Stratabound gold deposits in the western Qinling Mountains occur in Cambrian chert formation composed of carbonaceous chert and carbonaceous slate. The distinctive chert formation provides important grounds for the mi...Stratabound gold deposits in the western Qinling Mountains occur in Cambrian chert formation composed of carbonaceous chert and carbonaceous slate. The distinctive chert formation provides important grounds for the mineralization and controls on the formation of gold deposits. Study shows that Se is exceptionally higher in both host rocks and gold orebodies. It may be recovered as a valuable component in ores for total utilization, and in some localities even independent Se orebodies (which are mined exclusively for Se) may be delineated. In gold ore Se mainly occurs as independent minerals or in the isomorphous form in sulphides and there is a positive correlation between Se and Au.展开更多
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 ...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<sub>3</sub><sup>-</sup>, 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展开更多
The organic matter of three different chronological major carbonaceous rock gold-bearing formations of South China (Middle Proterozoic Shangqiaoshan group of northeastern Jiangxi, Lower Cambrian Shuikou group of north...The organic matter of three different chronological major carbonaceous rock gold-bearing formations of South China (Middle Proterozoic Shangqiaoshan group of northeastern Jiangxi, Lower Cambrian Shuikou group of northern Guangxi and Devonian Shetianqiao group of eastern Hunan) and related carbonaceous stratabound gold deposits such as Jinshan, Longshui and Shixia deposits, respectively, has been characterized by organic geochemical techniques. These organic geochemical results show that the average total organic carbon (TOC) content of the three chronological carbonaceous rock gold-bearing formations of South China ranges from 0.15% to 1.56%. The thermal maturity of the organic matter of host rocks in the three gold-bearing formations is high. The micro-component of the organic matter of the host rocks consists primarily of solid bitumen and graphite. The organic carbon and gold of the host rocks appear to syndeposit in situ during the formation of the gold-bearing formations. The organic carbon展开更多
基金This study was supported by the National Natural Science Foundation of China (Grant Nos. 49503048 and 49773197), a Sino-Austrian cooperation project (No. 4880099) and the Postdoctoral Science Foundation of China
文摘Stratabound gold deposits in the western Qinling Mountains occur in Cambrian chert formation composed of carbonaceous chert and carbonaceous slate. The distinctive chert formation provides important grounds for the mineralization and controls on the formation of gold deposits. Study shows that Se is exceptionally higher in both host rocks and gold orebodies. It may be recovered as a valuable component in ores for total utilization, and in some localities even independent Se orebodies (which are mined exclusively for Se) may be delineated. In gold ore Se mainly occurs as independent minerals or in the isomorphous form in sulphides and there is a positive correlation between Se and Au.
文摘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<sub>3</sub><sup>-</sup>, 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
文摘The organic matter of three different chronological major carbonaceous rock gold-bearing formations of South China (Middle Proterozoic Shangqiaoshan group of northeastern Jiangxi, Lower Cambrian Shuikou group of northern Guangxi and Devonian Shetianqiao group of eastern Hunan) and related carbonaceous stratabound gold deposits such as Jinshan, Longshui and Shixia deposits, respectively, has been characterized by organic geochemical techniques. These organic geochemical results show that the average total organic carbon (TOC) content of the three chronological carbonaceous rock gold-bearing formations of South China ranges from 0.15% to 1.56%. The thermal maturity of the organic matter of host rocks in the three gold-bearing formations is high. The micro-component of the organic matter of the host rocks consists primarily of solid bitumen and graphite. The organic carbon and gold of the host rocks appear to syndeposit in situ during the formation of the gold-bearing formations. The organic carbon
