沉积学报  2018, Vol. 36 Issue (6): 1157−1168

扩展功能

文章信息

王玥铭, 窦衍光, 李军, 徐景平, 蔡峰, 温珍河, 赵京涛, 陈晓辉
WANG YueMing, DOU YanGuang, LI Jun, XU JingPing, CAI Feng, WEN ZhenHe, ZHAO JingTao, CHEN XiaoHui
16 ka以来冲绳海槽中南部沉积物物源演化及其对古气候的响应
Sediment Provenance Change and Its Response to Paleochimate Change in the Middle Okinawa Trough since 16 ka
沉积学报, 2018, 36(6): 1157-1168
ACTA SEDIMENTOLOGICA SINCA, 2018, 36(6): 1157-1168
10.14027/j.issn.1000-0550.2018.102

文章历史

收稿日期:2017-09-13
收修改稿日期: 2018-01-21
16 ka以来冲绳海槽中南部沉积物物源演化及其对古气候的响应
王玥铭1 , 窦衍光2,3 , 李军2,4 , 徐景平3,5 , 蔡峰2,4 , 温珍河2,4 , 赵京涛2,4 , 陈晓辉2,4     
1. 中国海洋大学海洋地球科学学院, 山东青岛 266100;
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地质过程与环境功能实验室, 山东青岛 266061;
4. 青岛海洋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;
5. 南方科技大学海洋科学与工程系, 广东深圳 518055
摘要: 基于有孔虫AMS14C年龄年代框架,通过冲绳海槽中南部的OKT12孔沉积物黏土矿物的分析,探讨了16 ka以来冲绳海槽细颗粒沉积物的物源变化及其对源区气候的响应。研究结果显示,10 ka时黏土矿物组成发生明显变化,伊利石、绿泥石含量增加,高岭石、蒙皂石含量减少,指示物源由之前的长江和东海陆架源转变为台湾源。受到海平面上升影响,长江河口和冲绳海槽距离增加,夏季风增强,黑潮增强,既搬运台湾来源物质,又阻碍长江物质跨陆架输运,在这些因素综合作用下,长江物质减少、台湾物质增加。高岭石/(伊利石+绿泥石)和绿泥石/(伊利石+蒙皂石)比值在4 ka以来增加指示全新世晚期台湾源区侵蚀强度发生变化。4 ka前后物源判别显示,OKT12孔沉积物来源由台湾东北部河流变为台湾东南部河流,反映了该时期季风降雨导致源区台湾不同区域的侵蚀差异,可能与ITCZ南移、ENSO活动增强有关。
关键词: 冲绳海槽    黏土矿物    物源    全新世    古气候    
Sediment Provenance Change and Its Response to Paleochimate Change in the Middle Okinawa Trough since 16 ka
WANG YueMing1 , DOU YanGuang2,3 , LI Jun2,4 , XU JingPing3,5 , CAI Feng2,4 , WEN ZhenHe2,4 , ZHAO JingTao2,4 , CHEN XiaoHui2,4     
1. College of Marine Geosciences, Ocean University of China, Qingdao, Shandong 266100, China;
2. Qingdao Institute of Marine Geology, China Geological Survey, Qingdao, Shandong 266071, China;
3. Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266061, China;
4. Laboratory for Marine Mineral Resource, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266061, China;
5. Department of Ocean Science & Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
Foundation: National Natural Science Foundation of China, No.41776077, 41476070, 41530966; National Basic Research Program of China(973 Program), No.2013CB429704
Abstract: Based on an AMS14C age framework, clay mineral analysis of Core OKT12 from the Middle Okinawa Tough was conducted to determine sediment provenance and its response to Holocene climate change. A remarkable change took place at 10 ka with an increase of illite and chlorite, and a decrease of kaolinite and smectite, indicating that sediment provenance changed from Changjiang and the ECS shelf to Taiwan after 10 ka. With a rise in sea level the distance between the Changjiang estuary and the Okinawa Trough increased. The Kuroshio Current was strengthened following the evolution of the East Asia summer monsoon since the LGM. The Kuroshio Current was able to transport sediment from Taiwan to OT and to obstruct the cross-helf transport of Changjiang sediment, resulting in an increase in Taiwan material and a decrease in Changjing material. Kaolinite/(illite+chloite) and chlorite/(illite+smectite) ratios have increased since 4 ka, indicating sediment provenance erosion change during the Holocene. By comparing the clay mineral compositions from the main rivers in Taiwan, it was determined that sediment provenance changed from northeastern to southeastern Taiwan Rivers since 4 ka. Holocene sediment provenance change was probably a result of erosion difference induced by a typhoon precipitation distribution discrepancy due to the southern shift of ITCZ and the strengthening of ENSO.
Key words: Okinawa Trough    clay minerals    provenance    Holocene    paleochimate    
0 引言

陆源输入和古环境演变一直是边缘海沉积地质学关注的重点问题。冲绳海槽作为东海陆架与西太平洋的过渡地带,晚第四纪以来的连续沉积记录了陆源物质供给、海平面升降、洋流以及季风气候等演变过程,是研究东亚古环境演化和海陆相互作用的良好材料。末次盛冰期(LGM)以来,东海沉积物的物源供给格局发生较大变化:低海面时期,长江、黄河等大型河流穿越出露的陆架,向陆坡搬运东亚大陆风化剥蚀形成的巨量沉积物[1],现今,高海面状态下大陆河流搬运的沉积物大部分堆积在河口及内陆架[2-3],向冲绳海槽的跨陆架输运受到黑潮的阻碍[4-5];与之相对应在台风、地震等活动的作用下,台湾的山溪性河流向东海和冲绳海槽输入巨量的陆源物质[6]。前人对末次盛冰期以来冲绳海槽陆源沉积物的来源已进行了详尽的研究[7],盛冰期、冰消期早期的沉积速率高于全新世,陆源输入存在减少趋势[8]。对于从末次盛冰期到全新世冲绳海槽陆源物质的来源,一种观点认为物源没有发生变化,主要是来自长江、黄河及东海内陆架物质[9-11],另一种认为高海平面以来通过黑潮的搬运台湾物质可以输入冲绳海槽[12-14]

陆源碎屑中的黏土矿物粒径细,搬运距离长,对物源变化具有良好的指示作用。杨作升[15]对长江、黄河、珠江的黏土矿物进行研究,认为其黏土矿物可以用于判别陆架海区沉积物的来源和扩散。Liu et al.[16]根据黏土矿物组成识别南海东北部海区表层沉积物的来源为珠江、台湾和吕宋岛弧火山。另一方面,黏土矿物记录的物质来源变化对源区季风气候、风化剥蚀强度有一定的响应关系。刘志飞等[17]根据湄公河盆地的蒙皂石/(伊利石+绿泥石)和蒙皂石/高岭石比值反演东亚季风的演变,间冰期化学风化作用强,比值较高,代表强盛的夏季风降雨和减弱的冬季风环流;反之,低值对应于冰期的强冬季风。黏土矿物变化与地球轨道参数偏心率、岁差周期、低纬夏季日射量变化等也具有相关性,反映东亚季风变化的高纬冰盖和低纬热带驱动机制[18]

