the effect of rupture complexity on estimates of source size a general technique is proposed for estimating rupture geometry from measurements of body wave durations wherein measurements of the overall signal duration or the duration of a single pulse identified in all of the arrivals are inverted to estimate the geometry of the overall rupture or of a specific subevent respectively the complexity of a waveform is determined by comparing the overall signal duration to the duration of the most prominent pulse in the waveform this complexity is used to estimate the ratio of the average rupture velocity to the subevent rupture velocity the shear waves radiated by eight moderate 3 6 ml 4 9 multiply recorded aftershocks of the 1975 oroville california earthquake are analyzed using measurements of the corner frequency the characteristic frequency the pulse duration and the signal duration comparison of these four different estimates of source size indicates that the corner frequency and the characteristic frequency are more sensitive to the dominant subevent size than to the overall event size the difference between the estimates of source size determined from the signal duration measurements and the spectral measurements increases as the rupture complexity increases

the progressive evolution of a continental climate in southeast central european lowlands during the middle pleistocene recorded in loess paleosol sequences 1 abstract little is known about the long term quaternary climate evolution of central and south east europe because suitable terrestrial paleoenvironmental records are scarce we present a multiproxy record of loess paleosol sequences in the middle and lower danube basins over the past 700 k y in these lowlands the continentality of interglacial climate progressively increased during the middle pleistocene corresponding trends are seen in other climate prox ies in the same region and in the lowlands of the northern black sea but not or less clearly in climate archives from outside these lowlands we conclude that a small scale increase in paleoelevation of central european mountain ranges the alps carpathians and dinarides during the middle pleistocene might be the cause of the progressive increase in climate conti nentality of southeast european lowlands

containment of stick slip failures on a simulated fault by pore fluid injection unstable stick slip events have been confined to a portion of a finely ground 40 by 200 cm simulated fault in a granite sample by selectively injecting water onto the ends of the stressed fault source parameters of eight confined events generated at normal stresses between 0 7 and 4 1 mpa have been measured dynamic stress drops increased from 0 06 to 0 38 mpa with increasing normal stress such that the ratio of stress drop to normal stress is about 0 09 fractional shear stress drops of these events are less than 0 2 total fault slip measured at the center of the slipped portion ranged from 8 5 to 38 9 mu m maximum relative slip velocities at the same location ranged from 2 5 to 34 7 cm s slip velocity increased with increasing dynamic stress drop

dust flux estimates for the last glacial period in east central europe based on terrestrial records of loess deposits a review loess paleosol sequences are significant records of the mineral dust cycle of glacial interglacial periods as dust particles give rise to direct and indirect radiative forcing obtaining a reliable picture of the global and regional patterns of mineral dust fluxes during glacial periods can lead to a better understanding of the contribution of mineral dust to past climate changes recent progress in absolute dating of loess deposits in the carpathian basin in east central europe made it possible to provide correct aeolian flux estimates for the last glacial period marine isotope stage mis 2 mass accumulation rates mars from chronological data of 33 loess sites exhibited a wide range of values from 150 to 1422 g m 2 a 1 centered around median and mean values of 338 and 417 g m 2 a 1 marpm10marpm10 and marpm2marpm2 estimates have been also calculated using grain size measurements of many loess samples and loess mars in order to facilitate comparison with models and since particles larger than 10 m have a negligible radiative effect here we show that some previous model simulations of the dust cycle at the last glacial maximum lgm significantly underestimated the real aeolian flux ranges of our estimates marpm10 34 324marpm10 34 324 and marpm2 9 3 88 2gm 2a 1 in east central europe for this reason some simulations of dust induced direct radiative forcing of the lgm climate failed to yield reliable results for this mid latitude region as they have been based on three dimensional dust field models that are not capable of estimating the real aeolian fluxes in central europe a recent global model of top of the atmosphere toa radiative forcing by mineral aerosols at the lgm that has been based on more realistic parameterization of dust sources transport and deposition revealed zonally averaged surface cooling of 2 c for the latitudes of our study area this surface cooling and toa radiative forcing 2 to 3 w m 2 are greater than recognized in other models and draws our attention to the importance of further modeling the impact of mineral dust on lgm climate in order to gain insight into the spatial pattern of radiative forcing and better understand resulting climate response in mid latitude loess regions such as east central europe

