干旱区生态环境知识资源中心(Arid): Development of a steep erosional gradient over a short distance in the hyperarid core of the Atacama Desert, northern Chile

Arid

DOI	10.1016/j.gloplacha.2019.103068
	Development of a steep erosional gradient over a short distance in the hyperarid core of the Atacama Desert, northern Chile
	Mohren, Joel; Binnie, Steven A.; Ritter, Benedikt; Dunai, Tibor J.
通讯作者	Mohren, Joel
来源期刊	GLOBAL AND PLANETARY CHANGE
ISSN	0921-8181
EISSN	1872-6364
出版年	2020
卷号	184
英文摘要	Although generally considered to exist under hyperarid conditions over the long term, landscapes in many parts of the Coastal Cordillera of northern Chile have undergone fluvial erosion. Small-scale drainage systems in this mountain range are mostly isolated from river networks and associated processes originating in the Precordillera or the High Andes to the east, thus providing natural laboratories to investigate the interplay between erosion, atmospheric deposition, tectonics and local (micro-) climatic conditions. In this study, we present a set of cosmogenic Be-10 and Al-26 derived, catchment-wide erosion rates along a short (2.5 km) E-W transect on the northern rim of the Rio Loa Canyon in the Coastal Cordillera of northern Chile (latitude 21.4 degrees S). Here, a flat sedimentary gravel surface, which was deposited before the Middle Miocene, becomes increasingly dissected and changes into a badland-like topography to the west. The Be-10 erosion rates increase by approximately an order of magnitude from east to west, reflecting (1) localised tectonic movements, (2) geologically recent base level lowering, (3) time-integrated (micro-) climatic gradients and (4) the presence/absence of gyperete. These findings are corroborated by analysis of geomorphologic parameters, which point towards the presence of two fundamentally different erosional regimes in this small study area. These regimes are sharply delineated along a topographically modest tectonic ridge. To the west, a detachment-limited erosion regime prevails, while in the east a transport-limited regime is dominant. The presence or absence of gyperete, whose prevalence is governed by (micro-) climatic conditions, generally appears to reflect the respective erosional regimes. The erosion rates we infer point to a long-term process of differential drainage evolution in the study area, likely on timescales of millions of years.
英文关键词	Geomorphology Gypsum Erosion Crust Cosmogenic nuclides Atacama Desert
类型	Article
语种	英语
国家	Germany
收录类别	SCI-E
WOS记录号	WOS:000508491500013
WOS关键词	COSMOGENIC NUCLIDE ANALYSIS ; CENTRAL NAMIB DESERT ; ACCELERATOR MASS-SPECTROMETRY ; DIGITAL ELEVATION MODELS ; THRESHOLD HILLSLOPES ; FORE-ARC ; COASTAL CORDILLERA ; DENUDATION RATES ; FUNCTIONAL-RELATIONSHIPS ; CLIMATIC CONTROLS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
EI主题词	2020-01-01
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/312222
作者单位	Univ Cologne, Inst Geol & Mineral, Zulpicher Str 49b, D-50674 Cologne, Germany
推荐引用方式 GB/T 7714	Mohren, Joel,Binnie, Steven A.,Ritter, Benedikt,et al. Development of a steep erosional gradient over a short distance in the hyperarid core of the Atacama Desert, northern Chile[J],2020,184.
APA	Mohren, Joel,Binnie, Steven A.,Ritter, Benedikt,&Dunai, Tibor J..(2020).Development of a steep erosional gradient over a short distance in the hyperarid core of the Atacama Desert, northern Chile.GLOBAL AND PLANETARY CHANGE,184.
MLA	Mohren, Joel,et al."Development of a steep erosional gradient over a short distance in the hyperarid core of the Atacama Desert, northern Chile".GLOBAL AND PLANETARY CHANGE 184(2020).