mechanical significance of structural patterns identified by remote sensing studies a multiscale analysis of tectonic structures in crimea abstract based on remote sensing analyses of two panchromatic spot scenes that cover the western and eastern parts of crimea completed with the study of landsat thematic mapper scenes and local aerial photographs we determined the geometry of major structures folds and fractures the strikes of large fractures are quite homogeneous in the studied area three important sets are common n10 ne sw and nw se two strikes are particularly developed in the western part of crimea n25 and n105 along important faults we recognised the sense of motion which often corresponds to the latest or to the major stages of movement we also determined stress tensors by inversion of microtectonic data sets collected in the field combining remote sensing analysis with mechanical studies provides new views on the structural evolution of crimea we thus characterised major tectonic events responsible for most of the deformation in eastern crimea the structural patterns fit well with two major tectonic events 1 the latest one is a plio quaternary faulting event normal slip along n10 faults and strike slip motion along n10 and nw se faults corresponding to a transtensional regime with 3 trending e w 2 large fractures nw se and ne sw sets and fold and thrust development reveal a transpressional regime with 1 trending nne ssw during the berriasian in western crimea we characterised a more complex pattern of four major tectonic events 1 the plio quaternary tectonic phase induced left lateral displacement along nw se faults and normal slip along wsw ene faults and this deformation is in agreement with the strike slip regime that we reconstructed with 3 trending nne ssw 2 as for eastern crimea the berriasian phase was well expressed with folds thrusts and strike slip faults under a transpressional regime with 1 trending n s to nnw sse the two other events well identified in western crimea are 3 a n s directed extension that developed large n105 faults and 4 a nw se directed extension involving ne sw normal faults that we relate to the development of peripheral troughs in the oligocene western crimea suffered a more complicated structural evolution than eastern crimea from eastern to western crimea we also noticed the systematic deviation in the trends of the principal stress axes of the recent stress field and in the berriasian stress field as well these differences may be related to the presence of a major crustal discontinuity the transverse alushta simferopol fault

analyzing rockfall activity 1600 2002 in a protection forest a case study using dendrogeomorphology for the first time dendrogeomorphology has been used to investigate spatial and temporal variations of rockfall activity in a protection forest we report results of 564 cores from 135 severely injured larix decidua mill trees on the west facing taschgufer slope swiss alps while trees sampled reached an age of 297 years on average the oldest one attained breast height in ad 1318 for reasons of sample depth the analysis was limited to the period 1600 2002 in total we reconstructed 741 growth disturbances gd during the last four centuries impacts were most commonly found in trees located in the southern part of the slope where gd recurred more than once per decade in contrast trees in the northern part were less frequently disturbed by rockfall and define recurrence intervals of more than 150 years throughout the last four centuries rockfall has caused gd to the trees sampled on the taschgufer slope most frequently in the form of low magnitude high frequency events in addition we identified one high magnitude low frequency event in 1720 which displaced the forest fringe of the northern sector a considerable distance downslope and eliminated an entire forest stand to analyze past rockfall activity we introduce a brateq defined as the number of impacts per meter width of all tree surfaces sampled per decade results clearly demonstrate that this rockfall brateq continually decreased in both sectors after the large 1720 rockfall event significantly low rockfall bratesq can be observed during the 1850s 1960s and 1970s in the northern and during the 1820s in the southern sector in contrast high rockfall bratesq were identified during the 1870s and 1990s in the northern and during the 1770s in the southern sector reconstructed data further show that the forest recolonizing the southern sector after the 1720 event gradually improved its protective function reducing bratesq by a factor of 13 between the 1740s and the 1990s in the recent past bratesq oscillated around 0 7 gd 1 meter width 1 10 years 1 in the well established forest of the northern sector the efficacy of the protective forest was temporarily reduced by the rockfalls in 1720 resulting in increased rockfall bratesq since then the protective

impacts of age dependent tree sensitivity and dating approaches on dendrogeomorphic time series of landslides different approaches and thresholds have been utilized in the past to date landslides with growth ring series of disturbed trees past work was mostly based on conifer species because of their well defined ring boundaries and the easy identification of compression wood after stem tilting more recently work has been expanded to include broad leaved trees which are thought to produce less and less evident reactions after landsliding this contribution reviews recent progress made in dendrogeomorphic landslide analysis and introduces a new approach in which landslides are dated via ring eccentricity formed after tilting we compare results of this new and the more conventional approaches in addition the paper also addresses tree sensitivity to landslide disturbance as a function of tree age and trunk diameter using 119 common beech fagus sylvatica l and 39 crimean pine pinus nigra ssp pallasiana trees growing on two landslide bodies the landslide events reconstructed with the classical approach reaction wood also appear as events in the eccentricity analysis but the inclusion of eccentricity clearly allowed for more 162 landslides to be detected in the tree ring series with respect to tree sensitivity conifers and broad leaved trees show the strongest reactions to landslides at ages comprised between 40 and 60 years with a second phase of increased sensitivity in p nigra at ages of ca 120 130 years these phases of highest sensitivities correspond with trunk diameters at breast height of 6 8 and 18 22 cm respectively p nigra this study thus calls for the inclusion of eccentricity analyses in future landslide reconstructions as well as for the selection of trees belonging to different age and diameter classes to allow for a well balanced and more complete reconstruction of past events

a moderate melting model for the voring margin norway based on structural observations and a thermo kinematical modelling implication for the meaning of the lower crustal bodies high p wave velocities 7 1 7 8 km s lower crustal bodies lcbs imaged along volcanic margins are commonly interpreted as plume and breakup related thick mafic underplating this interpretation is partly challenged in this paper based on new seismic observations and modelling of the outer voring basin norway an exceptional strong amplitude reflection the t reflection is particularly well defined below the north gjallar ridge ngr between 7and 8 s twt the t reflection is located near the volcanic lava flows emplaced during the ne atlantic breakup 55 54 ma ago and coincides with the top of the lcb forming a mid crustal dome based on structural and temporal relationships we show that the dome clearly influences the structural development of the ngr and predates the continental breakup at least by 10 15 ma using a thermo kinematical model we tried also to investigate and quantify the relationships between the extension lcb and the magmatic production modelling suggests that significant paleocene early eocene magmatism can be produced without any temperature anomaly in the mantle if differential stretching occurs during the breakup initiation the conclusion of 2d thermo kinematical parametric analysis is that the magmatic model predicts either little extension 5 with significant melting along the outer voring basin we suggest that the continental part of the lcb could not necessarily be breakup related and so magmatic as has often been stated previously it is concluded here that the continental part of the lcb observed beneath the outer voring basin may be partly or fully attributed to inherited high pressure granulite eclogite lower crustal rocks the real amount of mafic material emplaced along the outer voring basin could be 20 40 less than thought

the morphology and dynamics of low amplitude bedwaves upon upper stage plane beds and the preservation of planar laminae experimental studies of subcritical unidirectional flow over upper stage plane beds of medium grained sand reveal the ubiquitous presence of low amplitude bedwaves flow depth was 0 11 m mean flow velocities were 0 86 1 0 m s 1 shear velocities were 0 058 0 71 m s 1 and dimensionless shear stresses were 0 56 0 87 bedwaves are asymmetrical in profile and range from 0 75 to 11 mm in height mainly 2 6 mm from 0 7 to 1 3 m in wavelength and have mean celerities of 10 mm s 1 flow records suggest that the bedwaves are associated with accelerating flow over the bedwave crests and flow which decelerates and diverges laterally over the troughs high resolution bed profiling during aggradation of the bed combined with subsequent box coring illustrates that these bedwaves are responsible for the planar laminae characteristic of upper stage plane beds lamina preservation is dependent upon the mean aggradation rate and the sequence of bedwaves of different height crossing any point individual laminae are more readily preserved at higher aggradation rates where the possibility of reworking by later bedwaves is reduced laminae are recognized by small changes in grain size and commonly a fining upwards at the top of laminae which is generated by fine grained material infiltrating a lower lamina in the leeside of a bedwave

time constraints for the evolution of a large slope collapse in karstified mountainous terrain of the southwestern crimean mountains ukraine abstract deep seated gravitational deformations are significant denudational agents of rock slopes at the margins of karstified plateaus of the crimean mountains ukraine the aim of this article is to study long term evolution of a giant rock slope failure close to the black sea coast in the southwestern tip of the mountains near foros town the failure evolved in highly anisotropic limestones overlying plastic flysch layers where the main headscarp follows a strike slip fault we tested a new chronological strategy based on 14 c and u th series dating of speleothems from unroofed caves exposed in the headscarp area of the slope failure this approach made it possible to state maximum age of the slope collapse in individual parts of the deformed slope obtained results indicate that extension of discontinuities together with their karstification can be traced to 300 ka bp whereas evolution of the main headscarp started 110 ka bp and since then it has propagated in the eastward direction the youngest slope failure in the easternmost part of the studied collapse is of late holocene age our study indicates that conditions for large rock slope failures in carbonate areas can be prepared by speleogenesis or combined effects of propagation of cracks and their solution based expansion furthermore large rock slope failures can be important factors for the genesis of unroofed caves

dendrogeomorphic reconstruction of past snow avalanche events in bâlea glacial valley făgăras massif southern carpathians romanian carpathians abstract snow avalanches are a major hazard in the southern carpathians romanian carpathians and cause damage to transportation routes or infrastructure and losses of human lives in these mountains the scientific understanding of avalanches is still poor the main objectives of this study were to reconstruct spatio temporal patterns of avalanche events to complement written records in the b lea glacial valley located in the central part of northern slope of the f g ras massif and to identify the winter weather conditions responsible for avalanche occurrence using a dendrogeomorphologic approach the analysis was based on tree ring series from 293 affected picea abies trees in four avalanche tracks our results from tree ring records yielded 24 and 17 snow avalanches in the 1867 2012 chronology in first and second track 24 and 12 snow avalanches in the 1870 2012 chronology in third and in fourth track the tree ring based analysis of the 586 extracted increment cores allowed the identification of 853 growth disturbances related to past avalanche activity the most frequent response is found as reaction wood 64 1 followed by abrupt growth changes 20 6 traumatic resin ducts 13 and callus tissue 2 3 a total of 77 event years with aai 10 were reconstructed the reconstruction revealed five high magnitude avalanches aai 30 25 medium magnitude avalanches 20 aai 30 and 47 small magnitude avalanches 10 aai 20 the return period values vary between 16 7 and 23 6 years based on the reconstructed chronologies our analyses identified 13 cases of synchronicity of events with aai 10 this synchronicity indicates the decisive role of local weather conditions which are responsible for the occurrence of extreme snow avalanches the weather conditions triggering extreme avalanche correspond with high amounts of snowfall and consequently thick snowpack even if the largest snowfalls are not necessarily associated with extreme avalanches

