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Eudald Carbonell - One of the best experts on this subject based on the ideXlab platform.
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evaluating the suitability of extended range Luminescence Dating techniques over early and middle pleistocene timescales published datasets and case studies from atapuerca spain
Quaternary International, 2015Co-Authors: Lee J Arnold, Alfredo Perezgonzalez, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The emergence of alternative Luminescence Dating techniques, such as thermally transferred optically stimulated Luminescence (TT-OSL), post-infrared infrared stimulated Luminescence (pIR-IRSL) and OSL Dating of individual quartz ‘supergrains’, has opened up new possibilities for establishing numerical age control on sedimentary deposits that exceed the traditional upper age limits of quartz OSL Dating. In this study, we evaluate the reliability of these ‘extended-range’ Luminescence Dating techniques over Middle and Early Pleistocene timescales using two approaches: (i) a broad-scale synthesis of extended-range Luminescence chronologies published so far as part of known-age comparison studies; (ii) a series of new TT-OSL and pIR-IRSL case studies at the palaeoanthropological sites of Galeria, Sima del Elefante and Gran Dolina (Atapuerca, Spain). The published known-age TT-OSL datasets (n = 82) and supergrain OSL datasets (n = 3) display good correspondence (i.e., suitably linear and proportion relationships) with associated age control. The known-age pIR-IRSL datasets (n = 228) display more inter-sample scatter, though there is general support for the reliability of more stringent pIR-IRSL protocols and multiple-elevated temperature pIR-IRSL approaches over Late and Middle Pleistocene timescales. While these reliability assessments are encouraging, there remains a clear need for more widespread, known-age empirical assessments of extended-range Luminescence techniques beyond ∼300–400 ka. The ages obtained at Atapuerca using single-grain TT-OSL and pIR-IRSL measurement temperatures of 225 °C (pIR-IR225) are in agreement with independent age control over an age range spanning ∼240–930 ka. In contrast, the pIR-IRSL chronologies obtained using a more stringent measurement temperature of 290 °C (pIR-IR290) consistently overestimate the expected ages of the Atapuerca sequences. The single-grain TT-OSL ages obtained at Gran Dolina permit calculation of a new weighted mean age of 846 ± 57 ka for the Homo antecessor palaeoanthropological horizon (unit TD6). The known-age Atapuerca case studies highlight the feasibility, and advantages, of applying TT-OSL Dating at the single-grain scale of analysis and demonstrate that the suitability of pIR-IRSL Dating protocols can vary significantly at a site or regional scale. Together, our analyses show that no single extended-range Luminescence Dating technique is likely to be universally applicable to all samples. Collectively, however, these approaches offer good potential for obtaining reliable chronologies, and they are likely to offer the greatest benefits when applied in tandem to individual samples.
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new Luminescence ages for the galeria complex archaeological site resolving chronological uncertainties on the acheulean record of the sierra de atapuerca northern spain
PLOS ONE, 2014Co-Authors: Martina Demuro, Alfredo Perezgonzalez, Ana Ortega, Lee J Arnold, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The archaeological karstic infill site of Galeria Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range Luminescence Dating techniques, namely post-infrared infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains, were applied to fossil-bearing sediments at Galeria. The Luminescence Dating results are in good agreement with published chronologies derived using alternative radiometric Dating methods (i.e., ESR and U-series Dating of bracketing speleothems and combined ESR/U-series Dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new Luminescence ages are significantly (∼50%) younger than previously published polymineral thermoLuminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galeria deposits. The Luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galeria have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galeria Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL Dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.
