trace element behavior and redox facies in core shales of upper pennsylvanian kansas type cyclothems the black shale submember of core shales of pennsylvanian kansas type cyclothems is highly enriched in redox sensitive trace elements tes relative to the overlying gray shale submember as well as to many other modern and ancient organic rich deposits controls on trace element behavior in the black shale can be inferred from trace element enrichment factors efs relative to gray shale and the relationship of tes to total organic carbon toc most tes conformed to one of two patterns 1 mo u v zn and pb exhibited moderate efs and strong covariation with toc in samples having 10 wt toc and 2 cu ni cr and co exhibited low efs and moderate to strong covariation with toc in all samples these patterns are inferred to represent different responses to benthic redox conditions the first pattern is characteristic of tes of strong euxinic affinity i e those taken up in solid solution by fe sulfide or involved in other reactions catalyzed by free h2s and resident mainly in authigenic phases whereas the second pattern is characteristic of tes of weak euxinic affinity i e those not strongly influenced by the presence of free h2s and resident mainly in the organic carbon or detrital fractions of the sediment these inferences allowed development of a multiproxy technique for assessing redox facies in black shale samples euxinic conditions were considered to have existed if at least two of four redox indicator trace elements mo u v zn showed euxinic levels of enrichment and nonsulfidic anoxic conditions were inferred otherwise the validity of the procedure is indicated by 1 agreement among all four redox indicators for a large majority of samples 69 of 185 2 among samples yielding a mixed redox signal a systematic sequence of te enrichment v zn mo u and 3 for tes of weak euxinic affinity reduced variance among samples representing each redox facies sequential enrichment may be a response to differential redox thresholds for accumulation e g v or postdepositional remobilization of trace elements e g u and may provide a basis for finer assessment of redox conditions in low oxygen paleoenvironments than permitted by simple classification schemes the multiproxy procedure for redox facies analysis developed in this study is likely to be more reliable than widely used single proxy indicators based on trace elements e g mo authigenic u or v v ni or c s fe systematics e g s toc or dop d 2004 elsevier b v all rights reserved

identifying rock slope failure precursors using lidar for transportation corridor hazard management abstract in the thompson and fraser river valleys rockfall and rockslides are a hazard for railway traffic in the region in june 2013 a 2600 m 3 rockslide occurred in the white canyon causing damage to infrastructure and interruption to service in the year preceding this failure the slope was monitored using terrestrial light detection and ranging lidar as part of the railway ground hazards research program initiative the purpose of this study is to evaluate a hazard management strategy for transportation corridors exposed to steep slopes involving the identification of rockfall precursors prior to significant slope failures for this failure deformation was observed in the seven months preceding collapse with an accelerating period occurring in the final 28 days a distinct pattern of smaller rockfalls was observed around the perimeter of the deforming rock block as well as loss of surficial material over the slides tension crack this study shows that with lidar monitoring precursors to rock slope failures can be identified allowing for better rock slope hazard management by focusing attention on areas with the highest probability of failure

review of earth science research using terrestrial laser scanning abstract the application of advanced remote sensing technologies including terrestrial laser scanning tls to the earth sciences has increased rapidly in the last two decades improving the spatial and temporal resolution of data terrestrial laser scanning units have evolved into a common tool in studies of spectral and structural geology seismology natural hazards geomorphology and glaciology special consideration of the advantages and limitations of tls in each of these fields is discussed in depth in the context of important work published in each field the workflow used in a tls survey is crucial to the success of the survey and field specific earth science workflows are therefore also discussed products based on tls data such as triangulated irregular networks tin and digital surface models dsm are commonplace tools throughout the earth sciences and the use of these tools to measure slip distributions fault geometries aeolian transport river bed morphologies and flows and other research problems is expanded on where appropriate the review concludes with a discussion of recent trends in tls instrument development and their potential impact on the use of tls in the earth sciences in the future

