DOI: 10.1016/j.quascirev.2015.12.021
Scopus记录号: 2-s2.0-84952895231
论文题名: Late Quaternary evolution of Lago Castor (Chile, 45.6°S): Timing of the deglaciation in northern Patagonia and evolution of the southern westerlies during the last 17 kyr
作者: Van Daele M. ; Bertrand S. ; Meyer I. ; Moernaut J. ; Vandoorne W. ; Siani G. ; Tanghe N. ; Ghazoui Z. ; Pino M. ; Urrutia R. ; De Batist M.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2016
卷: 133 起始页码: 130
结束页码: 146
语种: 英语
英文关键词: Deglaciation
; Patagonia
; Sediment drift
; Seismic reflection
; Westerlies
Scopus关键词: Catchments
; Sediments
; Seismic waves
; Seismology
; Deglaciations
; Patagonia
; Sediment drift
; Seismic reflections
; Westerlies
; Lakes
英文摘要: Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ~28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained - possibly through an outburst flood - when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ~20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ~17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase in wind strength at 46°S from 11.2 to 4.5 cal kyr BP, which supports the hypothesis that the SWWB broadened during the early and middle Holocene. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59701
Appears in Collections: 过去全球变化的重建
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作者单位: Renard Centre of Marine Geology, Ghent University, Krijgslaan 281, S8, Gent, Belgium; Instituto de Ciencias de la Tierra, Universidad Austral de Chile, Casilla 567, Valdivia, Chile; GEOPS, UMR 8148 Université de Paris - Sud 11, Bâtiment 504, Orsay, France; IsTerre, Institut des Sciences de la Terre, Université Joseph Fourier, Grenoble, France; Centro EULA, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Recommended Citation:
Van Daele M.,Bertrand S.,Meyer I.,et al. Late Quaternary evolution of Lago Castor (Chile, 45.6°S): Timing of the deglaciation in northern Patagonia and evolution of the southern westerlies during the last 17 kyr[J]. Quaternary Science Reviews,2016-01-01,133