stratigraphy and spatial and temporal paleoclimatic trends in southeastern eastern european loess paleosol sequences abstract the loess paleosol sections batajnica stari slankamen serbia mircea voda romania and stary kaydaky ukraine are presently located in areas of different types of steppe and are highly sensitive for recording climatic changes a stratigraphy for these three southeastern eastern european sections is presented based on pedostratigraphy and correlation of recently obtained susceptibility records with susceptibility data of other sections of the area koriten mostistea vyazivok of the chinese loess plateau and with the benthic 18o record of odp 677 six pedocomplexes were studied at the serbian and romanian sections and five at the ukrainian section the oldest are related to marine isotope stage mis 17 batajnica stari slankamen and mircea voda and mis 13 15 stary kaydaky some points concerning the existing loess chronostratigraphies of bulgaria ukraine and china are discussed comparative study of the profiles allows the tracing of paleoclimatic and paleoenvironmental changes in southeastern eastern europe in time and space reconstruction of paleoprecipitation based on susceptibility rainfall relationships and calculations of sedimentation rates are evaluated

the crvenka loess paleosol sequence a record of continuous grassland domination in the southern carpathian basin during the late pleistocene abstract in this study we compare two independent paleoenvironmental proxies for a loess sequence in northern serbia in the southern carpathian basin novel n alkane biomarkers and traditional land snail assemblages both are associated with other more widely used proxy data for loess sections such as environmental magnetism grain size and geochemical indices together these paleoenvironmental proxy records provide evidence for the continued dominance of grasslands during the late pleistocene in the southern carpathian basin it is contrary to other european loess provinces which are characterized by high diversity of late pleistocene environments ranging from tundra like to deciduous forest habitats these findings highlight the southeastern part of carpathian basin as an important but still insufficiently investigated biogeographical refugium and biodiversity preservation zone the reason for this is a mostly stable paleoclimate for much of the late pleistocene

weathering intensity and pedostratigraphy of the middle to upper pleistocene loess palaeosol sequence of wels aschet upper austria abstract on top of a fluvioglacial terrace near wels aschet a complex loess palaeosol sequence has been investigated to date the terrace is classified as a classical gunz unit older deckenschotter sedimentological and mineralogical analyses were carried out on the basis of palaeopedological field data the results show that in terms of mineralogical composition the palaeosols can clearly be differentiated and are characterised throughout by interglacial weathering intensity bulk mineralogical as well as clay mineralogical data allow a five stage ranking of weathering intensity based on indicator minerals from the bulk mineralogical perspective slightly weathered loess still contains carbonate minerals and primary chlorite whereas the intensely weathered soil horizons are characterised by the total or near absence of carbonate minerals and primary chlorite micas and feldspars in clay mineralogical results chlorite and the relation of 14 a and 18 a vermiculites as well as mixed layer minerals play an important role in determining the weathering stage primary chlorite can be present in slightly weathered loess loams and vermiculite 14 a is dominant there stage 1 and 2 from weathering stage 3 onwards the amount of vermiculite 18 a increases considerably and dominates the following stage 4 most intensive weathering causes the absence of illite stage 5 generally the studied interglacial palaeosols belong to at least stage 3 with the applied methodology four interglacial palaeosols have been demarcated as well as a highly weathered palaeosol within the terrace gravels of the gunz in wels aschet pedostratigrapy points to a classification of the older deckenschotter in mis 14 at minimum however since this glacial period was of low intensity and the weathering intensity of the basal palaeosol was significantly enhanced a correlation of the gunz terrace with mis 16 also seems possible

mixed layer illite vermiculite as a paleoclimatic indicator in the pleistocene red soil sediments in jiujiang southern china abstract the mineralogy and chemical composition of the jiujiang red soil sediments were investigated using x ray diffraction xrd x ray fluorescence xrf and inductively coupled plasma mass spectrometry icp ms mixed layer illite vermiculite i v was confirmed based on the conditions that a broad peak of 1 0 to 1 4 nm appeared in xrd after mg saturation and its d spacing did not change after glycol treatment but collapsed to 1 0 nm after heating owing to the loss of water and hydroxy cations from its interlayer the mixed layer i v contents fluctuate throughout the section but show a decreasing trend upwards suggesting decreased weathering towards the surface of the section the chemical index of alteration cia values and rb sr ratios also exhibit upward decreasing trends jointly revealing the climate shift from warm humid to cool dry from the middle to the late pleistocene although the general climate evolution can be evaluated by cia values and rb sr ratios sub climatic events within the jiujiang red soil sediments cannot be identified the sio2 al2o3 al2o3 fe2o3 and sio2 fe2o3 ratios clearly fluctuate along the section especially within the net like red soil sediments but they do not reveal multiple climate cycles this is because of an inhomogeneous distribution of sio2 al2o3 and fe2o3 in the white veins and the red matrix and also non uniform sampling the variation in the content of mixed layer i v show a strong positive correlation with changes in magnetic susceptibility of loess paleosol sediments and in marine oxygen isotope ratios revealing multiple sub climate cycles on a global scale since the middle pleistocene therefore the mixed layer i v contents not only reveal the whole climate trend documented in the red soil sediments since the middle pleistocene but also disclose the sub climate cycles related to the deposit pedogenesis process

