Mesopleistocene loess deposits in the Mamalyha 2 profile of Ukraine — interlaboratory comparison of the thermoluminescence dating results

The history of the interlaboratory comparison of TL dating results in Poland started in the 1980s. At that time the Lublin, Warsaw and Silesian laboratories made the first attempts at TL dating of the same loess samples from the Odonów profile. However, the cooperation ceased for many years due to great differences in the obtained TL age estimates. The next interlaboratory comparisons were made in the years 2000–2009 for the loess samples from several Polish (Dybawka, Tarnawce, Dankowice, Biały Kościół) and Ukrainian (Boyanychi, Halych, Velykyj Hlybochok, Yezupil) profiles. Most of the compared dates, obtained for the loess deposits from the Upper Pleistocene and younger part of the Middle Pleistocene, were consistent. This encouraged us to undertake the Gdańsk-Lublin interlaboratory cooperation in dating of 200-700 ka old loess deposits. Nine samples were taken from the Ukrainian profile Mamalyha 2 in 2009 for this purpose. The TL dating results indicate that comparable dates are obtained in two laboratories for loess deposits younger than 300 ka BP. The TL signal obtained in the Gdańsk laboratory for the samples older than 300 ka BP was saturated so such samples should not be dated by the multi-aliquot regeneration method. The results obtained in the Lublin laboratory for these deposits (489–682 ka) confirm that it is possible to date loess deposits older than 500 ka. It probably results from the use of total-bleach method with preheating at 160°C for the equivalent dose determination.     

New exposure of loess deposits in Boyanychi (Ukraine) — Results of thermoluminescence analyses

The loess site at Boynychi (the Volyn Upland) is of essential importance for the stratigraphy of Middle and Upper Pleistocene in Central Europe. The profile was recently dated by Fedorowicz and Prylypko in 2007 (parallel dating), and by Kusiak in 2009. The Upper Vistulian loesses are much thicker in the exposure from 2009 than in the earlier examined one (2007). The list of results obtained in the Gdańsk, Kiev and Lublin laboratories, respectively, can be divided in two. The first group contains the results obtained for the Horohiv and Korshiv pedocomplexes and for the loess from the penultimate glacial, which separates these pedocomplexes. The results from all laboratories are very similar and rather well describe the real age of dated deposits. The second group contains the widely differing results of dating of the Vistulian loesses. The TL ages obtained by Fedorowicz and Prylypko are considerably older than those obtained by Kusiak in the new exposure. The latter ones excellently correspond to the geologic-stratigraphic interpretation of the profile. Two incompatible series of TL dating results indicate that local variability of loess accumulation conditions in different stages of their formation may have resulted in incomplete luminescence zeroing of mineral material before deposition.     

The results of thermoluminescence dating in the Halych IIC (Ukraine) profile as the expression of the conditions of mineral material deposition

Many studies conducted in the last few years in Poland indicate that the results of thermoluminescence dating of loess are reliable and correspond well to their geological ages. They can form the basis for determination of the chronology of changes of palaeoenvironmental conditions. In this paper we report dating results from the Halych IIC profile (Halych Prydnistrov’ja region, Ukraine). Thermoluminescence dating of this profile gives new information about the influence of local conditions on the results of TL analysis. As much as 75% of the obtained results are distinctly overestimated, even by several hundred per cent, that is untypical of regional loess profiles. However, in the Halych Prydnistrov’ja region it is the second loess site in which such incompatibility of the expected age and thermoluminescence age is found. This fact indicates how this region is unique among the loess areas of SE Poland and NW Ukraine in respect of the conditions of mineral material transport and deposition. Further investigations are necessary to identify the reasons for regular overestimating of the TL results obtained for loess deposits of the Halych Prydnistrov’ja region.     

