lewis ponds a hybrid carbonate and volcanic hosted polymetallic massive sulphide deposit new south wales australia the lewis ponds zn pb cu ag au deposit located in the eastern lachlan fold belt central western new south wales exhibits the characteristics of both volcanic hosted massive sulphide and carbonate hosted replacement deposits two stratabound massive to disseminated sulphide zones main and toms occur in a tightly folded upper silurian sequence of marine felsic volcanic and sedimentary rocks they have a combined indicated resource of 5 7 mt grading 3 5 zn 2 0 pb 0 19 cu 97 g t ag and 1 9 g t au main zone is hosted by a thick unit of poorly sorted mixed provenance breccia limestone clast breccia and quartz crystal rich sandstone whereas toms zone occurs in the overlying siltstone pretectonic carbonate chalcopyrite pyrite and quartz pyrite stringer veins occur in the footwall porphyritic dacite south of toms zone strongly sheared dolomite chalcopyrite pyrrhotite veins directly underlie the toms massive sulphide lens the mineralized zones consist predominantly of pyrite sphalerite and galena paragenetically early framboidal dendritic and botryoidal pyrite aggregates and tabular pyrrhotite pseudomorphs of sulphate occur throughout the breccia and sandstone beds that host main zone but are rarely preserved in the annealed massive sulphide in toms zone main and toms zones are associated with a semi conformable hydrothermal alteration envelope characterized by texturally destructive chlorite dolomite and quartz rich assemblages dolomite chlorite quartz calcite and sulphides have selectively replaced breccia and sandstone beds in the main zone host sequence whereas the underlying porphyritic dacite is weakly sericite altered vuggy and botryoidal textures resulted from partial dissolution of the dolomite altered sedimentary rocks and unimpeded growth of base metal sulphides carbonate and quartz into open cavities the intense chlorite rich alteration assemblage underlying toms zone grades outward into a weak pervasive sericite quartz assemblage with distance from the massive sulphide lens limestone clasts and hydrothermal dolomite at lewis ponds are enriched in light carbon and oxygen isotopes the dolomite yielded 13cvpdb values of 11 to 1 and 18ovsmow values of 6 to 16 liquid vapour fluid inclusions in the dolomite have low salinities 1 4 7 7 equiv wt nacl and homogenization temperatures 166 232 c for 1 000 m water depth dolomitization probably involved fluid mixing or fluid rock interactions between evolved heated seawater and the limestone bearing facies prior to and during mineralization 34svcdt values range from 2 0 to 5 0 in the massive sulphide and 3 9 to 7 4 in the footwall carbonate chalcopyrite pyrite stringer veins indicating that the hydrothermal fluid may have contained mamgatic sulphur and a component of partially reduced seawater the sulphide mineral assemblages at lewis ponds are consistent with moderate to strongly reduced conditions during diagenesis and mineralization low temperature dolomitization of limestone bearing facies in the main zone host sequence created secondary porosity and provided a reactive host for fluid rock interactions main zone formed by lateral fluid flow and sub seafloor replacement of the poorly sorted breccia and sandstone beds base metal sulphide deposition probably resulted from dissolution of dolomite fluid mixing and increased fluid ph pyrite sphalerite and galena precipitated from a relatively low temperature 150 250 c hydrothermal fluid in contrast toms zone was emplaced into fine grained sediment at or near the seafloor above a zone of focused up flowing hydrothermal fluids copper rich assemblages were deposited in the toms zone footwall and massive sulphide lenses in main and toms zones as the hydrothermal system intensified during the d1 deformation fracture controlled fluids within the lewis ponds fault zone and adjacent footwall volcanic succession remobilized sulphides into syntectonic quartz veins lewis ponds is a rare example of a synvolcanic sub seafloor hydrothermal system developed within fossiliferous limestone bearing facies the close spatial association between limestone hydrothermal dolomite massive sulphide and dacite provides a basis for new exploration targets elsewhere in new south wales

extensive deformations of rock slopes in southern coast mountains southwest british columbia canada extensive deformations of mountain slopes occur in crystalline intrusive rocks in the southern coast mountains of british columbia typical morphological evidence of slope movement includes extensive systems of tension cracks grabens and antislope scarps collectively referred to here as linears these landforms involve displacements along penetrative joints observed in surface exposures kinematic tests on rock structural data indicate that the observed patterns of linears are generally consistent with the feasible gravitational movements along the dominant discontinuities most sites indicate sliding as the most likely initial mode of movement followed by or accompanied by toppling and toppling induced sliding movements and do not support the view that linears are the traces of active faults

determination of residual strength parameters of jointed rock masses using the gsi system abstract the geological strength index gsi system proposed in 1995 is now widely used for the estimation of the rock mass strength and the rock mass deformation parameters the gsi system concentrates on the description of two factors rock structure and block surface conditions the guidelines given by the gsi system are for the estimation of the peak strength parameters of jointed rock masses there are no guidelines given by the gsi or by any other system for the estimation of the rock mass residual strength that yield consistent results in this paper a method is proposed to extend the gsi system for the estimation of a rock mass s residual strength it is proposed to adjust the peak gsi to the residual gsir value based on the two major controlling factors in the gsi system the residual block volume v b r and the residual joint condition factor j c r methods to estimate the residual block volume and joint condition factor are presented the proposed method for the estimation of rock mass s residual strength is validated using in situ block shear test data from three large scale cavern construction sites and data from a back analysis of rock slopes the estimated residual strengths calculated using the reduced residual gsir value are found to be in good agreement with field test or back analyzed data

long term gravitational deformation of rocks by mass rock creep abstract subsurface rocks beneath slopes are deformed to various degrees in various ways by mass rock creep mrc when they are subjected to a gravitationally unstable state for a long period mrc forms folds faults and numerous kinds of fractures such deformation is one of the main factors for deteriorating rock masses on slopes and also precursors of many landslides mrc deformations which have often been ascribed to tectonic origins can be distinguished from tectonic ones by their deformational features landforms and relationships between slope morphology and subsurface structures mrc folds are flexural slip folds that have the following mesoscopic to microscopic characteristics their axial surfaces are not smooth but are jagged and many visible openings or open fractures develop in association with the folds the jagged axial surfaces become smoother at depth and openings decrease in width with increasing overburden at the deformation site macroscopic types of mrc folds change according to the relationship between foliations and slopes buckling folds form in consequent slopes drag folds form in a deeper part of obsequent slopes and bending folds form in slopes with steep dipping foliations consequent or obsequent by downslope bowing of foliations shear fractures and tension fractures are the main deformational structures formed by mrc in massive rocks among shear fractures those of listric origin are remarkable tension fractures in general occur either in networks dividing rocks into fragments that slip and rotate irregularly in relation to each other or in parallel arrays of steeply dipping fractures an mrc fault has a shear zone consisting of a pulverized zone with gouge and a phyllitic or brecciated zone in a densely foliated rock the phyllitic zone is formed by microscopic slip along foliations in a sparsely foliated rock the brecciated zone is formed by random crushing except for the faults made through the shear fractures in massive rocks landforms due to mrc are gentle slopes bounded by horseshoe knicklines upslope convex slopes ridge top depressions multiple ridges uphill facing scarps and ridge crossing depressions

field investigation of dried lakes in western united states as an analogue to desiccation fractures on mars potential desiccation polygons pdps tens to hundreds of meters in size have been observed in numerous regions on mars particularly in ancient 3 gyr old terrains of inferred paleolacustrine playa geologic setting and in association with hydrous minerals such as smectites therefore a better understanding of the conditions in which large desiccation polygons form could yield unique insight into the ancient climate on mars many dried lakebeds playas in western united states display large 50 m wide desiccation polygons which we consider to be analogues for pdps on mars therefore we have carried out fieldwork in seven of these dried lakes in san bernardino and the death valley national park regions complemented with laboratory and spectral analysis of collected samples our study shows that the investigated lacustrine playa sediments have a a soil matrix containing 40 75 clays and fine silt by volume where the clay minerals are dominated by illite muscovite followed by smectite b carbonaceous mineralogy with variable amounts of chloride and sulfate salts and significantly c roughly similar spectral signatures in the visible near infrared vis nir range we conclude that the development of large desiccation fractures is consistent with water table retreat in addition the comparison of the mineralogical to the spectral observations further suggests that remote sensing vis nir spectroscopy has its limitations for detailed characterization of lacustrine playa deposits finally our results imply that the widespread distribution of pdps on mars indicates global or regional climatic transitions from wet conditions to more arid ones making them important candidate sites for future in situ missions

