DOI: 10.5194/cp-8-1047-2012
Scopus记录号: 2-s2.0-84862225468
论文题名: The Aptian evaporites of the South Atlantic: A climatic paradox?
作者: Chaboureau A.-C. ; Donnadieu Y. ; Sepulchre P. ; Robin C. ; Guillocheau F. ; Rohais S.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2012
卷: 8, 期: 3 起始页码: 1047
结束页码: 1058
语种: 英语
Scopus关键词: Aptian
; arid region
; aridity
; catchment
; craton
; drainage network
; evaporite
; general circulation model
; humid environment
; hydrothermal activity
; mineralogy
; paleoclimate
; rifting
; salinity
; seawater
; water depth
; water temperature
; Africa
; Atlantic Ocean
; Atlantic Ocean (South)
; South America
英文摘要: For a long time, evaporitic sequences have been interpreted as indicative of an arid climate. Such systematic interpretations led to the suggestion that the Central segment of the South Atlantic (20-0°) was characterized by an arid climate during the upper Aptian. Indeed, synchronous to this period that corresponds to the rifting and to the opening of this part of the South Atlantic, a large evaporitic sequence spreads out from the equator to 20° S. Using the fully ocean atmosphere coupled model FOAM, we test the potential for the Aptian geography to produce an arid area over the Central segment. Sensitivity to the altitude of the rift shoulders separating the Africa and the South America cratons, to the water depth of the Central segment and to the drainage pattern have been performed. Using seawater salinity as a diagnostic, our simulations show that the southern part of the Central segment is characterized by very high salinity in the case of catchment areas draining the water out of the Central segment. Conversely, whatever the boundary conditions used, the northern part of the Central segment remains humid and salinities are very low. Hence, we conclude that the evaporites deposited in the southern part of the Central segment may have been controlled by the climate favouring aridity and high saline waters. In contrast, the evaporites of the northern part can hardly be reconciled with the climatic conditions occurring there and may be due to hydrothermal sources. Our interpretations are in agreement with the gradient found in the mineralogical compositions of the evaporites from the North to the South, i.e. the northern evaporites are at least 4 times more concentrated than the southern one. © 2012 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49577
Appears in Collections: 气候变化与战略
There are no files associated with this item.
Recommended Citation:
Chaboureau A.-C.,Donnadieu Y.,Sepulchre P.,et al. The Aptian evaporites of the South Atlantic: A climatic paradox?[J]. Climate of the Past,2012-01-01,8(3)