ultracataclasite structure and friction processes of the punchbowl fault san andreas system california abstract the punchbowl fault is an exhumed 40 km displacement fault of the san andreas system in the devil s punchbowl the fault contains a continuous ultracataclasite layer along which the punchbowl formation sandstone and an igneous and metamorphic basement complex are juxtaposed the fabric of the ultracataclasite layer and surrounding rock indicate that nearly all of the fault displacement occurred in the layer by analogy with nearby active faults we assume that the punchbowl fault was seismogenic and that the ultracataclasite structure records the passage of numerous earthquake ruptures we have mapped the ultracataclasite layer at 1 1 and 1 10 to determine the mode of failure and to constrain the processes of seismic slip on the basis of color cohesion fracture and vein fabric and porphyroclast lithology two main types of ultracataclasite are distinguished in the layer an olive black ultracataclasite in contact with the basement and a dark yellowish brown ultracataclasite in contact with the sandstone the two are juxtaposed along a continuous contact that is often coincident with a single continuous nearly planar prominent fracture surface pfs that extends the length of the ultracataclasite layer in all exposures no significant mixing of the brown and black ultracataclasites occurred by offset on anastomosing shear surfaces that cut the contact or by mobilization and injection of one ultracataclasite into the other the ultracataclasites are cohesive throughout except for thin accumulations of less cohesive reworked ultracataclasite along the pfs structural relations suggest that 1 the black and brown ultracataclasite were derived from the basement and sandstone respectively 2 the black and brown ultracataclasites were juxtaposed along the pfs 3 the subsequent final several kilometers of slip on the punchbowl fault occurred along the pfs and 4 earthquake ruptures followed the pfs without significant branching or jumping to other locations in the ultracataclasite by comparison with rock friction experiments the slip localization along the pfs in the ultracataclasite implies rate weakening behavior with a critical slip distance similar to laboratory values and thus relatively small nucleation and breakdown dimensions for earthquake ruptures of the various mechanisms proposed to explain the low strength of the san andreas and to produce dynamic weakening of faults those that require or assume extreme localization of slip are most compatible with our observations

a penultimate glacial monsoon record from hulu cave and two phase glacial terminations oxygen isotope records of three stalagmites from hulu cave china extend the previous high resolution absolute dated hulu asian monsoon record from the last to the penultimate glacial and deglacial periods the penultimate glacial monsoon broadly follows orbitally induced insolation variations and is punctuated by at least 16 millennial scale events we confirm a weak monsoon interval between 135 5 1 0 and 129 0 1 0 ka prior to the abrupt increase in monsoon intensity at asian monsoon termination ii based on correlations with both marine ice rafted debris and atmospheric ch 4 records we demonstrate that most of marine termination ii the full rise in antarctic temperature and atmospheric co 2 and much of the rise in ch 4 occurred within the weak monsoon interval when the high northern latitudes were probably cold from these relationships and similar relationships observed for termination i we identify a two phase glacial termination process that was probably driven by orbital forcing in both hemispheres affecting the atmospheric hydrological cycle and combined with ice sheet dynamics

the bering and okhotsk seas modern and past paleoceanographic changes and gateway impact abstract the high biological productivity and an efficient biological pumping in the subarctic pacific and adjacent seas make this region important to the modern carbon cycle and both modern and the past climate of the earth knowledge of the northern marginal seas of the pacific however is unsubstantial the bering sea is located between the pacific ocean and the arctic sea and plays an important role in ocean circulation involving balances of heat salt and various chemical properties thus it is necessary to unravel the geologic history of the bering sea as a gateway to the pacific and the arctic atlantic during the last 5 million years and beyond the okhotsk sea is considered a locus of north pacific intermediate water formation today the intermediate water formation is linked with seasonal sea ice cover diatom records from the okhotsk sea demonstrate that sea ice cover was distributed on the western side of the sea and the eastern part was open water during the last glacial maximum this configuration permitted a better ventilation of the glacial okhotsk sea through increased quantity of intermediate water presumably formed there at that time

last glacial holocene water structure in the southwestern okhotsk sea inferred from radiolarian assemblages abstract in order to reconstruct paleoceanographic conditions in the southwestern sw okhotsk sea radiolarian assemblages were analyzed from 10 surface sediments and 5 sediment cores obtained from various water depths ranging between 461 and 1348 m we also measured geochemical components such as biogenic opal calcium carbonate total organic carbon total sulfur and total nitrogen for one sediment core these data imply that the complicated water structure in the sw okhotsk sea changed with time from the last glacial to holocene the glacial surface water was characterized by low primary production in the summer and expanded sea ice coverage in the winter during this time the ventilation might have reached deeper than during the holocene during the major deglacial period including the melt water pulses 1a and 1b the deep sea oxygen content had declined with less ventilation and or more oxygen consumption with organic matter supply into the deeper depths the intermediate layer has been well ventilated and has supplied large amount of organic matter during the last 20 kyrs especially in the early mid holocene however such condition ceased during 3 to 2 ka the warm pacific deep water has been present since 9 ka the influence of warmer surface water such as the soya warm current swc increased in the coastal area during 7 to 4 ka and since 2 ka till present neritic derived productivity might be extended at 2 2 1 8 ka and since 1 2 ka till present

the production scheme of cycladophora davisiana radiolaria in the okhotsk sea and the northwestern north pacific implication for the paleoceanographic conditions during the glacials in the high latitude oceans 1 the sediment trap study clearly unraveled that the distinct peaks of c davisiana fluxes occurred during summer to autumn in both the okhotsk sea and the northwestern north pacific the production of c davisiana is closely related to the microbial production in the intermediate water in the okhotsk sea the distinct microbial biomass in the intermediate water which is associated with the seasonal sea ice rejected brine water during winter may support the high c davisiana abundance therefore the significantly high c davisiana abundance during the last glacial maximum lgm in the high latitude open oceans implies the distinct microbial biomass in the intermediate water caused by the seasonal sea ice coverage analogous to the present okhotsk sea

seismic slip recorded by fluidized ultracataclastic veins formed in a coseismic shear zone during the 2008 mw 7 9 wenchuan earthquake dark aphanitic material occurs as a thin w 7 9 wenchuan china earthquake it also forms injection veins in a 5 cm wide coseismic shear zone within the longmen shan thrust belt powder x ray diffraction data and microstructural analysis indicate that the veins contain little or no glassy material and are composed of fine grained fragments set in an ultrafine grained matrix all sourced from the country rock of interbedded siltstone and mudstone on the basis of x ray diffraction and mesostructural and microstructural features it is concluded that these veins are ultracataclastic veins generated by coseismic comminution with little melting accompanied by rapid fluidization in the coseismic shear zone during the 2008 wenchuan earthquake the findings support earlier suggestions that 1 ultracataclastic veins that resemble pseudotachylyte veins in appearance can be generated by crushing and rapid injection accompanied by fluidization of fine grained material during seismic faulting with little or no melting and 2 ultracataclastic veins formed in this way may record seismic slip events in seismogenic fault zones acting as earthquake fossils in much the same way as pseudotachylyte veins

