Millennial-scale depositional cycles related to British Ice Sheet variability and North Atlantic palcocirculation since 45 kyr
Abstract. Lithology, lithic petrology, planktonic foraminiferal bundances, and clastic grain sizes have been determined in a 30 m-long core recovered from the Barra Fan off northwest Scotland. The record extends back to around 45 kyr B.P., with sedimentation rates ranging between 50 and 200 cm/kyr....
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.7223 http://discovery.ucl.ac.uk/8804/1/1999PA000483.pdf |
| Summary: | Abstract. Lithology, lithic petrology, planktonic foraminiferal bundances, and clastic grain sizes have been determined in a 30 m-long core recovered from the Barra Fan off northwest Scotland. The record extends back to around 45 kyr B.P., with sedimentation rates ranging between 50 and 200 cm/kyr. The abundance of ice-rafted debris indicates 16 glacimarine events, including temporal equivalents to Heinrich events 1-4. Enhanced concentrations of basaltic material derived from the British Tertiary Province suggest that the glacimarine sediments record variations in a glacial source on the Hebrides helf margin. Glacirnarine zones are separated by silty intervals with high planktonic foraminifera concentrations that reflect an interstadial circulation regime in the Rockall Trough. The results uggest that the last British Ice Sheet fluctuated with a periodicity of 2000-3000 years, in common with the Dansgaard-Oeschger climate cycle. 1. |
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