Correlation BetweenC Ages and Aspartic Acid Racemization at the Upper Palaeolithic Site of the Abri Pataud (Dordogne, France)

The Upper Palaeolithic site of the Abri Pataud (Dordogne, France) has been the subject of numerous¹⁴C age determinations which cover the period from 20,400±450 years (OXA-373) to 34,250±675 years (Grn-4507). The racemization ratios of aspartic acid have been determined in 26 fossil bones. The bones are present in two different sedimentary surroundings: levels (fine deposits with numerous artefacts and fossil bones) and “éboulis” (coarse deposits derived from the neighbouring limestone cliff). Racemization ratios for total aspartic acid have a poor correlation with¹⁴C ages (respectivelyr²=0·59 and 0·82 for the two environments) but apparent racemization rates are clearly dependent on the type of deposits (levels: K=4·4×10⁻⁶year⁻¹; éboulis: K=9×10⁻⁶year⁻¹).Racemization ratios of aspartic acid in a high molecular weight protein fraction (>10,000 Da) correlate much better with¹⁴C ages (r²=0·999) for the samples from the levels (k=2·1×10⁻⁵year⁻¹). From this regression line we estimate ages for two Aurignacian levels: level 6≈29,560 years and level 9≈30,440 years .It is noteworthy that none of the regression lines intercepts the origin. Racemization of aspartic acid appears to occur only after a delay of many thousands of years. This phenomenon could be the result of a coupling between the degradation of proteins and the racemization of amino acids.     

The World's Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago

The systematic archaeological and geological survey and excavations at Gona between 1992–1994 led to the discovery of well-flaked stone artefacts which are currently the oldest known from anywhere in the world. More than 3000 surface and excavated artefacts were recovered at 15 localities documented east and west of the Kada Gona river. Based on radioisotopic dating (⁴⁰Ar/³⁹Ar) and magnetostratigraphy, the artefacts are dated between 2·6–2·5 million years ago (Ma). EG10 and EG12 from East Gona are the most informative with the highest density, providing the best opportunity for characterizing the oldest assemblages and for understanding the stone working capability of the earliest tool makers. Slightly younger artefact occurrences dated to 2·4–2·3 Ma are known from Hadar and Omo in Ethiopia, and from Lokalalei in Kenya. Cut-marked bones dated to 2·5 Ma from Bouri in Ethiopia are now providing important clues on the function of these artefacts. In addition, Australopithecus garhi known from contemporary deposits at Bouri may be the best candidate responsible for the oldest artefacts. Surprisingly, the makers of the Gona artefacts had a sophisticated understanding of stone fracture mechanics and control similar to what is observed for Oldowan assemblages dated between 2·0–1·5 Ma. This observation was corroborated by the recent archaeological discoveries made at Lokalalei. Because of the similarities seen in the techniques of artefact manufacture during the Late Pliocene–Early Pleistocene, it is argued here that the stone assemblages dated between 2·6–1·5 Ma group into the Oldowan Industry. The similarity and simplicity of the artefacts from this time interval suggests a technological stasis in the Oldowan.     

Accelerator C dates for early upper paleolithic (basal Aurignacian) at El Castillo Cave (Spain)

Three fragments of charcoal taken from different parts of the lowermost bed containing Aurignacian artifacts at El Castillo Cave yielded AMS dates of 37·7 (± 1·8) ka bp, 38·5 (± 1·8) ka bp, and 40·0 (± 2·1) ka bp (average 38·7 ± 1·9 ka bp). These dates are almost identical to new AMS dates from l'Arbreda cave in Catalunya on the same cultural horizon (average 38·5 ± 1·0 ka bp) and are significantly older than the earliest dates for Aurignacian industries in the Aquitaine and in other parts of Central and Western Europe.     

