Late Cenozoic glacial history and evolution of the Storegga Slide area and adjacent slide flank regions, Norwegian continental margin
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- 作者：Hjelstuen ; Berit Oline ; Petter Sejrup ; Hans ; Haflidason ; Haflidi ; Nyg??rd ; Atle ; Ceramicola ; Silvia ; et. al.
- 关键词：Late Cenozoic ; Continental margin ; Offshore Norway ; Glaciations
- 刊名：Marine and Petroleum Geology
- 出版年：2005
- 出版时间：January - February, 2005
- 年：2005
- 卷：22
- 期：1-2
- 页码：57-69
- 全文大小：1.79 M
文摘
Acoustic data and sediment cores collected from the Storegga Slide and its adjacent slide flanks, i.e. the Vøring Plateau to the north and the North Sea Fan to the south, have been used to study the Late Cenozoic glacial history and geological development of this region. Age constrains obtained from the investigated cores show that the Fennoscandian Ice Sheet reached the shelf edge during Marine Isotope Stages (MIS) 12, 10, 8, 6 and 2. Ice sheet fluctuations within each glaciation might have occurred, as is evidenced for the Last Glacial Maximum (MIS 2). The first extensive ice advance is identified in the Early Pleistocene, at c. 1.1 Ma; however, between 2.6 and 0.5 Ma the ice sheets were largely restricted to the fjords and inner shelf. During each glacial maximum, glacigenic debris flows (GDFs) transported basal till, deposited at the shelf edge, into the deep sea along the entire studied margin. The most voluminous GDF sequences are found on the southern Storegga Slide flank (North Sea Fan), where the individual flows are found as far as 500 km from the shelf edge. On the Vøring Plateau glacimarine/hemipelagic sedimentation has dominated the last c. 250,000 yr. During MIS 2 such sediments were rapidly deposited, covering the upper-slope-limited GDF units in this region. Between c. 15,700 and 15,000 14C yr BP, i.e. during the last deglaciation of the Norwegian margin, a presumed meltwater plume, released from the disintegrating Norwegian Channel Ice Stream, transported and rapidly deposited up to 20 m of fine-grained sediments in the region north of the North Sea Fan. The rapid deposition of large volumes of GDFs, glacimarine and meltwater related sediments might have influenced the stability of the slope sediments in the studied region, promoting conditions favorable for failure. Furthermore, these high sedimentation rates also partly account for the high subsidence rates observed on the Norwegian continental margin in the Late Cenozoic.