a case study integrating remote sensing and distinct element analysis to quarry slope stability assessment in the monte altissimo area italy abstract over last decade geomatic techniques have been increasingly used for the geometrical characterization of rock slopes terrestrial laser scanning and digital terrestrial photogrammetry in particular are now frequently used in the characterization of joint surfaces and slope geometry although the use of these techniques for the structural characterization of slopes is widely documented limited research has been undertaken to improve our understanding of the importance of the derived data quality in the construction of slope geometry imported into 3d numerical models one of the most common problems encountered in the use of these techniques especially in case of slopes with complex geometry is the presence of occlusions in this context the aims of this paper are to describe how the integrated use of terrestrial laser scanning digital terrestrial photogrammetry and topographic surveys can mitigate the influence of occlusions and how the slope geometry gained from these surveys can be important in slope stability analyses for this purpose a case study in the monte altissimo area apuan alps italy will be presented several geomatic techniques were used for studying a slope overhanging the granolesa quarry special emphasis will be given to the importance of using total station and differential gps surveys as tools for data fusion moreover in order to validate this procedure the accuracy and precision of the output were determined through comparison of 3d models derived from laser scanning and digital terrestrial photogrammetry furthermore two different analyses with the three dimensional distinct element code 3dec were carried out in order to highlight the advantages and limitations of using data obtained from terrestrial remote sensing techniques as opposed to models based on topographic maps

validation of fracture data recognition in rock masses by automated plane detection in 3d point clouds abstract this paper presents 1 an automated method to extract planes and their spatial orientation directly from 3d point clouds followed by 2 extensive validation tests accompanied by thorough statistical analysis and 3 a fracture intensity calculation on automatically segmented planes for the plane extraction a region growing segmentation algorithm controlled by several input parameters is applied to a point cloud of a granite outcrop within its complex surface shape more than 1000 compass measurements were conducted for validation in addition digitally handpicked planes in the software virtual reality geological studio vrgs were used for single plane comparison in a second test site we performed fracture intensity calculation in petrel based on results of the segmentation algorithm on mechanical layers of a clastic sedimentary succession the comparison of automated segmentation results and compass measurements of three different plane sets shows a deviation of 0 70 2 00 while the mean single plane divergence amounts to 4 97 hence this study presents a fast precise and highly adaptable automated plane detection method which is reproducible transparent objective and provides increased accuracy in outcrops with rough and complex surfaces moreover output formats of spatial orientation and location of planes are designed for simple handling in other workflows and software

close range terrestrial digital photogrammetry and terrestrial laser scanning for discontinuity characterization on rock cuts this paper reviews the application of close range terrestrial digital photogrammetry and terrestrial laser scanning for discontinuity characterization on rock cuts terrestrial remote sensing techniques are being increasingly used as a complement to traditional scanline and window mapping methods they provide more comprehensive information on rock cuts allow surveying of inaccessible outcrops and increase user safety selected case studies are used to estimate the accuracy of several 3d model registration approaches and the most time effort and cost effective methods are highlighted it is shown that simple registration networks are able to provide adequate measurement of discontinuity orientation for engineering purposes the case studies presented also illustrate the effects of sampling bias and limitations related to discontinuity characterization using remote sensing techniques vertical orientation bias and occlusion can be of particular concern when persistent discontinuities dip at the same angle as the camera scanner line of sight major advantages of the techniques are presented illustrating how terrestrial remote sensing techniques provide rapid spatial measurements of discontinuity location orientation and curvature and are well suited to the quantification of persistence magnitudes greater than 3 m

optimization of lidar scanning and processing for automated structural evaluation of discontinuities in rockmasses terrestrial light detection and ranging lidar can be used for the delineation and evaluation of geomechanically controlled hazards the united states geological survey 1 has adopted the use of lidar through numerous projects as discussed in 2 other examples of the use of lidar surveys for geological data collection include discussion of the process of acquiring digital outcrop models for stratigraphic modelling 3 mapping basalt flow units 4 structural mapping of a large landslide 5 and evaluation of rockfall source and accumulation zones 6 7 in non geologicalbased applications lidar has been used for projects ranging from volumetric analysis in open pit mines 8 to recording and cataloguing archaeological digs in ancient ruins 9 the equipment mobility accuracy and rate of data collection in comparison to conventional surveying and stereophotogrammetric methods have allowed existing surface analysis projects to proceed at unprecedented levels of detail and have promoted new applications the use of terrestrial ground based lidar as a structural analysis and measurement tool has been investigated in detail by kemeny and post 10 feng and roshoff 11 pringle et al 12 slob et al 13 and others once the data is acquired and the primary 3d model is generated as x y z data points with intensity scalars or mapped colourization via photo coupling the analytical process can proceed in a similar fashion to modern photogrammetric techniques such as those applied by haneberg et al 14 both applications can replace traditional field mapping processes including the use of a compass or inclinometer to measure orientation photos and notebooks to keep records and manual data entry further the conventional measurement of