cycladophora davisiana abundances as a paleoceanographic and stratigraphic tool in high latitude siliciceous sediments abstract like the oxygen isotope curve the relative abundance curve for cycladophora davisiana hereafter c curve exhibits synchronous fluctuations between high latitude regions it was also thought that high abundances of c davisiana indicated glacial periods although numerous short c curves have been calibrated to oxygen isotope curves spanning the last 100 kyr only two longer c curves have been associated with oxygen isotopes spanning the last 0 425 myr in the southern ocean and 1 1 myr in the sea of okhotsk this lack of well established long c curve calibrations to the oxygen isotope curve decreases the reliability of the c curve for periods beyond 100 ka furthermore recent work indicates that high abundances of c davisiana do not necessary indicate glacial conditions this study sought to establish a long c davisiana curve by directly calibrating the c curve to oxygen isotope records measured from benthic foraminifera in the north pacific over the last 740 kyr to discuss the paleoceanographic significance of the c curve and to check the suitability of the c curve as a stratigraphic tool samples were obtained from core c9001c which was recovered at a water depth of 1180 m east of the shimokita peninsula in the tohoku region of japan the core contained a continuous stratigraphic succession down to marine isotope stage 18 740 ka abundance peaks exceeding 5 of the total radiolarian fauna were defined as davisiana event dae and a total of 20 daes were observed over the last 740 kyr the daes were generally near interglacial glacial period boundary whereas peaks in the radiolarian total abundance reflecting warm surface radiolarian productivity occur mainly within the interglacial intervals the daes appear to reflect hydrological and productivity events in the intermediate water masses of the studied site during climatic transition we correlated the occurrence of 20 daes in shimokita area with c curve davisiana events identified in previous studies the c curve fluctuations appear to be generally synchronized in the north pacific sea of okhotsk and southern ocean supporting the interpretation that daes are intermediate water changes possibly caused by ice cover fluctuations in high latitude regions on the background of the glacial interglacial cycling

chemical investigation of mineralisation categories used to assess taphonomy abstract a recent case study from the geelbek dunes archaeological site in western cape province south africa revealed that counter to prevailing notions long term bone survivorship is not always linked to estimates of bone density porosity differences between modern cancellous and compact bones of different animals and skeletal parts provided density estimates for fossil bones taphonomic history was inferred from the physical condition and mineral burden of the fossil bones and represented by five mineralisation categories bones in mineralisation category one had the lowest secondary mineral burden whereas samples with very high secondary mineral contents were considered category five here we examine the proposed link between mineralisation category and taphonomic history by analysing fossils with non destructive energy dispersive x ray fluorescence spectroscopy we hypothesised that higher mineralisation categories should be evident as higher concentrations of elements associated with secondary minerals however chemical measurements could not distinguish fossil bones in mineralisation category one from those in category three furthermore bones in categories four and five could not be distinguished from one another a control of modern bone specimens and fossils in mineralisation category two formed separate and distinct clusters of principal component score values spectra from the geelbek dunes specimens were subsequently used to predict mineralisation categories for fossils from a nearby archaeological locality named anyskop blowout based on the surface chemistry anyskop fossils clustered in two principal groups low mineralisation categories one two and three and high mineralisation categories four and five energy dispersive x ray fluorescence spectroscopy provided useful taphonomic information for fossils from both the geelbek dunes and anyskop blowout although this surface biased technique was not well correlated with the five mineralisation categories

a pervasive link between antarctic ice core and subarctic pacific sediment records over the past 800 kyrs recently developed xrf core scanning methods permit paleoceanographic reconstructions on timescales similar to those of ice core records we have investigated the distribution of biogenic barium ba al opal and carbonate ca al in a sediment core retrieved from the abyssal subarctic pacific odp 882 50 n 167 e 3244 m over an interval that spans the full length of the epica dome c edc ice core record ba al and biogenic opal show a strong resemblance to the edc dd and co2 with generally high concentrations during interglacials and lower values during ice ages of the past 800 kyrs the sedimentary ba al and biogenic opal are most easily interpreted as indicating a reduced sinking flux of organic matter from the surface ocean during cold periods the ba al maxima during peak interglacials are accompanied by transient ca al peaks in these otherwise carbonate devoid sediments which are best explained by a deepening of the calcite lysocline presumably due to reduced storage of respired co2 in the deep north pacific for most of the luke warm interglacials noted between 420 and 750 ka in edc the ba al peaks in odp 882 are also lower further strengthening the evidence for a simple physical link between global climate and the biogeochemistry of the subarctic pacific

structural analysis of coseismic normal fault zones of the 2011 mw 6 6 fukushima earthquake northeast japan the 2011 m w 6 6 fukushima earthquake occurred in iwaki city 250 km southwest of the epicenter of the 2011 m w 9 0 tohoku japan earthquake and produced two subparallel 15 23 km long surface rupture zones with distinct displacements along two pre existing normal faults the shionohira and yunodake faults which strike north northwest south southeast and northwest southeast both dipping southwest respectively field investigations and structural analysis of the coseismic shear zones developed within the shionohira and yunodake fault zones reveal that 1 the coseismic shear zones consist of a fault core that includes a narrow fault gouge zone of 10 cm in width generally 1 5 cm a fault breccia zone of 50 cm in width and a damage zone of 5 50 m in width that is composed of cataclastic rocks fractures and subsidiary faults 2 the foliations characterized by s c fabrics developed in the shear zones indicate a dominantly normal fault slip sense consistent with that observed along the coseismic surface ruptures and 3 veinlet cataclastic rocks composed of unconsolidated fault gouges and fine grained materials occur as simple discrete veinlets and multiple cross cutting interconnected networks of veinlets these newly documented structural characteristics for two coseismic fault shear zones and associated cataclastic rocks indicate that the locations of coseismic slip zones associated with the 2011 fukushima earthquake were controlled by pre existing fault shear zones central to the shionohira and yunodake faults which have repeatedly moved as seismogenic normal faults since the timing of formation of associated cataclastic rocks our results demonstrate that the structural analyses of coseismic shear fault zones provide a powerful tool to study the nature and active faulting history of seismological faults

woce section p1w in the sea of okhotsk 1 oceanographic data description we describe the results of a world ocean circulation experiment woce survey line p1w from the open pacific ocean through the bussol strait and across the sea of okhotsk observations are presented of distributions of temperature and salinity dissolved oxygen and nutrients and some derived quantities discussion centers on the distribution of the sea of okhotsk component of the north pacific intermediate water mass and its properties the sea of okhotsk has been suggested as the only location where deep convection may occur within the north pacific or its marginal seas our analysis suggests that the surface 26 85 has recently been ventilated and arguments might be made to suggest that ventilation has occurred to 27 05 this is discussed here but detailed evidence is covered in a companion paper analyzing cfc observations the okhotsk component of the north pacific intermediate water extends to substantially greater depths and densities and so some other process is needed to create the denser water mass

how heating and cooling and wetting and drying can destroy dense faunal elements and lead to differential preservation abstract recent taphonomic research has demonstrated that bulk bone density significantly determines survivability in many archaeological and paleontological contexts researchers often assume that higher density skeletal elements invariably preserve better than lower density skeletal elements this assumption however is not universally valid here we present data on the taphonomy and preservation of assemblages from the geelbek dunes of the western cape province south africa these data indicate that skeletal preservation of fossil assemblages from deflation hollows can reflect an unexpectedly high proportion of porous low density skeletal parts high density skeletal parts including teeth and the shafts of long bones often shatter as a result of the repeated thermal shock and wetting and drying of the kind observed at geelbek this effect is greatest for highly mineralized bones from large mammals the data from geelbek demonstrate that survivability is affected by the size of the animal small mammals are represented by high proportions of non mineralized dense skeletal parts especially long bones

shallow dynamic overshoot and energetic deep rupture in the 2011 mw 9 0 tohoku oki earthquake strong spatial variation of rupture characteristics in the moment magnitude mw 9 0 tohoku oki megathrust earthquake controlled both the strength of shaking and the size of the tsunami that followed finite source imaging reveals that the rupture consisted of a small initial phase deep rupture for up to 40 seconds extensive shallow rupture at 60 to 70 seconds and continuing deep rupture lasting more than 100 seconds a combination of a shallow dipping fault and a compliant hanging wall may have enabled large shallow slip near the trench normal faulting aftershocks in the area of high slip suggest dynamic overshoot on the fault despite prodigious total slip shallower parts of the rupture weakly radiated at high frequencies whereas deeper parts of the rupture radiated strongly at high frequencies

