classification of huminite iccp system 1994 abstract in the new classification iccp system 1994 the maceral group huminite has been revised from the previous classification iccp 1971 int handbook coal petr suppl to 2nd ed to accommodate the nomenclature to changes in the other maceral groups especially the changes in the vitrinite classification iccp 1998 the new vitrinite classification iccp system 1994 fuel 77 349 358 the vitrinite and huminite systems have been correlated so that down to the level of sub maceral groups the two systems can be used in parallel at the level of macerals and for finer classifications the analyst now has according to the nature of the coal and the purpose of the analysis a choice of using either of the two classification systems for huminite and vitrinite this is in accordance with the new iso coal classification that covers low rank coals as well and allows for the simultaneous use of the huminite and vitrinite nomenclature for low rank coals

biomarker and carbon isotope variation in coal and fossil wood of central europe through the cenozoic abstract carbon isotope analyses of terrigenous organic matter are often used to reconstruct changes in the isotopic composition of upper ocean and atmospheric carbon reservoirs carbon isotope values from tree rings fossil wood and coal matrices have been related to climatic change e g temperature humidity via water use efficiency of land plants in this study we report on carbon isotope analyses on low rank coal deposits of the alpine realm and middle german lignite district covering the early eocene to pliocene time interval fossil wood and extracted wood cellulose from gymnosperms and angiosperms respectively are used for paleoenvironmental reconstructions the trend in 13c is parallel to the carbon isotope record obtained from benthic foraminifera because both data sets sample a common reservoir in the atmosphere the evaluation of the magnitudes of 13c variations of coal caused by environmental change requires the correction of the 13c data due to the effects of different contents of lipids in the organic matter differences in biogeochemical carbon cycling varying contributions of gymnosperms versus angiosperms to peat formation and differences in 13c of atmospheric co2 the resulting carbon isotope record of coal generally co varies with the estimated variability in mean annual temperatures during the tertiary based on paleobotanical data changes in humidity and pco2 may be responsible for deviations between the isotopic trend and the paleotemperature curve during the miocene the obtained temperature coefficient for 13c of c3 plants of about 0 3 c is in agreement with the results of previous studies

compositions sources and depositional environments of organic matter from the middle jurassic clays of poland abstract the comprehensive biomarker characteristics from previously undescribed middle jurassic clays of poland are presented the molecular composition of the organic matter om derived from clays of aalenian to callovian age has not changed significantly through time high relative concentrations of many biomarkers typical for terrestrial material suggest a distinct dominance of om derived from land plants increasing concentrations of c29 diaster 13 17 enes towards the northern part of the basin indicate an increase in terrestrial input this terrestrial material would have originated from the enhanced transport of organic matter from land situated at the northern bank of the basin i e the fennoscandian shield the organic matter was deposited in an oxic to suboxic environment as indicated by relatively low concentrations of c33 c35 homohopanes moderate to high pr ph ratio values an absence of compounds characteristic for anoxia and water column stratification such as isorenieratane aryl isoprenoids and gammacerane as well as common benthic fauna and burrows 18o measurements from calcitic rostra of belemnites suggest that the mean value of the middle jurassic sea water temperature of the polish basin was 13 1 c it is suggested that this mirrored the temperature of the lower water column because belemnites are considered here to be necto benthic the organic matter from the middle jurassic basin of poland is immature this is clearly indicated by a large concentration of biomarkers with the biogenic configurations such as hopanes hop 13 18 enes hop 17 21 enes diasterenes and sterenes the identification of preserved unaltered biomolecules like ferruginol 6 7 dehydroferruginol and sugiol in protopodocarpoxylon wood samples from these sediments present particularly strong evidence for the presence of immature om in the middle jurassic sediments moreover the occurrence of these polar diterpenoids is important due to the fact that they are definitely the oldest known natural products detected in geological samples

reassessing the rupture process of the 2009 l aquila earthquake mw 6 3 on the paganica fault and investigating the possibility of coseismic motion on secondary faults the kinematic rupture of the l aquila earthquake on the paganica fault is reassessed with a highly comprehensive set of data this very complete dataset is also used to explore the possibility that secondary faults may be involved in the coseismic process the main characteristics of the slip distribution of the paganica normal fault found by previous studies are confirmed an initial propagation around and up dip of the hypocenter associated with a high velocity rupture 3 5 km s a main asperity centered about 6 7 km southeast of the hypocenter rupturing in the subsequent stage with a maximum slip of nearly 1 5 m a total rupture measuring about 15 km along strike and 12 km along dip and an overall low average velocity rupture 2 km s the statement that the main features of the slip distribution are confirmed by different studies based on distinct inversion schemes is by itself an achievement knowing that many past studies provided strongly discrepant slip maps for common events moreover we focus specifically on the existence of slip at shallow depth and its relations with the other known active faults in the vicinity of the paganica fault we find that 1 as found in previous studies shallow slip near the ground surface up dip of the hypocenter is incompatible with the available synthetic aperture radar interferograms and 2 the only secondary fault that is likely to have been activated during the mainshock is the san gregorio synthetic fault located 2 3 km southwest of the paganica fault online material figures of waveform fitting using different velocity models time versus distance distribution of slip from the single fault model variations in the geometry of the paganica fault geometry of complex faults models and geodetic data modeling uncertainty on the slip value and the rupture time effect of noise on resolution tests quantification of the improvement on the gps data fitting with the preferred two faults model with respect to the single fault model and a posteriori modeling of leveling data

shallow subduction beneath italy three dimensional images of the adriatic european tyrrhenian lithosphere system based on high quality p wave arrival times 1 this paper presents a velocity model of the italian central mediterranean lithosphere in unprecedented detail the model is derived by inverting a set of 166 000 pg and pn seismic wave arrival times restricted to the highest quality data available the tomographic images reveal the geometry of the subduction collision system between the european adriatic and tyrrhenian plates over a larger volume and with finer resolution than previous studies we find two arcs of low vp anomalies running along the alps and the apennines describing the collision zones of underthrusting continental lithospheres our results suggest that in the apennines a significant portion of the crust has been subducted below the mountain belt from the velocity model we can also infer thermal softening of the crustal wedge above the subducting adriatic plate in the tyrrhenian back arc region strong and extensive low vp anomalies depict upwelling asthenospheric material the tomographic images also allow us to trace the boundary between the adriatic and the tyrrhenian plates at moho depth revealing some tears in the adriatic ionian subducting lithosphere the complex lithospheric structure described by this study is the result of a long evolution the heterogeneities of continental margins lithospheric underthrusting and plate indentation have led to subduction variations slab tears and asthenospheric upwelling at the present day the high resolution model provided here greatly improves our understanding of the central mediterranean s structural puzzle the results of this study can also shed light on the evolution of other regions experiencing both oceanic and continental subduction

a supershear transition mechanism for cracks seismic data indicate that fault ruptures follow complicated paths with variable velocity because of inhomogeneities in initial stress or fracture energy we report a phenomenon unique to three dimensional cracks locally stronger fault sections rather than slowing ruptures drive them forward at velocities exceeding the shear wave speed this supershear mechanism differentiates barrier and asperity models of fault heterogeneity which previously have been regarded as indistinguishable high strength barriers concentrate energy producing potentially destructive pulses of strong ground motion

very high rate 10 hz gps seismology for moderate magnitude earthquakes the case of themw6 3 l aquila central italy event accepted for publication in journal of geophysical research copyright 2010 american geophysical union

finite fault inversion of dinsar coseismic displacement of the 2009 l aquila earthquake central italy 1 we define the geometric and kinematic characteristics of the fault activated during the mw 6 3 6 april 2009 l aquila earthquake from the modeling of envisat and cosmo skymed the first ever x band interferogram inverted for a coseismic dislocation study dinsar interferograms our best fit solution for the main shock is represented by a normal fault 16 km long and 12 km wide with a small right lateral component dipping 47 sw with a maximum slip of 90 cm although the seismic dislocation probably ended at 1 km depth the updip projection of the fault plane corresponds to the northern segment of the mapped paganica s demetrio fault where alignment of surface breaks was observed in the field the absence of this fault in existing seismic source catalogues suggests that an improved approach involving detailed surface and subsurface geological and geophysical investigations is needed for a better assessment of the seismic hazard at the local scale

