grain rimming kaolinite in permian rotliegend reservoir rocks upper rotliegend sediments of permian age from the northeast netherlands show moderate to good reservoir

a comparison of burial maturity and temperature histories of selected wells from sedimentary basins in the netherlands sedimentary basins in the netherlands contain significant amounts of hydrocarbon resources which developed in response to temperature and pressure history during mesozoic and cenozoic times quantification and modelling of burial maturity and temperature histories are the major goals of this study allowing for a better understanding of the general geological evolution of the different basins as well as petroleum generation all major basins in the netherlands encountered at least one time of inversion and therefore moderate to high amounts of erosion in order to determine the amount of inversion the basins have experienced a 1d study was performed on 20 wells within three basins west netherlands central netherlands and lower saxony basins new vitrinite reflectance values were obtained and existing data re evaluated to gain a good data base the burial histories of six wells two for each studied basin are presented here to demonstrate the differences in basin evolution that led to their present shape and petroleum potential the permo triassic subsidence phase can be recognized in all three basins but with varying intensity in the jurassic the basins experienced different relative movements that culminated in the cretaceous when the influence of the inversion caused erosion of up to 2 500 m most wells show deepest burial at present day whereas the timing of maximum temperature differs significantly springer verlag 2007

interdecadal changes in summertime typhoon tracks abstract the present work examines interdecadal variations of typhoon tracks in the western north pacific wnp during the boreal summer june september for the period 1951 2001 typhoon tracks are expressed as percentage values of the total number of typhoon passages into a 5 5 latitude longitude grid box with respect to the total number of typhoons formed in the wnp the analysis period is divided into two interdecadal periods id1 1951 79 and id2 1980 2001 from id1 to id2 typhoon passage frequency decreased significantly in the east china sea and philippine sea but increased slightly in the south china sea the time series of typhoon passage frequency over the east china sea and south china sea further reveal a regime shift in the late 1970s while those over the philippine sea indicate a continuous downward trend of 9 decade 1 the interdecadal changes in typhoon tracks are associated with the westward expansion of the subtropical northwestern pacific high snph in the late 1970s the e

analysis of strained sedimentary fabrics review and tests accurate analysis of the homogeneous strain of ellipsoidal objects requires that certain premises are met these are 1 coaxiality of strain increments 2 accurate definition of finite strain axes and 3 perfectly passive behaviour of the objects with respect to the matrix the equations provide a mathematical model for this idealized scenario in practice the analysis is limited to data from plane surfaces and its success depends upon the type of initial fabric of the objects the frequency distribution of their initial shapes and errors of measurement of the final shapes rf1 2 and of final orientations together with the difficulty in locating the finite strain axes these factors greatly affect the outcome of the analysis and their combined effects have not been studied previously detailed observations on the orientations of strain and of the orientation distribution of the objects long axes sometimes indicate that the model is incompatible with the data strain analysis is then not possible

data mining in the dutch oil and gas portal a case study on the reservoir properties of the volpriehausen sandstone interval this paper presents the results of a data mining exercise on core measurements and reports of the triassic lower volpriehausen sandstone member rbmvl in the netherlands the availability of a large accurate online dataset via the dutch oil and gas portal nlog enables the definition of general reservoir property trends on a regional subregional scale accurately defined trends are capable of restricting the uncertainty range of key parameters in exploration studies e g porosity and permeability and thus of reducing risk plotting core porosity v core permeability resulted in a curved data cloud on a log normal plot although porosity permeability relationships are often defined by straight lines the dataset in this study shows that a curved relationship results in a better fit with permeability measurements over the entire porosity range two methods were applied to define a porosity depth relationship for sandstones of the rbmvl the results of both methods confirm and enable quantification of the well known trend of decreasing porosity with depth by assigning grain density attributes to the core measurements the dependency of the porosity depth relationship on sedimentary facies and diagenesis type grade could be determined this case study demonstrates the power of this free online dataset in understanding reservoir quality 2018 the author s

