Changes of the upper water column at the 45°N North Atlantic since marine isotope stage 3
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摘要: 北大西洋45°N区是北大西洋冰筏碎屑（IRD）带的中心区，其海洋沉积物包含高分辨率沉积环境和气候变化信息，对45°N区沉积记录的研究有利于反演末次冰期以来古海洋环境的变化。通过对岩心Hu71-377中IRD含量的统计、浮游有孔虫组合及氧和碳同位素（δ18O和δ13C）分析，重建了北大西洋45°N上层水体水团性质演化历史。结合AMS14C数据和氧同位素地层学，在氧同位素3期（MIS3）和2期（MIS2）中识别出5个Heinrich层，其中Heinrich 1、2和4层具有明显IRD峰值、Neogloboquadrina pachyderma高丰度和轻δ18O值特征，而Heinrich 3和5层的δ18O值未明显变轻。Heinrich 3和5层与Heinrich 1、2和4层的δ18O 差异可能反映了上层水体受融水输入的影响不同。δ13CN.incompta和δ13CN.pachyderma差值也反映了Heinrich事件期间混合层和温跃层的变化，它们的δ13C差值在Heinrich 1和2期间接近零，归因于强风驱动的海水垂向混合。而δ13CN.incompta和δ13CN.pachyderma差值在Heinrich 4和5期间增大，反映了季节性温跃层变浅，推测与北大西洋暖流增强有关。浮游有孔虫组合进一步反映了海洋上层水团性质, 特别是N. pachyderma和Neogloboquadrina incompta的相对丰度反映了MIS3期以来海表温度（SST）变化。
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关键词:
- Heinrich事件 /
- 浮游有孔虫组合 /
- 碳氧同位素 /
- 上层水团变化 /
- 北大西洋
Abstract: The 45°N of North Atlantic is located at the central zone of the ice-rafted detritus (IRD) belt of the North Atlantic, where the marine sediments contain rich environmental and climatic information of high-resolution. The sedimentary records there are used for reconstruction of the pale-oceanic environment since the last glacial in this study. IRD contents, planktonic foraminiferal assemblages and their oxygen and carbon isotopes (δ18O and δ13C) from the core Hu71-377, are used as major tools. Combined with AMS14C dating and oxygen isotope stratigraphy, five Heinrich layers are identified in the MIS3 and MIS2, in which the Heinrich layer 1, 2 and 4 have obvious IRD peaks, high relative abundance of Neogloboquadrina pachyderma and light δ18O values, but no obvious light δ18O are observed in the Heinrich layer 3 and 5. The difference in δ18O between the Heinrich layers 3 and 5 and the Heinrich layers 1, 2 and 4 may suggest the impacts of melt water on the upper water column. Further, the offsets between δ13CN.incompta and δ13CN.pachyderma may also reflect the changes in the mixed layer and thermocline during the Heinrich events. The δ13C offsets were close to zero during Heinrich 1 and Heinrich 2, attributing to the vertical mixing of seawater driven by strong winds. And the δ13C offsets became larger during Heinrich 4 and Heinrich 5, indicating that the seasonal thermocline became shallower, which supports the inference of the penetration of the North Atlantic Current. What’s more, the planktonic foraminiferal assemblages may reflect the properties of the water masses in the upper water column, especially the relative abundance of N. pachyderma and Neogloboquadrina incompta may indicate the sea surface temperature (SST) changes during MIS3. -