variance estimate in frequency domain deconvolution for teleseismic receiver function computation summary in this study the problem of estimating the receiver function variance is discussed the receiver function computation is performed through a frequency domain deconvolution oldenburg 1981 of the vertical seismogram from the radial and tangential seismograms this technique requires a knowledge of the noise contaminating the seismic signals and provides an estimate of the receiver function variance oldenburg 1981 modelled this noise as additive amnion 1992 proposed to estimate the noise level from the power spectral density in a pre signal time window in this paper this approach is used jointly with an additional inversion which yields a sequence of spikes as a model for the true receiver function the resulting residual in a time window preceding the direct p pulse is used in order to evaluate the receiver function variance and the actual noise level involved in the frequency domain deconvolution this variance estimate is compared with the one provided by oldenburg s original method the application of this method to teleseismic recordings of earthquakes 5 1 mb 6 1 with similar backazimuths and distances shows that considering the additive noise only is not sufficient to explain the uncertainty measured from the pre signal in the receiver function moreover the estimated uncertainty seems to be independent of the seismic event magnitude suggesting a signal generated noise affecting the receiver function the proposed approach provides a variance estimate for a single receiver function allowing one to assess the statistical accuracy of its amplitudes in agreement with the uncertainty involved in a stacking procedure this is particularly useful when poor quality waveforms from relatively small earthquakes mb 5 1 are analysed and data from nearly co located events are not available for stacking

low frequency and broad band source models for the 2009 l aquila italy earthquake summary the 2009 l aquila italy earthquake mw 6 3 produced an unprecedented number of seismological records for a normal faulting event and hence represents an important case study of damaging moderate magnitude earthquakes occurring in densely inhabited areas we have investigated the source process of the 2009 l aquila earthquake in both the low and broad band frequency ranges by analysing the teleseismic and strong motion data a low frequency 0 5 hz source model has been determined by waveform inversion of teleseismic and near field strong motion data yielding slip distributions with a major asperity located about 8 km southeast of the hypocentre the broad band 0 2 10 hz source characteristics were estimated using the empirical green s function method providing the strong motion generation area of about 42 km2 located southeast of the hypocentre below the village of onna this coincides with the location of the asperity from the inversion analysis indicating that the low frequency and broad band ground motions produced during the earthquake were generated at similar locations on the fault plane the position of the strong motion generation area also correlates well with the distribution of observed macroseismic mcs intensities reported by ingv the maximum macroseismic intensities of ix x were reported southeast of the epicentre with an intensity of x measured in onna the source properties of the 2009 l aquila mainshock reveal the estimated size of the strong motion generation area to be in agreement with predictions made using empirical source scaling relation for inland crustal earthquakes implying a stress drop of approximately 10 mpa this further indicates that the 2009 l aquila earthquake involved a stress drop similar to that of previously recorded earthquakes in the central and southern apennines

crustal fabric in the tibetan plateau based on waveform inversions for seismic anisotropy parameters 1 the tibetan plateau has the thickest continental crust on earth and fabrics within the crust that are anisotropic to seismic waves may provide clues to how it reached such extreme proportions and how it is currently deforming waveform modeling using a global minimization inversion technique applied to receiver functions computed from 11 stations spanning the north south length of the eastern plateau has yielded a suite of crustal models that include anisotropy these models suggest that the tibetan crust contains 4 14 anisotropy at different depths that is likely a result of both fossil fabrics and more recent deformation all models contain anisotropy in the surface layer and for most stations the alignment of the slow symmetry axis suggests a relationship with crustal fabrics associated with e w trending thrust faults or sutures middle to lower crustal anisotropy is present at most stations with a fast axis trending n s to nw se in the south nearly e w in the central plateau and n s to ne sw in the northern plateau this pattern appears consistent with recent ductile deformation due to both topographically induced flow and to boundary forces from subducting lithosphere at the northern and southern margins of the plateau the orientations of crustal anisotropy determined for most stations in this study are significantly different from shear wave splitting fast polarization directions implying distinct deformation in the crust and mantle

moho deepening and shallow upper crustal delamination beneath the central apennines abstract geologic interpretation of seismic data along the eastern half of the crop 11 deep seismic reflection profile running across the central apennines indicates that the adriatic moho deepens gradually from 34 km in the foreland areas to 47 km beneath the core of the belt this deepening is in agreement with local moho depths estimated from teleseismic receiver functions at several stations installed along the crop 11 profile on the contrary dss deep seismic soundings data image the moho at shallower depths the deepening of the adriatic moho illustrated in this paper supports the westward downgoing of a portion of adriatic continental crust and is consistent with the regional gravity anomalies provided that very high density rocks are present above the moho at the core of the central apennine belt we discuss geophysical and geologic data in the framework of alternative models of delamination of the adriatic crust at different depth

complexity of the mw 6 3 2009 l aquila central italy earthquake 2 broadband strong motion modeling 1 near fault strong ground motions 0 1 10 hz recorded during the mw 6 3 2009 l aquila earthquake exhibit great spatial variability modeling the observed seismograms allows linking distinct features of the observed wavefield to particular source and propagation effects and provides insights on strong motion complexity from this moderate magnitude event we utilize a hybrid integral composite approach based on a k square kinematic rupture model combining low frequency coherent and high frequency incoherent source radiation and providing omega squared source spectral decay several source model features proven to be stable by means of an uncertainty analysis in the preceding low frequency 2 hz

coal petrological and xylotomical characterization of miocene lignites and in situ fossil tree stumps and trunks from lusatia region germany palaeoenvironment and taphonomy assessment abstract the present paper investigates rank and composition of coal as well as depositional and hydrogeological settings persisting during the stage of peat accumulation and evaluates taphonomy and conditions for the in situ preservation of outstanding fossilized stump and trunks using coal petrological and xylotomical analyses the obtained results are further interpreted and compared with existing literature records lignite samples and fossil wood specimens were collected from the 2nd mfh 2nd miocene seam horizon or its equivalent present at meuro piskowitz and welzow sud open cast mines located in lusatia germany the examined lignite samples indicate low rank coals at lignite or subbituminous rank stage and are characterised by slight dominance of attrinite over textinite ulminite suberinite cutinite porigelinite resinite and corpohuminite macerals waterlogged conditions prevailing in the mire are associated with peat accumulation under anoxic conditions accompanied by low decomposition rates the determined facies indicators suggest a moderate to high as well as low gelification of the organic matter for the meuro and piskowitz open cast mines respectively in meuro open cast mine the prevalence of herbaceous plant in a mire or a bacterial fungal degradation of woody plant tissues can be envisaged whereas in the piskowitz open cast mine it is suggested that peat formed in a wet forest mire environment with a limited oxygen supply and a relatively low bacterial fungal degradation the studied fossil wood specimens revealed the presence of quasisequoioxylon piskowitzense preserved as an in situ fossilized stump as well as taxodioxylon cryptomerioides and sciadopityoxylon wettsteinii species preserved as fossilized trunks the examined species belong to the families of cupressacea sciadopityaceae and cupressaceae li sensu lato the taphonomy of the in situ fossilized stump and trunks can be explained by nutrient and oxygen poor oligotrophic mires distinguished as raised bogs and suggesting generally anoxic conditions during middle to late miocene climate transition

complexity of the rupture process during the 2009 l aquila italy earthquake summary in this study we investigate the rupture history of the 2009 april 6 mw 6 1 l aquila normal faulting earthquake by using a non linear inversion of strong motion gps and dinsar data both the separate and joint inversion solutions reveal a complex rupture process and a heterogeneous slip distribution slip is concentrated in two main asperities a smaller shallow patch of slip located updip from the hypocentre and a second deeper and larger asperity located southeastwards along strike direction the key feature of the source process emerging from our inverted models concerns the rupture history which is characterized by two distinct stages the first stage begins with rupture nucleation and with updip propagation at relatively high 4 0 km s 1 but still subshear rupture velocity the second stage starts nearly 2 0 2 5 s after nucleation and it is characterized by the along strike rupture propagation the largest and deeper asperity fails during this stage of the rupture process the rupture velocity is larger in the updip than in the along strike direction the updip and along strike rupture propagation are separated in time and associated with a mode ii and a mode iii crack respectively the comparison between the source models inferred in this study with the poisson ratio anomalies in the crustal volume containing the fault plane allows the interpretation of the delay in along strike rupture propagation in terms of a structural control of the rupture history our results show that the l aquila earthquake featured a very complex rupture with strong spatial and temporal heterogeneities suggesting a strong frictional and or structural control of the rupture process

