marine derived 14c calibration and activity record for the past 50 000 years updated from the cariaco basin abstract an expanded cariaco basin 14c chronology is tied to 230th dated hulu cave speleothem records in order to provide detailed marine based 14c calibration for the past 50 000 years the revised high resolution cariaco 14c calibration record agrees well with data from 230th dated fossil corals back to 33 ka with continued agreement despite increased scatter back to 50 ka suggesting that the record provides accurate calibration back to the limits of radiocarbon dating the calibration data document highly elevated 14c during the glacial period carbon cycle box model simulations show that the majority of observed 14c change can be explained by increased 14c production however from 45 to 15 ka 14c remains anomalously high indicating that the distribution of radiocarbon between surface and deep ocean reservoirs was different than it is today additional observations of the magnitude spatial extent and timing of deep ocean 14c shifts are critical for a complete understanding of observed glacial 14c variability

determining the burial time of single grains of quartz using optically stimulated luminescence abstract in the optical dating of sediments it is usually assumed that the optically stimulated luminescence osl signal has been completely reset by light exposure prior to burial this assumption is often not valid one approach to testing and perhaps circumventing this assumption is to examine the apparent date of last exposure to daylight of individual sediment grains this paper reports on the application for the first time of 2 new measurement protocols to the estimation of the radiation dose received during burial for individual quartz grains from an aeolian deposit of known age 10 000 year old which is considered likely to have been completely reset by sunlight at deposition additive dose laboratory doses added to the burial dose before osl measurement and regenerative dose doses added after measurement of osl from burial dose single aliquot protocols are applied to 28 and 25 individual grains respectively each grain provides an independent estimate d e of the burial dose the average d e from the additive dose protocol 21 8 1 1 gy is in good agreement with the average from the regenerative dose protocol 23 8 1 0 gy both agree well with 1 13 multiple grain regenerative dose single aliquot measurements each on 1 mg sub samples of 23 9 0 3 gy 2 9 multiple grain additive dose single aliquot measurements also on 1 mg sub samples of 22 4 0 7 gy and 3 one previously published multiple aliquot additive dose estimate of 23 5 0 6 gy using 52 sub samples each of 5 mg the resulting optical ages are in good accord with 14 c and thermoluminescence age determinations the distribution of equivalent doses in the single grains is however unexpectedly large 23 of mean d e given the very likely complete resetting of the osl signal at deposition possible reasons are discussed and it is concluded that heterogeneity in beta dosimetry is the most likely explanation the single grain optical dating protocols reported here allow a detailed examination of the dose distribution in very small samples thus they should enable accurate dates to be obtained for sediments and soils that contain poorly bleached or mixed age components as well as deposits in which quartz grains are present in extremely low abundance

a rise in the carbonate compensation depth of western tethys in the carnian late triassic deep water evidence for the carnian pluvial event the upper triassic of the lagonegro basin southern apennines southern italy is represented by hemipelagic cherty limestones of the calcari con selce formation deposited in an oceanic setting two stratigraphic sections petina chiana and pignola 2 representative of the evolution of the lagonegro basin during the carnian have been studied in detail with a multidisciplinary approach in the pignola 2 section within the calcari con selce formation a unique interval composed of green shales and radiolarites has been identified the absence of carbonate deposition within this interval is interpreted as evidence of a contemporaneous shallowing of the carbonate compensation depth conodont and palynomorph biostratigraphy constrain the age of this interval to the julian tuvalian lower carnian upper carnian boundary the age and characteristics of this interval suggest correlation with a putative climatic event known as the carnian pluvial event which has also been recognized in continental and shallow marine successions from different european localities this event is thus now documented also in a deep marine setting like the continental and shallow water settings it is characterized by a sudden input of siliciclastics petina chiana and pignola 2 integrate current knowledge of the carnian distribution of conodonts paragondolella praelindae kozur to date known only from the lower tuvalian has now been documented from the uppermost julian moreover a drastic turnover was recorded between julian and tuvalian conodont assemblages which is clearly associated with the carnian pluvial event thus a biotic crisis oceanographic changes associated with the rise of the carbonate compensation depth increased rainfall and an anomalous siliciclastic input occur contemporaneously at the time of the carnian pluvial event a similar pattern is associated with perturbations of the carbon cycle that occur during the jurassic and cretaceous e g in the early aptian thus it is hypothesized that the carnian pluvial event may have analogous causes

optical dating of deep sea sediments using single grains of quartz a comparison with radiocarbon abstract in this paper we demonstrate that optical dating of single grains of quartz offers an alternative means of dating deep sea sediments the precision and accuracy of the technique which has the potential to date sediments deposited during the last 500 000 years or so is limited by the random and systematic uncertainties associated with producing optical ages these result in total relative age uncertainties of between 10 and 20 at the 68 confidence interval which are similar in size to those associated with late quaternary oxygen isotope chronologies we analysed single grains of quartz from several depth intervals down core fr10 95 gc17 which was collected offshore from cape range peninsula western australia from a water depth of 1093 m in the eastern indian ocean the single grain optical ages are shown to be consistent with ams radiocarbon ages obtained from planktonic foraminifera from the same core we also show that marine sediments are not immune from partial or heterogeneous bleaching incomplete resetting of the optical dating signal where partial or heterogeneous bleaching of the optical dating signal is indicated we recommend that single grain dating be employed and the burial dose estimated from the population of grains with the lowest absorbed radiation dose

late quaternary mega lakes fed by the northern and southern river systems of central australia varying moisture sources and increased continental aridity optically stimulated and thermoluminescence ages from relict shorelines along with accelerator mass spectrometer 14c ages from freshwater molluscs reveal a record of variable moisture sources supplied by northern and southern river systems to lake mega frome in southern central australia during the late quaternary additional lacustrine palynological and terrestrial proxies are used to reconstruct a record that extends back to 105 ka confirming that lakes mega frome and mega eyre were joined to create the largest system of palaeolakes on the australian continent as recently as 50 47 ka the palaeohydrological record indicates a progressive shift to more arid conditions with marked drying after 45 ka subsequently lake mega frome has filled independently at 33 31 ka and at the termination of the last glacial maximum to volumes some 40 times those of today further sequentially declining filling episodes to volumes 25 10 those of today occurred immediately prior to the younger dryas stadial in the mid holocene and during the medieval climatic anomaly southern hemisphere summer insolation maxima are a poor predictor of palaeolake filling episodes an examination of multiple active moisture sources suggests that palaeolake phases were driven independently of insolation and at times by some combination of enhanced southern ocean circulation and strengthened tropical moisture sources

middle upper triassic carbonate platforms in minorca balearic islands implications for western tethys correlations abstract in order to progress in the knowledge of the middle to upper triassic evolution of the western tethys realm an integrated approach which includes new sedimentological sequence stratigraphic and biostratigraphic data has been accomplished in the carbonate marine successions muschelkalk facies of that age in minorca balearic islands spain the new biostratigraphy which includes six successive ammonoid biozones allowed to assign these carbonate successions to the uppermost anisian lower carnian interval the integration of the new chronostratigraphic framework with the sedimentological analysis allowed to recognize five main successive stages of carbonate platform evolution 1 initial marine transgression and shallow ramp development uppermost anisian 2 carbonate ramp drowning anisian ladinian boundary 3 prevalence of open sea conditions ladinian early carnian 4 abrupt sea level drop intra lower carnian and 5 shallow carbonate ramp and transition to sabkha systems keuper facies furthermore the sequence stratigraphic analysis allowed to divide some of these stages into depositional sequences minorca was located in the westernmost tethys area during the triassic in a key paleogeographic location close to the present day iberia sardinia and the cottian and southern alps the new data have allowed an interregional comparative analysis among these areas with recognition of major suprarregional events and episodes in the framework of the western tethys evolution

a late middle stone age artifact assemblage from sibudu kwazulu natal comparisons with the european middle paleolithic abstract it has been suggested that many behavioral innovations said to appear during the late middle stone age in sub saharan africa facilitated the expansion of anatomically modern humans from africa and the near east into europe at about 50 kyr the process eventually led to the replacement of neanderthals by modern humans and the emergence of the upper paleolithic however assemblages in this time range are little known in south africa in fact the transition from middle to the later stone age in southern africa is controversial the early appearance in south africa of many innovations such as sophisticated knapping techniques e g the use of soft hammer or indirect percussion in blade production of composite tools of microlithic and bladelet technologies remains to be established through technological analysis we present here the first results of a project designed to carry out detailed technological studies of several lithic assemblages in south africa and france dated to the transition period at this time we have completed the study of a post howiesons poort assemblage from the rock shelter site of sibudu the 2 m deep stratigraphic sequence of sibudu extends from howiesons poort at its base to final middle stone age directly under iron age layers we have analyzed in detail layer rsp ca 53 kyr 1 m above the howiesons poort levels which has provided a large assemblage of several thousand stone artifacts compared to published msa assemblages this industry is unusual for the very high proportions of retouched pieces 15 the technology is not very elaborate and there is no strong standardization of the end products there are no flakes of predetermined shapes retouch is used to modify irregular flakes to obtain desired edges knapping of flakes and blades is done by hard hammer soft hammer is used only for retouching tools interestingly the older howiesons poort blades were produced on the same raw materials by soft hammer raw material hornfels and dolerite was procured from distances of less than 20 km unifacial points are the dominant type and there is strong evidence of hafting and use as spear armatures detailed comparisons with middle paleolithic assemblages of western europe show that the late middle stone age technology in south africa is very similar to that of the middle paleolithic in fact we see no fundamental differences between the two entities as far as lithic technology is concerned implications for the out of africa hypothesis are discussed