周期阶坎是海底陆坡常见的地貌单元，以连续的波状底形为特征，是深水沉积体系的重要场所，是现今海洋学研究的热点。周期阶坎一般发育环境分为海底和陆上两类，其中在海底陆坡和坡折位置处向上游迁移的长波状底形最为常见。国外学者Paker和他的助手首先在明渠模拟实验中观察到一系列向上游迁移的台阶状底形，并正式提出“周期阶坎（cyclic steps）”一词[1]。国内钟广法等[2-3]最早发现并报道了南海东北部陆坡区海底峡谷谷底、越岸区和出口部位存在大量超临界流成因的大型沉积物波，将其解释为“周期阶坎”。大多学者对海底周期阶坎进行了研究[2-5]，但对于琼东南地区现今海底周期阶坎的研究颇少。在琼东南地区，以往学者更加关注于海底峡谷的研究，并发现在海底峡谷或水道中常伴生一种类似台阶状的底形，且都有规律地朝一个方向运动，最初认为这种底形为海底沉积物波[6]。然而关于琼东南陵水凹陷现今海底是否为周期阶坎还有待考究，研究区域内阶坎底形和其形成机制有助于理解海底流体活动，并为其他区域海底地貌单元识别提供参考。
本文基于琼东南盆地陵水凹陷浅层285 km2三维地震数据，对周期阶坎的构型和形成原因进行了分析。南海陆坡周期阶坎研究对加深海底地貌单元以及重力流沉积发育控制因素具有重要的意义。
1. 地质概况
琼东南盆地位于南海北部大陆边缘，地质构造复杂多变，属于陆架较窄和陆坡较陡的非典型被动大陆边缘性盆地[7]。物源主要来自越南和海南岛的双物源供给，发育滑塌体、峡谷和海底扇等沉积体系[7-8]。陆坡自西北向东南坡度整体逐渐变缓，陆坡海底发育大量的水道和大规模的重力流沉积[9]。
琼东南盆地陆坡区自西向东按照陆坡的宽度、有无明显的坡折带和陆坡倾角大小，分为盆地西部、盆地中部和盆地东部。陵水凹陷研究区位于琼东南盆地中部、水深700～1500 m的上陆坡区，坡度大约为2°～16°（图1a）。
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L1测线号6053，研究区最西侧；L2、L3测线号分别为6353、6653，依次靠近水道左侧区域；L4测线号6953，左侧水道壁附近；L5测线号7253，水道内部；L6测线号7553，右侧水道壁附近；L7和L8测线号分别为7854、8147，研究区最东侧。L1 inline 6053, on the westernmost side of the study area; L2, L3 inline 6353 and 6653, respectively, close to the left side of the channel; L4 inline 6953, near the left side of the channel wall; L5 inline 7253, channel Inside; L6 inline 7553, on the right side of the channel wall; L7 and L8 inline are 7854 and 8147 respectively, the easternmost side of the study area.2. 数据和方法
本研究所使用的数据主要源于中国海洋石油有限公司从琼东南盆地获得并拥有的约300 km2的三维地震数据。研究区三维地震数据面元大小为12.5 m×12.5 m（Inline×Crossline），采样率为2 ms，频带宽度为6～90 Hz，主频约45 Hz，最大垂向分辨率（λ/4）约15 m。
利用GeoFrame软件对研究区现今海底浅层目的层同相轴进行解释，解释的网格精度为10×10（CDP），并将解释的层位进行时深转换，提取地震属性倾角、方位角和均方根（图2a为倾角属性平面图）等。利用解释的三维地震层位数据结合Surfer软件绘制了现今海底地形图（图1b）。研究区海底地形图揭示现今海底发育阶梯状地貌，陆坡上存在多条小水道和一条清晰的大型水道（由两支小水道复合而成即水道复合体），水道壁附近台阶形态杂乱（图1b））。
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图 2 琼东南盆地现今海底阶梯地形分析图a. 倾角属性平面图（红色线是地震剖面所在位置图），b. 典型地震剖面图，c. 阶梯几何构型图。Figure 2. Present submarine cyclic step topography of the Qiongdongnan Basina. dip_ attribute map, b. typical seismic profile, c. stepped geometric configuration diagram.3. 周期阶坎底形的识别及特征描述
周期阶坎的识别依据主要基于三点：① 周期阶坎经常发育在高坡度和坡折带区域[10-16]；② 当坡度超过0.6°时，浊流可能达到超临界流状态[16-18]；③ 周期阶坎发育的波长较长，多为链状，不对称，向上游迁移，形态似台阶状[16-17, 19]。研究区发育的底形所处位置、坡度以及形态特征与形成“周期阶坎”的条件吻合。
