exhumation processes during post collisional stage in the variscan belt revealed by detailed 40ar 39ar study tanneron massif se france detailed 40ar 39ar geochronology on single grains of muscovite was performed in the variscan tanneron massif se france to determine the precise timing of the post collisional exhumation processes thirty two plateau ages obtained on metamorphic and magmatic rocks sampled along an east west transect through the massif vary from 302 2 to 321 2 ma and reveal a heterogeneous exhumation of the lower crust that lasted about 20 ma during late carboniferous in the eastern part of the massif the closure of the k ar isotopic system is at 311 315 ma whereas in the middle part of the massif it closes earlier at 317 321 ma these cooling paths are likely to be the result of differential exhumation processes of distinct crustal blocks controlled by a major ductile fault the la moure fault that separates both domains in the western part of the massif the ages decrease from 318 to 303 ma approaching the rouet granite which provides the youngest age at 303 6 1 2 ma this age distribution can be explained by the occurrence of a thermal structure spatially associated to the magmatic complex these ages argue in favour of a cooling of the magmatic body at around 15 ma after the country rocks in the western tanneron the emplacement of the rouet granite in the core of an antiform is responsible for recrystallization and post isotopic closure disturbances of the k ar chronometer in the muscovite from the host rocks these new 40ar 39ar ages clearly outline that at least two different processes may contribute to the exhumation of the lower crust in the later stage of collision during the first stage between 320 and 310 ma the differential motion of tectonic blocks limited by ductile shear zones controls the post collisional exhumation this event could be related to orogen parallel shearing associated with crustal scale strike slip faults and regional folding the final exhumation stages at around 300 ma take place within the tectonic doming associated to magmatic intrusions in the core of antiformal structures local ductile to brittle normal faulting is coeval to upper carboniferous intracontinental basins opening

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

developments in the characterization of complex rock slope deformation and failure using numerical modelling techniques recent advances in the characterization of complex rock slope deformation and failure using numerical techniques have demonstrated significant potential for furthering our understanding of both the mechanisms processes involved and the associated risk this paper illustrates how rock slope analyses may be undertaken using three levels of sophistication level i analyses include the conventional application of kinematic and limit equilibrium techniques with modifications to include probabilistic techniques coupling of groundwater simulations and simplistic treatment of intact fracture and plastic yield such analyses are primarily suited to simple translational failures involving release on smooth basal rear and lateral surfaces where the principle active damage mechanisms are progressive failure and or asperity breakdown level ii analyses involve the use of continuum and discontinuum numerical methods in addition to simple translation level ii techniques can be applied to complex translational rock slope deformations where step path failure necessitates degradation and failure of intact rock bridges along basal rear and lateral release surfaces active damage processes in this case comprise not only strength degradation along the release surface e g asperity breakdown but also a significant component of brittle intact rock fracture level iii analyses involve the use of hybrid continuum discontinuum codes with fracture simulation capabilities these codes are applicable to a wide spectrum of rock slope failure modes but are particularly well suited to complex translation rotational instabilities where failure requires internal yielding brittle fracturing and shearing in addition to strength degradation along release surfaces through a series of rock slope analyses the application of varied numerical methods are discussed particular emphasis is given to state of the art developments and potential use of level iii hybrid techniques d 2005 elsevier b v all rights reserved

orogen parallel tectonic transport in the variscan belt of northeastern sardinia italy implications for the exhumation of medium pressure metamorphic rocks a transpressive crustal scale dextral shear zone is documented in the variscan basement of northeastern sardinia it indicates the presence of a shear deformation parallel to the belt overprinting previous d1 structures related to nappe stacking and top to the s and sw thrusting the l2 stretch ing lineation points to an orogen parallel stretching and to a general change in the tectonic transport from d1 to d2 phase d1 developed during initial frontal collision whereas the d2 deformation was characterized by dextral shearing during the increasing curvature of the ibero armorican arc transpressional deformation developed in a regime of decreasing pressure it caused telescoping of the barrovian isograds and the exhumation of the low to medium grade metamorphic rocks in this sector of the variscan belt exhumation is due to continuing compression with an increasing compo nent of horizontal displacement the overall change of the shortening direction in a large sector of an orogenic belt with the occurrence of increasing orogen parallel displacement may be regarded as a general mechanism affecting the exhumation of rocks and preventing the thickened collisional crust from undergoing a generalized gravitational collapse

validation of regional and teleseismic travel time models by relocating ground truth events recently developed 3d global seismic velocity models have demon strated location improvements through independent regional and teleseismic travel time calibration concurrently a large set of high quality ground truth gt events with location accuracies 10 km or better gt0 gt10 has been collected for europe the mediterranean north africa the middle east and western eurasia in this study we demonstrate event location improvements using this new data set by applying the regional and teleseismic model based travel time calibrations independently and jointly besides relocating events using all arrivals a subset of the gt events was also relocated using controlled station geometries generated from a constrained boot strapping technique this approach simulates sparse networks and reduces the effect of correlated errors to ensure valid 90 error ellipse coverage statistics with respect to the gt events we compared event relocations with and without travel time cal ibrations considering statistics of mislocation error ellipse area 90 coverage or igin time bias origin time errors and misfit relocations of over 1200 gt events show that pn and or p calibration reduced mislocation for 60 70 of the events joint regional pn and teleseismic p travel time calibration provided the largest lo cation improvements and achieved approximately gt5 accuracy levels due to cor related errors event locations using large numbers of stations have deficient 90 error ellipse coverage however the coverages derived from the model errors are appropriate for the simulated sparse regional and teleseismic networks our valida tion effort demonstrates that the global model based calibrations of pn and teleseis mic p travel times reduce both location bias and uncertainty over wide areas