Geochronology of Palaeolithic cultures in the Hiran Valley, Saurashtra, India

The U and Th concentrations of 16 miliolite samples from the Hiran Valley in Saurashtra ranged from 0·3 to 2·14ppm and 0·12 to 0·82ppm respectively. The ²³⁴U/²³⁸U activity ratio ranged from 1·09 to 1·16, with a mean of 1·12±0·02. It agrees well with the seawater value of 1·14±0·02 within the quoted errors. Nine of the samples were datable by the ²³⁰Th/²³⁴U method and the ages ranged from 56·8 to 190 Kyr. The problem of chronology of Palaeolithic artifacts is interlinked with the miliolite and other coastal formations. The present investigations permit the development of a chronological framework for the Palaeolithic cultures in the Hiran Valley in particular, and generally in Saurashtra Peninsula. On the basis of radiometric dates and relative chronology, the Lower Palaeolithic cultures fall in a time-bracket of 190-69 Kyr bp. The Middle Palaeolithic industry is much older than 56·8 Kyr bp. The dates obtained for the Lower Palaeolithic cultures are perhaps the oldest reported to date.     

Lichenometric constraints on the age of the Huashan Grottoes, East China

Lichenometry is a method of dating that has been widely used in glaciated areas for determining the minimum age of exposure of a geomorphic landform during the late Holocene. This paper presents a regional calibration data set of lichen thallus sizes versus rock surface ages for the Huashan area, East China, based on measurements of yellow-green Rhizocarpon lichens on the known-age substrates at eight sites. An empirical relationship between thallus sizes and rock surface ages was established using both the traditional regression and the Bayesian approaches. Using the Bayesian calibration, the minimum age of the Huashan Grottoes was dated from 450 ± 60 to 330 ± 60 years ago, corresponding to the late Ming Dynasty (AD 1477–1632). These dates are generally consistent with those predicted from the regression-based linear growth curve. Our results suggest that applications of this technique can be safely extended to the non-glaciated areas.     

ADDITIONAL ARCHAEOMAGNETIC DATA ON THE SOUTH-WEST USA MASTER GEOMAGNETIC POLE CURVE*

Archaeomagnetic dating in the American south-west is progressing rapidly in terms of both method and application. Of particular importance has been the creation of a master curve of geomagnetic direction change for the region. However, confirmation, extension and refinement of this curve are always welcome contributions to the technique. So, efforts are under way to accumulate a large body of well-dated virtual geomagnetic pole positions and document these through publication so that the basis for dating samples of unknown age can be evaluated. This article adds 23 new dated pole positions to the list discussed in Eighmy (1991) and reports the results of our experiments with refining the south-west USA master curve, especially the creation of a new south-west master curve, SWCV595.     

Mummies, maize, and manure: multi-tissue stable isotope analysis of late prehistoric human remains from the Ayacucho Valley, Perú

This paper reports the δ¹³C and δ¹⁵N values of bone collagen, muscle and skin from several late prehistoric–early colonial (AD 1490–1640) mummies from Perú's Ayacucho Valley. The mean of the δ¹³C and δ¹⁵N values of bone collagen are −11.5 ± 1.4 and 11.1 ± 0.7‰, respectively. The mean of the δ¹³C values for Vinchos skin is −11.8 ± 1.2‰ and the mean of δ¹⁵N values is 13.2 ± 0.5‰. The samples of muscle tissue have a δ¹³C mean of −11.9 ± 0.9‰ and a δ¹⁵N mean of 12.7 ± 0.3‰. The data from bone collagen indicate maize was the basis of the region's subsistence economy. A significant correlation between δ¹³C and δ¹⁵N values of bone collagen (R² = 0.75) is consistent with the preferential fertilization of maize with composted manure. Both skin and muscle samples are consistently enriched in δ¹⁵N relative to paired samples of bone (2.1 ± 0.5 and 1.6 ± 0.7‰, respectively), possibly as a result of short term physiological stress or differential decomposition.     

Patterns of Diagenesis in Bone II: Effects of Acetic Acid Treatment and the Removal of Diagenetic CO3

Archaeological bones of varying preservation have been treated with 0·1 M acetic acid in order to investigate the effect on structural and chemical alterations caused by diagenesis. Acetic acid is commonly used as a “cleaning agent” for removing diagenetic carbonate from bone and enamel, in an attempt to recover original, biogenic signals for use in dietary and¹⁴C dating studies.Diagenetic parameters were measured before and after treatment on a range of archaeological bones with good and bad preservation. Histological preservation defined the behaviour of the correlating parameters, where correlation coefficients between carbonate content and crystallinity, microporosity and macroporosity increased significantly after treatment. For histologically well preserved material, acetic acid is effective at returning carbonate content to around that of modern bone. Where bone is extensively damaged by micro-organisms, “loose” diagenetic material can be removed, but a fraction largely composed of hypermineralized bioapatite remains, which, we believe, cannot be reliably used to obtain accurate biological signals.     

