| DOI: | 10.1016/j.gloplacha.2014.06.004
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| 论文题名: | Early glaciation already during the Early Miocene in the Amundsen Sea, Southern Pacific: Indications from the distribution of sedimentary sequences |
| 作者: | Uenzelmann-Neben G.; Gohl K.
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| ISSN: | 0921-8511
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| 出版年: | 2014
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| 卷: | 120 | | 起始页码: | 92
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| 结束页码: | 104
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| 语种: | 英语
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| 英文关键词: | Bottom water circulation
; Glacial development
; Sediment drifts
; Sedimentary sequences
; Variations in material input
; West antarctic ice sheet
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| Scopus关键词: | Glaciers
; Levees
; Sea ice
; Sediment transport
; Sedimentation
; Sedimentology
; Seismic waves
; Bottom-water circulation
; Glacial development
; Sediment drift
; Sedimentary sequence
; Variations in material input
; West antarctic ice sheets
; Glacial geology
; biostratigraphy
; bottom water
; continental slope
; delta
; deposition
; geoaccumulation
; glaciation
; ice sheet
; Miocene
; sediment transport
; sedimentation rate
; Amundsen Sea
; Bellingshausen Sea
; Ross Sea
; Southern Ocean
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| 英文摘要: | The distribution and internal architecture of seismostratigraphic sequences observed on the Antarctic continental slope and rise are results of sediment transport and deposition by bottom currents and ice sheets. Analysis of seismic reflection data allows to reconstruct sediment input and sediment transport patterns and to infer past changes in climate and oceanography. We observe four seismostratigraphic units which show distinct differences in location and shape of their depocentres and which accumulated at variable sedimentation rates. We used an age-depth model based on DSDP Leg 35 Site 324 for the Plio/Pleistocene and a correlation with seismic reflection characteristics from the Ross and Bellingshausen Seas, which unfortunately has large uncertainties. For the period before 21. Ma, we interpret low energy input of detritus via a palaeo-delta originating in an area of the Amundsen Sea shelf, where a palaeo-ice stream trough (Pine Island Trough East, PITE) is located today, and deposition of this material on the continental rise under sea ice coverage. For the period 21-14.1. Ma we postulate glacial erosion for the hinterland of this part of West Antarctica, which resulted in a larger depocentre and an increase in mass transport deposits. Warming during the Mid Miocene Climatic Optimum resulted in a polythermal ice sheet and led to a higher sediment supply along a broad front but with a focus via two palaeo-ice stream troughs, PITE and Abbot Trough (AT). Most of the glaciogenic debris was transported onto the eastern Amundsen Sea rise where it was shaped into levee-drifts by a re-circulating bottom current. A reduced sediment accumulation in the deep-sea subsequent to the onset of climatic cooling after 14. Ma indicates a reduced sediment supply probably in response to a colder and drier ice sheet. A dynamic ice sheet since 4. Ma delivered material offshore mainly via AT and Pine Island Trough West (PITW). Interaction of this glaciogenic detritus with a west-setting bottom current resulted in the continued formation of levee-drifts in the eastern and central Amundsen Sea. © 2014 Elsevier B.V. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904326684&doi=10.1016%2fj.gloplacha.2014.06.004&partnerID=40&md5=ef524c194f863395de8aacaf1ffca373
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/11417
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| Appears in Collections: | 全球变化的国际研究计划
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作者单位: | Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Am Alten Hafen 26, 27568 Bremerhaven, Germany
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| Recommended Citation: | |
Uenzelmann-Neben G.,Gohl K.. Early glaciation already during the Early Miocene in the Amundsen Sea, Southern Pacific: Indications from the distribution of sedimentary sequences[J],2014-01-01,120.
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