Extending the chronology of deposits at Blombos Cave, South Africa, back to 140 ka using optical dating of single and multiple grains of quartz

Optically stimulated luminescence (OSL) measurements are reported for both single aliquots (of two different sizes) and single grains of quartz from deposits within Blombos Cave. Ages have been obtained for six sediments from the Middle Stone Age (MSA) occupation levels and for two sterile sands, one underlying the archaeological sediment and one overlying the Later Stone Age occupation levels. The ages for the archaeological sediments were obtained from single-grain measurements that enabled unrepresentative grains to be rejected. The MSA occupation levels have ages that, within error limits, are in stratigraphic order and fall between the OSL age for the oldest dune sand (143.2+/-5.5 ka) and a previously published OSL age for the sterile sand ( approximately 70 ka) that separates the Middle and Later Stone Age deposits. The earliest MSA archaeological phase, M3, from where fragments of ochre were found as well as human teeth, is dated to 98.9+/-4.5 ka, coinciding with the sea-level high of oxygen isotope substage 5c. The cave then appears to be unoccupied until oxygen isotope substage 5a on the basis of four OSL ages for archaeological phase M2, ranging from 84.6+/-5.8 to 76.8+/-3.1 ka; these levels contained large hearths and bone tools. An age of 72.7+/-3.1 ka was obtained for the final MSA archaeological phase, M1, from which deliberately engraved ochre and shell beads were recovered along with bifacial stone points. We conclude that the periods of occupation were determined by changes in sea level, with abundant sources of seafood available in times of high sea level and with the cave being closed by the accumulation of large dunes during periods of low sea level, such as during oxygen isotope stages 4 and 6.     

An OSL chronology for the sedimentary deposits from Pinnacle Point Cave 13B--a punctuated presence

Optically stimulated luminescence (OSL) measurements are reported for single aliquots and single grains of quartz from sedimentary deposits within Cave 13B at Pinnacle Point, South Africa (PP13B). Ages have been obtained for 30 samples from the Middle Stone Age and from sterile geological deposits at the base and top of the sediment sequence. The ages for all the archaeological units have been obtained from single-grain measurements that enable unrepresentative grains to be rejected after they have been scrutinized for their OSL behavior. The shape of the equivalent dose distribution and the degree of spread in equivalent dose for each sample have also been scrutinized for evidence of depositional and post-depositional effects that can influence the accuracy of the age estimates. This study also used the same systematic approach as that used for the dating of the Howieson's Poort and Still Bay in South Africa. This single-grain approach results in more accurate and precise age estimates that place all ages measured and analyzed in this way on a common timescale. Four periods of human occupation have been dated to ~162ka, ~125ka, ~110ka, and ~99-91ka during Marine Isotope Stage (MIS) 6, 5e, 5d, and 5c, respectively. Occupation of the site appears to have occurred at periods of higher sea level and increased aeolian activity, and the cave was ultimately sealed by the accumulation of a large dune ~90ka ago that infilled the cave, but also blanketed the cliff face above the cave, thus preventing further habitation of the site until ~39ka.     

Optically stimulated luminescence dating of cave deposits at the Xiaogushan prehistoric site, northeastern China

The Xiaogushan cave site is one of the most important prehistoric sites in North China. The stone and bone artifacts found in the cave are similar to European contemporaneous artifacts. Cave deposits consist of five layers that have been dated from 46,353 ± 1179 to 4229 ± 135 cal. yr BP, using radiocarbon dating techniques on charcoal and bone samples collected from Layers 2-5. In this paper, optically stimulated luminescence (OSL) techniques were applied to date six samples taken from Layers 1-3. The luminescence properties of the fine-grained and coarse-grained quartz extracts indicate that the materials are suitable for OSL dating using a single-aliquot regeneration-dose (SAR) protocol. The OSL ages obtained are broadly consistent with the stratigraphy and the associated calibrated radiocarbon ages. The dating results show that the cave was first occupied by humans about 70 ka. The human occupation of the cave may be related to climate change. An occupation hiatus is inferred to between ∼17 to ∼10 ka. The stone and bone artifacts found in Layers 2 and 3 may indicate the Middle to Upper Paleolithic transitions in the region.     

