Optical Dating

The 'double SAR' protocol procedure permits the determination of two equivalent dose (De) values for each polymineral aliquot; an IRSL De resulting mostly from feldspars along with a post-IR OSL De for a mixed signal for quartz (mostly) and feldspar grains. The objective of the present study is to test for the first time its usefulness for polymineral, coarse silt, closely-spaced deep-sea sediment samples. A new, 'double SAR' IRSL dataset is presented for the sedimentation ages of a deep-sea sediment core of the Hellenic Trench, drilled from a water depth of 4 km, near the deepest site of the Mediterranean Sea, outside Pylos, Greece. Post IR quartz-based optical dating was previously proved to be consistent with AMS radiocarbon ages, obtained from planktonic foraminifera from the same core. IRSL De values are, with one exception, always much greater than the corresponding (post-IR) OSL results. This result suggests that for the present study 'double SAR' protocol procedure was proved to be extremely effective method for separating the luminescence signals from quartz and feldspars. Furthermore, De values obtained after infra-red stimulation and thermoluminescence generally agree within errors. This quantitative equivalence of those two sets of De values implies that as in the case of IRSL, TL signal is also feldspar-dominated. IRSL ages vary between 3.5 and 7.8 ka with associated errors up to 9%. Application of 'double SAR' protocol to coarse silt, closely-spaced deep-sea sediment samples seems advisable, despite the fact that the post-IR blue OSL signal is the most stable signal, and is preferred for dating.

After an intercomparison age experiment carried out in the framework of the first MODIS (MOrtar Dating Inter-comparison Study) project, the results showed general agreement both between optically stimulated luminescence (OSL) dating laboratories and with radiocarbon ( 14 C) dating results. As the needs for the selection of samples convenient for an inter-comparison are not the same between 14 C and OSL, for the second running, it has been decided to choose two different sample sets, one to share between the radiocarbon labs and one for the OSL dating ones. The results obtained by applying different experimental protocols (multigrain and single grain techniques) and different statistical models (weighted mean, central age mode, average dose model, minimum age model and exponential exposure dose) are discussed in this work.

The numerical ages available for the sediments on the Danube terraces in the Pest Plain are scarce. In this study, we present quartz OSL and K feldspar post-IR IRSL290 ages for the sandy fluvial, aeolian and slope sediments collected from Danube terraces IIb, III and V. The feldspar post-IR IRSL290 ages without residual dose subtraction are older than the quartz OSL ages, except for one sample, but the two sets of ages are overlapping within one or two sigma errors. In the bleaching experiment under natural sunlight during summer, an unbleachable component ranging from 2.5±0.7 Gy to 5.2±0.3 Gy after 30 h exposure to bright sunshine is observed and it corresponds to 3−8% of the measured K feldspar post-IR IRSL290 equivalent doses. These facts indicate that residual dose subtraction would be necessary before age calculation, in most cases. The saturated fluvial gravelly sand of terrace V of the Danube is older than ~ 296 ka based on feldspar post-IR IRSL290 measurements. This age does...

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. Resul...

The ediTor arTiCles The Wakulla springs lodge siTe (8Wa329): 2008 exCavaTions and neW osl daTing evidenCe W. Jack Rink, James s. DunbaR, anD k. e. buRDette bioTurbaTion and The Wakulla springs lodge siTe arTiFaCT disTribuTion DaviD k. thulman ground-pemeTraTing radar (gpr) survey, Wakulla springs sTaTe park, Wakulla CounTy, Florida: use oF gpr in supporT oF arChaeology DaviD anDy smith granulomeTriC analysis oF sedimenT samples From The Wakulla springs lodge siTe Wakulla CounTy, Florida Guy h. means The FirsT Florida "bling": paleoindian beads maRy GloWacki anoTher Wakulla springs masTodon? kevin m. PoRteR Wakulla springs arChaeologiCal researCh The volunTeer experienCe maRy steRneR laWson The purdy uniFaCe, a reCenTly reCognized early sTne Tool Type in Florida scott e. mitchell anD l. h. "monty" PhaRmeR paleoindian oCCupaTions along The sT. Johns river, Florida DaviD k. thulman geoarChaeologiCal invesTigaTions and osl daTing evidenCe in an arChaiC and paleoindian ConTexT aT The helen blazes siTe (8br27), brevard CounTy, Florida 87 W.Jack Rink, James s. DunbaR, Glen h. DoRan, chaRles FReDeRick, anD bRittney GReGoRy abouT The auThors erraTa TypologiCal, FunCTional, and ComparaTive ConTexTual analyses oF Woodland hasFTed biFaCes From kolomoki (9er1) thomas J. Pluckhahn anD sean P. noRman 112 Cover: Artist's depiction of a mastodon kill site and the volunteers of the Wakulla excavations.

The pre-Holocene Cenozoic sequence outcrops in the terrestrial part of the eastern margin of the Mekong Basin. However, the stratigraphy of the sequence is still unclear. Its detailed stratigraphy and chronology were therefore studied along the Dong Nai River, southern Vietnam, and the lithofacies and the relations among the formations were investigated from the outcrops. The ages of the deposits were determined by using optically stimulated luminescence (OSL) dating. The Ba Mieu Formation was deposited about 176G52 ka during marine isotope stage (MIS) 7-6. The Thu Duc Formation was deposited about 97G27 ka during MIS 5. Both the Ba Mieu and Thu Duc formations are composed of fluvial and tidally influenced coastal deposits. The newly proposed Nhon Trach Formation was originally an eolian (blanket) deposit, but it has been partly reworked by fluvial processes. The Nhon Trach Formation was deposited about 10.9G4.7 ka, in the last part of the Pleistocene to the beginning of the Holocene. The OSL ages for the Ba Mieu, Thu Duc, and Nhon Trach formations are younger than the ages previously assigned to these formations.

Введение
В рамках проекта “Сравнительное исследование истоков изобразительного искусства современной Сибири и Монголии”, совместная с Алтайском Государственным Техническим Университетом Российской Федерации, Российско-Монгольская полевая исследовательская группа в процессе знакомства с наскальными рисунками на территории Республики Алтай, обратила внимание на существование памятников, не вошедших в исследовательский оборот. Гора Жалгыз-Тобе, с высотой над уровнем моря в 1935 метров находится на западном берегу реки Чой, на расстоянии 10 км на юг от поселения КошАгач.ш. /парное дерево/, и на берегу реки Цагаан бургас (Чаган бургаз). Это одиночная гора, расположенная на расстоянии 60 км от пограничного перехода Монголии Улаан байшинт. В исследовательских работах название горы отмечено по разному (Жалгыс-Тобе, Жалгыс-Тепе, Жалгыз тюбе). Алтайцы называют Jаныс-Тобо зулай толгой. Казахи Жалгыз Төбе ганц толгой, с значение холм (гора). /Координаты: 49°52'26"N. 88°41'13"E/. Наскальные рисунки относятся к периоду от бронзового века (III-VIII век до нашей эры) до начала Средних веков (VI-XI век нашей эры). В соответствии с первыми исследованиями, проведёнными А.П.Окладниковым отмечено, что имеются более 700 рисунков с изображениями животных (козы, олени, жищники, быки) охоты, людей и оружия. В 1980 году исследователь-археолог В.Д. Кубарев открыл здесь памятники с древними руническими письменами. [ В.В. Горбунов. 1998]
Ключевые слова: Алтай, наскальный рисунок, тюркая, жужаньская культура
  Г. Амурсанаа. Galmandakhi Amarsanaa