environmental ecological and paleoanthropological implications of the late pleistocene mammalian fauna from equus cave northern cape province south africa abstract the late pleistocene deposits of equus cave northern cape province south africa have provided more than 30 000 taxonomically identifiable mammal bones from 48 species context associations and features of the bone assemblage implicate brown hyenas as the main accumulators the fauna is significant mainly because 1 it supplements previous evidence that regional climate was cooler and possibly also somewhat moister during part s of the late pleistocene but deviated less from the historic norm than in areas farther south 2 it shows that bond s springbok which became extinct in the early holocene differed from the surviving common springbok not only in important morphological respects but also in reproductive pattern and 3 it sustains earlier suggestions that an abundance of carnivores a paucity of small hard bones and increase in the cranial postcranial ratio with species size and exclusively attritional mortality profiles are features that tend to differentiate assemblages accumulated by brown hyenas from those accumulated by people in addition pending firmer dating the fragmentary human fossils from equus cave may support an exclusively african origin for anatomically modern humans

glacial holocene environment of the southeastern okhotsk sea evidence from geochemical and palaeontological data abstract environmental conditions and productivity changes in the southeastern okhotsk sea have been reconstructed for the last 20 ka using planktonic and benthic foraminiferal oxygen isotope records and calcium carbonate organic carbon and opal content data from two sediment cores species variability in benthic foraminiferal and diatom assemblages provides additional palaeoceanographic evidence ams radiocarbon dating of the sediments and oxygen isotope stratigraphy serve as the basis for the age models of the cores for the last 20 14 c kyr and for correlation between environmental variations in the okhotsk sea and regional and global climate changes benthic foraminiferal assemblages in the two cores depth 1590 and 1175 m varied with time so that we could recognise seven zones with different species composition changes in the benthic foraminiferal assemblages parallel major environmental and productivity variations during the last glaciation fluxes of organic matter to the sea floor showed strong seasonal variations indicated by the presence of abundant a weddellensis and infaunal uvigerina spp benthic foraminiferal assemblages changed with warming at 12 5 11 and 10 8 14 c kyr bp when productivity blooms and high organic fluxes were coeval with global meltwater pulses 1a and 1b younger dryas cooling caused a decline in productivity 11 10 kyr bp affecting the benthic faunal community subsequent warming triggered intensive diatom production opal accumulation and a strong oxygen deficiency causing significant changes in benthic fauna assemblages from 5 26 4 4 kyr bp to present time

settlement patterns during the earlier and middle stone age around langebaan lagoon western cape south africa the landscape around langebaan lagoon in the western cape of south africa contains a rich archive of middle and late pleistocene hominin behavior stone age localities of all ages are abundant and present a valuable perspective on the region s settlement history a complex pattern of land use is evident starting with an analysis of the earlier stone age esa collections from anyskop combined with a review of data from elandsfontein and duinefontein these late acheulian assemblages demonstrate an emphasis on handaxe production the exploitation of medium and large game and use of non local raw materials while seasonal pans provided water for animals and humans at these esa localities anyskop is distinctive because of its hilltop setting lacking water and direct access to game middle stone age msa assemblages from geelbek and anyskop combined with a review of data from hoedjiespunt sea harvest and ysterfontein provide further evidence for a regional settlement system that also incorporated non local raw materials into the lithic provisioning strategy some msa lithic technologies in the western cape were aimed at the production of bifacial points and blades as well as backed elements subsistence strategies expanded to encompass the utilization of both terrestrial and marine resources although symbolic artifacts are rare from these sites worked ochre is present at hoedjiespunt these behavioral patterns suggest that the middle and late pleistocene hominins who left these esa and msa materials behind were adept masters of their environment with adaptations well suited to the west coast landscape

multiphase late quaternary aeolian sediment accumulation in western south africa timing and relationship to palaeoclimatic changes inferred from the marine record abstract extensive aeolian deposits exist along the western margin of south africa from cape town through to the namib sand sea and represent a significant palaeoenvironmental archive recording millennial scale patterns of regional and hemispheric environmental change to establish the timing of dune development this study applies optically stimulated luminescence osl dating techniques to the aeolian features of the west coast in total 35 samples were obtained from six dune cores along a north south transect extending from elands bay 32 26 s 18 14 e to kleinsee 29 14 s 16 59 e ages from these dunes exhibit five distinct peaks suggesting phases of activity deposition at 4 5 16 24 30 33 43 49 and 63 73 ka the spatial and temporal extent of the data have allowed for correlations to be made with evidence from marine cores from the southeast atlantic and a more coherent regional environmental history to be developed results suggest that 1 environmental changes in this region are strongly linked to variations in wind strength and atmospheric circulation systems during the late quaternary and 2 luminescence ages from aeolian deposits cannot necessarily be equated with periods of increased aridity with other factors such as wind strength and sediment supply being of critical importance

geoarchaeological investigation of occupation deposits in blombos cave in south africa indicate changes in site use and settlement dynamics in the southern cape during mis 5b 4

ice age terminations 230th dated oxygen isotope records of stalagmites from sanbao cave china characterize asian monsoon am precipitation through the ends of the third and fourthmost recent ice ages as a result am records for the past four glacial terminations can now be precisely correlated with those from ice cores and marine sediments establishing the timing and sequence of major events in all four cases observations are consistent with a classic northern hemisphere summer insolation intensity trigger for an initial retreat of northern ice sheets meltwater and icebergs entering the north atlantic alter oceanic and atmospheric circulation and associated fluxes of heat and carbon causing increases in atmospheric co2 and antarctic temperatures that drive the termination in the southern hemisphere increasing co2 and summer insolation drive recession of northern ice sheets with probable positive feedbacks between sea level and co2

geochemical multielement signatures of glacial and interglacial facies of the okhotsk sea deepwater sediments during the past 350 kyr a response to global climate changes at the orbital and millennial scales the previously dated deepwater sediment core mr06 04 pc 7r length 1723 cm 350 kyr recovered from the central okhotsk sea os was analyzed for biogenic compounds and for 63 chemical elements using the inductively coupled plasma mass spectrometry method with a high resolution 1 cm 200 years a one box model with two main members and mathematical methods based on multielemental composition of sediments for the calculation of weight fractions at each time slice of two main types of geochemical facies that dominate during considerably diverse climatic periods glacial maxima and interglacial optima were proposed and tested this model can be applied to other analogous natural systems whose sedimentation is driven by two main types of geochemical facies the application of the developed model to the studied core revealed that variations of weight fractions of the typical interglacial and glacial geochemical facies in the sediments along the core depth named as warm and cold covariators respectively change synchronously with global and regional climate variability profiles of warm and inversed cold covariators coincide tightly and their values increase during warm marine isotope stages and substages and decrease during cold ones over the last 350 kyr millennial scale changes in covariators had occurred simultaneously with abrupt variability in the os productivity and sediment lithology and with millennial global climate variability some discrepancies in the warm and inversed cold covariators calculated using specific mathematical treatments revealed the episodic influence of volcanogenic matter presented in the core by visible tephra layers and cryptotephras

meso and microstructural analysis of coseismic shear zone of the 1999 mw 7 6 chi chi earthquake taiwan the surface rupture of the 1999 m w 7 6 chi chi taiwan earthquake was controlled primarily by the pre existing chelungpu fault zone which is distributed in a wide zone of up to 60 m although the main coseismic slip is localized in a narrow shear zone of 0 3 cm the chelungpu fault zone is composed of cataclasite fault breccia and gouge zones that are well observed in both the fault outcrops and the drill cores taken throughout the fault zone the foliations developed in the cataclasite and fault breccia zones are oriented parallel to that of the fault gouge zone where the main coseismic slip occurred the structural analyses of the shear zone and fault rocks show that the chelungpu fault zone has slipped as a thrust fault with a significant left lateral slip component since its formation in the pleistocene this oblique thrust motion is caused by the southeast northwest oblique convergence between the philippine sea plate and the eurasian plate