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Luminescence Dating and palaeomagnetic age constraint on hominins from sima de los huesos atapuerca spain
Journal of Human Evolution, 2014Co-Authors: Lee J Arnold, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Arantza Aranburu, Eudald CarbonellAbstract:Establishing a reliable chronology on the extensive hominin remains at Sima de los Huesos is critical for an improved understanding of the complex evolutionary histories and phylogenetic relationships of the European Middle Pleistocene hominin record. In this study, we use a combination of ‘extended-range’ Luminescence Dating techniques and palaeomagnetism to provide new age constraint on sedimentary infills that are unambiguously associated with the Sima fossil assemblage. Post-infrared-infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains provide weighted mean ages of 433 � 15 ka (thousands of years) and 416 � 19 ka, respectively, for allochthonous sedimentary horizons overlying the hominin-bearing clay breccia. The six replicate Luminescence ages obtained for this deposit are reproducible and provide a combined minimum age estimate of 427 � 12 ka for the underlying hominin fossils. Palaeomagnetic directions for the Luminescence dated sediment horizon and underlying fossiliferous clays display exclusively normal polarities. These findings are consistent with the Luminescence Dating results and confirm that the hominin fossil horizon accumulated during the Brunhes Chron, i.e., within the last 780 ka. The new bracketing age constraint for the Sima hominins is in broad agreement with radiometrically dated Homo heidelbergensis fossil sites, such as Mauer and Arago, and suggests that the split of the H. neanderthalensis and H. sapiens lineages took place during the early Middle Pleistocene. More widespread numerical Dating of key Early and Middle Pleistocene fossil sites across Europe is needed to test and refine competing models of hominin evolution. The new Luminescence chronologies presented in this study demonstrate the versatility of TT-OSL and pIR-IR techniques and the potential role they could play in helping to refine evolutionary histories over Middle Pleistocene timescales.
A S Murray - One of the best experts on this subject based on the ideXlab platform.
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Luminescence Dating of the iron age deposits from tell damiyah in the jordan valley
Radiocarbon, 2020Co-Authors: Sahar Al Khasawneh, A S Murray, Zeidan Kafafi, Lucas PetitAbstract:In this study, we investigate quartz-based Luminescence optical Dating of Iron Age deposits at the archaeological site of Tell Damiyah in the Jordan valley. Ten samples, taken from different occupation layers from two different excavation areas, proved to have good Luminescence characteristics (fast-component dominated, dose recovery ratio 1.032 ± 0.010, n=24). The optical ages are completely consistent with both available 14 C ages and ages based on stylistic elements; it appears that this material was fully reset at deposition, although it is recognised that the agreement with age control is somewhat dependent on the assumed field water content of the samples. Further comparison with different OSL signals from feldspar, or investigations based on dose distributions from individual grains would be desirable to independently confirm the resetting of this material. It is concluded that the sediments of Tell Damiyah are very suitable for Luminescence Dating. Despite the relatively large associated age uncertainties of between 5 and 10%, OSL at tell sites has the potential to provide ages for material very difficult to date by conventional methods, and to identify reworked mixtures of older artifacts in a younger depositional setting.
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new data on the chronology of the vale do forno sedimentary sequence lower tejo river terrace staircase and its relevance as a fluvial archive of the middle pleistocene in western iberia
Quaternary Science Reviews, 2017Co-Authors: Pedro P Cunha, Antonio A Martins, Janpieter Buylaert, A S Murray, Luis Raposo, Paolo Mozzi, Martin StokesAbstract:Abstract The Vale do Forno archaeological sites (Alpiarca, central Portugal) document the earliest human occupation in the Lower Tejo River, well established in geomorphological and environmental terms, within the Middle Pleistocene. In a staircase of six fluvial terraces, the Palaeolithic sites were found on the T4 terrace (+24 m, above river bed) which is made of a basal Lower Gravels unit (LG) and an overlying Upper Sands unit (US). Geomorphological mapping, coupled with lithostratigraphy, sedimentology and Luminescence Dating (quartz-OSL and K-feldspar post-IRIR 290 ) were used in this study. The oldest artefacts found in the LG unit show crude bifacial forms that can be attributed to the Acheulian. In contrast, the US unit has archaeological sites stratigraphically documenting successive phases of an evolved Acheulian. Luminescence Dating and correlation with the Marine Isotopic Stages suggest that the LG unit has a probable age of ca. 335 to 325 ka and the US unit an age of ca. 325 to 155 ka. This is in contrast to previous interpretations ascribing this terrace (and lithic industries) to the Last Interglacial and early phases of the Last Glacial. The VF3 site (Milharos), containing Micoquian (Final Acheulian) industries (with fine and elaborated bifaces), found in a stratigraphic level located between the T4 terrace deposits and a colluvium associated with Late Pleistocene aeolian sands, is younger than 155 ka but much older than 32 ka.
