摘要
烂泥沟金矿是以浊积岩为容矿岩石的微细浸染型金矿。有机岩石学分析表明，矿石与围岩中干酪根类型无明显差别，同属腐泥－腐植型。与围岩相比，矿石中干酪根成熟度（Ｒ０＝２．７４％－３．０６％）和含金性（６．１５—２４．８μｇ／ｇ）均较高；干酪根总含金量在全岩中所占的比例是围岩高于矿石。氯仿沥青“Ａ”的检测说明，矿石样品中可溶性有机质形成于强还原和高盐度环境，沥青质和含硫有机化合物发育。研究认为，干酪根含金性与碳的活化有关；不饱和的有机基因对金的动一定转换可能具有重要意义。
he Lannigou gold dePOsit is hosted in turbidite sequences of Middle Triassicfound in Southwest Guizhou, China, in which gold occurs as sub-micron and disseminated particles. The deposit was studied by many ways including organic petrology, organic geochemistry and gold test in kerogens in this paper.Total organic carbon content of whole rock in Lannigou ranges from 0.06% to1.18%, in which ores have slightly higher values than their host rocks. Kerogensseparated from both ores and hosts are all sapropelic-humic type (II2), and no apparent differeces are found. Comparing with the hosts, kerogens in the ores showhigher maturity(R, =2.74 %-3.06% )and noticeably higher gold content (6.15-24.80μg/g), and the differences are larger than 0.14%--0.46% and 4.79-23.44μg/g, respectively. However, the ratios of total gold content of kerogens to whole rocksare apparently higher for hosts than for ores.Organic geochemical analysis shows that soluble organic compounds may be preserved in some rocks with high maturity due to mineral preservation for organicmatter. Examination of saturated and aromatic hydrocarbons separated from chloroform bitumen 'A' demonstrated that organic matter in ores responses an environment characterized by high salinity and strong reducibility, and that much asphalteneand/or sulphur-bearing organic compound exists. In addition, dissimilar to ores,there are marked evidences of ocean biomarker compounds preserved in host samples.An integrated research shows that: (1) organisms of gold-hosted rocks, controlled by faults, were activated by both shearing and hydrothermal fluids in the faultzones, and thus became an excellent scarenger for small concentrations of dissolvedgold; (2) kerogen of humic type has much more aromatic nucleuses and is muchmore close to structure of activated carbon, so the Middle Triassic formation inLannigou is also suitable for concentration of sub-micro gold, though total contentof gold in the kerogen does not have industrial significance due to lower contentof organisms; (3) transportation and precipitation of gold may be to a large extentrelated to existence and destroy of unsaturated ligands, including aromatic and/orsulphur-bearing organic groups.
出处
《地质科学》
CAS
CSCD
北大核心
1995年第3期283-290,共8页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国科学院重点
博士后研究基金
关键词
干酪根
活性碳
络合物
金矿床
有机质
Kerogen, Activated carbon, Complex,Sub-micron and disseminated gold deposit, Lannigou, Guizhou province