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

glacial age hydrography of the far northwest pacific ocean stable isotope data on benthic foraminifera from more than 30 cores on the northern emperor seamounts and in the okhotsk sea are synthesized in paleohydrographic profiles spanning the depth range 1000 4000 m holocene core top benthic foraminiferal 18o and 13c data are calibrated to modern hydrographic properties through measurements of 13c of co2 and 18o of seawater cibicidoides stable isotope ratios are close to the 13c and equilibrium 18o of seawater whereas uvigerina 18o and 13c are variably offset from cibicidoides glacial maximum 13c of cibicidoides displays a different vertical profile than that of the holocene when results are adjusted by 0 32 to account for the secular change in 13c during the last glacial maximum the data coincide with the modern seawater and foraminiferal curves deeper than 2 km however at shallower depths 13c gradually increases by as much as 1 above the modern value furthermore above 2 km the benthic 18o decreases by 0 5 these results are consistent with a benthic front at 2 km in the north pacific see herguera et al 1992 but they differ from interpretations based on trace metal data which indicate a source of nutrient depleted deep water during glaciation the isotopic data suggest that during glaciation there was a better ventilated watermass at intermediate depths in the far northwestern pacific it was relatively fresher than deep waters there and deep waters were as nutrient rich as today

a middle stone age paleoscape near the pinnacle point caves vleesbaai south africa abstract open air middle stone age msa contexts in southern africa have received relatively little research attention compared to caves rock shelters msa caves rock shelters can provide long sequences of msa behaviors dominated by residential activities in circumscribed contexts but most procurement activities occurred on the landscape in uncircumscribed space we have a limited understanding of these activities at present making studies of open air sites crucial to alleviate this bias the south african coast paleoclimate paleoenvironment paleoecology paleoanthropology sacp4 project expanded its research scope to include msa archaeology from open air contexts we report on a series of msa open air assemblages that are exposed on ancient land surfaces suggestive of intact paleosols at vleesbaai and visbaai south africa importantly these sites occur in close proximity to the long cave rock shelter sequences at pinnacle point this presents the novel potential to study evidence of msa behavior in closed and open settings where their proximity to each other approximates the typical hunter gatherer daily foraging radius documented in ethnography we present a fabric and technological analysis of msa stone tool assemblages from three areas analysis of total station piece plotting of artifact bearing plunge suggests that the lithic assemblages have undergone limited post depositional disturbance the technological analysis and exploratory comparisons between these open air assemblages and msa cave and rock shelter contexts at pinnacle point cave 13b and 9 and cape st blaize cave suggest that the quartzite artifacts from vleesbaai were procured from locally available sources and may have been field processed there before being transported elsewhere perhaps to the caves rock shelters further the analysis suggests a dichotomous pattern of retouched tool discard where quartzite tools are discarded similarly across the landscape in contrast non quartzite tools may have been made primarily at the cave sites and discarded or lost more frequently on the landscape

repeated pleistocene glaciation of the east siberian continental margin during glacial periods ice sheets covered continental margins through much of arctic north america greenland and western eurasia marine structures suggest that an ice sheet up to a kilometre in depth periodically covered the east siberian continental shelf as well

global ice volume fluctuations north atlantic ice rafting events and deep ocean circulation changes between 130 and 70 ka multiproxy data from north atlantic deep sea sediment core neap18k provide a detailed record of climate through oxygen isotope stage ois 5 seven distinct large scale episodes of ice rafting c25 c19 were identified between 126 and 70 ka global ice volume reconstructions based on high resolution benthic 18 o records indicate that major ice rafting events were not confined to ice volume maxima at ois 5d and 5b but also occurred during periods of ice sheet growth and disintegration however iceberg discharges were restricted to times when sea levels were 40 65 m below present values ice rafting episode c25 the first large scale cooling of mid atlantic surface waters after the last interglacial occurred during the gradual buildup of continental ice sheets at the ois 5e 5d transition major ice sheet collapses allied to ice rafting events c24 and c21 were associated with rapid sea level increases of 20 and 40 m respectively suborbital climatic fluctuations in the neap18k sedimentary record denoted by prominent 7 5 4 5 and 3 k y cyclicities appear to correlate with both greenland atmospheric temperatures and changes in thermohaline circulation patterns inferred from benthic 13 c values and hence provide clear evidence of a highly interconnected north atlantic climatic regime during ois 5

fault structure control on fault slip and ground motion during the 1999 rupture of the chelungpu fault taiwan the chelungpu fault taiwan ruptured in a mw 7 6 earthquake on 21 september 1999 producing a 90 km long surface rupture analysis of core from two holes drilled through the fault zone combined with geologic mapping and detailed investigation from three outcrops define the fault geometry and physical properties of the chelungpu fault in its northern and southern regions in the northern region the fault dips 45 60 east parallel to bedding in both the hanging wall and footwall and consists of a narrow 1 20 cm core of dark gray sheared clay gouge the gouge is located at the base of a 30 to 50 m zone of increased fracture density confined asymmetrically to the hanging wall microstructural analysis of the fault gouge in dicates the presence of extremely narrow clay zones 50 300 lm thick that are interpreted as the fault rupture surfaces few shear indicators are observed outside of the fault gouge implying that slip was localized within the gouge zone slip localization along a bed parallel surface resulted in a narrow gouge zone that pro duced less high frequency ground motion and larger displacements average 8 m during the earthquake than in the southern region displacement in the southern region averaged only 2 m but ground shaking consisted of large amounts of high frequency ground motion the fault in the southern region dips 20 30 at the surface and consists of a wide 20 70 m thick zone of sheared foliated shale with numerous gouge zones these data demonstrate a potential correlation between fault structure i e gouge width geometry and earthquake characteristics such as displacement and ground motion i e acceleration

late quaternary changes in intermediate water oxygenation and oxygen minimum zone northern japan a benthic foraminiferal perspective 1 a strong oxygen minimum zone omz currently exists at upper intermediate water depths on the northern japanese margin nw pacific the omz results largely from a combination of high surface water productivity and poor ventilation of upper intermediate waters we investigated late quaternary history last 34 kyr of ocean floor oxygenation and the omz using quantitative changes in benthic foraminiferal assemblages in three sediment cores taken from the continental slope off shimokita peninsula and tokachi northern japan at water depths between 975 and 1363 m these cores are well located within the present day omz a region of high surface water productivity and in close proximity to the source region of north pacific intermediate water late quaternary benthic foraminiferal assemblages experienced major changes in response to changes in dissolved oxygen concentration in ocean floor sediments foraminiferal assemblages are interpreted to represent three main groups representing oxic suboxic and dysoxic conditions assemblage changes in all three cores and hence in bottom water oxygenation coincided with late quaternary climatic episodes similar to that known for the southern california margin these episodes in turn are correlated with orbital and millennial climate episodes in the greenland ice core including the last glacial episode bolling allerod b a younger dryas preboreal earliest holocene early holocene and late holocene the lowest oxygen conditions marked by dysoxic taxa and laminated sediments in one core occurred during the b a and the preboreal intervals suboxic taxa dominated mainly during the last glacial the younger dryas and most of the holocene dysoxic conditions during the b a and preboreal intervals in this region were possibly caused by high surface water productivity at times of reduced intermediate ventilation in the northwestern pacific remarkable similarities are evident in the late quaternary sequence of benthic foraminiferal assemblage change between the two very distant continental margins of northern japan and southern california the oscillations in omz strength reflected by these faunal changes were widespread and apparently synchronous over wide areas of the north pacific reflecting broad changes in intermediate water ventilation and surface ocean productivity closely linked with late quaternary climate change on millennial and orbital timescales

