High-resolution sclerochronological analysis of the bivalve mollusk Saxidomus gigantea from Alaska and British Columbia: techniques for revealing environmental archives and archaeological seasonality

The butter clam, Saxidomus gigantea, is one of the most commonly recovered bivalves from archaeological shell middens on the Pacific Coast of North America. This study presents the results of the sclerochronology of modern specimens of S. gigantea, collected monthly from Pender Island (British Columbia), and additional modern specimens from the Dundas Islands (BC) and Mink and Little Takli Islands (Alaska). The methods presented can be used as a template to interpret local environmental conditions and increase the precision of seasonality estimates in shellfish using sclerochronology and oxygen isotope analysis. This method can also identify, with a high degree of accuracy, the date of shell collection to the nearest fortnightly cycle, the time of day the shell was collected and the approximate tidal elevation (i.e., approx. water depth and distance from the shoreline) from which the shell was collected.Life-history traits of S. gigantea were analyzed to understand the timing of growth line formation, the duration of the growing season, the growth rate, and the reliability of annual increments. We also examine the influence of the tidal regime and freshwater mixing in estuarine locations and how these variables can affect both incremental structures and oxygen isotope values. The results of the sclerochronological analysis show that there is a latitudinal trend in shell growth that needs to be considered when using shells for seasonality studies.Oxygen isotope analysis reveals clear annual cycles with the most positive values corresponding to the annual winter growth lines, and the most negative values corresponding to high temperatures during the summer. Intra-annual increment widths demonstrate clear seasonal oscillations with broadest increments in summer and very narrow increments or no growth during the winter months. This study provides new insights into the biology, geochemistry and seasonal growth of S. gigantea, which are crucial for paleoclimate reconstructions and interpreting seasonality patterns of past human collection.     

Stone Age midden deposition assessed by bivalve sclerochronology and radiocarbon wiggle-matching of Arctica islandica shell increments

Sclerochronology, the study of the skeletal diaries of mollusks and corals, is a high-resolution geochronological tool of versatile usage in archaeology and paleontology with increasingly growing opportunities. Much of the recent efforts have concentrated on building multi-centennial bivalve growth records using annually deposited increments in the Holocene shells, comparable to tree-ring chronologies. In the context of geoarchaeology, the hitherto unachieved potential includes the application of sclerochronology to reconstruct long-term settlement histories. Here we contribute to both of these critical issues by presenting the first multi-shell sclerochronology constrained by methods originally developed in tree-ring research, using anthropogenically deposited bivalve shells of Arctica islandica excavated from a Stone Age midden in North Norway. Our systematic chronological approach to shell growth histories lays the foundation for a multi-dimensional dating framework that interacts between the incremental, radioisotopic and stratigraphic evidence. We show how the crossdating within and between the single-shell records yields a 155-year multi-shell sclerochronology, supported by the ¹⁴C AMS dates, that demonstrates minimum midden accumulation of 82 years and a depositional rate of 0.3 cm/yr. Sclerochronology paves the way for radiocarbon wiggle-matching, which narrows the probabilistic 2-σ uncertainty range for the oldest and youngest ¹⁴C AMS dates to 3150–2980 and 3060–2890 BC, respectively. We attribute the spectral characteristics of the chronology primarily to the North Atlantic Oscillation, suggesting essentially similar influences of climate variability on the Stone Age culture and our own society.     

Terminal Pleistocene Later Stone Age Human Remains from the Mlambalasi Rock Shelter,Iringa Region,Southern Tanzania

This paper introduces research at the Mlambalasi rock shelter in the Iringa Region of southern Tanzania. The deposits are composed of a historic and Iron Age occupation, a microlithic Holocene Later Stone Age (LSA), and then a macrolithic Late Pleistocene LSA. Middle Stone Age deposits are also present on the slope in front of the rock shelter. Excavations in A.D. 2002, 2006, and 2010 yielded fragmentary human remains as well as pottery, iron, stone tools, faunal bone, and glass and ostrich eggshell beads. Among the human remains, four individuals are present: two adults and a juvenile were found in the same LSA context, and another adult associated with the Iron Age/historic period. The most complete skeleton is an adult of indeterminate sex that was found in situ in an LSA deposit. Charcoal in proximity to the bone was AMS radiocarbon dated to 12,925 cal BC (OxA‐24620), which is consistent with radiocarbon dates on giant land snail shells from above and below the remains. The skeleton exhibits a series of pathological changes such as extensive dental wear and carious lesions, as well as damage most likely caused by termites, post‐mortem. The most striking aspect of this individual is its small size; stature and body mass estimations place it in the range of historic Khoesan from southern Africa. Consequently, this research adds to the discourse regarding the existence of small‐bodied people in the East African LSA. Findings from this new skeletal sample will contribute to studies of human biology and variation in Africa during the terminal Pleistocene and Holocene. Copyright © 2013 John Wiley & Sons, Ltd.     

