climate variations since the last interglacial recorded in czech loess 1 magnetic susceptibility organic matter content and grain size were measured on a loess palaeosol sequence deposited since the last interglacial at the dolni vestonice section in the czech republic high values in magnetic susceptibility and organic matter content in palaeosols pk0 pk2 and pk3 indicate that they were strongly influenced by long term pedogenesis and high vegetation density linked to interglacials or interstadials grain size variations record a series of cold wind strengthened events during the last glacial which we interpret as a record of the distinctive younger dryas episode and millennial scale climate oscillations that correlate with the grip ice core 18o record and north atlantic heinrich events these climate events as indicated by grain size peaks combined with previous climate records at french massif central and lago grande di monticchio in italy suggest that the climate over these areas might have undergone synchronous oscillations with the shifts in sea surface temperatures of the north atlantic and air temperature changes above greenland

palaeomagnetic and geochronological evidence for a major middle miocene unconformity in soke basin western anatolia and its tectonic implications for the aegean region cenozoic convergence between the eurasian and african plates and concurrent slab roll back processes have produced a progressive extension in back arc areas such as the aegean region and western anatolia there is still a long standing controversy as to whether this was a continuous or stepwise process to shed light on this controversy and on the driving mechanism of regional extension we present palaeomagnetic and geochronological results from the soke basin located at the southeastern rim of the izmir balikesir transfer zone our improved geochronology shows that volcanic activity in the region occurred between 11 66 and 12 85 ma middle to late miocene palaeomagnetic data for the soke basin show a c 23 clockwise rotation whereas early miocene data show a c 28 counterclockwise rotation the primary nature of the magnetization is indicated by a positive tilt test the resulting c 51 counterclockwise rotations during the middle miocene signify a major tectonic reorganization during a period when an interruption of exhumation of metamorphic massifs has been reported we suggest that the izmir balikesir transfer zone is the main driver of the reorganization in the region the regional fingerprint of this tectonic reorganization coincides with the acceleration of trench retreat and illustrates the surface impact of tearing of the hellenic slab supplementary material details of 40 ar 39 ar analysis including heating steps and the output pmag file including details of paleomagnetic analysis performed in this study are available at https doi org 10 6084 m9 figshare c 3690871

sedimentation and basin formation related to ophiolite nappe emplacement miocene sw turkey abstract the miocene kasaba basin in southwestern turkey is a peripheral foreland basin that resulted from the thrusting and emplacement of the lycian nappes ophiolite unit onto a previously stable carbonate platform the resulting basin fill is the product of the complex interaction of tectonic and sedimentary processes and records the timing and magnitude of tectonic events in the thrust belt initial emplacement of the nappes in the late aquitanian resulted in the foundering and irregular subsidence of the carbonate platform by burdigalian times continued loading of the carbonate platform resulted in the development of a sedimentary basin ca 170 km across fan deltas shed off the leading edge of the nappe pile passed basin wards into a series of small submarine fans at the same time a peripheral bulge developed in the central part of the carbonate platform along the margin of the basin opposite the nappe pile a thick wedge of sediments derived from the carbonate platform was shed northwestwards into the basin varying sedimentation rates and migrating facies belts in the overlying middle and upper miocene basin fill sequence document both the progressive emplacement of the lycian nappes approximately 100 km from the northwest over the basin margin and overstep of the peripheral bulge

luminescence dating of the loess profile at dolni vestonice czech republic abstract thermoluminescence tl and infra red stimulated luminescence irsl studies were carried out on 21 samples from loess profiles at dolni vestonice the irsl measurements gave systematically lower equivalent doses eds than the tl measurements this could be due to inadequate preheat being applied to the former dose rate intercomparisons confirm the view that alpha counting should be carried out on finely ground material comparison of ed determination by regeneration and additive dose methods did not suggest sensitivity increases on bleaching but for the older samples the tl ages were underestimated compared with the expected ages based on the correlation of palaeosol stratigraphy with the framework provided by the deep sea oxygen isotope record using the hypothesis of luminescence decay with a lifetime of 150 ka suggests that the previous ages assigned to the palaeosols may not be correct

the physics of wind blown loess implications for grain size proxy interpretations in quaternary paleoclimate studies abstract loess deposits are recorders of aeolian activity during past glaciations since the size distribution of loess deposits depends on distance to the dust source and environmental conditions at the source during transport and at deposition loess particle size distributions and derived statistical measures are widely used proxies in quaternary paleoenvironmental studies however the interpretation of these proxies often only considers dust transport processes to move beyond such overly simplistic proxy interpretations and toward proxy interpretations that consider the range of environmental processes that determine loess particle size distribution variations we provide a comprehensive review on the physics of dust particle mobilization and deposition furthermore using high resolution bulk loess and quartz grain size datasets from a last glacial interglacial sequence we show that because grain size distributions are affected by multiple often stochastic processes changes in these distributions over time allow multiple interpretations for the driving processes consequently simplistic interpretations of proxy variations in terms of only one factor e g wind speed are likely to be inaccurate nonetheless using loess proxies to understand temporal changes in the dust cycle and environmental parameters requires i a careful site selection to minimize the effects of topography and source distance and ii the joint use of bulk and quartz grain size proxies together with high resolution mass accumulation rate calculations if possible

aminostratigraphic evaluation of conflicting age estimates for the young loess of hungary abstract as part of a regional investigation of the aminostratigraphy of central european loess deposits we have sampled and analyzed the amino acid composition of fossil gastropod shells from stratotype loess profiles at mende basaharc and paks plus the profile at sutto in an effort to correlate independently loess paleosol formations of the young loess of hungary with loess units elsewhere in the region the measured extent of isoleucine epimerization in fossil gastropod shells preserved in loess sediments was used to evaluate the relative ages of stratigraphic units and correlate between discontinuous exposures based on amino acid epimerization ratios we propose a new chronology for the standard young loess profile of hungary amino acid geochronological data suggest that paleosol complexes mf bd1 2 and ba formed during interglaciations rather than interstades correlations are suggested with pk 2 3 last interglaciation pk 4 penultimate interglaciation and pk 5 respectively from previously described czech and slovak localities

long term surface temperature modeling of pluto abstract nasa s new horizons reconnaissance of the pluto system has revealed at high resolution the striking albedo contrasts from polar to equatorial latitudes on pluto as well as the sharpness of boundaries for longitudinal variations these contrasts suggest that pluto must undergo dynamic evolution that drives the redistribution of volatiles using the new horizons results as a template we explore the surface temperature variations driven seasonally on pluto considering multiple timescales these timescales include the current orbit 248 years as well as the timescales for obliquity precession peak to peak amplitude of 23 over 3 million years and regression of the orbital longitude of perihelion 3 7 million years these orbital variations create epochs of extreme seasons where one pole receives a short relatively warm summer and long winter while the other receives a much longer but less intense summer and short winter we use thermal modeling to build upon the long term insolation history model described by earle and binzel 2015 and investigate how these seasons couple with pluto s albedo contrasts to create temperature effects from this study we find that a bright region at the equator once established can become a site for net deposition we see the region informally known as sputnik planitia as an example of this and find it will be able to perpetuate itself as an always available cold trap thus having the potential to survive on million year or substantially longer timescales meanwhile darker low albedo regions near the equator will remain relative warm and generally not attract volatile deposition we argue that the equatorial region is a preservation zone for whatever albedo is seeded there this offers insight as to why the equatorial band of pluto displays the planet s greatest albedo contrasts

hidden tectonism on miranda s elsinore corona revealed by polygonal impact craters abstract we mapped the spatial distribution and orientations of polygonal impact craters pics on the classical uranian satellite miranda to gain insight into the complex tectonic history of this moon pic straight rim segments in regions without visible fractures can be used to infer sub regolith and or sub resolution fracture orientations we identified and analyzed 14 pics on miranda nine of which are located on its trailing hemisphere overprinting elsinore corona and the nearby cratered terrain these pics do not follow the e w orientations of the ridges within elsinore s bounding terrain indicating that these ridges are not underlain by deep rooted at least as deep as the crater bowl sub vertical normal or strike slip faults instead the ridges may be contractional features consisting of folds and possibly thrust faults or cryovolcanic features without fault structures furthermore the pics in this region indicate that a previously undetected nw oriented fracture system is present over much of miranda s trailing hemisphere another pic somewhat distal from elsinore on miranda s anti uranus hemisphere might be associated with the nw fractures as well additionally three pics are present proximal to verona rupes on miranda s uranus facing hemisphere these pics exhibit n s orientations consistent with the surrounding fractures that make up miranda s global rift system one other pic is proximal to arden and might be associated with the arden bounding terrain identification of the nw fracture system provides new information on miranda s complex geologic history based on cross cutting relationships with miranda s ancient subdued crater population the nw fracture system is older than elsinore however this fracture system also overprints elsinore suggesting reactivation of the nw fractures after this corona had formed along with discussion of miranda s geologic history we consider the possibility that miranda has undergone true polar wander and we compare its terrains and geologic features to similar features on the saturnian satellite enceladus