movement of the kuroshio axis to the northeast shelf of taiwan during typhoon events abstract we investigated the movement of the kuroshio axis on the northeast shelf of taiwan associated with the passage of typhoons using sea surface current data observed by the ocean radar system on yonaguni and ishigaki islands first we examined daily kuroshio axis variation on the northeast shelf of taiwan during typhoon events the ocean radar data showed that the kuroshio axis moved onto the shelf after passages of typhoons the kuroshio moved onto the shelf and stayed there after the passage of typhoon hai tang while the kuroshio maintained this pattern southerly wind blew continuously for 4 days the mean current speed northeast of taiwan after the typhoon s passage increased by 18 cm s 1 in addition the sea level difference between two satellite altimetry tracks east of taiwan increased by 14 4 cm these results suggest that coastal upwelling east of taiwan caused by the southerly wind generated an east west sea level difference that in turn generated a northward geostrophic current this current could have enhanced the kuroshio east of taiwan and pushed it onto the shelf

mesozoic resource potential in the southern permian basin area the geological key to exploiting remaining hydrocarbons whilst unlocking geothermal potential it is generally accepted that hydrocarbon exploration in northern europe has reached a mature stage a basin s maturity is defined by the underlying number of new discoveries and the declining production rate of mature fields spe 2015 for geoscientists a mature basin has well defined characteristics in terms of for example reservoir presence or trap formation e g byrne 2012 it is interesting therefore to note how much is still unknown about certain stratigraphic intervals in northern europe the mesozoic overburden of the southern permian basin sensu maystrenko et al 2008 doornenbal stevenson 2010 continues to provide fresh insights into the geological history of an area where as the name suggests historical hydrocarbon exploration has focused on the paleozoic the aim of this special publication is to increase knowledge of the mesozoic overburden as a driver for further hydrocarbon exploration production and the development of new geothermal energy sources the succeeding chapters are introduced by tectonic framework overviews that give a context for the papers that follow the remaining articles are organized in approximate stratigraphic order from old to young and include a variety of examples from semi regional to localized field or sub basin studies an overview of the study area for all the following chapters is given in figure 1 it is recognized that the overprinting mesozoic systems have different naming conventions across the study area e g the central european basin system sensu littke et al 2008 maystrenko et al 2008 here we use the title southern permian basin area to emphasize the resource opportunities associated with a region that has at least in large part been associated with hydrocarbon exploration and very large gas fields in the permian rotliegend for our purposes this includes part of the polish trough the highs surrounding the basin e g the ringkobing fyn high and analogous elements of the danish and norwegian offshore in this introduction an overview of the geological history and resource base of the area is presented as a framework for the chapters that follow a description of further prospective resources is then offered oil and gas plus geothermal potential

regional kinematics inferred from magnetic subfabrics in archean rocks of northern ontario canada strain analysis observations of l s fabrics and studies of the anisotropy of magnetic susceptibility ams and of anisotropy of isothermal remanence airm reveal a sequence of progressive fabric development during regional deformation l s fabrics of quartz and feldspar grains are most transposed in regional transpression whereas the ams subfabrics controlled by the properties of late metamorphic silicates record a later orientation of the ambient stress field anisotropy of magnetic remanence is caused by the still younger minerals magnetite and pyrrhotite its anisotropy is less transposed than the ams subfabric consequently the relative orientations of the three types of fabric yield a kinematic sequence of subfabrics developed during transpression the l s fabrics are most transposed the ams less transposed and the airm fabrics least transposed toward the plane of regional flattening the results indicate that the deformation recorded by the three subfabrics was non coaxial in the most general sense with all three principal directions spinning with respect to the rocks during progressive straining

characterization of the magnetic fabric of rocks abstract an inextensive system of magnetic susceptibility anisotropy factors is suggested which is sufficient in the majority of practical applications for characterizing the magnetic fabric of rocks the system involves three newly devised factors the corrected anisotropy degree the shape factor and the difference shape factor the first of these characterizes the quantity of anisotropy somewhat better than the commonly used anisotropy degree the shape factor characterizes the quality of anisotropy i e the shape of the susceptibility ellipsoid in a convenient way its definition is based on a certain analogy between the anisotropy ellipsoid and the strain ellipsoid the difference shape factor can replace the shape factor when only the differences between the principal susceptibilities are given while the mean susceptibility is unknown