late pleistocene holocene radiolarian and pollen records from sediments in the sea of okhotsk in two cores with oxygen isotope stratigraphy from the southern okhotsk sea marine pollen and siliceous microfauna record concurrent late glacial through holocene variations in regional terrestrial and marine environments glacial vegetation around the southern okhotsk basin which resembles the present tundra steppe of the northwest coast of this marginal sea yields to spruce dominated boreal forests during the glacial interglacial transition temperate forest components such as oak peak during the mid holocene decreasing oak accompanied by increasing spruce reflects the effect of global cooling on local vegetation during the last 4 kyr although the radiolarian fauna in the okhotsk sea samples is similar to that present in the northwest pacific the dominant species in both regions differ concentrations of radiolarians are low in latest glacial samples with higher concentrations occurring above and below this interval cycladophora davisiana the dominant radiolarian species in the majority of holocene okhotsk sea sediments is present at lower percentages in late glacial samples from our two sites thus this species holocene latest pleistocene abundance pattern in sea of okhotsk sediments is the reverse of that recorded in high latitude open ocean sites the combined marine pollen and radiolarian records indicate changes in the sea of okhotsk s physical oceanographic conditions and surrounding vegetation during the late glacial which were associated with this region s response to global climate change

preservation of elemental and isotopic source identification of sedimentary organic matter the amount and type of organic matter in the sediments of lakes and oceans contribute to their paleoenvironmental and paleoclimatological records only a small fraction of the initial aquatic organic matter survives destruction and alteration during sinking and sedimentation selective degradation modifies the character of the surviving small fraction of organic matter which becomes incorporated in bottom sediments organic matter alterations can continue to sub bottom depths of hundreds of meters corresponding to millions of years source and paleoenvironmental information nonetheless remains preserved in the molecular elemental and isotopic compositions of organic matter c n and 13c values of total organic matter in particular appear to retain paleoenvironmental information for multi myr time periods

co seismic thrusting rupture and slip distribution produced by the 2008 mw 7 9 wenchuan earthquake china field investigations reveal that the mw 7 9 wenchuan china earthquake of 12 may 2008 produced a 285 km long surface rupture zone with dominantly thrusting slip accompanied by a right lateral component along the central northern segments of the zone and left lateral component along the southern segment along the longmen shan thrust belt eastern margin of the tibetan plateau the co seismic ruptures mainly occurred along the pre existing yingxiu beichuan guanxian anxian and qingchuan faults which are the main faults of the longmen shan thrust belt the displacements measured in the field are approximately 0 5 6 5 m in the vertical typically 1 3 m accompanied by an average left lateral component of 2 m along the 50 km long southernmost segment of the rupture zone and an average right lateral component of 1 m along the 150 km long central northern segments the maximum thrust slip amount is estimated to be 10 m accompanied by 9 m of shortening across the rupture zone this finding is consistent with estimates based on seismic data the rupture length and maximum vertical displacement are the largest among all intracontinental thrust type earthquakes reported to date our findings demonstrate that i the wenchuan earthquake occurred upon pre existing active faults of the longmen shan thrust belt thereby controlling the spatial distribution of co seismic surface rupture and displacement and the rupture processes of the earthquake ii the long rupture length and large thrusting slip resulted from compressive stress associated with eastward extrusion of the tibet plateau as it accommodates the ongoing penetration of the indian plate into the eurasian plate and iii present day shortening strain upon the eastern margin of the tibetan plateau is mostly released by seismic slip along thrust faults within the longmen shan thrust belt

northeastern atlantic benthic foraminifera during the last 45 000 years changes in productivity seen from the bottom up we studied benthic foraminifera from the last 45 kyr in the 63 mu m size fraction in biogeochemical ocean flux studies bofs cores 5k 50 degrees 41 3 n 21 degrees 51 9 w depth 3547 m and 14k 58 degrees 37 2 n 19 degrees 26 2 w depth 1756 m at a time resolution of several hundreds to a thousand years the deepest site showed the largest fluctuations in faunal composition species richness and benthic foraminiferal accumulation rates the fluctuations resulted from changes in abundance of epistominella exigua and alabaminella weddellensis in the present oceans these species bloom opportunistically when a spring plankton bloom results in seasonal deposition of phytodetritus on the seafloor the phytodetritus species had very low relative abundances and accumulation rates during the last glacial maximum a strong increase in absolute and relative abundance of e exigua and a weddellensis during deglaciation paralleled the decrease in abundance of the polar planktonic foraminifer neogloboquadrina pachyderma s and the increase in abundance of warmer water planktonic species such as globigerina bulloides this strong increase in relative abundance of the phytodetritus species and the coeval increase in benthic foraminiferal accumulation rate were thus probably caused by an increase in the deposition of phytodetritus to the seafloor and thus probably of surface productivity when the polar front retreated to higher latitudes the abundance of phytodetritus species decreased during the younger dryas but not to the low levels of fully glacial conditions during heinrich events periods of excessive melt water formation and ice rafting benthic accumulation rates were very low as were the absolute and relative abundances of the phytodetritus species supporting suggestions that surface productivity was very low during these events in both cores pullenia and cassidulina species were common during isotope stages 2 3 and 4 as were bolivinid buliminid and uvigerinid species high relative abundances of these species have been interpreted as indicative either of sluggish deep water circulation or of high organic carbon fluxes to the seafloor in our cores relative abundances of these species are negatively correlated with benthic foraminiferal accumulation rates and we can thus not interpret them as indicative of increased productivity during glacials the percentage of these low oxygen species calculated on a phytodetritus species free basis decreased slightly at deglaciation at 5k but not at 14k this suggests that decreased production of north atlantic deep water during the last glacial might have slightly affected benthic foraminiferal faunas in the eastern north atlantic at 3547 m depth but not at 1756 m in conclusion major changes in deep sea benthic foraminiferal faunas over the last 45 000 years in our cores from the northeastern atlantic were the result of changes in surface water productivity not of changes in deep water circulation productivity was lower during the glacial probably because of extensive ice cover

environmental change in the sea of okhotsk during the last 1 1 million years on the basis of two sedimentary records from the central sea of okhotsk we reconstruct the closely coupled glacial interglacial changes in terrigenous flux marine productivity and sea ice coverage over the past 1 1 myr the correspondance of our sedimentary records to the china loess grain size record china loess particle timescale chiloparts suggests that environmental changes in both the sea of okhotsk area and in se asia were closely related via the siberian atmospheric high pressure cell during full glacial times our records point to a strong siberian high causing northerly wind directions the extension of the sea ice cover and a reduced amur river discharge deglacial maxima of terrigenous flux were succeeded by or synchronous to high productivity events marine productivity was strengthened during glacial terminations because of an effective nutrient utilization at times of enhanced water column stratification and high nutrient supply from fluvial runoff and sea ice thawing during interglacials se monsoonal winds prevailed analogous to today s summer situation of a pronounced mongolian heat low and a strong hawaiian high strong freshwater discharge induced by high precipitation rates in the amur drainage area and a seasonally reduced and mobile sea ice cover favored marine productivity although being considerably lower than during the terminations and a lowered flux of ice rafted detritus

south african palaeoenvironments during marine oxygen isotope stage 4 a context for the howiesons poort and still bay industries abstract spanning the period from 74 58 ka and being broadly coeval with marine oxygen isotope stage 4 mis 4 the still bay and howiesons poort industries represent important phases in the development of the material culture of early modern humans how and why these industries occurred when they did however remain matters for speculation a key element of this debate has been the question of what role environmental change during the early stages of the last glacial period may have had on influencing human activity unfortunately well dated palaeoenvironmental evidence from this period is limited and the debate has out of necessity been driven by the application of conceptual models of environmental change many of which associate colder and warmer global climates with increased aridity and humidity respectively in this paper the regional marine and terrestrial evidence is synthesised to create an evidence based palaeoenvironmental context based on the information available to date it appears that rather than being characterised by dry conditions mis 4 was a period of relatively cool moist climates the ubiquity of which transcends the modern regional climate boundaries it is suggested that orbital parameters at this time created greater interaction between tropical and temperate circulation systems bringing more moisture to the subcontinent these findings highlight the distinct nature of southern african climate systems and caution against the application extra regional conceptual models or inferring linear relationships with polar records