compositional maps of saturn s moon phoebe from imaging spectroscopy the origin of phoebe which is the outermost large satellite of saturn is of particular interest because its inclined retrograde orbit suggests that it was gravitationally captured by saturn having accreted outside the region of the solar nebula in which saturn formed by contrast saturn s regular satellites with prograde low inclination circular orbits probably accreted within the sub nebula in which saturn itself formed here we report imaging spectroscopy of phoebe resulting from the cassini huygens spacecraft encounter on 11 june 2004 we mapped ferrous iron bearing minerals bound water trapped co2 probable phyllosilicates organics nitriles and cyanide compounds detection of these compounds on phoebe makes it one of the most compositionally diverse objects yet observed in our solar system it is likely that phoebe s surface contains primitive materials from the outer solar system indicating a surface of cometary origin

meridional reorganizations of marine and terrestrial productivity during heinrich events 1 to study the response of the global carbon cycle to a weakening of the atlantic meridional overturning circulation amoc a series of freshwater perturbation experiments is conducted both under preindustrial and glacial conditions using the earth system model of intermediate complexity loveclim a shutdown of the amoc leads to substantial cooling of the north atlantic a weak warming of the southern hemisphere intensification of the northeasterly trade winds and a southward shift of the intertropical convergence zone itcz trade wind anomalies change upwelling in the tropical oceans and hence marine productivity furthermore hydrological changes associated with a southward displacement of the itcz lead to a reduction of terrestrial carbon stocks mainly in northern africa and northern south america in agreement with paleoproxy data in the freshwater perturbation experiments the ocean acts as a sink of co2 primarily through increased solubility the net atmospheric co2 anomaly induced by a shutdown of the amoc amounts to about 15 ppmv and 10 ppmv for preindustrial and glacial conditions respectively this background state dependence can be explained by the fact that the glacial climate is drier and the terrestrial vegetation therefore releases a smaller amount of carbon to the atmosphere this study demonstrates that the net co2 response to large scale ocean circulation changes has significant contributions both from the terrestrial and marine carbon cycle

rapid and cyclic aeolian deposition during the last glacial in european loess a high resolution record from nussloch germany abstract this paper reports the results of an investigation of the weichselian upper pleniglacial loess sequences of nussloch rhine valley germany based on stratigraphy palaeopedology sedimentology palynology malacology and geochemistry 13 c supported by radiocarbon tl and osl dating grain size and magnetic susceptibility records are taken at 5 cm intervals from the upper pleniglacial upg loess the data indicate cyclic variations in loess deposition between ca 34 and 17 ka when the sedimentation rate is especially high 1 0 1 2 m per ka for more than 10 m the grain size index gsi ratio of coarse silt versus fine silt and clay shows variations which are assumed to be an indirect measurement of wind intensity the sedimentation rate interpreted from the profiles indicates high values in loess loess events le 1 to le 7 and low or negligible values in tundra gley horizons g1 to g8 osl ages from the loess and 14 c dates from organic matter in the loess show that loess deposition was rapid but was interrupted by shorter periods of reduced aeolian sedimentation comparison between the data from nussloch and other european sequences demonstrates a progressive coarsening of the loess deposits between ca 30 and 22 ka this coarsening trend ends with a short but major grain size decrease and is followed by an increase to a new maximum at 20 2 ka w shape correlation between the loess gsi and the greenland ice core dust records suggests a global connection between north atlantic and western european global atmospheric circulation and wind regimes in addition the typical upper pleniglacial loess deposition begins at ca 30 31 ka close to heinrich event he 3 and the main period of loess sedimentation at about 25 2 ka is coeval to he 2 correlation of magnetic susceptibility and grain size records shows that the periods characterised by high gsi coincide with an increase in the amount of ferromagnetic minerals reworked from the rhine alluvial plain they suggest enhancement in the frequency of the storms from n nw these results are integrated within a palaeogeographical model of dust transport and deposition in western europe for the weichselian upper pleniglacial or late pleniglacial

grain size of fine grained windblown sediment a powerful proxy for process identification abstract dust transport by the wind is not a uniform process but may occur in different modes according to source area conditions and transport height and distance subsequently these differences are expressed in terms of grain size and fluxes of the aeolian deposits transport distances may vary from several tens of meters to thousands of kilometers while the height accordingly may vary from meters to more than thousand meters a relation with grain size distributions may be established on the base of type occurrences of different loess facies three main loess populations and several subpopulations of primary windblown origin may be defined according to their grain size dominated by fine sand to very coarse silt silt and very fine silt to clay respectively each of them reflects a specific aeolian process and transport conditions it follows that the grain size distribution of a loess deposit is an excellent proxy for the reconstruction of aeolian processes and wind circulation patterns apart from primary pure wind deposition loess may also be affected by secondary post depositional processes examples are settling of loess particles in a lacustrine setting and reworking by rivers or surface runoff although the primary loess characteristics are maintained reworking processes leave also their imprint in the grain size distribution as a useful tool for secondary process identification

large impact features on middle sized icy satellites abstract all of the large impact features of the middle sized icy satellites of saturn and uranus that were clearly observed by the voyager spacecraft are described new image mosaics and stereo and photoclinometrically derived digital elevation models are presented landforms related to large impact features such as secondary craters and possible antipodal effects are examined and evaluated of the large impacts odysseus on tethys appears to have had the most profound effect on its target satellite of any of the impact features we examined our modeling suggests that the odysseus impact may have caused the prompt formation of ithaca chasma a belt of tectonic troughs that roughly follow a great circle normal to the center of odysseus although other hypotheses remain viable we identify probable secondary cratering from tirawa on rhea we attribute a number of converging coalescing crater chains on rhea to a putative possibly relatively fresh 350 km diameter impact feature we examine the antipodes of odysseus the putative 350 km diameter rhean impact feature and tirawa and conclude that evidence from voyager data for damage from seismic focusing is equivocal although our modeling results indicate that such damage may have occurred we propose a number of observations and tests for cassini that offer the opportunity to differentiate among the various explanations and speculations reviewed and evaluated in this study

fluvial history of the sub carpathian basins poland during the last cold stage 60 8 cal ka bp abstract the fluvial landforms of the last cold stage are represented in the sub carpathian basins by a system of 2 3 terraces which grade into alluvial fans of a height of 15 20 8 12 and 6 8 m above the present riverbeds in the mountain foreland in the vistula river valley the 15 20 m high terrace covered with loess extends along the western margin of the sandomierz basin and northern margin of the carpathians away from the mountain margin it passes into the sandy terrace plain with dunes it is formed of at least two interpleniglacial alluvial fills the older one dated at 48 36 ka bp over 50 40 6 ka cal bp and the younger one dated 30 25 ka bp 34 1 29 0 ka cal bp thus pertaining to the upper pleniglacial this latter forms a terrace 15 m high in general accumulation of fluvial sediments interrupted with erosion phases dominated in the mountain foreland during the period 60 25 ka bp over 60 29 ka cal bp the most significant erosion phase took place before the maximum extension of the vistulian weichselian wisconsinian ice sheet i e before 25 20 ka bp 29 24 ka cal bp and was connected with a change from an oceanic to a more continental climate the next alluvial fill of terrace 8 12 m high with remnants of braided river channels was formed at the end of the upper plenivistulian the incision of the river channels below the present channel level was followed by aggradation in the late vistulian 15 13 ka bp 18 2 15 6 ka cal bp accompanied by a change in river channel system from braided to meandering in the wisloka and san river valleys alluvial plains extending by lateral erosion of large meanders were abandoned by rivers mainly in the younger dryas and the preboreal the late vistulian large palaeomeanders are missing along lower sola and lower dunajec these rivers fed from higher mountains had still tendency to braiding the climate cooling of the younger dryas brought an increase in the delivery of bedload to the river channels and a tendency to braiding in vistula valley drwinka depression the expansion of forest in the early holocene reduced the water discharge and the size of meanders as a result their width fallen by 3 5 times alluvial data showed also a distinct humid climatic phase ca 9 5 8 5 ka cal bp

identification and origins of iron sulfides in czech loess multiple rock magnetic and non magnetic techniques were employed to identify iron sulfides in late pleistocene czech loess deposits the results indicate that iron sulfides in the loess at znojmo section are mainly pyrrhotite and pyrite with stoichiometry ranging from fe10s11 to fes2 although early pedogenic origin of fine sulfide fraction can not be ruled out scanning electron microscopy sem of individual grains and microscopic observations of magnetic extracts show that iron sulfide grains are probably of detrital origin potential sources of these sulfides may have been eluvium loams above hypothetical ore deposits in the vicinity of the section or glacifluvial sediments from nearby glacial margins framboidal pyrite forms now completely replaced by iron oxides suggest that some particles of biogenic sulfides may have also been transported into loess from presumably fluvial sediments

shear sense criteria in the antalya and alanya thrust system southwestern turkey evidence for a southward emplacement abstract a northern as opposed to a southern origin of the antalya and alanya nappes in turkey has been a contentious issue among geologists the two hypotheses are essentially supported by contrasting geometrical and sedimentary arguments to introduce new information into the debate we have been analyzing for shear sense criteria in thrust contacts these data give clear evidence for a south directed vergence these results suggest that both the antalya and alanya nappes were derived from the same oceanic basin and continental margin as the other tauric nappes whose northern origin has long been recognized