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a Luminescence Dating intercomparison based on a danish beach ridge sand
Radiation Measurements, 2015Co-Authors: A S Murray, Janpieter Buylaert, Christine ThielAbstract:Abstract There is a need for large scale intercomparisons to determine the degree of coherence of Luminescence Dating measurements made by different laboratories. Here we describe results from a laboratory intercomparison sample based on a quartz-rich aeolian and/or coastal marine sand ridge from the Skagen peninsula, northern Jutland (Denmark). About 200 kg of sand was sampled at night from a single beach ridge. The sand was homogenised using a cement mixer and packed in ∼700 moisture and light-tight bags for distribution. The quartz Luminescence characteristics are satisfactory (e.g. fast-component dominated and good dose recovery) and our own equivalent dose determinations and measurements of radionuclide concentrations for twenty of these bags demonstrate the degree of homogenisation. One natural sample and one sample of pre-processed quartz was made available on request; analysis of all the responses gives a mean dose (pre-processed quartz) of 4.58 Gy, σ = 0.40 (n = 26), to be compared to the mean dose (self-extracted quartz) of 4.52 Gy, σ = 0.55 (n = 21). The mean age is 3.99 ± 0.14 ka, σ = 0.71 (n = 22), i.e. a relative standard deviation of 18%. We present an analysis of all the important quantitative and qualitative responses we received between 2007 and 2012 and discuss the implications for our Dating community and for users of Luminescence ages.
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age of barrier canyon style rock art constrained by cross cutting relations and Luminescence Dating techniques
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Joel L Pederson, A S Murray, Reza Sohbati, Tammy M Rittenour, Melissa S Chapot, Steven R Simms, Gary M CoxAbstract:Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon Dating have failed. We provide multiple age constraints through the use of cross-cutting relations and new and broadly applicable approaches in optically stimulated Luminescence Dating at the Great Gallery panel, the type section of BCS art in Canyonlands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research Dating both a rockfall that removed some figures and the rock’s exposure duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A.D. ∼1–1100 coincides better with the transition to and rise of the subsequent Fremont culture. This chronology is for the type locality only, and variability in the age of other sites is likely. Nevertheless, results suggest that BCS rock art represents an artistic tradition that spanned cultures and the transition from foraging to farming in the region.
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Luminescence Dating of scoria fall and lahar deposits from somma vesuvius italy
Quaternary Geochronology, 2014Co-Authors: Sumiko Tsukamoto, A S Murray, Kyoko S Kataoka, Takashi Oguchi, Goro KomatsuAbstract:Abstract Luminescence Dating has been applied to scoria and lahar deposits from Somma–Vesuvius, Italy. Samples include scoria from the AD472 and 512 (or 536) eruptions and lahar deposits. In order to find a stable Luminescence signal which is less affected by anomalous fading, infrared stimulated Luminescence (IRSL) signals at elevated temperatures after bleaching with IR at 50 °C (termed post-IR IRSL; pIRIR) were tested at different preheat and elevated stimulation temperatures. The fading rates of both IRSL and pIRIR signals reduced dramatically with increasing preheat and pIRIR stimulation temperatures. A pIRIR signal measured at 290 °C after a preheat at 320 °C (60 s) and an IR stimulation at 50 °C (100 s) was selected to calculate the equivalent dose ( D e ). The gamma spectrometry results indicate that the U-series nuclides are not in equilibrium and there is a large 226 Ra excess. The dose rates and ages were calculated by assuming a 226 Ra excess (over its parent 230 Th) at deposition, and that this unsupported excess then decayed to the present level. The resulting Luminescence ages of the two scoria samples agreed with the expected ages, and the ages of the lahar deposits indicate that they are associated with the AD1631 eruption.
Juan L Arsuaga - One of the best experts on this subject based on the ideXlab platform.