REFINING ESTIMATES FOR THE SEASON OF SHELLFISH COLLECTION ON THE PACIFIC NORTHWEST COAST: APPLYING HIGH‐RESOLUTION STABLE OXYGEN ISOTOPE ANALYSIS AND SCLEROCHRONOLOGY

Stable oxygen isotopes from estuarine bivalve carbonate from Saxidomus gigantea were analysed combined with high‐resolution sclerochronology from modern and archaeological shells from British Columbia, Canada, to determine the seasonality of shellfish collection from the archaeological site of Namu. The combination of high‐resolution sclerochronology and a micro‐milled sampling strategy for δ¹⁸O analysis permits a precise estimate of archaeological seasonality, because seasonal freshwater influxes and changes in temperature have dual effects on the δ¹⁸O value of the shell. Sclerochronological analysis identifies the timing and duration of growth that is temporally aligned to stable oxygen isotope results, since δ¹⁸O_shell appears to be strongly influenced by seasonal inputs of very low δ¹⁸O snowmelt‐water from adjacent coastal mountain ranges. The results show that shellfish were collected year‐round at this site over a 4000‐year period, and these data combined with other zooarchaeological lines of evidence support the interpretation of year‐round occupation.     

The Potential for Dating the Old Scatness Site,Shetland, By Optically Stimulated Luminescence

A series of deposits from the agricultural infield of the multiperiod settlement mound, Old Scatness, were investigated for their potential to yield optically stimulated luminescence dates. Luminescence properties of quartz grains were found to vary through the sequence, but dates were successfully obtained from five deposits, including anthropogenic soils, windblown sands and sands within midden deposits. Single‐aliquot equivalent dose measurement was found to be the most appropriate method for dating the deposits. The OSL dates obtained accorded well with the dates provided by archaeological evidence and included the post‐medieval, Iron Age, Bronze Age and Neolithic periods of Shetland, while a substantial midden was dated to the Bronze/Iron Age transition.     

METHODOLOGICAL DEVELOPMENTS IN THE LUMINESCENCE DATING OF BRICK FROM ENGLISH LATE‐MEDIEVAL AND POST‐MEDIEVAL BUILDINGS*

Fired clay brick samples, obtained from a group of seven high‐status late‐medieval and post‐medieval buildings in England ranging in age from c. ad 1390 to 1740, were dated by the luminescence method using an optically stimulated luminescence (OSL) technique. The results obtained indicate that, when applied to quartz extracted from brick, the technique is capable of producing dates that are in consistently good agreement with independent dating evidence for the buildings. For six samples taken from a group of four dating ‘control’ buildings the mean difference between the central values of luminescence and assigned ages was 5 ± 10 years (SD, n = 6). The methodology used is appropriate for application to other standing buildings in other temporal and geographic regions, and may be used with confidence where conventional dating methods are less certain. The study also examines the luminescence characteristics of quartz and the characteristics of the lithogenic radionuclides in brick samples and identifies various aspects related to the assessment of experimental uncertainty in testing the reliability of the method.     

Growth of the Lichen Buellia albula and its Potential for Lichenometric Dating in South‐eastern Australia

Lichenometric dating is a cheap, relatively rapid means of dating rock surfaces, which has generally been overlooked in Australia. While lichenometry finds its greatest application in arctic and alpine geomorphological studies, there has been limited application to archaeological studies. This project set out to test the technique in south‐eastern Australia, and assess its usefulness for dating post‐settlement artefacts. The diameters of Buellia albula lichens growing on well‐dated memorials in the Bendigo cemetery were measured, and the relationship between age and lichen diameter established. The results indicate that B. albula can be used to determine the age of exposed cement surfaces from the 1890s to the present. The positive results suggest the technique should be investigated in other applications and environments in Australia, particularly where alternative dating techniques cannot be used.     

