engineering geological and geoenvironmental evaluation of unesco world heritage site of meymand rock hewn village iran meymand a historic 2000 year old village is an important heritage site in iran that was included on the world heritage list in 2015 by unesco the village is located in a volcanic terrain and its structures such as houses a mosque a public bath and a fire temple have been carved in to the pyroclastic rocks of the masahim volcano in the present study the engineering geological and geoenvironmental aspects of the meymand village were investigated including the geomorphology and landscape of the village the technical classification of the pyroclastic rocks and their geomechanical properties and the geoenvironmental characteristics and problems of the village the engineering geological characteristics of the meymand site were also compared with those of similar sites of the cappadocia region in turkey and the kandovan village in iran which were widely studied by earlier researchers the results of the present study indicated that the erosion of massive volcanic rocks free from systematic structural discontinuity has formed the unique landscape of the village which is different from similar other sites according to technical classification the meymand pyroclastic rock is a lithic tuff of a low degree of welding that has very weak strength and low durability accelerated weathering tests that artificially simulated the meymand site conditions suggested that the meymand tuff is prone to atmospheric conditions as its strength and deformability are drastically reduced when it becomes wet or saturated laboratory tests and field evidence show that the meymand village is under threat of erosion due to natural and anthropogenic agents that gradually destroy the landscape and structures of this significant world heritage site therefore conservation projects should be planned and applied that ensure the preservation of the village

the calcarenite di gravina formation in matera southern italy new insights for coarse grained large scale cross bedded bodies encased in offshore deposits excellent outcrops of the upper pliocene lower pleistocene calcarenite di gravina around matera southern italy provide continuous exposure of coarse grained clastic basin margin shoreline to offshore facies among these facies the most conspicuous and volumetrically important are the transition slope deposits that form large scale high angle cross bedded lithosomes these are laterally extensive parallel with the paleoshoreline and show seaward progradation we interpret them to represent avalanches of sediment swept out onto a depositional slope below wave base from the shoreface zone by storm waves and wind driven currents three types of building blocks are recognized based on bedding patterns and facies architecture embryonic parasequences mature parasequences and simple sequences parasequences formed during stillstands of sea level and simple sequences during high frequency cycles of relative change of sea level these building blocks are stacked in a backstepping configuration and onlap onto cretaceous limestone substrate backstepping is believed to be due to a tectonically forced transgression that is punctuated by high frequency cycles of sea level modern analogs for these building blocks are the holocene prograding prisms detected in high resolution seismic lines of the mediterranean shelves the reflection patterns of these seismic units resemble the bedding architecture of the matera simple sequences and parasequences and show similarities of shape size position and orientation of coastal setting and direction of progradation comparison of the holocene prisms and the pliocene pleistocene accretional units in matera indicates that they may represent the same begin page 662 genetic process progradation of clastic prisms below the wave base level the matera accretional units also show similarities with other examples of laterally extensive large scale cross bedded sand bodies encased in offshore deposits such as some sandbanks differentiating between these laterally extensive and seaward prograding cross bedded sand bodies and some coarse grained gilbert type deltas is difficult however if interpretations are based only on two dimensional 2 d outcrops in dip section without high resolution data it is also difficult to distinguish between transition slope and prograding shoreface lithosomes this difficulty may be acute where only seismic or well log data are available however certain other architectural characteristics such as stacking and preservation of facies belts and position of bounding surfaces as well as differences in associated sedimentary structures and fossil content may be used for interpretation the matera example provides a mechanism for emplacement in offshore settings of elongate and strandline parallel sand and gravel deposits that prograde seaward and that preserve a coarsening upward internal succession this article offers an interpretation for other ancient examples of large scale cross bedded lithosomes encased in offshore deposits

seasonal water use patterns of juniperus ashei on the edwards plateau texas based on stable isotopes in water summary naturally occurring stable isotopes of oxygen and hydrogen were used to determine the seasonal water sources of juniperus ashei and its relationship with soil water content on the edwards plateau of central texas honey creek state natural area the patchy nature of juniper stands rooting in the thin soils over karstified carbonate bedrock imparts large spatial heterogeneity in soil water content and isotopic composition largely by differential shading but also by canopy interception there is a seasonal decrease in the oxygen isotope composition of juniper xylem water by 2 during the transition from hot dry summer conditions to the cool moist winter prior to this shift the xylem water isotope composition is similar to local springs presumed to represent local groundwater after this shift the xylem water composition is similar to soil water below 10 cm these results suggest a change in juniper water use from a dominantly deep water source during the summer to a dominantly soil source during the winter over the study period but the timing of this transition will likely vary from year to year

application of protective products to noto calcarenite south eastern sicily a case study for the conservation of stone materials noto is an important baroque urban center in south eastern sicily which was completely reconstructed after the severe earthquake of 1693 most of its monuments and historic buildings were built in pietra di noto stone a pale cream calcarenite quarried in outcrops located near the city this stone still currently used as building material is undergoing many forms of alteration and degradation which cause significant damage to monuments in this study three commercial protective products were tested on some noto calcarenite samples from quarries with the aim of assessing their protective effectiveness in particular petrographic analyses by optical microscopy were carried out for textural characterization of the stone materials capillary water absorption porosimetric and colorimetric procedures uv radiation and salt crystallization aging tests were performed to better evaluate interactions between protective products and substrate

petrography and reservoir physics ii relating thin section porosity to capillary pressure the association between pore types and throat size porosity in reservoir rocks is configured into a few types of pores whose size and shape are controlled by depositional fabric and postdepositional processes the size shape and abundance of each pore type can be objectively determined from thin section using image analysis and pattern recognition procedures each pore type tends to be associated with a limited range of throat sizes the association between pore type and throat size can be determined using regression procedures linking pore type data obtained from thin section with capillary pressure data to do so a set of samples is required wherein the association between pore type and throat size is fixed but where pore type proportions vary between samples this condition is met by a sample suite representing res rvoir facies from a single core or in many cases from a single field the relationship between pore type and throat size is an effective means to relate reservoirs in terms of the efficiency of the porous microstructure to multiphase flow parameters derived from the relationship can be used to construct accurate physical models that subdivide physical response in terms of the contributions of each pore type

effects of layering on triggering mechanisms of rainfall induced landslides in unsaturated pyroclastic granular soils1 rainfall induced landslides are widespread in shallow layered granular soil deposits in many cases slope instability is related to the decrease of suction during rainwater infiltration however

a new methodological approach to assess the stability of discontinuous rocky cliffs using in situ surveys supported by uav based techniques and 3 d finite element model a case study abstract this paper aims to present a new methodological approach for the stability assessment of coastal cliffs constituted of discontinuous rock masses the method entails in situ specific geostructural and geomechanical surveys three dimensional uav based photogrammetric structural models laboratory geotechnical tests and two and three dimensional finite element analysis fem the application of the method to a case study is then presented and discussed it regards a 600 m long sea rocky cliff located at sant andrea melendugno south of apulia se italy and faced to the southern adriatic sea here the cliff is made up of an about 15 m thick sequence of laminate calcisiltites alternate with bioturbated calcarenites belonging to the uggiano la chiesa fm middle upper pliocene the structural discontinuities detected with photogrammetry techniques were compared and validated with those derived from conventional in situ survey methods later on the paper discusses assumptions and results of two and three dimensional finite element models developed to investigate the potential failure mechanisms of the sea cliff accounting for pre existing weak planes or discontinuities with unfavourable orientation the failure mechanisms obtained by both fem analysis agree well with those typically observed in the study area

orthogonal microscopy image acquisition analysis technique for rock sections in polarizer angle domain abstract the microscopic identification of rock sections is one of the most basic research methods of petromineralogy which is important to the research of mineral composition pore throat characteristics interstitial filling etc the traditional manual identification method was time consuming and also burdened with errors due to the subjective nature of human judgment which can bring some uncertainties to the further results therefore this paper proposes a technique for image acquisition and analysis of rock sections based on sequential images of rock sections in angle domain under polarizing microscope the analysis includes the following three steps firstly based on the multi angles extinction feature of rock section the direction adaptive correlation coefficient method was used to characterize the edge of the rock sections and segment the rock grains a series of parameters including grain size roundness convexity flatness and roughness were also extracted to characterize the morphological features of rock grains quantitatively secondly the variation characteristics of multi channel parameters rgb and gray channel with angle domain were analyzed for different minerals and then the mineral composition was accurately identified on the basis of grain segmentation the pore structures including intergranular pores dissolved pores and throat were extracted and the parameters of pore structure were also obtained finally the distribution of the interstitials was characterized based on the change of the extinction characteristics of the interstitials in the pores image analysis technique based on rock sections with polarizing microscope provides an effective and convenient method for grain segmentation mineral composition classification pore identification and interstitial analysis

