oxygen isotope compositions of phosphate from arvicoline teeth and quaternary climatic changes gigny french jura oxygen isotope compositions of biogenic phosphates from mammals are widely used as proxies of the isotopic compositions of meteoric waters that are roughly linearly related to the air temperature at high and mid latitudes an oxygen isotope fractionation equation was determined by using present day european arvicoline rodents tooth phosphate d 18 op 20 98 f0 59 0 572 f0 065 d 18 ow this fractionation equation was applied to the late pleistocene karstic sequence of gigny french jura comparison between the oxygen isotope compositions of arvicoline tooth phosphate and greenland ice core records suggests to reconsider the previously established hypothetical chronology of the sequence according to the d 18 o value of meteoric water mean air temperature relationships the d 18 o value of arvicoline teeth records variations in mean air temperatures that range from 0j to 15jc

esr dating in quaternary geology abstract electron spin resonance esr a relatively new dating technique was first suggested by zeller et al 1967 zeller 1968 and levy 1968 it has made substantial progress in frequent applications in the last few years esr dating is based on the direct measurement of the amount of radiation induced paramagnetic electrons trapped in crystal defects these free electrons were generated by alpha beta and gamma radiation of natural radioelements e g u th k and have accumulated in the minerals over geologic time the esr age is obtained by dividing the total amount of accumulated radiation dose archaeological dose ad by the dose per year annual dose this review comprises four major parts the principles of the method the determination of the archaeological dose ad the determination of the annual dose and a compilation of datable materials several questions remain the evaluation of the ad the determination of the annual dose and particularly with respect to the nature and stability of the electron traps used for dating

cyclic sedimentation in brazilian caves mechanisms and palaeoenvironmental significance abstract caves associated with doline slopes in the tectonically stable area of eastern brazil display remarkable sequences of clastic sediment intercalated with calcite layers sediment erosion has also occurred allowing access to formerly sediment filled passages the palaeoenvironmental meaning and chronology of these three processes i e clastic sediment input clastic sediment erosion and speleothem precipitation were studied in both semi arid campo formoso and sub humid lagoa santa areas through 230 th dating and stratigraphical analyses the dry climate of the campo formoso area prevents speleothem deposition at present but soil erosion results in valley aggradation and cave infilling growth periods of speleothems and travertines in this area have allowed the recognition of recurrent past phases of increased humidity correlated with wet conditions recorded in southeastern brazil speleothem calcite at the lagoa santa area there is limited speleothem precipitation and sediment input at present however sediment entrainment is actively exhuming speleothems and exposing cave passages sediment erosion inside caves in the area is interpreted as being due to intermediate climatic conditions not wet enough to favour speleothem deposition and not too dry to allow doline slope erosion and sediment transport into caves due to the low rates of denudation and isostatic rebound inherent to tectonically stable areas cave passages will remain within the range of sediment infill and erosion for a much longer time than in tectonically active areas spanning in average at least three full glacial interglacial cycles as uplift proceeds cave passages will be decoupled from the doline bottom and no longer will be affected by erosion or infilling episodes sediment filled passages in many caves in the lagoa santa region are relict features that display ancient clastic and chemical precipitation the three processes described above have occurred throughout the life history of the caves resulting in complex sediment assemblages that can however show significant intra and inter site variations

late pleistocene detrital sediment yield of the jura glacier france abstract measures of present day glacial erosion vary widely with the technique employed this paper quantifies the glacial material trapped in a proglacial lake during the wurm glacial period the combe d ain site was occupied by a meltwater lake where all the detrital material entering it from the jura glacier accumulated sediment yield is computed from three factors 1 the size of the sediment source area 2 the length of time the system operated and 3 the volume of sediment trapped the sediment budget of the lake system suggests a detrital sediment yield of 4400 1700 metric tons per square kilometer and per calendar year this represents a denudation rate of 1 6 0 6 mm per year illustrating that mechanical erosion by the jura glacier is more intensive than other processes of erosion