    Mongolian National University of Arts an

Quaternary alluvial and colluvial sediments infill major river valleys and form alluvial fans and colluvium-filled bedrock depressions on the range fronts and within the Mount Lofty Ranges of southern Australia. A complex association of alluvial successions occurs in the Sellicks Creek drainage basin, as revealed from lithostratigraphy, physical landscape setting and optically stimulated luminescence (OSL) ages. Correlation of OSL ages with the Marine Oxygen Isotope record reveals that the alluvial successions represent multiple episodes of alluvial sedimentation since the penultimate glaciation (Marine Isotope Stage 6; MIS 6). The successions include a penultimate glacial maximum alluvium (Taringa Formation; 160 ± 15 ka; MIS 6), an unnamed alluvial succession (42 ± 3.2 ka; MIS 3), a late last glacial colluvial succession within bedrock depressions (ca 15 ka; MIS 2) and a late last glacial alluvium (ca 15 ka; MIS 2) in the lowest, distal portion of Sellicks Creek. In addition, the Waldeila Formation, a Holocene alluvium (3.5 ± 0.3 ka; MIS 1), and sediments deposited during a phase of Post-European Settlement Aggradation (PESA) are also identified. The age and spatial distribution of the red/brown successions, mapped as the Upper Pleistocene Pooraka Formation, directly relate to different topographic and tectonic settings. Neotectonic uplift locally enhanced erosion and sedimentation, while differences in drainage basin sizes along the margin of the ranges have influenced the timing and delivery of sediment in downstream locations. Close to the Willunga Fault Scarp at Sellicks Creek, sediments resembling the Pooraka Formation have yielded a pooled mean OSL age of 83.9 ± 7 ka (MIS 5a) corroborating the previously identified extended time range for deposition of the formation. Elsewhere, within major river valleys, the Pooraka Formation was deposited during the last interglacial maximum (128-118 ka; MIS 5e). In general, alluviation occurred during interglacial and interstadial pluvial events, while erosion predominated during drier glacial episodes. In both cases, contemporaneous erosion and sedimentation continued to affect the landscape. For example, in the Sellicks Creek drainage basin, which lies across an actively uplifting fault zone, late glacial age sediments (MIS 2) occur within the ranges and near the distal margin of the alluvial fan complex. OSL dating of the alluvial successions reported in this paper highlights linkages between the terrestrial and marine environments in association with sea-level (base-level) and climatic perturbations. While the alluvial successions relate largely to climatically driven changes, especially in major river valleys, tectonics, eustasy, geomorphic setting and topography have influenced erosion and sedimentation, especially on steep-sloped alluvial fan environments. 1. Luminescence dating of the Sellicks Creek alluvial fan complex reveals that sedimentation occurred predominantly during the later stages of glacial cycles accompanying lower sea-levels than present. 2. Luminescence dating confirms that the stratigraphically lower portions of the Pooraka Formation are beyond the range of radiocarbon dating. 3. Upper Pleistocene alluvial fan sedimentation at Sellicks Creek correlates with pluvial events in southeastern Australia.

Optically stimulated luminescence (OSL) dating is now commonly used to estimate the depositional age of Quaternary landforms along the southern Cape coast of South Africa. Due to the early onset of dose saturation in the quartz-rich sediments from this region, determining the age of deposits much older than the last three glacio-eustatic sea-level high stands has been a challenge. In this study, we explored the feasibility of using the thermally-transferred OSL (TT-OSL) dating method to obtain ages for aeolian and shallow marine deposits at three different localities that hold promise to further illuminate the long and complex Late Quaternary sea-level history of this region. The bleachability and behaviour of both the recuperated OSL (ReOSL) and the basic-transferred OSL (BT-OSL) signals were investigated, and used as independent chronometers to infer (a) the degree of bleaching of the sediments and (b) the stability of the ReOSL signal for dating of older samples. We examined the sensitivity of both signals to varying preheat temperatures and further developed the single-aliquot regenerative-dose procedure for TT-OSL dating of our samples. To verify our procedures, and to understand some of the underlying mechanisms responsible for the problems we observed, modern analogues and known-age Marine Isotope Sub-stage (MIS) 5e samples from the same localities were also measured. The Middle Pleistocene deposits investigated in this study produced statistically consistent ReOSL and BT-OSL ages compatible with sea-level high stands during Marine Isotope Stage 11. This result is of considerable significance, as it may yield new insights into maximum sea-level heights during this period, which is widely considered an appropriate analogue for future environmental conditions.

We investigate the feasibility of a modified single-aliquot regenerative-dose (SAR) protocol for OSL dating of individual grains from young samples (< 300 years) using dose-recovery tests. Parameters such as pre-heat temperature, test-and regenerative-dose size, an additional bleaching step at high-temperature and optical stimulation time are optimised to give the highest percentage of accepted grains. The optimised protocol makes use of a 50 Gy test dose, a single regeneration dose of 5 Gy, an additional bleaching step and an optical stimulation of 10 s. This protocol is applied to two coastal-dune samples. Equivalent doses close to those obtained for multiple-grain single-aliquot measurements can be retrieved if: (1) short integration intervals (0.034 s) are used for the natural and regenerated OSL signals as well as the test-dose responses and (2) the background is estimated from the subsequent 0.034 s, and the net signals are used to determine the equivalent dose. Standard background subtraction methods lead to overestimation of the equivalent dose for these samples due to incorporation of a slow OSL component that was not completely reset at the time of burial.

Optically Stimulated Luminescence (OSL) of young palaeoflood sediments): The challenge of accurately estimating the deposition age of incompletely-bleached samples in luminescence dating has motivated developments in both measurement and analysis methods over the last few years. In this study, we compare the behaviour of CAM and IEU models when applied to dose distributions from a sequence of eight recent (40-1000 yr) flash flood deposits, potentially affected by incomplete bleaching. These dose distributions were obtained from quartz single grains and quartz small multigrain aliquots (~30 grains). Comparison was made between the different measuring and analysing techniques applied. The most suitable method was assessed by comparison of these results with those available from independent age control. It is shown that the measurement of multigrain aliquots in combination with the minimum age model IEU on OSL dose distributions is appropriate for the accurate dating of young flash flo...

