integrating palaeocaves into palaeolandscapes an analysis of cave levels and karstification history across the gauteng malmani dolomite south africa abstract the drimolen palaeocave system in the fossil hominid sites of south africa unesco world heritage site is well known for numerous remains of early hominins such as paranthropus robustus and early homo these hominin fossils along with bone tools and notably diverse accumulation of non hominin primates and fauna have all been excavated from the main quarry area of the site where extensive lime mining took place here we report the first radiometric age of 1 712 0 269 ma for hominin bearing deposits associated with the dnh7 paranthropus robustus cranium in the main quarry area of the site which is consistent with recent biochronological estimates this age is similar to recent estimates for swartkrans member 1 hanging remnant somewhere between 2 3 and 1 8 ma which also contains paranthropus and early homo simultaneously we integrate the newly radiometrically dated main quarry deposits with a new fossil deposit the drimolen makondo discovered in 2013 that is situated some 50 m up the hill to the west from the main quarry it has experienced only limited disturbance from mining but much more extensive erosion preliminary excavations and analysis have revealed that the makondo infill is older than the main quarry dating to 2 706 0 428 ma its greater age is confirmed by biochronology the makondo thus overlap with the suggested end of deposition of australopithecus bearing sterkfontein deposits although it is yet to yield any hominin remains these new dates for the two drimolen palaeocave system deposits indicates that contrary to prior age estimates the drimolen site as a whole records the critical hominin and faunal turnover in south african palaeocommunities that occurred around 2 3 1 7 ma finally as the drimolen makondo represents a rare example of a pre 2 ma fossil bearing deposit in the gauteng exposures of the malmani dolomite we also integrate our results into the greater south african record of palaeodeposit formation most of which occur between 2 0 and 1 0 ma an analysis of the age of palaeocave infillings across the malmani dolomite suggests that as is classically the case with karst the height within the dolomite is broadly correlated to their age although with some notable exceptions that are likely related to localised geological features our analysis also indicates that most caves have undergone some form of secondary karstification related to a younger phase of cave formation contrasting with models that suggest the cavities all formed at the same time and that infill is related to erosion and the opening up of cave passages as such the reason that few pre 2 ma deposits have been identified in the gauteng exposures of the malmani dolomite is probably because these older caves have been eroded away identifying such early caves is critical in understanding whether earlier hominins may have once existed in south africa or if erosion of older deposits or an absence of speleogenesis at this time has made such early periods absent from the geological record

initial speleothem results from western flores and eastern java indonesia were climate changes from 47 to 5 ka responsible for the extinction of homo floresiensis little is known about climate changes on flores that influenced homo floresiensis during the period of occupation of liang bua 95 12 ka or the late surviving pygmy stegodon lineage both species became locally extinct at ca 12 ka previous palaeoclimate analysis in this region has established that a prolonged dry period ca 45 12 ka was followed by a rapid increase in rainfall but lacks a firm chronology here we report initial results for stalagmites from western flores and eastern java using delta o 18 data from contemporaneous records a series of isotopic shifts has been identified that reflects changes in the amount of rainfall and in moisture sources the isotopic signals from oxygen and carbon suggest differing ages for the rapid increase in rainfall at ca 13 ka and 17 16 5 ka respectively thus it cannot be determined from this evidence whether the abrupt disappearance of stegodon and homo floresiensis in western flores was coincident with a major change in climate or was caused instead or as well by a volcanic eruption at ca 12 ka or was related to the arrival of homo sapiens at liang bua by ca 10 5 ka copyright c 2007 john wiley sons ltd

chronostratigraphy of bramston reef reveals a long term record of fringing reef growth under muddy conditions in the central great barrier reef inshore reefs on australia s great barrier reef gbr are widely argued to be in decline although recent reports suggest that some may be more resilient than traditionally assumed resolution of this debate requires long term insights into past reef development and variability to provide context for the assessment of present reef condition long term reef growth histories can preserve extended records of reef growth and condition however they are rare especially for mainland attached fringing reefs which are themselves uncommon on the gbr we examined the internal structure and ecology at bramston reef a mainland attached fringing reef located in a protected bay on the central gbr eight reef matrix cores were collected across the reef flat sedimentological and palaeo ecological analyses coupled with u th dating were used to develop the first reef growth history for a shore attached fringing reef in this region twenty five hard coral genera were identified in the palaeo ecological analyses the key reef building genera including acropora montipora euphyllia porites and goniopora have contributed to reef growth since initiation and are represented in the extant coral community despite a change in accretion mode during the late holocene sedimentological and stratigraphic investigations demonstrate bramston reef has always grown in a mud rich setting u th ages indicate that reef initiation occurred at or before 5400 ybp in a palaeo water depth of 2 3 m bramston reef reached sea level by 4256 ybp when sea level was approximately 1 m higher than present after which rapid seaward progradation occurred until around 3000 ybp 19 cm yr on average between approximately 3000 and 1000 ybp seaward progradation of the reef flat slowed to 9 8 cm yr on average this deceleration of reef growth occurred long before european settlement of the queensland coast and was driven by natural constraints probably associated with limited accommodation space due to late holocene sea level fall our results demonstrate that mainland attached reef initiation and accretion can occur in muddy inshore environments over long timeframes centuries to millennia

the sima de los huesos hominids date to beyond u th equilibrium 350 kyr and perhaps to 400 500 kyr new radiometric dates the sima de los huesos site of the atapuerca complex near burgos spain contains the skeletal remains of at least 28 individuals in a mud breccia underlying an accumulation of the middle pleistocene cave bear u deningeri earlier dating estimates of 200 to 320 kyr were based on u series and esr methods applied to bones made inaccurate by unquantifiable uranium cycling we report here on a new discovery within the sima de los huesos of human bones stratigraphically underlying an in situ speleothem u series analyses of the speleothem shows the lower part to be at isotopic u th equilibrium translating to a firm lower limit of 350 kyr for the sh hominids finite dates on the upper part suggest a speleothem growth rate of c 1 cm 32 kyr this rate along with paleontological constraints place the likely age of the hominids in the interval of 400 to 600 kyr

geological setting and age of australopithecus sediba from southern africa we describe the geological geochronological geomorphological and faunal context of the malapa site and the fossils of australopithecus sediba the hominins occur with a macrofauna assemblage that existed in africa between 2 36 and 1 50 million years ago ma the fossils are encased in water laid clastic sediments that were deposited along the lower parts of what is now a deeply eroded cave system immediately above a flowstone layer with a u pb date of 2 026 0 021 ma the flowstone has a reversed paleomagnetic signature and the overlying hominin bearing sediments are of normal polarity indicating deposition during the 1 95 to 1 78 ma olduvai subchron the two hominin specimens were buried together in a single debris flow that lithified soon after deposition in a phreatic environment inaccessible to scavengers

global positioning system phase fluctuations and ultraviolet images from the polar satellite in a study designed to determine the temporal development of ionospheric irregularities in the auroral region in magnetic storm periods different types of simultaneous observations were compared for the storms of january 10 april 10 11 and may 15 1997 the data sets consisted of ultraviolet images uvi from the polar satellite phase fluctuations and total electron content tec from global positioning system gps recordings at a large number of sites magnetometer observations and hemispheric power precipitation the large scale global or macroscale picture of the magnetic storm showed the importance of universal time in the development of irregularities the hemispheric total power picture and the global indices such as kp show this macroscale picture of the entire storm period however individual sites show differences in localized magnetic field variations and the development of irregularities this we term the microscale the storms of january 10 and may 15 show the importance of local magnetic time and local magnetic variations at the sites while the storm of april 10 11 was dominated by the ut storm development during the intense activity of the storms total electron content shows minute by minute increases with the satellite moving to positions 6 km apart in the minute the structured precipitation either directly produces irregularities or indirectly sets instability conditions for irregularity development in the auroral region good correlation was established for the three storms between uvi intensity and phase fluctuation development the uvi lyman birge hopfield long 170 nm emission is sensitive to 100 200 km precipitation phase fluctuation development undoubtedly arises from perturbations in the f region as well topside and bottomside soundings have shown the high occurrence of spread f in the auroral region the comparison of the data sets from these storms and from other studies indicates that the creation of irregularities develops from conditions existing over a large range of bottomside heights i e at altitudes from 100 km to the f layer

mid pleistocene acheulean like stone technology of the bose basin south china stone artifacts from the bose basin south china are associated with tektites dated to 803 000 3000 years ago and represent the oldest known large cutting tools lcts in east asia bose toolmaking is compatible with mode 2 acheulean technologies in africa in its targeted manufacture and biased spatial distribution of lcts large scale flaking and high flake scar counts acheulean like tools in the mid pleistocene of south china imply that mode 2 technical advances were manifested in east asia contemporaneously with handaxe technology in africa and western eurasia bose lithic technology is associated with a tektite airfall and forest burning