from mesozoic rifting to apennine orogeny the gran sasso range italy the apennines are a low temperature accretionary prism generated by the west directed subduction of the adriatic ionian plate whose structural origin is still to be fully understood the highest and best exposed seg ment of the apennines the gran sasso range is here documented to unravel the tectonic history of the northern tip of gondwana it is located along a ne verging salient of thrust sheets decoupling the sedimentary cover of the subducting adriatic lithosphere field mapping and structural analysis along the e w trending left lateral transpressive segment of the salient highlight the interplay of the inherited mesozoic passive margin stratigraph ic and tectonic framework with the neogene contraction the rheological differences between the massive carbonate platform and the well bedded turbiditic and pelagic limestones determined along strike undulations of the thrusts geometries and fold styles during shortening heterogeneities are due to inherited syn and post rift mesozoic tectonics the gran sasso overturned anticline shows a backlimb anomalously tilted toward the foreland and we infer this dip as being related to a deeper back thrust of a triangle zone the pinching out of the foredeep sequence on the growth anticline forelimb dates the contractional phases of the region to the late messinian from the late pliocene to present the area has been uplifted and extended about 2 km by oblique normal faults cross cutting the accretionary prism some of them are seismically active as shown by the 2009 mw 6 3 l aquila earthquake

sedimentary basin exploration with receiver functions seismic structure and anisotropy of the dublin basin ireland abstractteleseismic receiver functions rfs were used to investigate the seismic structure of the southern margin of the dublin basin a potential geothermal site through an inversion based approach the elastic properties and seismic anisotropy of sedimentary basin units were examined using data from a linear array of closely spaced seismic stations our results were compared with sonic logs and lithostratigraphies from two nearby boreholes nge1 and nge2 and colocated active seismic data including a high frequency rf up to 8 hz allowed us to compute s wave velocity models with a vertical resolution 500 m the results indicated the presence of a subvertical lateral discontinuity in vs in correspondence with the main basin bounding fault blackrock newcastle fault bnf north of this discontinuity a shallow low velocity layer thickens from 0 7 to 1 0 km thick toward the inner basin in agreement with the geometry of the shallowest reflector found by active seismics a good correlation was al

control of the 2009 l aquila earthquake central italy by a high velocity structure a receiver function study 1 receiver functions rfs analyzed at two permanent broadband seismic stations operating in the epicentral area of the mw 6 3 2009 l aquila earthquake central italy yield insight on crustal structure along the fault rupture the harmonic decomposition of rfs highlights a subsurface structure in which both isotropic and anisotropic features are present we model the waveforms using recently developed monte carlo methods the retrieved models display a common depth structure between 10 and 40 km depth consistent with the under thrusting of the adria lithosphere underneath the apennines belt along the fault in the uppermost crust the s wave velocity structure is laterally heterogeneous right above the hypocenter we find a 4 6 km thick very high s wave velocity body vs as high as 4 2 km s that is absent in the se portion of the fault where the earthquake propagated the high vs body is coincident with the area of fewer aftershocks and is anticorrelated with the maximum slip patches of the earthquake as modeled by differential interferometric synthetic aperture radar dinsar and strong motion data we interpret this high vs body as a high strength barrier responsible for the high peak ground motion in the near field observed in the l aquila city and surroundings and for the complexity in the rupture evolution the retrieved seismic s wave velocity of this body far exceeds common vs values in the upper crust and it is more compatible with values observed in mafic basement rocks

possible fault plane in a seismic gap area of the southern apennines italy revealed by receiver function analysis 1 unusual features in teleseismic receiver function computed at a single three component seismic station reveal the presence of a dipping interface in the shallow crust with a pronounced seismic velocity contrast in the campania lucania region southern apennines italy the locus of this finding is the pergola melandro basin situated between the maximum intensity areas of two of the most destructive earthquakes reported in the italian seismic catalogue the m 7 0 val d agri earthquake 1857 and the ms 6 9 irpinia earthquake 1980 this area is not associated with known historical events and for this reason is currently object of investigation as a potential seismic gap where the probability of future ruptures is higher than in surrounding regions also for the static stress increase caused by the two above mentioned earthquakes through an inversion procedure applied to the computed receiver functions we are able to satisfactorily constrain the strike dip depth and velocity contrast of this crustal discontinuity whose geometric characteristics closely match those proposed by some authors for the sources of the two neighboring earthquakes we argue that the detected interface is the seismogenic source which fills the gap the findings of this study could open new perspectives both in the study of seismic gap areas and in the identification of historical earthquake sources offering a new and effective tool to locate investigate and constrain buried or unknown faults

p sh conversions in layered media with hexagonally symmetric anisotropy a cookbook reflectivity synthetic seismograms demonstrate that the type layering and orientation of 1 d anisotropy influences strongly the coda of teleseismic p waves at periods t 1 sec particularly p sh converted waves we assume the simplest form of anisotropy described by an elastic tensor with a symmetry axis of arbitrary orientation the resulting phase velocities vary as cos 2 with respect to that axis using three families of simple crustal models we compare the effects of an anisotropic surface layer with reverberations caused by both thick and thin layers of anisotropy at depth if anisotropy in the surface layer is significant the polarization of direct p can be distorted to generate a transverse component followed by ps and a prominent shear reverberation converted from direct p at the free surface if the anisotropic layer is buried the first and often the most prominent arrival on the transverse component is the p to sh conversion at its upper surface if the anisotropic layer is sufficiently thin p to sh conversions from its boundaries interfere to form a derivative pulse shape on the transverse component which could be mistaken as the signature of shear wave splitting if is horizontal compressional p and shear s anisotropy both produce similar waveform perturbations with four lobed azimuthal patterns suggesting that a weighted stack of p coda from different back azimuths would improve signal to noise for tilted between the horizontal and vertical however the effects of p and s anisotropy differ greatly the influence of p anisotropy on p to s conversion is greatest for a symmetry axis tilted at 45 to the vertical where its azimuthal pattern has two lobes rather than four combinations of p and s anisotropy typically lead to a composite azimuthal dependence in the p coda reverberations

in situ preservation and paleoenvironmental assessment of taxodiacea fossil trees in the bukkalja lignite formation bukkabrany open cast mine hungary abstract in summer 2007 sixteen taxodium tree trunks were found in situ standing position in the bukkabrany open cast mine the fossil trees were exposed during the excavation of the overburden layers of the bukkalja lignite formation bl the bukkabrany discovery is a global novum because the trees are very well preserved but not fossilized that makes the most detailed and direct analysis feasible in spite of the 7 8 million years passed the actual site and the host formation is rather intact lacking tectonic deformations deeper burial and or dewatering during uplift organic petrology of tree trunks and sedimentology of the overburden sands are the subjects of this study the extremely good preservation of fossil trunk tissues presence of high amount of cellulose and moisture content along with the slightly gelified state of the wood and the lack of deformation indicate that there was only limited alteration during the early diagenesis chemical investigation of standing trunks fossil driftwood nearby the late miocene trees and the fossil woods in the underlying lignite have revealed that their cellulose and total phenol concentrations were significantly lower than in intact recent trees applied for reference yet their preservation levels were quite high also proving that the chemical degradation of the fossil wood tissues had not been taken place extensively in the mire and the trees remained exceptionally well preserved sudden burial of the trees by strand plain sand beds indicates flooding by heavy storms or tsunamis which interrupted and terminated the peat formation and preserved the trunks from later oxidation and biodegradation

the 2009 l aquila central italy mw6 3 earthquake main shock and aftershocks 1 a m w 6 3 earthquake struck on april 6 2009 the abruzzi region central italy producing vast damage in the l aquila town and surroundings in this paper we present the location and geometry of the fault system as obtained by the analysis of main shock and aftershocks recorded by permanent and temporary networks the distribution of aftershocks 712 selected events with m l 2 3 and 20 with m l 4 0 defines a complex 40 km long nw trending extensional structure the main shock fault segment extends for 15 18 km and dips at 45 to the sw between 10 and 2 km depth the extent of aftershocks coincides with the surface trace of the paganica fault a poorly known normal fault that after the event has been quoted to accommodate the extension of the area we observe a migration of seismicity to the north on an echelon fault that can rupture in future large earthquakes