在前人研究的基础上,本文选取冲绳海槽中部OKT12岩芯,结合AMS14C数据,探讨16 ka以来黏土矿物记录的冲绳海槽中南部陆源物质来源演化及其对全新世气候变化的响应。

1 材料与方法 1.1 研究材料

OKT12岩芯是青岛海洋地质研究所2014年利用海大号科学考察船在冲绳海槽中部取得的重力活塞柱状样,坐标125.34 °E,26.05 °N,水深1 924.53 m,岩芯长度为4.68 m(图 1)。该柱状样主要由黏土质粉砂组成,1.36~1.48 m处发育火山灰层,AMS14C年代显示年龄为6.8~7.3 ka,与冲绳海槽及日本区域广泛分布的K-Ah火山灰层具有可对比性,如日本湖泊沉积记录K-Ah火山灰层年龄在7.3 ka[19]

图 1 东海陆架—冲绳海槽流系图及OKT12岩芯位置[12] Figure 1 Circulation system of East China Sea shelf-Okinawa Trough and location of Core OKT12[12]
1.2 实验方法 1.2.1 AMS14C测年

对岩芯以大致30 cm间隔选取12个层位样品挑选浮游有孔虫,在美国Beta实验室进行AMS14C测试。测试得到的14C年龄使用CALIB 7.0.4软件校正到日历年龄,考虑到冲绳海槽一直与太平洋连通,选择了标准的海洋校正数据库进行校正。400 a的大气与海水间的全球碳储库差异由程序自动减去。测年结果如表 1所示。

表 1 冲绳海槽OKT12孔AMS14C年龄 Table 1 AMS14C age of Core OKT12 from middle Okinawa Trough
样品编号 深度/cm 种属 原始年龄/Cal B.C. 校正年龄/Cal B.P. 年龄/Cal B.P. 2SIGMA/yr
OKT12-2 57 N.dutertrei 1 310~1 085 3 260~3 035 3 147.5 112.5
OKT12-3 87 N.dutertrei 2 875~2 635 4 825~4 585 4 705 120
OKT12-4 117 P.obliqueloculata-N.dutertrei 4 220~3 980 6 170~5 930 6 050 120
OKT12-6 177 N.dutertrei 6 660~6 470 8 610~8 420 8 515 95
OKT12-7 207 N.dutertrei 8 075~7 735 10 025~9 685 9 855 170
OKT12-8 237 N.dutertrei 8 805~8 595 10 755~10 545 10 650 105
OKT12-9 267 N.dutertrei 9 795~9 305 11 745~11 255 11 500 245
OKT12-10 297 N.dutertrei 10 610~10 270 12 560~12 220 12 390 170
OKT12-12 357 N.dutertrei 11 835~11 580 13 785~13 530 13 657.5 127.5
OKT12-13 387 N.dutertrei 12 435~12 140 14 385~14 090 14 237.5 147.5
OKT12-14 417 N.dutertrei 12 315~12 100 14 265~14 050 14 157.5 107.5
OKT12-15 447 N.dutertrei 13 930~13 655 15 880~15 605 15 742.5 137.5

本文使用的年代数据均为日历年龄,根据获得的控制点深度和AMS14C年龄,进行线性内插和外推获得所有沉积物样品的年龄。深度387 cm和417 cm两层位年代相近但存在倒转,力求357~447 cm之间的层位沉积速率的差别最小,因而去除447 cm层位的年代倒转的样品。依据沉积物沉积速率,外插计算得到OKT12孔底部的年龄在16.3 ka左右,建立岩芯基本年代框架。

1.2.2 黏土矿物分析

黏土矿物取样间隔为4 cm,使用黏土粒级矿物(< 2 μm)定向薄片X射线衍射(XRD)方法分析,测试在国土资源部油气资源与环境地质重点实验室完成。样品测试前使用0.2 N稀盐酸去除碳酸钙,用去离子水清洗离心后,根据Stoke沉降原理提取小于2 μm的颗粒。每个样品制成两份定向薄片,一份风干后制成自然定向片,上机测试后在乙二醇蒸汽中浸泡48 h,制成乙二醇饱和定向片再测试,另一份在490 ℃加热两个小时后,制成加热定向片上机测试。利用Rigaku D/max-rB型X射线衍射仪测试(CuKα),工作电压40 kV、电流100 mA,扫描范围3°~35°(2θ),步长2 °/min,使用Jade5.0软件对主要衍射峰面积进行拟合、提取特征峰强度值,利用Biscaye[20]的方法计算四种主要黏土矿物(蒙皂石、伊利石、高岭石和绿泥石)的相对含量,即选用乙二醇饱和片图谱上蒙皂石(17 Å)、伊利石(10 Å)、绿泥石和高岭石(7 Å)四种矿物的三个特征峰的峰面积作为基础数据进行计算,其强度因子分别为1、4、2,绿泥石和高岭石的含量比例以25°(2θ)左右3.54 Å/3.57 Å附近的衍射峰面积比值求得。

2 结果

OKT12岩芯的黏土矿物组成中伊利石含量最高,绿泥石次之,高岭石和蒙皂石含量较低(图 2)。最主要的组成矿物伊利石的含量在64.5%~74.6%,平均67.0%;绿泥石含量在15.4%~22.2%,平均17.6%;高岭石含量在5.5%~11.2%,平均9.6%;蒙皂石含量在0.2%~7.1%,平均4.9%。黏土矿物的变化可分为两个阶段,在16~10 ka阶段伊利石含量64.5%~71.6%,绿泥石含量15.4%~19.6%,高岭石的含量7.6%~11.2%,蒙皂石含量0.6%~7.1%,蒙皂石和高岭石的含量相对处于高值,而绿泥石和伊利石含量则相对低;10~0 ka阶段伊利石含量65.3%~74.6%,绿泥石含量17.8%~22.2%,高岭石的含量5.5%~9%,蒙皂石含量0.2%~6.2%,伊利石和绿泥石的含量增加,蒙皂石和高岭石减少。黏土矿物比值伊利石/蒙皂石、绿泥石/高岭石的变化趋势和伊利石、绿泥石含量变化相似,也是自10 ka时增大,全新世时比值要高于末次冰消期。

图 2 OKT12岩芯蒙皂石、伊利石、高岭石和绿泥石含量(%)以及伊利石/蒙皂石、绿泥石/高岭石比值 Figure 2 Smectite, illite, kaolinite and chlorite content, illite/smectite ratio and chlorite/kaolinite ratio of Core OKT12
3 讨论 3.1 黏土矿物物质来源

