reflectance of dispersed vitrinite in palaeozoic rocks with and without cleavage implications for burial and thermal history modeling in the devonian of rursee area northern rhenish massif germany abstract vitrinite reflectance is used as coalification parameter in coals and as maturity and palaeotemperature indicator in sedimentary rocks in high grade diagenetic rocks i e rocks at the boundary between diagenesis and metamorphism vitrinites become increasingly anisotropic therefore it has been suggested to study maximum minimum reflectance instead of mean reflectance for rocks which reached this stage in the present study vitrinite reflectance data from a folded sequence of the northern rhenish massif germany are combined with microtectonic study of thin sections in samples in which both bedding and cleavage are present we show that vitrinites in different microtectonic domains cleavage domains and microlithons show significant differences in both maximum vitrinite reflectance and vitrinite reflectance anisotropy this behaviour is due to a strong partitioning of deformation in cleavage domains as compared to microlithons so that vitrinite reflectance is controlled by the thermal and deformation history accordingly estimation of maximum palaeotemperatures during burial should be based on vitrinite reflectance measurements in microlithons unaffected by deformation after maximum burial based on this finding burial and temperature history of the rursee area in the eastern rhenish massif is reconstructed numerical simulations indicate a maximum burial at the siegen ems boundary of about 5000 m and a maximum burial temperature of about 220 c

high thermal maturity in the lower saxony basin intrusion or deep burial abstract the lower saxony basin lsb is situated at the southern rim of the northern permian basin the most important hydrocarbon bearing province in europe in its southern part areas of high thermal maturation up to 6 rr occur which were previously explained as being caused by magmatic intrusions of turonian to santonian age that affected carboniferous to lower cretaceous rocks in this area 2d numerical basin modelling was carried out in order to reconstruct the temperature histories along two parallel n s trending seismic sections along these sections new data about maturity distribution and temperature history were obtained by vitrinite reflectance measurements and apatite fission track analysis for the areas with highest maturity values low coalification gradients were established which agree well with earlier published data on wells further towards the west this new information does not support previous hypotheses on high heat flows from magmatic intrusions even if lateral heat transport is taken into account instead comparisons with a recently published map of the subsurface structure of the lsb indicate that maturity distribution may be closely related to major tectonic structures deep burial of individual structures of the lsb which are bordered by deep e w to ese wnw trending faults is further suggested by a rapidly increasing thicknesses of preserved cretaceous strata towards the south and b structural restoration of one of the seismic sections to achieve a fit between measured and calculated palaeo temperature and vitrinite reflectance data deep burial of carboniferous source rocks during cretaceous time has to be assumed due to an inversion phase in the early and middle upper cretaceous major amounts of sediment were removed and further uplift occurred in tertiary times in contrast the northern part of the lsb experienced maximum burial and temperatures during tertiary times

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

the cenozoic evolution of the roer valley rift system integrated at a european scale the roer valley rift system rvrs is located between the west european rift and the north sea rift system during the cenozoic the rvrs was characterized by several periods of subsidence and inversion which are linked to the evolution of the adjacent rift systems combination of subsidence analysis and results from the analysis of thickness distributions and fault systems allows the determination of the cenozoic evolution and quantification of the subsidence during the early paleocene the rvrs was inverted laramide phase the backstripping method shows that the rvrs was subsequently mainly affected by two periods of subsidence during the late paleocene and the oligocene quaternary time intervals separated by an inversion phase during the late eocene during the oligocene and miocene periods the thickness of the sediments and the distribution of the active faults reveal a radical rotation of the direction of extension by about 70 80j counter clockwise integration of these results at a european scale indicates that the late paleocene subsidence was related to the evolution of the north sea basins whereas the oligocene quaternary subsidence is connected to the west european rift evolution the distribution of the inverted provinces also shows that the early paleocene inversion laramide phase has affected the whole european crust whereas the late eocene inversion was restricted to the southern north sea basins and the channel area finally comparison of these deformations in the european crust with the evolution of the alpine chain suggests that the formation of the alps has controlled the evolution of the european crust since the beginning of the cenozoic

