DATING OF THE HOMINID (HOMO NEANDERTHALENSIS) REMAINS ACCUMULATION FROM EL SIDRÓN CAVE (PILOÑA,ASTURIAS, NORTH SPAIN): AN EXAMPLE OF A MULTI‐METHODOLOGICAL APPROACH TO THE DATING OF UPPER PLEISTOCENE SITES

The age of Neanderthal remains and associated sediments from El Sidrón cave has been obtained through different dating methods (¹⁴CAMS, U/TH, OSL, ESR and AAR) and samples (charcoal debris, bone, tooth dentine, stalagmitic flowstone, carbonate‐rich sediments, sedimentary quartz grains, tooth enamel and land snail shells). Detrital Th contamination rendered Th/U dating analyses of flowstone unreliable. Recent ¹⁴C contamination produced spurious age‐values from charcoal samples as well as from inadequately pretreated tooth samples. Most consistent ¹⁴C dates are grouped into two series: one between 35 and 40 ka and the other between 48 and 49 ka. Most ESR and AAR samples yielded concordant ages, ranging between 39 and 45 ka; OSL dating results permitted adequate bracketing of the sedimentary layer that contained the human remains. Our results emphasize the value of multi‐dating approaches for the establishment of reliable chronologies of human remains.     

ESR Dating of Micoquian Industry and Neanderthal Remains at K?lna Cave, Czech Republic

Electron spin resonance (ESR) and mass spectrometric U-series dating has been carried out on teeth recovered from K?lna cave during the excavations of 1961–76. Linear and early uptake (LU and EU) age estimates are similar due to low internal U content of the teeth. In general, ESR ages decrease upward in the section, but teeth from stone-rich (“lumpy”) layers give anomalously young ages, due to uneven dose-rate distribution. Elephant molars also give anomalously low ages, apparently due to self-absorption of gamma dose. Disregarding anomalous data, earliest appearance of Micoquian lithics and last occurrence ofDicerorhinus kirchbergensisin layer 9b is dated to 69±8 ka, which places them near the oxygen isotope stage (OIS) 5a/4 boundary. Neanderthal remains and the latest occurrence of Micoquian lithics in level 7a are dated to 50±5 ka, in good agreement with an uncalibrated radiocarbon date for this level of about 45 ka. The interstadial character of the fauna of this level also agrees with its date which places it in OIS 3. We also report that three stadial/interstadial cycles recognized in the lithological, faunal and palynological record of levels 9b through 7a at Kölna occurred during the timespan from about 70 to 50 ka.     

DIRECT GAMMA-RAY SPECTROMETRIC DATING OF FOSSIL BONES: PRELIMINARY RESULTS

A non-destructive gamma-ray spectrometry was used for direct dating of fossil animal and human bones taken from an alluvial Quaternary site in northern Italy. The ages were obtained using the U-Pa method: the chronological results are in agreement with palaeofaunal indicators and taphonomic data. The ages of two samples showed concordance with the U-Th method; in a third case good agreement was also found with the radiocarbon date, thus lending credence to our modified gamma spectrometric method.     

ESR Dating of Tooth Enamel: Comparison with AMSC at El Castillo Cave, Spain

At El Castillo, in Cantabrian Spain, uncalibrated AMS¹⁴C dating has shown the transition from Mousterian to Aurignacian to occur at 39·3±1·6 kaBP. We found ESR tooth enamel ages from the basal Aurignacian level at El Castillo to be 36·2±4·1 ka (early and linear uptake). The enamel and dentine had very low U contents, but ESR ages are strongly dependent upon knowledge of the moisture content history of the sediments. Although the Aurignacian ESR age is 8% younger than the weighted average uncalibrated AMS¹⁴C age of 39·6±1·3 ka obtained from charcoal samples, we have shown that the methods agree within experimental uncertainty. However, since no precise¹⁴C calibration yet exists for this period of time, we are unable to specify which of the ages is more accurate, nor are we able ascribe the apparent age discrepancy to a particular deficiency in the ESR method.     

Uranium-series dating rock art in East Timor

At many sites throughout the world rock art paintings have been covered by naturally deposited calcite laminations, which we demonstrate can be individually dated by recently improved uranium-series methods. Here we report the application of multi-collector inductively coupled plasma mass spectrometry to measure the ages for carbonate coatings that bracket red pigment at Lene Hara cave, East Timor, which could be evidence of human painting. These analyses establish the feasibility of dating milligram samples of finely layered calcite deposits associated with archaeological evidence of human occupation. In addition to confirming an age of less then 6300 years for the visible red paintings on the carbonate surface we also report a substantially older age of 24,000 to 29,300 years for a similar, older red pigment lamination providing possible evidence for an earlier painting episode.     