finding resolution for the howiesons poort through the microscope micro residue analysis of segments from sibudu cave south africa in this paper i present the results of a micro residue analysis of stone segments the type fossils of the howiesons poort technocomplex in south africa with an age of more than 60 ka at sibudu cave kwazulu natal fifty three segments were systematically analysed and 1826 organic micro residue occurrences were documented on the sample the distribution patterns of micro residues and other use traces are interpreted in terms of hafting and function it is shown that most of the tools were indeed hafted and most were probably used as inserts for hunting weapons there is evidence for differences and changes over time in haft materials and hafting configurations of the segments the study demonstrates how functional studies could improve our understanding of change and variability in human behaviour during the middle stone age a period that used to be portrayed as static or slow changing

late quaternary changes of the oxygen conditions in the bottom and intermediate waters on the western kamchatka continental slope the sea of okhotsk microfossil data on the foraminifers and radiolarians in the sediment core komex lv28 44 3 the kamchatka slope in the eastern sea of okhotsk exhibit the changes in the water oxygen conditions during the last 146 ky the paleoenvironmental proxies are the radiolarian species cycladophora davisiana as indicator of the upper intermediate water ventilation and the benthic planktonic foraminifers as indicators of the bioproductivity and bottom water oxygenation in case of sediment core lv28 44 3 the bottom water represents the lower intermediate one so that conclusions on paleoenvironments are applicable for the most range of the local intermediate water the well oxygenated intermediate and near bottom waters existed in the area of study during the penultimate glaciation of mis 6 early weichselian initiation of the last glaciation within mis 5b d and last glacial stages of mis 3 2 the intervals of the short low o2 bottom events with suboxic conditions dissolved o2 in water 0 3 1 2 ml l occur during the last interglacial mis 5e eemian stage 125 to 113 ka and during the last deglaciation 17 5 to 6 5 ka eemian low o2 bottom events are associated with the high bioproductivity of the subsurface water but poor ventilation on the upper intermediate depths the low o2 bottom events during the last deglaciation occurred at the high bioproductivity of the subsurface water and active ventilation on the upper intermediate depths

excavation of buried late acheulean mid quaternary land surfaces at duinefontein 2 western cape province south africa abstract duinefontein 2 dft2 preserves at least two buried land surfaces within a 10 m thick dune plume on the atlantic coast of south africa about 35 km north of cape town optically stimulated luminescence dating indicates that the sands enclosing the upper surface accumulated around 270 ky ago while the sands between the two surfaces were accumulating about 290 ky ago excavation so far has focused on the upper buried surface which is now exposed over 480 m 2 historically there was no body of fresh water nearby and the surrounding vegetation was a variant of the regional fine leafed shrub or fynbos pedogenic alteration of the sands and bones of water loving mammals and amphibians indicate however that the bones and associated acheulean artifacts accumulated near the edge of a large pond or marsh in addition the principal mammal species buffalo wildebeest and kudu imply a sharply different regional vegetation in which grass and broad leafed bush were much more common the artifacts are distributed across the upper buried surface in no apparent pattern but the large mammal bones tend to occur as clusters of skulls vertebrae ribs and other axial elements often in near anatomical order limb bones are mostly missing and the clusters appear to mark carcasses from which the limb bones were selectively removed the bones rarely show marks from stone tools but marks from carnivore teeth are common together with numerous hyena coprolites the abundant tooth marks suggest that hyenas and perhaps other carnivores were largely responsible for carcass disarticulation the human role appears to have been insignificant which suggests that local acheulean people obtained few large mammals whether by hunting or scavenging among the small number of other acheulean carcass sites for which bone damage observations are available the best documented sites suggest the same limited human ability to acquire large mammals but many additional sites will be necessary to determine if this was the acheulean norm greatly expanded excavation of the lower buried surface at dft2 can provide an additional high quality data point

tem microstructural analysis in a fault gouge sample of the nojima fault zone japan abstract a fault gouge sample recovered from 389 m depth of the disaster prevention research institute dpri 500 m bore hole of the nojima fault which triggered the 1995 m7 3 kobe earthquake was examined with transmission electron microscopy tem we observed different types of amorphous material containing tiny flakes of crystalline phases tem edx analysis of the matrix indicates a pure smectite composition suggesting that matrix and crystalline flakes have the same composition the detection of tiny crystalline flakes in the amorphous material may confirm previous assumption from the alteration of pseudotachylyte into smectite in fault rocks

structural analysis of a previously unknown active fault that triggered the 2013 mw 5 8 awajishima earthquake southwest japan the m w 5 8 awajishima earthquake occurred on 13 april 2013 in southwest awaji island 25 km southwest of the epicenter of the 1996 m w 6 8 kobe earthquake southwest japan analyses of aerial photographs and 3d perspective images field investigations and structural analysis of fault rocks reveal that 1 a previously undocumented fault here called the yamada fault strikes northwest southeast and dips southwest at 86 along a topographic lineament at the geological boundary between mesozoic granitic rocks and the late pliocene quaternary osaka group composed of interbedded sandstone and mudstone 2 the main shear zone of the yamada fault consists of a fault core with a 10 cm wide zone of fault gouge generally 1 5 cm a fault breccia zone of 100 cm wide and a damage zone of 10 50 m wide composed of cataclastic rocks and fractures 3 foliations characterized by s c fabrics that have developed in the shear zone indicate a dominantly thrust fault sense consistent with that revealed by the focal mechanism and 4 coseismic surface ruptures occurred locally along the main trace of the yamada fault consisting of numerous short fissures ranging in length from centimeters to several meters and concentrated in a zone 5 m wide our findings show that the newly identified yamada fault is an active fault and that it is probably the fault on which the 2013 m w 5 8 awajishima earthquake occurred therefore it is necessary to construct a fault model to better understand the deformation characteristics of the seismogenic source fault and for reassessing the seismic hazards on the densely populated awaji island of southwest japan

reconstruction of seismic faulting by high velocity friction experiments an example of the 1995 kobe earthquake 1 high velocity friction experiments on a fault gouge collected from the nojima fault activated during the 1995 kobe earthquake showed that the friction coefficient decreased from 0 63 to 0 18 over a slip weakening distance dc at high slip rates of 1 m s the dramatic drop in friction coefficient of more than 0 3 is consistent with that for the kobe earthquake estimated from seismological observations experimentally determined dc becomes 5 m at a higher normal stress of 1 85 mpa close to the order of magnitude of seismologically determined dc of 0 5 to 1 m the difference in dc is not significant because the fracture energy consumed during frictional slip is the same order of 106 n m for both cases here we show that frictional behavior of a fault during an earthquake can be predicted by conducting high velocity friction experiments