roughness at the base of the seismogenic zone contributing factors the cutout depth of microseismic activity in continental fault zones appears to correspond to the onset of greenschist metamorphic conditions at about 300 c it can generally be modeled as the transition from frictional to quasi plastic behavior in quartzofeldspathic crust shear resistance increases with depth through the frictional regime to peak at the transition beneath which it falls off exponentially with increasing temperature larger earthquake ruptures ml 5 5 nucleate around this transition depth where the highest concentrations of strain energy may accumulate varying depth and amplitude of the peak shear resistance along strike induce fluctuations in strain energy concentration at the base of the seismogenic zone factors affecting the depth of the transition include crustal composition geometry and mode of faulting fluid pressure levels in the frictional regime and water content in the quasi plastic regime quasi plastic strain rate and geothermal gradient evaluation of their relative importance is complicated because several are interdependent however compositional change may cause abrupt irregularities in seismogenic depth and peak shear resistance while regional variations in heat flow look to be particularly effective in creating long wavelength heterogeneities in strain energy concentration affecting faulting style

geodynamic and hydrodynamic evolution of the broad fourteens basin the netherlands in relation to its petroleum systems abstract data analysis in combination with 2d basin modelling is used to study the hydrogeologic and hydrodynamic response of the basin fill of the broad fourteens basin to its geodynamic evolution and the significance of this response for the evolution of the petroleum systems in the basin data analysis resulted in the identification of the major mechanical processes involved in overpressure and fluid flow evolution in the basin sedimentary loading and unloading tectonic compression and extension topography of the groundwater table and provided a timeframework for the important permeability alterations in the basin and the distinct phases of fluid flow observed present day diagenetic features and fracture characteristics in the basin indicate permeability alterations and paleo fluid flow during distinct periods of tectonic activity in the basin e g during late jurassic rifting and late cretaceous inversion the basin boundary fault zones were repeatedly reactivated during the periods of tectonic activity the 2d basin modelling included sedimentary loading and unloading topography of the water table and petroleum generation as pressure and fluid flow influencing mechanisms in addition the influence of time dependent permeability of fault zones on the overpressure history and the evolution of petroleum systems was modelled and evaluated the favoured modelling scenario including a time dependent permeability of faults shows that syn rift and post rift sedimentation in combination with gas generation induced overpressured conditions in restricted parts of the basin that is mainly in the deeper low permeable carboniferous shales and zechstein evaporites the calculated pre inversion overpressured conditions disappear during subsequent inversion of the basin predicted present day pressures in the reservoir horizons are near hydrostatic and reasonably in accordance with observed pressures the favoured scenario also explains the known location of oil fields and the location and saturation characteristics of the gas occurrences the model results further show that the difference in timing of oil charging of the p9 and q1 lower cretaceous reservoirs explains the observed differences in geochemical composition of the accumulated oils the biodegraded and water washed nature of the late cretaceous charged q1 oil reservoir is consistent with the concentrated topography induced groundwater flow through lower cretaceous reservoir units during the late cretaceous inversion period late charging of the lower cretaceous oil reservoir in the p9 area explains the non biodegraded character of the accumulated oils in general this paper shows the importance of using data analysis to obtain an a priori characterization of the basin geofluid evolution and shows that paleohydrodynamic conditions and time dependent permeability of the hydrogeological framework have influenced significantly the petroleum systems in the basin

neotectonics of the netherlands a review abstract earthquakes and vertical land movements inferred from geodetic levelling results demonstrate that the netherlands is situated on a tectonically active part of the earth s surface tectonic subsidence analyses of the sedimentary records in the basins and the history of tectonic uplift inferred from meuse river terraces show that the current tectonic activity is part of a deformation phase which began in the late early miocene which we take as the start of the neotectonic period the neotectonic faulting mode is normal slip this is in accordance with the present day orientation of the maximum horizontal stress and the vertical orientation of the maximum stress however the neotectonic fault zones are reactivated variscan or older wrench faults these faults have been reactivated repeatedly during the mesozoic and cenozoic in normal and wrenching modes and therefore represent fundamental crustal weakness zones as a result the surficial neotectonic fault pattern resembles the inherited wrenching fault pattern although the faulting mode is normal slip this is illustrated for the area where normal faults have displaced the meuse fluvial terrace system in the southeastern part of the netherlands the neotectonic vertical motions in and around the roer valley rift system have affected the courses of the rhine and meuse rivers from pliocene times until the present in addition a fluvial terrace staircase developed along the meuse river in response to the uplift of the ardennes rhenish massif and its foreland for example near maastricht furthermore small fault scarps are present along segments of the bounding fault zones of the roer valley graben the peel boundary fault zone and the feldbiss fault zone in other parts of the netherlands the neotectonic vertical motions have no direct expression in the morphology examples of possible indirect control on the morphology in these areas occur in glacial landscapes the zuiderzee basin and the coastal zone