Radiocarbon and U-series dating of the endemic deer Praemegaceros cazioti (Depéret) from “Grotta Juntu”, Sardinia

Radiocarbon and U-series methods (²³⁰Th/U and ²³¹Pa/²³⁵U) for absolute age determination have been applied to some fossil samples from Grotta Juntu, in North Eastern Sardinia (Italy). The remains belong to the endemic deer species Praemegaceros cazioti, which is here represented by an almost complete skeleton. The three dating methods lead to concordant ages of about 7500 years BP, indicating that the skeleton was maintained as closed system after burial. Taking into consideration these results, Praemegaceros cazioti from Grotta Juntu is now the youngest representative of this species in Sardinia.     

U-series Dating of Fossil Teeth and Carbonates from Snake Cave,Thailand

Snake Cave (Thailand) is an important site for the study of the evolution in Southeast Asia, leading to a discovery of rich and various faunas, including a human tooth. Fossils of large and small mammals converge to indicate, on the basis of faunal assemblage, a late Middle Pleistocene age for the fossiliferous layers; on the other hand, previous U-series dating of carbonates furnished a lower limit for the fossils of about 130 ky.In order to achieve a better comprehension of the chronology of the cave, the Uranium-series method for absolute age determination has been applied to some carbonates older than those studied previously and to fossils themselves.We used the isochron technique approach to yield valuable ages because spleleothem samples consist in a mixture of calcite and detrital contamination. The results obtained suggest that the main fossiliferous level is older than about 160 ky. The application of the U-series method to tooth samples from this tropical cave leads to erroneous ages, probably because of post depositional groundwater movements.     

U-series dating of soda straw stalactites from excavated deposits: method development and application to Blanche Cave, Naracoorte, South Australia

This study aimed to further test the method, reported by St Pierre et al. (2009), to develop robust chronologies of deposits in limestone caves through U/Th (Uranium/Thorium or U-Series) dating of soda straw stalactites. The chronology of fossil bearing deposits at Blanche Cave was further constrained with thermal ionisation mass spectrometry (TIMS) U/Th dating of 17 additional soda straw stalactite samples, and results were compared to recalibrated ¹⁴C ages of charcoal. The results support the assertion that soda straw stalactites can provide ages close to the time of sediment deposition and may be used as reliable chronological markers, particularly for periods reaching or beyond the radiocarbon dating limit. The application of an enhanced cleaning technique facilitated the reduction of detrital Th in samples, significantly increasing age accuracy and precision. Additionally U/Th age accuracy and precision was increased through the application of site-specific measured U/Th ratios to correct for the detrital ²³⁰Th component in samples.     

Uranium and thorium distributions in fossil bones from Olduvai Gorge,Tanzania and Kanam,Kenya

The micro-distributions of uranium and thorium have been studied in fossil bone cortices in samples from Olduvai Gorge, Tanzania and Kanam, Kenya, and compared with modern bones collected from the surface at Olduvai Gorge. Concentrations in excess of 800 ppm U and 200 ppm Th are recorded in sections of some fossil bones, whereas concentrations do not exceed 20 ppm U or 1 ppm Th in the modern bones. In fossil bones, Th has a larger intra-bone variation than U. The distribution profiles of the two elements across the fossil bone cortices are quite distinct and reflect differences in their geochemical behaviour in the supergene environment. In particular, the two possible oxidation states of U, compared with one for Th, allow U to be more mobile than Th, but also more susceptible to variations in the redox potential of the depositional environment. In some fossil bone samples secondary leaching of U has occurred, whereas Th is retained in the bone cortex. U is incorporated into fossil bone earlier than Th.     

Verification of the age of the Palaeolithic cave art at Creswell Crags,UK

Engravings representing Britain's first apparently Pleistocene cave art were discovered in Church Hole and Robin Hood caves, Creswell Crags. Representations of a deer, highly stylised females or birds and vulvae were engraved into the bedrock, and in some cases had been covered with a thin layer of flowstone. In the absence of radiocarbon datable pigments, uranium-series disequilibrium dating was undertaken on these flowstones to provide minimum ages for the engravings. Here we show that the oldest motif was carved earlier than 12,800 years ago which is consistent with radiocarbon dates for the Late Upper Palaeolithic archaeology at Creswell Crags. Thus we demonstrate the authenticity of the engravings and show them to be the oldest known examples in Britain.     