Le site du Ranc-Pointu no 2 à Saint-Martin-d’Ardèche : une occupation du Paléolithique moyen ancien dans le Sud-Est de la France

New investigations conducted in 2008 at Ranc-Pointu No. 2, a small cave located along the Ardèche River, led to the complete revision of the infilling and assemblages, confirming at least one human occupation in this small cave. There may have been two periods of occupation, but only the main one located at the top of the sequence (level ‘c’) has been firmly established. Revision of the large mammal corpus and sedimentological data suggests climatic warming from the base to the top of the sequence. The OSL dating of sub-level ‘c1’ to 145 ka must be discussed in relation to the interdisciplinary results. It suggests that this cave was occupied at the end of MIS 6 and therefore that human populations were present in the Ardèche gorges at the end of the Middle Pleistocene. Ranc-Pointu No. 2 would thus represent older Middle Palaeolithic occupations than in other caves located along the Ardèche River, such as Le Figuier or Saint-Marcel. In the Ardèche French department, only the bottom of the Moula-Guercy sequence and the top of the sequence at the site of Payre, both of which are northern sites, have recorded MIS 6 deposits.     

New ages for Middle and Later Stone Age deposits at Mumba rockshelter, Tanzania: optically stimulated luminescence dating of quartz and feldspar grains

The archaeological deposits at Mumba rockshelter, northern Tanzania, have been excavated for more than 70 years, starting with Margit and Ludwig Köhl-Larsen in the 1930s. The assemblages of Middle Stone Age (MSA) and Later Stone Age (LSA) artefacts collected from this site constitute the type sequences for these cultural phases in East Africa. Despite its archaeological importance, however, the chronology of the site is poorly constrained, despite the application since the 1980s of several dating methods (radiocarbon, uranium-series and amino acid racemisation) to a variety of materials recovered from the deposits. Here, we review these previous chronologies for Mumba and report new ages obtained from optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) measurements on single grains of quartz and multi-grain aliquots of potassium (K) feldspar from the MSA and LSA deposits. Measurements of single grains of quartz allowed the rejection of unrepresentative grains and the application of appropriate statistical models to obtain the most reliable age estimates, while measurements of K-feldspars allowed the chronology to be extended to older deposits. The seven quartz ages and four K-feldspar ages provide improved temporal constraints on the archaeological sequence at Mumba. The deposits associated with the latest Kisele Industry (Bed VI-A) and the earliest Mumba Industry (Bed V) are dated to 63.4 ± 5.7 and 56.9 ± 4.8 ka (thousands of years ago), respectively, thus constraining the time of transition between these two archaeological phases to ∼60 ka. An age of 49.1 ± 4.3 ka has been obtained for the latest deposits associated with the Mumba Industry, which show no evidence for post-depositional mixing and contain ostrich eggshell (OES) beads and abundant microlithics. The Nasera Industry deposits (Bed III) contain large quantities of OES beads and date to 36.8 ± 3.4 ka. We compare the luminescence ages with the previous chronologies for Mumba, and briefly discuss how the revised chronology fits in the context of existing archaeological records and palaeoclimatic reconstructions for East Africa.     

New Luminescence Ages for the Galería Complex Archaeological Site: Resolving Chronological Uncertainties on the Acheulean Record of the Sierra de Atapuerca,Northern Spain

The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.     

La macrofaune du Pléistocène supérieur d’El Harhoura 2 (Témara, Maroc) : données préliminaires

The El Harhoura 2 cave is situated in the commune of El Harhoura in the Temara region (Morocco). The entrance faces west, towards the ocean, around 200 m away from the current shoreline and about 16 m above sea level. The stratigraphy has currently 11 levels numbered from top to bottom. Level 1 is attributed to the early Neolithic. The archaeological material from level 2 places it within the Upper Palaeolithic (Iberomaurusian). Levels 3 to 11 are assigned to the Middle Palaeolithic (Aterian). Since 1977, a surface of 37 m² has been excavated, yielding particularly abundant remains of a large mammal fauna study in this paper.     

Limpet Shells from the Aterian Level 8 of El Harhoura 2 Cave (Témara,Morocco): Preservation State of Crossed-Foliated Layers

