Small aliquot and single grain IRSL and post-IR IRSL dating of fluvial and alluvial sediments from the Pativilca valley, Peru

Trauerstein, Mareike; Lowick, Sally E.; Preusser, Frank; Schlunegger, Fritz (2014). Small aliquot and single grain IRSL and post-IR IRSL dating of fluvial and alluvial sediments from the Pativilca valley, Peru. Quaternary geochronology, 22, pp. 163-174. Elsevier 10.1016/j.quageo.2013.12.004

[img] Text
1-s2.0-S1871101413001192-main.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (2MB) | Request a copy

Infrared stimulated luminescence (IRSL) and post-IR IRSL are applied to small aliquots and single grains to determine the equivalent dose (De) of eleven alluvial and fluvial sediment samples collected in the Pativilca valley, Central Peru at ca. 10°S latitude. Small aliquot De distributions are rather symmetric and display over-dispersion values between 15 and 46%. Small aliquot g-values range between 4 and 8% per decade for the IRSL and 1 and 2% per decade for the post-IR IRSL signal. The single grain De distributions are highly over-dispersed with some of them skewed to higher doses, implying partial bleaching; this is especially true for the post-IR IRSL. Measurements of a modern analog reveal that residuals due to partial bleaching are present in both the IRSL as well as the post-IR IRSL signal. The g-values of individual grains exhibit a wide range with high individual uncertainties and might contribute significantly to the spread of the single grain De values, at least for the IRSL data. Electron Microprobe Analysis performed on single grains reveal that a varying K-content can be excluded as the origin of over-dispersion. Final ages for the different approaches are calculated using the Central Age Model and the Minimum Age Model (MAM). The samples are grouped into well-beached, potentially well-bleached and partially bleached according to the evaluation of the single grain distributions and the agreement of age estimates between methods. The application of the MAM to the single grain data resulted in consistent age estimates for both the fading corrected IRSL and the post-IR IRSL ages, and suggests that both approaches are suitable for dating these samples.
Keywords

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Quaternary Geology

UniBE Contributor:

Trauerstein, Mareike; Lowick, Sally and Schlunegger, Fritz

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

1871-1014

Publisher:

Elsevier

Language:

English

Submitter:

Sally Lowick

Date Deposited:

06 Oct 2014 11:18

Last Modified:

06 Oct 2015 10:17

Publisher DOI:

10.1016/j.quageo.2013.12.004

Uncontrolled Keywords:

K-rich feldspar, IRSL, Post-IR IRSL, Small aliquots, Single grains, Over-dispersion, Minimum age model, K-content, Fading

BORIS DOI:

10.7892/boris.45334

URI:

https://boris.unibe.ch/id/eprint/45334

Actions (login required)

Edit item Edit item
Provide Feedback