NW-SE向剖面上周期阶坎（图2b）表现为波状亚平行结构地震相，多组同相轴互相平行并呈波浪状起伏，波形起伏较小，不对称，波脊逆坡迁移。波状底形是由波脊和波谷相间构成，似阶梯状，高度为6～10 m。周期阶坎类型为长波形、不对称、似正弦曲线多数向上游迁移，部分向下游迁移的新月形。
由于海水与地层之间的密度差，上下地层的振幅反射特征发生了明显变化，波阻抗系数增大，因此地震同相轴连续性较好，利于研究周期阶坎的具体形态特征。选取8条测线（图1b中L1—L8）计算和分析每一测线上周期阶坎的几何构型（图2c）。使用几何构型参数（波长（L）、倾角（θ）、波高（H）、迎流面长度（Lstep）、背流面长度（Llee）、迎流面夹角（α）、背流面夹角（β）以及迎流面与背流面长度的比值（R）），刻画海底阶梯形态。
数据统计结果表明：单个周期阶坎波高4～10 m，波长20～150 m，倾角2°～14°，波长/波高为4～30。研究区自西向东（自L1到L8）阶坎波长随着坡度变缓依次增加（图3），即区域内周期阶坎之间的间距不等。研究区水道内部的阶坎波长（L5）较水道外部波长变化曲线趋势更加明显。水道壁附近（L4、L6）波长随深度变化数据有跳跃变化。单个周期阶坎的迎流面与背流面随深度变化：① 长度：迎流面长20～140 m，背流面长10～40 m。迎流面长度波动范围更广，背流面长度变化则更加集中（图4）；② 角度：迎流面角度0.1°～0.15°，背流面角度0.2°～0.8°。整个曲线趋势总体是背流面角度远大于迎流面，极少数迎流面角度大于背流面角度。随深度变化整个8条测线上的周期阶坎：① 迎流面和背流面长度均逐渐增加，但迎流面长度增长趋势远大于背流面；② 迎流面角度变化集中，背流面角度波动范围更广。
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4. 讨论
琼东南盆地陵水凹陷现今海底开放陆坡上分布成片大面积的周期阶坎底形是如何形成的？有哪些有利条件导致了这些底形的形成？针对这些问题，在前人的研究基础之上综合研究区所处地质环境对形成区域周期阶坎底形的形成过程和成因机制进行了详细的探究。陵水凹陷现今海底发育的周期阶坎底形分布范围广、数量多、类型多而集中。
4.1 周期阶坎形成过程
周期阶坎的形成与流体动力学有关。区域内发育的周期阶坎底形是由于浊流携带的陆源碎屑物质通过海底峡谷或水道重力流流体通道从陆架途径陆坡向下游搬运，在搬运途中随流体动力学参数弗劳德数（
$Fr = U/\sqrt {RCgD} $ ，其中，R：浊流中沉积物折算密度，C：浊流中平均体积浓度，D：浊流的厚度）变化而形成的一种阶梯状底形[20]。研究区成片大面积分布的周期阶坎底形足够说明水流携带的泥沙等碎屑物质能量强。靠近上陆坡区，浊流能量强，单位时间内形成的周期阶坎底形数目多，在立体图上显示出它们之间排列更加紧凑（图1b）。靠近下陆坡区，坡度减小，水动力减弱，沉积物沉积厚度变薄，单位时间形成的周期阶坎数目减小，故形成的周期阶坎底形在下陆坡间距增大（图1b）。单独一条测线上形成的周期阶坎形态类同，但大小不同。一个完整的周期阶坎形成，需要两种水流流态：① 水流携带的泥沙等碎屑物质从阶梯底部向顶部运动过程中，由于水流流速不断地减小，流体从上一个阶段的超高速超临界流结束不断地向亚临界流转化，一部分水流动能被紊流消散，剩余的动能转化为位能，会导致液面升高，即水流产生的惯性小于流体自身的重力，形成亚临界流，此时Fr＜1[4, 21]。② 当Fr＞1时，水流向下游流动的惯性大于向上游传播的波速，产生超临界流，此时不可能有向上游移动的波[22]，从而形成长波长的迎流面。理想状态下，流体从第一个阶坎底部向顶部水力跳跃完成第一个周期阶坎，接下来将剩余的能量用来完成第二个周期阶坎，依次类推，直到水跃能量消失，底形将不存在。周期阶坎的形成是浊流从超临界流到亚临界流过程中水力跃变形成的底形。周期阶坎由一系列连续的陡峭背流面和平缓迎流面组成，并且经常在背流面与迎流面转换区域形成冲沟或深坑[20]。依据侵蚀作用的强弱，分为三种类型：① 沉积型周期阶坎。水流中携带的沉积物很难被带走从而在迎流面卸载，当超临界流流经每个阶梯底部时，向亚临界流转化并产生水跃。水流继续沿着迎流面上倾方向流动，流速逐渐减缓，水流能态进一步降低，水流侵蚀作用被削弱因而以沉积作用为主[18, 23]。② 过渡型周期阶坎。水流能态不足以达到超临界流形成水跃，沉积作用与侵蚀作用相当。③ 侵蚀型周期阶坎。当水流经过阶梯顶点后位能最大，位能沿背流面下倾方向不断加速转化为动能，即水流流速逐渐增大使得浊流携带的碎屑物质很难被保留下来，其水流流态从亚临界流向超临界流转化，因此以侵蚀作用为主，从而形成的阶坎底形背流面陡峭[24]。长波状周期阶坎的形成，迎流面以沉积作用为主，背流面以侵蚀作用为主。
研究区周期阶坎迎流面长度主要大于背流面长度，在规模上属于中型沉积型周期阶坎。随深度的增加，沉积物在平缓的一侧不断加积，使得周期阶坎迎流面一侧长度不断变长。周期阶坎平缓的迎流面和陡峭的背流面，使得沉积物发生了沉积/侵蚀差异作用，最终沉积波向浊流上游方向迁移逐渐形成月牙状[4, 23, 25-26]。另外，迎流面长度与背流面长度比值大于数值1，即周期阶坎底形呈不对称性。周期阶坎迎流面主要是以亚临界流沿上倾方向加速沉积形成的平缓状斜坡，而背流面是超临界流沿下倾方向水跃侵蚀作用形成的陡峭坡[18, 23]，说明迎流面沉积粒度比背流面粗。周期阶坎呈现的有规律的向下游排列的线性构造底形指示沉积物向下游搬运，其沉积波上游方向粒度最粗，向下游方向粒度逐渐变细。
