Tunnel engineering in the Iron Age: geoarchaeology of the Siloam Tunnel,Jerusalem

The Siloam Tunnel (ST) is the best-identified biblical structure that can be entered today. We use geological, structural, and chemical features of ST and its internal deposits to show that it is an authentic engineering project, without any pre-existing natural conduit that could have guided its excavators. Radiometrically and historically dated to ∼700 BCE, ST pinpoints the technological advance in leveling techniques that was essential for the construction of such a long tunnel without intermediate shafts. A combination of geological and archaeological evidence demonstrates that the circuitous route of ST and the final meeting of the two excavating teams are associated with continuous modifications of the plan to allow acoustic communication between hewers and the surface teams. Hydraulic plaster was applied throughout the tunnel in order to seal voids of dissolution and tectonic origin. Organic material accidentally entrapped in the plaster was carbon 14 dated, and speleothems were dated by U–Th, both corroborating the historic and epigraphic evidence ascribing the engineering advance in tunneling techniques to the Judahite King Hezekiah.     

Thorium-230 coral chronology of a late prehistoric Hawaiian chiefdom

Documenting the history of settlement in Hawaii during the last few centuries before European contact, is crucial to charting the evolution of the most complex chiefdom in Polynesia. It is precisely this period that Hawaii, and many Polynesian societies, underwent their most rapid changes in political, economic and social organisation. The last ∼500 to 300 years in the ¹⁴C calibration curve is problematic with wide fluctuations often rendering large age spans that do not precisely date single events, especially troubling with a culture-historical record of ∼1000 years duration. Here we present an extremely high precision ²³⁰Th chronology for archaeologically constrained coral samples from a range of occupancy sites. Our high precision dates allow the time of site use to be clearly demonstrated. They also provide the first dates for habitation sites in Hawaii that clearly show contemporaneous occupation—the major problem in settlement pattern archaeology. We demonstrate that two sites were occupied within the same year. Our refined chronology, provides new and exciting opportunities for tracking sociopolitical and economic developments during the last few centuries—the crucial period in the evolution and transformation of Polynesian societies.     

Palaeoenvironmental and chronological investigations of the Magdalenian sites of Goyet Cave and Trou de Chaleux (Belgium), via stable isotope and radiocarbon analyses of horse skeletal remains

Trou de Chaleux and Goyet are caves situated less than 30 km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave, and that Trou de Chaleux has two phases of occupation during the Late-glacial interstadial. However, the limited number of radiocarbon dates currently available makes it impossible to determine whether the sites are truly contemporaneous, and the assessment of their absolute chronologies is complicated by a plateau in the calibration curve. In this paper, bone collagen δ¹³C and δ¹⁵N signatures of horse bones from the two sites are used to reconstruct local palaeoenvironments. We hypothesise that if occupations at the two sites were contemporaneous, the horse collagen δ¹³C and δ¹⁵N isotope signatures from both sites will be similar, since comparable carbon and nitrogen isotopic values would reflect similar diets, ecologies and environments. To provide clear dating parameters, new AMS radiocarbon determinations are also presented. Results show that horse collagen δ¹³C and δ¹⁵N isotope signatures at the two sites are different, indicating that the populations were not subject to similar diets, ecologies and environments. The new radiocarbon dates confirm that the horse bones from Trou de Chaleux date to the Late-glacial interstadial, but they also show that in Goyet Cave Horizons 1 and 2, older horse remains dating to ca. 32?000–27?000 ¹⁴C yr BP are mixed with Late-glacial horse remains. The δ¹⁵N values of the Goyet Cave horse bones radiocarbon dated to the Pleniglacial are substantially higher than those that have Late-glacial radiocarbon dates. Therefore, we now hypothesise that the majority of the horse bones isotopically analysed from Goyet Cave Horizon 1 are Pleniglacial in age. Statistical analysis of the radiocarbon dates indicates that the Late-glacial occupation at the two sites was contemporaneous, and that while there may appear to be two phases of occupation at Trou de Chaleux, this may be an artefact of the radiocarbon calibration curve.     

Origin of palaeofluids in a normal fault setting in the Aegean region

The province of Burdur (SW Turkey) is seismically an active region. A structural, geochronological, petrographical, geochemical and fluid inclusion study of extension veins and fault‐related calcite precipitates has been undertaken to reconstruct the palaeofluid flow pattern in this normal fault setting in the Aegean region. A palaeostress analysis and U/Th dating of the precipitates reveals the neotectonic significance of the sampled calcites. Fluid inclusion microthermometry of calcites‐filling extension veins shows final melting temperatures (T_m ice) of 0°C. This indicates pure water, most likely of meteoric origin. The oxygen isotope values (?9.8‰ to ?6.5‰ VPDB) and the carbon isotopic composition (?10.4‰ to ?2.9‰ VPDB) of these calcites also show a near‐surface meteoric origin of the fluid responsible for precipitation. The microstructural characteristics of fault‐related calcites indicate that calcite precipitation was linked with fault activity. Final melting temperature of fault‐related calcites ranges between 0 and ?1.9°C. The oxygen isotope values show a broad range between ?15.0‰ and ?2.2‰ VPDB. Several of these calcites have a δ¹⁸O composition that is higher or lower than the oxygen isotopic composition of meteoric calcites in the area (i.e. between ?10‰ and ?6‰ VPDB). The δ¹³C composition largely falls within the range of the host limestones and reflects a rock‐buffered system. Microthermometry and stable isotopic study indicate a meteoric origin of the fluids with some degree of water–rock interaction or mixing with another fluid. Temperatures deduced from microthermometry and stable isotope analyses indicate precipitation temperatures around 50°C. These higher temperatures and the evidence for water–rock interaction indicate a flow path long enough to equilibrate with the host–rock limestone and to increase the temperature. The combined study of extension vein‐ and fault‐related calcite precipitates enables determining the origin of the fluids responsible for precipitation in a normal fault setting. Meteoric water infiltrated in the limestones to a depth of at least 1 km and underwent water–rock interaction or mixing with a residual fluid. This fluid was, moreover, tapped during fault activity. The extension veins, on the contrary, were passively filled with calcites precipitating from the downwards‐migrating meteoric water.     