terrestrial laser scanning in geology data acquisition processing and accuracy considerations terrestrial laser scanning or lidar is a recent innovation in spatial information data acquisition which allows geological outcrops to be digitally captured with unprecedented resolution and accuracy with point precisions and spacing of the order of a few centimetres an enhanced quantitative element can now be added to geological fieldwork and analysis opening up new lines of investigation at a variety of scales in all areas of field based geology integration with metric imagery allows 3d photorealistic models to be created for interpretation visualization and education however gaining meaningful results from lidar scans requires more than simply acquiring raw point data surveys require planning and typically a large amount of post processing time the contribution of this paper is to provide a more detailed insight into the technology data collection and utilization techniques than is currently available the paper focuses on the workflow for using lidar data from the choice of field area and survey planning to acquiring and processing data and finally extracting geologically useful data because manufacturer specifications for point precision are often optimistic when applied to real world outcrops the error sources associated with lidar data and the implications of them propagating through the processing chain are also discussed

structural relationships along a greenstone shallow water shelf contact belingwe greenstone belt zimbabwe the belingwe greenstone belt zimbabwe contains a thick tholeiitic basalt and komatiite sequence structurally above shallow water shelf rocks that in turn rest nonconformably over an older gneiss terrain the nature of the contact between the basalt komatiite sequence and underlying shallow water shelf rocks represents one of the most critical relationships upon which general models for the tectonic setting of greenstone belts and the petrotectonic environment of komatiites are based this contact is a 20 to 200 m thick high strain zone characterized by a wide variety of shear zone tectonites derived from both the shelf and overlying lava succession in the ultramafic part of the high strain zone tectonites include ductile ultramafic mylonites ultramafic ultramylonites ultramafic phyllonites and serpentinite schists enclosing less deformed ultramafic serpentinite blocks in the part of the shear zone derived from shallow water sedimentary rocks shear zone tectonites include chert c s mylonite phyllonite and iron rich argillaceous shear bands both parts of the shear zone are cut by brittle fault gouge fabrics we suggest that the tholeiitic basalt and komatiite sequence is allochthonous with respect to the shallow water shelf and refer to it as the mberengwa allochthon contrary to prior suggestions there is no evidence that the tholeiitic basalt and komatiite succession of the belingwe greenstone belt sits conformably over the shallow water shelf rocks documentation of the shear zone at the base of the mberengwa allochthon lends support to the idea that the allochthon represents a fragment of an off axis oceanic plateau structurally emplaced over a shallow water shelf during a convergent plate interaction prior to 2 6 ga

application of an integrated geotechnical and topographic monitoring system in the lorano marble quarry apuan alps italy abstract accurate slope stability analysis is essential for human activity in high risk geological contexts this may however not be enough in the case of quarrying where the dynamic and evolving environment also requires effective monitoring a well designed monitoring system requires the acquisition of a huge dataset over time improving knowledge of the study area and helping to refine prediction from stability analysis this paper reports the implementation of an integrated monitoring system in a marble quarry in the apuan alps italy and some of the results obtained the equipment consists of a traditional geotechnical monitoring system extensometers crackmeters and clinometers and two modern topographic monitoring systems a terrestrial interferometer and a robotic total station this work aims to provide in depth knowledge of the large scale rock mass behaviour as a result of marble exploitation thereby allowing continuous excavation the results highlight the importance of integrating different monitoring systems

