Ice-rafted detritus events in the Arctic during the last glacial interval, and the timing of the Innuitian and Laurentide ice sheet calving events

Polar research

Paula Zimmerman¹  Dennis A. Darby² 

[1] Dept. of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USA;Dept. of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USACorrespondence

关键词: Arctic Ocean;    ice-rafting events;    glacial collapses;    sea ice;    Fe grain provenance;   

DOI  :  10.1111/j.1751-8369.2008.00057.x

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

Ice-rafted detritus (IRD) layers in the Arctic Ocean not only indicate the source of this detrital sediment, but give insights into the ice drift and ice sheet history. Detrital sand-sized Fe oxide mineral grains that are matched to precise sources using the microprobe chemical fingerprint of each grain, along with elevated coarse IRD abundance and radiocarbon ages, are used to define IRD peaks from the Innuitian and Arctic portions of the Laurentide ice sheets. Because grains from these two areas can be entrained by sea ice from the shelves just offshore of the calving areas, peaks in these grains must be correlated to coarse IRD to identify iceberg calving events, and to distinguish them from sea-ice rafting. The sequence of IRD peaks deposited by icebergs from these two ice sheets indicate that both ice sheets calved bergs at accelerated numbers, six or seven times, from 11 to 36 Kya. The relatively short times between most of these IRD events suggest that the ice sheets did not completely collapse wit...

【 授权许可】

CC BY-NC