regional test of a model for shallow landsliding landslides mapped in 14 watershed analyses in oregon and washington provide a regional test of a model for shallow landsliding a total of 3224 landslides were mapped in watersheds covering 2993 km2 and underlain by a variety of lithologies including tertiary sedimentary rocks of the coast ranges volcanic rocks of the cascade range and quaternary glacial sediments in the puget lowlands gis geographical information system techniques were used to register each mapped landslide to critical rainfall values predicted from a theoretical model for the topographic control on shallow landsliding using 30 m dems digital elevation models a single set of parameter values appropriate for simulating slide hazards after forest clearing was used for all watersheds to assess the regional influence of topographic controls on shallow landsliding model performance varied widely between watersheds with the best performance generally in steep watersheds underlain by shallow bedrock and the worst performance in generally low gradient watersheds underlain by thick glacial deposits landslide frequency slides km2 varied between physiographic provinces but yielded consistent patterns of higher slide frequency in areas with lower critical rainfall values simulations with variable effective cohesion predicted that high root strength effectively limits shallow landsliding to topographic hollows with deep soils and locations that experience excess pore pressures but that low root strength leads to higher probabilities of failure across a greater proportion of the landscape 1998 john wiley sons ltd language en

tectonics and plate tectonics model for the variscan belt of europe abstract a plate tectonics model is presented to explain the tectonometamorphic characteristics of the european variscides after the closing of two oceanic domains by two sided subduction 500 420 ma and obduction 420 380 ma collision of the european and african continental plates occurred we propose that the subsequent complex intracontinental deformation 380 290 ma is the result of a double subduction of the continental lithosphere accompanied by crust mantle decollement this mechanism explains the progressive crustal thickening and migration of the deformation through time from the sutures toward the external parts of the variscan belt accounting for this model and for the relationships between the european variscides and the other paleozoic peri atlantic belts caledonides appalachian mauritanides and morocco we infer the relative positions of africa america and europe between the silurian and the permian

above the weathering front contrasting approaches to the study and classification of weathered mantle abstract weathered mantle comprises the materials above bedrock and below the soil it can vary in thickness from millimeters to hundreds of meters depending primarily on climate and parent material study of the weathered mantle comes within the realms of four disciplines geology geomorphology soil science and civil engineering each of which uses a different approach to describe and classify the material the approaches of engineers geomorphologists and geologists are contrasted and compared using example papers from the published literature soil scientists rarely study the weathering profile as such and instead concentrate upon soil forming processes and spatial distribution primarily in the solum engineers including engineering geologists study the stability and durability of the weathered mantle and the strength of the materials using sophisticated procedures to classify weathered materials but their approach tends to be one dimensional furthermore they believe that the study of mineralogy and chemistry is not useful geomorphologists deal with weathering in terms of process how the weathered mantle is formed and with respect to landform evolution using a spatial approach geologists tend to ignore the weathered mantle because it is not bedrock or to study its mineralogy and or chemistry in the laboratory i recommend that the approaches of the various disciplines be integrated geomorphologists and geologists should consider using engineering weathering classifications and geologists should adopt a spatial perspective to weathering as should engineers and engineering geologists

epicentre accuracy based on seismic network criteria summary we establish reliable and conservative estimates for epicentre location accuracy using data that are readily available in published seismic bulletins a large variety of seismic studies rely on catalogues of event locations making proper assessment of location uncertainty critical event location and uncertainty parameters in most global regional and national earthquake catalogues are obtained from traditional linearized inversion methods using a 1 d earth model to predict traveltimes reported catalogue uncertainties are based on the assumption that error processes are gaussian zero mean and uncorrelated unfortunately these assumptions are commonly violated leading to the underestimation of true location uncertainty especially at high confidence levels we find that catalogue location accuracy is most reliably estimated by station geometry we make use of two explosions with exactly known epicentres to develop local network location 0 2 5 accuracy criteria using monte carlo simulations of network geometry we find that local network locations are accurate to within 5 km with a 95 per cent confidence level when the network meets the following criteria 1 there are 10 or more stations all within 250 km 2 an azimuthal gap of less than 110 3 a secondary azimuthal gap of less than 160 and 4 at least one station within 30 km to derive location accuracy criteria for near regional 2 5 10 regional 2 5 20 and teleseismic 28 91 networks we use a large data set of exceptionally well located earthquakes and nuclear explosions beyond local distances we find that the secondary azimuthal gap is sufficient to constrain epicentre accuracy and location error increases when the secondary azimuthal gap exceeds 120 when station coverage meets the criterion of a secondary azimuth gap of less than 120 near regional networks provide 20 km accuracy at the 90 per cent confidence level while regional and teleseismic networks provide 25 km accuracy at the 90 per cent confidence level

geotechnical and landslide aspects in weathered granitoid rock masses serre massif southern calabria italy abstract the weathering processes produce important chemical and physical transformations in rock masses producing a decay of their strength and then stability in this study different methodologies were employed to define the physical mechanical properties and the minero petrographical changes at each grade of weathering useful to determine a geological model of the weathered granitoids involved in mass movements the paper focuses on a multidisciplinary research on the weathering profiles of the paleozoic granitoid rocks surrounding the village of fabrizia located in the serre massif southern calabria italy fabrizia lies on an old erosion surface composed of basement rocks made up of weathered granitoids belonging to the serre massif granitoid complex and overlain by thin eluvial colluvial deposits the tectonic uplift of the area combined with mediterranean climatic conditions both active at least since the quaternary are the main causes of the deep weathering of the plutonic rocks the weathered profiles of the granitoid complex have been studied through field observations borehole explorations with geotechnical tests and seismic surveys coupled to minero petrographical analysis and laboratory tests weathered profiles are mainly composed by rock masses varying from completely weathered and residual soil classes v vi to moderately weathered rocks class iii characterized by a progressive increase of geotechnical properties e g seismic wave velocity rock quality designation internal friction angle uniaxial compressive strength with a decrease of weathering the weathered rocks display a wide variety of mass movement landslide types are rockfalls for the fresher rocks class iii translational slides occur between different weathering degrees classes iv and v and rotational slides dominate at the top of the slopes and generally involve the weathering grades from class iv to classes v vi the shallow horizons are composed of thin eluvial colluvial deposits and more weathered granitoids classes v vi that may generate dangerous debris flows or debris avalanches during intense and prolonged rainfall the landslide surface is usually at a depth lower than 2 m in the debris flow type while deeper landslides depth 2 m are rotational and translational types with sliding surfaces occurring mainly in the transition between the classes iv and v the field survey coupled to geotechnical geophysical and minero petrographical data allowed the recognition of the different weathered horizons and relative geotechnical properties useful to the reconstruction of the reliable geological model the model represents an important support for the study of the landslide processes and for a sustainable management of the territory the used approach provided results to set a general reference framework for establishing more precise correlations between mass movement phenomena and weathering processes