4.2 周期阶坎的成因机制
近年来，众多学者研究认为周期阶坎在海底广泛存在[4, 16, 18]。Cattane等[20]研究认为周期阶坎的形成可能是浊流与原先存在的不规则地形之间相互作用，但Kubo等质疑Cattane等只是简单地夸大了地形对形成周期阶坎的影响，并没有考虑到浊流水力跃变输送的能量。之后，Spinewine等[27]实验结果和Kostic等[24]数值模拟结果均一致表明持续的浊流易于形成周期阶坎，与预先存在的地形没有直接的联系。王海荣等[28]认为浊流形成的沉积波具有迁移特征，周期阶坎的形成是多种成因共同的结果。在前人的研究基础之上，笔者从浊流和坡度两方面对研究区的周期阶坎进行了分析。
4.2.1 浊流
浊流是重力流的一种表现形式，浊流的流体动力学影响了深水沉积体系结构单元的演化，可以分为超临界流和亚临界流两种。浊流内部携带的碎屑物质属于高密度流体，流速一般很大[29]。研究区沉积波的地震剖面显示下切水道十分发育，周期阶坎的形成是浊流作用的结果。
周期阶坎与浊流有关的因素有：① 与浊流中高密度流体密切联系。陵水凹陷现今海底陆坡区靠近物源，地形高差大，偶然的事件沉积（异重流）引起泥砂混杂持续性、密度高的沉积物容易形成周期阶坎底形，且Cartigny数值模拟实验[12]证实，沉积物浓度是发生水力跃变的有力因素。水跃往往发生在沉积物浓度确定的范围内，浓度越大，形成周期阶坎的个数越多，规模越大[14]。② 与浊流粒度和沉积速率有关。丰沛的碎屑物质从“源”系统途经研究区汇入到深海盆地，沉积物沉积速率逐渐降低，沉积物粒度由粗变细。整个周期阶坎的迎流面长度自L1到L8不断地变长，其中沉积物的沉积厚度迎流面比背流面厚，形成的周期阶坎底形往往不稳定。研究区西部沉积物粒度比东部粗，西部沉积物的沉积速率比东部高。高的沉积速率易于波状底形的完整保存，而且容易形成不对称底形[14]。③ 与浊流的流量和流速有关。随流速的增加底形会依次出现：无颗粒运动的平坦床沙、沙纹、沙浪、沙丘、过渡丘（或低角度沙丘）、平坦床沙、周期阶坎、流槽和凹坑[22, 30-31]。随浊流流量的增加，超临界流的侵蚀能力逐渐增强，形成水力跃变的可能性越高，更容易形成周期阶坎底形。在前人理论研究基础之上，笔者认为研究区浊流的流速高而稳定，因此形成了大范围的周期阶坎底形。
周期阶坎的形成、演化过程与发育在陆架边缘斜坡和峡谷水道中的浊流体系密不可分[32]。到目前为止，部分学者已经证实了浊流形成的沉积波能够以周期阶坎底形出现[2, 19, 21, 33]。周期阶坎底形甚至在高山流水、冰川中都可以出现。
4.2.2 坡度
地形坡度是控制超临界流体发生水跃形成周期阶坎底形的关键因素。地形坡度较大时，浊流携带的沉积物位能高，其沿斜坡分力较大，侵蚀作用明显，因此形成侵蚀型和粗粒度的沉积型周期阶坎；随研究区域坡度的变缓，浊流所携带的沉积物能量逐渐递减，流体的搬运能力相应地也逐渐减弱，水力跳跃后在阶梯顶部需要的能量更大，其缓冲距离加大，大量的沉积物开始堆积，粒度较细的沉积物开始沿着上倾斜坡不断地堆积形成长高比不断增大的沉积型周期阶坎[23, 34-35]。鲁勇的水槽实验表明，在坡道转换处会发生水跃，其水跃强度随坡度的增加而增加。在坡度、水流量和体积比浓度相等的情况下，坡上的平均沉积厚度小于坡下平均沉积厚度，即迎流面沉积速率与背流面的沉积速率不同[34]。一般情况下，陡峭的坡度和高密度的弗劳德数有利于周期阶坎的形成[36]。然而，坡度超过0.92°形成周期阶坎底形可能性会降低。坡度越陡，流体重力沿斜坡的分量增大促使流体不断加速，从而抑制流体内产生水跃的能量且增大了转化为亚临界流的可能性[18]。
坡度是超临界流水形成周期阶坎底形的前提要素[3, 18]。在一定的条件下，由陡峭的斜坡过渡到相对平缓的斜坡可能会导致浊流发生水力跃变[37]。
5. 结论
（1）陵水凹陷现今陆坡海底具备的坡度较陡、近物源等为周期阶坎底形的发育提供了有利条件，周期阶坎底形是构成深水沉积体系的重要沉积单元。
（2）陵水凹陷现今海底发育一条宽约6.5 km具有明显侵蚀特征的大型水道，是构成“源-汇”系统的重要通道。水道内外发育的周期阶坎底形在地震剖面上表现为连续波状亚平行强振幅地震相。周期阶坎的发育指示现今海底浊流流速急剧，流量大。
（3）通过对周期阶坎底形形成机制进行分析，认为浊流和坡度是形成周期阶坎的最主要的因素。周期阶坎在坡度适中、浊流发育的地带容易形成。
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图 1 北大西洋Hu71-377与相关岩心[8,28-29]的位置以及洋流和SST分布
NAC—北大西洋暖流，LC—拉布拉多寒流，EGC—东格陵兰流，WGC—西格陵兰流，白色阴影表示IRD带。数据来源于World Ocean Atlas 18，由Ocean Data View绘制。
Figure 1. Location map for Core Hu71-377 and related cores[8,28-29]and the distribution of currents and SST in the North Atlantic
NAC—North Atlantic Current, LC—Labrador Current,EGC—East Greenland Current, WGC—West Greenland Current, white shade indicates the IRD belt. Data were download from World Ocean Atlas 18 and plotted by Ocean Data View.