fault valve behaviour in optimally oriented shear zones an example at the revenge gold mine kambalda western australia abstract quartz vein systems developed in and adjacent to shear zones host major gold deposits in the kambalda region of the norseman wiluna greenstone belt at the revenge mine two groups of mineralised reverse shear zones formed as conjugate near optimally oriented sets during ese subhorizontal shortening adjacent to a major transpressional shear system the shear zones developed at temperatures of about 400 c in a transitional brittle ductile regime deformation was associated with high fluid fluxes and involved fault valve behaviour at transiently near lithostatic fluid pressures during progressive evolution of the shear system early brittle and ductile deformation was overprinted by predominantly brittle deformation brittle shear failure was associated with fault dilation and the formation of fault fill veins particularly at fault bends and jogs a transition from predominantly brittle shear failure to combined shear along faults and extension failure adjacent to faults occurred late during shear zone evolution and is interpreted as a response to a progressive decrease in maximum shear stress and a decrease in effective stresses the formation of subhorizontal stylolites locally subvertical extension veins and minor normal faults in association with thrust faulting indicates episodic or transient reorientation of the near field maximum principal stress from a subhorizontal to a near vertical attitude during some fault valve cycles local stress re orientation is interpreted as resulting from near total shear stress release and overshoot during some rupture events previously described fault valve systems have formed predominantly in severely misoriented faults the shear systems at revenge mine indicate that fault valve action and associated fluctuations in shear stress and fluid pressure can influence the mechanical behaviour of optimally oriented faults

brittle deformation events at the western border of the bohemian massif germany investigations of brittle deformation structures present within the crystalline rocks of the bavarian oberpfalz reveal a complex late to post variscan crustal evolution upper carboniferous mainly westphalian granites were emplaced into semibrittle to brittle rocks of the zev zone of erbendorf vohenstraus and the egz erbendorf greenschist unit respectively from both the alignment of the granites and the direction of granite related tension gashes a north east south west extension must be assumed for the period of magmatic activities apart from the granite intrusions rapid crustal uplift about 1 5 km my led to an increase in the geothermal gradient from 40 c km late variscan post granitic the increased geothermal gradient persisted during the succeeding reverse faulting which results from late carboniferous probably stephanian east west and northeast south west compression although not evidenced directly in the area considered strike slip faults seem to have played an important part during the late variscan crustal evolution particularly in the early permian the strike slip events indicate further crustal shortening and indentation under north south compression a similar indentation was present in cretaceous time after a weak phase of early cretaceous reverse faulting which results from north south compression strike slip faults formed under north west south east and north south compression all these faults in particular the strike slip faults seem to be related to the cretaceous and lowermost tertiary convergence of the alpine carpathian orogeny a late stage of crustal extension characterized by a radial stress tensor 2 3 is indicated through high angle normal faults which probably formed during the subsidence of the adjacent neogene eger graben