nonlinear advection aridity method for landscape evaporation and its application during the growing season in the southern loess plateau of the yellow river basin the advection aridity approach to estimate actual evaporation from natural land surfaces is one of the better known implementations of bouchet s complementary principle detailed measurements at 2 12 and 32 m above the ground surface during the growing seasons of 2004 2007 allowed validation of a generalized nonlinear form of this approach above the highly variable terrain in changwu county in the southern loess plateau of the yellow river basin in china the obtained values of the parameters were found to lie well within the ranges to be expected on physical grounds or from previous measurements by different experimental means calibration on the basis of any one year of data allowed predictions within roughly 5 on average relative to the corresponding observed turbulent vapor fluxes the evaporation rates calculated with measurements at the highest level of 32 m displayed the least scatter but only slightly less than those calculated with measurements at the lower level of 12 m however those based on measurements at the lowest level of 2 m displayed considerably more scatter than those derived at the two higher levels this is consistent with the existence of a blending height at higher elevations above the ground where the effects of surface variability tend to fade away

history of subduction and back arc extension in the central mediterranean summary geological and geophysical constraints to reconstruct the evolution of the central mediterranean subduction zone are presented geological observations such as upper plate stratigraphy hp lt metamorphic assemblages foredeep trench stratigraphy arc volcanism and the back arc extension process are used to define the infant stage of the subduction zone and its latest back arc phase based on this data set the time dependence of the amount of subducted material in comparison with the tomographic images of the upper mantle along two cross sections from the northern apennines and from calabria to the gulf of lyon can be derived further the reconstruction is used to unravel the main evolutionary trends of the subduction process results of this analysis indicate that 1 subduction in the central mediterranean is as old as 80 myr 2 the slab descended slowly into the mantle during the first 20 30 myr subduction speeds were probably less than 1 cm year x1 3 subduction accelerated afterwards producing arc volcanism and back arc extension and 4 the slab reached the 660 km transition zone after 60 70 myr this time dependent scenario where a slow initiation is followed by a roughly exponential increase in the subduction speed can be modelled by equating the viscous dissipation per unit length due to the bending of oceanic lithosphere to the rate of change of potential energy by slab pull finally the third stage is controlled by the interaction between the slab and the 660 km transition zone in the southern region this results in an important re shaping of the slab and intermittent pulses of back arc extension in the northern region the decrease in the trench retreat can be explained by the entrance of light continental material at the trench

biomarker and stable carbon isotope systematics of fossil wood from the second lusatian lignite seam of the lubstow deposit poland abstract decay of fossil wood gelification collected from the middle miocene 2nd lusatian lignite seam at the lubstow open cast mine poland is characterised by its maceral variety fluorescence intensity and cellulose content cellulose decomposition leads to lower molar h c ratio values of the organic matter as indicated by higher total organic carbon toc content of samples characterised by low cellulose content biochemical formation of hydrocarbons in the wood due to enhanced microbial activity is evidenced by higher hydrocarbon content in the extracts higher relative proportions of n alkanes and hopanoids are observed in the hydrocarbon fractions of wood remains characterised by low cellulose yield the results provide evidence for the formation of these compounds during biogeochemical transformation of organic matter hopanoid contents are considered to reflect the activity of aerobic bacteria and or fungi because of enhanced perylene content in the hydrocarbon fractions from gelified wood samples fungi are considered as the major precursor carriers of this polycyclic aromatic hydrocarbon the results provide evidence that biomarker composition of fossil wood can be used to trace biochemical transformation processes chemotaxonomical classification of fossil wood fragments as gymnosperms most probably species of the coniferales families taxodiaceae cupressaceae are based on the molecular composition of terpenoid hydrocarbons and a mean 13 c value of 24 5 depletion of gelified samples in 13 c as compared to ungelified wood is caused by the effect of progressive decomposition of cellulose the data indicate that cellulose 13 c data mean 13 c 20 8 are also affected by wood decomposition and so only samples with comparable cellulose content should be used for the reconstruction of environmental changes inter species as well as intra plant variation in carbon isotope differences and of decay resistance between cellulose and lignin have to be taken into account

fossil wood from the middle cretaceous moreno hill formation unique expressions of wood mineralization and implications for the processes of wood preservation abstract the cretaceous turonian moreno hill formation of west central new mexico provides an opportune isotaphonomic setting to study wood preservation because both carbonized and mineralized wood are commonly found within the same sediments and often within individual specimens petrographic reflectance maceral and chemical analyses were used to compare and characterize mineralized and carbonized wood from the study site to investigate biases which influence mode of preservation coal in the form of coal inclusions is the most common form of fossil wood and mineralized wood is also widespread in the formation two striking specimens of in situ coalified stumps are particularly informative because each includes a mineralized ring that appears to represent the former location of sapwood most of the mineralized samples are primarily composed of quartz but a few specimens are predominantly mineralized with apatite calcite is present in charcoal samples where it permineralized but never replaced organic carbon this study points to two key factors that influence mineralization wood permeability and the chemical alteration of the wood prior to incorporation into the sediment the patterns of mineralization are consistent with hypothesized microbial involvement in the mineralization process the coexistence of coal and mineralized tissues in some samples suggests that the processes of silicification and phosphatization co occurred with coalification and that these processes are competitive within individual pieces of wood as such various stages of wood degradation have been preserved in mineralized samples from the moreno hill formation the study suggests that coal inclusions and mineralized wood coal associations may also be common in other ancient sediments even though weathering may obscure their presence such information is important for paleoecological and paleoenvironmental studies which utilize the occurrence of fossil wood to help reconstruct floral composition or climatic conditions

lipid biomarkers in the zoige hongyuan peat deposit indicators of holocene climate changes in west china abstract lipid biomarkers extracted from a peat core obtained from the northeast edge of the tibetan plateau have provided a 13 kyr record of regional climate change a period of warmer climate corresponding to the holocene optimum between 9 ka and 5 ka is evident in greater alteration of n alkanoic acids and n alkanols and in the appearance of biomarkers indicative of greater microbial activity concomitant increases in local precipitation that raised the water level of the peat bog are recorded by increases in the proportions of c23 and c25 n alkanes that are mainly derived from submerged floating plants alternations in submergent and emergent plant n alkane proxies reveal multi decimeter scale rises and falls in the bog water level that relate to variation in precipitation on the tibetan plateau during the holocene major low water level events occurred around 12 6 11 3 10 7 9 4 8 3 6 0 4 5 3 1 2 1 and 1 0 ka these events correlate well with cold dry events recorded in same region from other climatic proxies that reflect millennial scale holocene instability in the asian monsoon system our biomarker results also indicate that peat accumulation and preservation on the tibetan plateau are more sensitive to variability in monsoonal precipitation than in annual temperature

vegetation differences and diagenetic changes between two bulgarian lignite deposits insights from coal petrology and biomarker composition abstract during the miocene numerous sedimentary basins formed on the territory of bulgaria as a result of the extensional tectonic settings related to the post orogenic development of the late alpine orogen in this study we review the petrographic composition and biomarker assemblage of two adjacent basins in western bulgaria i e beli breg and staniantsi basins both contain lignite formed during late miocene c 6 ma despite similar tectonic settings and depositional environments the lignite seams possess different petrographic and organic geochemical characteristics reflecting differences in the peat forming palaeo communities and facies variations the peat forming vegetation in beli breg basin was dominated by decay resistant coniferous plants as indicated by abundant fossil wood remains very good tissue preservation and a biomarker assemblage dominated by diterpenoids in contrast staniantsi lignite is poor in fossil wood and contains a significant amount of triterpenoid biomarkers suggesting the predominance of angiosperm plants in the swamp the results of the biomarker analyses are consistent with palaeobotanical and palynological data from the literature the lignite seams in both basins formed under frequently changing eh conditions as indicated by the severe degradation of the non gymnosperm tissues the low gelification index values and the variations in pristane phytane ratio probably as a result of seasonal drying of the swamps and changes of the ground water table hopanoid contents in beli breg lignite are very low and are consistent with the abundance of decay resistant vegetation in contrast bacterial activity was obviously higher in the staniantsi swamp however resulting only in slightly enhanced gelification of plant tissues the geochemical data suggest that the diagenetic changes of the organic matter were mainly governed by thermal degradation rather than bacterial activity

