A contribution to the study of post-depositional alterations of pottery using TL dating analysis

In luminescence dating, the potassium concentration significantly contributes to the dose rate value in the age estimation. Within this study, fine-grain thermoluminescence dating has been applied on sherds of calcareous pottery of known age, excavated at a Roman site in Mallorca, Spain. For those of the samples that showed signs of severe potassium leaching, according to chemical and mineralogical examination, the thermoluminescence analysis provided overestimated dates. By using the known archaeological age of the samples, a corrected dose rate value can be estimated which provides the potassium concentration averaged for the burial period. Finally, a step-like model can then be used to estimate the fraction of the burial period after which most of the alteration effects took place.     

Iron Age Landscapes of the Benue River Valley,Cameroon

The Iron Age settlements of northern Cameroon were dispersed across the landscape, taking advantage of different eco-climatic zones to exploit a variety of natural resources. Situated at the interface of the upper and lower terraces of the Benue River, mound sites in the area around Garoua have occupation histories spanning multiple centuries. The site of Langui-Tchéboua displays evidence for rapid accumulation of sediments approximately 700 years ago, which may have been a deliberate construction strategy that would have allowed the site’s inhabitants to exploit resources in both floodplain and dryland contexts. The combined use of multiple dating methods and micromorphology provide novel insights into both the mechanisms of anthropogenic landscape change and possible motivations governing those choices.     

Dating the Ramat Saharonim Late Neolithic desert cult site

The Ramat Saharonim site, located in the central Negev desert, Israel, consists of four shrines in a shallow valley and 30 tumuli, aligned on two cuesta cliffs on the valley's sides. Previous assessments based on site surveys suggested a general chronological span from Late Neolithic period (ca. 5000–5500 BC) through the Early Bronze Age (third millennium BC). Excavations in one shrine and three tumuli revealed a well-constructed double wall at the shrine and seven primary adult burials in the three tumuli. Quartz from sediment samples post-dating the construction of the burials and shrine was dated by optically stimulated luminescence (OSL) using the single aliquot regenerative dose (SAR) protocol, and charcoal and leather samples were dated by ¹⁴C. The OSL results for a burial in one tumulus are 7500 ± 700 to 6000 ± 600 years. In a second tumulus, OSL ages of 2000 ± 200–1800 ± 170 years and a ¹⁴C age on leather of 390–200 BC (2340–2150 cal BP) imply that this burial is Nabatean and that the site was used also in the Hellenistic period. Two ¹⁴C ages on charcoal from the shrine give an age between 5280 and 4710 BC (7230–6660 cal BP). OSL single aliquot ages for sediment from the shrine are highly scattered and far too old (60,000 to 12,000 years). The unlikely old ages are due to insufficient resetting of the OSL signal of some of the quartz grains when sand was blown onto the site. Indeed, single grain measurements for six samples of sediment postdating the shrine show a very large range of grain ages, but with a distinct young population in all samples. Ages calculated from these young populations average 5400 ± 800, in better consistence with the ¹⁴C dates and confirming our supposition that only some of the transported grains were reset at the time of deposition. The combined OSL and ¹⁴C dating shows that the shrines and tumuli are contemporaneous and attributes the complex to the Late Neolithic. This has clear ramifications for our understanding of the period and the rise of desert pastoral societies.     

The existence of open areas during the Mesolithic: evidence from aeolian sediments in the Elbe–Jeetzel area,northern Germany

Traditionally Mesolithic hunter–gatherer cultures are supposed to have lived in a primeval forest environment with a closed vegetation cover during the Early and Mid-Holocene. It is not until the onset of subsequent Neolithic agricultural societies that the development of more expansive open areas is assumed. Therefore our perception of the Mesolithic economy in the European lowlands is highly affected by the idaea of adaptation to dense forest environments and a very stable system of resource exploitation. However, recent palaeoenvironmental studies provide evidence that areas of open landscapes must have existed at least temporarily during the Mesolithic and evoke the question whether human impact may be accountable for this.     

Archaeological investigations and OSL dating of terraces at Ramat Rahel,Israel

Abstract

Dating terraces, the most prominent feature of the agricultural landscape in many parts of the world, is a problem for archaeologists. This study presents an interdisciplinary approach that combines archaeological survey and excavations with direct sediment dating of terrace fill using Optically Stimulated Luminescence (OSL). The study focuses on Ramat Rahel, a multi-period site located in the southern outskirts of modern Jerusalem, Israel, where, on a defined terraced slope chosen for a small-scale landscape archaeology project, three main phases of terrace construction and use were identified. The earliest phase dates to the Late Byzantine/Early Islamic period, the second to medieval times, and the last to the Ottoman period. The results enable a comprehensive reconstruction of the changing local landscape through time and demonstrate the validity of OSL, when combined with archaeological investigations, as a reliable method for terrace dating.     