afromontane foragers of the late pleistocene site formation chronology and occupational pulsing at melikane rockshelter lesotho this paper provides a preliminary chronostratigraphic and palaeoenvironmental framework for the late pleistocene archaeological sequence at melikane rockshelter in mountainous eastern lesotho renewed excavations at melikane form part of a larger project investigating marginal landscape use by late pleistocene foragers in southern africa geoarchaeological work undertaken at the site supports in eld observations that melikane experienced regular often intensive input of groundwater via ssures in the shelter s rear wall this strong hydrogeological connection resulted in episodic disturbances of the sedimentary sequence exacerbated by other processes such as bioturbation despite this taphonomic complexity a robust chronology for melikane has been developed based on tightly cross correlated accelerator mass spectrometry ams 14 c with acid base wet oxidation stepped combustion abox sc pretreatment and single grain optically stimulated luminescence osl dating the results show that human occupation of melikane was strongly pulsed with episodes of late pleistocene occupation at w80 w60 w50 w46e38 and w24 ka at least three additional occupational pulses occurred in the holocene at w9 ka w3 ka and in the second millennium ad but these are dealt with only brie y in this paper implications of the late pleistocene pulsing for the colonisation of high elevations by early modern humans in africa ahead of dispersals into challenging landscapes beyond the continent are discussed

ash deposits in hayonim and kebara caves israel macroscopic microscopic and mineralogical observations and their archaeological implications abstract a study of the hearths and ash layers preserved in hayonim and kebara caves israel showed that they are composed of one or several different minerals these include the polymorph of caco3 calcite a variety of phosphate minerals and a suite of siliceous minerals the major component of the latter are siliceous aggregates that are present in wood detailed studies of the mineral associations in these fossil ash layers as well as in fresh wood ash using optical and scanning electron microscopy in the back scattered electron mode together with elemental analyses showed that ash in these caves undergoes a series of diagenetic changes the best preserved ash layers resemble fresh ash and are composed mainly of calcite with minor amounts of siliceous minerals the calcite reacts with phosphate rich solutions to form carbonated apatite and with time the latter dissolves and a variety of other phosphate containing minerals form with each diagenetic change some of the more soluble minerals are lost and ultimately only the ash derived siliceous minerals remain in both caves there are local accumulations of such siliceous minerals that are metres thick in fact ash derived minerals in general are major components of the sediments in both kebara and hayonim caves their diagenesis involves a hugh reduction in volume which in turn may have important effects on the geological structures and stratigraphy of the sediments the changing mineralogy of the sediments due to diagenesis complicates the use of present day estimates of radiation content of the sediments for correcting age estimates by thermoluminescence and electron spin resonance finally the presence of the relatively stable ash derived siliceous minerals in a sedimentary layer in other caves could be a useful means of identifying the presence of ash in other archaeological sites where macroscopic hearth features are absent

miocene pliocene tectonic evolution of the slovenian periadriatic fault implications for alpine carpathian extrusion models the periadriatic line pal is a remarkable several hundred kilometer long fault system of the alpine orogen its dextral character was documented by several authors using diverse criteria but detailed kinematics and timing of movements had not been investigated along its whole length structural and paleomagnetic measurements mapping and stratigraphic and sedimentological studies have helped to unravel the miocene pliocene evolution of the slovenian segment of the pal brittle deformation was characterized by nw se to n s compression and perpendicular tension deformation has resulted in dextral strike slip faulting folding and tilting of beds the first transpressional event corresponds to the first phase of lateral extrusion of the east alpine western carpathian northern pannonian block in the early miocene 24 17 5 ma after a short period of transtension during the karpatian 17 5 16 5 ma dextral transpression reoccurred during the middle miocene to pliocene and lasted up to the quaternary middle miocene dextral slip can be connected to the second phase of extrusion the highly deformed rocks within the dextral shear zones show variable clockwise sometimes counterclockwise rotations the mechanism of rotation seems to be complex ranging from regional rotation to local folding due to pure or simple shear domino type rotation

going underground experimental carbonization of fruiting structures under hearths we show that carbonized fruits and seeds recovered from middle stone age deposits in rock shelters are likely to have been carbonized as part of post depositional processes we buried indigenous south african fruits nuts and seeds at pre determined depths and distances from the centers of experimental fires the cold ashes of the hearths and the sand surrounding them were subsequently excavated using standard archaeological techniques and dry screening the fruiting structures from the oxidizing part of the fire were burnt to ashes whereas those buried in sand under anoxic conditions survived in varying forms those buried 5 cm below the center of the fire were carbonized those buried 10 cm below the center of the fire were dehydrated and those 5 cm and 10 cm below the surface at the outer edge of the fire were unaffected size moisture or oil content of the original fruit or seed did not appear to influence whether or not carbonization took place temperatures recorded 5 cm below the experimental fires suggest that the carbonization occurred at or before a maximum temperature of 328 c and also at lower maximum temperatures 152 c that were maintained for long periods even when the quantities of a particular wood are controlled open fires may produce variable underground temperatures and the temperatures below ancient hearths would have been equally variable we suggest that cyperaceae sedge nutlets the most numerous fruiting structures in the sibudu middle stone age archaeobotanical assemblage occur in the shelter as a result of human activity subsequent burial and accidental carbonization when hearths were built directly above the buried nutlets

new ages for the post howiesons poort late and final middle stone age at sibudu south africa abstract optically stimulated luminescence osl measurements are reported for single grains of quartz from deposits within sibudu rock shelter such measurements enable rejection of unrepresentative grains and application of the finite mixture and central age models to obtain the most reliable age estimates three types of single grain equivalent dose de distributions were observed one sample represented a single dose population three samples indicated mixing between iron age ia and middle stone age msa deposits and 10 samples in addition to the three mixed samples showed scattered distributions the latter type resulted from differences in the beta dose received by individual grains for these samples the beta doses were modelled and adjusted accordingly ages for the 14 samples collected from msa deposits post dating the howiesons poort hp resulted in three age clusters which are stratigraphically consistent with the three informally named cultural phases at sibudu namely the post hp late msa and final msa weighted mean ages of 58 5 1 4 ka 47 7 1 4 ka and 38 6 1 9 ka were calculated for these phases respectively the three phases were separated by two occupational hiatuses with durations of 10 8 1 3 ka and 9 1 3 6 ka we hypothesise that the punctuated presence of humans at sibudu was determined by large scale fluctuations in climate during oxygen isotope stage ois 3 which resulted in alternating wet and dry periods phases of occupation correspond to wet periods when fresh water was available in the tongati river whereas intervals of site abandonment correspond to dry periods when people were forced to migrate in search of a reliable source of fresh water where people migrated to remains unresolved

osl dating of the aterian levels at dar es soltan i rabat morocco and implications for the dispersal of modern homo sapiens the aterian is a distinctive middle palaeolithic industry which is very widely spread across north africa its dating and significance have been debated for nearly a century renewed interest in the aterian has arisen because of a recent proposal that its development and spread may be linked to the dispersal of anatomically modern humans the industry contains technological innovations such as thin bifacially flaked lithic points and pedunculates as well as evidence for personal ornaments and use of red ochre such markers as shell beads are believed to be indicative of symbolic behaviour dar es soltan i on the atlantic coast of morocco contains a thick sequence of aterian deposits that were thought to represent the later stages of development of this industry new optically stimulated luminescence dates and geomorphological study indicate a much older sequence and so far the earliest yet recorded ages for the aterian they suggest an appearance in the maghreb region during mis marine isotope stage 5

late quaternary hillslope evolution recorded in eastern south african colluvial badlands abstract infrared stimulated luminescence irsl ages have been obtained from a sequence of sandy colluvial deposits in northern kwazulu natal comparison of the irsl ages on sand sized potassium rich feldspars with radiocarbon dates on a horizon organic matter from buried palaeosols within the colluvial succession shows good agreement between the dating techniques when compared with palaeoenvironmental records the data suggest that the colluvium accumulated during arid stages of the late quaternary whilst pedogenesis repeatedly occurred at intervals of hillslope stability which may reflect periods of greater humidity temperature does not seem to have been a forcing factor in the landscape development extensive colluviation took place during the arid last glacial maximum but the occurrence of several palaeosols indicates that it was a time of fluctuating climatic conditions

