the stratigraphic and sedimentological significance of late devensian ice sheet surging in holderness yorkshire u k amino acid analyses of marine mollusc valves show that the basement till of holderness yorkshire is of late devensian age ca 20 000 bp and not pre ipswichian 125 000 bp as is traditionally supposed together with the overlying skipsea and withernsea tills the basement till is argued to be a deformation till resulting from the repeated onshore surging of late devensian ice over a muddy sea floor and the subglacial transport attenuation and mixing of marine sediment silts on the surface of the basement till yielding 14c dates of 18 500 and 18 240 bp have been regarded as minimum ages for late devensian glaciation in eastern england e g the dimlington stadial of rose 1985 1989 the amino acid data presented here indicates that the maximum of the late devensian glaciation in eastern england occurred earlier sedimentological interpretation of the late devensian tills of holderness as glacially reworked marine sediments supports previous glaciological models of the british ice sheet involving surging of ice lobes along the coast of eastern england the basement skipsea and withernsea tills are separated by shallow marine sediments and may be representative of deformable bed till facies deposited below pleistocene ice sheets moving over soft fine grained sediments

influence of partial consolidation during cone penetration on estimated soil behavior type and pore pressure dissipation measurements estimation of soil behavior type from cone penetration testing and the interpretation of dissipation tests is complicated in in termediate soil types such as silty sands sandy silts etc where partial consolidation occurs during penetration this issue is investigated in this paper using results from cavity expansion and finite element analyses as well as field and centrifuge piezocone data the implications for soil classification are examined using analytical expressions to explore the effect of normalized shear strength rigidity index and over consolidation ratio relative to the influence of partial consolidation and viscous effects under fully undrained conditions it is shown that partial drainage conditions can affect where data plots on soil behavior charts thus complicating soil classification the effect on dissipation tests following partial consolidation during cone penetration is shown to create errors in interpretation using experimental and numerical data a new approach is developed based in part on manipulation of solutions for pore pressure dissipation following undrained penetration to account for these errors when interpreting dissipation tests errors can become significant during standard cone penetration testing when the t50 dissipation time is less than about 50 s guidelines including equations and a chart are presented for practical use finally imple mentation of this approach is demonstrated in a brief case study doi 10 1061 asce gt 1943 5606 0000646 2012 american society of civil engineers ce database subject headings soil consolidation cone penetration tests soil properties pore pressure sand soil type silts author keywords cone penetration test cpt cone penetrometer penetration rate consolidation dissipation test soil behavior type coefficient of consolidation intermediate soils

modeling the stress dilatancy relationship of unsaturated silica sand in triaxial compression tests abstractit is well known that partial saturation increases the shear strength and dilatancy of unsaturated sand however little research has been carried out on the actual stress dilatancy relationship this paper shows that the increase in peak shear strength caused by partial saturation is consistent with an increase in dilatancy and that conventional stress dilatancy theories are still valid for unsaturated sand the use of state indexes as a proxy for dilatancy were investigated and extended to unsaturated sands additionally these indexes can be used to establish a critical state line that is based on material properties only the validity of the stress dilatancy theories and the use of state indexes offer simplicity in modeling the shear behavior of unsaturated sand this will be demonstrated in this paper with the nor sand model with which the wetting collapse can be explained as a consequence of a loss of dilatancy characteristics

new radiometric dating of water management features at the prehistoric purron dam complex tehuacan valley puebla mexico abstract recent investigations at the prehistoric purron dam complex in the tehuacan valley of southern puebla mexico applied radiometric dating to more securely date the complex ceramic based dating in the 1960 s placed the dam s origin to the formative period while formative period origins are widely accepted the chronology lacks resolution and direct dates samples from impounded sediments behind the dam and from prehistoric canal fill were dated through optically stimulated luminescence osl as well as both standard 14 c and accelerated mass spectrometry ams assays these samples directly date the functioning of the water management features within the complex the results confirm the formative period origins of the purron dam and offer new insights into the construction and functioning of the dam and irrigation system

petrophysical constraints on gravity magnetic interpretation in israel whether exploring for hydrocarbons and minerals or simply studying structural geology gravity and magnetic interpreters prefer to use density and magnetic susceptibility values that are determined for their area of investigation in exploration it is fairly common to have rock properties information from outcrops but it is rare to have real measured values for the subsurface the interpreter extrapolates from the surface bases assumptions on lithologies or uses approximate values from the literature this approach although unavoidable in many instances may lead to errors

oriented lake development in the context of late quaternary landscape evolution mckinley bay coastal plain western arctic canada abstract oriented lakes characterized by elongate forms central basins and shallow littoral shelves are common features of circum arctic coastal lowlands the environmental conditions geological processes and chronology associated with the development of oriented lakes however are little known but essential for understanding how such arctic lowlands evolve using combined techniques of field and drill log stratigraphy and sedimentology luminescence and radiocarbon dating methods and geomorphic mapping we reconstruct the landscape evolution leading toward oriented lake formation on the mckinley bay coastal plain of western arctic canada a region with over 900 oriented lakes most lakes with deep central basins are inherited from a preglacial braidplain ca 73 27 ka and alluvial braided channel network that extended beyond the glacial limit ca 18 6 14 3 ka eolian erosion active during the lateglacial and postglacial period ca 12 8 1 9 ka reworked fluvial deposits eolian processes modified existing basins and created other shallow deflationary basins as small barchanoid dunes migrated under cold dry paraglacial conditions between about 12 8 and 10 7 ka vegetation cover developed at the onset of the early holocene climatic optimum ca 10 7 ka and parabolic dunes were active between 9 6 and 4 6 ka thus oriented lakes developed in basins conditioned by fluvial and eolian processes in the absence of much near surface ground ice lateral expansion of deep basin lakes and shallow stabilized deflationary basins predominated during the late holocene through wind induced wave and current processes overall this sequence of oriented lake formation does not support a thaw lake cycle but rather small basin evolution of a periglacial landscape