expanding the utility of uranium series dating of speleothems for archaeological and palaeontological applications uranium series u series dating of speleothems is frequently used for palaeoclimate studies but its archaeological and palaeontological applications are limited to stratigraphically significant speleothem formations such as flowstones to provide maximum and minimum temporal points this study targeted soda straw stalactites for u series dating in contrast to other speleothem formations soda straw stalactites are fragile have typically short life spans usually only years but rarely up to a few hundred years and are frequently incorporated into cave deposits results of thermal ionisation mass spectrometry tims u series dating of soda straw stalactites from palaeontological excavations at blanche cave south australia show that small dense clean straws tend to yield ages closest to the time of stratigraphic deposition a correlation between soda straw u series ages and radiocarbon ages of charcoal from the site is shown multiple soda straw age determinations for a single stratigraphic unit are required in order to verify age concordance in conjunction with other dating methods u series dating of soda straw stalactites may help to significantly constrain the age of stratigraphic units and associated archaeological and palaeontological deposits in order to provide more robust chronologies here we advocate the collection of soda straw stalactites at future excavations of limestone cave sites

first light from a kilometer baseline scintillation auroral gps array we introduce and analyze the first data from an array of closely spaced global positioning system gps scintillation receivers established in the auroral zone in late 2013 to measure spatial and temporal variations in l band signals at 100 1000 m and subsecond scales the seven receivers of the scintillation auroral gps array saga are sited at poker flat research range alaska the receivers produce 100 s scintillation indices and 100 hz carrier phase and raw in phase and quadrature phase samples saga is the largest existing array with baseline lengths of the ionospheric diffractive fresnel scale at l band with an initial array of five receivers we identify a period of simultaneous amplitude and phase scintillation we compare saga power and phase data with collocated 630 0 nm all sky images of an auroral arc and incoherent scatter radar electron precipitation measurements to illustrate how saga can be used in multi instrument observations for subkilometer scale studies

gps phase scintillation at high latitudes during the geomagnetic storm of 17 18 march 2015 the geomagnetic storm of 17 18 march 2015 was caused by the impacts of a coronal mass ejection and a high speed plasma stream from a coronal hole the high latitude ionosphere dynamics is studied using arrays of ground based instruments including gps receivers hf radars ionosondes riometers and magnetometers the phase scintillation index is computed for signals sampled at a rate of up to 100 hz by specialized gps scintillation receivers supplemented by the phase scintillation proxy index obtained from geodetic quality gps data sampled at 1 hz in the context of solar wind coupling to the magnetosphere ionosphere system it is shown that gps phase scintillation is primarily enhanced in the cusp the tongue of ionization that is broken into patches drawn into the polar cap from the dayside storm enhanced plasma density and in the auroral oval in this paper we examine the relation between the scintillation and auroral electrojet currents observed by arrays of ground based magnetometers as well as energetic particle precipitation observed by the dmsp satellites equivalent ionospheric currents are obtained from ground magnetometer data using the spherical elementary currents systems technique that has been applied over the ground magnetometer networks in north america and north europe the gps phase scintillation is mapped to the poleward side of strong westward electrojet and to the edge of the eastward electrojet region also the scintillation was generally collocated with fluxes of energetic electron precipitation observed by dmsp satellites with the exception of a period of pulsating aurora when only very weak currents were observed

u series dating of locality 15 at zhoukoudian china and implications for hominid evolution this paper reports u series dates on speleothem samples from locality 15 at zhoukoudian one of the richest paleolithic sites in northern china the age of the lower part of layer 2 is securely bracketed between 155 000 and 284 000 yr the underlying layer 3 dates back at least 284 000 yr layer 4 further below should be older still possibly by a cycle on the specmap time scale before 284 000 yr ago these ages much greater than the previous estimates of 110 000 140 000 yr from u series and electron spin resonance dating of fossil teeth suggest that locality 15 was broadly contemporaneous with locality 4 new cave and with the uppermost strata of locality 1 peking man site the physical evolution and cultural development evidenced by the timing of the zhoukoudian localities are in line with the opinion of chinese anthropologists for a regional transition from homo erectus to archaic homo sapiens c 2004 university of washington all rights reserved

alpha thermochronology of carbonates abstract step heating experiments on 17 calcites from 11 different samples and 6 dolomites from 5 samples suggest a closure temperature of he in carbonates 70 10 c for a cooling rate of 10 c m y the bulk closure temperature in some samples may tend slightly higher due to the presence of diffusion domains larger and therefore more retentive than the sites in which the majority of he resides the diffusivity of he in calcite is independent of the genesis of the mineral igneous sedimentary metamorphic or the source of the he radiogenic common or laboratory induced and in all samples analyzed the effective diffusion dimension for he is smaller than the size of the crystals investigated although calcite is a low u mineral this shortcoming can be overcome by analyzing large samples 2 mm diameter provided samples have a minimum of 0 3 ppm u samples with smaller concentrations of alpha producers are unlikely to produce enough radiogenic 4he sufficient to overwhelm he present in the crystals at the time they passed through their closure temperature

climate people and faunal succession on java indonesia evidence from song gupuh song gupuh a partially collapsed cave in the gunung sewu limestones of east java indonesia contains over 16 m of deposits with a faunal sequence spanning some 70 ka major changes in the range of animals represented show the impact of climate change and humans the terminal pleistocene and early holocene was a period of maximum biodiversity human use of song gupuh and other cave sites in the region also intensified significantly from ca 12 ka together with a new focus on exploitation of small bodied species macaque monkeys and molluscs the first evidence for import of resources from the coast and use of bone and shell tools human activity especially after the onset of the neolithic around 2 6 ka subsequently contributed to a progressive loss of many species from the area including tapir elephant malayan bear rhino and tiger and this extinction process is continuing we conclude by discussing the biogeographical significance of song gupuh in the context of other sites in java e g punung wajak and further afield e g liang bua

u series dating of bone using the diffusion adsorption model abstract u series dating of bone has suffered problems of reliability since its inception because bone remains an open system with respect to uranium commonly applied a priori assumptions of u uptake such as early uptake or linear uptake are inadequate because they have no physical or chemical bases no means of demonstrating which model is suitable for a particular bone and no intrinsic tests of reliability despite this and numerous examples of anomalous u series dates such assumptions are still routinely applied we address this problem using the diffusion adsorption d a model of u uptake millard and hedges 1996 which incorporates a physicochemical description of u uptake using this model we show how the u uptake of a bone responds to geochemical changes in the burial environment which can lead to phenomena such as the removal of u from bones leaching or u uptake late in their burial history recent uptake and we show how the overall uptake history is reflected in distributions profiles of u and u series isotopes across a bone section we present measurements of u concentration profiles and 230 th 234 u profiles on archeological bone from a number of different sites and burial environments and compare the results to profiles predicted by the d a model bones that have undergone complex uptake histories which include u leaching or recent uptake are identified on the basis of these profiles and rejected as unsuitable for dating for bones that appear to have undergone uptake under constant geochemical conditions the d a model is applied to calculate u series dates with much improved reliability

mass spectrometric 230th 234u 238u dating of the devils hole calcite vein the devils hole calcite vein contains a long term climatic record but requires accurate chronologic control for its interpretation mass spectrometric u series ages for samples from core dh 11 yielded 230 th ages with precisions ranging from less than 1 000 years 2 for samples younger than 140 ka thousands of years ago to less than 50 000 years for the oldest samples 566 ka the 234 u 238 u ages could be determined to a precision of 20 000 years for all ages calcite accumulated continuously from 566 ka until 60 ka at an average rate of 0 7 millimeter per 10 3 years the precise agreement between replicte analyses and the concordance of the 230 th 238 u 234 u 238 u ages for the oldest samples indicate that the dh 11 samples were closed systems and validate the dating technique in general

u series dating and human evolution some of the major events in human evolution occurred during the middle pleistocene these include the evolutionary rise of the neanderthals in eurasia and of anatomically modern humans either in africa or on a broader geographical front in addition to major biogeographic changes among mammals including the hominine colonization of europe prior to the middle pleistocene the application of potassium argon and argon argon dating has yielded a relatively detailed chronological picture for the earlier phases of hominid evolution and from c 50 ky radiocarbon dating provides the backbone of our chronology for the extinction of the neanderthals colonization of europe by anatomically modern humans and all subsequent events between these however the middle pleistocene has only been amenable to precise chronometric dating for the past few decades before the advent of radiometric dating as glynn isaac 1975 famously observed the middle pleistocene was the muddle in the middle u series dating is one of a range of dating methods employed by archaeologists to provide a chronology for human evolution fig 1 other applicable methods include optically stimulated luminescence osl which can be used to date sediments perhaps back to about 0 5 my measuring the time since the last exposure to sunlight it is increasingly employed as a dating method especially since suitable sediments are common on archaeological sites e g aitken 1992 a related technique thermoluminescence tl can be used to date burnt flint artifacts e g aitken 1985 which provide a more direct date for specific human activity on a site although material that is suitably burnt is relatively rare potassium argon and argon argon dating have been the most useful techniques for calibrating early hominid evolution because its limit for dating extends considerably beyond the origins of the earliest hominids at around 5 my e g curtis and hay 1972 their application however is