equivalent dose distributions from single grains of quartz at sibudu south africa context causes and consequences for optical dating of archaeological deposits abstract optical ages for 14 sediment samples collected from the post howiesons poort late middle stone age msa and final msa deposits at sibudu kwazulu natal south africa were reported in a companion paper jacobs z wintle a g duller g a t roberts r g wadley l new ages for the post howiesons poort late and final middle stone age at sibudu south africa journal of archaeological science 2008 these ages were based on equivalent dose d e distributions that were overdispersed in this paper we investigate factors both internal and external to the grains that may contribute to such higher than expected overdispersion in single grain d e values intrinsic factors accounted for some but not all of the observed scatter and application of a set of rejection criteria filtered grains for which erroneous d e values would otherwise be calculated we investigated sediment mixing and differences in the beta dose received by individual grains in their burial environment as two likely reasons for the observed overdispersion the scatter in d e distributions for all the samples is best explained by grains that were deposited at the same time and which were well bleached but that subsequently received a range of beta doses a procedure is presented for adjusting the measured beta dose rate and its associated error we show that using a combination of single grain osl measurements of d e the finite mixture model and adjustment of the beta dose rate result in stratigraphically consistent ages these ages are more consistent than the ages obtained from multiple grain aliquot d e values and the average dose rates for each sample the multiple grain ages are about 10 older partly because of the variable dose rate and partly because these aliquots contained grains with undesirable osl characteristics

triassic climates state of the art and perspectives abstract the climate of the triassic period was characterized by a non zonal pattern dictated by a strong global monsoon system with effects that are most evident in the tethys realm this strong monsoonal regime is related to the aggregation of the pangaean supercontinent which by triassic time was already completed climate oscillations existed within this framework the harsh hot house climatic conditions that characterized the late permian and perhaps precipitated the end permian mass extinction were probably maintained during the early triassic and may account for the impoverished but distinctive faunal and floral lower triassic associations although metazoan reef builders were probably the most affected group carbonate production remained high at least in the western tethys realm the middle triassic was characterized locally by humid episodes although their geographical distribution has yet to be clarified the carnian pluvial event marks an episode of increased rainfall documented worldwide was the most distinctive climate change within the triassic different hypotheses have been proposed for its causes changes of atmospheric or ocean circulation driven by plate tectonics a peak of the global monsoon due to maximum continent aggregation or triggering by the eruption of a large igneous province subsequently the late carnian and norian seem to have been climatically stable although minor climatic changes have recently been described even from this time period finally the end triassic extinction event is also associated with climate change specifically warming and increased rainfall but this evidence comes mostly from the northern parts of the central atlantic magmatic province and the global pattern of climate change at the triassic jurassic boundary has still to be resolved many facets of triassic climate are intriguing and deserve further research however palaeoclimate studies on the triassic have so far been carried out only locally with different proxies those proxies will require inter calibration in order to depict correctly the temporal and geographical patterns of triassic climate

new paleontological evidence of the carnian strata in the mežica area karavanke mts slovenia conodont data for the carnian pluvial event abstract the carnian carbonate succession in the me ica area called raibl beds karavanke mts slovenia on the north of the periadriatic line in the eastern alps includes three clastic horizons of marly shaly rocks the most interesting is the second clastic horizon that contains unique layers or lenses of micritic limestone although many samples were collected for conodonts only one single sample yielded well preserved carnian julian specimens the monospecific conodont fauna is marked by elements of nicoraella budaensis that enables us to reconstruct a multielemental apparatus the sporomorph associations of the first and the second clastic horizons are well correlated to the humid sub phases in the raibl beds the recovered conodont fauna verifies the julian age of the second clastic horizon in the me ica area and it provides new significant information for definition of the carnian pluvial event in the karavanke mts

the carbonate clastic cycles of the east alpine raibl group result of third order sea level fluctuations in the carnian abstract the carnian raibl group of the eastern alps consists of three 50 100 m thick alternating carbonate and clastic third order cycles each of which can be traced for hundreds of kilometers tectono eustatic sea level fluctuations of a few tens of metres spanning a few millions of years are the driving mechanism of this cyclicity the carbonate intervals represent restricted marginal marine tidal and evaporitic environments the clastic intervals represent inner and outer shelf facies and are related to the fluviatile schilfsandstein of the germanic facies belt in the raibl group contrary to other carbonate clastic depositional settings relative sea level lowstands are dominated by carbonate production and highstands are dominated by clastic deposition each of the three raibl cycles corresponds to a type 2 sequence containing shelf margin transgressive and highstand systems tracts during sea level lowstands deltaic point sources were near the shelf margin allowing clastics to bypass the carbonate platform this setting corresponds to a shelf margin systems tract transgressive and highstand systems tracts developed during the subsequent sea level rise as deltaic clastics were reworked and redistributed over the carbonate platform and the deltas retrograded to the inner shelf the highstand systems tracts are capped by a type 2 sequence boundary which is conformable in the study area the systems tracts can be further subdivided into shallowing upward subcycles caused by fourth order sea level fluctuations believed to represent milankovitch rhythms the middle raibl cycle is consistently thinner and may represent a shorter termed third order sea level fluctuation our data also corroborate a second order transgressive trend for the carnian

late quaternary sea level change in south africa abstract a late quaternary sea level curve for south africa is presented on the basis of new and published data from a range of sea level indicators and a variety of locations available evidence suggests that sea level in south africa broadly follows that described from the caribbean but that deviations occur during sea level highstands during the last interglaciation oxygen isotope stage 5 and the late holocene coastal emergence produced higher sea levels in south africa than those identified in the caribbean during the same time intervals this is tentatively ascribed to predicted lithospheric deformation in continental margin settings

radiocarbon dating from 40 to 60 ka bp at border cave south africa abstract we present 21 radiocarbon dates on 19 charcoal samples from the sedimentary sequence preserved in border cave south africa the background radiocarbon activity for charcoal from the cave was determined to be 0 050 0 018 percent modern carbon from the analysis of a radiocarbon dead sample from unit 5wa radiocarbon ages for individual samples ranged from 25 2 to 58 2 ka bp the error weighted mean ages for successively older strata are 38 5 0 85 0 95 ka bp for unit 1wa 50 2 1 1 1 0 ka bp for units 2bs lr a and 2bs lr b 56 5 2 7 2 0 ka bp for unit 2bs lr c and 59 2 3 4 2 4 ka bp for unit 2wa this radiocarbon chronology is consistent with independent chronologies derived from electron spin resonance and amino acid racemization dating the results therefore provide further evidence that radiocarbon dating of charcoal by the abox sc technique can yield reliable radiocarbon ages beyond 40 ka bp they also imply that border cave 5 a modern human mandible predates 58 2 ka bp and that the middle stone age mode 3 later stone age mode 5 transition of border cave was largely effected between 56 5 and 41 6 ka ago

orbital forcing of climate over south africa a 200 000 year rainfall record from the pretoria saltpan late pleistocene variations in rainfall in subtropical southern african are estimated from sediments preserved in the pretoria saltpan a 200000 year old closed basin crater lake on the interior plateau of south africa we show that south african summer rainfall covaried with changes in southern hemisphere summer insolation resulting from orbital precession as predicted by orbital precession geometry berger 1978 this south african record is out of phase with north african palaeomonsoon indices street and grove 1979 rossignol strick 1983 mcintyre et al 1989 the amplitude of the rainfall response to insolation forcing agrees with climate model estimates prell and kutzbach 1987 these results document the importance of direct orbital insolation forcing on both subtropical north and south african climate as well as the predicted antiphase sensitivity to precessional insolation forcing

multiple negative carbon isotope excursions during the carnian pluvial episode late triassic abstract the carnian pluvial episode was a phase of global climatic change and biotic turnover that occurred during the early late triassic in marine sedimentary basins the arrival of huge amounts of siliciclastic sediments the establishment of anoxic conditions and a sudden change of the carbonate factory on platforms marked the carnian pluvial episode the sedimentary changes are closely associated with abrupt biological turnover among marine and terrestrial groups as for example an extinction among ammonoids and conodonts in the ocean and a turnover of the vertebrate fauna and the flora on land multiple negative carbon isotope excursions were recorded during the carnian pluvial episode in both organic matter and marine carbonates suggesting repeated injection of 13c depleted co2 into the ocean atmosphere system but their temporal and causal links with the sedimentological and palaeontological changes are poorly understood we here review the existing carbon isotope records and present new data on the carbon isotope composition of organic carbon in selected sections of the western tethys realm that record the entire carnian pluvial episode new ammonoid conodont and sporomorph biostratigraphic data were collected and coupled to an extensive review of the existing biostratigraphy to constrain the age of the sampled sections the results provide biostratigraphically constrained composite organic carbon isotope curves for the carnian which sheds light on the temporal and causal links between the main carbon isotope perturbations and the distinct environmental and biotic changes that mark the carnian pluvial episode the carbon isotope records suggest that a series of carbon cycle perturbations possibly recording multiple phases of volcanic activity during the emplacement of the wrangellia large igneous province disrupted carnian environments and ecosystems repeatedly over a remarkably long time interval of about 1 million years

