locating and quantifying geological uncertainty in three dimensional models analysis of the gippsland basin southeastern australia abstract geological three dimensional 3d models are constructed to reliably represent a given geological target the reliability of a model is heavily dependent on the input data and is sensitive to uncertainty this study examines the uncertainty introduced by geological orientation data by producing a suite of implicit 3d models generated from orientation measurements subjected to uncertainty simulations the resulting uncertainty associated with different regions of the geological model can be located quantified and visualised providing a useful method to assess model reliability the method is tested on a natural geological setting in the gippsland basin southeastern australia where modelled geological surfaces are assessed for uncertainty the concept of stratigraphic variability is introduced and analysis of the input data is performed using two uncertainty visualisation methods uncertainty visualisation through stratigraphic variability is designed to convey the complex concept of 3d model uncertainty to the geoscientist in an effective manner uncertainty analysis determined that additional seismic information provides an effective means of constraining modelled geology and reducing uncertainty in regions proximal to the seismic sections improvements to the reliability of high uncertainty regions achieved using information gathered from uncertainty visualisations are quantified in a comparative case study uncertainty in specific model locations is identified and attributed to possible disagreements between seismic and isopach data further improvements to and additional sources of data for the model are proposed based on this information finally a method of introducing stratigraphic variability values as geological constraints for geophysical inversion is presented

a geophysically constrained litho structural analysis of the eburnean greenstone belts and associated granitoid domains burkina faso west africa abstract interpretation of airborne geophysical data integrated with field structural and lithological observation was successfully employed in the creation of the litho structural framework in a poorly exposed paleoproterozoic granite greenstone terrain of the west african craton the geophysical data portray with sufficient detail all of the lithological units and structural features present the results suggest that the granitoid domains are formed by numerous small to medium sized plutons the existence of several generations of magmatic episodes has a significant impact on the development of a regional tectonic model the magnetic data provided a better definition of the actual pluton shapes and several highly magnetic late orogenic plutons were reliably identified relic f1 fold hinges were recognized in the hounde and boromo greenstone belts the d1 penetrative structures are generally affected by the d2 transcurrent shear zones which often form as well the granite greenstone belt boundaries previously unreported s2 shear zones including the bossie shear zone transecting the sideradougou granitoid domain and abundant small scale shear zones affecting all of the lithologies represent prospective areas for gold exploration airborne gamma ray spectrometry data aided in the mapping process in areas with less regolith cover including erosional ridges and parts of the banfora greenstone belt the magnetic data revealed at least three generations of doleritic dykes crosscutting the western burkina faso

concentrations of rare earth elements in topsoil from east china fifty topsoil samples collected from 12 different regions of east china have been analyzed for rare earth elements rees the average ree concentrations of the 50 topsoil samples are much higher than world average and are characterized by lree enrichment hree depletion eu depletion and ce enrichment however the ree concentration is not strongly affected by the climate of the sampling site it is controlled mainly by parent materials the plot of ce eu against eu sm is proved to be useful to distinguish different parent materials of topsoil each element in the 50 topsoil has a good correlation with its neighboring element seven of the 13 values are above 0 987

constrained 3d modeling of the mesoproterozoic benagerie volcanics australia abstract the benagerie volcanics form part of a hotspot track that affected large sections of eastern australia during the mesoproterozoic understanding the location and controls on eruption centres of the benagerie volcanics and coeval plutons is difficult because they do not outcrop and are known only from limited drillhole data we have applied various combinations of forward and inversion modeling of magnetic and gravity to well constrained petrophysics and drillholes areas to characterize the 3d geometry and extent of the volcanic province and its crustal architecture thereby adding to a better understanding of the emplacement mechanisms involved we interpret the sw limit of the benagerie shear zone corridor to be a major terrane boundary separating relatively magnetic crust to the sw from crust with low magnetic susceptibility to the ne 2d and 3d models show a pronounced thickening of felsic material coincident with the shear zone that may be interpreted as a plutonic root thereby corroborating interpretations that this shear zone acted as a structural conduit for the ascent and emplacement of magma

