GEOCHEMICAL CHARACTERISTICS AND GENESIS OF STRATABOUND GOLD DEPOSITS IN JIANGNAN GOLD METALLOGENIC BELT  

作　　者：马东升 刘英俊 

机构地区：[1]Department of Earth Sciences, Nanjing University, Nanjing 210008, PRC

出　　处：《Science China Chemistry》1992年第2期240-256,共17页中国科学（化学英文版）

摘　　要：This paper, based on the geochemical study and comparison of the gold-bearing formations and stratabound gold deposits hosted by the formations in the belt, shows that the most outstanding geochemical characteristics of the strata-bound gold deposits in the Proterozoic Jiangnan Metallogenic Belt, namely 'Jiangnan-type' gold deposits, are conjugated occurrence of gold-depleted strata associated with high frequency gold mineralization in regional scale and negative gold anomaly in the wall rock of gold orebodies in the local range, concentration of the low-abundance elements such as Au, Sb, W and As, and impoverishment of base metals in the ore. Their ore-forming solutions have a temperature range of 160—390℃, intermediate salinity mostly from 4 to 10 wt% NaC1 equiv., nearly neutral to weak alkaline, and are reduced, rich in HCO_3^-, ΣS and poor in C1. It is suggested that the ore-forming elements of the deposits mostly come from the gold-bearing formations and the metallogenic processes are majorly related to the joint effects of metamorphic fluid from the deep and thermal groundwater in the shallow. Therefore the Jiangnan-type gold deposits should be regarded as a genetic type of transition from deposits formed by metamorphic fluid to that by infiltrating hydrothermal solution of groundwater.This paper, based on the geochemical study and comparison of the gold-bearing formations and stratabound gold deposits hosted by the formations in the belt, shows that the most outstanding geochemical characteristics of the strata-bound gold deposits in the Proterozoic Jiangnan Metallogenic Belt, namely "Jiangnan-type" gold deposits, are conjugated occurrence of gold-depleted strata associated with high frequency gold mineralization in regional scale and negative gold anomaly in the wall rock of gold orebodies in the local range, concentration of the low-abundance elements such as Au, Sb, W and As, and impoverishment of base metals in the ore. Their ore-forming solutions have a temperature range of 160—390℃, intermediate salinity mostly from 4 to 10 wt% NaC1 equiv., nearly neutral to weak alkaline, and are reduced, rich in HCO₃^-, ΣS and poor in C1. It is suggested that the ore-forming elements of the deposits mostly come from the gold-bearing formations and the metallogenic processes are majorly

关 键 词：STRATABOUND gold deposit geochemistry METALLOGENESIS Proterozoic. 

分 类 号：O6[理学—化学]