deep explosive focal depths during maar forming magmatic hydrothermal eruption baccano crater central italy we describe the eruptive activity of the pleistocene composite baccano maar crater in the sabatini volcanic complex central italy combining stratigraphy grain size componentry and rare earth element and yttrium rey composition of its eruptive products with the stratigraphy and geothermal data derived from deep wells drilled on the baccano structural high the main lithological characteristics of the basal baccano maar pyroclastic deposit composed of more than 60 wt of non thermometamorphosed lithic clasts from the sedimentary basement show that the first eruption was magmatic hydrothermal in nature the lithology of the sedimentary lithic clasts indicates that the fragmentation level was at a depth of 1 000 to 1 200 m with fragment depth verified by deep well stratigraphy the 15 wt juvenile non vesicular glass components suggest that magma played a minor role in powering the eruption assuming that the high salinity hot hydrothermal fluids 365 1 400 m by the aggressive hydrothermal fluids enriched in acid components hf hcl and h2so4 may have contributed to increased co2 partial pressure that helped to drive the hydrofracturing this could have caused rapid vapour separation and pressure drop allowing the almost simultaneous breaking of the aquifer cover and brecciation of the calcareous units down to 1 000 to 1 200 m depth the relative abundance of calcareous lithics in the basal part of the first baccano eruptive unit representing about the upper 200 m of stratigraphy below the top of the baccano structural high reveals the descent of the piezometric surface during the eruption combining deep well information and maar product stratigraphy using also rey data from maar pyroclastic fragments and the basement rocks we draw an interpretative model for the baccano maar forming eruption concluding that a magmatic hydrothermal eruptions may originate deeper than previously thought and b hydrothermal fluids circulating in limestone aquifers may play an important role in triggering such eruptions

reflectance spectroscopy of soils post heating assessing thermal alterations in soil minerals abstract we examined the potential of reflectance spectroscopy across the vis nir swir spectral region to identify ex post facto the thermal processes that occur in heated soils and minerals and thus to monitor mineral changes in the soil we systematically investigated five israeli soils and six standard soil minerals using a controlled furnace from 150 c to 1000 c at 50 c intervals samples which had been heated and cooled soils and minerals were measured for reflectance across the 350 2500 nm spectrum using an asd field pro spectrometer to confirm the findings extracted from the spectral information traditional analytical methods xrd dta dtg psd sem eds were used the spectral information was found to be a good indicator for thermal processes occurring in the soil based on mineralogical changes the spectral changes across different spectral regions provided information about dehydroxylation of goethite to form hematite vis nir clay deformation lattice collapse due to dehydroxylation processes vis nir swir the condition of calcite swir and indirect processes such as re adsorption of water and rehydration of the new minerals e g pyrolysis of the calcite product swir we propose the use reflectance spectroscopy for post thermal analysis rs pta as a valid post heating diagnostic method for thermal processes occurring in minerals and soils the suggested method is simple and easy to perform and can be used in all domains laboratory and field point and image to monitor heat induced changes in soil minerals

effects of drying heating annealing and roasting on carbonate skeletal material with geochemical and diagenetic implications abstract carbonate skeletons subjected to drying heating annealing or roasting at elevated temperatures as part of routine sample preparation for chemical analyses or geochemical experiments differ significantly from skeletal materials as they occur in nature heating of skeletal samples can degrade organic material expel h2o and oh reduce the concentration of some trace elements and change the mineralogy and texture of the material thermal degradation of organics and expulsion of water in inclusions which can occur at temperatures of 100 105 c cause fracturing and pitting of skeletal samples areas of pitting reflect original concentrations of volatile phases within the skeleton coralline aragonites are partially or completely altered to calcite at temperatures of 150 c or higher the degree of alteration varies with temperature and duration of heating and genus of the coral high mg calcites hmcs tend to form calcian dolomite and multiple hmcs of lower mg content on heating but the rate of alteration is related to the taxonomic group rather than the mg content echinoids alter very rapidly dolomite detectable by x ray diffraction formed in clypeaster heated for 6 h at 200 c while the coralline red alga neogoniolithon showed no alteration after heating at 400 c for 23 h mineralogical alteration of coralline aragonites and echinoid hmcs is positively correlated with water loss skeletal carbonates comprise a very diverse and heterogeneous suite of materials and their diversity and heterogeneity are reflected in their responses to heating variations in rate and degree of alteration on heating in many cases between different subsamples of material produced by the same organism make it difficult to obtain a consistent product from heat treatment many workers have used high temperature experiments to model diagenetic processes and the results of this study have implications for diagenetic alteration as well as for laboratory analyses and experiments

spatial distribution analysis of landslides triggered by 2008 5 12 wenchuan earthquake china abstract the 2008 5 12 wenchuan earthquake seismic magnitude mw 7 9 according to the usgs triggered a great number of landslides a spatial database of landslides is built by interpreting the remote sensing rs data which covers 11 counties severely damaged by the earthquake with area of about 31 686 12 km2 the geological settings of the study area are detailed mapped including geologic structure and lithology the digital elevation model dem of the study area with resolution of 30 m 30 m is presented to address the topographic characteristics correlations between the occurrence of landslides with geological settings i e active faults the coseismic surface ruptures geological unit slope gradient slope elevation as well as slope aspect are analyzed using spatial modeling in gis with the aids of field investigations it can be concluded that the distance to the causative faults and slope gradient are much more important than other factors landslides are clustered distributed along the causative faults of f2 and f3 and landslides incidence are dramatically decreasing with the increasing of the distance to the causative faults the landslides incidence has an obvious increase near the active faults i e f1 landslide concentration lc landslides km2 has an obvious exponent increase with slope gradient however lc has no obvious relationship with geological unit and slope elevation the difference of lc value in each geological unit each slope elevation category maybe have been the result affected by slope gradient for each geological unit each slope elevation category and distance of each geological unit each slope elevation category to causative fault zone isoseismal map reflects the incidence of landslides in some degree and lc increases dramatically with intensity increasing almost all landslides occurred in the region above vi degree statistics result also indicates that in the near field of causative faults landslides tend to have the initial sliding direction similar to the movement of the causative faults and preliminary study shows that landslides incidence varies in different slopes with different structure and consequent slopes and obsequent slopes have a higher landslides incidence than other layered slopes

a new practical method for prediction of geomechanical failure time abstract predicting the failure time of geo hazards is an important rock mechanics problem we first evaluated the validity of the inverse velocity inv method to predict failure time of rock mass and landslides this method utilizes rates of displacement or strain to predict the actual failure time tf so the value of total displacement or strain before failure is not crucial second we developed a new method for computing failure time predictions based on the slope gradient to predict tf termed the slo method finally a simple conceptualised model representing safe and unsafe predictions was proposed to validate these hypotheses prediction of rock mass failure in the asamushi and vaiont landslides in situ studies was conducted furthermore laboratory conditions were incorporated into the research which include predictions using circumferential strain and axial strain from uniaxial compression creep test on shikotsu welded tuff swt and predictions of failure time for inada granite under brazilian creep tests it was found that the slo method is better than the inv method slo gave safe predictions in all the cases in contrast inv tends to give unsafe predictions predicted failure time tfp tf our findings reveal that predictions using circumferential strain are better than those made using axial strain for swt and notably given failure with very short tertiary creep the methods tend to show limited reliability however the slo method could find extensive application in predicting failure time of geo hazards for instance roof wall failure in mines etc

modelling of time dependent behavior of the basal sliding surface of the aknes rockslide area in western norway abstract numerical modelling based on the finite difference code flac3d and the burger creep viscoplastic material model has been used for analysing time dependent behavior of the unstable rock slope at aknes in western norway the rockslide has an estimated volume of 43 million m3 with a basal sliding surface located 105 115 m below the surface displacement measurements by gps and reflector points which since 2004 have revealed average annual displacements in the order of 26 mm year in the central part of the sliding area have been used to calibrate the model the modelling shows that a set of parameters believed to represent the conditions of the slope at present time 3 intact rock in the sliding plane and surface conditions representing good surface conditions in the gsi system results in displacements which stabilise within a 100 year period however as the shear strength parameters are reduced according to 1 intact rock in the sliding layer and surface conditions representing fair surface conditions in the gsi system increased displacement and indications of failure at the toe of the slope are evident within the same time span