isotopic evidence for late jurassic early cretaceous climate change abstract strontium oxygen and carbon isotope ratios have been determined from late jurassic early cretaceous belemnites from the volga basin russia and kawhia harbour new zealand 87sr 86sr ratios derived from well preserved belemnites from the volga basin support a middle tithonian age derived from the analysis of the endemic ammonite fauna the kawhia harbour section records a gradual rise in 87sr 86sr values and in comparison with the published 87sr 86sr curve suggests that the lower part of the section is latest oxfordian in age whilst the upper part of the section correlates well with the biostratigraphic correlation suggestion of an early middle tithonian age although the published strontium calibration curve shows a degree of scatter our new data confirm the uniform rise in 87sr 86sr values from the late jurassic into the early cretaceous such an increase may result from either a decrease in mid oceanic ridge spreading and or an increase in weathering rates and flux of radiogenic strontium although a eustatic drop in sea level and concurrent western cordillera uplift suggests that weathering may have been the controlling factor of late jurassic seawater strontium isotope composition palaeotemperatures derived from the well preserved belemnite 18ocarb values from the volga basin indicate that the middle volgian late kimmeridgian was warm 14 20 c followed by a slight cooling and a subsequent gradual increase to the jurassic cretaceous boundary the 18ocarb values from new zealand located at a palaeolatitude of 80 s if interpreted in terms of palaeotemperature indicate a high degree of variability such variability may not be related to palaeotemperature but to changes in oceanic chemistry resulting from the formation and dissolution of an ice sheet and or snow during the oxfordian kimmeridgian carbon isotope trends for the late jurassic show a fall in values from the oxfordian with lowest values occurring in the early middle tithonian before rising but without reaching values obtained in the oxfordian the overall low 13ccarb may be related to a global increase in continental weathering and or upwelling of cooler oceanic water enriched in oxidised organic carbon 12c enriched

the determination of statistical and deterministic hydrological landslide triggering thresholds hydrological landslide triggering thresholds separate combinations of daily and antecedent rainfall or of rainfall intensity and duration that triggered landslides from those that failed to trigger landslides they are required for the development of landslide early warning systems when a large data set on rainfall and landslide occurrence is available hydrological triggering thresholds are determined in a statistical way when the data on landslide occurrence is limited deterministic models have to be used for shallow landslides directly triggered by percolating rainfall triggering thresholds can be established by means of one dimensional hydrological models linked to the infinite slope model in the case of relatively deep landslides located in topographic hollows and triggered by a slow accumulation of water at the soil bedrock contact simple correlations between landslide occurrence and rainfall can no longer be established therefore real time failure probabilities have to be determined using hydrological catchment models in combination with the infinite slope model

landslides and climatic conditions in the barcelonnette and vars basins southern french alps france research into the climatic causes behind the triggering and reactivation of landslides has been carried out in two basins in the southern french alps where a great many landslides have occurred over more than a century correlations between landslides and climate are sometimes precise and closely related in time at other times imprecise and more distant the better known the type of landslide and the date of its occurrence the greater the correlation may appear be this as it may climate is never the sole cause this paper deals with the limits of the effects of climate

gondwana derived microcontinents the constituents of the variscan and alpine collisional orogens abstract the european variscan and alpine mountain chains are collisional orogens and are built up of pre variscan building blocks which in most cases originated at the gondwana margin such pre variscan elements were part of a pre ordovician archipelago like continental ribbon in the former eastern prolongation of avalonia and their present day distribution resulted from juxtaposition through variscan and or alpine tectonic evolution the well known nomenclatures applied to these mountain chains are the mirror of variscan resp alpine organization it is the aim of this paper to present a terminology taking into account their pre variscan evolution at the gondwana margin they may contain relics of volcanic islands with pieces of cadomian crust relics of volcanic arc settings and accretionary wedges which were separated from gondwana by initial stages of rheic ocean opening after a short lived ordovician orogenic event and amalgamation of these elements at the gondwanan margin the still continuing gondwana directed subduction triggered the formation of ordovician al rich granitoids and the latest ordovician opening of palaeo tethys an example from the alps external massifs illustrates the gradual reworking of gondwana derived pre variscan elements during the variscan and alpine tertiary orogenic cycles

evolution of the oceanic calcium cycle during the late mesozoic evidence from δ44 40ca of marine skeletal carbonates abstract the ca isotope compositions of 37 late mesozoic skeletal carbonates belemnites and brachiopods from the tethyan realm were analyzed by thermal tims and plasma mc icp ms ionization mass spectrometry a poor correlation between 44 40 ca and 18 o values of belemnites suggests only a weak temperature dependency for the ca isotope composition of belemnites likely less than 0 02 c the 44 40 ca record of belemnites was therefore used to reconstruct the ca isotope composition of paleo seawater 44 40 ca sw based on an experimentally determined fractionation factor between seawater ca and belemnite calcite cc sw of 0 9986 the inferred 44 40 ca sw record with an average stratigraphic resolution of 1 ma shows systematic temporal variation of 0 5 with the middle late jurassic 154 ma minimum of 1 4 and a subsequent general increase to the early cretaceous 124 ma maximum of 1 9 the global nature of the 44 40 ca sw record is supported by identical ca isotope compositions of coeval kimmeridgian belemnites collected from two distinct paleogeographic regions the southern new zealand and northern germany margin of the tethys ocean the observed late mesozoic 44 40 ca sw record was simulated using a simple ca isotope mass balance model and the results indicate that the variation in 44 40 ca sw record can be explained by changes in oceanic input fluxes of ca that were independent of the carbonate ion fluxes such as the hydrothermal ca flux or the release of ca to the oceans via dolomitization of marine carbonates

geophysical geotechnical and hydrological investigations of a small landslide in the french alps abstract geophysical geotechnical and hydrological surveys were conducted in the french alps on a small landslide in black marl material to assess the stability the geophysical survey consisting of electromagnetic geo electric and relative differences in water content the data on the basal slip surface together with geotechnical parameters cohesion and angle of internal friction were used to make a stability analysis this analysis revealed that a groundwater level of 4 m below the ground surface is the critical threshold for reactivating the landslide the hydrological investigation which entailed measurements of saturated permeability and pressure heads indicated that instability depended on long term wet conditions with little evapotranspiration