geological discontinuity persistence implications and quantification abstract persistence of geological discontinuities is of great importance for many rock related applications in earth sciences both in terms of mechanical and hydraulic properties of individual discontinuities and fractured rock masses although the importance of persistence has been identified by academics and practitioners over the past decades quantification of areal persistence remains extremely difficult in practice trace length from finite outcrop is still often used as an approximation for persistence this paper reviews the mechanical behaviour of individual discontinuities that are not fully persistent and the implications of persistence on the strength and stability of rock masses current techniques to quantify discontinuity persistence are then examined this review will facilitate application of the most applicable methods to measure or predict persistence in rock engineering projects and recommended approaches for the quantification of discontinuity persistence furthermore it demonstrates that further research should focus on the development of persistence quantification standards to promote our understanding of rock mass behaviours including strength stability and permeability

application of a new in situ 3d laser scanner to study the scale effect on the rock joint surface roughness application of a new in situ 3d laser scanner to study the scale effect on the rock joint surface roughness

forensic analysis of rockfall scars abstract we characterise and analyse the detachment scar surfaces of rockfalls to understand the mechanisms that underpin their failure rockfall scars are variously weathered and comprised of both discontinuity release surfaces and surfaces indicative of fracturing through zones of previously intact rock known as rock bridges the presence of rock bridges and pre existing discontinuities is challenging to quantify due to the difficulty in determining discontinuity persistence below the surface of a rock slope rock bridges form an important control in holding blocks onto rockslopes with their frequency extent and location commonly modelled from the surface exposure of daylighting discontinuities we explore an alternative approach to assessing their role by characterising failure scars we analyse a database of multiple rockfall scar surfaces detailing the areal extent shape and location of broken rock bridges and weathered surfaces terrestrial laser scanning and gigapixel imagery were combined to record the detailed texture and surface morphology from this scar surfaces were mapped via automated classification based on rgb pixel values our analysis of the resulting data from scars on the north yorkshire coast uk indicates a wide variation in both weathering and rock bridge properties controlled by lithology and associated rock mass structure importantly the proportion of rock bridges in a rockfall failure surface does not increase with failure size rather larger failures display fracturing through multiple rock bridges and in contrast smaller failures fracture occurs only through a single critical rock bridge this holds implications for how failure mechanisms change with rockfall size and shape additionally the location of rock bridges with respect to the geometry of an incipient rockfall is shown to determine failure mode weathering can occur both along discontinuity surfaces and previously broken rock bridges indicating the sequential stages of progressively detaching rockfall our findings have wider implications for hazard assessment where rock slope stability is dependent on the nature of rock bridges how this is accounted for in slope stability modelling and the implications of rock bridges on long term rock slope evolution

geochemical dissociation of major and trace elements in bed and suspended sediment phases of the phosphate mines effluent water jordan the bed and suspended slime sediment phases associated with effluent water that are produced from phosphate ore upgrading process at al abyad mine in the southern part of jordan were analyzed chemically and mineralogically the results show that the effluent water is highly oxic and mildly alkaline in nature the geochemical behavior of each phase was controlled by the effluent water physicochemical parameters sediment particle size mineralogical constituents of the studied phases and the prevailing climatic nature of the area bed sediments have higher concentrations of many elements than slime accordingly the bed sediments can be considered as a sink rather than a pool for many elements the geochemical dissociation of major oxides and trace elements between bed and slime sediments was evident using t test particularly between p2o5 sio2 cao k2o mn sr y and co and to lesser extent v u zn and cr this might be attributed to effluent water characteristics mineralogy and the presence of fine grained materials the spatial distribution of major oxide and trace element concentrations along the stream drainage exhibited a slight increase with distance either in bed or slime sediment phases however they increased suddenly at the last three sampling sites which might be due to the abundance of fine grained materials that are mainly composed of clay minerals montmorillonite that would enhance the adsorption process moreover the xrd results confirmed the existence of elemental geochemical dissociation as a function of mineral control