partial anhysteretic remanence and its anisotropy applications and grainsize dependence the distribution of remanence coercivities in a rock sample can be obtained by differentiating alternating field af demagnetization curves of anhysteretic remanent magnetization arm however significant errors can be introduced by grain interactions and by the noise inherent in differentiation we have found that 1 this error can be significantly reduced by measuring partial arm s parm s and 2 parm patterns show a strong empirical correlation with grain size parm s are imparted by exposing a sample to a small direct magnetic field in the presence of a large decreasing af the direct field is switched on over a specified range of af s thus magnetizing a fraction of the magnetite grains in the corresponding coercivity range we have further found in both synthetic and natural sediments that measurement of the anisotropy of parm enables us to detect the preferred orientations of distinct subpopulations of magnetite particles related to the size and shape of the grains

hydrocarbon habitat of the west netherlands basin the traditional hydrocarbon charge model for the west netherlands basin was that the carboniferous coal measures have generated only gas and the jurassic posidonia shale only oil however it is now concluded that both have generated oil and gas and that an additional possible source rock for oil occurs in the lower part of the lower jurassic aalburg formation geochemical fingerprints have been established to distinguish the different groups of gas and oil the occurrence of which is consistent with their geological setting and possible migration routes the main phase of hydrocarbon generation and expulsion occurred prior to the mid cretaceous and the occurrence of biodegraded oils indicates that significant amounts of hydrocarbons were already in place at the onset of the tertiary previously it had been considered that charge ended during the late cretaceous inversion however recent modelling studies indicate that along the south west margin of the basin and in the lows between inversion highs charge continued during the tertiary at rates that should have been sufficient to at least compensate for any loss of hydrocarbons through imperfect seals the distribution of biodegraded oils in jurassic and cretaceous reservoirs suggests that biodegradation must have occurred during the earliest tertiary when meteoric fresh waters had access to the reservoirs significantly reservoirs that were at that time so deeply buried that temperatures exceeded 70 to 80 c and that were thus at levels where bacteria cannot survive do not contain biodegraded oils for the fault bounded traps in triassic reservoirs juxtaposition with triassic and jurassic sandstones and shales is the principal control of trap integrity and determines the spill point traps bounded by faults that have been reactivated during the tertiary have clearly been breached traps at upper jurassic and cretaceous levels are usually faulted dip closures and have always been found to be full to their spill points within the limits of seismic resolution

methods and applications of magnetic anisotropy a special issue in recognition of the career of graham j borradaile methods and applications of magnetic anisotropy a special issue in recognition of the career of graham j borradaile

probabilistic tectonic heat flow modeling for basin maturation assessment method and applications tectonic modeling is often neglected in the basin modeling workflow and heat flow is most times considered a user input such heat flows can therefore result in erroneous basin modeling outcomes resulting in false overoptimistic identification of prospective areas or failure to identify prospects this is particularly true for areas with limited data control such as frontier basin areas or deep unexplored plays in mature basins three major factors obstruct routinely use firstly because of the focus of most tectonic models on lithosphere scale processes a large range of models including the mckenzie rift model fail to take into account effects which are of paramount importance for basement heat flow such as transient effects of sediment infill and erosion and changes in crustal heat production over time secondly lithosphere tectonic models often fail to allow inversion of basin data making forward tectonic modeling a cumbersome exercise non vertical sediment movements and 2d and 3d loading effects can play an important role hampering a unique inversion thirdly lithosphere tectonic models generally fail to aid the user to understand the sensitivity of the model results in terms of basin maturation for permissible ranges of tectonic model parameters and for uncertainties in tectonic scenarios such as absence or presence of underplating or two layered stretching vs a mckenzie model for this reason we have developed a multi 1d probabilistic tectonic heat flow model which is capable of calculating tectonic heat flows incorporating a variety of tectonic scenarios the model is capable of inversion of burial histories calibrated to temperature and maturity data calibration and sensitivity analysis is done through monte carlo sampling analysis using an experimental design technique for computational efficiency the tectonic heat flows can easily be used as input for basin modeling in commercially available 3rd party software 2009 elsevier ltd all rights reserved