bimodal porosity in oolitic reservoir effect on productivity and log response rodessa limestone lower cretaceous east texas basin running duke field houston county texas is on a small domal structure in the east texas basin the field currently consists of five gas wells producing from the lower cretaceous rodessa limestone seven additional gas completions have been plugged the rodessa yields water free gas production from zones with water saturations in excess of 60 porosity ranges from 7 to 14 the depositional model depicted for the rodessa in this field starts with the development of an active organic buildup this was successively overlain by ooid skeletal peloid lime sands lagoonal lime muds and subsequently by anhydrite and shale six lithofacies based on core study were recognized for the rodessa each facies has a uniform diagenetic history in the field making porosity development predictable for each facies the one grainstone facies forms the reservoir in the field and has two distinct diagenetic sequences one consists of a marine isopachous cement followed by a later partial infilling of pore space by sparry calcite the resulting intergranular porosity has a unimodal pore size distribution in the other sequence a discontinuous meteoric phreatic cement is followed by sporadic patches of sparry cement the resulting pore size distribution is bimodal with intergranular macropores and intercrystalline micropores within peloids and micritized ooids water free gas production is limited to the rock with the bimodal pore system macropores hold movable gas and micropores hold bound water within grains where core data are not available cross plotting techniques using geophysical logs are suggested as methods for separating the productive from the nonproductive grainstone

contributions of water supply from the weathered bedrock zone to forest soil quality one measure of forest soil quality is the ability of the soil to support tree growth in mediterranean type ecosystems such as most of california s forests there is virtually no rainfall during the summer growing season so trees must rely on water stored within the substrate water is the primary limitation to productivity in these forests many forest soils in california are relatively thin but are underlain by thick zones of weathered bedrock weathered granitic bedrock the most prevalent lithology has available water capacities 0 12 cm water cm rock that approach those of soils 0 2 cm water cm soil and because the weathered rock zone is usually so much thicker several meters than the soil 1 m it almost always constitutes the larger storage reservoir for plant available water the weathered bedrock retains the original rock fabric and is friable and easily excavated but the primary minerals are not thoroughly altered to clay minerals so it is not considered saprolite roots of ponderosa pine pinus ponderosa seedlings penetrate through the soil and encounter weathered bedrock within the first 2 years on many sites thus the influence of the weathered bedrock zone on plant growth begins early root access to the weathered bedrock is restricted to fractures which are often spaced about 50 cm apart water is extracted from the intervening rock matrix through unsaturated flow toward the root mat in the fractures and by mycorrhizal fungal hyphae that penetrate the rock matrix at one site in the sierra nevada 30 year old jeffrey pine p jeffreyi depleted the soil held water by mid june and relied on water stored in the weathered bedrock until the rainy season began in october in this case the weathered bedrock supplied at least 70 of the water used by the trees during the growing season in the same area we found that thin soils are not a detriment to pine productivity when they are underlain by a thick zone of weathered bedrock in mediterranean type ecosystems the weathered bedrock zone is an essential component of the plant water supply system and is thus an important contributor to forest soil quality

physico mechanical properties and durability performance of natural building and decorative carbonate stones from cyprus natural stone was the primary building material in cyprus in the past nowadays its use is mostly confined to decorative purposes and restoration projects this study represents the first thorough and systematic investigation of the characteristics of local carbonate stone the variety of the results recorded highlights the complexity of this natural geomaterial and hence the particular attention needed before selecting the appropriate lithotype in construction practice stones coming from the same geological formation exhibit significant variations in their physico mechanical properties the materials durability against salt crystallization is explained with reference to their pore structure and flexural strength revealing that in many cases small differences may have a significant impact on stone performance the study also investigates the use of novel microdestructive techniques in the prediction of the mechanical properties of the stones under study these techniques can be especially useful in the characterization of monumental stone where sampling is limited or when in situ characterization of stone is required natural stone has been extensively used throughout the history of mankind both for building and decorative purposes even though it is considered one of the most durable traditional geomaterials existing stone structures and monuments often show evidence of weathering and decay stress inflicted during use and by local climate are the major contributing factors to the degradation of building stone the precise response of individual stone samples is highly variable this is attributed to the complex nature and physico mechanical behaviour of natural stone understanding the materials performance under loading or different environmental conditions is therefore considered of crucial importance in ensuring the sustainable use of stone in construction practice

black crusts on travertine factors controlling development and stability the travertine buildings of budapest show extensive black crust formation which is related to high concentration of atmospheric pollution and a continental climate laminar black crusts framboidal black crusts and leached white surfaces are compared physical properties schmidt hammer rebound duroscope rebound mineralogical composition and elemental composition are measured framboidal black crusts contain more than 50 of acicular gypsum the crust surface displays idiomorphic rosette like gypsum crystals with particulates calcite and gypsum crystal aggregates the sulphur isotopic composition of the black crusts pinpoints the involvement of rain and dust in crust formation thick framboidal black crust has the lowest strength while thin laminar black crust and white dissolved surfaces show minor decrease in surface strength compared to unaltered travertine the crusts adhere to the travertine surface and rarely show mechanical decay forms that are typical features of porous limestone ashlars in budapest

triggering and predisposing factors for flow like landslides in pyroclastic soils the case study of the lattari mts southern italy abstract shallow flowslides debris flows and debris avalanches are rainfall induced landslides consisting in the shear failure of few metres of soils or in some cases even less than a metre which greatly increase downslope in volume and flow velocity the southern italian region of campania has been historically affected by such events involving pyroclastic soils mainly resting on steep carbonate slopes this paper deals with the analysis of factors influencing the occurrence of flow like landslides adopting the lattari mts in campania as a case study the results of two investigation campaigns carried out in the area allowed effective large scale geological and geotechnical characterization to be set up stratigraphic profiles mean physical properties and typical friction angles at the critical state for each soil layer were investigated the effect of suction on peak and critical shear strength whose drop is responsible for soil failure was analysed using detailed information on both the stratigraphic and geotechnical features of the soils involved in past flow like landslides typical triggering models were selected representing locally recurrent geomorphologic conditions at the basin scale the identified models were adopted for slope stability analyses carried out on four cross sections of flowslides occurring prior to the event to back analyse the triggering conditions from the evidence on the triggering mechanisms and the results of analyses the infinite slope approach is not always suitable to model slope stability conditions properly because the onset of landslides is also affected by local topographic and stratigraphic factors

investigation of ageing effects on riprap blocks used in gelingullu earthfill dam yozgat turkey this study aimed to determine the current geological and engineering features of granite blocks used as riprap material in the construction of gelingullu dam which is in use for nearly 20 years the riprap layer is divided into four zones a b c and d from the lowest lake water level to dam crest by noting the durations underwater samples taken from the zones were investigated for petrographic physical chemical and mechanical characteristics schmidt hardness hammer experiments were completed on site for blocks in the zones the shape features of the blocks were determined with the fractal dimension method physical weathering developed on sections close to the surface of blocks in zones a b and c which were in contact with water compared to blocks in zone d blocks in zones a b and c had higher porosity water absorption and los angeles abrasion loss values with lower density uniaxial compressive strength schmidt hardness rebound values and vp values the increased porosity of blocks from zones a b and c was caused by greater effects of physical factors like wetting drying and freeze thaw affecting the blocks in these zones in contact with lake water this increased the speed of fragmentation and weakening of the blocks according to the results obtained in the study it is understood that over nearly twenty years the weathering processes affecting the riprap layer have caused changes to the physical and mechanical features of the rock blocks

field hydrological monitoring of a sloping shallow pyroclastic deposit many mountainous areas in campania southern italy are characterized by steep slopes covered by unsaturated volcanic deposits shallow landslides are frequently triggered by intense and persistent

an investigation on the effect of accelerated weathering on strength and durability of tertiary sandstones qazvin province iran damages to stones induced by the action of freeze thaw and salt crystallization are considered to be of great importance in engineering construction these processes can influence the strength and durability of porous materials and consequently deteriorate them in this study the effects of freeze thaw f t and salt crystallization s c phenomena on strength and durability of upper red formation sandstones were investigated nine specimens of sandstones were collected from different parts of qazvin area iran and then their physical and mechanical characteristics were determined to assess the effect of f t and s c on physical and mechanical characteristics of sandstones 60 cycles of f t test and 20 cycles of s c test were performed physical and mechanical characteristics of these sandstones including wave velocity vp changes weight loss point load index and brazilian tensile strength were determined after different cycles for assessing the effect of freeze thaw and salt crystallization phenomena on slake durability index sdi of sandstones slake durability test was performed on specimens subjected to f t and s c then changes occurred in the sdi after 15 cycles were investigated finally the long term durability of sandstones against freeze thaw and salt crystallization action was evaluated using a decay function model this model postulates a first order process and provides some meaningful parameters such as decay constant and half life for the evaluation of long term durability of stones based on results obtained from current study it can be concluded that in comparison to freeze thaw salt crystallization can considerably reduce the strength and durability of sandstones also parameters obtained from decay function model showed that the rate of integrity loss is different for different weathering processes and stone durability can be predicted by this method with good accuracy