Survey of the Outline of an Early Roman Marching-camp in Germany by Rammner's Current Line Pertubation Method

The outline of the first discovered early Roman Marching-camp north of the Limes in Germany (Dorlar, State of Hessen) was determined by electrical resistivity sounding. The camp was inhabited sometime between 11 and 15 and used as base to conquer Dünsberg, a keltic-germanic oppidum. Rammner's Current Line Pertubation Method (CLP) detected soil disturbances caused by ancient Roman construction. The CLP-Method was used to measure the perturbation of a current due to inhomogeneities in the ground. Data processing made it possible to determine the outline of the Roman marching-camp with an accuracy of ±0·15 m. The electrical soundings were confirmed by selected excavations.     

Absolute dating of hominids and palaeolithic artifacts of the cave of La Chaise-de-Vouthon (Charente), France

Two adjacent chambers of the cave of La Chaise, Grotte de Bourgeois-Delaunay (B-D) and Grotte Suard, have been studied. Both were partly filled with detrital sediments containing lower and middle Palaeolithic artifacts and skeletal remains of pre-Neanderthalian hominids. Layers of stalagmitic calcite occur interstratified in the sediments of both chambers. Dates obtained by ²³⁰Th/²³⁴U ratios have provided a time scale for hominid and cultural evolution as represented in this cave.In B-D the lower travertine rests on a breccia containing cranial remains of juvenile Neanderthals. The base of the travertine dates to 151 ± 15 Ky (Ky = 1000 years BP); the top of the travertine yields a date of 112±5 Ky. The travertine contains pollen of an interglacial flora. Overlying detrital sediments 1·2 m in thickness contain artifacts transitional from Acheulian to Mousterian industries. They are capped by a travertine (Layer 7) whose base is dated at 100±6 Ky, and which is capped by stalagmites ranging in age down to 58±7 Ky. Overlying the travertine is sediment containing first Mousterian, and then Aurignacian artifacts.Near the base of the sediments filling Grotte Suard is a stalagmite layer dated to 249±30 Ky. It contains interglacial pollen and presumably dates to the beginning of the isotope stage 7 interglacial. Neanderthaloid hominid teeth and cranial fragments are found scattered through the overlying sediments, up to a capping stalagmitic layer whose base is dated at 101±7 Ky. The best described hominids from Suard are from a section that was probably overlying the capping stalagmite. The capping stalagmite is temporally correlated with layer 7 of B-D.     

ESR Dating of the Last Interglacial Mousterian at Karaïn Cave, Southern Turkey

We have obtained ESR ages on 18 teeth from archaeological levels AH16-AH27 exposed at the east profile in compartment E at Karaïn Cave. This sequence exhibits a transition in lithic assemblage from a Classic Charentian to a Karaïn (Zagros-type) Mousterian between levels AH27 and AH25, and two calcite-cemented soils at levels AH22 and AH16 which have been interpreted as climatic warm phases. Since we found no systematic increase in tooth ages with depth, we assigned this sequence a mean early uptake (EU) age of 108 ± 23 ka and mean linear uptake (LU) age of 121 ± 27 ka, on the basis of 37 subsamples from 16 teeth. In this site, the precision of individual tooth ages suffered little from the problems associated with uranium uptake. However, this advantage was offset due to uncertainties arising from the rather inhomogeneous nature of the enclosing strata which contained various sizes of limestone blocks with intervening sediment. This led to difficulties in ascribing a precise annual gamma radiation dose to individual teeth in such a "lumpy" gamma radiation field. Considerable scattering of the individual tooth ages occurred mainly because the annual gamma dose comprised greater than 50% of the total annual dose to the individual teeth. On the basis of the ESR dating results, we infer that deposition of the two different lithic assemblages and both the penultimate and the final climatic warm phases at Karaïn probably occurred during oxygen isotope stage 5. We also conclude that these lithic assemblages are significantly different than contemporaneous Levantine Mousterian industries which occur about 700 km to the southeast.     