The exploitation of mollusks by the first anatomically modern humans is a central question for archaeologists. This paper focuses on level 8 (dated around ∼ 100 ka BP) of El Harhoura 2 Cave, located along the coastline in the Rabat-Témara region (Morocco). The large quantity of Patella sp. shells found in this level highlights questions regarding their origin and preservation. This study presents an estimation of the preservation status of these shells. We focus here on the diagenetic evolution of both the microstructural patterns and organic components of crossed-foliated shell layers, in order to assess the viability of further investigations based on shell layer minor elements, isotopic or biochemical compositions. The results show that the shells seem to be well conserved, with microstructural patterns preserved down to sub-micrometric scales, and that some organic components are still present in situ. But faint taphonomic degradations affecting both mineral and organic components are nonetheless evidenced, such as the disappearance of organic envelopes surrounding crossed-foliated lamellae, combined with a partial recrystallization of the lamellae. Our results provide a solid case-study of the early stages of the diagenetic evolution of crossed-foliated shell layers. Moreover, they highlight the fact that extreme caution must be taken before using fossil shells for palaeoenvironmental or geochronological reconstructions. Without thorough investigation, the alteration patterns illustrated here would easily have gone unnoticed. However, these degradations are liable to bias any proxy based on the elemental, isotopic or biochemical composition of the shells. This study also provides significant data concerning human subsistence behavior: the presence of notches and the good preservation state of limpet shells (no dissolution/recrystallization, no bioerosion and no abrasion/fragmentation aspects) would attest that limpets were gathered alive with tools by Middle Palaeolithic (Aterian) populations in North Africa for consumption.     

Origins of the Iberomaurusian in NW Africa: New AMS radiocarbon dating of the Middle and Later Stone Age deposits at Taforalt Cave,Morocco

Recent genetic studies based on the distribution of mtDNA of haplogroup U6 have led to subtly different theories regarding the arrival of modern human populations in North Africa. One proposes that groups of the proto-U6 lineage spread from the Near East to North Africa around 40–45 ka (thousands of years ago), followed by some degree of regional continuity. Another envisages a westward human migration from the Near East, followed by further demographic expansion at ∼22 ka centred on the Maghreb and associated with a microlithic bladelet culture known as the Iberomaurusian. In evaluating these theories, we report on the results of new work on the Middle (MSA) and Later Stone (LSA) Age deposits at Taforalt Cave in Morocco. We present 54 AMS radiocarbon dates on bone and charcoals from a sequence of late MSA and LSA occupation levels of the cave. Using Bayesian modelling we show that an MSA non-Levallois flake industry was present until ∼24.5 ka Cal BP (calibrated years before present), followed by a gap in occupation and the subsequent appearance of an LSA Iberomaurusian industry from at least 21,160 Cal BP. The new dating offers fresh light on theories of continuity versus replacement of populations as presented by the genetic evidence. We examine the implications of these data for interpreting the first appearance of the LSA in the Maghreb and providing comparisons with other dated early blade and bladelet industries in North Africa.     

Nouvelles données sur la chronologie des sites paléolithiques en contexte lœssique du Nord-Est et du Sud-Est de la Roumanie (Périphérie orientale des Carpates)

In the present study, the chronology of several intraloessic Upper and Middle Palaeolithic sites, located in Moldova, Dobrogea and the eastern Danube Plain, is re-examined and better defined on the basis of new chronological data (IRSL ages on loess, ESR/U-Th ages on teeth) and also biostratigraphic and pedostratigraphic evidence. Middle Palaeolithic occupations have been identified in the MIS 6 loess L2 (interstadial episode), the MIS 7 pedocomplex S2 and the red soils S3 presumably assigned to MIS 9. These results are questioning the chronological extension of the Middle Palaeolithic in Romania which until early 2000 (Păunescu, 1999 a, b; Cârciumaru, 1999) was restricted to the Upper Pleistocene (short chronology: 130–35 ka; MIS 5-MIS 3). Hence, we demonstrate herein that Humans were already present during the Middle Pleistocene at the eastern periphery of the Carpathian Mountains, along the Danube valley and its tributary, the Prut River.     

Luminescence dating of Middle Stone Age deposits at Die Kelders

Luminescence dating of sediments has not been used extensively for dating Middle Stone Age deposits in South Africa, despite its potential for contributing to a poorly dated record. Such deposits at Die Kelders cave, on the southern South African coast, consist of narrow bands of occupation debris separated by thicker layers of aeolian sands containing much less evidence of occupation. Homogeneous, aeolian sediments are usually considered ideal for luminescence dating. Here we report luminescence analyses of five samples from these sands that demonstrate sufficient bleaching prior to burial to validate dating and that yield ages of about 60-70 ka, in agreement with other evidence from sedimentology, archaeology and electron spin resonance. Lack of significant differences in the ages suggests the deposits accumulated fairly rapidly during the early part of the Last Glaciation.     

Ages for hominin occupation in Lushi Basin, middle of South Luo River, central China

A newly discovered Paleolithic site in loess deposits in the Lushi Basin, South Luo River, central China, is dated using pedostratigraphic analysis, optically stimulated luminescence (OSL) and magnetostratigraphic analysis. This region is regarded as an important place for hominin occupation and settlement during the early to middle Pleistocene. Results indicate that the archaeological site dates from 600 ka to 620 ka, reinforcing the view that Homo erectus had occupied a large area of eastern Asia by 620 ka. The lithic assemblages of Lushi Basin is a flake and core technology, typical for this time period in north-central China. It may be compared with that at the Zhoukoudian locality 1 in north China and some sites in the Luonan Basin, and provides important data for understanding the behavior and stone tool technology of early Chinese hominins.     

