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首页> 外文期刊>Quaternary Science Reviews: The International Multidisciplinary Review Journal >Millennial-scale ice rafting events and Hudson Strait Heinrich(-like) Events during the late Pliocene and Pleistocene: A review (Review)
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Millennial-scale ice rafting events and Hudson Strait Heinrich(-like) Events during the late Pliocene and Pleistocene: A review (Review)

机译：上新世和更新世晚期的千禧年规模的漂流事件和哈德逊海峡海因里希事件

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Various types of abrupt/millennial-scale climate variability such as Dansgaard/Oeschger and Heinrich Events characterized the last glacial period. Over the last decade, a number of studies demonstrated that such millennial-scale climate variability was not limited to the last glacial but inherent to Quaternary climate. Here we review the occurrence and origin of millennial ice-rafting events in the North Atlantic during the late Pliocene and Pleistocene (last 3.4Ma) with a special focus on North Atlantic Hudson Strait (HS) Heinrich(-like) Events.We show that Heinrich Layers 5, 4, 2, and 1 in marine sediment cores from across the North Atlantic all bear the organic geochemical fingerprint of the Hudson area. Using this framework and combining previously published results, detailed investigations into the organic and inorganic chemistry of ice-rafted debris (IRD) found across the North Atlantic demonstrate that prior to MIS 16 (~650ka) IRD in the North Atlantic did not originate from the Hudson area of northern Canada. The signature of this early IRD is distinctly different compared to that of HS Heinrich Layers. Rather ice-rafting events during the late Pliocene and early Pleistocene predominantly emanated from the calving of the Greenland and Fennoscandian ice sheets and possibly minor contributions from local ice streams from the North American and British ice sheets. Compared to North Atlantic HS Heinrich Events, these early Pleistocene IRD-events had a limited impact on surface water characteristics in the North Atlantic. North Atlantic HS Heinrich(-like) Events first occurred during MIS 16. At the same time, the dominant frequency in silicate-rich IRD accumulation shifted from the obliquity (41-ka) to a 100-ka frequency across the North Atlantic. Iceberg survivability or a change in iceberg trajectory likely did not control this change in IRD-regime. These results lend further support for the existing hypothesis that an increase in size (thickness) of the Laurentide ice sheet controls the occurrence of North Atlantic HS Heinrich Events, favoring an internal dynamic mechanism for their occurrence.
机译：上一个冰川期是各种类型的突然/千年尺度的气候变异性，例如Dansgaard / Oeschger和Heinrich Events。在过去的十年中，许多研究表明，这种千年尺度的气候变化不仅限于最后的冰川，而且是第四纪气候所固有的。在这里，我们回顾了上新世晚期和更新世（最后3.4Ma）期间北大西洋千年漂流事件的发生和起源，特别关注北大西洋哈德逊海峡（HS）Heinrich（类似）事件。来自整个北大西洋的海因里希斯岩心中的海因里希第5、4、2和1层均带有哈德逊地区的有机地球化学指纹。使用此框架并结合先前发表的结果，对横跨北大西洋发现的冰筏碎片（IRD）的有机和无机化学进行的详细研究表明，在MIS 16（〜650ka）之前，北大西洋的IRD并非源自于加拿大北部哈德逊地区。与HS Heinrich Layers的签名相比，此早期IRD的签名明显不同。上新世晚期和更新世早期的漂流事件主要来自格陵兰和芬诺斯堪的亚冰盖的崩裂，以及北美和英国冰盖的局部冰流可能贡献很小。与北大西洋HS海因里希事件相比，这些早期更新世IRD事件对北大西洋地表水特征的影响有限。北大西洋HS海因里希（类）事件首次发生在MIS 16中。与此同时，北硅酸盐富含IRD的IRD积累的主导频率从倾角（41-ka）变为100-ka。冰山的生存能力或冰山的轨迹变化可能无法控制IRD体制的这种变化。这些结果进一步支持了现有的假设，即洛朗特冰盖尺寸（厚度）的增加控制了北大西洋HS海因里希事件的发生，有利于其发生的内部动力学机制。

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