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Volume 39 Issue 1
Feb.  2021
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YANG Tian, CAO YingChang, TIAN JingChun. Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin[J]. Acta Sedimentologica Sinica, 2021, 39(1): 88-111. doi: 10.14027/j.issn.1000-0550.2020.037
Citation: YANG Tian, CAO YingChang, TIAN JingChun. Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin[J]. Acta Sedimentologica Sinica, 2021, 39(1): 88-111. doi: 10.14027/j.issn.1000-0550.2020.037

Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin

doi: 10.14027/j.issn.1000-0550.2020.037
Funds:

National Natural Science Foundation of China 41802127, 42072126

The Research Project of Science and Technology Innovation Fund of CNPC in 2019 2019D⁃5007⁃0106

  • Received Date: 2020-02-26
  • Publish Date: 2021-02-10
  • In the last few years, great progress has been achieved in the understanding of gravity⁃flow deposits in marine basins, but the study of gravity⁃flow deposits in lacustrine basins lags far behind. Research on gravity⁃flow deposits in China and globally are summarized here to clearly illustrate the shortcomings of gravity⁃flow deposit research for lacustrine basins. Clarifying meanings and relationships between different terminologies, as well as detailed interpretation, are reliable ways of reducing terminology confusion. Gravity⁃flow transformation, flow⁃state transformation, and lubrication are mainly dynamic processes of gravity flow. Transportation, hindered settling, turbulence damping, and traction carpet are dynamic processes of gravity flow, whereas settling, sediment re⁃transportation, sustained supply from flooding rivers, and the settling of buoyant plumes, are the main mechanisms of gravity flow in a lacustrine basin. Comprehensive analysis of detailed facies⁃tract types, analysis of the internal structure of massive sandstone, and analysis of the characteristics of inverse⁃then⁃normal sequences are all important means of revealing the genesis of gravity⁃flow deposits. Gravity⁃flow channels are formed by erosion due to supercritically turbid currents. The material composition and source of gravity flow are dominated by factors external to the basin, while the effective segregation of gravity flow types is dominated by internal basin factors. The integration of internal and external basin factors are termed “source⁃to⁃sink” systems, covering the overall gravity⁃flow evolutionary processes. The depositional model of gravity flow caused by sustained supply from flooding rivers comprises gravity⁃depositional elements, which include channel⁃levée deposits, channel and lobe transition zones, and lobe deposits. Depositional models of gravity flow due to sediment re⁃transportation contain gravity⁃depositional elements, such as sediment failure at the delta front, chaotic deposits, and lobe deposits. Gravity⁃flow deposits are the main reservoirs for unconventional oil and gas in a lacustrine basin. The fine⁃grained deposits resulting from flow transformation have the potential for oil and gas generation and enrichment — and, at the same time, they are appropriate for hydraulic fracturing, which makes them the foremost lithofacies association for sweet⁃spot development in shale oil and gas exploration.
  • [1] Cao Y C, Wang Y Z, Gluyas J G, et al. Depositional model for lacustrine nearshore subaqueous fans in a rift basin: The Eocene Shahejie Formation, Dongying Sag, Bohai Bay Basin, China[J]. Sedimentology, 2018, 65(6): 2117-2148.
    [2] Xian B Z, Wang J H, Gong C L, et al. Classification and sedimentary characteristics of lacustrine hyperpycnal channels: Triassic outcrops in the South Ordos Basin, central China[J]. Sedimentary Geology, 2018, 368: 68-82.
    [3] Yang R C, Jin Z J, van Loon A J, et al. Climatic and tectonic controls of lacustrine hyperpycnite origination in the Late Triassic Ordos Basin, central China: Implications for unconventional petroleum development[J]. AAPG Bulletin, 2017, 101(1): 95-117.
    [4] Zou C N, Wang L, Li Y, et al. Deep-lacustrine transformation of sandy debrites into turbidites, Upper Triassic, central China[J]. Sedimentary Geology, 2012, 265-266: 143-155.
    [5] 操应长,杨田,王艳忠,等. 超临界沉积物重力流形成演化及特征[J]. 石油学报,2017,38(6):607-621.

    Cao Yingchang, Yang Tian, Wang Yanzhong, et al. Formation, evolution and sedimentary characteristics of supercritical sediment gravity-flow[J]. Acta Petrolei Sinica, 2017, 38(6): 607-621.
    [6] 操应长,杨田,王艳忠,等. 深水碎屑流与浊流混合事件层类型及成因机制[J]. 地学前缘,2017,24(3):234-248.

    Cao Yingchang, Yang Tian, Wang Yanzhong, et al. Types and genesis of deep-water hybrid event beds comprising debris flow and turbidity current[J]. Earth Science Frontiers, 2017, 24(3): 234-248.
    [7] 蒲秀刚,周立宏,韩文中,等. 歧口凹陷沙一下亚段斜坡区重力流沉积与致密油勘探[J]. 石油勘探与开发,2014,41(2):138-149.

    Pu Xiugang, Zhou Lihong, Han Wenzhong, et al. Gravity flow sedimentation and tight oil exploration in lower first member of Shahejie Formation in slope area of Qikou Sag, Bohai Bay Basin[J]. Petroleum Exploration and Development, 2014, 41(2): 138-149.
    [8] 邱振,邹才能. 非常规油气沉积学:内涵与展望[J]. 沉积学报,2020,38(1):1-29.

    Qiu Zhen, Zou Caineng. Unconventional petroleum sedimentology: Connotation and prospect[J]. Acta Sedimentologica Sinica, 2020, 38(1): 1-29.
    [9] 宋岩,李卓,姜振学,等. 非常规油气地质研究进展与发展趋势[J]. 石油勘探与开发,2017,44(4):638-648.

    Song Yan, Li Zhuo, Jiang Zhenxue, et al. Progress and development trend of unconventional oil and gas geological research[J]. Petroleum Exploration and Development, 2017, 44(4): 638-648.
    [10] 杨仁超,何治亮,邱桂强,等. 鄂尔多斯盆地南部晚三叠世重力流沉积体系[J]. 石油勘探与开发,2014,41(6):661-670.

    Yang Renchao, He Zhiliang, Qiu Guiqiang, et al. Late Triassic gravity flow depositional systems in the southern Ordos Basin[J]. Petroleum Exploration and Development, 2014, 41(6): 661-670.
    [11] 杨田,操应长,王艳忠,等. 深水重力流类型、沉积特征及成因机制:以济阳坳陷沙河街组三段中亚段为例[J]. 石油学报,2015,36(9):1048-1059.

    Yang Tian, Cao Yingchang, Wang Yanzhong, et al. Types, sedimentary characteristics and genetic mechanisms of deep-water gravity flows: A case study of the middle submember in Member 3 of Shahejie Formation in Jiyang Depression[J]. Acta Petrolei Sinica, 2015, 36(9): 1048-1059.
    [12] 袁选俊,林森虎,刘群,等. 湖盆细粒沉积特征与富有机质页岩分布模式:以鄂尔多斯盆地延长组长7油层组为例[J]. 石油勘探与开发,2015,42(1):34-43.

    Yuan Xuanjun, Lin Senhu, Liu Qun, et al. Lacustrine fine-grained sedimentary features and organic-rich shale distribution pattern: A case study of Chang 7 member of Triassic Yanchang Formation in Ordos Basin, NW China[J]. Petroleum Exploration and Development, 2015, 42(1): 34-43.
    [13] 赵贤正,蒲秀刚,周立宏,等. 断陷湖盆深水沉积地质特征与斜坡区勘探发现:以渤海湾盆地歧口凹陷板桥—歧北斜坡区沙河街组为例[J]. 石油勘探与开发,2017,44(2):165-176.

    Zhao Xianzheng, Pu Xiugang, Zhou Lihong, et al. Geologic characteristics of deep water deposits and exploration discoveries in slope zones of fault lake basin: A case study of Paleogene Shahejie Formation in Banqiao-Qibei Slope, Qikou Sag, Bohai Bay Basin[J]. Petroleum Exploration and Development, 2017, 44(2): 165-176.
    [14] 朱筱敏,钟大康,袁选俊,等. 中国含油气盆地沉积地质学进展[J]. 石油勘探与开发,2016,43(5):820-829.

    Zhu Xiaomin, Zhong Dakang, Yuan Xuanjun, et al. Development of sedimentary geology of petroliferous basins in China[J]. Petroleum Exploration and Development, 2016, 43(5): 820-829.
    [15] 邹才能,赵政璋,杨华,等. 陆相湖盆深水砂质碎屑流成因机制与分布特征:以鄂尔多斯盆地为例[J]. 沉积学报,2009,27(6):1065-1075.

    Zou Caineng, Zhao Zhengzhang, Yang Hua, et al. Genetic mechanism and distribution of sandy debris flows in terrestrial lacustrine basin[J]. Acta Sedimentologica Sinica, 2009, 27(6): 1065-1075.
    [16] Tian Y, Cao Y C, Wang Y Z, et al. Status and trends in research on deep‐ater gravity flow deposits[J]. Acta Geologica Sinica, 2015, 89(2): 610-631.
    [17] Zhang X W, Scholz C A, Hecky R E, et al. Climatic control of the Late Quaternary turbidite sedimentology of Lake Kivu, East Africa: Implications for deep mixing and geologic hazards[J]. Geology, 2014, 42(9): 811-814.
    [18] 何起祥,刘招君,王东坡,等. 湖泊相浊积岩的主要特征及其地质意义[J]. 沉积学报,1984,2(4):33-46.

    He Qixiang, Liu Zhaojun, Wang Dongpo, et al. Characteristics of lacustrine turbidites and their tectonic significance[J]. Acta Sedimentologica Sinica, 1984, 2(4): 33-46.
    [19] 赖婉琦,顾家裕. 渤海湾含油气盆地中的浊积岩[J]. 沉积学报,1984,2(4):47-57.

    Lai Wanqi, Gu Jiayu. Turbidity fan in the oil and gas-bearing basin in Bohai Bay[J]. Acta Sedimentologica Sinica, 1984, 2(4): 47-57.
    [20] Mulder T, Syvitski J P M, Migeon S, et al. Marine hyperpycnal flows: Initiation, behavior and related deposits. A review[J]. Marine and Petroleum Geology, 2003, 20(6/7/8): 861-882.
    [21] Zavala C, Ponce J J, Arcuri M, et al. Ancient lacustrine hyperpycnites: A depositional model from a case study in the Rayoso Formation (Cretaceous) of west-central Argentina[J]. Journal of Sedimentary Research, 2006, 76(1): 41-59.
    [22] 王德坪,刘守义. 东营盆地渐新世早期前三角洲缓坡区的泥石流砂质碎屑沉积[J]. 沉积学报,1987,5(4):14-24.

    Wang Deping, Liu Shouyi. Debris flow sediments of sandy clastic on the gentle slope area of prodelta in Oligocene, Dongying Basin[J]. Acta Sedimentologica Sinica, 1987, 5(4): 14-24.
    [23] 王德坪. 湖相内成碎屑流的沉积及形成机理[J]. 地质学报,1991(4):299-316.

    Wang Deping. The sedimentation and formation mechanism of lacustrine endogenic debris flow[J]. Acta Geologica Sinica, 1991(4): 299-316.
    [24] Shanmugam G. High-density turbidity currents; are they sandy debris flows?[J]. Journal of Sedimentary Research, 1996, 66(1): 2-10.
    [25] 李相博,刘化清,潘树新,等. 中国湖相沉积物重力流研究的过去、现在与未来[J]. 沉积学报,2019,37(5):904-921.

    Li Xiangbo, Liu Huaqing, Pan Shuxin, et al. The past, present and future of research on deep-water sedimentary gravity flow in lake basins of China[J]. Acta Sedimentologica Sinica, 2019, 37(5): 904-921.
    [26] 李相博,卫平生,刘化清,等. 浅谈沉积物重力流分类与深水沉积模式[J]. 地质论评,2013,59(4):607-614.

    Li Xiangbo, Wei Pingsheng, Liu Huaqing, et al. Discussion on the classification of sediment gravity flow and the deep-water sedimentary model[J]. Geological Review, 2013, 59(4): 607-614.
    [27] 廖纪佳,朱筱敏,邓秀芹,等. 鄂尔多斯盆地陇东地区延长组重力流沉积特征及其模式[J]. 地学前缘,2013,20(2):29-39.

    Liao Jijia, Zhu Xiaomin, Deng Xiuqin, et al. Sedimentary characteristics and model of gravity flow in Triassic Yanchang Formation of Longdong area in Ordos Basin[J]. Earth Science Frontiers, 2013, 20(2): 29-39.
    [28] 潘树新,刘化清,Zavala C,等. 大型坳陷湖盆异重流成因的水道—湖底扇系统:以松辽盆地白垩系嫩江组一段为例[J]. 石油勘探与开发,2017,44(6):860-870.

    Pan Shuxin, Liu Huaqing, Zavala C, et al. Sublacustrine hyperpycnal channel-fan system in a large depression basin: A case study of Nen 1 member, Cretaceous Nenjiang Formation in the Songliao Basin, NE China[J]. Petroleum Exploration and Development, 2017, 44(6): 860-870.
    [29] 鲜本忠,万锦峰,姜在兴,等. 断陷湖盆洼陷带重力流沉积特征与模式:以南堡凹陷东部东营组为例[J]. 地学前缘,2012,19(1):121-135.