hydrothermal co2 degassing in seismically active zones during the late quaternary natural co2 discharges are abundant in turkey as evident from ongoing deposition of recent terrace mound travertines and emplacement of significant travertine vein and breccia deposits in fractured damage zones of active fault systems we report high precision u series age data for the vein carbonates combined with important field observations and geochemical data to evaluate the travertine veining and co2 degassing history in seismically active areas field evidence suggests that travertine filled veins and associated breccias represent hydrothermal eruption products which probably formed by hydraulic fracturing in response to overpressure of co2 rich fluids stable isotope and ree data support the field observations and indicate that travertine veins formed as thermogene deposits from rapidly ascending co2 rich fluids travertine veins from the kirsehir geothermal field give u series ages in a range from 10 6 0 3 ka to 86 16 1 24 ka with a majority of ages failing between 10 6 0 3 and 11 3 0 2 ka vein samples from the pamukkale geothermal field yield u series ages between 21 1 0 1 ka and 73 6 0 6 ka two major age groups are evident in pamukkale that cluster coherently around 21 ka and 25 ka a large number of travertine veins we dated by high precision u series technique coincide with times of cold dry climate events this is different from surface sinter deposits in geothermal fields which more frequently form during warm and wet periods we propose that a significant reduction in surface discharge of co2 by spring or geothermal waters during dry climate periods may promote oversaturation of co2 in deep reservoirs host rock fracturing in response to seismic shaking and fluid overpressure results in rapid exsolution and expansion of the dissolved gas and may lead to hydrothermal eruptions crown copyright c 2009 published by elsevier b v all rights reserved

u th age evidence from carbonate veins for episodic crustal deformation of central anatolian volcanic province abstract central anatolia represents one of the most outstanding examples of intraplate deformation related to both continental collision and back arc extension generating non uniformly distributed stress fields in this study we provide direct field evidence of various stress directions and investigate carbonate filled fracture systems in the central anatolian volcanic province using u th geochronology and isotope geochemistry for evaluating the episodes of latest volcanic activity under regional stress field data reveal two independent fracture systems in the region successive fracture development has been controlled by two different volcanic eruption centers hasandag composite volcano and acigol caldera trace element and stable c and o and radiogenic sr isotope compositions of carbonate veins indicate different fluid migration pathways for two different fracture systems the u th age data for carbonate veins of two independent fracture systems indicate that the crustal deformation intensified during 7 episodic periods in the last 150 ka the nne trending first fracture system was formed as a result of strain cycles in a period from 149 2 5 through 91 1 5 to 83 2 5 ka bp subsequent deformation events represented by the ene trending second fracture zone have been triggered during the period of 53 3 5 44 0 6 and 34 1 ka bp before the first fracture zone resumed the activity at about 4 7 0 15 ka bp although further studies are needed to evaluate statistical significance of age correlations the periods of carbonate precipitation inferred from u th age distributions in this study are comparable with the previous dating results of surrounding volcanic eruption events

taphonomy of a south african cave geological and hydrological influences on the gd 1 fossil assemblage at gondolin a plio pleistocene paleocave system in the northwest province south africa abstract occasional excavation of in situ and ex situ deposits at the formerly mined gondolin paleocave system has yielded large and diverse samples of plio pleistocene faunas including isolated hominin and non hominin primate remains in 2003 new excavations into naturally decalcified in situ sediments near the gd 1 datum point near the northwest corner of the cave system were undertaken this paper describes the recovered faunal remains taphonomy of the assemblage and the geological and paleomagnetic context of the gd 1 deposits the deposits represent a series of inter stratified speleothem in washed sediments and talus deposits we suggest date to a time period prior to and just after the olduvai normal polarity event at around 1 7 1 8 ma surface sediments and clasts were introduced into the cave by rain water runoff entering a vertically oriented entrance that had formed along a rift in the area of gd 1 the faunal assemblage consists primarily of fragmentary diaphyseal fragments and isolated teeth taxonomically the small collection of specifically identifiable bovid and equid fossils is generally consistent with remains previously excavated from in situ deposits in the gondolin paleocave system gd 2 and dated to around 1 8 ma however the depositional histories of these two assemblages from gondolin are remarkably different the preservation and relative proportions of recovered skeletal elements at gd 1 is consistent with these materials having been initially accumulated outside the karstic system near the vertical cave entrance and then later hydrologically sorted and deposited inside the cave the sporadic to continuous water flow into the northwest corner of the cave system during the pleistocene gradually decalcified the excavated fossilbearing breccias and further modified the composition and spatial distribution of the fossil assemblage by introducing potentially younger deposits and skeletal materials this study highlights the variation in taphonomic processes that can occur within a single cave system and the complex pre and postdepositional geological and hydrological processes that can influence the taphonomic history of south african plio pleistocene karstic fossil assemblages

mass spectrometric u series dating of new cave at zhoukoudian china abstract we report here mass spectrometric u series dates on calcite samples from new cave one of the zhoukoudian localities the lowermost sub layer of the capping flowstone dates to ca 120 ka implying the absence of late pleistocene cultural deposits within the cave the second flowstone layer was formed between 248 and 269 ka marking possibly the minimum age of the hominid fossil three samples taken from the lowest accessible strata date to ca 300 ka suggesting an even greater antiquity for the cultural horizon at the bottom of the depositional sequence the new age assignment from previously estimated early late pleistocene to late middle pleistocene makes new cave broadly contemporaneous with the uppermost strata of the peking man site this is in line not only with the observation that the previously established chronological sequence for chinese middle late pleistocene sites may have been underestimated as a whole but also with the hypothesis that human occupation of the zhoukoudian sites has been more or less continuous over hundreds of thousand years

geoarchaeological and 3d visualisation approaches for contextualising in situ fossil bearing palaeokarst in south africa a case study from the 2 61 ma drimolen makondo abstract south africa contains a wealth of palaeokarst deposits that have yielded hominin fossils and early stone age archaeology despite the complex nature of deposition within many of these caves there has been a dearth of detailed geoarchaeological studies undertaken on these sites many sites in south africa have been interpreted using an overly simplistic member system based on simplified sedimentological attributes rather than chronostratigrahic units many of the defined members thus identify different but contemporary geological processes occurring in the caves this has caused serious confusion in reconstructing the life histories of palaeocaves and the ages of the fossil remains interned within them it is critical to uncover new sites that have not been extensively altered by decades of data collection and destructive mining techniques employed early in their discovery although unmined sites present their own problems with regards to extensive colluvium cover and access to fossil bearing units analysing strata that is found in situ enhances overall confidence of interpretations drawn a wealth of geoarchaeological and 3d visualisation techniques can now be employed to aid in the understanding of cave life histories as well as their excavation in this paper we present the first attempt to integrate and publish data from a range of such methods on south african fossil bearing palaeokarst using the newly discovered drimolen makondo deposit as a case study this includes the use of ground penetrating radar 3d visualisation through photogrammetry and multi scale 3d scanning micromophology and petrography palaeomagnetism mineral magnetism synchrotron radiation electron spin resonance uranium lead dating and biochronology our analysis has allowed us to successfully uncover the full extent of this new 2 61 ma fossil bearing palaeokarst deposit and to visualise and interpret its chronostratigraphy

problems associated with reworked teeth in electron spin resonance esr dating a single radiation sensitive esr signal at g 2 0018 occurs in well crystallized fossil tooth enamel but not in modern teeth in dating fossil teeth the equivalent radiation dose a needed to produce the observed esr signal is the integral with respect to time of the natural environmental dose rate experienced by the tooth after its deposition regardless of the uranium u uptake history assumed a reliable age estimate requires a good estimate for the external dose rate during the tooth s history if teeth in a stratigraphic unit have been reworked from older units or are post depositional intrusions external dose rates measured in situ do not accurately reflect those experienced by the tooth for teeth from a single unit significant variations in the calculated ages a s enamel or dentine u concentrations all indicate mixed sample collections where enough subsamples can be collected from single teeth isochron analyses negate the need for a separate external dose measurement while calculating the sample age and the external dose rate experienced by the tooth failing that modelling the sedimentary dose rates using time averaged total external dose calculations becomes necessary these principles are illustrated using teeth from the australopithecine sites sterkfontein and swartkrans south africa

geomorphic perspectives on the sterkfontein australopithecine breccias abstract breccias in the upper sterkfontein cave system levels have yielded artifact assemblages as well as homo and australopithecus africanus remains as mapped by the author this sytem can be subdivided into a northern sector comprising small bedding controlled passageways and a southern one with large galleries controlled by subvertical fracture zones and partly filled with two generations of external detrital sediment a four stage model describes the development of these deposits the implications of this study include 1 the caves formed in one rather than two phases as a result of structural rather than watertable controls 2 the lowest strata of both depositional generations 50 60 m below the hillcrest are probably the oldest t c partridge s sterkfontein formation only includes approximately the upper half of the stratigraphic column recognized here deposits underlying those he described are also fossiliferous and probably substantially older than the 2 8 million year age attributed to the lower units of the sterkfontein formation 3 the sterkfontein formation as defined by partridge is a composite stratotype comprising one surface exposure and another underground at mid to upper levels in the system their stratigraphic relationships are obscure and since the lower boundary of the formation also is in doubt erection of a formal stratotype is premature deep lying breccias may ultimately warrant another component extending the sterkfontein formation to the lowest known levels of the cave system