assessment of periglacial slope stability for the 1988 tschierva rock avalanche piz morteratsch switzerland the tschierva rock avalanche occurred on october 29 1988 in the area of the piz morteratsch switzerland releasing a total volume of 300 000 m3 the avalanche ran out over 1 km destroying a hiking trail before stopping on the tschierva glacier we analyze the setting of this periglacial slope failure combining geomechanical and cryosphere investigations to identify the primary factors contributing to the rock avalanche an approach to slope stability assessment is presented that copes with existing data limitations in an inaccessible alpine terrain results from the analyses of morphology geology glaciation history permafrost hydrology and meteorological data allowed preliminary inferences to be made regarding the influence of these factors on slope stability conceptual kinematic and numerical slope stability modeling critically analyzed the role of kinematic degrees of freedom glacier retreat and water infiltration from above the detachment zone results highlight the strong influence of discontinuity orientation with respect to the slope face the role of a fault zone with increased joint density and long term progressive development of persistent discontinuities induced by glacier retreat and groundwater loading cycles in leading to the rock avalanche the role of permafrost could not be clearly assessed however observations and analyses indicate that permafrost had no dominant influence on the slope failure extraordinary precipitation prior to the event is suggested to have played a role in triggering the rock avalanche especially in combination with observed superficial ice that could have sealed the rock face generating high water pressures our results emphasize the importance of analyzing multiple contributing factors when assessing alpine rock slope failures with careful consideration of data limitations prevailing in such areas

impact of weathering on the geomechanical properties of rocks along thermal metamorphic contact belts and morpho evolutionary processes the deep seated gravitational slope deformations of mt granieri salincriti calabria italy abstract numerous deep seated gravitational slope deformations dsgsds occur throughout italy that originate from particular tectono stratigraphic settings relief seismicity deglaciation as well as from intense and deep processes of chemico physical weathering of crystalline metamorphic rocks these dsgsds are particularly widespread in the calabrian mountains this study is focused on the mt granieri salincriti slope on the ionian side of the serre massif where granites and granodiorites stilo unit palaeozoic are in contact with metamorphites through a thermal metamorphic aureole this setting generates deep geochemical processes inducing intense chemical weathering these processes are mainly due to the interaction between groundwater and the sulphides that are contained in the local pegmatitic hydrothermal intrusions especially along the thermal metamorphic contact belt the mt granieri salincriti slope has an important dsgsd which is associated with many active and or quiescent landslides among these landslides the salincriti rock avalanche debris flow about 2 m m3 represents the paroxysmal and terminal stage of the deep creep deformations of mt granieri typifying a geological setting that is common in the calabrian arc this multi disciplinary study assessed the weathering susceptibility of the local crystalline metamorphic rocks especially those lying along thermal metamorphic contact belts by characterising the weathering horizons and the spatial distribution of weathering in the rock mass the study was also aimed at identifying the relations between weathering above all deep geochemical processes effects on rocks and slope morphodynamics the methodology was based on detailed geological data geological engineering surveys geomorphology and surface hydrogeology analyses as well as physico mechanical laboratory tests these investigations supported by a monitoring program led to the development of an engineering geological model of the slope geological character attributed to a thermal metamorphic contact belt geomorphological evidence and geomechanical elements elucidated the interactions between deep geochemical processes and weak belts in the investigated rocks as well as the critical role that these interactions play in the evolution of deep seated creep deformations and associated shallow landslides

creep and time dependent damage in argillaceous rocks abstract this paper presents the results of laboratory tests on the time dependent behaviour of three rocks characterized by a high proportion of clay particles the viscosity of these sedimentary rocks was studied under different loading conditions in uniaxial compression static or cyclic creep tests and quasistatic tests low loading strain rate were performed across various orientations of fabric planes the quasistatic tests showed similarities in the mechanical response of these three argillaceous rocks a late phase of dilation and a linear development of volumetric deformation before the beginning of unstable crack propagation the development of secondary and tertiary creep phases during the creep tests highlighted the existence of a deviatoric stress threshold below which only primary creep is observed long term creep tests also showed that the volumetric variation is not constant during the development of viscoplastic deformations a microstructural analysis of thin sections extracted from specimens after the tests gave evidence of cataclastic and granular creep damage to the argillaceous matrix occurs and no cracks were observed in the quartz and carbonate grains this evidence was also demonstrated for tests with loading at a high strain rate finally this study highlights the significant viscoplasticity of argillaceous rocks the mechanical properties deteriorate rapidly when crack propagation becomes unstable and the viscoplastic strains seem to be due to clay particle slips known as granular creep

hydrothermal phlogopite and anhydrite from the sh2 well sabatini volcanic district latium italy fluid inclusions and mineral chemistry

study of the reed dolomite aided by remotely sensed imagery central white inyo range easternmost california remote sensing methods are of great value in assessing the stratigraphy and geologic structure of inaccessible terrains especially where lithologic contrasts are marked in this paper we show that such techniques can be successfully applied to a massive carbonate unit the reed dolomite exposed in the waucoba mountain blanco mountain and mount barcroft quadrangles of east central california airborne ns 001 satellite landsat tm and spot panchromatic imagery combined with conventional geologic mapping were employed to demonstrate that observed spectral variations on false color images were caused by subtle compositional variations of the dolomite based on reflectance differences and field investigations six discrete bedding units were recognized in exposures of th reed dolomite from lower to upper they are 1 very coarse grained granular gray pisolitic blocky dolomite 2 medium grained white oolitic massive dolomite 3 fine to coarse grained light gray oolitic massive crystalline dolomite and rare interbedded rusty quartzarenite 4 medium fine grained cross stratified locally ocherous brown interlayered quartzarenite tan siltstone and sandy dolomite 5 fine grained thin bedded sparsely oolitic buff dolomite and 6 fine grained fissile dull white dolomite subunit 4 and underlying subunit 3 appear to interfinger with subunit 4 representing a more proximal shelf facies in the southeast corner of the mapped area subunit 4 is present and subunit 3 is absent with the situation reversed along the western and northern portions of the range subunit 5 thins to a feather edge on the north near the barcroft granodiorite thickness variations of the different reed stratigraphic entities in the eastern and northern white inyo range may reflect attenuation caused by granitoid intrusion as well as original stratigraphic variations the broad expanse of reed dolomite directly northeast of the sage hen flat pluton is due to north south trending folds details of the white inyo anticlinorium are now better resolved in the central portion of the ra ge where previously undetected folds faults and homoclinal sections are revealed in false color imagery of the macroscopically featureless reed dolomite thickness trends and facies boundaries for the newly recognized subunits trend north south or north northeast throughout the study area locally reflecting the gentle west northwest continental shelf paleoslope of the passive margin of western north america during latest precambrian early cambrian this study is important to petroleum geologists because it demonstrates that detailed stratigraphy and structure can be determined using remote sensing techniques in semiarid regions where massive indistinct carbonate units crop out in some cases no single processing method allows spectral discrimination of all lithostratigraphic entities furthermore the spectral characteristics of a specific unit have been shown to vary even within a single image hence our work underscores the site specific limitations of individual multispectral methods and illustrates why a combination of diverse methods needs to be employed finally geologic lessons learned within the study area may be extrapolated to similar terrains elsewhere within the basin and range province end page 1008

slope instability mechanisms in dipping interbedded conglomerates and weathered marls the 1999 rufi landslide switzerland in may of 1999 melting snow cover combined with heavy rainfalls in the northeastern part of switzerland resulted in the occurrence of numerous shallow landslides many of these slides were located in the subalpine molasse a series of interbedded marls conglomerates and sandstones the subalpine molasse is highly prone to such sliding activity given the dip of bedding the surface topography and the weak nature of the marls that rapidly degrade when exposed to weathering historically the subalpine molasse has been the source of numerous slides of varying orders of magnitude and the surficial morphology is primarily dictated by previous rockslides which periodically reactivate as secondary soil slips given the conditions contributing to the slope failure and the history of previous sliding similar slides within the region are highly probable this paper presents the findings from a detailed investigation of one such slide the 1999 rufi slide results from a detailed engineering geological investigation show that the initial rockslide failure plane predominantly developed and passed through the marl beds as dictated by the penetration of the weathering front into the marls and not along reactivated shears or the bedding plane contact between the marls and overlying conglomerates numerical modelling results based on a coupled hydromechanical distinct element analysis were able to reproduce this mechanism by incorporating a progressive strength degradation procedure correlated to mapped weathering grades

