The Late Weichselian glaciation of the Franz Victoria Through, northern Barents Sea: ice sheet extent and timing
High resolution seismic pro®les (PARASOUND, 4 kHz) and three sediment cores from the Franz Victoria Trough and the adjacent continental slope were studied in order to constrain the timing and extent of the northern Svalbard/Barents Sea ice sheet during the Late Weichselian glaciation. Stacked debris...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2000
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.8176 http://www.ngu.no/glacipet/photos/internal/pdfs_of_articles/kleiber_knies_niessen2000.pdf |
| Summary: | High resolution seismic pro®les (PARASOUND, 4 kHz) and three sediment cores from the Franz Victoria Trough and the adjacent continental slope were studied in order to constrain the timing and extent of the northern Svalbard/Barents Sea ice sheet during the Late Weichselian glaciation. Stacked debris ¯ow lobes and layers of glacimarine diamicton on the lower continental slope indicate that large quantities of glacially derived sediments were deposited by the northern Svalbard/Barents Sea ice sheet directly onto the upper continental slope at approximately 23 14C ka. A grounding-line advance to the shelf break is supported by the identi®cation of diamicton, interpreted as till, in the seismic pro®le near the shelf break. After several ice sheet instabilities marked by signi®cant input of ice rafted detritus to the continental margin, the disintegration of the northern Svalbard/Barents Sea ice sheet (Termination Ia) is indicated by a distinct pulse of ice rafted detritus at 15.4 14C ka and the transition to an isotopically de®ned meltwater signal. The drastic change in sedimentary pattern on the upper continental slope, dated to about 13.4 14C ka, is interpreted as grounding-line retreat from the shelf edge. A further stepwise retreat of the northern Svalbard/Barents Sea ice sheet is indicated by pulses of ice rafted detritus which appear to be contemporaneous with the onset of distinct ice rafting events in adjacent areas and pulses of glacimarine sedimentation in the southwestern Barents Sea. q 2000 |
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