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evaluating the suitability of extended range Luminescence Dating techniques over early and middle pleistocene timescales published datasets and case studies from atapuerca spain
Quaternary International, 2015Co-Authors: Lee J Arnold, Alfredo Perezgonzalez, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The emergence of alternative Luminescence Dating techniques, such as thermally transferred optically stimulated Luminescence (TT-OSL), post-infrared infrared stimulated Luminescence (pIR-IRSL) and OSL Dating of individual quartz ‘supergrains’, has opened up new possibilities for establishing numerical age control on sedimentary deposits that exceed the traditional upper age limits of quartz OSL Dating. In this study, we evaluate the reliability of these ‘extended-range’ Luminescence Dating techniques over Middle and Early Pleistocene timescales using two approaches: (i) a broad-scale synthesis of extended-range Luminescence chronologies published so far as part of known-age comparison studies; (ii) a series of new TT-OSL and pIR-IRSL case studies at the palaeoanthropological sites of Galeria, Sima del Elefante and Gran Dolina (Atapuerca, Spain). The published known-age TT-OSL datasets (n = 82) and supergrain OSL datasets (n = 3) display good correspondence (i.e., suitably linear and proportion relationships) with associated age control. The known-age pIR-IRSL datasets (n = 228) display more inter-sample scatter, though there is general support for the reliability of more stringent pIR-IRSL protocols and multiple-elevated temperature pIR-IRSL approaches over Late and Middle Pleistocene timescales. While these reliability assessments are encouraging, there remains a clear need for more widespread, known-age empirical assessments of extended-range Luminescence techniques beyond ∼300–400 ka. The ages obtained at Atapuerca using single-grain TT-OSL and pIR-IRSL measurement temperatures of 225 °C (pIR-IR225) are in agreement with independent age control over an age range spanning ∼240–930 ka. In contrast, the pIR-IRSL chronologies obtained using a more stringent measurement temperature of 290 °C (pIR-IR290) consistently overestimate the expected ages of the Atapuerca sequences. The single-grain TT-OSL ages obtained at Gran Dolina permit calculation of a new weighted mean age of 846 ± 57 ka for the Homo antecessor palaeoanthropological horizon (unit TD6). The known-age Atapuerca case studies highlight the feasibility, and advantages, of applying TT-OSL Dating at the single-grain scale of analysis and demonstrate that the suitability of pIR-IRSL Dating protocols can vary significantly at a site or regional scale. Together, our analyses show that no single extended-range Luminescence Dating technique is likely to be universally applicable to all samples. Collectively, however, these approaches offer good potential for obtaining reliable chronologies, and they are likely to offer the greatest benefits when applied in tandem to individual samples.
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new Luminescence ages for the galeria complex archaeological site resolving chronological uncertainties on the acheulean record of the sierra de atapuerca northern spain
PLOS ONE, 2014Co-Authors: Martina Demuro, Alfredo Perezgonzalez, Ana Ortega, Lee J Arnold, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The archaeological karstic infill site of Galeria Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range Luminescence Dating techniques, namely post-infrared infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains, were applied to fossil-bearing sediments at Galeria. The Luminescence Dating results are in good agreement with published chronologies derived using alternative radiometric Dating methods (i.e., ESR and U-series Dating of bracketing speleothems and combined ESR/U-series Dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new Luminescence ages are significantly (∼50%) younger than previously published polymineral thermoLuminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galeria deposits. The Luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galeria have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galeria Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL Dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.
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Luminescence Dating and palaeomagnetic age constraint on hominins from sima de los huesos atapuerca spain
Journal of Human Evolution, 2014Co-Authors: Lee J Arnold, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Arantza Aranburu, Eudald CarbonellAbstract:Establishing a reliable chronology on the extensive hominin remains at Sima de los Huesos is critical for an improved understanding of the complex evolutionary histories and phylogenetic relationships of the European Middle Pleistocene hominin record. In this study, we use a combination of ‘extended-range’ Luminescence Dating techniques and palaeomagnetism to provide new age constraint on sedimentary infills that are unambiguously associated with the Sima fossil assemblage. Post-infrared-infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains provide weighted mean ages of 433 � 15 ka (thousands of years) and 416 � 19 ka, respectively, for allochthonous sedimentary horizons overlying the hominin-bearing clay breccia. The six replicate Luminescence ages obtained for this deposit are reproducible and provide a combined minimum age estimate of 427 � 12 ka for the underlying hominin fossils. Palaeomagnetic directions for the Luminescence dated sediment horizon and underlying fossiliferous clays display exclusively normal polarities. These findings are consistent with the Luminescence Dating results and confirm that the hominin fossil horizon accumulated during the Brunhes Chron, i.e., within the last 780 ka. The new bracketing age constraint for the Sima hominins is in broad agreement with radiometrically dated Homo heidelbergensis fossil sites, such as Mauer and Arago, and suggests that the split of the H. neanderthalensis and H. sapiens lineages took place during the early Middle Pleistocene. More widespread numerical Dating of key Early and Middle Pleistocene fossil sites across Europe is needed to test and refine competing models of hominin evolution. The new Luminescence chronologies presented in this study demonstrate the versatility of TT-OSL and pIR-IR techniques and the potential role they could play in helping to refine evolutionary histories over Middle Pleistocene timescales.