evolution of the lower saxony basin abstract the lower saxony basin is a 300 km long and 65 km wide late jurassic and early cretaceous trough which parallels the northern margin of the rhenish massif this basin became inverted during the senonian and paleocene the lower saxony basin is the most important oil province of germany past production amounts to 200 10 6 t of oil 1 5 10 9 bbl the lower saxony basin is superimposed on the late carboniferous variscan foredeep basin and the frontal structures of the variscan fold belt during the permian to middle jurassic the area formed part of the northwest european basin differential subsidence of the lower saxony basin was initiated during the late jurassic and persisted till albian time this involved reactivation of permo carboniferous fracture systems by divergent wrenching a major aptian deep seated laccolith is evident in the western part of the lower saxony basin during the senonian and paleocene sinistral convergent wrenching induced uplift of the basin floor and folding of its sedimentary fill the margins of the inverted lower saxony basin are thrust over the adjacent stable platform areas the differential subsidence of the lower saxony basin can be related to a period of major crustal extension in the north sea rift basin inversion coincides with important orogenic events in the alpine system and is thought to have been induced by intra plate compressional stresses

geothermal history of the carboniferous in south limburg the netherlands the geothermal history of upper carboniferous rocks in the former mining district of south limburg the netherlands is complex maturity modelling as calibrated by vitrinite reflectance measurements and volatile matter content shows that the present day coalification patterns of the carboniferous were established in late westphalian to early permian times variations in the degree of coalification were mapped using as a reference level the upper westphalian a coal seam gb 23 modelled burial and thermal histories for the area indicate that regional variations in overburden heatflow and in timing of thermal events in front of the variscan orogen caused the spatial variation in coalification in the southern part of the area differences in overburden combined with a generally high heatflow determined the coalification patterns in the northeastern part of south limburg an additional thermal event related to a permian intrusion overprinted the earlier coalification pattern the coalification data are consistent with basement heatflow values during the carboniferous in the order of 46 to 71 mw m2 and erosion following the variscan orogeny of some 2900 m of sediments around sittard and as much as 5400 m in the southeasternmost part of south limburg

numerical modelling of burial and temperature history as an approach for an alternative interpretation of the bramsche anomaly lower saxony basin the lower saxony basin germany is one of the several sedimentary basins within the central european basin system in its southwestern part anomalously high maturity of organic matter has been observed to reach 4 5 vrr in upper jurassic and lower cretaceous sedimentary rocks in an area which coincides with a magnetic and a positive gravimetric anomaly this anomaly was often interpreted as the consequence of a deep seated igneous intrusion the so called bramsche massif however results obtained from calibrated numerical modelling are not in accordance with this scenario instead a burial by approximately 4 km of now eroded cretaceous rocks was revealed to be the probable cause for the anomaly data and modelling results from six boreholes and two pseudo wells support this view

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

injection veins of crushing originated pseudotachylyte and fault gouge formed during seismic faulting this paper describes the injection veins of crushing originated pseudotachylyte and fault gouge formed along the iida matsukawa fault in granitic cataclasite southern nagano prefecture central japan the pseudotachylyte which shows a dense and aphanitic appearances and fault gouge occur as simple veins fault vein along the main fault plane and as complex network veins injection vein in the neighboring cataclasite locally the injection veins of pseudotachylyte and fault gouge can be traced back to the fault veins powder x ray diffraction patterns and petrological analysis indicate that both of the pseudotachylyte and fault gouge consist entirely of fine grained angular clasts and that the pseudotachylytes and fault gouges have a similar x ray diffraction patterns with that of the host granite the similarity of chemical compositions and distribution patterns of grain size also show that the injection veins of pseudotachylyte and fault gouge have the same source material as that of fault veins field occurrences and petrological characteristics strongly suggest that the injection veins of pseudotachylyte and fault gouge formed during seismic faulting by a rapid intrusion and fluidization of crushed fine grained materials generated in the shear zone in a gas solid fluid system

new information on the thermal history of the southwestern lower saxony basin northern germany based on fission track analysis the southwestern part of the lower saxony basin lsb is characterized by gravity and magnetic anomalies and by an extremely high thermal maturity of organic matter this was for many years attributed to a late cretaceous intrusion but actually deep burial is being debated the complex thermal history of the area has been studied by fission track analysis zircon data provide evidence for widespread hydro thermal activity during the permian and upper jurassic lower cretaceous apatite ages indicate a major cooling event in the mid cretaceous 89 72 ma reflecting the time of inversion of the lsb during the cretaceous the cooling of the basin centre was rapid compared to the basin margins apatite fission track ages from borehole samples which are recently within the upper part of the apaz indicate a young heating of the sedimentary sequences until present

