渤海湾盆地黄骅坳陷南部古近系孔店组沉积时期构造古地理演化  

Tectonopalaeogeography during the deposition of Paleogene Kongdian Formation in Kongnan area,Huanghua Depression of Bohai Bay Basin

作　　者：杨桥[1] 漆家福[1] 常德双 李明刚[1] 

机构地区：[1]中国石油大学北京油气资源与探测国家重点实验室,北京102249 [2]东方地球物理公司研究院大港分院,天津300280

出　　处：《古地理学报》2009年第3期306-313,共8页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:40772085)资助

摘　　要：黄骅坳陷南部的古近系孔店组是渤海湾裂陷盆地古近纪最早的沉积地层。孔店组分布在相向倾斜的沧东断层与徐西断层构成的地堑之中。综合分析盆地剖面构造特征、残留地层厚度分布及层序结构、断层生长指数等,认为黄骅坳陷南部孔店组沉积时期经历了从伸展拗陷(或拗断)盆地向伸展断陷盆地的构造古地理演化。孔三段、孔二段沉积时期,黄骅坳陷南部发育大量规模小的正断层,断层分布均匀、活动强度较弱,且彼此间的差异性较小,同沉积期的活动断层基本上不影响沉积区的沉降—沉积作用,充填的沉积层总体上表现为平行、亚平行或凹叠状的层序结构,沧东断层和徐西断层上盘残留地层缺失边缘相。这些特征说明沧东断层和徐西断层可能并没有构成控制孔三段、孔二段沉积时期的边界,孔三段、孔二段沉积时期沉积区可能总体上表现为伸展"拗陷"或"拗断"的构造古地理面貌。孔一段沉积时期,正断层活动明显增强,且断层活动强度的差异性明显,地壳伸展变形主要集中在沉积区内部的几条规模较大的主干基底断层和沧东断层、徐西断层上,沧东断层、徐西断层成为对沉积区有约束的边界断层,充填的沉积层总体上表现为楔状层序结构,沉积区可能总体上表现为伸展"断陷"的构造古地理面貌,并破坏了孔三段、孔二段沉积时期的盆地原型。The Paleogene Kongdian Formation in the southern Huanghua Depression is the earliest deposited strata in the Bohai Bay rifted basin. The Kongdian Formation was distributed in the inclining graben constituted by the Cangdong fault and Xuxi fault. Based on the comprehensive analyses of the profile structural characteristics, the isopach of remnant strata thickness, the sequence configuration and fault growth index, it is concluded that the southern Huanghua Depression experienced a tectonopalaeogeography evolution from a stretching depressional basin to a stretching rifted basin during the deposition of the Kongdian Formation. During the deposition of Members 2 and 3 of the Kongdian Formation, large amounts of small-scaled normal faults were developed in the southern Huanghua Depression. These faults were evenly distributed, the moving strength was weaker and their differences were smaller. The syndepositional active faults had little influence on subsidence and deposition in the depositional area. The sequence configuration was characterized by paralleling, sub-paralleling pattern. Marginal facies was not developed in the upthrow of the Cangdong and Xuxi faults. These characters indicate that the Cangdong and Xuxi faults were possibly not the boundaries controlling the deposition of Members 2 and 3 of the Kongdian Formation. During the deposition of Members 2 and 3 of the Kongdian Formation, the study area was characterized by a ＂depressional rift＂ or ＂depressional fault＂ framework. During the deposition of the Member 1 of Kongdian Formation, the normal faults moved strongly and the difference of the moving strength was obvious. The stretching deformation was mainly concentrated in the inner part of the depositional area. Several largescaled trunk faults and the Cangdong and Xuxi fauhs were marginal faults controlling the depositional area. The deposition was dominated by a wedge-like sequence configuration. The tectonopalaeogeography was characterized by a stretching ＂rift＂ setting and it complicated

关 键 词：黄骅坳陷 断层活动 伸展盆地 盆地原型 构造古地理 

分 类 号：P618.130.2[天文地球—矿床学]