luminescence dating in less than ideal conditions case studies from klasies river main site and duinefontein south africa abstract luminescence dating results are reported for two south african archaeological sites where changes in the dose rate through time are apparent a subtraction procedure involving analysis of both quartz and potassium feldspar extracts is applied to detect and correct for these changes at the middle stone age site of klasies river the dose rate changes inferred from geologic evidence for shell dissolution turn out not to be significant having occurred rapidly after deposition the dates here range from 50 115 ka in broad agreement with other evidence the important howiesons poort component here appears to date somewhat later about 55 60 ka than at several other sites in south africa at the acheulian site of duinefontein the dose rate changes also thought to be caused by shell dissolution are on the other hand very significant the subtraction ages here 125 300 ka agree with independent chronological assessments

a segment is not a monolith evidence from the howiesons poort of sibudu south africa segments from the howiesons poort of sibudu south africa can be separated into at least three populations based on quartz hornfels and dolerite rocks used for their production length breadth thickness and tip cross sectional areas are significantly different between segments made on the three rock types segments are not monoliths and they were not intended as a single tool type they were flexible enough to be mounted to shafts in a variety of ways several hafting strategies are evident including the use of different adhesive recipes most segments were probably parts of hunting weapons based on use trace analysis but weapon types varied quartz segments have standardized shapes short and deep perhaps because they were hafted as transverse arrowheads while hornfels and dolerite segments may on occasion also have been parts of projectiles the large dolerite segments could sometimes have served as parts of spearheads with two segments hafted back to back howiesons poort segment technology is sophisticated its makers appreciated distinct properties of rocks their flaking wear and impact possibilities further they recognized the best sizes and shapes for use with each kind of weapon they understood the qualities and applications of various adhesive recipes and they knew how to make a variety of hafts from materials that included bone and wood

luminescence ages for three middle palaeolithic sites in the nihewan basin northern china and their archaeological and palaeoenvironmental implications the nihewan basin is a key region for studying the palaeolithic archaeology of east asia however because of the lack of suitable dating methods and representative lithic technologies in this region the middle palaeolithic sites in this basin have been designated based mainly on stratigraphic correlation which may be unreliable in this study three palaeolithic sites motianling queergou and banjingzi which have been assigned previously to the middle palaeolithic are dated based on luminescence dating of k feldspar grains our results show that the cultural layers at motianling queergou and banjingzi have ages of 315 13 268 13 and 86 4 ka corresponding to marine isotope stages 9 8 and 5 respectively suggesting that motianling and queergou should be assigned to the lower palaeolithic while the age of banjingzi is consistent with a middle palaeolithic attribution our results suggest that reassessing the age of middle palaeolithic sites in the nihewan basin and elsewhere in north china is crucial for understanding the presence or absence of the middle palaeolithic phase in china our dating results also indicate that the sanggan river developed sometime between about 270 and 86 ka ago

optical dating of holocene sediments from a variety of geomorphic settings using single grains of quartz this paper presents an improved method for the optical dating of holocene sediments from a variety of geomorphic settings we have measured the equivalent dose de in individual grains of quartz using green laser light for optical stimulation and have simulated the de distributions for multiple grain synthetic aliquots using the single grain data for 12 samples of known independent age we show that application of a minimum age model to the single grain and small 10 grain aliquot de data provides the most accurate estimate of the burial dose for nine of the samples examined 3 aeolian 5 fluvial and 1 marine the weighted mean de as obtained using the central age model gives rise to burial age overestimates of up to a factor of 10 for these nine samples whether single grains small aliquots or large 100 grain aliquots are used for the other three samples two aeolian and one fluvial application of either the minimum age model or the central age model to the single grain small aliquot and large aliquot de data yields burial ages in accord with the independent age control we infer that these three samples were well bleached at the time of deposition these results show that heterogeneous bleaching of the optical dating signal is commonplace in nature and that aeolian transport offers no guarantee that the sample will be well bleached at the time of deposition we also show that grains sensitive to infrared ir stimulation can give rise to low de values which will result in significant underestimation of the burial dose and hence of the age of deposition we demonstrate that use of a modified single aliquot regenerative dose protocol incorporating ir stimulation prior to green light stimulation deals effectively with contamination by ir sensitive grains we conclude that application of the modified protocol to single grains or small aliquots of quartz using the lowest de population to estimate the burial dose is the best means of obtaining reliable ages for holocene sediments from a wide range of depositional environments d 2003 elsevier b v all rights reserved

the carnian humid episode of the late triassic a review from 1989 to 1994 a series of papers outlined evidence for a brief episode of climate change from arid to humid and then back to arid during the carnian stage of the late triassic epoch this time of climate change was compared to marine and terrestrial biotic changes mainly extinction and then radiation of flora and fauna subsequently termed albeit incorrectly the carnian pluvial event cpe by successive authors interest in this episode of climatic change has increased steadily with new evidence being published as well as several challenges to the theory the exact nature of this humid episode whether reflecting widespread precipitation or more local effects as well as its ultimate cause remains equivocal bed by bed sampling of the carnian in the southern alps dolomites shows the episode began with a negative carbon isotope excursion that lasted for only part of one ammonoid zone a austriacum however that the carnian humid episode represents a significantly longer period both environmentally and biotically is irrefutable the evidence is strongest in the european middle eastern himalayan north american and japanese successions but not always so clear in south america antarctica and australia the eruption of the wrangellia large igneous province and global warming causing increased evaporation in the tethyan and panthalassic oceans are suggested as causes for the humid episode

criteria for identifying bone modification by termites in the fossil record three geographically dispersed middle and later stone age cave sites in south africa and a middle stone age cave site in ethiopia share a similar taphonomic signature that includes destruction of bones associated with variable forms of star shaped features clusters of microscopically visible sub parallel striations edge gnawing pits and etching of the bone surface similar traces preserved on plio pleistocene fauna are interpreted by different authors as the possible work of termites or ants considering that ambiguity exists in the interpretation of these traces and that there are no modern examples available for comparison we set out to create a reference collection of bones modified by southern african termites here we present the results of an actualistic experiment conducted with the harvester termite trinervitermes trinervoides sjostedt isoptera termitidae in the sterkfontein valley south africa results show that within six months all bones were approximately half covered with a dark surface residue had an etched surface appearance and recorded boreholes and destruction particularly of less dense elements and epiphyses star shaped marks edge gnawing and clusters of sub parallel striations on the periosteal surface were faint after six months but became clearly visible and more plentiful after 12 months a finding attributed to the termites being more active in austral autumn and spring this result demonstrates the pertinence of insect modification studies to our understanding of regional palaeoenvironment palaeoecology and palaeoclimate this experiment has demonstrated that t trinervoides can destroy bone in all stages of preservation favouring fresh thin cortical and spongy bone with meat and marrow the presence of appreciable quantities of calcium carbonate in termite mounds suggests that termites may be drawn to dolomitic cave sites and the calcium rich bones they contain to satisfy their mineral requirements they therefore have the potential to bias taxonomic and element representation minimum number of individuals and age profiles in a faunal assemblage and may account in part for the patchy preservation of faunal remains including hominins in fossil deposits and or the lack of bone artefacts at some middle stone age cave sites preserving long sequences of occupation

an experimental micromorphological investigation of bedding construction in the middle stone age of sibudu south africa abstract we conducted experiments to compare the micromorphological signatures of modern burnt sedge and grass bedding to laminated layers of carbonized material and phytoliths in middle stone age deposits at the shelter sibudu the experiments were designed to clarify the formation processes associated with the laminated layers and to investigate whether these previously identified layers of bedding were deliberately burned or not the results indicate that the laminated layers were most likely produced by human activity related to the construction maintenance and burning of bedding furthermore our experiments demonstrate that large volumes of vegetal material could have produced the relatively thin archaeological deposits of burnt bedding

gondolelloid multielement conodont apparatus nicoraella from the middle triassic of yunnan province southwestern china abstract the morphology and position of elements in the apparatus are keys to resolving the taxonomy homology evolutionary relationships structure function and feeding patterns among conodont taxa fused clusters preserving natural associations between elements provide direct information on element morphology the positions of elements within the apparatus and even their original three dimensional arrangement here we report 41 fused conodont clusters from member ii of the guanling formation in luoping county yunnan province southwestern china which provide a basis for inferring the multielement composition of the apparatus of the early middle triassic nicoraella the apparatus is composed of 15 elements a single s0 element two pairs of s1 4 m and p1 2 elements like other apparatuses in gondolellidae i e the genera novispathodus and neogondolella these luoping biota clusters are significant because a they permit a positional homology based comparison of multielement novispathodus with form genera such as cypridodella s1 enantiognathus s2 and hindeodella s3 and s4 b they facilitate a review of apparatus composition within superfamily gondolelloidea c they provide direct insight into apparatus architecture currently interpreted largely in light of distantly related carboniferous polygnathacean ozarkodinins and d these clusters along with collections of discrete conodont elements provide a model for inferring the multielement composition of closely related species known only from discrete element collections