salt weathering influence of evaporation rate supersaturation and crystallization pattern micro and macroscale experiments which document the dynamics of salt damage to porous stone have yielded data which expose weaknesses in earlier interpretations previously unexplained differences are found in crystal morphology crystallization patterns kinetics and substrate damage when comparing the growth of mirabilite na2so4 10h2o and thenardite na2so4 versus halite nacl the crystallization pattern of sodium sulphate was strongly affected by relative humidity rh while a lesser rh effect was observed for sodium chloride macroscale experiments confirmed that mirabilite crystallizing at rh 50 per cent and thenardite crystallizing at rh 50 per cent tend to form subflorescence in highly localized areas under conditions of constant rh and temperature this crystallization pattern was more damaging than that of halite since halite tended to grow as efflorescence or by filling the smallest pores of the stone in a homogeneous fashion a result which contradicts wellman and wilson s theoretical model of salt damage low rh promoted rapid evaporation of saline solutions and higher supersaturation levels resulting in the greatest damage to the stone in the case of both sodium sulphate and sodium chloride crystallization at any particular crystallization condition sodium chloride tended to reach lower supersaturation levels resulting in the crystallization of isometric crystals and created negligible damage while sodium sulphate reached higher supersaturation ratios resulting in non equilibrium crystal shapes resulting in significant damage esem showed no damage from sodium sulphate due to hydration instead after water condensation on thenardite crystals rapid dissolution followed by precipitation of mirabilite took place resulting in stone damage by means of crystallization pressure generation it is concluded that salt damage due to crystallization pressure appears to be largely a function of solution supersaturation ratio and location of crystallization these key factors are related to solution properties and evaporation rates which are constrained by solution composition environmental conditions substrate properties and salt crystallization growth patterns when combined with a critical review of salt damage literature these experiments allow the development of a model which explains variations in damage related to combinations of different salts substrates and environmental conditions

empirical prediction of porosity and permeability in sandstones current efforts to predict porosity and permeability in sandstones prior to drilling are focused on empirical and process oriented models empirical predictions are based on the correlation between porosity and permeability and a limited number of parameters obtained from calibration data sets or estimated from appropriate geologic models of these parameters the most important are detrital composition grain size sorting and temperature history or pressure history or both despite its limitations the empirical approach provides accurate predrill predictions of reservoir quality in many sandstones containing not only primary but also secondary porosity and permeability predictions of the average porosity and permeability of target sandstones are arbitrarily defined h re as accurate if they fall within 2 porosity of the mean measured porosity and within the same order of magnitude as the mean measured permeability in a sample population representing the interval of interest the effectiveness of the empirical predictive approach is illustrated by case studies from the taranaki basin new zealand and yacheng field people s republic of china these studies indicate that empirical predictions are basin specific or even play specific and require at least some understanding of fundamental processes affecting reservoir quality of a given sandstone target process oriented approaches attempting to model the effect of diagenesis on reservoir quality are hampered by inadequate quantitative understanding of the processes responsible for preserving primary porosity and generating secondary porosity and permeability until adequate quantification of the sandstone diagenesis processes is achieved empirical models have a distinct advantage over process oriented models in providing reliable predictions of reservoir quality in many sandstone intervals

on capillary barrier effects and debris slide triggering in unsaturated layered covers abstract the present work is focused on investigating the potential role of capillary barriers on the stability of layered soil deposits laying upon high permeability steep slopes in presence of capillary barrier effects often possible on a soil stratigraphy characterized by contrasting hydraulic properties pyroclastics deposit over pumices silt upon fractured bedrock silt over sand failure might originate in less permeable layers where unsaturated conditions might provide a crucial contribution to stability basic ideas and considerations have been drawn from a peculiar case study the catastrophic landslide occurred in campania southern italy on may 1998 which is discussed in this paper from a different perspective the areal extent of failures distribution their dense concentration at the steeper and higher slopes the extremely high number of initial failures occurred within a relatively short time span suggest that the intimate cause of the event is related at some extent to the soil state characteristic parameters rather than positive pore pressure pulses from water circulation in coarser layers or groundwater level rising from bedrock and springs a widespread loss of soil strength related to saturation can contribute to explain such phenomena capillary barrier effects favor accumulation and lateral distribution of percolating rainfall and possibly divert flowlines downslope thus leading to localized increases in water content and loss of strength diversion of percolating waters facilitates lateral redistribution of soil moisture along the slope with possible further localized saturation because more permeable layers may act temporarily as barriers and not as drains as one could expect numerical 2 d infiltration models with parameters calibrated versus laboratory data show a relevant influence of capillary barrier effects on infiltration in layered slopes with vertically stratified variations of hydraulic properties and point out significant localized moisture accumulation with possible consequences on slope stability landslide initiation phenomena in layered covers might thus be conditioned by the increase in saturation within the least permeable soil layers due to capillary barrier phenomena

analyses on variations in the unsaturated characteristics of a mine waste dump slope during rainfall field measurement units and a system were constructed and installed in a waste dump slope at the imgi mine to investigate and analyze the variations in the unsaturated characteristics of the soil the field instrumentation system was composed of a data acquisition system a solar system and measuring sensors the rainfall matric suction and volumetric water contents were continuously measured from the units in the instrumented site and analyzed with the soil water characteristic curve swcc estimated from laboratory experiments the variations in matric suction and volumetric water content were primarily affected by the rainfall intensity at the surface of the slope the largest increase and decrease in the changes in matric suction and volumetric water content were observed during the wetting and drying processes respectively the matric suction and volumetric water content measured from the instrumented area were compared with the swccs obtained from the laboratory test and the measured data were located between the drying and wetting paths the drying and wetting paths obtained from the laboratory test are regarded as primary drying and wetting curves respectively therefore the measured data can be defined as scanning curves which are located between primary drying and wetting curves the variations in matric suction according to volumetric water content were dependent on depth and a wide range of variations was observed at shallow depths it was confirmed that the unsaturated soil near the ground surface has the sensitive reaction induced by the infiltration and evaporation in nature

a three dimensional back analysis of the collapse of an underground cavity in soft rocks abstract the assessment of stability of man made underground caves excavated in the past and later on abandoned represents a serious challenge for land and urban planning operations especially for the areas of possible interaction of the caves with overlying structures and infrastructures several areas of southern italy are characterized by the presence of abandoned underground quarries for the extraction of soft calcarenite rocks which now threatens the overlying environment due to the risk of collapse and the consequent generation of sinkholes this work presents a back analysis of a sinkhole occurred in 2011 in the town of marsala caused by the collapse of an underground quarry as a representative case study of these phenomena based on the available geometrical and geological dataset as well as the field observations of the phenomenon in this article the assumptions and the results about the genesis of the 2011 sinkhole as derived from a three dimensional finite element back analysis aimed at reconstructing the stress strain evolution that brought to the ground failure collapse is discussed in particular the 3 d numerical analyses have been performed in order to identify the factors responsible of the genetic mechanism of the sinkhole the finite element analysis has been carried out by accounting for the geotechnical characterization of the marsala calcarenites derived from both specific laboratory tests performed on samples taken from the site and literature data available on the same rock material the numerical results have been then validated by means of the comparison with field observations and also compared with those achieved through a 2 d model of the same case study

durability of carbonate rock as building stone with comments on its preservation carbonate rocks have been extensively used as building stones because of their availability workability and attractiveness unfortunately however some stones suffer from chemical attack or freeze thaw activity the environmental affects especially those due to pollution of the atmosphere are discussed in terms of weathering processes salt crystallization and acid deposition a review of some recent research in relation to deterioration of stone in urban environments is given and carbonate rocks are classified in relation to position within a building geographical location and degree of pollution some comments on stone preservation are provided especially in terms of the properties a preservative should possess

steep slope monitoring in unsaturated pyroclastic soils based on monitoring results the paper describes the hydrological response of a steep hillslope covered by unsaturated pyroclastic soils the instrumented site is located just beside an area which experienced a catastrophic flowslide two years prior to the survey monitoring involved rainfall and matric suction measured at different locations and depths investigations focused on the hydrological response of the slope so as to model the effects of rainfall and then predict the onset of slope failure triggered by critical rainfall

diagenetic processes influencing porosity in sandstones from the triassic buntsandstein of the iberian range spain abstract sandstones of the triassic buntsandstein of spain were studied in an attempt to quantify effects of diagenetic processes such as compaction cementation and leaching on reservoir properties samples were taken from shell well siguenza 44 3 some 110 km northeast of madrid drilled on the siguenza high in the iberian range the sandstones are arkoses to sublitharenites of a typical triassic redbed facies characteristic of the whole region the present day depth of the base buntsandstein is 538 m whilst a maximum burial depth of ca 2600 m was estimated from vitrinite reflectance 0 94 to 1 14 kaolinite temperature 76 c and illite crystallinity kuebler index 4 9 from an estimated average initial porosity of 38 porosity was reduced to the present value of 13 the strongest process to reduce porosity was found to be mechanical compaction causing a loss of 15 followed by chemical compaction pressure solution with a loss of about 6 the cement 11 4 r v apparently reduced the initial porosity by about only 5 early carbonate and sulphate cements are interpreted to have stabili sed the rock framework working against mechanical compaction and pressure solution this is supported by an increase in sutured grain contacts where early cements are absent or rare the later quartz cement interpreted to be largely the product from pressure solution has reduced porosity in a ratio of 0 5 1 this suggests that compaction continued after the formation of the late quartz cement although leaching was observed especially in feldspar grains clay and k feldspar neomorphosis is interpreted to have counteracted the formation of substantial secondary porosity permeability in the buntsandstein is generally low average 17 4 md and has been strongly affected by the alteration of feldspars to clay causing a wide range of permeability from 0 11 to 73 0 md