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图 2 岩心Hu71-377深度-年龄模型（a）和沉积速率（b）
Figure 2. The depth-age model（a）and sedimentation rates of core Hu71-377（b）
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图 4 北大西洋Hu71-377岩心IRD、有孔虫相对丰度、δ18O和δ13C、壳体质量等指标与岩心SO82_5-2[29] 和DSDP609[37]的δ18O和δ13C指标
“?”表示岩心SO82_5-2中Heinrich 2的年龄模型存在不确定性，因为van Kreveld等[29]未对Heinrich 2有详细定义，并且与其他Heinrich层相比，Heinrich 2中δ18O和δ13C特征不明显。
Figure 4. IRD, relative abundance of foraminifera, δ18O and δ13C, and weights of foraminifera in core Hu71-377 and their correlation with δ18O and δ13C from core SO82_5-2[29] and core DSDP609[37]
“?”represents an uncertain age model of Heinrich 2 in core SO82_5-2, since van Kreveld et al.（2000） [29] did not provide detailed definition for Heinrich 2 and the δ18O and δ13C in Heinrich 2 in SO82_5-2 are not well correlated with other Heinrich layers
表 1 岩心Hu71-377 14C年龄及日历年龄
Table 1 14C Age and Calendar Age of the core Hu71-377
深度/cm 实验ID 14C年龄/a 测试材料 日历年龄/ka 0 ～ 2 UCI-212015 1930±15 G. inflata 1.333 68.5 ～ 69.5 UCI-214037 11545±25 G. inflata 12.860 115 ～ 116 UCI-23843 15840±60 N. pachyderma 18.174 256 ～ 257 UCI-212021 25610±80 G. inflata 28.887 389 ～ 390 UCI-214039 37120±230 G. bulloides 40.920 
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表 2 NGRIP冰芯、DSDP609岩心和Hu71-377岩心的Heinrich事件相关控制点
Table 2 Heinrich events in the ice core NGRIP, core DSDP609 and core Hu71-377
下载: 导出CSV
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[1] Lozier M S, Li F, Bacon S, et al. A sea change in our view of overturning in the subpolar North Atlantic [J]. Science, 2019, 363(6426): 516-521. doi: 10.1126/science.aau6592
[2] Cléroux C, Cortijo E, Anand P, et al. Mg/Ca and Sr/Ca ratios in planktonic foraminifera: Proxies for upper water column temperature reconstruction [J]. Paleoceanography and Paleoclimatology, 2008, 23(3): PA3214.
[3] Holliday N P, Bersch M, Berx B, et al. Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic [J]. Nature Communications, 2020, 11: 585. doi: 10.1038/s41467-020-14474-y
[4] Bagniewski W, Meissner K J, Menviel L. Exploring the oxygen isotope fingerprint of Dansgaard-Oeschger variability and Heinrich events [J]. Quaternary Science Reviews, 2017, 159: 1-14. doi: 10.1016/j.quascirev.2017.01.007
[5] Zhang X, Prange M. Stability of the Atlantic overturning circulation under intermediate (MIS3) and full glacial (LGM) conditions and its relationship with Dansgaard-Oeschger climate variability [J]. Quaternary Science Reviews, 2020, 242: 106443. doi: 10.1016/j.quascirev.2020.106443
[6] Dansgaard W, Johnsen S J, Clausen H B, et al. Evidence for general instability of past climate from a 250-kyr ice-core record [J]. Nature, 1993, 364(6434): 218-220. doi: 10.1038/364218a0
[7] Rasmussen S O, Bigler M, Blockley S P, et al. A stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy [J]. Quaternary Science Reviews, 2014, 106: 14-28. doi: 10.1016/j.quascirev.2014.09.007
[8] Bond G C, Heinrich H, Broecker W S, et al. Evidence for massive discharges of icebergs into the North Atlantic Ocean during the last glacial period [J]. Nature, 1992, 360(6401): 245-249. doi: 10.1038/360245a0
[9] Voelker A H L. Global distribution of centennial-scale records for Marine Isotope Stage (MIS) 3: a database [J]. Quaternary Science Reviews, 2002, 21(10): 1185-1212. doi: 10.1016/S0277-3791(01)00139-1
[10] Heinrich H. Origin and consequences of cyclic ice rafting in the northeast Atlantic Ocean during the past 130, 000 years [J]. Quaternary Research, 1988, 29(2): 142-152. doi: 10.1016/0033-5894(88)90057-9
[11] Hemming S R. Heinrich events: Massive late Pleistocene detritus layers of the North Atlantic and their global climate imprint [J]. Reviews of Geophysics, 2004, 42(1): RG1005.
