Universität zu Köln

Bartz, Melanie, Duval, Mathieu ORCID: 0000-0003-3181-7753, Brill, Dominik ORCID: 0000-0001-8637-4641, Zander, Anja, King, Georgina E., Rhein, Alexander, Walk, Janek, Stauch, Georg, Lehmkuhl, Frank ORCID: 0000-0002-6876-7377 and Brueckner, Helmut (2020). Testing the potential of K-feldspar pIR-IRSL and quartz ESR for dating coastal alluvial fan complexes in arid environments. Quat. Int., 556. S. 124 - 144. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 1873-4553

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Abstract

Coastal alluvial fans (CAF) are important geo-archives due to their sensitivity to both tectonic activity and climatic changes. Thus, they can give key insights for geomorphic and sedimentary processes. In this study we test the potential of K-feldspar post infrared-infrared stimulated luminescence (pIR-IRSL) and quartz electron spin resonance (ESR) methods for dating alluvial fan complexes in arid environments. The existing chronological data from marine terraces that interact with CAF make the Atacama Desert in northern Chile an excellent setting for this research. Samples have been collected from alluvial, marine and aeolian sediments embedded in the CAF complexes, allowing evaluation of the different signal properties and bleaching characteristics of the pIR-IRSL and ESR signals over Late Pleistocene time scales. pIR-IRSL dose distributions of clast-rich alluvial fan samples are characterised by higher scatter and demonstrate heterogeneous bleaching, while matrix-rich alluvial fan deposits show rather homogeneous poor bleaching in the dose dispersion as indicated by a modern analogue sample. In contrast, marine and aeolian deposits are homogeneously well bleached, supported by a modern littoral sample. Following the quartz multiple centre (MC) ESR dating approach (Al and Ti centres), bleaching of the different centres prior to deposition has been achieved. While the Ti-H centre provides mostly lower doses than the Ti-Li centre, in most cases the Al centre provides the highest dose values. This pattern is consistent with their respective bleaching kinetics and suggests that the Ti centre signals most likely provide the closest estimate to the true burial dose for samples with doses > 200 Gy. ESR and pIR-IRSL ages are consistent at 2 sigma for the marine, aeolian and clast-rich debris-flow deposits, which is in agreement with existing chronological data in this area. It appears that the mode of sediment transport on alluvial fans, either as matrix- or clast-rich flows, plays an important role in sediment bleaching. While clast-rich alluvial fan deposits are likely better bleached, we cannot exclude insufficient bleaching during matrix-rich alluvial fan flows; our dating results suggest that both pIR-IRSL and ESR dating overestimate the true burial age. The combination of pIR-IRSL and MC ESR dating can be considered as a promising tool for deciphering alluvial fan formation over (Late) Pleistocene time scales.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Bartz, Melanie UNSPECIFIED UNSPECIFIED UNSPECIFIED Duval, Mathieu UNSPECIFIED orcid.org/0000-0003-3181-7753 UNSPECIFIED Brill, Dominik UNSPECIFIED orcid.org/0000-0001-8637-4641 UNSPECIFIED Zander, Anja UNSPECIFIED UNSPECIFIED UNSPECIFIED King, Georgina E. UNSPECIFIED UNSPECIFIED UNSPECIFIED Rhein, Alexander UNSPECIFIED UNSPECIFIED UNSPECIFIED Walk, Janek UNSPECIFIED UNSPECIFIED UNSPECIFIED Stauch, Georg UNSPECIFIED UNSPECIFIED UNSPECIFIED Lehmkuhl, Frank UNSPECIFIED orcid.org/0000-0002-6876-7377 UNSPECIFIED Brueckner, Helmut UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-323515
DOI:	10.1016/j.quaint.2020.03.037
Journal or Publication Title:	Quat. Int.
Volume:	556
Page Range:	S. 124 - 144
Date:	2020
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Place of Publication:	OXFORD
ISSN:	1873-4553
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ELECTRON-SPIN-RESONANCE; INFRARED-STIMULATED LUMINESCENCE; HOLOCENE DEBRIS FLOWS; RIVER EBRO BASIN; NORTHERN CHILE; DOSE-RATE; LANDSCAPE EVOLUTION; SEDIMENTARY QUARTZ; MIDDLE PLEISTOCENE; FADING-CORRECTION Multiple languages Geography, Physical; Geosciences, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/32351