Fine-grained gravity flow deposits and their significance for shale oil within high-accommodation sequences in faulted and down-warped lacustrine basins of China
FENG Youliang1, ZOU Caineng1, YANG Zhi1, JIANG Wenqi2, ZHANG Tianshu1, ZHANG Hong1, LIU Chang1, WANG Xiaoni1
1 Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China; 2 College of Earth and Space Sciences, Peking University,Beijing 100871,China
Abstract Gravity flows,including coarse-grained and fine-grained gravity flows,are the most important sedimentation processes in deep-lake environments. Fine-grained gravity flow sediments hold significant potential as unconventional shale oil “sweet spot intervals”. The distribution characteristics of fine-grained gravity flow sediments within sequence stratigraphic frameworks in lacustrine basins are of great significance to the prediction of shale oil “sweet spot intervals”. Through systematic comparative study of gravity flow deposits and sequence frameworks in major lacustrine basins in China,it is found that gravity flow sedimentary systems are mainly deposited in high accommodation sequences. In the lowstand systems tracts(LST)of the faulted/rifted lacustrine basins,coarse-grained gravity flow deposits are developed at proximal sublauctrine fans and thin fine-grained gravity flow sediments are deposited at distal sublaucustrine fans. The distribution of sublacustine fans is controlled by valley and syn-sedimentary structural slope breaks. Fine-grained channel-levee-lobe systems are developed in transgressive systems tracts(TST). Unconfined-channel sublacustrine fans are developed in highstand systems tracts(HST),and fine gravity flow deposits are distributed in distal sublacustrine fans. Large fine-grained channel-levee-lobe systems influenced by flooding occurred in transgressive systems tracts(TST)of down-warped lacustrine basins. On the steeper slope of syn-depositional flexural breaks,fine-grain sublacustrine fan systems are present. Both fine-grained sublacustrine fan systems and fine-grained channel-levee-lobe systems can be deposited in highstand systems tracts(HST)and lowstand systems tracts(LST). Fine-grained gravity flow deposits at distal sublacustrine fans and channel-levee-lobe systems can form “sweet spot intervals” of shale oil. Mudflow deposits form “sweet spot intervals”of foliation type,fine-grained debris flow,fine-grained turbidity current,fine-grained hyperpycnal flow and fine-grained transition flow deposits form “sweet spot intervals”of lamination type and bedding type,while fine-grained concentrated density flow deposits only form “sweet spot intervals”of bedding type. Fine-grained gravity flow deposits are favorable “sweet spot intervals” for shale oil exploration and development.
Fund:Financially supported by PetroChina Science and Technology Projects(Nos. 2021DJ18,2021DJ1802)
About author: FENG Youliang,born in 1963,holds a Ph.D. in geosciences and is a senior engineer at the Department of Petroleum Geology,PetroChina Research Institute of Petroleum Exploration and development. He is mainly engaged in research on sequence stratigraphy,sedimentology,and petroleum geology in lacustrine basins. E-mail: fyouliang@petroChina.com.cn.
Cite this article:
FENG Youliang,ZOU Caineng,YANG Zhi et al. Fine-grained gravity flow deposits and their significance for shale oil within high-accommodation sequences in faulted and down-warped lacustrine basins of China[J]. JOPC, 2024, 26(4): 941-961.
FENG Youliang,ZOU Caineng,YANG Zhi et al. Fine-grained gravity flow deposits and their significance for shale oil within high-accommodation sequences in faulted and down-warped lacustrine basins of China[J]. JOPC, 2024, 26(4): 941-961.