u series dating of the late pleistocene mammalian fauna from wood quarry steetley nottinghamshire uk we present the u series dating of bones from wood quarry steetley quarry cave using the diffusion adsorption model to account for uranium uptake the results give a weighted mean date of 66 8 3 0 kyr placing this assemblage within or just before marine oxygen isotope stage 4 the fauna is thought to correlate with the banwell bone cave mammal assemblage zone of the early devensian in britain our results support the idea that this assemblage zone immediately precedes the assemblage represented nearby at pin hole in creswell crags which is contemporary with the mid devensian and correlates with mis 3 our dates and dates for the banwell bone cave mammal assemblage zone from stump cross cavern and evidence from other sites may indicate a longevity for this fauna copyright 2005 john wiley sons ltd

late quaternary coastal evolution and aeolian sedimentation in the tectonically active southern atacama desert chile abstract analyses of aeolianites and associated dune surficial carbonate and marine terrace sediments from north central chile 27 54 s yield a record of environmental change for the coastal southern atacama desert spanning at least the last glacial interglacial cycle optically stimulated luminescence dating indicates phases of aeolian dune construction at around 130 111 98 77 69 and 41 28 ka thin section and stable carbon and oxygen isotope analyses suggest a predominantly marine sediment source for the three oldest dune phases aeolianites appear to have accumulated mainly from tectonically uplifted interglacial marine sediments that were deflated during windier and or stormier intervals bedding orientations indicate that sand transporting winds varied in direction from s ese during mis 5e and wnw ese during mis 5c 5a winds from the southeast quadrant are unusual today in this region of the atacama suggesting either major shifts in atmospheric circulation or topographic airflow modification thin section evidence indicates that the aeolianites were cemented by two phases of vadose carbonate tentatively linked to wetter periods around 70 and 45 ka tectonic uplift in the area has proceeded at an average rate of 305 542 mm kyr 1 the study illustrates the complexity of understanding onshore offshore sediment fluxes in the context of late quaternary sea level fluctuations for an area undergoing rapid tectonic uplift

shear wave velocity to evaluate in situ state of cohesionless soils shear wave velocity vs measurements were carried out in a triaxial testing program on three different cohesionless soils the vs was measured using bender elements during consolidation and at ultimate steady state after consolidation the soil samples were loaded in shear under constant strain rate triaxial compression either drained or undrained to determine their ultimate steady or critical state uss at large strains the vs measurements were used to develop relationships between the void ratio e mean normal effective stress p and vs the shear loading results were expressed within the framework of critical state soil mechanics the results of the vs and uss information were combined with the state parameter concept to develop an equation to use field measured vs to estimate the in situ consolidation state within a soil thus the contractive dilative boundary with respect to vertical effective stress for large strain loading can be determined from in situ measurements of vs these can then b

reconciliation of late quaternary sea levels derived from coral terraces at huon peninsula with deep sea oxygen isotope records a major discrepancy between the late quaternary sea level changes derived from raised coral reef terraces at the huon peninsula in papua new guinea and from oxygen isotopes in deep sea cores is resolved the two methods agree closely from 120 ka to 80 ka and from 20 ka to 0 ka ka 1000 yr before present but between 70 and 30 ka the isotopic sea levels are 20 40 m lower than the huon peninsula sea levels derived in earlier studies new high precision u series age measurements and revised stratigraphic data for huon peninsula terraces aged between 30 and 70 ka now give similar sea levels to those based on deep sea oxygen isotope data planktonic and benthic 18o data using the sea level and deep sea isotopic data oxygen isotope ratios are calculated for the northern continental ice sheets through the last glacial cycle and are consistent with results from greenland ice cores the record of ice volume changes through the last glacial cycle now appears to be reasonably complete

late holocene inland dune activity in the uk a case study from breckland east anglia inland dune fields found in breckland east anglia uk have previously been correlated with the widespread late devensian coversands of the region and a seventeenth century sandflood which is known to have inundated the village of santon downham a programme of optically stimulated luminescence and radiocarbon dating undertaken on the dunes at wangford warren and santon downham reveals that episodic aeolian activity has taken place during the last 7000 years five sand depositional phases on breckland dunes are identified c 6500 c 1600 1100 c 500 c 400 335 and from c 200 30 years before present between c 2120 1840 years ago and within the period 1100 300 years ago quiescent periods allowed the development of fen peat and soils local controlling factors on aeolian activity in breckland appear to be related to anthropogenic activities and livestock sheep and rabbits reducing vegetation cover and decreased precipitation and sea levels which led to lowering of water tables breckland aeolian activity when compared to the national and sub continental holocene aeolian activity record shows a high level of concordance the underlying forcing factor for late holocene dune activity in the uk and elsewhere in europe appears to be climatic instability in the north atlantic associated with both the little ice age and previous similar events which led to increased storminess climatic variability and lower temperatures

climatic and environmental reconstructions based on fossil assemblages from middle devensian weichselian deposits of the river thames at south kensington central london uk abstract fossiliferous silts within the late pleistocene kempton park gravel of the river thames valley were exposed in 1980 during foundation works for the ismaili centre in south kensington london the results of a multidisciplinary study of the geomorphology sediments fossil plants vertebrates molluscs ostracods and insects are reported the silts were deposited under two distinct climatic regimes a lower unit accumulated when the climate was arctic and an upper when the temperatures were at least as warm as those of the present day both these units occupy the same channel system and are separated from one another by less than a metre of sediment implying that the climatic change was probably sudden and intense the strongest evidence for this climatic difference comes from a study of the coleoptera which show an almost complete replacement of the arctic element in the fauna by a suite of temperate species palaeotemperature reconstructions using the mutual climatic range method based on the coleopteran assemblages from the lower unit suggest that the mean temperature of the warmest month was 9 2 c and that of the coldest month 22 10 c for the upper unit the mean temperature of the warmest month had risen to about 17 c and that of the coldest month to about 4 c the episode represented by the lower unit with its arctic climate had not previously been recognized in the thames valley the fauna from the upper temperate unit is very similar to that from other sites in the kempton park gravel such as that from isleworth 10 km upriver which like the upper unit at the ismaili centre was characterized by the virtual absence of trees it would appear that in such cases this treelessness does not indicate cold conditions equivalent to those of the modern tundra but may instead result from a combination of ecological and temporal factors the value of multidisciplinary studies in reaching such conclusions is emphasized the temperate episode described here is correlated with the thermal maximum at the early part of the upton warren interstadial complex an earlier suggestion based on amino acid epimerization ratios that the upton warren interstadial correlates with oxygen isotope sub stage 5a is not supported by the data which show no evidence of the forested environments that characterized this period in both britain and the adjacent continent it is thought that the temperate deposits at the ismaili centre belong to the middle pleniglacial rather than the early devensian weichselian and are equivalent to oxygen isotope stage 3

