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Gas Hydrate Dissociation During Sea‐Level Highstand Inferred From U/Th Dating of Seep Carbonate From the South China Sea
Author(s) -
Chen Fang,
Wang Xudong,
Li Niu,
Cao Jun,
Bayon Germain,
Peckmann Jörn,
Hu Yu,
Gong Shanggui,
Cheng Hai,
Edwards R. Lawrence,
Ning Youfeng,
Jin Meng,
Huang Huiwen,
Wu Cong,
Sun Yuedong,
Chen Hong,
Zhou Yang,
Chen Duofu,
Feng Dong
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl085643
Subject(s) - clathrate hydrate , geology , carbonate , aragonite , interglacial , oceanography , seawater , methane , hydrate , dissociation (chemistry) , geochemistry , paleontology , calcite , glacial period , chemistry , organic chemistry
Gas hydrates represent a huge reservoir of methane in marine sediments, prone to dissociation in response to environmental changes. There is consensus that past events of gas hydrate dissociation in the marine environment mainly occurred during periods of low sea level. Here, we report geochemical data for 2‐m‐thick layers of seep carbonate collected from a hydrate‐bearing drill core from ~800‐m water depth in the northern South China Sea. The aragonite‐rich carbonates reveal positive δ 18 O values, confirming a genetic link with gas hydrate dissociation. Uranium‐thorium dating of seep carbonates indicates that gas hydrates at the study site dissociated between 133,300 and 112,700 years BP, hence coinciding with the Last Interglacial (MIS 5e) sea‐level highstand. We put forward the concept that a climate‐driven increase in temperature was responsible for a period of pronounced gas hydrate dissociation.