DOI: 10.1016/j.quascirev.2016.05.036
论文题名: Timing of wet episodes in Atacama Desert over the last 15 ka. The Groundwater Discharge Deposits (GWD) from Domeyko Range at 25°S.
作者: Sáez A. ; Godfrey L.V. ; Herrera C. ; Chong G. ; Pueyo J.J.
刊名: Quaternary Science Reviews
出版年: 2016
卷: 145 起始页码: 82
结束页码: 93
语种: 英语
英文关键词: Central Andes
; Groundwader Discharge Deposits
; Holocene
; Pluvial events
; Summer monsoons
; Wetlands
Scopus关键词: Atmospheric thermodynamics
; Deposits
; Discharge (fluid mechanics)
; Groundwater
; Moisture
; Precipitation (meteorology)
; Wetlands
; Central Andes
; Discharge deposits
; Holocenes
; Pluvial events
; Summer monsoon
; Landforms
; climate variation
; deposition
; discharge
; facies analysis
; groundwater
; historical record
; Holocene
; monsoon
; paleoclimate
; paleohydrology
; timescale
; wetland
; Amazon Basin
; Atacama Desert
; Chile
; Gran Chaco
英文摘要: A chronologically robust reconstruction of timing and dynamics of millennial time scale wet episodes encompassing the entire Atacama Desert during the last 15 ka has been constructed. To accomplish this, a new composite paleoclimatic record from Groundwater Discharge Deposits (GWD) in the Sierra de Varas (Domeyko Range, southern Atacama in Chile at 25°S) has been compiled and compared with other published paleohydrologic records from the Atacama region. In Sierra de Varas (SV), three millennial timescale wet climate phases have been characterized: around 14.5 ka cal BP, 12.2-9.8 ka cal BP, and 4.7 ka cal BP to the present day. These wet phases are interpreted from intervals of GWD facies formed during periods when the springs were active. GWD facies include: (1) black organic peat, rooted mudstones and sandstones formed in local wetland environments, and (2) gypsum-carbonate rich layers formed by interstitial growth. GWD intervals alternate with gravelly alluvial material deposited during arid phases. A trend towards less humid conditions during the Late Holocene wet episode characterizes GWD sedimentary series in Sierra the Varas, suggesting the onset of a dry episode over the last few centuries. Around 0.7 ka BP a very short wet episode is recorded in the central part of the desert suggesting this was the time of maximum humidity for the entire late Holocene wet period. A brief arid phase occurred between 1.5 and 2.0 ka BP indicated by the absence of GWD in the Domeyko Range. The paleoclimatic reconstruction encompassing the entire Atacama region shows that both the intensity and occurrence of wetter conditions were governed mainly by the distance to the source of moisture, and secondarily by the elevation of the sites. In the northern Atacama (16-20°S), four wet phases fed by N-NE summer monsoon precipitations have been proposed: Tauca phase (18-14 ka cal BP) and Coipasa phase (13-10 ka cal BP) during the Late Glacial, followed by Early Holocene and Late Holocene phases. In contrast, southern Atacama records (23-28°S) display only three pluvial periods which result from SE summer monsoon precipitation and outbreaks from the Westerlies during wintertime. The Early Holocene in the southern Atacama was a period of aridity, generating important landscape differences to those in the Northern Atacama where conditions were wetter. The core of Atacama (20-23°S) is the overall driest part of the desert because it is located in the distal limits of both N-NE and SE sources of moisture, the Amazon Basin and Gran Chaco areas, respectively. © 2016 Elsevier Ltd. 资助项目: Sáez, A.
; Department of Earth and Ocean Dynamics, Facultat de Geologia, Universitat de Barcelona, Marti Franqués s/n, Spain
; 电子邮件: a.saez@ub.edu
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59554
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth and Ocean Dynamics, Facultat de Geologia, Universitat de Barcelona, Marti Franqués s/n, Barcelona, Spain; Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ, United States; Departamento de Ciencias Geológicas, Universidad Católica del Norte, Avenida Angamos, Antofagasta, Chile; Facultat de Geologia, Universitat de Barcelona, Marti Franqués s/n, Barcelona, Spain
Recommended Citation:
Sáez A.,Godfrey L.V.,Herrera C.,et al. Timing of wet episodes in Atacama Desert over the last 15 ka. The Groundwater Discharge Deposits (GWD) from Domeyko Range at 25°S.[J]. Quaternary Science Reviews,2016-01-01,145