Janpieter Buylaert - One of the best experts on this subject based on the ideXlab platform.
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new data on the chronology of the vale do forno sedimentary sequence lower tejo river terrace staircase and its relevance as a fluvial archive of the middle pleistocene in western iberia
Quaternary Science Reviews, 2017Co-Authors: Pedro P Cunha, Antonio A Martins, Janpieter Buylaert, A S Murray, Luis Raposo, Paolo Mozzi, Martin StokesAbstract:Abstract The Vale do Forno archaeological sites (Alpiarca, central Portugal) document the earliest human occupation in the Lower Tejo River, well established in geomorphological and environmental terms, within the Middle Pleistocene. In a staircase of six fluvial terraces, the Palaeolithic sites were found on the T4 terrace (+24 m, above river bed) which is made of a basal Lower Gravels unit (LG) and an overlying Upper Sands unit (US). Geomorphological mapping, coupled with lithostratigraphy, sedimentology and Luminescence Dating (quartz-OSL and K-feldspar post-IRIR 290 ) were used in this study. The oldest artefacts found in the LG unit show crude bifacial forms that can be attributed to the Acheulian. In contrast, the US unit has archaeological sites stratigraphically documenting successive phases of an evolved Acheulian. Luminescence Dating and correlation with the Marine Isotopic Stages suggest that the LG unit has a probable age of ca. 335 to 325 ka and the US unit an age of ca. 325 to 155 ka. This is in contrast to previous interpretations ascribing this terrace (and lithic industries) to the Last Interglacial and early phases of the Last Glacial. The VF3 site (Milharos), containing Micoquian (Final Acheulian) industries (with fine and elaborated bifaces), found in a stratigraphic level located between the T4 terrace deposits and a colluvium associated with Late Pleistocene aeolian sands, is younger than 155 ka but much older than 32 ka.
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pottery versus sediment optically stimulated Luminescence Dating of the neolithic vinca culture serbia
Quaternary International, 2017Co-Authors: Stephen Bate, Janpieter Buylaert, Thomas Stevens, Slobodan B Markovic, Per Roos, Nenad TasicAbstract:Optically stimulated Luminescence (OSL) Dating was applied to the Neolithic Vinca culture's type-site, Vinca Belo-Brdo, to establish best protocols for routine Luminescence Dating of similar Holoce ...
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a Luminescence Dating intercomparison based on a danish beach ridge sand
Radiation Measurements, 2015Co-Authors: A S Murray, Janpieter Buylaert, Christine ThielAbstract:Abstract There is a need for large scale intercomparisons to determine the degree of coherence of Luminescence Dating measurements made by different laboratories. Here we describe results from a laboratory intercomparison sample based on a quartz-rich aeolian and/or coastal marine sand ridge from the Skagen peninsula, northern Jutland (Denmark). About 200 kg of sand was sampled at night from a single beach ridge. The sand was homogenised using a cement mixer and packed in ∼700 moisture and light-tight bags for distribution. The quartz Luminescence characteristics are satisfactory (e.g. fast-component dominated and good dose recovery) and our own equivalent dose determinations and measurements of radionuclide concentrations for twenty of these bags demonstrate the degree of homogenisation. One natural sample and one sample of pre-processed quartz was made available on request; analysis of all the responses gives a mean dose (pre-processed quartz) of 4.58 Gy, σ = 0.40 (n = 26), to be compared to the mean dose (self-extracted quartz) of 4.52 Gy, σ = 0.55 (n = 21). The mean age is 3.99 ± 0.14 ka, σ = 0.71 (n = 22), i.e. a relative standard deviation of 18%. We present an analysis of all the important quantitative and qualitative responses we received between 2007 and 2012 and discuss the implications for our Dating community and for users of Luminescence ages.