diagenetic replacement controlled by force of crystallization many diagenetic replacements in sedimentary rocks occur along thin solution films between the authigenic and host phases rather than conventionally invoking bulk pore water undersaturation for host phase dissolution we propose that many diagenetic replacements occur by a force of crystallization controlled replacement mechanism whereby nonhydrostatic stresses resulting from authigenic crystal growth are principally responsible for host phase dissolution this model explains diagenetic features such as the restriction of host phase dissolution to authigenic host crystal contacts and euhedral authigenic crystal faces in planar contact with unreplaced host phases as well as the relative replacement tendencies of some common authigenic minerals

petrographic quantification of brecciated rocks by image analysis application to the interpretation of elastic wave velocities abstract this paper presents a new procedure to quantify the petrology of materials with complex and heterogenic rock fabric features the classical methodologies for petrographic quantification by image analysis are not appropriate for this kind of rock due to both the high chromatic complexity of these materials and the scale with which the samples are studied the proposed process is particularly interesting for materials with complex chromatic characteristics such as highly fractured rocks concrete etc two commercial varieties of highly fractured brecciated dolostones were selected for this study in order to test the designed methodology this new procedure is based on the analysis process of colour images obtained from mesoscopic sample scanning six petrographic parameters and diagrams have been designed in order to quantify the most influential aspects in compressional v p and shear v s ultrasonic wave propagation these petrographic parameters and diagrams are brecciation density brecciation density map clast size distribution fine grained matrix content shape preferred orientation and rose diagrams the results demonstrate that the proposed methodology is suitable for quantifying the petrography of these kinds of materials furthermore the variations measured in v p and v s are fully explained by the values measured for the following parameters brecciation density fine grained matrix content clast size distribution and preferred orientation of clasts

surface hardness as a proxy for weathering behaviour of limestone heritage a case study on dated headstones on the isle of portland uk this study estimates stone weathering rates using in situ surface hardness testing surface hardness changes are precursors to erosion and may be utilized to describe stone weathering behaviour the method proposed here complements previous approaches to determining stone weathering rates by surface loss change a time series covering 1 248 years of exposure is investigated using a sample of 12 headstones in two nearby cemeteries using an equotip d surface hardness tester rates of change in surface hardness for top and bottom sections of the headstones were determined and the data evaluated using robust nonparametric statistical methods when considering all headstones as one time series nonlinear behaviour is observed with rates of decline in surface hardness slowing over time however breakpoint analysis shows a breakpoint at c 100 years with higher rates of surface hardness decline as measured by qc 50 the regression coefficient for 0 50 quantile regression up to that point and lower rates thereafter up to c 100 years surface hardness declines more rapidly in the top versus bottom sections possible explanations for the differing rates in surface hardness changes are a inherent natural stone variability and or different weathering stress history b the use of two different portland limestone varieties c synergistic effects of microclimates and lichen cover in order to gain a deeper insight into stone weathering behaviour future studies could combine surface hardness measurements with surface change methods such as micro erosion meter and lead plug index over short and long term time series on architectural heritage under real world conditions

rocky coast geomorphology and erosional processes a case study along the murgia coastline south of bari apulia se italy many sites along the apulian coast se italy are composed of weathered and fractured carbonate rocks affected by intense erosion and the development of slope instabilities here coastal morphology was mostly produced by quaternary tectonics the severe and selective action of modern erosion by sea waves and locally was strongly conditioned by human influences in addition due to the carbonate nature of rock masses the role exerted by karst processes has to be considered this paper provides a critical review of the common eroding processes and factors affecting coastal morphology in a typical mediterranean coastal carbonate environment a stretch of the murgia coastline south of bari between san vito and polignano a mare made up of cliffs and shore platforms interrupted by small pocket beaches was considered for qualitative and quantitative assessment of shoreline recession the coastal stretch was monitored by means of field surveys between 1997 and 2003 furthermore a comparison of vertical aerial photographs covering the period 1966 1997 scales 1 33 000 1 10 000 and 1 5000 topographic maps scales 1 5000 year 1987 1 2000 year 1982 and archival terrestrial photographs taken since the 1930s was also employed in some zones characterised by a gently sloping shore platform a significant shoreline retreat was calculated at about 20 m in the last 100 years 0 2 myr 1 which was caused above all by human activity here in fact the presence of small ancient coastal quarries

weathering of submerged stressed calcarenites chemo mechanical coupling mechanisms long portions of the apulian coast are steep cliffs in carbonate soft rocks these especially the calcarenite are affected by weathering processes that markedly alter their mechanical properties with time potentially leading to instability of coastal geomorphological structures such alterations are mainly due to chemical reactions between the solid and fluid phases and are driven by chemical variables which are internal variables and hence uncontrollable in a search for the variables that drive the process of rock weakening recourse is made to the micro scale at which most of the chemical processes are observed and quantified observations using scanning electron microsope thin sections and x ray computed tomography analyses appear to be crucial for the understanding interpretation and definition of the degradation mechanisms of the material a chemo mechanical coupled model at the meso scale of the chemically reactive stressed porous system is presented and framed in the context of a multi sca

physical modeling investigation of rainfall infiltration in steep layered volcanoclastic slopes abstract infiltration processes in layered slopes can be strongly affected by the different hydraulic properties of the soils constituting the layers with potential downslope flow diversion that can have effects on slope stability as well as on runoff generation and groundwater recharge in this respect volcanoclastic soil covers represent a typical example as layers with strongly contrasting textures are deposited during the various eruptive phases in this paper the results of a transient infiltration test carried out in a densely instrumented physical model of a layered volcanoclastic sloping cover are presented the soil cover was constituted by a layer of gravelly pumices interbedded between two layers of finer ashes sandy loams even with such an extreme contrast in texture capable of significantly delaying the advancement of infiltration through the layer of pumices flow diversion occurred only temporarily at the interface between the upper layer of ashes and the pumices in fact although a long lasting intense rainfall was applied into an initially dry soil profile the downslope diverted water volume in form of a subsurface runoff was just a small fraction of the total applied rainfall in fact the accumulation of water above the upper edge of the pumices responsible of the subsurface runoff soon led to the establishment of a large water potential gradient which redirected the infiltrating flow through the pumices and stopped the downslope flow diversion

monitored and simulated variations in matric suction during rainfall in a residual soil slope this research combines field laboratory and numerical investigations to estimate the development of a wetting front within a 1 2 m residual soil mantle on a steep forested slope during rainfall events the field monitored variations in matric suction due to rain water infiltration during various events revealed that the maximum infiltration rate was much higher when the wetting front resided in the upper 20 cm of soil compared to the case when the wetting front advanced to depths 20 cm laboratory investigations on soil hydraulic properties i e soil water characteristic curve and hydraulic conductivity were useful to establish the parameters of a multilayer finite element model for one dimensional vertical infiltration these parameters were subsequently calibrated by matching the predicted and field measured transient pore water pressure responses during actual rainstorms with irregular rainfall patterns the calibrated simulation model was used to assess the migration of the wetting front under uniform rainfall with different intensities based on the numerical results a hyperbolic equation was developed to predict the duration of uniform rainfall required for the propagation of wetting front to a certain depth for a given rainfall intensity the proposed equation was subsequently tested against field monitored advancements of the wetting front during real rainstorms with variable rainfall intensity

the control of mineral constituents and textural characteristics on the petrophysical mechanical pm properties of different rocks of the himalaya abstract petrophysical and mechanical pm properties of a rock are primarily controlled by its mineral constituents and various textural parameters similar rock types in different tectonic setups may be characterized by different mineralogical compositions and textural properties because they might have suffered different deformational processes this paper presents a study on the mineralogical and textural control on various pm properties in quartzites granitoids gneisses metabasics and dolomite collected from different tectonic set ups the inter relationships among mineral constituents various textural parameters unconfined compressive strength ucs schmidt hammer rebound r value seismic wave both p and s waves velocity and their attenuation characteristics were obtained using regression analyses it has been concluded that there exists no relation between ucs and seismic wave velocity in quartzite granitoids and gneisses moderate positive relationship in metabasics and strong negative relationship in dolomite it has further been noted that in quartzite and dolomite monominerelic rocks grain size dominantly control the seismic wave velocity as the relatively coarser grained samples have higher seismic wave velocity whereas ucs is strongly controlled by grain size as well as the quantity and the orientation of the weak minerals like muscovite biotite calcite etc in gneisses and granitic gneisses preferred orientation of minerals especially the mica minerals although in present small quantity is the main factor controlling ucs and seismic velocity both these properties increase with the increase in intensity of preferred alignment of minerals whereas in metabasics it is the presence of amphibole pyroxene minerals feldspar that dominantly controls the seismic wave velocity