    Xian Benzhong, Wan Jinfeng, Jiang Zaixing, et al. Sedimentary characteristics and model of gravity flow deposition in the depressed belt of rift lacustrine basin: A case study from Dongying Formation in Nanpu Depression[J]. Earth Science Frontiers, 2012, 19(1): 121-135.
    [30] 杨仁超,金之钧,孙冬胜,等. 鄂尔多斯晚三叠世湖盆异重流沉积新发现[J]. 沉积学报,2015,33(1):10-20.

    Yang Renchao, Jin Zhijun, Sun Dongsheng, et al. Discovery of hyperpycnal flow deposits in the Late Triassic lacustrine Ordos Basin[J]. Acta Sedimentologica Sinica, 2015, 33(1): 10-20.
    [31] 杨田,操应长,王艳忠,等. 异重流沉积动力学过程及沉积特征[J]. 地质论评,2015,61(1):23-33.

    Yang Tian, Cao Yingchang, Wang Yanzhong, et al. Sediment dynamics process and sedimentary characteristics of hyperpycnal flows[J]. Geological Review, 2015, 61(1): 23-33.
    [32] 鲜本忠,王璐,刘建平,等. 东营凹陷东部始新世三角洲供给型重力流沉积特征与模式[J]. 中国石油大学学报(自然科学版),2016,40(5):10-21.

    Xian Benzhong, Wang Lu, Liu Jianping, et al. Sedimentary characteristics and model of delta-fed turbidites in Eocene eastern Dongying Depression[J]. Journal of China University of Petroleum, 2016, 40(5): 10-21.
    [33] 袁静,梁绘媛,梁兵,等. 湖相重力流沉积特征及发育模式:以苏北盆地高邮凹陷深凹带戴南组为例[J]. 石油学报,2016,37(3):348-359.

    Yuan Jing, Liang Huiyuan, Liang Bing, et al. Sedimentary characteristics and development model of lacustrine gravity flow: A case study of Dainan Formation in deep sag belt of Gaoyou Depression, northern Jiangsu Basin[J]. Acta Petrolei Sinica, 2016, 37(3): 348-359.
    [34] 周立宏,陈长伟,韩国猛,等. 断陷湖盆异重流沉积特征与分布模式:以歧口凹陷板桥斜坡沙一下亚段为例[J]. 中国石油勘探,2018,23(4):11-20.

    Zhou Lihong, Chen Changwei, Han Guomeng, et al. Sedimentary characteristics and distribution patterns of hyperpycnal flow in rifted lacustrine basins: A case study on lower Es1 of Banqiao slope in Qikou Sag[J]. China Petroleum Exploration, 2018, 23(4): 11-20.
    [35] Talling P J, Masson D G, Sumner E J, et al. Subaqueous sediment density flows: Depositional processes and deposit types[J]. Sedimentology, 2012, 59(7): 1937-2003.
    [36] 宋明水,向奎,张宇,等. 泥质重力流沉积研究进展及其页岩油气地质意义:以东营凹陷古近系沙河街组三段为例[J]. 沉积学报,2017,35(4):740-751.

    Song Mingshui, Xiang Kui, Zhang Yu, et al. Research progresses on muddy gravity flow deposits and their significances on shale oil and gas: A case study from the 3rd oil-member of the Paleogene Shahejie Formation in the Dongying Sag[J]. Acta Sedimentologica Sinica, 2017, 35(4): 740-751.
    [37] 谈明轩,朱筱敏,耿名扬,等. 沉积物重力流流体转化沉积—混合事件层[J]. 沉积学报,2016,34(6):1108-1119.

    Tan Mingxuan, Zhu Xiaomin, Geng Mingyang, et al. The flow transforming deposits of sedimentary gravity flow-hybrid event bed[J]. Acta Sedimentologica Sinica, 2016, 34(6): 1108-1119.
    [38] 谈明轩,朱筱敏,刘伟,等. 旋回阶梯底形的动力地貌及其相关沉积物发育特征[J]. 地质论评,2017,63(6):1512-1522.

    Tan Mingxuan, Zhu Xiaomin, Liu Wei, et al. The morphodynamics of cyclic steps and sedimentary characteristics of associated deposits[J]. Geological Review, 2017, 63(6): 1512-1522.
    [39] 杨仁超,尹伟,樊爱萍,等. 鄂尔多斯盆地南部三叠系延长组湖相重力流沉积细粒岩及其油气地质意义[J]. 古地理学报,2017,19(5):791-806.

    Yang Renchao, Yin Wei, Fan Aiping, et al. Fine-grained, lacustrine gravity-flow deposits and their hydrocarbon significance in the Triassic Yanchang Formation in southern Ordos Basin[J]. Journal of Palaeogeography, 2017, 19(5): 791-806.
    [40] Gilluly J. Geologic contrasts between continents and ocean basins[M]//Poldervaart A. Crust of the earth: A symposium. New York: Geological Society of America, 1955: 7-18.
    [41] Zhang X W, Scholz C A. Turbidite systems of lacustrine rift basins: Examples from the Lake Kivu and Lake Albert rifts, East Africa[J]. Sedimentary Geology, 2015, 325: 177-191.
    [42] Katz B J. Lacustrine basin hydrocarbon exploration–current thoughts[J]. Journal of Paleolimnology, 2001, 26(2): 161-179.
    [43] Katz B J, Liu X C. Summary of the AAPG research symposium on lacustrine basin exploration in China and Southeast Asia[J]. AAPG Bulletin, 1998, 82(7): 1300-1307.
    [44] Dodd T J H, McCarthy D J, Richards P C. A depositional model for deep‐lacustrine, partially confined, turbidite fans: Early Cretaceous, North Falkland Basin[J]. Sedimentology, 2019, 66(1): 53-80.
    [45] Fongngern R, Olariu C, Steel R, et al. Subsurface and outcrop characteristics of fluvial‐dominated deep‐lacustrine clinoforms[J]. Sedimentology, 2018, 65(5): 1447-1481.
    [46] 刘芬,朱筱敏,李洋,等. 鄂尔多斯盆地西南部延长组重力流沉积特征及相模式[J]. 石油勘探与开发,2015,42(5):577-588.

    Liu Fen, Zhu Xiaomin, Li Yang, et al. Sedimentary characteristics and facies model of gravity flow deposits of Late Triassic Yanchang Formation in southwestern Ordos Basin, NW China[J]. Petroleum Exploration and Development, 2015, 42(5): 577-588.
    [47] Kremer K, Corella J P, Adatte T, et al. Origin of turbidites in deep Lake Geneva (France⁃Switzerland) in the last 1500 years[J]. Journal of Sedimentary Research, 2015, 85(12): 1455-1465.
    [48] Nelson C H, Escutia C, Goldfinger C, et al. External controls on modern clastic turbidite systems: Three case studies[M]//Kneller B, Martinsen O J, McCaffrey B. External controls on deep water depositional systems: Climate, sea-level, and sediment flux. Tulsa: SEPM Special Publication, 2009: 57-76. .
    [49] Feng Z Q, Zhang S, Cross T A, et al. Lacustrine turbidite channels and fans in the Mesozoic Songliao Basin, China[J]. Basin Research, 2010, 22(1): 96-107.
    [50] Dasgupta P. Sediment gravity flow—the conceptual problems[J]. Earth-Science Reviews, 2003, 62(3/4): 265-281.
    [51] 李祥辉,王成善,金玮,等. 深海沉积理论发展及其在油气勘探中的意义[J]. 沉积学报,2009,27(1):77-86.

    Li Xianghui, Wang Chengshan, Jin Wei, et al. A review on deep-sea sedimentation theory: Significances to oil-gas exploration[J]. Acta Sedimentologica Sinica, 2009, 27(1): 77-86.
    [52] 梁建设,田兵,王琪,等. 深水沉积理论研究现状、存在问题及发展趋势[J]. 天然气地球科学,2017,28(10):1488-1496.

    Liang Jianshe, Tian Bing, Wang Qi, et al. Research review, existing problems and future direction of deepwater sedimentary theory[J]. Natural Gas Geoscience, 2017, 28(10): 1488-1496.
    [53] Middleton G V, Hampton M A. Sediment gravity flows: Mechanics of flow and deposition[M]//Middleton G V, Bouma A H. Turbidites and deep-water sedimentation: Short course lecture notes, Part I. Los Angeles: AAPG, 1973.
    [54] 何起祥. 沉积动力学若干问题的讨论[J]. 海洋地质与第四纪地质,2010,30(4):1-10.

    He Qixiang. A discussion on sediment dynamics[J]. Marine Geology & Quaternary Geology, 2010, 30(4): 1-10.
    [55] 吴因业,张天舒,冯荣昌,等. 四川侏罗系半深湖环境的超临界流浊积砂体沉积特征[C]//2015年全国沉积学大会沉积学与非常规资源论文摘要集. 武汉:中国地质学会沉积地质专业委员会,中国矿物岩石地球化学学会沉积学专业委员会,2015:2. [

    Wu Yinye, Zhang Tianshu, Feng Rongchang, et al. The sedimentary characteristics of supercritical turbidite sand bodies in semi-deep lake environment of Jurassic in Sichuan province[C]//2015 China national conference of sedimentology. Wuhan: Professional Committee of Sedimentary Geology, Chinese Geological Society, Professional Committee of Sedimentology, Chinese Society of Mineralogy and Petrochemistry, 2015: 2.]
    [56] 李相博,刘化清,完颜容,等. 鄂尔多斯盆地三叠系延长组砂质碎屑流储集体的首次发现[J]. 岩性油气藏,2009,21(4):19-21.

    Li Xiangbo, Liu Huaqing, Wanyan Rong, et al. First discovery of the sandy debris flow from the Triassic Yanchang Formation, Ordos Basin[J]. Lithologic Reservoirs, 2009, 21(4): 19-21.
    [57] 耳闯,顾家裕,牛嘉玉,等. 重力驱动作用:滦平盆地下白垩统西瓜园组沉积时期主要的搬运机制[J]. 地质论评,2010,56(3):312-320.

    Chuang Er, Gu Jiayu, Niu Jiayu, et al. Gravity-driven processes: A more important transport mechanism of deposits in Xiguayuan Formation of Lower Cretaceous in Luanping Basin, northern Hebei[J]. Geological Review, 2010, 56(3): 312-320.
    [58] 潘树新,郑荣才,卫平生,等. 陆相湖盆块体搬运体的沉积特征、识别标志与形成机制[J]. 岩性油气藏,2013,25(2):9-18, 25.

    Pan Shuxin, Zheng Rongcai, Wei Pingsheng, et al. Deposition characteristics, recognition mark and form mechanism of mass transport deposits in terrestrial lake basin[J]. Lithologic Reservoirs, 2013, 25(2): 9-18, 25.
    [59] Shanmugam G. New perspectives on deep-water sandstones: Implications[J]. Petroleum Exploration and Development, 2013, 40(3): 316-324.
    [60] Lowe D R. Sediment gravity flows: II, depositional models with special reference to the deposits of high-density turbidity currents[J]. Journal of Sedimentary Research, 1982, 52(1): 279-297.
    [61] 金杰华,操应长,王健,等. 深水砂质碎屑流沉积:概念、沉积过程与沉积特征[J]. 地质论评,2019,65(3):689-702.

    Jin Jiehua, Cao Yingchang, Wang Jian, et al. Deep-water sandy debris flow deposits: Concepts, sedimentary processes and characteristics[J]. Geological Review, 2019, 65(3): 689-702.
    [62] 裴羽,何幼斌,李华,等. 高密度浊流和砂质碎屑流关系的探讨[J]. 地质论评,2015,61(6):1281-1292.

    Pei Yu, He Youbin, Li Hua, et al. Discuss about relationship between high-density turbidity current and sandy debris flow[J]. Geological Review, 2015, 61(6): 1281-1292.
    [63] Kuenen P H, Migliorini C I. Turbidity currents as a cause of graded bedding[J]. The Journal of Geology, 1950, 58(2): 91-127.
    [64] 李存磊,张金亮,宋明水,等. 基于沉积相反演的砂砾岩体沉积期次精细划分与对比:以东营凹陷盐家地区古近系沙四段上亚段为例[J]. 地质学报,2011,85(6):1008-1018.

    Li Cunlei, Zhang Jinliang, Song Mingshui, et al. Fine division and correlation of glutenite sedimentary periods based on sedimentary facies inversion: A case study from the Paleogene strata of Upper Es4 in the Yanjia area, Dongying Depression[J]. Acta Geologica Sinica, 2011, 85(6): 1008-1018.
    [65] Hughes Clarke J E. First wide-angle view of channelized turbidity currents links migrating cyclic steps to flow characteristics[J]. Nature Communications, 2016, 7(1): 11896.
    [66] Bates C C. Rational theory of delta formation[J]. AAPG Bulletin, 1953, 37(9): 2119-2162.
    [67] Mulder T, Syvitski J P M. Turbidity currents generated at river mouths during exceptional discharges to the world oceans[J]. The Journal of Geology, 1995, 103(3): 285-299.
    [68] Yuan J, Yu G D, Song M S, et al. Depositional characteristics and reservoir potential of Paleogene sediment gravity flow deposits on a faulted slope of the Zhanhua Sag, Bohai Bay Basin, China[J]. Journal of Asian Earth Sciences, 2019, 177: 89-106.
    [69] 金杰华,操应长,王健,等. 涠西南凹陷陡坡带流一段上亚段异重流沉积新发现[J]. 地学前缘,2019,26(4):250-258.