2 05 ga isotopic ages for transvaal mississippi valley type deposits evidence for large scale hydrothermal circulation around the bushveld igneous complex south africa abstract the known dimensions of hydrothermal fluid circulation associated with emplacement of the 2 055 ga bushveld igneous complex bic are extended with new isotopic ages for paleoproterozoic mineral deposits in wallrocks transvaal supergroup surrounding the bic a fluorite rich mississippi valley type mvt deposit in the zeerust district dated at 2 05 ga sm nd isochron age has nd isotopic compositions that are identical to coeval f rich lebowa granite late in the bic intrusive sequence suggesting transport of magmatic fluids 100 km beyond the present margins of the bic hydrothermal illite from the zn pb mvt bushy park deposit dated at 2 05 ga by k ar geochronology links widespread mvt deposits of the kaapvaal craton to large scale basinal brine circulation associated with emplacement of the bic these data in combination with gold vein phosphate mineral and paleomagnetic resetting ages indicate a regional scale bushveld age hydrothermal system circulating 700 km outward from the prese

new u th ages for pleistocene megafauna deposits of southeastern queensland australia arguments over the extinction of pleistocene megafauna have become particularly polarised in recent years causes for the extinctions are widely debated with climate change human hunting and or habitat modification or a combination of those factors being the dominant hypotheses however a lack of a spatially constrained chronology for many megafauna renders most hypotheses difficult to test here we present several new u th dates for a series of previously undated megafauna bearing localities from southeastern queensland australia the sites were previously used to argue for or against various megafauna extinction hypotheses and are the type localities for two now extinct pleistocene marsupials including the giant koala phascolarctos stirtoni the new dating allows the deposits to be placed in a spatially and temporally constrained context relevant to the understanding of australian megafaunal extinctions the results indicate that the joint texas caves megafaunal assemblage is middle pleistocene or older 292 ky the cement mills gore megafaunal assemblage is late pleistocene or older 53 ky and the russenden cave bone chamber texas caves megafaunal assemblage is late pleistocene 55 ky importantly the new results broadly show that the sites date prior to the hypothesised megafaunal extinction window i e 30 50 ky and therefore cannot be used to argue exclusively for or against human climate change extinction models without first exploring their palaeoecological significance on wider temporal and spatial scales

microatoll record for large century scale sea level fluctuations in the mid holocene coral microatolls have been long used as precise indicators of past sea level but their use for precise definition of detailed sea level fluctuations is still rare here we report twelve high precision thermal ionization mass spectrometric th 230 ages for twelve rims of five mid holocene microatolls from all emerged reef terrace at leizhou peninsula northern south china sea this is a tectonically stable area enabling lis to reconstruct both the timing and trajectory of local sea level fluctuations accurately the elevations of these microatoll rims and cores were accurately determined relative to the surface of modern livin microatolls at the same site the results indicate that the sea level during the period of 7050 6600 yr bp years before ad 1950 was about 171 to 219 cm above the present with at least four cycles of fluctuations over this 450 yr interval sea level fluctuated by 20 40 cm on century scales crown copyright c 2009 published by university of washington all rights reserved

severe and localized gnss scintillation at the poleward edge of the nightside auroral oval during intense substorm aurora in this paper we study how gps glonass and galileo navigation signals are compromised by strong irregularities causing severe phase scintillation 1 in the nightside high latitude ionosphere during a substorm on 3 november 2013 substorm onset and a later intensification coincided with polar cap patches entering the auroral oval to become auroral blobs using global navigation satellite systems gnss receivers and optical data we show severe scintillation driven by intense auroral emissions in the line of sight between the receiver and the satellites during substorm expansion the area of scintillation followed the intense poleward edge of the auroral oval the intense auroral emissions were colocated with polar cap patches blobs the patches did not contain strong irregularities neither before entering the auroral oval nor after the aurora had faded signals from all three gnss constellations were similarly affected by the irregularities furthermore two receivers spaced around 120km apart reported highly different scintillation impacts with strong scintillation on half of the satellites in one receiver and no scintillation in the other this shows that areas of severe irregularities in the nightside ionosphere can be highly localized amplitude scintillations were low throughout the entire interval

speleology and magnetobiostratigraphic chronology of the buffalo cave fossil site makapansgat south africa speleological stratigraphic paleomagnetic and faunal data is presented for the buffalo cave fossil site in the limpopo province of south africa speleothems and clastic deposits were sampled for paleomagnetic and mineral magnetic analysis from the northern part of the site where stratigraphic relationships could be more easily defined and a magnetostratigraphy could therefore be developed for the site this is also where excavations recovered the fossil material described a comparison of the east and south african first and last appearance data with the buffalo cave fauna was then used to constrain the magnetostratigraphy to produce a more secure age for the site the magnetostratigraphy showed a change from normal to reversed polarity in the basal speleothems followed by a short normal polarity period in the base of the clastic deposits and a slow change to reversed directions for the remainder of the sequence the biochronology suggested an optimal age range of between 1 0 ma and 600 000 yr based on faunal correlation with eastern and southern africa a comparison of the magnetobiostratigraphy with the gpts suggests that the sequence covers the time period from the olduvai event between 1 95 and 1 78 ma through the jaramillo event at 1 07 ma to 990 000 yr until the bruhnes matuyama boundary at 780 000 yr the faunal bearing clastic deposits are thus dated between 1 07 ma and 780 000 yr with the main faunal remains occurring in sediments dated to just after the end of the jaramillo event at 990 000 yr

evaluating the structural character and tectonic history of the witwatersrand basin abstract the witwatersrand basin in south africa has been the focus of gold exploitation for more than 100 years and the subject of hundreds of research investigations principally sedimentological and metallogenic and recently geophysical and geochronological surprisingly the basin wide structural character has not been fully investigated despite the fact that gold metallogenic models have been proposed that want structural architectures as conduits for gold mobilisation and or sites of deposition i e the modified placer and hydrothermal models these models which have polarised viewpoints on the source for gold placer versus metamorphic or hydrothermal source assume an underlying structural character to the basin and structural relationships between goldfields but these assumptions have never been tested through evaluation of the existing structural dataset as corollary the published data for the structural character of the free state welkom klerksdorp west wits line west rand central rand east rand and south rand goldfields are summarised and evaluated to search for basin wide similarities and or correlations that would support tectonic models for the witwatersrand basin and explain its metallogenic character unfortunately the large published historical database 90 years proved to be quite limited with respect to geometric kinematic and or relative chronological detail but must be evaluated against an advanced understanding of earth processes tectonics and the structural geology approach the dataset is largely qualitative rather than quantitative but is useful in establishing broad tectonic trends of the formation and tectonic evolution for the witwatersrand basin it suggests that two deformation events umzawami and ukubambana events mark the end of deposition in the witwatersrand and transvaal basins respectively with development of fold thrust belts at ca 2 7 and 2 2 2 0 ga and these can be correlated with supercontinental cycles the intervening period i e 2 7 2 2 ga was characterised by at least 4 basin forming events that culminated in the deposition of the volcanic sedimentary sequences of the klipriviersberg group and the sedimentary sequences of the platberg chuniespoort and pretoria groups basin formation was facilitated by the reactivation of structures formed during the umzawami event or older as feeder dykes normal listric faults or growth faults the limited structural data for the witwatersrand basin unsurprisingly also leads to the conclusion that gold was macroscopically to mesoscopically remobilised from a primary placer source but remobilisation was localised goldfields scale and not is a basin wide phenomena

