海洋地质与第四纪地质2017，Vol.37Issue(6)：100-109,10.DOI:10.16562/j.cnki.0256-1492.2017.06.011
南海北部神狐海域水合物钻探区沉积物地球化学特征
GEOCHEMISTRY OF THE SEDIMENTS IN SHENHU HYDRATE DRILLING AREA, NORTHERN SOUTH CHINA SEA
摘要
Abstract
The formation and decomposition of gas hydrate as well as the methane leakage caused by associated biogeochemical processes may change the depositional environment of the seabed.To identify the decomposition of hydrate as well as the change in marine environment caused by the seeping methane will contribute to the understanding of the processes of hydrate formation and decomposition.In this paper,we selected the Core SH3 as a case from the Shenhu hydrate drilling area in the northern part of South China Sea to study the formation and deterioration of hydrate.Carbon and sulfur contents,main and trace elements,especially redox sensitive elements are measured.Data from pore water and previous researches are also studied.The study suggests that the sediments of the Shenhu area are mainly sourced from a fluvial origin with a little of loess and felsic igneous materials.From the data of U,Mo contents and U/Mo ratio,as well as carbon and sulfur contents,it is inferred that the layers at 10～25 mbsf in the core of SH3 is mainly formed in a reduced depositional environment,resulted from sulfate reduction by the anaerobic oxidation of methane.The change in redox condition of depositional environment may lead to the fractionation of LREE/HREE and MREE/HREE in the layers.In the SH3 core sediment,there is a sub-oxidized depositional environment at the level of about 180～215 mbsf.It is supposed to be caused by the deposition of turbidites.The depositional environment of fine-grained sediments,at the same time,also leads to the fractionation of light and heavy rare earth elements.To sum up,we have succeeded in revealing material source,environment change in the Shenhu area and the specific role of hydrate-sedimentary environment in this paper and the results are very useful for understanding of the origin of gas hydrate.关键词
水合物钻探区/天然气水合物/沉积环境/神狐海域Key words
the Shenhu area/hydrate drilling area/gas hydrate/sedimentary environment分类
海洋科学引用本文复制引用
邬黛黛,谢瑞,杨睿,孙甜甜,杨飞,刘丽华,吴能友..南海北部神狐海域水合物钻探区沉积物地球化学特征[J].海洋地质与第四纪地质,2017,37(6):100-109,10.基金项目
青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室开放基金(KC201703) （KC201703）
中国石油-中科院科技合作项目(2015A-4813) （2015A-4813）
中国科学院青年创新促进会项目(2014321) （2014321）
国家自然科学基金项目(41273022) （41273022）