early fluid migration in a deep part of the larderello geothermal field a fluid inclusion study of the granite sill from well monteverdi 7 abstract metamorphic magmatic to hydrothermal fluids trapped in fluid inclusion planes fip were studied in a microfractured granite sill from a deep level 3483 3486 m b g l of the well monteverdi 7 larderello geothermal field this granite has recorded a complex succession of fluid migration through a dense set of healed microcracks nine generations of fluids trapped within specific microcrack networks are distinguished and include vapors and liquids of the c h o n s system aqueous liquids and brines with distinctive sets of cation chlorides licl nacl nacl cacl 2 and nacl detailed studies of the geometrical and chronological relationships between the fluid inclusion planes allow the establishment of a clear relative chronology with the c h o n s and licl fluids being earlier than the nacl cacl 2 and nacl aqueous liquids and brines in particular it can be shown that the c h o n s and licl fluids are strongly associated in space and time since the corresponding fluid inclusion planes display evidence of mutual contamination of inclusions within the planes significant changes in the physical chemical parameters occurred in the conditions of fluid trapping during the evolution of the larderello field all observed paleofluids have compositions differing from that encountered in the present day fluids and record a complex p t t x evolution from an early stage dominated by magmatic and metamorphic derived fluids towards a later stage dominated by more surficial waters at the early stage hydrothermal circulation occurred under lithostatic pressure at a depth of ca 4 5 km at temperatures as high as 450 500 c such conditions are very reminiscent of contact metamorphism and were probably created by the deep intrusive body detected by geophysical studies batini et al 1983 1985 the involved fluids are c h o n s vapors and liquids of metamorphic derivation and aqueous li bearing brines of probable magmatic derivation they are consistent with the hypothesis of the intrusive being a granite at the later stage physical conditions had evolved towards hydrostatic pressure at a depth close to the present 3 5 km one and temperatures of 400 350 c still higher than the present day ones early fluids were no longer present the observed fluids record the involvement of more surficial waters both meteoric and connate transient boiling events were probably occurring heralding the present day conditions vapor dominated geothermal system nevertheless no trapped fluids display similar composition and density with the present day geothermal fluids at larderello in old geothermal fields such as larderello it must be emphasized that the use of fluid inclusions in order to reconstruct past hydrothermal evolution is strongly dependent onto pressure estimation since significant temperature corrections may be needed in the larderello case failing to take in account the pressure effects would have led to seriously misleading conclusions

development of progressive landslide failure in cohesive materials the development of progressive failure in slopes is a poorly understood process and relatively few advances in terms of the mechanics of the development of failure have been made since 1967 however advances in the understanding of the development of fractures in brittle materials provide new insights into landslide mechanics in addition the link between the deformation mechanism and movement type allows interpretation of displacement records to determine the mechanisms acting within a slope this paper utilizes these insights into deformation processes combined with reinflation stress path triaxial experiments to propose a new model for the development of a progressive first time failure within a slope this model is able to explain the development of failure when the factor of safety is greater than unity the existence of saito linearity a linear trend when the reciprocal of velocity prior to failure is plotted against time during tertiary creep and the development of failures during periods of apparently increasing normal effective stress

deep seated failure propagation in a fractured rock slope over 10 000 years the la clapiere slope the south eastern french alps abstract the la clapiere area tinee valley alpes maritimes france is a typical large complex unstable rock slope affected by deep seated gravitational slope deformations dgsd with tension cracks scarps and a 60 106 m3 rock slide at the slope foot that is currently active the slope surface displacements since 10 ka were estimated from 10be ages of slope gravitational features and from morpho structural analyses it appears that tensile cracks with a strike perpendicular to the main orientation of the slope were first triggered by the gravitational reactivation of pre existing tectonic faults in the slope a progressive shearing of the cracks then occurred until the failure of a large rock mass at the foot of the slope by comparing apertures variations and changes in direction between cracks of different ages three phases of slope surface displacement were identified 1 an initial slow slope deformation spreading from the foot to the top characterized by an average displacement rate of 4 mm yr 1 from 10 5 6 ka bp 2 an increase in the average displacement rate from 13 to 30 mm yr 1 from the foot to the middle of the slope until 3 6 ka bp and 3 development of a large failure at the foot of the slope with fast displacement rates exceeding 80 mm yr 1 for the last 50 years the main finding of this study is that such a large fractured slope destabilization had a very slow displacement rate for thousands of years but was followed by a recent acceleration the results obtained agree with several previous studies indicating that in situ monitoring of creep of a fractured rock slope may be useful for predicting the time and place of a rapid failure

applying terzaghi s method of slope characterization to the recognition of holocene land slippage abstract during site investigations engineering geologists are expected to recognize landslides both active and dormant those without substantial experience evaluating the evolution of geomorphic features associated with localized mass wasting often mischaracterize site conditions karl terzaghi suggested seven steps in characterizing natural hillslopes including 1 a literature review 2 site reconnaissance 3 a program of subsurface exploration 4 preparation of sketches and diagrams illustrating the essential features 5 preparation of a preliminary geology report 6 observation and mapping of geologic structures exposed during excavation for construction and 7 development of contingency plans for anticipated variations in old landslide features based on our interpretation of terzaghi s original principles we review some of the most common interpretive problems with nomenclature of landslide features describe common mistakes in characterizing old landslides and present technical approaches that often aid in the recognition of old landslide features a wide variance in geological terms exists for describing landslides and various terms have been applied to the same features by workers in different areas which often leads to confusion some of these terms include nomenclature such as slip surfaces alluvial fans colluvium and slope creep active surficial landslides are relatively easy to recognize when they are well exposed although these features tend to become obscured with time anomalous hummocky topography often provide key recognition features of a slope s geomorphic evolution deeper seated bedrock landslides can be more difficult to recognize because their features become increasingly mollified with time these features can often be identified by anomalous geomorphic features such as isolated saddles or anomalous discontinuous benches these features are some of the best locations to excavate borings or exploratory trenches well placed trenches across headscarp grabens can provide more detailed structure of old landslides and are usually a cost effective approach additional subsurface exploration can often be employed to characterize landslides small diameter borings are usually employed for geotechnical investigations but can easily be applied to landslides depending on the mean particle size diameter d50 downhole logging of large diameter holes is the best method to evaluate complex subsurface conditions such as dormant bedrock landslides

mapping of neoproterozoic source rocks of the huqf supergroup in the sultanate of oman using remote sensing abstract in recent years the neoproterozoic huqf supergroup formations of the oman salt basins have been the target for oil exploration the present study maps the surficial exposure of the huqf supergroup in and around khufai dome of the huqf area in the sultanate of oman using low cost multi spectral remotely sensed satellite data and image processing methods such as decorrelation stretching principal component analysis pca and spectral angle mapper sam as alternative to expensive and time consuming tools which have the capability and potential to be used by geoscientists for oil exploration in this research the study of advanced spaceborne thermal emission and reflection radiometer aster spectral bands 8 3 and 1 by decorrelation stretching well discriminated the masirah bay the khufai the shuram and the buah formations of the nafun group the source rocks of huqf supergroup with the quaternary deposits the analysis of visible and near infrared shortwave infrared spectral bands of aster by pca clearly showed the occurrence and spatial distribution of such formations in the rgb principal component images r pc1 g pc2 b pc3 the spatial distributions of such formations are assessed by confusion matrix after using maximum likelihood ml spectral angle mapper sam and spectral information divergence sid algorithms the matrix of ml algorithm has provided the best overall accuracy of 92 93 and kappa coefficient of 0 92 the minerals of the formations were detected by sam further the detection of such mineral groups was confirmed through the aster thermal infrared tir spectral indices image developed using the carbonate index ci quartz index qi and mafic index mi all results of image analyses are evaluated in the field and laboratory studies the study also evaluates the satellite data and image processing methods for the formations of jabal akhdar the equivalent formations of the khufai dome to show the sensor capability and the use of the image processing methods to study the source rocks the results of the study provided similar discriminations comparable to the khufai dome therefore the data and the techniques are recommended to the exploration geologists for use in similar regions of the world

structural control and types of movements of rock mass in anisotropic rocks case studies in the polish flysch carpathians abstract types of gravitational movements in the flysch carpathians are related to tectonic and lithologic anisotropy of rock massifs this article presents the main types of mass movements in the highly anisotropic flysch massifs lateral spreading and rock flow topple translational rotational and compound sliding and complex type of mass movements which are illustrated by chosen forms described using structural analysis joints faults and other structural planes orientation topple is the typical mass movement for double ridges and top trenches e g gaworzyna in the beskid s decki mts translational landslides with flat structural sliding surfaces typical for shallow forms can develop along bedding planes e g duszatyn western bieszczady mts as well as along joints opuszna gorce mts and fault planes rzeki gorce mts currently used classification of the structural landslides is applied only to translational landslides shearing zones of deep seated landslides are composed of structural sections of joints faults bedding planes and shearing elements consequently most of the carpathian landslides have developed as compound type with non circular sliding zones representing complex movements combined with various types of displacement rotation translation and or topple purely rotational movements with circular failure typical for isotropic material have developed in the flysch where thick bedded hard sandstones are underlain by plastic shales e g mt kostrza in the beskid wyspowy mts the influence of anisotropy of these rocks on sliding surface is significantly reduced and plastic type rocks stimulate rock flow development which is usually later transformed into complex landslides with predominant rotational movement e g rotational landslide with topple and flow elements on mt muronka in the beskid l ski mts compound landsliding on mt lubon wielki beskid wyspowy mts represents an antithetic rotational slide with topple and rotational type movements