paleoclimatic significance of the mineral magnetic record of the chinese loess and paleosols the origins of the magnetic susceptibility variations of the chinese loess and paleosols are explored by scanning and transmission electron microscopy of magnetic extracts and by magnetic modeling of magnetic hysteresis data to provide quantified estimates of the major magnetic components microscopy identifies several distinct size and shape characteristics in the magnetic carriers lithogenic magnetites intact and abraded dominate the coarse grained magnetic fraction the smallest of the coarse grains is 2 i m the remaining magnetic materal is ultrafine in size with two types of magnetite particles present type a particles strongly resemble soil magnetites produced by inorganic precipitation type b particles which occur rarely are probably bacterial in origin quantitative modeling of these magnetic assemblages shows that over 90 of the susceptibility variations is accounted for by the superparamagnetic magnetite component compared to the loess units the paleosols are richer in magnetite particularly of superparamagnetic size and have a threefold higher ratio of magnetite to hematite we identify pedogenic formation of magnetite as the major contributor to the loess magnetic record matching this record against other paleoclimatic records we find an extremely high correlation with the standard 18o record the chinese loess sequences record a very high resolution magnetic stratigraphy directly related to changing climate

solid state ice volcanism on the satellites of uranus voyager images of the uranian satellites ariel and miranda show flow features with morphologies indicating that ice has been extruded to the satellites9 surfaces in the solid state these images provide the first observational evidence for solid state ice volcanism in the solar system topographic profiles have been measured across a number of flow features on ariel with a simple model of extrusion spreading and cooling of a viscous flow the initial viscosity of the flow material is found to have been no more than about 10 16 poise far lower than expected for h 2 o ice at the ambient surface temperatures in the uranian system sharply reduced viscosities may have resulted from incorporation of ices like nh 3 or ch 4 in the uranian satellites

direction of ophiolite emplacement inferred from cretaceous and tertiary sediments of an adjacent autochthon the bey daglari southwest turkey the late mesozoic to mid tertiary depositional history of an autochthonous block in southwest turkey is outlined in relation to the direction of emplacement of adjacent allochthonous units in this area a lively debate persists as to whether the antalya complex located along the mediterranean coast should be correlated with the lycian nappes sited to the northwest in central western anatolia both allochthonous bodies include mesozoic ophiolites and similar shallow to deep water sedimentary facies correlation of the antalya complex and the lycian nappes requires transport over the adjacent autochthon the bey daglari here field data from the southern part of the bey daglari are used to trace the depositional history of the autochthon from late cretaceous to late miocene time a pattern of late mesozoic pelagic carbonate deposition giving way to more heterogeneous sedimentation in the early tertiary is documented by early miocene the autochthon was blanketed by a thick sequence of miocene elastics mostly derived from an ophiolite evidence from sedimentary structures shows that transport was from the east and northeast depositional models are advanced which involve an early miocene delta submarine fan giving way in later miocene times to an alluvial fan demonstration that in this area the ophiolite material was derived from the east provides additional important evidence of the existence of a southerly mesozoic oceanic basin distinct in origin from the lycian nappes to the north

the migration of volatiles on the surfaces of mercury and the moon radar observations of mercury have provided the startling discovery of the probable existence of substantial deposits of ices in permanently shaded polar regions butler et al 1993 harmon et al 1994 this has renewed the old argument about the existence of such deposits in the polar regions of the moon it is most likely necessary for volatiles to be able to migrate to the polar regions of these bodies in order to build up such deposits this paper presents the results of the extension of a monte carlo simulation of the migration of molecules on the surface of mercury by butler et al 1993 the results of the simulations show that for typical conditions on mercury 5 15 of all h 2 o which is placed randomly on the surface migrates to stable permanently shaded polar regions for the moon the numbers are 20 50 the numbers for the migration of co 2 are 2 for mercury and 13 for the moon these percentages are similar to those previously calculated and support the idea of ice deposits in the polar regions of both mercury and the moon

fluxes of fast and epithermal neutrons from lunar prospector evidence for water ice at the lunar poles maps of epithermal and fast neutron fluxes measured by lunar prospector were used to search for deposits enriched in hydrogen at both lunar poles depressions in epithermal fluxes were observed close to permanently shaded areas at both poles the peak depression at the north pole is 4 6 percent below the average epithermal flux intensity at lower latitudes and that at the south pole is 3 0 percent below the low latitude average no measurable depression in fast neutrons is seen at either pole these data are consistent with deposits of hydrogen in the form of water ice that are covered by as much as 40 centimeters of desiccated regolith within permanently shaded craters near both poles

crater population and resurfacing of the martian north polar layered deposits present day accumulation in the north polar layered deposits npld is thought to occur via deposition on the north polar residual cap understanding current mass balance in relation to current climate would provide insight into the climatic record of the npld to constrain processes and rates of npld resurfacing a search for craters was conducted using images from the mars reconnaissance orbiter context camera one hundred thirty craters have been identified on the npld 95 of which are located within a region defined to represent recent accumulation high resolution imaging science experiment images of craters in this region reveal a morphological sequence of crater degradation that provides a qualitative understanding of processes involved in crater removal a classification system for these craters was developed based on the amount of apparent degradation and infilling and where possible depth diameter ratios were determined the temporal and spatial distribution of crater degradation is interpreted to be close to uniform through comparison of the size frequency distribution of these craters with the expected production function the craters are interpreted to be an equilibrium population with a crater of diameter d meters having a lifetime of 30 75d 1 14 years accumulation rates within these craters are estimated at 7 2d 0 14 mm yr which corresponds to values of 3 4 mm yr and are much higher than rates thought to apply to the surrounding flat terrain the current crater population is estimated to have accumulated in the last 20 kyr or less

vegetation history and palaeoclimate of the last glacial period at lago grande di monticchio southern italy a high resolution palynological study of a 51 m core from lago grande di monticchio southern italy has provided a palaeonvironmental record for the last glacill a annual lamination based chronology supported by radiometric and tephrochronological dates provides an absolute timescale for this record that spans 76 300 years correlations are established between the pollen stratigraphy the grip ice core 18o record and foraminiferal assemblages from atlantic core v23 81 both dansgaard oeschger and heinrich events are reflected by changes in the pollen stratigraphy revised dates are estimated for heinrich events h1 h6 a quantitative palaeoclimate reconstruction based upon the pollen data provides evidence of the climate changes in southern italy associated with these and other fluctuations during the last glacial

climate variations in europe over the past 140 kyr deduced from rock magnetism rapid shifts in climate during the last glacial are now well documented particularly from the oxygen isotope records of the two greenland ice cores grip1 2 and gisp23 in the grip record1 2 these climate events are also seen during the preceding eemian interglacial which may be an analogue for the future climate warmed by the greenhouse effect but these shifts are not found in the eemian section of the gisp2 core3 casting doubt on whether the rapid shifts in the grip oxygen isotope record really do represent a climate signal here we present magnetic susceptibility pollen and organic carbon records from maar lake deposits in the massif central france these data provide an independent record of past climate and we find that they correlate well with the ice core records during the last glacial during the eemian two rapid cooling events seen in our record also correlate with those seen in the grip ice core supporting the idea that rapid climate change did occur in the eemian interglacial and demonstrating that it extended to continental europe

thermal inertia and bolometric bond albedo values for mimas enceladus tethys dione rhea and iapetus as derived from cassini cirs measurements abstract spectra taken by cassini s composite infrared spectrometer cirs between 10 and 600 cm 1 17 1000 m of surface thermal emission of mimas enceladus tethys dione rhea and iapetus have been used to derive the thermal inertia and bolometric bond albedo values only an upper limit for the bolometric bond albedo of iapetus dark leading side could be determined due to the insensitivity of the thermal model to albedo when albedos are very low the thermal inertia in this region however is better constrained the cirs coverage of enceladus is extensive enough that the latitudinal variation in these values from 60 s to 70 n has been determined in 10 wide bins the bolometric bond albedos determined here are consistent with literature values which show the surface of the saturnian icy moons to be covered in ice contaminated to varying degrees the thermal inertia of the moons is shown to be in the range 9 20 j m 2 k 1 s 1 2 approximately 2 6 times lower than that of the galilean satellites implying a less well consolidated and more porous surface the thermal inertias of iapetus and phoebe are somewhat higher suggesting that the very low thermal inertias of satellites from rhea inwards may be related to their probable coating of e ring material latitudinal variations on the surface of enceladus show that the bolometric bond albedo and thermal inertia increase towards the active plume source at the south pole

towards a revised chronostratigraphy of loess in austria with respect to key sections in the czech republic and in hungary abstract the stratigraphic ages of some well known and characteristic paleosols in austrian and hungarian loess sections have been questioned by several workers since the mid 1970s in particular a generally accepted correlation of austrian and hungarian loess stratigraphies with the well established czech loess stratigraphy has not been put forward this paper presents 41 new thermoluminescence tl dates and the first results from amino acid chronology of key sections in these areas the results are in agreement and suggest a new interregional correlation of loess paleosol sequences for loess older than the last interglacial quartz and feldspar inclusions yield more reliable tl ages than the polymineralic fine grain fraction