uncertainty estimation for a geological model of the sandstone greenstone belt western australia insights from integrated geological and geophysical inversion in a bayesian inference framework

three dimensional model and late stage warping of the plattengneis shear zone in the eastern alps abstract the plattengneis shear zone is a 250 600 m thick flat lying cretaceous eclogite facies mylonitic shear zone with north over south transport direction that is exposed over almost 1000 km2 in the koralpe region along the eastern margin of the alps although the shear zone is one of the largest in the alps its role in the eoalpine metamorphic evolution and the subsequent exhumation of the region remain enigmatic and its large scale geometry is not well understood the outcrop pattern suggests that the shear zone is made up of a single sheet that is folded into a series of open syn and antiforms with wavelengths of about 10 km eclogite bodies occur above within and below the shear zone and there is no metamorphic grade change across the shear zone in the south the fold axes strike east west and plunge shallowly to the east in the north the fold axes are oriented in north south direction and form a dome shaped structure of the shear zone total shortening during this late stage warping event was of the order of 5 indirect evidence constrains this folding event to have occurred between 80 and 50 ma and the fold geometry implies that the final exhumation in the koralpe occurred somewhat later than further north interestingly the shear zone appears to strike out of the topography in the south and dip into the topography in the north so that north of the shear zone only hanging wall rocks are exposed and south of it only foot wall rocks possibilities for the geometric relationship of the plattengneis shear zone with the surrounding south dipping detachments are discussed

method and analysis for the upscaling of structural data abstract 3d geological models are created to integrate a set of input measurements into a single geological model there are many problems with this approach as there is uncertainty in all stages of the modelling process from initial data collection to the approach used in the modelling scheme itself to calculate the geological model this study looks at the uncertainty inherent in geological models due to data density and introduces a novel method to upscale geological data that optimises the information in the initial dataset this method also provides the ability for the dominant trend of a geological dataset to be determined at different scales by using self organizing maps som s to examine the different metrics used to quantify a geological model we allow for a larger range of metrics to be used compared to traditional statistical methods due to the som s ability to deal with incomplete datasets the classification of the models into clusters based on the geological metrics using k means clustering provides a useful insight into the models that are most similar and models that are statistical outliers our approach is guided and can be calculated on any input dataset of this type to determine the effect that data density will have on a resultant model these models are all statistical derivations that represent simplifications and different scales of the initial dataset and can be used to interrogate the scale of observations

vein mineralization at the damang gold mine ghana controls on mineralization abstract two distinct styles of au mineralization occur at the damang gold mine palaeoproterozoic sediments of the tarkwaian group host both one style of mineralization is stratabound within quartz lithic conglomerates of the banket series the second style of mineralization is associated with an extensive low displacement fault fracture mesh that formed in a compressional stress regime late in the deformational history and after the peak metamorphism regional deformation within the tarkwaian involved initial nw se directed shortening d 1 a major nne trending f 1 anticline hosts the damang orebody broadly n s shortening during d 2 resulted in the formation of e w trending thrusts with small displacements the d 3 shortening direction was similar to that of d 1 steep d 1 faults were reactivated and a new set of low angle thrusts and associated flat lying extension veins were formed the bulk of the mineralization observed at damang is associated with the low displacement d 3 fault fracture mesh the presence of flat lying extensional veins and the reactivation of some misoriented d 1 structures is indicative of periodic episodes of supralithostatic fluid pressures low differential stress and fault valve behavior towards the end of the deformation history

rare earth elements and clay minerals of soils of the floodplains of three major rivers in bangladesh the rare earth elements ree particle size distribution and mineralogical composition in the 2 m clay fraction from the soils on the floodplains developed by the three major rivers of the brahmaputra meghna and ganges in bangladesh were analyzed ree as the chondrite normalized curve or the plot of ce eu against eu sm did not differentiate the soils according to the river floodplains whereas the clay mineralogy did particle size distribution varied between the soils and the soil horizons

