Application of high-precision sequence stratigraphy in marine fine-grained sedimentary rocks: A case study of the Doushantuo Formation in northern Sichuan

doi:10.13745/j.esf.sf.2022.10.19

Abstract

Abstract:

Establishing a high-precision sequence stratigraphic framework in marine fine-grained sedimentary rocks is important for an effective prediction of organic-rich intervals and high-quality unconventional oil/gas reservoirs which is still a challenge in unconventional oil/gas sedimentology and fine-grained sequence stratigraphy. Taking the fine-grained sedimentary rocks of the Doushantuo Formation in northern Sichuan as the research object typical sections are selected. Through detailed field investigation of outcrops and high-precision analysis of thin sections, the turbidite sequence section and fine-grained sedimentary section of the Doushantuo Formation are divided into 7 lithofacies types according to sedimentary structure and lithology: (1) massive coarse sandstone, (2) bedding sandstone, (3) sand-rich-interlayer siltstone, (4) collapse-crumpled silty mudstone, (5) grain-rhythmic silty mudstone, (6) intermittent sandy laminar mudstone, and (7) dark-laminar mudstone. The upper mixed sediments are divided into shallow-water mixed lithofacies which include fine-grained dolomite, calcareous sandstone, and spherulitic limestone, and deep-water mixed lithofacies including micrite limestone and calcareous mudstone. On this basis, six types of sedimentary facies are identified from bottom to top: slope facies, gentle-slope facies, deep-water shelf facies, shallow-water shelf facies, mixed tidal-flat facies, and mixed shelf facies. Through field outcrop observation, four third-order sequence boundaries are identified: lithofacies catastrophe surface SB1 of Doushantuo Formation sandstone and Nantuo Formation moraine; scouring contact surface SB2; and lithofacies transformation surfaces SB3 and SB4. According to lithofacies superposition style and sedimentary structural types, 56 parasequences and 18 parasequence sets are delineated; four types of parasequence styles—gravity-flow/wave-controlled gentle slope, wave-controlled shelf and mixed parasequences—are summarized; 9 system tracts are identified; and three complete third-order sequence units (SQ1-SQ3) and top transgressive system tract (TST4) are delineated. Combined with the characteristics of sedimentary facies and sequence, it is considered that the Doushantuo Formation has experienced a “steep-slope, to gentle-slope, to shelf, to mixed-platform” evolutionary process.

Key words: Northern Sichuan depression, Doushantuo Formation, fine-grained sedimentation, lithofacies, high-frequency sequence

CLC Number:

P539.2
P586

KUANG Mingzhi, LI Yifan, FAN Tailiang, ZHANG Tan, LIU Wangwei, LIU Nan. Application of high-precision sequence stratigraphy in marine fine-grained sedimentary rocks: A case study of the Doushantuo Formation in northern Sichuan[J]. Earth Science Frontiers, 2023, 30(4): 164-181.

Figures/Tables 13

Fig.1 Thickness distribution map (a, modified from [19,21]) and comprehensive stratigraphic column (b, modified from [24]) of the Doushantuo Formation in Sichuan basin, and simplified geological map of the northern margin of the Yangzi plate (c, modified from [15]).

Fig.2 Hydrodynamic model and corresponding lithofacies characteristics of continental shelf edge. Modified after [32-33].

Fig.3 Lithofacies characteristics of slope-gentle slope sedimentary system of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.4 Lithofacies characteristics of deep-water shelf-shallow-water shelf sedimentary system of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.5 Lithofacies characteristics of mixed tidal-flat-mixed shelf sedimentary system of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.6 Sequence boundary characteristics of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.7 Parasequence lithofacies assemblage and sedimentary characteristics of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.8 Stratigraphic column of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.9 Characteristics of sequence SQ1 of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.10 Characteristics of sequence SQ2 of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.11 Characteristics of sequences SQ3 and TST4 of the Doushantuo Formation, Zhenba-Xiaoyang section

Fig.12 Regional map showing the profile location in the northern margin of Yangzi (a, modified from [19,21]) and stratigraphic sequence correlation in the Doushantuo Formation across the study area (b, modified from [3,23])