RADIOCARBON DATING OF MESOLITHIC OPEN‐AIR SITES IN THE COVERSAND AREA OF THE NORTH‐WEST EUROPEAN PLAIN: PROBLEMS AND PROSPECTS

This paper discusses the problems with sampling materials and sampled contexts in the framework of radiocarbon dating of Mesolithic sites situated in generally dry, acid and bioturbated coversand deposits within north‐western Europe. The case studies presented all relate to the coversand regions of northern Belgium and the Netherlands, two areas for which very large sets of radiocarbon dates performed on different organic components are currently available. The study points out that charred hazelnut shells from surface hearths and charcoal from hearth pits guarantee the most secure dating results, while the dating of calcined bones and food crusts from Final Mesolithic pottery so far remains problematic.     

Underwater Investigation on a Marble Cargo Wreck at Capo Bianco near Isola di Capo Rizzuto,Crotone, Italy

The cargo of marble blocks off Capo Bianco was dated to the Roman period. New sampling and analysis has identified Carrara marble, and also Rosso di Francia and Portargento, which strongly suggests a post‐medieval date. This leads to the suggestion that nearby finds dating between the second half of the 18th century and the first half of the 19th may come from the same ship, perhaps sailing from France and Liguria to deliver stone in southern Italy. This is rare evidence of the post‐medieval marble trade and demonstrates the importance of archaeometric analysis for the interpretation of wrecked cargos. © 2011 The Authors     

THE AMINOCHRONOLOGY OF MAN‐INDUCED SHELL MIDDENS IN CAVES IN NORTHERN SPAIN*

Here, we provide the first report on the ages of 54 archaeological levels in 38 caves in northern Spain by means of the aspartic acid d /l ratio measurements in Patella shells, with good results. For this purpose, we developed an age calculation algorithm that allows the numerical dating of deposits from other archaeological localities in the area and nearby regions. We conclude that the sample size—that is, the number of shells analysed within a single level—reinforces the importance of analysing numerous specimens per horizon and the understanding of the time‐averaging concept. The ultrastructure of different species of Patella shells was also studied, showing calcite in their apexes and aragonite at their margins.     

The paleolithic site of Longwangchan in the middle Yellow River,China: chronology,paleoenvironment and implications

The Longwangchan Paleolithic site, situated on the Yellow River terraces in the Hukou area, Shaanxi province, China, was found in 2003–2004, and two areas (Localities 1 and 2) of the site were excavated in 2005–2008. Abundant stone artifacts including microliths, a grinding stone fragment and a shovel, with some animal bones and shells, were recovered from Locality 1. In this study, the cultural deposits from Locality 1 were dated using radiocarbon and optical dating techniques, and the sediment properties of the deposits were analyzed. The results show that the age of the deposits ranges from 29 to 21 ka and most of them were deposited between 25 ka and 29 ka. This indicates that corresponds to late Marine Isotope Stage (MIS) 3 and early MIS 2. During the human occupation period, the climate in this area became colder and drier. Sediments from beds where the grinding slab and the shovel were found were dated to ∼25 ka, which is the oldest among the grinding stones found in China. The microliths and the grinding stone are important evidence for an incipient socio-economic process that eventually led to the regional transition from hunting-foraging to farming.     

SIMS‐SS,A NEW OBSIDIAN HYDRATION DATING METHOD: ANALYSIS AND THEORETICAL PRINCIPLES*

The water diffusion mechanism in obsidian has been revisited with the advent of a new dating approach employing secondary ion mass spectrometry (SIMS). The water diffusion SIMS(+) profile and the concept of a surface saturation (SS) layer in obsidians both provide a sound basis for the new diffusion age equation (SIMS‐SS) and are supported by dated world examples ( Liritzis et al. 2004 ). Here, we present the basic physical–chemical analysis of the mass transport phenomenon on which the new dating method is based. The crucial age parameter of the SIMS‐SS dating approach for archaeological obsidians—that is, the surface saturation (SS) layer—is supported by both theoretical and experimental data.     