[12] Broecker W. Massive iceberg discharges as triggers for global climate change [J]. Nature, 1994, 372(6505): 421-424. doi: 10.1038/372421a0
[13] Guo C C, Nisancioglu K H, Bentsen M, et al. Equilibrium simulations of Marine Isotope Stage 3 climate [J]. Climate of the Past, 2019, 15(3): 1133-1151. doi: 10.5194/cp-15-1133-2019
[14] Tolderlund D S, Be A W H. Seasonal distribution of planktonic foraminifera in the western North Atlantic [J]. Micropaleontology, 1971, 17(3): 297-329. doi: 10.2307/1485143
[15] Schiebel R, Hemleben C. Classification and taxonomy of extant planktic foraminifers[C]//Planktic Foraminifers in the Modern Ocean. Berlin: Springer, 2017: 11-110.
[16] McIntyre A, Kipp N G, Bé A W H, et al. Glacial North Atlantic 18, 000 years ago: A CLIMAP reconstruction[M]//Cline R M, Hays D J. Investigation of Late Quaternary Paleoceanography and Paleoclimatology. Boulder, Colorado: Geological Society of America, 1976: 43-76.
[17] CLIMAP Project Members. The surface of the ice-age earth [J]. Science, 1976, 191(4232): 1131-1137. doi: 10.1126/science.191.4232.1131
[18] Ruddiman W F, McIntyre A. The mode and mechanism of the last deglaciation: Oceanic evidence [J]. Quaternary Research, 1981, 16(2): 125-134. doi: 10.1016/0033-5894(81)90040-5
[19] Ruddiman W F, Raymo M E, Martinson D G, et al. Pleistocene evolution: northern hemisphere ice sheets and North Atlantic Ocean [J]. Paleoceanography and Paleoclimatology, 1989, 4(4): 353-412.
[20] Pflaumann U, Duprat J, Pujol C, et al. SIMMAX: A modern analog technique to deduce Atlantic sea surface temperatures from planktonic foraminifera in deep-sea sediments [J]. Paleoceanography and Paleoclimatology, 1996, 11(1): 15-35.
[21] Sarnthein M, Pflaumann U, Weinelt M. Past extent of sea ice in the northern North Atlantic inferred from foraminiferal paleotemperature estimates [J]. Paleoceanography and Paleoclimatology, 2003, 18(2): 1047.
[22] Rashid H, Boyle E A. Mixed-layer deepening during Heinrich events: a multi-planktonic foraminiferal δ18O approach [J]. Science, 2007, 318(5849): 439-441. doi: 10.1126/science.1146138
[23] Rashid H, Boyle E A. Response to comment on “Mixed-layer deepening during Heinrich events: a multi-planktonic foraminiferal δ18O approach” [J]. Science, 2008, 320(5880): 1161.
[24] Kohfeld K E, Fairbanks R G, Smith S L, et al. Neogloboquadrina pachyderma (sinistral coiling) as paleoceanographic tracers in polar oceans: evidence from northeast water polynya plankton tows, sediment traps, and surface sediments [J]. Paleoceanography and Paleoclimatology, 1996, 11(6): 679-699.
[25] Brummer G J A, Metcalfe B, Feldmeijer W, et al. Modal shift in North Atlantic seasonality during the last deglaciation [J]. Climate of the Past, 2020, 16(1): 265-282. doi: 10.5194/cp-16-265-2020
[26] Ruddiman W F. Late Quaternary deposition of ice-rafted sand in the subpolar North Atlantic (lat 40° to 65°N) [J]. GSA Bulletin, 1977, 88(12): 1813-1827. doi: 10.1130/0016-7606(1977)88<1813:LQDOIS>2.0.CO;2
[27] Scott D B, Baki V, Younger C D, et al. Empirical method for measuring seasonality in deep-sea cores [J]. Geology, 1986, 14(8): 643-646. doi: 10.1130/0091-7613(1986)14<643:EMFMSI>2.0.CO;2
[28] Grousset F E, Labeyrie L, Sinko J A, et al. Patterns of ice-rafted detritus in the glacial north Atlantic (40-55°N) [J]. Paleoceanography and Paleoclimatology, 1993, 8(2): 175-192.