u series dating of hominin fossil bearing panlong cave in guangdong province southern china two hominin teeth and an abundance of faunal remains were recovered from panlong cave in guangdong province southern china in 1987 the site has remained largely unknown to the prehistoric community mainly for the lack of reliable chronological constraints this paper reports high precision mass spectrometric u series dating of eight calcite samples from the extant cross section based on the dates on the overlying flowstone layers the hominin teeth should be definitely older than 292 10 ka furthermore as indicated by the u series ages on the secondary calcite formations the fossiliferous deposits should be older than 441 18 ka these dates support the paleontological inference that panlong cave may predate the nearby maba hominin site the hominin specimens from the site may thus represent an early member of the ailuropoda stegodon fauna and one of the oldest non erectus middle pleistocene hominin fossils in southern china

uranium thorium protactinium dating systematics abstract with precise 234u 230th and 231pa data available 230th and 231pa ages can now be tested rigorously for concordancy if the material is not concordant the isotopic characteristics of this material may be examined in some detail here models similar to those used to describe the u pb system are evaluated for use in u th pa studies for the case in which initial 230th and 231pa concentrations are effectively zero the systematics of concordia plots in relation to models of variation in 234u episodic u loss or gain continuous u loss or gain and continuous 234u 230th and 231pa gain or loss are considered for the case in which initial u concentration is significant for example in many carbonate deposits we also examine linear u uptake models for the case in which initial u concentration is effectively zero for example in teeth and bones such models should prove useful in interpreting data from materials that have behaved as open systems in particular these models may help constrain the nature of diagenetic processes and in some situations it may be possible to determine or constrain true ages with materials that have behaved as open systems

esr dating of tooth enamel from yunxian homo erectus site china abstract two almost complete fossil hominid crania ev9001 and ev9002 were found in 1989 and 1990 in middle pleistocene terrace deposit of han river yunxian county hubei province china they are classified as homo erectus nine fossil animal teeth stratigraphically associated with the skulls were selected for electron spin resonance esr dating the simple exponential function was used for determination of the accumulated dose de and its appropriateness was discussed on the base of the experimental study the closed system assumption was checked and the early uranium uptake model was applied to age determination a mean age value was yielded to be 581 93 ka it deviates from the palaeomagnetic dating result of 830 870 ka micro regional complete saturation of esr signal in enamel of very high u content may account for the underestimation of esr ages nevertheless both esr and palaeomagnetic dating results place yunxian crania in between the homo erectus of lantian and zhoukoudian which means that yunxian crania constitute an important link in the human evolutionary lineage of china

a multi disciplinary seriation of early homo and paranthropus bearing palaeocaves in southern africa abstract fossils of early homo and paranthropus have been recovered from several sites in southern africa unfortunately their precise age has historically been difficult to assess hampering the reconstruction of their relationships to each other and to fossils from eastern africa multi dating strategies combining biochronological archaeological palaeomagnetic electron spin resonance esr and uranium series techniques are now clarifying their age the following sequencing of sites is suggested swartkrans member 1 2 0 ma gondolin 1 8 ma kromdraai 1 8 1 7 ma sterkfontein m5a 1 8 1 4 ma swartkrans m2 1 7 1 1 ma sterkfontein m5b 1 4 1 1 ma sterkfontein m5c 1 3 0 8 ma swartkrans m3 1 0 0 6 ma the position of coopers d and drimolen is difficult to access because they only have faunal age ranges 1 9 1 6 ma esr suggests mixing is a potential major problem in multi generational sites the oldest southern african representatives of early homo and paranthropus occur around 2 1 1 9 ma in swartkrans member 1 and are recorded almost continuously in the palaeocave deposits until around 1 0 0 6 ma in swartkrans member 3 currently these data suggest that paranthropus and homo first occur significantly later in the southern african record than the eastern african record moreover paranthropus persists much later in southern africa than in eastern africa

geoarchaeological finds below liang bua flores indonesia a split level cave system for homo floresiensis we report on new geoarchaeological finds in a recently discovered cave chamber liang bawah cave under neath positioned below liang bua on the island of flores indonesia where the type specimen for homo floresiensis was recovered from late pleistocene sediment at the rear of liang bua a 23 m long shaft inclined at 60 leads to a lower chamber measuring 23 m x 24 m x 5 m high about half the size of liang bua stone artefacts and bones were found shallowly buried in rubble at the base of the shaft and around a 5 m high mud mound that fills the northwest sector of liang bawah we recovered 17 stone artefacts made from chert and volcanics and more than 220 well preserved bone elements belonging to endemic giant rats pigs primates small murid rodents bats and introduced species multi collector inductively coupled plasma mass spectrometer mc icpms analysis of uranium and thorium in carbonate coatings on four bones yielded ages of similar to 240 180 ka endemic giant rat femur similar to 110 60 ka unidentified phalanx similar to 33 23 ka pig skull fragment and similar to 7 3 ka giant rat femur which overlap with the similar to 95 to 17 ka occupation of liang bua by h floresiensis the similar to 33 23 ka age of the pig skull fragment indicates that sus sp may have dispersed into island southeast asia earlier than previously recognised the passageway at the rear of liang bawah and a currently buried front entrance represent two possible transport paths for cultural and faunal material to the cave chamber analysis of the geomorphic evolution of liang bawah shows that it may have been a late pleistocene depocentre for material transported from the occupation chamber of liang bua and a repository for human subsistence refuse or pit fall trap via the rear passage these physical attributes and the antiquity of the faunal remains found thus far indicate that liang bawah could contain an archive of the late pleistocene and potentially remains of h floresiensis c 2015 elsevier b v all rights reserved

lower pliocene hominid remains from sterkfontein cosmogenic aluminum 26 and beryllium 10 burial dates of low lying fossiliferous breccia in the caves at sterkfontein south africa show that associated hominid fossils accumulated in the lower pliocene these dates indicate that the skeleton stw 573 and newly discovered specimens from jacovec cavern have much the same age approximately 4 million years these specimens are thus of an age similar to australopithecus anamensis from east africa

duration and structure of the past four interglaciations reanalysis and additional dating of the devils hole 18o paleotemperature record confirm that the last interglaciation in the great basin the continental analog of marine isotopic substage 5e lasted 22 000 yr consistent with the vostok paleotemperature record which suggests a duration of 19 000 yr for this event in antarctica the three preceding interglaciations in the devils hole record analogs of marine isotopic substages 7e 9c and 11c range from 20 000 to 26 000 yr in duration a 20 000 yr duration for the last interglaciation is consistent with tims uranium series dated sea level high stands thus the widely held view that interglaciations were of 11 000 to 13 000 yr duration and constituted only about 10 of mid to late pleistocene climatic cycles needs reexamination the warmest portion of each interglaciation in the devils hole time series is marked by a 18o plateau signifying apparent climatic stability for periods of 10 000 to 15 000 yr duration

contemporary flowstone development links early hominin bearing cave deposits in south africa abstract the cradle of humankind cave sites in south africa preserve fossil evidence of four early hominin taxa australopithecus africanus australopithecus sediba paranthropus robustus and early homo in order to integrate this record into a pan african scenario of human evolutionary history it is critical to have reliable dates and temporal ranges for the southern african hominins in the past a lack of precise and accurate chronological data has prevented the evaluation of the temporal relationships between the various sites here we report new uranium lead u pb radiometric ages obtained from sheets of calcium carbonate flowstone inter bedded between clastic cave sediments at the site of swartkrans providing bracketing ages for the fossiliferous deposits the fossil bearing units of swartkrans specifically the hanging remnant and lower bank of member 1 are underlain by flowstone layers dated to 2 25 0 05 ma and 2 25 0 08 ma and capped by layers of 1 8 0 01 ma and 1 7 0 07 ma the age bracket of the member 1 deposits is therefore between 2 31 and 1 64 ma however by combining the u pb with biostratigraphic data we suggest that this can be narrowed down to between 1 9 and 1 8 ma these data can be compared with other recently dated sites and a radiometrically dated u pb age sequence formed sterkfontein member 4 swartkrans member 1 malapa and cooper s d from this new u pb dataset a pattern of contemporary flowstone development emerges with different caves recording the same flowstone forming event specifically overlapping flowstone formation takes place at swartkrans and sterkfontein at 2 29 ma and 1 77 ma and at sterkfontein and malapa at 2 02 ma this suggests a regional control over the nature and timing of speleothem development in cave deposits and these flowstone layers could assist in future correlation both internal to specific deposits and regionally between sites