The challenge of accurately estimating the deposition age of incompletely-bleached samples in luminescence dating has motivated developments in the analysis of single grain dose distributions, and a number of statistical approaches have been proposed over the last few years. In this study, we compare the behaviour of the arithmetic average, the so-called 'robust statistics', the Central Age Model (CAM), the Minimum Age Model (MAM) and the Internal-External Consistency Criterion (IEU), when applied to single-grain and small multi-grain (~30 grains per aliquot) dose distributions from a sequence of eight recent (40-1000 years old) flash-flood deposits. These sediments are expected to be incompletely bleached, but all have age control from historical records. Modifications were made to allow the use of the standard CAM and MAM models with dose distributions containing near zero and negative dose values. An assessment of minimum uncertainty on individual dose estimates is based on the over-dispersion (OD) determined in dose recovery tests making use of gamma-irradiated samples. We then present a detailed analysis of the impact of appropriate uncertainty assignment on minimum (MAM and IEU) burial dose estimates. The results of the various models are discussed in terms of the accuracy of the resulting age, and we conclude that, overall, the IEU approach generates the most accurate ages. We also demonstrate that accurate IEU ages can be obtained from multi-grain measurements if an age off-set of ~40 years can be considered to be unimportant for the samples in question. From our study we conclude that these and similar young slack-water flood deposits can be accurately dated using quartz OSL, opening up the possibility of establishing time series of flood discharge in catchments for which no instrumental or historical record exists.

Radiocarbon dating of bulk organic matter is the most commonly used method for establishing chronologies of lake sediments for palaeoclimate reconstructions on the Tibetan Plateau. However, this method is likely to be problematic because the dated material often suffers from old carbon contamination. Recently, advances in luminescence-based chronological techniques have provided new options for dating lacustrine sediments. In the current study, we tested for the first time the applicability of a new post-IR IRSL (pIRIR) measurement protocol for dating fine-grained polymineral material from a deep-lake sediment core from the central part of Tangra Yumco, on the southern Tibetan Plateau. Our results show that: (i) radioactive disequilibria in the uranium decay chain were observed in the studied lake sediments, and thus taken into account for dose rate calculation by using a dynamic modelling approach; (ii) the suitability and robustness of the pIRIR protocol measured at 150°C (pIRIR150) for our samples are confirmed by a set of luminescence characteristic tests as well as the agreement with an independent age control; (iii) turbidite deposition partly caused an insufficient resetting of luminescence signals and thus apparent overestimation in luminescence dating; (iv) compared with the luminescence-based age-depth model, the 14 C ages of bulk organic matter from the studied core generally yielded an age difference of ∼2 ka, which is attributed to hardwater reservoir effects in Tangra Yumco. This study highlights the need for multidating approaches of lake sedimentary archives on the Tibetan Plateau.

In this study dunes from south east India were dated using optically stimulated luminescence (OSL) to reconstruct the depositional history. A belt of dunes has developed parallel to the coast between Pondicherry and Karikal in Tamil Nadu, south east India. In the area between Cuddalore and Porto Novo the dune belt is 5 km wide. A transect from the coast to the most western dune inland was investigated. Changes in the environmental conditions are recorded in the dunes. They show features including unconformities, changes in the direction of bedding, erosional features, water escape structures and remnants of human settlements. The OSL results show that strong changes in the environmental conditions occurred about 100 and 300 years ago. The latter event marks also the termination of settlement in this place. The settlement period started about 1500 years previously. The periods of sand mobility and stabilisation of the land surface by soil formation correlate with changes in the precipitation record of India. The investigated dunes very likely reflect fluctuations in the monsoon activity during the last 3500 years in south east India.

Based on radiocarbon and optically stimulated luminescence (OSL) results obtained in the last 5 yr, this paper discusses the absolute chronology of the formation of one of the largest sand dunes within NW Belgium, the Great Ridge of Maldegem-Stekene. Multiproxy analysis of 6 sedimentary sequences points to a complex formation history covering the entire Late Glacial. Dry phases, characterized by eolian deflation and sedimentation, alternated with wet phases in which numerous mostly shallow dune slacks were filled with freshwater. The latter reached their highest water level during the first half of the Allerød, attracting both animals (e.g. European elk) and humans (Federmesser hunter-gatherers). Near the end of the Allerød, all dune slacks finally disappeared as they were filled in with windblown sand (&quot;coversand&quot;), likely forcing prehistoric hunter-gatherers to leave the area.

A new IRSL dataset is presented for the age and setting of a critical Late Glacial Maximum tephra isochron marker. The rhyolitic tephra, known as the Kawakawa Tephra, occurs as a 14 cm thick layer within a 5.9 m thick loess section overlying alluvial gravels in the Rangitikei River valley, SW North Island of New Zealand. Ages range from 21 at the base to 5 ka near the top of the loess and bracket an age of 17.0 AE 2.2 for the tephra. The new IRSL ages are in agreement with published and unpublished luminescence ages from other localities of loess, sand and ash above and below the tephra and of the tephra itself, that indicate an age of ca. 19 ka for the Kawakawa Tephra. This age is considerably younger than the generally accepted 14 C 27.1 ka cal yrs BP age of the Kawakawa Tephra and highlights an unresolved discrepancy between the two dating systems.

In this study dunes from south east India were dated using optically stimulated luminescence (OSL) to reconstruct the depositional history. A belt of dunes has developed parallel to the coast between Pondicherry and Karikal in Tamil Nadu, south east India. In the area between Cuddalore and Porto Novo the dune belt is 5 km wide. A transect from the coast to the most western dune inland was investigated. Changes in the environmental conditions are recorded in the dunes. They show features including unconformities, changes in the direction of bedding, erosional features, water escape structures and remnants of human settlements. The OSL results show that strong changes in the environmental conditions occurred about 100 and 300 years ago. The latter event marks also the termination of settlement in this place. The settlement period started about 1500 years previously. The periods of sand mobility and stabilisation of the land surface by soil formation correlate with changes in the precipitation record of India. The investigated dunes very likely reflect fluctuations in the monsoon activity during the last 3500 years in south east India.

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. Resul...

Violet stimulation is a new development in optical dating which has been suggested to extend the upper age limit of optically simulated luminescence (OSL) dating of quartz. Despite the reported advantage, few validation tests and applications have been published so far. The present study investigated the violet stimulated luminescence (VSL) using a single aliquot regenerative dose (SAR) protocol and a multiple aliquot additive dose (MAAD) protocol. Sedimentary quartz samples from four archaeological sites in Europe with independent age controls spanning 40-900 ka were used, including Grotte Mandrin (France), Brooksby Quarry (UK), Cueva Negra del Estrecho del Río Quípar (Spain) and Sima de las Palomas del Cabezo Gordo (Spain). The equivalent dose of a relatively young sample (~40 ka) was successfully determined. However, significant underestimations were observed for older samples with higher doses. These findings indicate the need for further development of the measurement protocol to date high-dose natural samples.