inferring total organic carbon and major element geochemical and mineralogical characteristics of shale core from hyperspectral imagery hyperspectral systems that image drill core can capture detail mineralogical information at the millimeter scale and thus have the potential to enable investigators to characterize shale composition and heterogeneity complementing the direct chemical and x ray diffraction analysis of core samples and guiding detailed sampling this method provides insight into petrophysical and geomechanical properties because these properties are significantly correlated to rock composition we tested this approach on a continuous long core from the shale sequence of the horn river group in the horn river basin british columbia sampled at a spacing of 1 m 40 in and analyzed for geochemical composition these data enable the calibration of spectral imagery to rock composition and specifically predict total organic carbon toc and the abundance of sio2 al2o3 k2o and cao we then imaged nine samples from the woodford shale from the permian basin texas for a blind test to assess the predictive models the models were then used to predict toc and geochemical data over detailed imagery of 300 m 984 ft of horn river group shale core and portray their spatial variability downhole as images and profiles in its simplest form hyperspectral imagery can be enhanced to highlight fabric in shale core that otherwise is difficult to visualize because of low brightness in addition we show that spectral imagery of shale can also be processed to either convey mineralogical quartz clay and carbonate or geochemical information the resulting views can readily be used to guide the selection of samples and may provide tools for scaling reservoir properties from individual plugs to reservoir volumes

olivine carbonate mineralogy of the jezero crater region a well preserved ancient delta deposit in combination with ample exposures of carbonate outcrops makes jezero crater in nili fossae a compelling astrobiological site we use compact reconnaissance imaging spectrometer for mars crism observations to characterize the surface mineralogy of the crater and surrounding watershed previous studies have documented the occurrence of olivine and carbonates in the nili fossae region we focus on correlations between these two well studied lithologies in the jezero crater watershed we map the position and shape of the olivine 1 m absorption band and find that carbonates are found in association with olivine which displays a 1 m band shifted to long wavelengths we then use thermal emission imaging spectrometer themis coverage of nili fossae and perform tests to investigate whether the long wavelength shifted redshifted olivine signature is correlated with high thermal inertia outcrops we find that there is no consistent correlation between thermal inertia and the unique olivine signature we discuss a range of formation scenarios for the olivine and carbonate associations including the possibility that these lithologies are products of serpentinization reactions on early mars these lithologies provide an opportunity for deepening our understanding of early mars and given their antiquity may provide a framework to study the timing of valley networks and the thermal history of the martian crust and interior from the early noachian to today

shortwave infrared hyperspectral imaging a novel method for enhancing the visibility of sedimentary and biogenic features in oil saturated core a common challenge of logging core from heavy oil reservoirs is that sedimentary and biogenic features are difficult to see in fine grained well sorted and oil saturated strata in this study hyperspectral imaging is shown to be an effective method for enhancing the visibility of sedimentary fabric and trace fossils in oil saturated core shortwave infrared swir hyperspectral imagery of lower cretaceous mcmurray formation oil sands core from northeastern alberta canada was investigated at various wavelengths and resolutions color composite imagery consisting of wavelength bands at 2162 2199 and 2349 nm in the red green and blue channels respectively dramatically enhanced the clarity of sedimentary features in structureless appearing oil sand in many cases spectral imagery revealed features that are completely invisible to the unaided eye in coarser grained sections fine to coarse sand the enhanced contrast of sedimentological features is attributed predominantly to variability in grain size and bitumen saturation in finer grained sections very fine to fine sand enhanced contrast is mainly ascribed to variability in relative abundance of clays a spatial resolution of at least 0 25 mm pixel is required for imaging trace fossils while lower resolutions 1 2 1 5 mm pixel are sufficient for enhancing the visibility of most sedimentary structures

mapping lithology of the sarfartoq carbonatite complex southern west greenland using hymap imaging spectrometer data the sarfartoq carbonatite complex occurs in the southern west greenland in a transition zone between archaean gneiss complex to the south and a proterozoic mobile belt to the north the sarfartoq carbonatite complex consists of a core zone composed of dolomite carbonatite and minor sovite calcite carbonatite surrounded by a fenite zone and a marginal zone of gneisses frequently altered due to hydrothermal activity high spatial and spectral resolution imaging spectrometer data recorded by the hymap imaging system were used to map lithology of the sarfartoq carbonatite complex a careful analysis of the spectral reflectance properties of the carbonatite lithology preceded the hymap data analysis stage the spectral reflectance measurements showed that the various lithologic units including dolomite carbonatite sovite fenite and the marginal alteration zone have distinct spectral reflectance characteristics the analysis of the hymap data was based on an unsupervised clustering algorithm the self organizing maps som for the mapping of the main lithology and a hierarchical tree for the mapping of sparsely occurring sovite rocks spectral mixture analysis was applied to map fractional abundances and compare with the som results the resulting lithological map shows the spatial distribution of dolomite carbonatite sovite fenite with abundant carbonatite dykes representing the outer core of the carbonatite complex fenite and hematized gneiss marginal alteration zone the results compare well with the field data collected for the assessment of the mapping accuracy and due to the spatially contiguous nature of the hyperspectral data could be used to better map the outcropping carbonatite lithology the spectral reflectance measurements and the mapping results provide information of petrological importance for the carbonatite core zone

thermal infrared emission spectroscopy of anhydrous carbonates the objective of this study is to present the thermal emission spectra of various anhydrous calcite and dolomite series carbonate minerals to illustrate the effect of the structural cation ca 2 mg 2 fe 2 mn 2 zn 2 on shifting the positions of the carbonate absorption bands all of the carbonate mineral emission spectra included in this study exhibit three absorption features related to three specific vibrational modes of the carbonate anion co 3 2 these anion vibrations include the out of plane bend the asymmetric stretch and the in plane bend i e the 2 3 and 4 modes respectively the positions of the absorption band emissivity minima are unique for each carbonate chemistry and are thus diagnostic of mineralogy the average 2 3 and 4 wavenumber positions for the various carbonate minerals are as follows calcite caco 3 883 1523 and 712 cm 1 magnesite mgco 3 901 1572 and 748 cm 1 siderite feco 3 876 1523 and 736 cm 1 rhodochrosite mnco 3 877 1535 and 726 cm 1 smithsonite znco 3 882 1509 and 742 cm 1 dolomite camg co 3 2 894 1547 and 728 cm 1 and kutnahorite camn co 3 2 882 1526 and 716 cm 1 carbonates as a general mineral class crystallize in a variety of geological environments however each specific carbonate mineralogy typically is limited to a narrow range of geologic settings in which it forms thermal infrared emission data to be received from the mars global surveyor thermal emission spectrometer will contain the spectral signature of carbonates if they are present above the detectibility limit on the surface of mars this study presents the spectral information necessary to recognize carbonate as a mineral class as well as identify the specific type of carbonate from thermal emissivity data knowledge of distinct carbonate mineralogy will be useful for interpreting the environmental conditions that were present on mars during the carbonate formation the result of this study is that the major carbonate mineral species calcite dolomite magnesite siderite and smithsonite can be identified from thermal infrared emission data provided moderate 10 cm 1 spectral sampling because of the similarity of absorption band positions between kutnahorite and calcite high 2 cm 1 spectral sampling is required to distinguish kutnahorite moderate spectral sampling data are also sufficient to determine the amount of mg and fe in mg fe solid solution minerals to within 3 5 of the cation abundance

three dimensional analysis of a deep seated landslide in central taiwan the unstable slope which is located at lushan central taiwan slid when heavy rainfall occurred in recent decades posing a threat to a nearby village slope stability analysis in three dimensions is more realistic and can advance comprehension of the sliding mechanism the landslides caused by two heavy rainfall events are simulated in sequence using finite element modeling the three dimensional 3d modeling is established according to the data of extensive investigations including field reconnaissance borehole drilling laboratory experimentation and monitoring of groundwater tables and displacements in particular it requires skills for the generation of a sliding surface and the division of the 3d model the difference in lithology and a joint set initiated the instability of the slope forming the fractures on the slope the sliding surface with greatest depth over 100 m has not yet extended to the lower slope resulting in greater displacements on the upper and middle slopes than those on the lower slope the 3d numerical modeling not only reasonably simulates the displacements induced by the rainfall events but also enables 3d visualization and details of the sliding mechanism also it is capable of revealing the features that cannot be explained in a 2d analysis