THE PETRALONA HOMINID SITE: URANIUM-SERIES RE-ANALYSIS OF ‘LAYER 10’CALCITE AND ASSSOCIATED PALAEOMAGNETIC ANALYSES

Separate sublayers of the ‘layer 10’calcite from the Mausoleum of Petralona Cave, Greece, have been re-analysed by Uranium-series and palaeomagnetic methods. The results confirm earlier findings that the whole of layer 10 represents a long time span, from about 160 ka to more than 350 ka, the latter being the dating limit of the U-series method using alpha-spectrometry. The minimum age refers to the upper brown sublayer that is now believed to correspond directly to the brown calcite that cemented the hominid skull to the adjacent cave wall; there was too little of the skull calcite to date directly by alpha-spectrometry. The age shifts caused by making corrections for the amount of detritus in the sublayer are effectively insensitive to assumed initial values of the amount of common ²³⁰Th present. Consequently, the minimum age estimate for the skull is about 160 ka, in approximate agreement with several earlier estimates. Palaeomagnetic analyses of ‘layer 10’and underlying sedimentary layers showed that the magnetization is unstable and cannot be used as a basis for age control in the Mausoleum.     

Preliminary U-series and Thermoluminescence dating of excavated deposits in Liang Bua sub-chamber,Flores, Indonesia

We report the results of a test excavation of deposits in a limestone cave sub-chamber located beneath the main chamber of Liang Bua, Flores, Indonesia; the discovery site of the small hominin species, Homo floresiensis. Well-preserved remains of extinct Pleistocene fauna and stone artefacts have previously been identified on the surface of a sediment cone within the sub-chamber. Our excavation of the deposits, at the base of the sediment cone in the sub-chamber (to 130 cm depth) yielded only a few fragmentary bones of extant fauna. Uranium/Thorium (U-series or U/Th) dating of soda straw stalactites excavated from 20 to 130 cm in depth demonstrates that the excavated sediments were deposited during the Holocene. Red Thermoluminescence (TL) dating of the sediments at the base of the excavation (130 cm depth) indicates these sediments were last exposed to sunlight at 84 ± 15 ka (thousand years), similar to red TL ages of cave sediments from the main chamber. Together, these results indicate that the surface faunal remains, which are morphologically analogous to Pleistocene finds from the main chamber excavations, were transported to the sub-chamber relatively recently from the main chamber of Liang Bua and probably originated from conglomerate deposits at the rear of the cave and from deposits around the front entrance. There is no evidence for hominin occupation of the sub-chamber, instead it seems to have acted as a sink for cultural materials and fossil remains transported from the surface via sinkholes. Despite the small number of finds from the test excavation, it is possible that more extensive excavations may yield additional transported cultural and faunal evidence at greater depths.     

A NEW DIRECT RADIOCARBON AMS DATE FOR AN UPPER PALAEOLITHIC HUMAN BONE FROM SIBERIA

A new AMS radiocarbon date has been obtained from a Siberian human bone sample taken directly from a cranial fragment. The specimen comes from the north‐east Siberian site of Pokrovka 2 (55⁰19′46.30″N, 92⁰26′48.80″E). The remains consist of the anterior portion of the cranium or the superior part of the face; that is, the forehead and the roof of the eye sockets. Sadly, indifferent features of the frontal bone do not allow a confident diagnosis of the sex of the individual. The evidence suggests, however, that the remains are probably those of a young adult (teenager) and an anatomically modern human, rather than a Neanderthal. Radiocarbon dating was undertaken at the Oxford Radiocarbon Accelerator Unit (ORAU). The radiocarbon age determination of the bone fragment, 27 740 ± 150 bp (OxA‐19850), is one of the earliest direct dates for a modern human from Siberia. The Pokrovka cranial fragment dates to the middle Upper Palaeolithic of Eurasia and is broadly contemporary with the human remains from the famous eastern European site of Sunghir. When the radiocarbon age is compared with the Cariaco Basin ¹⁴C data set and the Greenland oxygen isotope record of NGRIP, it corresponds with Greenland Interstadial 5, a warmer phase of the Last Glacial period, although this is a preliminary conclusion, and is based on climate records that may or may not be wholly synchronous between the two locations.     

URANIUM-SERIES DATING OF BONES AND TEETH FROM CHINESE PALAEOLITHIC SITES

The reliability of uranium-series dating of fossil bones and teeth is studied. On this basis the first absolute chronology for about 20 important Chinese palaeolithic sites is proposed. A two-stage model for open-system samples is discussed.     

Paleodemographic analysis of a fossil porcupine (Hystrix refossa Gervais, 1852) population from the Upper Pleistocene site of Geula Cave (Mount Carmel,Israel)

For decades zooarchaeological studies mainly focused on teeth age profiles to derive central hypotheses concerning human subsistence during the Pleistocene. Behavior was often related to hunting and/or scavenging strategies according to two models: attritional versus catastrophic. However, few studies have estimated basic demographic parameters using standard methods of population ecology, which are necessary for a more confident interpretation of animal paleopopulation structures. Thanks to a remarkably rich fossil bone assemblage from the Upper Pleistocene cave of Geula (Mount Carmel, Israel), in this paper we perform a paleodemographic analysis of Hystrix refossa, Gervais 1852 (Mammalia, Rodentia). We first consider phylogenetic and morphometric dental criteria for the comparison of Pleistocene porcupine species, followed by an examination of taphonomic conditions of the bone assemblage. We focus strongly on the age structure of the fossil population, presenting a new methodological approach that combines life tables and Leslie matrix models – one of the best-known methods in population ecology for assessing population growth and age distribution. We detail demographic parameters derived from cross-sectional life tables and past trends in the porcupine population at Geula Cave using simple matrix projection model. Finally, we were able to perform an elasticity analysis to identify which demographic component was potentially the most critical for influencing growth. We show that the population of H. refossa did not decline or shrink but was stable. Our results permit us to characterize Geula Cave as a natural shelter for porcupines, with limited evidence to scavenging and hunting by either hyenas or humans.     