Three independent chronometric techniques are used for dating petroglyphs: AMS 14C dating of weathering rind or ganics encapsulated by natural coatings; analysis of rock varnish microlaminations; and cation-ratio dating. We discuss recent advances in each of these techniques, new empirical data from eastern California and western Wyoming, and the im plications of these data for the Pre-Clovis versus Clovis-first debate. Petroglyphs are particularly useful in this debate be cause they are unequivocally human in origin, and because they were not subject to the radical changes in erosion and de position that characterized the Late Pleistocene and affected preservation of other aspects of the archaeological record. We also discuss the recent controversy concerning cation-ratio dating, and demonstrate that the controversy derives from a fail ure to properly follow scientific method in "testing" the technique, not from an inadequacy of the technique itself.

A comparative study using quartz optically stimulated luminescence (OSL) and feldspar post-infrared infrared stimulated luminescence (post-IR IRSL) was undertaken on Quaternary fluvial sediments from an unnamed tributary of the Moopetsi River in South Africa. The aim is to assess whether the post-IR IRSL signal can be used to date incompletely bleached sediments. Several post-IR IRSL signals using varying stimulation and preheat temperatures were investigated; of these the post-IR IRSL 225 signal was deemed most appropriate for dating because it bleached most rapidly. The feldspar post-IR IRSL 225 equivalent dose (D e ) values from this site are consistently larger than those from quartz OSL, probably due to differences in the bleaching characteristics of the two signals. Additionally, the post-IR IRSL 225 D e values within a sample showed less variation in precision than the quartz D e data, possibly due to greater averaging between grains in the feldspar small aliquots. The agreement between ages based on the OSL and post-IR IRSL 225 signals was better for younger samples (<20 ka) than for older ones (>50 ka); the cause of this variation is unclear.

Preface. This is the second in a series of two reports which describe the luminescence dating methods used to construct chronologies for sediment stratigraphies associated with, and enclosing artefacts of First Nations historic significance in the Battle River Valley area, near Hardisty, east-central Alberta. The luminescence ages reported herein, and in the previous report, provide the chronological control to the archaeological investigations at this site, led by Rob Wondrasek, and commissioned by Enbridge, ahead of the construction of the Edmonton-Hardisty Pipeline. The background to the luminescence investigations is provided in the previous report: '

Preface. This is the second in a series of two reports which describe the luminescence dating methods used to construct chronologies for sediment stratigraphies associated with, and enclosing artefacts of First Nations historic significance in the Battle River Valley area, near Hardisty, east-central Alberta. The luminescence ages reported herein, and in the previous report, provide the chronological control to the archaeological investigations at this site, led by Rob Wondrasek, and commissioned by Enbridge, ahead of the construction of the Edmonton-Hardisty Pipeline. The background to the luminescence investigations is provided in the previous report: '

My oral presentation at GEOHYDRO-2011 was at 11:00 am (Tues, Aug 30, 2011) in the session Quaternary Geology, Paleoenvironments and Geomorphology. After my power point presentation (30 slides) the floor was opened for questions. Colleagues who are doing similar geochronological dating work in Canada asked questions which essentially wanted to know about our methodological approaches and how they related to protocols they were using in their labs. In particular they wanted to know about the following: • what methods we use to normalize our samples (weight or irradiation) • what sources we use for irradiating our samples • if we have problems with signal contamination from feldspar when using post –IR blue-OSL stimulation with the portable OSL reader on bulk samples These were very constructive questions and, following my responses, I got some very interesting feedback. We will incorporate some of this feedback as we proceed with our research. Later during the conference I also had th...

This report is concerned with optically stimulated luminescence (OSL) dating investigations of sediments associated with, and enclosing artefacts of First Nations historic significance in the Battle River Valley area, near Hardisty, east central Alberta. The OSL ages reported here provide chronological control to the archaeological investigations at this site, led by Rob Wondrasek, which have identified thousands of historical artefacts, including projectile points and lithic fragments indicative of occupation. The investigations were commissioned by Enbridge, ahead of the construction of the Edmonton-Hardisty Pipeline, and form one part of a historic resources impact assessment study, to characterise the archaeological site, and evaluate/mitigate the impact of the pipeline related excavations. This report describes the background to the investigation, sampling, and luminescence analysis undertaken to generate sediment chronologies for the Hardisty sediment stratigraphies. Ken Munyi...

The development of functional portable optically stimulated luminescence (OSL) readers over the last decade has provided practitioners with the capability to acquire luminescence signals from geological materials relatively rapidly, which allows for expedient preliminary chronostratigraphic insight when working with complex depositional systems of late Quaternary age. Typically, when using the portable OSL reader, infrared (IR) or blue post‐IR OSL signals are acquired from bulk unprocessed materials, in contrast to regular luminescence dating, which is usually based on measurements on pure quartz or feldspar mineral separates, or on select silt‐sized polymineralic portions. To demonstrate the utility of portable OSL measurements, this paper outlines the basic features of portable OSL readers and their constraints. Subsequently, case studies in which the instrument has been used to elucidate cryptostratigraphic variations in sedimentary sequences for geomorphological applications are...

The transition from the Earlier Stone Age (ESA) to the Middle Stone Age (MSA) in the interior of southern Africa is associated with the Fauresmith Industry. Major cultural developments found in the Fauresmith include regular use of ochre and other coloured minerals, prepared core technology including blade and point production, and the use of hafted spears. Chronological control for the Fauresmith is weak so that critical questions regarding the relationship of this industry to the evolution of modern humans remain unresolved. Here we present ages for the Bestwood 1 site, an open-air locality in the Northern Cape Province (South Africa) where an extensive Fauresmith occupation is found underlying sand deposits. Optically stimulated luminescence (OSL) was first applied to samples from the sands overlying the Bestwood 1 occupation horizon, and from the occupation horizon itself, in order to establish the chronology of the site. However, sediment mixing resulting from bioturbation processes has been observed, causing post-depositional bleaching of the majority of the grains, thus limiting the use of OSL. In addition, given the identification of the lithic assemblage to the Fauresmith, it seems likely that the sands were beyond the dating range of conventional OSL. Due to its hard-to-bleach properties, the thermally transferredoptically stimulated luminescence (TT-OSL) signal was deemed suitable for detecting the least-bleached grains. Single grain TT-OSL analyses combined with the finite mixture model (FMM) were conducted in order to isolate the oldest grains that could be contemporaneous with the time of deposition of the sediment associated with the ESA assemblage. High scattering of the equivalent doses is consistent with bioturbation processes that mixed sediment; the distribution of the equivalent dose values suggests that younger grains were incorporated into the ESA layers, thus supporting the use of the oldest component determined using the FMM to calculate the TT-OSL ages. This approach allowed us to establish the time for the Fauresmith occupation at 366 ± 32 ka, and the age of the overlying sand deposits, spanning from 350 ± 22 ka to 226 ± 13 ka.