stratigraphical and palaeontological data from the early pleistocene pirro 10 site of pirro nord puglia south eastern italy the pirro nord palaeontological and archaeological locality has been the object of recent field research to investigate the fossil content of its early pleistocene vertebrate palaeocommunities and to understand the genesis of the karst network and related deposits that delivered the lithic industry representing the earliest human occupation of europe known so far spanning 1 7e1 3 ma the succession of the pirro 10 site has been described in terms of facies and fossil vertebrate content of the 37 distinguished sedimentary units su on the whole the succession is made of chemical and clastic sediments that include debris fall and alluvial deposits su are distinguished according to lithology colour discontinuities lamination fossil concentration and taphonomical parameters palaeomagnetic data and biochronological characteristics refer the pirro 10 site to the latest late villafranchian mammal age of the italian biochronological mammal scale the fossil content is quite homogenous common taxa are axis eurygonos hystrix refossa ursus etruscus canis mosbachensis together with small mammal remains mainly represented by chiroptera and the arvicolid microtus allophaiomys e x gr ruffoi a significant change in the taxonomic record occurs in

glass bearing crustal xenoliths buchites erupted during the recent activity of stromboli aeolian islands abstract three xenoliths erupted as ejecta during recent violent explosion of stromboli volcano aeolian islands were investigated in this paper they consist of high temperature mineral association cordierite hercynite spinels sillimanite plagioclase mullite corundum and abundant glass 10 70 vol and may be classified as buchites the peraluminous composition of the xenoliths their trace element distribution and ree patterns support their origin from granulite and amphibolite facies metapelites of the calabrian continental crust which is considered the crystalline basement beneath stromboli buchites have an isotopic composition comparable to that of stromboli extrusives and significantly different from that of the calabrian basement the glass is generally colourless and has a si al alkali rich composition except for one sample where a fe mg ca rich reddish brown glass also occurs these two kinds of glass show complicated textures where patches of reddish brown glass are often surrounded by plagioclase and or cordierite or forms streaks and swirls with the colourless glass cordierite plagioclase and oxides have different compositions according to their position in the xenoliths ca rich plagioclase an72 95 mg poor cordierite mg values 47 66 and al rich spinels are in the inner portions of the xenoliths and associated with colourless glass on the contrary close to the contact with the host lava or associated with coloured glass cordierite shows higher mg values ti fe bearing oxides occur and plagioclase is chemically similar to the basalt phenocrysts an66 71 the abundant and fresh glass and the idiomorphic shape of the high temperature minerals suggest that the xenoliths were hold in the basaltic magma before its extrusion for a significant time to allow their partial or nearly complete melting and subsequent nucleation and growth of new phases during this stage the interaction between the anatectic liquid and the basaltic magma affected the original isotopic composition of the xenoliths and in some cases produced glass and mineral phases cordierite plagioclase and oxides with different composition

pollen analysis of a long upper pleistocene continental sequence in a velay maar massif central france abstract a new 20 m sequence is presented which is based on 279 spectra derived from a coring at le bouchet lake massif central france the vegetational history of this region is described back to the end of the last interglacial ribains interglacial the two preglacial early glacial forested interstadials st geneys 1 and st geneys 2 are evidence for the first time in the massif central in spite of the altitude of the site 1200 m they suggest a quite temperate vegetation with the same mesophilous character as during the holocene the pleniglacial appears to be threefold with two cold episodes lower and upper pleniglacial divided by a long complex period of moderate climatic improvement the vegetation history of this mountain region is compared with that evidenced for the same period on the basis of the sequence of les echets at a lower altitude 267 m botanical and climatic inferences are discussed

expansion and retreat of the jura ice sheet france during the last glacial maximum in continental environments while there is no uninterrupted record of glaciation glacier activity can be reconstructed from the nature and geometry of sediments trapped by lake filling examination of the combe d ain lake filling provides insight into the history of the jura mountains during the last glacial maximum lgm from the evidence of outcrops borehole cores and seismic reflection profiles of the lake filling we show that glaciation was marked by three stages of stabilization then recessional moraines marked five episodes of stabilization in the course of glacial retreat comparison with b 18 o data from ice cores of greenland makes possible to date the last glacial maximum at 25 500 22 000 cal bc and

lithospheric contributions to arc magmatism isotope variations along strike in volcanoes of honshu japan major chemical exchange between the crust and mantle occurs in subduction zone environments profoundly affecting the chemical evolution of earth the relative contributions of the subducting slab mantle wedge and arc lithosphere to the generation of island arc magmas and ultimately new continental crust are controversial isotopic data for lavas from a transect of volcanoes in a single arc segment of northern honshu japan have distinct variations coincident with changes in crustal lithology these data imply that the relatively thin crustal lithosphere is an active geochemical filter for all traversing magmas and is responsible for significant modification of primary mantle melts