evidence from shear wave splitting for the restriction of seismic anisotropy to the upper crust the existence of anistropy in the propagation speed of seismic waves through the earth s crust has been attributed to the non random alignment of microcracks in the crust1 for sparsely distributed parallel vertical cracks perturbation theory predicts the splitting of a shear wave into two orthogonally polarized waves2 4 here we present extremely clear evidence for shear wave splitting in three component seismograms from crustal and sub crustal microearthquakes recorded in the shikoku district of japan quantitative analysis of travel time differences between split shear waves leads to the conclusion that the observed anisotropy is limited to the upper crust shallower than 10 15 km this model is consistent with recent results from reflection seismology5 and implies that microcrack density or orientation changes from the upper to the lower crust

velocity shift in heterogeneous media with anisotropic spatial correlation summary converted waves analysis is used to map the anisotropy as a function of depth in the upper mantle stacking of sv a ndt component records of several seismic events well distributed in azimuth helps to detect these converted waves weighting coe cients are used to extract the anisotropic signal in the records synthetic examples show that a harmonic analysis helps to separate azimuthal anisotropy eiects from the eiects of lateral heterogeneity such as those resultingfrom dipping structures a good azimuthal coverage of the data set is important in order to separate the diierent eiects in the stack sections obtained for diierent azimuthal orders the procedure is applied to data observed at geoscope station can and gives a model with two anisotropic layers in the upper mantle the upper layer located between the crust and a depth of140 km has its fast axis in an east west direction the lower layer 40 km thick has its fast axis in a north south direction the fast axis directions are in agreement with results obtained from surface wave analysis and tectonic information

moho depth and vp vs ratio in peninsular italy from teleseismic receiver functions 1 we present a new data set of moho depth estimates for peninsular italy obtained from receiver functions analysis and a grid search approach teleseismic records from 174 broadband seismic stations were used to compute the receiver function data set in general our results agree well with previous knowledge adding original information in many regions where previous data were lacking or uncertain we find broad regions with consistent moho depth namely 1 the peri tyrrhenian areas bordering the homonymous sea have a 20 to 25 km deep moho 2 the foreland regions adriatic apulia iblean with 30 35 km deep moho 3 the apennines belt where we find westward deepening of the adriatic moho down to 50 km depth that well delineate the westward adria subduction overlayed by the shallow tyrrhenian moho 4 calabria shows a flat 40 km deep moho suddenly dipping at high angle from the tyrrhenian coast westward defining the ionian subduction and 5 a clear separation between northern and southern apennines is marked by a region of almost flat moho possible evidence of a detached slab in between we also find that in the northern apennines the shallow tyrrhenian moho is continuous for more than 200 km from the sea to under the northern apennines with a generally flat geometry and a few undulations suggesting either the boudinage or episodic pulses of extension of the tyrrhenian crust during its pliocene quaternary stretching the eastward extent of the tyrrhenian moho below the apenninic belt approximately corresponds to the eastward extent of the observed extension in the upper crust as mapped by the normal faulting earthquakes in this portion of the apennines we interpret an intracrustal discontinuity sw dipping below the belt parallel to the adria moho as the top of the lower crust being subducted beneath the apennines the subcrustal earthquakes of this region down to 80 km depth seem to be located within this subducted crustal layer the southern apennines show the same general geometry of subduction as the northern arc although the former have a less defined on land extended region and no earthquakes in the lower crust uppermost mantle in between the central apennines present a different moho geometry no clear doubling of the two plates but rather a constant bilateral deepening possibly associated to a crustal root with no evidence of a subduction setting this reinforces the hypothesis of a detached slab in this area we also present the first large scale mapping of average crustal vp vs ratios for peninsular italy the results although representing averages over the whole crust enhance some interesting features the most evident are belts of high vp vs in the thinned crust of the apennines where extension has long been active in the quaternary probably as an effect of highly fractured rocks with abundant fluid circulation strong correlation exists between areas of high vp vs and quaternary volcanoes suggesting the presence of fluids at depth

ultra thick triassic dolomites control the rupture behavior of the central apennine seismicity evidence from magnetic modeling of the l aquila fault zone high resolution tomography from the 2009 l aquila extensional seismic sequence has shown that the mw 6 1 main shock and most of the aftershocks occurred within a high velocity body 6 6 vp 6 8 km s located between depths of 3 and 12 km the nature of the high vp body has remained speculative although exhumed mafic deep crustal and upper mantle rocks serpentinites have been favored we used 3d magnetic anomaly modeling to investigate the plausibility of these favored sources for the l aquila body the modeling does not support the presence of high velocity serpentinites with a 30 50 serpentinization degree and gabbros accordingly we conclude that the high vp body may represent non magnetic upper triassic and possibly lower liassic dolomites that have been drilled in neighboring wells for 2 4 km this conclusion is also consistent with the lack of a coherent gravity anomaly for the body we speculate that ultra thick triassic dolomites reaching a thickness of 8 km may have been deposited in syntectonic wedges formed at the northern margin of the ionian sea where oceanic spreading occurred in mid late triassic times

petrology and organic geochemistry of the lower miocene lacustrine sediments most basin eger graben czech republic abstract thirty samples of the lacustrine sediments from three localities of the most basin including coal samples were studied by petrological and organic geochemical methods the consistent results indicate the relatively stable surface development of the sediments in the environment of the holesice lom and osek members biological material with contribution of microbial activity participated in the storing which led to the formation of clayey coal in the results of the chemical composition dominated sesqui diand triterpene compounds completely different sediments of libkovice member contained low proportions of small organic particles dispersed in the sediment in the extracts of these samples prevailed hopanes perylene and sulphur after the action of microorganisms the base of the organic fraction also formed remains of terrestrial plants and liptinite macerals especially alginite liptodetrinite and bituminite that are typical for lacustrine sediments

a short term establishment of forest fen habitat during pliocene lignite formation in the ptolemais basin nw macedonia greece the intermontane basin of ptolemais is part of a major tectonic trench located in nw greece and includes around 65 of greek coal reserves the upper xylite layer uxl is a distinct lignite layer being 3 6 m thick and outcropping in the upper part of the pliocene lignite bearing sequence at the notio field and tomeas eksi mines of ptolemais compared with the xylite rich lithotypes the matrix lithotypes within uxl contain more ash micropetrographic studies suggest that the upper xylite layer is rich in huminite 90 textinite dominates in the xylite rich lithotypes while attrinite dominates in the matrix lithotypes the liptinite content is 10 while inertinite rarely occurs palaeobotanical determination revealed that the xylite rich coal originated from coniferous vegetation specifically from glyptostrobus europaeus the occurrence of g europaeus as a coal forming element is significant because though this kind of vegetation was common in many greek coals of miocene age this is the first time it has been recorded from the pliocene this study suggests that the upper xylite layer is autochthonous according to coal facies diagrammes peat accumulated under pure telmatic conditions in a relatively wet forest fen both herbaceous and arboreal vegetation contributed to peat formation

roughness dependent geographical interpolation of surface wind speed averages modele bicouche de couche limite pour le calcul regional du climat en moyenne sur une saison du vent de surface a partir des donnees de station dans la couche de surface les mesures du vent sont corrigees objectivement pour une exposition imparfaite de la station a l aide de la rugosite deduite du facteur de rafale pour chaque secteur azimutal ceci fournit a 60 m une v du vent de messechelle u m representation de blocs d etendue 5 5 km 2 le moyennage regional de u m dans la couche d eleman est effectuee par des methodes geistrophiques de similitude analyse de toutes les donnees de vent relatives aux pays bas plats a l aide d une serie de 30 ans de l indice annuel de ventosite en vue de l ajustement temporel des series non simultanees ceci conduit a une cartographie objectivement interpolee pour les vents de surface augmentee des valeurs de distribution et de v extreme extension possible de la methode a un terrain complexe