the effect of weathering on pore geometry and compressive strength of selected rock types from turkey weathering processes cause important changes in rock porosity besides porosity distribution of pore sizes is significant for the identification of changes due to rock weathering and its effects on fabric the formation of secondary porosity in different types of rock taken from different parts of turkey was examined and the results are presented in this paper the aim of this study was to observe changes in porosity due to weathering effective porosity mercury intrusion porosimetry and optical and scanning electron microscopy were used to evaluate the changes in pore geometry of the rocks additionally the dry density water absorption and uniaxial compressive strength of the rocks at different weathering stages were determined analysis of experimental data showed that microstructure of the rocks in relation to weathering is the main feature which controls their physical and mechanical properties the study revealed that fabric characteristics particularly the pore and fracture geometry are very important characteristics for assessment of the behaviour of weathered rock

petrographic features influencing basic geotechnical parameters of carbonate soft rocks from apulia southern italy abstract a multidisciplinary petrographic and geotechnical approach aimed at understanding the conditioning by rock fabric on the mechanical properties of carbonate soft rocks is shown in this paper the analysed rocks extensively crop out in the apulia region and can be referred to three geological units pietra leccese late burdigalian early messinian calcarenite di gravina middle pliocene early pleistocene and salentino supersynthem midde late pleistocene 69 specimens of carbonate soft rocks belonging to all these units were selected from different sectors of apulia region and characterized according to petrographic physical and mechanical properties petrographic data allowed us to group all specimens in the following six classes i wackestone ii mud dominated packstone iii packstone iv grainstone v floatstone vi rudstone differently uniaxial compression strength ucs values classify the most part of specimens in very low and low strength revealing a dominant weak resistance and high deformability particular attention has been given to the relationships between petrographic features and physical and mechanical parameters of the apulian soft rocks by means of statistical tests based on the univariate analysis of variance one way anova and on the principal component analysis pca at first statistical analysis revealed that the rock geotechnical values are strictly dependent from the geological units particularly the samples of pietra leccese show significantly higher means of ucs young s modulus et and dry unit weight than samples of the calcarenite di gravina fm conversely samples of this latter unit have significantly higher means of porosity imbibition coefficient and permeability coefficient than those ones of the pietra leccese fm moreover statistical analysis was applied to estimate if geotechnical values differ according to the petrographic classes of the calcarenite di gravina fm and to verify the covariance between the geotechnical parameters of this unit the following results have been remarked i floatstone and rudstone have significantly higher means of ucs and dry unit weight and lower means of porosity than finer grained classes ii mud dominated packstone has significantly lower means of ucs dry unit weight et and permeability coefficient and higher means of porosity and imbibition coefficient than other petrographic classes iii grain dominated matrix free rudstone and grainstone have significantly higher values of permeability coefficient than mud dominated classes iv the occurrence of carbonate lithoclasts and of different dominant couples of sparry cement in pore spaces are two of the most important controlling factors of the rock strength and can also explains much of the intraformational variability observed in geotechnical data total porosity has not a clear correlation with permeability this means that the contribution of isolated pore spaces to the total porosity is relevant in apulian soft rocks as also suggested by the relatively low values of permeability compared to the relatively high percentages of total porosity a multidisciplinary characterization of carbonate soft rocks based on petrographic analysis and geotechnical determination of physical and mechanical properties is here recommended for future studies since this approach can give useful information to understand the peculiar behaviour of carbonate soft rocks and to drive the subsequent geotechnical investigations

a preliminary analysis of failure mechanisms in karst and man made underground caves in southern italy abstract natural and anthropogenic caves may represent a potential hazard for the built environment due to the occurrence of instability within caves that may propagate upward and eventually reach the ground surface inducing the occurrence of sinkholes in particular when caves are at shallow depth the effects at the ground surface may be extremely severe apulia region southern italy hosts many sites where hazard associated with sinkholes is very serious due to presence of both natural karst caves and anthropogenic cavities the latter being mostly represented by underground quarries the pliocene pleistocene calcarenite a typical soft rock was extensively quarried underground by digging long and complex networks of tunnels with time these underground activities have progressively been abandoned and their memory lost so that many apulian towns are nowadays located just above the caves due to urban expansion in the last decades therefore a remarkable risk exists for society which should not be left uninvestigated the present contribution deals with the analysis of the most representative failure mechanisms observed in the field for such underground instability processes and the factors that seem to influence the processes as for example those causing weathering of the rock and the consequent degradation of its physical and mechanical properties aimed at exploring the progression of instability of the cavities numerical analyses have been developed by using both the finite element method for geological settings represented by continuous soft rock mass and the distinct element method for jointed rock mass conditions both the effects of local instability processes occurring underground and the effects of the progressive enlargement of the caves on the overall stability of the rock mass have been investigated along with the consequent failure mechanisms in particular degradation processes of the rock mass as a consequence of wetting and weathering phenomena in the areas surrounding the caves have been simulated the results obtained from the numerical simulations have then been compared with what has been observed during field surveys and a satisfactory agreement between the numerical simulations and the instability processes as detected in situ has been noticed

dynamic response of a rocky cliff under the sea wave pulse a study along the adriatic coast of polignano apulia italy the dynamic behavior of a rocky cliff under severe sea waves has been analyzed in the location of polignano facing on the adriatic coast of apulia southern italy in this area the classical and at the same time complex problem of the stability of a cliff in calcareous rocks is burdened by the presence on the top of the cliff of the ancient town to analyze the behavior of the cliff under the impulsive transfer of energy generated by the sea waves two types of measures were carried out on the rocky mass 1 ambient noise and 2 strong motion records the first type of measures which may be executed in a short time with a high spatial density has provided a recognition of the intrinsic and anisotropic dynamic behavior of the coastal cliff the accelerometric records carried out during heavy storms in december 2009 and january 2010 allowed to evaluate the energy transfer from waves to cliff in terms of maximum values and temporal and directional distribution to facilitate a correct interpretation of the measures also a geomechanical characterization of the rocky mass has been carried out through the rock mass rating system bieniawski the geomechanics classification in rock engineering applications proceedings of the 4th isrm cong montreux pp 51 58 1979 bieniawski engineering rock mass classifications wiley new york p 251 1989 and the markland s test a useful technique for estimating the stability of rock slopes when the rigid wedge sliding type of failure is expected pp 10 1972 the first allowed to classify the rocky masses in terms of quality the second one to individuate the potential failure mechanisms of the cliff

weathering of sandstone lotus petals at the angkor site a 1 000 year stone durability trial this article is based on field investigations carried out at ta keo and banteay srei temples angkor cambodia which have similar environmental histories and display the same recurrent decorative pattern lotus petal in three different sandstone lithotypes based on two original scales of mechanical and chemical weathering the degree of deterioration of c 2000 sandstone petals was visually assessed resulting in the proposal of a durability scale an explanatory scheme was provided based on laboratory analyses of stone materials icp aes xrd sem eds polarizing microscopy and mercury injection the key drivers of sandstone durability are both mineralogical and petrophysical the remarkable preservation of the pink sandstone is due to the quartzose nature of its clasts the non swelling clay content of its abundant matrix kaolinite and its porosity structure large connected pores and probable non connected porosity the overall good preservation of the green sandstone is due to its extremely low porosity and specific surface area associated with its strong cementation the severe deterioration of the grey sandstone is due to its laminated structure oriented biotites the susceptibility to hygric swelling and solution of its binding agents chlorite smectite and calcite and its porosity structure which evolves during a two stage weathering sequence the first stage is characterized by a bimodal porosity due to the partial clogging of macropores by swelling clays and the second stage by a substantial increase in porosity and the penetration of salts barite and anhydrite conversely oxidation phenomena associated with weathering can lead to a drastic reduction of porosity

rock fabric heterogeneity and its influence on the petrophysical properties of a building limestone lede stone belgium as an example lede stone is an important historical stone in belgium with many ceased and disappeared historical quarries owing to its geological nature this stone exhibits considerable variation in petrophysical properties three macroscopical different facies from the solely remaining quarry area in balegem belgium were profoundly characterized for their pore network properties and petrophysical properties the pore network was exhaustively studied combining water imbibition under vacuum mercury intrusion porosimetry and x ray computed microtomography the three facies not only have a strong difference in total porosity but also differ in terms of pore connectivity and pore size distribution linked to the variability in microfacies this has profound implications on the water transfer properties such as atmospheric water absorption capillary water absorption om nidirectional drying and water vapor resistance the petrophysical behavior is illustrated with a salt ageing test the results can be used for restoration and conservation of lede stone in the built cultural heritage

interpretation of subsurface hydrocarbon shows hydrocarbons occur in the subsurface in four modes 1 continuous phase oil or gas 2 isolated droplets of oil or gas 3 dissolved hydrocarbons and 4 associated with kerogenous rocks all of these modes of occurrence can result in what is described as a subsurface hydrocarbon show each show type has markedly different implications to exploration and must be differentiated as the first step in show interpretation only continuous phase occurrences of oil and gas indicate that a trapped and potentially producible accumulation of hydrocarbons has been discovered free oil or gas recovery from the formation or subsurface hydrocarbon saturations of greater than 55 indicates a continuous phase occurrence continuous phase shows can be interpreted quantitatively the static hydrocarbon column downdip from a continuous phase occurrence can be calculated from one well bore if the subsurface oil or gas saturation capillary properties hydrocarbon water interfacial tension oil density and water density of the reservoir are known producing wells are by definition continuous phase oil or gas and estimates of oil water or gas water contacts from normally available exploration data are practical and reasonably accurate based on a documented field study continuous phase oil or gas can extend either updip or downdip from a commercial reservoir these continuous phase shows can also be interpreted quantitatively to determine how large an oil or gas column is required downdip to explain the show by this method it can be determined whether an exploratory well penetrated the updip waste zone or downdip transition zone of an oil or gas field field studies illustrate that quantitative show interpretation of noncommercial shows can provide reliable estimates of the downdip hydrocarbon column this type of data can be used in a systematic manner to explore for subtle stratigraphic and combination traps