neandertal extinction and the millennial scale climatic variability of ois 3 population models seeking climate as a triggering factor for the extinction of neandertals and the colonisation of europe by anatomically modern humans are contradictory due to uncertainties in the dating methods in the cultural attribution of archaeological layers and to the lack of terrestrial continuous and well dated palaeoclimatic sequences this is particularly the case for the iberian peninsula where neandertal populations seem to have survived later than in other regions of europe a review of the available palaeoclimatic evidence for ois3 of iberia reveals that this mainly consists of low resolution fragmentary ill dated and often ill interpreted records correlation between palaeoenvironmental sequences from two images pollen rich deep sea cores and archaeological data from western europe the electronic archive of the radiocarbon dates is available at qsr website http www elsevier nl locate quascirev indicates that aurignacian moderns colonised france and the north of iberia at the onset of the h4 event during this cold episode a probable contraction of neandertal populations is recorded in southern iberia where no aurignacian settlements are detected such a decline in population density is correlated with the particular desert steppe like environments made up of artemisia chenopodiaceae and ephedra characterising the h4 of this area while reducing the size of neandertal populations this inhospitable environment may have favoured their persistence in this region mainly exploiting herds of herbivores adapted to graminees rich grasslands the aurignacian moderns were probably not interested in colonising these arid mediterranean biotopes and did that only after the h4 event

historical climatic record from flood sediments deposited in the interior of spiralka cave czech republic abstract magnetic susceptibility was measured on more than four hundred samples collected from a 5 m high section of fine grained sediments deposited during flood events in the interior of spiralka cave spiralka cave is located in the northeastern portion of the moravian karst czech republic in the upper 1 5 m of this profile mineral magnetic fe arm sirm s ratio t and other non magnetic measurements heavy mineral concentration loss on ignition and particle grain size indicate that variations are controlled by the concentration of magnetite and by magnetic grain size i e increased magnetic susceptibility results from increased concentration of coarse grained magnetite a positive correlation with ti and zr concentrations in this part of the profile with our magnetic susceptibility record is a detrital signal responding to changing environmental conditions in the catchment area furthermore a comparison of our susceptibility record to the record of winter temperature anomalies constructed from both instrumental and historical records collected at the klementinum observatory in prague shows a remarkable correlation the most probable explanation of these correlations is that during years with warmer winters positive winter temperature anomalies and less snow cover the floods were less intensive but probably had access to larger tracts of cultivated land as agriculture tended to expand during these warmer periods cultivation of the land provided flood waters with greater access to coarser grained magnetite like materials exposed by tilling of soils lower in the profile interpreting the environmental significance of magnetic susceptibility variations is more complex as remobilization of iron has occurred nevertheless the magnetic susceptibility record when coupled with non magnetic measurements can be shown to correlate to known environmental conditions present in central europe during the deposition of the lower portion of the profile

the last glacial interglacial record of rodent remains from the gigny karst sequence in the french jura used for palaeoclimatic and palaeoecological reconstructions abstract a multidisciplinary approach has produced an exceptional chronological log of climatic patterns for the upper pleistocene sequence of gigny cave jura france covering the pre eemian eemian interglacial middle glacial and upper pleniglacial as well as a part of the holocene multivariate analysis correspondence and component analysis of rodent associations from the sequence is used here to characterize the different climatic stages in terms of relative temperature plant cover and moisture faunal analysis establishes 1 positive and negative correlations among the variations of the different species 2 the significance of axis 1 component analysis which in terms of temperature opposes cold environments with contrasted continental biotopes 3a the significance of axis 2 component analysis which reflects vegetation patterns ranging from open to closed habitats 3b the significance of axis 3 component analysis which expresses trends in moisture 4 various correlations between faunal and climatic parameters temperature plant cover and moisture 5 evaluation of faunal diversity shannon index ranging from 0 74 to 2 27 showing that diversity increases with temperature and the complexity of vegetation but is not sensitive to moisture lastly the comparison of multivariate methods with the weighted semi quantitative hokr method shows the complementarity of the two approaches the first methods quantifying climatic parameters while the second seems to provide more precise evaluations of the main seasons of rainfall