reconstructing recent landslide activity in relation to rainfall in the llobregat river basin eastern pyrenees spain abstract a chronology of recent landslides in the upper basin of the llobregat river eastern pyrenees has been reconstructed from technical reports field reconnaissance and dendrogeomorphological analysis the precipitation conditions responsible for triggering and reactivating landslides have been deduced by analysis of rainfall records from two rain gauges located in the area two different rainfall patterns relate to landslide occurrence i without antecedent rainfall high intensity and short duration rains trigger mostly debris flows and shallow slides developed in colluvium and weathered rocks a rainfall threshold of around 190 mm in 24 h initiates failures whereas more than 300 mm in 24 48 h are needed to cause widespread shallow landsliding ii with antecedent rain moderate intensity precipitation of at least 40 mm in 24 h reactivates mudslides and both rotational and translational slides affecting clayey and silty clayey formations in this case several weeks and 200 mm of precipitation are needed to cause landslide reactivation dendrochronological analysis shows that landslide activity in the eastern pyrenees was relatively low between 1926 and 1959 but has since increased significantly with reactivation now occurring about every 3 years

tree ring dated landslide movements and their relationship to seismic events in southwestern montana usa abstract to determine periods of incremental landslide movement and their possible relationship to regional seismic events the tree ring records of 32 tilted and damaged conifers at three sites on landslides in the gravelly range of southwestern montana were examined several signs of disturbance in the tree ring record indicating landslide movement were observed commonly the tree ring record displayed a marked reduction in annual ring width and or the reaction wood formation the tree ring records from the three landslide sites indicate multiple periods of movement during the 20th century many of the periods of movement indicated by the strongest signals most trees at the sites occurred the year following significant earthquakes in the region those seismic events for which evidence in the tree ring record was found at one or more of the three sites are the 1983 borah peak 1959 hebgen lake 1935 helena 1925 clarkson and 1908 virginia city earthquakes this study suggests that many of the landslide movements were triggered by or are coincident with earthquakes as much as 200 km from the study area

the dating of bedrock landslide reactivations using dendrogeomorphic techniques the mazak landslide outer western carpathians czech republic landslides predisposed by the anisotropy of flysch bedrock are typical features of mass movements affecting the outer western carpathians a dendrogeomorphic investigation involving an extensive dendrometric n 1680 survey and tree ring analysis of 176 norway spruce trees picea abies l karst was used to reconstruct the spatial and temporal activity of the mazak landslide situated in the highest part of the czech outer western carpathians as revealed by geomorphic analysis and electrical resistivity tomography the landslide is a translational medium depth 30 m bedrock feature originating at the intersection of inclined bedding planes with diagonal nw nnw striking and longitudinal ne striking sets of joints and faults a tree ring analysis shows nine major landslide years 1929 1940 1949 1960 1972 1980 1985 1997 2000 accompanied by six additional years with minor reactivations 1933 1945 1955 1958 1977 1996 during the past hundred years 1912 2011

the effectiveness of dendrogeomorphic methods for reconstruction of past spatio temporal landslide behaviour abstract dendrogeomorphic methods are in fact frequently used for spatio temporal landslide behaviour reconstruction however their real accuracies have not yet been deeply evaluated the purpose of this study is to evaluate the effectiveness and accuracy of tree ring based methods by comparing them with field monitoring data on landslide behaviours a total of 876 increment cores have been extracted from 219 p sylvestris individuals to reconstruct the past spatio temporal activity of the ubietova landslide 1977 the landslide re activation events recorded within the tree ring series of each tree have been spatially interpolated those data have been compared with the long term field monitoring based on the measured changes in the stabilized geodetic point positions in general the tree ring based spatio temporal landslide evolution revealed a higher landslide activity than the monitoring based one particularly in the lower part of the landslide however higher activity was recorded from the monitoring in the northern part of the upper half of the landslide while approximately 30 of the studied landslide area revealed highly similar normalized values based on both approaches the best fit between the results 80 was in areas with mean cumulative surface displacements of approximately 200 mm monitoring based results and mean event recurrence time of 14 5 years tree ring based results the potential sources of uncertainties that should be considered in future dendrogeomorphic research are the irregular spatial positions and spatial density of trees the physiology of the tree species the inertia of tree growth responses within tree ring sequences and the type of studied landslide

the bouma division a and the possible duration of turbidity currents abstract experimental data arnott and hand 1989 combined with theoretical arguments suggest that the transition in a turbidite from division a to division b occurs at a deposition rate of unsupported grains of about 6 7 10 4 m s 1 in the case of fine medium quartz sand a second rate may be calculated from properties measured at the transition from division b to division c allen 1971b these rates together permit an estimate to be made of the order of magnitude of the duration of deposition from a turbidity current the calculated order of a few tens of minutes for a mio pliocene turbidite described and interpreted hydraulically by komar 1985 is in broad agreement with his independent estimate based on the sequenc of sedimentary structures

relationship between diagenesis and reservoir quality in sandstones of the garn formation haltenbanken mid norwegian continental shelf a quantitative model is proposed for the dependence of porosity and permeability on diagenesis in subarkosic arenites of the middle jurassic garn formation porosity variation is controlled by the combined effects of compaction and quartz cementation in general more porosity has been lost by compaction than by quartz cementation but compactional porosity loss appears to have occurred relatively early in the burial history before burial below 2 km below the sea floor thus progressive reduction of the total porosity with increasing burial below 2 km results mainly from quartz cementation permeability is a function of the abundance of intergranular macroporosity which is interpreted to be a measure of effective porosity at depths less than 3 5 km below the sea fl or intergranular macroporosity generally comprises more than 50 percent of the total porosity but at greater depth as total porosity decreases below about 16 percent the ratio of effective to ineffective porosity drops below one this depth corresponds to the onset of extensive illitization and grain dissolution which results in major reorganization of the pore system generation of secondary porosity by feldspar dissolution appears not to have been beneficial to reservoir quality in the garn formation but it is regarded as an intrinsic part of the overall process of porosity destruction with increasing diagenesis

tree ring eccentricity in the dendrogeomorphic analysis of landslides a comparative study abstract the chronological aspects of landslide research are of great interest regarding the hazard assessment of landslide triggers dendrogeomorphic methods provide a good ratio of chronology length and dating resolution an alternative to the standard dendrogeomorphic approaches used in landslide research based on reaction wood analysis a reaction to stem inclination is the analysis of tree ring eccentricity this study tests three frequently used dendrogeomorphic approaches based on tree ring eccentricity and verifies the results by comparing them with the results obtained by the standard dendrogeomorphic expert approach in total 125 individual fagus sylvatica l trees growing on the block type landslide of lipova stra in the foothills of the orlicke hory mts central europe were sampled and used for the analysis the first tested approach identifies landslide signals based on the analysis of mean eccentricity values from two moving windows the second tested approach determines landslide signals from a series of eccentricity values based on the use of an eccentricity threshold from reference trees the last tested approach organizes the eccentricity values into categories and identifies landslide signals based on the defined temporal patterns of the individual categories the limitations of each approach are revealed and recommendations for increasing the robustness of each approach are presented moreover the sensitivity of f sylvatica trees to landslide signals was tested using each approach the obtained results suggest the need for a specific sampling design regarding tree age for each tree ring eccentricity based approach

origin and growth mechanism of authigenic chlorite in sandstones of the lower vicksburg formation south texas abstract authigenic chlorite occurring as grain coatings pore fillings and rosettes is common in deltaic sandstones of the lower vicksburg formation in south texas chlorite rosettes are isolated and occur late in the diagenetic history whereas grain coating and pore filling chlorite occur early predating the development of secondary porosity and the precipitation of quartz overgrowths and fe poor calcite grain coating and pore filling chlorite which are interstratified with approximately 15 percent 7 a layers are fe rich with a mean fe fe mg ratio of 0 68 stable isotope data 18o averages 13 5o oo smow indicate that the grain coating and pore filling chlorite began precipitating between 20 c to 40 c within the upper 1 8 km 6000 ft of burial sandstones of the lower vicksburg formation were deposited in a relatively shallow deltaic environment as part of a large fluvial system draining the volcanics of sierra madre occidental mexico and trans pecos texas weathering of these volcanics brought large amounts of particulate fe to the river mouth an increase in salinity in the distributary channel complex caused fe flocculation and deposition during periods of high river discharge or when coastal currents acted to concentrate particulate fe large amounts of particulate fe were deposited in the delta system this resulted in thick layers of fe rich clay odinite around grains during periods of low river discharge or when coastal currents caused wide distribution of particulate fe less particulate fe was deposited it is proposed that the grain coating and pore filling chlorite began forming through the transformation of an fe rich clay precursor in the formation water hydropressure zone following ostwald processes the presence of this synsedimentary fe rich clay and its recrystallization to fe chlorite strongly influenced fluid flow and played a large role in developing the diagenetic heterogeneity seen in lower vicksburg sandstones today

spatio temporal analysis of a complex landslide in the northern apennines italy by means of dendrochronology dendrochronology is used to determine the spatial and temporal development of movements in a complex landslide located in the northern apennines the analysis of trees growing on the landslide body enabled us to date their colonisation pattern which starts from the 1920s and increases mainly after 1950 since then sampled trees recorded with growth anomalies the movements involving the landslide body in 1956 1957 1982 1983 1990 1995 and 1998 these movements are reactivations of the main landslide that probably occurred in the last decades of the 19th century in 1980 trees on the upper landslide body were involved in a rock fall due to the expansion of the main scarp microsections cut out from selected tree ring sequences allowed seasonal dating of the highlighted movements which mostly occurred in early spring meteorological and seismic time series were analyzed in order to relate them with reactivations and to search for correlations and triggering events the seismic activity although characterized by low magnitudes could be able either to trigger the movements 1990 or to destabilize the ground where rainfalls could have been playing the first role in triggering the reactivation probably in 1982 1983 and 1995 the other reactivations seem to be linked either to long lasting rainfalls or to monthly rainfall peaks mostly following dry periods

spatial and temporal analysis of mass movement using dendrochronology tree growth and inclination on sloping land is affected by mass movement suitable analysis of tree growth and tree form can therefore provide considerable information on mass movement activity this paper reports a new automated method for studying the temporal and spatial aspects of mass movement activity ringwidth data from only a few cores per tree are required the method uses filtering techniques and statistical time series analysis preliminary results for two landslides in the barcelonnette area of the french alps show a relative stability of movement activity over the last hundred years no trend and short periodicity six to seven year periods of mass movement activity the advantages of the method over other mostly visual methods are its clearness flexibility repeatability and rapidity however further testing is needed to examine its reliability