Optical dating of earthquake related sediments were investigated including one modern sample and three samples from a trench excavated across the 1985 Ms7.4 Wuqia Earthquake surface rupture. The results indicated that equivalent dose (D e ) values vary with grain size and the method used for D e determination. The residual dose of the modern sample is 0.1 ka (0.2 +0.2 -0.1 Gy) for the quartz single grain measurements. Only 1.5-3.6% of the grains have a detectable OSL signal. Single grain quartz ages are similar to the expected ages. Fine grain quartz results overestimate the D e values and are much older than single grain quartz and coarse grain quartz small aliquot standardized growth curve (SA-SGC) ages. Single grain quartz OSL dating may be optimal for dating earthquake related deposits, but SA-SGC can save measurement time and has potential for dating some poorly bleaching samples.

En 2013 et 2015, deux séquences loessiques de 8 m d'épaisseur avec paléosols ont été mises au jour dans la basse vallée de la Saône sur deux sites distants de 20 km. La séquence de Quincieux, développée sur une basse terrasse de la Saône, montre un paléosol inférieur complexe à fentes de gel, des limons laminés avec des blocs d'origine alpine dispersés, un paléosol ou horizon brunifié médian, des limons argileux gris à lits sableux, des loess massifs et un dernier sol complexe, holocène. La séquence de LyonApollinaire, adossée au relief sud entourant la plaine de Vaise, montre un unique paléosol complexe (6 m) au sommet érodé, surmonté de sables fins, limoneux, gris, massifs à lités, tronqués par des aménagements contemporains. Les restes de faunes y sont peu nombreux à la différence de ceux, avec traces humaines, présents dans les paléosols de Quincieux mais dont seul le plus ancien a fait l'objet d'une fouille partielle en 2014. Des échantillonnages multiindicateurs ont été réalisés pour reconstituer les contextes chronologique, pédologique et environnemental des occupations humaines. Les dates 14 C obtenues à la base des sableslimoneux gris des deux séquences fournissent un âge similaire de 18 ka. Les différents âges obtenus (OSL et 14 C) dans l'horizon brunifié médian à Quincieux sont cohérents autour de 20 ka. En revanche, ceux du paléosol inférieur montre une variabilité plus importante entre 27 et 40 ka sujette à discussion. Pour LyonApollinaire, les datations obtenues, cohérentes, indiquent la complexité du paléosol dont la base et le sommet peuvent se corréler respectivement au paléosol inférieur et à l'horizon brunifié médian de Quincieux. Les condi tions stationnelles-contexte de versant éloigné de la plaine alluviale-pourraient expliquer cette différence. Ces séquences, uniques pour la basse vallée de la Saône, sont plus difficilement comparables avec celles du nord de la France.

A luminescence date of 80 ka for sediments associated with bone harpoon points recovered at Katanda in East Africa has been reassessed using additional samples. An original problem with radiation quenching has been overcome by using a higher preheat. Single-aliquot analyses suggest su$cient bleaching. New OSL dates, while scattered, support the original date and the antiquity of the site.

A luminescence date of 80 ka for sediments associated with bone harpoon points recovered at Katanda in East Africa has been reassessed using additional samples. An original problem with radiation quenching has been overcome by using a higher preheat. Single-aliquot analyses suggest su$cient bleaching. New OSL dates, while scattered, support the original date and the antiquity of the site.

Optical dating is increasingly being applied to fluvial deposits to derive rates of geomorphological and sedimentary processes. Partial bleaching of the water-transported sediment grains is a common occurrence, however, and creates problems in deriving burial ages. This paper presents results from optically stimulated luminescence (OSL) dating performed on samples collected from discrete reaches of palaeochannels of the Klip River, South Africa, in order to determine when bedload transport last occurred. The samples were analysed using the single-aliquot regenerative-dose protocol on aliquots made up of $30 quartz grains. OSL ages were calculated using both the finite mixture model and minimum age model; comparison of the ages for samples with radiocarbon ages for overlying organic-rich sediment indicates that the finite mixture model gives more accurate results. Samples collected from along the same reach of palaeochannel do not always give consistent burial ages, and careful interpretation of the results is needed. This study demonstrates the importance of the selection of sample locations, and the need for appropriate analysis of the equivalent dose distributions to derive the burial dose and hence the age of a sample.

The site of Blombos Cave (BBC) is well known for archaeological remains that have advanced our understanding of the development of modern human behaviour during the Middle Stone Age (MSA). Occupation of the cave occurred against a backdrop of landscape-scale environmental and sedimentary processes that provide the broader context for finer-scale interpretations of the site-formation history and archaeological patterns detected in the cave deposits. Aeolian and palaeosol sequences are abundant in the vicinity of BBC and these provide a partial view of the past landscapes available to the inhabitants of the cave. An important extension to the palaeo-landscape around BBC currently lies submerged on the Agulhas Bank, as sea levels were lower than at present for the entire period of human occupation of BBC. In this paper, we revisit the optically stimulated luminescence (OSL) chronology for the full sequence of sediment deposition inside BBC, increasing the number of dated samples to a total of 40 and revising the period of MSA occupation to between 97.7 ± 7.6 and 71.0 ± 5.7 ka (uncertainties at 95.4% probability). We describe the geological successions at four main areas around BBC, estimate the time of sediment deposition using OSL, and describe and interpret three seismic profiles on the Agulhas Bank, offshore of BBC. By correlating these onshore and offshore geological sequences with the sedimentary deposits inside BBC, we place the archaeological record within a landscape-scale chrono-stratigraphic framework to examine how environmental changes may have regulated the presence or absence of humans in the cave and surrounding terrain between about 100 and 70 ka.

UDC 551.435.84(234.372.3) Michal Šujan, Alexander Lačný, Régis Braucher, Peter Magdolen & Aster Team: Early Pleistocene age of fluvial sediment in the Stará Garda Cave revealed by 26 Al/ 10 Be burial dating: implications for geomorphic evolution of the Malé Karpaty Mts. (Western Carpathians) Assessment of vertical movements of tectonically bounded blocks is crucial for determination of geohazards in densely inhabited zones, such as the border zone of western Slovakia and eastern Austria. The morphostructure of the Malé Karpaty Mts. divides the Vienna and Danube basins in the Western Carpathian-Eastern Alpine junction, and its neotectonic activity is of high importance. This study was focused on 26 ACTA CARSOLOGICA 46/2-3-2017 252 MICHAL ŠUJAN, ALEXANDER LAčNÝ, RéGIS BRAUCHER, PETER MAGDOLEN & ASTER TEAM is in good agreement with a widespread preservation of the planation surface called "Mid-mountain level". In contrast are relatively high values of palaeodenudation rates inferred from isotopic concentrations. Generally, our results indicate that the Malé Karpaty Mts. horst underwent relatively intense but short uplift in the Early Pleistocene, followed by very moderate uplift up to the recent.