sr and nd isotopic compositions of mafic xenoliths and volcanic rocks from the oga peninsula northeast japan arc genetic relationship between lower crust and arc magmas abstract whole rock and constituent hornblende and plagioclase geochemical and isotopic compositions of 52 mafic xenoliths from the ichinomegata maar in the oga peninsula located on the backarc side of northeastern japan were investigated to further understand the nature of lower crustal materials beneath the oga peninsula the inter rock variations in isotopic compositions 87sr 86sr ratios of 0 703245 0 705246 and 143nd 144nd ratios of 0 512910 0 512608 correlate negatively with 87rb 86sr and 147sm 144nd ratios a continuous and arcuate trend in a sr nd isotope diagram suggests a two component mixing curve is present at lower 87sr 86sr and higher 143nd 144nd ratios this trend extends towards and partly overlaps quaternary volcanic rock compositions from the toga ichinomegata xenolith hosting pumice and kampu volcanoes on the oga peninsula herein oga volcanic rocks this overlapping suggests a common control on the isotopic variations within both xenoliths and volcanic rocks this common control is most likely to be the metasomatism of intact original lower crustal material by parental magmas of the oga volcanic rocks herein termed the oga parental magma in addition to the contamination of the oga parental magma by the crustal material after contact between the two this metasomatism also caused isotopic re homogenization of these constituent minerals meaning hornblende and plagioclase within individual xenoliths have the same sr nd isotopic compositions i e they show no intra rock variations suggesting thermal re setting however inter rock variations imply that full metasomatism and destruction of the original isotopic and geochemical characteristics of the lower crust did not occur these inter rock variations are consistently present as changes in the geochemistry of constituent minerals with k2o rb sr sm and nd concentrations varying in hornblende and anorthite contents an varying in plagioclase the original lower crustal material as one end member of a mixing curve is assumed to have a 87sr 86sr ratio of 0 705250 and a 143nd 144nd ratio of 0 512570 whereas the oga parental magma forming the other end member on the mixing curve has a 87sr 86sr ratio of 0 702958 and a 143nd 144nd ratio of 0 512933 as represented by oga volcanic rocks with the lowest 87sr 86sr and highest 143nd 144nd ratios stage 3 lavas from kampu volcano near ichinomegata maar the isotopic compositions of other oga volcanic rocks vary from the most contaminated toga rhyolitic pumices 87sr 86sr of 0 703723 0 703885 and 143nd 144nd of 0 512906 0 512847 through to the ichinomegata host pumice 87sr 86sr of 0 703398 and 143nd 144nd of 0 512895 this research indicates that both the ichinomegata mafic xenoliths and the oga volcanic rocks have undergone isotopic changes creating an overlap in compositions caused by metasomatism and contamination respectively this relationship between lower crustal and volcanic rocks can be also be applied to trench side volcanic rocks if the ichinomegata lower crustal material extends to the trench side of the ne japan arc the island arc tholeiites typically found within the volcanic front probably also contain a similar if not identical lower crustal component

chronostratigraphic context of the middle to upper palaeolithic transition recent data from belgium abstract the chronological and palaeoenvironmental context for the industries identified in europe during the middle to upper palaeolithic transition mupt is not accurately known this situation is mainly due to insufficient knowledge of the context of the archaeological data much of which comes from old excavations any major progress in the understanding of the mupt can only be achieved with the study of long sedimentary sequences providing a semi continuous record and situating archaeological remains in a reliable palaeoenvironmental and chronological framework strict attention must also be paid to stratigraphic control and site formation processes interdisciplinary studies undertaken over the last ten years in belgium contribute to research on the mupt belgium plays an important role due to its specific geological context that includes many caves a well developed loess cover which acts as a reference sequence for the upper pleistocene and the presence of tephras this enables detailed reconstruction of climatic change and more accurate chronological control in cave sequences initial results from new fieldwork on long sequences are presented here walou and scladina caves as well as the open air site of maisieres canal combined with results of recent analyses on old material mainly from the spy and trou de l abime collections they enable establishment of a reliable and more accurate chronostratigraphic framework for the archaeological assemblages and provide new data on the humans responsible for them thus around 45 000 bp a mousterian industry was made by neandertals in trou de l abime around 40 000 38 000 bp belgium was still occupied by neandertals associated with a typical middle palaeolithic as shown in walou the spy neandertals have recently been directly dated by 14c to 36 000 bp but the techniques of the early excavations prevent clear identification of the associated industry still the 14c results are more coherent with the lincombian ranisian jerzmanowician lrj chronology than the mousterian both of which are identified at spy the earliest convincing age for the belgian aurignacian is about 32 000 33 000 bp maisieres canal and spy