quantification of climate and vegetation from southern african middle stone age sites an application using late pleistocene plant material from sibudu south africa abstract in southern africa numerous middle stone age msa sites document important steps in technological and behavioural development leading to significant changes in the lifeways of modern humans to assess whether these cultural changes and developments may be related to environmental changes we need to ascertain past environments to do this we apply a new quantitative method the gis based coexistence approach cagis on fossil plant material from the msa site sibudu kwazulu natal south africa previous qualitative environmental interpretations of the fossil fauna and flora of the site remain ambiguous because much of the material is anthropogenically introduced it is difficult to distinguish between the effects of natural changes in the local vegetation and behavioural changes of the people that inhabited the shelter cagis can be applied to such biased assemblages and seems to be an adequate method to directly quantify palaeoclimate and vegetation parameters at an archaeological site the cagis analysis shows that during the howiesons poort hp industry winters were slightly colder and drier than present whereas during summer temperatures and precipitation were similar to today post hp winters were drier and colder than present presumably colder than during the hp summer temperatures remained the same but summer precipitation decreased from the hp to post hp vegetation cover was less than today may be even less than during the hp the late msa was observably warmer than the older periods especially during winter at the same time summer precipitation slightly increased and vegetation became more dense but still remained generally open similar to today s anthropogenic landscape generally climatic changes are most pronouncedly reflected in winter temperature parameters especially in minimum winter temperatures and to a lesser extent by changes in summer precipitation the observed ecological trends seem to be affected mainly by variations through time in winter temperatures this refinement of interpretation was not discernible using previous methods for analysing the sibudu data

integrated stratigraphy and palaeoclimate history of the carnian pluvial event in the boreal realm new data from the upper triassic kapp toscana group in central spitsbergen norway the late triassic climate is characterized by arid conditions interrupted by a humid phase known as the carnian pluvial event cpe this wet phase is well documented in the tethyan realm but evidence from the boreal realm is scarce here we present evidence from quantitative palynology for the cpe from the kapp toscana group on central spitsbergen integrated with organic carbon isotope data linked to the geomagnetic polarity time scale our data reveal an early to mid julian 1 age for the tschermakfjellet formation the transition to the julian 2 is located in the de geerdalen formation and the isfjorden member is confirmed as mostly tuvalian 3 in age the aulisporites astigmosus pollen assemblage zone that marks the base of the cpe in the tethys realm at the base of the julian 2 is assigned to the julian 1 in the boreal region palaeoclimate proxy data inferred from principal component analysis indicate wetter conditions from the julian 2 onwards which is in agreement with the establishment of local swamp vegetation on top of a delta plain the palaeotemperature curve indicates a period of cooler climate during the early julian 1 followed by warming during the late julian 1 supplementary materials a list of all identified morphotaxa of pollen spores and aquatic palynomorphs is available at http www geolsoc org uk sup18879

reconstructing the history of sediment deposition in caves a case study from wonderwerk cave south africa we applied cosmogenic isotope burial dating magnetostratigraphy and grain size distribution analysis to elucidate the history of the sedimentary sequence composed of fine quartz sands and silts of wonderwerk cave located on the southern edge of the kalahari desert south africa the source for the quartz sand is the kalahari sand dunes presently located 100 km to the north of the cave field observations and grain size analysis suggest a sediment transport scenario that includes eolian transport of kalahari sand abraded to a size of 70 100 m to the kuruman hills temporary storage on the hill slopes and valleys surrounding wonderwerk cave and later transport and deposition inside the cave our results suggest simple burial ages for sediments from both the front and back of the cave that range between 2 63 0 17 ma and 1 56 0 10 ma following initial exposure of 310 620 k y however 26 al 10 be ratios of 3 98 0 24 and 4 08 0 22 measured in a sand sample collected from the surface outside the cave may imply an initial burial signal equivalent to 0 78 0 15 ma thus reducing the possible age range of the buried samples to between 1 85 0 23 and 0 78 0 18 ma the paleomagnetic results for the front of the cave gave a polarity sequence of n r n n where n indicates normal polarity and r indicates reverse polarity this sequence can be correlated with both the older and younger cosmogenic burial age ranges the correlation suggests that in the cave front cosmogenic burial ages and the acquisition of stable remanent magnetization were not significantly affected by chemical and physical processes and that postburial production of cosmogenic isotopes was insignificant in contrast at the back of the cave the paleomagnetic polarity sequence of r n cannot be correlated with the cosmogenic burial ages since the temporal gap between the initial penetration of the sediment into the cave and the final acquisition of a stable remanent magnetization may have been long 10 5 yr and the single polarity transition can be correlated to any reverse normal transition that occurred during the quaternary this highlights the need for caution when cosmogenic burial ages and paleomagnetic sequences are compared the buried sediments in wonderwerk cave show similar grain size distributions to the fine sand sediment presently exposed at the surface in the vicinity of the cave furthermore calculated preburial 10 be concentrations for the buried sediment are similar to those measured in sediment outside the cave these similarities suggest that the environmental conditions and rates of geomorphic processes that persisted during sand deposition in wonderwerk cave during the late pliocene and early pleistocene may have been similar to those currently experienced in the southern kalahari the kuruman hills and the western ghaap plain these conditions favor the transport of fine grained quartz sand to the vicinity of the cave

termination of carbonate slope progradation an example from the carnian of the dolomites northern italy abstract the demise of carbonate platforms during carnian time is a widespread phenomenon of the western tethys but the controlling factors are not well understood the dolomites of the southern alps northern italy are well known for their large scale ladinian and carnian prograding carbonate platforms platform growth stopped during the early carnian and both platforms and basinal areas were subsequently covered by mixed carbonate siliciclastic sediments raibl group we present a carbonate platform whose slope progradation came to a halt prior to draping by the siliciclastic sediments judging from the height of the clinoforms a platform to basin relief of at least 100 m existed during the final stage of progradation this paleo slope was colonized by coral patches draped by skeletal packstones to microbial bindstones forming typically lens shaped mounds on the steep slope the formation of mounds on the platform flank was only possible because the downslope transport of detritus from the platform and or upper slope was stopped the sedimentary evolution in the adjacent basin indicates a poorly oxygenated environment with abundant brackish water ostracods of low diversity based on the inherited platform to basin relief and the lithofacies of the basin fill a local sea level drop in the order of 60 80 m is postulated with rising sea level the accommodation space between former basin and platform became filled by shallow marine mixed carbonate siliciclastic sediments the abundance of epibenthic suspension feeders of the basin fill such as megalodonts suggests increased nutrient supply the termination of slope progradation was a multiphased process triggered by a stagnation of the regional subsidence a reduction of water circulation followed by a sea level drop the influx of freshwater and the input of siliciclastics fluctuating salinity caused intermittently a biotically stressed environment

single grain osl dating at la grotte des contrebandiers smugglers cave morocco improved age constraints for the middle paleolithic levels abstract optically stimulated luminescence osl measurements of individual quartz grains are reported for middle paleolithic mp or middle stone age msa deposits in la grotte des contrebandiers morocco single grain measurements enable rejection of grains that may lead to under or over estimation of age due to malign luminescence properties or remobilisation of grains after burial we identified the former using a range of experimental procedures and objective rejection criteria three post depositional factors influenced the distribution pattern of equivalent dose d e values for the remaining single grains the disintegration of roof spall liberating unbleached older grains into otherwise well bleached sediments the intrusion of a small number of younger grains from the overlying upper paleolithic deposits and small scale differences in the beta dose received by individual grains roof spall contamination was a significant problem so we characterised the osl signals and obtained d e values for the calcareous sandstone in which the cave is formed which allowed bedrock derived grains in the mp msa deposits to be identified and rejected prior to age determination we collected 31 samples from the mp msa deposits and were able to calculate ages for 30 of them these ages suggest that mp msa occupation of contrebandiers was restricted to the interval between about 120 and 90 ka ago marine isotope stages 5d to 5b weighted mean osl ages were obtained for samples associated with archaeologically sterile deposits at the base of the excavations 126 9 ka followed by two phases of the moroccan mousterian 122 5 and 115 3 ka interspersed with archaeologically sterile deposits 112 4 ka the base and top of the aterian were dated to 107 4 and 96 4 ka respectively based on the grand weighted mean ages of 116 3 and 103 3 ka for the moroccan mousterian and aterian at contrebandiers we suggest that these two industries may be separated by an occupation hiatus of up to 13 3 ka at this site our single grain osl chronology confirms previous age estimates obtained for contrebandiers and other sites in the vicinity but are generally more precise and stratigraphically more coherent due to the inherent advantages of measuring individual quartz grains and rejecting contaminant and other unsuitable grains before age determination