BAYESIAN ANALYSIS OF PLEISTOCENE CHRONOMETRIC METHODS*

Bayesian analysis of radiocarbon dates on Holocene archaeological sites has become well established. Application to Pleistocene sites dated by multiple techniques would be advantageous. This paper develops the necessary mathematical apparatus in the form of likelihoods for luminescence dating, and uranium‐series dating, and considers the possibility for amino‐acid racemization dating. Application of the new methods is illustrated using the stratigraphic sequences of dates from the sites of Saint‐Césaire and La Chaise‐de‐Vouthon. For application to amino‐acid racemization dating, fuller publication of data is found to be required.     

Evidence for inter-island transport of heirlooms: luminescence dating and petrographic analysis of ceramic inhaling bowls from Carriacou,West Indies

Ceramic snuffing tubes and inhaling bowls used for ingesting hallucinogenic substances are known from several islands in the West Indies, but their chronological distribution is often vague. A partial inhaling bowl found at the site of Grand Bay on Carriacou in deposits dating between ca. A.D. 1000–1200, along with two other unprovenienced specimens from the local museum, were dated using luminescence (TL and OSL) to determine their antiquity. Surprisingly, the dates had a weighted average of 400 ± 189 B.C., making them several hundred years older than all ¹⁴C assays from the island; however, they do overlap in age with similar artifacts found on Puerto Rico and Vieques Island over 750 km away. Additional luminescence dating of two stylistically distinct Suazan ceramic sherds excavated from stratified deposits at Grand Bay fall within the expected ceramic and radiocarbon chronology. These data, coupled with petrographic analysis of the specimens, suggests that they were not made using local materials. Instead, they appear to have been transported to the island, possibly hundreds of years later, as heirlooms. This may be the first evidence for inter-island transport of drug paraphernalia in the Caribbean.     

A review of rock art dating in the Kimberley, Western Australia

This paper critically reviews the various approaches used to estimate the age of the rock art in the Kimberley region of Western Australia. They include: (i) the relative superimposition of styles; (ii) the use of diagnostic subject matter (depictions of extinct animals, stone tool technology, introduced European and Asian objects and animals); (iii) the recovery of a ‘painted’ slab from a dated archaeological unit; (iv) radiocarbon dating of beeswax figures, charcoal pigments, organic matter in overlying mineral deposits and ‘accreted paint layers’ (oxalate rich crusts and amorphous silica skin), pollen grains from an overlaying mud-wasp nest; and (v) optically stimulated luminescence (OSL) dating of quartz grains from overlying mud-wasp nests. Future directions for rock art dating in the Kimberley include uranium-series dating of overlying and underlying mineral deposits.     

On the Possible Origins of an Unusual (Mid to Late Holocene) Coastal Deposit,Old Punt Bay,South‐East Australia

An unusual coarse, shelly sedimentary unit is found elevated above present mean sea level in a sheltered pocket embayment at Old Punt Bay in south‐eastern Australia. The coarse sediments, diverse microfauna, and large shelly macrofauna of mixed affinity suggest that the deposit is the result of high‐energy deposition. The deposit was previously thought to have been deposited 1000–1300 cal bp based on one shell dated using ¹⁴C and amino acid racemisation. However, additional ¹⁴C dating indicates a likely age of ～2500 cal bp . Regardless of age constraints, the presence of rock‐encrusting oyster shells and large articulated bivalves, suggests that the depositional event must have been capable of removing and transporting coarse sediments (rock clasts), bivalves, and oysters shells from a variety of seaward environments and depositing them with little abrasion, something storm waves are unlikely to do. The deposit may be tsunamigenic. If a tsunami origin is accepted, the new dating results indicate that it is possibly coeval with a tsunami event previously reported to have affected several other sites along the coast of New South Wales at c. 2900 cal bp . Consequently, this deposit provides evidence for the event at a new site and importantly, a tighter constraint on the likely date of the events occurrence. It further adds weight to the developing catalogue of palaeotsunamis that may have affected the south‐eastern coast of Australia. Regardless of the deposit's origins, if viewed from a coastal planning perspective, this deposit indicates that this part of the coast has experienced large‐scale overwash events in the past that if repeated, would be catastrophic. There are serious implications for risk management.     