climate change increases frequency of shallow spring landslides in the french alps in this contribution past process activity is reconstructed on seven landslide bodies of the riou bourdoux catchment southeastern french alps based on an unusually dense data set of 3036 tree ring series extracted from 759 conifers we provide evidence for 61 landslide reactivations since a d 1898 based on logistic regressions and threshold analyses of monthly rainfall data and temperature anomalies we determine that the combination of snow rich winters and positive temperature anomalies in spring enhanced snowmelt seems to have driven landslide reactivations in the past since the early 1990s however landslide reactivations clearly have been on the rise and thereby exhibit excessive and unprecedented rates of activity 12 5 events per 10 yr at the scale of the riou bourdoux catchment from the data evidence exists for a shift from snowmelt induced landslides controlled by winter precipitation to reactivations controlled by spring temperatures therefore this contribution also adds evidence to the hypothesis that climate change and related warmer springs could further enhance landslide activity in the course of the 21 st century

emplacement of clay into sand by infiltration abstract laboratory experiments and examination of core samples from holocene sand bodies demonstrate that vadose infiltration of muddy water through sand is an effective mechanism by which clay can be emplaced into sand infiltrated clays form coatings on and bridges between sand sized framework grains clay particles are mostly oriented parallel to grain surfaces in coatings and perpendicular to grain surfaces in bridges the amount of clay emplaced as coatings and bridges is determined by complexly interacting variables that include sand grain size clay particle size clay particle shape concentration of suspended sediment and clay composition of these relatively coarse sand sizes and high concentrations of suspended sediment appear to promote the emplacement of the most infiltrated clay in holocene sands the formation of grain coatings and bridges is facies dependent infiltrated clays are most effectively emplaced in environments characterized by high suspended sediment concentrations fluctuating water levels and minimal sediment reworking e g point bar and delta plain in contrast virtually no infiltrated clay is emplaced in environments characterized by low suspended sediment concentration and continuous reworking e g beach and tidal delta

optically stimulated luminescence dating of sediments over the past 200 000 years optical dating of sediment using optically stimulated luminescence has become important for studying earth surface processes and this technique continues to develop rapidly a group of closely linked luminescence methods can be used to estimate the time since grains of quartz and feldspar were last exposed to daylight by detecting their subsequent response to environmental ionizing radiation exposure the technique is well suited to the dating of deposits as young as one year to several hundred thousand years recent technical developments have established a dating protocol with improved precision a high degree of reliability and an in built means to detect incomplete signal removal during deposition this approach has been extended to age estimation for single grains opening up a wider range of potential environments and new possibilities for understanding postdepositional grain movement ongoing research offers the possibility of significant age range extension and novel applications including low t

huanglong cave a late pleistocene human fossil site in hubei province china abstract this contribution discusses recent paleoanthropological findings from huanglong cave a late pleistocene human fossil site from yunxi county hubei province china three excavations in the huanglong cave from 2004 to 2006 yielded seven human teeth some stone and bone tools possible burnt sediment and other evidence possibly related to hominin activities based on the presence of extinct faunas 20 of total taxa identified the deposits dated to the late pleistocene electron spin resonance esr and uranium series u series dating analyses on associated teeth and speleothems have resulted in divergent chronometric ages esr 44 34 ka u series 103 79 ka analysis indicates 1 most of the morphological and metric features of the human teeth from huanglong cave fall within the range of variation of modern chinese but a few characters may still link them to more archaic hominins 2 some activity induced abrasion and other tooth use marks were identified including pronounced tooth chipping and interproximal grooves on the anterior teeth 3 the sample of blackened deposit has a high carbon content over 70 experienced high temperatures and likely was of cultural origin and not natural 4 the mammal fossils represent the ailuropoda stegodon faunal unit which lived in southern china throughout the pleistocene synthesizing all of these findings especially the human teeth that display modern human characteristics huanglong cave will offer some new insights into various issues currently being debated in late pleistocene human evolutionary research

denisovan dna in late pleistocene sediments from baishiya karst cave on the tibetan plateau a late middle pleistocene mandible from baishiya karst cave bkc on the tibetan plateau has been inferred to be from a denisovan an asian hominin related to neanderthals on the basis of an amino acid substitution in its collagen here we describe the stratigraphy chronology and mitochondrial dna extracted from the sediments in bkc we recover denisovan mitochondrial dna from sediments deposited 100 thousand and 60 thousand years ago ka and possibly as recently as 45 ka the long term occupation of bkc by denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the tibetan plateau

dendrogeomorphological analysis of a slope near lago calabria italy dendrogeomorphology first introduced by alestalo 1971 has been applied successfully in the spatial and temporal analysis of mass movements by many authors shroder 1978 investigated landslides in the table cliffs plateau of utah finding peak periods of mass movement reactivation many authors terasme 1975 shroder 1978 hupp 1984 strunk 1992 denneler and schweingruber 1993 found that trees subject to stress due to mass movement have manifested strong and sudden decreases in ring growth this effect on tree growth was also found by orombelli and gnaccolini 1972 in dating the vajont landslide in italy through the study of tilted conifers another important kind of information on the causes of landslide movement was pointed out in the papers of jibson and keefer 1988 and filion et al 1991 those authors discovered coincidence between the dating of tree disturbances and past strong earthquakes in the mississippi valley and riviere du gouffre respectively dendrochronology was used by hupp 1984 van asch and van steijn 1991 and strunk 1992 to evaluate the frequency of landslide activity kashiwaya et al 1989 have investigated the relationship between tree ring width and heavy rainfall in the landslide prone area of kobe district in japan

geomorphological and historical data in assessing landslide hazard traditionally earth scientists assess landslide occurrence on the basis of geomorphological investigations carried out through aerial photograph interpretation and eldwork conversely local administrators primarily evaluate the impact of natural catastrophes such as landsliding on the basis of historical records and data owing to the substantial difference in the structure and spatial density of these two types of information it is dif cult to compare them directly and few investigators have attempted this we compared landslide information derived from geomorphological mapping and historical data in a pilot area the staffora river basin northern italy to do this we generated two multivariate statistical models where the dependent variable was either the mapped landslide deposits geomorphological model or the historical sites affected by landslide induced damage historical model by quantitatively comparing these two model maps we demonstrate that the geomorphological model performs better in terms of percentage of terrain units correctly predicted as stable or unstable the historical model underestimates landslide hazard mainly where human structures are lacking however it highlights slopes where landslide movements take place with a high frequency at the temporal scale of human life hence the joint use of these two models may facilitate the knowledge of the overall instability conditions of a given region and the identi cation of the landslides that are most frequently reactivated copyright 2003 john wiley sons ltd

subsidence of the voring basin and the influence of the atlantic continental margin the post cretaceous subsidence history of the voring basin part of the atlantic passive margin offshore mid norway has been investigated extension and factors related to rifting and continental break up during the palaeocene have been quantified using both forward and reverse basin modelling techniques in the preferred geological model it is assumed that rifting occurred in the voring basin during the palaeocene prior to break up following an earlier rift event during the late jurassic during palaeocene rifting the basin may have been dynamically uplifted by the iceland mantle plume in the east of the basin there was no palaeocene extension subsidence analysis shows that in the centre of the basin forward and reverse models converge to predict a modest palaeocene stretching factor of c 1 15 in the west of the basin closest to the atlantic margin forward models of upper crustal faulting also predict a of c 1 15 but reverse backstripped models of subsidence predict a of up to 1 75 we suggest that lower crustal and mantle lithosphere thinning close to the margin were greater than the extension accommodated by upper crustal faulting and that some lower crustal mantle lithosphere stretching associated with continental separation was partitioned below the voring basin up to 150 km landwards of the margin

tree ring based estimation of landslide block displacement evaluation of a new experimental approach abstract the mechanisms and velocities of landslide movements are important information for assessing hazards associated with landslides this contribution introduces a new approach in reconstructing the past rate of landslide displacement using dendrogeomorphic methods the principle of this method is based on the analysis of exposed roots in tension cracks or scarps of active landslides the identification and dating of anatomical changes in root ring series in various root segments induced by gradual root exposure due to crack spreading enable the estimation of the rate of root exposure and the calculation of the displacement rate of landslide blocks we analysed anatomical reactions of 87 root cross sections in tension cracks of an active landslide the moravskoslezske beskydy mts in the outer western carpathians microscopical analysis of microcuts from cross sections showed the reduction in the earlywood vessel sizes indicating the year of root exposure we identified 17 years of exposure between 1997 and 2015 we calculated the individual displacement rates of the landslide expressed as the segment rate between the two adjacent samples of tension crack spreading and the mean spreading rate for all roots crossing one tension crack the average total spreading rate for each tension crack was 3 2 cm year 1 with a maximum of 4 3 cm year 1 and a minimum of 1 7 cm year 1 although this new approach has some uncertainties and limitations it remains a low cost technique that allows us to reconstruct the minimal past rate of landslide displacement without the need of long term monitoring

how different are the results acquired from mathematical and subjective methods in dendrogeomorphology insights from landslide movements abstract knowledge of past landslide activity is crucial for understanding landslide behaviour and for modelling potential future landslide occurrence dendrogeomorphic approaches represent the most precise methods of landslide dating where trees annually create tree rings in the timescale of up to several hundred years despite the advantages of these methods many open questions remain one of the less researched uncertainties and the focus of this study is the impact of two common methods of geomorphic signal extraction on the spatial and temporal results of landslide reconstruction in total 93 norway spruce picea abies l karst trees were sampled at one landslide location dominated by block type movements in the forefield of the orlicke hory mts bohemian massif landslide signals were examined by the classical subjective method based on reaction compression wood analysis and by a numerical method based on eccentric growth analysis the chronology of landslide movements obtained by the mathematical method resulted in twice the number of events detected compared to the subjective method this finding indicates that eccentric growth is a more accurate indicator for landslide movements than the classical analysis of reaction wood the reconstructed spatial activity of landslide movements shows a similar distribution of recurrence intervals ri for both methods the differences maximally 30 of the total ri ranges in results obtained by both methods may be caused by differences in the ability of trees to react to tilting of their stems by a specific growth response reaction wood formation or eccentric growth finally the ability of trees to record tilting events by both growth responses in their tree ring series was analysed for different decades of tree life the highest sensitivity to external tilting events occurred at tree ages from 70 to 80 years for reaction wood formation and from 80 to 90 years for eccentric growth response this means that the ability of p abies to record geomorphic signals varies with not only eccentric growth responses but also with age

regional tree ring based chronology of landslides in the outer western carpathians abstract landslides are a type of mass wasting and denote any downslope movement of soil and rock under the influence of gravity as such they can represent a dangerous natural hazard process especially in case that they affect inhabited areas or transport infrastructure because the occurrence of landslides is typically favoured by terrain and lithological conditions the process is frequently concentrated in relatively small isolated regions exhibiting suitable initial conditions of terrain instability extensive regional assessments of landslide activity have been used in the past to uncover common triggers and process patterns mostly in the aftermath of large regional disasters by contrast however regional reconstructions of past landslide activity have not been realized with dendrogeomorphic techniques and with the aim to date past landslide histories over extended time periods and with annual dating precision this study therefore aims at disentangling landslide dynamics at the regional scale covering ca 600 km2 by using growth ring records of trees that grow on active landslides the studied area of the host nsko vsetinska hornatina mts central europe is well known for its high landslide activity but has so far been lacking a detailed chronology of past events to this end we dated past activity on 26 landslide bodies using tree ring series from 1322 disturbed trees to reconstruct 327 landslide reactivations during the last century the reconstructed landslide database allowed correlations between landslide types and their frequencies or occurrence as well as inferences between selected morphometric parameters with landslide frequency and magnitude we also observe periods of increased landslide activity 1940s 1960s 1980s and 1990s and events of regional importance e g 1961 1985 and 1997 as well as a significant decrease in landsliding during the last two decades