pore and hygric properties of porous limestones a case study from bratislava slovakia abstract most historic stone monuments in bratislava slovakia are built with various types of porous light and weakly cemented sedimentary rocks these neogene sandstones and limestones also known as leitha limestones were quarried in the vienna basin the various sedimentary environments are reflected in the heterogeneity of lithotypes and their cementation the distinctly different pore structure of these rocks is reflected in their very variable physical properties and consequently in the distinct durability petrographic and petrophysical properties were determined on main ashlar types of the two most important historical monuments of bratislava the castle and st martin9s cathedral fresh samples of leitha limestones were also obtained from the existing or abandoned quarries the study includes a detailed petrographic examination of major rocks types and an assessment of their mineralogical composition by x ray diffraction and microscopy hygric properties and porosity influence the weathering stability and the chances to apply conservation treatment parameters such as pore volume pore size distribution by mercury porosimetry specific surface of pores by nitrogen adsorption bet analysis as well as water sorption capillary water uptake and drying behaviour were measured and compared for the six studied lithotypes

sandstone degradation an experimental study of accelerated weathering the investigated rock material belongs to the group of upper cretaceous quader sandstones which are very important construction stones in poland and germany the mineral composition of the rocks is relatively uniform they are quartzose sandstones the most important feature is their good workability and comparatively high weathering resistance still regardless of the apparent resemblance the observations carried on buildings and monuments show differences in weathering processes the undertaken test was an attempt to verify the proposed before rock classification performed on the basis of parameterization of porosimetric cumulative intrusion volume curves the aim of the experiment was the evaluation of the sandstone petrography including the structure texture and porosity of the rock influence on the weathering process the modelling of accelerated weathering was conducted in chamber for ageing acceleration where some weather circumstances were simulated insolation rain and frost as the result of the weathering experiment it could be stated that the dominant mechanism of the sandstones deterioration was granular disintegration and weight loss as a consequence of sample destruction the most important factor influencing rock deterioration is rock texture especially the character of grain contacts the effective porosity is a requisite of potential for the stone to take in and hold water and hence of resistance to weathering in case of silica cemented sandstones the deciding criterion influencing weathering resistance is pore structure in case of sandstones with clay cement the most important is mineral composition of the rock

water source utilization by woody plants growing on dolomite outcrops and nearby soils during dry seasons in karst region of southwest china summary in the seasonally dry karst region of southwest china woodland vegetation is frequently associated with rocky outcrops we used stable isotope techniques to determine the water sources of two woody plant species the semideciduous tree rademachera sinica and the deciduous shrub alchornea trewioides across three surface types continuous and isolated dolomite outcrops as well as adjacent surfaces with soils main water sources for r sinica growing on the continuous outcrops shifted from deep water sources e g water in the saturated zone on march 23 2009 the late dry season of 2008 2009 to rainwater stored in rock fissures of the unsaturated zone on november 8 2009 the early dry season of 2009 2010 r sinica growing on nearby thin soils exhibited a similar shift of main water sources from deep water sources in the late dry season to shallow soil water 0 30 cm in the early dry season however they extracted deep water sources from the bottom of nearby outcrops rather than from deeper layers below the soil surface main water sources for r sinica growing on the isolated outcrops shifted from previous one to two months ago rainwater in the late dry season to the mixture of recent within the last one month and previous rainwater in the early dry season while using little or no deep water sources in contrast a trewioides growing on these two kinds of outcrops always relied on recent rainwater while those growing on soils always relied on shallow soil water the shift of water sources for tree species especially those growing on continuous rock outcrops and nearby soils may allow them to maintain normal transpiration throughout the year which increases the amount of evapotranspiration in the watershed and further enhances the water storage capacity of the study area

experimental investigation on the performance of schmidt hammer test in durability assessment of carbonate building stones against freeze thaw weathering although schmidt hammer test has been widely used for assessment of weathering state of rocks its application for evaluation of rock durability remains rare this study aims at investigating the performance of the schmidt hammer test in the durability assessment of carbonate building stones against frost weathering for this purpose nine types of carbonate rocks were collected from various quarries of iran and subjected to a series of tests including determination of petrographical physical mechanical ultrasonic and rebound hardness properties moreover long term weathering test of freeze thaw up to 100 cycles were carried out and ultrasonic detection was used to detect the weathering induced damages of rocks in ultrasonic detections ultrasonic parameters of maximum amplitude amax spatial attenuation s and compressional wave velocity vp were determined before and after freeze thaw tests and then their change rates were determined the change rates of amax s and vp including ka k and kp respectively were considered as the functions of the degree of the frost induced damages of rocks and consequently as indications of the rock durability results showed that there are close correlations between the schmidt hammer rebound value rn and ka k and kp however the correlation between rn and kp was weaker than those between rn and ka and k because of the disproportionate response of vp to the rock deterioration it was concluded that the schmidt hammer test is capable to evaluate the durability of carbonate building stones and can be used for a rapid and onsite evaluation of rock durability at different quarry faces hence it allows selecting more durable rocks for different applications in new constructions and also in replacement works in historical sites

effects of mineral suspension and dissolution on strength and compressibility of soft carbonate rocks abstract calcarenites are highly porous soft rocks formed of mainly carbonate grains bonded together by calcite bridges the above characteristics make them prone to water induced weathering frequently featuring large caverns and inland natural underground cavities this study is aimed to determine the main physical processes at the base of the short and long term weakening experienced by these rocks when interacting with water we present the results of microscale experimental investigations performed on calcarenites from four different sites in southern italy sem thin sections x ray ct observations and related analyses are used for both the interpretation definition of the structure changes and the identification quantification of the degradation mechanisms two distinct types of bonding have been identified within the rock temporary bonding tb and persistent bonding pb the diverse mechanisms linked to these two types of bonding explain both the observed fast decrease in rock strength when water fills the pores short term effect of water identified with a short term debonding std and a long term weakening of the material when the latter is persistently kept in water saturated conditions long term effect of water identified with a long term debonding ltd to highlight the micro hydro chemo mechanical processes of formation and annihilation of the tb bonds and their role in the evolution of the mechanical strength of the material mechanical tests on samples prepared by drying partially saturated calcarenite powder or a mix of glass ballotini and calcarenite powder were conducted the long term debonding processes have also been investigated using acid solutions in order to accelerate the reaction rates this paper attempts to identify and quantify differences between the two types of bonds and the relative micro scale debonding processes leading to the macro scale material weakening mechanisms

geochemical petrographic and petrophysical characterization of the lower bakken shale divide county north dakota abstract the lower bakken shale is a key member of the bakken petroleum system which is a prolific unconventional accumulation in north america unconventional accumulations have unpredictable lateral variations in hydrocarbon production due to a variety of factors including porosity permeability and other rock properties therefore understanding the geochemical source rock potential petrological and petrophysical properties of these units is essential in evaluating the hydrocarbon potential for the lower bakken shale this study utilized cores from four wells within three fields in divide county north dakota with samples collected for rock eval pyrolysis organic petrology petrographic thin section studies xrd sem porosity pore size and pore fluid distribution helium porosimetry and nmr t2 porosity techniques were used to estimate porosity and also to check the quality of the results and avoid discrepancies results showed that maturity in the study area varies from immature to early mature using tmax and solid bitumen reflectance organic petrology showed the dominance of solid bitumen and marine alginites which confirms the type ii kerogen identified from pyrolysis and marine depositional environment in the study area major organic matter types identified from sem studies involve stringy om om mineral admixture particulate om and pure om which host the majority of the organic matter pores furthermore pore types identified from sem include mineral matrix pores organic matter pores and microfracture pores porosity values based on both helium and nmr varies but the difference was nominal and attributed to the presence of abundant clay minerals pore sizes are distributed within micropores mesopores and macropores with thermal maturity toc and clay mineral proportion having a major influence on pore distribution clay bound water was identified to be the dominant fluid within the shale samples using the t2 cutoff values and supporting evidence from the abundance of clay matrix porosity