understanding geomorphic responses to environmental change a 19 000 year case study from semi arid central texas usa understanding the impact of past climatic changes on landscape stability is crucial in order to predict and mitigate the effects of future changes however in arid and semi arid environments reconstructions are often hampered by a poor understanding of the relationship between sediment deposition and climate we present here data from central texas a region that is sensitive to environmental change but has received relatively little attention the study integrates a chronology of 29 optically stimulated luminescence osl ages from six sedimentary sites in a range of depositional contexts with a 19 000 a climate record derived from pollen extracted from the adjacent boriack bog by comparing the two records we aimed to assess the relationship between climate change and geomorphic activity data show that extensive aeolian and colluvial deposition occurred during the mid to late holocene with sedimentation generally increasing during more arid phases however a number of depositional events on slopes were associated with moister episodes and sediment was also deposited in a summit setting immediately after phases of increased precipitation linkages between climate change and geomorphic response were therefore complex being controlled by both sediment supply and transport energy the climatic fluctuations identified in the boriack bog record highlight the sensitivity of central texas to environmental change while disparities in conditions recorded between it and other palaeoenvironmental sites in the southern usa emphasise the need for further work in order to enhance understanding of landscape sedimentary response to climate copyright c 2010 john wiley sons ltd

the upper pleistocene deposits at cassington near oxford england for much of the middle and all of the upper pleistocene the upper thames valley has remained outside the limit of ice advance the main agents of landform evolution have been the river thames and its tributaries which have cut down episodically and in so doing have abandoned a series of river terraces this study reports the findings of an investigation into exposures in the deposits underlying the floodplain terrace at cassington near oxford england the sequence exposed reveals a stratigraphy of basal predominantly fine grained lithofacies overlain by coarser gravel lithofacies the fluvial architecture of these deposits indicates a major change in fluvial style from a low energy meandering to a high energy braided channel system the flora and fauna from the lower fine grained lithofacies display a marked change from temperate at the base to colder conditions towards the top indicating a close association between deteriorating climate and changing fluvial depositional style amino acid and luminescence geochronology from the basal fine grained lithofacies suggest correlation with oxygen isotope stage 5 and hence it is argued that the major environmental change recorded at the site relates to the oxygen isotope stage 5 4 transition deposition of much of the overlying gravel sequence probably occurred during oxygen isotope stage 4 suggesting that the latter half of the devensian may be less significant in terms of fluvial landscape evolution in the upper thames valley than was believed previously c 1998 john wiley sons ltd

recent tims dating results from british late pleistocene vertebrate faunal localities context and interpretation new tims dates from british sites underpin and extend the growing model of mammalian faunal history during the late pleistocene the sequence of british faunas during the three successive warm phases of mis 5 presents a challenging model in which the mammal faunas of the first two temperate phases 5e and 5c is dominated by species of a classically interglacial character while that of the final phase sub stage 5a is dominated by bison and reindeer this we see as the cold fauna appearing in britain during the cool isotope sub stage 5b and subsequently isolated by the rising sea level of isotope sub stage 5a all these three faunas are true island faunas copyright 2007 john wiley sons ltd

aeolianite and barrier dune construction spanning the last two glacial interglacial cycles from the southern cape coast south africa the southern cape region of south africa has extensive coastal aeolianites and barrier dunes whilst previously reported limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea level fluctuations that have taken place during the late quaternary sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial interglacial cycles aeolianite deposition has occurred on the southern cape coast at ca 67 80 88 90 104 128 160 189 and 200 ka before the present using this and other published data coupled with a better understanding of late quaternary sea level fluctuations and palaeocoastline configurations it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea level high stands these marine transgressions and regressions allowed onshore carbonate rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions the lack of carbonates in more recent dunes oxygen isotope stages 1 2 and 4 5 is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and or changes in the balance between the warm agulhas and nutrient rich benguela ocean currents

pre weichselian quaternary glaciations of the british isles the netherlands norway and adjacent marine areas south of 68 n implications for long term ice sheet development in northern europe within this paper we review the pre weichselian glacial history of northern europe focussing on evidence from the british isles netherlands norway and adjacent marine areas that record the activity of the british bis and scandinavian sis ice sheets the objective of the paper is to examine the long term evolution of the two ice sheets in order to determine their level of synchronicity and their relationship to the plio pleistocene record of northern hemisphere glaciation geological evidence demonstrates striking long term similarities between the behaviour of the bis and sis with a step wise intensification in the glacial signal 1 first ice rafted debris ird input onto the continental margin at ca 2 7 2 6 ma and restricted glaciation prior to ca 1 1 ma 2 initiation of more lowland style glaciation from 1 1 ma 3 repeated shelf edge glaciations from 0 45 ma these steps coincide with a major intensification of the northern hemisphere climate signal at the beginning of the quaternary and the mid pleistocene transition temporal and spatial variabilities in the behaviour of different sectors of the bis and sis appear to reflect regional scale geographic latitude elevation climatic moisture temperature and glaciological deformable beds controls that modulate the build up of ice volume in the main ice accumulation areas relative to global climate forcing and its subsequent lateral expansion 2010 nerc

