摘要
该矿床是桂西北典型的微细浸染型金矿床。本文通过地层含金性比较、矿体外围的金负异常、Li与Au的相关性、稳定同位素、有机质特征及模拟实验等方面的分析,探讨了金牙金矿床中成矿元素的物质来源,认为中三叠统板纳组是主要的矿源层。
The Jinya finely-disseminated gold deposit is a typical gold deposit occur ring in turbidite of Middle Triassic Banna Formation in northeastern Guangxi, with gold mainly present in pyrite, arsenopyrite, clay minerals and organic carbon. This paper makes a tentative discussion on the material source of gold and sulfur for this deposit in the light of the following aspects: ① No intrusives have been found near or beneath the orebody, so ore-forming materials seem unlikely to have been derived from igneous rocks; ② gold abundance varies only unnoticeably in Lower Permian-Middle Triassic strata, whereas the variation coefficient of gold is highest in Banna Formation, suggesting that activation and migration of metals were ready to occur in Banna Formation; ③ wall rocks contain very low gold and sulfur, which exhibit the tendency of migration from wall rocks to the orebody; ④ in the upper part of the host horizon there exists a layer of black shale which contains higher gold and organic carbon than other horizons; liquid hydrocarbon produced by organic materials in the heating process might have extracted gold from this layer or upper strata, and when hydrocarbon substances approached the orebody, gold would be released due to elevated temperature; ⑤ sulfur isotope character implies that sulfur in ores and that in regional strata are of the same source; ⑥ gold displays positive correlation with lithium in regional strata and in ores, suggesting that lithium and gold migrated synchronously from strata to orebody; ⑦ leaching experiments on auriferous siltstone of Banna Formation show that gold has strong tiavel capability in rocks. These arguments demonstrate that Banna Formation must have served as the major material source for this ore deposit.
出处
《矿床地质》
CAS
CSCD
北大核心
1992年第3期233-240,共8页
Mineral Deposits