synchroneity of climatic change and extinctions in the late triassic although the late triassic was a time of widespread aridity evidence exists for a significant increase in rainfall during the middle to late carnian upper triassic playa lake sediments were interrupted by late carnian fluviatile sandstones with erosive bases and high kao linite illite ratios there was also an increase in the clastic component of marine sequences during this interval middle and upper carnian marine carbonates show an extreme depletion in 13 c values consistent with increased fresh water influx large scale karstic phenomena in limestone areas subaerially exposed during the late triassic are a further indication of increased rainfall important faunal and floral changes occurred during the carnian norian interval marine invertebrate turnover was greatest at the lower middle carnian boundary and terrestrial extinctions were concentrated at the carnian norian boundary the cause of this carnian pluvial episode may have been related to the rifting of pangea through disruption of atmospheric and oceanic circulation patterns eustatic changes or the effects of volcanism associated with rifting a change in surface ocean temperature salinity or ph or habitat loss may have caused the decline of many shallow marine invertebrates at the start of the middle carnian a return to arid conditions at the carnian norian boundary would account for the turnover among terrestrial vertebrates and plants

high resolution absolute dated indian monsoon record between 53 and 36 ka from xiaobailong cave southwestern china the oxygen isotopic record of stalagmite xbl 1 from southwestern china reveals millennial scale variability of the indian monsoon between 53 and 36 ka synchronous with changes in the east asian monsoon recorded at hulu cave and similar to dansgaard oeschger cycles recorded in greenland ice our record in general confirms the chronology of hulu cave if our correlations between greenland and the xiaobailong cave record are correct both the greenland ice sheet project 2 and greenland ice core project ss09sea chronologies are accurate within quoted errors a dry interval that we correlate with heinrich event 5 h5 and the greenland stadial preceding greenland interstadial 12 gis 12 is centered ca 48 0 ka and a shift to drier conditions correlated to the end of gis 12 is ca 43 5 ka overall the variability of the indian monsoon from xbl 1 data on millennial scales is similar to and correlated with high latitude ice core rec ords from the northern hemisphere however some indian monsoon characteristics more closely resemble but are anticorrelated with features in the antarctic record suggesting some link to climate of the high southern latitudes in addition to the clear link to the climate of the high northern latitudes

earliest modern humans in southern africa dated by isoleucine epimerization in ostrich eggshell the oldest anatomically modern human remains are beyond the range of radiocarbon dating and associated deposits lack material suitable for most other dating methods consequently age estimates for early human skeletal material and correlative stratigraphic horizons in southern africa are frequently based on paleoclimatic correlations to the deep sea record and extrapolated sedimentation rates both of which incorporate a number of untested assumptions here we focus on one substage of the middle stone age of southern africa the howiesons poort industry a distinctive culture stratigraphic marker in sequences south of the zambezi anatomically modern human skeletal material has been found associated with or even older than the howiesons poort layer in stratified deposits at border cave and klasies river main site we have dated or bracketed the howiesons poort horizon at border cave boomplaas cave and apollo 11 cave three stratified cave sites in southern africa based on the extent of isoleucine epimerization in associated ostrich eggshells we conclude that the howiesons poort lithic industry is bracketed by limiting dates of 56 and 80 ka and is most likely centered on 66 5 ka anatomically modern human remains in deeper levels are more than 100 ka old lending support to the hypothesis of an african origin for homo sapiens

technical considerations and methodology for creating high resolution color corrected and georectified photomosaics of stratigraphic sections at archaeological sites abstract using a conventional off the shelf digital single lens reflex camera and flashes we were able to create high resolution panoramas of stratigraphic profiles ranging from a single meter to over 5 m in both height and width at the middle stone age site of pp5 6 at pinnacle point mossel bay south africa the final photomosaics are isoluminant rectilinear and have a pixel spatial resolution of 1 mm furthermore we systematically color corrected the raw imagery this process standardized the colors seen across the photomosaics while also creating reproducible and meaningful colors for relative colorimetric analysis between photomosiacs here we provide a detailed discussion about the creation and application of our photomosaics in the first part of the paper we examine the specific characteristics of modern digital single lens reflex dslr cameras and lenses that were important to us in developing our methodology we also provide a detailed discussion about how to reproduce the methodology in the field and to post process the imagery in the final section of the paper we give several examples to show how we apply our photomosaics within an empirical 3d gis database these examples are provided to show how photographic data can be integrated with other digitally captured data and used to study the relationships between the stratigraphic features seen in the photomosaics and the 3d distribution of excavated archaeological piece plots geochronological samples and other kinds of geological samples

optical dating in archaeology thirty years in retrospect and grand challenges for the future in 1982 when richard klein first became one of the editors of this journal the luminescence dating community was embarking on a new phase of exploratory research attention was turning from the use of thermoluminescence tl dating to estimate the time of last heating of archaeological objects such as pottery and burnt flint to the tl dating of unheated sediments that had been transported by wind and then deposited on the landscape this revolutionary development enabled the extension of tl dating to sedimentary deposits in a variety of environmental settings and to the multitude of archaeological sites that lack suitably heated artefacts in sediment dating the age of most interest is usually the time elapsed since grains of quartz or feldspar were last exposed to sunlight as the energy of the sun s rays is sufficient to evict electrons from their light sensitive traps these traps are steadily refilled after sediment deposition and the longer the grains remain buried the more tl they will emit when measured in 1985 huntley and colleagues proposed optical dating as a simpler and superior means of stimulating the light sensitive traps in quaternary sediments and this is now the principal luminescence based method of dating geological and archaeological deposits optical dating is an umbrella term for an armada of acronyms the most common in archaeological contexts being osl optically stimulated luminescence tt osl thermally transferred osl irsl infrared stimulated luminescence and pirir post infrared irsl all of these variants are founded on the same basic tenet measurement of a light sensitive signal to determine typically the last time that sediment grains were sun bleached but each approach has its virtues and vices in this paper we review this family of luminescence dating techniques and look back on 30 years of optical dating in archaeology some of the more interesting and important achievements are highlighted including the critical insights gained in the last two decades from osl measurements of individual grains of quartz we also look to the future of optical dating in archaeological contexts efforts to extend the age limits of optical dating to older hominin and archaeological sites will remain a key goal and understanding how archaeological sites of all ages form and evolve over time could be improved greatly by combining micromorphology analysis with optical dating of undisturbed intact sediments the latter poses a series of particularly formidable technical challenges but if the past is any guide to the future then we can expect optical dating to illuminate much more of human history before celebrating its golden jubilee

testing of a single grain osl chronology across the middle to upper palaeolithic transition at les cottes france abstract the timing of the middle palaeolithic to upper palaeolithic transition in france is important to help understand when where and how neanderthals have been replaced by homo sapiens radiocarbon dating has been the dating workhorse in constructing the chronological framework pertinent to these questions in this study we are testing whether single grain osl dating has the accuracy and precision to be useful as a complementary dating method the site of les cottes provides an ideal testing ground because of its stratigraphic integrity and reliable radiocarbon chronology we applied single grain osl dating of quartz to 19 samples and multi aliquot met pirir dating of potassium rich feldspar grains to 5 samples to explicitly test assumptions of pre depositional resetting of the osl signal and post depositional exposure to variable beta dose rates the good agreement between the single grain osl and the multi aliquot met pirir ages suggest that the optical signals of both quartz and feldspar grains were reset prior to deposition and that much of the extra scatter observed in the equivalent dose distribution of quartz grains are likely due to the small scale differences in beta dose delivered to individual grains both the quartz osl and feldspar met pirir ages show great consistency with the 14 c ages on bone collected from the same units this gives confidence in the measurement and analytical approaches used to derive both the equivalent dose and dose rate the numerator and denominator respectively of the luminescence age equation these results suggest that a systematic and detailed single grain osl dating study can have the accuracy and precision that is necessary to play a powerful role in the dating of the middle and upper palaeolithic transition and other questions of importance in this time range and geographical area

putslaagte 1 pl1 the doring river and the later middle stone age in southern africa s winter rainfall zone abstract existing data suggest weak human occupation of southern africa s winter rainfall zone wrz during later marine isotope stage mis 3 the causes of which are unknown here we report briefly on the results of recent surveys of alluvial terrace sites of the doring river in the wrz which document occupation over a broad expanse of the later middle stone age msa and pleistocene later stone age we then report on test excavations at one terrace site denoted putslaagte site 1 pl1 describe in detail the assemblage of flaked stone artefacts produced from that excavation and present two osl ages obtained from 0 8 m to 1 5 m below surface the results suggest that a artefact accumulations at pl1 are dense b the technological systems documented are characteristically msa but differ in form from the range of systems known from other excavated sites in the region and c that the assemblages accumulated in mis 3 taken together with the survey data the results introduce new variation into the later msa in southern africa and imply reorganisation of land use in the wrz in late mis 3 rather than abandonment we suggest that a research emphasis on rock shelter deposits may have produced misleading depictions of regional occupation