improvement of photogrammetric jrc data distributions based on parabolic error models this research describes the influences of the focal length of lenses as well as camera to object distances that control the accuracy and precision of 3d photogrammetry models used for assessing joint roughness coefficients jrc a parabolic error model which is developed by a series of photogrammetric laboratory tests is used to improve the jrc data distributions obtained from the photogrammetry 3d models the influences of camera to object distances and focal lengths on the accuracy of jrc values are investigated in laboratory conditions a series of photogrammetry tests are performed under different conditions by varying the camera to object distances and the camera lens focal lengths the camera positions are controlled on a sliding device to increase the accuracy of geo referencing the results suggest the allowable photographic distances for the employed photogrammetry equipment e g camera and focal lengths of lenses to estimate jrc values through comparison with the manually measured values the root mean square error rmse of jrc functions which are correlated with the camera distances and the normalized jrc values are depicted as different size parabolic curves according to the employed focal lengths these models successfully improve on the accuracy of the originally obtained jrc distributions

a scale independent approach to fracture intensity and average spacing measurement fracture intensity the number of fractures per unit length along a sample line is an important attribute of fracture systems that can be problematic to establish in the subsurface lack of adequate constraints on fracture intensity may limit the economic exploitation of fractured reservoirs because intensity describes the abundance of fractures potentially available for fluid flow and the probability of encountering fractures in a borehole traditional methods of fracture intensity measurement are inadequate because they ignore the wide spectrum of fracture sizes found in many fracture systems and the consequent scale dependence of fracture intensity an alternative approach makes use of fracture size distributions which allow more meaningful comparisons between different locations and allow microfractures in subsurface samples to be used for fracture intensity measurement comparisons are more meaningful because sampling artifacts can be recognized and avoided and because common thresholds of fracture size can be enforced for counting in different locations additionally quantification of the fracture size distribution provides a mechanism for evaluation of uncertainties estimates of fracture intensity using this approach for two carbonate beds in the sierra madre oriental mexico illustrate how size cognizant measurements cast new light on widely accepted interpretation of geologic controls of fracture intensity

a procedure for partitioning bulk sediments into distinct grain size fractions for geochemical analysis a method to separate sediments into discrete size fractions for geochemical analysis has been tested the procedures were chosen to minimize the destruction or formation of aggregates and involved gentle sieving and settling of wet samples freeze drying and sonication pretreatments known to influence aggregates were used for comparison freeze drying was found to increase the silt clay ratio by an average of 180 percent compared to analysis of a wet sample that had been wet sieved only sonication of a wet sample decreased the silt clay ratio by 51 percent the concentrations of metals and organic carbon in the separated fractions changed depending on the pretreatment procedures in a manner consistent with the hypothesis that aggregates consist of fine grained organic and metal rich particles the coarse silt fraction of a freeze dried sample contained 20 44 percent higher concentrations of zn cu and organic carbon than the coarse silt fraction of the wet sample sonication resulted in concentrations of these analytes that were 18 33 percent lower in the coarse silt fraction than found in the wet sample sonication increased the concentration of lead in the clay fraction by an average of 40 percent compared to an unsonicated sample understanding the magnitude of change caused by different analysis protocols is an aid in designing future studies that seek to interpret the spatial distribution of contaminated sediments and their transport mechanisms

automated method for extracting and analysing the rock discontinuities from point clouds based on digital surface model of rock mass abstract often when rock discontinuities with complex distributions occur in steep terrain it is difficult to rapidly survey and accurately measure their spatial distribution by traditional surveying and mapping methods this paper presents a methodology for automated extraction of rock discontinuities from a point cloud and the resulting 3d digital surface model of the rock mass first feature planes of rock discontinuities are identified and classified using both their orientation and position in a double nested mean shift clustering algorithm second the points corresponding to feature planes are extracted using a region growth algorithm and seed points finally geological information is acquired by analysing the geometric features of the extracted sub set of points from the point cloud this approach can directly extract planar features associated with joints and it eliminates spurious points in a point cloud associated with objected such as vegetation a case study of a rock slope along a highway is presented using the proposed method a sensitivity analysis of relevant clustering parameters in the mean shift clustering algorithm is conducted to acquire their optimal values and to assess their robustness the proposed method produces results that agree with the traditional survey methods and greatly improves the survey efficiency