沉积环境对雅浦海沟沉积颗粒物组成和分布的影响  

Influence of sedimentary environment on composition and distribution of sediments in the Yap Trench

作　　者：吴彬 李栋[1,2] 赵军[1,2] 刘诚刚[1,2] 孙承君[3] 陈建芳[1,2] 潘建明[1,2] 韩正兵[1,2] 胡佶[1,2] Wu Bin;Li Dong;Zhao Jun;Liu Chenggang;Sun Chengjun;Chen Jianfang;Pan Jianming;Han Zhengbing;Hu Ji(Laboratory of Marine Ecosystem and Environment,Second Institute of Oceanography,State Oceanic Administration,Hangzhou 310012,China;Key laboratory of Marine Ecosystem and Biogeochemistry,State Oceanic Administration,Hangzhou 310012,China;Marine Ecology Center,The First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,China)

机构地区：[1]国家海洋局第二海洋研究所海洋生态与环境实验室,浙江杭州310012 [2]国家海洋局海洋生态系统与生物地球化学重点实验室,浙江杭州310012 [3]国家海洋局第一海洋研究所海洋生态中心,山东青岛266061

出　　处：《海洋学报》2018年第10期167-179,共13页

基　　金：国家自然科学基金青年科学基金项目(41606090);国家重点基础研究发展计划(973计划)项目(2015CB755904);国家海洋局第二海洋研究所基本科研业务费专项(JG1516)

摘　　要：通过对西太平洋雅浦海沟不同水深沉积物中总有机碳(TOC)、总氮(TN)、碳稳定同位素(δ^(13)C)、粒度组成和比表面积(SSA)等参数的分析,探讨了雅浦海沟不同水深沉积颗粒物来源、分布及其影响因素的异同。结果表明,雅浦海沟沉积物TOC含量和δ^(13)C平均值分别为(0.34%±0.14%)和(-20.8‰±0.7‰),其中海洋浮游植物、陆源土壤和维管植物来源有机碳(OC)的贡献分别为(70%±3%)、(22%±3%)和(8%±2%),且不同水深差异不大,海沟内沉积物的横向输运可能是深部沉积OC的重要输入途径。由于水深更深站位沉积颗粒物中具有更强的微生物活动和在水柱中更长的保留时间,导致其TOC和TN含量较低,但δ^(13)C无明显差异。水深较浅站位TN含量、SSA、粒径组成和中值粒径等参数垂向变化波动较更深站位更为显著,表明海沟沟壁水深较浅处物源输入和沉积环境的不稳定。同时,由于低OC含量、低SSA以及高密度的海底火山喷出岩在海沟水深较浅的沟壁坡折处的广泛分布,导致该区域粒径组成与TOC含量无显著相关性,而较深站位中TOC含量与粉砂呈正相关,与砂和黏土含量呈负相关。整体而言,雅浦海沟沉积物中粉砂粒级颗粒物是OC的主要载体,而SSA是影响海沟沉积OC剖面分布的最重要因素。The total organic carbon(TOC),total nitrogen(TN),stable carbon isotope(δ13 C),grain size composition and specific surface area(SSA)in sediment cores from different water depths in the southern Yap Trench(West Pacific Ocean)were measured in order to study the differences of sources,distributions of sedimentary particles and influencing factors.The average TOC content andδ13 C of Yap Trench sediments were around(0.34%±0.14%)and(-20.8‰±0.7‰),and the proportions of marine phytoplankton-,terrestrial soil-and vascular plant-derived organic carbon(OC)were(70%±3%),(22%±3%)and(8%±2%),respectively.No remarkable difference were found between these two sediment cores,which probably indicating lateral transportation was the major pathway of sediment inputs in the deeper Yap Trench.Due to stronger microbial activity and longer retention time of sedimentary particles,TOC and TN contents were pretty lower in deeper site,but no remarkable difference inδ13 C value between two sites.The vertical variations of TN content,SSA,grain size composition and median grain size in the shallower site were more drastic than those in the deeper site,suggesting unstable sedimentary particle inputs and sedimentary environment in shallower trench slope region.Widespread distribution of basalt lava with much lower OC content and SSA and higher density in the shallower break area of trench slope,lead to poor correlations between particle size compositions and TOC content in shallower site.Oppositely,it showed significantly positive relationship between TOC content and silt%and negative relationship with clay%and sand%in deeper site.Generally,silt-sized sedimentary particle probably was the major carrier of OC in the Yap Trench,and SSA value was the most important factor affecting the vertical profile of sedimentary OC in the trench.

关 键 词：雅浦海沟 沉积有机碳 来源 分布 比表面积 粒度 

分 类 号：P736.21[天文地球—海洋地质]