黏土矿物受原岩性质、风化程度、构造活动、气候变化等因素影响,在不同的环境下形成不同的矿物组合,因此可以用于判别黏土矿物的来源。冲绳海槽区域黏土矿物组成也被广泛用于判别陆源物质来源,如冲绳海槽北部的PC-1孔的物源主要由黄河变为黄河和台湾[21];对冲绳海槽中南部的OKI04[22]、KX12-3[23]、DGKS9604[24]、A7[25]等岩芯的研究多认为陆源物质来源由黄河和长江变为长江、东海陆架和台湾,特别是台湾物质成为主要来源[24],尤其是台湾东部河流[22]

黏土矿物是母岩风化的产物,黏土矿物间性质差异较大:高岭石是潮湿气候下母岩在酸性介质中被强烈淋滤形成的,温暖潮湿的气候有利于高岭石的形成和保存;绿泥石形成于干旱寒冷气候化学风化受抑制的条件下,如冰川和干旱地区;伊利石形成于气候干冷淋滤作用弱的条件下,可进一步风化为高岭石;蒙皂石是在寒冷气候下形成的,火山物质在碱性介质中易转化为蒙皂石[26]

为了判断OKT12孔黏土矿物来源,选择伊利石+高岭石、蒙皂石和绿泥石三种矿物组合进行三角图投点,与物源端元进行对比分析。物源端元包括长江、黄河、东海陆架、台湾东、西部河流以及浙江、福建的钱塘江、瓯江、台湾兰阳溪等河流,物源端元的黏土矿物组合特征有明显不同(表 2):长江端元黏土矿物组成的特点是伊利石+高岭石含量较高约为80%,蒙皂石含量中等[15, 27-29];黄河物质则以相对高的蒙皂石含量为特征,最高可达20%以上[15, 27-29];东海陆架与前两者接近,伊利石+高岭石含量近乎介于长江和黄河之间,蒙皂石含量与长江相当[30-32];台湾来源的黏土组成与大陆具有明显的区别,其蒙皂石的含量极低,基本为0%,绿泥石和伊利石+高岭石含量变化较大,整体上台湾西部的伊利石+高岭石含量更高,而东部的绿泥石含量相对更高[31-36]。在台湾广泛分布硬页岩、板岩、千枚岩以及基性火山岩变质岩系、新近纪浅海相碎屑沉积岩、第四纪河流相碎屑沉积物,这些岩石风化形成的黏土和河流沉积物中的黏土以伊利石和绿泥石为主[37]

表 2 黏土矿物物源端员含量组成 Table 2 Characteristic of clay minerals of different provenances
物源端员 样品数 蒙皂石/% 伊利石/% 高岭石/% 绿泥石/% 参考文献来源
长江 8 6.6 71 9.4 13 [27]
5.5 68 12.7 13.9 [28]
87 10 65 14 11 [15]
8 6(3~11) 66(58~78) 16(11~20) 12(8~19) [29]
黄河 14 15.2 62.5 9.7 12.5 [27]
23.2 59 8.5 9.3 [28]
35 16 62 10 12 [15]
8 12(7~12) 62(57~68) 10(7~18) 16(11~23) [29]
东海内陆架 7 3(0~3) 77(71~84) 9(6~16) 12(9~16) [30]
42 6±2 65±4 9±2 20±3 [31]
6 7 64 12 17 [32]
钱塘江 5 3.4 64.2 13.7 18.7 [2]
瓯江 5 5 64 12 19 [2]
台湾东部 双溪 3 0 76±6.6 11±7.6 13±14.4 [33]
花莲溪 8 0 52±19.6 0±3.4 48±20.6 [33]
秀姑峦溪 3 0 64±5.4 0±3.4 36±8.6 [33]
兰阳溪 6 0 78±8.6 6±2.6 17±10.4 [34]
台湾西部 淡水河 2 0±0.1 73±2.2 3±0.7 24±3.7 [33]
头前溪 2 0±0.1 66±4.8 0±2.3 34±6.3 [33]
大安河 3 0±0.1 81±10.2 1±1.3 18±9.7 [33]
大甲溪 3 0±0.1 73±2.2 2±0.3 25±2.7 [33]
乌溪 3 0±0.1 69±1.8 7±4.7 34±6.3 [33]
浊水溪 4 0±0.1 75±4.2 1±1.3 24±3.7 [33]
浊水溪 5 0±0.1 71±0.2 1±1.3 28±1.7 [31]
浊水溪 3 0±0.1 69±1.8 1±1.3 30±2.3 [35]
浊水溪 6 0±0.1 70±0.8 1±1.3 29±1.3 [32]
曾文溪 3 0±0.1 72±1.2 8±5.7 20±7.7 [33]
高坪溪 4 0±0.1 75±4.2 2±0.3 23±4.7 [33]
高坪溪 19 1±0.9 55±25.8 1±1.3 43±15.3 [36]

图 3显示,16~10 ka阶段的伊利石、高岭石以及蒙皂石含量相对较高,更接近与长江和东海内陆架的黏土矿物组成,而10 ka以来,绿泥石含量相对增加,绿泥石/高岭石比值也增加,表明绿泥石指示的台湾来源物质增加。虽然图 3中钱塘江和瓯江的黏土组成与东海陆架和OKT12岩芯的样品十分接近,但是二者的沉积物供应量较少,无法与长江或是台湾来源相比,因此,钱塘江和瓯江不作为冲绳海槽主要的陆源物质来源。岩芯中蒙皂石的含量在全新世并没有与台湾端员完全一致,一方面,来自长江、东海陆架的陆源输入并没有完全阻断,可带来一定量的蒙皂石;另一方面,少量的火山物质的混入可导致蒙皂石含量升高,7 ka的蒙皂石峰值体现了火山物质的影响[14, 38]

图 3 黏土矿物组成三角图判别物源 Figure 3 Clay mineral ternary plot provenance analysis

本文采用黏土矿物的物源判别结果与前人研究一致,冲绳海槽中部的KX12-3孔[23]、OKI04孔[22]、OKI02孔[39]在进入全新世后都出现绿泥石含量增加的现象。来自台湾的陆源输入不仅在黏土矿物中有所反映,通过其他的指标也可以进行判别。Sr-Nd同位素对于陆源物质的来源具有良好的指示作用,冲绳海槽中部的DGKS9604孔的87Sr/86Sr和εNd在7~14 ka发生变化,87Sr/86Sr从0.715 0左右降低到0.711 0,而εNd从-11.6左右增大到-10.8左右,低87Sr/86Sr比值和高εNd指示台湾物质的加入[40],类似的Sr-Nd同位素变化在冲绳海槽北部的PC-1孔也可见[41]。Diekmann et al.[13]发现的K/Ti比值与黏土组成变化一致,台湾页岩、板岩富含K,长江沉积物富含相对Ti,在11.2 ka左右K/Ti比值增大,指示台湾来源物质增多。冲绳海槽西南部沉积速率高达5 m/ka,发育快速沉积事件,高沉积速率是由于降雨增多导致台湾东北部兰阳溪携带大量物质向冲绳海槽搬运[42]

