scholarly journals Optically stimulated luminescence dating of young fluvial deposits of the Middle Elbe River Flood Plains using different age models

2014 ◽  
Vol 41 (1) ◽  
pp. 36-56 ◽  
Author(s):  
Alexander Kunz ◽  
Dorthe Pflanz ◽  
Tobias Weniger ◽  
Brigitte Urban ◽  
Frank Krüger ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Flood Plain ◽  
Optically Stimulated Luminescence ◽  
Luminescence Dating ◽  
Coarse Grain ◽  
Elbe River ◽  
Data Set ◽  
Fine Grain ◽  
Depositional Age ◽  
The Elbe River

Abstract In the last few decades optically stimulated luminescence (OSL) dating has become an important tool in geochronological studies. The great advantage of the method, i.e. dating the depositional age of sediments directly, can be impaired by incomplete bleaching of grains. This can result in a scattered distribution of equivalent doses (DE), leading to incorrect estimation of the depositional age. Thoroughly tested protocols as well as good data analysis with adequate statistical methods are important to overcome this problem. In this study, samples from young fluvial sand and flood plain deposits from the Elbe River in northern Germany were investigated to compare its depositional ages from different age models with well-known historical dates. Coarse grain quartz (100–200 μm and 150–250 μm) and polymineral fine grains (4–11 μm) were dated using the single aliquot regenerative (SAR) dose protocol. The paleodose (DP) was calculated from the DE data set using different approaches. Results were compared with the development of the Elbe River, which is well-documented by historical records and maps covering the last 1,000 years. Depending on the statistical approach it can be demonstrated that depositional ages significantly differ from the most likely depositional age. For the investigated coarse grain quartz samples all ages calculated from the MAM-3UL, including their uncertainties, are within the historical documented age. Results of the polymineral fine grain samples are overestimating the historically documented depositional age, indicating undetectable incomplete bleaching. This study shows the importance of using an adequate statistical approach to calculate reliable OSL ages from fluvial sediments.

scholarly journals Constraining the Age of Floodplain Levels Along the Lower Section of River Tisza, Hungary

2016 ◽  
Vol 9 (1-2) ◽  
pp. 39-44 ◽  
Author(s):  
György Sipos ◽  
Tímea Kiss ◽  
Orsolya Tóth
Keyword(s):  
Flood Plain ◽  
Luminescence Dating ◽  
Coarse Grain ◽  
Lower Section ◽  
Vegetation Control ◽  
Fine Grain ◽  
Energy Environment ◽  
The Given ◽  
Luminescence Characteristics ◽  
Grain Size Fractions

Abstract During the Late Pelistocene-Holocene transition the fluvial landscape of the Great Hungarian Plain changed considerably as a consequence of tectonic, climatic and geomorphological factors. Geochronology, and especially luminescence dating, is a very important tool in reconstructing these changes. The present study focuses on the Lower-Tisza region and addresses the timing of the development of different floodplain levels. In the meantime the luminescence characteristics of the investigated alluvial sediments were also assessed, with a special emphasis on the comparison of silty fine grain and sandy coarse grain results, as in the given medium and low energy environment fine grain sediments are more abundant, however, based on the literature, coarse grain samples are more reliable in terms of luminescence dating. Measurements were performed on 12 samples originating from the point bars of two large palaeo-meanders, representing different floodplain levels along the river. Results indicate the applicability of both grain size fractions for dating purposes, though fine grain subsamples overestimate in average by 1.5 ka the ages yielded by coarse grain subsamples. Consequently, fine grain samples can be used for outlining only general trends, and results need to be controlled by coarse grain measurements where possible. Based on the ages received, the upper floodplain was actively formed until 13-15 ka, when incision and the development of an intermediate floodplain level started. The meander on the intermediate flood plain level developed then very actively until 9 ka. As indicated by the received age information the intensity of meander formation could be highly affected by climatic and especially vegetation control. However, reconstruction can be refined later by further sampling and the application of the results of the present paper.

scholarly journals Single Aliquot Regeneration (SAR) Optically Stimulated Luminescence Dating Protocols Using Different Grain-Sizes of Quartz: Revisiting the Chronology of Mircea Vodă Loess-Paleosol Master Section (Romania)

2020 ◽  
Vol 3 (1) ◽  
pp. 19 ◽  
Author(s):  
Ștefana-M. Groza-Săcaciu ◽  
Cristian Panaiotu ◽  
Alida Timar-Gabor
Keyword(s):  
Dose Range ◽  
Test Dose ◽  
Optically Stimulated Luminescence ◽  
Luminescence Dating ◽  
High Dose ◽  
Response Curves ◽  
Fine Grain ◽  
Current State ◽  
Optically Stimulated Luminescence Dating ◽  
Fine Quartz