Unit Description Interpretation 108 7.5 YR 6/4 Light brown fine sand/silt with moderate sub-rounded limestone pebbles. Poorly sorted. Homogeneous. Sharp boundary to Unit 106. Colluvium/'plough soil' 107 7.5 YR 3/1 Very dark grey ash and charcoal with moderate, fine twiggy charred plant macrofossils. Where Unit 106 sits immediately below Unit 107 is calcined and 7.5 YR 8/1 White. Sharp boundary to: In situ burning during digging operations. 106 2.5 YR 5/6 Red, hard, blocky clay in sub-rectangular aggregates to coarse pebble size. Internal structure of the blocks is laminar. Occasional subangular limestone cobbles. Limestone is harder, less carbonate-rich and more mineralized than Unit 105. Well to moderately sorted. Sharp boundary to Unit 105. Upcast from deeper in shaft than Unit 105 and therefore of older material 105 2.5 Y 8/2 Pale brown clast and matrix-supported limestone gravel of subangular boulders to granules in a granular to medium sand limestone-derived matrix. Clasts show some preferred orientations (Figure 2). Poorly sorted. Sharp lower boundary to Unit 101, diffuse to Unit 104. Fresh limestone excavated from shaft and deposited on mound 104 2.5 Y 7/6 Yellow clast and matrix-supported gravel of sub-angular limestone pebbles in a granular to medium sand limestone-derived matrix. Clasts are horizontally-lain limestone, harder than those in Unit 105 and have laminar structures. Poorly sorted. Sharp boundary. Excavated material from shaft deposited on mound but from a different source facies than Unit 105 103 10 YR 8/3 Pink matrix and clast-supported gravel of sub-angular and subrounded limestone fine pebbles and granules in a coarse-medium sand limestone-derived matrix. Sharp boundary to Unit 101. Re-deposited, highly weathered limestone 102 10 YR 4/2 Dark greyish brown ash. Top part of the unit is calcined at the upper contact. Sharp boundary to Unit 101. Combustion on palaeosol surface 101 7.5 YR 6/3 Light brown fine sand/silt formed as fine pebble and granular colloids. Reverse bedded as a result of moderate clay translocation towards lower contact. Frequent sub-rounded to sub-angular limestone pebbles and granules, most of which are weathered/pitted. Sharp boundary to bedrock. Soil forming within limestonepre-mound 3 Mound 2, North facing Figure SM.D1.1.2. Casa del Manzano, Jumilla, Mound 2: North-facing section. Unit Description Interpretation 210 2.5 YR 4/4 Reddish brown (matrix) diamict of sub-angular limestone pebbles to granules in a matrix of clay aggregates (colloids). Frequent coarse to fine roots. Sharp boundary (except where blurred by rooting) to: Debris from cleaning of qanat 209 10 YR 7/3 Very pale brown matrix and clast-supported gravel of dub-angular limestone pebbles and granules in a coarse to fine sand (limestone derived) matrix. Gravel particles are orientated with the bedding plain. The upper part of the unit is cemented, the lower part less so. Poorly sorted. Diffuse boundary to: Debris from cleaning of qanat 208 10 YR 8/3 Very pale brown matrix (and occasionally clast) supported gravel of cobble to granular-sized limestone in a granular to fine sand (limestonederived) matrix. Limestone clasts are chaotically organized. Sharp lower boundary: Debris from cleaning of qanat 207 10 YR 5/2 Greyish brown humic fine sand/silt with frequent sub-angular and rare sub-rounded limestone pebbles and granules. Poorly sorted. Frequent fine roots. Sharp boundary to Unit 205 Incipient soil development in the top of Unit 205 206 2.5 Y 7/3 Pale brown compact fine sand/silt/clay forming aggregates of granular and pebble size. Moderately sorted. Sharp boundary to Unit 203 Weathered mudstone and illuvial clay 205 10 YR 7/3 Very pale brown clast-supported gravel of sub-angular limestone pebbles (and cobbles towards surface). Gravels are orientated chaotically. Matrix is of granules with moderate coarse sand. Diffuse boundary to Unit 203 Original mound formed from shaft debris 204 2.5 Y 8/2 Pale brown fine sand. Well sorted. Sharp boundary to: Aeolian 203 7.5 YR 7/3 Pink matrix and clast-supported gravel of sub-angular chaotically orientated limestone cobbles to granules in a granular to medium sand matrix. Poorly sorted. Diffuse boundary to Unit 202 and sharp boundary to Unit 201. Original mound formed from shaft debris 202 10 YR 7/3 Very pale brown clast and matrix-supported gravel of chaotic subangular cobbles and pebbles in a granular to medium sand matrix. Crude fining upwards sequence from clast-supported at base to matrix-supported at the top. Poorly sorted. Occasional medium roots. Original mound formed from shaft debris 201 10 YR 5/3? Humic silt/fine sand with frequent sub-rounded and sub-angular limestone pebbles and granules bedded parallel to the bedding plain. Frequent fine roots. Poorly sorted. Sharp boundary to limestone bedrock Pre-qanat B horizon of palaeosol 4 Mound 3, South facing Figure SM.D1.1.3. Casa del Manzano, Jumilla, Mound 3: South-facing section. Unit Description Interpretation 10 YR 6/6 Brownish yellow fine sand. Otherwise as Unit 309 (but looser). Cleaning of (upcast from) shaft 2.5 Y 8/2 Pale brown indurated fine sand/sandstone formed of calcined/hydroxidebonded pebble to cobble-sized sandstone aggregates in a fine sand (derived from sandstone) matrix. Poorly sorted. Sharp boundary to Unit 324 Cleaning of (upcast from) shaft 10 YR 6/8 Brownish yellow indurated fine sand with hydroxide mottling (to pebble size) of 10 YR 8/2 Very pale brown. Homogeneous. Forming sub-angular blocks of pebble size. Sharp boundary to Unit 323 Cleaning of (upcast from) shaft 10 YR 6/6 Brownish yellow fine sand with hydroxide staining. Otherwise as Unit 309 (but looser). Sharp boundaries to Units 323 and 325 Cleaning of (upcast from) shaft 10 YR 6/8 Brownish yellow matrix-supported gravel of sub-angular pebble-sized 'sandstone' clasts in a fine sand matrix. The 'sandstone' is a conglomerate of fine sand. Crude normally bedded sequence as aggregates have a greater tendency to have broken down near the surface. Poorly sorted. Sharp boundary to Unit 322 Cleaning of (upcast from) shaft 10 YR 6/8 Brownish yellow compact matrix supported gravel of sub-angular 'sandstone' clasts in a fine sand matrix. The matrix is derived from the breakdown of sandstone. Sharp boundary to Unit 321 Cleaning of (upcast from) shaft 10 YR 6/8 Brownish yellow matrix-supported gravel of sub-angular pebble-sized 'sandstone' clasts in a fine sand matrix. The 'sandstone' is a conglomerate of fine sand on Unit 319. Crude normally bedded sequence as aggregates have a greater tendency to have broken down near the surface. Poorly sorted. Diffuse boundary to Units 319 and 320 Cleaning of (upcast from) shaft 10 YR 6/6 Brownish yellow fine sand with moderate, localized fine-medium roots. Well sorted. Sharp boundary to Unit 319 Upcast from shaft/aeolian sediment 10 YR 6/8 Brownish yellow indurated fine sand with hydroxide mottling (to pebble size) of 10 YR 8/2 Very pale brown. Homogeneous. Forming sub-angular blocks of pebble size. Sharp boundaries to Units 316-318 Original mount-upcast from shaft 10 YR 6/8 Brownish yellow clast and matrix-supported gravel of sub-angular, pitted limestone pebbles and granules (rare cobbles at base) in a coarse to fine sand matrix. Clasts are mostly orientated following the dip of the bedding. Matrix and clast-support in pockets. Poorly sorted. Sharp boundary to Unit 315. Original mount-upcast from shaft 10 YR 6/6 Brownish yellow well sorted fine sand. Homogeneous. Sharp boundary to Unit 315. Weathering of Unit 316 7.5 YR 7/3 Pink matrix-supported gravel of sub-rounded limestone pebbles in a fine sand to granular matrix. Compact (partially indurated). Highly weathered. Poorly sorted. Sharp boundary to Unit 315. Initial 'scrape' from top of shaft 10 YR 5/4 Yellowish brown fine sand/silt with moderate to frequent sub-rounded limestone clasts. Homogeneous, Moderately to poorly sorted. Sharp boundary to bedrock. Pre-mound palaeosol 10 YR 6/8 Brownish yellow matrix-supported gravel of sub-angular pebble-sized 'sandstone' clasts in a fine sand matrix. The 'sandstone' is a conglomerate of fine sand on Unit 308. Crude normally bedded sequence as aggregates have a greater tendency to have broken down near the surface. Poorly sorted. Diffuse boundary to Unit 309 Cleaning of (upcast from) shaft 10 YR 6/6 Brownish yellow clast and matrix-supported 'gravel' of sub-angular 'sandstone' cobbles and coarse pebbles in a fine sand matrix. Cobbles and pebbles are aggregations of fine sand as found in Unit 308. Aggregates have broken down in the top part of the unit to form a crude normally bedded sequence. Poorly sorted. Sharp boundary to Unit 301 Cleaning of (upcast from) shaft 10 YR 6/8 Brownish yellow indurated fine sand with hydroxide mottling (to pebble size) of 10 YR 8/2 Very pale brown. Homogeneous. Forming sub-angular blocks of pebble size. Sharp boundaries to Units 303 and 301 Cleaning of (upcast from) shaft 10 YR 6/6 Brownish yellow fine sand with moderate, localized fine-medium roots. Well sorted. Sharp boundary to Units 305 and 306 Aeolian 10 YR 6/8 Brownish yellow clast and matrix-supported gravel of sub-angular, pitted limestone pebbles and granules (rare cobbles at base) in a coarse to fine sand matrix. Clasts are mostly orientated following the dip of the bedding. Matrix and clast-support in pockets. Poorly sorted. Sharp lower boundaries. Cleaning of (upcast from) shaftmound extension 10 YR 6/3 Pale brown fine sand/silt (mostly fine sand). Homogeneous. Well sorted. Sharp boundary to Unit 304. Fluvial or colluvial reworking of Unit 306 10 YR 6/6 Brownish yellow well sorted fine sand. Homogeneous. Sharp boundary to Unit 303. Fluvial or colluvial reworking of Unit 306 10 YR 7/4 Very pale brown clast and matrix supported gravel of sub-angular limestone cobbles, sub-rounded limestone pebbles and granules in a coarse to fine sand matric. Normally bedded. Poorly sorted. Diffuse boundary to Unit 304 Original...

