Quartz age extension applied to SE Asian cover sands

Cresswell, A.J. , Sanderson, D.C.W. , Carling, P.A. and Darby, S.E. (2022) Quartz age extension applied to SE Asian cover sands. Quaternary Geochronology, 69, 101271. (doi: 10.1016/j.quageo.2022.101271)

Abstract

A significant feature of the surface sediments of southeast Asia is a regionally extensive layer of distinctive red, quartz-rich, cover sand observed throughout Vietnam, Cambodia, Laos and Thailand, and further afield. In many locations, these cover sands immediately overlay a laterite layer containing tektites, known as the Muong Nong type, associated with a large meteorite impact between 750 and 800ka in Indochina. Sections of these cover sands at sites in Thailand, Laos and Vietnam have been investigated using field and laboratory profiling, and quartz SAR procedures. In some locations the sections consist of a layer of low-sensitivity quartz with saturated signals overlain by a visibly indistinguishable layer of high-sensitivity quartz with ages less than c. 35ka. Further work has been undertaken to attempt to extend quartz luminescence dating for the older materials, including samples associated with the tektites, using thermally stimulated or transferred luminescence to access traps that are expected to saturate at higher doses. Luminescence was recorded during sample heating and hold, giving thermoluminescence (TL-ramp) and isothermal decay (ID) data, in addition to optically stimulated luminescence after the transfer (Thermally Transferred Optically Stimulated Luminescence, TT-OSL) measurements. These measurements have produced equivalent dose values of up to 250Gy, and ages of 70–125ka, for these older materials, which is significantly younger than would be expected from the association with the tektites. Investigation of the traps associated with these signals has produced properties consistent with prior investigations, suggesting that these are not sufficiently stable at environmental temperatures above 25 °C to permit age extension using these methods.

• Item Type: Articles
• Additional Information: Carling benefited from a Leverhulme Emeritus Fellowship (2016–2018) and from support in the field provided by Prof. R. Tada (Japan Society for the Promotion of Science (JSPS) KAKENHI Fostering Joint International Research (B) 18KK0092 (2018–2021)). The luminescence analyses were part funded by the Biotechnology and Biological Sciences Research Council under a Global Challenges Research Fund Foundation Award for Global Agriculture and Food Systems Research (BB/P022693/1) awarded to Darby.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sanderson, Professor David and Cresswell, Dr Alan
• Authors: Cresswell, A.J., Sanderson, D.C.W., Carling, P.A., and Darby, S.E.
• Subjects: G Geography. Anthropology. Recreation > GB Physical geography; G Geography. Anthropology. Recreation > GE Environmental Sciences; Q Science > QC Physics
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Quaternary Geochronology
• Publisher: Elsevier
• ISSN: 1871-1014
• ISSN (Online): 1878-0350
• Published Online: 17 March 2022
• Copyright Holders: Copyright © 2022 Elsevier B.V.
• First Published: First published in Quaternary Geochronology 69: 101271
• Publisher Policy: Reproduced in accordance with the publisher copyright policy