A comparison of multiple luminescence chronometers at Voordrag, South Africa

Colarossi, Debra; Duller, G.A.T.; Roberts, Helen M.; Tooth, Stephen; Botha, G.A.

doi:10.1016/j.quageo.2020.101094

Cited by 9 publications

(10 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Brook et al, 2006; Grodek et al, 2013; Srivastava et al, 2006). Where possible, depositional ages are based on single grain analysis, as it allows for the well‐bleached component to be isolated (Colarossi et al, 2020; Duller, 2008). Single grain analysis shows that detectable signals derive from 2 to 3% of grains, and as small aliquot 180–210 μm multigrain discs contain ~68 grains per disc (Burow, 2020; Heer et al, 2012), it is likely that D e s are derived from only one to two grains.…”

Section: Resultsmentioning

confidence: 99%

“…As the ability to radiometrically date geomorphological records has improved (e.g. Colarossi et al, 2020), and the controls on the formation of landforms by sediment transport are understood (e.g. Larkin et al, 2020; Mayaud et al, 2017; Paola et al, 2009), so has the contribution of geoproxies such as fluvial records to assessing the amplitude and nature of hydrological change (Stone & Thomas, 2013; Thomas & Burrough, 2012).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Holocene fluvial depositional regimes of the Huab River, Skeleton Coast, Namibia

Walsh

Caracciolo

Ravidà

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

Dryland fluvial systems respond to hydroclimate changes on Quaternary timescales, yet deciphering the palaeoenvironmental histories they preserve is often complex.Whilst hydrological signals are preserved in sediment stores as variations in sediment amount, character, and composition, studies in dryland settings such as Namibia that link sedimentological and compositional changes to palaeoflow are limited. Focusing on the Huab River, Skeleton Coast, this paper presents the first integrated study of textural, compositional, and stratigraphic features from a Namibian fluvial archive.Petrographic and heavy mineral assemblages from Raman laser spectroscopy are combined with lithostratigraphic and particle size analysis. Together with a chronology established through 42 optically stimulated luminescence ages, we reconstruct provenance, changes in river style, and fluvial response to climate.The Huab lithostratigraphic record details periods of flashy ephemeral flow interbedded with flow within well-defined channels. Compositional assemblages indicate that humid conditions during the early to mid-Holocene resulted in activation of sediment stores across the catchment. Episodic discharge within an ephemeral river from 12 to 9 ka was followed by a more sustained river flow in a channelized system from 7 to 5 ka. During the late Holocene, better hydraulic sorting, increased mechanical breakdown of polycrystalline grains, and flash flood lithofacies suggest that flow occurred within a more arid climate. This fine-scaled analysis of an ephemeral fluvial system indicates the utility of assessing compositional changes to distinguish between depositional regimes. This is an important approach for reconstructing fluvial response to climate and for obtaining palaeoenvironmental records from complex sedimentary archives in dryland river settings.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Holocene fluvial depositional regimes of the Huab River, Skeleton Coast, Namibia

Walsh

Caracciolo

Ravidà

et al. 2022

Earth Surf Processes Landf

View full text Add to dashboard Cite

show abstract

“…This indicates that the 3-mm aliquot is too large to obtain the true dose for the young poorly bleached sediments. Some studies have shown that the D e of small aliquots (~2 mm or >100 grains) is overestimated compared Frontiers in Earth Science frontiersin.org with the expected D e , as the number of grains on the small aliquots is too large to distinguish the well-bleached population, although they used the lowest 5% or MAM (Wu et al, 2010;Colarossi et al, 2020). For the wellbleached sample DSG6, the D e distributions have no dependency on the aliquot sizes and age models except the lowest 5% D e of the 1-mm aliquot is negative (Figure 6).…”

Section: Resultsmentioning

confidence: 99%

Dose dependency of aliquot sizes and age models from modern alluvial fan deposits of Helan Mountain, China

Liu

Li²,

Zhao³

et al. 2022

Front. Earth Sci.

View full text Add to dashboard Cite

Alluvial fan deposits are identified as evidence of regional climatic variations and tectonic events; therefore, it is crucial to establish absolute time series by dating alluvial fan deposits. Limited exposure to light poses a challenge to accurately estimating the buried ages for alluvial deposits with optically stimulated luminescence (OSL). This challenge has been positively developed by controlling the number of grains on each disk to measure and choosing suitable statistical models for the equivalence dose (De) distribution to analyze. In this research, three modern alluvial samples and one modern loess-like sample were collected from the Dashuigou alluvial fan of Helan Mountain, China. The De distributions of these four samples were studied by the application of small aliquots (1-, 3-, and 5-mm aliquots) of quartz OSL with the average dose model, central age model, unlogged minimum age model (MAM), lowest 5%, internal/external consistency criterion minimum age model (IEU), and finite mixture model. It is concluded that an overestimation of De lower than 1 Gy can be obtained using quartz OSL dating of 1-mm aliquots (∼50 grains) with MAM and IEU for the alluvial sediments. The lowest 5% method may underestimate the De values of the 1-mm aliquots for young samples. This research makes the dose dependency of aliquot sizes and age models more definite and opens up the possibility of dating paleoalluvial deposits to establish a chronological framework to decipher the implications of paleoclimates and tectonics.

show abstract

“…Optically stimulated luminescence (OSL) dating measurements of quartz grains, especially from older samples, often include data from grains with saturated palaeodoses (e.g. Thomsen et al, 2016;Colarossi et al, 2020). The proportion of saturated grains can vary substantially between samples and is influenced not only by the magnitude of each grain's equivalent dose (D e ), but also by the dose at which each grain's OSL signal saturates.…”

Section: Introductionmentioning

confidence: 99%

“…Dose recovery experiments suggest that measurements with more than 50% of saturated grains may not provide accurate dose estimates (Duller 2012), and some studies of natural samples have attributed underestimations of single grain ages relative to multi-grain ages to the effects of saturated grains (e.g. Thomsen et al, 2016;Colarossi et al, 2020). If these saturated grains contain useful chronological data, more accurate D e values, and hence ages, could potentially be obtained if these grains could be incorporated into the analysis.…”

Section: Introductionmentioning

confidence: 99%

Challenges of dating quartz OSL samples with saturated grains: Lessons from single-grain analyses of low dose-rate samples from Victoria Falls, Zambia

Chapot

Duller

Barham

2022

Quaternary Geochronology

Self Cite

View full text Add to dashboard Cite

A comparison of multiple luminescence chronometers at Voordrag, South Africa

Cited by 9 publications

References 55 publications

Holocene fluvial depositional regimes of the Huab River, Skeleton Coast, Namibia

Holocene fluvial depositional regimes of the Huab River, Skeleton Coast, Namibia

Dose dependency of aliquot sizes and age models from modern alluvial fan deposits of Helan Mountain, China

Challenges of dating quartz OSL samples with saturated grains: Lessons from single-grain analyses of low dose-rate samples from Victoria Falls, Zambia

Contact Info

Product

Resources

About