自生黄铁矿指示海底甲烷渗漏  

Authigenic Pyrite Indicates Seafloor Methane Seepage

作　　者：张企盈 苗晓明 常鑫 孔凡兴 谷玉 刘喜停 ZHANG Qiying;MIAO Xiaoming;CHANG Xin;KONG Fanxing;GU Yu;LIU Xiting(Key Laboratory of Submarine Geosciences and Prospecting Technology,College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Laboratory for Marine Geology,Qingdao Marine Science and Technology Center,Qingdao 266237,China)

机构地区：[1]中国海洋大学海洋地球科学学院,海底科学与探测技术教育部重点实验室,山东青岛266100 [2]青岛海洋科技中心海洋地质过程与环境功能实验室,山东青岛266237

出　　处：《地球科学进展》2024年第6期589-601,共13页Advances in Earth Science

基　　金：国家自然科学基金项目(编号:42276060);山东省优秀青年基金项目(编号:ZR2021YQ26)资助。

摘　　要：海底甲烷渗漏是海洋环境中甲烷的重要来源,对全球碳循环和极端环境生物地球化学循环具有重要影响,示踪和重建海底(古)甲烷渗漏活动具有重要的科学意义。在甲烷渗漏活动过程中,硫酸盐驱动的甲烷厌氧氧化作用普遍发育,从而改变孔隙水地球化学特征,并导致自生矿物的形成。其中,自生黄铁矿是硫酸盐驱动的甲烷厌氧氧化作用的典型自生矿物之一,可作为记录甲烷渗漏活动的良好指标。综述了硫酸盐驱动的甲烷厌氧氧化作用衍生自生黄铁矿的地球化学特征和形貌特征,评估了其在示踪和重建海底(古)甲烷渗漏活动的潜力。结果表明,自生黄铁矿的硫和铁同位素及原位微量元素和同位素可以有效识别硫酸盐驱动的甲烷厌氧氧化作用过程,甲烷渗漏环境沉积物中自生黄铁矿的形貌和含量与正常海洋沉积物存在明显差异,彰显了自生黄铁矿示踪和重建海底(古)甲烷渗漏事件的巨大潜力。Seafloor methane seepage is an important source of methane affecting the global carbon cycle and extreme environmental biogeochemical cycles.Therefore,identifying modern and ancient seafloor methane seepage is of great scientific significance.During methane leakage,Sulfate-Driven Anaerobic Oxidation of Methane(SD-AOM)commonly occurs,changing the geochemical characteristics of pore water and forming of authigenic minerals.Authigenic pyrite is a typical authigenic mineral in SD-AOM and can be used as a good indicator for recording methane leakage.This study summarizes the geochemical and morphological characteristics of SD-AOM-derived authigenic pyrite and evaluates its potential for tracing and reconstructing seabed(paleo)methane leakage.The results show that the sulfur and Fe isotopes,as well as in situ trace elements and isotopes of authigenic pyrite,can effectively identify the SD-AOM process.In addition,significant differences are observed in the morphology and content of authigenic pyrite in sediments in these environments compared with normal marine sediments,highlighting the great potential of authigenic pyrite for tracing and reconstructing seabed(paleo-)methane leakage events.

关 键 词：甲烷渗漏 自生黄铁矿 硫同位素 微量元素 微生物硫酸盐还原 

分 类 号：P744.4[天文地球—海洋科学]