海洋地质与第四纪地质2025，Vol.45Issue(6)：103-116,14.DOI:10.16562/j.cnki.0256-1492.2025081802
冲绳海槽中北段海底冷泉活动岩石记录与过程研究
Records and analyses of submarine cold seep activity in the middle and northern Okinawa Trough
摘要
Abstract
Cold-seep carbonates serve as reliable geological archives that preserve critical information on seepage activity and paleo-marine sedimentary environments.Their mineralogical and geochemical characteristics effectively record fluid sources and composition,seepage intensity,and redox conditions during past periods of active seepage.Although cold seeps are widely distributed in the Okinawa Trough of the East China Sea,the relationship between carbonate records and paleoenvironmental changes during past active periods in this region remains poorly understood.This study focuses on carbonate crusts from the active"Guanshan"seep site in the middle and northern Okinawa Trough,employing systematic mineralogical,elemental,and isotopic geochemical analyses to elucidate the environmental conditions during carbonate formation.The results demonstrate that the cold-seep carbonate crusts are predominantly composed of aragonite(average 58.3%).All samples exhibit moderately negative δ13C values(-40.4‰ to-28.4‰)coupled with highly enriched δ18O signatures(+4.0‰ to+5.8‰),indicating a thermogenic methane source and relatively high methane flux in the study area.The formation of Guanshan cold-seep carbonates was primarily driven by sulfate-driven anaerobic oxidation of methane(SD-AOM)near the seafloor,with gas hydrate dissociation likely enhancing seepage activity.These carbonates precipitated in a relatively oxic,shallow subsurface environment.Measurements of carbon and oxygen isotopes(δ13C,δ18O),coupled with rare earth element(REE)patterns,provide key constraints on the formation models of distinct cold seep carbonates.关键词
自生碳酸盐岩/地球化学/环境重建/冷泉/冲绳海槽Key words
authigenic carbonate/geochemistry/paleoenvironmental reconstruction/cold seep/Okinawa Trough分类
海洋科学引用本文复制引用
WANG Chen,LI Ang,YANG Jinxiu,SUN Zhilei,XU Cuiling,ZHAO Li,LIU Kunyi..冲绳海槽中北段海底冷泉活动岩石记录与过程研究[J].海洋地质与第四纪地质,2025,45(6):103-116,14.基金项目
自然科学基金项目"冲绳海槽中北段海底甲烷多期次渗漏演化历史与触发机理研究"(42376069),"琼东南海域天然气水合物稳定域陆向尖灭边界处的甲烷运聚过程与机理研究"(42476070) （42376069）
泰山学者青年专家项目(TSQN202408292) （TSQN202408292）
天然气水合物勘探开发国家工程研究中心开放基金课题(NERCY[202401]) （NERCY[202401]）
地质调查项目(20240301805) （20240301805）