uncertainty reduction through geologically conditioned petrophysical constraints in joint inversion abstractwe have developed a joint geophysical inversion workflow that aims to improve subsurface imaging and decrease uncertainty by integrating petrophysical constraints and geologic data in this framework probabilistic geologic modeling is used as a source of information to condition the petrophysical constraints spatially and to derive starting models the workflow then uses petrophysical measurements to constrain the values retrieved by geophysical joint inversion the different sources of constraints are integrated into a least squares framework to capture and integrate information related to geophysical petrophysical and geologic data this allows us to quantify the posterior state of knowledge and to calculate posterior statistical indicators to test this workflow using geologic field data we have generated a set of geologic models which we used to derive a probabilistic geologic model in this synthetic case study we found that the integration of geologic information and petrophysical con

age constraints on tarkwaian palaeoplacer and lode gold formation in the tarkwa damang district sw ghana two major epigenetic gold forming events are recorded in the world class gold province of southwest ghana a pre tarkwaian event was the source of the world class tarkwa palaeoplacers whereas post birimian and tarkwaian deformation which was related to the eburnean orogeny gave rise to the world class e g prestea to giant e g obuasi orogenic gold deposits which have made the region famous for more than 2 500 years a maximum age of 2133 4 ma for tarkwaian sedimentation is provided by 71 of 111 concordant shrimp ii u pb dates from detrital zircons in tarkwaian clastic rocks from damang and bippo bin northeast of tarkwa the overall data distribution broadly overlaps the relatively poorly constrained ages of birimian volcanism and associated dixcove type granitoid emplacement indicating syntectonic development of the tarkwaian sedimentary basin these zircon ages argue against derivation of the palaeoplacer gold from an orogenic gold source related to the compressional phase of an orogeny significantly older than the eburnean orogeny instead they suggest that the gold source was either orogenic gold lodes related to an earlier compressional phase of a diachronous eburnean orogeny or ca 2200 2100 ma intrusion related gold lode the co2 rich fluid inclusions in associated vein quartz pebbles are permissive of either source at the damang deposit an epigenetic orogenic lode gold system clearly overprinted and sulphidised low grade palaeoplacer hematite magnetite gold occurrences in the banket series conglomerate within the tarkwaian sedimentary sequence gold mineralisation is demonstrably post peak metamorphism as gold related alteration assemblages overprint metamorphic assemblages in host rocks in alteration zones surrounding the dominant subhorizontal auriferous quartz veins there are rare occurrences of hydrothermal xenotime which give a shrimp u pb age of 2063 9 ma for gold mineralisation the similar structural timing of epigenetic gold mineralisation in tarkwaian host rocks at damang to that in mainly birimian host rocks elsewhere in southwest ghana particularly at obuasi suggests that 2063 9 ma is the best available age estimate for widespread orogenic gold mineralisation in the region argon argon ages of 2029 4 and 2034 4 ma for hydrothermal biotite from auriferous quartz veins appear to represent uplift and cooling of the region below about 300 c as estimates of the temperature of gold mineralisation are higher at around 400 c if peak metamorphism with temperatures of about 550 c is assumed to have occurred at about 2100 ma the biotite ages in combination with the xenotime age suggest a broadly constant uplift rate for the region of about 1 km per 10 million years from about 2100 to 2025 ma