multi method characterisation of an active landslide case study in the pays d auge plateau normandy france shallow landslides are among the most frequent natural hazards in the pays d auge plateau normandy france but no study has yet focused on the functioning of these phenomena at a detailed scale this study aims to identify the structure and mechanical properties of a representative case study in the region the main objective is to understand landslide dynamics and behaviour in order to assess triggering conditions and quantify triggering thresholds the results will help complement the regional landslide hazard mapping based on landslide statistical susceptibility mapping and quantification of triggering thresholds the landslide morphology and internal structure were identified using a multi method approach a morphodynamic map was produced in the field using car tographic gps to depict the surface morphology and map the estimated landslide activity these field measurements were completed by an analysis of all available aerial photo images from the french national geographic institute ign to identify the occurrence dates and possible landslide reactivations the landslide structure was defined using multiple electrical tomography profiles boreholes augerings and penetration tests despite the overall low electrical resistivity of the landslide materials i e b 80 m the electrical profiles showed good agreement with the interpreted structure based on direct observations augerings and penetration tests the landslide slip surface internal morphology and palaeotopography were identified a finite slope model was used to calculate the landslide safety factor based on the internal structure and geotechnical data the evolution of this safety factor according to the rainfall and the groundwater levels shows that the landslides are more likely to occur after long episodes of high cumulative precipitations with an important role being played by the preliminary conditions and the rise of the surficial groundwater table level

paleoclimatic control of biogeographic and sedimentary events in tethyan and peri tethyan areas during the oxfordian late jurassic abstract the paleobiogeographical distribution of oxfordian ammonites and coral reefs in northern and central europe the mediterranean area north and east africa and the middle east and central asia is compared with the distribution in time and space of the most important lithofacies interest in the oxfordian is focused on changes in facies and in biogeographical patterns that can be interpreted as the results of climatic events paleotemperature trends inferred from oxygen isotopes and paleoclimatic simulations are tested against fossil and facies data a late callovian early oxfordian crisis in carbonate production is indicated by the widespread absence of lower oxfordian reefal formations there is a gap hiatus in deposition on epicontinental platforms with middle oxfordian deposits resting paraconformably on upper callovian while shales accumulated in adjacent intracratonic basins simultaneously in mediterranean tethys radiolarites accumulated in deep troughs while rosso ammonitico facies formed on pelagic swells however deposition on swells was also discontinuous with numerous gaps hiatuses and sequences that are much reduced in thickness middle callovian deposits are generally overlain by middle oxfordian limestones the dearth of carbonates is consistent with a cooling event lasting about 1 my by the middle oxfordian a warming leading to greenhouse type conditions is suggested on the basis of both biogeographical mostly coral reef distribution and geochemical data carbonates spread onto an extensive european platform while radiolarites reached a maximum development in the mediterranean tethys two distinct latitudinal belts with seemingly different accumulation regimes are therefore inferred similar latitudinal belts were also present in the late oxfordian when carbonates were widespread the distribution of reefal facies in the late oxfordian early kimmeridgian fits relatively well with gcms simulations that imply low rainfall in the tethyan mediterranean area and slightly higher precipitation in central and northern europe local salinity variations reflecting more arid or humid conditions may bias the paleotemperature signal inferred from 18o values biogeographical and facies distributions combined with 18o values unravel the ambiguity and support a late callovian early oxfordian cooling followed by warming in the later oxfordian

regional travel time uncertainty and seismic location improvement using a three dimensional a priori velocity model we demonstrate our ability to improve regional travel time prediction and seismic event location accuracy using an a priori 3d velocity model of western eurasia and north africa wena1 0 travel time residuals are assessed relative to the iasp91 model for approximately 6000 pg pn and p arrivals from seismic events having 2 epicenter accuracy between 1 km and 25 km ground truth 1 gt1 and gt25 respectively recorded at 39 stations throughout the model region ray paths range in length between 0 and 40 local regional and near teleseismic providing depth sounding that spans the crust and upper mantle the dataset also provides representative geographic sampling across eurasia and north africa including aseismic areas the wena1 0 model markedly improves travel time predictions for most stations with an average variance reduction of 29 for all ray paths from the gt25 events when we consider gt5 and better events alone the variance reduction is 49 for location tests we use 196 geographically distributed gt5 and better events in 134 cases 68 of the events locations are improved and average mislocation is reduced from 24 9 km to 17 7 km we develop a travel time uncertainty model that is used to calculate location coverage ellipses the coverage ellipses for wena1 0 are validated to be representative of epicenter error and are smaller than those for iasp91 by 37 we conclude that a priori models are directly applicable where data coverage limits tomographic and empirical approaches and the development of the uncertainty model enables merging of a priori and data driven approaches using bayesian techniques online material correction surfaces and histograms of travel time residuals for 40 stations

reconstructing the palaeoenvironment of the middle russian sea during the middle late jurassic transition using stable isotope ratios of cephalopod shells and variations in faunal assemblages abstract oxygen and carbon isotope data of well preserved belemnite rostra and ammonite shells are presented from the callovian oxfordian boundary uppermost lamberti to lowermost cordatum zones of the dubki section near saratov in the russian platform palaeotemperatures calculated for nektobenthic belemnites averages of 5 c and 8 c for cylindroteuthids and belemnopseids respectively show the presence of cold bottom waters in the central part of the middle russian sea during the studied interval palaeotemperatures calculated for ammonites which are assumed to have lived in near surface waters are considerably higher average 13 c the presented data show a vertical thermal gradient in the middle russian sea the belemnite oxygen isotope record and the relative abundances of ammonite families in the dubki section do not correlate with each other probably as a result of different depth habitats of ammonites and belemnites a review of literature isotope data shows the climatic zonation in european seas at the middle late jurassic transition despite the flux of cold polar waters to the middle russian sea and the area of scotland there is no evidence for glaciation at the middle late jurassic transition changes in water circulation during a sea level highstand were likely a source of spreads of cold bottom waters and cardioceratid ammonite fauna in this time period the belemnite isotope record of the callovian oxfordian boundary in the russian platform is characterized by significant scatter of 13c values no temporal carbon isotope trend is observed the 13c values of russian belemnite rostra average 2 6 vpdb being 1 to 2 higher than the values of coeval lower oxfordian belemnites from the area of the submediterranean ammonite province higher than submediterranean 13c values of russian belemnite rostra are likely related to high biologic productivity and or high organic matter burial in semi isolated boreal subboreal marine basins

