scholarly journals Thermal behaviour of organic radicals and paramagnetic centres in chert: A case study of Bergeracois brown chert, Dordogne, France

2021 ◽  
Author(s):  
Renaud Joannes-Boyau ◽  
Anja Scheffers ◽  
Rémy Chapoulie ◽  
Christelle Lahaye ◽  
Jeff Parr ◽  
...  
Keyword(s):  
Firing Temperature ◽  
Organic Radicals ◽  
Esr Dating ◽  
Luminescence Signal ◽  
Tl Dating ◽  
Spin Resonance ◽  
Absolute Dating ◽  
Precision And Accuracy ◽  
Paramagnetic Centres

In order to successfully understand the complex evolution of prehistoric societies, archaeologists require absolute dating tools, which are not only accurate but also widely applicable. Thermoluminescence (TL) dating is one such approach that has been successfully used to establish a general chronological framework for prehistoric sites and is particularly suited for use on heated lithic artefacts. Experiments conducted in this study have clearly shown the applicability of Electron Spin Resonance (ESR) isothermal modelling in combination with TL dating to constrain firing temperature. This expands the potential application for TL dating to include artefacts treated at low firing temperatures. The present study shows potential in terms of precision and accuracy for framing the “equivalent firing temperature”. At the same time, the comparison of the TL signal with the lattice-defects and aluminium centres invigorate the use of ESR dating on heated flint, especially with samples that have received low thermal treatment. The presence of organic matter in large quantity raises concern on the pyrolysis effect on the luminescence signal; however, the use of ESR isothermal and isochronal modelling could potentially lead to the ability to overcome current interferences of the organic radicals within the dating signal of TL.

scholarly journals Thermal behaviour of organic radicals and paramagnetic centres in chert: A case study of Bergeracois brown chert, Dordogne, France

2014 ◽  
Vol 23 ◽  
pp. 26-34 ◽  
Author(s):  
Renaud Joannes-Boyau ◽  
Anja Scheffers ◽  
Rémy Chapoulie ◽  
Christelle Lahaye ◽  
Jeff Parr ◽  
...  
Keyword(s):  
Thermal Behaviour ◽  
Organic Radicals ◽  
Paramagnetic Centres

scholarly journals Identification of Paleoearthquakes and Coseismic Slips on a Normal Fault Using High-Precision Quantitative Morphology: Application to the Jiaocheng Fault in the Shanxi Rift, China

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 2) ◽  
Author(s):  
Junjie Zou ◽  
Honglin He ◽  
Yusuke Yokoyama ◽  
Adam D. Sproson ◽  
Yoshiki Shirahama ◽  
...  
Keyword(s):  
Active Faults ◽  
Normal Fault ◽  
Seismic Events ◽  
Quantitative Morphology ◽  
Coseismic Slip ◽  
Slip History ◽  
Absolute Dating ◽  
Future Work ◽  
Shanxi Rift

Abstract The quantitative morphology of bedrock fault surfaces combined with aerial surveys and field identification is a useful approach to identify paleoearthquakes, obtain coseismic slips, and evaluate the seismogenic capacity of active faults in bedrock areas where traditional trenching methods are not applicable. Here, we report a case study of the Jiaocheng Fault (JCF) in the Shanxi Rift, China. Although several studies have been conducted on the JCF, its coseismic slip history and seismogenic capacity are still unclear. To address these problems, we investigated two bedrock fault surfaces, Sixicun (SXC) and Shanglanzhen (SLZ), on the JCF’s northern segment using quantitative morphological analysis together with aerial and field surveys. Quantitative fractal analysis based on the isotropic empirical variogram and moving window shows that both bedrock fault surfaces have the characteristics of vertical segmentation, which is likely due to periodic earthquakes, the coseismic slip of which can be determined by the height of the segments. Three seismic events at SXC, with a coseismic vertical slip of 1.74, 1.65, and 1.99 m, and three seismic events at SLZ, with a coseismic vertical slip of 1.32, 2.35, and 1.88 m, are identified. Compared with the previous studies, these three seismic events may occur in the Holocene, but it requires absolute dating ages to support, which is also the focus of our future work. Considering the seismologic capability (M>7.5) and the relationship between the recurrence interval of ~2.6 kyr and elapsed time of more than 3 kyr, the seismic hazard of the northern and middle segments of the JCF requires immediate attention.

Electron spin resonance (ESR) dating of pre-Quaternary faults in the Sichuan basin, SW China

2018 ◽  
Vol 163 ◽  
pp. 142-151
Author(s):  
Dengfeng Qiu ◽  
Quanyou Liu ◽  
Jinbiao Yun ◽  
Zhijun Jin ◽  
Dongya Zhu ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Sichuan Basin ◽  
Esr Dating ◽  
Sw China ◽  
Spin Resonance ◽  
The Sichuan Basin

scholarly journals First experimental evaluation of the alpha efficiency in coarse-grained quartz for ESR dating purposes: implications for dose rate evaluation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Melanie Bartz ◽  
Lee J. Arnold ◽  
Nigel A. Spooner ◽  
Martina Demuro ◽  
Isidoro Campaña ◽  
...  
Keyword(s):  
Dose Rate ◽  
Experimental Evaluation ◽  
Coarse Grained ◽  
Esr Dating ◽  
Large Variability ◽  
Sources Of Uncertainty ◽  
A Value ◽  
Spin Resonance ◽  
Rate Evaluation ◽  
Quartz Grains

AbstractWe present the first experimental evaluation of the alpha efficiency value for electron spin resonance (ESR) dating of coarse quartz grains, which is used for the evaluation of the internal and external alpha dose rate components. Based on our results, we recommend the use of an a-value of 0.07 ± 0.01 (1σ) for both the Al and Ti centres. Although we acknowledge that quartz ESR alpha efficiency may be sample dependent, and could also be impacted by other sources of uncertainty, this potential variability is presently impossible to evaluate given the absence of other experimental a-values available in the ESR dating literature. Measured radioactivity of quartz grains from the Moulouya catchment (NE Morocco) provides an internal dose rate in the range of 50–70 µGy/a when using an a-value of 0.07. The use of this empirically derived a-value for the evaluation of the internal and external alpha dose rate has a limited overall impact on the final ESR age results: they change by <2% and <3%, respectively, in comparison with those obtained with an assumed a-value. However, the large variability observed among the broader sample dataset for quartz internal radioactivity and hydrofluoric acid (HF) etching rates underscores the potential importance of undertaking experimental evaluations of alpha dose rate parameters for each dated sample.

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