inner region humidity characteristics of the neutral boundary layer over prairie terrain radiosonde observations were carried out over prairie terrain in the flint hills region of eastern kansas during the fife first islscp field experiment international satellite land surface climatology project experiments in 1987 analysis of 13 specific humidity profiles measured under neutral conditions revealed that they can be described by a logarithmic dependency on z d0 where z is the height above the zero plane reference at 330 m above sea level and d0 26 9 m the assumed displacement height with a roughness height z0 1 05 m this logarithmic layer was found to occupy the range 52 28 z 0 z0 104 37 which is consistent with previous experimental results good agreement was obtained r 0 87 between the evaporation values derived from the radiosonde profiles and mean values determined independently at six ground stations distributed over the 15 15 km experimental region on the basis of only one profile the scalar roughness for water vapor z0 was found to be 3 to 5 orders of magnitude smaller than z0

stump horizon in the bilina mine most basin czech republic gc ms optical and electron microscopy in identification of wood biological origin article i nfo numerous coalified tree stumps remained preserved in situ in the so called stump horizon the palaeontologic horizon no 31 which represents clayey overburden of themain coal seam in the bilina open cast mine in the most basin czech republic the petrological and chemical composition palaeobotanical origin and preservation of 24 selected tree stumps were studied by optical and scanning electron microscopy and gas chromatography mass spectrometry gc ms composition of the fossil wood is dominated by ulminite particularly texto ulminite b textinite forms up to 38 vol in the decomposed tree stumps corpohuminite dominates in bark and root tissues partly gelified and deformed woody tissuescontain both corpohuminite and resinite fillings randomreflectance of ulminite ranges from 0 33 to 0 39 and carbon content from 49 wt to 78 wt samples represent pure woody material with small admixtures of clay minerals siderite and very rare pyrite observations by scanning electron microscopy revealed various levels of deformed secondary xylem with more or less swollen cell walls conspicuous tracheids uniseriate rays of a different height and round or cylinder like resin or corpohuminite bodies according to our results and other published data the wood might belong to glyptostroboxylon and taxodioxylon genera that are supposed to belong to glyptostrobus and quasisequoia plants respectively representatives of the coniferous family cupressaceae the biomarker composition in the extracts of the fossil wood includes sesquiterpenoids cedrane drimane eudesmane diterpenoids abietane fichtelite 16 h phyllocladane and their degraded compounds the terpenoids are derived from precursors produced by the source plants and microorganisms the terpenoid signatures support a relationship to the cupressaceae family with input of microbial species these characteristics were identical for all studied samples significant variations have been observed in sesquiterpenoid cedrane and diterpenoid 16 h phyllocladane contents

the formation of areally averaged roughness lengths it is argued that the best area average of the roughness length zo in heterogeneous terrain is that which if it applied in homogeneous terrain would produce the correct spatial average value of the surface stress a heuristic argument is presented to show that this effective value of z0 zeff0 can be obtained by averaging drag coefficients based on a blending height the blending height of about l 200 where l is the horizontal scale of the roughness variations is the characteristic height at which the flow changes from equilibrium with the local surface to independence of horizontal position these calculations are compared with numerical simulations of planetary boundary layer flow over variations in roughness length and show good agreement the values of surface stress which result are always greater than those which would be deduced by assuming a local flow equilibrium through the whole depth of the boundary layer for variations of z0 on short length scales zeff0 approaches the largest values of z0 within the averaging area

orogens and slabs vs their direction of subduction abstract subduction zones appear primarily controlled by the polarity of their direction i e w directed or e to nne directed probably due to the westward drift of the lithosphere relative to the asthenosphere the decollement planes behave differently in the two end members in the w directed subduction zone the decollement of the plate to the east is warped and subducted whereas in the e to nne directed it is ramping upward at the surface there are w directed subduction zones that work also in absence of active convergence like the carpathians or the apennines w directed subduction zones have shorter life 30 40 ma than e or ne directed subduction zones even longer than 100 ma the different decollements in the two end members of subduction should control different ptt paths and therefore generate variable metamorphic assemblages in the associated accretionary wedges and orogens these asymmetries also determine different topographic and structural evolutions that are marked by low topography and a fast eastward migrating structural wave along w directed subduction zones whereas the topography and the structure are rapidly growing upward and expanding laterally along the opposite subduction zones the magmatic pair calc alkaline and alkaline tholeiitic volcanic products of the island arc and the back arc basin characterise the w directed subduction zones magmatic rocks associated with e or ne directed subduction zones have higher abundances of incompatible elements and mainly consist of calc alkaline shoshonitic suites with large volumes of batholithic intrusions and porphyry copper ore deposits the subduction zones surrounding the adriatic plate in the central mediterranean confirm the differences among subduction zones as primarily controlled by the geographic polarity of the main direction of the slab the western margin of the adriatic plate contemporaneously overridden and underthrust europe toward the west to generate respectively the alps and the apennines while the eastern margin subducted under the dinarides hellenides these belts confirm the characters of the end members of subduction zones as a function of their geographic polarity similarly to the pacific subduction zones

paleoenvironmental implications from biomarker and stable isotope investigations on the pliocene velenje lignite seam slovenia a pliocene lignite seam up to 160 m thick occurs in the velenje basin slovenia the seam originated in a topogenous mire and evolved within a non marine transgressive setting differences in soluble organic matter yield and hydrocarbon content of borehole samples from the lignite are related to differences in the composition of free lipids of microbial origin and or hydrocarbons derived from the biogeochemical degradation of plant tissue variations of the redox conditions within the mire are reflected by pristane phytane ratios the abundance of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms which is consistent with palynomorphic spectra dominated by pollen of the sequoia taxodium metasequoia plant community rather than by angiosperms evidence is also provided that the content of land plant derived biomarkers and the preservation of plant tissue is controlled by the input of resin rich decay resistant conifers sections of the seam characterized by a high degree of gelification of humotelinite gelification index show high contents of hop 17 21 ene but low hopane concentrations the results suggest that the gelification of plant tissue may be governed by the activity of anaerobic rather than aerobic bacteria despite the minor variation in the proportions of gymnosperms versus angiosperms in the peat forming vegetation a general influence of the floral assemblage on carbon isotopic composition of the coals 13c 25 3 to 27 0 is proposed carbon cycling during biogeochemical decomposition of plant tissue by bacteria is assumed to affect the 13c value of the lignite petrographic and geochemical data of gelified and ungelified fossil wood provide evidence that gelification may be governed by microorganisms e g anaerobic bacteria different from those responsible for decreasing cellulose contents during early diagenetic aerobic degradation of wood based on the molecular composition of terpenoid biomarkers the wood fragments are identified as derived from gymnosperms the relative proportions of saturated versus aromatic hydrocarbon fractions of fossil gymnosperms display a general tendency towards lower values in gelified wood remains this indicates that bacteria involved in gelification of plant tissue may also be involved in aromatisation of diterpenoid hydrocarbons the chemotaxonomical classification of the macrofossils as gymnosperms is corroborated by the mean carbon isotopic compositions of the macrofossils 13c 24 5 and the extracted cellulose 13c 22 0 the higher isotopic difference of about 2 5 between cellulose and fossil wood compared to that found in modern trees can most probably be explained by the smaller effect of 13c discrimination for cellulose when compared with wood during decomposition chem geol 158 1999 121 compared with the coals the 13c values of wood and extracted cellulose are affected to a minor extent by microbial activity

convective support of long wavelength topography in the apennines italy two different free air gravity datasets from the apennines have been analysed in the frequency domain to investigate the mechanisms of support of topography at short wavelength 150 km shows that such topography is not supported by elastic stresses in the lithosphere but is dynamically supported by mantle convection the distribution of gravity anomalies and topography suggests that the mantle is rising beneath the main topographic bulge of the apennines and that this flow is maintained by buoyancy forces rather than being driven by movement of the subducted slab