short term soil formation events in last glacial east european loess evidence from multi method luminescence dating here we provide a robust luminescence chronology for stayky ukraine a reference profile in european late pleistocene loess stratigraphy based on optically stimulated luminescence osl dating on quartz 4 11 m 63 90 m and post infrared infrared stimulated luminescence pir irsl on polymineral fine grains for the bug loess unit the equivalent of marine isotope stage mis 2 results are in agreement between methods demonstrating that the suite of embryonic soils previously interpreted as reflecting climate variability similar to greenland interstadials gi actually date to 29 27 15 ka with most emplaced around or after 20 ka this temporal span is further confirmed by age depth modelling of available data apart from gi 2 no interstadial type climate events are recorded in greenland ice core data for that time interval as short term pedogenetic phases are also documented in records from central western europe there is a need for more research into the european mid latitude terrestrial environments response to mis 2 hydroclimate variability the dating of vytachiv paleosol previously debatably linked to various gi events within mis 3 resulted in ages of 40 4 ka and 53 4 ka at the lower transition and 26 2 ka to 30 2 ka in the overlying loess these ages indicate that the truncated vytachiv paleosol is either not continuous or that it encompasses a broader age range within mis 3 than previously considered in both cases data would not allow for an unambiguous linking of this paleosol with specific gi events as previously attempted the pir irsl290 dating of the loams immediately underneath pryluky unit in the range of 120 ka to 168 ka and of the pryluky mollisol from 90 ka to 126 ka confirm the broad correspondence of this unit with mis 5 although poor dose recovery results open the possibility for further testing on the degree these ages provide overestimated results quartz data severely underestimate the pir irsl290 ages for these samples the application of pir irsl290 dating for the underlying dnieper till previously linked to the saalian glaciation resulted in natural signals at the level of laboratory saturation yielding minimum ages of c 700 ka for the same sample the natural sar osl signals for 4 11 m quartz were found significantly below laboratory saturation level resulting in finite ages of 250 270 ka interpreted here as underestimates while coarse quartz 63 90 m signals reached about 85 of the laboratory saturation level these data suggest extreme caution must be taken when dating such old samples using quartz osl results from our high resolution luminescence dating raises important implications for the chronological representativeness of stayky as a key loess site in eastern europe beyond mis 2

pollen analytical biostratigraphy of the last five climatic cycles from a long continental sequence from the velay region massif central france in the volcanic region of velay massif central france lake sediment sequences derived from maar craters situated close to one another ribains praclaux and lac du bouchet have been correlated on the basis of tephrostratigraphical analyses this has enabled the construction of a sequence 2980 pollen spectra that begins during the glaciation preceding the holsteinian and ends in the present this sequence covers the period from 450 ka i e from the end of marine oxygen isotope stage 12 to the present time and includes five climatic cycles the study of a second core from the praclaux site completed the long velay sequence the biostratigraphy of the whole sequence is described in detail and illustrated by a synthetic and simplified pollen diagram thirteen temperate forest episodes interglacials or interstadials and as many cold periods glacials or stadials are defined each temperate episode is characterised by particular forest development and vegetation dynamics and all of them with the exception of the holocene begin and end with a pinus forest the vegetation dynamics observed during the holocene resemble more closely those recorded during the interstadials than during the interglacials copyright 2000 john wiley sons ltd

high resolution record of the last climatic cycle in the southern carpathian basin surduk vojvodina serbia abstract high resolution study of the surduk loess palaeosols sequence in serbia vojvodina has been performed within a research project eole focusing on the impact of rapid climatic changes during the last climatic cycle in the european loess belt the methodology used for this multidisciplinary approach is based on a continuous sampling column that allows a very accurate correlation between all studied proxies magnetic susceptibility grain size and organic carbon and the dated samples irsl 14 c according to the stratigraphical and sedimentological data the surduk loess sequence appears as a very complete record of the last climatic cycle 19 m and exhibits a similar pattern than other contemporaneous loess sequences from western central and eastern europe the main difference is the evidence of a drier environment all over the last climatic cycle sedimentological and palaeopedological data the high resolution grain size record 5 cm is well correlated with stratigraphical boundaries and highlights a strong variability within the loess deposition especially during the upper pleniglacial between ca 33 and 15 ka during the upper pleniglacial a succession of millennial timescale events characterised by the deposition of coarser loess are particularly well evidenced by grain size data as in some west european records finally an attempt to correlate the variations of grain size parameters at surduk with the greenland grip dust record is proposed according to this study millennial timescale climatic events that characterise the north atlantic area during the last climatic cycle have thus been recorded in the environments located at the southern border of the european loess belt

non magnetic indicators of pedogenesis related to loess magnetic enhancement and depletion examples from the czech republic and southern siberia abstract we carried out a multiparameter investigation for non magnetic proxies of the intensity of pedogenesis in loess paleosol sections from two different climate settings dolni v stonice central europe and krasnogorskoye southern siberia the work was performed in order to clarify the problem of two opposite scenarios of magnetic susceptibility ms patterns in these two profiles the chinese model with magnetically enhanced paleosols and the siberian alaskan model with magnetically depleted paleosols the age constraints on the krasnogorskoye section were inferred from an independent correlation with the well dated dolni v stonice section based on ms and sediment color cie l and with the ms log from lake baikal the pedologic description of the loess paleosol sections and their correlation was considerably improved by the use of vis spectral proxies cie l reflectance in the red band their weathering intensity can be effectively characterized by diffuse reflectance spectroscopy drs and geochemical cec and rb sr proxies whereas the ms is strongly dependent on the type of soil chernozems vs brown soils the geochemical proxies in particular cec proved to be relatively independent of the soil type these parameters are less affected by region specific conditions than the ms signal the non magnetic proxies indicate relatively dissimilar climatic trends at the two sites during the last glacial interglacial cycle a long distance correlation based solely on the ms signal can be adversely affected by switching between the chinese and the siberian alaskan magnetic modes this having been observed at the krasnogorskoye section in general no single universal proxy of weathering or pedogenesis intensity would be applicable across broad regions or considerable climatic gradients paleoclimatologic interpretations of large regions should always be based on a carefully designed multi proxy approach

tectonic transport directions of the lycian nappes in southwest turkey constrained by kinematic indicators abstract the orientation asymmetry and cross cutting relationships of the structures along the contact zone between the lycian nappes and the menderes massif suggest the presence of three deformation phases in the milas region of southwest turkey the first deformation phase d1 is characterized by a ductile deformation with top to the ne sense of shear structural data of the first deformation measured along the uppermost part of the menderes massif and the base of the lycian nappes suggest that the lowermost unit of the lycian nappes was emplaced initially from southwest to northeast onto the menderes massif during the early eocene the second deformation phase d2 is also ductile in nature and is characterized by an e w trending stretching lineation with a bivergent sense of shear which is probably related to the load of the overlying nappes a third deformation phase d3 is characterized by south dipping normal faults with top to the s sense of movement this third deformation phase can be related to southward movement of the lycian nappes along a low angle decollement zone the tectonic contact between the menderes massif and the lycian nappes and their strongly deformed rocks are unconformably covered by approximately flat lying coal bearing early middle miocene sedimentary rocks which constrains the upper time limit for all three deformation phases

evidence from voyager ii photometry for early resurfacing of umbriel the uranian satellite umbrieps dark heavily cratered surface is remarkable for its apparent uniformity in voyager ii images1 its most conspicuous geological feature is a comparatively high albedo annulus shaped deposit which covers the floor of the 40 km diameter crater wunda1 here we present new voyager ii albedo maps of umbriel which reveal that its surface is subdivided into low contrast crudely polygonal areas ranging in size from tens to hundreds of kilometres fig 1 the largest polygons are elongate with systematically trending northeast southwest boundaries some of the polygonal areas form topographic depressions several kilometres in depth we suggest that this newly discovered global albedo pattern is a relic of the early tectonic disruption of umbriel s surface

voyager 2 in the uranian system imaging science results voyager 2 images of the southern hemisphere of uranus indicate that submicrometersize haze particles and particles of a methane condensation cloud produce faint patterns in the atmosphere the alignment of the cloud bands is similar to that of bands on jupiter and saturn but the zonal winds are nearly opposite at mid latitudes 70 degrees to 27 degrees where winds were measured the atmosphere rotates faster than the magnetic field however the rotation rate of the atmosphere decreases toward the equator so that the two probably corotate at about 20 degrees voyager images confirm the extremely low albedo of the ring particles high phase angle images reveal on the order of 10 2 new ringlike features of very low optical depth and relatively high dust abundance interspersed within the main rings as well as a broad diffuse low optical depth ring just inside the main rings system nine of the newly discovered small satellites 40 to 165 kilometers in diameter orbit between the rings and miranda the tenth is within the ring system two of these small objects may gravitationally confine the e ring oberon and umbriel have heavily cratered surfaces resembling the ancient cratered highlands of earth s moon although umbriel is almost completely covered with uniform dark material which perhaps indicates some ongoing process titania and ariel show crater populations different from those on oberon and umbriel these were probably generated by collisions with debris confined to their orbits titania and ariel also show many extensional fault systems ariel shows strong evidence for the presence of extrusive material about halfof miranda s surface is relatively bland old cratered terrain the remainder comprises three large regions of younger terrain each rectangular to ovoid in plan that display complex sets of parallel and intersecting scarps and ridges as well as numerous outcrops of bright and dark materials perhaps suggesting some exotic composition