This study presents single-grain optically stimulated luminescence (OSL) chronologies for the archaeological site of Galería de las Estatuasthe first systematically excavated Middle Palaeolithic site within the karst system of the Sierra de Atapuerca archaeological complex, northern Spain. The single-grain OSL ages are compared with paired single-grain thermally transferred OSL (TT-OSL) dating results for a selection of samples in order to better assess quartz signal bleaching characteristics of endokarstic deposits preserved at Atapuerca. In total, seven luminescence dating samples were collected from four lithostratigraphic units exposed in two excavation pits (GE-I and GE-II). The single-grain OSL equivalent dose (D e) distributions are characterised by generally low overdispersion (20-30%), suggesting appropriate bleaching at deposition. The resultant single-grain OSL ages reveal that the sediment sequence and archaeological remains excavated in pit GE-I accumulated 80-112 ka, while the upper layers of excavation area GE-II were deposited 70-79 ka. The replicate single-grain TT-OSL ages are in agreement with the OSL chronologies at 2σ for three of the four samples investigated; although in all cases the TT-OSL ages were systematically older than their single-grain counterparts. Apparent TT-OSL residual doses (i.e., TT-OSL D e values in excess of their corresponding OSL D e values) of 9-65 Gy were observed for all samples. These excess TT-OSL D e values are generally low in comparison to the natural dose ranges of TT-OSL dating applications undertaken elsewhere in the Atapuerca karst system. The single-grain TT-OSL and OSL dating comparisons build on daylight bleaching experiments and modern analogue studies performed on other Atapuerca exogeneous infill deposits and suggest reasonable potential for TT-OSL signal resetting down to relatively low levels for at least some sediments preserved in the Atapuerca karstic cavities. The quartz single-grain OSL chronologies obtained in this study place the Middle Palaeolithic sequence of Galería de las Estatuas within marine isotope stage (MIS) 5 and the beginning of MIS 4, and provide firm evidence for human occupation of the Sierra de Atapuerca during a previously unreported time period.

After an intercomparison age experiment carried out in the framework of the first MODIS (MOrtar Dating Inter-comparison Study) project, the results showed general agreement both between optically stimulated luminescence (OSL) dating laboratories and with radiocarbon ( 14 C) dating results. As the needs for the selection of samples convenient for an inter-comparison are not the same between 14 C and OSL, for the second running, it has been decided to choose two different sample sets, one to share between the radiocarbon labs and one for the OSL dating ones. The results obtained by applying different experimental protocols (multigrain and single grain techniques) and different statistical models (weighted mean, central age mode, average dose model, minimum age model and exponential exposure dose) are discussed in this work.

Anomalous fading of the infrared stimulated luminescence (IRSL) signal from the polymineral fine-grain and K-feldspar fractions of aeolian sediments from Hungary has been studied. The samples in this study have previously been dated using the multiple aliquot additive dose (MAAD) protocol to measure the IRSL signal. The IRSL measurements using MAAD were conducted w4 weeks after the irradiation, making it difficult to assess to what extent these age estimates were affected by anomalous fading. In this study, equivalent doses were obtained using the single aliquot regenerative dose (SAR) protocol. The fading rate for each sample was calculated using the different IRSL components and different parts of the decay curve. For each sample, the middle part of the decay curve always showed a lower fading rate than the initial part of the decay curve. The difference between the fading rates for different parts of the decay curve was greater for the K-feldspars than for the polymineral fine grains. Fading corrected ages were calculated by integrating both the initial and the middle part of the decay curve. These ages were compared with optically stimulated luminescence (OSL) ages from quartz, infrared radiofluorescence (IR-RF) ages obtained from K-feldspars and also with independent ages, provided by radiocarbon dating of shells and charcoal, and uranium-series dating of travertine.