detailed mass spectrometric u series analyses of two teeth from the archaeological site of pech de l aze ii implications for uranium migration and dating abstract we report th u ages obtained by thermal ionization mass spectrometry of cross sections of two teeth from the archaeological site of pech de l aze ii the aim of this study is to reconstruct the pathways and time dependency of uranium uptake into different constituents of the two teeth a previous esr dating study of the two teeth yielded age estimates in the range of about 130 000 to 200 000 years which was in agreement with the geological assignment of riss for layers from which the specimens were recovered the closed system u series ages of all analyses range from 48 to 137 ka thus yielding age estimates which are between 30 and 90 ka too young the apparent closed system u series ages of the dentine and cement fractions at the top of the teeth are the oldest becoming gradually younger towards the interior of the two teeth the difference between apparent u series ages of dentine at the outer and inner parts of the two teeth is about 35 ka the enamel sections show the same patterns in u concentration and progression of apparent th u ages as the adjacent dentine samples but with generally younger ages our results indicate that uranium migrates both from the top and the base into the dentine of the teeth and from there into the adjacent enamel depending on the position of the sample significant uranium uptake appears to have taken place over many tens of thousands of years modelling the u uptake histories using a parametric model shows that for the cement and dentine components uptake is intermediate between linear uptake lu and early uptake eu closed system the enamel although often assumed to approximate more closely a closed system shows evidence of more recent u uptake these results also imply that it is not possible to use a simple single parameter u uptake model for all components of a given tooth either for u series or esr dating

archaeologically relevant dating techniques for the next century small hot and identified by acronyms abstract this paper presents a brief review of the development and application of dating techniques in addition to radiocarbon which are useful in an archaeological context for hominid evolution these include potassium argon argon argon and fission track dating for dating the emergence of anatomically modern man these include electron spin resonance uranium series amino acid racemization and luminescence dating new approaches are discussed which provide the basis for exciting new applications in the coming decades

australopithecus sediba at 1 977 ma and implications for the origins of the genus homo newly exposed cave sediments at the malapa site include a flowstone layer capping the sedimentary unit containing the australopithecus sediba fossils uranium lead dating of the flowstone combined with paleomagnetic and stratigraphic analysis of the flowstone and underlying sediments provides a tightly constrained date of 1 977 0 002 million years ago ma for these fossils this refined dating suggests that au sediba from malapa predates the earliest uncontested evidence for homo in africa

gps signal corruption by the discrete aurora precise measurements from the mahali experiment measurements from a dense network of gps receivers have been used to clarify the relationship between substorm auroras and gps signal corruption as manifested by loss of lock on the received signal a network of nine receivers was deployed along roadways near the poker flat research range in central alaska with receiver spacing between 15 and 30 km instances of large amplitude phase fluctuations and signal loss of lock were registered in space and time with auroral forms associated with a sequence of westward traveling surges associated with a substorm onset over central canada the following conclusions were obtained 1 the signal corruption originated in the ionospheric e region between 100 and 150 km altitude and 2 the gps links suffering loss of lock were confined to a narrow band 20 km wide along the trailing edge of the moving auroral forms the results are discussed in the context of mechanisms typically cited to account for gps phase scintillation by auroral processes

mass spectrometric u series dating of the chaoxian hominin site at yinshan eastern china the fossils of chaoxian hominin widely accepted as representing archaic homo sapiens in eastern china were recovered from the middle or slightly higher levels of layer 2 deposits of a collapsed cave at yinshan anhui province results of mass spectrometric u series dating of intercalated speleothem calcites are presented based mainly on four broadly coeval calcite samples the hominin fossils should be bracketed in the range of 310 360 ka or somewhat older these ages are much older than the previous estimate at 160 200 ka based on the u series dating of fossil teeth and bones and may be cited as supporting evidence for an earlier h erecrus archaic h sapiens interface in china c 2009 elsevier ltd and inqua all rights reserved

coupled esr and u series dating of fossil teeth from yiyuan hominin site northern china abstract coupled esr and u series analyses of mammalian fossil teeth were carried out on two localities of yiyuan hominin site locality 1 and 3 in northern china the u migration history of the fossil samples could be reconstructed by the combination of the two techniques and overcome the limitation of stand alone esr and u series age estimation we obtained a combined esr u series age au model range from 420 to 320 ka from nine teeth recovered from the two localities which pinpoints the deposition of hominin layer of yiyuan site to mis 11 to 9 the age results in this study places yiyuan site at the same time range of zhoukoudian locality 1 and hexian homo erectus sites comparing with other hominin sites this study of yiyuan homo erectus site highlights the possibility of coexistence between homo erectus and archaic h sapiens in china

preliminary u series and thermoluminescence dating of excavated deposits in liang bua sub chamber flores indonesia we report the results of a test excavation of deposits in a limestone cave sub chamber located beneath the main chamber of liang bua flores indonesia the discovery site of the small hominin species homo floresiensis well preserved remains of extinct pleistocene fauna and stone artefacts have previously been identified on the surface of a sediment cone within the sub chamber our excavation of the deposits at the base of the sediment cone in the sub chamber to 130 cm depth yielded only a few fragmentary bones of extant fauna uranium thorium u series or u th dating of soda straw stalactites excavated from 20 to 130 cm in depth demonstrates that the excavated sediments were deposited during the holocene red thermoluminescence tl dating of the sediments at the base of the excavation 130 cm depth indicates these sediments were last exposed to sunlight at 84 15 ka thousand years similar to red tl ages of cave sediments from the main chamber together these results indicate that the surface faunal remains which are morphologically analogous to pleistocene finds from the main chamber excavations were transported to the sub chamber relatively recently from the main chamber of liang bua and probably originated from conglomerate deposits at the rear of the cave and from deposits around the front entrance there is no evidence for hominin occupation of the sub chamber instead it seems to have acted as a sink for cultural materials and fossil remains transported from the surface via sinkholes despite the small number of finds from the test excavation it is possible that more extensive excavations may yield additional transported cultural and faunal evidence at greater depths c 2012 elsevier ltd all rights reserved

textural and geochemical discrimination between xenotime of different origin in the archaean witwatersrand basin south africa abstract xenotime ypo4 of detrital diagenetic and hydrothermal origin within siliciclastic rocks of the archaean witwatersrand basin south africa has been identified on the basis of petrography and in situ ion microprobe shrimp age data the chemical composition of xenotime determined by in situ electron microprobe analysis can be correlated with its origin this allows the origin of any xenotime grain to be assessed by a non destructive microanalytical method prior to ion microprobe geochronology the main chemical discriminators are mree hree abundance normalised hree slope and eu anomaly and in some cases u and th contents igneous detrital xenotime 2800 ma is distinguished from diagenetic 2780 ma and hydrothermal

new cosmogenic burial ages for sterkfontein member 2 australopithecus and member 5 oldowan the cave infills at sterkfontein contain one of the richest assemblages of australopithecus fossils in the world including the nearly complete skeleton stw 573 little foot in its lower section as well as early stone tools in higher sections however the chronology of the site remains controversial owing to the complex history of cave infilling much of the existing chronology based on uranium lead dating and palaeomagnetic stratigraphy has recently been called into question by the recognition that dated flowstones fill cavities formed within previously cemented breccias and therefore do not form a stratigraphic sequence earlier dating with cosmogenic nuclides suffered a high degree of uncertainty and has been questioned on grounds of sediment reworking here we use isochron burial dating with cosmogenic aluminium 26 and beryllium 10 to show that the breccia containing stw 573 did not undergo significant reworking and that it was deposited 3 67 0 16 million years ago far earlier than the 2 2 million year flowstones found within it the skeleton is thus coeval with early australopithecus afarensis in eastern africa we also date the earliest stone tools at sterkfontein to 2 18 0 21 million years ago placing them in the oldowan at a time similar to that found elsewhere in south africa at swartkans and wonderwerk

zhoukoudian in transition research history lithic technologies and transformation of chinese palaeolithic archaeology abstract zhoukoudian near beijing is where the homo erectus sinathropus pekinensis peking man fossils were found in the 1920s and has always been a focus for studies of palaeolithic archaeology in china this paper discusses two aspects of zhoukoudian in transition research histories and lithic technologies from a historical perspective the study considers the change in research paradigms and perspectives to examine how research at zhoukoudian has transformed chinese palaeolithic archaeology in the last two decades this paper will give an overview on lithic assemblages at zhoukoudian to illustrate the complexity of lithic industries in north china which are not yet fully understood in conclusion the study suggests more research problems rather than prestige collections that were inherited by the current generation of scholars who call for careful reviews of valuable historic data including lithic faunal sediment and human remains before any further interpretations are produced this study suggests that lithic industries in transition at zhoukoudian can provide another line of evidence to support the continuous development of pleistocene hominid evolutions especially leading to the origins of modern humans in china