dune activity as a record of late quaternary aridity in the northern kalahari new evidence from northern namibia interpreted in the context of regional arid and humid chronologies abstract sediments from presently vegetated linear dune ridges in the caprivi strip of northern namibia are optically dated to assess the timing of dune building phases and aridity in the late quaternary the dunes have been constructed from sediments likely to have been initially transported into the area by fluvial processes dune sediments do not preserve obvious evidence of hiatuses in deposition in the dated period 48 121 ka but continuous deposition and therefore continuous aridity is considered unlikely given differences in dated phases compared with chronologies from western zimbabwe to the southeast and western zambia to the north that include ages derived from the same equivalent sampling depths laboratory experiments provide evidence that dune sediments have not been bioturbated since deposition such that sample palaeodoses determined from different sampling depths are a true reflection of the duration of sediment burial independent chronologies from cave sediments provide evidence that humid episodes have occurred in the region within the dated range of dune construction it is concluded that dune construction in the late quaternary has been punctuated that the preserved record reflects the attributes of the aeolian processes that affect linear dune development and that the late quaternary record of dune building in the middle and northern kalahari was spatially complex

age of pleistocene faunas from bacon hole wales at present it is difficult to match british early upper pleistocene vertebrate faunas with the growing evidence for complex climatic change at this time derived from the oceanic oxygen isotope record and from long pollen cores however we report here new analyses of dated faunal assemblages from bacon hole wales which indicate that the ipswichian interglacial fauna dated at 125 kyr bp was followed by a devensian interstadial fauna dated at 81 kyr bp which still supported some supposedly typical inter glacial mammals combined with evidence of an intervening cold fauna from stump cross cave dated at more than 83 kyr bp these indications of complexity in faunal change at the ipswichian devensian transition are more consistent with the oxygen isotope and pollen core data than traditional views

characterization of unsaturated mine waste a case history it is becoming increasingly common in the mining industry for either crushed ore or filtered mine waste to be stacked to a significant height 100 m in a moist state with little compaction resul

tectonic eustatic and climatic significance of raised beaches of val de saire cotentin normandy france detailed mapping morphostratigraphical and geochronological analyses were undertaken in the val de saire cotentin normandy northern france these studies have identified a series of middle and upper pleistocene age deposits overlying four wave cut platforms pf iv pf i which can be associated with temperate high sea level events and equated with mis 11 9 7 and mi substage 5e a sea level stand recorded at 20 m ngf at the la mondree site seems to correspond to mi substage 5c or 5a the completeness of the val de saire record and particularly the width of platform iv mis 11 has so far no equivalent on the south coast of the english channel this study provides contribution to an understanding of the impact of the interglacial glacial cycles in a coastal intraplate situation the cyclicity of the morphogenesis is explained by interaction between eustatic variations and strongly expressed activity of slow uplift ca 60 mm kyr through the middle pleistocene several osl dates from the gravel to sand sequence of the eemian weichselian cycle indicate that these deposits represent the marine regression of the end of the last interglacial

ams radiocarbon dating of middle and upper palaeolithic bone in the british isles improved reliability using ultrafiltration recent research at the oxford radiocarbon accelerator unit orau has shown that ultrafiltration of gelatin from archaeological bone can in many instances remove low molecular weight contaminants these can sometimes be of a different radiocarbon age and unless removed may severely influence results particularly when dating bones greater than two to three half lives of 14c in this study this methodology is applied to samples of late middle and early upper palaeolithic age from the british isles in many instances the results of redating invite serious reconsideration of the chronology for these periods copyright 2006 john wiley sons ltd

sedimentary history of za hajovnou cave moravia czech republic a unique middle pleistocene palaeontological site za hajovnou cave in the javoricko karst moravia czech republic has a rich record of middle pleistocene typical holsteinian flora and fauna dominated by bear ursus deningeri sedimentological geochemical mineralogical geophysical palynological and zoopalaeontological analyses of the sediments along with u th dating of flowstones place the deposits into a numerical timeframe the cave origin dates to a period before the mid miocene badenian transgression the oldest fluvial deposits are lower pleistocene spanning the brunhes matuyama boundary the later terrestrial deposits range from middle pleistocene to holocene the most important result of u th dating is that the main holsteinian senso lato fossil bed can be correlated with mis 9 the lower fossil bed is probably mis 11 and the upper fossil bed mis 5e this represents one of the still relatively few numerically dated holsteinian sites contradicts the global chronostratigraphical correlation table that places the holsteinian only in mis 11 and supports the concept that the holsteinian is not a single unit and likely not confined to a single interglacial c 2013 elsevier ltd and inqua all rights reserved

prehistoric and colonial land use in the chihuahuan desert as inferred from pollen and sedimentary data from coahuila mexico abstract pollen along with context sedimentary data of two desert bottom sites in south coahuila mexico reconstruct holocene environment in the chihuahuan desert in relation to possible human influence on vegetation during the holocene examined pollen sites here derive from the margins and bottoms of the playa lake of the laguna mayran lm first at the reported site of cuota 4 lm4 archaeologically dated deposits of the initial spanish colonial period here are correlated with a xeric environment followed by an early modern mesic period of increased rainfall with wetland plants second at the reported site of coahuila highway 30 ch30 unconformable discontinuous deposits with intermittent representation of early middle and late holocene sedimentation are analyzed showing periodic changes in hydrology at ch30 possible cultivation based on cucurbitaceae pollen occurs in a defined wet phase dating to circa 1500 bp finally origins of pollen taphonomy at ch30 are defined by analog samples from the chihuahuan desert zone in the menchacas basin near cuatro cienegas are analyzed the pilot pollen analog study is based on inferred pollen recruitment mechanics in different sediments as well as moss pollsters in the menchacas basin in the chihuahuan desert in middle coahuila