the effect of target properties on crater morphology comparison of central peak craters on the moon and ganymede we examine the morphology of central peak craters on the moon and ganymede in order to investigate differences in the near surface properties of these bodies we have extracted topographic profiles across craters on ganymede using galileo images and use these data to compile scaling trends comparisons between lunar and ganymede craters show that crater depth wall slope and amount of central uplift are all affected by material properties we observe no major differences between similar sized craters in the dark and bright terrain of ganymede suggesting that dark terrain does not contain enough silicate material to significantly increase the strength of the surface ice below crater diameters of 12 km central peak craters on ganymede and simple craters on the moon have similar rim heights indicating comparable amounts of rim collapse this suggests that the formation of central peaks at smaller crater diameters on ganymede than the moon is dominated by enhanced central floor uplift rather than rim collapse crater wall slope trends are similar on the moon and ganymede indicating that there is a similar trend in material weakening with increasing crater size and possibly that the mechanism of weakening during impact is analogous in icy and rocky targets we have run a suite of numerical models to simulate the formation of central peak craters on ganymede and the moon our modeling shows that the same styles of strength model can be applied to ice and rock and that the strength model parameters do not differ significantly between materials

a key extensional metamorphic complex reviewed and restored the menderes massif of western turkey article i nfo this paper provides a review of the structure and metamorphism of the menderes massif in western turkey and subsequently a map view restoration of its neogene unroofing history exhumation of this massif among the largest continental extensional provinces in the world is generally considered to have occurred along extensional detachments with a ne sw stretching direction restoration of the early miocene history however shows that these extensional detachments can only explain part of the exhumation history of the menderes massif and that ne sw stretching can only be held accountable for half or less of the

neotectonic intersection of the aegean and cyprus tectonic arcs extensional and strike slip faulting in the isparta angle sw turkey abstract the isparta angle and adjacent antalya bay areas constitute an important segment of the eastern mediterranean region located at the intersection of the southward convex aegean and cyprus arcs some recent tectonic maps show the isparta angle as a nw se compressional lineament extending eastwards into the kyrenia range of northern cyprus however fault data from the onshore isparta angle together with offshore shallow seismic reflection data show that the present morpho tectonic setting is dominated by extension the last phase of compression to affect the area studied in the late miocene was accompanied by regional nappe emplacement lycian nappes onshore fault planes measured from fault zones bounding both the limbs and the core of the isparta angle are oriented predominantly ne sw nw se and n s superimposed slickenfibres show that reverse faults were succeeded in turn by right lateral faults then by normal faults the fault phases are dated by stratigraphical and geomorphological evidence reverse faults date from the late miocene or earlier compressional deformation whereas the right lateral faults mainly developed during latest miocene early pliocene normal faulting dominated from the late pliocene recent an interpretation of shallow seismic reflection data shows that antalya bay is characterised by a nw se trending asymmetrical graben system that has continued to be active during the late miocene early pliocene right lateral strike slip resulted from shear along the eastern termination of a zone of extension and rotation that characterises the western aegean this shear was focused in a n s direction by inherited zones of structural weakness in the basement antalya complex the switch to ne sw extension in the late pliocene quaternary relates to a regional change in stress direction throughout the aegean region and was accompanied by strong uplift of the bey da lari region of the taurus mountains bordering the isparta angle in the west the isparta angle is the link between a the extensional province of western turkey bounded to the south by the actively subducting hellenic arc and b the uplifted anatolian plateau bounded to the south by the cyprus subduction zone understanding the miocene to recent tectonic development helps elucidate the kinematics of the region the new structural data presented lend no support for recent suggestions that the isparta angle and antalya bay represent parts of a regional compressional zone related to plate collision

bright and dark polar deposits on mercury evidence for surface volatiles measurements of surface reflectance of permanently shadowed areas near mercury s north pole reveal regions of anomalously dark and bright deposits at 1064 nanometer wavelength these reflectance anomalies are concentrated on poleward facing slopes and are spatially collocated with areas of high radar backscatter postulated to be the result of near surface water ice correlation of observed reflectance with modeled temperatures indicates that the optically bright regions are consistent with surface water ice whereas dark regions are consistent with a surface layer of complex organic material that likely overlies buried ice and provides thermal insulation impacts of comets or volatile rich asteroids could have provided both dark and bright deposits

superimposed basin formation during neogene quaternary extensional tectonics in sw anatolia turkey insights from the kinematics of the dinar fault zone abstract in the extensional province of sw anatolia the cross cutting relationship between the nw and ne oriented neogene and quaternary basins is an ongoing debate in the understanding of the tectonic evolution of this area in order to contribute to this issue we carried out a structural and kinematic study along the seismogenic nw trending dinar fault zone dfz this structure was initially controlled by the sedimentary and tectonic evolution of the ne oriented neogene baklan acigol and burdur basins and later by the nw oriented quaternary dinar basin on the basis of 1000 structural and kinematic data in conjunction with basin stratigraphy the dfz can be divided into three almost parallel and continuous bands that are a the hangingwall where quaternary sediments are deformed by normal faults with mechanical striations b the inner zone corresponding to the present dinar fault scarp where nw trending normal faults with mechanical striations are dominant and c the outer zone located in the footwall of the structure comprising the area between the fault scarp and undeformed bedrock where faults exhibit variable orientation and kinematics from strike slip to normal dip slip these kinematics are mainly indicated by calcite shear veins and superimposed mechanical striations respectively this suggests that the dfz changed kinematics over time i e the dfz initiated as dominant dextral strike slip to oblique slip fault system and continued with a dominant normal movement therefore we hypothesize that the nw trending dfz was initially a transfer zone during the late miocene pliocene coeval to the sedimentary and structural evolution of the ne trending baklan acigol and burdur basins during the quaternary the dfz representing an already weakened crustal sector played the role of a normal fault system providing the accommodation space for the quaternary dinar basin hydrothermal circulation and volcanism at ne nw trending faults intersection implies structurally driven conduits channeling fluids from depth to surface

a wunda full world carbon dioxide ice deposits on umbriel and other uranian moons abstract carbon dioxide has been detected on the trailing hemispheres of several uranian satellites but the exact nature and distribution of the molecules remain unknown one such satellite umbriel has a prominent high albedo annulus shaped feature within the 131 km diameter impact crater wunda we hypothesize that this feature is a solid deposit of co 2 ice we combine thermal and ballistic transport modeling to study the evolution of co 2 molecules on the surface of umbriel a high obliquity 98 body considering processes such as sublimation and jeans escape we find that co 2 ice migrates to low latitudes on geologically short 100s 1000 s of years timescales crater morphology and location create a local cold trap inside wunda and the slopes of crater walls and a central peak explain the deposit s annular shape the high albedo and thermal inertia of co 2 ice relative to regolith allows deposits 15 m thick or greater to be stable over the age of the solar system we conclude that wunda located at low latitude 7 9 s and near the center of the trailing hemisphere where co 2 detections are strongest likely contains a solid co 2 ice deposit we discuss prospects for similar co 2 ice deposits on crater floors on the other major uranian moons and predict that they are present on ariel titania and possibly oberon but not miranda or smaller satellites such deposits have likely not been observed due to the limited nature of voyager 2 image coverage

loess chronology of the last interglacial glacial cycle in bohemia and moravia czech republic abstract combined infrared and green light stimulated luminescence and thermoluminescence dating applied to the extensively studied bohemian and moravian loess palaeosol sequences from sedlec suchdol kutna hora dolni v stonice lechovice mod ice bulhary and cerven kopec provides a reliable chronological framework for the last interglacial glacial cycle based on this luminescence dating study a new chronology is proposed for the last interglacial glacial loess palaeosol sequences from the czech republic irsl and tl dating suggests that the bt horizon of a truncated brown forest soil lower pk iii formed during the last interglacial equivalent to oxygen isotope substage 5e the upper chernozem of pkii belongs to oxygen isotope stage 3 if the combined irsl and tl age estimates are taken into account although from geological estimates an age range within oi substage 5a is most likely the upper weichselian loess accumulated at a very high rate owing to the high accumulation rate there is no time difference in sedimentation ages between the tundra gley palaeosols above pk i which include the upper weichselian sediments in central europe