On the applicability of post-IR IRSL dating to Japanese loess

Recent work on infrared stimulated luminescence (IRSL) dating has focussed on finding and testing signals which show less or negligible fading. IRSL signals measured at elevated temperature following IR stimulation at 50°C (post-IR IRSL) have been shown to be much more stable than the low temperature IRSL signal and seem to have considerable potential for dating. For Early Pleistocene samples of both European and Chinese loess natural post-IR IRSL signals lying in the saturation region of the laboratory dose response curve have been observed; this suggests that there is no significant fading in nature. As a contribution to the further testing of post-IR IRSL dating, we have used 18 samples from two Japanese loess profiles for which quartz OSL and tephra ages up to 600 ka provide age control. After a preheat of 320°C (60 s), the polymineral fine grains (4–11 μm) were bleached with IR at 50°C (200 s) and the IRSL was subsequently measured at 290°C for 200 s. In general, the fading uncorrected post-IR IRSL ages agree with both the quartz OSL and the tephra ages. We conclude that the post-IR IRSL signal from these samples does not fade significantly and allows precise and accurate age determinations on these sediments.     

Luminescence dating of volcanogenic outburst flood sediments from Aso volcano and tephric loess deposits, southwest Japan

Luminescence dating has been applied to volcanogenic outburst flood sediments (Takuma gravel bed) from Aso volcano, Japan, and tephric loess deposits overlying the gravel bed. The poly-mineral fine grains (4–11 μm) from loess deposits were measured with pulsed optically stimulated luminescence (pulsed OSL) and post-IR infrared stimulated luminescence (pIRIR) methods, whereas the Takuma gravel bed containing no quartz, was measured with IRSL and pIRIR methods using sand sized (150–200 μm) plagioclase. The loess deposits date back at least to ～50 ka by consistent IRSL, pIRIR and pulsed OSL ages from the lowermost part of the loess deposits from one section. The ages obtained from the bottom part of the other loess section are not consistent each other. However, we consider that the pIRIR age (72±6 ka) which showed negligible anomalous fading is most reliable, and regard as a preliminary minimum age of the Takuma gravel bed. The equivalent doses (D_e) for the plagioclase from the Takuma gravel bed have a narrow distribution and the weighted mean of the three samples yield an age of 89±3 ka. This age is in agreement with the last caldera-forming eruption of Aso volcano (～87 ka) and it is likely that the pIRIR signal has not been bleached before the deposition. IRSL dating without applying pIRIR using small aliquots was also conducted, however, the IRSL signal shows no clear evidence of an additional bleaching during the event of outburst flood from the caldera lake.     

OSL dating using quartz fine grains extracted from loess in Upper Palaeolithic sites of Nihewan Basin, northern China

Although radiocarbon (¹⁴C) dating, uranium-series dating, and optically stimulated luminescence (OSL) dating have been conducted for Upper Palaeolithic sites in the Nihewan Basin, northern China, there is room for constructing a detailed chronological framework. In this study, loess sediments collected from two Upper Palaeolithic sites, Youfang site and Hutouliang site, were dated using the single-aliquot regenerative-dose (SAR) OSL protocol. OSL measurements for palaeodoses estimation used fine-grained quartz samples extracted from loess. OSL dating results were obtained as 10–17 ka. These OSL ages were consistent with the related stratigraphy of Palaeolithic sites, archaeological evidence and independent ¹⁴C ages.     

New radiometric ages for the Early Upper Palaeolithic type locality of Brno-Bohunice (Czech Republic): comparison of OSL,IRSL, TL and C dating results

New radiometric data are reported from the recent excavation of the type locality of the Early Upper Palaeolithic entity of the Bohunician. Recently obtained radiocarbon (¹⁴C) data on charcoal are compared with new Optically Stimulated Luminescence (OSL) dating of sediment. OSL ages were determined on sediment from the archaeological occupation at Brno-Bohunice, as well as from the over- and underlying loessic sediments. Multiple techniques were applied, which all gave congruent results. While a dual protocol (post IR-OSL) failed the quality criteria tests, ages were obtained by Multiple-Aliquot-Additive-Dose (MAAD) on polymineral material and Single-Aliquot-Regeneration (SAR) on fine grain quartz extract as well as on polymineral material. Fading tests show significant loss of Infrared Stimulated Luminescence (IRSL) after storage for 3 and 12 months for one sample, but little or no fading for others. The resulting (uncorrected) age estimates are smaller than those on quartz by OSL methods. The latter are considered to be more reliable estimates of the sedimentation age of these deposits. The measured OSL doses do not show a simple distribution and the lowest 5% was used for age calculation to represent the most likely sedimentation age. The quartz from the loess overlying the archaeological layer is OSL dated to 30.9 ± 3.1 ka, while the sediment for the paleosol which contains the archaeological layer gave an age of 58.7 ± 5.8 ka. The attribution of this paleosol to the Hengelo interstadial is therefore questionable. However, if the Hengelo interstadial is correlated with the Dansgaard/Oeschger (D/O) event 12, statistical agreement within 2-σ is achieved. The OSL result for the archaeological layer is in accordance with a weighted average TL date on heated flint artifacts of 48.2 ± 1.9 ka from this layer as well as calibrated radiocarbon data (CalPal Hulu 2007) from nearby locations. However, radiocarbon data on charcoal samples obtained during excavation at Brno-Bohunice 2002 provide age estimates between 30 and 40 ka ¹⁴C-years, which translate to approximately (33) 35–44 ka on the calendric time scale according to the Hulu 2007 model. For the underlying loess a depositional age of 104.3 ± 10.6 ka was obtained by OSL. The presented OSL ages indicate that a simple correlation of soil sequences between sites within a region has to be verified by chronometric dating.     

