基于海陆对比建立苏北—南黄海盆地晚二叠世—早三叠世地层格架

以层序地层学和沉积学理论为指导，依托大陆架科学钻探CSDP-2井并结合WX5-ST1井、N5井及南京江宁地区典型剖面，利用岩性、测井、古生物等资料，在识别苏北-南黄海盆地各级层序界面的基础上，将研究区上二叠统-下三叠统划分为2个长期基准面旋回（LC1、LC2）和3个中期基准面旋回（MC1-MC3）。研究表明，南黄海盆地与苏北盆地实为被海岸线分割的同一沉积盆地，其上二叠统-下三叠统具有良好的可对比性，其中：LC1长期基准面旋回（上二叠统）不对称性明显，最大海泛面MFS1对应于龙潭组中下部浅海陆棚相的泥岩，LC2长期基准面旋回（下三叠统）因后期印支运动抬升剥蚀，仅存基准面上升半旋回；研究区MC1旋回期（龙潭组）主要发育潮坪、泻湖、三角洲等海陆过渡相，各地水深相差不大；MC2、MC3时期（大隆组、青龙组）发育浅海陆棚、潮坪、泻湖及碳酸盐岩台地等沉积相，水体演变为南西深而北东浅，分析认为是东吴运动时期盆地差异抬升的结果。

Establishment of Stratigraphic Framework of Late Permian to Early Triassic in Northern Jiangsu and South Yellow Sea Basin Based on Land-Sea Comparison

We studied the sedimentary strata and identified the sequential interfaces of the northern Jiangsu and South Yellow Sea basin by using lithology, well logging, paleontology and other data, and divided the Upper Permian-Lower Triassic strata of the research area into two large cycles (LC1 and LC2) and three intermediate cycles (MC1-MC3) based on continental shelf drilling program Well CSDP-2, in combination with Well N5, Well WX5-ST1 and typical section of Jiangning area in Nanjing under the theoretical instruction of sequence stratigraphy and sedimentology. This research shows that the South Yellow Sea basin and the northern Jiangsu basin are actually the same sedimentary basin separated by coastlines, and their Upper Permian-Lower Triassic strata are very well comparable. The LC1 large scale cycle has obvious asymmetry, and the highest base level MFS1 corresponds to the mudstone of shallow sea shelf facies in the middle and lower part of Longtan Formation. The LC2 large scale cycle was denuded by the Indosinian movement, and only half cycle of the basic-level rising remains. The study area mainly developed tidal flat, lagoon, delta and other marine and land transitional facies in the MC1 cycle (Longtan Formation), indicating the relatively stable water depth from place to place; however, during the MC2 and MC3 cycles (Dalong Formation and Qinglong Formation), the sedimentary facies such as shallow sea shelf, tidal flat, lagoon,and carbonate platform developed, and the water became deeper in the southwest and shallower in the northeast. This is the result of basin differential uplifts during Tungwu Movement.