biogeography and evolution of body size in marine plankton body size is a central feature of any organism reflecting its physiology ecology and evolutionary history marine microplankton are major contributors to the particulate inorganic carbonate foraminifers and coccolithophorids and opal flux radiolaria and diatoms in the ocean and hence size changes in these organisms can influence global biogeochemical cycles this paper is discussing abiotic influences on micro and macroecological size changes among major marine plankton groups linking these to evolutionary size changes during the neogene we review the patterns and outline the causes of size changes geographically and through time in coccolithophorids foraminifers and radiolarians the main feature of the neogene size record is a dramatic size increase in foraminifers a similarly dramatic reduction in the size range of coccolithophorids and highly variable size patterns in radiolarians we argue that the observed pattern is too complex to be explained by a simple common forcing and propose that speculations on the response of oceanic biomineralisation to global warming have to consider the scales at which marine plankton evolve

size matters preliminary results from an experimental approach to interpret middle stone age hearths abstract this paper reports on ten fire experiments and their significance for interpreting hearths from the middle stone age site sibudu kwazulu natal south africa the experiments were conducted on four different substrata and four wood taxa were used in the experiments four of the experiments consisted of a single fire while the other experiments consisted of multiple fires on top of each other the experimental fires produced hearth areas of 962 1 1661 9 cm and hearth depths of 3 12 cm hearth size and depth do not correlate hearth area seems to correlate with the fuel load used in a hearth and it is argued that this can be used in interpretations of fire use at an archaeological site nine hearths from the same layer at sibudu are used as examples and it is argued that variation in hearth area indicates variation in hearth use some hearths at sibudu were possibly only used once whereas others represent long term use and or repeated reloading of the same hearth

blombos cave southern cape south africa preliminary report on the 1992 1999 excavations of the middle stone age levels the later and middle stone age levels at blombos cave bbc were excavated over four field seasons between 1992 and 1999 here we report on the results from the middle stone age msa levels the taphonomy and depositional history of the msa levels is complex due to faulting folding and spalling careful observations during excavation have assisted in understanding some of these taphonomic and site formation processes microstratigraphic analysis currently in progress will add to this information the uppermost msa level the still bay phase contains high densities of bifacial points the fossile directeur of the still bay industry placing the still bay within the msa culture sequence has been problematic in the past because still bay assemblages are rarely found in situ and previous excavations were inadequately recorded however with the regional data discussed in the text the still bay can be securely placed before the howiesons poort dated at 65 70 ka flaked stone makes up the greatest proportion of all artefacts with the highest incidence of retouch and use of fine grained non local materials found in the still bay levels the ochre assemblage is remarkable for the mass of material compared to other msa sites finds uncommon in an msa context are two pieces of ochre from the still bay phase engraved with a geometric design a fragment of deliberately engraved bone also 28 shaped and polished bone tools recovered mainly from a phase just below the still bay blombos cave is the first site where well preserved faunal remains have been recovered in association with the still bay allowing for unique insights into human subsistence behaviour and palaeoenvironmental reconstruction large fish bones marine shells seals and dolphins attest to extensive exploitation of aquatic resources and a wide range of terrestrial animals were hunted and gathered the few human teeth recovered are heavily worn and damaged thus the issue of morphological modernity cannot be addressed the bbc findings are a useful adjunct to findings from other msa coastal sites in the southern cape especially klasies river kr and die kelders cave 1 dk1 uniquely bbc provides insights into human behaviour during a phase of the msa never before studied in detail

a multidisciplinary biofacies characterisation of the late triassic late carnian rhaetian kapp toscana group on hopen arctic norway abstract a multidisciplinary study of the kapp toscana group de geerdalen flatsalen and svenskoya formations on hopen svalbard provides an enhanced palaeoenvironmental interpretation for the upper triassic succession on the island the biofacies of the formations were characterised using a combination of palynological palynofacies and micropalaeontological analyses micropalaeontological palynofacies and 13corg data are presented from hopen for the first time six distinct biofacies assemblages were recognised i lower undifferentiated de geerdalen formation characterised by a dominance of fern spores and low abundance assemblages of foraminifera and ostracods interpreted to reflect deposition in a deltaic environment during maximum marine regression ii upper de geerdalen formation hopen member rich in bisaccate gymnosperm pollen and the alga plaesiodictyon mosellaneum consistent with deposition in a brackish marginal marine setting iii lower flatsalen formation characterised by microforaminiferal linings marine phytoplankton and super abundant agglutinated foraminifera considered to reflect deposition in a shallow marine environment iv middle flatsalen formation dominated by dinoflagellate cysts radiolaria and ostracods indicating deposition in a relatively distal dysoxic anoxic marine environment a maximum flooding surface is inferred based on the acme of radiolarians and dominance of dinoflagellate cysts v upper flatsalen formation corresponding to a decrease in marine palynomorphs absence of radiolaria agglutinated foraminifera and ostracods and an increase in terrestrial organic matter and vi svenskoya formation characterised by a dominance of terrestrial palynomorphs and deposited in a fluvio deltaic environment the biofacies units are integrated with the established litho chrono and palynostratigraphic framework for the island and contribute to an enhanced palaeogeographic understanding of the barents sea region during the late triassic

cemented ash as a receptacle or work surface for ochre powder production at sibudu south africa 58 000 years ago the white ash of sibudu hearths sometimes became cemented and when this was the case some of these crusts were used as work surfaces or receptacles particularly in occupations dating about 58 000 years ago substantial deposits of red and yellow ochre powder have been found on these crusts this suggests that the ochre was not associated with hearths for heat treatment because yellow ochre readily transforms to red even at low temperatures xrf readings suggest that the ochre used at the site derives from different geological sources micromorphological studies imply that phosphatization caused the cementation of the ashes in some hearths while gypsum growth hardened one of the hearths described here

the early occupation of the eastern pilbara revisited new radiometric chronologies and archaeological results from newman rockshelter and newman orebody xxix abstract for over 30 years the radiometric chronologies of newman rockshelter and newman orebody xxix have been central to archaeological discussions on the pleistocene aboriginal occupation of the hamersley plateau and greater pilbara region until 2009 these two sites were heralded as having the oldest evidence of human occupation on the plateau dating to the last glacial maximum lgm 26 20 ka more recently however the excavations at several other rockshelters have shown that ancient aboriginal peoples occupied the hamersley plateau many thousands of years before the onset of the last glacial cycle when regional climatic conditions were wetter and more amenable this paper presents the results of our re excavation of both newman rockshelter and newman orebody xxix our research has resulted in the compilation and analysis of large lithic datasets for each of these sites and the construction of geo chronologies using modern radiometric techniques including ams radiocarbon dating and optically stimulated luminescence dating these new radiometric chronologies and artefact data indicate that both sites were occupied between 45 and 40 ka despite having significant early occupational evidence neither of the rockshelters present strong evidence for sustained or persistent site use during the lgm proper ca 23 19 ka however there is substantial evidence for more routine occupation of these localities during the terminal pleistocene and holocene

burned bone in the howieson s poort and post howieson s poort middle stone age deposits at sibudu south africa behavioral and taphonomic implications abstract despite a growing awareness of the wide range of information that can be provided by detailed analyses of burned bone from archaeological contexts such analyses are still relatively uncommon this paper focuses on the behavioral and taphonomic implications of burned bone from the middle stone age msa site of sibudu cave south africa reporting on the analysis of a large sample 377 000 fragments of bone recovered from the howieson s poort hp and post hp msa deposits at the site faunal remains were initially sorted into burning categories based on changes in color microscopic analyses focused on the optical properties of the bone matrix degree of preservation of the bone structure reflectance and fluorescence indicated that the color is a valid indicator of thermally altered bone in the sibudu assemblage the association of burned bone with hearths the intensity of burning damage and the sheer quantity of thermally altered bone suggests that the bone was not burned primarily as a result of natural fires we propose that the high incidence of burned bone primarily reflects two types of site maintenance activities first the discarding of bone into fire as a means of disposing of food waste as also argued by cain 2005 using burned animal bone to look at middle stone age occupation and behavior j archaeol sci 32 873 884 for a smaller sample of material from the post hp and late msa deposits at the site and second the incidental burning of bone on near the surface during the periodic burning of plant based bedding in considering the taphonomic implications of the burned bone we demonstrate that calcined bone is in fact more heavily fragmented than unburnt or moderately burned bone furthermore cortical preservation was negatively correlated with the intensity of burning damage which has implications for the study of surface modifications these results indicate the importance of conducting thorough taphonomic analyses prior to making comparisons between units that show differing degrees or intensities of burning damage