    Jin Jiehua, Cao Yingchang, Wang Jian, et al. New discovery of hyperpycnal flow deposits in the section of the steep slope belt in the Weixinan Sag[J]. Earth Science Frontiers, 2019, 26(4): 250-258.
    [70] 谈明轩,朱筱敏,朱世发. 异重流沉积过程和沉积特征研究[J]. 高校地质学报,2015,21(1):94-104.

    Tan Mingxuan, Zhu Xiaomin, Zhu Shifa. Research on sedimentary process and characteristics of hyperpycnal flows[J]. Geological Journal of China Universities, 2015, 21(1): 94-104.
    [71] Mulder T, Chapron E. Flood deposits in continental and marine environments: Character and significance[M]//Slatt R M, Zavala C. Sediment transfer from shelf to deep water—revisiting the delivery system:AAPG studies in geology. Tulsa: APPG, 2011: 1-30.
    [72] Zavala C. The new knowledge is written on sedimentary rocks⁃a comment on Shanmugam’s paper “the hyperpycnite problem”[J]. Journal of Palaeogeography, 2019, 8(1): 23.
    [73] Haughton P, Davis C, McCaffrey W, et al. Hybrid sediment gravity flow deposits–classification, origin and significance[J]. Marine and Petroleum Geology, 2009, 26(10): 1900-1918.
    [74] Talling P J. Hybrid submarine flows comprising turbidity current and cohesive debris flow: Deposits, theoretical and experimental analyses, and generalized models[J]. Geosphere, 2013, 9(3): 460-488.
    [75] Felix M, Peakall J. Transformation of debris flows into turbidity currents: Mechanisms inferred from laboratory experiments[J]. Sedimentology, 2006, 53(1): 107-123.
    [76] Hovikoski J, Therkelsen J, Nielsen L H, et al. Density-flow deposition in a fresh-water lacustrine rift basin, Paleogene Bach Long Vi Graben, Vietnam[J]. Journal of Sedimentary Research, 2016, 86(9): 982-1007.
    [77] Williams L S. Sedimentology of the Lower Cretaceous reservoirs of the Sea Lion Field, North Falkland Basin[J]. Petroleum Geoscience, 2015, 21(2/3): 183-198.
    [78] Parker G, Garcia M, Fukushima Y, et al. Experiments on turbidity currents over an erodible bed[J]. Journal of Hydraulic Research, 1987, 25(1): 123-147.
    [79] Postma G, Cartigny M J B. Supercritical and subcritical turbidity currents and their deposits: A synthesis[J]. Geology, 2014, 42(11): 987-990.
    [80] Normandeau A, Lajeunesse P, Poiré A G, et al. Morphological expression of bedforms formed by supercritical sediment density flows on four Fjord‐Lake deltas of the south‐eastern Canadian Shield (eastern Canada)[J]. Sedimentology, 2016, 63(7): 2106-2129.
    [81] Jin Q, Wang R, Zhu G Y, et al. The lacustrine liangjialou fan in the Dongying depression, eastern China: Deep‐water reservoir sandstones in a Non‐Marine Rift Basin[J]. Journal of Petroleum Geology, 2005, 28(4): 397-412.
    [82] Wang J D, Li S Z, Santosh M, et al. Lacustrine turbidites in the Eocene Shahejie Formation, Dongying Sag, Bohai Bay Basin, North China Craton[J]. Geological Journal, 2013, 48(5): 561-578.
    [83] 王伟锋,胡瑜,于正军,等. 东营三角洲前缘坡移扇储集体特征及成因研究[J]. 石油实验地质,2016,38(5):600-608.

    Wang Weifeng, Hu Yu, Yu Zhengjun, et al. Reservoir characteristics and genesis of slope fans in Dongying delta front[J]. Petroleum Geology & Experiment, 2016, 38(5): 600-608.
    [84] 鄢继华,陈世悦,宋国奇,等. 三角洲前缘滑塌浊积岩形成过程初探[J]. 沉积学报,2004,22(4):573-578.

    Yan Jihua, Chen Shiyue, Song Guoqi, et al. Preliminary study on the formation of fluxoturbidite in front of delta[J]. Acta Sedimentologica Sinica, 2004, 22(4): 573-578.
    [85] 鄢继华,陈世悦,姜在兴. 东营凹陷北部陡坡带近岸水下扇沉积特征[J]. 石油大学学报(自然科学版),2005,29(1):12-16,21.

    Yan Jihua, Chen Shiyue, Jiang Zaixing. Sedimentary characteristics of nearshore subaqueous fans in steep slope of Dongying Depression[J]. Journal of the University of Petroleum, China, 2005, 29(1): 12-16, 21.
    [86] 隋风贵,罗佳强,郝雪峰,等. 东营中央洼陷带缓坡远岸浊积扇体系序列及其含油气性[J]. 矿物岩石,2003,23(3):76-81.

    Fenggui Sui, Luo Jiaqiang, Hao Xuefeng, et al. The sequence of far-shore turbidite fan systems on gentle slope and its petroleum-bearing feature in central depression belt of Dongying[J]. Journal of Mineralogy and Petrology, 2003, 23(3): 76-81.
    [87] 张善文,曾溅辉,肖焕钦,等. 济阳坳陷岩性油气藏充满度大小及分布特征[J]. 地质论评,2004,50(4):365-369.

    Zhang Shanwen, Zeng Jianhui, Xiao Huanqin, et al. Oil-gas filling degree and distribution characteristics of the lithological oil-gas reservoir in the Jiyang Depression[J]. Geological Review, 2004, 50(4): 365-369.
    [88] 王留奇,姜在兴,操应长,等. 东营凹陷沙河街组断槽重力流水道沉积研究[J]. 石油大学学报(自然科学版),1994,18(3):19-25.

    Wang Liuqi, Jiang Zaixing, Cao Yingchang, et al. Sedimentation in fault-trough gravity channel at Shahejie Formation of Dongying Depression[J]. Journal of the University of Petroleum, China, 1994, 18(3): 19-25.
    [89] Mutti E, Bernoulli D, Lucchi F R, et al. Turbidites and turbidity currents from Alpine ‘flysch’ to the exploration of continental margins[J]. Sedimentology, 2009, 56(1): 267-318.
    [90] Shanmugam G. 50 years of the turbidite paradigm (1950s—1990s): Deep-water processes and facies models—a critical perspective[J]. Marine and Petroleum Geology, 2000, 17(2): 285-342.
    [91] Talling P J. On the triggers, resulting flow types and frequencies of subaqueous sediment density flows in different settings[J]. Marine Geology, 2014, 352: 155-182.
    [92] Yang T, Cao Y C, Liu K Y, et al. 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[J]. Marine and Petroleum Geology, 2019, 102: 231-257.
    [93] Fisher R V. Flow transformations in sediment gravity flows[J]. Geology, 1983, 11(5): 273-274.
    [94] Gani M R. From turbid to lucid: A straightforward approach to sediment gravity flows and their deposits[J]. The Sedimentary Record, 2004, 2: 4-8.
    [95] Mutti E. Turbidite sandstones [M]. Istituto di Geologia Università di Parma, Italy, 1992: 1-256.
    [96] Felix M, Leszczyński S, Ślączka A, et al. Field expressions of the transformation of debris flows into turbidity currents, with examples from the Polish Carpathians and the French Maritime Alps[J]. Marine and Petroleum Geology, 2009, 26(10): 2011-2020.
    [97] Talling P J, Allin J, Armitage D A, et al. Key future directions for research on turbidity currents and their deposits[J]. Journal of Sedimentary Research, 2015, 85(2): 153-169.
    [98] Talling P J, Paull C K, Piper D J W. How are subaqueous sediment density flows triggered, what is their internal structure and how does it evolve? Direct observations from monitoring of active flows[J]. Earth-Science Reviews, 2013, 125: 244-287.
    [99] Yang T, Cao Y, Friis H, et al. Origin and evolution processes of hybrid event beds in the Lower Cretaceous of the Lingshan Island, eastern China[J]. Australian Journal of Earth Sciences, 2018, 65(4): 517-534.
    [100] 李存磊,任伟伟,唐明明. 流体性质转换机制在重力流沉积体系分析中应用初探[J]. 地质论评,2012,58(2):285-296.

    Li Cunlei, Ren Weiwei, Tang Mingming. Preliminary study on gravity flow depositional system based on fluid properties conversion theory[J]. Geological Review, 2012, 58(2): 285-296.
    [101] 李林,曲永强,孟庆任,等. 重力流沉积:理论研究与野外识别[J]. 沉积学报,2011,29(4):677-688.

    Li Lin, Qu Yongqiang, Meng Qingren, et al. Gravity flow sedimentation: Theoretical studies and field identification[J]. Acta Sedimentologica Sinica, 2011, 29(4): 677-688.
    [102] 操应长,王思佳,王艳忠,等. 滑塌型深水重力流沉积特征及沉积模式:以渤海湾盆地临南洼陷古近系沙三中亚段为例[J]. 古地理学报,2017,19(3):419-432.