processes of loess lithogenesis during the pleistocene holocene southeast siberia regional studies have been conducted on loess deposits cohesive sands and loess like neoformations in the technogenesis zones in southeast siberia cryogenic processes and distribution of geological formations have been ascribed to influential factors of loess lithogenesis the processes of loess formation are active in the present environment

malacological characteristics of the middle to upper pleistocene transitional interval mis 7 5 observed in the batajnica locality serbia abstract the batajnica loess section is one of the most complete middle and late pleistocene records known in the vojvodina region serbia the main aim of the malacological investigations was to study the latest middle pleistocene cold interval and to see how the mollusc successions reacted to the climate changes during the cold warm transition the deposits which belong to the upper part of pedocomplex v s2 v l2 loess and partly to the v s1 soil were sampled the penultimate glacial loess v l2 of the batajnica site corresponds to the cold interval marine isotope stage mis 6 the molluscs indicate moderate or sometimes warm climate and dry or moderate steppe like environment composed of adjacent mosaics of drier and humid habitats the mollusc complexes of v s2 soil mis 7c v l2 loess mis 6 and v s1 paleosol mis 5e show almost the same species composition which suggests the existence of a comparatively moderate or warm climate during the late middle pleistocene cold interval in contrast the mollusc complexes mis 6 from western and eastern europe have less species and few individuals compared with the batajnica section comparison with the late middle pleistocene mollusc associations from the northern and southern margins of the fruska gora mountain confirms its environmental originality the northern side of the mountain was characterized by a humid and relatively colder environment than the other areas of the vojvodina region batajnica irig and ruma the mollusc fauna obtained in the batajnica site suggests that this adjacent area represented a refugium for the thermophilous and arid tolerant species where they were able to survive during the cold periods of the pleistocene and thus confirms the hypothesis of p sumegi

pleistocene environmental dynamics recorded in the loess of the middle and lower danube basin abstract the substantial loess deposits of the middle and lower danube basin in southeastern europe represent one of the thickest and most comprehensive terrestrial palaeoenvironmental records on the continent yet are also the least well understood environmental conditions over the last million years have resulted in relatively continuous deposits uninterrupted by glaciation and tundra conditions which nevertheless reflect oscillations between relatively warm humid interglacial and cold dry glacial intervals this relative environmental stability may have proven important for hominins migrating into and through the region the loess stratigraphy comprises distinct loess paleosol sequences reflecting glacial interglacial phases which can be quantified for intensity using environmental magnetism and geochemistry these phases are emphasised by variations in vegetation and malacofauna which respond to climatic change the loess deposits demonstrate broadly similar sedimentological characteristics across the basin danubian loess deposits initiated in response to the tectonic formation of the pannonian basin retreat of the large palaeolakes and increased sediment supply from the danube the period from 1 ma 500 ka mis 27 13 was characterised by alternating loess deposition and pedogenesis during glacial and interglacial periods respectively in response to relatively humid forested conditions this period represents the opening of the danube corridor and provides the backdrop for initial hominin arrival into europe after 500 ka and particularly after mis 9 loess accumulation rates increased in response to relatively more steppic arid environments mis 9 and 13 15 were the most humid phases of the last 600 ky the mis 5 interglacial period was the warmest and relatively most humid period preceding the holocene and was followed by substantially increased loess accumulation during mis 4 which may be linked to north atlantic circulation the complexity of the mis 3 interstadial paleosol suggests that conditions were not uniformly warm and wet during this time mis 3 corresponds with the first arrival of anatomically modern humans to europe the last glacial maximum and younger dryas of mis 2 were characterised by substantially increased loess accumulation indicating cold steppe environments most likely influenced by the north atlantic although conditions were sufficiently mild that the region acted as a refugium for thermophilic biota as may also have been the case for most of the pleistocene glacial cycles the holocene soil represents relatively wamer and more humid conditions corresponding to the current interglacial