[29] Van Kreveld S, Sarnthein M, Erlenkeuser H, et al. Potential links between surging ice sheets, circulation changes, and the Dansgaard-Oeschger cycles in the Irminger Sea, 60-18 kyr [J]. Paleoceanography and Paleoclimatology, 2000, 15(4): 425-442.
[30] Jonkers L, Moros M, Prins M A, et al. A reconstruction of sea surface warming in the northern North Atlantic during MIS 3 ice-rafting events [J]. Quaternary Science Reviews, 2010, 29(15-16): 1791-1800. doi: 10.1016/j.quascirev.2010.03.014
[31] Chapman M R, Shackleton N J, Duplessy J C. Sea surface temperature variability during the last glacial-interglacial cycle: assessing the magnitude and pattern of climate change in the North Atlantic [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2000, 157(1-2): 1-25. doi: 10.1016/S0031-0182(99)00168-6
[32] Rashid H, Piper D J W, Drapeau J, et al. Sedimentology and history of sediment sources to the NW Labrador Sea during the past glacial cycle [J]. Quaternary Science Reviews, 2019, 221: 105880. doi: 10.1016/j.quascirev.2019.105880
[33] Lougheed B C, Obrochta S P. A rapid, deterministic age-depth modeling routine for geological sequences with inherent depth uncertainty [J]. Paleoceanography and Paleoclimatology, 2009, 34(1): 122-133.
[34] Heaton T J, Köhler P, Butzin M, et al. Marine20-the marine radiocarbon age calibration curve (0-55,000 cal BP) [J]. Radiocarbon, 2020, 62(4): 779-820. doi: 10.1017/RDC.2020.68
[35] Seierstad I K, Abbott P M, Bigler M, et al. Consistently dated records from the Greenland GRIP, GISP2 and NGRIP ice cores for the past 104 ka reveal regional millennial-scale δ18O gradients with possible Heinrich event imprint [J]. Quaternary Science Reviews, 2014, 106: 29-46. doi: 10.1016/j.quascirev.2014.10.032
[36] Bond G, Broecker W, Johnsen S, et al. Correlations between climate records from North Atlantic sediments and Greenland ice [J]. Nature, 1993, 365(6442): 143-147. doi: 10.1038/365143a0
[37] Obrochta S P, Miyahara H, Yokoyama Y, et al. A re-examination of evidence for the North Atlantic “1500-year cycle” at site 609 [J]. Quaternary Science Reviews, 2012, 55: 23-33. doi: 10.1016/j.quascirev.2012.08.008
[38] Griem L, Voelker A H L, Berben S M P, et al. Insolation and glacial meltwater influence on sea-ice and circulation variability in the northeastern Labrador Sea during the last glacial period [J]. Paleoceanography and Paleoclimatology, 2019, 34(11): 1689-1709. doi: 10.1029/2019PA003605
[39] Lisiecki L E, Stern J V. Regional and global benthic δ18O stacks for the last glacial cycle [J]. Paleoceanography and Paleoclimatology, 2016, 31(10): 1368-1394.
[40] Came R E, Oppo D W, McManus J F. Amplitude and timing of temperature and salinity variability in the subpolar North Atlantic over the past 10 k.y. [J]. Geology, 2007, 35(4): 315-318. doi: 10.1130/G23455A.1
[41] Clark P U, Dyke A S, Shakun J D, et al. The last glacial maximum [J]. Science, 2009, 325(5941): 710-714.
[42] Cortijo E, Labeyrie L, Vidal L, et al. Changes in sea surface hydrology associated with Heinrich event 4 in the North Atlantic Ocean between 40° and 60°N [J]. Earth and Planetary Science Letters, 1997, 146(1-2): 29-45. doi: 10.1016/S0012-821X(96)00217-8
[43] Bond G C, Lotti R. Iceberg discharges into the North Atlantic on millennial time scales during the last glaciation [J]. Science, 1995, 267(5200): 1005-1010. doi: 10.1126/science.267.5200.1005
[44] Xiao W S, Wang R J, Polyak L, et al. Stable oxygen and carbon isotopes in planktonic foraminifera Neogloboquadrina pachyderma in the Arctic Ocean: an overview of published and new surface-sediment data [J]. Marine Geology, 2014, 352: 397-408. doi: 10.1016/j.margeo.2014.03.024
[45] Missiaen L, Pichat S, Waelbroeck C, et al. Downcore variations of sedimentary detrital (238U/232Th) ratio: implications on the use of 230Thxs and 231Paxs to reconstruct sediment flux and ocean circulation [J]. Geochemistry, Geophysics, Geosystems, 2018, 19(8): 2560-2573. doi: 10.1029/2017GC007410
[46] Govin A, Braconnot P, Capron E, et al. Persistent influence of ice sheet melting on high northern latitude climate during the early Last Interglacial [J]. Climate of the Past, 2012, 8(2): 483-507. doi: 10.5194/cp-8-483-2012
[47] Zaric S, Donner B, Fischer G, et al. Sensitivity of planktic foraminifera to sea surface temperature and export production as derived from sediment trap data [J]. Marine Micropaleontology, 2005, 55(1-2): 75-105. doi: 10.1016/j.marmicro.2005.01.002
[48] Ottens J J. Planktic foraminifera as North Atlantic water mass indicators [J]. Oceanologica Acta, 1991, 14(2): 123-140.