    Cao Yingchang, Wang Sijia, Wang Yanzhong, et al. Sedimentary characteristics and depositional model of slumping deep-water gravity flow deposits: A case study from the middle Member 3 of Paleogene Shahejie Formation in Linnan subsag, Bohai Bay Basin[J] Journal of Palaeogeography, 2017, 19(3): 419-432.
    [103] Covault J A, Kostic S, Paull C K, et al. Cyclic steps and related supercritical bedforms: Building blocks of deep-water depositional systems, western North America[J]. Marine Geology, 2017, 393: 4-20.
    [104] Symons W O, Sumner E J, Talling P J, et al. Large-scale sediment waves and scours on the modern seafloor and their implications for the prevalence of supercritical flows[J]. Marine Geology, 2016, 371: 130-148.
    [105] Cartigny M J B, Ventra D, Postma G, et al. Morphodynamics and sedimentary structures of bedforms under supercritical‐flow conditions: New insights from flume experiments[J]. Sedimentology, 2014, 61(3): 712-748.
    [106] Normandeau A, Dietrich P, Lajeunesse P, et al. Timing and controls on the delivery of coarse sediment to deltas and submarine fans on a formerly glaciated coast and shelf[J]. GSA Bulletin, 2017, 129(11/12): 1424-1441.
    [107] Covault J A, Kostic S, Paull C K, et al. Submarine channel initiation, filling and maintenance from sea‐floor geomorphology and morphodynamic modelling of cyclic steps[J]. Sedimentology, 2014, 61(4): 1031-1054.
    [108] Lang J, Brandes C, Winsemann J. Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)[J]. Sedimentary Geology, 2017, 349: 79-102.
    [109] Postma G, Hoyal D C, Abreu V, et al. Morphodynamics of supercritical turbidity currents in the channel-lobe transition zone[M]//Lamarche G, Mountjo J, Bull S, et al. Submarine mass movements and their consequences: 7th international symposium. Cham: Springer, 2016: 469-478.
    [110] Wynn R B, Kenyon N H, Masson D G, et al. Characterization and recognition of deep-water channel-lobe transition zones[J]. AAPG Bulletin, 2002, 86(8): 1441-1462.
    [111] Mohrig D, Ellis C, Parker G, et al. Hydroplaning of subaqueous debris flows[J]. GSA Bulletin, 1998, 110(3): 387-394.
    [112] Ilstad T, Elverhøi A, Issler D, et al. Subaqueous debris flow behaviour and its dependence on the sand/clay ratio: A laboratory study using particle tracking[J]. Marine Geology, 2004, 213(1/2/3/4): 415-438.
    [113] Kneller B C, Branney M J. Sustained high‐density turbidity currents and the deposition of thick massive sands[J]. Sedimentology, 1995, 42(4): 607-616.
    [114] Hiscott R N. Traction-carpet stratification in turbidites—fact or fiction?[J]. Journal of Sedimentary Research, 1994, 64(2a): 204-208.
    [115] Sohn Y K. On traction-carpet sedimentation[J]. Journal of Sedimentary Research, 1997, 67(3): 502-509.
    [116] Cartigny M J B, Eggenhuisen J T, Hansen E W M, et al. Concentration-dependent flow stratification in experimental high-density turbidity currents and their relevance to turbidite facies models[J]. Journal of Sedimentary Research, 2013, 83(12): 1047-1065.
    [117] Bagnold R A. Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear[J]. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1954, 225(1160): 49-63.
    [118] Naruse H, Masuda F. Visualization of the internal structure of the massive division in experimental sediment-gravity-flow deposits by mapping of grain fabric[J]. Journal of Sedimentary Research, 2006, 76(5): 854-865.
    [119] Baas J H, Best J L, Peakall J. Depositional processes, bedform development and hybrid bed formation in rapidly decelerated cohesive (mud–sand) sediment flows[J]. Sedimentology, 2011, 58(7): 1953-1987.
    [120] Baas J H, Best J L, Peakall J. Predicting bedforms and primary current stratification in cohesive mixtures of mud and sand[J]. Journal of the Geological Society, 2016, 173(1): 12-45.
    [121] Baker M L, Baas J H, Malarkey J, et al. The effect of clay type on the properties of cohesive sediment gravity flows and their deposits[J]. Journal of Sedimentary Research, 2017, 87(11): 1176-1195.
    [122] Malarkey J, Baas J H, Hope J A, et al. The pervasive role of biological cohesion in bedform development[J]. Nature Communications, 2015, 6(1): 6257.
    [123] Haughton P D W, Barker S P, McCaffrey W D. ‘Linked’ debrites in sand‐rich turbidite systems‐origin and significance[J]. Sedimentology, 2003, 50(3): 459-482.
    [124] Talling P J, Amy L A, Wynn R B, et al. Beds comprising debrite sandwiched within co‐enetic turbidite: Origin and widespread occurrence in distal depositional environments[J]. Sedimentology, 2004, 51(1): 163-194.
    [125] Sumner E J, Talling P J, Amy L A. Deposits of flows transitional between turbidity current and debris flow[J]. Geology, 2009, 37(11): 991-994.
    [126] Craig M J, Baas J H, Amos K J, et al. Biomediation of submarine sediment gravity flow dynamics[J]. Geology, 2020, 48(1): 72-76.
    [127] Zavala C, Arcuri M. Intrabasinal and extrabasinal turbidites: Origin and distinctive characteristics[J]. Sedimentary Geology, 2016, 337: 36-54.
    [128] Hage S, Cartigny M J B, Sumner E J, et al. Direct monitoring reveals initiation of turbidity currents from extremely dilute river plumes[J]. Geophysical Research Letters, 2019, 46(20): 11310-11320.
    [129] Hizzett J L, Hughes Clarke J E, Sumner E J, et al. Which triggers produce the most erosive, frequent, and longest runout turbidity currents on deltas?[J]. Geophysical Research Letters, 2018, 45(2): 855-863.
    [130] Piper D J W, Normark W R. Processes that initiate turbidity currents and their influence on turbidites: A marine geology perspective[J]. Journal of Sedimentary Research, 2009, 79(6): 347-362.
    [131] Clare M A, Talling P J, Hunt J E. Implications of reduced turbidity current and landslide activity for the Initial Eocene Thermal Maximum–evidence from two distal, deep-water sites[J]. Earth and Planetary Science Letters, 2015, 420: 102-115.
    [132] Atwater B F, Carson B, Griggs G B, et al. Rethinking turbidite paleoseismology along the Cascadia subduction zone[J]. Geology, 2014, 42(9): 827-830.
    [133] Polonia A, Nelson C H, Romano S, et al. A depositional model for seismo-turbidites in confined basins based on Ionian Sea deposits[J]. Marine Geology, 2017, 384: 177-198.
    [134] Sumner E J, Siti M I, McNeill L C, et al. Can turbidites be used to reconstruct a paleoearthquake record for the central Sumatran margin?[J]. Geology, 2013, 41(7): 763-766.
    [135] Girard F, Ghienne J F, Rubino J L. Occurrence of hyperpycnal flows and hybrid event beds related to glacial outburst events in a Late Ordovician proglacial delta (Murzuq Basin, SW Libya)[J]. Journal of Sedimentary Research, 2012, 82(9): 688-708.
    [136] Mutti E, Davoli G, Tinterri R, et al. The importance of ancient fluvio-deltaic systems dominated by catastrophic flooding in tectonically active basins[J]. Memorie di Scienze Geologiche, Università di Padova, 1996, 48(1): 233-291.
    [137] Mulder T, Alexander J. The physical character of subaqueous sedimentary density flows and their deposits[J]. Sedimentology, 2001, 48(2): 269-299.
    [138] Ponce J J, Carmona N. Coarse-grained sediment waves in hyperpycnal clinoform systems, Miocene of the Austral foreland basin, Argentina[J]. Geology, 2011, 39(8): 763-766.
    [139] Ito M. Downfan transformation from turbidity currents to debris flows at a channel-to-lobe transitional zone: The lower Pleistocene Otadai Formation, Boso Peninsula, Japan[J]. Journal of Sedimentary Research, 2008, 78(10): 668-682.
    [140] Pritchard D, Gladstone C. Reversing buoyancy in turbidity currents: Developing a hypothesis for flow transformation and for deposit facies and architecture[J]. Marine and Petroleum Geology, 2009, 26(10): 1997-2010.
    [141] Basilici G, De Luca P H V, Poiré D G. Hummocky cross-stratification-like structures and combined-flow ripples in the Punta Negra Formation (Lower-Middle Devonian, Argentine Precordillera): A turbiditic deep-water or storm-dominated prodelta inner-shelf system?[J]. Sedimentary Geology, 2012, 267-268: 73-92.
    [142] Morsilli M, Pomar L. Internal waves vs. surface storm waves: A review on the origin of hummocky cross‐tratification[J]. Terra Nova, 2012, 24(4): 273-282.
    [143] Tinterri R. Combined flow sedimentary structures and the genetic link between sigmoidal-and hummocky-cross stratification[J]. GeoActa, 2011, 10: 43-85.
    [144] 何起祥. 沉积地球科学的历史回顾与展望[J]. 沉积学报,2003,21(1):10-18.

    He Qixiang. Sedimentary earth sciences: Yesterday, today and tomorrow[J]. Acta Sedimentologica Sinica, 2003, 21(1): 10-18.
    [145] Davarpanah Jazi S, Wells M G. Dynamics of settling‐riven convection beneath a sediment‐laden buoyant overflow: Implications for the length‐scale of deposition in lakes and the coastal ocean[J]. Sedimentology, 2020, 67(1): 699-720.
    [146] Parsons J D, Bush J W M, Syvitski J P M. Hyperpycnal plume formation from riverine outflows with small sediment concentrations[J]. Sedimentology, 2001, 48(2): 465-478.
    [147] Mutti E. Thin-bedded plumites: An overlooked deep-water deposit[J]. Journal of Mediterranean Earth Sciences, 2019, 11: 61-80.
    [148] Yang T, Cao Y C, Liu K Y, et al. Origin of deep-water fine-grained sediments as revealed from the Lower Cretaceous rifting basin sequence in the Lingshan Island, Yellow Sea, eastern China[J]. Journal of Asian Earth Sciences, 2019, 186: 104065.
    [149] Kane I A, Pontén A S M. Submarine transitional flow deposits in the Paleogene Gulf of Mexico[J]. Geology, 2012, 40(12): 1119-1122.
    [150] Pierce C S, Haughton P D W, Shannon P M, et al. Variable character and diverse origin of hybrid event beds in a sandy submarine fan system, Pennsylvanian Ross Sandstone Formation, western Ireland[J]. Sedimentology, 2018, 65(3): 952-992.
    [151] Southern S J, Kane I A, Warchoł M J, et al. Hybrid event beds dominated by transitional‐low facies: Character, distribution and significance in the Maastrichtian Springar Formation, North‐West Vøring Basin, Norwegian Sea[J]. Sedimentology, 2017, 64(3): 747-776.
    [152] Talling P J, Malgesini G, Felletti F. Can liquefied debris flows deposit clean sand over large areas of sea floor? Field evidence from the Marnoso‐renacea Formation, Italian Apennines[J]. Sedimentology, 2013, 60(3): 720-762.
    [153] Fonnesu M, Felletti F, Haughton P D W, et al. Hybrid event bed character and distribution linked to turbidite system sub‐environments: The North Apennine Gottero Sandstone (North‐West Italy)[J]. Sedimentology, 2018, 65(1): 151-190.
    [154] Liu J P, Xian B Z, Wang J H, et al. Sedimentary architecture of a sub-lacustrine debris fan: Eocene Dongying Depression, Bohai Bay Basin, East China[J]. Sedimentary Geology, 2017, 362: 66-82.
    [155] Stow D A V, Johansson M. Deep-water massive sands: Nature, origin and hydrocarbon implications[J]. Marine and Petroleum Geology, 2000, 17(2): 145-174.
    [156] Stevenson C J, Peakall J. Effects of topography on lofting gravity flows: Implications for the deposition of deep-water massive sands[J]. Marine and Petroleum Geology, 2010, 27(7): 1366-1378.
    [157] 鲜本忠,万锦峰,董艳蕾,等. 湖相深水块状砂岩特征、成因及发育模式:以南堡凹陷东营组为例[J]. 岩石学报,2013,29(9):3287-3299.

    Xian Benzhong, Wan Jinfeng, Dong Yanlei, et al. Sedimentary characteristics, origin and model of lacustrine deep-water massive sandstone: An example from Dongying Formation in Nanpu Depression[J] Acta Petrologica Sinica, 2013, 29(9): 3287-3299.
    [158] 李相博,刘化清,张忠义,等. 深水块状砂岩碎屑流成因的直接证据:“泥包砾”结构:以鄂尔多斯盆地上三叠统延长组研究为例[J]. 沉积学报,2014,32(4):611-622.

    Li Xiangbo, Liu Huaqing, Zhang Zhongyi, et al. “Argillaceous parcel” structure: A direct evidence of debris flow origin of deep-water massive sandstone of Yanchang Formation, Upper Triassic, the Ordos Basin[J]. Acta Sedimentologica Sinica, 2014, 32(4): 611-622.
    [159] Li X B, Liu H Q, Pan S X, et al. Subaqueous sandy mass-transport deposits in lacustrine facies of the Upper Triassic Yanchang Formation, Ordos Basin, central China[J]. Marine and Petroleum Geology, 2018, 97: 66-67.
    [160] Li X B, Yang Z L, Wang J, et al. Mud-coated intraclasts: A criterion for recognizing sandy mass-transport deposits-deep-lacustrine massive sandstone of the Upper Triassic Yanchang Formation, Ordos Basin, central China[J]. Journal of Asian Earth Sciences, 2016, 129: 98-116.
    [161] Zavala C, Arcuri M, Di Meglio M, et al. A genetic facies tract for the analysis of sustained hyperpycnal flow deposits[M]//Slatt R M, Zavala C. Sediment transfer from shelf to deep water—revisiting the delivery system: AAPG Studies in Geology61. Tulsa: AAPG, 2011: 31-51.
    [162] Kane I A, Hodgson D M. Sedimentological criteria to differentiate submarine channel levee subenvironments: Exhumed examples from the Rosario Fm. (Upper Cretaceous) of Baja California, Mexico, and the Fort Brown Fm. (Permian), Karoo Basin, S. Africa[J]. Marine and Petroleum Geology, 2011, 28(3): 807-823.
    [163] Covault J A, Sylvester Z, Hubbard S M, et al. The stratigraphic record of submarine-channel evolution[J]. The Sedimentary Record, 2016, 14(3): 4-11.
    [164] Fildani A, Hubbard S M, Covault J A, et al. Erosion at inception of deep-sea channels[J]. Marine and Petroleum Geology, 2013, 41: 48-61.
    [165] Fildani A, Normark W R, Kostic S, et al. Channel formation by flow stripping: Large‐cale scour features along the Monterey East Channel and their relation to sediment waves[J]. Sedimentology, 2006, 53(6): 1265-1287.
    [166] Mayall M, Jones E, Casey M. Turbidite channel reservoirs—Key elements in facies prediction and effective development[J]. Marine and Petroleum Geology, 2006, 23(8): 821-841.
    [167] Lamb M P, Parsons J D, Mullenbach B L, et al. Evidence for superelevation, channel incision, and formation of cyclic steps by turbidity currents in Eel Canyon, California[J]. GSA Bulletin, 2008, 120(3/4): 463-475.
    [168] Mayall M, Kane I A, McCaffrey W D. Internal architecture, bedforms and geometry of turbidite channels. A conference held at the Geological Society, London, June 20-21st 2011[J]. Marine and Petroleum Geology, 2013, 41: 1-6.
    [169] Normark W R, Piper D J W, Sliter R. Sea‐evel and tectonic control of middle to late Pleistocene turbidite systems in Santa Monica Basin, offshore California[J]. Sedimentology, 2006, 53(4): 867-897.
    [170] Richards M, Bowman M, Reading H. Submarine-fan systems I: Characterization and stratigraphic prediction[J]. Marine and Petroleum Geology, 1998, 15(7): 689-717.
    [171] 胡孝林,刘新颖,刘琼,等. 深水沉积研究进展及前缘问题[J]. 中国海上油气,2015,27(1):10-18.

    Hu Xiaolin, Liu Xinying, Liu Qiong, et al. Advances in research on deep water deposition and their frontier problems[J]. China Offshore Oil and Gas, 2015, 27(1): 10-18.
    [172] Mutti E, Tinterri R, Benevelli G, et al. Deltaic, mixed and turbidite sedimentation of ancient foreland basins[J]. Marine and Petroleum Geology, 2003, 20(6/7/8): 733-755.
    [173] Pattison S A J, Bruce Ainsworth R, Hoffman T A. Evidence of across‐helf transport of fine‐grained sediments: Turbidite‐filled shelf channels in the Campanian Aberdeen Member, Book Cliffs, Utah, USA[J]. Sedimentology, 2007, 54(5): 1033-1064.
    [174] Petter A L, Steel R J. Hyperpycnal flow variability and slope organization on an Eocene shelf margin, Central Basin, Spitsbergen[J]. AAPG Bulletin, 2006, 90(10): 1451-1472.
    [175] Kneller B, Buckee C. The structure and fluid mechanics of turbidity currents: A review of some recent studies and their geological implications[J]. Sedimentology, 2000, 47(1): 62-94.
    [176] Helland-Hansen W, Sømme T O, Martinsen O J, et al. Deciphering Earth's natural hourglasses: Perspectives on source-to-sink analysis[J]. Journal of Sedimentary Research, 2016, 86(9): 1008-1033.
    [177] Walker R G. Deep-water sandstone facies and ancient submarine fans: Models for exploration for stratigraphic traps[J]. AAPG Bulletin, 1978, 62(6): 932-966.
    [178] Posamentier H W,Kolla V,刘化清. 深水浊流沉积综述[J]. 沉积学报,2019,37(5):879-903.