观测资料也证实现代台湾物质的输入影响,Hsu et al.[43]通过沉积物捕获器观测台湾东北陆架向深海输运的沉积物通量,发现其与兰阳溪的径流量正相关,并且受到台风影响作用下的输运占到长期输运通量的50%以上,地震可以引发巨量沉积物输运,台湾的沉积物入海通量可达380 Mt/yr[6]

冲绳海槽沉积物物源演化体现了海平面变化、黑潮、源区风化、河流输入、东亚季风等因素的综合影响,海平面升降会影响海岸线、河口的位置,黑潮强度控制着台湾来源物质的输入,季风降雨影响河流的径流量,这些因素的共同作用下导致前述10 ka时期的物源变化。

在16~10 ka阶段海平面波动上升,低海平面时古长江和黄河河口与冲绳海槽之间的距离更近,其携带的沉积物可以更多的搬运到冲绳海槽,这应该是此阶段物源更接近长江的原因[8]。在海平面上升的过程中,陆架的潮流作用比现今强烈[44],陆架物质受到再侵蚀后也可能向冲绳海槽搬运[23-24]。长江和陆架物质的输入在冰消期使冲绳海槽中部的沉积速率达到40~50 cm/ka,相对全新世更高,但是在海平面上升过程中,沉积速率逐渐减小,陆源输入减少(图 4)。

图 4 16 ka以来物源变化及其环境影响因素指标 物源指标A、B为沉积速率、绿泥石/高岭石比值;环境指标C~F包括冲绳海槽中部DGKS9604孔U37K-SST[45]、黏土组成恢复的台湾源物质含量[24]、海平面变化曲线[46-47]和东亚冬夏季风相对强弱变化[48] Figure 4 Sediment provenance and its related environmental change indices Sediment provenance indices: A.linear sedimentation rate; B.chlorite/kaolinite ratio. Environmental indices: C.U37K based SST of DGKS9604 from middle Okinawa Trough[45]; D.content of Taiwan source inferred from clay minerals[24]; E.sea level change[46-47]; F.relative strength of East Asia Winter/Summer Monsoon[48]

黑潮作为经过冲绳海槽最主要的流系,其强弱显著影响着台湾物质的搬运。虽然末次冰盛期黑潮是否移出冲绳海槽存在争议[25, 45, 49-50],盛冰期时黑潮强度减弱无疑。有孔虫黑潮指示种Pulleniatina obliquiloculata的含量在10 ka以前相对较低、有孔虫δ18O偏重[51],UK37重建的海水表层温度(SST)虽然呈上升趋势但还是处于相对低值[45](图 4),代表黑潮搬运动力强弱的粉砂粒级(Sortable Silt)含量相对较低[13],受到夏季风的变化控制[52],此阶段黑潮的强度较弱。因而全新世之前OKT12孔绿泥石/伊利石比值相对较低,表明此阶段黑潮搬运的台湾物质相对较少,冰消期时台湾物质的贡献大概在20%左右[24]

10 ka以来研究区物源发生明显变化,绿泥石/高岭石比值、SST、台湾源的含量都迅速增大(图 4)。随着海平面的不断上升,10 ka以来岩芯沉积速率降低到18.1~22.3 cm/ka,表明源区与冲绳海槽的距离增大。冲绳海槽中部DGKS9604孔也显示全新世台湾来源的黏土矿物显著增加,其含量最高可达60%,体现了黑潮对于沉积物的搬运能力[24]。全新世黑潮的变化与东亚季风密切相关,从全新世早期开始,在岁差变化影响下,北半球夏季辐射量达到最大,热带辐合带(ITCZ)北移,东亚夏季风增强导致黑潮增强[25]。Jian et al.[49]认为黑潮重新进入冲绳海槽的时间在7.3 ka,Xu et al.[53]认为自10.5~8.5 ka起冲绳海槽的水团就已经成为黑潮影响下的高温高盐性质。夏季风控制下重新进入冲绳海槽/加强的黑潮一方面,成为搬运台湾物质的主要动力,另一方面,又成为阻挡现代长江物质直接输入冲绳海槽的水障[25, 39],陆坡区出现一不同于陆架和海槽的悬浮体低值区,表明夏季来自长江和东海陆架的中底层悬浮体无法向深海继续搬运[4-5]

全新世早期OKT12孔全新世黏土矿物组成的显著变化,反映了主要物源区由长江、东海陆架向台湾物质的转变,是海平面变化、黑潮变动的综合体现。

3.2 全新世源区侵蚀变化的响应

前述讨论表明,10 ka以来冲绳海槽中南部沉积物以台湾物质为主。然而,全新世OKT12孔黏土矿物组成并不是完全不变的,10 ka以来黏土矿物含量还有次级的波动。高岭石/(伊利石+绿泥石)和绿泥石/(伊利石+蒙皂石)比值在4 ka以来增加,绿泥石—(伊利石+蒙皂石)—高岭石三端元判别图显示4 ka以来样品的绿泥石含量相对增加(图 5)。10~4 ka阶段时黏土矿物组成更接近台湾东北部的双溪、兰阳溪和西南部的曾文溪,而4 ka以来阶段黏土矿物组成更接近西部的浊水溪、乌溪和淡水溪。黏土矿物组成虽然在一定程度上指示物源,但还需考虑到河流输沙量(表 3)、搬运机制、搬运距离等因素。台湾西部河流如浊水溪、高屏溪具有较高的输沙量[54],研究显示10 ka以来浊水溪带来的沉积物大多沉积在台湾海峡内形成斜坡沉积体(Clinoform)以及沉积在从河口向北延伸的海岸带平原[55]。台湾暖流可以携带西部河流沉积物向北输运至东海及冲绳海槽南部[56],但输运量还有待进一步研究。台湾西部河流对冲绳海槽黏土矿物的贡献可能有限,并且全新世晚期的沉积通量相对早期有所减少[55],不作为主要物源进行讨论。台湾东部河流不仅具有高的输沙量而且输入的沉积物可以直接被黑潮搬运,4 ka以来台湾东部河流贡献量可能更大,如具有更高绿泥石含量的台湾东南部花莲溪、秀姑峦溪。因此,10 ka以来OKT12孔黏土矿物物源可能是由全新世早中期台湾东北部河流为主转变到全新世晚期的台湾东南部河流来源为主。10 ka以来OKT12孔黏土矿物组成的变化反映了台湾不同流域河流在不同时期对冲绳海槽沉积物的贡献程度不同,导致黏土矿物组成发生改变。源区风化侵蚀的差异可能是导致上述物源变化的原因。南海黏土矿物研究显示湄公河源区变化是由源区风化侵蚀程度变化造成的,蒙皂石/(高岭石+绿泥石)和高岭石/(伊利石+绿泥石)比值以及伊利石化学指数指示全新世沉积物经历了更强烈的化学风化,夏季降雨增加导致湄公河下游相对上游侵蚀更强[57]。同样受到季风以及人类活动影响,长江携带入海的沉积物来源自末次冰期以来也发生变化,εNd和Sc/Th比值揭示在末次冰消期晚期以及全新世早期长江侵蚀的主要区域由原来的上游变为中下游,而在全新世晚期又回到以上游流域侵蚀为主[58]。这些研究表明流域侵蚀风化差异会在沉积物的矿物、化学组成上有所记录,那么OKT12孔4 ka时黏土矿物的变化也可能是全新世以来台湾季风降雨导致的差异风化侵蚀所致。

