10 Be dating reveals early-middle Holocene age of the Drygalski Moraines in central West Greenland
10 Be dating reveals early-middle Holocene age of the Drygalski Moraines in central West Greenland
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10 测年揭示了格陵兰岛西部中部的 Drygalski 冰碛的全新世早中时期
DOI：
10.1016/j.quascirev.2015.08.034
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发表时间：
2016
影响因子：
4
通讯作者：
Mathieu Morlighem
中科院分区：
文献类型：
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作者：
Sandra L. Cronauer;J. Briner;S. Kelley;S. Zimmerman;Mathieu Morlighem
我们利用湖泊沉积物分析和著名的 Drygalski 冰碛的宇宙成因 10Be 暴露测年，重建了格陵兰岛西部中部努苏苏瓦克半岛的格陵兰冰盖边缘从全新世开始的历史。位于 Drygalski 冰碛外侧基岩上的不稳定因素将局部冰消作用限制在 ~9.9 ± 0.6 ka (n = 2)。三个 Drygalski 冰碛嵴的平均 10Be 年龄从外到内分别为 8.6 ± 0.4 ka (n = 2)、8.5 ± 0.2 ka (n = 3) 和 7.6 ± 0.1 ka (n = 2)。内部两个冰碛之间的栖息不稳定因素平均为 7.8 ± 0.1 ka (n = 2)，并且与冰碛年龄一致。来自前冰川湖的沉积物，其集水区延伸到目前冰盖终点（内陆）估计 2 公里处，将冰盖最小范围从 5.4 ka 限制到 0.6 ka。冰碛年代学与湖泊沉积物地层学相结合表明，从 9.9 到 5.4 ka 期间，冰缘可能仍保持在距当前位置约 2 公里的范围内。这种意想不到的全新世早期稳定，先是冰层快速消退，随后是约 5.4 至 0.6ka 之间的最小冰层范围，与全新世早期温暖和北半球夏季日照最大值的许多记录形成鲜明对比。我们认为冰缘稳定性可能与邻近的海洋温度有关，该温度在全新世中期达到最佳温度。
We reconstruct the history of the Greenland Ice Sheet margin on the Nuussuaq Peninsula in central West Greenland through the Holocene using lake sediment analysis and cosmogenic10Be exposure dating of the prominent Drygalski Moraines. Erratics perched on bedrock outboard of the Drygalski Moraines constrain local deglaciation to ∼9.9 ± 0.6 ka (n = 2). Three Drygalski Moraine crests yield mean10Be ages of 8.6 ± 0.4 ka (n = 2), 8.5 ± 0.2 ka (n = 3), and 7.6 ± 0.1 ka (n = 2) from outer to inner. Perched erratics between the inner two moraines average 7.8 ± 0.1 ka (n = 2) and are consistent with the moraine ages. Sediments from a proglacial lake with a catchment area extending an estimated 2 km beneath (inland of) the present ice sheet terminus constrain an ice sheet minimum extent from 5.4 ka to 0.6 ka. The moraine chronology paired with the lake sediment stratigraphy reveals that the ice margin likely remained within ∼2 km of its present position from ∼9.9 to 5.4 ka. This unexpected early Holocene stability, preceded by rapid ice retreat and followed by minimum ice extent between ∼5.4 and 0.6 ka, contrasts with many records of early Holocene warmth and the Northern Hemisphere summer insolation maximum. We suggest ice margin stability may instead be tied to adjacent ocean temperatures, which reached an optimum in the middle Holocene.
DOI：
10.1177/0959683612460785
发表时间：
2013-03
期刊：
The Holocene
影响因子：
--
作者：
K. Perner;M. Moros;A. Jennings;J. Lloyd;K. Knudsen
通讯作者：
K. Perner;M. Moros;A. Jennings;J. Lloyd;K. Knudsen