compositional heterogeneity of impact melt rocks at the haughton impact structure canada implications for planetary processes and remote sensing connecting the surface expression of impact crater related lithologies to planetary or regional subsurface compositions requires an understanding of material transport during crater formation here we use imaging spectroscopy of 6 clast rich impact melt rock outcrops within the well preserved 23 5 ma 23 km diameter haughton impact structure canada to determine melt rock composition and spatial heterogeneity we compare results from outcrop to outcrop using clasts groundmass and integrated clast groundmass compositions as tracers of transport during crater fill melt rock formation and cooling supporting laboratory imaging spectroscopy analyses of 91 melt bearing breccia and clast samples and microscopic x ray fluorescence elemental mapping of cut samples paired with spectroscopy of identical surfaces validate outcrop scale lithological determinations results show different clast rich impact melt rock compositions at three sites kilometers apart and an inverse correlation between silica rich sandstone gneiss and phyllosilicate rich shales and gypsum rich rocks that suggests differences in source depth with location in the target stratigraphy gypsum is primarily sourced from 1 km depth while gneiss is from 1 8 km depth sandstone from 1 3 km and shales from 1 6 1 7 km observed heterogeneities likely result from different excavation depths coupled with rapid quenching of the melt due to high content of cool clasts results provide quantitative constraints for numerical models of impact structure formation and give new details on melt rock heterogeneity important in interpreting mission data and planning sample return of impactites particularly for bodies with impacts into sedimentary and volatile bearing targets e g mars and ceres

influence of structural anisotropy on creep of rocksalt from simla himalaya india an experimental approach abstract the influence of structural anisotropy on time dependent deformation creep of rocksalt from shali formation precambrian himachal pradesh india was investigated to analyze the differential mobility of rocksalt body in nature the effect of structural anisotropy orientation of bedding planes with respect to the compression axis on the compressive strength yield strength modulus of elasticity failure strain and yield strain of rocksalt has been analyzed on cubic samples 5 5 5 cm3 to collect the basic input for the purpose of creep of rocksalt time dependent compression of cubic samples perpendicular parallel and oblique to bedding planes were subjected to constant stresses equal to 30 40 50 60 70 75 and 80 of their uniaxial compressive strengths for presenting analogous situation of variable stressing of rocksalt caused by over laying rocks and tectonic stresses the results of experimental deformation reveal the strong control of structural anisotropy on development of instantaneous strain transient strain steady state strain and accelerated strain however the influence of structural anisotropy on deformation of rocksalt decreases with increment in stress levels at higher stress level creeps the control of structural anisotropy on deformation became negligible the progress of time dependent deformation occurs due to evolution of minute tensile and shear crack arrays in proportions at lower stress creep the development of tensile crack arrays and shear crack arrays is assisted by structural anisotropy however at higher stress levels the creep of rocksalt is facilitated by reduction in tensile crack arrays and domination of shear crack arrays resulting in shearing where the anisotropic rocksalt exhibits isotropic behaviour thus the mobility of rocksalt bodies is dependent on characteristic of structural anisotropy and stress conditions

carbonate deposition in an ephemeral siliciclastic alluvial system jurassic shuttle meadow formation newark supergroup hartford basin usa abstract nonmarine carbonate accumulation from a sedimentologic perspective has multiple possible origins clastic load springs groundwater discharge soil development biochemical seasonal changes cave speleothems and eolian influx many of these carbonates contain diagnostic textures from which origin is easy to ascertain however differentiating between clastic and spring groundwater carbonates especially in depositional systems dominated by siliciclastics is not always simple here criteria for recognition are developed subsurface hydrology and tectonic origin of the depositional basin source rocks surrounding the basin sedimentologic packaging and extent of the carbonates in question as well as their sedimentary structures and fossil content and stable isotopic analyses of the carbonates can all aid in determining carbonate origin and correctly assessing sedimentary and basin evolution the present study focuses on a nonmarine carbonate deposit found within the jurassic shuttle meadow formation of the hartford basin one of many rift basins which formed as a result of the opening of the north atlantic ocean during the late triassic to early jurassic the upper 50 m of the formation at plainville connecticut is interpreted as continental in origin and is composed of five facies red ripple cross laminated muddy siltstones to sandstones fr sr massive red siliciclastic mudstones fm buff fine to medium grained horizontally laminated sandstones sh red to white disrupted calcareous shales fl3 and rare micritic carbonates pm facies fr sr sh and fm are interpreted as an alluvial plain system in an ephemeral setting with bedload sheetflooding as the dominant depositional mechanism similar to the channel country drainage system of central australia in addition preservation of lateral accretion sandstone sheets accretionary benches indicate that the shuttle meadow alluvial system was rapidly accreting the anomalous existence of carbonate beds in facies fl3 and pm in the smf bedload dominated siliciclastic sequence is attributed mainly to the unique nature of the clastic sediment load in the basin no direct evidence for a spring groundwater input is apparent the shallow carbonate lake margin or a pond with vegetation and periodic exposure is envisioned as the depositional environment the intraclastic texture of the micrites with rare primary relict lamination indicates early diagenetic alteration from root penetration desiccation cracks and burrowing

spectral reflectance 400 2500 nm properties of coals adjacent sediments metamorphic and pyrometamorphic rocks in coal fire areas a case study of wuda coalfield and its surrounding areas northern china abstract although remote sensing is an effective tool extensively employed to detect and monitor coal fires continuous spectral reflectance properties of typical land surfaces such as coals adjacent sediments metamorphic rocks and pyrometamorphic rocks in coal fire regions have not been reported yet field and laboratory spectral reflectance of coals bituminous anthracite and coal waste sediments rocks sandstones siltstone desert sands limestones and shale metamorphic and pyrometamorphic rocks located in wuda coalfield and its surrounding areas are investigated for the reflective domain ranging from 400 nm to 2500 nm the results indicate that coal depicts the lowest reflectance 2 10 and strong absorption bands between 2200 and 2500 nm resulting from organic matter pyrometamorphic rocks are characterized by weak absorption features at 1400 and 1900 nm due to partial dehydration and strong ferric absorption features between 850 and 1100 nm attributed to thermal alteration and oxidation of the rocks sediments exhibit common absorptions features at 2200 and 2300 nm probably related to al oh vibrations and carbonate degenerate c o vibrations respectively spectral reflectance increases with a decrease of the coal rank and particle size the investigations on spectral reflectance properties of typical land surfaces in coal fire regions provide the basic understanding for applications of hyperspectral or multispectral remote sensing to classify land covers and to demarcate coal fire risk areas in similar geological settings

deep seated gravitational slope deformation in lushan taiwan transformation from cleavage controlled to weakened rockmass controlled deformation abstract the northern slope in lushan nsl in central taiwan is recognized as a large deep seated gravitational slope deformation dsgsd in anisotropic slate and is often activated by typhoons and heavy rainfall however a recent southward movement of the dsgsd was apparently not caused by translational sliding along the eastward dipping cleavage in the nsl because the regional attitudes of the cleavages in the nsl moderately vary and no major fault has been observed in the field the deformed cleavages with their random dips indicate that the deformation of the rockmass was caused by older mass movements in addition ancient progressive erosion of the nsl toe by the talowan river which passes through the eastern side of the slope induced deep large scale mass movement toward the east based on detailed core recognition measurements including the cleavage dips log q values and inclinometer measurements we identified five geometrical styles and geotechnical zones of the deformed rockmasses for characterization of the evolution of the nsl dsgsd with regard to the spatial distributions of old mass movements and recent transformations curves obtained from recent inclinometer measurements suggested two deformation behaviors namely specific sliding and progressive deformation the underlying rockmass with overturned and flexural folding in cleavages at the slope toe have baffled a recent southward advancement of the dsgsd consequently the deep specific sliding surface close to the basal disintegrated rockmass at the center of the nsl was transformed into progressive deformation which mostly occurred in the overturned rockmass at the toe based on our observations we propose the following relationship between the p wave velocity vp km s and log qc where qc is a normalized q as an empirical model for slate in taiwan vp 0 6 log qc 4 0 this empirical model might be suitable for the low uniaxial compressive strength slate in the lushan area and could be used for the quantitative evaluation of the geotechnical zone of the dsgsd of the nsl

heating and freezing experiments on aqueous fluid inclusions in anhydrite recognition and effects of stretching and the low temperature formation of gypsum aqueous fluid inclusions in anhydrite that are frozen during microthermometry commonly develop new daughter crystals heating these inclusions induces the new daughter crystals to decompose repeated cycles of crystal growth and decomposition may result in morphological changes of the fluid inclusions this phenomenon of new mineral growth presumed to represent the low temperature hydrate gypsum has been recognized for over 20 years nevertheless its occurrence and its significance to the determination of inclusion salinities are not widely appreciated similarly the potential of inclusions in anhydrite to stretch when overheated is commonly assumed yet tests demonstrating the phenomenon have not been reported changes in the ice melting temperature of aqueous inclusions in anhydrite before and after gypsum formation were documented showing that hydration of the host anhydrite may significantly lower the ice melting temperature and increase the salinity of the residual inclusion fluid heating inclusions to induce gypsum to decompose results in the release of bound water restoring the inclusions to their original salinity the homogenization temperatures of inclusions that have undergone these phenomena are generally unchanged indicating that the inclusions specific volumes are unchanged however heating aqueous inclusions in anhydrite more than ten degrees or so above their homogenization temperature commonly results in stretching therefore those who study aqueous inclusions in anhydrite must avoid the determination of ice melting temperatures if new gypsum daughter crystals are present and must determine homogenization temperatures sequentially with rising temperature to avoid overheating and stretching