The loess-paleosol archive from Mircea Vodă (Romania) represents one of the most studied sections in Europe. We are applying here the current state of the art luminescence dating protocols for revisiting the chronology of this section. Analysis were performed on fine (4–11 µm) and coarse (63–90 µm) quartz extracts using the single aliquot regenerative (SAR) optically stimulated luminescence (OSL) dating protocol. Laboratory generated SAR dose response curves in the high dose range (5 kGy for fine quartz and 2 kGy for coarse quartz) were investigated by employing a test dose of either 17 or 170 Gy. The results confirm the previously reported different saturation characteristics of the two quartz fractions, with no evident dependency of the equivalent dose (De) on the size of the test dose. The OSL SAR ages are discussed and compared to the previously obtained results on quartz and feldspars. The previous reports regarding the chronological discrepancy between the two quartz fractions are confirmed. However, while previous investigations on other sites concluded that this discrepancy appears only above equivalent doses of about 100 Gy, here fine grain quartz ages underestimate coarse quartz ages starting with equivalent doses as low as around 50 Gy.

scholarly journals The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Paul HGM Dirks ◽  
Eric M Roberts ◽  
Hannah Hilbert-Wolf ◽  
Jan D Kramers ◽  
John Hawks ◽  
...  
Keyword(s):  
Optically Stimulated Luminescence ◽  
Luminescence Dating ◽  
Esr Dating ◽  
Younger Age ◽  
Optically Stimulated Luminescence Dating ◽  
Spin Resonance ◽  
The Us ◽  
Fossil Bones ◽  
Minimum Age ◽  
Depositional Age

New ages for flowstone, sediments and fossil bones from the Dinaledi Chamber are presented. We combined optically stimulated luminescence dating of sediments with U-Th and palaeomagnetic analyses of flowstones to establish that all sediments containing Homo naledi fossils can be allocated to a single stratigraphic entity (sub-unit 3b), interpreted to be deposited between 236 ka and 414 ka. This result has been confirmed independently by dating three H. naledi teeth with combined U-series and electron spin resonance (US-ESR) dating. Two dating scenarios for the fossils were tested by varying the assumed levels of 222Rn loss in the encasing sediments: a maximum age scenario provides an average age for the two least altered fossil teeth of 253 +82/–70 ka, whilst a minimum age scenario yields an average age of 200 +70/–61 ka. We consider the maximum age scenario to more closely reflect conditions in the cave, and therefore, the true age of the fossils. By combining the US-ESR maximum age estimate obtained from the teeth, with the U-Th age for the oldest flowstone overlying Homo naledi fossils, we have constrained the depositional age of Homo naledi to a period between 236 ka and 335 ka. These age results demonstrate that a morphologically primitive hominin, Homo naledi, survived into the later parts of the Pleistocene in Africa, and indicate a much younger age for the Homo naledi fossils than have previously been hypothesized based on their morphology.

scholarly journals Is the Genotype-Phenotype Map Modular?: A Statistical Approach Using Mouse Quantitative Trait Loci Data

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 305-311 ◽  
Author(s):  
Jason G Mezey ◽  
James M Cheverud ◽  
Günter P Wagner
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Statistical Approach ◽  
Genetic Effects ◽  
Statistical Distribution ◽  
Data Set ◽  
Alveolar Region ◽  
Phenotypic Characters ◽  
Statistical Support ◽  
Complex Characters

Abstract Various theories about the evolution of complex characters make predictions about the statistical distribution of genetic effects on phenotypic characters, also called the genotype-phenotype map. With the advent of QTL technology, data about these distributions are becoming available. In this article, we propose simple tests for the prediction that functionally integrated characters have a modular genotype-phenotype map. The test is applied to QTL data on the mouse mandible. The results provide statistical support for the notion that the ascending ramus region of the mandible is modularized. A data set comprising the effects of QTL on a more extensive portion of the phenotype is required to determine if the alveolar region of the mandible is also modularized.

The occurrence of xenoestrogens in the Elbe river and the North Sea

Chemosphere ◽  
2001 ◽  
Vol 45 (3) ◽  
pp. 245-259 ◽  
Author(s):  
O.P Heemken ◽  
H Reincke ◽  
B Stachel ◽  
N Theobald
Keyword(s):  
North Sea ◽  
Elbe River ◽  
The North ◽  
The North Sea ◽  
The Elbe River
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