Comparing different post-IR IRSL approaches for the dating of Holocene coastal foredunes from Ruhnu Island,Estonia

Different post-IR Infrared Stimulated Luminescence (IRSL) approaches are applied to sediments from a Holocene coastal foredune sequence on Ruhnu Island in the eastern Baltic Sea. The comparison of D _e-values and ages determined by the different approaches is complimented by fading and bleaching experiments. The fading experiments imply strong fading of IRSL (50°C) signals and no fading of any of the post-IR IRSL signals, but this is not confirmed by the determined D _e-values. In fact, post-IR IRSL (150°C) D _e-values agree within errors with those calculated for IRSL (50°C). From the bleaching experiments it is inferred that the higher values observed for post-IR IRSL at more elevated stimulation temperatures (225°C/290°C) are likely related to either thermal transfer and/or slow-to-bleach components within the signal. For the dating of the Holocene foredune sequence of Ruhnu Island, the post-IR IRSL (150°C) approach is preferred and these agree with the limited independent age control available from radiocarbon dating. Accordingly, the sequence formed between ca. 7.0 ka and 2.5 ka ago.     

A chronometric tool for Hawaiian archaeology: the hydration dating of Pu'u Wa'awa'a trachytic glass

The Pu'u Wa'awa'a trachytic glass deposit located on the Big Island of Hawai'i was a source of lithic tools for much of Hawaiian prehistory. Routinely encountered at habitation sites, the glass has the potential to provide absolute dates based upon the degree of surface hydration. Infrared photoacoustic spectroscopy and secondary ion mass spectrometry were used to monitor the diffusion of water in archaeological and experimental samples. Accelerated laboratory hydration experiments show that water diffusion in trachytic glass containing a structural water content of 0.16% ± 0.03% is linear with time. Application of the calibration to trachytic glass artifacts from the Kahalu'u habitation cave have produced chronometric dates in the 17th–18th centuries. These age estimates are in agreement with radiocarbon dates and artifactual data that bracket the site occupation. However, the glass dates do not correlate well with site stratigraphy and this suggests that slight sample imperfections that retain water may be one factor that results in ages that are too early for later occupation levels.     

Evidence of open-air late prehistoric occupation in the Trieste area (north-eastern Italy): dating, 3D clay plaster characterization and obsidian provenancing

Abundant clay burnt plaster remains and a few flaked tools, including an obsidian artefact, found on the ground surface not far from Trieste (north-eastern Italy) provide rare evidence of a possible prehistoric open-air occupation in the area. To confirm and detail their ancient origin, a plaster sample has been dated between 4000 and 2000 B.C. via thermoluminescence. Outer and inner structure of selected plaster samples has been characterized using several techniques, i.e. X-ray diffraction, scanning electron microscopy and X-ray computed micro-tomography, obtaining information about their production technology. The last technique has allowed to image and virtually extract vegetal remains and imprints. Their 3D morphological study has contributed to collect information about the ancient environment and has provided clues to define the plaster production season. The provenance of the obsidian artefact from Lipari Island, revealed by prompt gamma activation analysis, suggests that the finding site was part of long-distance connection systems and probably worked as intermediate point between the north-eastern Adriatic coastal areas and the inner Karst plateau.     

Strofilas (Andros Island,Greece): new evidence for the cycladic final neolithic period through novel dating methods using luminescence and obsidian hydration

The recently excavated coastal prehistoric settlement of Strofilas on Andros Island (Cyclades, Greece) in the Aegean sheds new light on the transitional phase from the Final Neolithic to Early Cycladic period regarding masonry, fortification, and richly engraved rock art. The fortification possesses early evidence of preserved defensive architecture, as evidenced from the plethora of scattered finds from within and around the settlement. Important features are carvings on rock walls which mainly depict ships, animals, and fish. Initial archaeometric dating via the application of luminescence dating of two samples from the fortified wall bearing engraved ships, and by obsidian hydration of two blades employing the new SIMS-SS method (secondary ion mass spectrometry via surface saturation), has been undertaken to determine the site's chronology. The former yields an average date of 3520 (±540) BC and the latter an average date of 3400 (±200) years BC, both of which, within overlapping errors, suggest the main settlement occurred during the Final Neolithic.     

Radiocarbon pottery dating: the chemical compounds of organic fractions, the reliability of 14C dates (preliminary results)

In recent times, a large number of radiocarbon dates appeared for the Southern Neolithic on the basis of pottery dating because other organic matter has practically not been preserved. There are two organic fractions of pottery useful for dating: food residues and carbon from the pottery matrix itself. Food residues are often dated, but this material is not always preserved and is prone to being removed during the cleaning of the pottery. The clay mass of the pottery contains carbon, often directly visible upon breaking of the pottery. The article focusses on determining the chemical composition of the organic fractions in the pottery and the origin of the carbon. For this aim we used the nuclear magnetic resonance (NMR) method to identify the chemical compounds in the food residue and in the pottery matrix. As an example we used pottery from the Neolithic sites: Zamost??e (Central Russia) and the Varfolomeevskay sites (Southern European Russia, Low Volga region) from archaeological collections. The results obtained demonstrate that the food residue and the pottery matrix contain practically the same organic compounds, even if the relative abundances of various compounds are different in these materials. The origin of the carbon from pottery is discussed.     