time and temperature in petroleum formation application of lopatin s method to petroleum exploration n v lopatin in the soviet union has developed a method for taking both time and temperature into account as factors in thermal maturation of kerogen lopatin s time temperature index of maturity tti values correlate with the thermal regimes corresponding to generation and preservation of hydrocarbons because such information is potentially of great interest for oil exploration a calibration and evaluation have been made of lopatin s method within the limitations of the data presently available the following statements can be made 1 the rate of the chemical reactions involved in thermal maturation of organic material appears to double with every 10 c 18 f rise in temperature 2 threshold values of lopatin s time temperature index of maturity tti are 15 onset of oil generation 75 peak oil generation 160 end oil generation 500 40 oil preservation deadline 1 000 50 oil preservation deadline 1 500 wet gas preservation deadline 65 000 dry gas preservation deadline 3 tti values calculated from lopatin reconstructions consistently agree with other maturation parameters commonly used by petroleum geochemists potential applications of lopatin s method for oil exploration include timing of oil generation calculation of volume of hydrocarbons generated within a basin and determination of economic deadlines

late cretaceous and cenozoic intra plate compressional deformations in the alpine foreland a geodynamic model abstract the mesozoic grabens and wrench induced troughs of western and central europe developed in response to triassic early cretaceous intra plate tensional stresses which affected the arctic north atlantic and the tethys borderlands during the rifting phase preceding the opening of the respective oceans this resulted in the fragmentation of the continental crust of the alpine foreland during the late cretaceous and tertiary alpine orogeny collision related compressive stresses exerted on the foreland induced the reactivation of these fracture systems causing the inversion of mesozoic grabens and the uplifting of major basement blocks at distances up to 1300 km to the north of the present alpine deformation front the structural style of these inverted basins and basement uplifts is indicative of compressional and transpressional deformations the total amount of crustal shortening associated with these deformations is unlikely to exceed a few tens of kilometres these displacements require a coupling between the foreland and the orogen at the alpine a subduction zones and within the foreland a decoupling at intra crustal levels between the crust and mantle and or at deeper lithospheric levels the example of the alpine foreland indicates that compressive stresses inducing major deformations can be transmitted from a collisional plate boundary through continental lithosphere over distances of up to 1300 km circumstantial evidence suggests that collision related compressive stresses not large enough to give rise to significant deformations can be transmitted through continental lithosphere over even greater distances

insights into the post emplacement history of the saunstein granitic dyke showing heterogeneous deformation and inconsistent shear sense indicators bavarian forest germany the recent mapping survey undertaken in the bavarian forest led to the discovery of several eew trending sinistral shear zones usually affecting granitic dykes or areas intruded by dykes we studied a granitic dyke affected by one of these shear zones the deformation in the dyke as well as in other dykes of the region is not homogeneous and concentrates mainly next to the contact to the country rock the differences in mineralogy between dyke and host probably controlled the distribution of strain favoring the deformation of the lithology richer in quartz i e the granite dyke next to a rheological boundary i e the contact to the host rock as inferred from microfabrics and quartz textures quartz deformation occurred by dislocation creep accommodated by grain boundary migration and subgrain rotation recrystallization intracrystalline glide on prism planes in the direction indicate a temperature of w500e550 c only in the most strained fine grained bands was deformation achieved by grain boundary sliding a late shear sense reversal after the principal sinistral deformation in the dyke led to the development of a dextral quartz shape fabric this reflects on the one hand how quartz is able to record late low strain overprints and on the other hand how oblique quartz foliations may lead to wrong interpretations when being used without corroboration of other shear sense indicators

