Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea

doi:10.1016/j.dsr2.2015.11.007

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院油气资源研究重点实验室

	Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea
	Chen, Jiangxin 1,2; Song, Haibin 3; Guan, Yongxian 4; Yang, Shengxiong 4; Pinheiro, Luis M.5,6; Bai, Yang 3; Liu, Boran 1,2; Geng, Minghui 3
刊名	DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
	2015-12-01
卷号	122 页码:106-117
关键词	Gully Crescent Pockmark Sediment Deformation Fluid Flow South China Sea
DOI	10.1016/j.dsr2.2015.11.007
文献子类	Article
英文摘要	Based on new high-resolution multi-beam bathymetry and multichannel seismic reflection data, two new groups of numerous pockmarks and mud volcanoes were discovered in the northern Zhongjiannan Basin at water depths between 600 and 1400 m. Individual pockmarks are circular, elliptical, crescent-shaped or elongated, with diameters ranging from several hundreds to thousands of meters and tens or hundreds of meters in depth, and they often form groups or strings. Crescent pockmarks, approximately 500-1500 m wide in cross-section and 50150 m deep, occur widely in the southern study area, both as individual features and in groups or curvilinear chains, and they are more widespread and unique in this area than anywhere else in the world. Conical mud volcanoes, mostly with kilometer-wide diameters and ca. 100 m high, mainly develop in the northern study area as individual features or in groups. Seismic data show that the observed pockmarks are associated with different kinds of fluid escape structures and conduits, such as gas chimneys, diapirs, zones of acoustic blanking, acoustic turbidity and enhanced reflections, inclined faults, small fractures and polygonal faults. The mapped mud volcanoes appear to be fed from deep diapirs along two main conduit types: the conventional conduits with downward tapering cones and another other conduit type with a narrow conduit in the lower half and emanative leakage passages in the upper half. Various types of pockmarks are found and a comprehensive pockmark classification scheme is proposed, according to: (a) their shape in plan view, which includes circular, elliptical, crescent comet-shape, elongated and irregular; (b) their magnitude, which includes small, normal, giant and mega-pockmarks; and (c) their composite pattern, which includes composite pockmarks, pockmark strings and pockmark groups. For the genesis of the crescent pockmark (strings), a 5-stage speculative formation model is proposed, implying possible controlling factors of gravity sliding/slumping, fluid escape activity and sandbodies intrusion. Seismic data suggest that the mud volcanoes have likely undergone two episodes of evolution, which include a widespread drastic formation of mud volcanoes with dome-like structures, a wide range of seepage occurrences and the formation of complex sediments in the first stage, and the appearance of pockmarks, conical mud volcanoes (groups), and the formation of deformed, filled or broken buried complex sediments by continuous fluid flow processes during stage 2, in the Pliocene and the Quaternary. Pockmark gullies are extensively found along the slope, due to the interaction of slope failure and fluid escape processes. The Cenozoic sedimentary cover is thin in the Northern Zhongjiannan basin, which evolved from a Late Cretaceous or Palaeogene-Oligocene rift to the Neogene-Quaternary post-rift thermal subsidence, and therefore intense deep thermogenic fluid flow can easily affect the soft Cenozoic sediments, produce complex sediment deformation, and form numerous fluid flow structures at the seafloor, in particular pockmarks and mud volcanoes that dominantly emerged during the period of post-rift thermal subsidence and neotectonic movement since ca. 5.5 Ma. (C) 2015 Elsevier Ltd. All rights reserved.
WOS关键词	POLYGONAL FAULT SYSTEMS ; CONICAL SANDSTONE INTRUSIONS ; LOWER CONGO BASIN ; NORWEGIAN TRENCH ; CONTINENTAL-MARGIN ; FLOOR POCKMARKS ; OFFSHORE NORWAY ; MEGA-POCKMARKS ; BED POCKMARKS ; SCOTIAN SHELF
WOS研究方向	Oceanography
语种	英语
WOS记录号	WOS:000367106500011
资助机构	National Natural Science Foundation of China(91128205) ; National Natural Science Foundation of China(91128205) ; National Natural Science Foundation of China(91128205) ; National Natural Science Foundation of China(91128205)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/62148]
专题	地质与地球物理研究所_中国科学院油气资源研究重点实验室
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Tongji Univ, Sch Ocean & Earth Sci, State Key Lab Marine Geol, Shanghai 200092, Peoples R China 4.Guangzhou Marine Geol Survey, Guangzhou 510760, Guangdong, Peoples R China 5.Univ Aveiro, Dept Geociencias, P-3800 Aveiro, Portugal 6.Univ Aveiro, CESAM, P-3800 Aveiro, Portugal
推荐引用方式 GB/T 7714	Chen, Jiangxin,Song, Haibin,Guan, Yongxian,et al. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea[J]. DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY,2015,122:106-117.
APA	Chen, Jiangxin.,Song, Haibin.,Guan, Yongxian.,Yang, Shengxiong.,Pinheiro, Luis M..,...&Geng, Minghui.(2015).Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea.DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY,122,106-117.
MLA	Chen, Jiangxin,et al."Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea".DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY 122(2015):106-117.