rates and timing of vertical axis block rotations across the central sierra nevada walker lane transition in the bodie hills california nevada 1 we use paleomagnetic data from tertiary volcanic rocks to address the rates and timing of vertical axis block rotations across the central sierra nevada walker lane transition in the bodie hills california nevada samples from the upper miocene 9 ma eureka valley tuff suggest clockwise vertical axis block rotations between ne striking left lateral faults in the bridgeport and mono basins results in the bodie hills suggest clockwise rotations r r 95 confidence limits of 74 8 since early to middle miocene 12 20 ma 42 11 since late miocene 8 9 ma and 14 10 since pliocene 3 ma time with no detectable northward translation the data are compatible with a relatively steady rotation rate of 5 2 ma 1 2 since the middle miocene over the three examined timescales the average rotation rates have probably not varied by more than a factor of two over time spans equal to half of the total time interval our paleomagnetic data suggest that block rotations in the region of the mina deflection began prior to late miocene time 9 ma and perhaps since the middle miocene if rotation rates were relatively constant block rotation in the bodie hills is similar in age and long term average rate to rotations in the transverse ranges of southern california associated with early transtensional dextral shear deformation we speculate that the age of rotations in the bodie hills indicates dextral shear and strain accommodation within the central walker lane belt resulting from coupling of the pacific and north america plates

geodiversity exploration of 3d geological model space abstract the process of building a 3d model necessitates the reconciliation of field observations geophysical interpretation geological data uncertainty and the prevailing tectonic evolution hypotheses and interpretations uncertainty is compounded when clustered data points collected at local scales are statistically upscaled to one or two points for use in regional models interpretation is required to interpolate between sparse field data points using ambiguous geophysical data in covered terranes it becomes clear that multiple interpretations are possible during model construction the various interpretations are considered as potential natural representatives but pragmatism typically dictates that just a single interpretation is offered by the modelling process uncertainties are introduced into the 3d model during construction from a variety of sources and through data set optimisation that produces a single model practices such as these are likely to result in a model that does not adequately represent the target geology a set of geometrical geodiversity metrics are used to analyse a 3d model of the gippsland basin southeastern australia after perturbing geological input data via uncertainty simulation the resulting sets of perturbed geological observations are used to calculate a suite of geological 3d models that display a range of geological architectures the concept of biodiversity has been adapted for the geosciences to quantify geometric variability or geodiversity between models in order to understand the effect uncertainty has models geometry various geometrical relationships depth volume contact surface area curvature and geological complexity are used to describe the range of possibilities exhibited throughout the model suite end member models geodiversity metrics are classified in a similar manner to taxonomic descriptions further analysis of the model suite is performed using principal component analysis pca to determine important geometrical characteristics the configuration of the model space is determined through identifying outlier model examples which potentially represent undiscovered model species

stochastic fracture generation accounting for the stratification orientation in a folded environment based on an implicit geological model article i nfo this paper presents a new approach in generating stochastic discrete fracture networks the particularity of the approach isthatitallows us tosimulate thetheoreticalfamiliesoffractures thatare expected ina foldedenviron ment the approach produces fractures that are consistent with the local stratigraphic orientation the fractures are modeled as simplerectangular planarobjects whenthey are modeled they arerotatedaccordingtothe local stratigraphic orientation as the stratigraphy is modeled using an implicit approach we use the gradient of this geological potential field to retrieve the information about the geological orientation the fracture number and size are following user defined probability density functions 2015 elsevier b v all rights reserved

inversion of geological knowledge for fold geometry abstract the process of building three dimensional 3d geological models can be framed as an inverse problem where a model describing the 3d distribution of rock units is non uniquely derived from geological observations the inverse problem theory provides a powerful framework for inferring these parameters from all geological observations in a similar way to how a geologist can iteratively update their structural interpretation while mapping existing geological knowledge is usually indirectly incorporated into 3d models using the geologist s non unique interpretation as form lines cross sections and level maps these approaches treat constraints derived from geological knowledge in the same way as direct observations diluting and confusing both information provided by geological knowledge and hard data resulting in significant subjectivity we present a geological inversion using bayesian inference where geological knowledge can be incorporated directly into the interpolation scheme with likelihood functions and informative prior distributions we demonstrate these approaches on a series of synthetic fold shapes as a proof of concept and a case study from the proterozoic davenport province in the northern territory australia the combined inversion of geological data and knowledge significantly reduces the uncertainty in possible fold geometries where data is sparse or highly ambiguous this could be used by geologists while mapping to propagate information about uncertainties throughout the mapping model building process and would allow for different structural interpretations to be rapidly tested for targeted data collection