climatic fluctuations and seasonality during the late jurassic oxfordian early kimmeridgian inferred from δ18o of paris basin oyster shells abstract oxygen isotope data from biostratigraphically well dated oyster shells from the late jurassic of the eastern paris basin are used to reconstruct the thermal evolution of western tethyan surface waters during the early oxfordian early kimmeridgian interval seventy eight oyster shells were carefully screened for potential diagenetic alteration using cathodoluminescence microscopy isotope analyses were performed on non luminescent parts of shells n 264 intra shell 18 o variability was estimated by microsampling along a transect perpendicular to the growth lines of the largest oyster shell the sinusoidal distribution of the 18 o values along this transect and the dependence of the amplitude of variations with bathymetry suggest that intra shell variability reflects seasonal variations of temperature and or salinity average amplitudes of about 5 c in shallow water environments and of about 2 3 c in deeper offshore environments are calculated these amplitudes reflect minimum seasonal temperature variation our new data allow to constrain existing paleotemperature trends established from fish tooth and belemnite 18 o data and are in better agreement with paleontological data more specifically a warming trend of about 3 c is reconstructed for oceanic surface waters during the early to middle oxfordian transition with maximum temperatures reaching 24 c in the transversarium zone late middle oxfordian from the transversarium zone to the bimmamatum zone a cooling of about 7 c is indicated whereas from the bimmamatum zone temperatures increased again by about 7 c to reach 24 c in average during the cymodoce zone early kimmeridgian

oxygen isotope fluctuations in a modern north sea oyster crassostrea gigas compared with annual variations in seawater temperature implications for palaeoclimate studies abstract a total of 181 oxygen isotope values from sequential samples of the left shell of a modern pacific oyster crassostrea gigas that lived on a sub tidal oyster bank in the list basin north sea germany shows periodically varying values between 1 3 and 2 5 in order to test whether these 18 o fluctuations reflect seawater temperature changes the isotope values of the shell were compared to actual seawater temperature variations from the region c gigas serves as an excellent proxy for temperature of palaeoseawater and the results show that the examined oyster precipitated its shell in 18 o equilibrium with the ambient seawater a cessation of the oyster shell calcification starts at water temperatures below 6 c at lower temperatures than previously thought for crassostrea for palaeoclimate investigations the termination of shell production is important because the lowest temperatures might not be represented in the shell higher water temperatures are therefore potentially over represented in time spans when the shell grows faster and mean oxygen isotope values may potentially bias the mean seawater temperatures of annual variations towards higher temperatures

weathering grade of rock masses as a predisposing factor to slope instabilities reconnaissance and control procedures weathering of rock masses often assumes importance as a predisposing factor to slope instability and it is possible to map it at various scales depending on the different purposes the effects of weathering processes are particularly intense on crystalline rocks plutonic and metamorphic these rocks are present in large areas of the globe and widespread in calabria the relationships between rock mass weathering grades and slope instabilities are analysed with reference to sectors 1 50 000 scale and areas 1 10 000 scale where crystalline rocks are strongly affected by weathering to this aim a reconnaissance procedure has been proposed to delimitate the zones with different weathering condition three macro classes at average scale 1 50 000 and six classes at detail scale 1 10 000 in this procedure first analysis of aerial photos and then field observations of representative situations have been used the reconnaissance procedure has been verified in a selected study area acri whose geological features are provided by the comparison with weathering maps obtained by means of a control procedure this last procedure consists of observations and index tests carried out in check points located in representative check sites discolouration sound when struck by geological hammer effect of the point of geological pick breaking with the hands rebound of schmidt hammer grain size analysis the results obtained confirm through quantitative data that the weathering of a rock mass can be assumed as a predisposing factor to slope instability at average scale 1 50 000 the reconnaissance procedure is able to give weathering maps representative for this type of evaluation the ratio between the landslides area in each weathering macro class and the whole landslide area goes from 67 to 14 for the macro class a and from 24 to 9 for the macro class b at detail scale 1 10 000 it is necessary to use a control procedure to obtain weathering maps indicative of predisposition to slope instabilities

reply to comment on improving sparse network seismic location with bayesian kriging and teleseismically constrained calibration events by stephen c myers and craig a schultz by a douglas we thank alan douglas douglas 2004 for his thoughtful comments on myers and schultz 2000 in myers and schultz 2000 we improve seismic location accuracy and uncertainty estimates for a sparse regional network by improving travel time predictions and better characterizing residual uncertainties station specific travel time corrections and associated uncertainty estimates are calculated using the bayesian kriging methodology of schultz et al 1998 the bayesian kriging methodology is an empirical approach that exploits the spatial correlation of travel time residuals to interpolate an empirical calibration set of travel time residuals into a minimum variance geographically continuous surface of travel time corrections and an associated uncertainty surface in myers and schultz 2000 we test the bayesian kriging approach by relocating events in the 1991 racha georgia earthquake sequence 42 n 43 e we compare uncalibrated locations based on p wave travel times for the ak135 model kennett et al 1995 and calibrated locations calibrated travel times and uncertainties to benchmark locations that are constrained with a dense local distance network the calibration data set consists of event locations that are constrained by a teleseismic network one goal of the study was to assess the utility of teleseismically constrained events for calibration we find that better travel time prediction for regional paths can be achieved by using the teleseismically constrained calibration events and the improved travel time prediction improves regional network location accuracy a major advantage of bayesian kriging over many other interpolation techniques is the propagation of uncertainty from the calibration data set into a travel time prediction uncertainty surface sources of data set uncertainty include calibration event locations phase observations for calibration events and calibration event spacing we find that coverage ellipses evernden 1969 are representative of observed epicenter accuracy i e confidence level of the coverage ellipse is indicative of the number of occurrences of the benchmark location within the ellipse when the