scaling of ground motion parameters state of stress and focal depth the ground motion parametersrv and ra where r is hypocentral distance v is peak velocity is density and a is peak acceleration are found observationally to be strong functions of stress state and linearly related to focal depth z if the stress state and focal depth are properly taken into account then the ground motion parameters depend on the seismic moment m0 as expected from basic scaling principles that is rv m01 3 and ra is independent of earthquake size regression lines fitted to observations covering broad ranges in seismic moment and focal depth indicate that for extensional and compressional tectonic regimes corresponding to normal and thrust or reverse faulting earthquakes respectively peak acceleration is given by ra 1 08 mpa 3 06 mpa km z normal and ra 5 65 mpa 8 76 mpa km z thrust and for peak velocity rv m01 3 10 4 m2 s n m 1 3 3 00 0 69 km 1 z normal and rv m01 3 10 4 m2 s n m 1 3 4 63 1 82 km 1 z thrust for strike slip earthquakes the data currently are insufficient to define regression fits but such lines would definitely lie between those for the normal and thrust stress regimes these equations are appropriate for ground motion at small hypocentral distance as recorded in a whole space it follows that for comparable hypocentral depth peak acceleration in a compressional tectonic regime for example much of the eastern united states is a factor of about 3 greater than in an extensional regime such as nevada and for peak velocity a similar comparison yields a factor of 2 difference the similarity in behavior of the peak acceleration parameter to crustal strength estimated from byerlee s law of friction with respect to depth and stress state indicates that crustal strength is probably the factor governing the seismic source processes that give rise to the high frequency peak ground motion analysis of the peak acceleration data in the context of crustal strength suggests bounds on this ground motion parameter as recorded at a typical surface site that depend on stress state specifically a normal 0 5 g and a thrust 1 9 g thus the state of stress as well as the focal depth clearly is an important factor to be taken into account in the prediction of seismic ground motion

constitutive relations for fault slip and earthquake instabilities constitutive relations for fault slip are described and adopted as a basis for analyzing slip motion and its instability in the form of earthquakes on crustal faults the constitutive relations discussed include simple rate independent slip weakening models in which shear strength degrades with ongoing slip to a residual frictional strength and also more realistic but as yet less extensively applied slip rate and surface state dependent relations for the latter the state of the surface is characterized by one or more variables that evolve with ongoing slip seeking values consistent with the current slip rate models of crustal faults range from simple single degree of freedom spring slider systems to more complex continuous systems that incorporate nonuniform slip and locked patches on faults of depth dependent constitutive properties within elastic lithospheric plates that may be coupled to a viscoelastic asthenosphere

a mechanical model of precursory source processes for some large earthquakes a mechanical model is presented of precursory source processes for some large earthquakes along plate boundaries it is assumed that the pre seismic period consists of the upward progression of a zone of slip from lower portions of the lithosphere towards the earth s surface the slip front is blocked by local asperities of different size and strength these asperities may be zones of real alteration of inherent strength or instead may be zones which are currently stronger due to a local slowdown of a basically rate dependent frictional response such blocking by a single large asperity or array of asperities produces quiescence over a segment of plate boundary until gradual increase of the stress concentration forces the slip zone through the blocked region at one end of the gap thus nucleating a seismic rupture that propagates upwards and towards the other end this model is proposed to explain certain distinctive seismicity patterns that have been observed before large earthquakes notably quiescence over the gap zone followed by clustering at its ends prior to the main event a discussion of mechanical factors influencing the process is presented and some introductory modelling performed with the use of a generalized elsasser model for lithospheric plates and the line spring model for part through flaws slip zones at plate boundaries is outlined briefly

the late pleistocene belotinac section southern serbia at the southern limit of the european loess belt environmental and climate reconstruction using grain size and stable c and n isotopes the belotinac loess section is one of the southernmost loess paleosol environmental archives for the late quaternary in serbia the climate at this site is intermediate between the continental and the mediterranean realms which makes this loess archive potentially highly sensitive to past climatic changes this paper presents new insights into the paleoenvironmental history during the last glacial period in southern serbia using grain size and isotope proxy data the grain size parameters from the belotinac section reveal variations in the paleowind dynamics and weathering intensity and suggest the nearby valley of the ju na morava river as an important source of aeolian sediments in this area based on a multiproxy dataset alternating phases of weak interstadials and phases of enhanced loess deposition at this site were identified nitrogen isotope data suggest that during marine isotope stage 3 ecosystems of high biomass productivity and rather open n cycles prevailed during marine isotope stage 2 productivity was reduced and the n cycle was more strongly closed probably due to a shorter growing season and more pronounced temperature decline carbon isotope data indicate a possible contribution of c4 plants to the holocene vegetation but not to the glacial and interstadial ecosystems of the late pleistocene changes in atmospheric co2 level are not reflected in the carbon isotope record these findings are discussed in the light of paleoclimate proxy datasets from the morava river valley and carpathian basin as well as through comparison of carbon isotope records from loess sections in se central europe and in the rhine valley two different loess provinces exist in terms of glacial interglacial humidity changes a province of glacial drying and a province of glacial humidification the first includes loess sites under more oceanic influence where loess 13c records indicate humid interglacials and interstadials and relatively drier glacial periods the second includes the loess sites of the carpathian basin and especially the southern serbian loess area of belotinac where loess 13c records indicate more intensive aridity during interglacials but a reduced soil moisture deficit and a more humid climate due to lower evapotranspiration in interstadials and even more in glacial periods