speleothem derived asian summer monsoon variations in central china 54 46 ka the oxygen isotope signature delta o 18 of stalagmite si3 collected from shizi cave in north east sichuan province provides an asian summer monsoon asm record in central china for the period 54 46 ka the si3 delta o 18 record clearly shows a negative delta o 18 excursion centred around 49 4 ka which was reported in hulu cave in east china but not identified in the speleothem records from south west china as a whole this record displays a higher coherence with the two hulu records from east china than with the speleothem delta o 18 records from south west china suggesting that at 54 46 ka central china was influenced more by the east asian summer monsoon than by the indian summer monsoon it also displays a significant negative delta o 18 excursion at 47 5 46 6 ka which is not clearly documented in two other speleothem delta o 18 records previously reported from south west china this suggests that details of the greenland interstadial 12 warrant further investigations in future in monsoonal china the si3 delta o 18 record displays more significant centennial scale variations than the other four speleothem delta o 18 records from east and south west china which may be due to the fact that the study site is closer to the north west boundary of the asm and more sensitive to variations of the asm than east and south west china copyright c 2011 john wiley sons ltd

linking desert evolution and coastal upwelling pliocene climate change in namibia a late pliocene high resolution pollen record from the southeast atlantic ocean drilling program site 1082 registers vegetation development in southwest africa the marine record is continuous ranges from 3 5 to 1 7 ma and has a millennial resolution between 2 9 and 1 9 ma changes in climate and vegetation correspond to the matuyama diatom maximum of the namibian upwelling system and seem to be highly susceptible to latitudinal shifts in the polar front zone of the southern ocean a northward advance of the polar fronts is connected with an increase in winter rainfall in southwest africa rapid desiccation in namibia at 2 2 ma is associated with increasing upwelling and decreasing sea surface temperatures along the coast

assessing the paleoenvironmental potential of pliocene to holocene tufa deposits along the ghaap plateau escarpment south africa using stable isotopes the tufa deposits of the ghaap plateau escarpment provide a rich yet minimally explored geological archive of climate and environmental history coincident with hominin evolution in south africa this study examines the sedimentary and geochemical records of ancient and modern tufas from buxton norlim limeworks groot kloof and gorrokop to assess the potential of these sediments for providing reliable chronologies of high resolution paleoenvironmental information chronometric dating demonstrates that tufa formation has occurred from at least the terminal pliocene through to the modern day the stable isotope records show a trend toward higher more variable 18o and 13c values with decreasing age from the end of the pliocene onwards the long term increase in 18o values corresponds to increasingly arid conditions while increasing 13c values reflect the changing proportion of c3 c4 vegetation in the local environment analysis of the thabaseek tufa in particular provides valuable evidence for reconstructing the depositional and chronological context of the enigmatic taung child australopithecus africanus collectively the results of the present study demonstrate the potential of these deposits for developing high precision records of climate change and ultimately for understanding the causal processes relating climate and hominin evolution

application of sedimentary and chronological analyses to refine the depositional context of a late pleistocene vertebrate deposit naracoorte south australia cave deposits of infill sediments and associated vertebrate fossils provide a valuable source of information on terrestrial palaeoenvironments climatic conditions and palaeocommunities in the deposits of the naracoorte caves world heritage area such records span the last 500 ka and are renowned for their rich diverse vertebrate assemblages previous research into the grant hall deposit of victoria fossil cave suggested that it may preserve the only peak last interglacial ca 125 ka faunal community within the world heritage area the current work tested this existing model for the age of faunal remains from grant hall using multiple techniques physical and geochemical properties of the visually homogeneous sediments were analysed at regular intervals through the sequence to establish meaningful stratigraphic divisions and sediment provenance optically stimulated luminescence dating of individual quartz grains indicates that sediments accumulated in grant hall from 93 8 to 70 5 ka minimum ages provided by u th dating of fossil teeth 72 3 2 2 to 38 2 0 8 ka are consistent with the luminescence chronology and show that the deposit represents a more recent faunal accumulation than previously modelled for the site u th ages on calcite straws within the deposit are significantly older than the sediments and fossil teeth 500 to 186 4 1 ka as such they provide no further constraint on the chronology of the deposit but do indicate that speleothem deposition was active over much of the middle pleistocene sedimentary analyses resulted in the identification of five depositional units contrasting with previous divisions which were based only on visual observation of the sedimentary sequence sediments within each unit are broadly classified as sandy silts with soil structures and may be indirectly derived from the lunettes of nearby bool lagoon although their ultimate provenance is unknown as a result of this work palaeoenvironmental reconstruction based on fossil remains in the deposit may be more accurately related to prevailing climatic and environmental conditions at the time of accumulation it also contributes to an understanding of the temporal occurrence of regional vertebrate faunas through the late pleistocene reinforcing the value of developing stratigraphically constrained chronologies for cave deposits based on multiple techniques

uranium series chronology and environmental applications of speleothems an increasing number of scientists recognize the value of speleothems1 as often extremely well preserved archives of information about past climate vegetation hydrology sea level nuclide migration water rock interaction landscape evolution tectonics and human action well constrained data are required to document past changes reconstruct past patterns and predict future responses of the earth system at a wide range of spatial and temporal scales speleothems are particularly useful in this regard because they can be found in many locations of the globe sampled at high resolution and reliably dated using high precision uranium series techniques speleothems are bodies of mineral material formed in caves as the result of chemical precipitation from groundwater flowing or dripping in a cave most speleothems are composed of calcite formed by slow degassing of co2 from supersaturated groundwater but aragonite and gypsum forms are also common particularly near cave entrances where evaporative effects are important a host of different speleothem types decorate the walls ceilings and floors of caves and their mineralogy and morphology is a function of fluid flow and chemistry of waters feeding a particular location as well as the ambient conditions temperature chemistry light in the air or water filled void subaerial forms include the familiar stalagmites stalactites draperies flowstones subaqueous forms include rimstone pools rafts mammillary calcite wall coatings and dog tooth spar for an extensive review of the types of speleothem that have been observed see hill and forti 1997 speleothems are used in a multitude of ways to explore past environmental conditions perhaps the most fundamental of which is their very presence or absence deposition of speleothems relies on sufficient water supply and soil co2 to enable dissolution and transport of reactants in the vadose zone to underlying caves in arid or glacial times conditions may not have been favorable for speleothem formation

are u th dates correlated with historical records of earthquakes constraints from coseismic carbonate veins within the north anatolian fault zone u th dating of carbonate veins in connection with active tectonics has recently been used as an attractive tool for constraining the absolute timing of late quaternary crustal deformations in this study for the first time we correlate u th ages of travertine deposits in coseismic fissures along the north anatolian fault zone with records of paleoseismological studies supported by historical earthquake catalogued data u th ages are assessed in relation to the recurrence interval and the size and epicenter distance of major holocene earthquakes our statistical evaluations on age correlations indicate that the carbonate vein precipitation is concentrated in eight different periods along the north anatolian fault zone the periods are well correlated with historical earthquake records and with previous dating results of the nearby trench studies at least six of the periods correspond to the earthquakes reported in the historical catalogues the age correlations of carbonate precipitation intervals for the last millennium show a recurrence along the eastern north anatolian fault zone with a mode at 130 330 years that is consistent with a previously proposed paleoseismic recurrence interval of the fault recorded events in carbonate veins indicate a close epicenter d vi paleoearthquakes our results suggest that coseismic carbonate veins could be used to determine paleoseismic records as a supplementary tool to augment paleoseismological techniques this tool has advantages over traditional paleoseismological methods for the understanding of long term earthquake behavior particularly for prehistoric late pleistocene events which cannot be dated easily by traditional paleoseismological methods

regional and global context of the late cenozoic langebaanweg lbw palaeontological site west coast of south africa the palaeontological site of langebaanweg lbw is internationally renowned for its prolific diverse and exceptionally well preserved mio pliocene vertebrate faunas the site is located on the southern west coast of south africa which represents a passive intraplate trailing edge setting the southern african subcontinent is also removed from glacial influence and has experienced no cenozoic volcanic activity rates of vertical crustal motion are consequently low and late cenozoic shoreline datums at lbw chiefly reflect glacio eustatic sea level history the primary aim of this study is to clarify the chronology as well as the regional and global context of lbw and to review previous work on these aspects lbw is ideally situated to document the complex interactions of ocean atmosphere and land and their respective influence on climate evolution given its location near the coast and mix of marine estuarine and terrestrial faunas and depositional settings this paper also provides a background to the study of the vast existing faunal collections and a guide to undiscovered fossil deposits towards these ends the first detailed geological topographic maps of the site and surrounds accompanied by a summary stratigraphic column are provided virtual geological modelling using a subsurface database has clarified the spatial and temporal relationships of sedimentary facies as well as their depositional settings the geological and palaeontological record at lbw tracks and documents the major regional and global climatic oceanographic events of the late cenozoic during the oligocene drawdown in sea levels the landscape was etched by river incision fluctuating sea levels of the neogene periodically reversed the trend from erosion to deposition preserving contemporary faunas and floras in the oligocene palaeovalleys earlier miocene pollen from fluvial facies indicates a humid sub tropical climate reflecting a warm southern atlantic ocean the abrupt late middle miocene global cooling monterey excursion coincided with intensified cold upwelling in the benguela current and extensive phosphate authigenesis a globally documented early pliocene highstand possibly related to the shoaling of the isthmus of panama reached 90 m above sea level asl implying extensive melting of the cryosphere palaeomagnetic data in tandem with global sea level reconstructions suggested an age of 5 15 0 1 ma for the faunas and a correlation with the earlier part of this transgression a subtropical c3 vegetation is indicated by the faunas and floras but with a significant contribution by sclerophytic fynbos pointing to a cooler and more seasonal climate than in the miocene a mid pliocene highstand to 50 m asl truncated the early pliocene succession at lbw and the globally documented late pliocene highstand to 30 m asl saw the atlantic shoreline approaching lbw for the last time with the progressive climatic cooling and instability of the terminal pliocene culminating in the growth of the arctic ice cap strengthening southerly winds driven by a tighter coiled south atlantic anticyclone deposited extensive coastal dune fields over the region