Thermoluminescence age of quartz xenocrysts in basaltic lava from Oninomi monogenetic volcano, northern Kyushu, Japan

We determined the eruption age of basaltic rocks by application of thermoluminescence (TL) method, which is often used for TL dating, to quartz. Mafic magma only rarely includes quartz because of their mutual disequilibration. The basaltic lavas reported herein include quartz as xenocrysts, as corroborated by their rounded or anhedral shape. The basaltic lava used for this study is from the Oninomi monogenetic volcano in northern Kyushu, Japan. The volcano eruption was estimated as occurring 7.3–29 ka because the lava exists between two widespread tephras: Aira-Tanzawa ash (26–29 ka) and Kikai-Akahoya ash (7.3 ka). We succeed-ed in collecting ca. 200 mg of quartz by decomposition of 30 kg of the lava samples. TL measurements for the lava indicate the eruption age as 15.8 ± 2.5 ka, which is fairly consistent with the stratigraphical estimation. Although the TL method has played a considerable part in constraining the timescale of Quaternary events, its application has been limited to silicic samples. The present result demonstrates the availability of quartz for dating even of mafic rock.     

X荧光成分分析实验对测量陶瓷器热释光年代的影响研究

为了考察对一件已经经过X荧光分析实验的陶瓷样品进行热释光年代测定时,年代结果是否会受到X荧光分析实验的影响及其影响程度,本工作选取了古代与现代的陶器、瓷器及三彩样品共26件,在常规、经过胎体成分分析、经过釉层成分分析三种实验条件下测量比较热释光年代的变化.研究发现,对不同时代不同类型的样品,X荧光成分分析实验对热释光测年的影响程度不同;对部分样品的测年结果无影响,对部分样品的年代有增大的影响,但增大的程度不会使热释光测年结果产生真假颠倒的结论.     

Attempts at thermoluminescence dating of fired materials from the Przeworsk Culture settlements

The thermoluminescence (TL) dating method has a significant measurement error margin reaching almost 10%. Due to this fact it could be considered as little effective in case of such sites from the Roman period as burial grounds with many artefacts useful for archaeological dating. However, for many settlements from this period, where pottery is the only kind of artefacts, the TL method can give notable results. The main purpose of the study was to make an attempt at TL dating of pottery and clay daub samples from the Nieszawa Kolonia and Kręcieszki sites and to compare the obtained dates with the results of archaeological dating of selected features from the Przeworsk Culture settlements. In the Kręcieszki site the fragments of burnt clay daub were dated by the TL method for the first time in the Lublin laboratory. It turned out that clay daub is an equally good dating material as pottery. It can be found that the TL dating of pottery from Nieszawa Kolonia confirms two stages of settlement. The first settlement stage is related to the phases B2-B2/C1-C1a of the Roman period, i.e. from the beginning of the 2^nd to the beginning of the 3^rd century. The second group of TL dates corresponds to the phases C2D that is to the second stage of settlement, from the second half of the 3^rd century to the half of the 5^th century AD. The results of TL dating of pottery and clay daub in the Kręcieszki site are rather similar and correspond to the phase B1/B2 of the period of Roman influence, determined from pottery style, but can also indicate the phase B2/C1.     

