干旱区生态环境知识资源中心(Arid): The origin of the magnetic record in Eocene-Miocene coarse-grained sediments deposited in hyper-arid/arid conditions: Examples from the Atacama Desert

Arid

DOI	10.1016/j.palaeo.2018.12.009
	The origin of the magnetic record in Eocene-Miocene coarse-grained sediments deposited in hyper-arid/arid conditions: Examples from the Atacama Desert
	Pizarro, H.1,2; Rousse, S.2; Riquelme, R.1; Veloso, E.3; Campos, E.1; Gonzalez, R.1; Bissig, T.4,6; Carretier, S.2; Fernandez-Mort, A.1,5; Munoz, S.1
通讯作者	Pizarro, H.
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
ISSN	0031-0182
EISSN	1872-616X
出版年	2019
卷号	516 页码:322-335
英文摘要	Magnetic proxies for paleoclimate are tools widely used to understand climate variability, yet current proxies focus on loess-derived soils in humid to temperate climate zones, whereas coarse-grained sediments in arid-hyperarid climate zones remain poorly investigated. To test the potential paleoclimatic-environmental significance of the magnetic record of coarse-grained sediments deposited in a region with a mean annual precipitation (MAP) < 200 mm yr(-1), we selected three previously studied sedimentary sequences from the Atacama Desert (Centinela area) and explored their magnetic properties, paedogenic features, salt chemistry and mineralogy. These sequences were deposited under different climate-environmental conditions from the Eocene to the Miocene, and correspond, from oldest to youngest, to the Atravesados II gravels (Atli), the Arrieros gravels (Arr) and the Ratones sediments (Rat). The magnetic susceptibility values (k) obtained in the stratigraphic record of the gravels are mainly controlled by the concentration of detrital (titano)magnetite, which is concentrated in the finest fraction ( < 0.5 mm) of sediments. The values decrease in the coarse sediments from Atli to Arr following a climatic transition from arid to hyperarid conditions, an interpretation that is supported by the transition from carbonate-rich (MAP similar to 40 mm yr(-1)) to sulfate-rich paleosols (MAP < 10 mm yr(-1)), and changes in the tectonic conditions and/or sedimentary source. In contrast, the Rat fine-grained sediments record changes in paleo-wetland dynamics. The high frequency-dependent magnetic susceptibility (kfd%) values obtained from these layers are mainly controlled by the concentration of authigenic magnetite-maghemite and/or hematite crystals of superparamagnetic/single magnetic size. The increase in kfd% is linked to an increase in the authigenic degree, which is related to variations in the depth of the local water table. These results demonstrate the potential of magnetic proxies to reveal climatic/environmental signals in coarse-grained sediments deposited under desert climate conditions.
英文关键词	Atacama paleoclimate Magnetic proxies Atacama gravels Paleoenvironment Wetland deposits Paleosols
类型	Article
语种	英语
国家	Chile ; France ; Canada ; Spain
收录类别	SCI-E
WOS记录号	WOS:000456903000026
WOS关键词	FREQUENCY-DEPENDENT SUSCEPTIBILITY ; PORPHYRY COPPER-DEPOSIT ; CHINESE LOESS ; CLIMATE-CHANGE ; MODERN SOILS ; IRON-OXIDES ; BASIN ; ARIDITY ; UPLIFT ; ENHANCEMENT
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS研究方向	Physical Geography ; Geology ; Paleontology
来源机构	French National Research Institute for Sustainable Development
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/217862
作者单位	1.Univ Catolica Norte, Dept Ciencias Geol, Av Angamos 0610, Antofagasta, Chile; 2.Univ Toulouse, GET, IRD, CNRS,UPS, 14 Ave E Belin, F-31400 Toulouse, France; 3.Pontificia Univ Catolica Chile, Dept Ingn & Geotecnia, Av Vicuna Mackenna 4860, Santiago, Chile; 4.Univ British Columbia, Dept Earth Ocean & Atmospher Sci, Mineral Deposit Res Unit, 2020-2207 Main Mall, Vancouver, BC V6T 1Z4, Canada; 5.Univ Complutense Madrid, Fac CC Geol, Dept Petrol & Geoquim, C Jose Antonio Novais, E-28040 Madrid, Spain; 6.Goldcorp Inc, 3400-666 Burrard St, Vancouver, BC V6C 2X8, Canada
推荐引用方式 GB/T 7714	Pizarro, H.,Rousse, S.,Riquelme, R.,et al. The origin of the magnetic record in Eocene-Miocene coarse-grained sediments deposited in hyper-arid/arid conditions: Examples from the Atacama Desert[J]. French National Research Institute for Sustainable Development,2019,516:322-335.
APA	Pizarro, H..,Rousse, S..,Riquelme, R..,Veloso, E..,Campos, E..,...&Munoz, S..(2019).The origin of the magnetic record in Eocene-Miocene coarse-grained sediments deposited in hyper-arid/arid conditions: Examples from the Atacama Desert.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,516,322-335.
MLA	Pizarro, H.,et al."The origin of the magnetic record in Eocene-Miocene coarse-grained sediments deposited in hyper-arid/arid conditions: Examples from the Atacama Desert".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 516(2019):322-335.