Interpretation of the Thermogravimetric Curves of Ancient Pozzolanic Concretes

Pozzolanic concretes submitted to thermogravimetric (TG) analysis show a continuous weight loss starting from about 400 °C. In order to reconcile these observations with those from other analytical methods, it is necessary to attribute this weight loss to CO₂ removal. It has been proposed, in the literature, that silicates and CaCO₃ react at lower temperatures, producing calcium silicates and CO₂. In this paper, the FTIR spectra collected on samples submitted to TG analysis, stopped at conveniently selected temperatures, provide direct evidence that the continuous weight loss recorded with thermogravimetric analysis of the pozzolanic concrete in the temperature range 400–900 °C is to be attributed to the reaction between the silicates and calcite, with the formation of CO₂ and of a silicate that is richer in CaO. Therefore it is justifiable that the whole weight loss, in the temperature range 400–900 °C, should be taken into account in the calculation of the CaCO₃ content of the concrete. Moreover, the described procedure—of recovering small samples (2 mg) from the sample‐holder of the TG apparatus at various steps of the heating rate and comparing the FTIR spectra—can help in identifying the pozzolanic nature of a concrete that, in general, is not easily recognizable from the trend of the thermoanalytical curve.     

Ancestral Puebloan mtDNA in context of the greater southwest

Ancient DNA (aDNA) was extracted from the human remains of seventy-three individuals from the Tommy and Mine Canyon sites (dated to PI-II and PIII, respectively), located on the B-Square Ranch in the Middle San Juan region of New Mexico. The mitochondrial DNA (mtDNA) haplogroups of 48 (65.7%) of these samples were identified, and their frequency distributions were compared with those of other prehistoric and modern populations from the Greater Southwest and Mexico. The haplogroup frequency distributions for the two sites were statistically significantly different from each other, with the Mine Canyon site exhibiting an unusually high frequency of haplogroup A for a Southwestern population, indicating the possible influence of migration or other evolutionary forces. However, both sites exhibited a relatively high frequency of haplogroup B, typical of Southwestern populations, suggesting continuity in the Southwest, as has been hypothesized by others (8, 9, 29, 45 and 57). The first hypervariable region of twenty-three individuals (31.5%) was also sequenced to confirm haplogroup assignments and compared with other sequences from the region. This comparison further strengthens the argument for population continuity in the Southwest without a detectable influence from Mesoamerica.     

The pre-AD 585 extension of the U.S. Southwest archaeomagnetic reference curve

A set of 104 independently dated archaeomagnetic directions was used to extend the U.S. Southwest reference curve back to 375 cal BC and to calculate isolated mean VGPs centered on 960 cal BC and 2390 cal BC. Prior to this study, most U.S. Southwest reference curves extended to only ca. AD 585. This study employed Sternberg’s moving window technique with variably sized windows, rather than fixed windows, to smooth the dataset into a continuous curve. The size of each averaging window was determined by the density of data captured by the window, such that each window had a minimum data density of 5.0 and a minimum window size of 50 years. This approach differs from previous studies in the U.S. Southwest, which have applied a uniformly sized averaging window to a dataset regardless of the temporal distribution of the data.     

Prehistory of Chihuahua and Sonora,Mexico

The North American Southwest includes much of Mexico as well as the southwestern United States. The area north of the international border has been studied intensively and its culture history is widely known; the portion south of the border has usually been ignored. This essay proposes a new term for the entire culture area, Northern Mexico, and provides a summary of local sequences for two states in the region, Chihuahua and Sonora. The general sequence in the U.S. Southwest (Paleo-Indian, Archaic, and Ceramic periods) also holds in northwest Mexico. Preceramic occupations are poorly known. The Ceramic period saw the rise of a number of local cultures, which varied greatly in adaptation and social complexity. The basic culture pattern of Northern Mexico is derived from that of central Mexico, but direct Mesoamerican intervention in the region was apparently limited. While the issue of Mesoamerican-Northern Mexican relationships has dominated scholarly debate for decades, the greater need is to define and explain cultural variability within and between local sequences.     

