Spatio-temporal relationship between two kinds of deep-water sedimentation on the Ying-Qiong slope, South China Sea

doi:10.13745/j.esf.sf.2022.10.20

Abstract

Abstract:

Large amounts of oil and gas are discovered in recent years in the Yingqiong slope deep-water area, northwestern South China Sea, demonstrating the region’s high potential for oil and gas exploration and production. Deep-water sedimentation is often controlled by various mechanisms including gravity flow and contour current. Where and when these mechanisms operate and interact, and to what extent they affect or control sedimentary patterns, can result in different understandings of the regional sedimentary facies distribution due to spatio-temporal variability of hydrodynamic properties. This in turn can complicate the determination of sand body type and distribution and thus hinder gas and oil exploration and development in the region. Based on the seismic facies and stratigraphic superimposed pattern presented by the seismic data, this paper confirms the existence of two types of Miocene sedimentary systems on the Yingqiong slope: gravity (flow) and contour current sedimentary systems. These two systems are adjacent to each other sequentially in time and space, with the former superimposing over the latter in a stepwise pattern prograding towards the slope while the latter exhibiting a retrograde pattern. The boundary between the two systems indicates a special, diachronic “facies transition” interface, and, accordingly, the spatio-temporal relationship between the two distinct sedimentary processes (gravity flow and contour current) is restored. The stepwise progradation-retrogradation relationship between the two sedimentary systems can be attributed to three factors: the abundant supply of clastic materials from a multi-directional Middle-Miocene source system; the resulting strong gravity flow activity; and contour currents induced by deep-water circulation in the South China Sea. The magnitude of gravity flow largely controls the distribution range of the contour current sedimentary system, leading to a spatio-temporal stepwise progradation-retrogradational pattern.

Key words: the South China Sea, Yingqiong slope, deep-water, gravity flow, contour current

CLC Number:

P736.21

WANG Hairong, YU Chengqian, FAN Tailiang, CHAI Jingchao, WANG Hongyu, GAO Hongfang. Spatio-temporal relationship between two kinds of deep-water sedimentation on the Ying-Qiong slope, South China Sea[J]. Earth Science Frontiers, 2023, 30(4): 196-208.

Figures/Tables 10

Fig.1 Overview of the Yingqiong slope, northern South China Sea

Table 1 Experimental parameters for seismic data acquisition and processing

震源	总容量	主频	炮间距	接收道数	道间距	采样率	记录长度	覆盖次数
G/G.I.气枪阵列	1 600 in³ (2 000 psi)	60~80 Hz	37.5 m	240	12.5 m	1 ms	9 s	40 fold

Fig.2 Framework of the deep-water sedimentary system in the Yingqiong slope area. The sedimentary system can be divided into two types-gravity flow and contourite depositional systems. The inserted figure shows the geographical location of the study area.

Fig.3 Seismic response characteristics of gravity flow deposits in the Yingqiong slope deep-water area. See Fig.2 for section location.

Fig.4 Seismic response characteristics of contourites in deep-water area of the Yingqiong slope. See Fig.1 for section locations.

Fig.5 Seismic profiles. (A) Composite seismic profile along two intersecting survey lines. The most remarkable feature is that contourites are gradually buried in steps by gravity flow deposits, and this process ceases at the most active contourites on the right. (B) Enlarged profile. The five horizons identified in the gravity flow depositional system are cut off at the intersection with the contourite depositional system, which indicate a stepwise progradation-retrogradation relationship between the two sedimentary systems. See Fig.8 for section location.

Fig.6 Seismic profiles of the study area. (A) East-west seismic profile. Bounded by the channel units of contourites in the middle of the profile, contourites on the left are buried by gravity flow de-posits from the west and the north. Whereas on the right, there are still active contourites on the seabed. (B, C) Enlarged profiles. See Fig. 8 for section location.

Fig.7 Ordered spatio-temporal distribution of two kinds of sedimentary systems. A, B and C are three east-west seismic profiles arranged in sequence from north to south (refer to D for section locations). The shaded areas represent gravity flow deposits. The change of sediment thickness between different sections indicates the orderly southward progradation of gravity flow and the orderly forced southward retrogradation of contourites.

Fig.8 Temporo-spatial relationship between the two depositional processes or systems

Fig.9 Spatio-temporal correlation model between two types of deposition modes in the study area, showing geological changes through stages A, B and C in chronological order.