Middle Palaeolithic and Neolithic Occupations around Mundafan Palaeolake,Saudi Arabia: Implications for Climate Change and Human Dispersals

The Arabian Peninsula is a key region for understanding climate change and human occupation history in a marginal environment. The Mundafan palaeolake is situated in southern Saudi Arabia, in the Rub’ al-Khali (the ‘Empty Quarter’), the world’s largest sand desert. Here we report the first discoveries of Middle Palaeolithic and Neolithic archaeological sites in association with the palaeolake. We associate the human occupations with new geochronological data, and suggest the archaeological sites date to the wet periods of Marine Isotope Stage 5 and the Early Holocene. The archaeological sites indicate that humans repeatedly penetrated the ameliorated environments of the Rub’ al-Khali. The sites probably represent short-term occupations, with the Neolithic sites focused on hunting, as indicated by points and weaponry. Middle Palaeolithic assemblages at Mundafan support a lacustrine adaptive focus in Arabia. Provenancing of obsidian artifacts indicates that Neolithic groups at Mundafan had a wide wandering range, with transport of artifacts from distant sources.     

The environmental context for the origins of modern human diversity: a synthesis of regional variability in African climate 150,000-30,000 years ago

We synthesize African paleoclimate from 150 to 30 ka (thousand years ago) using 85 diverse datasets at a regional scale, testing for coherence with North Atlantic glacial/interglacial phases and northern and southern hemisphere insolation cycles. Two major determinants of circum-African climate variability over this time period are supported by principal components analysis: North Atlantic sea surface temperature (SST) variations and local insolation maxima. North Atlantic SSTs correlated with the variability found in most circum-African SST records, whereas the variability of the majority of terrestrial temperature and precipitation records is explained by local insolation maxima, particularly at times when solar radiation was intense and highly variable (e.g., 150-75 ka). We demonstrate that climates varied with latitude, such that periods of relatively increased aridity or humidity were asynchronous across the northern, eastern, tropical and southern portions of Africa. Comparisons of the archaeological, fossil, or genetic records with generalized patterns of environmental change based solely on northern hemisphere glacial/interglacial cycles are therefore imprecise.We compare our refined climatic framework to a database of 64 radiometrically-dated paleoanthropological sites to test hypotheses of demographic response to climatic change among African hominin populations during the 150-30 ka interval. We argue that at a continental scale, population and climate changes were asynchronous and likely occurred under different regimes of climate forcing, creating alternating opportunities for migration into adjacent regions. Our results suggest little relation between large scale demographic and climate change in southern Africa during this time span, but strongly support the hypothesis of hominin occupation of the Sahara during discrete humid intervals ∼135-115 ka and 105-75 ka. Hominin populations in equatorial and eastern Africa may have been buffered from the extremes of climate change by locally steep altitudinal and rainfall gradients and the complex and variable effects of increased aridity on human habitat suitability in the tropics. Our data are consistent with hominin migrations out of Africa through varying exit points from ∼140-80 ka.     

El Kowm Oasis,human settlement in the Syrian Desert during the Pleistocene

The area of the El Kowm oasis in the centre of today's Syria is a unique showcase of Middle Eastern prehistory not only for its geographic position within the Arabian Desert, but also for the depth of its history. In fact the core area, about a dozen kilometres across, with the numerous natural springs were an important attractor for game and humans, visiting regularly this region since more than 1.8 million years. All over the periods, from the Lower Palaeolithic to the arrival of farmers, definitely arid conditions prevailed, perfectly showing human adaption to this particular environment, as has been clearly demonstrated by several extensive excavations of exceptionally rich Palaeolithic sites. Exceptional preservation conditions due to a particular geological setting in the context of active or dry springs offer an extraordinary resolution of human behaviour within a limited landscape during the complete period of the Pleistocene, illustrating cognitive capacities of early man to cope readily with arid environments, challenge the migration routes proposed by Out of Africa diffusion models, typically considered to be corridors with a superior environmental potential.     