development of concepts concerning the genesis and emplacement of tethyan ophiolites in the eastern mediterranean and oman regions this article uses evidence mainly from the eastern mediterranean and oman to help understand the origin and emplacement of ophiolites field studies in these regions emphasize the diversity of ophiolite related sedimentary and tectonic processes topics to be discussed here include the sedimentary covers of ophiolites their metamorphic soles related melanges and emplaced continental margin slope rise units modes of ophiolite emplacement will also be considered and tectonic reconstructions that have a direct bearing on the origin and emplacement of ophiolites the writer argues that there is compelling evidence that many ophiolites formed by spreading above intraoceanic subduction zones evidence from their intact sedimentary covers however indicates that such subduction was only incipient in most cases as directly associated volcanic arcs or back arc basins are rare metamorphic soles record fragments of oceanic lithosphere derived from settings ranging from open ocean to continental slope rise settings underlying melanges record the subduction of most of the ocean lithosphere formed at spreading ridges continental margin units beneath ophiolites demonstrate that these ophiolites were formed in ocean basins that were mainly initiated by continental rifting in the eastern mediterranean and oman regions ophiolite emplacement was commonly achieved by trench margin collision although strike slip transpression and large scale accretion along subducting margins played a role in some cases taking account of the mesozoic palaeotectonic setting of the eastern mediterranean region it is widely believed that ophiolites of two main ages mid jurassic and late cretaceous were formed in several small oceanic basins separated by rifted microcontinents the history of tethys in pre mesozoic time remains more open to question lastly giant subduction related ophiolites as in oman cyprus or the balkans may not be forming anywhere in the world ocean today but may instead relate to rare events in earth history when regional to global plate boundaries were drastically reorganised

pedogenesis and paleoclimate interpretation of the magnetic susceptibility record of chinese loess paleosol sequences in the chinese loess paleosol sequences from luochuan haanxi province china variations in the magnetic susceptibility have been accepted as an excellent proxy for paleoclimate and the standard interpretation is that climatic processes have enhanced the magnetic susceptibility of the paleosols beyond the base line level of the loess by using mineral magnetic properties and a soil chemistry extraction procedure we show that most of the magnetic susceptibility signal in both the paleosols and the loess is due to pedogenesis in effect loess deposition and pedogenesis are competing processes at all times and the presence of a paleosol simply indicates that the latter process was predominant these results imply that any interpretation of the paleoclimate record of loess paleosol sequences must recognize the pedogenic nature of the magnetic susceptibility signal and that the focus of future research must be on the critical role of climate in the development of the paleosols

moisture evolution in central asia since 26 ka insights from a kyrgyz loess section western tian shan abstract central asia ca is located in the hinterland of the eurasian continent and faces an extreme risk of continued aridification under the current global warming trend to predict future climate change in ca paleoclimate studies provide essential references however the mechanisms underlying climate changes in ca remain relatively poorly known here we investigate moisture variations in ca as recorded in a 6 m loess section in the western tian shan kyrgyzstan which has accumulated since 26 ka based on the radiometric ams 14c dating we reconstructed the evolution of the wind regime and moisture conditions in the western tian shan with a modified grain size index gsim and a new l proxy l while the frequency dependent magnetic susceptibility fd redness a and yellowness b did not provide reliable paleoclimatic indicators due to weak pedogenesis and other controlling factors the gsim records demonstrated a precipitation maximum in summer before 15 ka shifting to a maximum in spring after 15 ka probably associated with large scale modulation of the latitudinal climatic zones and atmospheric circulation in response to retreat of the northern hemisphere ice sheets based on the l records we place emphases on the important role of temperature modulated evaporation in moisture evolution across ca however this has only influenced moisture evolution in spring and summer with little effect on winter moisture conditions moreover the l records may also indicate that atmospheric humidity can partly affect the long term effective moisture variations

late pleistocene loess of the lower rhine abstract from the lower rhine a compiled 25 7 m thick late pleistocene loess paleosol sequence is differentiated into five lithostratigraphic units the rheingau member mis 5 the keldach member weichselian early pleniglacial gs 21 1 18 mis 4 the ahrgau member weichselian middle pleniglacial mis 3 and the hesbaye and brabant members weichselian late pleniglacial mis 2 it correlates well with climate fluctuations known from ice cores and deep sea cores the sequence was continuously sampled by 335 samples it cuts through all essential layers and soils of the late pleistocene upper loess formation a continuous coarse silt index csi curve shows a maximum in the hesbaye member 31 24 ka b2k indicating the strongest wind conditions during the early late pleistocene further csi highs lie in the keldach and early brabant members csi lows are found the early and middle rheingau member gi 25 gi 22 the jackerath spenrath soils within the deeper keldach member gi 20 19 the early ahrgau member gi 17 gi 12 and finally in the elfgen soil gi 2 at the base of the brabant member the organic carbon culminates in the titz humus zone presumably at the end of gi 21 indicating scanty oxidation during the following cold lower weichselian pleniglacial period the garzweiler solcomplex forming a prevailing period of soil formation between 130 and 78 ka bp mis 5e a is considered as interglacial complex rhine interglacial complex continuing the style of the older interglacial complexes of mis 7 9 etc the ahr interstadial complex mis 3 is seen as immature complex of warm phases with fabric of the interglacial complexes author s suggestion the rhine interglacial complex covers mis 5e a and restricts the weichselian glacial to mis 4 through mis 2 this procedure follows the style of the older interglacial complexes

facies and palaeogeographic evidence for the miocene evolution of the isparta angle in its regional eastern mediterranean context abstract we summarise facies evidence for four miocene basins lycian aksu kopru and manavgat within the isparta angle facies patterns are plotted on six palaegeographic maps restored to their pre late miocene setting these maps are used to help infer the various controls on deposition facies trends and structural features suggest that the individual basins were kinematically linked within the overall african eurasia convergence zone the miocene basins represent a classic example of how related basins may develop within an evolving orogen subject to variable controls through time the dominant control was tectonic although autocyclic sedimentary processes e g reef growth and both relative and eustatic sea level change played a significant role from the palaeogeographic reconstructions and the tectonic context of the isparta angle we infer that during the early miocene the westerly lycian basin and the neighbouring aksu basin experienced flexural subsidence related to southeastward thrusting of the lycian nappes more distal effects of the forebulge may have caused uplift around the aksu and kopru basins initiating n s half grabens bounded by master faults on the eastern side of each basin later the eastern basins of the isparta angle were influenced by regional northward subduction and inferred slab retreat within a remnant of the southern neotethys located within the mediterranean sea at the intersection of the south aegean and cyprus arcs

ams 14c and osl irsl dating of the dunaszekcső loess sequence hungary chronology for 20 to 150 ka and implications for establishing reliable age depth models for the last 40 ka abstract as revealed by 18 ams radiocarbon and 24 osl irsl ages the dunaszekcs loess paleosol sequence is an excellent terrestrial record of paleoenvironmental change in the carpathian basin for the last 130 ka with significant soil forming episodes during the eemian interglacial 130 115 ka mis 5e and in some subsequent mis 5 stages and distinct periods of loess accumulations during the mis 4 and mis 2 charcoals from the sequence made it possible to test the accuracy of 14 c ages from mollusc shells this approach revealed that 14 c ages from some gastropods having small shells succinella oblonga vitrea crystallina are statistically indistinguishable from the ages of charcoals while others clausiliidae sp chondrula tridens show age anomalies up to 600 800 years osl and pirir 290 ages are found to be consistently older while post ir osl ages are younger than the 14 c ages from charcoals and molluscs by some thousands of years except for pirir 225 ages that match the radiocarbon ages quite well osl and irsl ages have scatters up to 7 10 thousand years within 40 ka while charcoals and small molluscs yield consistent ages with relatively low variability beyond the observation that some small molluscs seem to yield reliable 14 c ages calibrated 2 age ranges of the radiocarbon data ca 500 800 years for 20 to 30 ka are an order of magnitude narrower than those of the osl irsl methods 1800 4000 years for 25 to 35 ka thus for establishing chronologies within 40 ka which are both accurate and precise enough to address issues like synchroneity of millennial scale paleoenvironmental events across regions e g north atlantic and europe ams radiocarbon dating of shells of specific loess molluscs and charcoals may probably be a powerful chronological tool however additional work is definitely required involving 14 c and osl irsl dates from other loess sequences to further test the performance of these two supposedly robust chronometers

geological terrains and crater frequencies on ariel the southern hemisphere of ariel a satellite of uranus can be divided into several terrain types data on the size frequency distribution of craters for those different terrain types indicate that these terrains formed over a relatively short period of time much information on ariel s geological history can be gained from these data

application of sr isotope stratigraphy and sedimentary analysis to the origin and evolution of the neogene basins in the isparta angle southern turkey abstract four miocene basins are located within the isparta angle in southern turkey one of these the darioren basin is well established as the foreland basin to the adjacent lycian nappes which marks the western margin of the isparta angle the tectonic origin of the other three basins aksu kopru and manavgat has remained enigmatic largely because of the difficulties of dating the lowermost part of the succession continental and shallow marine conglomerates and limestones comparison of carbonate 87 sr 86 sr with the ocean water sr isotope record provides a powerful chronological tool for marine sediments by using sr isotope ratios in this way ages of the neritic limestones have been derived despite the absence of age diagnostic fossils these data constrain the age of the underlying conglomerates as lower to middle burdigalian the timing of deepening and subsidence events suggested by these new dates taken together with palaeocurrent measurements from conglomerates suggest that the basin configuration of the isparta angle was initiated in the lower burdigalian and was directly related to movement on north south oriented faults depocentre development in the north of the aksu basin is consistent with a tectonic origin for all three basins by flexurally induced block faulting of the foreland in front of the lycian nappes along pre existing structural weaknesses

