Antarctic ice-rafted detritus (IRD) in the South Atlantic: Indicators of iceshelf dynamics or ocean surface conditions?

Abstract Ocean sediment core TN057-13PC4/ODP1094, from the Atlantic sector of the Southern Ocean, contains elevated lithogenic material in sections representing the last glacial period compared to the Holocene. This ice-rafted detritus is mainly comprised of volcanic glass and ash, but has a signifi...

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Bibliographic Details
Main Authors: Simon H. H. Nielsen, D. A. Hodell
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Antarctic
Sandwich Islands
South Sandwich Islands
Southern Ocean
Antarc*
Ice Sheet
Sea ice
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.501.5776
http://pubs.usgs.gov/of/2007/1047/srp/srp020/of2007-1047srp020.pdf
Description
Summary:Abstract Ocean sediment core TN057-13PC4/ODP1094, from the Atlantic sector of the Southern Ocean, contains elevated lithogenic material in sections representing the last glacial period compared to the Holocene. This ice-rafted detritus is mainly comprised of volcanic glass and ash, but has a significant input of what was previously interpreted as quartz during peak intervals (Kanfoush et al., 2000, 2002). Our analysis of these clear mineral grains indicates that most are plagioclase, and that South Sandwich Islands is the predominant source, similar to that inferred for the volcanic glass (Nielsen et al., in review). In addition, quartz and feldspar with possible Antarctic origin occur in conjunction with postulated episodes of Antarctic deglaciation. We conclude that while sea ice was the dominant ice rafting agent in the Polar Frontal Zone of the South Atlantic during the last glacial period, the Holocene IRD variability may reflect Antarctic ice sheet dynamics.

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