susceptibility mapping of instability related to shallow mining cavities in a built up environment anthropogenic activities and urbanization frequently spread over areas underlain by unstable karst ground or man made cavities leading to potential risk situations for buildings infrastructure and population the roof of the cavities may rapidly propagate upwards eventually resulting in progressive ground settlement and or sudden collapse these processes are frequently accelerated or triggered by various human activities e g overloading water recharge water table decline in this paper the susceptibility to instability of artificial cavity networks under an urban area in apulia region southern italy was assessed and evaluated here there is dense network of underground quarries excavated for the extraction of massive calcarenite for building and ornamental stone that are currently affected by severe instability problems identifying the zones of the cavities most prone to instability is of great practical importance susceptibility models have been developed analyzing the statistical relationships between the cavity sections with evidence of instability and a number of predisposing factors mainly related to the 3d geometry of the voids roof thickness and the presence of overloads the models produced by the discriminant analysis and the logistic regression approaches were independently and quantitatively evaluated through the construction of roc curves although the two models are characterized by different input data treatment as the logistic regression allows using continuous and discrete variables or any combination of both types even if they do not have a normal distribution the roc curves highlighted for both methods a satisfactory congruence between the model results and the observed data consequently from the model performance analysis the two models were evaluated comparable in terms of result reliability the methodology should be considered as a general first level analysis for near surface underground cavities aimed at identifying critical cave sectors that can be the focus of more detailed analyses especially those associated with sensitive zone related to the presence of buildings roads and frequent presence of human activity

an image analysis technique to measure grain size variation in thin sections of soft clastic sediments this paper presents a simple and fast image analysis technique to measure grain size variation in thin sections of soft elastic sediments optical and backscattered electron microscope photographs are digitised from thin sections cut by freeze drying to avoid disturbing the sediments processing of the 256 grey scale images produces binary black and white images where white pixels represent the clay rich sedimentary matrix and black pixels represent elastic grains data measured include grain surface grain perimeter and centre of gravity two indices are defined to quantify grain size d 0 equivalent disk diameter and p phase percentages the technique is applied to silt and clay laminations attributed to the d division of a distal turbidite from lake baikal the data obtained using image analysis are similar to the conventional descriptions of such deposits indices calculated on very small samples e g on a single lamina allow for greater precision in interpretation of sedimentary processes compared to photomicrographs backscattered electron microscope images have better qualities and allow to quantify variations in the grain size along a sediment core the technique produces objective and quantified grain size observations in less time than conventional petrographic methods c 1998 elsevier science b v all rights reserved

an integrated geological geotechnical and geophysical approach to identify predisposing factors for flowslide occurrence abstract this study combines geological geotechnical and geophysical analyses to construct a 3d model of the subsoil based on a significant amount of data collected at a test site in the lattari mountain range in southern italy several investigation techniques were applied to study the spatial variability of the local stratigraphic setting and relevant geophysical and geotechnical parameters at the slope scale by integrating field and laboratory measurements such as geological logs soil sampling 2d and 3d electrical resistivity tomography surveys time domain reflectometry profiles and characteristic curves of electrical resistivity vs saturation degree the continuous stratigraphy of the pyroclastic cover in question was reconstructed and 3d models of effective saturation degree in different pyroclastic horizons were retrieved as the proposed procedure is applied to study flowslide initiation the test site was implemented on a 32 slope affected by historical flowslides the following factors predisposing to flowslides were identified steep stratigraphic contact between shallower soils and bedrock impermeable layers that buffer the draining of the fractured limestone preferential rainwater infiltration paths and spatial distribution of water content in the soil

thermal and salt crystallization effects on marble deterioration examples from western anatolia turkey six commercially available and extensively used turkish marbles having different textural properties were subjected to ageing tests in order to assess their resistance against salt crystallization with thermal effect the change in physico mechanical properties of the marbles including weight dry unit weight effective porosity water absorption dry and saturated sonic velocities uniaxial compressive strength ucs indirect brazilian tensile strength flexural strength abrasion value and impact resistance has been determined for various stages of the ageing tests the results are evaluated in terms of the grain size grain boundary and grain size distribution of the marbles based on the test results the physico mechanical properties of the marbles are not uniformly affected from the ageing tests the water absorption effective porosity ucs sonic velocity and abrasion value of the marbles are found to be good parameters to assess the deterioration and quality of the marbles whereas the weight loss unit weight brazilian tensile strength and impact resistance of the marbles are not the marbles having small grain size dominant grain size distribution in a narrow range and irregular grain boundary are more resistant against the ageing tests than the ones with large grain size grain size distribution in a wide range and straight grain boundary

investigation on rainwater infiltration into layered shallow covers in pyroclastic soils and its effect on slope stability abstract in recent years a number of flowslides and debris flows triggered by rainfall affected a wide mountainous area surrounding the piana campana southern italy the involved slopes are covered with unsaturated air fall layered pyroclastic deposits which stability is guaranteed by the contribution of suction to shear strength to understand the mechanisms of infiltration and to assess the soil suction distribution in such layered deposits infiltration experiments have been carried out in small scale slopes the interpretation of the results has been made with the aid of a 2d mathematical model the results highlight that the presence of coarse textured unsaturated pumiceous layers interbedded between finer ashy layers can delay the wetting front advancement thus initially confining the infiltration process within the uppermost finer layer a diversion of the flow from the vertical towards the slope direction occurs when the soil approaches saturation however whereas a high hydraulic gradient establishes across pumices water infiltration into the deepest layer begins and part of the water crosses the pumices before the complete saturation of the uppermost soil profile

acid rain damage to carbonate stone a quantitative assessment based on the aqueous geochemistry of rainfall runoff from stone an onsite experimental procedure was used to identify and quantify acid rain damage to carbonate stone based on the change in rain runoff chemical composition observed changes in runoff from stone are attributed to the interaction of acidic species present in the rain with the stone surface onsite data obtained during the summer and fall of 1984 at three locations in the northeastern united states indicate that carbonate stone surface recession is related to acid deposition although the study is continuing current data are not adequate to distinguish differences in the acid stone reaction between limestone and marble nor among the three study sites a single linear relation between carbonate stone surface recession the dependent variable and hydrogen ion loading to the stone surface the independent variable appears to describe the data set

on the technical properties of the carovigno stone from apulia italy physical characterization and decay effects by means of experimental ageing tests apulia southern italy is typified by widespread outcrops of rocks exploited in the last centuries in historical architectures and religious constructions as building and decorative stone today as in the past these stones represent an important source for region economy and prestige due to their uses for modern works restoration of local medieval churches and also exporting abroad among these a noteworthy and still poorly known material is the carovigno stone in this paper firstly an overall view on the mineralogical and petrophysical features of the stone was reached through a multianalytical approach based on several investigation procedures and techniques including ultrasonic test x ray diffractometry scanning electron microscopy optical microscopy mercury intrusion porosimetry in order to simulate decay phenomena the carovigno stone samples were processed to three different ageing tests cycles of thermal treatments at different high temperatures cycles of heating cooling and cycles of exposure to decahydrate sodium sulphate and sodium chloride saline solutions during and after each ageing processes mineralogical transformations and petrophysical changes were evaluated results suggested that the carovigno stone is a fine grained calcarenite pure or nearly pure characterized by high porosity and consequently very notable thermal stress resistance conversely the type and amount of porosity causes stone predisposition to salt crystallization decay

sea level changes since the middle ages along the coast of the adriatic sea the case of st nicholas basilica bari southern italy abstract during the last decade several papers have been published to estimate the relative sea level change from coastal archaeological indicators of the last 3 4 ka bp in many locations of the italian coasts and the mediterranean sea the use of the archaeological information has been poorly focused for the middle ages due to the few available coastal installations for this period thus not allowing precise sea level estimation for the last 1000 years to complement the instrumental data available for the last 100 120 years this study discusses an archaeological marker of the middle ages used to reconstruct the story of the sea level changes in the last 1000 years at the st nicholas basilica built in 1087 ad along the coast of bari apulia southern italy the elevations of the ancient floor levels of the crypt underwent repeated flooding due to a continuous rising of the groundwater table which required restoration and uplifting of pavements between 1087 and 1956 to keep them dry the palaeo sea levels have been obtained by measuring the position of the groundwater table the elevation of which is mainly driven by sea level since the time of the construction of the basilica the elevation of the archaeological markers and the water table were compared against the latest predicted sea level curve for the holocene along the coast of bari as this coastal area is unaffected by significant vertical tectonic motion over the last 125 ky the data detail the timing of the relative sea level rise since the middle ages and can be used to improve the predicted sea level curve for this region for the last 1000 years

physical properties and textural parameters of calcarenitic rocks qualitative and quantitative evaluations abstract petrophysical and mechanical properties of sedimentary rocks are influenced by size shape and packing of grains porosity cement and matrix content all controlled strongly by depositional fabric and postdepositional processes this paper presents a study on the textural characteristics of soft and porous calcarenites and the main methods to determine petrophysical data the examined calcarenites sampled from three quarry districts located in apulia southeastern italy are fine grained and coarse grained grainstones a and d and medium grained packstones b belonging to a plio pleistocenic formation calcarenite di gravina outcropping in the whole region the study involved particularly textural analysis on thin sections using optical petrographic microscopy and evaluation of total and effective porosity by means of standard geotechnical laboratory tests mercury intrusion porosimetry and image analysis grain size frequency distribution was also carried out by traditional sieve and sedimentation analysis on disaggregated materials and image analysis computer analysis of digital images was performed on photomicrographs applying the methods of quantitative stereology to pore size and grain size distributions a comparison between results showed that each technique used has its limitations linked to the textural characteristics primarily geometry and topology of the pore network granulometry grain shape and packing of calcarenites