prediction of permeability in quartz rich sandstones examples from the norwegian continental shelf and the fontainebleau sandstone abstract correctly predicting sandstone permeability from variables such as porosity composition and texture is one of the major problems of petroleum geology and hydrology using data sets comprising composition texture porosity and permeability for sandstone samples from the norwegian continental shelf and the fontainebleau sandstone we have tested several previously suggested methods for permeability prediction and also suggest a new method for sandstones containing significant volumes of clay our results indicate that permeability is successfully predicted from porosity and mean grain size by the kozeny equation for most sandstones with clay contents less than 3 when porosities exceed 6 14 with the lowest threshold values of porosity tending to occur in the sandstones containing least clay the kozeny equation also seems to enable calculation of the probable maximum possible permeabilities for sandstones with given porosities and grain sizes for clay contents above 3 the kozeny equation typically overpredicts permeability including a percolation threshold in the kozeny equation using estimated macroporosity rather than total porosity or applying a form of the equation where internal surface area is used as input instead of grain size does not provide generally acceptable permeability estimates however a modified kozeny equation which includes a parameter reflecting the type of pore system often provides useful permeability estimates even for clay rich samples this parameter can often be regarded as a constant for a specific formation or sandstone unit when porosity variations are not excessive mercury injection data suggest that its value is controlled by the width and connectivity of the dominant flow paths through the system which in turn are probably determined by factors such as volume and distribution of clay

a tectonic model for the norwegian passive margin with implications for the ne atlantic early cretaceous to break up a sub regional tectonic study of the mid norwegian margin has been assimilated into a broader regional study of the ne atlantic margin the ne atlantic margin experienced several extensional events between devonian post orogenic collapse and break up in early tertiary this paper focuses on the extensional events between early cretaceous and early tertiary it is suggested that ne trending early cretaceous rifting followed the entire margin from the southern rockall trough to the bjornoya basin of the sw barents sea this rift had a markedly different trend than the preceding n trending late jurassic rift of e g the north sea seamounts may have been emplaced in the highly thinned basin axes during early cretaceous rifting subsequent rift events followed the early cretaceous rift trend an enigmatic 9mid9 cretaceous event probably extensional is observed in the northern part of the mid norwegian margin the event is expressed by faulting in the inner voring basin and by uplift of the outer voring and lofoten margins uplift is associated with a widespread unconformity uplift of the gjallar ridge in the voring basin culminated during the latest cretaceous to early tertiary rifting with structural geometries broadly similar to those seen in core complexes a new tectonic model for ne atlantic margin is proposed based on these observations and builds on analogues from the modern rift system in the red sea and woodlark basin of papua new guinea

frequency and spread of debris floods on fans a dendrogeomorphic case study from a dolomite catchment in the austrian alps growth disturbances in tree ring series have been regularly used to date debris flow events in mountain environments in contrast no studies are available to date that have reconstructed debris floods by means of dendrogeomorphology therefore the aim of this study was to determine the event frequency and the spread of debris floods in the gratzental tyrol austria the analysis of growth disturbances in the tree ring series of 227 picea abies l karst and larix decidua mill allowed the reconstruction of 37 events for the last 200 years the lateral spread and preferable avulsion locations of reconstructed debris flood events were assessed based on the dating of the events and the spatial position of trees affected by an event on the fan results show that the gratzentalbach preferentially avulsed to the east but affected trees were evenly spread over the fan reconstructed data illustrates the high potential of dendrogeomorphology for hazard assessment of debris floods

a new geochemical classification of sedimentary environments because of the relative constancy of ph in most subaqueous sediments and the general lack of measurability of eh these parameters are not practically useful for classifying sedimentary environments in their place a new classification is offered which derived from studies of modern sediments is based on the presence or absence of dissolved oxygen and dissolved sulfide in the sediments at the time of authigenic mineral formation sedimentary environments are first of all divided into oxic and anoxic depending upon the presence or absence of measurable dissolved oxygen anoxic environments in turn are divided into sulfidic and non sulfidic depending upon the presence of measurable dissolved sulfide anoxic nonsulfidic environments are further divided into postoxic or resulting from oxygen removal without sulfate reduction weakly reducing and methanic or resulting from complete sulfate reduction with consequent methane formation strongly reducing the environments are shown to succeed one another during early diagenesis in the order oxic post oxic sulfidic methanic iron and manganese minerals characteristic and stable in each environment are listed and discussed so that they may be used to distinguish the environments when studying the ancient geological record

dish structures in some paleocene deep sea sandstones norwegian sector north sea origin of the dish forming clays and their effect on reservoir quality abstract the clay mineralogy of dish structured sandstones supports the intrastratal rather than the interstratal redistribution of clays during the formation of dish structures authigenic fe chlorite is the predominant constituent clay mineral in the dish structures interbedded mudstones comprise illite smectite with minor illite and chlorite dish structured horizons cause a marked reduction in average vertical permeability

compaction of lithic sands experimental results and applications compaction experiments showed that the degree of physical compaction of a lithic sand is related to the amount and type of lithic material present these experiments produced a product that is texturally indistinguishable from natural lithic sandstones generally sedimentary lithic fragments are more ductile than metamorphic lithic fragments volcanic lithic fragments when altered to phyllosilicate minerals by weathering or diagenesis are extremely ductile mineralogy and intragranular microporosity influence ductility ratios based on weight percent of soft ductile minerals clay and micas to hard brittle minerals quartz and feldspar within the lithic fragments provides a good indication of ductility a ratio greater than 1 indicates the lithic material will be h ghly ductile microporous lithic fragments are more ductile than dense lithic fragments physical compaction models were developed based on experimental data from well sorted lithic sandstones for which the percentage of preserved porosities were functions of the effective stress the type of lithic material and the quantity of lithic material these models are derived from laboratory sandstones with at least 25 lithic grains in the following categories moderately ductile metamorphic lithic fragments highly ductile shale lithic fragments and extremely ductile altered volcanic lithic fragments application of the compaction models of the experimental compaction techniques to modern subsurface sand samples or outcrop equivalents can provide valuable estimates of the preserved porosities i e reservoir potential for lithic sandstones that may be exploratory objecti es in frontier basins examples using the models and experimental compaction techniques for exploration are given experimental data showed that precompaction cement and overpressure may be beneficial to porosity preservation an early formed partial cement can retard compaction and preserve porosity by stabilizing the sand pack a later cement does not have this beneficial effect overpressure when developed early retards compaction by reducing the effective stress of course a late developing overpressure is not effective at preserving porosity because compaction is an irreversible process

contribution of dendrochronology to the determination of magnitude frequency relationships for landslides abstract the determination of magnitude frequency m f relationships is necessary for landslide hazard assessment ideally this is achieved by using inventories of past landslide events recorded by technical units or aerial photo interpretation however direct sources of landslide data are often unavailable dendrogeomorphological techniques allow us to determine the frequency of events but few attempts have been made to estimate landslide magnitude by analysing the spatial distribution of disturbed trees this paper addresses m f determination for rockfalls debris flows and complex slides obtained by dendrogeomorphology the cases presented require the appropriate understanding of both the geomorphological context and the disturbance caused by landslide motion on trees both small and large rockfalls can be identified and dated by reconstructing the trajectories in the forest stand the larger the rockfall size the longer the path the higher the number of affected trees and the greater the area of deposition of rock fragments the area of damaged trees is proposed as an indicator of the rockfall magnitude the frequency and extent of a series of debris flows were reconstructed by mapping their deposits using relative dating criteria and by dating damaged trees local and global mudslide reactivations were deduced by sampling various tree generations and by analysing the location of the disturbed trees in the landslide units magnitude cumulative frequency curves were determined for the three cases

deep structures and breakup along volcanic rifted margins insights from integrated studies along the outer voring basin norway three dimensional multichannel seismic survey and well data allows a deeper insight into rifting mechanisms and crustal structure of the norwegian volcanic rifted margin a surprising high velocity lower crustal dome marked by a strong amplitude reflection t reflection is described below the north gjallar ridge ngr near the volcanic plateau formed during the late paleocene early eocene breakup faulting along the ngr occurs during early campanian paleocene and is controlled by the crustal dome the t reflection was previously related to either the top of mafic underplated crust or soft lower crust updomed during the continental breakup the influence and timing of the crustal dome on the basin structure shows clearly that the dome predates the continental breakup based on the structural relationship and the results of the modelling it is therefore concluded that the t reflection does not necessarily originate from an anomalous tertiary magmatic event related to the breakup underplated material but could be also partly attributed to pre breakup mafic material or and inherited high pressure granulite eclogite rocks in the continental domain q 2004 elsevier ltd all rights reserved

how clay grain coats inhibit quartz cement and preserve porosity in deeply buried sandstones observations and experiments observations and hydrothermal experiments were used to derive new information about how clay grain coats inhibit quartz cement and preserve porosity in deeply buried sandstones samples of deeply buried porous sandstones with different types of clay coats were split in two coats removed from one of each pair of splits and grain surfaces inspected with scanning electron microscopy quartz grains in a fluvial deltaic sandstone buried to 115c had no visible authigenic quartz on grain surfaces cleaned of diagenetic chlorite coats though well developed overgrowths occurred on nearby naturally uncoated grains however in similar sandstones buried to 164c quartz grain surfaces exposed by chlorite coat removal were covered with small 5 m mainly anhedral syntaxial quartz overgrowths similar overgrowths were observed under various detrital and diagenetic clay coats in porous eolian sandstones buried to temperatures up to 215c we conclude that clay coats may retard quartz nucleation at moderate temperatures but at high temperatures many coats permit quartz nucleation and preserve porosity by limiting cement growth to investigate cement growth limitation mechanisms samples with coats removed were subjected to quartz cementing conditions in a hydrothermal reactor during experiments the naturally occurring small overgrowths on clay cleaned grains coalesced and grew suggesting that clay particles in coats inhibit cement growth by forming barriers to early overgrowth coalescence although the fraction of grain surface coverage is the primary control on cement inhibition by coats cement growth interference textures vary with coat type providing a mechanism by which coat composition may be a secondary control on inhibitory effectiveness in deeply buried sandstones quartz cement can fill significant microporosity within diagenetic chlorite coats potentially affecting mechanical and petrophysical rock properties