[1] 蔡希源,李思田. 2003. 陆相盆地高精度层序地层学: 隐蔽油气藏勘探基础、方法与实践: 基础理论篇. 北京: 地质出版社,33-62. [Cai X Y,Li S T.2003. High Resolution Sequence Stratigraphy of Continental Basins: Basic Ideas,Methology and Practice for Exploring Subtle Oil Pools. Beijing: Geological Publishing House,33-62] [2] 冯有良. 1999. 东营凹陷下第三系层序地层格架及盆地充填模式. 地球科学, 24(6): 635-642. [Feng Y L.1999. Lower tertiary sequence stratigraphic framework and basin filling model in Dongying depression. Earth Science, 24(6): 635-642] [3] 冯有良,邱以刚. 2003. 高精度层序地层学在济阳坳陷下第三系隐蔽油气藏勘探中的应用. 石油学报, 24(1): 49-57. [Feng Y L,Qiu Y G.2003. Application of high_resolution sequence stratigraphy to exploration of LowerTertiary subtle reservoirs in Jiyang Subbasin. Acta Petrolei Sinica, 24(1): 49-57] [4] 冯有良,徐秀生. 2006. 同沉积构造坡折带对岩性油气藏富集带的控制作用: 以渤海湾盆地古近系为例. 石油勘探与开发, 33(1): 22-25,31. [Feng Y L,Xu X S.2006. Syndepositional structural slope-break zone controls on lithologic reservoirs:a case from Paleogene Bohai Bay Basin. Petroleum Exploration and Development, 33(1): 22-25,31] [5] 冯有良,何立琨,郑和荣,王宁,江秀芳. 1991. 山东牛庄洼陷沙河街组三段前三角洲斜坡重力流沉积. 石油与天然气地质, 11(3): 313-319. [Feng Y L,He L K,Zheng H R, Wang N,Jiang X F.1991. Gravity flow deposits of prodelta slope from 3rd member of Shahejie Formation,Niuzhuang region Shandong. Oil Gas Geology, 11(3): 313-319] [6] 冯有良,李思田,解习农. 2000. 陆相断陷盆地层序形成动力学及层序地层模式. 地学前缘, 7(3): 119-132. [Feng Y L,Li S T,Xie X N.2000. Dynamics of sequence generation and sequence stratigraphic model in continental rift subsidence basin. Earth Science Frontiers, 7(3): 119-132] [7] 冯有良,周海民,任建业,郑和荣,苗顺德. 2010. 渤海湾盆地东部古近系层序地层及其对构造活动的响应. 中国科学: 地球科学, 40(10): 1356-1376. [Feng Y L,Zhou H M,Ren J Y,Zheng H R,Miao S D.2010. Sequence stratigraphy of Paleogene in the eastern Bohai Bay Basin and its response to tectonic activities. Scientia Sinica(Terrae), 40(10): 1356-1376] [8] 冯有良,邹才能,蒙启安,吴卫安,鲁卫华,朱吉昌. 2018a. 构造及气候对后裂谷盆地层序建造的影响: 以松辽盆地西斜坡晚白垩世为例. 地球科学, 43(10): 3445-3461. [Feng Y L,Zou C N,Meng Q A,Wu W A,Lu W H,Zhu J C.2018a. Tectonic and climatic influences on architecture of sequences and sedimentary systems in a post-rift basin: insight from Late Cretaceous northern Songliao Basin. Earth Science, 43(10): 3445-3461] [9] 冯有良,胡素云,李建忠,曹正林,吴卫安,赵长义,崔化娟,袁苗. 2018b. 准噶尔盆地西北缘同沉积构造坡折对层序建造和岩性油气藏富集带的控制. 岩性油气藏, 30(4): 14-25. [Feng Y L,Hu S Y,Li J Z,Cao Z L,Wu W A,Zhao C Y,Cui H J,Yuan M.2018b. Controls of syndepotitional structural slope-break zones on sequence architecture and enrichment zones of lithologic reservoirs in northwestern margin of Junggar Basin. Lithologic Reservoirs, 30(4): 14-25] [10] 冯有良,杨智,张洪,张天舒,李攀,侯鸣秋,蒋文琦,王小妮,朱吉昌,李嘉蕊. 2023. 咸化湖盆细粒重力流沉积特征及其页岩油勘探意义: 以准噶尔盆地玛湖凹陷风城组为例. 地质学报, 97(3): 839-863. [Feng Y L,Yang Z,Zhang H,Zhang T S,Li P,Hou M Q,Jiang W Q,Wang X N,Zhu J C,Li J R.2023. Fine-grained gravity flow sedimentary features and their petroleum significance within saline lacustrine basins: a case study of the Fengcheng Formation in Mahu depression,Junggar basin,China. Acta Geologica Sinica, 97(3): 839-863] [11] 李思田,潘元林,陆永潮,任建业,解习农,王华. 2002. 断陷湖盆隐蔽油藏预测及勘探的关键技术: 高精度地震探测基础上的层序地层学研究. 地球科学, 27(5): 592-598. [Li S T,Pan Y L,Lu Y C,Ren J Y,Xie X N,Wang H.2002. Key technology of prospecting and exploration of subtle traps in lacustrine fault basins: sequence stratigraphic researches on the basis of high resolution seismic survey. Earth Science, 27(5): 592-598] [12] 林畅松,潘元林,肖建新,孔凡仙,刘景彦,郑和荣. 2000. “构造坡折带”: 断陷盆地层序分析和油气预测的重要概念. 