TL dates for the Middle Paleolithic site of Combe-Capelle Bas,France

The Middle Paleolithic site of Combe-Capelle Bas, France, is known primarily from the excavations of Ami in the early part of the last century and more recently from the excavations of Dibble and Lenoir. Up to now, the only dates available for the site were based on geologic and paleoclimatic data. Most recently, Texier and Bertran suggest that the formation of the principal Mousterian deposits date to prior to OIS 6 and likely represent OIS 8 or even 10. The results of TL dating of burnt flints from these same deposits (Levels I-1D, I-1E, and I-2B), reported here, contradict this finding. They indicate an age of between 37 to 60 ka with six of the seven flints falling between 50–60 ka. This date fits well with Mousterian sites previously dated in this region of France.     

Optical dating of alluvial deposits at the orogenic front of the andean precordillera (Mendoza,Argentina)

Well constrained numerical ages of alluvial fan sediments are key to understanding the chronology of alluvial episodes and tectonic activity at the front of the Andean Precordillera. We tested the application of radiocarbon and optically stimulated luminescence (OSL) dating in the distal part of an alluvial fan five kilometers north of Mendoza. For OSL dating a large number of aliquots (n > 70) — each composed of ∼50 quartz grains — were measured in order to obtain reliable burial ages despite scattered dose distributions. Owing to a feldspar contamination in all samples, an infrared stimulation was inserted before each OSL measurement, which reduced the feldspar OSL signal successfully. By using the minimum age model we obtained stratigraphically consistent burial ages of alluvial deposits in a depth profile. The uppermost ∼1 m of sediment is composed of debris flow deposits buried 770±76 years ago. Three plant remnants used for radiocarbon dating from the same layer, however, yielded ages younger than 350 years, which are interpreted to underestimate the depositional age. Underneath the debris flow, a major unconformity cuts a series of distal alluvial fan sediments with interstratified floodplain deposits, which are composed of sandy and calciterich silt layers, respectively. Three samples from this unit which were distributed over one meter of sediment thickness yielded statistically concordant OSL ages of 12.3±1.2 ka, 12.3±1.2 ka, and 11.7±1.1 ka. The deposition of these sediments during the latest Pleistocene coincides with a phase of cool and humid climate, which occurred before the alluvial fan propagated farther into the foreland. The overlying debris flow sediments are associated with alluvial fan incision during the arid Late Holocene.     

Multi-method luminescence investigations on quartz grains of different sizes extracted from a loess section in Southeast Romania interbedding the Campanian Ignimbrite ash layer

In this study we present luminescence investigations of four samples of loess bracketing the Campanian Ignimbrite/Y5 tephra at the Rasova-Valea cu Pietre site, on the eastern bank of the Danube River, southeastern Romania. Investigations involved SAR-OSL dating on aliquots of fine (4–11 μm) and medium-grained (63–90 μm) quartz, as well as single grain analyses on 125–180 μm quartz. Luminescence dating results coupled with glass-shard chemical fingerprinting assign the depositional age and origin of the ash layer to that of the Campanian Ignimbrite/Y5 tephra, dated elsewhere using ⁴⁰Ar/³⁹Ar to 39.28 ± 0.11 ka. Fine-grained (4–11 μm) quartz SAR-OSL analyses yielded ages of 44.4 ± 4.5 ka below the ash, and 41.4 ± 4.2 ka above the ash layer. Single grain analysis on coarse-grained quartz, however, demonstrates that coarse material from these samples exhibits low sensitivity and responds poorly to internal checks of the SAR protocol in comparison with the finer sediment. This observation highlights the need for more extensive investigations into the luminescence properties of quartz as well as into the origin of quartz contributions from different primary sources in the Lower Danube loess steppe.     