high frequency rayleigh wave tomography using traffic noise from long beach california abstractusing a dense seismic array in long beach california we have investigated the effectiveness of using traffic noise for passive subsurface imaging spectral analysis revealed that traffic induced vibrations dominate the ambient seismic noise field at frequencies between 3 and 15 hz using the ambient noise crosscorrelation technique at these frequencies we have extracted fundamental and first order mode rayleigh waves generated by interstate 405 and local roads we picked group traveltimes associated with the fundamental mode and used them in a straight ray tomography procedure to produce group velocity maps at 3 0 and 3 5 hz the velocity trends in our results corresponded to shallow depths and coincided well with lithologies outlined in a geologic map of the survey area the most prominent features resolved in our velocity maps were the low velocities to the north corresponding to less consolidated materials high velocities to the south corresponding to more consolidated materials a low vel

geochemical characterization and origin of southeastern and eastern european loesses serbia romania ukraine abstract the loess paleosol sections of batajnica stari slankamen serbia mircea voda romania and stary kaydaky ukraine were geochemically characterized based on discriminant analysis of major and trace elements the ratios of al ti fe ti and al fe the a cn k ternary plot and element enrichment depletion relative to the average composition of the upper continental crust the origin of the loess material in the southern pannonian basin vojvodina the lower danube basin dobrudja and the dnieper area was evaluated by comparison with the representative element composition of possible source areas and by considering the geomorphodynamic setting also the background values of the initial magnetic susceptibility of the loesses were taken into account for the lower danube basin dobrudja and the ukraine paleowind direction was reconstructed based on the geographic distribution of sandy soil texture and dunes related to river systems finally loesses were evaluated as possible samples of the average upper continental crust our results show that danube and dnieper loess areas can be clearly distinguished the former reveal higher al and fe contents the latter higher si zr hf content and indications of effective mineral and grain size sorting we can confirm that vojvodina loess originated from danube alluvial material and loess of the dnieper area from glaciofluvial sediments of the fennoscandinavian ice sheet the dobrudja loess derived also predominantly from danube alluvium but shows significant contribution of a second loess source probably the glaciofluvial sediments of the ukraine this was forced by northerly katabatic winds from the fennoscandinavian ice sheet whereas wnw winds prevailed in the western walachian plain the studied loesses reflect the average composition of the upper continental crust yet biases exist due to selective mineral element enrichment and depletion in the course of previous sedimentary recycling phases respectively material of all studied loess deposits seems to derive originally from sedimentary rocks

preseismic rupture progression and great earthquake instabilities at plate boundaries we present a procedure for modeling the initially quasi static upward progression of a zone of slip from some depth in the lithosphere toward the earth s surface along a transform plate margin culminating in a great crustal earthquake stress transmission in the lithosphere is analyzed with a generalized elsasser model in which elastic lithospheric plates undergo plane stress deformation and are coupled by an elementary foundation model to a maxwellian viscoelastic asthenosphere upward progression of rupture over a finite length of plate boundary corresponding to a seismic gap along strike is analyzed by a method based on the line spring concept whereby a two dimensional antiplane analysis of the upward progression provides the relation between lithospheric thickness averaged stress and slip used as a boundary condition in the generalized elsasser plate model the formulation results in a nonlinear integral equation for the rupture progression as a function of time and distance along strike a simpler approximate single degree of freedom analysis procedure is described and shown to lead to instability results that can be formulated in terms of the slip softening slope at the boundary falling below the elastic unloading stiffness of the surroundings the results also indicate a delay of ultimate seismic instability due to the stiffer short versus long time asthenospheric response and predict a final period of self driven creep toward instability the procedures for prediction of rupture progression and instability are illustrated in detail for an elastic brittle crack model of slip zone advance and parameters of the model are chosen consistently with great earthquake slips and stress drops for example an effective crack fracture energy of the order 4 106 j m2 at the peak 7 to 10 km below surface of a gaussian bell shaped distribution of fracture energy with depth with variance of the order 5 km simulating strength build up in a seismogenic layer leads to prediction of nominal seismic stress drops of 30 to 60 bars and slips of 2 to 5 m in great strike slip earthquake ruptures breaking 100 to 400 km along strike precursory surface straining in the self driven stage is predicted to proceed at a distinctly higher rate over time intervals beginning 3 to 10 months before such an earthquake this interval being greater for longer distances along strike over which the preseismic upward rupture progression takes place

