摘要
随着鄂尔多斯盆地西南部上古生界二叠系碎屑岩油气藏的不断发现,其物源引起了人们特别的关注和重视。应用数理统计方法,对鄂尔多斯盆地西南部二叠系下石盒子组盒8段的碎屑组分及S岩屑分布特征、重矿物组合、古水流方向进行分析,并与源岩进行对比,分析探讨了该地区二叠系下石盒子组盒8段的物源问题。分析结果表明:研究区存在三个物源区,即盆地北部物源来自阴山古陆西段太古界的沉积变质岩和中基性火山岩,盆地西南部物源来自中北祁连和西秦岭物源区的高级变质岩及部分岩浆岩和少量的沉积岩,盆地南部物源来自北秦岭物源区的高级变质岩及部分岩浆岩和少量的沉积岩,并指出三大物源的交汇区大致在环县-华池一带。这些分析和结论不但澄清了鄂尔多斯盆西南部二叠系下石盒子组盒8段物源研究中长期不清的问题,而且对研究盆地其他地区的下石盒子组物源变化规律提供了一定的参考。
With the successive discovering of clasticrock oil-gas reservoirs in Permian of upper Paleozoic in the southwest area of Ordos basin,special attention has been paid to the material sources of these reservoirs.By applying mathematical statistics and in combination with the debris composition,the distribution characteristics of heavy minerals and paleocurrent direction,the source areas of the 8th member of the Xiashihezi formation of Permian in the region have been analyzed in contrast with native rocks.The analysis results show that three provenance exist in the studied area.The provenance of north of the basin is derived from the Archean sedimentary metamorphic rock and the sex volcanic rocks of Yinshan paleoland,the provenance of the southwest of the basin is derived from the senior metamorphic rocks and part of magmatic rocks and a small amount of sedimentary rock of north Qilian and west Qinling and the provenance of the south of the basin is derived from senior metamorphic rocks and part of magmatic rocks and a small amount of sedimentary rock of north Qinling.Besides,three provenance approximately intersect the Huan county-Huachi area.The problems existing in the research on the material sources of upper Paleozoic in the southwest area of Ordos basin not only have been settled,a certain reference to research the sediment provenance of the basin in other parts of the Xiashihezi formation of Permian has been offered as well.
出处
《石油地质与工程》
CAS
2012年第3期1-5,136,共5页
Petroleum Geology and Engineering
基金
国家重大专项"中国大型气田形成条件
富集规律及目标评价"(2008ZX05007-005)课题的部分研究成果
关键词
鄂尔多斯盆地
物源分析
重矿物组合
岩屑
古水流
Ordos basin
provenance analysis
heavy mineral combination
clastic debris
paleocurrent direction