Fig.13 Sedimentary evolution model of the Doushantuo Formation in the study area

References 40

[1]	李路顺, 汪泽成, 肖安成, 等. 扬子板块北缘新元古代盆地结构与马槽园群归属研究[J]. 地学前缘, 2022, 29(6): 291-304. DOI
[2]	汪正江, 王剑, 江新胜, 等. 华南扬子地区新元古代地层划分对比研究新进展[J]. 地质论评, 2015, 61(1): 1-22.
[3]	汪泽成, 刘静江, 姜华, 等. 中—上扬子地区震旦纪陡山沱组沉积期岩相古地理及勘探意义[J]. 石油勘探与开发, 2019, 46(1): 39-51. DOI
[4]	董大忠, 高世葵, 黄金亮, 等. 论四川盆地页岩气资源勘探开发前景[J]. 天然气工业, 2014, 34(12): 1-15.
[5]	徐春春, 沈平, 杨跃明, 等. 乐山—龙女寺古隆起震旦系—下寒武统龙王庙组天然气成藏条件与富集规律[J]. 天然气工业, 2014, 34(3)1-7.
[6]	杨志如, 王学军, 冯许魁, 等. 川中地区前震旦系裂谷研究及其地质意义[J]. 天然气工业, 2014, 34(3)80-85.
[7]	朱光有, 赵坤, 李婷婷, 等. 中国华南陡山沱组烃源岩的形成机制与分布预测[J]. 地质学报, 2021, 95(8): 2553-2574.
[8]	JIANG G Q, SHI X Y, ZHANG S H, et al. Stratigraphy and paleogeography of the Ediacaran Doushantuo Formation (ca. 635-551 ma) in South China[J]. Gondwana Research, 2011, 19(4): 831-849. DOI URL
[9]	刘静江, 李伟, 张宝民, 等. 上扬子地区震旦纪沉积古地理[J]. 古地理学报, 2015, 17(6)735-753.
[10]	LI Y Q, HE D F, LI D, et al. Ediacaran (Sinian) palaeogeographic reconstruction of the Upper Yangtze area, China, and its tectonic implications[J]. International Geology Review, 2020, 62(12): 1485-1509. DOI URL
[11]	杨爱华, 朱茂炎, 张俊明, 等. 扬子板块埃迪卡拉系(震旦系)陡山沱组层序地层划分与对比[J]. 古地理学报, 2015, 17(1): 1-20.
[12]	陈孝红, 周鹏, 张保民, 等. 峡东埃迪卡拉系陡山沱组稳定碳同位素记录及其年代地层意义[J]. 中国地质, 2015, 42(1): 207-223.
[13]	安志辉, 童金南, 叶琴, 等. 湖北宜昌樟村坪地区陡山沱组地层划分与对比[J]. 地球科学, 2018, 43(7): 2206-2221.
[14]	ZHAO G C, CAWOOD P A. Precambrian geology of China[J]. Precambrian Research, 2012, 222/223: 13-54. DOI URL
[15]	李智武, 冉波, 肖斌, 等. 四川盆地北缘震旦纪—早寒武世隆—坳格局及其油气勘探意义[J]. 地学前缘, 2019, 26(1): 59-85. DOI
[16]	周晓峰, 杨风丽, 杨瑞青, 等. 扬子克拉通埃迪卡拉系陡山沱组构造-岩相古地理恢复及油气意义[J]. 古地理学报, 2020, 22(4): 647-662.
[17]	MERDITH A S, COLLINS A S, WILLIAMS S E, et al. A full-plate global reconstruction of the Neoproterozoic[J]. Gondwana Research, 2017, 50: 84-134. DOI URL
[18]	管树巍, 吴林, 任荣, 等. 中国主要克拉通前寒武纪裂谷分布与油气勘探前景[J]. 石油学报, 2017, 38(1): 9-22. DOI
[19]	杨跃明, 文龙, 罗冰, 等. 四川盆地达州-开江古隆起沉积构造演化及油气成藏条件分析[J]. 天然气工业, 2016, 36(8): 1-10.
[20]	何登发. 中国多旋回叠合沉积盆地的形成演化、地质结构与油气分布规律[J]. 地学前缘, 2022, 29(6): 24-59. DOI
[21]	段金宝, 梅庆华, 李毕松, 等. 四川盆地震旦纪-早寒武世构造-沉积演化过程[J]. 地球科学, 2019, 44(3): 738-755.
[22]	谷志东, 殷积峰, 姜华, 等. 四川盆地宣汉—开江古隆起的发现及意义[J]. 石油勘探与开发, 2016, 43(6): 893-904.
[23]	WANG H, LI Z W, LIU S G, et al. Ediacaran extension along the northern margin of the Yangtze Platform, South China: constraints from the lithofacies and geochemistry of the Doushantuo Formation[J]. Marine and Petroleum Geology, 2020, 112: 104056. DOI URL