图 5 10~0 ka黏土矿物组成三角图 Figure 5 Clay mineral ternary plot for samples of 10-0 ka
表 3 研究区周边入海河流的基本特征 Table 3 Basic hydrological characteristic of surrounding inflow rivers
河流 长度/km 流域面积/km2 径流量/(km3/a) 输沙量/(Mt/a)
黄河 5 464 75.2×104 43 1 089
长江 6 300 181×104 928 500
钱塘江 605 4.99×104 39 6.7
瓯江 338 1.78×104 15 2.7
兰阳溪 73.06 979 2.773 7.98
双溪 26.81 132 1.15
花莲溪 57.28 1 507 3.809 20.61
秀姑峦溪 81.15 179 4.179 19.97
淡水河 158.87 2 726 7.044 11.45
头前溪 63.03 566 0.989 2.56
大安河 95.76 758 1.573 4.97
大甲溪 140.21 1 235 2.596 4.03
乌溪 116.75 2 026 3.727 6.79
浊水溪 186.4 3 155 6.095 63.87
曾文溪 138.47 1 177 2.361 31
高屏溪 170.9 3 256 8.455 35.61
注:数据来源文献[29, 54]。

台湾构造活动相对活跃,发育山溪性河流,气候温暖降雨充沛,季风降雨导致强烈的物理剥蚀和沉积物的快速搬运,化学风化受到极大的限制[59]。OKT12孔黏土矿物中以风化程度较低的伊利石、绿泥石为主指示沉积物的成熟度较低,在源区或流域盆地的居留时间短,向海输运速度快,沉积物经历的化学风化较弱,以物理侵蚀为主[60-62]。研究发现,频繁的地震活动和台风引起的洪水是导致台湾强烈侵蚀的主要原因[6]

OKT12孔绿泥石/(伊利石+蒙皂石)和高岭石/(伊利石+绿泥石)比值在4 ka发生变化是由于差异侵蚀造成的物源变化,造成侵蚀差异的降雨强度可能是受到ITCZ和ENSO变化影响。ITCZ的移动在大尺度下控制热量分布、水汽循环,影响千百年尺度的东亚季风和高频的ENSO变化[63-64]。ITCZ影响下董哥洞石笋δ18O、Cariaco盆地的Ti含量以及西太平洋暖池区MD81孔SST变化与OKT12孔绿泥石/(伊利石+蒙皂石)和高岭石/(伊利石+绿泥石)比值具有可对比性(图 6)。董哥洞石笋δ18O在3.5 ka时正偏1.1‰指示全新世晚期受ITCZ南移影响东亚夏季风减弱[64]。Cariaco盆地记录的Ti含量变化反映显示自5.4 ka以来降雨强度减弱气候趋于干旱,且呈ENSO活动增强导致的高频变化[66]。西太平洋暖池区MD81孔Mg/Ca比值恢复的SST在4~2 ka显著波动降低,也指示强El Nino事件[65]。南美湖泊沉积记录显示5 ka以来ENSO的频率明显增加[68],ITCZ的南移导致了ENSO活动增强[65]。在西北太平洋强烈的ENSO活动导致超强台风袭击台湾的频率升高,产生强降雨[69]。这些沉积记录表明ITCZ在全新世晚期南移,继而导致ENSO活动增强,强烈的台风带来极端降雨导致了台湾的差异侵蚀。

图 6 7 ka以来源区变化和环境变化对比 A.高岭石/(伊利石+绿泥石);B.绿泥石/(伊利石+蒙皂石);C.西太平洋MD81的Mg/Ca比恢复的SST [65];D.董哥洞δ18O曲线[64];E.Cariaco盆地Ti含量[66];F.台湾Retreat Lake含水率[67] Figure 6 Comparison of sediment provenance and paleoenvironmental changes since 7 ka A. Kaolinite /(illite+chlorite) ratio; B. chlorite /(illite+smectite) ratio; C.Mg/Ca-based SST from western Pacific core MD81[65]; D.δ18O curve from Dongge cave[64]; E.Ti content of Cariaco Basin[66]; F.water content of Retreat Lake Taiwan[67]

此外,台湾湖泊沉积记录的源区气候变化具有区域性差异,气候干湿分布不均也可能是造成台湾的差异侵蚀的原因。台湾东北部Retreat Lake湖泊沉积记录显示在4.5~2.1 ka存在沉积间断,沉积物含水率(图 6F)、TOC含量自5 ka显著降低,指示降雨减少,相对干旱[66]。然而台湾南部的Tung-Yuan Pond沉积物的陆生植物有机质含量重建的降雨强度指数记录全新世存在若干降雨强盛期,除了7.7~5 ka全新世最适宜期外,全新世早期10.6和8.6 ka、晚期4.2~2 ka都是气候相对湿润的时期[70]

综上,全新世晚期黏土矿物含量变化指示,ITCZ的南移,ENSO活动增强,强降雨导致不同区域的侵蚀速率不同,台湾东部南北不同流域河流输运沉积物的贡献量不同,使得4 ka以来冲绳海槽记录的黏土矿物组成发生变化。

4 结论

(1) 16 ka以来冲绳海槽中部OKT12岩芯黏土矿物含量发生明显变化,自10 ka以来蒙皂石、高岭石含量降低,伊利石、绿泥石含量升高,伊利石/蒙皂石、绿泥石/高岭石比值也升高。

(2) 冲绳海槽中部黏土矿物的物源在10 ka发生重大变化,由之前的长江、东海陆架,转变为之后的台湾源,对体现了对海平面上升、东亚夏季风增强、黑潮变动的响应。

(3) 4 ka时黏土矿物组成的变化可能指示物源从全新世早中期台湾东北部河流变为全新世晚期的台湾东南部河流。受ITCZ的南移、ENSO活动增强影响,台风引起的强降雨分布不均导致台湾岛的差异侵蚀是造成源区变化的原因。

