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DOI	10.1016/j.quageo.2019.05.001
	Luminescence dating of sediments from central Atacama Desert, northern Chile
	del Rio, Ian 1,2; Oliveira Sawakuchi, Andre 3; Gonzalez, Gabriel 1,2
通讯作者	del Rio, Ian
来源期刊	QUATERNARY GEOCHRONOLOGY
ISSN	1871-1014
EISSN	1878-0350
出版年	2019
卷号	53
英文摘要	This study examines the feasibility of applying luminescence dating methods to quartz and potassium feldspar (K-feldspar) grains from Quaternary continental deposits of the Mejillones Peninsula and Coastal Cordillera in Central Atacama, northern Chile. Sediment burial ages were calculated using single-aliquot regenerative-dose (SAR) protocols applied to the optically stimulated luminescence (OSL) signal of quartz as well as infrared stimulated luminescence (IRSL) and post-infrared infrared stimulated luminescence (post-IR IRSL) signals of K feldspar. Considering that the target sedimentary deposits comprise the Late Pleistocene age range, K-feldspar grains were dated using fading-corrected IRSL signals measured at 50 degrees C (IR50) and post-IR IRSL measured at 225 degrees C (pIRIR(225)) to minimize the potential effect of residual doses on calculated ages. The results of the analytical procedures indicate that quartz grains extracted from the studied sediments present a very weak or even no fast OSL component. The combination of a low OSL sensitivity, signal instability and equivalent dose distributions with high overdispersion (>40% for most samples) hinder reliable age estimation using quartz aliquots. Bleaching test results show that the IR50 signal from K-feldspar aliquots is well reset after 20-24 h of light exposure, while the pIRIR(225) signal may present residual doses corresponding to between 10 and 15% of the natural signal. IR50 fading rates are similar to 6-7%/decade for most studied samples, with exception of one sample which yielded a g-value of 18.77 +/- 2.06%/decade. Fading rates for the pIRIR(225) signal yielded variable results among sampling sites, with g-values ranging between 0.70 +/- 0.24 and 6.77 +/- 1.05%/decade. The dating results point out that quartz OSL ages are largely underestimated in relation to K-feldspar fading-corrected IR50 and pIRIR(225) ages. Fading-corrected pIRIR(225) K-feldspar ages indicate that the alluvial sedimentation in the downthrown block of an active normal fault in Mejillones Peninsula occurred between 163.4 +/- 18.4 ka and 87.4 +/- 6.6 ka. K-feldspar ages also allow to constrain the age of fault scarp degradation and fault reactivation in two main branches of the Atacama Fault System. In the Naguayan Fault, pIRIR(225) ages indicate that faulting occurred after 21.4 +/- 3.2 ka while in the Salar del Carmen Fault, faulting is recorded after 14.7 +/- 1.0 ka.
英文关键词	Quartz OSL dating K-feldspar post-IR IRSL dating Atacama desert Age underestimation Pleistocene
类型	Article
语种	英语
国家	Chile ; Brazil
收录类别	SCI-E
WOS记录号	WOS:000480376300001
WOS关键词	OPTICALLY STIMULATED LUMINESCENCE ; IR IRSL SIGNAL ; COASTAL CORDILLERA ; INDIVIDUAL GRAINS ; QAIDAM BASIN ; QUARTZ ; FELDSPAR ; SINGLE ; OSL ; DEPOSITS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/218211
作者单位	1.Univ Catolica Norte, Dept Ciencias Geol, Ave Angamos 0610, Antofagasta, Chile; 2.Natl Res Ctr Integrated Nat Disaster Management C, Vicuna Mackenna 4860, Santiago, Chile; 3.Univ Sao Paulo, Inst Geosci, Rua Logo 562, BR-05508080 Sao Paulo, SP, Brazil
推荐引用方式 GB/T 7714	del Rio, Ian,Oliveira Sawakuchi, Andre,Gonzalez, Gabriel. Luminescence dating of sediments from central Atacama Desert, northern Chile[J],2019,53.
APA	del Rio, Ian,Oliveira Sawakuchi, Andre,&Gonzalez, Gabriel.(2019).Luminescence dating of sediments from central Atacama Desert, northern Chile.QUATERNARY GEOCHRONOLOGY,53.
MLA	del Rio, Ian,et al."Luminescence dating of sediments from central Atacama Desert, northern Chile".QUATERNARY GEOCHRONOLOGY 53(2019).