comparison of δ18o analyses on individual planktic foraminifer orbulina universa shells by sims and gas source mass spectrometry author s wycech jb kelly dc kozdon r orland ij spero hj valley jw abstract 2018 elsevier b v the oxygen isotope 18o compositions of final chamber fragments of individual shells of the planktic foraminifer orbulina universa were measured in situ via secondary ion mass spectrometry sims and by traditional gas source mass spectrometry gsms entailing acid digestion of sampled calcite the paired sims gsms analyses were performed on final chamber fragments of fossil shells taken from the top of a sediment core holocene as well as shells grown in laboratory culture multiple iterations of sims gsms analyses were conducted on final chamber fragments treated with a variety of cleaning protocols the series of paired analyses yielded an average sims gsms 18o offset 18osims gsms of 0 9 0 1 2 se the volume of material analyzed in 10 m sims spots is 105 times smaller than that analyzed by gsms hence the extent to which these 18osims gsms values represent real differences in analyte vs instrumental factors remains unclear possible contributing factors to the sims gsms 18o difference include sample standard mismatch by sims differences in standardization of sims and gsms and non calcite contaminants in samples although the two datasets are consistently offset sims values reproduce inter shell 18o variability delineated by shell fragment gsms values this strong positive covariance proved useful for bringing the two datasets into agreement i e 18osims gsms 0 and confirms that sims based foraminifer 18o values record changes in calcification temperature and or 18o of seawater whether shells of foraminifer taxa with differing microcrystalline structures chemical composition and or preservation histories register a similar 18osims gsms value is a subject of ongoing testing

study on nonlinear damage creep constitutive model for high stress soft rock rock engineering especially deep rock engineering undergoing long term effects of external loading and gravity all or most may gradually damage deformation or creep deformation accumulation leading rock structures to damage crack such as severe plastic deformation or even progressive failure in this paper based on the nonlinear damage creep characteristics of rock and damage variable a new nonlinear damage creep constitutive model of high stress soft rock is defined in series with the improved burgers model hooke model and st venant model this new nonlinear damage creep constitutive model can work out fairly reasonably explanations for the soft rock creep deformation a series of uniaxial compression creep tests were performed to study the creep damage characteristics of typical soft rock in jinchuan no 2 mine in the northwest of china using the increment step loading and single step loading the results of creep experiments and nonlinear damage creep constitutive model results are very consistent in this study the new model not only can reflect the whole course of creep deformation but also can reasonably describe the soft rock under different initial creep stage steady state creep stage and accelerated creep stage therefore the new nonlinear creep damage model is a reasonable reference model for the research of soft rock creep

surface displacements and surface age estimates for creeping slope landforms in northern and eastern iceland using digital photogrammetry abstract in this study three areas of different active coarse debris slope processes are investigated in northern and eastern iceland surface displacement of some glacier derived rock glaciers and a debris covered glacier in the holar area a moving debris accumulation close to siglufjor ur and a debris layer in sey isfjor ur are measured the displacement fields are obtained by cross correlation matching of multi temporal orthophotos orthophotos are generated using a z i imaging digital photogrammetric workstation and various series of air photos from 1964 to 1994 cross correlation matching is done with the cias software the results are analyzed and used for rough surface age estimates in addition type and cause of movement are discussed the velocity of the debris covered glacier and the rock glaciers in the holar area averages from 0 14 to 0 67 m a 1 the debris accumulation at almenningsnof close to siglufjor ur shows an average displacement of 0 19 m a 1 with a maximum value of 0 84 m a 1 the displacements at almenningsnof agree well with displacements surveyed by gps by the icelandic road authorities the measured velocities in sey isfjor ur although using air photos taken 30 years apart turned out not to be significant but the homogenous direction of the displacement vectors suggests that the debris is currently creeping based on the surface age results all the landforms in holar are suggested to have developed during the late holocene cooling period with ages from around 1500 and 3000 to around 5000 years for the different landforms these surface age estimates coincide with data from moraine datings nearby and holocene climatic development in the north atlantic region

multi scale landslide susceptibility analysis along a mountain highway in central taiwan abstract for the past decade climate change has caused increasingly more frequent extreme rainfall events in taiwan during which concentrated and intense rainfall has induced large scale flooding and landslides considering the urgency of protecting isolated villages and residential areas near highways from large scale landslides this study analyzed landslide susceptibility along nantou county road 89 in the upstream region of the wu river in taiwan to assess landslide hazards spatially landslide susceptibility analysis was implemented at the catchment scale to predict landslide susceptibility this study employed an atmospheric general circulation model with downscaling estimation information from boreholes was used to analyze the temporal behavior and complex mechanisms of large scale landslides at the local scale on the basis of the results this paper discusses the different findings from the catchment and local scale analyses for the major large scale landslides the rankings of landslide susceptibility values can be obtained to prioritize the remediation of the landslides and the multiscale landslide susceptibility analysis could be applied to mountain highways with complex landslide hazard

modelling hillslope evolution linear and nonlinear transport relations many recent models of landscape evolution have used a diffusion relation to simulate hillslope transport in this study a linear diffusion equation for slow quasi continuous mass movement e g creep which is based on a large data compilation is adopted in the hillslope model transport relations for rapid episodic mass movements are based on an extensive data set covering a 40 yr period from the queen charlotte islands british columbia a hyperbolic tangent relation in which transport increases nonlinearly with gradient above some threshold gradient provided the best fit to the data model runs were undertaken for typical hillslope profiles found in small drainage basins in the queen charlotte islands results based on linear diffusivity values defined in the present study are compared to results based on diffusivities used in earlier studies linear diffusivities adopted in several earlier studies generally did not provide adequate approximations of hillslope evolution the nonlinear transport relation was tested and found to provide acceptable simulations of hillslope evolution weathering is introduced into the final set of model runs the incorporation of weathering into the model decreases the rate of hillslope change when theoretical rates of sediment transport exceed sediment supply the incorporation of weathering into the model is essential to ensuring that transport rates at high gradients obtained in the model reasonably replicate conditions observed in real landscapes an outline of landscape progression is proposed based on model results hillslope change initially occurs at a rapid rate following events that result in oversteepened gradients e g tectonic forcing glaciation fluvial undercutting steep gradients are eventually eliminated and hillslope transport is reduced significantly

visible and near infrared spectra of carbonate rocks reflectance variations related to petrographic texture and impurities grain size statistics derived from thin section point measurements were used to classify carbonate rock textures and to identify related spectral characteristics in the visible and near infrared 0 4 2 5 m wavelength range although the statistics did not permit all the carbonate textural varieties generally recognized by petrologists to be distinguished three broad textural classes of pure carbonate material were found that produced distinctive spectra further refinement of the statistical technique may permit other textural classes to be identified however internal scattering in carbonate rocks is a complex phenomenon involving the grain size distribution as well as the nature and abundance of inclusions and internal grain defects to yield an optimum textural classification for spectroscopic studies all such scattering contributors would have to be quantified the spectral effects of iron oxide clay silica and organic matter impurities were examined by comparing texturally similar pure and impure carbonate rock samples of these impurities organic matter had the greatest spectral influence and amounts as low as 0 01 wt commonly caused marked reductions in sample brightness and absorption band intensity in contrast the spectral effects of rock texture were subtle and could only be identified in samples that were nearly free of organic matter impurities the pronounced organic matter spectral effects imply that the organic matter in most carbonates is very finely disseminated samples collected from different regions usually showed different degrees of organic spectral quenching however no correlations were evident between sample reflectance and contained kerogen h c ratios or kerogen amounts additional analytical work is needed to examine organic matter compositional variation and associated spectral quenching effects in detail from the present study it appears likely that contained organic matter will be a dominant factor in the visible and near infrared spectral expression for most carbonate rocks and perhaps for other sedimentary lithologies spectral quenching by organic matter will likely complicate remote sensing and laboratory spectral determinations of carbonate composition on the other hand variations in quenching may prove to be useful for distinguishing rocks that have experienced unusual diagenetic thermal or other conditions affecting the organic matter contents