地球科学, 25(3): 260-266. [Lin C S,Pan Y L,Xiao J X,Kong F X,Liu J Y,Zheng H R.2000. Structural slope-break zone: key concept for stratigraphic sequence analysis and petroleum forecasting in fault subsidence basins. Earth Science, 25(3): 260-266] [13] 林畅松,郑和荣,任建业,刘景彦,邱以刚. 2003. 渤海湾盆地东营、沾化凹陷早第三纪同沉积断裂作用对沉积充填的控制. 中国科学(D辑),(11): 1025-1036. [Lin C S,Zheng H R,Ren J Y,Liu J Y,Qiu Y G.2003. The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags,Bohai Bay Basin. Science in China(Series D), 33(11): 1025-1036] [14] 刘全有,李鹏,金之钧,孙跃武,胡广,朱东亚,黄振凯,梁新平,张瑞,刘佳宜. 2022. 湖相泥页岩层系富有机质形成与烃类富集: 以长7为例. 中国科学(地球科学), 52(2): 270-290 [Liu Q Y,Li P,Jin Z J,Sun Y W,Hu G,Zhu D Y,Huang Z K,Liang X P,Zhang R,Liu J Y.2022. Organic-rich formation and hydrocarbon enrichment of lacustrine shale strata: a case study of Chang 7 Member.Scientia Sinica(Terrae), 52(2): 270-290]. [15] 吕奇奇,付金华,罗顺社,李士祥,周新平,蒲宇新,闫红果. 2022. 坳陷湖盆重力流水道—朵叶复合体沉积特征及模式: 以鄂尔多斯盆地西南部三叠系延长组长7段为例. 石油勘探与开发, 49(6): 1143-1156. [Lyu Q Q,Fu J H,Luo S S,Li S X,Zhou X P,Pu Y X,Yan H G.2022. Sedimentary characteristics and model of gravity flow channel-lobe complex in a depression lake basin: a case study of Chang 7 Member of Triassic Yanchang Formation in southwestern Ordos Basin,NW China. Petroleum Exploration and Development, 49(6): 1143-1156] [16] 蒙启安,纪友亮. 2009. 塔南凹陷白垩纪古地貌对沉积体系分布的控制作用. 石油学报, 30(6): 843-848. [Meng Q A,Ji Y L.2009. Controlling of paleo geomorphology to distribution of sedimentary system in the Cretaceous of Tanan Depression. Acta Petrolei Sinica, 30(6): 843-848] [17] 吴千然,鲜本忠,高先志,田荣恒,张浩哲,刘建平,高钰坤,王鹏宇. 2023. 强制湖退期湖底扇沉积构型的多样性与砂体分布特征: 以渤海湾盆地东营凹陷沙三段中亚段为例. 石油勘探与开发, 50(4): 782-794. [Wu Q R,Xian B Z,Gao X Z,Tian R H,Zhang H Z,Liu J P,Gao Y K,Wang P Y.2023. Diversity of depositional architecture and sandbody distribution of sublacustrine fans during forced regression: a case study of Paleogene Middle Sha 3 Member in Dongying Sag,Bohai Bay Basin,East China. Petroleum Exploration and Development, 50(4): 782-794] [18] 姚益民. 1994. 中国含油气区的古近系. 北京: 石油工业出版社, 1-76. [Yao Y M.1994. Paleogene of Hydrocarbon-Bearing Districts in China. Beijing: Petroleum Industry Press,1-76] [19] 邹才能,冯有良,杨智,蒋文琦,张天舒,张洪,王小妮,朱吉昌,魏琪钊. 2023. 中国湖盆细粒重力流沉积作用及其对页岩油“甜点段”发育的影响. 石油勘探与开发, 50(5): 883-897. [Zou C N,Feng Y L,Yang Z,Jiang W Q,Zhang T S,Zhang H,Wang X N,Zhu J C,Wei Q Z.2023. Fine-grained gravity flow sedimentation and its influence on development of shale oil sweet spot intervals in lacustrine basins in China. Petroleum Exploration and Development, 50(5): 883-897] [20] Baas J H,Best J L,Peakall J,Wang M.2009. A phase diagram for turbulent,transitional,and laminar clay suspension flows. Journal of Sedimentary Research, 79: 162-183. [21] Baas J H,Best J L,Peakall J.2011. Depositional processes,bedform development and hybrid bed formation in rapidly decelerated cohesive(mud-sand)sediment flows. Sedimentology, 58: 1953-1987. [22] Baas J H,Best J L,Peakall J.2016a. Predicting bedforms and primary current stratification in cohesive mixtures of mud and sand. Journal of the Geological Society, 173: 12-45. [23] Baas J H,Best J L,Peakall J.2016b. Comparing the transitional behaviour of kaolinite and bentonite suspension flows. Earth Surface Processes and Landforms, 41: 1911-1921. [24] Baker M L,Baas J H,Malarkey J,Jacinto R S,Craig M J,Kane I A,Barker S.2017. The effect of clay type on the properties of cohesive sediment gravity flows and their deposits. Journal of Sedimentary Research, 