the petrogenesis of a type magmas from the amram massif southern israel the 550 530ma alkaline magmatic suite of the amram massif southern israel was emplaced during the transition from an orogenic to an intra plate tectonic setting in the northeastern arabian nubian shield ans the suite ranges from 45 6t o 788 wt sio2 and consists of rhyolites alkali quartz syenites quartz syenites monzonites and co magmatic mafic to felsic alkaline dikes these rocks define a continuous chemical evolutionary trend and reveal a correlation between decreasing stratigraphic age and increasing silica content the felsic members of the suite display a type characteristics and are genetically linked through fractionation to the more mafic ones moderately positive initial end values a2 05 low initial 87 sr 86 sr values 07036 2 high mgo and fe2o3 concentrations 410 895 and 100 125 wt respectively and relatively flat rare earth element patterns la yb na 64 09 in the amram mafic dikes 456 495 wt sio2 suggest their derivation from the sub continental lithospheric mantle above the garnet stability zone the melts program was used to quantitatively model the chemical evolution of the suite extensive anhydrous fractionation 490 of plagioclase alkali feldspar clinopyroxene olivine and minor timagnetite and apatite from parental mafic magmas represented by the amram mafic dikes produced the rhyolitic compositions as well as the intermediate members of the suite this suggests the presence of a large unexposed body of cumulate rocks at depth as well as fusion of a large source region equivalent to an 5km layer in the lithospheric mantle regarded as a representative example for similar a type outcrops in this region this petrogenetic model further suggests that neoproterozoic early cambrian a type magmatism in the northeastern ans represents a significant post orogenic addition of mantlederived material to the juvenile crust this magmatic episode was of a similar magnitude to that of the cenozoic extensionrelated alkaline volcanism of the arabian plate

luminescence dating of sediments using single aliquots new procedures abstract the application of luminescence dating to quaternary sediments has been hampered by the labour intensive procedures involved determination of equivalent doses using single aliquots measured using an automated luminescence reader offers a significant reduction in labour equivalent dose determinations using two single aliquot additive dose methods are compared with equivalent doses measured using standard multiple aliquot methods for a suite of 12 dune sand samples from southwest north island new zealand the single aliquot correction method based upon adjusting the magnitude of the measured luminescence signal is found to give underestimates for those samples whose equivalent dose is greater than 80 gy and whose luminescence response to dose is non linear a second correction method based upon adjusting the value of the total added dose that the sample has received is described this second method gives equivalent dose results similar to those measured using standard multiple aliquot methods over the range from 0 1 to 400 gy

people and large carnivores as biostratinomic agents in lateglacial cave assemblages biostratinomic analysis processes acting between death and burial of lateglacial mammal bone assemblages from three caves in northern england demonstrates the value of re examining archived assemblages with ams radiocarbon dating of key specimens these assemblages shed light on the ecology of a region at the northern limit of lateglacial human activity in britain during the lateglacial interstadial bears wolves and humans expanded into the region bears by around 12 500 14c yr bp and the earliest evidence for human presence is around 12 300 14c yr bp at victoria cave wolf activity included predation and scavenging of large ungulates and scavenging bear carcasses apparently resulting from hibernation deaths the scavenging of bear carcasses is possibly confined to the first part of the lateglacial interstadial whereas evidence for wolf scavenging large ungulates increases later in the interstadial after about 11 800 14c yr bp perhaps reflecting changes in the productivity of the lateglacial ecosystem and in human subsistence patterns the assemblage from sewell s cave is wolf den debris from the very end of the lateglacial interstadial around 10 800 14c yr bp whilst that from kinsey cave is dominated by large bodied carnivores and is argued to have a quite different taphonomic history copyright 2007 john wiley sons ltd

seasonal control on coastal dune morphostratigraphy under a monsoon climate mui ne dunefield se vietnam abstract having developed in the later quaternary period the mui ne dunefield representing the upper most portion of a major coastal barrier complex in se vietnam formed by wind regimes associated with the asian monsoon climate the barrier complex is 100 km long and higher than 150 m in elevation but despite its large dimensions research on its geomorphological and geological characterization is limited several active dune fields extend 2 10 km landwards from the coast while the rest of the barrier surface is stabilized we applied ground penetrating radar gpr and quartz optically stimulated luminescence osl dating to the transverse dunes of the mui ne dunefield to characterize the morphostratigraphy and recent aeolian sedimentation history currently the dunes have a relief of typically 5 10 m and a wavelength of 50 100 m they are driven by the northeasterly winter monsoon winds and reversed with minor relief in response to the southwesterly summer monsoon gpr profiles and osl ages define three morphostratigraphic units the modern holocene and pleistocene dune units the gpr data of the modern dune unit is dominated by a series of steep reflections that dip exclusively towards the west reflecting the winter monsoon and is punctuated by reactivation surfaces evidence for the wind reversal is not preserved in the sediment successions but is represented by reactivation surfaces thus a subunit bounded by the reactivation surfaces defines annual deposition the preservation potential of a subunit varies with the migration rate of the transverse dune and in the fastest migrating dunes approximately one subunit was preserved every year 1 1 0 6 subunit yr the modern dunes are generally younger than 100 years and have migrated wsw at net rates of 0 6 2 5 m yr the holocene dune unit is as thick as the modern unit although it spans a period ten times longer reflecting the lower preservation potential of the transverse dunes as sedimentary records due to erosion associated with their migration the rate of dune migration suggests that an aeolian contribution of coastal sands has occurred following the sea level highstand of the middle holocene accounting for the extent of the active dunefields this mode of the barrier accumulation is considered as an analogue for earlier highstand events however the dunefields only cover a fraction of the entire barrier it is thus inferred that barrier formation occurred over a long period probably encompassing several glacial interglacial cycles sand accumulation during the lowstand either by transport of sand from the subaerially exposed shelf and or reworking of sand emplaced during the prior highstand may contribute significantly to the barrier development