the belotinac section southern serbia at the southern limit of the european loess belt initial results abstract the palaeoclimate record preserved in loess deposits in s serbia is poorly understood this is in strong contrast to the situation in the north of the country vojvodina region where similar deposits have been intensively investigated in recent years this study presents a first detailed description initial proxy analysis magnetic susceptibility colour total organic carbon and preliminary luminescence chronology of a loess palaeosol sequence that is exposed in an abandoned quarry at belotinac near the city of nis s serbia the sequence is about 10 m thick and preserves three loess units and three weakly developed palaeosol units although its potential remains to be fully tapped the preliminary results demonstrate that the sequence offers a unique record of climate and environmental change during the late pleistocene at the transition between mediterranean and continental europe

roles of sorting and chemical weathering in the geochemistry and magnetic susceptibility of xiashu loess east china abstract uncertainties in paleoenvironmental interpretations for traditional chemical analysis of bulk samples result from different grain size sub populations of sediments containing variable distributions of elements and minerals therefore it is important to understand the elemental and mineral distribution in different grain sizes in determining the quantitative relationship between chemical weathering and climatic change we sieved a series of xiashu loess samples into three sub populations of different grain sizes 45 m respectively and then analyzed each population for rubidium rb strontium sr rare earth elements and magnetic susceptibility in comparison with elemental concentrations of bulk samples clay mineralogy and illitic crystallinity our results show that distinct elemental distributions and magnetic susceptibilities for different grain size sub populations are controlled by sorting and or chemical weathering although we also suggest that the xiashu loess may have the same provenance as the central chinese loess maximum concentrations of rb and fine grained magnetic minerals in the less than 2 m sub population coupled with our finding of maximum sr in the larger than 45 m fraction indicate that sr was lost during chemical weathering grain size sub population analysis is therefore an effective method for extracting paleoenvironmental information because individual sub populations show minimal variations in initial rb sr ratios compared to bulk analysis of all sizes together furthermore a negative correlation between rb sr ratios and sr concentrations for the r 2 0 97 may indicate that clay is a sensitive indicator of intensity of chemical weathering and is an ideal sub population for determining rb sr ratios but not for magnetic susceptibility

middle and late pleistocene loess sequences at batajnica vojvodina serbia abstract loess sequences in the vojvodina region northern serbia reveal a continuous record of paleoclimatic variations during the middle and late pleistocene the most detailed stratigraphic information comes from remarkable exposures on the cliffs of the right danube bank from vukovar to belgrade the batajnica loess section has been recognized as one of the most complete middle and late pleistocene records in this region a more than 40 m thick loess paleosol succession represents environmental transition from relative thin loess layers and rubified soils in lower part of profile to thick loess and fossil chernozems characterizing the last three glacial interglacial cycles the proposed stratigraphic model is based on a detailed magnetic susceptibility ms record which is related to the deep sea isotope stratigraphy and on correlation with other eurasian loess records using the distinct ms pattern of selected loess paleosol couplets this new stratigraphic model suggests serious revision of previous chronological interpretations ms as function of depth shows a well known pattern of low values in loess and high values in paleosols indicating strong enhancement of magnetic minerals during soil formation with the exception of the recent soil v s0 which is strongly contaminated by archaeological artifacts the third paleosol v s3 reveals the highest values in ms and a very distinct double peak the rock magnetic signal at batajnica resembles the typical pattern of the enviromagnetic records determined from other eurasian loess sites the paleopedological interpretations rubification index values and rock magnetic record at batajnica yield valuable data for the reconstruction of paleoclimatic fluctuations for the last 5 glacial interglacial cycles at least moreover the record provides an important link between the classical central european loess sites and the central asian and chinese loess provinces

an introduction to the middle and upper pleistocene loess paleosol sequence at ruma brickyard vojvodina serbia abstract six loess units and five paleosols are preserved in the 20 m thick exposure of middle and late pleistocene sediments at ruma brickyard vojvodina serbia amino acid geochronology provides stratigraphic correlations between loess paleosol units sl l1 s1 sl l2 s2 sl l3 s3 and sl l4 at ruma with loess of glacial cycles b c and d and e respectively at other central and southeastern european localities the profile represents one of the best potential sections in the region for reconstructing detailed paleoclimates and paleoenvironments of the last ca 350 000 yr initial sedimentological magnetic and malacological evidence indicate many episodes of drier conditions in the region than in other parts of central and southeastern europe during the later part of the middle and late pleistocene