[24]	DING Y, LI Z W, LIU S G, et al. Sequence stratigraphy and tectono-depositional evolution of a late Ediacaran epeiric platform in the Upper Yangtze area, South China[J]. Precambrian Research, 2021, 354: 106077. DOI URL
[25]	邓胜徽, 樊茹, 李鑫, 等. 四川盆地及周缘地区震旦(埃迪卡拉)系划分与对比[J]. 地层学杂志, 2015, 39(3): 239-254.
[26]	王文之, 肖文摇, 和源, 等. 四川盆地震旦系陡山沱组烃源岩地球化学特征与有机质富集机制[J]. 高校地质学报, 2019, 25(6): 860-870. DOI
[27]	李一凡, 魏小洁, 樊太亮. 海相泥页岩沉积过程研究进展[J]. 沉积学报, 2021, 39(1): 73-87.
[28]	袁桃, 魏祥峰, 张汉荣, 等. 四川盆地及周缘上奥陶统五峰组—下志留统龙马溪组页岩岩相划分[J]. 石油实验地质, 2020, 42(3)371-377, 414.
[29]	姜在兴, 梁超, 吴靖, 等. 含油气细粒沉积岩研究的几个问题[J]. 石油学报, 2013, 34(6): 1031-1039. DOI
[30]	冉波, 刘树根, 孙玮, 等. 四川盆地及周缘下古生界五峰组-龙马溪组页岩岩相分类[J]. 地学前缘, 2016, 23(2): 96-107. DOI
[31]	LAZAR O R, BOHACS K M, SCHIEBER J, et al. Mudstone primer:lithofacies variations, diagnostic criteria, and sedimentologic-stratigraphic implications at lamina to bedset scales[M]. Tulsa, Oklahoma, USA: SEPM (Society for Sedimentary Geology), 2015.
[32]	ZHAO Y P, WANG H, YAN D T, et al. Sedimentary characteristics and model of gravity flows in the Eocene Liushagang Formation in Weixi’nan depression, South China Sea[J]. Journal of Petroleum Science and Engineering, 2020, 190: 107082. DOI URL
[33]	SCHIEBER J. Mud re-distribution in epicontinental basins-Exploring likely processes[J]. Marine and Petroleum Geology, 2016, 71: 119-133. DOI URL
[34]	MACQUAKER J H S, BENTLEY S J, BOHACS K M. Wave-enhanced sediment-gravity flows and mud dispersal across continental shelves: reappraising sediment transport processes operating in ancient mudstone successions[J]. Geology, 2010, 38(10): 947-950. DOI URL
[35]	REINECK H E, SINGH I B. Genesis of laminated sand and graded rhythmites in storm-sand layers of shelf mud[J]. Sedimentology, 1972, 18(1/2): 123-128. DOI URL
[36]	GRUNDVÅG S A, JELBY M E, OLAUSSEN S, et al. The role of shelf morphology on storm-bed variability and stratigraphic architecture, Lower Cretaceous, Svalbard[J]. Sedimentology, 2021, 68(1): 196-237. DOI URL
[37]	吴靖, 姜在兴, 吴明昊. 细粒岩层序地层学研究方法综述[J]. 地质科技情报, 2015, 34(5): 16-20.
[38]	姜在兴. 层序地层学研究进展: 国际层序地层学研讨会综述[J]. 地学前缘, 2012, 19(1): 1-9.
[39]	VAN WAGONER J C, POSAMENTIER H W, MITCHUM R M, et al. An overview of the fundamentals of sequence stratigraphy and key definitions[J]. Sea-Level Changes: An Integrated Approach, 1988, 42: 39-45.
[40]	何治亮, 高志前, 张军涛, 等. 层序界面类型及其对优质碳酸盐岩储层形成与分布的控制[J]. 石油与天然气地质, 2014, 35(6): 853-859.