Magnetic susceptibility and ice-rafted debris in surface sediments of the Nordic Sea

Magnetic susceptibility and ice-rafted debris of surface sediments in the Nordic Seas were investigated to reconstruct source areas and recent transport pathways of magnetic minerals. From the distribution of magnetic susceptibility and ice-rafted debris and published data on petrographic tracers for iceberg drift, we reconstructed a counter-clockwise iceberg drift pattern during cooler phases in the Holocene, which is similar to conceptual and numerical models for Weichselian iceberg drift. The release of basaltic debris at Scoresby Sund played a significant role for the magnetic signature of stadial/interstadial events during isotope stage 3 recorded in sediment cores of the Nordic Seas.

本研究针对挪威海（Nordic Seas）表层沉积物中的磁化率（magnetic susceptibility）与冰筏碎屑（ice-rafted debris, IRD）开展调查，旨在重建磁性矿物的物源区与近代运移路径。基于磁化率与冰筏碎屑的分布特征，以及已发表的冰山运移岩石示踪剂数据，本研究重建了全新世（Holocene）冷期阶段的逆时针冰山运移模式，该模式与魏克塞尔冰期（Weichselian）冰山运移的概念模型及数值模型结果高度一致。斯科雷斯比松（Scoresby Sund）峡湾玄武岩碎屑的释放，对挪威海沉积物岩芯中记录的同位素3期（isotope stage 3）冰阶（stadial）/间冰阶（interstadial）事件的磁化率特征具有显著作用。