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a robust feldspar Luminescence Dating method for middle and late pleistocene sediments
Boreas, 2012Co-Authors: Janpieter Buylaert, A S Murray, Mayank Jain, Kristina Jorkov Thomsen, Christine Thiel, Reza SohbatiAbstract:Luminescence Dating is used extensively to provide absolute chronologies for Late Pleistocene sediments. Nowadays, most optical dates are based on quartz optically stimulated Luminescence (OSL). However, the application of this signal is usually limited to the last ∼100 ka because of saturation of the quartz Luminescence signal with dose. In contrast, the feldspar infrared stimulated Luminescence (IRSL) dose–response curve grows to much higher doses; this has the potential to extend the datable age range by a factor of 4–5 compared with quartz OSL. However, it has been known for several decades that this IRSL signal is unstable, and this instability often gives rise to significant age underestimation. Here we test against independent age control the recently developed feldspar post-IR IRSL approach to the Dating of sediments, which appears to avoid signal instability. A physical model explaining our observations is discussed, and the method is shown to be accurate back to 600 ka. The post-IR IRSL signal is reduced by exposure to daylight more slowly than that from quartz and low-temperature IRSL, preventing its general application to young (e.g. Holocene) sediments. Nevertheless, this new approach is widely applicable (feldspar of appropriate Luminescence behaviour is even more ubiquitous than quartz). These characteristics make this a method of great importance for the Dating of Middle and Late Pleistocene deposits.
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infrared stimulated Luminescence Dating of an eemian mis 5e site in denmark using k feldspar
Boreas, 2011Co-Authors: Sebastien Huot, Janpieter Buylaert, A S Murray, Peter Van Den HauteAbstract:Buylaert, J.-P., Huot, S., Murray, A.S. & Van den haute, P.: Infrared stimulated Luminescence Dating of an Eemian (MIS 5e) site in Denmark using K-feldspar. Boreas, 10.1111/j.1502-3885.2010.00156.x. ISSN 0300-9483. Infrared stimulated Luminescence (IRSL) Dating of K-feldspars may be an alternative to quartz optically stimulated Luminescence (OSL) Dating when the quartz OSL signal is too close to saturation or when the quartz Luminescence characteristics are unsuitable. In this paper, Eemian (MIS 5e) coastal marine sands exposed in a cliff section on the coast of southern Jutland (Denmark) are used to test the accuracy and precision of IRSL Dating using K-feldspars. This material has been used previously to test quartz OSL Dating (Murray & Funder 2003): a small systematic underestimation of <10% compared to the expected age of ∼130 ka was reported. In our study, a single-aliquot regenerative-dose (SAR) IRSL protocol is used to determine values of equivalent dose (De) and the corresponding fading rates (g values). A significant age underestimation (of up to ∼35%) is observed; this is attributed to anomalous fading. Using a single site-average fading rate of 3.66 ± 0.09%/decade to correct the IRSL ages for all samples provides good agreement between the average fading-corrected K-feldspar age (119 ± 6 ka) and the independent age control (132–125 ka). This is despite the reservations of Huntley & Lamothe (2001) that their fading correction method is not expected to work on samples older than ∼20–50 ka. This fading-corrected feldspar result is not significantly different from the overall revised quartz age (114 ± 7 ka) also presented here. We conclude that fading-corrected IRSL ages measured using K-feldspar may be both precise and accurate over a greater age range than might be otherwise expected.
Lee J Arnold - One of the best experts on this subject based on the ideXlab platform.