NEW ARCHAEOINTENSITY RESULTS FROM GREEK MATERIALS*

This paper reports palaeointensity results from Greek materials from EC and AD periods, recently obtained in the Sofia palaeomagnetic laboratory. The classical Thellier method was applied and of 26 specimens studied 20 gave acceptable results. The paper aims to compare the newly obtained results with previously published ones from Greece and neighbouring territories relating to the same period of time. The trend of palaeointensity obtained for the period 2900–1700 BC coincides well with the Bulgarian intensity variation curve, while the younger period, 1900–1200 BC, needs further investigation because of the contradictory results obtained by different authors. It is also established that the bricks from the church of Agios Ioannis are earlier than the date of the building's construction and are reused.     

Stable carbon and nitrogen isotope variations in tooth dentine serial sections from Wharram Percy

Here we report δ¹³C and δ¹⁵N measurements of serial sections of human deciduous and permanent tooth dentine from archaeological samples taken from the medieval village site of Wharram Percy, Yorkshire, UK. We found a pattern of enrichment, for both δ¹³C and δ¹⁵N, where the tooth crown was greater than the cervical part of the root, which in turn was greater than the apical portion of the root and the associated rib collagen values. This pattern reflects a decrease in the consumption of isotopically enriched breast milk and the introduction of less enriched weaning foods in the diet. The (mean±SD) difference between the deciduous second molar crowns and corresponding rib samples from the same individuals after 2 years of age was 1.2±0.4‰ for δ¹³C and 3.2±0.8‰ for δ¹⁵N. The δ¹⁵N values are as predicted, but as there were no C₄plants at Wharram Percy, this 1.2‰ enrichment in δ¹³C represents clear evidence of a carbon trophic level effect in collagen from breastfeeding infants. Carbon and nitrogen results also show that the infant diet among those who died in infancy did not differ from those who survived into childhood. This study demonstrates the promise of using dentine serial sections to study the temporal relationships of breastfeeding, weaning, and dietary patterns of single individuals.     

Hydrogen isotope systematics of hair: archeological and forensic applications

The hydrogen isotope systematics of hair have been explored and several applications demonstrate the type of information that can be recovered from archeological and forensic hair samples. Experiment with modern hair demonstrate that sources of protein-based hydrogen in keratin are food and water. On the basis of a deuterium-enriched drinking study, it was found that 31% of hydrogen in human hair is derived from ingested water. At least 9% of total hydrogen in human hair is isotopically exchangeable with water or water vapor at 25 °C. Nearly complete exchange occurs in a matter of hours. The δD value of body water is approximately 17±10‰ (n=7) more negative than human hair, although there is much scatter in data for modern hair, which is clearly related to variability of the isotopic composition of ingested food and water. Archeological hair samples were analyzed from (i) a 370 year old Incan mummy sacrificed at 5300 m altitude in Argentina (Geoarchaeology 14 (1999) 27) and (ii) from a Woolly Mammoth from Siberia. High spatial resolution data along the length of hair from the mummy indicate seasonal variations in carbon, nitrogen and hydrogen isotope ratios. No hydrogen isotope anomalies are seen in the youngest hair at the base of the scalp, indicating that the individual probably lived at 1600 m, and spent less than a week at high altitudes before death. The mammoth also preserves a seasonal signal, suggesting hair growth rates of 33 cm/year, faster than human hair, but slower than horse tail hair. The limited isotopic range across seasons for the mammoth is consistent with a north-south migration on the order of 1000 km.     

Extra-territorial interventions in conflict spaces: Explaining the geographies of post-Cold War peacekeeping

The period since the end of the Cold War has presided over a dramatic expansion in the number of multilateral peacekeeping operations (PKOs). Yet individual states have varied significantly in their enthusiasm for peacekeeping and, moreover, demonstrated a greater propensity to participate in operations located in certain countries than others. Our contribution in the present paper is to provide new insights into how geography underpins these spatial variations. Uniquely, we make use of a geographically disaggregated dataset of multilateral PKOs, which allows us to capture various dyadic linkages between sending and receiving countries. Our results confirm previous work indicating that more democratic countries are more likely to participate in PKOs, but extend these findings by showing that countries' commitment to human rights has a similar positive influence. We also show that aspects of spatial proximity (physical distance, same region) and relational proximity (colonial ties) between potential sending and receiving states raise the likelihood of participation. Yet we find that two relational variables widely discussed in the literature as possible correlates of peaceful interactions – bilateral trade and joint membership of intergovernmental organisations (IGOs) – have no statistically discernable influence on countries' involvement in particular PKOs.