    Posamentier H W, Kolla V, Liu Huaqing. An overview of deep-water turbidite deposition[J]. Acta Sedimentologica Sinica, 2019, 37(5): 879-903.
    [179] Jia J L, Liu Z J, Miao C S, et al. Depositional model and evolution for a deep-water sublacustrine fan system from the syn-rift Lower Cretaceous Nantun Formation of the Tanan Depression (Tamtsag Basin, Mongolia)[J]. Marine and Petroleum Geology, 2014, 57: 264-282.
    [180] 刘建平,鲜本忠,王璐,等. 渤海湾盆地东营凹陷始新世三角洲供给型重力流地震沉积学研究[J]. 古地理学报,2016,18(6):961-975.

    Liu Jianping, Xian Benzhong, Wang Lu, et al. Seismic sedimentology of delta-fed turbidites of the Eocene in Dongying Sag, Bohai Bay Basin[J]. Journal of Palaeogeography, 2016, 18(6): 961-975.
    [181] Azpiroz-Zabala M, Cartigny M J B, Talling P J, et al. Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons[J]. Science Advances, 2017, 3(10): e1700200.
    [182] de Leeuw J, Eggenhuisen J T, Cartigny M J B. Linking submarine channel–levee facies and architecture to flow structure of turbidity currents: Insights from flume tank experiments[J]. Sedimentology, 2018, 65(3): 931-951.
    [183] Meiburg E, Kneller B. Turbidity currents and their deposits[J]. Annual Review of Fluid Mechanics, 2010, 42: 135-156.
    [184] Symons W O, Sumner E J, Paull C K, et al. A new model for turbidity current behavior based on integration of flow monitoring and precision coring in a submarine canyon[J]. Geology, 2017, 45(4): 367-370.
    [185] Xu J P, Sequeiros O E, Noble M A. Sediment concentrations, flow conditions, and downstream evolution of two turbidity currents, Monterey Canyon, USA[J]. Deep Sea Research Part I: Oceanographic Research Papers, 2014, 89: 11-34.
    [186] 王星星,王英民,高胜美,等. 深水重力流模拟研究进展及对海洋油气开发的启示[J]. 中国矿业大学学报,2018,47(3):588-602.

    Wang Xingxing, Wang Yingmin, Gao Shengmei, et al. Advancements of the deep-water gravity flow simulations and their implications for exploitation of marine petroleum[J]. Journal of China University of Mining & Technology, 2018, 47(3): 588-602.
    [187] Cantero M I, Cantelli A, Pirmez C, et al. Emplacement of massive turbidites linked to extinction of turbulence in turbidity currents[J]. Nature Geoscience, 2011, 5(1): 42-45.
    [188] Hage S, Cartigny M J B, Clare M A, et al. How to recognize crescentic bedforms formed by supercritical turbidity currents in the geologic record: Insights from active submarine channels[J]. Geology, 2018, 46(6): 563-566.
    [189] Paull C K, Talling P J, Maier K L, et al. Powerful turbidity currents driven by dense basal layers[J]. Nature Communications, 2018, 9(1): 4114.
    [190] Schieber J. Mud re-distribution in epicontinental basins ⁃ Exploring likely processes[J]. Marine and Petroleum Geology, 2016, 71: 119-133.
    [191] Schieber J, Southard J, Thaisen K. Accretion of mudstone beds from migrating floccule ripples[J]. Science, 2007, 318(5857): 1760-1763.
    [192] Boulesteix K, Poyatos‐Moré M, Flint S S, et al. Transport and deposition of mud in deep‐water environments: Processes and stratigraphic implications[J]. Sedimentology, 2019, 66(7): 2894-2925.
    [193] Fildani A, Clark J, Covault J A, et al. Muddy sand and sandy mud on the distal Mississippi fan: Implications for lobe depositional processes[J]. Geosphere, 2018, 14(3): 1051-1066.
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Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin

doi: 10.14027/j.issn.1000-0550.2020.037
Funds:

National Natural Science Foundation of China 41802127, 42072126

The Research Project of Science and Technology Innovation Fund of CNPC in 2019 2019D⁃5007⁃0106

Abstract: In the last few years, great progress has been achieved in the understanding of gravity⁃flow deposits in marine basins, but the study of gravity⁃flow deposits in lacustrine basins lags far behind. Research on gravity⁃flow deposits in China and globally are summarized here to clearly illustrate the shortcomings of gravity⁃flow deposit research for lacustrine basins. Clarifying meanings and relationships between different terminologies, as well as detailed interpretation, are reliable ways of reducing terminology confusion. Gravity⁃flow transformation, flow⁃state transformation, and lubrication are mainly dynamic processes of gravity flow. Transportation, hindered settling, turbulence damping, and traction carpet are dynamic processes of gravity flow, whereas settling, sediment re⁃transportation, sustained supply from flooding rivers, and the settling of buoyant plumes, are the main mechanisms of gravity flow in a lacustrine basin. Comprehensive analysis of detailed facies⁃tract types, analysis of the internal structure of massive sandstone, and analysis of the characteristics of inverse⁃then⁃normal sequences are all important means of revealing the genesis of gravity⁃flow deposits. Gravity⁃flow channels are formed by erosion due to supercritically turbid currents. The material composition and source of gravity flow are dominated by factors external to the basin, while the effective segregation of gravity flow types is dominated by internal basin factors. The integration of internal and external basin factors are termed “source⁃to⁃sink” systems, covering the overall gravity⁃flow evolutionary processes. The depositional model of gravity flow caused by sustained supply from flooding rivers comprises gravity⁃depositional elements, which include channel⁃levée deposits, channel and lobe transition zones, and lobe deposits. Depositional models of gravity flow due to sediment re⁃transportation contain gravity⁃depositional elements, such as sediment failure at the delta front, chaotic deposits, and lobe deposits. Gravity⁃flow deposits are the main reservoirs for unconventional oil and gas in a lacustrine basin. The fine⁃grained deposits resulting from flow transformation have the potential for oil and gas generation and enrichment — and, at the same time, they are appropriate for hydraulic fracturing, which makes them the foremost lithofacies association for sweet⁃spot development in shale oil and gas exploration.

YANG Tian, CAO YingChang, TIAN JingChun. Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin[J]. Acta Sedimentologica Sinica, 2021, 39(1): 88-111. doi: 10.14027/j.issn.1000-0550.2020.037
Citation: YANG Tian, CAO YingChang, TIAN JingChun. Discussion on Research of Deep⁃water Gravity Flow Deposition in Lacustrine Basin[J]. Acta Sedimentologica Sinica, 2021, 39(1): 88-111. doi: 10.14027/j.issn.1000-0550.2020.037
  • 作为陆相湖盆重要的沉积砂体类型之一,深水重力流沉积砂体及其伴生的细粒沉积是目前岩性油气藏及非常规油气勘探的主要对象[115],对保障我国能源安全意义重大。同时,湖盆中重力流砂体的形成与分布受物源供给、构造活动及气候条件等诸多因素的综合控制[3,1617],蕴含了丰富的古构造及古气候演化信息。因而,开展湖盆深水重力流沉积的相关研究,不仅对于构造演化、气候变化等古地理信息重建具有重要指导意义,而且它作为非常规油气沉积学的核心内容之一,可从成因上探讨优质储层发育机制,为有利储层、非常规油气甜点区(段)与资源分布预测提供重要依据,有助于非常规油气的高效勘探开发[8]。陆相湖盆深水重力流沉积的研究一直是中国历代沉积学家关注的重点,如何起祥等[18]、赖婉琦等[19]就将浊积岩的触发机制划分为洪水成因和沉积物垮塌成因两种类型,洪水成因的浊积岩即现阶段国际上流行的洪水成因异重流流沉积[2021];而王德坪等[22],王德坪[23]首次提出的三角洲前缘沉积物垮塌再搬运形成泥石流砂质碎屑沉积的认识比后来Shanmugam[24]所指出的砂质碎屑流沉积认识提前了约10年。近年来,围绕海相重力流沉积研究成果在陆相湖盆中的应用,陆相湖盆重力流沉积相关研究取得了长足的进步[11,15,2531]。基于砂质碎屑流、异重流、混合流和超临界流的流体类型认识,丰富了我们对于陆相湖盆重力流流体类型的理解[11,15,3031];洪水持续供给和三角洲再搬运供给重力流成因机制的认识,揭示了湖相重力流砂体广泛发育的本质[11,3233];重力流水道控制及砂质碎屑流块体主导的不同沉积模式研究,解释了湖相重力流砂体复杂的分布规律及其内幕结构[15,28,34]。但是,重力流沉积是涉及重力流“触发—搬运—沉降” 的综合动力学过程[11,3536],现阶段湖盆重力流沉积研究多重视砂体识别和分布规律的研究,而轻视重力流沉积动力学过程的分析与理解,这也是造成湖盆重力流沉积相关研究与国际重力流沉积理论认识还存在一定差距的主要原因[56]

    目前,湖盆重力流研究中针对重力流流体转化、流态转化、水道形成演化及成因机制识别等涉及沉积动力学过程的相关研究还相对薄弱[56,2526,3739]。此外,陆相湖盆一般具有规模小、水体较浅、多物源、近物源、富物源、构造活动强烈等沉积背景特征,与海相盆地规模较大、水体较深、物源单一、源—汇分明、长距离搬运、构造相对稳定等一般沉积背景特征迥异[20,4041]。考虑到海相盆地与陆相湖盆沉积构造背景的差异[4243],湖盆的重力流沉积应该还具有其特殊性[4445],但相关认识还极为有限。总体上,陆相湖盆深水重力流沉积研究中还存在学术术语混杂[7,1011,31,46]、重力流类型与成因机制不明确[4,21,41,47]、重力流沉积分布控制因素与沉积模式不完善[41,4749]等系列问题。因而,系统总结湖盆深水重力流沉积的研究成果,明确湖盆深水重力流沉积中存在的不足,进而加快湖盆深水重力流沉积相关问题的深入研究,形成我国湖相特色的深水重力流研究学科优势是当务之急。笔者不惧浅薄,试图围绕湖相重力流沉积研究中的术语使用、动力学过程、沉积成因、沉积模式及研究手段和方法等主要方面谈一些粗浅的认识,以求抛砖引玉,引起国内沉积学同仁的重视,湖盆的重力流沉积研究仍大有可为。

  • 重力流沉积研究中一个突出的问题即概念术语的混杂[5052],在陆相湖盆的研究中表现尤为突出。一方面,不同的研究者对重力流沉积相关概念和术语的认识存在一定分歧;另一方面,不同的研究者对相同的概念术语的理解存在偏差[5152],导致相同的沉积现象可能被不同的术语描述或者相同的术语描述不同的沉积现象,从而影响了重力流的整体统一对比研究[35,5051]。针对陆相湖盆中常用的描述重力流流体类型和沉积砂体的重要概念术语内涵做进一步的阐述,以达到统一认识的目的。

  • 针对陆相湖盆中重力流流体类型的认识,除了传统认识的碎屑流、颗粒流、液化流与浊流的认识外[53],近年来,围绕砂质碎屑流(sandy debris flow)、异重流(hyperpycnal flow)、混合流(hybrid flow)、超临界浊流(supercritical turbidity current)等流体类型的最新报道进一步丰富了湖盆重力流流体类型的认识[56,15,30,3738,5455];同时,这些新认识的流体类型如何理解,与传统流体类型之间如何区别,存在何种联系则是现阶段相关概念理论认识的难点。

    砂质碎屑流沉积在国内湖盆中的研究始于鄂尔多斯盆地[15,56],尔后迅速席卷全国,相关沉积在全国各大陆相含油气盆地陆续被发现[11,29,33,5758],砂质碎屑流沉积一时成为湖相重力流沉积的主要代名词。砂质碎屑流是一种富砂质具塑性流变性质的深水重力流,代表一个从黏性至非黏性碎屑流连续过程系列,内部呈线性层流,沉积物整体停止流动,块状固结,其沉积物支撑机制主要是基质强度、颗粒间的摩擦强度和浮力[24,59],以块状砂岩、含碎屑逆粒序砂岩沉积为代表。Shanmugam[24]基于碎屑流理论的相关认识对Lowe[60]原有的高密度浊流的概念提出了质疑和批判;实际上,砂质碎屑流与高密度浊流在自然界均存在[5,35,6162],盲目以砂质碎屑流替代高密度浊流显然不妥[50,6162],明确二者的差异才是相关研究的核心。