the toarcian bajocian deltaic system in the north german basin subsurface mapping of ancient deltas morphology evolution and controls research focussing on the morphology and morphodynamics of modern river deltas has contributed much to the understanding of reservoir geometry and prediction of hydrocarbon splays and deep geothermal aquifers the interplay of allogenic and autogenic controls results in complex histories of modern river deltas comprising subsequent regressive and transgressive stages of delta formation the application to ancient examples is still ambiguous and in particular the detailed morphological description of ancient deltas is often hampered by limited subsurface data this basin scale study employs a data set of 15 cored wells and more than 450 logged wells in combination with lithofacies biofacies and architectural analysis to reconstruct high resolution subsurface facies and sand thickness maps of the toarcian bajocian deltaic system in the north german basin the results of this study show the evolution from smaller elongate river dominated delta types in the lower and upper toarcian 15 000 to 20 000 km and a larger lobate river dominated delta in the upper aalenian 40 000 km to a cuspate mixed river dominated and wave modified delta in the upper bajocian 25 000 km the river dominated parts are composed of subsequently formed of distributary deltaic channel belts and associated sheetsands of the delta plain and distributary mouth bar complexes with bar finger sand architectures of the delta front increasing marine processes in the bajocian resulted in modification of delta complexes forming a shoreface setting with foreshoals arc like chains of ooid bearing barrier shoals and back barrier lagoons the complex history of the toarcian bajocian deltaic system was mainly controlled by allogenic sea level fluctuations that triggered the delta progradation and subordinately by allogenic basin reorganisation autogenic process change of channel avulsion led to locally reduced sediment flux and culminated in lobe abandonment and transgressive shorelines differential compaction of underlying deltaic deposits result in strong differences in accommodation space and contributed to much to large scale delta shifts 300 km this article is protected by copyright all rights reserved

salt as a 3d element in structural modeling example from the central european basin system abstract based on a well constrained 3d structural model of the central european basin system 3d modeling has been carried out to understand the regional scale regularities between movements of the upper permian zechstein salt and the major post permian tectonic events the 3d reconstruction of the paleo thickness of upper permian salt at the end of the permian period demonstrates that areas of thickened upper permian salt correlate with the present day distribution of the largest salt structures within the central european basin system this spatial correlation implies that the distribution of salt thickness at the end of deposition partially controlled the structural style of the basin during post permian phases of salt tectonics moreover the results of 3d salt redistribution for post permian times indicate that the initiation of salt movements took place in the triassic the triassic extensional events triggered several phases of salt movements within the coeval depocenters of the central european basin system such as the glueckstadt graben the horn graben the norwegian danish basin the fjerritslev trough and the himmerland graben and the polish basin during the late jurassic early cretaceous extensional transtensional tectonic event the strongest salt movement occurred within the central graben the lower saxony basin and the pompeckj block the intensity of the late jurassic early cretaceous phase of salt tectonics is essentially declining from the marginal areas of the central european basin system towards the horn graben the glueckstadt graben and adjacent areas the late early cretaceous early late cretaceous is characterized by tectonic quiescence without strong salt movements over the entire study area the next regional phase of salt movements was triggered by late cretaceous early cenozoic inversion involving almost the entire central european basin system in terms of renewed salt movements inversion related thick skinned salt tectonics is observed along the nw se trending elbe fault system and the teisseyre tornquist zone where strongest compressional deformations were localized on the contrary a thin skinned character of salt movements was prevailing within the largest part of the north german basin post inversion cenozoic subsidence was also accompanied by salt activity related either to diapiric rise due to regional shortening and or to local roughly e w directed extension the cenozoic phase of salt movements was especially prominent within the marginal troughs of the glueckstadt graben