87: 1176-1195. [25] Boulesteix K,Poyatos-More M,Flint S S,Taylor K G,Hodgson D M, Hasiontis S T.2019. Transport and deposition of mud in deep-water environments: processes and stratigraphic implications. Sedimentology, 66(7): 2894-2925. [26] Bowman A P,Johnson H D.2014. Storm-dominated shelf-edge delta successions in a high accommodation setting: the palaeo-Orinoco Delta(Mayaro Formation),Columbus Basin,South-East Trinidad. Sedimentology, 61: 792-835. [27] Chamberlain C P,Wan X Q,Graham S A,Carroll A R,Doebbert A C,Sageman B B,Blisniuk P,Kent-Corson M L,Wang Z,Wang C S.2013. Stable isotopic evidence for climate and basin evolution of the Late Cretaceous Songliao Basin,China. Palaeogeography,Palaeoclimatology,Palaeoecology, 385: 106-124. [28] Chen P,Xian B Z,Li M J,Liang X W,Wu Q R,Zhang W M,Wang J H,Wang Z,Liu J P.2021. A giant lacustrine flood-related turbidite system in the Triassic Ordos Basin,China: sedimentary processes and depositional architecture. Sedimentology, 68: 3279-3306. [29] Craig M J,Baas J H,Amos K J,Strachan L J,Manning A J,Paterson D M,Hope J A,Nodder S D,Baker M L.2020. Biomediation of submarine sediment gravity flow dynamics. Geology, 48: 72-76. [30] Dal Corso J,Gianolla P,Rigo M,Franceschi M,Roghi G,Mietto P,Manfrin S,Raucsik B,Budai T,Jenkyns H C,Reymond C E,Caggiati M,Gattolin G,Breda A,Merico A,Preto N.2018. Multiple negative carbon-isotope excursions during the Carnian Pluvial Episode(Late Triassic). Earth-Science Reviews, 185: 732-750. [31] Dodd T J H,McCarthy D J,Amy L,Plenderleith G E,Clarke S M.2022. Hybrid event bed character and distribution in the context of ancient deep-lacustrine fan models. Sedimentology, 69: 1891-1926. [32] Feng Y L,Li S T,Lu Y C.2013. Sequence stratigraphy and architectural variability in Late Eocene lacustrine strata of the Dongying Depression,Bohai Bay Basin,Eastern China. Sedimentary Geology, 295: 1-26. [33] Feng Y L,Jiang S,Wang C F.2015. Sequence stratigraphy,sedimentary systems and petroleum plays in a low-accommodation basin: middle to upper members of the Lower Jurassic Sangonghe Formation,Central Junggar Basin,Northwestern China. Journal of Asian Earth Sciences, 105: 85-103. [34] Feng Y L,Jiang S,Hu S Y,Li S T,Lin C S,Xie X N.2016. Sequence stratigraphy and importance of syndepositional structural slope-break for architecture of Paleogene syn-rift lacustrine strata,Bohai Bay Basin,E. China. Marine and Petroleum Geology, 69: 183-204. [35] Feng Y L,Yang Z,Zhu J C,Zhang S,Fu X L.2021a. Sequence stratigraphy in post-rift river-dominated lacustrine delta deposits: a case study from the Upper Cretaceous Qingshankou Formation,northern Songliao Basin,northeastern China. Geological Journal, 56: 316-336. [36] Feng Y L,Zou C N,Li J Z,Lin C S,Wang H J,Jiang S,Yang Z,Zhang S,Fu X L.2021b. Sediment gravity-flow deposits in Late Cretaceous Songliao postrift downwarped lacustrine basin,northeastern China. Marine and Petroleum Geology, 134: 105378. [37] Feng Z Q,Zhang S,Cross T A,Feng Z H,Xie X N,Zhao B,Fu X L,Wang C S.2010a. Lacustrine turbidite channels and fans in the Mesozoic Songliao Basin,China. Basin Research, 22: 96-107. [38] Feng Z Q,Jia C Z,Xie X N,Zhang S,Feng Z H,Cross T A.2010b. Tectonostratigraphic units and stratigraphic sequences of the nonmarine Songliao Basin,Northeast China. Basin Research, 22: 79-95. [39] Haughton P,Davis C,McCaffrey W,Barker S.2009. Hybrid sediment