末次冰消期(1.9万年)以来冲绳海槽中部黏土矿物来源及其环境响应  

Clay mineral provenance and its response to paleochimate in the central Okinawa Trough since the last Deglaciation(19 ka)

作　　者：田旭 胡邦琦[2,3] 王飞飞 黄威[2,3] 丁雪 宋维宇[2,3] 徐方建 TIAN Xu;HU Bangqi;WANG Feifei;HUANG Wei;DING Xue;SONG Weiyu;XU Fangjian(National Deep Sea Center,Qingdao 266237,Shandong,China;Qingdao Institute of Marine Geology,China Geological Survey,Ministry of Natural Resources,Qingdao 266071,Shandong,China;Laboratory for Marine Mineral Resources,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266071,Shandong,China;School of Geosciences,China University of Petroleum,Qingdao 266580,Shandong,China)

机构地区：[1]国家深海基地管理中心,山东青岛266237 [2]中国地质调查局青岛海洋地质研究所,山东青岛266071 [3]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266071 [4]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《中国地质》2020年第5期1501-1511,共11页Geology in China

基　　金：国家自然科学基金(41976192,41576058);黄土与第四纪地质国家重点实验室开放基金(SKLLQG1707,SKLLQG1805);中国地质调查局项目(DD20191010,DD20160137)联合资助。

摘　　要：基于采自冲绳海槽中部的CS2站柱状沉积物黏土矿物和AMS14C年代分析,探讨了末次冰消期以来冲绳海槽中部黏土矿物的物质来源及其环境指示意义。结果显示,CS2站黏土矿物以伊利石为主,其次为绿泥石,高岭石和蒙脱石含量较少。根据黏土矿物分布趋势变化,CS2站柱状沉积物可划分为3个阶段:阶段Ⅰ(19~12 ka BP)和阶段Ⅱ(12~8 ka BP)期间沉积物主要来源于长江,台湾和黄河物质也有一定影响,其物质来源主要受海平面升降的控制;阶段Ⅲ(8~0 ka BP)主要来源于长江和台湾,黄河贡献有限,主要受黑潮演化的影响。CS2站(蒙脱石+高岭石)/(伊利石+绿泥石)比值可以作为东亚季风演化的矿物学指标,指标变化显示出东亚冬季风强度相对夏季风的强度在16.4~14.8 ka BP和12.8~11.6 ka BP期间有两次显著的加强,指示当时气候相对寒冷干燥,结果可以与格陵兰冰心δ18O和三宝洞δ18O记录等很好对比。In this paper,the authors discussed the clay mineral provenances and their environmental significance since the last Deglaciation on the basis of clay minerals and AMS14C dating analysis carried out for Core CS2,which was located in the central Okinawa Trough.The results show that Core CS2 mainly consists of illite and lesser amounts of chlorite,with associated kaolinite and smectite.Downcore variability of clay mineral content allows Core CS2 to be divided into three units.The sediments were primarily derived from Changjiang with lesser amounts from Huanghe and Taiwan in unit 1(19-12 ka BP)and unit 2(12-8 ka BP),which was mainly controlled by sea level change.In unit 3(8-0 ka BP),the sediments were primarily derived from Changjiang and Taiwan,with lesser amounts from Huanghe,which was mainly controlled by Kuroshio evolution.The ratios of(smectite+kaolinite)/(illite+chlorite)at CS2 were adopted as proxies for East Asian monsoon evolution.The consistent variation of this clay proxy with those from Sanbao Caveδ18O and GISP2δ18O shows that two profound shifts of the East Asian winter monsoon intensity and the intensity of winter monsoon relative to summer monsoon occurred at 16.4-14.8 ka BP and12.8-11.6 ka BP.

关 键 词：末次冰消期 1.9万年 黏土矿物 物质来源 古环境 地质调查工程 冲绳海槽 

分 类 号：P736.2[天文地球—海洋地质]