neanderthals in the outermost west technological adaptation in the late middle palaeolithic re colonization of britain marine isotope stage 4 3 abstract despite its long research history and particular palaeogeographic context the british late middle palaeolithic lmp of marine isotope stage 4 and 3 has not been fully integrated in broader discussions of neanderthal behavioural adaptations this is due not only to the lack of a comprehensive account of the archaeological record but also to perceptions that the numerically small character of the record itself and its position at the margins of the neanderthal world are unpromising research contexts this paper addresses the first problem by reporting results from a study of the british lmp lithic assemblages most securely assigned to late mis 4 and mis 3 using a technologically focused approach designed to derive the maximum information from the available material the results suggest a coherent and broadly uniform techno economic system characterised by clear raw material selectivity and high levels of mobility bifaces and scrapers are common and show strong evidence for curation transportation and maintenance discoid centripetal and alternate core reduction methods occur alongside more informal approaches with virtually no evidence for levallois this new data equally demonstrates the relevance of the british lmp to current questions about the diversity of later neanderthal techno economic organisation additionally as this record is the only clearly defined example of a middle palaeolithic colonisation in europe this study provides an opportunity to examine associated behavioural adaptations within the mammoth steppe ecosystem of mis 3

holocene fluctuations of lake ngami middle kalahari chronology and responses to climatic change abstract lake ngami a 3000 km 2 basin at the distal end of the okavango delta botswana has a complex suite of shorelines ranging from the lake sump at 919 m asl up to 945 m asl linked to topographic thresholds and inflows current and fossil in the okavango system the lake has been ephemeral throughout the 20th century and completely dry since 1982 yet held a substantial body of water up to a level of 930 m asl when visited by european travellers in the mid nineteenth century the historical decline in the lake has been well documented and used as evidence for regional desiccation but the holocene record based on archaeological studies and radiocarbon dating of inorganic carbonates is more speculative a study of a 30 km 2 diatomite at the eastern end of the basin indicates that a substantial freshwater lake at a level of at least 932 m asl was present throughout the holocene linked to a now abandoned inflow of the kunyere river a programme of 18 luminescence age determinations of the peripheral dautsa and magotlwanen shoreline sequences suggests that they are old features that have been constructed on a lacustrine substrate dating back to 90 100 ka or earlier and have been modified by holocene fluctuations in lake level and subsequent aeolian reworking the water level peaked at 936 m asl between 4 and 3 ka returned to 934 m at 2 8 2 ka ponding water into the phatane gap and fell rapidly thereafter to 932 m and thence to historical levels the 936 m level can be correlated with increased throughflow in the okavango delta hence increased rainfall in the catchment the subsequent decline can be attributed to episodic closure and rerouting of okavango distributaries in particular the thaoghe perhaps aided by anthropogenic activities as such the desiccation of the lake is not indicative of regional climatic change

late quaternary palaeoenvironments of the winter rainfall zone of southern africa palynological and sedimentological evidence from the agulhas plain abstract south africa s winter rainfall zone is a climatically sensitive region lying at the interface of the earth s temperate and sub tropical climatic systems its seasonally arid climate has generally prevented the preservation of long and organic rich sedimentary deposits producing a spatially limited and temporally biased quaternary record this paper seeks to address this issue further and develop a fuller understanding of the wider climatic changes in this region during the late quaternary modern climatic data does not support the definitions of the winter rainfall zone presented in previous syntheses and this factor amongst others may explain difficulties in resolving the palaeoenvironmental record in this region we present palaeoenvironmental evidence from the agulhas plain an area marginal to the modern winter rainfall zone cored sedimentological and palynological records from two pans are integrated with previously reported records of aeolian activity providing evidence for phases of enhanced aridity and humidity during the late quaternary the record is fragmentary which may reflect the cycling of sediment between the pans and their accompanying lunette dunes lacustrine sedimentary sequences dating to c 33 ka 47 ka provide evidence for enhanced humidity consistent with evidence in the winter and year round rainfall zones increased humidity is also recorded from c 2 ka following drier conditions than the present c 2 7 2 5 ka palynological evidence supports the sedimentological interpretations of pan water status and offers rare insights into the nature of the region s unique fynbos vegetation during the late pleistocene

ipswichian fauna of victoria cave and the marine palaeoclimatic record the lack of age dating methods which can be applied beyond the limit of radiocarbon dating makes the global correlation of continental climatic events and stratigraphic sequences with the continuous palaeoclimate record obtained by isotopic and faunal analysis of deep sea sediment cores1 3 a difficult task often only a relative time scale can be obtained using complex and perhaps tenuous litho and biostratigraphical data speleothems may assist in this correlation for embodied in their calcium carbonate structures are elemental and isotopic variations which indicate both their age and climatic conditions prevailing during their deposition speleothems may be reliably dated by the 230th 234u method to an age of 350 kyr bp providing they consist of non porous unrecrystallized calcite which is essentially free of clastic detrital sediments4 6 they may also provide palaeoclimatic information for previously glaciated areas 1 because their presence indicates that groundwater movement was not prevented by ice formation at the surface and co2 was produced in the soil zone by root respiration and plant decay limestone bedrock may then be dissolved and reprecipitated as speleothems in caves below the surface and 2 because of the variations in stable isotopic content and fluid inclusion waters contained therein4 7 8 additional climatic and chronological information may be obtained where speleothems are interstratified with deposits characteristic of a particular climatic regime and with deposits containing organic remains we describe here the results of dating speleothems encrusting the remains of mammals from victoria cave in northern england and discuss their significance in terms of the correlation between continental and oceanic palaeoclimatic records