References 42

[1]	MASSÉ L, FAUGÈRES J C, HROVATIN V. The interplay between turbidity and contour current processes on the Columbia Channel fan drift, Southern Brazil Basin[J]. Sedimentary Geology, 1998, 115(1/2/3/4): 111-132. DOI URL
[2]	ELLIOTT G M, PARSON L M. Influence of sediment drift accumulation on the passage of gravity-driven sediment flows in the Iceland Basin, NE Atlantic[J]. Marine and Petroleum Geology, 2008, 25(3): 219-233. DOI URL
[3]	MCCAVE I N. Formation of sediment waves by turbidity currents and geostrophic flows: a discussion[J]. Marine Geology, 2017, 390: 89-93. DOI URL
[4]	ANSELMETTI F S, EBERLI G P, DING Z D. From the Great Bahama Bank into the Straits of Florida: a margin architecture controlled by sea-level fluctuations and ocean currents[J]. Geological Society of America Bulletin, 2000, 112(6): 829-844. DOI URL
[5]	RASMUSSEN S, LYKKE-ANDERSEN H, KUIJPERS A, et al. Post-Miocene sedimentation at the continental rise of Southeast Greenland: the interplay between turbidity and contour currents[J]. Marine Geology, 2003, 196(1/2): 37-52. DOI URL
[6]	SEJRUP H P, HAFLIDASON H, HJELSTUEN B O, et al. Pleistocene development of the SE Nordic Seas margin[J]. Marine Geology, 2004, 213(1/2/3/4): 169-200. DOI URL
[7]	MULDER T, LECROART P, HANQUIEZ V, et al. The western part of the Gulf of Cadiz: contour currents and turbidity currents interactions[J]. Geo-Marine Letters, 2006, 26(1): 31-41. DOI URL
[8]	HABGOOD E L, KENYON N H, MASSON D G, et al. Deep-water sediment wave fields, bottom current sand channels and gravity flow channel-lobe systems: gulf of Cadiz, NE Atlantic[J]. Sedimentology, 2003, 50(3): 483-510. DOI URL
[9]	GONG C L, WANG Y M, REBESCO M, et al. How do turbidity flows interact with contour currents in unidirectionally migrating deep-water channels?[J]. Geology, 2018, 46(6): 551-554. DOI URL
[10]	NORMANDEAU A, CAMPBELL D C, CARTIGNY M J B. The influence of turbidity currents and contour currents on the distribution of deep-water sediment waves offshore eastern Canada[J]. Sedimentology, 2019, 66(5): 1746-1767. DOI URL
[11]	ERCILLA G, JUAN C, PERIÁÑEZ R, et al. Influence of alongslope processes on modern turbidite systems and canyons in the Alboran Sea (southwestern Mediterranean)[J]. Deep Sea Research Part I: Oceanographic Research Papers, 2019, 144: 1-16. DOI URL
[12]	FAUGÈRES J C, GONTHIER E, MULDER T, et al. Multi-process generated sediment waves on the Landes Plateau (Bay of Biscay, North Atlantic)[J]. Marine Geology, 2002, 182(3/4): 279-302. DOI URL
[13]	CHEN H J, ZHAN W H, LI L Q, et al. Occurrence of submarine canyons, sediment waves and mass movements along the northern continental slope of the South China Sea[J]. Journal of Earth System Science, 2017, 126(5): 1-28. DOI URL
[14]	WANG D X, WANG Q, CAI S Q, et al. Advances in research of the mid-deep South China Sea circulation[J]. Science China Earth Sciences, 2019, 62(12): 1992-2004. DOI
[15]	WANG H R, YU C Q, HUO Z P. Origin of deep-water sediment wave fields in the Northern Continental Slope, South China Sea[J]. Arabian Journal of Geosciences, 2021, 14(13): 1233. DOI
[16]	王海荣. 南海北部大陆边缘深水沉积过程-响应及其主控因素[D]. 北京: 中国石油大学(北京), 2007.
[17]	孙启良, 解习农, 吴时国. 南海北部海底滑坡的特征、灾害评估和研究展望[J]. 地学前缘, 2021, 28(2): 258-270. DOI
