地质科学2026，Vol.61Issue(1)：59-67,9.DOI:10.12017/dzkx.2026.005
鄂尔多斯盆地东北部奥陶系马五5亚段岩相古地理特征
Lithofacies paleogeographic characteristics of the 5th sub-member of Ma 5 of Ordovician Majiagou Formation in the northeastern Ordos Basin
摘要
Abstract
The 5th sub-member of Ma 5 of Ordovician Majiagou Formation in the northeastern Ordos Basin is one of the key target layers for natural gas exploration.However,the understanding of its sedimentary characteristics remains insufficient,which restricts further exploration planning.Therefore,a systematic study on the lithofacies paleogeography of the 5th sub-member of Ma 5 of Ordovician Majiagou Formation in the northeastern Ordos Basin was conducted using integrated data from drilling,core samples,and thin sections,aiming to predict the distribution of favorable reservoir zones.The research results indicate that:1)the 5th sub-member of Ma 5 of Ordovician Majiagou Formation in the northeastern Ordos Basin develops microfacies such as grain banks,microbial mounds,dolomitic lagoons,and calcareous lagoons;2)the paleogeographic pattern of alternating uplifts and sags controlled the sedimentary differentiation of the 5th sub-member of Ma 5 of Ordovician Majiagou Formation,with grain banks distributed in a ring-like pattern around the central paleo-uplift,while microbial mounds and dolomitic lagoons are distributed along the high paleo-topographic areas in the eastern basin,and calcareous lagoons are mainly found in the sag areas;3)grain banks and microbial mounds developed pre-existing pores due to grain accumulation or microbial frameworks,while dolomitic lagoons developed pores due to bioturbation and early dolomitization.These three microfacies are considered favorable reservoir facies zones for the 5thsub-member of Ma 5 of Ordovician Majiagou Formation.It is concluded that the Wushenqi-Wuqi area and the Mizhi area are favorable reservoir distribution zones for the 5th sub-member of Ma 5 of Ordovician Majiagou Formation in the northeastern Ordos Basin,and merit further exploration.关键词
鄂尔多斯盆地东北部/奥陶系/马五5亚段/岩相古地理/丘滩体/云质潟湖Key words
The northeastern Ordos Basin/Ordovician/The 5thsub-member of Ma 5 of Ordovician Majiagou Formation/Lithofacies palaeogeography/Mound-shoal complex/Dolomitic lagoon分类
天文与地球科学引用本文复制引用
石磊,鲁慧丽,李雪娇,周铭子,李欣阳..鄂尔多斯盆地东北部奥陶系马五5亚段岩相古地理特征[J].地质科学,2026,61(1):59-67,9.基金项目
中国石油长庆油田公司科技项目"鄂尔多斯盆地中元古界—奥陶系构造沉积演化、成源机制与勘探新领域研究"(编号:2024D1JC06)和中国石油集团公司攻关性应用性科技专项"碳酸盐岩油气富集规律及有利区带研究"(编号:2023ZZ16YJ01)资助 （编号:2024D1JC06）