a tethys wide mid carnian upper triassic carbonate productivity crisis evidence for the alpine reingraben event from spiti indian himalaya abstract a significant mid carnian lithological change from carbonatic to siliciclastic sedimentation is described from the spiti himalaya n india the recorded sudden increase of terrigenous influx occurs at the boundary from the chomule to the rama formation it is dated within the late lower carnian uppermost aonoides zone and isochronous all over the tethys himalaya bio and chemostratigraphic data point to a synchrony with changes in carbonate productivity known from on area of wide extent along the nw tethys the reingraben event of the northern calcareous alps austria defines a regional decline in carbonate productivity related to both a platform demise and enhanced siliciclastic input laminated shales found in a distal part of the spiti basin document the onset of anoxic conditions within the deeper shelf synchronous to the reingraben event in austria high resolution biostratigraphy and identical 13ccarb curves are therefore in support of a direct link between the change in spiti and the reingraben event our data combined with a comprehensive review of previously postulated scenarios regarding the reingraben event suggest linking of climatic change with siliciclastic input and a carbonate productivity crisis initiated by onset of a relatively humid megamonsoonal late lower carnian atmospheric system that affected both the southern and northwestern tethys and point to a supra regional trigger of the alpine reingraben event

still bay and serrated points from umhlatuzana rock shelter kwazulu natal south africa abstract umhlatuzana rock shelter is a long sequence middle and later stone age site in kwazulu natal south africa jonathan kaplan excavated the site and analysed the material in the 1980s as a rescue project for many years thereafter the collection remained untouched partly because of doubts raised about the stratigraphic integrity of the site using single grain osl dating we show that post depositional mixing of sediment was restricted to time specific small scale events the osl ages obtained for the howiesons poort and pre howiesons poort are comparable to those of other southern african sites with unambiguous howiesons poort and still bay industries based on morphological and other characteristics we reason that the still bay is represented at umhlatuzana and announce the presence of a serrated point assemblage closely associated in time with the still bay points

constraints on jalisco block motion and tectonics of the guadalajara triple junction from 1998 2001 campaign gps data a gps campaign network in the state of jalisco was occupied for 36 h per station most years between 1995 and 2005 we use data from 1998 2001 to investigate tectonic motion and interseismic deformation in the jalisco area with respect to the north america plate the twelve stations used in this analysis provide coverage of the jalisco block and adjacent north america plate and show a pattern of motion that implies some contribution to jalisco block boundary deformation from both tectonic motion and interseismic deformation due to the offshore 1995 earthquake the consistent direction and magnitude of station motion on the jalisco block with respect to the north america reference frame 2 mm year to the southwest 95 confidence level perhaps can be attributed to tectonic motion however some station velocities within and across the boundaries of the jalisco block are also non zero 95 confidence level and the overall pattern of station velocities indicates both viscoelastic response to the 1995 earthquake and partial coupling of the subduction interface together termed interseismic deformation our results show motion across the northern colima rift the eastern boundary of the jalisco block which is likely to be sinistral oblique extension rather than pure extension we constrain extension across both the colima rift and the northeastern boundary of the jalisco block the tepic zacoalco rift to 8 mm year 95 confidence level slow compared to relative rates of motion at nearby plate boundaries

timing of millennial scale climate change in antarctica and greenland during the last glacial period a precise relative chronology for greenland and west antarctic paleotemperature is extended to 90 000 years ago based on correlation of atmospheric methane records from the greenland ice sheet project 2 and byrd ice cores over this period the onset of seven major millennial scale warmings in antarctica preceded the onset of greenland warmings by 1500 to 3000 years in general antarctic temperatures increased gradually while greenland temperatures were decreasing or constant and the termination of antarctic warming was apparently coincident with the onset of rapid warming in greenland this pattern provides further evidence for the operation of a bipolar see saw in air temperatures and an oceanic teleconnection between the hemispheres on millennial time scales

new ages for the upper palaeolithic site of xibaimaying in the nihewan basin northern china implications for small tool and microblade industries in north east asia during marine isotope stages 2 and 3 it has been suggested that the small tool and microblade upper palaeolithic industries coexisted in the nihewan basin of northern china for about 8 14 000 years during marine isotope stage mis 2 this inference was based on uranium series ages of around 15 and 18 ka for bovid teeth recovered from the latest small tool site of xibaimaying the youngest occurrence of such tools in the region and optically stimulated luminescence osl dating of the earliest typical microblade site youfang 26 29 ka in this study we re dated the xibaimaying site using single grain osl methods and the resulting ages indicate that the cultural layer was deposited 46 3 ka ago during mis 3 more than 20 millennia earlier than previously thought and older also than the so called earliest primitive and typical microblade tools found at zhiyu 31 39 ka cal bp and youfang these new ages for human occupation of xibaimaying remove support for the parallel development of the small tool and microblade industries in the nihewan basin during the upper palaeolithic but reliable age estimates from additional sites are needed to confidently infer the nature of the chronological relationship between these two upper palaeolithic industries and the associated toolmakers

an improved osl chronology for the still bay layers at blombos cave south africa further tests of single grain dating procedures and a re evaluation of the timing of the still bay industry across southern africa this paper presents a series of new single grain optically stimulated luminescence osl ages for the still bay at blombos cave south africa and compares them to previously published osl thermoluminescence tl and electron spin resonance esr ages for this site details are provided about the measurement and analytical procedures including a discussion of the characteristics of the osl signals of individual quartz grains this forms the basis for further investigations into the sensitivity of the equivalent dose de estimates to a range of different analytical approaches including changes in the size of the test dose the choice of signal integration interval the subtraction of an appropriate background and isolation of the most light sensitive fast component of quartz osl we also report the results of an inter operator test of de determination using seven new samples from blombos cave and demonstrate the reproducibility of results obtained for two samples that had been dated previously at another laboratory and were measured and analysed again in this study together these tests validate the robustness of the blombos cave single grain osl age estimates to a variety of alternative osl dating procedures we have incorporated for the first time these ages for blombos cave into a data set of all single grain osl ages for still bay and howieson s poort sites across southern africa and have used a statistical model to re evaluate the timing and duration of the still bay industry we calculate the most plausible start and end dates of the still bay as 72 2 ka and 71 3 ka respectively amounting to a duration of 0 9 ka and estimate with conventional 95 confidence that this industry began no earlier than 75 5 ka ended no later than 67 8 ka and lasted no longer than 6 6 ka

an improved single grain osl chronology for the sedimentary deposits from diepkloof rockshelter western cape south africa the single grain optically stimulated luminescence osl chronology for the sedimentary deposit at diepkloof rockshelter reported by jacobs et al 2008c has recently been critiqued and several reasons proposed for why the osl ages for the intermediate and early howieson s poort hp and still bay sb techno complexes might be inaccurate tribolo et al 2013 presented a series of osl and thermoluminescence tl ages that were in agreement with each other but for some part of the sequence at least were much older than the osl chronology of jacobs et al 2008c in this paper we have tested the criticisms of tribolo et al 2013 and colleagues related to both the equivalent dose de estimates and the beta dose rates by performing a series of targeted experiments combined with updates and re assessments of our error calculations we show that the de estimates are stable over a range of alternative measurement conditions and also over time we also demonstrate the reproducibility of our measurement procedures for the beta dose rates and their accuracy tested against a range of independently obtained estimates we show that for the stratigraphic units sus where there are major discrepancies in age between jacobs et al 2008c and tribolo et al 2013 notably the intermediate hp and early hp and for which both studies had single grain osl ages the estimation of potassium k in the sediment surrounding the dated grains is critical we provide new and updated de and dose rate estimates and final ages which we compare with our previous age estimates and those of tribolo et al 2013 the differences in the size of the errors associated with the ages reported in the two independent studies are also addressed we can show that our ages are robust and consistent with the original chronology but we cannot satisfactorily explain why the tl and osl ages provided by tribolo et al 2013 might be wrong so the dating conundrum at diepkloof rockshelter remains as a result we caution against the development of hp and sb age models based on only one of the chronologies for this site at this stage extrapolation of the tribolo et al 2013 chronology to a re interpretation of the southern african msa would appear to be premature especially as the ages do not differ systematically between the two studies and as differences between tl and osl ages are not an issue at other sites in southern africa where both dating methods have been applied further work is needed to resolve the question of the diepkloof chronology

age dating and the orbital theory of the ice ages development of a high resolution 0 to 300 000 year chronostratigraphy using the concept of orbital tuning a continuous high resolution deep sea chronostratigraphy has been developed spanning the last 300 000 yr the chronology is developed using a stacked oxygen isotope stratigraphy and four different orbital tuning approaches each of which is based upon a different assumption concerning the response of the orbital signal recorded in the data each approach yields a separate chronology the error measured by the standard deviation about the average of these four results which represents the best chronology has an average magnitude of only 2500 yr this small value indicates that the chronology produced is insensitive to the specific orbital tuning technique used excellent convergence between chronologies developed using each of five different paleoclimatological indicators from a single core is also obtained the resultant chronology is also insensitive to the specific indicator used the error associated with each tuning approach is estimated independently and propagated through to the average result the resulting error estimate is independent of that associated with the degree of convergence and has an average magnitude of 3500 yr in excellent agreement with the 2500 yr estimate transfer of the final chronology to the stacked record leads to an estimated error of 1500 yr thus the final chronology has an average error of 5000 yr