西山矿区煤中有机碳同位素特征与其成熟度之间的联系

Relationship Between Organic Carbon Isotope Characteristics and Maturity in Xishan Coalfield

分析了西山矿区屯兰矿7个煤层共19个煤样品的有机碳同位素丰度,研究了各煤层之间碳同位素值(δ^(13)C_(org)值)的分布特征和变化趋势。研究成果表明:屯兰煤中δ^(13)C_(org)值的变化范围在-25.6‰～-23.3‰之间,平均值为-24.3‰;自下而上由9煤至02煤的δ13C值呈现出总体偏正的趋势,仅在7煤发生了偏负现象,煤中δ^(13)C_(org)的增大可能是受到二叠纪华北地区温度上升的影响;随着成熟度增加,不同煤层煤的δ^(13)C_(org)-Rmax相关性曲线总体上呈现出一定的正相关关系;采用多项式回归函数模型确定了δ^(13)C_(org)-Rmax之间的关系。

This paper analyzes the organic carbon isotope abundance of 19 coal samples from 7 coal seams in Tunlan coalmine,Xishan coalfield, and studies the distribution characteristics and changing trend of carbon isotope value（δ^13Corg） among various coal seams. The research results show that δ^13Corg values in Tunlan coal range from-25.6‰ to-23.3‰, with an average value of-24.3‰. The δ^13 C values of 9 coal to 02 coal（from bottom to top） showed a generally positive trend, with only 7 coal showing a negative trend. The increase of δ^13Corg in coal may be influenced by the temperature rise in the Permian North China region. With the increase of maturity, the δ^13Corg-Rmaxcorrelation curves of different coal seams show a certain positive correlation. The polynomial regression function model was used to determine the relationship between δ^13Corg-Rmax.