矿的区域分布受控于峨眉山玄武岩及其边缘凝灰岩分布区;区域性控矿构造,如扬子陆块西南缘的深部构造和区域性深大断裂,控制了金矿成矿域及矿田的形成和分布;局部性构造决定了矿床的定位,也决定了矿体空间分布及产出特征;蚀变控矿因素主要有硅化、黄铁矿化;各类岩层因能干性不同而分别起着导矿、容矿及盖矿作用;金矿床具有明显的层控性.这些认识,可指导黔西南乃至滇黔桂峨眉山玄武岩及凝灰岩分布区的同类型金矿的勘查及研究工作.

ORE-CONTROLLING FACTORS OF GOLD DEPOSITS IN VOLCANIC TUFF IN THE SOUTHWESTERN GUIZHOU PROVINCE

Based on project results of land resources investigation on gold resources assessment in Panxian and Xinren district of Guizhou province, ore-controlling factors of the gold deposits in the Emeishan basalts and tuff in the southeastern Guizhou province have been systematically analyzed. The regional distribution of gold deposits is controlled by the distribution of the Emeishan basalts, and the tuff around the basalts. Regional ore-controlling structures, such as deep faults and regional structures which are particular in southwest edge of Yangtze plate, control the formation and distribution of metallogenic belts and gold deposits. Local ore-controlling structures control the location, shape, occurrence and spatial distribution of the gold ore bodies. The main alteration types in gold deposits are silicification and pyritization. Different stratified structures also have important influences on the migration, accommodation and preservation of ore-forming materials. Strata and lithology are important ore-controlling factors, which indicate that gold deposits are stratabound.