on the persistence of weathering abstract the term weathering has been in use for a very long time but it has come to mean different things to different people and hence as scientific short hand it no longer functions here we question the tenets underpinning the most common usage of the term and note that the climate process linkage implicit to the term is often missing and amounts to misdirection rather than climate as the primary driver behind specific weathering processes it is argued that rock properties constitute the dominant control further a case is made for reconsideration of our present bipartite mechanical chemical division of weathering processes and of the weathering processes currently deemed to be those that occur as process studies become evermore reductionist in nature so the functionality of the term comes more and more into question the linkage between process and landform the scaling up attribute is seen as a current weakness and one that will become more confusing as reductionist approaches continue as a way forward it is suggested that weathering stripped of specific preconceived notions of specific processes be envisaged as a function of energy transfer and be investigated in that light identification of new processes as well as restructuring of known processes particularly when considering weathering on other planets is a potential outcome of such an approach with a process foundation rooted in energy transfer rock decay provides a better umbrella term and liberates researchers from the inescapable conceptual baggage implicit to the term weathering

landslides triggered in weathered crystalline rocks of moderate latitudes a case study in mediterranean environment the maures massif france abstract the main purpose of this study is to characterize shallow and moderately deep landslide prone materials in crystalline rocks at moderate latitudes the procedure is based by a four step approach coupling the geomorphological approach the geotechnical approach and slope stability analyses based on limit equilibrium equations firstly different weathering horizons were identified with different thicknesses and characteristics depending on the original lithology these observations led to the development of a weathering model with two steps a regional paleo weathering step and a geomorphological weathering step secondly conceptual models of weathered horizon thicknesses were created according to the lithological context these models led to the identification of three major weathering types thirdly slope stability models were computed for three types of weathered lithology favourable theoretically to slope failure granit micaschists gneiss for each case the different models properly computed landslide occurrences and their locations for highly saturated weathered materials that corresponded to field observations to finalize the study a first analysis of precipitation data was carried out to define some triggering trends for slope failures in this environment therefore based on this simple approach it is possible to define some trends for shallow and moderately deep landslides in weathered crystalline environment located in moderate latitudes with mediterranean climate finally the information can be used by end users and practitioners for public works management on these slopes

landslide susceptibility in a mountainous geoecosystem tijuca massif rio de janeiro the role of morphometric subdivision of the terrain abstract the mountainous area of rio de janeiro is highly susceptible to landslides of creep translational and debris flow types these process operations are spatially non uniform due to local interactions of several controlling factors affecting the regolith formation and mechanical behavior including geomorphological geological geotechnical vegetation and land management variables this paper presents a methodology for morphometric subdivisions of the terrain based on hydro geomorphological parameters that may affect the landslide types indicated above it includes the so called hollow density h d and the strahler s drainage density parameters d d multiplied by the basin gradient g b to give the so called drainage efficiency index dei the range of dei values is classified so as to receive a legend for mapping the dei classes polygons are superposed to slope geometry and critical slope angles to produce the so called hydro geomorphological map the role played by these parameters in controlling landslide susceptibility is here evaluated by integrating this late map with relevant geological geotechnical vegetation and land use variables the final landslide susceptibility map 1 10 000 scale was successfully compared with the spatial distribution of several landslide scars originated during an extreme rainfall event in the western portion of tijuca massif february 1996 local morphometric controls over granite rocks with large in situ block formation together with forest degradation have controlled the occurrence of landslides in areas of medium to high susceptibility

preservation of delta 18 o and delta 13 c in belemnite rostra from the jurassic early cretaceous successions stratigraphic collection of 263 belemnite rostra guards from jurassic to lower cretaceous sediments in the moscow area of russia northern germany england new zealand and morocco were analyzed to determine temporal variations in their delta 18 o and delta 13 c as a proxy for isotopic composition of surface seawater internal structures of the rostra were studied using cathodoluminescence and sem techniques their trace element fe mn mg and sr and the stable carbon and oxygen isotope compositions the average stratigraphic resolution is about 1 ma these samples represent a broad range of paleolatitudes and paleoceanographic settings ranging from 42 degrees n to 82 degrees s covering boreal to subtropical brackish to open marine shelf paleoenvironments the rostra originally contained domains enriched in organic matter that were later replaced by luminescent diagenetic calcite thereby generating an impression of seasonal growth rings diagenetic calcite accounts for up to 6 8 percent of the rostrum the trace element content of the rostra range from 227 to 3935 ppm for mg 379 to 1514 ppm for sr and up to 305 and 3662 ppm for mn and fe respectively however selective drilling of only primary calcitic domains resulted in 90 percent of all analyzed samples to fall within the range of trace element values typical for modern low mg calcite shells the chemical and textural data suggest that the primary calcite of the rostra is well preserved as is its isotopic signature the delta 13 c and delta 18 o measurements define oscillating temporal bands of about 3 to 4 per mil width around more or less modern marine values of 2 and 1 per mil respectively oxygen isotopes in the well preserved rostra most likely reflect temperature variations within a approximately 14 or 8 degrees c range the observed 3 to 4 per mil spread of values between contemporaneous specimens which is comparable to the scatter of data reported for modern low mg calcitic brachiopod shells probably reflects the diversity of local ecosystems although some of the spread may be due to real short term temporal variations within single biozones the delta 13 c values of the rostra define a band similar to that of the oxygen isotopes and the temporal oscillations of both isotope curves are commonly in phase the above dataset complemented by the results of jones jenkyns and hesselbo 1994 and jones and others 1994 yields a composite delta 18 o and delta 13 c variations in belemnite guards for the entire jurassic early cretaceous interval for delta 18 o the oscillating band indicates that the most negative values occur at times of independently postulated global and or regional anoxic events such as those in the toarcian and kimmeridgian as well as the aptian these oaes appear to be characterized by up to 10 degrees c higher seawater temperatures than the intervening background times the delta 13 c record shows 13 c depletion for the kimmeridgian event but enrichment for the other two suggesting that the delta 13 c temporal oscillations and oaes are not simply a reflection of surficial productivity due to operation of the biological pump but rather of changing oceanic circulation patterns due to variations in latitudinal surface temperature gradients

