Testing the accuracy of OSL and pIR IRSL dating of young geoarchaeological sediments in coastal Peru

Sánchez, Jorge Sanjurjo; Viveen, Willem; Sara-Lafosse, Rafael Vega-Centeno

doi:10.1016/j.quageo.2022.101382

Cited by 4 publications

(11 citation statements)

References 51 publications

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“…Indeed, the MAM returned consistent ages for sediments taken from the upper part of the Lima fan in a recent study (Sanjurjo-Sanchez et al, 2022), while the CAM provided overestimated ages.…”

Section: Luminescence Agesmentioning

confidence: 69%

“…As the 50 C IR stimulation (IRSL 50 ) removes the close trap-hole pairs which are prone to tunnelling, the left, distant trap-hole pairs stimulated at a high temperature show less, or negligible, fading (Jain & Ankjaergaard, 2011;Li & Li, 2011;Thomsen et al, 2008). Indeed, studies of the Peruvian Andes using (pIR) IRSL ages of K-feldspars provided negligible fading (Sanjurjo-Sanchez et al, 2022;Trauerstein et al, 2014;Viveen et al, 2020Viveen et al, , 2022. Thus, pIR IRSL 225 signals will be preferably used for dating.…”

Section: Luminescence Datingmentioning

confidence: 99%

“…In young sediments, the burial dose is usually small and comparable with the residual dose, whereas in old sediments, the burial dose is normally much larger and the residual dose is negligible. This problem was observed in sediments dated by IRSL from the top of the fluvial fan when compared with 14 C ages of charcoal recovered from the same sediments (Sanjurjo-Sanchez et al, 2022). Taking into account the mismatch of ages and the statistical parameters, it is very possible that the ages of the uppermost samples were overestimated using the CAM due to incomplete bleaching, thus making the MAM more suitable for dating of these younger samples (Reimann et al, 2012).…”

Section: Luminescence Agesmentioning

confidence: 99%

“…They obtained ages up to 109 ± 7.9 ka at three sites (Figure 3). The OSL ages of Villacorta et al are, however, stratigraphically inconsistent and quartz has shown to be an unsuitable mineral for luminescence dating in Western Peru, because the OSL signal is dominated by medium and slow OSL components, providing underestimated burial ages (Sanjurjo‐Sanchez et al, 2022; Steffen, Preusser, & Schlunegger, 2009a). In the absence of detailed methods and results in Villacorta (2018) and Villacorta et al (2019), we have doubts about their luminescence ages.…”

Section: Study Areamentioning

confidence: 99%

“…It also provides an alternative age model that may resolve some of the issues that have arisen over the past decades relating to contradicting age estimates of the Lima fan sediments. Estimates vary from ~500 to ~10 ka based on stratigraphic interpretations (Le Roux et al, 2000), luminescence (Sanjurjo‐Sanchez et al, 2022; Villacorta et al, 2019), and cosmogenic nuclide dating (Litty et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

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A 121‐ka record of Western Andean fluvial response to suborbital climate cycles recorded by rhythmic grain size variations of the Lima fluvial fan

Viveen,

Sanjurjo‐Sanchez,

Bravo‐Lembcke

et al. 2024

Earth Surf Processes Landf

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A complete, fluvial stratigraphic record for the last glacial period of the Western Andes in Peru is not available due to preservation issues and spatial variability in sedimentation. Deposits are typically restricted to incomplete records of fluvial terraces or localised occurrences of alluvial fans and landslides. These landforms are thought to have formed under a regime of climate cyclicity controlling increases in precipitation. Because of the fragmented preservation of these deposits, as well as dating uncertainties, it remains unclear if orbital climate cycles, such as the precession cycle, or suborbital cycles, such as the wet Heinrich events, are driving Andean sedimentation. In this paper, we try to answer this question through a sedimentological–stratigraphical analysis of a much more complete sedimentary sequence than usually found in the region. We present the results of a grain size analysis of 5000 clasts and 13 new luminescence ages of a 52‐m‐long, stratigraphic section of the Lima fluvial fan in Peru. Bayesian age–depth modelling resulted in a robust chronostratigraphic framework and derived sedimentation rates. The stratigraphic record registered sedimentation from 121.7 ± 4 to ka. Three major sedimentation periods occurred between 121.7 to , 87 ± 1 to , and to ka. These periods registered various unconformities and coarsening–fining upward sequences which chronologically correlate to suborbital pluvial periods, recognised from speleothems and lake records, that drove fluvial deposition. They also correlate with the timing of other recognised sedimentation events throughout the Western Andes. Marine regression resulted in fan progradation and not in incision. The Lima fan stratigraphy represents therefore the most complete, last glacial fluvial record for the Peruvian Western Andes to date and it highlights the potential of fluvial fans as recorders of suborbital climate variability.

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Section: Luminescence Agesmentioning

confidence: 69%