接触变质煤中碳酸盐矿物成因探讨

Inquire into the genesis of carbonate minerals in cantact metamorphic coals

山西大同和山东临沂煤田的接触变质煤中含有大量碳酸盐矿物,根据显微镜鉴定、化学分析、低温煤灰的X射线衍射分析、差热分析、碳同位素测定,碳酸盐的矿物成分主要为白云石和方解石,其成因主要与侵入煤层的火成岩及其伴随的富含CO_2气体的气、液物质有关。

There are many gangue carbonate minerals in contact metamorphic coals in Dangtong Coal-field, Shanxi, and Linyi Coal-field, Shandong. The main minerals of cabonate are dolomite and calcite based on microscopic analysis, X-ray diffrac-tograms of low-tomperature ashing, chemical analysis, differential thermoanalysis and isotopic analysis. The genesis of these carbonates is related to the igneous and the amount of CO2 in volatiles and solution accompanying the intrusion which injected into the coal bed.