marine and terrestrial sedimentation across the t j transition in the north german basin abstract the global mesozoic sea level rise contributed to the stepwise flooding of the central european basin ceb across the t j transition and transformed the ceb from a late triassic inland playa to an early jurassic semi enclosed inland sea the calibration of sections from north germany and thuringia using high resolution palynomorph and ammonite biostratigraphy contributes to the improved temporal and spatial resolution of this decisive period the herein proposed deltoidospora concavisporites dc zone placed between the rhaetian ricciisporites polypodiisporites rp zone and the hettangian pinuspollenites trachysporites zone marks the transitional zone of overlapping rhaetian and hettangian palynomorphs in brackish marine brackish and terrestrial environments of the north german basin ngb thus the dc zone enables the identification of the t j transition in the ngb following a short term ingression in the late norian corollina porcellispora subzone the first rhaetian transgression contributed to substantial marine terrestrial facies shifts the diachronous transgressive onlap of brackish marine strata culminated in a first rhaetian maximum flooding in the upper corollina enzonalasporites zone to lower rhaetipollis limbosporites rl zone after a regressive maximum in the middle rl zone the next transgression culminated in a second rhaetian maximum flooding in the upper rl zone following the end triassic regression herein assigned to the upper rp zone the diachronous transgressive onlap of marine shales marks the change to marine jurassic environments the herein proposed deltoidospora concavisporites dc zone placed between the rhaetian ricciisporites polypodiisporites rp zone and the hettangian pinuspollenites trachysporites zone marks the transitional zone of overlapping rhaetian and hettangian palynomorphs in brackish marine brackish and terrestrial environments of the north german basin ngb thus the dc zone enables the identification of the t j transition in the ngb at the western gate of the ceb the onset of marine hettangian strata with ammonites dated as the p erugatum biohorizon at st audrie s bay postdates the base hettangian gssp by 250 kyr from there to thuringia the diachronous onlap of marine hettangian strata with ammonites herein dated as the p plicatulum biohorizon took place over 100 kyr the first jurassic maximum flooding is dated as the interval of the p psilonotum to p plicatulum biohorizons lower planorbis zone rhaetian hettangian 3rd order sequences of the ceb correlate with contemporaneous sequences described from tethyan and peri tethyan basins pointing to circum tethyan eustatic cycles the 4th order sequences are evident in the rhaetian hettangian but only a set of rhaetian 4th order sequences can be correlated in the ngb so far

subsidence analysis and modelling of the roer valley graben se netherlands abstract the roer valley graben southeastern netherlands forms the most northern branch of the european cenozoic rift system sedimentary backstripping of exploration wells provides control on vertical tectonic motions during the complex post paleozoic geodynamic evolution of the area the roer valley graben evolved by repeated reactivation of permo carboniferous fracture systems at least three episodes of extension related subsidence are recorded these occurred during the late permian early triassic 255 240 ma the middle jurassic 168 165 ma and the late cenozoic 36 0 ma a late jurassic early cretaceous stretching phase is weakly inferred from incomplete data crustal stretching values calculated from the tectonic subsidence curves can account for the reflection seismic controlled crustal configuration of the roer valley graben area results demonstrate a close relationship between the roer valley graben and the basins in the north sea during the mesozoic in contrast the cenozoic evolution of the roer valley graben is independent from that of the north sea and is related to the development of the rhine graben

organic petrological characterization of westphalian coals from the netherlands correlation between tmax vitrinite reflectance and hydrogen index maceral analyses tmax hydrogen index and vitrinite reflectance measurements have been carried out on a large set of westphalian coal samples from cored wells situated in the netherlands generalized maceral group analyses indicate substantial differences between the sedimentary regimes in the vicinity of the variscan deformation belt and more distal areas the hydrogen index of the coals from these different sedimentation areas is also significantly different the apparent variation of tmax vitrinite reflectance correlations are discussed in relation to maceral group composition and hydrocarbon generation during maturation the correlation between both maturity parameters is compared with literature data the differences between our maturity data and published data are significant these differences are quantified and illustrated by geological reconstruction of the south limburg area the netherlands it is demonstrated that the use of generalized correlation schemes for the purpose of geological modeling may lead to a misinterpretation of the geological history

repeated hydrothermal quartz crystallization and cataclasis in the bavarian pfahl shear zone germany abstract field and microstructural data of the pfahl shear zone in north eastern bavaria germany reveal the intimate spatial temporal connection between fragmentation fluid influx and quartz crystallization these processes and their interaction led to complex structured quartz units i a dense network of early quartz veins ii two domains of fine grained reddish to grayish quartz masses iii an extended central zone of massive white quartz and iv late cross cutting closely spaced parallel fractures and partly open quartz veins the fine grained quartz domains result from repeated and coeval cataclasis fluidization and quartz precipitation material transport in these domains is at least partly governed by the flow of mobile fluid quartz particle suspensions the complex internal meso to microstructures of the massive white quartz are generated by repeated processes of fragmentation and grain growth in general the brittle part of the pfahl shear zone represents a key example of cyclic dissolution precipitation and fragmentation on large scale