meta igneous granulite xenoliths from mount ruapehu new zealand fragments of altered oceanic crust meta igneous granulite mig xenoliths in lavas from mount ruapehu taupo volcanic zone new zealand have variable but relatively high 18o 8 2 to 11 7 and 87sr 86sr 0 70506 to 0 70872 and end ranging from 1 5 to 6 2 they show a strong positive correlation between 87sr 86sr and 18o both of which are also broadly correlated with mg number but lack any correlation between 87sr 86sr and end the xenoliths have been mineralogically re equilibrated at lower crustal temperatures 800 930 c and pressures 7 10 kbar geochemical and isotopic evidence suggests they are fragments of oceanic crust that have been altered previously in an ocean floor hydrothermal system alternatively they may be igneous rocks of unknown origin hydrothermally altered in the lower crust irrespective of this uncertainty the xenoliths provide rare samples of the lower crustal basement beneath taupo volcanic zone and represent a potential source rock for the voluminous rhyolites and ignimbrites that dominate the zone

u series dating and taphonomy of quaternary vertebrates from brazilian caves abstract the geochronology and taphonomy of internationally important fossil bearing cave deposits were studied both in the semi arid northern bahia area and the subtropical southeastern lagoa santa area of brazil taphonomic analysis suggests that the processes responsible for bone accumulation in the brazilian caves vary between sites and taphonomic bias can therefore be significant in causing differences in faunal composition in the toca da boa vista caves the presence of single articulated skeletons and the entrance related distribution indicate that random penetration of animals is the main mechanism of fossil accumulation a process that biases the assemblage to smaller species and takes place over extended time periods in nearby toca dos ossos cave transport by runoff in the cave river is predominant and biases the fauna remains to larger more robust bones and species deposition probably also occurred only at times of enhanced runoff giving a more contemporaneous assemblage similar processes were responsible for emplacement of the copious fossil remains in the more humid lagoa santa area where terrigenous fossil deposits are found intercalated by massive speleothem calcite layers in this area runoff under a drier climate probably accounts for the sediment emplacement inside caves in both areas the mode of emplacement implies bias in the fossil record resulting in fossil assemblages that do not mirror surface faunas limiting palaeoenvironmental reconstruction mass spectrometric u series analysis of speleothem calcite overlaying fossil remains gives minimum ages for fossil deposition these ages confirm the previous view that many of the deposits derive from the late glacial but also show that much older material some 350 000 yr is also present the habitat requirements of critical fossil species such as bats and monkeys strongly suggest that they derive from much wetter periods when forest cover was present in the currently semi arid northern bahia area taphonomy exerts a major control on the diversity and mode of emplacement of cave fossil deposits in eastern brazil and thus detailed sedimentological and hydrological studies coupled with a sound geochronological approach are essential in quantifying the relative importance of each taphonomic processes before faunal and palaeoecological interpretations can be attempted

late pleistocene climatic change in the french jura gigny recorded in the δ18o of phosphate from ungulate tooth enamel oxygen isotope compositions of phosphate in tooth enamel from large mammals i e horse and red deer were measured to quantify past mean annual air temperatures and seasonal variations between 145 ka and 33 ka in eastern france the method is based on interdependent relationships between the delta 18 o of apatite phosphate environmental waters and air temperatures horse equus caballus germanicus and red deer cervus elaphus remains have delta 18 o values that range from 14 2 to 17 2 indicating mean air temperatures between 7 degrees c and 13 degrees c oxygen isotope time series obtained from two of the six horse teeth show a sinusoidal like signal that could have been forced by temperature variations of seasonal origin intra tooth oxygen isotope variations reveal that at 145 ka winters were colder 7 2 degrees c than at present 3 1 degrees c while summer temperatures were similar winter temperatures mark a well developed west east thermal gradient in france of about 9 degrees c much stronger than the 4 degrees c difference recorded presently negative winter temperatures were likely responsible for the extent and duration of the snow cover thus limiting the food resources available for large ungulates with repercussions for neanderthal predators c 2011 university of washington