Ground stone tool production and use in the Late Upper Palaeolithic: The evidence from Riparo Dalmeri (Venetian Prealps,Italy)

Abstract

The site of Riparo Dalmeri yielded numerous flint, bone, and shell artifacts, as well as faunal and botanical remains, which are evidence of the Late Upper Palaeolithic (or Late Epigravettian culture, ca. 16,000–12,000 cal b.p.) occupation of the Alps region. The importance of the site is related to the discovery of 267 stones painted with anthropomorphic, zoomorphic, and geometric designs. Here we report on ground stone tools from Riparo Dalmeri investigated by means of an integrated technofunctional and experimental approach to reconstruct their production and use. The results support the hypothesis that the ground stone artifacts were employed in specialized activities (e.g., hide treatment, flintknapping) as well as in the production of some of the painted stone artifacts.     

Archaeological and archaeomagnetic dating at a site from the ager Tarraconensis (Tarragona,Spain): El Vila-sec Roman pottery

A very accurate archaeological dating of a Roman site in NE Spain (El Vila-sec) was made based on the typology of pottery artifacts. Three different phases were identified with activity ranging from the mid-1st century BC to the early-3rd century AD. Analyses of bricks from kilns at El Vila-sec produced data on their stored archaeomagnetic vector. These data were compared with the secular variation curve for the Iberian Peninsula and the SCHA.DIF.3K regional archaeomagnetic model. Both, the reference curve and the model, produced probability distributions for the final period of use for two kilns from the second archaeological phase that were not used during the third phase. At a 95% confidence level, both time distributions cover a wide chronological range including the presumed archaeological age. Both the Iberian secular variation curve and the SCHA.DIF.3K regional model proved to be suitable models for dating the site, although on their own they do not produce a single unambiguous solution. This archaeomagnetic approach could also be applied to neighbouring archaeological sites that have an imprecise archaeological age.     

The use of OSL dating in unstructured sands: the archaeology and chronology of the Hutton Sands at Canteen Kopje (Northern Cape Province, South Africa)

Archaeological research at the site of Canteen Kopje, Northern Cape Province, South Africa, has focused on the rich Earlier Stone Age assemblages recovered from the Younger Vaal Gravels. This paper presents the results of excavation and optically stimulated luminescence (OSL) dating of the overlying Hutton Sands. We discuss the evidence for colonial period interaction between diamond miners and indigenous groups at the site, as well as the presence of an earlier phase of terminal Middle Stone Age/early Later Stone Age occupation. The OSL analyses demonstrate the potential distortion of OSL ages due to substantial bioturbation and its effect on the dating of archaeological sites situated in unconsolidated sands.     

Palaeolithic engravings and sedimentary environments in the Côa River Valley (Portugal): implications for the detection,interpretation and dating of open-air rock art

The pre-Magdalenian phase of the Côa River Valley open-air rock art is mostly distributed at the boundary between the rocky valley slopes and the floodplain that correspond to the most favourable geomorphological setting for the preservation of pecked and deeply superposed engravings of the most famous artistic phase of the area. The natural vertical panels of the engraved art located at this geomorphological interface have suffered weathering during two cold events of the Lateglacial. They were buried by several colluvial and alluvial deposits. The reconstruction of the sedimentary and archaeological context of the CôaRiver Valley engraving permits a better assessment of the preservation processes and interpretation of Palaeolithic open-air rock art.     

The Houston Advanced Research Center (HARC): A Private Initiative for Industrial Development

The private sector can create unique institutions that help to achieve industrial and economic goals. To demonstrate this growth model, the Houston Advanced Research Centre (HARC) was created as a private non-profit organization, part of a new town development north of Houston, Texas. Over its 17-year history, HARC has successfully linked university, industry and governmental research in this framework. During this time, four strategies have been tested: large or sensitive R&D projects, strong links with member universities, efforts to bring technology to the marketplace, and policy analysis and advice. Of these, the latter three are today's successes as HARC has become a more responsive, service-oriented organization. Also, sustainable development has emerged as a unifying theme, reflecting part of the organization's initial legacy from its founder, George P. Mitchell. The Woodlands has grown around HARC as a place to live for over 50,000 people, a growing job base, and realization of the initial "research forest" concept with more than 100 firms and 4,500 employees.