Hommes et climats au Paléolithique supérieur dans le bassin de la Somme (France)

Nearly 40 years of intensive research conducted in the Somme basin has demonstrated the discontinuity in the human occupation of the area during the Upper Palaeolithic. The northern position of the Somme basin within the loessic region appears to be an explanatory factor in this discontinuity, the nature of which increasingly appears related to climate and environmental factors. Archaeological occupations have been systematically attributed to phases of warming or climate improvement. On the other hand, an absence of human occupation has been consistently observed during the coldest periods. The extreme poverty of the biomass contemporary to the loessic deposits of the Upper Pleniglacial could partly explain this discontinuity specific to the far northwest of Europe (southern England, northern Belgium, Netherlands, and northern Germany). Although only 150 or 200 km away, the southern Paris Basin, which is located on the fringes of the loessic region of northern France and Normandy, presents a more continuous human occupation, which appears to have benefitted from more favourable conditions.     

Datations SMA et nouveaux regards sur l’archéo-séquence du Rond-du-Barry (Polignac,Haute-Loire)

A series of 36 radiocarbon AMS ages produced from separate bone fragments has prompted a new appraisal of the archaeological sequence of the Rond-du-Barry Cave (Polignac, Haute-Loire). A huge rock-fall of unknown age underlies Unit H, which contains evidence of the oldest human occupation of the site consisting of a Middle Palaeolithic assemblage dated to between 40 and 33 kyr. The first Upper Palaeolithic occupation of the Cave occurred later. In Unit F, three Badegoulian occupation sectors can be identified that are dated to between 20 and 17.5 kyr. The uppermost units, E and D yielded Middle and Upper Magdalenian dates of between 15.4 and 12.4 kyr. Within Unit E, a tephra related layer (E6) is likely to belong to a distal southern lobe of an eruptive event that was centred in the Chaîne des Puys, 100 km to the north. Unit D shows evidence of being re-worked at least during Mesolithic/Neolithic times, circa 6.5/4.9 kyr. The sum of this new evidence demonstrates the existence of a previously unrecognised stratigraphic and spatial complexity within the Rond-du-Barry archaeological deposits, which demands that new investigations be made in this cave.     

Last Interglacial fossil elephant trackways dated by OSL/AAR in coastal aeolianites,Still Bay,South Africa

The impressive Pleistocene coastal aeolianite exposures in sea cliffs east of Still Bay on the west–southern coast of South Africa host a rich archive of fossil mammalian trackways, including the African elephant (Loxodonta africana). Neither the ichnofossils nor their host sediments have been described in any detail and chronologies remained uncertain. This paper presents a new optically stimulated luminescence (OSL) and amino acid racemisation (AAR) chronology (the first joint application of OSL/AAR dating in South Africa). This provides a temporal framework for assessing the palaeoenvironmental significance of dune sedimentation patterns, pedogenesis and ichnology.The Pleistocene aeolianite exposures at Still Bay represent the recently eroded remnants of a dune cordon, mainly built by coalesced parabolic dune systems. Sedimentary facies are dominated by large-scale planar cross-stratification formed by foreset progradation in the nose and trailing arms of the dunes and low-angle bedding, chiefly representing sedimentation in low relief interdune terrain. The main dune building wind regime was westerly, associated with cyclonic polar frontal systems (as at the present time). The OSL and AAR dating demonstrate ages ranging from MIS 5e to 5b and termination of Pleistocene aeolian sedimentation at ～ 90 ka. The Pleistocene aeolianite is separated from the overlying Holocene dunes (dated to ～ 8 ka), by a major hiatus recorded by a horizon of intense pedogenesis.Elephant footprints were seen in profile, as casts on the underside of beds and as natural impressions. The taphonomic processes controlling the morphology and preservation of these unique ichnofossils were found to be complex. The presence of Loxodonta africana at Still Bay represents the southernmost occurrence of this species recorded to date and possibly, a closer proximity of woodland during MIS 5. This and other observations may indicate a higher moisture regime than at present. There is no available evidence that the elephants were predated by contemporary Middle Stone Age people.     

Végétation et climat au Pléistocène inférieur et moyen à La Pineta (Isernia,Italie)

Palynological investigation from the Lower Palaeolithic site of La Pineta (Isernia, Molise) reports the environmental and climatic conditions of an old human occupation site in Italy, between the end of the Lower Pleistocene and the beginning of the Middle Pleistocene. The pollen record shows that the end of the Lower Pleistocene was marked by an arid episode. This is related to change in the climatic cycles periodicity from 41 to 100 ka, which occurred between 900 and 800 ka. The post-archaeological layers show new favourable moisture conditions at the beginning of the Middle Pleistocene, when the 100 ka cycles prevail. To cite this article: V. Lebreton, C. R. Palevol 1 (2002) 11–17.