paleoenvironment of the upper oligocene trbovlje coal seam slovenia abstract in the trbovlje region slovenia an upper oligocene coal seam up to 30 m thick developed in a topogenous mire and evolved within a transgressive setting the lower ash rich part of the seam unit i accumulated in a forest swamp strongly influenced by fluvial activity palynomorph spectra are dominated by taxodiaceae cupressaceae pollen ash yields decrease in the middle unit ii and upper part of the seam unit iii indicating decreasing fluvial activity an increase in cao contents reflects increasing amounts of inflowing water from an alkaline lake which progressively controlled peat hydrology in units ii and iii high sulfur contents in the nonmarine coal are a result of the carbonate rich water abundant pollen and spores from myricaceae and polypodiaceae indicate that unit ii represents a bush moor during deposition of unit iii this environment was replaced by a reed moor sapropelic coal unit iv and sapropelic shale unit v accumulated in a relatively large lake which was established by another water table rise the interpreted environmental changes are confirmed by biomarker data pristane phytane ratios reflect variations of the redox conditions within the mire and reach a minimum in the sapropelic unit iv the abundances of gymnosperm and angiosperm derived terpenoid hydrocarbons testify the predominance of gymnosperms over angiosperms during early peat stages unit i and increasing proportions of angiosperms during deposition of units ii and iii highest contents of diterpenoids coincide with maxima in the preservation of plant tissue tpi within unit i wet forest swamp suggesting that tpi is partly controlled by the input of resin rich decay resistant conifers sections of the seam characterized by advanced gelification show low steroids hopanoids ratios the results imply that gelification of plant tissue is related to increased microbial activity evidence is provided that the hopanes could be used as a measure for the activity of aerobic bacteria whereas for the hop 17 21 ene a microbial origin from anaerobic iron reducing bacteria is assumed a general influence of the floral assemblage and of varying contributions of algal biomass on carbon isotopic composition of the organic matter 13 c 24 0 to 28 1 is proposed carbon cycling during biogeochemical decomposition of plant tissue by bacteria is assumed to affect the 13 c values of the coal fossil wood collected from the seam is identified as derived from gymnosperms based on the molecular composition of terpenoid hydrocarbons this chemotaxonomical classification is corroborated by the mean carbon isotopic compositions of the fossil wood 13 c 24 0 and by the 13 c value 21 8 of the extracted cellulose from one macrofossil the low cellulose content of the sample 2 7 together with the slightly higher isotopic difference of 1 6 between cellulose and fossil wood compared to that found in modern trees can most probably be explained by the possible reversal in 13 c discrimination for cellulose when compared with wood in highly degraded samples

complexity of the mw 6 3 2009 l aquila central italy earthquake 1 multiple finite extent source inversion 1 strong ground motion recordings of the mw 6 3 2009 l aquila earthquake are analyzed by a newly proposed slip inversion technique the source model consists of multiple finite extent mufex subsources the slip amplitude rupture velocity rake and risetime are assumed constant within each subsource the size and location of the mufex subsources have to be inferred independently from other methods preferably those free of strong constraints such as constant rupture velocity over the whole fault etc here we use two published approaches satisfying such requirement the truncated singular value decomposition and the iterative multiple point source deconvolution each mufex subsource is characterized by an individual set of trial nucleation points rupture velocities and nucleation times which are grid searched for each combination of these parameters the subsources slip is determined by the least squares approach this procedure thus provides not only the best fitting model but also a whole range of acceptable models allowing for the uncertainty analysis the method is demonstrated on three synthetic tests when applied to the l aquila data both the best fitting model and the uncertainty analysis suggest that the event consisted of two major episodes one with the rupture propagating immediately after the nucleation in the updip direction the other being delayed by 3 4 s with dominant propagation toward the se along the deeper part of the fault the retrieved complexity of the rupture propagation warns against attempts to stabilize inversions by the use of a constant rupture velocity over the whole fault

rupture history of the 2009 l aquila italy earthquake from non linear joint inversion of strong motion and gps data 1 we image the rupture history of the 2009 l aquila central italy earthquake using a nonlinear joint inversion of strong motion and gps data this earthquake ruptured a normal fault striking along the apennines axis and dipping to the sw the inferred slip distribution is heterogeneous and characterized by a small shallow slip patch located up dip from the hypocenter 9 5 km depth and a large deeper patch located southeastward the rupture velocity is larger in the up dip than in the along strike direction this difference can be partially accounted by the crustal structure which is characterized by a high velocity layer above the hypocenter and a lower velocity below the latter velocity seems to have affected the along strike propagation since the largest slip patch is located at depths between 9 and 14 km the imaged slip distribution correlates well with the on fault aftershock pattern as well as with mapped surface breakages

palaeoseismology of the l aquila faults central italy 2009 mw 6 3 earthquake implications for active fault linkage summary urgent urban planning problems related to the 2009 april mw 6 3 l aquila earthquake prompted immediate excavation of palaeoseismological trenches across the active faults bordering the aterno river valley namely the mt marine mt pettino and paganica faults cross cutting correlations amongst existing and new trenches that were strengthened by radiocarbon ages and archaeological constraints show unambiguously that these three investigated structures have been active since the last glacial maximum period as seen by the metric offset that affected the whole slope alluvial sedimentary succession up to the historical deposits moreover in agreement with both 18th century accounts and previous palaeoseismological data we can affirm now that these faults were responsible for the catastrophic 1703 february 2 earthquake mw 6 7 the data indicate that the paganica san demetrio fault system has ruptured in the past both together with the conterminous mt pettino mt marine fault system along more than 30 km and causing an mw 6 7 earthquake and on its own along ca 19 km as in the recent 2009 event and in the similar 1461 ad event this behaviour of the l aquila faults has important implications in terms of seismic hazard assessment while it also casts new light on the ongoing fault linkage processes amongst these l aquila faults

structural architecture of the central apennines interpretation of the crop 11 seismic profile from the adriatic coast to the orographic divide 1 we present an interpretation of the eastern half portion of the crop 11 line a deep reflection seismic profile 265 km long that cuts across the central apennines from the tyrrhenian coast to the adriatic coast in the study area the line cuts across a pile of thrust sheets that underwent tectonic transport between the messinian and the pleistocene in its easternmost part the line runs through the plio pleistocene deposits of the adriatic foredeep in the foreland region the crop 11 line integrates previous information on the crustal structure derived from petroleum exploration and from deep seismic sounding refraction experiments in particular the crop 11 line confirms the existence of a very thick sedimentary sequence underlying the mesozoic tertiary carbonates of the apulia platform interpreted as the paleozoic triassic sedimentary cover of a pre cambrian crystalline basement in the mountain chain where the base thrust of the orogenic wedge reaches a depth of about 25 km this sedimentary sequence appears to be the deepest geological unit incorporated in the thrust system this interpretation of the crop 11 profile suggests an unusual thin skin tectonic style implying the detachment from the original basement and the incorporation in the post tortonian tectonic wedge of a very thick paleozoic triassic sedimentary sequence possibly affected by low grade metamorphism in the lower part other new suggestions from the crop 11 seismic data concern the origin of the fucino basin one of the most remarkable plio pleistocene intramontane basins the normal faults bordering this structural depression as other important normal faults present in the central apennines e g the caramanico fault system in the majella region seem to have been controlled by gravitational collapse processes driven by uplift during crustal shortening rather than by a generalized extension subsequent to the apennine compression as usually reported in the geological literature if this interpretation is correct the strong seismic activity in correspondence to the apennine watershed may be related to the very recent increase in the structural relief caused by an out of sequence propagation of the active thrusts

coseismic and initial post seismic slip of the 2009 mw 6 3 l aquila earthquake italy from gps measurements summary here we report the preliminary results of gps data inversions for coseismic and initial afterslip distributions of the mw 6 3 2009 april 6 l aquila earthquake coseismic displacements of continuous and survey style gps sites show that the earthquake ruptured a planar sw dipping normal fault with 0 6 m average slip and an estimated moment of 3 9 1018 nm geodetic data agree with the seismological and geological information pointing out the paganica fault as the causative structure of the main shock the position of the hypocentre relative to the coseismic slip distribution supports the seismological evidence of southeastward rupture directivity these results also point out that the main coseismic asperity probably ended downdip of the paganica village at a depth of few kilometres in agreement with the small 1 10 cm observed surface breaks time dependent post seismic displacements have been modelled with an exponential function the average value of the estimated characteristic times for near field sites in the hanging wall of the fault is 23 9 5 4 d the comparison between coseismic slip and post seismic displacements for the first 60 d after the main shock shows that afterslip occurred at the edges of the main coseismic asperity with a maximum estimated slip of 25 cm and an equivalent seismic moment of 6 5 1017 nm the activation of the paganica fault spatially intermediate between the previously recognized main active fault systems suggests that strain accumulation in the central apennines may be simultaneously active on distinct parallel fault systems

