柴北缘大煤沟矿区侏罗纪煤系层序地层及其煤岩变化特征  

Coal petrography variation in the sequence stratigraphic frame of the Jurassic coal measures of Dameigou mine area in Northern Qaidam Basin

作　　者：鲁静[1] 邵龙义[1] 鞠奇 刘天绩 文怀军 李永红 张发德 高迪[1] 

机构地区：[1]中国矿业大学煤炭资源与安全国家重点实验室,北京100083 [2]青海省煤田地质局,青海西宁810000

出　　处：《煤田地质与勘探》2009年第4期9-14,共6页Coal Geology & Exploration

基　　金：国家重点基础研究发展计划(973计划)项目(2006CB202200);国家自然科学基金项目(40672103)

摘　　要：为揭示陆相盆地成煤沼泽内基准面变化与煤岩组分的关系,应用层序地层学理论和方法,对柴北缘大煤沟矿区侏罗纪煤系层序格架下的煤岩变化规律进行了研究。研究区共识别出区域不整合面、河流下切谷、区域构造应力转换面和地层颜色突变面等9个层序界面;将侏罗纪煤系划分为3个二级层序、8个三级层序。研究区主要煤层(F煤)形成于三级层序SⅢ6湖侵体系域中晚期的废弃辫状河冲积平原之高位沼泽环境,煤岩显微组分以高惰质组(平均57.7%)和低镜质组(平均32.0%)为特征。根据垂向上煤岩显微组分的变化特征,将F煤划分为1个四级层序和5个五级层序。垂向上F煤镜质组含量总体向上呈增加趋势,反映了泥炭沼泽内三级层序SⅢ6湖侵体系域基准面上升速率逐渐加快的动力学背景。In order to reveal the relationship between the base level in the bog of inland basin and the coal petrography variation, principle of the sequence stratigraphy has been used to study the coal petrography variation in the sequence stratigraphic frame of the Jurassic coal measures of Dameigou mine area in Northern Qaidam Basin. A total of 9 sequence boundaries have been identified （including regional unconformity surface, incised valley, regional tectonic stress transforming interface and color of strata discontinuous surface）, which divided Jurrasic coal measures into 3 second-order sequences and 8 third-order sequences. The major coals （coal F） in the research area were formed in the environment of highstand swamp in the abandoned braided fiver plain, the coal macerals are characterized by high inertinite （average 59.1%） and low vitrinite （average 23.9 %）. According to the variation of coal maceral in the vertical profile, coal F has been divided into 1 fourth-order sequence and 5 fifth-order sequences. In the vertical profile, vitrinite content of coal F has a trend of increase as a whole, which reflects the dynamic background of gradual rise of base level rise of the lacustrine transgressive system tract of the third-order sequence SⅢ6.

关 键 词：柴北缘 侏罗系 层序地层学 煤岩特征 

分 类 号：P539.2[天文地球—古生物学与地层学]