paleoclimate of southwestern china for the past 50 000 yr inferred from lake sediment records abstract long sediment cores 12 5 and 13 5 m from two lakes in yunnan province were used to infer the paleoclimate of southwest china over the past 50 000 yr during the holocene and marine isotope stage mis 3 bio induced carbonate precipitation and organic matter om production was high suggesting warm temperatures and high primary productivity in contrast sediment inorganic carbon ic and organic carbon oc concentrations were low in last glacial deposits from 38 000 to 12 000 cal yr b p indicating cool temperatures and low productivity the 50 000 yr record has alternating peaks of carbonate and coarse grain 38 m quartz that reflect warm moist interglacial or interstadial conditions alternating with cold dry glacial or stadial conditions respectively spectral analysis of the carbonate and quartz signals reveals power concentrated at periods of 7200 and 8900 cal yr respectively that may reflect a nonlinear climate response to precessional forcing at a time of reduced eccentricity modulation mcintyre and molfino 1996 oxygen isotope values of calcite from yunnan lake cores indicate the summer monsoon was weak during the last glaciation from 50 000 to 12 000 cal yr b p the summer monsoon intensified between 12 000 and 8000 cal yr b p but weakened gradually in response to insolation forcing during the mid to late holocene our results support the overpeck et al 1996 model that posits a weak summer monsoon during the last glaciation that responded nonlinearly to insolation forcing when its intensity was affected by eurasian snow cover and ice sheet extent the summer monsoon intensified and responded linearly to seasonal insolation forcing in the holocene when ice volume diminished

dating of mining induced subsidence based on a combination of dendrogeomorphic methods and in situ monitoring abstract mining induced subsidence is a worldwide environmental problem that leads to damage to infrastructure and property thus knowledge of its past recent development is critically needed during land use planning moreover the temporal occurrence of subsidence is greatly variable with tendencies for gradual to abrupt movements subsidence rates can currently be achieved via radar interferometry but these data usually cover short time periods and are less accurate in forested areas in such cases dendrogeomorphic dating can provide chronologies of past subsidence activity in addition comparisons of tree ring based data with in situ monitoring may answer the sensitivity and reliability of dating methods in these specific conditions of continuous ground movement geomorphic mapping and dendrogeomorphic dating were performed at two forested landslide sites affected by coal mining subsidence in the upper silesian basin czech republic and the resulting chronology from one site was compared with levelling campaigns occurring from 1998 to 2015 based on 284 increment cores from 71 trees we were able to identify 7 subsidence events at the site dominated by a pioneering forest and 19 subsidence events at the site overgrown by a mature forest with the most frequent responses occurring from 1956 to 1971 and 2005 2011 the occurrence of multiple compression wood growth intervals some occurring in different directions of tree stems more than 30 of sampled trees indicated complex deformations presented by the flow like mechanism of waterlogged surfaces ongoing subsidence spreading and fragmentation of larger blocks and grabens a comparison of tree ring based chronology with in situ monitoring revealed good synchronicity with the periods of increased subsidence rates between 1 and 3 m year 1 thus indicating the high relevance of dendrogeomorphic methods for the determination of the most intense periods of ground subsidence our results show the first comparison of dendrogeomorphic methods with in situ monitoring of human induced subsidence areas and provide an alternative option for reconstructing decadal to centennial development of the affected areas

dendrogeomorphic approaches for identifying the probable occurrence of debris flows and related torrential processes in steep headwater catchments the hrubý jesenik mountains czech republic abstract culminating parts of mid mountain ranges in central europe are interwoven by a network of high gradient streams these parts together with the surrounding slopes form a coupling system in which hazardous geomorphic processes such as landslides debris flows or flash floods can occur in the case of the hrub jesenik mountains eastern sudetes czech republic we present an evaluation of the debris flows and related torrential processes in the high gradient streams of the selected catchment based on dendrogeomorphic methods in addition to the classical dendrogeomorphic approaches we refined the procedure of identifying certain and probable events using new weighted indexes for event reconstruction additionally because of the steep narrow channels without a characteristic accumulation cone a new spatial approach is defined based on the spacing of disturbed trees for each event random distribution or clustering and location of disturbed trees in an individual section of the valley floor using kernel density analysis for each event and calculating the particular grids in arcgis software we are able to describe the spatial reach and probable nature of an event debris flow or hyperconcentrated flow dendrogeomorphic analysis of 397 sampled trees predominantly coniferous trees revealed 24 torrential events 15 certain nine probable since 1928 with peaks in 1991 1997 and 2010 according to index values in addition the spatial distribution of disturbed trees grouped in clusters in these years indicates debris flow events in the upper parts of the catchment it seems that new dendrogeomorphic approaches should be valuable in remote steep headwater catchments where several types of processes affect the valley floors

a reconstruction of snow avalanche characteristics in montana u s a using vegetative indicators on a utilise les cernes annuels des arbres pour etablir la date d occurence et la nature des dommages de l avalanche de fevrier 1979 au sud du glacier national park

the changing ability of norway spruce p abies to record hydro geomorphic processes based on the age and diameter of the tree stem a dendrogeomorphic approach dendrogeomorphic reconstructions of debris flows and related hydro geomorphic processes i e debris floods and flash floods are widely used in territories with incomplete chronologies and potential future hazards in recent years the tree ring analysis of disturbed trees affected by dangerous geomorphic processes has developed into a discipline with sophisticated methodical approaches and with annual up to monthly accuracy of dating field sampling strategies are based on various ranges of sample depth i e different amounts of sampled trees of different age structures the age and diameter of trees influence the ability of trees to respond to geomorphic processes therefore we investigate age dependent and diameter dependent tree sensitivity our study for the first time addresses the sensitivity to hydro geomorphic processes in detail we tested 462 individuals of norway spruce picea abies l karst a very common species used in the dendrogeomorphic reconstructions in the apical part of the medium high mountains where there is widespread occurrence of debris flows and debris floods the tree sensitivity analysis was performed based on the position of growth disturbances within the increment cores of trees original age and original diameter of the tree before the tree was affected p abies shows very high tree sensitivity in the first two decades of the tree lifespan with increasing age and diameter trees are less sensitive recorders of debris flows floods moreover the intensity of growth disturbances significantly decreases with tree age mature trees 51 120 years record the geomorphic events mainly through abrupt growth changes suppression and release and tangential rows of traumatic resin ducts in contrast scars the onset of reaction wood and traumatic resin ducts are dominant growth disturbances in young thin trees 11 30 years diameter 0 15 cm different occurrences of particular growth disturbances as well as the different age and diameter dependent sensitivities emphasize the need for the inclusion of new variable that will take into account the amount of sensitive trees for each year after that adequate mixture of sampled tree i e mixture of age classes which is necessary for the completeness of debris flow flood chronologies could be balanced regarding their sensitivity

single grain optical dating of grave infill associated with human burials at lake mungo australia abstract recent age constraints on australia s oldest human remains mungo i and iii found at lake mungo in western new south wales relied on optical dating of sands from the same stratigraphic units as those into which the remains had been inserted 42 3 ka and those that overlay the graves 38 2 ka giving a burial age of 40 2 ka this indirect means of dating the burials was necessary because the original site from which the remains had been excavated had been completely eroded away at the time of the original excavation of the mungo iii grave blocks of sediment from the grave infill were collected for sediment fabric analysis these sediment blocks were impregnated with polyester resin sectioned for analysis and the remaining resin impregnated sediment blocks were then stored in a cupboard where they have lain for the last 30 years here we report on optical dating of single grains of quartz extracted from one of these sediment blocks grains extracted from the centre of the block show a wide distribution of equivalent doses 0 0 0 3 to 43 7 8 3 gy indicating that not all of the grains have remained hidden from light light safe following excavation we show that the population of grains with the maximum equivalent dose produces an age consistent with that of the previous study indicating that some of the grains have remained light safe we also use linearly modulated optically stimulated luminescence to identify light safe grains these yield an age of 41 4 ka which represents a direct optical age for the grave infill and which is consistent with the age obtained in the previous study for sands from the same stratigraphic unit as that containing the burial the results reported here demonstrate the potential of applying optical dating to archived sediment samples that have not been stored in a light safe environment

tree ring analysis in the reconstruction of slope instabilities associated with earthquakes and precipitation the crimean mountains ukraine the crimean mountains in ukraine constitute a seismically active region that is abundant in various types of mass movement the limestone escarpments that rise above the black sea coast in the vicinity of the town of yalta are particularly subject to considerable rockfall landslide and debris flow processes that often endanger infrastructure and human life one of these very active slopes is the area of the ancient taraktash rockslide characterised by active block type movements lateral spreading toppling and incipient sliding rockfalls ongoing sliding activities and debris flows the aims of this study were i to employ tree ring analysis to reconstruct a record of slope instabilities mainly block type movements rockfalls landslides and debris flows within the taraktash slope deformation over a period of more than two centuries and ii to establish the degree of correlation between periods of enhanced slope activity and both historical earthquakes and climatic data the temporal frequency of significant slope processes was addressed through a tree ring analysis that took 738 increment cores from 255 crimean pine trees pinus nigra ssp pallasiana the tree ring record reveals periods of increased activity of block type movements rockfalls and landslides during the major earthquakes in 1790 1875 1927 and 1986 although the slope processes studied are predominantly driven by seismic activity their intensity and duration are also dependent on climatic factors this is especially true for landslides and debris flows which occurred mainly in years characterised by high precipitation totals

can low magnitude earthquakes act as a triggering factor for landslide activity examples from the western carpathian mts poland abstract there are numerous examples of the impact of strong earthquakes on landslide activity there is however very little information about the ability of low magnitude earthquakes m

optical dating of sediments a new method for dating sediments is proposed which determines the time since the sediment was last exposed to sunlight an argon ion laser is used to excite electrons from thermally stable light sensitive traps and the subsequent luminescence used as a measure of the past radiation dose two sample sequences spanning the periods 0 700 kyr and 0 6 kyr show steadily increasing luminescence with age an age of 62 8 kyr is obtained for a silt radiocarbon dated at 58 8 0 3 kyr problems were found with two much younger samples

