摘要
南华北盆地主要发育3期断裂:第一期是在三叠纪末挤压构造背景下形成的逆冲断裂,断裂走向以近E-W向为主、主要由南向北逆冲;第二期是与晚侏罗世一早白垩世构造运动相关的走滑拉张断裂,断裂走向以NNE向为主,左行走滑,常沿印支期挤压断裂带发育;第三期是与晚白垩世一古近纪构造运动相关的正断裂,断裂走向以近S・N向或NEE向为主。三叠纪末印支期断裂的冲断抬升作用一方面使该区主力炷源岩石炭一二叠系受严重剥蚀,另一方面破坏了炷源岩的连续性和稳定性;晚侏罗世一早白垩世的走滑拉张断裂与印支期断裂一起,呈棋盘格式平面切割了南华北盆地,与之伴生的火成岩对绘源岩也有一定的破坏作用;晚白垩世一古近纪的拉张断裂则进一步加强了坯源岩的不连续性。后两期拉张断裂常常通天,对前期形成的油气藏有一定的破坏作用。因此,对于南华北盆地的油气勘探,需要避开走滑断裂或拉张断裂,避开火成岩体;针对上古生界,要寻找连续性较好的绘源岩层;针对中、新生界,要寻找有利于绘源岩发育的沉积相带。
There are three periods main faults in the southern North China Basin. The first period faults are thrust faults because of compressive stress in Late Triassic, with near EW trend, thrusting direction from south to north. The second period faults are strike slip faults mainly trending NNE caused by tensional-shear stress in Late Jurassic-Early Cretaceous. The third period faults are a series of normal faults mainly trending NNE related with the structural movement in Late Cretaceous and Paleogene. Thrusting and uplifting of the faults in Late Triassic resulted in serious erosion and discontinuity to Carbon-Permian source rocks. The faults in Late Jurassic-Early Cretaceous and the faults in Late Triassic cut the southern North China Basin just as chess board, and the igneous rock associated with the faults destroyed the source rocks in a certain degree. The faults in Late Cretaceous and Paleogene reinforced the discontinuity of source rocks. The faults in later two periods usually reached the land surface and destroyed the oil and gas reservoir formed before Late Jurassic. Therefore, the oil and gas exploration in the southern North China Basin should avoid the strike slip faults, normal faults and igneous body, search for the Paleozoic source rocks of good continuity, hunt for the sedimentary facies belts in favor of developing source rocks.
作者
王步清
徐秋晨
王艳红
刘恩然
石砥石
Wang Buqing;Xu Qiuchen;Wang Yanhong;Liu Enran;Shi Dishi(Oil and Gas Survey Center,China Geological Survey,Beijing100083)
出处
《地质科学》
CAS
CSCD
北大核心
2020年第1期109-121,共13页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
政府间国际科技创新合作重点专项“中美石炭—二叠系页岩储层评价技术合作研究”(编号:2017YFE0106300)和中国地质调查局项目“合肥盆地及周缘油气资源战略调查”(编号:DD20190725)资助。
关键词
南华北盆地
断裂
构造特征
构造演化
油气勘探
Southern North China Basin
Structural characteristic
Fault
Petroleum exploration