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evaluating the suitability of extended range Luminescence Dating techniques over early and middle pleistocene timescales published datasets and case studies from atapuerca spain
Quaternary International, 2015Co-Authors: Lee J Arnold, Alfredo Perezgonzalez, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The emergence of alternative Luminescence Dating techniques, such as thermally transferred optically stimulated Luminescence (TT-OSL), post-infrared infrared stimulated Luminescence (pIR-IRSL) and OSL Dating of individual quartz ‘supergrains’, has opened up new possibilities for establishing numerical age control on sedimentary deposits that exceed the traditional upper age limits of quartz OSL Dating. In this study, we evaluate the reliability of these ‘extended-range’ Luminescence Dating techniques over Middle and Early Pleistocene timescales using two approaches: (i) a broad-scale synthesis of extended-range Luminescence chronologies published so far as part of known-age comparison studies; (ii) a series of new TT-OSL and pIR-IRSL case studies at the palaeoanthropological sites of Galeria, Sima del Elefante and Gran Dolina (Atapuerca, Spain). The published known-age TT-OSL datasets (n = 82) and supergrain OSL datasets (n = 3) display good correspondence (i.e., suitably linear and proportion relationships) with associated age control. The known-age pIR-IRSL datasets (n = 228) display more inter-sample scatter, though there is general support for the reliability of more stringent pIR-IRSL protocols and multiple-elevated temperature pIR-IRSL approaches over Late and Middle Pleistocene timescales. While these reliability assessments are encouraging, there remains a clear need for more widespread, known-age empirical assessments of extended-range Luminescence techniques beyond ∼300–400 ka. The ages obtained at Atapuerca using single-grain TT-OSL and pIR-IRSL measurement temperatures of 225 °C (pIR-IR225) are in agreement with independent age control over an age range spanning ∼240–930 ka. In contrast, the pIR-IRSL chronologies obtained using a more stringent measurement temperature of 290 °C (pIR-IR290) consistently overestimate the expected ages of the Atapuerca sequences. The single-grain TT-OSL ages obtained at Gran Dolina permit calculation of a new weighted mean age of 846 ± 57 ka for the Homo antecessor palaeoanthropological horizon (unit TD6). The known-age Atapuerca case studies highlight the feasibility, and advantages, of applying TT-OSL Dating at the single-grain scale of analysis and demonstrate that the suitability of pIR-IRSL Dating protocols can vary significantly at a site or regional scale. Together, our analyses show that no single extended-range Luminescence Dating technique is likely to be universally applicable to all samples. Collectively, however, these approaches offer good potential for obtaining reliable chronologies, and they are likely to offer the greatest benefits when applied in tandem to individual samples.
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new Luminescence ages for the galeria complex archaeological site resolving chronological uncertainties on the acheulean record of the sierra de atapuerca northern spain
PLOS ONE, 2014Co-Authors: Martina Demuro, Alfredo Perezgonzalez, Ana Ortega, Lee J Arnold, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Eudald CarbonellAbstract:The archaeological karstic infill site of Galeria Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range Luminescence Dating techniques, namely post-infrared infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains, were applied to fossil-bearing sediments at Galeria. The Luminescence Dating results are in good agreement with published chronologies derived using alternative radiometric Dating methods (i.e., ESR and U-series Dating of bracketing speleothems and combined ESR/U-series Dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new Luminescence ages are significantly (∼50%) younger than previously published polymineral thermoLuminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galeria deposits. The Luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galeria have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galeria Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL Dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.
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Luminescence Dating and palaeomagnetic age constraint on hominins from sima de los huesos atapuerca spain
Journal of Human Evolution, 2014Co-Authors: Lee J Arnold, Martina Demuro, J M Pares, Juan L Arsuaga, Jose Maria Bermudez De Castro, Arantza Aranburu, Eudald CarbonellAbstract:Establishing a reliable chronology on the extensive hominin remains at Sima de los Huesos is critical for an improved understanding of the complex evolutionary histories and phylogenetic relationships of the European Middle Pleistocene hominin record. In this study, we use a combination of ‘extended-range’ Luminescence Dating techniques and palaeomagnetism to provide new age constraint on sedimentary infills that are unambiguously associated with the Sima fossil assemblage. Post-infrared-infrared stimulated Luminescence (pIR-IR) Dating of K-feldspars and thermally transferred optically stimulated Luminescence (TT-OSL) Dating of individual quartz grains provide weighted mean ages of 433 � 15 ka (thousands of years) and 416 � 19 ka, respectively, for allochthonous sedimentary horizons overlying the hominin-bearing clay breccia. The six replicate Luminescence ages obtained for this deposit are reproducible and provide a combined minimum age estimate of 427 � 12 ka for the underlying hominin fossils. Palaeomagnetic directions for the Luminescence dated sediment horizon and underlying fossiliferous clays display exclusively normal polarities. These findings are consistent with the Luminescence Dating results and confirm that the hominin fossil horizon accumulated during the Brunhes Chron, i.e., within the last 780 ka. The new bracketing age constraint for the Sima hominins is in broad agreement with radiometrically dated Homo heidelbergensis fossil sites, such as Mauer and Arago, and suggests that the split of the H. neanderthalensis and H. sapiens lineages took place during the early Middle Pleistocene. More widespread numerical Dating of key Early and Middle Pleistocene fossil sites across Europe is needed to test and refine competing models of hominin evolution. The new Luminescence chronologies presented in this study demonstrate the versatility of TT-OSL and pIR-IR techniques and the potential role they could play in helping to refine evolutionary histories over Middle Pleistocene timescales.
