DOI: 10.1016/j.quascirev.2018.08.010
Scopus记录号: 2-s2.0-85053064063
论文题名: Ice marginal dynamics of the last British-Irish Ice Sheet in the southern North Sea: Ice limits, timing and the influence of the Dogger Bank
作者: Roberts D.H. ; Evans D.J.A. ; Callard S.L. ; Clark C.D. ; Bateman M.D. ; Medialdea A. ; Dove D. ; Cotterill C.J. ; Saher M. ; Cofaigh C.Ó. ; Chiverrell R.C. ; Moreton S.G. ; Fabel D. ; Bradwell T.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2018
卷: 198 起始页码: 181
结束页码: 207
语种: 英语
英文关键词: British-Irish Ice sheet
; Dogger Bank
; Europe
; Geomorphology
; Glaciation
; North Sea
; Quaternary
Scopus关键词: Geochronology
; Geomorphology
; Glacial geology
; Glaciers
; Lakes
; Luminescence
; Sediments
; Submarine geology
; Timing circuits
; British-Irish ice sheet
; Dogger Bank
; Europe
; Glaciation
; North Sea
; Quaternary
; Ice
; geochronology
; geomorphology
; glaciation
; glaciolacustrine deposit
; ice flow
; ice margin
; ice sheet
; Last Glacial
; luminescence dating
; moraine
; Quaternary
; seafloor
; Atlantic Ocean
; Dogger Bank
; England
; Lincolnshire
; Norfolk Island
; North Sea
; North Sea
; United Kingdom
英文摘要: The southern North Sea is a particularly important area for understanding the behaviour of the British-Irish Ice Sheet (BIIS) during the last glacial cycle. It preserves a record of the maximum extent of the eastern sector of the BIIS as well as evidence for multiple different ice flow phases and the dynamic re-organisation of the BIIS. However, to date, the known ice sheet history and geochronology of this region is predominantly derived from onshore geological evidence, and the offshore imprint and dynamic history of the last ice sheet remain largely unknown. Using new data collected by the BRITICE-CHRONO project this paper explores the origin and age of the Dogger Bank; re-assesses the extent and age of the glaciogenic deposits across the shallow areas of the North Sea between the Dogger Bank and the north Norfolk coast and; re-examines the dynamic behaviour of the BIIS in the southern North Sea between 31.6 and 21.5 ka. This paper shows the core of the Dogger Bank to be composed glaciolacustrine sediment deposited between 31.6 and 25.8 ka. Following its formation the western end of the Dogger lake was overridden with ice reaching ∼54°N where the ice margin is co-incident with the southerly extent of subglacial tills previously mapped as Bolders Bank Fm. This initial ice override and retreat northwards back across the Dogger lake was complete by 23.1 ka, but resulted in widespread compressive glaciotectonism of the lake sediments and the formation of thrust moraine complexes. Along the northern edge of the bank moraines are on-lapped by later phase glaciolacustrine and marine sediments but do not show evidence of subsequent ice override. The shallow seafloor to the west and southwest of the Dogger Bank records several later phases of ice advance and retreat as the North Sea Lobe flowed between the Dogger Bank and the Yorkshire/Lincolnshire coasts and reached North Norfolk. New optically stimulated luminescence (OSL) ages from Garrett Hill on outwash limit the arrival of the BIIS on the Norfolk coast to 22.8–21.5 ka. Multiple till sheets and chains of moraines on the seafloor north of Norfolk mark dynamic oscillation of the North Sea Lobe margin as it retreated northwards. This pattern of behaviour is broadly synchronous with the terrestrial record of deposition of subglacial, glaciofluvial and glaciolacustrine sediments along the Yorkshire coast which relate to post Dimlington Stadial ice marginal oscillations after 21.5 ka. With respect to forcing mechanisms it is likely that during the early phases of the last glacial maximum (∼30-23ka) the interaction between the southern margin of the BIIS and the Dogger Lake was critical in influencing flow instability and rapid ice advance and retreat. However, during the latter part of the last glacial maximum (22–21 ka) late-phase ice advance in the southern North Sea became restricted to the western side of the Dogger Bank which was a substantial topographic feature by this time. This topographic confinement, in addition to decoupling of the BIIS and the Fennoscandian Ice Sheet (FIS) further north, enabled ice to reach the north Norfolk coast, overprinting the seabed with late-phase tills of the Bolders Bank Fm. © 2018 The Authors
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112043
Appears in Collections: 气候减缓与适应
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作者单位: Department of Geography, Durham University, Durham, DH1 3LE, United Kingdom; Department of Geography, University of Sheffield, Sheffield, S10 2TN, United Kingdom; British Geological Survey, The Lyell Centre, Research Avenue South, Edinburgh, EH14 4AP, United Kingdom; School of Ocean Sciences, Bangor University, Menai BridgeLL59 5AB, United Kingdom; Department of Geography, University of Liverpool, Liverpool, L69 7ZT, United Kingdom; Natural Environment Research Council, Radiocarbon facility, East KilbrideScotland G75 OQF, United Kingdom; SUERC, Rankine Avenue, Scottish Enterprise Technology Park, East KilbrideScotland G75 0QF, United Kingdom; Biological and Environmental Sciences, University of Stirling, Stirling, Scotland FK9 4LA, United Kingdom
Recommended Citation:
Roberts D.H.,Evans D.J.A.,Callard S.L.,et al. Ice marginal dynamics of the last British-Irish Ice Sheet in the southern North Sea: Ice limits, timing and the influence of the Dogger Bank[J]. Quaternary Science Reviews,2018-01-01,198