[18]	SUN Q L, CARTWRIGHT J, LÜDMANN T, et al. Three-dimensional seismic characterization of a complex sediment drift in the South China Sea: evidence for unsteady flow regime[J]. Sedimentology, 2017, 64(3): 832-853. DOI URL
[19]	张功成, 贾庆军, 王万银, 等. 南海构造格局及其演化[J]. 地球物理学报, 2018, 61(10):4194-4215.
[20]	王海荣, 王英民, 邱燕, 等. 南海北部陆坡的地貌形态及其控制因素[J]. 海洋学报, 2008, 30(2): 70-79.
[21]	王海荣, 王英民, 邱燕, 等. 南海北部大陆边缘深水环境的沉积物波[J]. 自然科学进展, 2007, 17(9):1235-1243.
[22]	FAUGÈRES J C, STOW D A V, IMBERT P, et al. Seismic features diagnostic of contourite drifts[J]. Marine Geology, 1999, 162(1): 1-38. DOI URL
[23]	REBESCO M, HERNÁNDEZ-MOLINA F J, VAN ROOIJ D, et al. Contourites and associated sediments controlled by deep-water circulation processes: state-of-the-art and future considerations[J]. Marine Geology, 2014, 352: 111-154. DOI URL
[24]	庞雄, 陈长民, 邵磊, 等. 白云运动: 南海北部渐新统-中新统重大地质事件及其意义[J]. 地质论评, 2007, 53(2):145-151.
[25]	庞雄. 深水重力流沉积的层序地层结构与控制因素: 南海北部白云深水区重力流沉积层序地层学研究思路[J]. 中国海上油气, 2012, 24(2):1-8.
[26]	任建业, 雷超. 莺歌海-琼东南盆地构造-地层格架及南海动力变形分区[J]. 地球物理学报, 2011, 54(12):3303-3314.
[27]	林畅松, 张燕梅, 李思田, 等. 中国东部中新生代断陷盆地幕式裂陷过程的动力学响应和模拟模型[J]. 地球科学:中国地质大学学报, 2004, 29(5): 583-588.
[28]	李思田, 林畅松, 张启明, 等. 南海北部大陆边缘盆地幕式裂陷的动力过程及10 Ma以来的构造事件[J]. 科学通报, 1998, 43 (8): 797-809..
[29]	CHE PERCY P H, Chen Z Y, Zhang Q M. Sequence stratigraphy and continental margin development of the northwestern shelf of the South China Sea[J]. AAPG Bulletin, 1993, 77(5): 842-862.
[30]	马畅, 葛家旺, 赵晓明, 等. 南海北部琼东南盆地第四系陆架边缘轨迹迁移及深水沉积模式[J]. 地学前缘, 2022, 29(4): 55-72. DOI
[31]	ZHAO Q H, LI Q Y, JIAN Z M. Deep Waters and Oceanic Connection[M]// WANG P, LI Q. The South China Sea. Dordrecht: Springer, 2009: 395-437.
[32]	XIE Q, XIAO J G, WANG D X, et al. Analysis of deep-layer and bottom circulations in the South China Sea based on eight quasi-global ocean model outputs[J]. Chinese Science Bulletin, 2013, 58(32): 4000-4011. DOI URL
[33]	FAUGHN J L. NAGA Report, vol. 1, Scientific results of marine investigations of the South China Sea and the Gulf of Thailand 1959-1961[R]. La Jolla, California: Scripps Institution of Oceanography, 1974: 1-177.
[34]	LÜDMANN T. Upward flow of North Pacific Deep Water in the northern South China Sea as deduced from the occurrence of drift sediments[J]. Geophysical Research Letters, 2005, 32(5): L05614.
[35]	ZHU M Z, GRAHAM S, PANG X, et al. Characteristics of migrating submarine canyons from the middle Miocene to present: implications for paleoceanographic circulation, northern South China Sea[J]. Marine and Petroleum Geology, 2010, 27(1): 307-319. DOI URL
[36]	LI Q Y, ZHAO Q H, ZHONG G F, et al. Deepwater ventilation and stratification in the Neogene South China Sea[J]. Journal of China University of Geosciences, 2007, 18(2): 95-108. DOI URL
[37]	谢玲玲. 西北太平洋环流及其与南海水交换研究[D]. 青岛: 中国海洋大学, 2009.
[38]	LEI C, ALVES T M, REN J Y, et al. Rift structure and sediment infill of hyperextended continental crust: insights from 3D seismic and well data (Xisha trough, South China Sea)[J]. Journal of Geophysical Research: Solid Earth, 2020, 125(5): e2019JB018610.
[39]	苏明, 李俊良, 姜涛, 等. 琼东南盆地中央峡谷的形态及成因[J]. 海洋地质与第四纪地质, 2009, 29(4): 85-93.
[40]	姚根顺, 袁圣强, 吴时国, 等. 琼东南盆地深水区双物源沉积模式及勘探前景[J]. 石油勘探与开发, 2008, 35(6):685-691.
[41]	吕明. 莺-琼盆地低位沉积模式的新探讨[J]. 中国海上油气(地质), 2002, 16(4):222-230.
[42]	卓海腾, 王英民, 徐强, 等. 南海北部莺歌海盆地东方区上新统侧积复合体沉积特征及成因[J]. 古地理学报, 2013, 15(6):787-794.