DOI: 10.1016/j.palaeo.2014.05.038
论文题名: Eolian sand sheet deposition in the San Luis paleodune field, western Argentina as an indicator of a semi-arid environment through the Holocene
作者: Forman S.L. ; Tripaldi A. ; Ciccioli P.L.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 411 起始页码: 122
结束页码: 135
语种: 英语
英文关键词: Eolian sand sheet
; Holocene
; Semi-arid paleoenvironment
; Western Pampas
英文摘要: Eolian deposits are common in the western Pampas of Argentina, and most are assumed to be associated with glacial conditions. Stratigraphic and sedimentologic studies coupled with OSL dating in San Luis Province document for the first time a nearly continuous sequence of eolian sand sheet deposits that span most of the Holocene. Petrology and geochemical analyses indicate that the source of the sand is from pre-existing Pleistocene eolian sediments. Sand sheet deposition between ca. 12 and 1 ka is associated with sparse, Monte-type vegetation that occurs with drier conditions (MAP 450-100 mm) than the late 20th century (~ 700 mm). This paleoenvironmental inference is consistent with nearby pollen and lake level records. A persistent semi-arid environment in western Argentina during the Holocene may reflect sustained warm SSTs in the western equatorial Atlantic Ocean, which may have suppressed the pressure gradient between the South Atlantic Anticyclone and Chaco Low and thus, the flux of summer moisture to western Argentina. There appears to be a paleoclimatic "dipole" response between a dry western Argentina and a wet southeastern Brazil, which is consistent with the increasing strength of the South American Monsoon through the Holocene. Sand sheet accretion appears to cease by 800 to 200. years ago with wetter conditions and succession to Espinal vegetation prior to European contact. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69237
Appears in Collections: 过去全球变化的重建
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作者单位: Dept. of Geology, Baylor University, One Bear Place #97354, Waco, TX, United States; IGEBA-CONICET, Dept. of Geological Sciences, University of Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
Recommended Citation:
Forman S.L.,Tripaldi A.,Ciccioli P.L.. Eolian sand sheet deposition in the San Luis paleodune field, western Argentina as an indicator of a semi-arid environment through the Holocene[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,411