The Firing Temperature of Pottery from Ancient Mesopotamia,Turkey, Using Luminescence Methods: A Case Study for Different Grain‐Size Fractions

The assessment of the firing temperature of a prehistoric pottery sample collected from ancient Mesopotamia, Turkey was studied using luminescence techniques. The methods for this estimation involved the observation of the thermal and pre‐dose sensitization with various re‐firing temperatures for both TL and the OSL signals. In the former case, the 110°C TL peak and the rest of the glow curve were used as proxies in this study. In the framework of a first attempt to investigate the impact of grain‐size dependence on the sensitization of the luminescence signals, the aforementioned study was performed with four different pottery grain‐size fractions: (i) less than 60 μm, (ii) 60–90 μm, (iii) 90–180 μm and (iv) 180–250 μm. The results clearly demonstrated the firing temperature mark of ～500°C in for the grain size of 90–180 μm, while—as in the case of the lower grain‐size fraction—a third proxy, the ratio of the pre‐dosed to the thermal sensitization, was seen to indicate the firing temperature. The remaining two grain‐size fractions failed to provide any meaningful results with regard to the firing temperature estimation. The dependence of the TL characteristics on the grain size was explained in the framework of the mixed mineralogy.     

On the intrinsic accuracy and precision of luminescence dating techniques for fired ceramics

Luminescence dating techniques have been used extensively for archaeological and geological samples. Such techniques are based on thermally or optically stimulated signals. This paper presents simulations of several luminescence techniques for equivalent dose (ED) estimation for ceramic materials containing quartz. The simulations are carried out using a recently published comprehensive kinetic model for quartz, consisting of 11 electron and hole traps and centers. The complete sequence of the experimental protocols for several thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques are simulated using the same set of kinetic parameters. The specific simulated protocols are: additive dose TL protocol, predose technique (both additive and multiple activation versions), phototransfer protocol, single aliquot regenerative optically stimulated luminescence (SAR-OSL) protocol, and SAR thermoluminescence protocol (SAR-TL). One hundred random variants of the natural samples were generated by keeping the transition probabilities between energy levels fixed, while allowing simultaneous random variations of the concentrations of the 11 energy levels. The relative intrinsic accuracy and precision of the protocols are simulated by calculating the equivalent dose (ED) within the model, for a given natural burial dose of the sample. The intrinsic accuracy of these techniques is estimated by simulating natural irradiation of the samples with a known burial dose, followed by simulation of the luminescence method used to recover the estimated dose ED. The percent difference between the burial dose and the ED value represents the simulated accuracy of the luminescence technique. The relative intrinsic precision of these techniques is estimated by fitting Gaussian probability functions to the ED values obtained with the 100 model variants. It is found that the various techniques can reproduce natural paleodoses in the range 10 mGy–10 Gy with a typical intrinsic accuracy of +1 to 10%. Techniques based on single aliquot protocols were found in general to be more precise than techniques requiring the use of multiple aliquots. In addition, techniques based on interpolation of experimental data were found to be consistently both more precise and accurate than those based on extrapolation of experimental data.     

The formation process of a paleoindian open-air site in Central Brazil: integrating lithic analysis,radiocarbon and luminescence dating

Lithic analysis, radiocarbon dating and luminescence dating are applied to a stratified open-air Paleoindian site in Central Brazil, lending some balance to a published record dominated by rock shelter sites. Most lithics are found in two discrete occupation layers. Lithics found outside these layers are attributed to post-depositional movement of small flakes mainly upwards. Single-grain luminescence dating on quartz grains also suggest post-depositional movement. Both wind and bioturbation are suspected mechanisms. The luminescence analysis does not provide precise depositional dates in this situation but does support such dates suggested by radiocarbon.     

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.     

Age determination of Petra's engineered landscape – optically stimulated luminescence (OSL) and radiocarbon ages of runoff terrace systems in the Eastern Highlands of Jordan

The unfavourable mountainous environment of the Petra region in southern Jordan was modified by ancient engineers to supply the Nabataean/Roman city of Petra with food and water. The area was reclaimed by installing extended runoff terrace systems and hydraulic structures. The agricultural terrace systems have so far been dated based on surface pottery, and the chronology of the systems is under debate. In this study, optically stimulated luminescence (OSL) and radiocarbon dating techniques were successfully applied to date these terrace systems. Samples were taken from the fills of agricultural terraces and underneath their walls to determine the chronology of the construction, use and abandonment of the agricultural terraces. The results suggest that runoff farming in the Petra region started around the beginning of the Common Era, and construction, use and maintenance lasted at least until 800 AD.