[49] Morley A, Babila T L, Wright J, et al. Environmental controls on Mg/Ca in Neogloboquadrina incompta: A core-top study from the subpolar North Atlantic [J]. Geochemistry, Geophysics, Geosystems, 2017, 18(12): 4276-4298. doi: 10.1002/2017GC007111
[50] Irvali N, Galaasen E V, Ninnemann U S, et al. A low climate threshold for south Greenland Ice Sheet demise during the Late Pleistocene [J]. Proceedings of the National Academy of Sciences of the United States of America, 2020, 117(1): 190-195. doi: 10.1073/pnas.1911902116
[51] Villanueva J, Grimalt J O, Cortijo E, et al. Assessment of sea surface temperature variations in the central North Atlantic using the alkenone unsaturation index (U37k’) [J]. Geochimica et Cosmochimica Acta, 1998, 62(14): 2421-2427. doi: 10.1016/S0016-7037(98)00180-X
[52] Madureira L A S, Van Kreveld S A, Eglinton G, et al. Late Quaternary high-resolution biomarker and other sedimentary climate proxies in a Northeast Atlantic Core [J]. Paleoceanography and Paleoclimatology, 1997, 12(2): 255-269.
[53] Eynaud F, De Abreu L, Voelker A, et al. Position of the polar front along the western Iberian margin during key cold episodes of the last 45 ka [J]. Geochemistry, Geophysics, Geosystems, 2009, 10(7): Q07U05.
[54] Marchitto T M, Curry W B, Lynch-Stieglitz J, et al. Improved oxygen isotope temperature calibrations for cosmopolitan benthic foraminifera [J]. Geochimica et Cosmochimica Acta, 2014, 130: 1-11. doi: 10.1016/j.gca.2013.12.034
[55] Curry W B, Oppo D W. Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic ocean [J]. Paleoceanography and Paleoclimatology, 2005, 20(1): PA1017.
[56] Keigwin L D, Boyle E A. Late quaternary paleochemistry of high-latitude surface waters [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 1989, 73(1-2): 85-106. doi: 10.1016/0031-0182(89)90047-3
[57] Mook W G, Bommerson J C, Staverman W H. Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide [J]. Earth and Planetary Science Letters, 1974, 22(2): 169-176. doi: 10.1016/0012-821X(74)90078-8
[58] Zhan R, Winn K, Sarnthein M. Benthic foraminiferal δ13C and accumulation rates of organic carbon: Uvigerina Peregrina group and Cibicidoides Wuellerstorfi [J]. Paleoceanography and Paleoclimatology, 1986, 1(1): 27-42.
[59] Lynch-Stieglitz J, Fairbanks R G, Charles C D. Glacial-interglacial history of Antarctic intermediate water: relative strengths of Antarctic versus Indian Ocean sources [J]. Paleoceanography and Paleoclimatology, 1994, 9(1): 7-29.
[60] Polyak L, Curry W B, Darby D A, et al. Contrasting glacial/interglacial regimes in the western Arctic Ocean as exemplified by a sedimentary record from the Mendeleev Ridge [J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2004, 203(1-2): 73-93. doi: 10.1016/S0031-0182(03)00661-8
[61] 李铁刚, 孙荣涛, 张德玉, 等. 晚第四纪对马暖流的演化和变动: 浮游有孔虫和氧碳同位素证据[J]. 中国科学 D辑: 地球科学, 2007, 50(5):725-735 doi: 10.1007/s11430-007-0003-2 LI Tiegang, SUN Rongtao, ZHANG Deyu, et al. Evolution and variation of the Tsushima warm current during the late quaternary: Evidence from planktonic foraminifera, oxygen and carbon isotopes [J]. Science in China Series D: Earth Sciences, 2007, 50(5): 725-735. doi: 10.1007/s11430-007-0003-2
[62] Elderfield H, Vautravers M, Cooper M. The relationship between shell size and Mg/Ca, Sr/Ca, δ18O, and δ13C of species of planktonic foraminifera [J]. Geochemistry, Geophysics, Geosystems, 2002, 3(8): 1-13.
[63] Donner B, Wefer G. Flux and stable isotope composition of Neogloboquadrina pachyderma and other planktonic foraminifers in the southern ocean (Atlantic sector) [J]. Deep Sea Research Part I: Oceanographic Research Papers, 1994, 41(11-12): 1733-1743. doi: 10.1016/0967-0637(94)90070-1
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