Combined archaeomagnetic and thermoluminescence study of a brick kiln excavated at Fontanetto Po (Vercelli,Northern Italy)

A combined archaeomagnetic and thermoluminescence study was carried out as part of a rescue archaeological excavation on a kiln discovered during the installation of methane gas pipelines beneath a rice field, along the southern border of Fontanetto Po village (Vercelli province, Italy). A total of 23 independent brick samples have been collected, oriented in situ with an inclinometer; the use of magnetic and sun compass was not possible due to the existence of metallic tubes beneath the kiln and a plastic cover above it. Standard archaeomagnetic procedures have been used for the determination of the archaeomagnetic inclination and absolute geomagnetic intensity. Stepwise thermal demagnetization shows a very stable characteristic remanent magnetization and the calculated mean inclination of the 23 samples is I = 65.3° with α₉₅ = 2.4° and k = 156. Archaeointensity experiments have been performed using the classical Thellier method as modified by Coe, with regular partial thermoremanent magnetization (pTRM) checks. The cooling rate and remanence anisotropy effects upon thermoremanent magnetization (TRM) have been investigated in all the specimens. A total of 19 archaeointensity determinations (at specimen level) that correspond to linear NRM–TRM plots were used for the calculation of the site mean archaeointensity that is 46.4 ± 2.9 μT. Archaeomagnetic dating results show two possible dating intervals for the last 1000 years, calculated at 95% confidence interval: a first one from 1511 to 1614 AD, and a second one from 1768 to 1872 AD. Thermoluminescence (TL) study has been also performed on two brick samples from the kiln's internal wall, using conventional laboratory procedures. According to the thermoluminescence results the kiln's last usage lies between 1796 and 1914 AD. This age is in good agreement with the second dating interval obtained by the archaeomagnetic analysis. The combined archaeomagnetic and thermoluminescence results suggest that the last firing of the kiln could have occurred between the end of the 18th century and the beginning of 20th century.     

Reassessing the Developmental and Chronological Relationships of the Formative of Coastal Ecuador

The Ecuadorian Formative was initially interpreted as a result of long-distance diffusion, and migration, more recent research has changed our perception of the Valdivia, Machalilla, and Chorrera culture complexes. In this analysis, these archaeological investigations are reassessed in order to reevaluate our understanding regarding the nature of these prehistoric cultures. Formative chronologies, distributions, interrelationships are reviewed in the light of Pre-Hispanic occupations in El Oro Province. Previous investigations on the Ecuadorian littoral are examined. Results indicate (1) Valdivia and Machalilla are part of the same ceramic tradition and (2) the interrelationships of these complexes to Late Formative Period ceramic sequences are more complex than previously assumed. (3) A major adaptive shift related to an increased dependence upon agriculture occurred during Valdivia VI–VIII, and continued into the Late Formative with the widespread distribution of Chorrera related material culture. (4) Long-distance interaction with the Ecuadorian highlands resulted in the spread of what may be termed a Chorrera horizon and formed the basis of subsequent Andean cosmology where it was symbolically represented according to local and regional artistic canons and over a vast area of Andean South America.     

Stable carbon isotope ratios and their relevance to the determination of accurate radiocarbon dates for lime mortars

Attempts have been made to date mortar by radiocarbon analysis. Potential problems are discussed, and the possible use of stable carbon isotopes to detect contamination by geological carbonates is investigated.     

The coastal landslides of Shetland

Little is known of hard-rock coastal landsliding in Scotland. We identify 128 individual coastal landslides or landslide complexes >50 m wide along the coasts of Shetland. Most are apparently translational slides characterized by headscarps, displaced blocks and/or debris runout, but 13 deep-seated failures with tension cracks up to 200 m inland from cliff crests were also identified. Thirty-one sites exhibit evidence of at least localized recent activity. Landslide distribution is primarily determined by the distribution of coastal cliffs >30 m high, and they are preferentially developed on metasedimentary rocks. Analysis of 16 landslides on Fetlar (NE Shetland) indicates that most are translational dip-slip failures; 3 represent deep-seated failures and several exhibit active frontal erosion attributable to basal sapping by storm waves. As these landslides terminate in shallow water, failure was probably initiated when rising sea level resulted in footslope erosion and upslope propagation of instability, causing downslope displacement of landslide blocks on upper slopes. ¹⁰Be exposure dating of two headscarps yielded ages of 4.8?±?0.2 ka and 4.4?±?0.2 ka, consistent with the onset of footslope erosion as sea level rose. Our results suggest that landslides have played a hitherto undocumented but important role in retreat of cliffed coastlines in Scotland.     