seismic estimates of stress release five seismic estimates of stress release are compared for eight multiply recorded aftershocks of the 1975 oroville california earthquake the dynamic stress drop the arms stress drop and the apparent stress provide stable estimates which are strongly correlated across the data set the uncertainties of these estimates the standard error of the mean divided by the mean are approximately 15 estimates of the brune stress drop are uncorrelated with estimates of the average static stress drop calculated from the seismic moments and the rupture geometries of the aftershocks determined from the signal durations of the recorded s waves the brune stress drops are most strongly correlated with the arms stress drops implying that the brune stress drop provides an estimate of the average dynamic stress drop as brune originally proposed

iron mineralogical proxies and quaternary climate change in se european loess paleosol sequences abstract the loess paleosol sequences batajnica stari slankamen serbia and mircea voda romania represent key archives for the climate and landscape development of the middle and lower danube basin during the last 700 000 years for deciphering the quaternary climate evolution in these regions the batajnica stari slankamen and mircea voda sites are for the first time studied by a multi proxy approach based on iron mineralogical parameters changes in the iron mineralogical composition are identified and characterized by rock magnetic investigations diffuse reflectance spectroscopy drs and munsell color based proxies the results show that environmental conditions during mid and early middle pleistocene interglacials were more favorable for hematite formation suggesting a more oxidizing pedoclimate as in the more recent interglacials this is also reflected in a gradual increase of the anhysteretic remanent magnetization vs saturation isothermal remanent magnetization arm sirm ratio in the studied profiles changes in this ratio can be linked to a preferential hematitization of coarse grained ferrimagnetica and relates to warmer climate conditions and a more extended estival dry period at the same time rock magnetic parameters indicate a preferential destruction of fine grained magnetic particles in older paleosols resulting from seasonal excess moisture a progressive cooling and decrease of rainfall during the middle and late pleistocene is evidenced not only for interglacial pedocomplexes but also for glacial loess layers this finding is in line with previously published proxy records of silicate weathering and clay formation at these sites and similar trends reported from other sites in the european steppe belt relating iron mineralogical proxies to paleopedological characteristics and proxies of silicate weathering additionally a change in the seasonal pattern of the interglacial temperature and precipitation regime from a mediterranean type to a steppe type climate is revealed highlighting the potential of such a multi proxy approach possible triggers for this paleoenvironmental evolution are discussed as well finally highlighting a quaternary uplift hypothesis which best could explain the inferred trend of cooling aridification and increasing continentality accordingly changes in atmospheric circulation and rain shadow effects induced by small scale uplift of european mountain belts alps carpathians dinaric alps would provide a driving mechanism for the westward extension of the eurasian steppe belt into central and se europe during the quaternary

pedology and mineralogy of loess profiles at kapela batajnica and stalac serbia abstract profiles with multiple paleosols developed in loess at kapela batajnica and stalac were studied by chemical physical and mineralogical methods to determine paleoclimatic changes through the pleistocene the cyclic nature of sedimentary and pedogenetic processes is indicated by the caco 3 content and silt and clay mineralogy stalac is 200 km south of kapela batajnica and differences between individual paleosols at the two sites are attributed to local differences in soil parent material composition weathering intensity or erosion of the paleosols the profile at stalac provides an important link between typical middle european and se european loess paleosol sequences and indicates the relative influences of the mediterranean and continental climates statistical analysis of values for the hydrolytic alteration index of thorez and other mineral ratios calculated at 0 5 m vertical intervals suggests a steady decrease in interglacial weathering rates since the gunz mindel pedocomplexes f8 and f9 and a gradual change from warm humid to temperate dry conditions the climatic curve for the kapela batajnica sequence suggests continental conditions and correlates well with the nw european climatic curve up to the gunz mindel interglacial pedocomplex f8 the curve for the lower part of the stalac sequence shows a stronger mediterranean influence and correlates well with the curve for greece but the upper part of the stalac sequence above the riss 1 riss 2 pedocomplex f6 shows an increased continental climatic influence

