浙江中生代火山岩区浅成热液型金、银矿床的金银赋存状态和富集规律  

EXISTING FORMS AND ENRICHMENT LAWS OF AU, AG OF EPITHERMAL-TYPE GOLD-SILVER DEPOSITS IN MESOZOIC VOLCANIC ROCKS OF ZHEJIANG

作　　者：胡永和 许峰林 李长江 徐步台 蒋叙良 

机构地区：[1]浙江省地质矿产研究所

出　　处：《地质找矿论丛》1993年第1期84-94,共11页Contributions to Geology and Mineral Resources Research

基　　金：浙江省自然科学基金

摘　　要：浙江中生代火山岩区"浅成热液"型金、银矿床的金、银主要呈独立的矿物形式出现,矿物种类多达二十多种,常见的有银金矿、金银矿、辉银矿-螺状硫银矿等,主要载金矿物为黄铁矿、毒砂;主要载银矿物为方铅矿.嵌布形式以"裂隙金(银)"为主.多期次活动、多期次蚀变的叠加和在火山构造之上的张或张扭性断裂,最有利于Au、Ag的富集,银矿化与深色硅化和菱锰矿化关系较密切,伴(共)生银主要富集在Zn/Pb比值小于2.4的铅锌矿床(点)矿体的上部或浅部;金矿化多富集在硅化-冰长石化-绢云母化-伊利石化-黄铁矿(毒砂)化带或伊利石化-地开石化、镜(赤)铁矿化带.Based on the data of the polished and thin sections of rock and ore, the chemical analyses of mono-minerals or electro-probe analyses, the ore-floatation experiments and combined with geological characters the existing forms and enrichment laws of Au and Ag of gold-silver deposits in Mesozoic volcanic rocks of Zhejiang can be preliminarily summarized. 1. Au and Ag are mostly in the forms of independent minerals, only a few silver being as isomorphism in crystal lattice of galena. Dozens of the independent minerals have been found, of which electrum, kustelite, argentite-acanthite, plybasite, silver-tetrahedrite, native gold, native silver and so on are common. The paragenetic associations among these main Au-and Ag-bearing minerals are not similar in different ore-areas. 2. Main carrier of gold are pyrite, arsenopyrite, and galena etc. are main carrier of silver, of which Au and Ag mostly exist in the forms of independent minerals with micrograin and often occur in 'fracture gold (silver)', only a few gold (silver) being as 'inclusive gold (silver)'. 3. Gold and silver deposits (mineralization occurrences) often occured in tension, and/or tension-shear fractures overlapping volcanic structures. Especially those fractures with multi-time active (or reactive) and altered fault zones are mostly advantageous to the enrichment of Au and Ag. 4. Ag-mineralizations are often related to dark-grey silicification and manganese spar mineralization. The associated silver mineralizations majorly rich in Zn/Pb ratio of less than 2.4, and usually occur in the upper (or shallow) of the ore-body. 5. Au-mineralizations mostly rich in silicification——adularia——sericitization——illite——pyrite (arsenopyrite) zone; or illite——dickite; specularite (hematite) mineralization zone.

关 键 词：金矿床 银矿床 赋存 火山岩 热液型 

分 类 号：P618.510.2[天文地球—矿床学]