A Robust, Multisite Holocene History of Drift Ice off Northern Iceland: Implications for North Atlantic Climate

• Published in: The Holocene
• Main Authors: Andrews, John T., Darby, Dennis A., Eberle, Dennis, Jennings, Anne E., Moros, Matthias, Ogilvie, Astrid
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ODU Digital Commons 2009
• Subjects: Ice rafted debris; Iceland; Quartz; Drift ice; Holocene; Arctic basin; Climate; Geology; Oceanography; Arctic; Arctic Ocean; Arctic Basin; Climate change; North Atlantic
• Online Access: https://digitalcommons.odu.edu/oeas_fac_pubs/285; https://doi.org/10.1177/0959683608098953; https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1296/viewcontent/Andrews_2009_A_robust__multisite_Holocene_hist.pdf

An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative xray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quartz wt.% varied between 0.2 and 3.4 and maximum values ranged between 2.8 and 11.8 wt.%. High values were attained in the early Holocene and minimum values were reached 6–7 cal. ka BP. Quartz wt.% then rose steadily during the late Holocene. Our data exhibit no correlation with counts on haematite-stained quartz (HSQ) grains from VM129-191 west of Ireland casting doubt on the ice-transport origin. A pilot study on the provenance of Fe oxide grains in two cores that cover the last 1.3 and 6.1 cal. ka BP indicated a large fraction of the grains between 1 and 6 cal. ka BP were from either Icelandic or presently unsampled sources. However, there was a dramatic increase in Canadian and Russian sources from the Arctic Ocean ~1 cal. ka BP. These data may indicate the beginning of an Arctic Oscillation-like climate mode.