Preliminary U-series and Thermoluminescence dating of excavated deposits in Liang Bua sub-chamber,Flores, Indonesia

We report the results of a test excavation of deposits in a limestone cave sub-chamber located beneath the main chamber of Liang Bua, Flores, Indonesia; the discovery site of the small hominin species, Homo floresiensis. Well-preserved remains of extinct Pleistocene fauna and stone artefacts have previously been identified on the surface of a sediment cone within the sub-chamber. Our excavation of the deposits, at the base of the sediment cone in the sub-chamber (to 130 cm depth) yielded only a few fragmentary bones of extant fauna. Uranium/Thorium (U-series or U/Th) dating of soda straw stalactites excavated from 20 to 130 cm in depth demonstrates that the excavated sediments were deposited during the Holocene. Red Thermoluminescence (TL) dating of the sediments at the base of the excavation (130 cm depth) indicates these sediments were last exposed to sunlight at 84 ± 15 ka (thousand years), similar to red TL ages of cave sediments from the main chamber. Together, these results indicate that the surface faunal remains, which are morphologically analogous to Pleistocene finds from the main chamber excavations, were transported to the sub-chamber relatively recently from the main chamber of Liang Bua and probably originated from conglomerate deposits at the rear of the cave and from deposits around the front entrance. There is no evidence for hominin occupation of the sub-chamber, instead it seems to have acted as a sink for cultural materials and fossil remains transported from the surface via sinkholes. Despite the small number of finds from the test excavation, it is possible that more extensive excavations may yield additional transported cultural and faunal evidence at greater depths.     

An improved OSL chronology for the Still Bay layers at Blombos Cave,South Africa: further tests of single-grain dating procedures and a re-evaluation of the timing of the Still Bay industry across southern Africa

This paper presents a series of new single-grain optically stimulated luminescence (OSL) ages for the Still Bay at Blombos Cave, South Africa, and compares them to previously published OSL, thermoluminescence (TL) and electron-spin resonance (ESR) ages for this site. Details are provided about the measurement and analytical procedures, including a discussion of the characteristics of the OSL signals of individual quartz grains. This forms the basis for further investigations into the sensitivity of the equivalent dose (D_e) estimates to a range of different analytical approaches, including changes in the size of the test dose, the choice of signal integration interval, the subtraction of an appropriate background, and isolation of the most light-sensitive (‘fast’) component of quartz OSL. We also report the results of an inter-operator test of D_e determination using seven new samples from Blombos Cave, and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study. Together, these tests validate the robustness of the Blombos Cave single-grain OSL age estimates to a variety of alternative OSL dating procedures. We have incorporated, for the first time, these ages for Blombos Cave into a data set of all single-grain OSL ages for Still Bay and Howieson's Poort sites across southern Africa, and have used a statistical model to re-evaluate the timing and duration of the Still Bay industry. We calculate the most plausible start and end dates of the Still Bay as 72.2 ka and 71.3 ka, respectively – amounting to a duration of 0.9 ka – and estimate (with conventional 95% confidence) that this industry began no earlier than 75.5 ka, ended no later than 67.8 ka and lasted no longer than 6.6 ka.     

Chronology during the Bronze Age in the archaeological site Tell Qubr Abu al-‘Atiq, Syria

Archaeosediments are deposits with a direct or indirect anthropogenic component. They provide useful information about past human activities and interaction with the environment. When other materials, such as pottery, are present in archaeosediment layers, the combination of TL ages from pottery and OSL ages from sediments can provide complete data about the occupation and evolution of an archaeological setting. In Mesopotamia, tells are mounds formed by the debris of human occupation and the accumulation of muddy sediments mainly due to the decomposition of mud bricks in ancient towns. Many other materials such as pottery fragments, bones and charcoal can be found in the sediment layers. The combination of OSL, TL and radiocarbon ages can be very useful in the case of the Bronze Age Period in Syria, allowing the occupation sequence of such archaeological sites to be reconstructed. Tell Qubr Abu al-’Atiq, is located on the left bank of the Middle Euphrates River (Syria). The archaeological artefacts found in the sediment layers (pottery) collected during excavations in two areas of the site, indicated the occupation of the tell during the Early and Late Bronze Age by typological pottery classification. The radiocarbon ages of charcoal indicate that human occupation fits the archaeological hypothesis, providing an older and maximum occupation period between 2800 and 2300 BC and a younger period between 1400 and 900 BC. OSL dating of sediments shows ages younger than charcoal, while TL ages of pottery are generally older than sediment and charcoal ages. This can be explained as the different materials correspond to different events. The charcoal and pottery correspond to occupation periods, while sediments correspond to the further destruction of the site.     