economic coalbed methane production in the canadian foothills solving the puzzle abstract the producibility of methane at economic rates from thick and very gassy coals in the canadian foothills and mountains remains a major challenge these structurally deformed and often sheared coals are generally characterized by low permeabilities which is the main limiting factor restricting the flow of gas through natural fractures a preliminary evaluation of the cleating in the coals and of the jointing in the interburden clastics was carried out in the elkview mine of se british columbia field observations were supplemented by microscopic evidence on coal microtextures produced by shearing and their impact on coal permeability permeability of the coals tested at simulated in situ stress conditions and parallel to bedding surfaces was highly variable ranging from 2 09 md in seam 3 greenhills mine to less than 0 001 md in the sheared seam 10 elkview mine this variation may be rationalized based on variations in maceral composition stress history degree of shearing and the mode of deformation of the coal seams in these tectonically complex regions shearing gave rise to a variety of complex textures in coal such as slickensides shear cones and striated features small scale thrusts in the hangingwall and brittle and ductile microtextures furthermore the coal seams act as aquitards to the flow of water most likely because of low permeability water flow occurs at the contact between coal and interbedded coarser clastics and within the highly fractured and jointed sandstone units the cone of effective depressurization required for coal gas drainage to occur in the study area is influenced by a the development of a joint system in the more competent clastic beds that would provide the high permeability pathways for water and gas and b the ability of the rocks above the coals to re pressurize as a result of either surface recharge or water flow both laterally and vertically within the succession therefore multidisciplinary studies of hydrology coalification history and structure would help increase our understanding of the mechanisms and timing of cleat development effect of shearing on coal permeability and presence of systematic fractures in the non coaly lithologies

striated conical structures and related fractures in bituminous coal of the southern canadian rocky mountains abstract striated structures many of which are conical in form are common mesoscopic features in bituminous and semi anthracite coals of the southern canadian rocky mountains the structures are planar conical to pyramidal in outline and are characterized by striae which radiate from a common apex and bifurcate or horsetail to form secondary structures on the master surface they are up to 20 cm in length 4 cm in width and have apical angles varying from 10 to 50 the striated structures occur at numerous localities in both highly sheared and relatively unsheared coal seams the conical striated structures closely resemble some shatter cones developed in fine grained rocks whereas the planar striated structures are somewhat similar to chevron structured hackle marked joints the pyramidal structures are apparently unique to coal all three types of structures are considered to be the result of brittle shear fracture based on their occurrence orientation and morphology the apparently restricted occurrence of the structures to coal is likely a function of the homogeneity and low tensile and compressive strength of bituminous and semi anthracite coals possibly augmented by high inter and or intra particle gas pressure resulting from devolatization of the coal during progressive coalification

missing records and depositional breaks in french late pleistocene cave sediments abstract cave entrance and rock shelter infillings are positioned within the pleistocene chronology for three areas of france northern alps franche comte and perigord despite minor local variations it is possible to identify regional types with a consistent depositional record over long intervals of time the interregional variability relates to the frequency and position of the gaps within the infillings sites in the northern alps have not yielded any artifacts older than the upper paleolithic magdalenian and dated sedimentary sequences do not go back beyond the older dryas more complete sequences in franche comte contain mousterian industries two major gaps occur here one lasting about 50 000 yr during the lower glacial and lower pleniglacial periods and the other lasting some 10 000 yr during the upper pleniglacial the sequences are more complete in the perigord where all major climatic phases have been identified with no significant sedimentary gaps differences in sedimentary records can be explained by variations in regional conditions during the last interglacial glacial cycle and especially by the distance from the maximum advance of ice daring glaciation

the significance of stratigraphic discontinuities in iberian middle to upper palaeolithic transitional sites the extinction of the neanderthals remains an open question and the current chronological archaeological and paleoclimatic evidence reflects complex regionally diverse scenarios for the iberian peninsula the existence of early upper palaeolithic assemblages in the north of spain raises questions about the influence of incoming upper palaeolithic groups on the native neanderthals however this evidence remains unexplained from a historical perspective at the same time recent paleoclimatic data suggest that the environmental effects of heinrich event 4 entailed a gap in human presence at the middle to upper palaeolithic boundary casting doubts on the archaeological evidence from the north of spain in order to evaluate the evidence of continuity vs discontinuity of human occupation in the iberian peninsula at the passage from the middle to the upper palaeolithic a concise overview was conducted of lithostratigraphic data available in the archaeological literature on iberian sites known to represent the middle to upper palaeolithic transition the bulk of published sites show stratigraphic discontinuity between the latest middle and earliest upper palaeolithic evidence and in many cases the sedimentary record reflects cold climatic conditions this data support the existence of a gap in human presence in disagreement with theories involving contact and acculturation and suggesting that climate might have played a significant role in the population dynamics of the iberian peninsula at the middle to upper palaeolithic boundary

