Geological Characterization of the Eocene Pinghu Movement in the Xihu Sag and Its Hydrocarbon Geological Significance

doi:10.19657/j.geoscience.1000-8527.2021.045

Abstract

Abstract:

The Pinghu Movement is an important Cenozoic tectonic process, but its influence on the Xihu sag is still unclear. Based on three-dimensional (3D) seismic data interpretation and comprehensive geological analysis, the geological characteristics of the Pinghu Movement in the Xihu sag are systematically summarized. The study shows that the movement was a major tectonic event in the Xihu sag, controlling the extensional stress field transformation in the Eocene Xihu sag. The extensional direction was NW-SE before the movement, and changed to NWW-SEE after the movement. Because of the Pinghu Movement, the tectonic deformation and sedimentary filling of the Xihu sag changed greatly. The early NE-trending faulting gradually weakened, while NNE-trending faulting began, migrating the subsidence center from the northern part of the sag to the middle part. The magmatism was concentrated from the periphery of the sag to the interior. As a response to a major kinematic adjustment of the Eocene West Pacific tectonic system, the Pinghu Movement has affected the distribution of coal-bearing sequences of the Pinghu Formation in the sag.

Key words: Xihu sag, Pinghu Movement, geological characteristics, source rock, Eocene

CLC Number:

TE121.2

QI Peng, GUO Gang, REN Yaping, CUI Min, WANG Xin. Geological Characterization of the Eocene Pinghu Movement in the Xihu Sag and Its Hydrocarbon Geological Significance[J]. Geoscience, 2021, 35(04): 1098-1105.

Figures/Tables 7

Fig.1 General geologic characteristics of the Xihu sag

Fig.2 Seismic reflection characteristics of the bottom Pinghu Formation in the Xihu sag

Fig.3 Characteristics of lithology and logging curves of the bottom Pinghu Formation in the Xihu sag

Fig.4 Pinghu Movement controlled the subsidence center migration during the Baoshi-Pinghu Fm. sedimentation in the Xihu sag

Fig.5 Pinghu Movement controlled the Paleogene magmatic migration in the East China Sea Basin

Fig.6 NE and NNE-trending fault distributions at the bottom Pinghu Formation in the Xihu sag and their activity

Fig.7 Pinghu Movement controlled the extension during the Baoshi-Pinghu Fm. sedimentation in the Xihu sag

References 24

[1]	张国华, 张建培. 东海陆架盆地构造反转特征及成因机制探讨[J]. 地学前缘, 2015, 22(1):260-270.
[2]	郭真, 刘池洋, 田建锋. 东海盆地西湖凹陷反转构造特征及其形成的动力环境[J]. 地学前缘, 2015, 22(3):59-67.
[3]	宋小勇, 储呈林, 芮志峰. 东海盆地西湖凹陷构造样式及其演化[J]. 高校地质学报, 2010, 16(1):86-93.
[4]	何苗, 侯国伟, 秦兰芝, 等. 西湖凹陷H构造群及周边花港组沉积环境及砂体刻画[J]. 现代地质, 2018, 32(1):162-172.
[5]	高伟中, 田超, 赵洪, 等. 西湖凹陷平湖斜坡带非构造油气藏勘探潜力探讨[J]. 海洋石油, 2015, 35(1):22-26+57.
[6]	蒋一鸣, 周倩羽, 李帅, 等. 西湖凹陷西部斜坡带平湖组含煤岩系沉积环境再思考[J]. 中国煤炭地质, 2016, 28(8):18-25.
[7]	唐贤君, 蒋一鸣, 张绍亮. 平湖斜坡带火山岩层发育构造环境及油气地质意义[J]. 地质科技情报, 2018, 37(1):27-36.
[8]	周心怀, 蒋一鸣, 唐贤君. 西湖凹陷成盆背景、原型盆地演化及勘探启示[J]. 中国海上油气, 2019, 31(3):1-10.
[9]	刘金水, 廖宗廷, 贾健谊, 等. 东海陆架盆地地质结构及构造演化[J]. 上海地质, 2003, 23(3):1-6.
[10]	唐贤君, 蒋一鸣, 张绍亮. 平湖斜坡带火山岩层发育构造环境及油气地质意义[J]. 地质科技情报, 2018, 37(1):27-36.
[11]	侯国伟, 李帅, 秦兰芝, 等. 西湖凹陷西部斜坡带平湖组源-汇体系特征[J]. 中国海上油气, 2019, 31(3):29-39.
[12]	沈然清, 李上卿, 谢仁海. 东海盆地岩浆活动[M]//刘申叔,李上卿,等. 东海油气地球物理勘探. 北京: 地质出版社, 2001:60-69.
[13]	王锋, 朱文斌, 胡德昭, 等. 东海盆地长江坳陷新生代反转构造研究[J]. 大地构造与成矿学, 2005, 29(2):176-181.
[14]	周心怀. 西湖凹陷地质认识创新与油气勘探领域突破[J]. 中国海上油气, 2020, 32(1):1-12.
[15]	楼章华, 朱蓉, 金爱民, 等. 杭州斜坡带油气构造特征研究及石油地质条件分析 [R]. 北京:中海油研究总院有限责任公司, 2015:20-24.
[16]	朱立新, 宋在超. 东海西湖凹陷原型盆地构造格架与演化分析[J]. 海洋石油, 2016, 36(1):1-6.
[17]	任建业. 中国近海海域新生代成盆动力机制分析[J]. 地球科学, 2018, 43(10):3337-3361.
[18]	NORTHRUP C J, ROYDEN L H, BURCHFIELB C. Motion of the Pacific Plate relative to Eurasia and its potential relation to Cenozoic extension along the eastern margin of Eurasia[J]. Geology, 1995, 23(8):719-722. DOI URL
[19]	TAPPONNIER P, LACASSIN R, LELOUP P H, et al. The Ailaoshan-Red River metamorphic belt:Tertiary left-lateral shear between Indochina and South China[J]. Nature, 1990, 343(6257):431-437. DOI URL
[20]	任凤楼, 柳忠泉, 邱连贵, 等. 渤海湾盆地新生代各坳陷沉降的时空差异[J]. 地质科学, 2008, 43(3):546-557.
[21]	宋春刚, 曹强, 叶加仁, 等. 东海盆地西湖凹陷主力烃源岩特征及分布[J]. 石油学报, 2016, 37(8):962-974.
[22]	张兰, 汪文基, 何贤科, 等. 东海西湖凹陷平湖组富煤环境相控储层预测技术[J]. 现代地质, 2019, 33(2):337-344.
[23]	田杨, 叶加仁, 雷闯, 等. 断陷盆地海陆过渡相烃源岩发育模式:以西湖凹陷平湖组为例[J]. 地球科学, 2019, 44(3):898-908.
[24]	沈玉林, 秦勇, 郭英海, 等. 基于米氏聚煤旋回划分的西湖凹陷平湖组煤系烃源岩发育特征[J]. 石油学报, 2016, 37(6):706-714.