optical dating in archaeology thirty years in retrospect and grand challenges for the future in 1982 when richard klein first became one of the editors of this journal the luminescence dating community was embarking on a new phase of exploratory research attention was turning from the use of thermoluminescence tl dating to estimate the time of last heating of archaeological objects such as pottery and burnt flint to the tl dating of unheated sediments that had been transported by wind and then deposited on the landscape this revolutionary development enabled the extension of tl dating to sedimentary deposits in a variety of environmental settings and to the multitude of archaeological sites that lack suitably heated artefacts in sediment dating the age of most interest is usually the time elapsed since grains of quartz or feldspar were last exposed to sunlight as the energy of the sun s rays is sufficient to evict electrons from their light sensitive traps these traps are steadily refilled after sediment deposition and the longer the grains remain buried the more tl they will emit when measured in 1985 huntley and colleagues proposed optical dating as a simpler and superior means of stimulating the light sensitive traps in quaternary sediments and this is now the principal luminescence based method of dating geological and archaeological deposits optical dating is an umbrella term for an armada of acronyms the most common in archaeological contexts being osl optically stimulated luminescence tt osl thermally transferred osl irsl infrared stimulated luminescence and pirir post infrared irsl all of these variants are founded on the same basic tenet measurement of a light sensitive signal to determine typically the last time that sediment grains were sun bleached but each approach has its virtues and vices in this paper we review this family of luminescence dating techniques and look back on 30 years of optical dating in archaeology some of the more interesting and important achievements are highlighted including the critical insights gained in the last two decades from osl measurements of individual grains of quartz we also look to the future of optical dating in archaeological contexts efforts to extend the age limits of optical dating to older hominin and archaeological sites will remain a key goal and understanding how archaeological sites of all ages form and evolve over time could be improved greatly by combining micromorphology analysis with optical dating of undisturbed intact sediments the latter poses a series of particularly formidable technical challenges but if the past is any guide to the future then we can expect optical dating to illuminate much more of human history before celebrating its golden jubilee

kaolin coating of stylolites effect on quartz cementation and general implications for dissolution at mineral interfaces abstract the deeply buried 4 km 160 c quartz rich sandstones of the middle jurassic garn formation in well 6507 7 1 offshore mid norway typically contain 20 30 quartz cement and only 3 9 porosity the exception is a less than 1 5 m thick interval at the top of the formation where quartz cement volumes typically drop to 8 16 and porosities are in the range 7 19 the uppermost part of the garn formation is not isolated from the rest of the formation by any type of impermeable barrier the sandstones are water filled indicating that the change in cementation does not correspond to a hydrocarbon contact and there are no significant changes in grain size grain coating abundance grain mineralogy or other factors that could give a lower quartz surface area for development of quartz overgrowths within the uppermost 1 5 m of the sandstones however in the samples from the less cemented interval illitization of authigenic kaolin is either not detectable or very restricted compared to deeper down in the cores where illitization of kaolin is usually complete we propose that the cause of reduced quartz cementation in the top of the garn formation may be the coating of stylolites developed from primary illitic clay rich and micaceous laminae with authigenic kaolin as quartz cementation proceeds and the authigenic kaolin rich rock adjacent to the stylolites is dissolved although we do not have evidence indicating that this may be a common phenomenon of major importance for preservation of reservoir quality our observations may help to unravel the mechanisms of quartz dissolution at stylolites specifically we suggest that the lack of significant surface charge on kaolin compared to illite and mica may lead to a reduced thermodynamic drive for quartz dissolution at kaolin quartz contacts similarly lack of dissolution at clean quartz quartz surfaces may be due to smaller and equal surface charges setting up oppositely directed electric fields that cancel each other whereas the positive surface charge of carbonate minerals may actually enhance the electric fields from negatively charged illitic clay and mica which may explain the extensive dissolution often seen at stylolites in limestones

morpho tectonic evolution of the crimean mountains ukraine as constrained by apatite fission track data introductionthe crimean mountains cm formthe westernmost prolongation of thecaucasus crimean thrust and foldbelt fig 1 muratov et al 1984 nikishin et al 1998 2001 saintotet al 1999 saintot and angelier 2002 despite the fact that the regionis one of the best explored territoriesin the former soviet union e g muratov 1960 kazantsev 1982 muratov et al 1984 slavin 1989 saintot et al 1999 nikishin et al 2001 mileev et al 2006 the scarcityof geochronological data limits geo dynamic reconstructions and does notallow veri cation of often contradic tory evolutionary scenarios see e g gintov and borisenko 1999 mileevet al 2006 this paper presents the rst ther mochronological data from the cm aimed at improving the existing mod els of exhumation uplift and land scape evolution e g muratov 1960 lysenko 1972 1976 saintot et al 1999 nikishin et al 2001 mileevet al 2006 this work also constrainsthe genesis and chronology of elevatedkarsti ed palaeosurfaces which occurmore extensively in the cm than inother european alpides understand ing the chronology and preservationof the palaeosurfaces in the cm andtheir relationship to post orogenicdeposits has important implicationsfor the survival of old inherited land forms in the mobile mountain belts ingeneral geological and geomorphologicalsettingthe cm are considered to be theremnantsofananticlinoriumstructure destroyed during the formation of theblack sea basin in short the tectonicevolution of the cm comprises i triassic earlycretaceous i e cimme rian compressional phases whenanticlinorium and s to se vergentthrust and fold structures formed mileev et al 1996 yudin 1999 golonka 2004 ii severalextensionalphasesduringthelateberriasian lateeocene associated with platform sed imentation kazantsev 1982 slavin 1989 and iii apost eocenecompres sive stage related to the collision of thearabian plate with eurasia leading tothe subduction of the east black seabasin under the russian platform andexhumation and uplift of individualblocks of the anticlinorium frombeneath the platform deposits saintotet al 1999 nikishin et al 2001 mileev et al 2006 according to mileev et al 1992 the accretional wedge of the cmformed in two main stages during theearly middle jurassic and late juras sic early cretaceous berriasian thelate cimmerian late jurassic berriasian compressional phase isbelieved to be the most importantphase for the genesis of the anticlino rium and the s to se vergent nappes mileev et al 1996 2006 saintotet al 1999 as pointed out by priva lov 2001 during the late cimmerianphase the regional stress eld was notpurely compressional but transpres sional inducing clockwise rotation ofthe cm in the late berriasian subsi dence commenced and late cimmerianstructures were unconformably over lain by platform sediments mainlysandstones conglomerates and lime stones continuous platform depositsare preserved along the northernmargin of the cm kazantsev 1982 with thickness varying from 0 3 to8 km field observations in the north ern slope of the cm revealed localizedthrusting of upper jurassic limestoneonto lower cretaceous platformdeposits kazantsev 1982 yudin 1999 sedimentation in platformregimes terminates in the late eocenein response to the uplift induced bythe east black sea basin indentation which was in turn caused by thearabia eurasia collision nikishinet al 2001 oligocene neogene sed imentation represented e g by theabstract

evaluation of growth disturbances of picea abies l karst to disturbances caused by landslide movements abstract dendrogeomorphic methods are frequently used in landslide analyses although methods of landslide dating based on tree rings are well developed they still indicated many questions the aim of this study was to evaluate the frequently used theoretical scheme based on the event response relationship seventy four individuals of norway spruce picea abies l karst exhibiting visible external disturbance were sampled on the girova landslide the largest historical flow like landslide in the czech republic this landslide reactivated in may 2010 and post landslide tree growth responses were studied in detail these growth responses were compared with the intensity and occurrence of visible external tree disturbance tilted stems damaged root systems and decapitation twenty nine trees 39 2 died within one to four years following the 2010 landslide movement the trees that died following the landslide movement were significantly younger and displayed significantly greater stem tilting than the live trees abrupt growth suppression was a more frequent response among the dead trees whereas growth release dominated among the live trees only two trees 2 7 created no reaction wood in response to the landslide movement forty four percent of the trees started to produce reaction wood structure after a delay which generally spanned one year some eccentric growth was evident in the tree rings of the landslide year and was significant in the first years following the landslide movement missing rings were observed only on the upper sides of the stems and no false tree rings were observed the results confirm the general validity of event response relationship nevertheless this study points out the limitations and uncertainties of this generally accepted working scheme

spatio temporal reconstruction of snow avalanche activity using tree rings pierres jean jeanne avalanche talus massif de l oisans france snow avalanches are a major threat in many parts of the alps where they periodically damage infrastructure disrupt transportation corridors or even cause loss of life nonetheless the spatial behavior of past avalanche activity and the analysis of areas affected during particular events remain often imprecise it was therefore the purpose of this study to reconstruct spatio temporal patterns of past avalanche activity on a forested avalanche talus in the french alps pierres jean jeanne talus massif de l oisans france a total of 232 european larches larix decidua mill with clear signs of snow wasting events was analyzed and growth disturbances gd related to avalanche activity was assessed such as tangential rows of traumatic resin ducts the onset of compression wood or abrupt growth suppression and release in total 901 gd were identified in the tree ring samples indicating that 20 high magnitude avalanches occurred between ad 1919 and 1994 the mean return period of snow avalanches was 4 years with a 26 probability that an avalanche occurs in any particular year interpolated maps allowed for explicit spatial estimates of return periods throughout the talus showing a rapid increase of return frequency from 2 5 to 50 years with increasing distance from the talus apex the distribution of avalanche years seems to be quite homogeneous in time with a gap between 1951 and 1959 snowfall from a nearby meteorological station saint christophe en oisans 10 km from the study site indicated that the five most recent high magnitude events on record occurred due to above average snowfall anomalies in december and january associated with abnormally low air temperatures findings suggest that a strong snow metamorphism under high temperature gradients in january could explain the occurrence of high magnitude snow avalanches 2010 elsevier b v all rights reserved

mass movements and tree rings a guide to dendrogeomorphic field sampling and dating abstract trees affected by mass movements record the evidence of geomorphic disturbance in the growth ring series and thereby provide a precise geochronological tool for the reconstruction of past activity of mass movement the identification of past activity of processes was typically based on the presence of growth anomalies in affected trees and focused on the presence of scars tilted or buried trunks as well as on apex decapitation for the analyses and interpretation of disturbances in tree ring records in contrast clear guidelines have not been established with largely differing or no thresholds used to distinguish signal from noise at the same time processes with a large spatial footprint e g snow avalanches landslides or floods will likely leave growth anomalies in a large number of trees whereas a falling rock would only cause scars in one or a few trees along its trajectory based on the above considerations we examine issues relating to the interpretation and dendrogeomorphic dating of mass movements particular attention is drawn to sampling in terms of sample distribution across a study site the actual selection of trees as well as to sample size i e number of trees sampled based on case studies from snow avalanche debris flow and landslide sites we demonstrate that thresholds can indeed improve dating quality and at the same time minimize noise in time series we also conclude that different thresholds need to be used for different processes and different periods of the reconstruction especially for the early stages of the reconstruction when the number of potentially responding trees will be much smaller this paper seeks to set standards for dendrogeomorphic fieldwork analysis and interpretation for different processes of mass movements

thermokarst dynamics in western siberia insights from dendrochronological research abstract thermokarst dynamics and their underlying causes are investigated and reconstructed on the basis of muzhy weather station records western siberia of air temperature precipitation and snow cover and a tree ring chronology analysis of siberian stone pine pinus sibirica du tour the results indicate that the development of thermokarst over the last 50 years has depended primarily on increasing precipitation rather than increasing air temperature reconstruction of past thermokarst borderlines shows that the rate of thermokarst expansion in the second half of the 20th century increased to 7 4 cm year as compared to past rates ranging from 4 to 8 1 cm year