cave clastic sediments and implications for speleogenesis new insights from the mugnano cave montagnola senese northern apennines italy abstract the study of cave clastic sediments has been considered one of the hottest topics during the last years because of their importance in paleoclimatic reconstructions and archaeological surveys this paper focuses on clastic deposits of the mugnano cave a small cave located in the siena district northern apennines italy showing unique features regarding the sedimentary fill mostly made of grey blue dolomitic silts the sedimentary succession was investigated through a detailed sedimentological analysis aimed at a better understanding of sedimentary processes active during the deposition the entire succession was subsequently reinterpreted through an allostratigraphic approach the recognition of an important erosional surface associated with a significant change in sedimentation allowed the distinguishing of two main allounits labelled mg1 and mg2 furthermore the different kinds of sediments collected in the cave were analysed using the xrf and xrd techniques in order to establish their chemical and mineralogical compositions the integration of lithological sedimentological allostratigraphic and mineralogical data permits formulation of an interesting hypothesis about speleogenetic processes that influenced the cave with particular reference to the processes capable of generating the underground space in this context most of the current available space results from a complex interplay between different processes disintegration of a particular lithofacies of the bedrock consequent production of sediments and deposition into a subterranean lake these sediments were removed from the cave during some non depositional and erosive phases which led to a positive balance in the available space

archaeological discontinuity in ultima esperanza a supra regional overview abstract the regional archaeological discontinuity between ca 11 761 272 cal bp and the beginning of the holocene at ultima esperanza chile will be discussed the absence of humans as measured by the deposition of artifacts on dated deposits was originally detected at the site scale especially at cueva del medio and cueva lago sofia 1 but recent excavations at several other sites extend it to the full scale of the cerro benitez locality it is suggested that this is not a case of abandonment of a colonized region but instead a case of discontinuation in the logistical use of a particular environmental patch accordingly the early holocene human presence in the cerro benitez locality is seen as the result of a new exploration by human foragers adapting to the increasingly forested environments of ultima esperanza

climatic stages recorded in sediments of the gunang cave south korea abstract this paper presents and analyses lithological stratigraphic and geochronological data on the gunang cave which is an important archaeological site in south korea it discusses problems of the age and origin of its sedimentary sequence which consists of clastics and hardpan speleothems the sediments compose a 4 m thick lens near the cave entrance the lens formed during the middle late pleistocene and holocene according to 14 c and u th dating the changes of cave environments are reconstructed based on sedimentological palynological mineralogical magnetic and geochemical data the clastic sediment unit consists of roof fallen limestone debris cemented by fine grained matrix the matrix is dominated by silt 80 which aeolian component is 60 65 the amount of the wind blown component is persistent throughout the clastic layers suggesting a relatively stable depositional process in dry environment in contrast three lime cemented hardpans formed in a wet environment of groundwater seepage the revised age model suggests that the hardpans formed in early mis1 mis 5 5 and mis 7 and therefore correspond to the wetness maximums of these warm stages

picritic primary magma and its source mantle for oshima ōshima and back arc side volcanoes northeast japan arc oshima shima volcano is an endmember of a geochemical variation which is characterized by a low feo content toward the back arc side across the ne japan arc analyses of the basalts show primitive characteristics variation trends of the chemical compositions indicate initial olivine control then olivine clinopyroxene control from a picritic to a differentiated basalt the more magnesian basalts have the more magnesian olivine phenocrysts the most magnesian mgo 15 of all rock samples contains olivine phenocrysts with a composition of fo 93 7 as a liquidus phase and is considered a product of a mantle derived magma the possible range in feo and mgo content of source mantle for the oshima shima magma can be demonstrated ichinomegata lherzolite inclusions also from the back arc side of ne japan is unlikely to be a candidate for the source mantle for high feo the upper mantle beneath the back arc side is considered to be compositionally zoned a fe rich mantle ichinomegata lherzolite at shallower place and a fe poor mantle the source mantle for back arc side volcanoes

settling in sahul investigating environmental and human history interactions through micromorphological analyses in tropical semi arid north west australia the pleistocene continent of sahul was first settled by people who arrived by watercraft from island south east asia about 50 000 years ago some of the oldest archaeological sites in sahul are located in the southern kimberley in northwest australia this area lies within the southern zone of influence of the tropical monsoon and thus has always been highly sensitive to changes in monsoon dynamics over time how these climatic changes have affected the colonisation and occupation of australia is an important research theme in australian archaeology this paper illustrates the contribution and challenges of micromorphology in deciphering palaeoenvironmental and anthropogenic markers in a still largely unexplored australian context micromorphological analysis of two archaeological sequences in the napier range carpenters gap 1 and 3 provides a complementary and comprehensive reconstruction of the human climate history in this area spanning nearly 50 000 years of australian human presence the results demonstrate an opportunistic use of sites by people through time surprisingly independent of local climatic variation suggesting highly flexible subsistence strategies

