塔里木盆地环满加尔地区主要不整合形成过程及剥蚀量研究

STUDY ON THE FORMATION OF UNCONFORMATIES AND THE AMOUNT OF ERODED SEDIMENTATION IN TARIM BASIN

在塔里木盆地构造特征分析及地层研究的基础上 ,利用沉积盆地波动过程分析的原理和方法 ,建立了塔里木盆地典型井的剖面波动方程。研究表明 ,S/AnS ,D3/AnD3,T/AnT及J/AnJ是塔里木盆地重要的不整合 ,它们对盆地内的油气生成、运移、以及聚集、保存起控制作用。志留系与下伏地层的不整合发生在奥陶纪末 ,隆起剥蚀主要分布在塔中—巴楚及塔北地区。塔中地区剥蚀较大 ,塔中 18至塔中 5一带剥蚀量达 80 0～ 110 0m ,向南北两侧剥蚀量变小。三叠系与下伏地层的不整合发生在早二叠世末期 ,这次构造运动在塔里木盆地北部表现明显。不整合剥蚀量在塔北及塔东地区等值线近北西—南东向分布 ,由北东向南西逐渐减小 ,由提 1、草 2井区的 2 0 0 0m减至学参 1至塔中 32井区的 10 0m。巴楚地区为 10 0～ 60 0m ,从东南向北西剥蚀量增大。侏罗系与下伏地层的不整合是印支运动的结果 ,剥蚀量具有由塔中向塔东地区逐渐增大 (由 2 0 0m增加到 2 50 0m以上 ) ,巴楚隆起由南东向北西方向增大。塔北隆起大部分地区剥蚀量为 50 0～ 10 0 0m。

On the basis of the analysis of structural characteristics and study of stratigraphy, and by using the principle and approach of wave process analysis, the authors set up the wave process equations in section of typical areas in the Tarim basin. It is shown that the unconformities S/AnS, D 3/AnD 3,T/AnT and J/AnJ which control the formation, migration, accumulation and conservation of oil and gas are of importance in the evolution of the Tarim basin. S/AnS was formed during the late caledonian orogeny and mainly distributed at the Tazhong,Bachu and Tabei Areas. The amount of erosion is great in the areas of Tazhong 18 and Tazhong 5(800～1000m), and becomes smaller to the south and north. T/AnT started at the end of the Permian and behaved extensively in the North of the Tarim basin. The contour of eroded thickness is along NW—SE and becomes smaller from NE to SW(2000m at areas of Ti1 and Cao 2100m at areas of Xuecan1 and Tazhong2. The amount of erosion is 100～600m in the Bachu Area and becomes greater to the NW from SE. J/AnJ is the result of Indochina movement, and the amount of erosion becomes greater from Tazhong to Tadong(200m to 2500m). The amount of erosion in the Bachu uplift becomes greater from SE to NW, and is more than 500～1000m in the most of Tabei uplift.