3d modeling of the ashanti belt southwest ghana evidence for a litho stratigraphic control on gold occurrences within the birimian sefwi group abstract a three dimensional model of the gold rich paleoproterozoic ashanti greenstone belt has been built with a hybrid geological modeling method using geomodeller and gocad then inverted using vpmg software the model helps to identify the main regional scale controls leading to abundant gold mineralization in the southeast of the belt by highlighting the lithological distribution and geometry of geological structures the three dimensional geological model shows that 85 of gold occurrences in the ashanti greenstone belt are proximal to a specific tholeiitic metabasaltic horizon bv1 this result is noteworthy given that the relatively thin 300 m thick bv1 layer represents only 10 by volume of the modeled sefwi group stratigraphy a map of distance between the topography and the bv1 layer is produced and identifies areas showing a high probability to host gold deposits in the southeast of the ashanti belt possible structural controls performed by the bv1 tholeiitic metabasaltic rocks on the location of gold occurrences are discussed and we hypothesize that the bv1 layer acted as a mineralization trap or source of gold both hypotheses agree with examples from the literature and explain the observed distribution of the mineralized sites

a multidisciplinary study of a syntectonic pluton close to a major lithospheric scale fault relationships between the montmarault granitic massif and the sillon houiller fault in the variscan french massif central 2 gravity aeromagnetic investigations and 3 d geologic modeling 1 new gravity and aeromagnetic investigations have been carried out to understand the emplacement mechanisms of a granitic pluton and the relationships with a nearby lithospheric scale fault this paper concerns the second part of a methodological multidisciplinary study and complements previous geochronologic and anisotropy of magnetic susceptibility ams studies on the same pluton in the northern part of the variscan french massif central fmc the montmarault massif crops out along the sillon houiller fault shf bouguer and aeromagnetic anomaly maps imply thickening of the pluton along the shf and suggest laccolitic spreading northwestward on the basis of petrophysical measurements direct two dimensional 2 d joint gravity and magnetic modeling has been performed along 10 cross sections in order to quantitatively constrain the 3 d pluton geometry and its relationships with surrounding geologic units these geophysical cross sections new structural information field and ams measurements and petrophysical data have been integrated into a regional 3 d geological and geophysical model altogether the results obtained from geochronology petromagnetic fabrics part 1 gravity and aeromagnetic investigations as well as 3 d modeling part 2 demonstrate that the montmarault pluton was emplaced during the namurian period along the shf our results further show that at that time in response to a nw se regional extension if the shf existed it behaved as a normal fault mylonites attesting for synmagmatic normal motion on the northeastern part of the montmarault pluton strengthen this tectonic scenario during the late carboniferous the fmc experienced ne sw extension along the shf by 80 km of brittle left lateral wrench offset this second tectonic event is well recorded in the stephanian coal basins which were formed along nw se listric brittle faults and constrain the present day shape of the montmarault pluton

stochastic structure constrained image guided inversion of geophysical data abstractinverse modeling of geophysical data involves the recovery of a subsurface structural model and the distribution of petrophysical properties independent information regarding the subsurface structure is usually available with some uncertainty from the expertise of a geologist and possibly accounting for sedimentary and tectonic processes we have used the available structural information to construct a model covariance matrix and to perform a structure constrained inversion of the geophysical data to obtain a geophysical tomogram m we have considered that the geologic models y were built from random variables and were described with a priori probability density function in the bayesian framework we have explored for the a posteriori probability density of the geologic models i e the structure of the guiding image with the markov chain monte carlo method and we inverted at the same time in a deterministic framework the geophysical data the sampling of the geologic models was performed