A dental study comparing age estimations of the human remains from the Swedish warship Vasa

The great Swedish warship Vasa capsized and sank in Stockholm harbour on her maiden voyage in 1628. The ship was raised from the seabed in 1961 and skeletal remains were recovered from at least 25 individuals, with teeth and jaws from 17 of them. The skeletal material was odontologically examined, including dental radiographs. Teeth lost both ante‐mortem and post‐mortem were recorded and variations in tooth anatomy noted. Acquired changes were recorded including enamel hypoplasia, attrition, dental caries and periodontal recession. Age estimations based on a separate odontological study, osteological changes and tooth attrition had been made in 1989. Ages were estimated additionally by three non‐destructive dental methods based on (a) the length of the apical translucent zone, (b) selected measurements both on intact teeth and from ratios on dental radiographs and (c) ratios of the length and width measurements on dental radiographs from selected teeth. Several sources of post‐mortem changes had been observed, among them vivianite in 33 teeth from four individuals. The results of the dental examination showed that few teeth had been lost ante‐mortem, there was a low caries rate and little loss of periodontal attachments. With few exceptions, there is fairly good agreement between the different methods of estimating age. Age estimates based on dental attrition were, however, significantly different from the other dental methods and age estimates calculated from apical translucency ought to be regarded with scepticism due to post‐mortem changes. The chronological ages of the victims will never be known, but age estimates based on all the age‐markers available will probably reach a fairly close approximation. Copyright © 1999 John Wiley & Sons, Ltd.     

Zu papyri osloenses III

The sixth Roman ode of Horace has usually been dated to 29/28 B.C. from the reference to the great temple restoration programme in the first stanza. This dating, however, tends to affect our reading of the whole cycle. An ‘inner’ dramatic date deliberately established by the poet (post Actium but before 28 B.C.) should not be mistaken for the time of writing (after 28, probably about 25 B.C.). There are even calculated effects arising from the poet's use of a dramatic date. Moreover, the poem is not independent to the effect that it is a self‐contained expression of the poet's political stance. Its provoking diagnosis of contemporary society is a warning reflecting Augustus’ policy and paving the way for reforms. It is instructive to compare epode XVI, to which III 6 bears resemblances which seem to support the late dating of the epode (cf. the author's Horaz und Actium 1984).     

State‐of–the–art imaging in palaeopathology: the value of multislice computed tomography in visualizing doubtful cranial lesions

Non‐invasive imaging techniques are of great value in palaeopathology. Computed tomography (CT) is widely established to visualize changes in human remains that occurred both pre and post mortem. Since 1999 an advanced form of helical CT—so called Multislice‐CT (MSCT)—has become available for clinical purposes. We now present for the first time three historic cranial lesions of doubtful aetiology visualized by MSCT. Both original images and virtual reconstructions of the specimens are of high quality. In combination with peri‐lesional bone density measurements these images allow an improved assessment of aetiology. The cases presented are diagnosed by MSCT as being of intra vitam nature in two individuals and of post mortem character in one case. Time consuming post‐processing analysis and the still small number of scanners presently available may limit application of this new technique. Nevertheless, based on our preliminary results, we strongly recommend non‐invasive evaluation by MSCT to be used for non‐clinical purposes such as palaeopathological research. Copyright © 2002 John Wiley & Sons, Ltd.     

A PROVENANCE STUDY OF TANG SANCAI FROM CHINESE TOMBS AND RELICS BY INAA*

In order to group specimens of Tang Sancai of unknown provenance to the different kilns according to their chemical compositions, we studied the elemental abundance patterns of Tang Sancai body samples from different tombs, relics and kilns by instrumental neutron activation analysis (INAA). Our results indicated that the development process of Tang Sancai in the Prospering Tang period could be divided into at least two phases, with ad 705 or so as the boundary between them. The results of factor analysis showed that the red‐bodied samples were more likely to be produced near Xi’an, whereas the white‐bodied Tang Sancai wares dating to before ad 705 were most probably produced at Huanye Kiln (also known as ‘Gongxian’ Kiln), and the figures were very likely made at an undiscovered kiln near Luoyang or an undiscovered part of Huangye Kiln. Among the white‐bodied samples dated from ad 705 to ad 755, both types of figures and wares were mainly produced near Xi’an and Luoyang.