A palynological investigation of a second millennium BC bank-system in the black moss of Achnacree

Evidence of agricultural activity in Scotland during the Bronze Age is sparse. A bank system of that date, covered by a deep peat accumulation, in Argyllshire, Scotland has preserved a podzolic palaeosol. Palynological investigation of the palaeosol allows a consideration of potential prehistoric land use. The existence of a well developed iron pan in the palaeosol divides the soil pollen into two contrasting groups, suggesting two quite distinctive periods of land use. Also discussed are the problems which the processes of podzolization cause pollen analysts, the dating of buried soils and the possibility of periodicity in pollen movement through a soil.     

Radiocarbon age determinations of fossil Margaritifera auricularia (Spengler) from the River Thames in West London

In the early 1900s shells of a large freshwater mussel, Margaritifera auricularia (Spengler), were discovered in calcreted gravel dredged from the channel of the Thames at several sites between Mortlake and Battersea in west London. These specimens were said to have been associated with Neolithic polished stone axes, supposedly as food remains. M. auricularia is now extinct in Britain, but it has been reported living in several large rivers in southern Europe although apparently not in recent years. Three radiocarbon dates of 4140±50, 4340±45 and 4860±40 bp have been obtained from Thames specimens, supporting a Neolithic age for these shells. The theory that the shells represent debris from imported human food is discounted and it is considered more likely that M. auricularia was actually living in the Thames in Neolithic times. Its extinction in Britain should be seen as part of a general recession during the Post-glacial, as revealed by fossil occurrences to the north and east of its present-day range.     

Relative and absolute dating of the human skull and skeleton from Galley Hill,Kent

Over a period of some 100 years it has gradually been accepted that the human skeletal remains found in the late nineteenth century in ancient gravels at Galley Hill, Kent are not those of early man, but are of much more recent date. This conclusion was finally verified by means of relative (N, F) and absolute (¹⁴C) dating. Here we present the results of further analysis of the remains from Galley Hill for their uranium content by a method having general application to the relative dating of fossil human and other mammalian bone.     

Palynological and temporal inference in the context of prehistory,with special reference to the evidence from lake and peat deposits

There is an increasing use of palynological data to infer prehistoric agricultural activity. The uncritical acceptance of the technique of pollen analysis by archaeologists and palynologists is questioned. Attention is focussed upon the nature of clearance activity and problems of its inference from pollen spectra; the spatial distribution of palaeoenvironmental sites; and the proximity of such sites to those of prehistoric activity. The resolution apparent in peat and lake sediment pollen profiles together with problems of dating and temporal inference, are examined. In response to a perceived lack of formalization in palynological research, some simple models of clearance activity are presented. The complexity involved in environmental reconstruction is emphasized by reference to the use of supplementary data to augment the orthodox pollen record.     

The Medieval Building Sequence and Dating of Clevedon Court,North Somerset

The construction date of the medieval manor house at Clevedon Court has long been said to be ‘c. 1320’, but no explanation or justification has ever been published. Stylistic, documentary and archaeological evidence is assembled to show that, following three distinct building phases, the house was completed during the decade ending in 1320. Analysis of the development of reticulated tracery helps to determine the date of the iconic chapel window. Other elements of the medieval house are considered and explained.     

Hayonim Cave: a TL-based chronology for this Levantine Mousterian sequence

The thermoluminescence dating method was applied to 77 heated flints from the Mousterian layers of Hayonim Cave in order to provide a precise TL-based chronology for this important Levantine sequence. A detailed dosimetric study was performed by using 76 dosimeter capsules and revealed strong spatial dose-rate variations. In parallel, Fourier transform infrared spectrometry enabled the identification of various mineral assemblages in the sediments of the cave and to localize the boundaries of these assemblages. By comparing these two data sets, it is shown that low dose-rate values (∼500 μGy/a) are systematically recorded in areas where the calcite-dahllite (CD) assemblage is preserved, whereas higher values (up to 1300 μGy/a) are associated with the leucophosphite, montgomeryite, variscite and siliceous aggregates (LMVS) assemblage. The dosimetric and mineralogical information was combined in order to assess, where possible, the dose-rate experienced by each flint during its burial. Some of the flint samples analyzed were too close to mineral assemblage boundaries and were therefore discarded. This rigorous selection led to TL ages ranging from 230 to 140 ka for the lower part of the Mousterian sequence (layers F and Lower E), which contains lithic industries characterized by blade production using the laminar method.