参考文献
[1]
Li G X, Li P, Liu Y, et al. Sedimentary system response to the global sea level change in the East China Seas since the last glacial maximum[J]. Earth-Science Reviews, 2014, 139: 390-405. DOI:10.1016/j.earscirev.2014.09.007
[2]
Xu K H, Li A C, Liu J P, et al. Provenance, structure, and formation of the mud wedge along inner continental shelf of the East China Sea:a synthesis of the Yangtze dispersal system[J]. Marine Geology, 2012, 291-294: 176-191. DOI:10.1016/j.margeo.2011.06.003
[3]
Liu J P, Xu K H, Li A C, et al. Flux and fate of Yangtze River sediment delivered to the East China Sea[J]. Geomorphology, 2007, 85(3/4): 208-224.
[4]
郭志刚, 杨作升, 张东奇, 等. 冬、夏季东海北部悬浮体分布及海流对悬浮体输运的阻隔作用[J]. 海洋学报, 2002, 24(5): 71-80. [ Guo Zhigang, Yang Zuosheng, Zhang Dongqi, et al. Seasonal distribution of suspended matter in the northern East China Sea and barrier effect of current circulation on its transport[J]. Acta Oceanologica Sinica, 2002, 24(5): 71-80. DOI:10.3321/j.issn:0253-4193.2002.05.009]
[5]
杨作升, 郭志刚, 王兆祥, 等. 黄东海陆架悬浮体向其东部深海区输送的宏观格局[J]. 海洋学报, 1992, 14(2): 81-90. [ Yang Zuosheng, Guo Zhigang, Wang Zhaoxiang, et al. Macroscopic transportation pattern of suspended sediment from Yellow Sea and East China Sea to eastern deep area[J]. Acta Oceanologica Sinica, 1992, 14(2): 81-90.]
[6]
Dadson S J, Hovius N, Chen H, et al. Links between erosion, runoff variability and seismicity in the Taiwan orogen[J]. Nature, 2003, 426(6967): 648-651. DOI:10.1038/nature02150
[7]
赵德博, 万世明. 冲绳海槽沉积物物源示踪研究进展[J]. 海洋地质前沿, 2015, 31(2): 32-41. [ Zhao Debo, Wan Shiming. Research progress of tracing sediment sources in Okinawa Trough[J]. Marine Geology Frontiers, 2015, 31(2): 32-41.]
[8]
孟宪伟, 杜德文, 刘焱光, 等. 冲绳海槽近3.5万a来陆源物质沉积通量及其对气候变化的响应[J]. 海洋学报, 2007, 29(5): 74-80. [ Meng Xianwei, Du Dewen, Liu Yanguang, et al. Terrestrial flux in sediments from the Okinawa Trough and its response to climate changes over the past 35000 a[J]. Acta Oceanologica Sinica, 2007, 29(5): 74-80. DOI:10.3321/j.issn:0253-4193.2007.05.009]
[9]
Kao S J, Lin F J, Liu K K. Organic carbon and nitrogen contents and their isotopic compositions in surficial sediments from the East China Sea shelf and the southern Okinawa Trough[J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2003, 50(6/7): 1203-1217.
[10]
刘焱光.近4万年来冲绳海槽物质来源的定量估计及其对气候变化的响应[D].青岛: 中国海洋大学, 2005. [Liu Yanguang. Estimation of the provenance and flux of the sediments in the Okinawa Trough using quantitative analysis since late 40 Ka[D]. Qingdao: Ocean University of China, 2005.]
[11]
Katayama H, Watanabe Y. The Huanghe and Changjiang contribution to seasonal variability in terrigenous particulate load to the Okinawa Trough[J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2003, 50(2): 475-485. DOI:10.1016/S0967-0645(02)00469-1
[12]
Dou Y G, Yang S Y, Shi X F, et al. Provenance weathering and erosion records in southern Okinawa Trough sediments since 28 ka:Geochemical and Sr-Nd-Pb isotopic evidences[J]. Chemical Geology, 2016, 425: 93-109. DOI:10.1016/j.chemgeo.2016.01.029
[13]
Diekmann B, Hofmann J, Henrich R, et al. Detrital sediment supply in the southern Okinawa Trough and its relation to sea-level and Kuroshio dynamics during the Late Quaternary[J]. Marine Geology, 2008, 255(1/2): 83-95.
[14]
徐兆凯, 常凤鸣, 李铁刚, 等. 24 ka来冲绳海槽北部沉积物来源的高分辨率常量元素记录[J]. 海洋地质与第四纪地质, 2012, 32(4): 73-82. [ Xu Zhaokai, Chang Fengming, Li Tiegang, et al. Provenance of sediments in the northern Okinawa Trough over the last 24 ka:high resolution record from major elements[J]. Marine Geology & Quaternary Geology, 2012, 32(4): 73-82.]
[15]
杨作升. 黄河、长江、珠江沉积物中粘土的矿物组合、化学特征及其与物源区气候环境的关系[J]. 海洋与湖沼, 1988, 19(4): 336-346. [ Yang Zuosheng. Mineralogical assemblages and chemical characteristics of clays from sediments of the Huanghe, Changjiang, Zhujiang rivers and their relationship to the climate environment in their sediment source areas[J]. Oceanologia et Limnologia Sinica, 1988, 19(4): 336-346.]
[16]
Liu Z F, Colin C, Li X J, et al. Clay mineral distribution in surface sediments of the northeastern South China Sea and surrounding fluvial drainage basins:Source and transport[J]. Marine Geology, 2010, 277(1/2/3/4): 48-60.
[17]
刘志飞, Colin C, Trentesaux A, 等. 青藏高原东部和湄公河盆地晚第四纪风化剥蚀与东亚季风演化在南海中的记录[J]. 矿物岩石地球化学通报, 2005, 24(1): 30-38. [ Liu Zhifei, Colin C, Trentesaux A, et al. Late Quaternary weathering and erosion of the eastern Tibetan Plateau and the Mekong basin and East Asian monsoon evolution recorded by the sediments from the South China Sea[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2005, 24(1): 30-38. DOI:10.3969/j.issn.1007-2802.2005.01.005]
[18]
刘志飞, 赵玉龙, 李建如, 等. 南海西部越南岸外晚第四纪黏土矿物记录:物源分析与东亚季风演化[J]. 中国科学(D辑):地球科学, 2007, 37(9): 1176-1184. [ Liu Zhifei, Zhao Yulong, Li Jianru, et al. Late Quaternary clay minerals off Middle Vietnam in the western South China Sea:implications for source analysis and East Asian monsoon evolution[J]. Science China (Seri. D):Earth Sciences, 2007, 37(9): 1176-1184.]
[19]
Kitagawa H, Fukuzawa H, Nakamura T, et al. AMS 14C dating of varved sediments from Lake Suigetsu, Central Japan and Atmospheric 14C change during the Late Pleistocene[J]. Radiocarbon, 1995, 37(2): 371-378. DOI:10.1017/S0033822200030848
[20]
Biscaye P E. Mineralogy and sedimentation of recent deep-sea clay in the Atlantic Ocean and adjacent seas and oceans[J]. GSA Bulletin, 1965, 76(7): 803-832. DOI:10.1130/0016-7606(1965)76[803:MASORD]2.0.CO;2
[21]
Xu Z K, Li T G, Chang F M, et al. Clay-sized sediment provenance change in the northern Okinawa Trough since 22 kyr BP and its paleoenvironmental implication[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2014, 399: 236-245. DOI:10.1016/j.palaeo.2014.01.016