stability of detrital heavy minerals on the norwegian continental shelf as a function of depth and temperature abstract petrographic analysis of 1931 thin sections from sandstones of pliocene to devonian age on the norwegian continental shelf indicate that the heavy minerals zircon tourmaline rutile apatite and spinel survive to depths exceeding 5000 m and to temperatures of around 200 c without showing signs of intrastratal dissolution on the other hand the maximum depth and temperature of occurrence for amphibole are 841 m and 40 c around 1500 m and 55 c for sphene when 0 5 km of probable uplift is taken into account 2231 m and 92 c for kyanite 2559 m and 95 c for epidote 2810 m and 109 c for staurolite and 4589 m and 175 c for garnet initial signs of garnet dissolution occur at around 2000 m depth and all garnets are partially dissolved at depths greater than 3500 m monazite is present down to 4858 m and 182 c and chloritoid to 3811 m and 149 c it is however uncertain whether this is due to the low number of samples deeper than 4858 m and to the rare occurrence of chloritoid or to intrastratal dissolution the same sequence of heavy mineral stability is found when volume of quartz cement is used as a proxy for time temperature exposure quartz cement is not found in samples containing amphibole or detrital sphene a maximum of a fraction of a percent quartz cement is found in samples containing kyanite up to 1 together with epidote up to 6 with staurolite up to 24 with chloritoid up to 25 with garnet whereas maximum values of 25 35 are present together with zircon tourmaline rutile patite spinel and monazite the sequence of persistence of heavy minerals versus depth found in this study is very similar to results from several previous studies although unstable heavy minerals survive to greater depths in very young and rapidly buried sandstones and there are some differences regarding the stability of sphene and epidote heavy mineral dissolution has created secondary pores and possibly has contributed to precipitation of kaolinite illite quartz and carbonates in the studied sandstones but these reactions are of very limited volumetric importance

catastrophic slope failure and its origins case of the may 2010 girova mountain long runout rockslide czech republic abstract one of the largest long runout landslides in the modern history of the czech republic originated on the southern slopes of the girova mountain outer western carpathians at the end of extreme rainfalls in may 2010 the structurally predisposed girova mountain rockslide occurred very quickly within fault weakened deeply weathered flysch bedrock its main phase during which a wedge like block collapsed in the upper part of slope lasted for a few hours the overloaded slope collapsed and its motion lasted for the following 3 days the may 2010 girova mountain rockslide is an excellent case of a recurrent long runout landslide nested within a deep seated gravitational slope deformation with a long history of late quaternary mass movements the chronology of slope failures within the studied slope was reconstructed by means of radiocarbon dating and dendrogeomorphological analysis at least one holocene long runout landslide 7 4 cal ka bp and several smaller failures 1 5 and 0 6 cal ka bp preceded this recent catastrophic failure dendrogeomorphological analysis showed that the failure had been preceded by at least 80 year long creep movement that accelerated over the years due to extreme rainfall events despite the fact that extreme precipitation of may 2010 represented the last incremental change before catastrophic collapse of the slope its main reason was gradual weakening of rock massif and concentrated creeping with some accelerated phases in the upper part of the slope deformation

sandstone porosity loss a big picture view of the importance of compaction proper assessment of the relative importance of porosity loss by compaction and cementation is important to the prediction of porosity in sandstones studies of mass transport during diagenesis and the modeling of basin fluid flow quantitative estimation of the amounts of porosity loss by compaction and cementation can be made from standard point count data on cement and pore space abundance this method is discussed and its sources of error are evaluated error in the method arises mainly from uncertainty in initial sandstone porosities and the amount of local grain dissolution during burial data on the porosity of modern sands indicate that assumed initial porosities of 40 to 45 will produce small average errors in the calculation of compactional porosity loss for clean sandstones grain dissolution whether resulting in local porosity enhancement by export in solution of former grain mass or local precipitation of authigenic cement will cause an underestimation of the significance of compaction a large database of point count data from diverse sandstones is used to provide a broad perspective on the importance of compaction and cementation to sandstone porosity loss it is shown that the global importance of compactional porosity loss has generally been under appreciated in fact compaction mechanical and chemical is probably the dominant mechanism of porosity loss in most sandstones the extent of compactional porosity loss is related to sand grain composition and basin thermal structure

evidence for repeated re activation of old landslides under forest local reactivations of landslides in forests are rarely reported in landslide catalogues the occurrence of hillslope sections with fresh morphological landslide features in forested old deep seated landslides however suggests that landslide reactivations are not restricted to residential areas in this study a dendrogeomorphological analysis of beech stands was used to investigate the periods of reactivation of a deep seated rotational slide in the koppenberg forest flemish ardennes belgium the relation to rainfall and the correspondence to landslide reactivations reported in a nearby built up area were also analysed a dendrometrical study preceding the dendrochronological analysis proved that compared with the nearby reference site trees on the koppenberg forest landslide site were significantly more inclined and showed more knees indicating that the landslide site has not stabilized yet as the sampled trees are younger than the landslide dendrochronology did not allow determination of the year in which the landslide was initiated but analysis of two different tree ring width parameters i e ring eccentricity and growth change calculated for trees sampled on the koppenberg landslide and the reference site proved to be of great help in determining the temporal sequence of landslide reactivation during the past 80 years several periods indicative of local reactivations i e 1943 1945 1949 1952 1967 1970 1972 1977 1979 1981 1988 1997 were found within the investigated landslide but delineation of the spatial extent of the reactivations during these indicative periods was not straightforward these periods generally correspond to years with above average rainfall finally the fact that at least 34 of the years indicative of reactivation of the koppenberg forest landslide correspond to a year in which a landslide reactivation was reported in the flemish ardennes suggests that in built up areas apart from anthropogenic interventions natural triggering factors remain very important copyright 2009 john wiley sons ltd

probability maps of landslide reactivation derived from tree ring records pra bellon landslide southern french alps probability maps of landslide reactivation are presented for the pra bellon landslide located in the southern french alps based on results obtained with dendrogeomorphic analysis spatiotemporal patterns of past landslide activity was derived from tree ring series of 403 disturbed mountain pine trees growing in the landslide body in total 704 growth disturbances were identified in the samples indicating 22 reactivation phases of the landslide body between 1910 and 2011 the mean return period was 4 5 years given the spatiotemporal completeness of the reconstruction probabilities of landslide reactivation were computed and illustrated using a poisson distribution model and for 5 20 50 and 100 years probability of landslide reactivation is highest in the central part of the landslide body and increases from 0 13 for a 5 year period to 0 94 for a 100 year period conversely probabilities of reactivation are lower at its margins the proposed method differs from conventional approaches based on statistical analyses or physical modeling that have demonstrated to have limitations in the prediction of spatiotemporal reactivation of landslides our approach is in contrast based on extensive data on past landslides and therefore allowed determination of quantitative probability maps of reactivation derived directly from the frequency of past events this approach is considered a valuable tool for land managers in charge of protecting and forecasting people and their assets from the negative effects of landslides as well as for those responsible for land use planning and management it demonstrates the reliability of dendrogeomorphic mapping that should be used systematically in forested shallow landslides

the origin of shallow landslides in moravia czech republic in the spring of 2006 abstract at the end of march 2006 the czech republic cz witnessed a fast thawing of an unusually thick snow cover in conjunction with massive rainfall most watercourses suffered floods and more than 90 shallow landslides occurred in the moravian region of eastern cz primarily in non forested areas this region geologically part of the outer western carpathians is prone to landslides because the bedrock is highly erodible mesozoic and tertiary flysch the available meteorological data depth of snow water equivalent of the snow cumulative rainfall air and soil temperatures from five local weather stations were used to construct indices quantitatively describing the snow thaw among these the total cumulative precipitation tcp combines the amount of water from both thawing snow and rainfall this concurrence of rain and runoff from snow melt was the decisive factor in triggering the landslides in the spring the tcp index was applied to data of snow thaw periods for the last 20 years when no landslides were recorded this was to establish the safe threshold of tcp without landslides the calculated safe threshold value for the region is ca 100 mm of water delivered to the soil during the spring thaw corresponding to ca 11 mm day 1 in 2006 10 of the landslides occurred under or at 100 mm of tcp the upper value of 155 mm covered all of the landslides

centennial scale process activity in a complex landslide body in the qilian mountains northeast tibetan plateau china abstract mass movements in china typically encompass landslides rockfalls and debris flows and these processes affect almost 70 of all mountain areas of china an improved understanding of geomorphic process dynamics and their drivers and process histories are important prerequisites for a proper assessment and a sustainable management of mountain hazards tree rings have on varied occasions proven to be a reliable tool for the acquisition of data on past mountain hazards here we present the first reconstruction of past landslide activity on a slope in the qilian mountains northeast tibetan plateau china to this end a total of 543 qilian juniper sabina przewalskii kom samples were selected from 239 trees growing on or next to a complex landslide body with the aim to reconstruct past landslide histories at the site the dataset of disturbed trees was complemented with 174 increment cores from 84 reference qilian juniper trees growing on three adjacent yet undisturbed sites based on the dating of the samples and the interpretation of growth disturbances gd in the tree ring series of affected trees we provide the first reconstruction of past landslides as retrieved from a dendrogeomorphic record covering more than a millennium 956 2011 ce results show that the first detectable gd occurred as early as in 1042 ce followed by seven major landslide reccurrences in 1703 1816 1848 1863 1913 1970 and 1982 comparison between our landslide record and a dendroclimatic precipitation reconstruction points to the crucial role of major longer term wet precipitation anomalies on landslide occurrence

extensional geometry of the mid norwegian margin before early tertiary continental breakup abstract interpretation of reflection seismic data integrated with existing crustal models provide an interpretation of the deeply buried mesozoic extensional geometry of the voring and more margins in the norwegian sea whereas late paleozoic to triassic basins are limited by high angle normal faults with nw and se dips the late jurassic early cretaceous voring and more basins are characterised by low angle normal faults that dip towards the nw between the voring and more basins at the se end of the jan mayen fracture zone a synthetic transfer zone is interpreted geometrical models based on basin and fault geometries show that the rift system detached near the upper crust lower crust transition in the study area this rift system accommodated between 110 and 140 km of post early jurassic extension according to the geometry of the present day pre cretaceous upper crust a simple geometrical forward model suggests that a substantial part of this stretching occurred during the late cretaceous paleocene thinning the central and nw segments of the late jurassic early cretaceous rift