evolution of the mount woods inlier northern gawler craton southern australia an integrated structural and aeromagnetic analysis structural mapping integrated with interpretation and forward modelling of aeromagnetic data form complimentary and powerful tools for regional structural analysis because both techniques focus on architecture and overprinting relationships this approach is used to constrain the geometry and evolution of the sparsely exposed mount woods inlier in the northern gawler craton the mount woods inlier records a history of poly phase deformation high temperature metamorphism and syn and post orogenic magmatism between ca 1736 and 1584 ma the earliest deformation involved isoclinal folding and the development of bedding parallel and axial planar gneissic foliation s1 this was accompanied by high temperature upper amphibolite to granulite facies metamorphism at ca 1736 ma during subsequent north south shortening d2 open to isoclinal south southeast oriented f2 folds developed as the palaeoproterozoic successions of the inlier were thrust over the archaean nuclei of the gawler craton the syn d2 engenina adamellite was emplaced at ca 1692 ma the post d2 history involved shear zone development and localised folding exhumation of metamorphic rocks and deposition of clastic sediments prior to the emplacement of the ca 1584 ma granite balta suite the mount woods inlier is interpreted as the northern continuation of the kimban orogen

three dimensional mineral prospectivity modeling for targeting of concealed mineralization within the zhonggu iron orefield ningwu basin china abstract the zhonggu iron orefield is one of the most important iron orefields in china and is located in the south of the ningwu volcanic basin within the middle and lower yangtze metallogenic belt of eastern china here we present the results of new 3d prospectivity modeling that enabled the delineation of areas prospective for exploration of concealed and deep seated baixiangshan type mineralization and yangzhuang type mineralization within the zhonggu orefield both of these deposits are kiruna type fe apatite deposits but are hosted by different formations within the ningwu basin the modeling approach used during this study involves 3 steps 1 combining available geological and geophysical data to construct 3d geological models 2 generation of 3d predictive maps from these 3d geological models using 3d spatial analysis and 3d geophysical methods 3 combining all of the 3d predictive maps using logistic regression to create a prospectivity map this approach integrates a large amount of available geoscientific data using 3d methods including 3d geological modeling 3d 2d geophysical methods and 3d spatial analysis and data integration methods the resulting prospectivity model clearly identifies highly prospective areas that not only include areas of known mineralization but also a number of favorable targets for future mineral exploration the 3d prospectivity modeling approach showcased within this study provides an efficient way to identify camp scale concealed and deep seated exploration targets and can easily be adapted for regional and deposit scale targeting

regional dome evolution and its control on ore grade distribution insights from 3d implicit modelling of the navachab gold deposit namibia abstract we introduce a novel approach to analyse and assess the structural framework of ore deposits that fully integrates 3d implicit modelling in data rich environments with field observations we apply this approach to the early palaeozoic navachab gold deposit which is located in the damara orogenic belt namibia compared to traditional modelling methods 3d implicit modelling reduces user based modelling bias by generating open or closed surfaces from geochemical lithological or structural data without manual digitisation and linkage of sections or level plans instead a mathematically defined spatial interpolation is used to generate 3d models that show trends and patterns that are embedded in large drillhole datasets in our 3d implicit model of the navachab gold deposit distinctive high grade mineralisation trends were identified and directly related to structures observed in the field the 3d implicit model and field data suggest that auriferous semi massive sulphide ore shoots formed near the inflection line of the steep limb of a regional scale dome where shear strain reached peak values during fold amplification this setting generated efficient conduits and traps for hydrothermal fluids and associated mineralisation that led to the formation of the main ore shoots in the deposit both bedding parallel and highly discordant sets of auriferous quartz sulphide veins are interpreted to have formed during the later lock up stage of the regional scale dome additionally pegmatite dykes crosscut and remobilise gold mineralisation at the deposit scale and appear to be related to a younger joint set we propose that kilometre scale active folding is an important deformation mechanism that influences the spatial distribution and orientation of mineralisation in ore deposits by forming structures traps and pathways for fluids at different preferred sites and orientations we also propose that areas that experience high shear strain located along the inflection lines of folds can act as preferred sites for syn deformational hydrothermal mineralisation and should be targeted for regional scale exploration in fold and thrust belts our research also suggests that examination of existing drillhole datasets using 3d implicit modelling is a powerful tool for spatial analysis of mineralisation patterns when combined with fieldwork this approach has the potential to improve structural understanding of a variety of ore deposits