structural features of the subducting slab beneath the kii peninsula central japan seismic evidence of slab segmentation dehydration and anisotropy 1 seismic evidence of lithospheric slab segmentation dehydration and anisotropic rocks beneath the kii peninsula central japan is detected with receiver function rf analyses by stacking radial and transverse rfs with moveout perturbations we estimate the downdip azimuth dip angle and depth of the slab moho beneath each seismic station comparing the downdip azimuth to the slab convergence azimuth we can classify the slab into three segments the segments correspond to both the fault zones of past megathrust earthquakes and to the spatial distribution of intraslab seismicity the slab moho lies just above the intraslab seismicity in the southwestern kii peninsula slab moho lies deeper at the eastern part of the peninsula at the bottom of seismicity this suggests that earthquakes occur only within the slab mantle under the southern kii peninsula the dip angle of slab moho becomes steeper at 40 to 50 km depth perhaps caused by dehydration transformation of basalt to eclogite at some stations located in the western part of the kii peninsula rf estimated dip angle of the interface is much steeper than that estimated by spatial trends in seismicity since the local seismicity distribution reflects well the larger scale geometry of the slab the rf estimated dip angle may imply anisotropic wave speeds within strongly sheared and or hydrated media around the slab moho these detailed features of the slab may be one key in distinguishing the source regions of megathrust earthquakes in the nankai region

chemical evolution of miocene wood example from the belchatow brown coal deposit central poland abstract miocene conifer wood samples from the belchatow brown coal deposit in poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification petrographic analysis ultimate analysis electron microprobe technique and ftir spectroscopy were used in this study our data show several progressive trends in functional groups distribution that take place during the wood transformation from group 1 to group 4 such as an overall increase in aromaticity an increase in lignin cellulose ratio and an increase in oxygen functionalities other observations include an increase in aliphatic stretching and bending functionalities from groups 1 to 3 followed by a decrease in the wood of group 4 appearance of aliphatic out of plane bands in group 3 and increase in group 4 an increase in ch2 ch3 in group 4 compared to the other groups and decrease in o h groups in group 4 compared to other groups these observations together with other chemical and petrological observations indicate that the progressive elimination of cellulose and modification of lignin are dominant processes of the wood transformation

the 2009 l aquila earthquake central italy a source mechanism and implications for seismic hazard an edited version of this paper was published by agu copyright 2009 american geophysical union

parameters determining the carbon isotopic composition of coal and fossil wood in the early miocene oberdorf lignite seam styrian basin austria abstract petrographical and geochemical data of gelified and ungelified fossil wood from the early miocene oberdorf lignite seam styrian basin austria provide evidence that the early diagenetic aerobic degradation of wood by fungi may be followed by further decomposition under reducing conditions by the activity of anaerobic bacteria based on the molecular compositions of terpenoid hydrocarbons the wood fragments in the lignite are identified as gymnosperms this result is corroborated by the mean isotopic composition 13c 24 2 of the macrofossils the isotopic difference between fossil wood and extracted cellulose of most samples 3 9 2 5 is higher than in modern trees which can be explained by the smaller effect of 13c discrimination during decomposition of cellulose when compared with wood the mean carbon isotope values found for gymnosperms and coals 24 2 and 24 7 respectively confirm the results from biomarker analyses indicating that the peat forming vegetation of the oberdorf seam was dominated by gymnosperm taxa minor variation in the relative contributions of gymnosperms and angiosperms to coal deposition is of negligible influence on the isotopic composition of the coals cross correlations between 13c of the coals soluble organic matter yield and the proportions of liptinite macerals of higher plant origin imply that the carbon isotopic composition may be affected by the contents of plant lipids because of their 13c values ranging from 5 to 10 less than whole plant tissue values an isotopic shift of the coals towards more negative values due to the activity of prokaryotes i e anaerobic bacteria in organic matter degradation is proposed the results obtained from the early miocene oberdorf lignite indicate that the carbon isotope ratios of the coals are primarily affected by varying contributions of different parts of whole plant tissue due to their different isotopic and molecular compositions e g epicuticular leaf waxes resins wood and their different decay resistance against the early diagenetic changes involved in organic matter decomposition carbon cycling during anoxic decomposition of plant derived organic matter is assumed to affect the 13c values of coal 13c values of wood and extracted cellulose are affected only to a minor extent

vascular plant biomarkers as proxies for palaeoflora and palaeoclimatic changes at the dogger malm transition of the paris basin france abstract vascular plant biomarkers are used here as a chemostratigraphic tool for tracing both palaeoflora and palaeoclimatic changes during the callovian and oxfordian in the paris basin the retene cadalene ratio shows low values in claystones from the middle callovian to the end of the lower oxfordian then increases drastically from the end of the lower oxfordian cordatum zone synchronously with the progressive development of the oxfordian carbonate platform the relative proportion of retene a conifer biomarker is strongly correlated with the abundance of some of its diagenetic precursors and with saturated diterpanes some of these are very common and abundant in the pinaceae family while specific markers for non pinaceae conifers are not detected thus the increase in the retene cadalene ratio around the cordatum zone reflects the rising proportion of pinaceae on the london brabant massif which was the nearest land from the locations studied as pinaceae show many morphological adaptations to dry climate compared to the other plants reported in the jurassic taphofloras of the paris basin their increasing proportion indicates an increasing aridity this climatic change is also supported by published geochemical palaeobiogeographical palynological palaeobotanical and mineralogical data a comparable increase in the relative proportion of retene was also described for the oxfordian of western australia which could be an argument for a worldwide increase in aridity at the end of the lower oxfordian

finite element inversion of dinsar data from the mw 6 3 l aquila earthquake 2009 italy 1 fault slip distribution is usually retrieved from geodetic data assuming that the local crust is an elastic homogeneous and isotropic half space in the last decades spatially dense geodetic data e g dinsar maps have highlighted complex patterns of coseismic deformation that require new modeling tools such as numerical methods able to represent rheological and geometrical complexities of the earth s crust in this work we develop a procedure to perform inversion of geodetic data based on the finite element method accounting for a more realistic description of the local crust the method is applied to the 2009 l aquila earthquake mw 6 3 using dinsar images of the coseismic displacement results highlight the non negligible influence of the medium structure homogeneous and heterogeneous models show discrepancies up to 20 in the fault slip distribution values furthermore in the heterogeneous models a new area of slip appears above the hypocenter we also perform a resolution study showing that the information about fault slip distributions retrieved from geodetic data should be considered as averaged on surrounding patches

nuclear magnetic resonance studies of ancient buried wood i observations on the origin of coal to the brown coal stage various wood fragments buried in sediments under anaerobic conditions for from 450 yr to approximately 8 myr have been examined by solid state 13c nuclear magnetic resonance cellulose and other carbohydrates the major components of holocene wood have been shown to be gradually hydrolyzed or otherwise lost under the conditions of burial lignin structures however are preserved relatively unchanged and become concentrated by difference as the carbohydrates disappear thus a fragment of coalified wood isolated from a miocene brown coal was found to be still composed of approximately 75 lignin and 25 cellulose on the basis of our observations we suggest that coalification of woody tissue progresses directly from lignin to coal and that such coalification may be retarded until most of the cellulose disappears

crustal structure and moho depth profile crossing the central apennines italy along the n42 parallel 1 we present results from a teleseismic receiver function study of the crustal structure in the central apennines italy data from 15 stations deployed in a linear transect running along the n42 parallel were used for the analysis a total number of 364 receiver functions were analyzed the crustal structure has been investigated using the neighborhood algorithm inversion scheme proposed by sambridge 1999a obtaining crustal thicknesses bulk crustal vp vs ratio and velocity depth models in each inversion the degree of constraint of the different parameters has been appraised by the bayesian inference algorithm by sambridge 1999b the study region is characterized by crustal complexities and intense tectonic activity recent volcanism orogenesis active extensional processes and these complexities are reflected in the receiver functions however the relatively close spacing among the seismometers about 20 km helped us in the reconstruction of the crustal structure and moho geometry along the transect crossing the apennines from west to east the moho depth varies by more than 20 km going from a relatively shallow depth around 20 km on the tyrrhenian side deepening down to about 45 km depth beneath the external front of the apenninic orogen and rising up again to about 30 km depth in correspondence of the adriatic foreland despite the strong variability of the crustal thickness the average crustal vs values show little variation along the transect fluctuating around 3 km s the average vp values obtained from the vs and vp vs are generally lower than 6 km s