gravity flow deposits-Classification,origin and significance. Marine and Petroleum Geology, 26: 1900-1918. [40] Jia J L,Liu Z J,Bechtel A,Strobl S A I,Sun P C.2013. Tectonic and climate control of oil shale deposition in the Upper Cretaceous Qingshankou Formation(Songliao Basin,NE China). International Journal of Earth Sciences, 102: 1717-1734. [41] Meng Q A,Zhang S,Sun G X,Fu X L,Wang C,Shang Y.2016. A seismic geomorphology study of the fluvial and lacustrine-delta facies of the Cretaceous Quantou-Nenjiang Formations in Songliao Basin,China. Marine and Petroleum Geology, 78: 836-847. [42] Meng Q R,Wu G L,Fan L G,Wei H H.2019. Tectonic evolution of early Mesozoic sedimentary basins in the North China Block. Earth-Science Reviews, 190: 416-438. [43] Mulder T,Alexander J.2001. The physical character of subaqueous sedimentary density flows and their deposits. Sedimentology, 48: 269-299. [44] Mulder T,Syvitski J P M,Migeon S,Faugères J C,Savoye B.2003. Marine hyperpycnal flows: initiation,behavior and related deposits: a review. Marine and Petroleum Geology, 20: 861-882. [45] Mutti E.2019. Thin-bedded plumites: an overlooked deep-water deposit. Journal of Mediterranean Earth Sciences, 11: 1-20. [46] Niu X B,Yang T,Cao Y C,Li S X,Zhou X P,Xi K L,Dodd T J H.2023. Characteristics and formation mechanisms of gravity-flow deposits in a lacustrine depression basin: examples from the Late Triassic Chang 7 oil member of the Yanchang Formation,Ordos Basin,Central China. Marine and Petroleum Geology, 148: 106048. [47] Pan S X,Liu C Y,Li X B,Liang S J,Chen Q L,Zhang W T,Zhang S C.2019. Giant sublacustrine landslide in the Cretaceous Songliao Basin,NE China. Basin Research, 31: 1066-1082. [48] Potter P E,Maynard J B,Pryor W A.1980. Sedimentology of Shale: Study Guide and Reference Source. New York: Springer-Verlag,1-60. [49] Ryge M C,Gibling M R.2006. Natural geomorphic variability recorded in a high-accommodation setting: fluvial architecture of the Pennsylvanian Joggins Formation of Atlantic Canada. Journal of Sedimentary Research, 76(11): 1230-1251. [50] Schieber J,Southard J B.2009. Bedload transport of mud by floccule ripples: direct observation of ripple migration processes and their implications. Geology, 37: 483-486. [51] Schieber J.2016. Mud re-distribution in epicontinental basins: exploring likely processes. Marine and Petroleum Geology, 71: 119-133. [52] Stow D A V,Huc A Y,Bertrand P.2001. Depositional processes of black shales in deep water. Marine and Petroleum Geology, 18: 491-498. [53] Sumner E J,Talling P J,Amy L A.2009. Deposits of flows transitional between turbidity current and debris flow. Geology, 37: 991-994. [54] Sun N L,Chen T Y,Zhong J H,Gao J B,Shi X Y,Xue C Q,Swennen R.2022. Petrographic and geochemical characteristics of deep-lacustrine organic-rich mudstone and shale of the Upper Triassic Chang 7 member in the southern Ordos Basin,Northern China: implications for shale oil exploration. Journal of Asian Earth Sciences, 227: 105118. [55] Talling P J,Masson D G,Sumner E J,Malgesini G.2012. Subaqueous sediment density flows: depositional processes and deposit types. Sedimentology, 59: 1937-2003. [56] Tang W B,Zhang Y Y,Pe-Piper G,Piper D J W,Guo Z J,Li W.2020. Soft-sediment deformation structures in alkaline lake deposits of Lower Permian Fengcheng Formation,Junggar Basin,NW China: implications for syn-sedimentary tectonic