errors in hypocenter location picking model and magnitude dependence abstract the location procedures of seismic events are influenced by two major classes of errors the error in picking individual seismic phases and modeling error due to the departure of the real earth from the reference model used in the location both classes of error influence the estimate of location and it is difficult to separate them the role of picking errors can be assessed by a nonlinear analysis using a monte carlo procedure arrivals times are perturbed with random numbers drawn from a normal distribution and the event is relocated using these perturbed arrival times by repeating the procedure many times a cluster of locations is obtained which can be used to investigate the effects of picking errors on the hypocenter this analysis is insensitive to velocity model errors as these are fixed for a given combination of stations and phases some care must be exercised when analysing multidimensional distributions in two dimensional slices because of a projection effect the modeling error due to the influence of lateral heterogeneity in the earth is examined by comparing the locations of the same event using different combinations of phases and network geometries which reinforces the need to use arrivals other than p for accurate depth resolution the sensitivity of p arrivals to changes in depth are swamped by model errors and inclusion of depth sensitive phases such as pp is highly recommended the effect of picking errors on location is found to be much smaller than the mislocation caused by neglecting lateral heterogeneity when only p arrivals are used consequently the monte carlo analysis which is primarily aimed at picking errors only is most appropriate when multiple phases have been used to more accurately constrain the hypocenter especially for the depth component altering the type of phase data used in the location plays a similar role in changing the network geometry in that both are mechanisms that influence the nature of the constraint on the hypocenter by relocating events with network geometries corresponding to the different magnitudes it is found that the location of the event can be affected significantly by the magnitude and when using robust statistics to describe earthquake residuals the mislocation can occur in a systematic manner the effect is marked in regions with significant lateral variations in seismic velocities for example low magnitude events in the flores sea are found to be dragged toward australia as a result of the fast paths to australian stations relative to the iasp 91 reference velocity model

south variscan terrane accretion sardinian constraints on the intra alpine variscides structural data are presented that show that the sardinian variscides form the boundary of the variscan intra alpine terrane thrust onto a gondwana foreland this model replaces the currently held hypothesis that the south armorican suture zone continues into the sardinian variscides the orogenic activity propagated toward the foreland in two distinct waves 1 thrusting burial and barrovian type metamorphism that reached the internal orogen in late devonian times and lasted in the external orogen until early carboniferous times transpressional strain partitioning is suggested by frontal thrusting in the external orogen and lateral displacement in the internal orogen 2 normal faulting exhumation and local buchan type metamorphism were superimposed on the internal orogen probably since early carboniferous times and reached the external orogen contemporaneously with the late carboniferous emplacement of voluminous granitic intrusions extensional doming and lateral displacement indicate a transtensional regime the sense of orogen parallel displacement during both stages was left lateral on inward dipping movement planes and right lateral on outward dipping movement planes the resulting left lateral displacement between the intra alpine terrane and the gondwana foreland is due to the bending of the variscan belt during which the sardinian segment underwent a bookshelf type movement within an overall right lateral displacement regime

dominant weathering profiles of granite in southern peninsular malaysia abstract one of the most important challenges in the study of slope stability foundations and excavation of rocks is to understand their weathering states this issue is more important in tropical climates where severe weathering produces thick weathering profiles with different sequences of weathering thick weathering profiles are normally classified or graded based on field observation geological studies and the material properties of the rocks this paper presents the results of an extensive study of changes in the geological and morphological characteristics of granite in a tropical region due to severe weathering a total of 40 panels of rock exposure were studied in four active granite quarries located in johor southern peninsular malaysia the proposed dominant weathering profiles of granite are mainly based on the sequences of weathering zone topography and geological conditions joint characterization and the dominant color of rock material in addition two additional weathering subzones are introduced in the completely and the highly weathered zones based on the presence of corestones boulders it is believed that the proposed dominant weathering profiles can contribute to engineering design and the classification of weathered granitic rock in the tropical region

distribution of glycerol dialkyl glycerol tetraethers in soils from two environmental transects in the usa abstract glycerol dialkyl glycerol tetraethers gdgts of both archaeal and bacterial origin form the basis of new temperature proxies applicable to soil and lake and marine sediments in soil branched gdgts are prevalent and their abundance of methyl or cyclic groups has been calibrated to mean annual temperature mat using mbt and cbt indices however soil ph is also known to be an important variable controlling the distribution of branched gdgts precipitation amount helps control soil moisture as well as ph and soil moisture is a leading variable affecting microbial diversity and activity in soil we have evaluated the distribution of gdgts from two soil transects in the usa a dry western transect covering six western states and a wet east coast transect from maine to georgia in order to assess the effect of precipitation on the distribution of soil gdgts our results show distinctly different gdgt distributions across climatic regions with dry western soils characterized predominantly by thaumarchaeotal isoprenoid iso gdgts and as a consequence low bit index values 0 2 0 6 and moist temperate east coast transect soils expressing mostly branched br gdgts and higher bit values 0 9 1 the predominance of iso gdgts in the western soils is related to the degree of aeration which in turn is related to precipitation amount and also to soil ph we also observed a substantial increase in the offset between measured mat and mbt cbt based mat below an annual precipitation of 700 800 mm yr 1 implying an impact of precipitation amount on mbt cbt based temperature reconstruction the data suggest that while soil tetraethers work well as a temperature proxy in moist temperate regimes they do not produce reliable measurements of temperature in sediments sourced from areas with 1 precipitation moreover erosion of soils with low bit values into lacustrine or marginal marine environments will not be detected via the bit index which can potentially affect paleotemperature reconstruction from sediments and so provide erroneous estimates of soil carbon delivery bit index values also show a correlation with precipitation amount the abundance of iso gdgts in western transect soils allowed calculation of tex 86 values but no correlation was found between tex 86 calculated temperature and mean annual temperature