differences between the responses of european larch larix decidua mill and norway spruce picea abies l karst to landslide activity based on dendrogeomorphic and dendrometric data abstract investigations of mass movement hazards need to be supported by accurate data regarding past frequencies of landslide reactivations dating landslide events using tree rings is a reliable approach for vegetated slopes in temperate climates despite the enhanced use of dendrogeomorphic research during recent decades little is known about the specific responses of larix spp to landslide movements we investigated the active section 0 6 ha of a complex landslide in the vsetinske vrchy mts outer western carpathians that is overgrown by a forest stand composed of european larch larix decidua mill and norway spruce picea abies l karst using the dendrometric and dendrogeomorphic data identified from 74 trees 33 l decidua and 41 p abies including the number and types of growth disturbances gds and compiled event chronologies we compared the responses of both tree species to the same landslide reactivations we observed the same mean tree stem inclination for both tree species whereas the inclination azimuths differed l decidua generally showed a higher number of stem bends compared to p abies similar proportions of subjectively identified gds compression wood cw and abrupt growth suppression gs and mathematically identified gds tree ring eccentricities were observed in both tree species however the total number of gd tree 1 was slightly higher in l decidua 4 1 than in p abies 3 2 a higher abundance of gs was identified in l decidua at the expense of cw compared to p abies the event chronology based on the mathematical approach revealed slightly more landslide signals than for the subjective approach mainly in l decidua however the largest known landslide reactivation in 1997 was recorded in all cases in both tree species based on the cw analysis it was shown that larger stem inclinations are associated with longer persistence of cw in p abies rather than l decidua resulting in the possible masking of younger landslide events by contrast p abies compensates for that limitation by having a generally shorter mean duration of cw than l decidua overall it seems that the complexity of landslide movements and root system architecture influenced the number and character of gds in both tree species in addition we did not find any relationships between the measured dendrometric parameters and number of gds to better assess the most suitable trees for dendrogeomorphic dating prior to sampling therefore we recommend sampling both tree species when they overgrow the same landslide body so that the final event chronology will be more robust and possible limitations of one tree species can be eliminated by the benefits of the second

can tree tilting indicate mechanisms of slope movement abstract slope movements are a common natural hazard that is why considerable funds are spent annually to limit their effects or to research their prevention this study evaluates dendrometric approaches as a fast and low cost alternative to classical methods of slope movement mechanism analysis a total of 1688 trees growing on the mazak landslide in the moravskoslezske beskydy mts and 100 reference trees growing out of the landslide area were analysed the mazak landslide is approximately 400 m in length and presents varied morphological features scarps rotated blocks scree slopes shallow landslide areas etc the slope and direction of stem inclination was recorded for each tree the results were categorized into four distinct landforms scarp with outcrops of bedrock scree slope front of partial landslide block plateau of partial landslide block and were then compared with parameters for the reference trees the general model of tree tilting for the landslide area was verified and partially confirmed trees growing on the plateau of rotated blocks are predominantly oriented upslope trees growing on scree slopes of shallow movement and creep are predominantly oriented downslope trees growing on rocky scars do not differ significantly from the reference trees trees growing from fronts of rotated blocks are oriented both upslope and downslope from these results several recommendations regarding dendrometric evidence of slope movement mechanisms are presented i all trees growing on the landslide are to be analysed ii old trees maintain stem tilt intensities and directions for long periods but young trees are more sensitive to ground movements iii tree root depth influences root sensitivity to movements of various depths iv the general shape of a stem can denote specific mechanisms of slope movement and v comparisons with reference trees should always be conducted to exclude potential non geomorphic effects on tree stem tilt

dendrochronological and geomorphological investigations to assess water erosion and mass wasting processes in the apennines of southern tuscany italy abstract the tyrrhenian side of the central apennines is located in a lively geological context in which uplift denudation dynamics played a key role in landscape evolution intense water erosion and gravitational processes led to the development of spectacular badlands on the widespread clayey hillslopes the crete d arbia badlands as part of the crete senesi of southern tuscany represent one of the most beautiful examples of these landforms developed on pliocene clays on the other hand these rapidly evolving landforms endanger the artistic heritage of the area as with the monte oliveto maggiore abbey that was constructed on the top of a badland hillslope and confers additional value to the landscape in the perspective of monitoring and reconstructing some significant phases of the relief evolution of this area an integrated approach has been used which is based on dendrogeomorphology and geomorphological monitoring techniques in particular the correspondence between the data from dendrogeomorphological indicators and the measured denudation rates on badland hillslopes was tested the sampling for dendrogeomorphological analysis has been performed in two stages on 45 trees of the pinus pinea l species on hillslopes affected by soil creep and shallow landslides in order to identify annual ring growth anomalies compression wood and roots exposure trees local behaviour is not homogeneous but some common trends have been detected on the basis of the anomaly index and compression wood since 1993 several monitoring stations at badland denudation hot spots have been equipped with erosion pins quantitative data from monitoring stations compared to pluviometric series indicated critical phases of denudation that were supported by dendrochronological data the integrated approach between dendrogeomorphology and geomorphological monitoring techniques allowed calibration of both tools in order to extend the analysis in the period preceding the field measurements this kind of approach capable of implementation in many contexts could be particularly helpful in order to forecast the relief evolutionary trend

new ages for the upper palaeolithic site of xibaimaying in the nihewan basin northern china implications for small tool and microblade industries in north east asia during marine isotope stages 2 and 3 it has been suggested that the small tool and microblade upper palaeolithic industries coexisted in the nihewan basin of northern china for about 8 14 000 years during marine isotope stage mis 2 this inference was based on uranium series ages of around 15 and 18 ka for bovid teeth recovered from the latest small tool site of xibaimaying the youngest occurrence of such tools in the region and optically stimulated luminescence osl dating of the earliest typical microblade site youfang 26 29 ka in this study we re dated the xibaimaying site using single grain osl methods and the resulting ages indicate that the cultural layer was deposited 46 3 ka ago during mis 3 more than 20 millennia earlier than previously thought and older also than the so called earliest primitive and typical microblade tools found at zhiyu 31 39 ka cal bp and youfang these new ages for human occupation of xibaimaying remove support for the parallel development of the small tool and microblade industries in the nihewan basin during the upper palaeolithic but reliable age estimates from additional sites are needed to confidently infer the nature of the chronological relationship between these two upper palaeolithic industries and the associated toolmakers

spatio temporal patterns of recurrent slope instabilities affecting undercut slopes in flysch a dendrogeomorphic approach using broad leaved trees abstract the undercut slope of the skalicka stra nice vrchy hill situated in the piedmont of the carpathian mountains czech republic is a regional landslide hotspot notorious for its repeated recent and historical sliding reactivations we performed tree ring analysis of a large number n 274 of broad leaved trees to reconstruct the spatio temporal patterns of landslide reactivation for a period spanning more than one hundred years 1884 2011 although tree rings of broad leaved trees are less reliable archives of landslide activity than those of conifers the application of a methodology based on the weighting of disturbance signals within eccentricity series generated a usable dataset of sliding activity affecting anisotropic flysch bedrock although some known landslide years could not be found or were expressed by only weak signals in the reconstructed dataset the majority of landslide events reconstructed from the tree ring series coincide with hydrometeorological data revealing a correlation with heavy summer rainfalls lasting from two to ten days the spatial distribution of landslide recurrence derived from the tree ring records together with electrical resistivity tomography and a kinematic analysis of slope failures suggest a close link between the concentration of landslide activity and the presence of faulted or fractured flysch bedrock

fossil and recent debris flows in medium high mountains moravskoslezske beskydy mts czech republic abstract the significance of debris flows for the morphogenesis of the medium high mountains of central europe has long been neglected herein we provide evidence from the moravskoslezske beskydy mountains flysch western carpathians czech republic where fossil pleistocene debris flow events in spite of their low recent activity were important erosion and accumulation agents in shaping the mountainous terrain geomorphological and sedimentological analyses helped to differentiate between two classes of debris flow deposits deposits of the 1st class are relatively voluminous contemporary terraced landforms which originated in the pleistocene transport limited conditions recent activity of debris flows presented by the 2nd class accumulations is characterized by the presence of low magnitude events mostly originated during the reworking of older diamictons the inheritance of large volumes of old debris flow diamictons in steep mountainous terrain is the evidence of slow erosional transformation of the last glacial landforms pointing to the fact that recent topography of the mountains is not in full equilibrium with contemporary climatic and environmental conditions

dendrogeomorphic chronologies of landslides dating of true slide movements dendrogeomorphic chronologies of landslide movements are frequently used to investigate past landslide activity slide areas are often affected by other slope movements e g creep simultaneously trees growing on landslides record all types of ground movements which potentially creates significant noise in tree ring based chronologies of landslide movements the effect of creep movements on dendrogeomorphic landslide chronologies was evaluated in a block type landslide in the south western foreland of the orlicke hory mts in total 272 trees p abies and f sylvatica were sampled 1088 increment cores on the sub horizontal surfaces of rotated slide blocks which were presumably created only by slide movements and on the steep internal scarps separating landslide blocks which were presumably created and affected by a combination of slide and creep movements ground movements were dated based on growth disturbances identified in an analysis of eccentric tree growth the trees growing on the internal landslide scarps separating the rotated blocks exhibited a significantly higher number and frequency of growth disturbances than those growing on the sub horizontal block surfaces all eight dated block surface movements were also identified on the internal scarps creep based events represented as many as 70 of the dated movement events on the internal scarps varying the it thresholds did not filter out more than 40 of the noise without significantly reducing the number of true dated slide events a significant difference was observed between the ability of p abies and f sylvatica to record ground movements by eccentric growth probably due its shallower roots and weaker anchoring of the tree to landslide blocks p abies appears to be more sensitive to surficial ground movement which potentially increases the proportion of dated creep events noise thus the careful selection of sampled tree species with different physiologies should be considered during dendrogeomorphic field sampling

high resolution fingerprints of past landsliding and spatially explicit probabilistic assessment of future reactivations aiguettes landslide southeastern french alps the purpose of this study was to reconstruct spatio temporal patterns of past landslide reactivation and the possible occurrence of future events in a forested area of the barcelonnette basin southeastern french alps analysis of past events on the aiguettes landslide was based on growth ring series from 223 heavily affected mountain pine pinus uncinata mill ex mirb trees growing on the landslide body a total of 355 growth disturbances were identified in the samples indicating 14 reactivation phases of the landslide body since ad 1898 accuracy of the spatio temporal reconstruction is confirmed by historical records and aerial photographs logistic regressions using monthly rainfall data from the histalp database indicated that landslide reactivations occurred due to above average precipitation anomalies in winter they point to the important role of snow in the triggering of reactivations at the aiguettes landslide body in a subsequent step spatially explicit probabilities of landslide reactivation were computed based on the extensive dendrogeomorphic dataset using a poisson distribution model for an event to occur in 5 20 50 and 100 yr high resolution maps indicate highest probabilities of reactivation in the lower part of the landslide body and increase from 0 28 for a 5 yr period to 0 99 for a 100 yr period in the upper part of the landslide body probabilities do not exceed 0 57 for a 100 yr period and somehow confirm the more stable character of this segment of the aiguettes landslide the approach presented in this paper is considered a valuable tool for land use planners and emergency cells in charge of forecasting future events and in protecting people and their assets from the negative effects of landslides