ESR dating of the Donggutuo Palaeolithic site in the Nihewan Basin, northern China

The fluvio-lacustrine sequences in the Nihewan Basin, northern China, provide important terrestrial archives about Palaeolithic settlements and, therefore, about early human occupation in high northern latitude in East Asia. Here we present detailed ESR dating of the Donggutuo Palaeolithic site, located in this basin. Four levels A, B, C and E of the Donggutuo archaeological layer yield ESR ages ranging from 1060±129 ka to 1171±132 ka with a mean of 1119±132 ka. The ages are consistent with the paleomagnetic data, which show that the Donggutuo Palaeolithic site lies just below the onset of the Jaramillo normal subchron (0.99–1.07 Ma). Furthermore, our results indicate that the reliable ESR dating range of bleached quartz using Ti-Li centre can be effectively extended to 1100 ka and the Ti-Li centre was zeroed before the last deposition, which requires improvement of the understanding of the bleaching mechanism conditions.     

Luminescence geochronology and paleoenvironmental implications of coastal deposits of southeast Cyprus

Quaternary stratigraphy and sea level changes have been extensively investigated in many areas of the Mediterranean. However, numerical dating of coastal deposits and the associated paleoenvironmental information are limited for the coasts of Cyprus, principally based on radiometric and radiation-exposure geochronological techniques on fossils which bear a range of limitations and uncertainties. As such, optically stimulated luminescence (OSL) dating techniques are deemed to be the most suitable in direct dating of the coastal sediments of Cyprus. In the southeastern Cyprus, coastal dunes (aeolianites) now forming elongated ridges appear as morphological features running parallel to the current shoreline presenting an indicator of sea level and climate changes of great paleoenvironmental significance. We present our first chronological results for the exposed aeolianites and underlying littoral deposits formed along the southeastern coastal Cyprus ranging from 78.4 ± 9.9 to 56.2 ± 7.4 ka. The post-infrared–infrared stimulated luminescence (pIR-IRSL) revealed that dune formation took place during the marine isotope stages (MISs) 3, 4, and possibly 5a. Late Holocene reworking is proposed for a distinctively isolated dune with an age of ~1.3 ka ago. This study also showed that pIR-IRSL dating of feldspars may be a reliable alternative to quartz OSL dating when the quartz luminescence characteristics are unsuitable.     

Thermoluminescence dates for the Middle Palaeolithic site of Chez-Pinaud Jonzac (France)

Thermoluminescence dating of heated flint artefacts from the Middle Palaeolithic sequence of Chez-Pinaud Jonzac (France) places an assemblage of Quina type Mousterian into MIS 4, while the overlying assemblage of Denticulate Mousterian which is followed by two layers with Mousterian of Acheulean Tradition are all assigned to MIS 3. TL dating is used to verify the mixed nature of deposits from which diagnostic Middle as well as Upper Palaeolithic tools were recovered. The TL ages are significantly different for samples from this layer and broadly agree with the archaeological attributions. While the study is generally limited by the low number of heated samples available, a correlation with a generalized chronostratigraphic sequence is possible by including proxy data from the faunal remains associated with the lithic assemblages in question. The Quina Mousterian in southwestern France, therefore, can be placed by chronometric dating methods in MIS 4 to MIS 3.     

Examining quartz OSL age underestimation for loess samples from Luochuan in the Chinese Loess Plateau

When using quartz OSL to date loess samples from the Chinese Loess Plateau, it has been reported that the agreement between OSL ages and the independent ages is limited to the samples younger than ～70 ka with a corresponding D_e of ～230 Gy, and a sample with an expected age of 780 ka was dated to 107 ka, corresponding to 403 Gy. The growth curves of these samples do not saturate at doses of 700 Gy, and a linear growth part was observed for doses higher than 200 Gy. However, the maximum measured age of ～100 ka imply that the D_e determined using this linear part of a growth curve could be problematic, or that the quartz OSL signal is not as stable as previously thought and has a barrier age of ～100 ka. In the current study, we examine the reasons for the age underestimation. We examined the shape of growth curves, anomalous fading, thermal stability, etc. The results show that, for the loess samples examined, quartz OSL does not fade anomalously, and the barrier age of ～100 ka is due to the fact that the OSL signals are less thermally stable, the lifetime of 0.311 Ma at 20°C obtained is much smaller than those for quartz samples from other regions such as Australia (～100 Ma).