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

high resolution paleoproductivity fluctuations during the past 24 kyr as indicated by benthic foraminifera in the marginal arctic ocean abstract analyses of benthic foraminifera in sediment cores taken at about 1000 m water depth at the yermak plateau and the barents sea slope adjacent to the position of the ice sheet edge during the last glacial maximum show that paleoproductivity was reduced to about a third of its present level during peak glacial stadials these reduced values are still higher than values for modern permanently ice covered regions suggesting that the core locations were at least partially ice free even during stadials paleoproductivity at the core locations was higher than or equal to that of today during initial deglaciations and warm substages peak paleoproductivity occurred in samples with low salinity surface waters as indicated by oxygen isotope values of planktonic foraminifera and slightly after increased abundance of atlantic species suggesting that enhanced advection of warmer waters from the atlantic supported the initial ice sheet retreat during the holocene climatic optimum productivity was much less than at present on the yermak plateau high at the barents sea site perhaps because of increased advection of atlantic water to the latter site and heavier ice coverage at the former after this optimum paleoproductivity at both sites was similar with slightly lower values during cold periods such as the little ice age

repeated large subduction zone earthquakes in the nankai suruga trough evidence from submarine liquefactions 1 subduction zones are generally characterized by large earthquakes that contribute about 90 of the total seismic moment worldwide and can cause great damage from tsunamis such as the 2004 sumatra mw 9 0 earthquake here we report recurrent large subduction zone earthquakes revealed by extensive submarine liquefactions formed in the nankai suruga trough where the philippine sea plate is subducting beneath the eurasian plate field evidence and grain size analysis of liquefied deposits show that the multiple liquefactions were repeatedly induced by strong earthquake shaking during the pleistocene in the eastern nankai suruga subduction zone the recognition and analysis of submarine liquefactions provide reliable paleoseismic evidence in the nankai suruga subduction zone

evaluating the use of dune sediments as a proxy for palaeo aridity a southern african case study abstract the dominance of dryland environments in the southern hemisphere makes the study of these regions of critical importance for the development of regional hemispheric and global models of environmental change unfortunately the wetting and drying cycles associated with semi hyperarid climates are not conducive to the preservation of traditional organic proxy data sources the last decade however has seen the development of a number of alternative archives including the application of luminescence dating techniques to dunes and other aeolian deposits in continental situations the existence of relict dune fields has long been thought to be evidence of drier conditions during the pleistocene and direct ages from these features have been interpreted almost exclusively as indicating phases of aridity however an increasing number of ages from a broader range of environments are calling into question the assumption that aeolian activity can be simply equated with aridity presented here is a comparison of dune ages that have been obtained from across southern africa with a range of proxies from both terrestrial and marine records taken as a whole three primary phases of activity can be identified at 60 40 35 20 and 17 4 ka the frequent discordance with other terrestrial records indicating coeval increases in humidity and the close correlation of these phases with wind strength proxies suggest that aridity is unlikely to be the sole or even primary forcing mechanism for aeolian activity in the region and the palaeoclimatic significance of these sedimentary archives needs to be reassessed

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

relation of subtropical atlantic temperature high latitude ice rafting deep water formation and european climate 130 000 60 000 years ago abstract a new high resolution record of sea surface temperature from the subtropical western north atlantic documents a series of abrupt coolings within marine isotope stage 5 which can be objectively correlated with marine core evidence for increased ice sheet discharge at subpolar latitudes and reduced north atlantic deep water formation these results indicate that ice sheet forcing of deep ocean circulation influenced surface temperatures over much of the north atlantic a proposed correlation to the pollen record of grande pile france indicates that each cold event seen in the pollen sequence has a unique counterpart in the record of subtropical ocean temperature if this correlation is correct it suggests that the warmest part of the european eemian ended suddenly in response to oceanographic changes and that the subsequent post temperate phase of the eemian extended well into the interval of ice sheet growth corresponding to marine isotope substage 5d

thickness of the seismic slip zone this article reviews geologic and other evidence constraining the thickness of the principal slip zone psz that accommodates the bulk of coseismic shear displacement during an individual rupture event surface deformation from rupturing may occupy swaths tens of meters or more in width but trenches across active faults generally reveal that incremental slip is accommodated by a psz that is tens of centimeters or less in thickness geomorphic evidence coupled with the observations from trenching suggest a psz may stay well localized for distances of several kilometers through many rupture episodes mine exposures and exhumed fault zones demonstrate that pszs separating different lithologies within the fault core although contained within damage zones of variably fractured rock ranging up to hundreds of meters in thickness often comprise just a few centimeters of gouge ultracataclasite that have accommodated large finite displacements 1 km microstructural studies demonstrate incremental slip localized still further down to 1 10 mm as do other fault rock assemblages slickensides and slickenfibers fault veins of pseudotachylyte friction melt intravein septa in hydrothermal fault infills the accumulated evidence indicates that localization of coseismic shearing to less than 10 cm on planar faults is widespread throughout the crustal seismogenic zone with extreme localization to less than 1 cm not uncommon however some distributed coseismic shear may also develop especially at rupture irregularities coseismic reduction of shear resistance from friction melting t 1000 c or from transient thermal pressurization of aqueous fluids t 100 c requires slip during moderate to large earthquakes u 1 m to be restricted to narrow zones respectively a few centimeters or tens of centimeters in thickness given the evidence for slip localization the apparent scarcity of pseudotachylyte suggests either that seismic friction melting is a rare phenomenon or that pseudotachylyte is only rarely preserved in recognizable form within mature hydrated fault zones

okhotsk sea ice coverage and kamchatka glaciation over the last 350ka evidence from ice rafted debris and planktonic δ18o high resolution records of ice rafted debris ird and oxygen isotope records spanning an e w trending transect across the okhotsk sea unravel the marine and terrestrial cryogenic history of ne siberia over the last 350 kyr ird predominantly dispersed basin wide by sea ice shows lowest fluxes during interglacial periods implying a reduced and seasonal sea ice coverage highest ird accumulation rates are observed during glacial and deglacial periods with a more extended but highly dynamic ice cover although being rather synchronous ird fluxes are on average higher in the western okhotsk sea than in the eastern part pointing to a persistent but mobile particle supplying sea ice cover even during full glacial conditions presumably less dense in the eastern parts mis 6 is exceptional in this respect asynchronous fluxes of ird which vary spatially reflect rapid paleoclimatic and paleo glaciomarine changes ird accumulation rates were by factor 2 3 higher during mis 6 as compared to the last glacial maximum and the ird depositional center shifted from the western okhotsk sea early mis 6 toward kamchatka late mis 6 synchronous to a distinct change in the ird mineral composition both the characteristic composition of late mis 6 ird originating from the sredinny mountain range of kamchatka and their significantly enhanced accumulation rates refer to intensified iceberg dispersal across the eastern part of the okhotsk sea at 138 ka 135 ka 129 ka and 128 ka bp this scenario affords the presence of extended mountain glaciers protruding down to sea level on the western side of kamchatka anomalously light planktonic stable oxygen isotopes during mis 6 3 termination ii and mis 5 5 5 4 suggest significant freshwater supply related to the westward drainage of kamchatka glaciers the intensified kamchatka glaciation observed during late mis 6 was repeated during mis 3 iceberg discharges into the eastern okhotsk sea are observed at 60 ka 51 ka 42 ka 38 ka 36 ka and 31 ka and may partly correspond to n atlantic heinrich events

radiolarians under the seasonally sea ice covered conditions in the okhotsk sea flux and their implications for paleoceanography abstract four time series sediment traps at two stations and three piston cores from the okhotsk sea were quantitatively examined for coarse sized radiolarian shells 63 m traps were deployed at 300 m and 1550 m at station m4 53 01 n 145 30 e and at 300 m and 700 m at station m6 49 30 n 146 28 e during august 1998 through may 2000 the chronologies of the piston cores were established applying 18 o and paleomagnetic intensity variations they provide records extending back to marine isotope stage mis 5 51 the modern and past changes in radiolarian assemblages are associated with environmental and productivity changes radiolarian fluxes in the sediment traps exhibited significant summer to autumn flux peaks with suppressed values during the winter when sea ice covered the sea surface at the trap sites total radiolarian accumulation rate rar variations in each core tended to correspond to glacial interglacial cycles and increased during the last deglaciation in particular the temporal rar variation in core xp98 pc1 off kamchatka showed a similar trend with the climatic changes expressed by 18 o values during the glacial interglacial cycles for the last 125 kyr regional differences were also apparent rars showed extremely low values during 12 40 kyr and 63 70 kyr in core xp98 pc2 central okhotsk sea indicating the enhanced sea ice impact the sea ice coverage might have continued for a significant part of the year during the intervals since radiolarians did not appear to increase even during the summer to autumn rar variations in core xp98 pc4 off sakhalin showed higher values than xp98 pc2 during mis 2 and 4 thus in eastern sakhalin around site xp98 pc4 sea ice coverage might have been seasonal but not perennial even during mis 2 and 4 among the radiolarian taxa cycladophora davisiana was the most abundant species at the lower traps and in all cores the fluxes of c davisiana at lower traps showed much higher values than those of upper traps and also showed similar temporal patterns with the fluxes of aluminum and terrigenous materials therefore c davisiana fluxes may be associated with terrigenous organic materials increased nutrient supply from the continental shelves presumably transported by seasonal sea ice and released by sea ice melting might be mainly responsible for the high production of c davisiana in the okhotsk sea especially during the last deglaciation

