摘要
正常海相沉积物中普遍存在有机质硫酸盐还原作用(OSR),但在冷泉区,硫酸盐还原-甲烷厌氧氧化作用(SR-AOM)则占据主导地位。如何区分这两种硫酸盐还原途径,对研究极端环境下的生物地球化学过程具有重要意义。为进一步概括、了解冷泉区与SR-AOM相关的自生矿物的多硫同位素特征及其建模应用,在广泛调研国内外与SR-AOM相关的多硫同位素研究成果的基础上,综述了SR-AOM成因的黄铁矿和冷泉重晶石的多硫同位素特征。在此基础上,分别针对黄铁矿和冷泉重晶石概括已被广泛应用的稳定状态盒模型和1-D反应转移模型。SR-AOM成因的黄铁矿相比OSR成因的黄铁矿具有更高的δ34S值和Δ33S值。同时,SR-AOM成因的黄铁矿的δ34S值和Δ33S值呈负相关性,不同于OSR的正相关性。此外,冷泉重晶石的负Δ33S-δ´34S相关性与受OSR控制的孔隙水硫酸盐的正相关性亦明显不同。在冷泉环境中,与SR-AOM相关的自生矿物多硫同位素特征能有效示踪该极端条件下硫同位素的演化,且有利于区分SR-AOM和OSR,这为研究极端环境下的生物地球化学过程和示踪潜在的天然气水合物矿藏提供了有效依据。
Organoclastic sulfate reduction(OSR)exists extensively within normal marine sediments,whereas,sulfate reduction coupled with anaerobic oxidation of methane(SR-AOM)are dominated process in the cold-seep areas.How to distinguish these two sulfate reduction pathways is of great significance to the study of biogeochemical processes in extreme environments.Here,in order to further understand the characteristics of multiple sulfur isotopes of authigenic minerals associated with SR-AOM in the cold seep and their modeling applications,this study conducts extensive investigations into the research results of multiple sulfur isotopes related to SR-AOM at home and abroad,mainly focusing on the multiple sulfur isotopic characteristics of pyrite and barite of SR-AOM.Based on this,the widely used steady-state box model and 1-D diagenetic reaction-transport model are proposed for pyrite and barite respectively.The pyrite of SR-AOM origin has higherδ34S andΔ33S values than that of OSR.Theδ34S andΔ33S values of pyrite formed by SR-AOM shows a negative correlation,which is different from that of OSR.The negativeΔ33S-δ´34S correlation of barite significantly different from that of OSR-induced pore water sulfate reveals a positive correlation.The multiple sulfur isotopic characteristics of authigenic minerals related to SR-AOM in the cold seep can effectively trace the evolution of sulfur isotopes and assist to distinguish SR-AOM from OSR.This provides an effective basis for further research on biogeochemical processes in extreme environments and for tracing potential gas hydrate deposits.
作者
张覃谊
邬黛黛
刘丽华
ZHANG Qinyi;WU Daidai;LIU Lihua(Key Laboratory of Gas Hydrate,Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institution of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou 510301,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2022年第3期62-75,共14页
Marine Geology & Quaternary Geology
基金
广东省基础与应用基础研究基金“南海北部冷泉区甲烷厌氧氧化(AOM)作用耦合模式研究”(2021A1515011509)
广州市科技计划“南海北部冷泉区有孔虫特征研究及其对甲烷渗漏的指示”(201904010311)
广东省促进经济发展专项资金“南海天然气水合物成藏特性研究(海洋经济发展用途)”(GDME-2018D002)。