probing the regoliths of the classical uranian satellites are their surfaces mantled by a layer of tiny h2o ice grains abstract we investigate whether the surfaces of the classical moons of uranus are compositionally stratified with a thin veneer of mostly tiny h2o ice grains 2 m diameters mantling a lower layer composed of larger grains of h2o ice dark material and co2 ice 10 50 m diameters near infrared observations 1 2 5 m have determined that the h2o ice rich surfaces of these moons are overprinted by concentrated deposits of co2 ice found almost exclusively on their trailing hemispheres however best fit spectral models of longer wavelength datasets 3 5 m indicate that the spectral signature of co2 ice is largely absent and instead the exposed surfaces of these moons are composed primarily of tiny h2o ice grains to investigate possible compositional layering of these moons we have collected new data using the infrared array camera irac onboard the spitzer space telescope 3 5 m spectral modeling of these new data is consistent with prior analyses suggesting that the exposed surfaces of the uranian moons are primarily composed of tiny h2o ice grains furthermore analysis of these new data reveal that the trailing hemispheres of these moons are brighter than their leading hemispheres over the 3 to 5 m wavelength range except for miranda which displays no hemispherical asymmetries in its irac albedos our analyses also reveal that the surface of ariel displays five distinct regional scale albedo zones possibly consistent with the spatial distribution of co2 ice on this moon we discuss possible processes that could be enhancing the observed leading trailing albedo asymmetries exhibited by these moons as well as processes that could be driving the apparent compositional stratification of their near surfaces

high resolution paleoclimatic proxy data from the mis3 2 transition recorded in northeastern hungarian loess abstract the bodrogkeresztur loess paleosol sequence in northeastern hungary was investigated to improve our understanding of the paleoenvironmental conditions at the foothills of the carpathians and their impact on the gravettian population the main part of the section is comprised of eolian deposits that enable the reconstruction of the paleoenvironmental conditions this study comprises grain size geochemical color and rock magnetic analysis as well as luminescence and radiocarbon dating the chronological data place this section from later mis 3 until present but also suggest erosion of the sediment in the late mis 2 and the early holocene moreover generally more humid conditions during late mis3 and early mis2 are observed in comparison to other regions in the carpathian basin main dust source was most likely the tisza floodplain and the material was probably transported to the site from a northeastern wind direction increased weathering led to the formation of a well developed mis3 paleosol the loess exhibits elevated values of frequency dependent magnetic susceptibility that highlight the relatively mild conditions during loess formation nevertheless two loess layers with high sand abundance in the profile indicate colder and dryer conditions with increased eolian dynamics during short periods within mis2 finally the bodrogkeresztur section highlights the unique microclimatic conditions at the foothill areas of the carpathian basin which may have offered a favorable environment for the gravettian population

oberon color photometry from voyager and its geological implications abstract three primary terrains are exposed at the surface of oberon average cratered terrain bright crater rays and prominent dark deposits often seen on but not restricted to crater floors we have applied hapke s 1986 icarus 67 264 280 photometric model to voyager imaging and earth based observations to determine photometric properties and colors of oberon s terrains and compare the results with those for the other uranian satellites all terrains on oberon exhibit photometric roughnesses 21 that are lunar like and similar to average global photometric roughnesses of titania and umbriel the asymmetry factors are backscattering for all terrains 0 35 g 0 20 and fall within the observed range for other uranian satellites at visual wavelengths g becomes more backscattering with decreasing single scattering albedo 0 25 0 0 61 the brightest materials on oberon are relatively neutral in color typical of materials covering other uranian satellites but the violet clear and green clear albedo ratios for the darkest terrains on oberon are atypically large for uranian satellites the variation can be modeled in terms of a binary mixture of low albedo and high albedo materials having slightly different colors oberon s leading hemisphere is dominantly covered with dark surface materials identical in color to dark deposits on crater floors while materials on the trailing hemisphere are richer in a spectrally neutral icy component with dark materials occurring in small irregular patches bright ray craters appear to have excavated into a relatively cleaner spectrally neutral icy crust dark materials at the surface may be effusive flood deposits a dark layer below the icy crust which is more exposed on the leading hemisphere due to preferential erosion by impacts or possibly exogenic in origin

late neogene oroclinal bending in the central taurides a record of terminal eastward subduction in southern turkey abstract the tauride fold thrusts belt formed during s n convergence between africa and eurasia since cretaceous time the western end of the central taurides strike nw se highly obliquely to the overall convergence direction and connect to the ne sw beydaglari lycian nappe flank of the western taurides forming the so called isparta angle in neogene time the western and central taurides and the inner part of the isparta angle became overlain by neogene sedimentary basins including manavgat koprucay and aksu characterized by marine clastics and carbonates the eastern limb of the isparta angle experienced multidirectional miocene to present extension whereas e w shortening affected the marine sedimentary basins in the heart of the isparta angle to quantitatively reconstruct the neogene kinematic evolution of the taurides towards restoring the subduction system accommodating africa eurasia convergence we paleomagnetically assess if and when vertical axis rotations affected the manavgat koprucay and aksu basins in early miocene to pliocene times we show that the northern koprucay basin rotated 20 30 clockwise the manavgat basin underwent 25 35 counterclockwise rotation and the aksu basin underwent no rotation since the early middle miocene it was previously shown that the beydaglari region underwent a post middle miocene 20 counterclockwise rotation these results show that the prominent oroclinal salient geometry of the western taurides thus acquired at least in part since miocene times that the koprucay basin rotated relative to the aksu basin along the aksu thrust and that the beydaglari platform rotated relative to the aksu basin along the bucak thrust which must have both been active until late neogene time this synchronous e w shortening in the heart of the isparta angle and multidirectional extension in its eastern limb may be explained by relative westward retreat of an eastward dipping subducting antalya slab that has previously been imaged by seismic tomography and a benioff zone the neogene bucak thrust west of the aksu basin may represent the most recent surface expression of the antalya subduction zone

paleoenvironmental significance of the magnetic fabrics in chinese loess paleosols since the last interglacial 130 ka abstract we compare new anisotropy of magnetic susceptibility ams data with previously determined paleoclimatically sensitive parameters for a loess profile at lingtai central loess plateau china to unravel factors that control loess ams magnetic lineations are clustered along ne sw and nw se orientations during cold and warm periods respectively which probably corresponded to paleowind directions of both winter and summer monsoons anomalously steep magnetic foliations coincidentally occur at the paleoclimatic stage boundaries indicating sediment disturbance lineation strength appears to be sensitive to millennial scale rapid paleoclimatic fluctuations generally the winter monsoon produces a lower degree of lineation than the summer monsoon furthermore by studying lineation subsets for the cold and warm periods we find that the cold interval lineation strengths co vary with grain size over the last 70 ka during the last interglacial about 74 128 ka the lineation and declination of the susceptibility maximum dec k max are sensitive to rapid fluctuations in winter and summer monsoons long term trends of magnetic foliation and anisotropy degree replicate grain size variations with superimposed short term peaks related to post depositional compaction as suggested by density the ams shape parameter t indicates oblate fabrics these new findings will not only improve our understandings of loess ams but also expand the possibilities of paleoclimatic studies in the chinese loess

map view restoration of aegean west anatolian accretion and extension since the eocene 1 the aegean region greece western turkey is one of the best studied continental extensional provinces here we provide the first detailed kinematic restoration of the aegean region since 35 ma the region consists of stacked upper crustal slices nappes that reflect a complex paleogeography these were decoupled from the subducting african adriatic lithospheric slab especially since 25 ma extensional detachments cut the nappe stack and exhumed its metamorphosed portions in metamorphic core complexes we reconstruct up to 400 km of trench perpendicular ne sw extension in two stages from 25 to 15 ma the aegean forearc rotated clockwise relative to the moesian platform around euler poles in northern greece accommodated by extensional detachments in the north and an inferred transfer fault se of the menderes massif the majority of extension occurred after 15 ma up to 290 km by opposite rotations of the western and eastern parts of the region simultaneously the aegean region underwent up to 650 km of post 25 ma trench parallel extension leading to dramatic crustal thinning on crete we restore a detachment configuration with the mid cycladic lineament representing a detachment that accommodated trench parallel extension in the central aegean region finally we demonstrate that the sakarya zone and cretaceous ophiolites of turkey cannot be traced far into the aegean region and are likely bounded by a pre 35 ma n s fault zone this fault became reactivated since 25 ma as an extensional detachment located west of lesbos island the paleogeographic units south of the izmir ankara sava suture however can be correlated from greece to turkey

the pluto system initial results from its exploration by new horizons the pluto system was recently explored by nasa s new horizons spacecraft making closest approach on 14 july 2015 pluto s surface displays diverse landforms terrain ages albedos colors and composition gradients evidence is found for a water ice crust geologically young surface units surface ice convection wind streaks volatile transport and glacial flow pluto s atmosphere is highly extended with trace hydrocarbons a global haze layer and a surface pressure near 10 microbars pluto s diverse surface geology and long term activity raise fundamental questions about how small planets remain active many billions of years after formation pluto s large moon charon displays tectonics and evidence for a heterogeneous crustal composition its north pole displays puzzling dark terrain small satellites hydra and nix have higher albedos than expected