a formal mammalian biostratigraphy for the late pleistocene of britain abstract a series of distinctive mammalian assemblages spanning much of the british late pleistocene is defined on the basis of type localities and a formal biozonation proposed the joint mitnor cave mammal assemblage zone includes the famous hippopotamus fauna of the early part of the last interglacial complex oxygen isotope substage 5e this is succeeded by the bacon hole mammal assemblage zone in which hippopotamus is no longer present and species like mammoth roe deer and northern vole re enter the british region this assemblage zone appears to represent the later substages of ois 5 a faunal grouping dominated by bison and reindeer is named the banwell bone cave mammal assemblage zone and is believed to correlate closely with the early devensian ois 4 the pin hole mammal assemblage zone includes the familiar mammoth steppe faunas of the middle devensian ois 3 dominated by horse woolly rhinoceros and mammoth the lateglacial interstadial is characterized by the gough s cave mammal assemblage zone in which horse red deer and humans are well represented part of ois 2 no definitive evidence for human activity can be found for a period spanning the last interglacial complex ois 5 and the early devensian ois 4 human populations return to britain with the pin hole mammal assemblage zone fauna during the middle devensian ois 3 and reappear after the dimlington stadial during the late devensian ois 2 but in a different faunal association

cyclic liquefaction of loose gassy sand gas can be found in many soils but none more common than in seabed soils gas charged sediments are known to be widely distributed throughout the world s oceans numerous research programs have studied saturated soil response to cyclic loading however little is known about the behavior of gassy soils subjected to cyclic loading the response of loose gassy specimens subjected to cyclic loading was studied in a laboratory program triaxial tests were performed on specimens of reconstituted ottawa sand prepared to various gas contents and densities the specimens were consolidated and then sheared under undrained cyclic loading gas content was measured at the beginning and end of each test using time domain reflectometry the response of the gassy specimens has been shown to be influenced by the soil state and grain characteristics and the intensity duration and frequency of the cyclic loading the propensity of a soil to liquefy is represented by a cyclic resistance ratio defined as the cyclic stres

mass spectrometric dating of flowstones from stump cross caverns and lancaster hole yorkshire palaeoclimate implications a terrestrial flowstone sequence 97 cm thick from stump cross caverns yorkshire has been dated by both mass spectrometric and alpha spectrometric 238u 234u 230th dating and is demonstrated to have been deposited predominantly during interstadial periods over the last 170 ka with no growth in periods of glaciation or within the oxygen isotope stage 5 interglacial growth also occurs within oxygen isotope stages 4 and 6 the former possibly correlating with interstadials recognised in high resolution ice and ocean core records comparison with the timing of growth of a mass spectrometrically dated lancaster hole flowstone also from the same region demonstrates only limited agreement these differences are due to two factors limiting deposition at stump cross flooding of the cave passage in warm periods and the development of continuous permafrost or glacier cover in periods of severe climatic deterioration deposition at lancaster hole was controlled by limitations in ground water supply rather than flooding of the cave passage the results presented here demonstrate that in addition to regional palaeoclimate factors local site conditions may limit speleothem growth we conclude that in future palaeoclimate studies the growth record from several coeval speleothem samples must be considered before a regional palaeoclimate interpretation can be made

uranium series dates from the windy pits of the north york moors united kingdom implications for late quaternary ice cover and timing of speleogenesis windy pits are open fissures within the corallian strata of the north york moors here we present nine thermal ionization mass spectrometry tims u th dates on speleothem from the windy pits the first radiometric dates on calcite for these features and for this region the dates cluster within three time periods the interglacial peaks of marine isotope stage mis 7 208 to 190 ka mis 5 127 ka to 109 ka and the holocene correlating with the marine isotope record and with the broad pattern of interglacial calcite deposition observed for northern england however of the two high resolution studies available for comparison the windy pit dates match only the lancaster hole dates the location of the windy pits outside of the devensian ice limits within the ice free but periglaciated region suggests that the region has remained ice free since some time before mis 7 the prevalence of widespread and prolonged permafrost conditions suggests a plausible mechanism for these open rift caves in slope side periglacial mass movement copyright 2008 john wiley sons ltd

an absolute chronology for the raised beach and associated deposits at sewerby east yorkshire england the raised beach sediments revealed in the cliffs at sewerby east yorkshire are widely regarded as ipswichian in age previously reported evidence for this dating is reviewed and new results from a range of luminescence dating techniques applied to the blown sand deposit overlying the raised beach are reported these provide the first absolute date for the sewerby site of 120 84 11 82 ka which places the blown sand at the boundary between oxygen isotope stages ois 5e and 5d as the underlying raised beach is little older than the blown sand it probably formed during ois stage 5e as suggested by the faunal evidence

pronounced warmth during early middle pleistocene interglacials investigating the mid brunhes event in the british terrestrial sequence the mid brunhes event mbe is a climatic transition occurring between mis 13 and 11 that separates two climatic modes 1 early middle pleistocene interglacials 780 450 ka that are characterised by only moderate warmth and 2 middle and late pleistocene interglacials occurring after 450 ka that are characterised by greater warmth consistent with or warmer than the holocene this event is observable within a variety of long climate records such as specmap and epica but its effect on terrestrial systems is poorly understood the impact of this event is examined in the british terrestrial sequence by comparing the occurrence of a range of thermophilous plant and animal species and climate reconstructions derived from assemblages containing them from interglacials of the early middle pleistocene with those from the late middle and late pleistocene this comparison reveals that interglacial climates during the early middle pleistocene in britain were as warm as and in some cases warmer than those that occurred during the late middle and late pleistocene this interpretation is supported by sea surface temperature records in the north atlantic which show that temperatures during early middle pleistocene interglacials were at least as warm as those experienced during the holocene there is therefore no evidence in climate records of britain and the north atlantic for a mid brunhes event this suggests that the mbe is not a global climatic transition but is restricted to specific regions in particular the higher latitudes of the southern hemisphere further work is needed to understand the regional variability and cause of the mbe