Holocene Elevated Sea Levels on the North Coast of Vietnam

We present evidence of elevated Holocene sea levels on the north coast of Vietnam, comprising radiocarbon dating of raised coastal geomorphological and palaeobiological features at localities on the margins of the Bac Bo (Red River) Plain. This evidence indicates that by ca. 5500 cal yr B.P. mid‐tide lay approximately 5.4 m above national datum, that is 3.25 m above present local mid‐tide. By c. 3500 cal yr B.P., sea level was lowering and, by ca. 2000 cal yr B.P., mid‐tide lay at or above 1.5 m above present local mid‐tide. It is not yet possible to infer patterns of sea‐level fluctuation other than an overall lowering of elevation, although the separation of the raised and modern erosion notches does suggest two dominant mid to late Holocene periods of erosion — probably periods of sea‐level still‐stand or relatively slow sea‐level change. The intervening period of relatively rapid sea‐level change and associated reduced erosion probably dates to after ca. 2000 cal yr B.P..     

Restrictions on fluorine depth profiling for exposure age dating in archaeological bones

Archaeological fragments of bone and teeth that are exposed to a humid environment take up fluorine from the surrounding soil. The fluorine ion replaces the hydroxyl group in the mineral phase of the bone, forming chemically more stable fluorapatite. In cortical parts of the long bone diaphysis a fluorine concentration profile can be observed, which decreases from the outer surface and the marrow cavity towards the inner parts of the bone matrix. Geological time spans are needed for this process to reach equilibrium and for the distribution to become uniform. As the shape of the profile, which can be described by a diffusion model, contains information on the exposure duration of the fossil object, several attempts to use fluorine profiling as a dating method have been undertaken. The distribution of fluorine in an archaeological sample however is strongly influenced by environmentally induced processes of bone diagenesis, i.e. alteration in the structure and composition of the mineral phase and degradation of organic components that may make the time information indistinct. The primary chemical composition of bones can thus be obscured by diagenesis within tens, hundreds or thousands of years. This depends more on the diagenetic environment than on the geological age. To observe the impact of environmental influence on the profile shape, samples from several burial sites featuring various soil conditions have been analyzed for their fluorine distribution and preservation state. This paper provides an overview on the restrictions that have to be considered when attempts are undertaken to relate a fluorine diffusion pattern to the archaeological age of a bone specimen.     

放射性碳素测定年代报告(三四)

本报告发表的是中国社会科学院考古研究所考古科技实验研究中心碳十四实验室在2006年到2007年期间测定的30个考古数据。数据表示方式同此前所发报告。为方便应用另做几点说明如下。1.碳十四年代半衰期按5568年计算。2.校正年代所用程序为OxCal,校正曲线为1998年公布版本。3.与以往报告相同,所给年代误差范围均为±16,年代范围的概率分布为68.2%。4.由于树轮年代校正曲线各区段形状不同,校     

Obsidian hydration dating: accuracy and resolution limitations imposed by intrinsic water variability

Obsidian hydration dating typically yields a range of ages for a single chronometric measurement, even after controlling for source chemistry and effective hydration temperature. Previously published data suggest that this range is due to hydration rate variations caused by variability in the concentration of intrinsic water, and specifically hydroxyl ions, in the obsidian. Such variability exists within any given obsidian source, and even within any particular specimen. This paper analyzes the effect on age estimates of intrinsic water variability and concludes that if a controlled sample of obsidian yields a range of ages, there is no way to tell whether the range is due to long site use or to variations in hydroxyl concentration. At present there is no robust and cost-effective protocol for measuring hydroxyl concentration. Suggested guidelines for obsidian hydration dating are developed using a case study. These findings do not invalidate obsidian hydration as a chronometric technique, but they do suggest limits to the temporal resolution achievable.     

A New Type of Composite Anchor Dated to the Fatimid-Crusader Period from the Dead Sea, Israel

Two composite anchors of a kind not hitherto identified, each composed of a re-used ashlar block, a wooden shank, two arms and a rope, were discovered recently on the Dead Sea shoreline. Two additional anchor weights of identical type were found in the same region. The two well-preserved anchors were dated to the Fatimid-Crusader period. The shank and the arms were made from local tree species: Christ thorn and tamarisk, and both ropes of date-palm.
© 2008 The Authors     

关于《倦勤斋陈设档》的几点认识

本文分析了故宫博物院所藏《倦勤斋陈设档》的状况,并据《陈设档》所载内容.结合历史事件及历史文献的记载,参阅《中国古籍善本总目》等著录情况.对陈494《陈设档》的立档年限进行了考证。