strain anisotropy of anhysteretic remanence and anisotropy of magnetic susceptibility in a slaty tuff finite strain data for the borrowdale slaty tuffs compare variably with the anisotropy of magnetic susceptibility ams and anisotropy of anhysteretic remanent magnetization aarm finite strain determined from lapilli rims shows that slaty cleavage was formed by coaxial flattening with x y z in the ratio 1 74 1 21 and 0 48 aarm was measured in different coercivity windows to isolate contributions from magnetite of different grain sizes a 0 3 mt for multi domain md b 3 15 mt for pseudo single domain psd and c 15 60 mt for single domain sd ams combines petrofabric contributions from silicates as well as magnetite magnetite grains may grow recrystalize or rearrange domains after or during metamorphism and postdate or overlap with the silicate s fabric evolution ams foliation defined by paramagnetic chlorites is parallel to slaty cleavage aarm foliation for sd magnetites is offset clockwise from ams foliation which may reflect late crystallization or domain rearrangement of magnetites in response to a latter noncoaxial increment ams fabric shape consistently corresponds to strain ellipsoids and indicates that the strain induced ams fabric is susceptible to the change of oblateness rather than strain intensity furthermore investigation of the different aarm subfabrics and finite strain shows that only sd magnetite s aarm correlates with finite strain and weakly at that 2001 elsevier science b v all rights reserved

anisotropies of partial anhysteretic remanence and susceptibility in compacted black shales grainsize and composition dependent magnetic fabric we have quantified the magnetic fabric of the highly compacted heebner shale pennsylvanian of kansas in terms of the anisotropies of partial anhysteretic remanent magnetization parm and low field susceptibility hysteresis loops exhibit almost purely paramagnetic behavior and the ratio of high field linear susceptibility to low field susceptibility is very close to one the susceptibility anisotropy therefore reflects the fabric of the paramagnetic matrix while the remanent anisotropies are due to the preferred orientations of ferrimagnetic grains both the paramagnetic and ferrimagnetic fabrics are dominated by a horizontal foliation with a weak northeasterly lineation but the parm anisotropies are generally much larger than the susceptibility anisotropy the degree of foliation measured with parm s decreases markedly with increasing coercivities indicating stronger foliation in the coarser grainsize fraction in contrast the parm mean lineations are grainsize independent suggesting a post compactional origin related to tectonic compression the susceptibility lineation appears to have a slightly different azimuth and may therefore be due to paleocurrents

coaxial deformed and magnetic fabrics without simply correlated magnitudes of principal values abstract results of a detailed strain analysis of accretionary lapilli in the borrowdale volcanic sequence of england indicate a bedding memory component to the rock s fabric a simple new strain analysis method uses variation in thickness of lapilli rims and appears not to be influenced by the bedding fabric the orientations of the principal magnetic susceptibilities show a strong correlation with the principal strain orientations as in other studies but we can detect no correlation between strain magnitudes and principal susceptibility magnitudes in the same small specimens

application of fluid flow systems analysis to reconstruct the post carboniferous hydrogeohistory of the onshore and offshore netherlands abstract the reconstruction of the post carboniferous hydrogeohistory of the onshore and offshore netherlands is part of an ongoing tno project on fluid flow systems analysis on geological timescales the scope of the project is to assess the present day hydrogeological and fluid flow conditions of the sedimentary basins in the onshore and offshore netherlands and to analyse and model the evolution of fluid flow systems in these basins in order to increase the process based knowledge of the causes of present day physico chemical characteristics of rocks and fluids in the sedimentary fill of the dutch part of the north sea basin this article concerns the first phase of the project and provides an overview of the characteristic features of the post carboniferous evolution of external and internal processes acting on the sedimentary fill and their role in shaping the hydrogeological and hydrodynamical setting of the netherlands the post carboniferous evolution of the fluid flow conditions is described for five geological time periods during each time period different forces have acted simultaneously on the fluids and different fluid flow systems have coexisted and interacted the present day active driving forces and processes influencing fluid flow conditions include sedimentary loading gas generation tectonic forces topographic relief of the water table fluid density differences and human activities the article presents a brief outline of the resulting fluid flow systems observed direct and indirect indicators of fluid flow pressure temperature salinity sediment diagenetic minerals are consistent with the reconstructed hydrogeological and hydrodynamic setting of the netherlands