shear wave velocity based probabilistic and deterministic assessment of seismic soil liquefaction potential abstractshear wave velocity vs offers a means to determine the seismic resistance of soil to liquefaction by a fundamental soil property this paper presents the results of an 11 year international project to gather new vs site data and develop probabilistic correlations for seismic soil liquefaction occurrence toward that objective shear wave velocity test sites were identified and measurements made for 301 new liquefaction field case histories in china japan taiwan greece and the united states over a decade the majority of these new case histories reoccupy those previously investigated by penetration testing these new data are combined with previously published case histories to build a global catalog of 422 case histories of vs liquefaction performance bayesian regression and structural reliability methods facilitate a probabilistic treatment of the vs catalog for performance based engineering applications where possible uncertainties of the variables comprising both the seismic demand an

ancient and modern cold climate aeolian sand deposition a review although partly active aeolian sand sheets and dunes cover large areas in the zones of dis continuous permafrost little precise information is available about the influence of cold climate conditions on modern aeolian processes this means that palaeoenvironmental reconstructions in the stabilised mainly late pleistocene dune fields and cover sand regions in the sand belts of the european lowlands and the northern great plains of the usa and canada are necessarily still based on ancient evidence cold climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains glacial outwash plains till plains and lake shores the common parabolic and transverse dune forms resemble those observed in temperate regions although a variety of periglacial features has been identified in late pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces the nature of annual sedimentation cycles and the processes by which strata were deposited and or contorted but surprisingly little is known about the role of vegetation in the process of sand accumulation dunes are most informative with respect to reconstructions of past wind regimes which offer important data for verification of palaeoclimatic simulations

wolverine in northern england at about 83 000 yr b p faunal evidence for climatic change during isotope stage 5 abstract cave sediments from stump cross cave in northern england contain pleistocene mammal remains uranium series dating of calcium carbonate deposits closely associated with the fossiliferous horizons has established an absolute age of 83 000 6000 yr b p for a faunal assemblage largely comprised of wolverines gulo gulo this date lies firmly within the younger portion of oxygen isotope stage 5 the occurrence of wolverines in the vicinity of stump cross cave at ca 83 000 yr b p indicates a significant climatic deterioration from ca 120 000 yr b p when an ipswichian interglacial fauna with hippopotamus was present in this part of northern england

morphology of the basement and hormuz salt distribution in offshore abu dhabi from constrained 3 d inversion of gravity and magnetic data abstract many seismic surveys and exploration wells have been conducted in offshore abu dhabi united arab emirates however the neoproterozoic basement and the infracambrian hormuz salts were not imaged or penetrated by seismic and well data to delineate the morphology of the basement and distribution of salt bodies we applied a 3 d constrained inversion method to aerogravity and aeromagnetic data covering offshore abu dhabi well and seismic data were used to constrain and validate the inversion results the magnetic inversion model resulted in a robust basement model that varies in depth from 8 to 10 km with two highs at 8 and 8 5 km highlighting possibly magmatic bodies in contrast the gravity inversion model does not delineate very well the basement morphology possibly due to the lower density salt bodies masking the gravity response of the higher density basement by calculating and removing the gravity response of the magnetic basement model from the observed gravity data we recovered the residual gravity response of the hormuz salts the 3 d gravity inversion of the residual shows that the hormuz salts are more wide spread and thicker than previously thought with a depth to top of salt varying from 5 5 to 8 5 km this salt model suggests that the giant oilfields in offshore abu dhabi such as umm shaif nasr abu al bukhoosh zakum sarb and hail occur exactly above crests of salt pillows in addition a series of smaller oilfields are found located at the margin of the northern basement high and three structural lineament trends ne sw nw se and n s were identified from the inverted basement and salt models reactivation of these fault trends and associated diapiric salt uplifts as observed in the seismic sections and curvature map played a major role in shaping the basement morphology and mobilization of the hormuz salts

methodological considerations in the optical dating of quartz abstract the optically stimulated luminescence from quartz grains extracted from sediments at two archaeological sites has been studied the sites were the upper palaeolithic site at hengistbury head dorset u k and the upper aterian site at chaperon rouge morocco problems associated with the technique of optical dating are discussed particularly the thermal treatment that is necessary to remove thermally unstable charge following artificial irradiation and the extrapolation of growth curves to estimate the equivalent dose the technique used is described and some preliminary dates are presented

coarse sand beach ridges at cowley beach north eastern australia their formative processes and potential as records of tropical cyclone history storm surges generated by tropical cyclones have been considered a primary process for building coarse sand beach ridges along the north eastern queensland coast australia this interpretation has led to the development of palaeotempestology based on the beach ridges to better identify the sedimentary processes responsible for these ridges a high resolution chronostratigraphic analysis of a series of ridges was carried out at cowley beach queensland a meso tidal beach system with a 3 m tide range optically stimulated luminescence ages indicate that 10 ridges accreted seaward over the last 2500 to 2700 years the ridge crests sit 3 5 to 5 1 m above australian height datum ca mean sea level a ground penetrating radar profile shows two distinct radar facies both of which are dissected by truncation surfaces hummocky structures in the upper facies indicate that the nucleus of the beach ridge forms as a berm at 2 5 m australian height datum equivalent to the fair weather swash limit during high tide the lower facies comprises a sequence of seaward dipping reflections beach progradation thus occurs via fair weather wave accretion of sand with erosion by storm waves resulting in a sporadic sedimentary record the ridge deposits above the fair weather swash limit are primarily composed of coarse and medium sands with pumice gravels and are largely emplaced during surge events inundation of the ridges is more likely to occur in relation to a cyclone passing during high tide the ridges may also include an aeolian component as cyclonic winds can transport beach sand inland especially during low tide and some layers above 2 5 m australian height datum are finer than aeolian ripples found on the backshore coarse sand ridges at cowley beach are thus products of fair weather swash and cyclone inundation modulated by tides knowledge of this composite depositional process can better inform the development of robust palaeoenvironmental reconstructions from the ridges this article is protected by copyright all rights reserved

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