evidence for general instability of past climate from a 250 kyr ice core record recent results1 2 from two ice cores drilled in central greenland have revealed large abrupt climate changes of at least regional extent during the late stages of the last glaciation suggesting that climate in the north atlantic region is able to reorganize itself rapidly perhaps even within a few decades here we present a detailed stable isotope record for the full length of the greenland ice core project summit ice core extending over the past 250 kyr according to a calculated timescale we find that climate instability was not confined to the last glaciation but appears also to have been marked during the last interglacial as explored more fully in a companion paper3 and during the previous saale holstein glacial cycle this is in contrast with the extreme stability of the holocene suggesting that recent climate stability may be the exception rather than the rule the last interglacial seems to have lasted longer than is implied by the deep sea specmap record4 in agreement with other land based observations5 6 we suggest that climate instability in the early part of the last interglacial may have delayed the melting of the saalean ice sheets in america and eurasia perhaps accounting for this discrepancy

rock magnetic detection of distal ice rafted debries clue for the identification of heinrich layers on the portuguese margin abstract high resolution measurements of concentration and grain size dependent magnetic parameters along a sedimentary sequence deposited on the portuguese margin 38 n during the last 120 ka allowed the detection of multiple thin layers slightly enriched by a coarse lithogenic fraction sizes mineralogy shapes and mode of deposition identify the material as ice rafted detritus ird the four most recent events dated by calibrated radiocarbon ages are contemporaneous with heinrich events he1 he4 older events can be identified as he5 he6 or with minor ird that occurred during stage 5 the resolution and sensitivity obtained with rock magnetic methods enable the detection of multiple secondary events showing that iceberg delivery was a frequent phenomenon directly linked to temperature variations over ice caps heinrich events representing the extreme cases

the stability and transport of carbon dioxide on iapetus abstract carbon dioxide has been detected associated with iapetus dark material by the cassini spacecraft this co2 may be primordial and or resulting from ongoing production by photolysis of water ice in the presence of carbonaceous material allamandola l j sandford s a valero g j 1988 icarus 76 225 252 although any primordial co2 would likely be complexed with the dark material and thus stable against thermal transport to iapetus poles buratti b j and 28 colleagues 2005 astrophys j 622 l149 l152 active production of co2 would result in some fraction of the co2 being mobile enough to allow the accumulation of co2 at iapetus poles we develop a computer model to simulate ballistic transport of co2 ice on iapetus accounting for iapetus gravitational binding energy and polar cold traps we find that the residence time of co2 ice outside the polar regions is very short a sheet of co2 ice near the equator of iapetus decreases in thickness at a rate of 50 mm year 1 the sublimated co2 will ballistically move around iapetus until it reaches the polar cold traps where it can be sequestered for up to 15 years if the total surface inventory of co2 exceeds 3 10 7 kg the polar ice cap will be permanent while co2 is moving around the surface a small percentage will eventually reach escape velocity and be lost from the system as such a seasonal polar cap is lost at rate of 12 every solar orbit as the co2 moves between the two polar cold traps

evidence for massive discharges of icebergs into the north atlantic ocean during the last glacial period sediments in the north atlantic ocean contain a series of layers that are rich in ice rafted debris and unusually poor in foraminifera1 here we present evidence that the most recent six of these heinrich layers deposited between 14 000 and 70 000 years ago record marked decreases in sea surface temperature and salinity decreases in the flux of planktonic foraminifera to the sediments and short lived massive discharges of icebergs originating in eastern canada the path of the icebergs clearly marked by the presence of ice rafted detrital carbonate can be traced for more than 3 000 km a remarkable distance attesting to extreme cooling of surface waters and enormous amounts of drifting ice the cause of these extreme events is puzzling they may reflect repeated rapid advances of the laurentide ice sheet perhaps associated with reductions in air temperatures yet temperature records from greenland ice cores appear to exhibit only a weak corresponding signal moreover the 5 10 000 yr intervals between the events are inconsistent with milankovitch orbital periodicities raising the question of what the ultimate cause of the postulated cooling may have been

geoarchaeology of upper palaeolithic loess sites located within a transect through moravian valleys czech republic abstract the middle and upper palaeolithic sites situated within the system of moravian and south silesian valleys are key localities for understanding the patterns of seasonal mobility that enabled humans to exploit the north european plain and a possibility to distinguish the importance of the weather and climate for their subsistence practises loess accumulations that have covered the best preserved open air palaeolithic sites in central europe display the climatic record covering at least 30 000 years the sedimentological microstratigraphical and geochemical record of three studied upper palaeolithic loess sites show significant changes documenting increased precipitation towards the north a progressive coarsening of the loess deposits during the upper pleniglacial contrasting with the progressive fining toward the north european glaciation was detected this methodological approach explains more precisely the context of formation processes connected also with human activity within the corridor between the north european plain and the danube basin through which a wide range of organisms including humans and their prey species were channelled

vegetation and climate changes during the late pliocene and early pleistocene in sw turkey response to comments by elitez et al quaternary research 84 pp 448 456

high resolution record of the environmental response to climatic variations during the last interglacial glacial cycle in central europe the loess palaeosol sequence of dolni věstonice czech republic abstract high resolution multidisciplinary investigation of key european loess palaeosols profiles have demonstrated that loess sequences result from rapid and cyclic aeolian sedimentation which is reflected in variations of loess grain size indexes and correlated with greenland ice core dust records this correlation suggests a global connection between north atlantic and west european air masses herein we present a revised stratigraphy and a continuous high resolution record of grain size magnetic susceptibility and organic carbon 13c of the famous of dolni vestonice dv loess sequence in the moravian region of the czech republic a new set of quartz osl ages provides a reliable and accurate chronology of the sequence s main pedosedimentary events the grain size record shows strongly contrasting variations with numerous abrupt coarse grained events especially in the upper part of the sequence between ca 20 30 ka this time period is also characterised by a progressive coarsening of the loess deposits as already observed in other western european sequences the base of the dv sequence exhibits an exceptionally well preserved soil complex composed of three chernozem soil horizons and 5 aeolian silt layers marker silts this complex is at present the most complete record of environmental variations and dust deposition in the european loess belt for the weichselian early glacial period spanning about 110 to 70 ka allowing correlations with various global palaeoclimatic records osl ages combined with sedimentological and palaeopedological observations lead to the conclusion that this soil complex recorded all of the main climatic events expressed in the north grip record from greenland interstadials gis 25 to 19

crater formation and modification on the icy satellites of uranus and saturn depth diameter and central peak occurrence depth diameters d d for fresh craters on the intermediate sized icy satellites of uranus and saturn have been determined using photoclinometry and shadow lengths and are compared with similar measurements on the terrestrial planets simple bowl shaped craters on icy satellites including those on miranda for which the highest resolution data are available are systematically 20 40 shallower than on the terrestrial planets this pronounced difference between crater depths on icy and rocky surfaces indicates that differences in impact velocity or surface gravity are not as important as the differences in mechanical properties between ice and rock in controlling simple crater morphology experimental impact studies indicate that differences in material properties such as angle of internal friction can control crater depth alternatively breccia lenses may be thicker in icy satellite simple craters complex craters on the icy satellites become significantly deeper with increasing crater diameters unlike complex craters on terrestrial planets which are nearly constant in depth central peaks and hence floor rebound are also volumetrically and morphologically more prominent than wall slumping rim collapse on the icy satellites the magnitude of viscous relaxation of very large craters e g herschel and odysseus on the icy satellites can be estimated from extrapolation of the d d fits at smaller crater diameters the transition diameter from simple to complex morphology is inversely correlated with gravity as it is on the terrestrial planets but at significantly smaller diameters than would be expected from a simple extrapolation of the terrestrial trend thus crater modification especially floor rebound is easier to initiate on icy satellites estimated effective cohesions for shocked icy material are lower by a factor of 10 20 relative to rock although estimated effective viscosities are similar the distinct systematic differences between crater morphology on icy and rocky worlds indicate that gross material property differences between rock and ices play a key role in crater formation and modification but gravity is still the primary driving force

multiproxy evidence of middle and late pleistocene environmental changes in the loess paleosol sequence of bůhzdař czech republic abstract loess paleosol sequences preserve information that can be used to reconstruct paleoenvironments a dense network of reliably analyzed sequences from different geographic locations is crucial to address ecological and climatic trends which occurred during the pleistocene this paper focuses on a loess paleosol sequence in b hzda situated 9 km nw of prague czech republic geochemical approaches total organic carbon xrf elemental analyses xrd mineralogy 13c and 18o stable isotopes are combined with grain size distributions and optically stimulated luminescence osl to assess the climatic conditions at the time of formation of the strata the oldest loess at this location was formed circa 200 ka ago mis 7 making it the oldest loess in central bohemia for now the b hzda loess paleosol sequence was highly affected by several erosion events eemian paleosols mis 5e being completely missing the partly relocated paleosols situated at the lower part of the b hzda sequence represent a period of increased humidity during late mis 7 and mis 6 despite the fact that the b hzda profile is not particularly thick 5 m significant changes in paleoclimate reconstructions have been detected