摘要
煤中Au含量的异常作为潜在的Au资源开发利用区日益引起地质工作者的重视，笔者通过对黔西南地区116个上二叠统龙潭组、长兴组煤样及矸石样的Au含量进行了中子活化分析（IN．AA），研究了煤中Au的分布特征、赋存状态，探讨煤中Au的主要来源及富集机理。研究表明：贵州省西南部地区煤中Au含量为1～30ng／g，平均值为13．75n#g，大大超过沉积岩丰度和世界煤平均丰度；Au含量高异常的地区主要分布在紫云一垭都深断裂、师宗一贵阳深断裂及开远一平塘断裂所构成的“三角形”区域内；含Au热液是黔西南煤中Au的主要物质来源，地幔热柱及深部岩浆活动是含Au热液流体向煤层运移的热动力源，当含Au热液在构造驱动下沿断裂构造带迁移上升进入煤层后，由于浓度、温度、压力、pH等物理化学条件的改变及有机质的作用，使得成矿流体失稳而导致研究区煤中Au等成矿元素沉淀富集。
The anomalous concentration of gold in coals makes it a potential resource exploitation area of gold that has win geological workers＇ attention. Instrumental neutron activation analysis（INAA） on concentration of gold of 116 coal samples and gangue samples of Longtan Formation of the upper Permian and Changxing Formation in Southwestern Guizhou Province was conducted so as to make investigations on gold＇ s distribution characteristics and occurrence modes and to further probe into its main source and enrichment mechanism. Studies show that concentration range of gold in coals in Southwestern Guizhou is from 1 ng/g to 30 ng/g,with an average value being 13.75 ng/g,which is well above the sedimentary rock abundance and the world average abundance of coal. Areas where the anomalous con- centration of gold is really high are principally in the ＂triangle＂ area composed of Ziyun-Yadu deep fault, Shizong- Guiyang deep fault and Kaiyuan-Pingtang fault. Hydrothermal solution containing gold is the main material source for the gold in coals in Southwestern Guizhou Province while mantle plume and deep magmatic activities are the thermo- dynamic source for the solution＇ s migration into coal beds, that is, after the hydrothermal solution containing gold, un- der tectonic forcing, migrated to the coal bed along fault belt, ore-forming fluid would lose stability because of organic matter effect and physicochemical changes such as concentration, temperature, pressure and pH value,which led to the precipitation and enrichment of ore-forming elements like gold in coals in the research area.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2013年第11期2017-2022,共6页
Journal of China Coal Society
基金
江西省重大科技专项资助项目(20124ABE02107)
江苏高校优势学科建设工程资助项目
关键词
黔西南
晚二叠世
煤
AU
异常含量
富集机理
Southwestern Guizhou Province
Late Permian
coal
gold
anomalous concentration
enrichment mechanism
