17.3 ka以来冲绳海槽中南部有机质来源——对古海洋环境演化的响应  

Organic Matter Sources in the Middle Southern Okinawa Trough since 17.3 ka:A response to paleoenvironmental evolution

作　　者：邢淑晓 窦衍光[1,3] 赵京涛 蔡峰[1,4] 李清 邹亮[1] 王利波 XING ShuXiao;DOU YanGuang;ZHAO JingTao;CAI Feng;LI Qing;ZOU Liang;WANG LiBo(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao,Shandong 266071,China;China University of Geosciences(Beijing),Beijing 100083,China;Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,Shandong 266061,China;Laboratory for Marine Mineral Resource,Qingdao National Laboratory for Marine Science and Technology,Qingdao,Shandong 266061,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,山东青岛266071 [2]中国地质大学(北京),北京100083 [3]青岛海洋科学与技术国家实验室,海洋地质过程与环境功能实验室,山东青岛266061 [4]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,山东青岛266061

出　　处：《沉积学报》2022年第3期691-700,共10页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41776077);国家海洋局国际合作项目(GASI GEOGEO04)。

摘　　要：基于AMS14C测年、有机碳、氮含量及其同位素等指标分析,探讨了冲绳海槽中南部OKT-3孔末次冰消期以来沉积物有机质来源及其对古海洋环境演化的响应。结果显示,OKT-3孔沉积物中有机质主要由中国大陆和中国台湾等陆源有机质,以及海洋自生有机质组成。末次冰消期至全新世晚期(17.3~4 ka B.P.),中国大陆源有机质贡献逐渐下降,中国台湾源有机质贡献逐渐上升,表明海平面变化、黑潮变动是该阶段有机质来源的主要控制因素。4~1.5 ka期间,陆源有机质供给变化趋势与黑潮变动不一致,表明该时期陆源输入非黑潮单一控制,还可能受季风降雨等变化影响。值得注意的是,OKT-3孔海源有机质贡献在B-A和PB时期高、YD时期低,与北太平洋地区的生产力变化相似,反映了北太平洋中层水(NPIW)对海水表层生产力的控制作用,NPIW是连通冲绳海槽与北太平洋的重要纽带。A piston core(OKT-3)is collected from the middle southern Okinawa Trough(26.018°N,125.282°E)at a water depth of 1792 m,providing depositional records since 17.3 ka.Total organic carbon,total nitrogen content,and organic carbon isotope data in this study,combined with previous data,have been analyzed to discuss the organic matter source and its response to paleoenvironmental evolution since the last deglaciation.The organic component of core OKT-3 is composed of terrestrial and marine organic matter.Terrestrial organic matter is mainly derived from the Changjiang and Taiwan Rivers,which is controlled by sea level change,the Kuroshio Current,and climate variation.The Changjiang-sourced organic matter of core OKT-3 showed a decreasing trend during 17.3~4 ka B.P.,consistent with the decreasing contribution of Changjiang-derived detrital sediments.In contrast,the Taiwan-sourced organic matter,which is transported by the Kuroshio Current,showed an increasing trend.It is worth noting that the Changjiang-sourced and Taiwan-sourced organic matter did not exhibit synchronous changes with the Kuroshio Current during 4~1.5 ka B.P.,which may be controlled by summer monsoon.Marine organic matter from core OKT-3showed two peaks during B?lling-?ller?d and Pre-Boreal periods,with low values during the Younger Dryas period.Consistency between marine organic matter and primary productivity suggests that North Pacific Intermediate Water(NPIW)acts as a conveyor belt transporting nutrient from the North Pacific to the Okinawa Trough.NPIW passes through the Kerama Gap to the Okinawa Trough and carries nutrients to the surface water by way of upwelling.The consistency between marine organic matter andδ15N further suggests there may exist a link between the Okinawa Trough and the North Pacific,and NPIW may play an important role.

关 键 词：海源有机质 陆源有机质 北太平洋中层水 冲绳海槽 末次冰消期 

分 类 号：P736.21[天文地球—海洋地质]