activity. Sedimentary Geology, 406: 105719. [57] Tang W B,Zhang Y Y,Pe-Piper G,Piper D J W,Guo Z J,Li W.2021. Permian to early Triassic tectono-sedimentary evolution of the Mahu Sag,Junggar Basin,Western China: sedimentological implications of the transition from rifting to tectonic inversion. Marine and Petroleum Geology, 123: 104730. [58] Tian X,Gao Y,Li Z Y,Carlos Z,Chen Z Y,Huang Y J,Yu E X,Wang C S.2021. Fine-grained gravity flow deposits and their depositional processes: a case study from the Cretaceous Nenjiang Formation,Songliao Basin,NE China. Geological Journal, 56: 1496-1509. [59] Vail P R,Audemard F,Bowman S A,Einser P N,Perez-Cruz C.1991. The stratigraphic signatures of tectonics,eustasy and sedimentology: an overview. In: Einsele G,Ricken W,Seilacher A(eds). Cycles and Events in Stratigraphy. Berlin: Springer-verlag,617-659. [60] van Wagoner J C,Mitchun R M,Campion K M,Rahmanian V D.1990. Siliciclastic sequence stratigraphy in well,core and outcrops and outcrops: concepts for high-resolution correlation of times and facies. AAPG Methods in Exploration Series, 7: 1-55. [61] Veiga G D,Schwarz E,Spalletti L A,Massaferro J L.2013. Anatomy and sequence architecture of the early post-rift in the Neuquén Basin(Argentina): a response to physiography and relative sea-level changes. Journal of Sedimentary Research, 83(8): 746-765. [62] Wang C S,Feng Z Q,Zhang L M,Huang Y J,Cao K,Wang P J,Zhao B.2013. Cretaceous paleogeography and paleoclimate and the setting of SKI borehole sites in Songliao Basin,Northeast China. Palaeogeography,Palaeoclimatology,Palaeoecology, 385: 17-30. [63] Xi D P,Cao W X,Huang Q H,Do Carmo D A,Li S,Jing X,Tu Y J,Jia J Z,Qu H Y,Zhao J,Wan X Q.2016. Late Cretaceous marine fossils and seawater incursion events in the Songliao Basin,NE China. Cretaceous Research, 62: 172-182. [64] Xu C,Shan X L,He W T,Zhang K,Rexiti Y,Su S Y,Liang C,Zou X T.2021. The influence of paleoclimate and a marine transgression event on organic matter accumulation in lacustrine black shales from the Late Cretaceous,southern Songliao Basin,Northeast China. International Journal of Coal Geology, 246: 103842. [65] Xu Y H,He D F.2022. Triassic provenance shifts and tectonic evolution of southeast Ordos Basin,Central China. Palaeogeography,Palaeoclimatology,Palaeoecology, 598: 111002. [66] Yang T,Cao Y C,Liu K Y,Wang Y Z,Zavala C,Friis H,Song M S,Yuan G H,Liang C,Xi K L,Wang J.2019. Genesis and depositional model of subaqueous sediment gravity-flow deposits in a lacustrine rift basin as exemplified by the Eocene Shahejie Formation in the Jiyang Depression,Eastern China. Marine and Petroleum Geology, 102: 231-257. [67] Zavala C,Arcuri M.2016. Intrabasinal and extrabasinal turbidites: origin and distinctive characteristics. Sedimentary Geology, 337: 36-54. [68] Zheng R H,Zeng W R,Li Z P,Chen X,Man K X,Zhang Z H,Wang G L,Shi S.2022. Differential enrichment mechanisms of organic matter in the Chang 7 Member mudstone and shale in Ordos Basin,China: constraints from organic geochemistry and element geochemistry. Palaeogeography,Palaeoclimatology,Palaeoecology, 601: 111126. [69] Zou C N,Qiu Z,Zhang J Q,Li Z Y,Wei H Y,Liu B,Zhao J H,Yang T,Zhu S F,Tao H F,Zhang F Y,Wang Y M,Zhang Q,Liu W,Liu H L,Feng Z Q,Liu D,Gao J L,Liu R,Li Y F.2022. Unconventional petroleum Sedimentology: a key to understanding unconventional hydrocarbon accumulation. Engineering, 18: 62-78.