microstructures of early jurassic toarcian shales of northern europe the toarcian early jurassic posidonia shale formation is a possible unconventional gas source in northern europe and occurs within the cleveland basin united kingdom the anglo paris basin france the lower saxony basin and the southwest germany basin germany and the roer valley graben the west netherlands basin broad fourteens basin the central netherlands basin and the dutch central graben in the netherlands outcrops can be found in the united kingdom and germany since the posidonia shale formation does not outcrop in the netherlands sample material suitable for experimental studies is not easily available here we have investigated lateral equivalent shale samples from six different locations across northern europe germany the netherlands the north sea and united kingdom to compare the microstructure and composition of toarcian shales the objective is to determine how homogeneous or heterogeneous the shale deposits are across the basins using a combination of ion beam polishing scanning electron microscopy and x ray diffraction the work presented here shows that the toarcian shales of northern europe display considerable homogeneity in mineralogy and microstructure in the different investigated samples and formations where the largest variability is the carbonate content ranging from almost zero up to 80 we conclude that the outcrop locations in germany and the united kingdom are suitable analogues with respect to their mineralogy and microstructure for experimental studies on the posidonia shale in the dutch subsurface 2016 the authors

magnetic fabrics in l s tectonites how many specimens abstract single large blocks 10 30 kg of homogeneously strained fine grained slate or schist with homogeneous fabrics reveal subtle but sometimes significant variations in magnetic fabric from large numbers up to 100 of closely spaced cylindrical cores traditional samples of three to six cores per block or per site may suffice for low precision regional determinations of fabric orientations if suitably fine grained and homogeneous however for the most precise definition of anisotropy of magnetic susceptibility axes ams small sample sizes

magnetic anisotropy in the trenton limestone results of a new technique anisotropy of anhysteretic susceptibility a new method for determining magnetic anisotropy using anhysteric remanence susceptibility is described the magnetic fabric of a collection of trenton limestone specimens has been determined using this method as well as by conventional anisotropy of magnetic susceptibility the results demonstrate the usefulness of the new method for finding the magnetic fabric of rock units such as the trenton in which the bulk magnetic susceptibilities are low a model is proposed to explain the observed foliated and lineated fabric as a consequence of overburden compaction and regional horizontal stresses the original fabric is inferred to have been isotropic the anisotropy resides in secondary magnetite of late paleozoic age it is argued that the observed magnetic fabric must therefore be alleghenian or younger in age our method has the potential to determine paleostress directions in carbonates elsewhere provided our assumptions are correct

magnetic fabrics in archean granitoids northwestern ontario isolation of accessory and matrix contributions by inspection of ams data abstract pre tectonic and post tectonic granitoid plutons in the same area share similar orientations for their ams anisotropy of magnetic susceptibility foliation and lineation and these are similar in orientation to the l s fabrics of the country rock which bears a vertical ene wsw foliation the ams fabrics in the granitoids are composite blending contributions from accessory but highly susceptible magnetite with those from paramagnetic matrix silicates we isolate magnetic sub fabrics in the granitoids by a simple numerical approach that standardizes the mean tensor for susceptibility of specimens thereby suppressing the skewing effect of high susceptibility accessories i e magnetite this approach approximately separates the contributions of ferro magnetic and of paramagnetic minerals to ams though not as completely as technical laboratory experiments

sedimentary basin inversion and intra plate shortening abstract sedimentary basin inversion the shortening of formerly extensional basins is accommodated mainly by compressional reactivation of extant faults and fractures across a wide range of scales as such inversion is a large scale manifestation of byerlee friction the dynamic criterion for fault reactivation governing the effective shear strength of the shallow crust basin inversion generates distinctive deformational architecture and it is implicated strongly in sedimentary basin exhumation as a principal source of horizontal stress inversion drives significant sedimentary porosity reduction and resultant fluid flow upper crustal deformation is critically dependent on fluid overpressure i e pore fluid pressures greater than would be calculated from a hydrostatic gradient and perhaps more than in any other tectonic setting overpressures are potentially large during sedimentary basin inversion this review therefore includes discussion of the role of fluid overpressure in inversion and the evidence for it collectively inversion has profound implications good and bad for the prospectivity of many petroliferous sedimentary basins thus recognizing the evidence for basin inversion quantifying its magnitude and understanding the mechanisms that accommodate inversion and other phenomena affected by it have become essential components of the basin analyst s remit

