贵州盘州米妥勘查区煤层顶底板Ga矿富集特征及成因  

Ga enrichment characteristics and metallogenic genesis of coal seam roof and floor in Mituo exploration area,Panzhou,Guizhou

作　　者：张小祥 Zhang Xiaoxiang(Water Source Team of Guizhou Coal Geology Bureau,Guiyang 550018,Guizhou,China)

机构地区：[1]贵州省煤田地质局水源队,贵州贵阳550018

出　　处：《地质学刊》2023年第2期153-158,共6页Journal of Geology

基　　金：贵州省2021年度重点矿产资源大精查项目“贵州省盘州市米妥勘查区煤炭资源精查”(MCHC-ZC20212218-8)。

摘　　要：为查清贵州盘州米妥勘查区煤层顶底板及煤中Ga的赋存状况,开展钻孔勘探工作,采集煤层顶底板泥化样品39件,煤样品25件,使用电感耦合等离子体发射光谱法测定Ga含量,根据样品中Ga含量的实测结果,结合勘查区聚煤时期的古地理环境及煤层顶底板沉积物源等特征,分析上二叠统煤层顶底板中Ga矿的富集特征及成因。结果表明:米妥勘查区煤中Ga富集程度低,25件煤样品中Ga的平均含量为7.90μg/g,远低于边界品位;煤层顶底板中Ga富集程度高,21件顶板样品中Ga含量为31.8~46.2μg/g,平均值为39.6μg/g,18件底板样品中Ga含量为31.1~51.4μg/g,平均值为41.3μg/g,底板中Ga含量均值略高于顶板。顶底板中Ga的含量达到我国煤中伴生矿的工业指标,该区域煤层顶底板及围岩具有稀散金属矿找矿前景。分析沉积的古地理环境特征及沉积物源,认为聚煤时期古地理环境多为陆相及海陆交互相,导致煤层顶底板多为泥岩及泥质砂岩,陆源碎屑物为Ga沉积提供了很好的来源,流水、风力等搬运作用为Ga提供了很好的富集方式。To find out the occurrence of Ga in the roof and floor of coal seam and in coal of Mituo exploration area,Panzhou,Guizhou,the paper explored borehole data,collected 39 argillated samples of coal seam roof and floor,25 samples of coal seam,used the inductively coupled plasma optical emission spectrometry to determine the Ga content.Based on the tested Ga content of samples,in combination with the characteristics of the paleogeographic environment and the sediment source of the roof and floor of coal seam during the coal accumulation period in the exploration area,the enrichment characteristics and metallogenic genesis of Ga in the Upper Permian coal seam roof and floor were deeply analyzed.The results show that the enrichment degree of Ga is low in the coal of Mituo exploration area.The average content of Ga in 25 coal samples is 7.90μg/g,which is much lower than the boundary grade.Moreover,the concentration of Ga in the roof and floor of coal seam is high.The content of Ga in 21 roof samples is from 31.8μg/g to 46.2μg/g,with an average of 39.6μg/g;the content of Ga in 18 floor samples is from 31.1μg/g to 51.4μg/g,with an average of 41.3μg/g,which shows that the average content of Ga in the floor is slightly higher than that in the roof.The content of Ga in the roof and floor of the coal seam reaches the industrial index of associated ore in coal in China,and the roof and floor of coal seam and its surrounding rock are good targets for prospecting scarce metal deposits.By analyzing the characteristics of paleogeographic environment and sediment sources,it is concluded that the paleogeographic environment in the coal accumulation period was mainly continental facies and sea-land alternate facies,which resulted in mudstone and argillaceous sandstone in the roof and floor of coal seam.Terrigenous detritus provided a good source for Ga deposition,and transportation including water and wind promoted Ga enrichment.

关 键 词：GA 富集特征 成矿成因 煤 贵州盘州米妥 

分 类 号：P611[天文地球—矿床学] P618.74[天文地球—地质学]