displacement above the hypocenter of the 2011 tohoku oki earthquake the moment magnitude m w 9 0 2011 tohoku oki mega thrust earthquake occurred off the coast of northeastern japan combining global positioning system gps and acoustic data we detected very large sea floor movements associated with this event directly above the focal region an area with more than 20 meters of horizontal displacement that is four times larger than those detected on land stretches several tens of kilometers long along the trench the largest amount reaches about 24 meters toward east southeast just above the hypocenter furthermore nearly 3 meters of vertical uplift occurred contrary to observed terrestrial subsidence

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

community evolution of neogene micromammals from langebaanweg e quarry and other west coast fossil sites south western cape south africa abstract this paper provides an overview of the micromammalian palaeocommunities found in fossil bearing palaeontological and archaeological west coast sites dating from the mio pliocene as represented by the site of langebaanweg e quarry and other sites dating from the late middle pleistocene until the late holocene recent excavations at langebaanweg have resulted in the addition of more murid genera to previously compiled faunal lists an updated faunal list is presented and a comparison is made on a generic level between the micromammals from langebaanweg and the considerably younger west coast fossil sites of elands bay cave steenbokfontein cave the saldanha bay yacht club site and hoedjiespunt 1 and some modern owl pellet collections the palaeobiogeographical and palaeoenvironmental significance of the different west coast micromammal communities and the evolution of the west coast rodent community is examined nine of the micromammal genera found at lbw are present in some or all of the west coast fossil sites dating from the late middle pleistocene until the holocene this indicates the endurance of many of the genera present at lbw and in the kalahari south west arid and namib regions from the mio pliocene up until the present

s c cataclasite in granitic rock abstract foliated cataclasites in granitic rocks along the rokko awaji fault zone japan display s c fabrics similar to those of mylonites the s c cataclasites have s surfaces defined by shape preferred orientation of biotite fragments and aggregates of quartz and feldspar fragments and c surfaces defined by microshears all quartz and feldspar fragments show mainly brittle deformational microstructures the biotite fragments however have some fabric characteristics like those observed in s c mylonites such as biotite fish cleavage steps bending and folding these differences in microfabric between biotite quartz and feldspar suggest that there are marked differences in their deformational behavior under the same deformational conditions biotite deformed by a combination of brittle plastic shearing processes and quartz and feldspar were brittlely damaged one of the most significant microstructural differences between s c cataclasites and s c mylonites is the absence of dynamically recrystallized grains in the s c cataclasites the microstructural characteristics and the geological evidence suggest that the s c cataclasites in the rokko awaji fault zone formed at temperatures between 150 and 250 c corresponding to depths of 5 8 km at a continental geothermal gradient of 30 c km before being uplifted and exposed this study of cataclastically deformed rocks shows that the fault zone rheology of the upper 5 10 km of crust is greatly influenced by deformational processes in s c cataclasites

stable isotope and lithologic evidence of late glacial and holocene oceanography of the northwestern pacific and its marginal seas abstract stable isotopes geochemical lithological and micropaleontological results from cores from the far northwest fnw pacific and the okhotsk and bering seas are used to reconstruct the regional environment for the last glaciation the deglacial transition and the holocene 18 o records of planktonic foraminifera of the region show two light shifts during deglacial time provoked by the freshening of the surface water and climate warming these north pacific terminal events t1anp and t1bnp with ages of 12 500 and 9300 yr b p respectively occur almost simultaneously with two episodes of accelerated glacier melting around the north atlantic along with the isotopic shifts the caco 3 content in regional sediments increased abruptly 1a and 1b carbonate peaks probably due to changes of productivity and pore water chemistry of surface sediments organic matter and opal concentration increased during the transition between t1anp and t1bnp events in the sediments of the fnw pacific and the southern part of the bering sea and opal content increased in the holocene in the bering and okhotsk seas 13 c records of cores from the okhotsk and bering seas and the fnw pacific do not contradict the hypothesis of increased intermediate water formation in the region during glaciation during deglaciation accumulation of the coarse terrigenous component decreased in sediments of the bering sea and the fnw pacific before the t1anp event probably as a result of rising sea level and opening of the bering strait

orbital and millennial scale environmental and hydrological changes of the central okhotsk sea over the last 136 kyr inferred from micropaleontological radiolarian and benthic foraminifera geochemical and lithological proxies and the mechanisms responsible for them abstract the response of benthic foraminifera bf and radiolarian production in the central okhotsk sea os to orbital and millennial changes of climate and environment over the last 136 kyr have been studied on the basis of the sediment core pc 7r with available productivity geochemical and lithological records and a modified age model we used the calculated accumulation rate of microfossils ar fluxes of the main ecological groups and species indicative of radiolarians and of bf as quantity responses in their production which is related to environmental and hydrological changes of the water column and surface sediment in the central os and to global and regional climate changes the responses of the opportunistic bf alabaminella weddellensis and the suboxic group during the last 136 kyr were mostly related to changes in organic fluxes from the surface sea ice cover and surface sediment oxygenation at both orbital and millennial time scales the ar of radiolarians from the surface dichothermal and mesopelagic groups significantly differed from the ar of bf the ar has a maximum during the middle and late marine isotope stage 5e and lower values during the earlier holocene while the minimum happened during cold marine isotope stages 6 4 and 2 with maximal ventilation of os intermediate water production of the mesopelagic radiolarian cycladophora davisiana in the os was mostly related to the lateral delivery of terrigenous material and om into the water column from the northwestern shelf and or from the western subarctic pacific due to the sensitivity of marine organisms to environmental conditions the production of radiolarians and bf sharply changed with the extinction of amphimelissa setosa since heinrich stadial 8 is related to the termination of global environment cooling and the hydrology changes of the early last glacial

late pleistocene holocene activity and paleoseismicity of the nojima fault in the northern awaji island southwest japan abstract field investigations and analyses of tectonic landforms show that the topographical markers of terrace risers and alluvial fans formed in the late pleistocene holocene have been systematically offset by 40 62 m along the nojima fault on which the 1995 mw 6 9 kobe earthquake occurred analysis of tectonic landforms trench excavations and radiocarbon dating results reveal that i at least two large earthquakes prior to the 1995 mw 6 9 kobe earthquake occurred in the past 1800 years ii the most recent event occurred in 1000 ce and the penultimate large earthquake event took place in 200 ce suggesting an average recurrence interval of 900 yr for large earthquakes on the nojima fault based on the deformation features of tectonic landforms and radiocarbon dating ages the late pleistocene holocene strike slip right lateral rate is estimated to be 2 0 3 0 mm yr with an average of 2 5 mm yr for the nojima fault these findings show that previous studies had significantly overestimated the recurrence interval and underestimated the slip rate of the nojima fault accordingly the nojima fault poses a much greater seismic hazard than previously believed and therefore it is necessary to reassess the potential seismic hazard for the densely populated awaji kobe regions southwest japan