The Holocene beach-ridge plain of Phra Thong Island (Ko Phra Thong, SW Thailand) provides sedimentary evidence of several palaeotsunamis, in addition to the deposit of the 2004 Indian Ocean tsunami. Due to poor preservation conditions, these palaeoevent layers are restricted to swales. Correlation across beach ridges, which is important e.g. to reconstruct inundation distances, remains a major challenge. A primary tool for establishing a precisely confined correlation of the sand sheets is the use of chronological data. Since the application of radiocarbon dating is limited by the scarcity of appropriate material, this study utilised optically stimulated luminescence (OSL) dating of tsunamigenic quartz grains. Generally, the sediments showed favourable luminescence properties regarding signal intensity, dose recovery and thermal stability. Disturbances of the OSL signal due to partial bleaching were corrected using the minimum age model. At least three palaeoevents-being 490-550, 925-1035 and 1740-2000 yr old-were distinguished by dating the discontinuous sand sheets at four different sites. Besides this chronological framework, the OSL data provide the opportunity to correlate the discontinuous sand sheets between spatially separated sites within the same swale as well as across ridges. This allows for first estimates of inundation distances for the palaeotsunamis documented on Phra Thong Island. Furthermore, the two younger events overlap in age with contemporaneous tsunami and earthquake evidence from other coasts bordering the Indian Ocean.

The emergence of ‘standing stone’ monuments within the European Late Prehistoric landscape is considered to be
associated with a pivotal human cultural transition from hunting and gathering to agriculture and permanent
settlement, being the earliest monuments currently dated by radiocarbon to the 5th millennium BCE. However,
many standing stones were first erected, subsequently collapsed, and then re-erected during the following three
millennia. The excavation of the site of an apparently in situ statue-menhir at Cruz de Cepos in NE Portugal
provided the rare opportunity in Iberian prehistory to apply radiocarbon and luminescence techniques to
establish the date of construction. On the basis of the iconography, the standing stone was assigned to a
sculptural tradition of north-western and western Iberia, loosely dated to the Early/Middle Bronze Age (ca.
2000/1900–1250 BCE). The optically stimulated luminescence (OSL) and dosimetry characteristics of quartz
extracted from sediment samples taken from locations associated with the socket pit and surrounding backfilling
deposits were examined, producing OSL single grain ages at eight locations. Comparison of the OSL and calibrated
radiocarbon ages shows very good agreement, with the mid-3rd millennium BCE dates confirming original
erection during the Copper Age and not a much later transformation of the monument. These encouraging results
indicate that OSL has the potential to provide reliable dating of depositional processes related to the construction
process and is suitable for wider application to megalithic monuments of this type.

The upper limit of optically stimulated luminescence (OSL) dating technique is usually defined by signal saturation. In nature the OSL signal saturates even faster than in the laboratory. Here we present a study on natural saturation of OSL and thermally transferred OSL (TT-OSL) signals of quartz grains from Nilotic origin. Quartz samples from two representative sections from the coastal plain of Israel, and which span approximately similar time frames, were used to construct semi-natural dose response curves (DRC) for OSL and TT-OSL by plotting the natural signal of samples against their depth and equivalent dose (De). Samples from these two sections, as well as from other sites, define typical OSL and TT-OSL DRC's for Nilotic quartz that was transported to the eastern shores of the Mediterranean Sea. The constructed semi-natural OSL DRC is unique to the quartz of Nilotic origin and indicates the upper limit for reliable OSL dating of this quartz at 140 Gy due to signal saturation. The natural TT-OSL luminescence grows linearly up to 400 Gy, and is constant for 400-600 Gy. Steady-state between TT-OSL trap-filling, due to ionizing radiation, and concurrent thermal emptying of these traps is achieved at 600 Gy. TT-OSL dating of the Nilotic quartz is expected to underestimate ages over ~120 ka due to the low thermal stability of the signal.

Kathu Pan 6 (Northern Cape Province) is an open-air site exposed by sinkhole activity that includes a Middle Stone Age Howiesons Poort (HP) component in a stratigraphic sequence that also includes Later Stone Age, early Middle Stone Age, and Earlier Stone Age (Fauresmith) assemblages. Here, we present the dating of the Kathu Pan 6 sequence using multiple luminescence signals: optically stimulated luminescence (blue OSL) and thermally transferred OSL (TT-OSL) on quartz; and the infrared stimulated luminescence (IRSL) post IR-IR 290 signal on potassium feldspar. The results obtained from analyses of different minerals and signals for the archaeological deposits do not always conform but the quartz OSL provides the most accurate set of ages for the HP at KP6 (between 100 ± 6 and 74 ± 5 ka). This age range places the KP6 HP earlier than any of the scenarios considered plausible by Jacobs and Roberts (

Previous studies on the application of optically stimulated luminescence dating on quartz extracted from Romanian loess yielded inconsistent age estimates between different grain sizes. The present work reports a high-resolution SAR-OSL chronology for the L1 (MIS 2e4), S1 (MIS 5) and L2 (MIS 6) units of the loess-palaeosol profile from Costineş ti, that contains at least five loess-palaeosol alternations and is located on the Black Sea Shore (Dobrogea, SE Romania). Analysis were performed on fine (4e11 mm) and coarse (63e90 mm) quartz grains extracted from 25 samples collected at very high resolution (10 e20 cm). Luminescence investigations confirm the reliability of the SAR-OSL dating protocol previously applied to Romanian loess (preheat at 220 C for 10 s, cutheat to 180 C and elevated temperature OSL (ETOSL). The doseeresponse curve is best described by the sum of two saturating exponential functions. The results confirm the different saturation characteristics of fine and coarse grains of quartz, as reported in previous studies on loess sections in SE Romania. The equivalent doses obtained for coarse grains are higher than those obtained for fine grains, for all samples. The fine quartz OSL age estimates are significantly younger than the coarse quartz age results, as in the case of previous studies on the Mircea-Vod a and Mostiş tea loess sections. Coarse quartz in samples collected from the upper part of S1 yielded ages of 94 AE 11 ka, 116 AE 11 ka and 120 AE 10 ka that do not seem to underestimate the true burial age. The same observation applies to the upper part of L2. Overall, from the luminescence results it can be concluded that the S1 palaeosol formed during the MIS 5, and the discrepancy observed on coarse and fine quartz OSL ages is a general feature of SE Romanian loess.