towards an integrated inversion of geoscientific data what price of geology abstract the inversion of multiple geoscientific datasets to define structures in hard rock terrains has for the most part been limited to geophysical methods supported by rock property constraints in this paper we expand the range of constraints available to geological modellers by defining a series of misfit functions that are used to define the quality of a given geological model with respect to the available geological data these misfit functions encompass both spatial and temporal observations and include primary data such as the location of an outcrop or bore hole location of a given rock type the orientation of its different generations of foliations as well as secondary geologic observations such as age relationships when we combine geologic conditions with geophysical misfit functions which already exist for many geophysical measures we have the potential to better constrain two and 3d models of the earth as a first test a subset of these misfit functions are applied to a set of synthetic three dimensional volumetric models built with an implicit surface modelling scheme by perturbing the input structural data within a narrow range we can simulate a range of significantly different three dimensional models for which we can then apply both geological and geophysical misfit functions several joint geological geophysical inversion schemes may be developed based on this methodology with the ultimate goal being an inversion scheme that simultaneously minimizes both geological and geophysical misfit

defining folds on three dimensional surfaces we present a new method for the structural analysis of folded surfaces the method requires a generalized definition of a fold as a patch consisting of contiguous points with gaussian curvature and mean curvature of consistent sign four classes of folds result from this definition antiforms and synforms each of synclastic and anticlastic forms this new analysis is illustrated with reference to several examples

towards incorporating uncertainty of structural data in 3d geological inversion abstract all geological models are subject to several kinds of uncertainty these can be classified into three different types data imprecision and quality inherent randomness and incomplete knowledge with our approach we address uncertainties introduced by input data quality in complex three dimensional 3d models of subsurface structures geological models as input data we consider parameters of geological structures i e formation and fault boundary points and orientation measurements our method consists of five steps construction of an initial geological model with an implicit potential field method assignment of probability distributions to data positions and orientation measurements simulation of several input data sets construction of several model realisations based on these simulated data sets and finally the visualisation and analysis of the uncertainties we test our approach in two generic models a simple graben setting and a complex dome structure the first model shows that our approach can evaluate uncertainties from different structures and their interaction furthermore it indicates that the final uncertainty of the model is not simply the sum of all input data uncertainties but complex interactions exist the second example demonstrates that our approach can handle full three dimensional settings with overturned surfaces results of the uncertainty simulation can be visualised and analysed in several ways ranging from borehole histograms to uncertainty maps for complex 3d visualisation and analysis we use indicator functions when we apply these we can treat the visualisation of uncertainties in complex settings in a self consistent manner with our simulation method it is possible to analyse and visualise the uncertainties directly introduced by imprecision in the input data our approach is intuitive and straight forward and suitable in both simple and complex geological settings it enables detailed insights into the model quality even for the non expert in cases where a geological model is the basis for geophysical simulation it opens up the way to geological data driven ensemble modelling and inversion

that s why it s called interpretation impact of horizon uncertainty on seismic attribute analysis in the late 1960s early 1970s seismic stratigraphy revolutionized the petroleum industry by providing an objective meaningful technique for describing the stratigraphic record and predicting the distribution of potential reservoir source and seal facies within the last 10 years the uses of seismic data have evolved from sequence interpretation and qualitative assessment of reservoir trends to evaluations that include more quantitative prediction of reservoir properties throughout the industry seismic attribute analysis has become a commonly utilized tool for quantitative evaluation of reservoir properties from seismic data

high heat geodynamic setting during the palaeozoic evolution of the mount painter province sa australia evidence from combined field structural geology and potential field inversions