quantitative modelling of hydrocarbon expulsion and quality grading of tight oil lacustrine source rocks case study of qingshankou 1 member central depression southern songliao basin china the quality of source rocks plays an important role in the distribution of tight and conventional oil and gas resources despite voluminous studies on source rock hydrocarbon generation expulsion and overpressure a quality grading system based on hydrocarbon expulsion capacity is yet to be explored such a grading system is expected to be instrumental for tight oil and gas exploration and sweet spot prediction this study tackles the problem by examining late cretaceous lacustrine source rocks of the qingshankou 1 member in the southern songliao basin china by evaluating generated and residual hydrocarbon amounts of the source rock the extent of hydrocarbon expulsion is modelled through a mass balance method the overpressure is estimated using petromod software through correlation between the hydrocarbon expulsion and source rock evaluation parameters total organic carbon toc kerogen type vitrinite reflectance ro and overpressure three classes of high quality effective and ineffective source rocks are established high quality class contains toc 2 type i kerogen ro 1 0 overpressure 7mpa sharp increase of hydrocarbon expulsion along with increasing toc and overpressure and high expulsion value at ro 1 source rocks with toc and ro 0 8 type ii2 iii kerogen overpressure 3mpa and low hydrocarbon expulsion volume are considered ineffective rocks with parameters between the two are considered effective the high quality class shows a strong empirical control on the distribution of tight oil in the songliao basin this is followed by the effective source rock class the ineffective class has no measurable contribution to the tight oil reserves because the hydrocarbon expulsion efficiency of source rocks is controlled by many factors the lower limits of the evaluation parameters in different basins may vary however the classification method of tight source rocks proposed in this paper should be widely applicable

the pore system of sedimentary rocks as a key factor in the durability of building materials abstract we studied the pore system of six different types of sedimentary stone two limestones two sandstones one dolostone and one travertine techniques based on the direct observation of the pore system optical and scanning electron microscopes digital image analysis were combined with others used for indirect characterization mercury intrusion porosimetry n 2 adsorption hydric tests and vapour permeability in addition we performed accelerated decay tests to determine the durability of the stones and to check the consistency of the results obtained in the pore system study digital image analysis allowed us to calculate the pore size distribution and the total porosity digital image analysis always gave higher values for total porosity than those determined by porosimetry and hydric tests which only measure open porosity the density values were congruent with the mineralogy of the stones the stone that obtained the best results in the various tests in terms of its petrophysical parameters was dolostone while the worst performance was by one of the two limestones these results were confirmed by the decay tests the combined use of these different techniques gave us an accurate interpretation of the pore systems of the six different stones and also enabled us to correct misleading interpretations caused by the limitations of using one single technique our findings also provide useful information to help prevent the decay of these stones

petrography and reservoir physics i objective classification of reservoir porosity porosity observed in thin section can be objectively classified using a combination of digital acquisition procedures and pattern recognition algorithms pore types are derived from the frequency distributions of sizes and shapes of patches of porosity exposed in thin section each pore type is represented by a characteristic distribution of sizes and shapes found in thin section most sandstone reservoirs contain fewer than six pore types much of the intersample variability in reservoir physics is associated with changes in pore type abundance the advantages of this approach to porosity classification are 1 the criteria for classification are objectively defined 2 classification procedure is rapid accurate and precise 3 pore types are understood easily in ter s of conventional genetic classification schemes and 4 pore type data are related strongly to petrophysical properties

a visual determination method for uniaxial compressive strength estimation based on croatian carbonate rock materials abstract to identify visually detectable elements that influence carbonate rock strength a detailed inspection of 231 samples mainly from the adriatic carbonate platform in croatia was conducted prior to laboratory testing anova was used to detect statistically significant carbonate rock material parameters that influence ucs lithology fabric defects and porosity lfdp and their optimal classes anova was also used to find a statistically significant model that contains four major effects on the strength of carbonate rock lfdp with three two way interactions lithology fabric fabric defects and defects porosity according to four basic influential parameters the new procedure is coined lfdp determination and is described in detail the presented results indicate that the lfdp determination method is reliable enough for use in engineering geological practice on croatian carbonate rocks but also for use in other regions while the presented method may be applied to other regions worldwide its suitability to local conditions should be tested the lfdp determination method is simple efficient inexpensive and versatile it can be applied to outcrops cuts quarries tunnels borehole cores and similar however it is important to note that this method cannot replace laboratory testing and should be only used to collect preliminary information on carbonate rock material properties and possible ranges in ucs values

geotechnical characterization of limestones employed for the reconstruction of a unesco world heritage baroque monument in southeastern sicily italy a detailed laboratory characterization of limestones employed for the reconstruction of saint nicholas cathedral a unesco world heritage monument in southeastern sicily is presented herein with the purpose of achieving a complete knowledge on the behavior of such rocks under stress whose engineering geological aspect had not been investigated before for scientific purposes specimens were sampled at three sites where this rock is quarried from two lithofacies of the same geological formation and are similar to other limestone varieties quarried worldwide and employed as construction material although slight differences between the samples occur at a macroscopic scale geotechnical tests highlighted relevant differences from the physical and mechanical points of view in order to look for one or more factors responsible of such dissimilarities a statistical analysis was carried out and interesting outcomes were achieved with the help of a microscopic analysis of the specimens moreover attention was paid on the modes of failure of tested specimens under compression whose attitude was described and correlated to selected properties of the rock results have both a practical implication because of the employment of this rock type as engineering material worldwide and a scientific relevance due to the peculiar behavior that such rock offered under stress

petroleum source rocks and stratigraphy of bakken formation in north dakota abstract the bakken formation devonian and mississippian of north dakota consists of upper and lower black organic rich shales separated by a calcareous siltstone middle member the formation is a relatively thin unit maximum thickness 145 ft 44 2 m with the lower shale attaining a maximum thickness of 50 ft 15 2 m and the upper shale a maximum thickness of 23 ft 7 m the shales are hard siliceous pyritic fissile and noncalcareous they contain abundant conodonts and tasmanites and have planar laminations accented by pyrite the upper and lower shales were apparently deposited in an offshore marine anoxic environment where anoxic conditions may have been caused by a stratified water column resulting from restricted circulation organic matter in the black shales was derived mostly from planktonic algae organic carbon measurements revealed the bakken shales to be very organic rich average of 11 33 wt of organic carbon and visual kerogen typing revealed this organic matter to be predominantly an amorphous type that is inferred to be sapropelic the onset of hydrocarbon generation was determined to occur at an average depth of 9 000 ft 2 74 km by interpreting plots of geochemical parameters with depth e g ratios of hydrocarbon to nonhydrocarbon saturated hydrocarbon to organic carbon pyrolytic hydrocarbon to organic carbon and the pyrolysis production index hydrocarbon content and thermal kerogen breakdown increase greatly in the bakken shales where they are buried at depths greater than 9 000 ft 2 74 km the effective source area of the bakken as determined by maps f the above geochemical parameters lies mostly in mckenzie williams dunn and billings counties oil generation was probably initiated in the bakken about 75 ma late cretaceous at a temperature of about 100 c 212 f with initial expulsion of oil from the bakken probably occurring 70 ma late cretaceous the amount of oil generated by the bakken in north dakota as calculated from pyrolysis data is 92 3 billion bbl if only 10 of this oil was actually expelled from the shales it could easily account for the 3 billion bbl of known type ii oil reserves in the williston basin this paper is a summary of work done for an m s thesis at the university of north dakota end of article last page 953

the influence of rock fabric in the durability of two sandstones used in the andalusian architectural heritage montoro and ronda spain abstract natural stone has been a popular and reliable building material throughout history appearing in many historic monuments and in more recent buildings research into the intrinsic properties of specific stones is important because it gives us a greater understanding of the factors that limit and act on them this can help prevent serious problems from occurring in our buildings bringing both esthetic benefits and financial savings to this end the main objective of this research has been to study the influence of the fabric and the mineral composition of two types of sandstone on their durability the first is a red continental sandstone from the buntsandstein age called molinaza roja which is quarried in montoro cordoba the second is quarried in ronda malaga and is sold under the trade name of arenisca ronda it is a light pink whitish calcarenite deposited during the late tortonian to late messinian we characterized their petrological and petrophysical properties by studying their rock fabrics porous systems and mechanical properties in order to obtain a complete vision of the behavior of their rock fabrics we also carried out two decay tests the salt crystallization and the freeze thaw tests we then measured the effects on the textures of the altered samples during and after the decay tests and we evaluated the changes in the porous system by comparing the results between intact and altered samples we found that arenisca ronda is less durable because it has a high quantity of expandable clays smectites and a high percentage of pores in the 0 1 1 m range in which the pressure produced by salt crystallization is strongest in molinaza roja the decay agents caused significant sanding due to loss of cohesion between the clasts especially during the salt crystallization test in both stones the anisotropies oriented textures have an important role in their hydric and dynamic behavior and also affect their mechanical properties especially in the compression resistance no changes in color were detected