南黄海中部泥质区沉积物碎屑锆石U-Pb年龄物源判别  

Detrital zircon U-Pb age and provenance discrimination in sediments of the central mud area in the South Yellow Sea

作　　者：王忠蕾 陆凯[1,3] 孙军 张勇 朱晓青[1,2] 胡刚 何梦颖 黄湘通 密蓓蓓[1] WANG Zhonglei;LU Kai;SUN Jun;ZHANG Yong;ZHU Xiaoqing;HU Gang;HE Mengying;HUANG Xiangtong;MI Beibei(Qingdao Institute of Marine Geology,CGS,Qingdao 266237,China;Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;School of Geography,Nanjing Normal University,Nanjing 210023,China;School of Ocean and Earth Science,Tongji University,Shanghai 200092,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,青岛266237 [2]青岛海洋科学与技术试点国家实验室,青岛266237 [3]中国海洋大学海洋地球科学学院,青岛266100 [4]南京师范大学地理科学学院,南京210023 [5]同济大学海洋与地球科学学院,上海200092

出　　处：《海洋地质与第四纪地质》2022年第5期70-82,共13页Marine Geology & Quaternary Geology

基　　金：青岛海洋科学与技术试点国家实验室山东省专项经费(2022QNLM05032);中国地质调查局海洋地质调查专项(DD20221710)。

摘　　要：对南黄海中部泥质区南侧4个表层沉积物和SYS90-1A孔中5个沉积物样品进行碎屑锆石U-Pb定年,具体分析了研究区表层沉积物物源差异及约1.0 Ma以来沉积物物源变化。结果显示,泥质区沉积物主要来自黄河,而泥质区外部南侧沉积物可能主要由长江供应。SYS90-1A孔主要记录了早更新世晚期以来的沉积记录,不同时期物源差异明显:中更新世早期以长江源物质为主,利用磁化率开展旋回地层学分析,根据天文年代调谐确定该时期具体时代为0.59~0.71 Ma;早更新世晚期至中更新世以及中更新世中期以来以黄河源物质为主。这一结果与前人关于南黄海早更新世以来沉积物以黄河源物质为主的认识不同,长江源物质对南黄海泥质区沉积物贡献需要重新认识。上述表层沉积物样品和钻孔沉积物样品碎屑锆石U-Pb年龄分布与朝鲜半岛河流沉积物完全不同,说明该区域自早更新世晚期以来沉积物主要来自中国大陆。Detrital zircons taken from four surface sediments and five sediment samples from SYS90-1A borehole in the southern part of the central mud area of the South Yellow Sea was U-Pb dated and their provenances were discriminated,based on which the changes since about 1.0 Ma in the provenance of the sediment samples were analyzed.Results show that the sediments in the mud area are mainly from the Yellow River,and the sediments in the south of the mud area may be transported by the Yangtze River.The borehole SYS90-1A mainly records the deposits since the late Early Pleistocene,showing obvious provenance differences in different stages.In the early Middle Pleistocene,the sediments were mainly transported from the Yangtze River;and cyclic stratigraphy that was determined based on magnetic susceptibility and astronomical chronology tuning showed that the specific time of the stage is 590~710 ka.From the late early Pleistocene to the middle Pleistocene and since the middle Pleistocene,the sediments were mainly from the Yellow River.This result is different from the previous understanding that the sediments in the South Yellow Sea since the Early Pleistocene were mainly derived from the Yellow River,and the contribution of the sediments from the Yangtze River to the mud area needs to be re-recognized.The detrital zircon U-Pb age distribution of all samples is completely different from that of the fluvial sediments of the Korean Peninsula,indicating that the sediments in this area are mainly from China's Mainland since the late Early Pleistocene.

关 键 词：中部泥质区 碎屑锆石U-PB年龄 物源判别 南黄海 

分 类 号：P736[天文地球—海洋地质]