[22]
Wang J Z, Li A C, Xu K H, et al. Clay mineral and grain size studies of sediment provenances and paleoenvironment evolution in the middle Okinawa Trough since 17 ka[J]. Marine Geology, 2015, 366: 49-61. DOI:10.1016/j.margeo.2015.04.007
[23]
Xu Z K, Li T G, Clift P D, et al. Sediment provenance and paleoenvironmental change in the middle Okinawa Trough during the last 18.5 ky:clay mineral and geochemical evidence[J]. Quaternary International, 2017, 440: 139-149. DOI:10.1016/j.quaint.2016.07.058
[24]
Dou Y G, Yang S Y, Liu Z X, et al. Clay mineral evolution in the central Okinawa Trough since 28 ka:implications for sediment provenance and paleoenvironmental change[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2010, 288(1/2/3/4): 108-117.
[25]
Zheng X F, Li A C, Kao S J, et al. Synchronicity of Kuroshio Current and climate system variability since the Last Glacial Maximum[J]. Earth and Planetary Science Letters, 2016, 452: 247-257. DOI:10.1016/j.epsl.2016.07.028
[26]
汤艳杰, 贾建业, 谢先德. 粘土矿物的环境意义[J]. 地学前缘, 2002, 9(2): 337-344. [ Tang Yanjie, Jia Jianye, Xie Xiande. Environment significance of clay minerals[J]. Earth Science Frontiers, 2002, 9(2): 337-344. DOI:10.3321/j.issn:1005-2321.2002.02.011]
[27]
范德江, 杨作升, 毛登, 等. 长江与黄河沉积物中粘土矿物及地化成分的组成[J]. 海洋地质与第四纪地质, 2001, 21(4): 7-12. [ Fan Dejiang, Yang Zuosheng, Mao Deng, et al. Clay minerals and geochemistry of the sediments from the Yangtze and Yellow rivers[J]. Marine Geology & Quaternary Geology, 2001, 21(4): 7-12.]
[28]
Xu D Y. Mud sedimentation on the East China Sea shelf[C]//Proceedings of international symposium on sedimentation on the continental shelf with special reference to the East China Sea. Hangzhou: China Ocean Press, 1983: 506-516.
[29]
Yang S Y, Jung H S, Lim D I, et al. A review on the provenance discrimination of sediments in the Yellow Sea[J]. Earth-Science Reviews, 2003, 63(1/2): 93-120.
[30]
Liu J P, Li A C, Xu K H, et al. Sedimentary features of the Yangtze River-derived along-shelf clinoform deposit in the East China Sea[J]. Continental Shelf Research, 2006, 26(17/18): 2141-2156.
[31]
Xu K H, Milliman J D, Li A C, et al. Yangtze-and Taiwan-derived sediments on the inner shelf of East China Sea[J]. Continental Shelf Research, 2009, 29(18): 2240-2256. DOI:10.1016/j.csr.2009.08.017
[32]
徐勇航, 陈坚, 王爱军, 等. 台湾海峡表层沉积物中黏土矿物特征及物质来源[J]. 沉积学报, 2013, 31(1): 120-129. [ Xu Yonghang, Chen Jian, Wang Aijun, et al. Clay minerals in surface sediments of the Taiwan Strait and their provenance[J]. Acta Sedimentologica Sinica, 2013, 31(1): 120-129.]
[33]
Li C S, Shi X F, Kao S J, et al. Clay mineral composition and their sources for the fluvial sediments of Taiwanese rivers[J]. Chinese Science Bulletin, 2012, 57(6): 673-681. DOI:10.1007/s11434-011-4824-1
[34]
郑智睿.南冲绳海槽表层沉积物中黏土矿物之研究[D].台北: 台湾大学, 2008. [Cheng Chih-Jui. Clay mineral distribution in surface sediment of the southern Okinawa Trough[D]. Taipei: Taiwan University, 2008.]
[35]
Wan S M, Li A C, Clift P D, et al. Development of the East Asian monsoon:mineralogical and sedimentologic records in the northern South China Sea since 20 Ma[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2007, 254(3/4): 561-582.
[36]
Liu Z F, Tuo S T, Colin C, et al. Detrital fine-grained sediment contribution from Taiwan to the northern South China Sea and its relation to regional ocean circulation[J]. Marine Geology, 2008, 255(3/4): 149-155.
[37]
梁小龙, 杨守业, 印萍, 等. 黄海与东海周边河流及泥质区沉积物黏土矿物的分布特征和控制因素[J]. 海洋地质与第四纪地质, 2015, 35(6): 1-15. [ Liang Xiaolong, Yang Shouye, Yin Ping, et al. Distribution of clay mineral assemblages in the rivers entering Yellow Sea and East China Sea and the muddy shelve deposits and control factors[J]. Marine Geology & Quaternary Geology, 2015, 35(6): 1-15.]
[38]
李军. 冲绳海槽中部A7孔沉积物地球化学记录及其对古环境变化的响应[J]. 海洋地质与第四纪地质, 2007, 27(1): 37-45. [ Li Jun. Variation of geochemical records in core A7 sediments from middle Okinawa Trough during the past 18 ka BP and its response to paleo-environmental changes[J]. Marine Geology & Quaternary Geology, 2007, 27(1): 37-45.]
[39]
Zheng X F, Li A C, Wan S M, et al. ITCZ and ENSO pacing on East Asian winter monsoon variation during the Holocene:sedimentological evidence from the Okinawa Trough[J]. Journal of Geophysical Research:Oceans, 2014, 119(7): 4410-4429. DOI:10.1002/2013JC009603
[40]
Dou Y G, Yang S Y, Liu Z X, et al. Sr-Nd isotopic constraints on terrigenous sediment provenances and Kuroshio Current variability in the Okinawa Trough during the late Quaternary[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2012, 365-366: 38-47. DOI:10.1016/j.palaeo.2012.09.003
[41]
Li T G, Xu Z K, Lim D, et al. Sr-Nd isotopic constraints on detrital sediment provenance and paleoenvironmental change in the northern Okinawa Trough during the late Quaternary[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2015, 430: 74-84. DOI:10.1016/j.palaeo.2015.04.017
[42]
李传顺, 江波, 李安春, 等. 冲绳海槽西南端中全新世以来的沉积速率与物源分析[J]. 科学通报, 2009, 54(9): 1303-1310. [ Li Chuanshun, Jiang Bo, Li Anchun, et al. Sedimentation rates and provenance analysis in the southwestern Okinawa Trough since the mid-Holocene[J]. Chinese Science Bulletin, 2009, 54(9): 1303-1310.]
[43]
Hsu S C, Lin F J, Jeng W L, et al. Observed sediment fluxes in the southwesternmost Okinawa Trough enhanced by episodic events:flood runoff from Taiwan rivers and large earthquakes[J]. Deep Sea Research Part Ⅰ:Oceanographic Research Papers, 2004, 51(7): 979-997. DOI:10.1016/j.dsr.2004.01.009
[44]
Uehara K, Saito Y. Late Quaternary evolution of the Yellow/East China Sea tidal regime and its impacts on sediments dispersal and seafloor morphology[J]. Sedimentary Geology, 2003, 162(1/2): 25-38.