    高密度浊流的概念首先由Kuenen et al.[63]提出,Lowe[60]对高密度浊流的内涵及沉积物特征做了系统阐述,一般指沉积物体积浓度大于20%~30%,沉积物颗粒由流体湍动、浮力、受阻沉降(hindered settling)、颗粒碰撞分散压力和基质强度综合支撑的高密度流体,其形成的垂向沉积序列称为Lowe序列。由于研究早期将湖盆浊流沉积等价于重力流沉积,因而针对高密度浊流沉积的单独报道较为少见;尔后,砂质碎屑流概念的强势袭入使得湖盆的重力流研究中长期忽视了高密度浊流沉积的研究。实际上,在陆相湖盆,特别是断陷湖盆陡坡带广泛发育的粗碎屑重力流沉积中可能存在大量的高密度浊流沉积[5,62,64],高速超临界状态下浊流对粗粒沉积物的搬运作用是高密度浊流沉积存在的有力佐证[65]

    异重流(hyperpycnal flow)最早由Bates[66]引入沉积地质学领域,定义为从河口流出的比环境水体密度高的密度流;Mulder et al.[67]对Bates的定义作了改动,将异重流定义为由于携带沉积物颗粒,导致流体密度大于稳定环境水体的密度,沿盆地底部流动的高密度流体。湖盆异重流研究陆续受到重视[23,28,3031,34,6869],但是对湖盆异重流概念的内涵理解还存在一定的分歧,特别是异重流所能携带的沉积物粒度方面还未能达成共识,多数学者认为异重流仅能携带粉细砂及其以下粒径的沉积物[31,70]。Mulder et al.[71]提出根据搬运沉积物方式的差异,可以将异重流进一步分为底床载荷主导异重流(bed load dominated hyperpycnal flow)和悬浮载荷主导异重流(suspended load dominated hyperpycnal flow)两种类型,如此可见,异重流同样能够搬运细砂粒径以上的粗碎屑沉积物[72]。但是,仅用搬运形式的限制并不能很好的区分异重流与其他流体的关系和区别,经典浊流沉积中同样包含底床载荷和悬浮载荷搬运两种形式。笔者以为,异重流的概念包含广义与狭义两个层次,广义的异重流指洪水成因的高密度流体,包含了碎屑流、浊流等多种流体类型;而狭义的异重流系指洪水持续供给成因的、流体湍动支撑的准稳态浊流。

    混合流(hybrid flow)主要指同一重力流事件中由于流体转化形成的同时具有多种流变学性质的流体,其所形成的沉积序列称为混合事件层(hybrid event bed)[7374]。从沉积作用过程的连续性考量,碎屑流与浊流之间必然存在过渡流体类型,大量研究证实无论是碎屑流向浊流的转化还是浊流向碎屑流的转化都可以形成混合事件层[73,75],但相关认识在湖盆重力流沉积中的报道还不多见[6,25,7677]。湖盆作为沉积物的容纳空间,细粒物质无法排除,沉积物杂基含量较高,具备混合事件层广泛发育的条件,应引起重视[6,37]

    超临界浊流(supercritical turbidity current)主要是指根据水下弗洛德数的定义(Fr d = U /(gRCh)1/2R=ρ s/ρ-1,U为流体速度,g为重力加速度,h为流体的厚度,C为悬浮沉积物的体积浓度,R为重力流与环境水体的密度差,ρ s为重力流密度,ρ为环境水体密度)将水下弗洛德数大于1的浊流称为超临界浊流[78]。超临界浊流由于高流速和流体分层作用,是目前浊流搬运粗碎屑沉积并形成块状层理的最新认识[5,38,79],为明确高密度浊流与砂质碎屑流的争论提供了新的视角。湖盆中超临界浊流沉积作用的研究初见端倪[55,80];但是如何从岩芯尺度识别超临界浊流沉积还有待深入研究[5,38]

  • 对湖盆中重力流沉积砂体的描述则充分体现了湖相特色,出现了湖底扇[81]、浊积扇[82]、坡移扇[83]、滑塌浊积扇[82]、滑塌透镜体[84]、近岸水下扇[85]、远源浊积岩[86]、斜坡浊积岩[87]、沟道重力流沉积[88]和块体沉积[23]等一系列描述术语。受海底扇模式的影响,对湖盆深水重力流沉积体的描述中沉积学者们偏爱“扇”的概念;实际上,并非所有重力流沉积都具有扇体形态[8990],如滑塌浊积扇、滑塌透镜体、滑塌浊积岩、斜坡浊积岩描述的均为滑塌成因、扇体形态不明显的深水重力流沉积[82,87]。分类标准的不统一则是造成重力流沉积砂体的描述性术语混杂的主要原因,如湖底扇、近岸水下扇等是基于形态的分类术语,而浊积扇、坡移扇等则是基于成因与形态结合的分类术语。现已知湖盆重力流砂体成因多样[11,46,9192],将重力流成因归入到砂体描述中势必会造成术语的进一步混杂;而笼统的以扇体形态来描述部分非扇体形态的砂体又难免以偏概全。因而,笔者建议采用国外关于重力流沉积构型要素逐层分析的方法来系统刻画湖盆重力流砂体沉积[89],即系统分析湖盆重力流沉积的搬运区(峡谷、三角洲前缘垮塌带、侵蚀凹槽、供给水道等)、过渡区(水道—朵叶转换带)、沉积区(分支水道、朵叶、混杂沉积、深湖平原等)沉积特征,以重力流沉积构型要素特征及组合差异性来反映其成因及分布特征,从而回避单纯的形态及形态与成因分类对重力流砂体描述的影响[51]。当然,相关术语使用问题的解决并不能一蹴而就,不同研究者在条件容许情况下可以增加所使用术语内涵的介绍,以增进不同研究区重力流研究的整体统一对比研究,减少术语使用的混淆。

  • 沉积作用的连续性决定了重力流在搬运过程中会发生流体的转化,主要包含体转化、重力转化、面转化、淘洗转化四种主要形式[93],既可以发生碎屑流向浊流的转化,亦可发生浊流向碎屑流的转化[73]。流体转化过程导致在碎屑流和浊流之间会存在过渡流体类型,这是导致重力流流体类型复杂且不统一的主要原因[50,73,94];同时,流体转化导致不同类型的重力流沉积在侧向上毗邻,这也是重力沉积岩相—岩相组合—相域分析的基础[89,95]。碎屑流向浊流的转化过程已为大家所熟知(图1a),如Shanmugam[59]倡导的先存沉积物从滑动滑塌转化为砂质碎屑流再转化为浊流的过程,包含流体稀释作用为主的七种转化机制[6,75],导致沉积近端以高浓度碎屑流沉积为主,沉积远端以低浓度浊流沉积为主,高浓度碎屑流与低浓度浊流之间存在连续演化的不同渐变流体类型[9596]。浊流向碎屑流的转化是近年来沉积学界的研究热点[9798]图1a),主要涉及黏土矿物类型及含量对流体湍动抑制作用在内的五种主要机制[6,74,99],是沉积远端泥质碎屑流沉积广泛分布的主要原因,对于理解重力流砂体的沉积非均质性有重要意义。此外,还有部分学者提出重力流沉积晚期浊流向牵引流转化的认识[100101],认为鲍马序列中的Tb⁃Td段为牵引流沉积产物;这一观点需要斟酌,浊流在搬运的过程中能与底床发生剪切作用从而形成牵引特征的层理构造,但流体性质仍然为重力流[35]。湖盆中碎屑流向浊流转化的观点已深入人心,但是,针对碎屑流与浊流之间的过渡沉积类型的认识还较为少见[100,102];而浊流向碎屑流转化的认识还处于萌芽阶段[6,37]图2a,b)。前期的研究发现在涠西南凹陷流沙港组(图2c~e)、鄂尔多斯盆地三叠系(图2f)和济阳坳陷沙河街组(图2g)均存在广泛发育的流体转化成因的重力流混合事件层。从流体转化的角度,动态的看待重力流的形成与分布问题是解决重力流分类及分布相关认识争议的有效路径,符合沉积作用连续性的基本原理,是今后需要加强的方向。

    Figure 1.  Dynamic processes of sediment gravity flow during transportation

    Figure 2.  Hybrid event beds in lacustrine basin

  • 流态转化同样是重力流沉积物搬运过程中的重要沉积动力学过程,现阶段相关研究主要集中在浊流的超临界态与亚临界态的转化[79,103104]图1b)。前文已述,根据水下弗洛德数的定义,浊流可划分为超临界浊流(Fr d>1)和亚临界浊流(Fr d<1),超临界浊流是深水条件下高密度粗碎屑沉积物搬运的重要机制,并且在搬运的过程中伴随水力跳跃作用,会发生超临界浊流与亚临界浊流的相互转化,形成大量的超临界态底形(逆行沙丘、流槽—凹坑)及大型的阶梯状连续底形—旋回坎(cyclic steps)[79,105106]。超临界浊流多发育在限制性深水环境,是造成深水重力流水道发育的主要地质营力[103,107108];同时,在水道与朵叶转化带,由于限制性浊流向非限制性浊流转化,强烈的水跃作用导致该区超临界浊流与亚临界浊流转化频繁,是深水块状砂岩和侵蚀、牵引构造集中发育的主要部位[109110]。超临界浊流的发现为合理解释深水块状砂岩的高密度浊流成因与砂质碎屑流成因争议提供了新的视角[5,105],即大量粗略成层构造(crude stratification)发育的块状砂岩主要为高密度浊流成因。湖盆中浊流的流态转化及超临界浊流沉积作用的零星研究主要体现在湖盆底部阶梯状连续底形的观测及表征[80]和沉积构造的识别方面[55],超临界浊流作用下湖盆重力流水道的形成演化过程及湖盆超临界浊流沉积的典型识别标志和分布规律研究将展现出强大的生命力[5,38]

  • 水滑作用(hydroplaning)是碎屑流向深水盆地搬运中的润滑机制之一,其核心认识是在非渗透性黏性碎屑流头部由于局部限制的水体压力增大,导致碎屑流头部与底部分离且在流体头部产生润湿效应,从而减少了流体头部与底部的剪切拖拽作用,使得碎屑流能够在较缓坡度下以较快的速度向深水盆地搬运较远距离[111]。虽然水滑作用主要作用在碎屑流头部,其影响范围有限[74];但是,限制在头部的水体由于剪切作用会与碎屑流头部向后的部分逐渐混合,在碎屑流底部形成一层高含水层,减少碎屑流整体与盆地底部的剪切拖拽作用,从而有利于碎屑流整体向深水盆地搬运,该过程称为底部剪切润湿[112]图1c)。在水滑作用和底部剪切润湿综合作用下,碎屑流可以向深水盆地搬运较长距离而不至于解离转化[74,111112],是导致深水盆地中碎屑流沉积发育的可能机制之一[7374]。滑水作用和底部剪切润湿作用进一步受碎屑流中黏土矿物类型和含量控制[112],何种矿物和含量控制下的碎屑最有利于向深水盆地搬运的相关认识还有待深入研究。在陆相湖盆中广泛发育的砂质碎屑流分布特征同样受润湿机制控制,其黏土矿物类型和含量、有机质类型和含量、胞外聚合物发育程度的差异可能是控制砂质碎屑流发育程度、搬运距离及分布规律的重要影响因素[61],是今后相关研究需要加强的方向。

  • 随着重力流向深水盆地搬运,在流体动量逐渐减小的情况下,沉积物发生沉降,不同的沉降过程可形成沉积特征差异显著的沉积物[113],熟知的沉降过程除浊流主导逐级递减沉降和碎屑流主导整体固结沉降外还包括牵引毯作用、受阻沉降、湍流抑制等主要的沉降动力学过程[35]

  • 牵引毯作用(traction carpet)主要是指在浊流底部形成的薄层高浓度惯性沉积层的剪切沉积作用,导致粒径不同的沉积物同时沉淀的现象[35,114115]。根据沉积物浓度的局部差异,牵引毯沉积层进一步可划分为底部的摩擦区(沉积物浓度45%~65%),中间的碰撞区(沉积物浓度9%~45%)和上部的过渡区(沉积物浓度小于9%)三个主要部分[115116]图3a)。牵引毯的沉积特征主要受牵引毯持续作用时间和内部结构差异组成控制(摩擦区与碰撞区的厚度比例),单层牵引毯沉积以逆粒序层理为典型特征,其垂向上的叠加能够形成分层构造(spaced stratification)或粗略成层构造(分层间距5~10 cm)显著且呈现整体逆粒序或复杂粒序的厚层砂体[115116]。牵引毯内部组成的差异进一步受剪切力大小、沉积物沉降速率和沉积物粒度大小等因素控制,相对粗粒沉积物中碰撞区更发育,相对细粒沉积物中摩擦区更发育[115116]。牵引毯沉积在湖盆的粗碎屑重力流沉积中十分发育,应该与纹层间距较小的平行层理区别对待,能够为合理的解释湖盆粗碎屑重力流砂体的形成与分布提供新的指导。

    Figure 3.  Dynamic processes of sediment gravity flow while settling

  • 受阻沉降(hindered settling)主要指在较高沉积物浓度条件下,沉积物颗粒向下沉降过程中会相互影响,导致沉积物颗粒的逐渐递减沉降状态受到阻碍,流体湍动受到抑制,沉积底形不发育;最终沉积物颗粒在相互作用下整体沉降,形成块状砂岩沉积[60,113]图3b)。受阻沉降在沉积物体积浓度超过10%时开始发挥作用,且随着沉积物体积浓度的增加,受阻沉降作用更加显著[117]。受阻沉降被认为是高密度浊流形成块状砂岩的主要机制之一[60,113],该种成因的块状砂岩与砂质碎屑流形成的块状砂岩的争议成为近年来深水重力流沉积研究中的一个焦点[24],通过沉积物颗粒的定向排列统计学分析可能是找出二者成因差异的有效方法[118]。在陆相湖盆中,关于高密度浊流成因块状砂岩与砂质碎屑流块状砂岩差异性对比研究还较为少见[62],相关研究工作有待加强。