thermal ionization mass spectrometry u series dating of a hominid site near nanjing china mass spectrometric u series dating of speleothems from tangshan cave combined with ecological and paleoclimatic evidence indicates that nanjing man a typical homo erectus morphologically correlated with peking man at zhoukoudian should be at least 580 k y old or more likely lived during the glacial oxygen isotope stage 16 similar to 620 ka such an age estimate which is similar to 270 ka older than previous electron spin resonance and alpha counting u series dates has significant implications for the evolution of asian h erectus dentine and enamel samples from the coexisting fossil layer yield significantly younger apparent ages that of the enamel sample being only less than one fourth of the minimum age of nanjing man this suggests that u uptake history is far more complex than existing models can handle as a result great care must be taken in the interpretation of electron spin resonance and u series dates of fossil teeth

open system modelling for u series and esr dating of teeth abstract the study of the constituents of teeth dentine and enamel by a combination of esr and u series techniques offer unique constraints on the history of uranium migration into these materials our results imply that it is inappropriate to assume a simplified u uptake model for neither the components of a single tooth nor for the faunal remains of a given site however the combination of both methods may provide a new technique for establishing reliable chronologies for archaeological quaternary sites of up to several hundred thousand years

u series dating of soda straw stalactites from excavated deposits method development and application to blanche cave naracoorte south australia this study aimed to further test the method reported by st pierre et al 2009 to develop robust chronologies of deposits in limestone caves through u th uranium thorium or u series dating of soda straw stalactites the chronology of fossil bearing deposits at blanche cave was further constrained with thermal ionisation mass spectrometry tims u th dating of 17 additional soda straw stalactite samples and results were compared to recalibrated c 14 ages of charcoal the results support the assertion that soda straw stalactites can provide ages close to the time of sediment deposition and may be used as reliable chronological markers particularly for periods reaching or beyond the radiocarbon dating limit the application of an enhanced cleaning technique facilitated the reduction of detrital th in samples significantly increasing age accuracy and precision additionally u th age accuracy and precision was increased through the application of site specific measured u th ratios to correct for the detrital th 230 component in samples c 2011 elsevier ltd all rights reserved

temporal overlap of humans and giant lizards varanidae squamata in pleistocene australia abstract an obvious but key prerequisite to testing hypotheses concerning the role of humans in the extinction of late quaternary megafauna is demonstrating that humans and the extinct taxa overlapped both temporally and spatially in many regions a paucity of reliably dated fossil occurrences of megafauna makes it challenging if not impossible to test many of the leading extinction hypotheses the giant monitor lizards of australia are a case in point despite commonly being argued to have suffered extinction at the hands of the first human colonisers who arrived by 50 ka it has never been reliably demonstrated that giant monitors and humans temporally overlapped in australia here we present the results of an integrated u th and 14c dating study of a late pleistocene fossil deposit that has yielded the youngest dated remains of giant monitor lizards in australia the site colosseum chamber is a cave deposit in the mt etna region central eastern australia sixteen new dates were generated and demonstrate that the bulk of the material in the deposit accumulated since ca 50 ka the new monitor fossil is minimally 30 ky younger than the previous youngest reliably dated record for giant lizards in australia and for the first time demonstrates that on a continental scale humans and giant lizards overlapped in time the new record brings the existing geochronological dataset for australian giant monitor lizards to seven dated occurrences with such sparse data we are hesitant to argue that our new date represents the time of their extinction from the continent rather we suspect that future fossil collecting will yield new samples both older and younger than 50 ka nevertheless we unequivocally demonstrate that humans and giant monitor lizards overlapped temporally in australia and thus humans can only now be considered potential drivers for their extinction

responses of quaternary rainforest vertebrates to climate change in australia a new previous termmiddle pleistocenenext term vertebrate fossil record from eastern australia dated by u disequilibrium series records the first quaternary record of an australian tropical rainforest fauna this exceptionally rich fauna underwent extinction after a long period of relative faunal stability spanning several glacial cycles and persisted probably until 280 000 years ago some time between 280 000 and 205 000 years ago the rainforest fauna was replaced by a xeric adapted fauna since that time the xeric adapted fauna was replaced by a mesic adapted fauna which was established by the holocene this is the first vertebrate faunal evidence in australia of the previous termmiddle pleistocenenext term mid brunhes climatic event mbe a major climatic reorganisation that led to increased aridity in northern australia from around 300 000 years ago several independent palaeoclimate proxies suggest that the climatic shift to aridity was due to increased climatic variability and weakened northern monsoons which may be manifested in the extinction of the aseasonal rainforest fauna and its replacement by an arid adapted fauna we extend the temporal ranges of several taxa from the pliocene into the previous termmiddle pleistocene next term we also reveal a longer palaeobiogeographic connection of rainforest taxa and lineages shared between new guinea and australia than was previously thought and show that their extinction on mainland australia occurred sometime after 280 000 years ago

recent mantle degassing recorded by carbonic spring deposits along sinistral strike slip faults south central australia abstract the interior of the australian continent shows evidence for late quaternary to recent fault controlled mantle 3 he and co 2 degassing a series of interconnected nw striking sinistral faults the norwest fault zone nfz in south central australia are associated with travertine mounds the latter show a regular spacing of 50 70 km u series ages on 26 samples range from 354 7 to 1 19 0 02 ka 2 errors and suggest a clustering every 3 4 ka since 26 ka geochemical data demonstrate a remarkable mantle to groundwater connection isotopic data indicate that the groundwater is circulating to depths 3 km and interacting with neoproterozoic cambrian basement and mantle volatiles 3 he 4 he isotope ratios show that the he comes in part from the mantle this demonstrates that the nfz cuts through the entire crust and provides pathways for mantle degassing scaling relationships suggest that the series of sinistral faults that make up the nfz are interconnected at depths and have a significant strike length of 60 70 km or more the nfz occurs where a major compositional boundary and a significant heat flow anomaly occurs and a major step in lithospheric thickness has been mapped we discuss a tectonic model in which recent stress field heat flow and lithospheric structure in central australia reactivated a set of steeply dipping neoproterozoic faults which may now be growing into a crustal lithospheric scale structure

dating pleistocene archeological sites by protein diagenesis in ostrich eggshell eggshells of the african ostrich struthio camelus ubiquitous in archeological sites in africa have been shown by laboratory simulation experiments to retain their indigenous organic matrix residues during diagenesis far better than any other calcified tissue yet studied the rate of l isoleucine epimerization to d alloisoleucine follows reversible first order kinetics and has been calibrated for local temperature effects and used to estimate the age range of stratified archeological sites age estimates are consistent with radiocarbon dates from several stratified archeological sites with adequate calibration this technique can provide accurate ages to within 10 to 15 percent for strata deposited within the last 200 000 years in the tropics and the last 1 000 000 years in colder regions such as china

climatic cycles investigated by sediment analysis in peking man s cave zhoukoudian china abstract the cave sediments at locality 1 in zhoukoudian which are more than 40 m thick have been divided into 17 layers according to recent dating by thermal ionization mass spectrometry tims the age of the sediments has been increased by about 200 ka on the basis of cluster and factor analyses of mammal fossils and sporopollen in the cave sediments and of the vicarious paleoclimatic indexes such as the weathering index and content of trace elements the paleoclimatic cycles recorded by the cave sediments have been quantitatively established based on the age of layer 2 410 ka bp by tims and the occurrence of the brunhes matuyana palaeomagnetic boundary in the upper part of layer 14 layers 1 14 of the cave sediments may be recorrelated with stages 11 19 of the 18o curve of deep sea cores or s4 s7of the loess sequences in china the secondary climatic variations in each paleoclimatic cycle may be correlated to one another to some extent according to deep sea core chronology the upper culture layer layer 4 the lower culture layer layer 8 9 and the bottom culture layer layer 10 were formed between about 470 and 670 ka bp and peking man should be at least 400 ka old