improving sparse network seismic location with bayesian kriging and teleseismically constrained calibration events monitoring the comprehensive nuclear test ban treaty will require improved seismic location capability for small magnitude events the international monitoring system ims is well suited to locate events that are large enough to be recorded at teleseismic distances however small events are likely to be recorded on a sparse subset of ims stations at regional to upper mantle distances less than 30 and sparse network locations can be strongly effected by travel time errors that result from path specific velocity model inaccuracies in an effort to improve sparse network location capability we outline a procedure that applies empirical corrections to travel times determined with an appropriate velocity model more specifically bayesian kriging and calibration events constrained with a global network are used to estimate epicenter specific travel time corrections for a test sparse network of stations we calculate travel time residuals for the calibration events relative to the ak135 velocity model travel time residuals are assigned to the respective calibration epicenter forming a set of spatially varying travel time correction points the spatial set of correction points is declustered to reduce the dimension of the observations with minimal reduction in accuracy of the travel time corrections we then use the declustered set of calibration points and bayesian kriging to form continuous travel time correction surfaces for each station of the test network the effectiveness of travel time correction surfaces is evaluated by locating with and without corrections a subset of the 1991 racha earthquake sequence caucasus mountains for which we have accurate locations that were independently determined with a dense local network when no travel time correction is applied the mean horizontal distance between the local and test network locations is 42 km and there is a distinct bias in sparse network locations toward the north northwest the mean difference between local and sparse network locations is cut to 13 km when corrections are applied and the bias in location is significantly reduced when calibration events in the racha vicinity are not used to make the correction surfaces there is still a significant improvement in location with mean mislocations of 15 km when corrections are not applied only one of the locally determined locations lies within the associated 90 coverage ellipse determined with the test sparse network however by using travel time corrections and estimates of model uncertainty determined using kriging representative error ellipses are obtained this study demonstrates that kriging correction surfaces based on global network constrained calibration events can improve the ability to accurately locate lower magnitude events while providing representative coverage ellipses

thermal and mechanical evolution of an orogenic wedge during variscan collision an example in the maures tanneron massif se france synthesis of structural petrological and geochronological data for the maures tanneron massif and its integration in the framework of adjacent massifs i e sardinia and corsica has allowed us to propose a new model of evolution for the southern variscan belt after siluro devonian subduction associated with high pressure low temperature hp lt metamorphism m 0 c 10 15 8c km 21 and subsequent carboniferous nappes stacking the belt underwent strong reworking related to back thrusting nappes stacking and back thrusting were associated with typical barrovian metamorphism m 1 c 20 30 8c km 21 starting at 360 ma that progressively evolved to higher temperature metamorphisms m 2 c 40 60 8c km 21 and m 3 c 60 80 8c km 21 during 330 300 ma in the internal part of the belt progressive increase of the thermal gradient is interpreted as a consequence of gravitational instabilities triggered in the partially molten orogenic root continuous compressive forces applied to the belt allowed vertical extrusion of the orogenic root in fold dome structures the mass transfer is accommodated by orogen parallel transpressive shearing synchronous with m 3 during late carboniferous time the orogenic wedge is characterized by two main tectono metamorphic units decoupled by a major shear belt an internal zone with migmatites and syntectonic granitoids where hp relicts have been exhumed and an external zone that escaped the late ht event and preserved precious structures

paleoceanographic changes during the early cretaceous valanginian hauterivian evidence from oxygen and carbon stable isotopes we investigated valanginian hauterivian bulk rock and belemnite samples from vocontian basin sections in southeastern france for their stable carbon and oxygen isotope signature firstly because these sections permit calibration with high resolution biostratigraphy based on ammonites and secondly because detailed isotope studies for the hauterivian are lacking the results show that 13c values for bulk rock decrease during the late valanginian early hauterivian with 1 and increase again during the late hauterivian with 1 the 18o signal for bulk rock samples is mostly disturbed by diagenesis the belemnites show carbon and oxygen isotope values that are lower and higher than bulk rock samples respectively we explain this as the result of the belemnites recording a deeper water signal with lighter 13c values and heavier 18o values implicating colder water at greater depth the overall preservation of the belemnites is very good and permits the construction of a paleo temperature trend this trend shows warm deeper water temperatures during the late early valanginian 15 c and progressively cooler temperatures during the late valanginian and early hauterivian 11 c during the late hauterivian temperatures increase again 13 c we relate this cooling trend for deeper water to a second order sea level rise which allowed for the exchange of cold boreal and warm tethyan water masses the influx of cold nutrient rich water had a profound effect on carbonate producing biota along the northern margin of the tethys during the hauterivian leading to prolonged phases of condensation and platform destruction during the early hauterivian the carbonate system along the northern tethyan margin shifted into a green water mode of carbonate production high rates of carbonate production under mesotrophic conditions also observed in other parts of the world meant that the global carbon cycle became buffered shown by the stable trends in carbon isotopes

micro sheeting of granite and its relationship with landsliding specifically after the heavy rainstorm in june 1999 hiroshima prefecture japan certain types of granite in mountainous areas are microscopically sheeted to a depth of 50 m due to unloading under the stress field that reflects slope morphology micro sheets generally strike parallel to major slope surfaces and gently dip downslope forming cataclinal overdip slopes the cataclinal overdip slope accelerates creep movement of micro sheeted granite which in turn loosens and disintegrates granite via the widening or neoformation of cracks probably in combination with stress release temperature change and changes in water content near the ground surface the surface portion of micro sheeted granite is thus loosened with a well defined basal front which finally slides in response to heavy rain innumerable landslides of this type occurred in hiroshima prefecture western japan following the heavy rainstorm of 29 june 1999 following such landslides the weathering of micro sheeted granite exposed on the landslide scar recommences setting the stage for future landslide

characteristics of weathering zones of granitic rocks in malaysia for geotechnical engineering design tropical climatic conditions cause severe weathering to rock masses resulting in thick weathering profiles consisting of different weathering zones with complex characteristics feasible geotechnical engineering design requires a detailed understanding of the characteristics of each weathering zone a typical weathering profile is usually characterized by field scale observation and geological study this paper presents the characteristics of weathering zones of various granitic rocks in the south of malaysia this region has a tropical climatic condition the study was carried out in four active quarries located in johor province malaysia and forty sections were investigated in the study areas a typical granitic weathering profile was characterized based on the geological and structural parameters i e joint characteristics corestone occurrence rock soil ratio mass homogeneity color of rock and discoloration at joints surfaces the profile includes common zones ranging from fresh to residual soil however two subzones are introduced based on corestone boulder occurrence in the highly weathered and completely weathered zones this study based on detailed field observations at the mentioned quarries followed by analysis presents an amalgamated picture of weathering zones in granitic profiles of a tropical region like malaysia moreover it is believed that the characterization of the typical weathering profile allows further classification of generally complex weathered rock masses for a specific geotechnical engineering design