  • 湍流抑制(turbulence damping)是重力流中沉积物沉降的重要机制之一,沉积物浓度的增加导致的受阻沉降其作用也是使湍流受到抑制,因而二者之间多相互联系;除了受阻沉降导致的湍流抑制,黏土矿物、生物胞膜、黏土有机质复合体等强凝聚力物质的少量增加都会导致湍流作用受到抑制[119122]。强凝聚力物质的加入造成的湍流抑制作用是导致浊流向碎屑流转化的主要原因之一[73,123124],使得沉积物由逐级递减沉降机制转化为整体固结沉降机制,从而影响沉积物的沉积特征及其分布(图3c)。Sumner et al.[125]的实验证实当浊流速度为1.2 m/s时需要高岭土体积分数为12%时发生流体转化,当浊流流速为0.2 m/s时需要高岭土体积分数仅为4%时就能发生流体转化形成碎屑流。深水重力流中的黏土、有机质循环过程及其导致的湍流抑制作用是目前深水重力流研究的热点[121,126],特别是陆相湖盆中的重力流黏土杂基、生物胞膜、及黏土有机质复合体发育,在不同条件下这些因素如何影响重力流的形成和分布有待深入研究。同时,这种湍流抑制作用形成的细粒沉积物多具有薄层砂岩与泥质沉积条带状互层的沉积组构[120121],同时有机质富集[126],是油气生成和富集的有利场所,是非常规页岩油气潜在的有利发育区。

  • 得益于深水重力流监测技术的快速发展,近年来对重力流的成因认识有了长足的进步[91],现阶段关于深水重力流成因的认识包括多种触发机制作用下的沉积物再搬运成因和沉积物持续补给成因两种主要机制[74,91,127];最新的研究表明漂浮流体的卸载沉降同样是形成深水重力流的重要成因机制[128129]。不同成因机制重力流砂体沉积特征及分布规律存在一定差异,且蕴含了不同的构造活动及气候变化等古地理信息。

  • 沉积物再搬运成因深水重力流沉积是最为流行的成因认识,系指在地震活动、风暴作用、边坡失稳、气体释放等外界触发机制下[5,130],浅水区沉积物发生垮塌再搬运,向深水盆地搬运演化(滑动/滑塌→碎屑流→浊流),形成重力流沉积的综合过程(图4a)。陆相湖盆由于构造活动频繁,以断层活动和边坡失稳触发的再搬运成因重力流最为常见,该过程形成的重力流沉积物以砂质碎屑流沉积为主[11,15,2930],其搬运过程受滑水作用和剪切润湿控制,沉积近端以沉积物浓度稀释控制下的流体转化为主,沉积远端可发育湍流抑制作用导致的浊流向碎屑流的转化[6]。由于经历滑动、滑塌等块体搬运过程,该类成因的重力流沉积多与滑动、滑塌变形构造及软沉积物变形构造共生,是再搬运成因重力流沉积的重要特征之一[11,15]。由于沉积物垮塌再搬运与古地震活动和构造演化密切相关,因而,通过再搬运成因的重力流沉积在时间尺度上的重复规律研究,对古地理信息重建具有重要指导意义[131]。但是,由于沉积物垮塌再搬运触发机制多样,且受先存沉积物物质组成、积累程度、地形坡度等因素综合控制[130],试图通过重力流沉积及其伴生的软沉积物变形特征来明确重力流成因的触发机制研究是困难的[132134],特别是简单的将滑动、滑塌和软沉积物变形构造发育的再搬运成因重力流沉积与古地震活动直接联系的思考需要慎重[132,134]

    Figure 4.  Formation mechanisms of sediment gravity flow

  • 沉积物持续供给成因深水重力流主要包含风暴再悬浮作用和洪水作用形成的异重流直接向深水盆地搬运形成的重力流沉积[130];陆相湖盆由于风暴作用相对较弱,以洪水持续供给形成的异重流最为发育[20,127],是近年来湖盆重力流沉积研究的热点[3031]图4b)。陆相湖盆周围广泛发育的山区小河流在洪水作用下能够将高浓度的沉积物直接向深水盆地搬运,其搬运沉积物受源区沉积物供给和洪水能量强弱的综合控制,发育碎屑流和浊流等多种重力流流体类型[31,135136]。由于洪水持续补给推进作用,重力流的形成一般经历数天至数周,形成准稳态浊流[137];浊流对底部高浓度沉积物的剪切拖拽作用是牵引毯作用及其垂向叠置形成块状砂岩的有利条件[115];同时,在洪水动量和地形坡度的双重作用下,洪水成因的重力流易于达到超临界状态,流态转化形成的侵蚀构造及旋回坎沉积发育[138]。洪水成因高密度浊流强烈的侵蚀作用导致流体泥质含量增加,发生浊流向碎屑流的转化;沉积晚期低密度浊流的浮力反转作用也是导致向碎屑流转化的主要原因[139140]。持续剪切拖拽作用和洪水能量的频繁变化,使得洪水持续补给成因的重力流沉积牵引构造发育,上攀交错层理及丘状交错层理是洪水成因的异重流沉积典型的沉积识别标志[127,136],简单的将丘状交错层理归因于近岸风暴作用沉积成因值得商榷[141143]。由于异重流沉积作用多受气候条件控制,其沉积特征及重复规律的研究对探究古气候演化有重要启示意义[17,20];虽然现今重力流监测表明洪水形成的异重流只能携带粉砂及以下粒径的沉积物[91],从气候演化的角度来考量,地质历史时期的洪水未必不能携带细砂以上粒径的粗碎屑沉积物,“将今论古”的同时也需要注意条件的演变[144]。同时,沉积地理位置、地形坡度、物源区母岩性质与洪水能量大小等都是控制异重流沉积中是否发育粗碎屑的关键控制因素[3031]

  • 最新的重力流实际监测研究发现,即使在不发生沉积物再搬运或者洪水的情况下,重力流沉积仍然可以频繁形成[128129]。通过对加拿大哥伦比亚Squamish三角洲前端深水重力流沉积及河流流量、沉积物浓度的系统监测,发现正常河流携带的细粒沉积物入海形成的漂浮羽流在大潮混合作用下的卸载是形成深水重力流的重要机制[128]图4c)。实际上,漂浮羽流向重力流的转化主要受流体扩散或沉降驱动的对流所控制,漂浮羽流与环境水体的盐度差异是控制这种转化的最重要内因,盐度差异越小越有利于漂浮羽流向重力流的转化[145146]。如此看来,虽然在陆相湖盆中漂浮羽流不受潮汐混合影响,但是河流水体盐度与湖盆水体盐度的差异一般较小,利于漂浮羽流向重力流转化。这种漂浮羽流卸载成因的深水重力流沉积以薄层细粒沉积物垂向上的频繁互层叠加形成的砂泥互层沉积组构为典型沉积特征,云雾状构造(“cloudy”structure)、砂质团块及液化构造发育,与浊流的远端沉积和侧缘沉积存在显著差异[147]。这种认识为湖盆的深水细粒沉积研究提供了新的沉积学视角,深水重力流可能是湖盆细粒沉积最重要的搬运和沉积机制[148];如何从岩芯尺度去准确的识别漂浮羽流卸载沉积仍然是摆在我们面前的难题。

  • 不同成因的重力流沉积具有复杂的沉积演化过程,不同沉积过程能够形成相同沉积构造的沉积产物,同一种重力流类型具有多种成因,并且不同成因的重力流沉积能够同时发生、相互影响[130],如洪水形成的异重流同样能促进三角洲前缘沉积物的再搬运过程[130],因而准确的识别重力流成因及形成过程需要系统的沉积学过程对比研究[89]

  • 基于沉积特征精细解析的重力流沉积砂体相分析过程是明确其成因的有效方法[60,89,95],在地层格架划分及地层对比的基础上,通过包括岩相类型—岩层类型—岩相组合类型—相域(facies tract)类型的系统解析,能够为重力流沉积成因及其演化过程分析提供可靠的证据[95,149152]。岩相类型分析强调沉积物粒度及沉积构造特征,以明确基本沉积动力特征。岩层类型分析旨在解析一次重力流事件沉积响应特征,以明确一次重力流事件沉积动力学特征在垂向上的演化和组合,进而明确重力流沉积流体类型[149,151]。岩相组合类型分析通过垂向上不同岩相类型及岩层类型的叠置关系,以明确相对大尺度沉积环境。相域的分析通过解析一次重力流事件沉积响应在侧向上的组合关系,以明确一次重力流事件侧向上的演化过程[152153]图5)。如此,通过重力流沉积物垂向和侧向上的分布规律分析,明确其形成演化过程,以明确其成因[89]。湖盆重力流沉积中的相分析以岩芯和露头为主要工作对象[4,154],受侧向连续性制约,无论是岩相类型还是相域类型的分析都具有广阔的工作空间。

    Figure 5.  The principle of facies analysis (modified from Mutti[95])

  • 深水重力流沉积中块状砂岩的形成机制是其重要的研究内容,现阶段关于块状砂岩的成因包含高密度浊流底部受阻沉降导致的整体卸载[155]、高密度浊流底部的牵引毯垂向叠加[116]、高密度浊流底部的持续液化层卸载[113]、不同强度黏性碎屑流的块状固结[90,152]、细粒沉积物的淘洗漂浮[156]等多种认识。不同成因的重力流砂体形成的块状砂岩之间可能存在一定的差异[155],特别是在陆相湖盆中,砂质碎屑流块状固结形成的块状砂体多发育于沉积物再搬运成因重力流沉积砂体中,块状砂岩内部均一且泥质碎屑多见[4,154,157]图6a);而高密度浊流底部持续液化层的卸载和细粒沉积物淘洗漂浮形成的块状砂岩多发育于洪水持续供给成因重力流沉积砂体中,块状砂岩的内部可见微弱的频繁粒序变化[21,113,156]图6b)。此外,块状砂岩内部部分含有物的组成及其特征同样可以指示其形成过程,如“泥包砾”是深水砂质碎屑流成因的块状砂岩可靠的判别标志[158160]。因此,块状砂岩内部沉积特征显微结构的精细解析研究能够为重力流砂体成因提供一定依据[113,127],是今后湖盆重力流研究中需要加强的方面。

    Figure 6.  Characteristics of massive sandstone

  • 洪水持续供给成因的深水重力流沉积过程受洪水能量强弱变化控制,洪水能量多具有先增大后减小的特征,对应可形成内部含侵蚀界面的逆正沉积序列[2021,91],这种沉积序列的厚度受沉积物堆积速率和堆积位置的控制,从毫米到米级尺度均可发育(图7a~c)。同时,洪水强弱变化频繁震荡的特征在其沉积序列中也有对应的沉积特征响应,主要表现为整体以逆正粒序为主的沉积序列,内部还包含了次一级的沉积物粒度大小的频繁微弱变化[2021,91]图7c)。沉积近端由于强烈的侵蚀作用,逆粒序多被完全侵蚀,以正粒序垂向叠加为主要特征;沉积中部和沉积远端逆正粒序能够得到有效保存[71,91,161],结合沉积远端由流体密度差控制形成的漂浮沉积(lofting)[140],是有效识别洪水持续供给成因重力流沉积的可靠标志。当然,除了洪水强弱控制下的异重流能够形成深水重力流沉积中的逆正粒序沉积以外,高密度浊流底部的牵引毯作用[116]、水道—朵叶系统的漫溢作用[162]、复合退积垮塌作用[130]及等深流对重力流的改造等[20]都可形成逆正沉积序列。因此,对湖相重力流砂体中的逆—正粒序的沉积成因也需要具体问题具体分析。

    Figure 7.  Characteristics of inverse then normal sequence

  • 重力流水道的形成和演化过程对理解重力流砂体传输、分布及其内幕结构有重要意义,一直是深水重力流沉积研究中的热点问题[163165]。重力流水道的形成主要受浊流侵蚀能力强弱控制,侵蚀过程与沉积充填过程综合作用形成深水盆地特征鲜明的水道—堤岸系统[166]。超临界浊流强烈的侵蚀作用为合理解释重力流水道的形成和演化提供了理论依据,基于现代重力流水道地貌学研究和深水重力流监测研究证实,深水超临界浊流的侵蚀作用首先形成线状排列的不连续冲刷槽,尔后持续作用形成连续性重力流水道;水道内部在次生环流的作用下发生侧向的迁移和弯曲,局部重力流溢出伴随侵蚀作用形成分支水道[5,104,164165,167];野外露头的研究工作同样证实了这一观点[108]图8)。就海相盆地而言,大量沉积物积累后的垮塌再搬运和洪水持续补给长距离传输可能都是形成超临界浊流的有利条件[130],因而在海相深水盆地中的水道—堤岸沉积广泛发育,虽然部分学者认为水道—堤岸系统主要由洪水持续供给形成的异重流形成[89,127];在陆相湖盆中,已报导的重力流水道—堤岸沉积多与洪水持续供给形成的异重流密切相关[21,28,41]。重力流水道的形成演化及其几何学特征的研究还存在诸多问题[168],特别是陆相湖盆不同成因的重力流沉积其水道发育特征及差异对比研究可能是下一个研究亮点。