AN ATTEMPT AT DATING THE SWANSCOMBE SKULL BONES USING NON-DESTRUCTIVE GAMMA-RAY COUNTING

A low-background germanium spectrometer was used to measure the gamma-ray spectra of the three parts of the Swanscombe skull. Detailed studies of the method showed that it was possible to make accurate measurements of the content of ²²⁶ Ra and ²³¹ Pa but less accurate ones of ²³⁸U and ²³⁵U. Results from the three samples were inconsistent, showing that their exposure to radioactive ground water must have been very different, although they were found close together. The uncertainty in the ratio of ²³⁴U to ²³⁸U in the ground water and the lack of knowledge of the time at which the bones acquired the uranium also prevented the deduction of any reliable dates for these specimens.     

A juvenile human frontal bone from the French Upper Palaeolithic site of Lacave: significance and problems of interpretation

In 1902, a portion of a juvenile human frontal bone was excavated by Armand Viré from the cave of Lacave in the Dordogne valley of southwestern France. The specimen is clearly from an Upper Palaeolithic context, although problems in interpreting the stratigraphy and postdepositional history in the cave render it essentially impossible to determine whether it is from a Magdalenian or Solutrean context. The morphology of the specimen is modern, as would be expected considering its relatively late Upper Palaeolithic context. Examination of aspects of brow ridge and frontal sinus development, as well as metopic suture obliteration, allows estimation of a developmental age of approximately 7–8 years for the specimen. Sex is indeterminate, and there is no pathology present. Apart from serving as an example of the problems of interpreting fragmentary skeletal remains from early 20th century excavations, the Lacave frontal represents one of the relatively few subadult cranial specimens known from the European Upper Palaeolithic. As such it is a valuable addition to the fossil record of early modern humans from Europe. Copyright © 1999 John Wiley & Sons, Ltd.     

Probable human hair found in a fossil hyaena coprolite from Gladysvale cave,South Africa

Until now, the oldest known human hair was from a 9000-year-old South American mummy. Here we report fossil hairs of probable human origin that exceed that age by about 200,000 years. The hairs have been discovered in a brown hyaena (Parahyaena brunnea) coprolite from Gladysvale cave in South Africa. The coprolite is part of a hyaena latrine preserved in calcified cave sediment dated between 195,000 and 257,000 years ago. This find supports the hypothesis that hyaenas accumulated some of the early hominin remains found in cave sites, and provides a new source of information on Pleistocene mammals in the Sterkfontein Valley.     

The significance of the fossil hominid skull from Petralona,Greece

Evidence is accumulating that the hominid cranium found in the Petralona cave in 1960 is associated with cave deposits of middle Pleistocene age. If this is so, the fossil is the most complete middle Pleistocene cranium yet discovered and provides important morphological, metrical and radiographic information on the possible evolutionary transition from Homo erectus to Homo sapiens. The classification of the specimen is discussed and it is suggested that a grade system within Homo spaiens should be erected. The Petralona fossil would be allocated to Homo sapiens grade 1 rather than to Homo erectus or to a subspecies of Homo sapiens.     

Assessing bone transformation in late Miocene and Plio‐Pleistocene deposits of Kenya and South Africa

Bone reactivity offers a potential way to record local physical–chemical conditions prevailing in fossilization environments and archaeological sites. In the present study, a series of fossil bone samples from the karstic environments of the Bolt's Farm cave system (Cradle of Humankind, South Africa) and from fluvio‐lacustrine environments of the Tugen Hills (Gregory Rift, Kenya) is analysed. The chemical composition and infrared and nuclear magnetic resonance (NMR) spectroscopic properties of fossil samples point to a transformation of the biogenic apatite and formation of secondary apatite. Depending on the sample, the secondary apatite corresponds to a carbonate‐bearing hydroxy‐ or fluor‐apatite. The maximum fraction of secondary apatite is close to 60%, coinciding with previous observations in experimental alteration of bone in aqueous solutions and suggesting that a fraction of pristine biological apatite is likely to be preserved. The present results also suggest that the acetic acid treatment of fossil samples moderately increases their average crystallinity but may dissolve carbonate‐rich domains of secondary apatite.