四川盆地中部-北部地区沧浪铺组层序地层研究

Study on sequence stratigraphy of Canglangpu Formation in the central-northern Sichuan Basin

文舰 彭军 陈友莲 褚江天 邱玉超 戴鑫2

西南石油大学地球科学与技术学院，四川 成都 610500 中国石油西南油气田分公司勘探开发研究院，四川 成都 610066

School of Geosciences and Technology, Southwest Petroleum University, Chengdu 610500, China Research Institute of Petroleum Exploration and Development, PetroChina Southwest Oil＆Gas Field Company, Chengdu 610051, China

为进一步加强对四川盆地中部-北部地区沧浪铺组层序界面识别、层序特征及其发育主控因素的认识，文中运用Vail经典层序地层学原理，以野外露头剖面、钻测井资料为基础，结合区域地质背景，对沧浪铺组海相碎屑岩与碳酸盐岩进行层序地层学研究。研究结果表明：研究区沧浪铺组可识别出地层叠置转换面和岩性岩相转换面2种层序界面类型，据此可将沧浪铺组划分为2个Ⅱ型三级层序（SQ1和SQ2），每个三级层序内部仅发育并保存了海侵体系域（TST）和高位体系域（HST），呈现缓慢海侵、快速海退的特点；沧浪铺组三级层序在垂向及横向上均具有良好的可对比性和等时性，厚度变化具有规律性。

In order to further strengthen the understanding of sequence bountary recognition, sequence characteristics and main controlling factors of Canglangpu Formation in central and northern Sichuan basin, this paper applies Vail classical sequence stratigraphy principle, based on outcrop profile and drilling-logging data, and combined with regional geological background, to conduct sequence stratigraphy research on Marine clastic rocks and carbonate rocks of Canglangpu Formation. The results show that two types of sequence bountary of Canglang Formation in the research area can be identified including strata overlapping transition surface and lithology and lithofacies transition surface. Thus the Canglangpu Formation can be divided into two typeⅡ third-order sequences （SQ1 and SQ2）, only the transgressive system tract（TST）and highstand system tract (HST) were developed and preserved in each third-order sequence, showing the characteristics of slow transgression and rapid regression. The third-order sequence of Canglangpu Formation has good comparability and isochrony in both vertical and horizontal directions, and the thickness changes regularly.

10.6056/dkyqt202004004