single domain particles in rocks and magnetic fabric analysis magnetic susceptibility anisotropy is commonly used as a guide for determining stress and flow axes in rocks and for assessing the suitability of anisotropic rocks for palaeomagnetic purposes we have recently demonstrated however in laboratory produced samples that as theoretically expected susceptibility anisotropy is dependent on particle size multidomain particles of magnetite or similar strongly magnetic particles with shape anisotropy exhibit a maximum susceptibility parallel to their easy remanent magnetization axes whereas uniaxial single domain particles exhibit a maximum susceptibility perpendicular to their easy magnetization axes hence susceptibility anisotropy does not yield an unambiguous determination of particle alignment in rocks independent of domain state by demonstrating uniaxial single domain anisotropy characteristics for the first time in a rock specimen we show here that susceptibility measurements by themselves may not correctly identify the degree or type of alignment of ferro or ferrimagnetic particles in rocks in particular apparently foliated rocks can actually be lineated and vice versa moreover rocks with low anisotropy of susceptibility can have a much higher anisotropy of remanence remanence anisotropy methods are shown to give unambiguous determinations of the degree and type of alignment

estimation of interannual and interdecadal variations of typhoon induced primary production a case study for the outer shelf of the east china sea 1 using multiplatform satellite data and 13 typhoon passages from 1998 through 2004 an empirical relationship to assess typhoon forced primary production pp enhancement in the outer shelf of the east china sea is introduced the constructed relationship requires variables of typhoon maximum sustained wind typhoon transit speed and bottom depth of the location below the typhoon track as this relationship does not require ocean color data it enabled us to reconstruct the interannual and interdecadal variations of typhoon forced pp enhancement from 2004 back to 1980 typhoon forced pp enhancements and typhoon contributions to summer fall new production during el nino years tended to be higher than those during la nina years typhoon enhanced pp also has shown a tendency to be higher during the 1991 2004 period than during the 1980 1990 one the method we detail in this study is applicable for other tropical cyclone trajectory basins

magnetic fabrics and petrofabrics their orientation distributions and anisotropies abstract magnetic fabric and other petrofabric anisotropies may be described by second rank tensors represented by ellipsoids for a homogeneous petrofabric that is adequately sampled a stereoplot of the orientation distribution of the tensors principal axes maximum intermediate and minimum should show three orthogonal concentrations the concentrations form some combination of shapes from circular clusters through partial girdles to full girdles the concentrations elliptical eccentricities are constrained by the symmetry of the sample orientation distribution i e l l s l s etc as well as the individual sample anisotropies the mean orientations of principal axes must be orthogonal just as with individual sample tensors this requires tensor statistics for their calculation jelinek 1978 furthermore elliptical confidence cones for the means should parallel principal planes preserving overall orthorhombic symmetry however in practice sub orthorhombic symmetry may arise from unrepresentative sampling but it may also be a useful indicator of multiple or heterogeneous petrofabrics in the case of magnetic fabrics the wide range in average susceptibility values and variation in magnetic mineralogy permit small numbers of high susceptibility samples to deflect the orientation of the tensor mean away from the majority of samples normalizing the samples by their bulk susceptibility overcomes this but the orientation of high susceptibility outliers may signify an event or subfabric of importance that we should not discard therefore stereoplots of both normalized and non normalized orientation distributions should be compared preferably also identifying the outliers it is important to distinguish the shape of the orientation distribution ellipsoid from the shape of the individual magnetic fabric ellipsoids the qualitative l s nomenclature is best replaced by tj where tj 1 oblate tj 1 prolate jelinek 1981 invariably the orientation distribution is described by an ellipsoid whose shape is more spherical than that of the individual sample anisotropy ellipsoids because the latter have scattered orientations furthermore the shape of the orientation distribution ellipsoid need bear no relation to the shape of individual sample ellipsoid anisotropies the concepts are illustrated with 1119 measurements of anisotropy of magnetic susceptibility ams from seven areas and with 188 measurements of anisotropy of anhysteretic remanence aarm from two areas