Origin of ice-rafted debris: Pleistocene paleoceanography in the western Arctic Ocean
Origin of ice-rafted debris: Pleistocene paleoceanography in the western Arctic Ocean
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DOI：
10.1029/96pa02557
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发表时间：
1996-12-01
期刊：
影响因子：
--
通讯作者：
Vincent, JS
中科院分区：
文献类型：
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作者：
Bischof, J;Clark, DL;Vincent, JS
本文通过对北冰洋中西部5个冰柱中大于250 μ m的冰筏碎屑成分的颗粒计数，并与加拿大西北部冰柱碎屑成分进行了对比，以确定冰筏碎屑的来源，重建更新世冰筏碎屑的漂流通道和表层流。冰筏碎屑成分在碳酸盐和石英为主的组合之间反复交替，沿着有变质岩、火成岩、弹性岩和一些燧石。石英含量最高的是阿尔法海岭，而碳酸盐百分比最高的是北风海岭（NWR）和楚科奇冰帽。碳酸盐的来源是班克斯和维多利亚群岛周围地区以及加拿大北方部分地区。石英很可能起源于伊丽莎白女王群岛中部。位于阿尔法海岭东南部的IRD主要由来自北方埃尔斯米尔岛和北方格陵兰岛的镁铁质结晶岩组成。在过去的100万年里，至少有6个主要的冰期被确定，在此期间，冰山在博福特海向西漂移，在北冰洋中部直向北漂移，在东南阿尔法海岭向东北漂移。
The composition of Pleistocene ice-rafted debris (IRD) >250 mu m was analyzed quantitatively by grain counting in five sediment cores from the western central Arctic Ocean and compared with the composition of till clasts from NW Canada in order to determine the dropstone origin and to reconstruct the Pleistocene ice driftways and surface currents, The IRD composition alternates repeatedly between carbonate- and quartz-dominated assemblages, along with metamorphic and igneous rocks, elastic rocks, and some chert. The highest quartz content is found on the Alpha Ridge, while carbonate percentages are highest on the Northwind Ridge (NWR) and the Chukchi Cap, The source for the carbonates is the area around Banks and Victoria Islands and parts of northern Canada. Quartz most likely originated from the central Queen Elizabeth Islands. IRD on the southeastern Alpha Ridge is dominated by mafic crystalline rocks from northern Ellesmere Island and northern Greenland, At least six major glacial intervals are identified within the last 1 million years, during which icebergs drifted toward the west in the Beaufort Sea, straight northward in the central Arctic Ocean, and northeastward on the SE Alpha Ridge.