苏北泰兴黄桥地区剥蚀厚度恢复及其意义  

Recovery of the Erosion Thickness and Its Significances in Huangqiao Area, Taixing, Northern Jiangsu

作　　者：田媛媛[1] 蒲仁海[1] 吴聿元[2] 张淮[2] 黄敏[2] 

机构地区：[1]西北大学大陆动力学国家重点实验室,地质学系,西安710069 [2]中国石油化工股份有限公司华东分公司,南京210011

出　　处：《地质论评》2012年第2期297-302,共6页Geological Review

基　　金：中国石化勘探先导性研究项目(编号G1408-09-KK-0)的成果

摘　　要：苏北泰兴黄桥地区的二叠系孤峰组灰黑色页岩和龙潭组黑色泥岩与煤层是一套重要的海相—海陆过渡相生烃层系,受印支期挤压造山、燕山期断陷、喜马拉雅早期断陷等构造运动影响,它们经历了复杂的埋藏和生烃作用。虽然在北部深陷区埋深达万米以上,可能发生了持续的生烃,但其他大部分凸起构造上的现今埋深只有200～2000m,凹陷和斜坡构造上埋深2000～5000m,不同构造部位的生烃强度与剥蚀厚度和埋藏史有关。根据井点最大厚度估算的该区印支期的最大剥蚀厚度为2256m。钻井泥岩声波时差法和地震剖面上地层趋势外推法恢复的该区燕山期和喜马拉雅早期最大剥蚀厚度分别为900m和550m,主要剥蚀区位于东、南、西次凸斜坡带,随时间推移较大剥蚀厚度位置向东、西方向扩展。根据恢复的剥蚀厚度和埋藏—构造热演化分析得知,北部和西部凹陷主体区的二叠系烃源岩在燕山期末至今达到了主生烃期,斜坡和次级凸起区处于低成熟—未成熟阶段。The dark-gray shale of Permian Gufeng Formation and black shale and coal of Permian Longtan Formation in the Huangqiao area, Taixing City, northern Jiangsu, compose an important marine and marine-- continental transitional hydrocarbon layer system. Being controlled by the tectonic movement of the Indosinian crumpling orogenesis, the Yanshanian rift and the early Himalayan rift and so on, they experienced a complex burial and hydrocarbon generation. Although its depth has more thanl0 kilometers in the northern deep depression and may have a continuous hydrocarbon generation, its current depth are only 200 ~ 2000 meters in horsts and 2000 5000 meters in depressions and slopes. The hydrocarbon generation intensity in different struetural position is related to erosion thickness and its burial history. Based on the thiekness of well sites, the estimated largest eroded thickness is 2256 meters in Indosinian movement, and the methods of shale interval transit time and seismic erosion interpretation have showed that its largest erosion thickness is 900 meters in Yanshanian movement and 550 meters in Himalayan movement. The main eroded area is located in the eastern, southern and western horsts, and the newly eroded thickness was larger eastward and westward. The recovered eroded thickness and burial--tectonic-- thermal evolution analysis showed that the Permian source rocks in the northern and western depression began to generate hydrocarbon in Yanshanian stage. Source rocks in slopes and horsts do not mature in present.

关 键 词：黄桥地区 剥蚀厚度 古构造演化 生烃期 

分 类 号：P618.13[天文地球—矿床学]