[45]
Yu H, Liu Z X, Berné S, et al. Variations in temperature and salinity of the surface water above the middle Okinawa Trough during the past 37 kyr[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2009, 281(1/2): 154-164.
[46]
Lambeck K, Yokoyama Y, Purcell T. Into and out of the Last Glacial Maximum:sea-level change during Oxygen Isotope Stages 3 and 2[J]. Quaternary Science Reviews, 2002, 21(1/2/3): 343-360.
[47]
Liu J P, Milliman J D, Gao S, et al. Holocene development of the Yellow River's subaqueous delta, North Yellow Sea[J]. Marine Geology, 2004, 209(1/2/3/4): 45-67.
[48]
Wang L, Sarnthein M, Erlenkeuser H, et al. East Asian monsoon climate during the Late Pleistocene:high-resolution sediment records from the South China Sea[J]. Marine Geology, 1999, 156(1/2/3/4): 245-284.
[49]
Jian Z M, Wang P X, Saito Y, et al. Holocene variability of the Kuroshio Current in the Okinawa Trough, northwestern Pacific Ocean[J]. Earth and Planetary Science Letters, 2000, 184(1): 305-319. DOI:10.1016/S0012-821X(00)00321-6
[50]
蓝东兆, 陈承惠, 李超. 冲绳海槽末次冰期以来黑潮流游移在沉积硅藻中的记录[J]. 古生物学报, 2003, 42(3): 466-472. [ Lan Dongzhao, Chen Chenghui, Li Chao. Sedimentary diatom records on excursion of Kuroshio current in Okinawa Trough since last glaciation[J]. Acta Palaeontologica Sinica, 2003, 42(3): 466-472. DOI:10.3969/j.issn.0001-6616.2003.03.015]
[51]
Xiang R, Sun Y B, Li T G, et al. Paleoenvironmental change in the middle Okinawa Trough since the last deglaciation:Evidence from the sedimentation rate and planktonic foraminiferal record[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2007, 243(3/4): 378-393.
[52]
Qu T D, Lukas R. The bifurcation of the North Equatorial Current in the Pacific[J]. Journal of Physical Oceanography, 2003, 33(1): 5-18.
[53]
Xu X D, Oda M. Surface-water evolution of the eastern East China Sea during the last 36, 000 years[J]. Marine Geology, 1999, 156(1/2/3/4): 285-304.
[54]
Kao S J, Milliman J D. Water and sediment discharge from small mountainous rivers, Taiwan:the roles of lithology, episodic events, and human activities[J]. The Journal of Geology, 2008, 116(5): 431-448. DOI:10.1086/590921
[55]
Liu J P, Liu C S, Xu K H, et al. Flux and fate of small mountainous rivers derived sediments into the Taiwan Strait[J]. Marine Geology, 2008, 256(1/2/3/4): 65-76.
[56]
Tseng R S, Shen Y T. Lagrangian observations of surface flow patterns in the vicinity of Taiwan[J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2003, 50(6/7): 1107-1115.
[57]
Colin C, Siani G, Sicre M A, et al. Impact of the East Asian monsoon rainfall changes on the erosion of the Mekong River basin over the past 25, 000 yr[J]. Marine Geology, 2010, 271(1/2): 84-92.
[58]
Bi L, Yang S Y, Zhao Y, et al. Provenance study of the Holocene sediments in the Changjiang (Yangtze River) estuary and inner shelf of the East China sea[J]. Quaternary International, 2017, 441: 147-161. DOI:10.1016/j.quaint.2016.12.004
[59]
Bi L, Yang S Y, Li C, et al. Geochemistry of river-borne clays entering the East China Sea indicates two contrasting types of weathering and sediment transport processes[J]. Geochemistry, Geophysics, Geosystems, 2015, 16(9): 3034-3052. DOI:10.1002/2015GC005867
[60]
Garzanti E, Resentini A. Provenance control on chemical indices of weathering (Taiwan river sands)[J]. Sedimentary Geology, 2016, 336: 81-95. DOI:10.1016/j.sedgeo.2015.06.013
[61]
Selvaraj K, Chen C T A. Moderate chemical weathering of subtropical Taiwan:constraints from solid-phase geochemistry of sediments and sedimentary rocks[J]. The Journal of Geology, 2006, 114(1): 101-116. DOI:10.1086/498102
[62]
Zhao Y, Yang S Y, Liu J T, et al. Reconstruction of silicate weathering intensity and paleoenvironmental change during the late Quaternary in the Zhuoshui River catchment in Taiwan[J]. Quaternary International, 2017, 452: 43-53. DOI:10.1016/j.quaint.2016.12.013
[63]
赵永平, 陈永利, 王凡, 等. 热带太平洋海洋混合层水体振荡与ENSO循环[J]. 中国科学(D辑):地球科学, 2007, 37(8): 1120-1133. [ Zhao Yongping, Chen Yongli, Wang Fan, et al. Mixed-layer water oscillations in tropical Pacific for ENSO cycle[J]. Science China (Seri. D):Earth Sciences, 2007, 37(8): 1120-1133.]
[64]
Dykoski C A, Edwards R L, Cheng H, et al. A high-resolution, absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China[J]. Earth and Planetary Science Letters, 2005, 233(1/2): 71-86.
[65]
Stott L, Cannariato K, Thunell R, et al. Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch[J]. Nature, 2004, 431(7004): 56-59. DOI:10.1038/nature02903
[66]
Haug G H, Hughen K A, Sigman D M, et al. Southward migration of the intertropical convergence zone through the Holocene[J]. Science, 2001, 293(5533): 1304-1308. DOI:10.1126/science.1059725
[67]
Selvaraj K, Chen C T A, Lou J Y, et al. Holocene weak summer East Asian monsoon intervals in Taiwan and plausible mechanisms[J]. Quaternary International, 2011, 229(1/2): 57-66.
[68]
Moy C M, Seltzer G O, Rodbell D T, et al. Variability of El Niño/Southern Oscillation activity at millennial timescales during the Holocene epoch[J]. Nature, 2002, 420(6912): 162-165. DOI:10.1038/nature01194
[69]
Chen H F, Wen S Y, Song S R, et al. Strengthening of paleo-typhoon and autumn rainfall in Taiwan corresponding to the Southern Oscillation at late Holocene[J]. Journal of Quaternary Science, 2012, 27(9): 964-972. DOI:10.1002/jqs.v27.9
[70]
Yang T N, Lee T Q, Meyers P A, et al. Variations in monsoonal rainfall over the last 21 kyr inferred from sedimentary organic matter in Tung-Yuan Pond, southern Taiwan[J]. Quaternary Science Reviews, 2011, 30(23/24): 3413-3422.