petrographic and geochemical characterization of the upper cretaceous coal and mudstones of gombe formation gongola sub basin northern benue trough nigeria implication for organic matter preservation paleodepositional environment and tectonic settings abstract under exploration of the upper cretaceous petroleum systems in the northern benue trough nigeria has been attributed largely to lack of subsurface samples and non integration of organic and inorganic geochemical methods recent access to surface sampling from maiganga coalfield revealed a need for detailed evaluation of the sedimentary facies types for better understanding of the hydrocarbon potential of the area detailed maceral point count py gc chnso as well as major oxides and trace element icp ms analysis were used to characterize the gombe formation coals and the mudstones for determination of the organic matter origin preservation paleodepositional environment tectonic setting and paleoclimatic condition during sedimentation evaluation based on the maceral composition tpi gi values plot of trace elements v versus ni and sedimentary succession suggest deposition of predominantly terrigenous organic matter 45 to 73 huminite maceral in an upper deltaic setting for the maiganga facies the maceral analysis associated with py gc studies indicates that the sedimentary facies of gombe formation have potential to generate liquid hydrocarbon this can be estimated from an average of 21 50 liptinite content and the ternary plot of the py gc pyrolysate m p xylene n octene and phenol suggesting presence of type ii and type ii iii kerogen within the basin assessment of the paleodepositional environment based on the trace elements composition indicates a moderate stratified water column and salinity within a relatively sub oxic to oxic conditions during sedimentation the major oxide composition as well as the binary plots of sio2 versus al2o3 k2o na2o and log sio2 versus k2o na2o for the shales and mudstones revealed a predominance of semi arid to slightly humid warm paleoclimatic conditions and a passive continental margin setting this is in accordance with the cretaceous tectonic events of the west and central africa which affected the petroleum system in the entire benue trough

sediment yield from glacio lacustrine calcareous deposits during the postglacial period in the combe d ain jura france the middle valley of the river ain jura cuts through glacio lacustrine deposits laid down in an ice dammed lake during the most recent glacial advance the total volume eroded is about 6 21 10 8 m 3 for a surface area of 3 7 10 7 m 2 erosion occurred between 18 ka bp and 6 ka bp i e over a duration of some 12 ka sediment yield from the area was of the order of 2500 t km 2 a 1 which is comparable with modern day sediment yield from nw african badlands these high values are ascribed to the amenability of glacio lacustrine deposits to mechanical weathering and to the rapid geomorphological changes that affected glacial and paraglacial sedimentary cover after the retreat of the ice the valley slopes were destabilized by mass wasting earthflow and mudflow which was the predominant erosional process the slopes are currently stabilized or very exceptionally active 1998 john wiley sons ltd

quaternary depositional facies in cave entrances and their relation to landscape evolution the example of cuvieri cave eastern brazil abstract the correct determination of sedimentation processes in caves is often complicated by the unique characteristics of cave environments and their relationship to surface soil a study at cuvieri cave has allowed new insights into the dynamics and evolution of these types of sedimentary facies and their relation to the nearby landscape the cave is located in the lagoa santa karst eastern brazil and contains fossiliferous deposits of pleistocene holocene age at the base of three vertical pits near the cave entrance facies analysis was applied to sediments to understand sedimentation process and sediments were described according to their morphology grain size micromorphology chemical composition paleontological content and age results indicate that all deposits present a soil like aspect and although they record several depositional conditions sedimentary structures and textures are similar among different facies as such facies were defined by a combination of matrix color degree of cementation and sedimentological characteristics additionally abundance of fauna remains their taxonomic composition extant vs extinct completeness and degree of individuals articulation was evaluated differences between facies were produced by two main factors i change in source area and transport route from the epikarst to doline colluviation and back to epikarst and ii change in type of sediment cover injected from doline fed soils followed by talus debris and finally soils from modern epikarst the change in both factors is related to the landscape evolution mainly with the development and progressive enlargement and deepening of the nearby doline additionally the change in the type of sediment cover injected could also be related to climatic evolution the complex evolution of cuvieri cave sediments occurred over at least the last 300 kyr and is marked by periods in which entrance opening allowed the incorporation of vertebrate both extinct and extant remains into the sediment detailed multidisciplinary field and laboratory analyses are essential in unraveling the long history of sedimentation in caves providing a framework in which multiple events of sediment input and erosion can be correctly interpreted and related to the evolution of the landscape