a critical reevaluation of palaeoclimate proxy records from loess in the carpathian basin abstract in the carpathian basin loess is the most important archive of quaternary palaeoclimate evolution but only in the past two decades systematic and high resolution investigations were conducted those studies remarkably improved our knowledge of the regional past environmental change palaeoclimate inferences based on the magnetic susceptibility and grain size distribution as the most commonly used palaeoenvironmental proxies for the carpathian basin loess indicate colder and drier climatic conditions during glacials when compared to interglacials with an increasing number of studies using novel proxies in loess research such a traditional understanding of dry and cold glacials and humid and warm interglacials in the carpathian basin has been questioned as an illustrative example mollusc based climate reconstructions suggest generally warm and very dry summer conditions with mean july temperatures up to 21 c for the southern carpathian basin during the last glacial results based on stable carbon isotopes strongly oppose such high summer temperatures but studies based on n alkanes are in general agreement with the mollusc data when it comes to the vegetation reconstruction indicating mostly steppic conditions however n alkanes studies contradict warm and dry glacial conditions as indicated by mollusc based reconstructions pointing instead to cold and relatively humid glacials in addition there is an ongoing debate whether or not millennial scale climatic oscillations can be observed in the carpathian basin loess as well as whether this area was an important northern hemisphere dust source or rather a sink of far distance dust transport consequently the current state of the art of the palaeoclimate reconstructions from loess in the carpathian basin is rather inconsistent in order to make sense of the existing palaeoclimate data from the carpathian basin loess we have reevaluated and reinterpreted the available data we discuss and propose a coherent interpretation of rock magnetic grain size malacological stable carbon and nitrogen isotope n alkane and bacterial membrane lipid data for the last glacial cycle loess archives from the carpathian basin we show that glacial conditions in the carpathian basin led to a notable increasing north south gradient in temperature and an even stronger expressed decreasing trend in humidity and that most of the biomarker proxy data conducted in loess for the very dry southern part of the carpathian basin show a strong bias towards arid conditions in particular palaeotemperature reconstructions seem to be misleading glacial conditions were drier and colder than previously proposed summer temperatures likely under 15 c during glacials but notably warmer than in other parts of western central and eastern europe the vegetation consisted mostly of steppic environments during both glacials and interglacials we indicate that the carpathian basin has a potential to be a major dust source of the northern hemisphere during glacials although it was at the same time exposed to the deposition of fine far distance travelled dust moreover the main issues in the regional and continental correlation of loess are highlighted as well as the sensitivity of the carpathian basin loess to the millennial scale climate variability recorded in other northern hemisphere records finally we suggest that the onset of loess formation in the investigated area occurred during the middle pleistocene transition and it was probably related to intensive silt production related to glacier dynamics in the alpine ice cap

earthquake aftereffects and triggered seismic phenomena the physical basis for delayed aftereffects of large crustal earthquakes is analyzed these effects apparently range in scale from typical aftershocks near the source region of a prior earthquake to the triggering of groundwater and deformation related anomalies possibly including other large earthquakes at locations as much as a few hundred kilometers from the source of a great earthquake observational reports of such aftereffects are reviewed and possible mechanisms for their occurrence are discussed

mineral composition vs soil forming processes in loess soils a case study from krakow southern poland abstract the mineral composition of soil parent material has a clear impact on soil formation soil properties especially chemical properties and mineral transformation in soil environment despite many studies concerning loess soils detailed quantitative studies on the mineral composition and transformation of clay minerals in loess soils formed during holocene and the influence of the mineral composition of parent material on the properties of loess soils are rare the main aims of the present study were 1 to determine the influence of loess mineral composition on soil genesis and 2 to determine layer silicate transformations and clay mineral formation in loess soils in relation to soil forming processes using qualitative and quantitative x ray diffraction analyses xrd and qxrd the obtained results show that the occurrence of carbonate minerals i e calcite and their influence on chemical properties of soil play a crucial role in the evolution of loess soils in loess that does not contain carbonates dispersion and translocation of clay particles including clay minerals down the profile occur this leads to the formation of luvisols and albeluvisols in carbonate loess clay minerals and soil organic matter form stable humus mineral complexes leading to the accumulation of humus and the formation of chernozems the transformation of mica and or smectite and or vermiculite to hydroxy interlayered minerals hims is the dominant process in the studied loess soils developed in a temperate climate because intense weathering of layer silicates is possible after removal of carbonates from soil profile this indicates that the occurrence of carbonates which maintain soil ph on a level of about 7 or higher is most likely the main factor controlling the rate of weathering of layer silicates in a loess soil environment in carbonate loess the dissolution and leaching of carbonates prevail over the weathering of silicates it is highly likely that the continuous leaching of carbonates assuming that the climate will not change will lead to more intense weathering of layer silicates