    Figure 8.  Formation and evolution processes of gravity flow channel (modified from Fildani et al. [164])

  • 不同成因重力流砂体的形成和分布受盆地内部因素和盆地外部因素综合控制,盆地外部因素主要控制物质成分和来源,而盆地内部因素主要控制重力流分异效率,最终决定了盆地重力流沉积类型及分布特征[48,71,89,136,169171]图9)。

    Figure 9.  The controlling factors of the distribution of gravity flow deposits in lacustrine basin[170]

  • 现代和古代重力流沉积系统研究表明,构造活动、沉积物供给和气候与海(湖)平面的相互作用关系是控制重力流形成及分布的主要盆外因素[48]。构造活动的强弱决定了物源区与沉积盆地的地形高差,一方面决定了汇水区流体的流量和流速,另一方面可以作为沉积物垮塌的触发机制,进而控制了搬运沉积物的大小和重力流发生的频率[172173]。物源区的性质决定了其抗风化剥蚀的能力及其供给沉积物的类型,从而决定了沉积物的搬运形式和沉积体的发育规模[136]。气候变化一方面控制了风化剥蚀速率和汇水区流量,另一方面决定了相对海(湖)平面的高低,从而决定了沉积物的搬运形式和沉积体的分布位置[20,174]。不同的控制因素在不同的深水重力流沉积系统中起着不同的控制作用,如何确定重力流形成及分布的主控因素仍然有待系统的对比分析工作[48]

  • 沉积盆地水体密度、地形坡度及盆底地貌则是决定重力流形成及分布的主要盆内因素[130]。盆地水体密度大小决定其与洪水持续供给流体之间的密度差,从而控制了异重流的形成及演化过程,特别是决定了浮力反转机制作用下的漂浮沉积是否发生,例如,当异重流中的水体密度与沉积盆地水体密度相近时,漂浮相(lofting)一般不发育[127]。地形坡度主要控制了重力流搬运演化过程中的流体分异效率,从而决定了重力流砂体的分布特征及岩相分异规律[95,130],这也是造成如陆相断陷盆地陡坡带深水重力流沉积以粗碎屑和细碎屑混杂堆积为主,而缓坡带深水重力流沉积中粗碎屑与细碎屑分异显著的原因。盆底地貌则控制了重力流沉积物最终的卸载场所和卸载方式,从而决定了重力流砂体的沉积特征和分布规律[74,175],重力流总是沿着盆底相对低部位优先搬运沉积。

  • 无论是盆地外部因素还是内部因素,都不可能独立作用影响重力流砂体的形成和分布,如气候变化导致降雨量的增加促使汇水盆地的流量增加,搬运沉积物的能力增强,从而有利于异重流的形成[136];同时,降雨对沉积盆地水体密度的稀释作用可能会导致异重流搬运演化过程中的漂浮作用不发育[20]。因此,不同的控制因素之间总是互相影响、彼此联系,试图明确某一控制因素对重力流砂体形成和分布的单一影响十分困难[48];通过不同控制因素的综合分析来探究其综合作用下的重力流砂体形成和分布规律是目前可行的思路,即现今时髦的“源—汇”系统控制下的重力流砂体分布规律研究[98,176]。核心思想是将盆外与盆内因素对重力流沉积形成和分布的控制作用综合到“源—汇”系统演化的框架内,通过“源—汇”系统类型及演化的研究,来探究重力流砂体形成及分布规律[176]图10)。例如,具有不同类型及面积汇水盆地(drainage basin)的物源区,其形成的重力流砂体的类型和分布存在显著差异,单一汇水路径的物源区,多形成单一朵叶形态的重力流砂体;多汇水路径叠合的物源区,其形成的重力流砂体具有多朵叶叠合的特征[71]。“源—汇”系统控制下的重力流砂体形成演化过程及分布规律研究的相关工作初现端倪,具有广阔的探索前景。

    Figure 10.  The formation and evolution process of gravity⁃flow deposits, with the control of source to sink system[172]

  • 重力流砂体沉积分布模式研究旨在建立普适性的重力流砂体分布预测途径,从早期风靡一时的扇模式到深水斜坡模式再到基于沉积构型要素组合的沉积分布模式研究揭示了重力流砂体分布的复杂性,普适性的沉积模式可能并不存在[8990,177]。通过重力流沉积构型要素的系统解析,以沉积构型要素组合特征来刻画重力流砂体的分布规律无论是在现代重力流沉积还是在古代重力流沉积中都能较好适用,是目前重力流砂体分布模式主要的研究思路[89,100,178]图11)。就陆相湖盆而言,基于重力流砂体成因和分布的研究揭示重力流砂体可以划分为两种主要的沉积模式,即沉积物再搬运成因沉积模式和洪水持续供给成因沉积模式[11,33,46]。洪水持续供给成因沉积模式从重力流沉积构型要素的角度考量,主要包含峡谷、侵蚀凹槽、重力流水道—堤岸沉积、水道—朵叶转换带沉积、朵叶沉积等沉积构型要素,从沉积近端到沉积远端,重力流水道—堤岸沉积、水道—朵叶转换带和朵叶沉积依次过渡构成其典型沉积构型要素组合,整体扇体形态显著[28,179]图12a)。沉积物再搬运成因沉积模式从重力流沉积构型要素的角度考量,主要包含侵蚀凹槽、三角洲前缘垮塌带、朵叶沉积、混杂沉积等沉积构型要素,从沉积近端到沉积远端,三角洲前缘垮塌带、混杂沉积和朵叶沉积依次过渡构成其典型沉积构型要素组合,整体扇体形态不突出[15,154]图12b)。陆相湖盆中不同成因的重力流砂体的沉积构型要素组成及其组合关系还有待大量沉积实例的进一步验证,特别是沉积物再搬运成因沉积中重力流水道—堤岸沉积构型要素是否发育的问题还有待进一步深入研究[180]

    Figure 11.  The depositional architecture elements of deep⁃water gravity⁃flow deposits[89]

    Figure 12.  The depositional and distribution model of deep⁃water gravity⁃flow deposits

  • 研究方法和研究手段的进步是理论认识不断深入的动力源泉,重力流沉积相关理论认识的进步与近年来重力流沉积研究中兴起的水槽模拟实验研究、数值模拟实验研究和深水实际监测研究存在密切的联系[97,181186]。如水槽模拟实验再现了超临界流体底形的形成过程,为理解深水超临界浊流形成演化及沉积特征提供了可靠依据[105];数值模拟实验研究证实了在浊流底部的流体分层作用能够抑制沉积物的搬运改造,是块状砂岩形成的主要原因[187];深水实际监测研究记录了自然界的重力流真实搬运演化过程,为深水超临界流发育和重力流形成演化新认识的研究提供了可靠证据[65,181,188189],同时揭示了漂浮羽流卸载是深水重力流重要的成因机制[128129]。当然,在使用上述新的研究方法时也需要认识到相关研究方法存在的不足,水槽模拟实验研究主要受限于边界条件与研究尺度同实际沉积的可比性,相对小尺度的水槽模拟实验研究可能缺失了部分实际地质条件下的流体参数及演化过程信息[35];数值模拟实验研究受纳维—斯托克斯方程的限制,对浊流的底床载荷搬运及流体侵蚀作用的刻画效果不佳[183];深水实际监测则主要针对现今的相对低密度流体,受重力流破坏性的限制,对相关高密度流体的观测还十分困难。此外,现今地质条件与地质历史时期地质条件的差异也是需要考虑的问题[89,97,136]。综上,传统的野外露头、钻井资料和地震资料在陆相湖盆深水重力流沉积的研究中仍然不可替代,传统方法研究与新技术方法研究的结合能够为重力流相关研究提供更广阔的思路。

  • 湖相重力流相关沉积是非常规油气沉积学的核心研究内容之一,它广泛发育于我国东部及中西部陆相湖盆,是致密油气与页岩油气等非常规油气赋存的主要场所[12]。一方面,作为事件沉积的一种重要表现形式,重力流能够将相对粗粒的碎屑颗粒搬运到深水盆地沉积,形成典型的“泥包砂”沉积组构;这些重力流粗碎屑沉积由于与优质烃源岩紧邻,利于油气的富集,是我国陆相湖盆致密油气最重要的发育场所[1011,25]。如,东营凹陷北部陡坡带沙河街组四段以近岸水下扇沉积为主的致密油气[1]、东营凹陷洼陷带沙河街组三段以砂质碎屑流和浊流沉积为主的致密油气[11]、鄂尔多斯盆地延长组以砂质碎屑流沉积为主的致密油气[10,25,56]、松辽盆地白垩系嫩江组以异重流沉积为主的致密油气[28]

    另一方面,陆相湖盆深水细粒沉积广泛发育,蕴藏了丰富的页岩油气;除了传统的悬浮沉积成因外,深水重力流作为细粒沉积的重要成因机制逐步受到重视[3536,39,76,126,128129,147,190192]。细粒沉积物在黏土矿物和生物胞膜外聚合物等作用下通过絮凝的方式可形成相对大颗粒的絮凝粒,以重力流的形式沿盆地底部发生长距离搬运[190192],对深水细粒沉积物和有机质的富集意义重大[126]。此外这种以漂浮羽流卸载沉降形成的重力流突破了传统重力流形成触发机制的要求,具有长时间稳定发育的典型特征,为细粒沉积物和有机质的大量富集提供了合理的沉积学解释[128129,145,147]。同时,细粒重力流由于其流体物质组成富含黏土矿物和有机质,其沉积物特征、搬运演化过程及分布规律都与传统粗粒重力流之间存在明显差异[119122,125126,192193]。除了熟知的细粒碎屑流沉积(图13a)与细粒浊流沉积以外(图13b,f);在黏土矿物和有机质综合作用下,细粒重力流在搬运过程中更易发生湍流抑制作用导致浊流向泥质碎屑流转化[119121,125126],形成重力流混合事件层(图13c,d)或砂泥条带状频繁互层的碎屑流与浊流过渡流体沉积(图13e,g)。流体转化成因的细粒沉积具有易于油气生成和富集,且易于压裂的先天优势[76,148],可能是页岩油气中的“甜点”区发育的优势沉积岩相组合类型。现阶段关于重力流混合事件层与过渡流体沉积同页岩油气富集之间的关系还尚不明确,相关研究可能会为细粒非常规油气勘探开发提供新的思路[148]

    Figure 13.  Deep⁃water fine⁃grained gravity⁃flow deposits in the Chang 7 Formation, Ordos Basin

  • (1) 加强砂质碎屑流、高密度浊流、异重流、混合流、超临界浊流等术语内涵及其相互关系的理解能够增强对陆相湖盆重力流流体类型的认识。对沉积砂体相关术语的理解需要从重力流沉积构型要素及其组合关系来综合分析,增加不同术语的解释说明是减少术语混淆的有效途径。

    (2) 陆相湖盆重力流搬运过程中会发生碎屑流与浊流的相互转化及超临界态浊流与亚临界态浊流的相互转化,滑水作用和基底润湿作用是导致碎屑流向深水盆地长距离搬运而不发生转化的主要原因。除了悬浮沉降和块状固结沉降方式,受阻沉降、湍流抑制及牵引毯作用是湖盆重力流砂质沉积物重要的沉降机制。陆相湖盆深水重力流主要包含沉积物再搬运、洪水持续供给、漂浮羽流卸载等成因机制,重力流沉积岩相类型—岩层类型—岩相组合类型—相域类型的系统解析、块状砂岩内部沉积特征精细解析和逆正粒序沉积特征分析,都能够为重力流沉积成因分析提供有效信息。

    (3) 陆相湖盆中重力流水道的形成主要受超临界浊流侵蚀作用控制,盆地外部因素主要控制重力流物质成分和来源,而盆地内部因素主要控制重力流分异效率,其综合表现形式即“源—汇”系统控制下的重力流砂体形成演化过程。洪水持续供给成因沉积模式,从沉积近端到沉积远端,重力流水道—堤岸沉积、水道—朵叶转换带和朵叶沉积依次过渡构成其典型沉积构型要素组合,整体扇体形态显著;沉积物再搬运成因沉积模式,从沉积近端到沉积远端,三角洲前缘垮塌带、混杂沉积和朵叶沉积依次过渡构成其典型沉积构型要素组合,整体扇体形态不突出。

    (4) 陆相湖盆重力流沉积研究在传统的野外露头、钻井资料和地震资料研究基础上应加强水槽模拟实验、数值模拟实验和深水实际监测综合研究,通过不同盆地性质(断陷盆地、坳陷盆地、前陆盆地)重力流沉积的综合对比研究,可望深化湖盆重力流沉积相关理论认识。

    (5) 湖盆重力流沉积形成的粗碎屑沉积和伴生的细粒沉积是致密油气、页岩油气赋存的重要场所,流体转化成因的细粒沉积具有易于油气生成和富集,且易于压裂的先天优势,可能是页岩油气中的“甜点”区发育的优势沉积岩相组合类型。

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