reflectance spectroscopy in the visible and near infrared 0 35 2 55 µm applications in carbonate petrology reflectance spectroscopy in the visible and near infrared 0 35 to 2 55 m offers a rapid inexpensive nondestructive tool for determining the mineralogy and for investigating the minor element chemistry of the hard to discriminate carbonate minerals and can in one step provide information previously obtainable only by the combined application of two or more analytical techniques when light interacts with a mineral certain wavelengths are preferentially absorbed the positions and widths of absorptions due to vibrations of the carbonate radical and the positions and shapes of absorptions due to transition metal cations if present can be used to determine mineralogy relative intensities of absorptions due to transition metal cations can be used to determine concentration of these cations because absorptions due to fe2 and mn2 occur in different regions of the spectrum the presence of one cation does not interfere with analysis for the other detection limits for mn2 are about 0 1 wt mn and for fe2 are about 0 01 wt fe this technique is also very sensitive to the presence of water and indicates that aqueous fluid inclusions are nearly ubiquitous in carbonate minerals and rocks spectra indicate that inclusions are particularly abundant in skeletal carbonates and that the quantity of inclusions in skeletal material varies from one type of organism to another spectra indicate that inclusions are lost during diagenesis of skeletal material providing a new criterion for diagenetic studies

quantitative reassessment of brick red lutites evidence from reflectance spectrophotometry abstract brick red lutites are distinctive bright red sediments deposited in the western north atlantic these unique sediments were derived from permo carboniferous outcrops in the canadian maritime provinces transported out the gulf of st lawrence through the cabot straits and redistributed by the western boundary undercurrent along the north american continental margin in this study we used fourteen cores taken off eastern north america to more precisely examine the input and depositional history of brick red lutites our study differs from previous studies in the manner in which the red sediment was identified unlike previous studies which used color charts to assess the presence of brick red lutites we used visible light reflectance spectrophotometry the primary mineral imparting a red color to brick red lutites is hematite experiments with known quantities of hematite in a matrix mineralogically similar to western north atlantic sediment indicate that the presence of hematite can be detected at weight percentages of less than 0 1 using spectral reflectance data we characterized the distribution of brick red lutites for two broadly defined time levels latest glacial and early holocene as expected the maximum input of brick red lutite was during late glacial time and input decreased reaching a minimum during the early holocene since the early holocene there has been little change in the distribution of this unique red sediment on the north american margin however our reflectance spectra indicate renewed accumulation of hematite rich sediment at the present time in the cabot straits

aster capability in mapping of mineral resources of arid region a review on mapping of mineral resources of the sultanate of oman abstract advanced space borne thermal emission and reflection radiometer aster has exclusive capability to map minerals and ore deposits and able to discriminate rock types useful for geological applications especially the improved spectral and spatial resolutions of spectral bands of the sensor are well utilized by the exploration geologists working on arid region where the surface deposits are directly exposed to the sensor without disturbances of the vegetation several fruitful research studies have been carried out to map mineral resources in arid region with inaccessible rugged mountains and deserts area where it is difficult to do conventional geological mapping these were demonstrated and documented in the scientific publications using the aster spectral bands and image processing methods this study reviews scientific literatures published on mapping of the economic mineral resources of the sultanate of oman using aster and simples image processing methods

hyperspectral image analysis of different carbonate lithologies limestone karst and hydrothermal dolomites the pozalagua quarry case study cantabria north west spain ground based hyperspectral imaging combined with terrestrial lidar scanning is a novel technique for outcrop analysis which has been applied to early and late albian carbonates of the pozalagua quarry cantabrian mountains spain an image processing workflow has been developed for differentiating limestone from dolomite providing additional sedimentary and diagenetic information and the possibility to quantitatively delineate diagenetic phases in an accurate way spectral absorption signatures can be linked to specific sedimentary or diagenetic products such as recent and palaeokarst hydrothermal karst solution enlarged fractures and different dolomite types some of the spectral signatures are related to iron manganese organic matter clay and or water content ground truthing accessible parts of the quarry showed that the classification based on hyperspectral image interpretation was very accurate this technique opens the possibility for quantitative data evaluation on sedimentary and diagenetic features in inaccessible outcrops this study demonstrates the potential of ground based imaging spectroscopy to provide information about the chemical mineralogical distribution in outcrops which could otherwise not be established using conventional field methods

slope creep behavior observations and simulations rock slopes undergoing long term effects of weathering and gravity may gradually deform or creep downslope leading to geological structures such as bending bucking fracturing or even progressive failure this study uses geomechanics based numerical modeling to qualitatively explain the cause and evolution of slope creep behavior constitutive models used include the creep mohr coulomb and anisotropic models the last two models are used with the strength reduction in calculation first the results of field investigation around a landslide site occurring in slate are present the causes and modes of creep structures observed on slopes and underground are studied second the study investigates the influences of slope topography and anisotropy orientations on slope creep behavior finally progressive failure of slopes with different shapes is examined the simulated results show that the bending type of structures develops near slope surfaces and the buckling type of structures is associated with the deformation or slides of a slope the creep pattern varies with the orientation and position of an original planar structure the shear zone involves a joint or fracture along which displacement has taken place moreover creep behavior is more significant on slopes with greater height and inclination as well as on steeper portions whether on concave or convex slopes in addition with the same topographic conditions consequent slopes with coinciding cleavage and obsequent slopes with steep cleavage result in greater creep behavior without the effects of anisotropic cleavage concave and straight slopes develop failure surfaces from the crowns downwards whereas convex slopes develop failure surfaces from the toes upwards

internal structure and deformation of an unstable crystalline rock mass above randa switzerland part ii three dimensional deformation patterns the monitoring of slope displacements over time provides the basis for most rockslide early warning systems yet the prediction of catastrophic failure from these records is highly problematic and tenuous especially if the underlying kinematics and instability mechanism are poorly understood an example is the moving slope above the town of randa in the swiss alps this slope is considered typical of those in crystalline rock that lacks a natural highly persistent weakness plane dipping towards the valley that can serve as a through going detachment surface for kinematic release in part i the companion paper to this the findings from a comprehensive geological and geophysical investigation to image the internal structures of the unstable rock mass were presented in this paper we develop a kinematic model that describes the pattern of displacement vectors for the rock mass along these structures both on surface and at depth the displacements were estimated from 5 years of data from an extensive monitoring system which included surface geodetic and crackmeter measurements borehole inclinometer and extensometer measurements up to 120 m depth and microseismicity the results showed that the displacement field is highly heterogeneous internal deformation is accommodated by both shear and opening mode dislocation of faults and fracture zones which dip moderately to steeply into the slope microseismicity is most intense near the front of the scarp where surface translation in large part reflects the toppling of blocks accommodated by slip along the steeper dipping fractures the small displacement rates at the study site of up to 2 cm year coupled with a modest deviation of up to 15 from vertical of the boreholes posed severe problems for the estimation of horizontal displacements from the inclinometer data we describe the error analysis of these data in some detail since it is relevant for similar installations elsewhere conclusions drawn from this work highlight the importance of integrating various types of data in order to better understand the complex block kinematic processes whose evolution governs the long term progressive failure of unstable rock slopes

large rock slope failures in the highlands of scotland characterisation causes and spatial distribution abstract a comprehensive database of larger rock slope failures rsfs has been compiled and characterised for a whole mountain range possibly for the first time apart from iceland most rsfs in the scottish highlands occurred soon after deglaciation a threshold size of 0 25 km 2 focuses on rsfs which contribute significantly to gross erosion in the glacial paraglacial cycle and on the spatial concentration of this poorly recognised process database verification indicates that at least 90 of the total extant population in the highlands is covered standard mass movement typologies are broadly applicable but require some refinement to characterise rsfs in a passive margin glaciated mountain range comprised mainly of ancient metasediments most larger rsfs here are complex and difficult to categorise a continuum from cataclasmic failures including rock avalanches through arrested translational slides to almost in situ slope deformations is identified the prevailing modes of large rsf are arrested short travel translational sliding and gravitational sagging cataclasmic failure is rare and sub cataclasmic outcomes are more evident a significant class of deformations exhibits compressional rather than extensional features and may be responding to localised glacio isostatic rebound stresses the large rsf population is widely but very unevenly distributed across the main mountain areas 65 are in seven main clusters with the rest non randomly scattered previous glaciological lithological and seismotectonic explanations are insufficient to explain this spatial pattern and overlook the basic engineering geology prerequisites for failure massifs of similar relief and lithology can display intense or sparse rsf incidence geomorphological appraisal suggests an association with recently active glacial breaches of main and secondary watersheds with rsf being scarce or absent in valleys inherited from tertiary uplift and in mountain groups away from the main watersheds valleys which adapted early to ice discharge are seen as stress hardened with their slopes unlikely to reach critical thresholds for failure after subsequent reoccupations by ice concentrated erosion in the last glaciations is most likely to be found close to where breaches are actively forming or enlarging such erosion in the slope foot and valley floor may have daylighted failure planes or generated rebound stresses augmenting those from other endemic sources sufficiently to provoke widespread paraglacial rsf slope stress models for deglaciated valleys and comparative studies in other glaciated mountain ranges are required to test this concept and may assist in geohazard assessments