Cold seep systems in the South China Sea: An overview

Three decades after the discovery of cold seep systems, various sites of hydrocarbon seepage have been found in the South China Sea (SCS). Over the past decade, these sites have become model systems for understanding the variability of hydrocarbon seepage and associated biogeochemical processes. In...

Full description

Bibliographic Details
Published in:Journal of Asian Earth Sciences
Main Authors: Feng, Dong, Qiu, Jian-Wen, Hu, Yu, Peckmann, Joern, Guan, Hongxiang, Tong, Hongpeng, Chen, Chong, Chen, Jiangxin, Gong, Shanggui, Li, Niu, Chen, Duofu
Format: Report
Language:English
Published: PERGAMON-ELSEVIER SCIENCE LTD 2018
Subjects:
Hydrocarbon seep
Methane
Chemosynthesis
Hydrate
Carbonate
Mud volcano
Pockmark
South China Sea
DRIVEN ANAEROBIC OXIDATION
SULFUR ISOTOPE FRACTIONATION
NORTHERN CONTINENTAL-SLOPE
METHANE TRANSITION ZONE
AUTHIGENIC CARBONATES
GAS HYDRATE
SULFATE REDUCTION
MUD VOLCANOS
LIPID BIOMARKER
FLUID SOURCES
Geology
Geosciences
Multidisciplinary
Methane hydrate
Online Access:http://ir.giec.ac.cn/handle/344007/29806
https://doi.org/10.1016/j.jseaes.2018.09.021
Description
Summary:Three decades after the discovery of cold seep systems, various sites of hydrocarbon seepage have been found in the South China Sea (SCS). Over the past decade, these sites have become model systems for understanding the variability of hydrocarbon seepage and associated biogeochemical processes. In this review, we describe the cold seep systems of the SCS with an emphasis on seafloor manifestations, fluid sources, biogeochemical processes, and macroecology. Seafloor features associated with seeps include mud volcanoes, pockmarks, and carbonate deposits. A common characteristic of cold seeps is the occurrence of authigenic (i.e., in situ precipitated) carbonate minerals. These carbonates commonly exhibit low delta C-13 and high delta O-18 values, suggesting the incorporation of methane-derived carbon and oxygen derived from gas hydrate water. Biogeochemical processes such as sulfate-driven anaerobic oxidation of methane (SD-AOM), the key process at seeps, have been studied in detail with the aim of establishing geochemical proxies to trace these processes into the geological past. We also detail the features characterizing seep ecosystems. Understanding the impact of decomposing methane hydrate on the marine carbon budget remains challenging and requires additional seafloor observations as well as models predicting how gas hydrate responds to changing conditions such as temperature increase, sea level rise, and episodic mass wasting.

Similar Items