DOI: 10.1016/j.palaeo.2015.10.038
论文题名: Early to Middle Miocene climate in the Atacama Desert of Northern Chile
作者: Oerter E. ; Amundson R. ; Heimsath A. ; Jungers M. ; Chong G. ; Renne P.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 441 起始页码: 890
结束页码: 900
语种: 英语
英文关键词: Andes Mountains
; Atacama paleoclimate
; Hyperaridity
; Paleosol
; Pedogenic carbonate
; Stable isotopes
英文摘要: The Cenozoic paleoclimate of the Atacama Desert is not well known. We examined 14 early to mid-Miocene paleosols exposed in the El Tesoro Mine, near Calama, Chile. The paleosols developed on an aggrading alluvial fan system, and lie above the mineralized gravel horizons that host a copper ore body. Soil-forming conditions that oscillated between chemical weathering and clay production (humid: analogous to modern Alfisols) to environments favoring the accumulation of pedogenic carbonate (arid to semi-arid: analogous to modern Aridisols) are indicated. In contrast, the region is presently hyperarid, and soils accumulate sulfates, chlorides, and nitrates. While total chemical analyses clearly show the accumulation of Ca by the carbonate-rich paleosols, none of the soils exhibit significant losses of elements by leaching. The δ18O values of the carbonates range from -8.79‰ to -3.16‰ (VPDB). The O isotope data, when combined with published data from the region, reveal a significant divergence in the O isotope composition of precipitation in the eastern and western margins of the Andean plateau since the early Miocene, suggesting that simple interpretations of declining δ18O values of carbonate with increasing elevation may not be appropriate. These paleosols clearly indicate that wetter conditions prevailed in what is now the Atacama Desert during the early to mid-Miocene. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68695
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Environmental Science, Policy and Management, University of California, 130 Mulford Hall, Berkeley, United States; School of Earth and Space Exploration, Arizona State University, Tempe, AZ, United States; Universidad Católica del Norte, Antofagasta, Chile; Berkeley Geochronology Center, 2455 Ridge Rd., Berkeley, United States; Department of Earth and Planetary Science, University of California, Berkeley, United States
Recommended Citation:
Oerter E.,Amundson R.,Heimsath A.,et al. Early to Middle Miocene climate in the Atacama Desert of Northern Chile[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,441