post variscan evolution of the lithosphere in the rhine graben area constraints from subsidence modelling in the area of the cenozoic rhine rift system crustal and lithospheric thicknesses range between 24 and 35 km and 60 and 120 km respectively this rift system transects the deeply truncated variscan orogen and superimposed permo carboniferous wrench induced troughs and late permian and mesozoic thermal sag basins at the time of its westphlian consolidation the variscan orogen was probably characterized by 45 60 km deep crustal roots that were associated with its rheno hercynian saxo thuringian saxo thuringian bohemian and bohemian moldanubian sutures all of which are transected by the cenozoic rhine rift system during the stephanian early permian wrench induced disruption of the variscan orogen subducted lithospheric slabs were detached causing upwelling of hot mantle material during the resulting thermal surge partial delamination and or thermal thinning of the continental mantle lithosphere induced regional uplift at the same time the variscan orogenic roots were destroyed and crustal thicknesses reduced to 28 35 km in response to the combined effects of mantle derived melts interacting with the lower crust regional erosional unroofing of the crust and on a more local scale by its mechanical stretching towards the end of the early permian the potential temperature of the asthenosphere returned to ambient levels with this regional long term thermal subsidence of the lithosphere commenced controlling the development of a new system of late permian and mesozoic thermal sag basins however the evolution of these basins was repeatedly overprinted by minor short term subsidence accelerations that reflect the build up of far field stresses related to rifting in the tethyan and atlantic domains comparison of observed and modelled subsidence curves suggests that in the area of the rhine rift system the lithosphere had equilibrated with the asthenosphere at the end of the cretaceous at depths of 100 120 km before it became thermally destabilized again by cenozoic rifting and plume related magmatism modelled subsidence curves indicate that by the end of early permian times the thermal thickness of the remnant mantle lithosphere ranged between 10 and 50 km in areas that were later incorporated into mesozoic thermal sag basins this corresponds to mid permian thermal lithosphere thicknesses of 40 80 km the geological society of london 2004

burial and thermal evolution of coal bearing strata and its mechanisms in the southern north china basin since the late paleozoic abstract during the interaction between the south china plate and the north china plate the southern north china basin sncb underwent a strong tectonic thermal evolution in the early mesozoic recently burial history reconstruction and thermal maturity simulation of coal bearing strata from the late carboniferous to the present were carried out in the sncb rock eval pyrolysis 12 samples vitrinite reflectance 60 samples apatite fission track aft analysis 17 samples and petromod 1d were performed on wells located in the sncb geothermal gradients were found to range between 30 3 and 36 4 c km averaging 31 0 c km and present heat flow was found to vary between 51 and 58 averaging 55 mw m2 the paleo heat flow model with higher heat flow peaks of 86 mw m2 during the first rifting phase resulted in the best fit between the calculated and the observed vitrinite reflectance and bottom hole temperatures in the modeling using this model of thermal maturity history combined with aft analysis we analyze the main hydrocarbon generation stages and discuss the coupling relationship of thermal maturity history with tectonic evolution the results indicate that tectonic activities restrict the thermal maturity evolution of source rocks to a large extent by controlling the geotemperature the thermal history demonstrates that two phases of heating 315 163 ma 83 38 ma depositing happened to the source rocks separated by two cooling 163 83 ma 38 23 ma uplifting events the maturity history indicates that the process of hydrocarbon generation can be divided into three stages in the sncb 315 163 ma thermal genesis gas generation stage 163 83 ma gas reservoir destruction stage 83 0 ma secondary biogas generation stage hydrocarbon generation started as early as 198 ma with a peak at 162 ma and expulsion started at around 195 ma the taiyuan and shanxi formations source rocks reached a high maturity 1 0

conjugate shear zones in the southern bohemian massif austria implications for variscan and alpine tectonothermal activity abstract mylonitic fabrics developed within conjugate wrench ductile shear and fault systems in the southern bohemian massif display both dextral nw se trending systems and sinistral ne sw trending systems shear senses contrasting temperature conditions of deformation can be observed in the different shear zones temperatures above 650 c were reached in the pfahl shear zone shearing under greenschist facies conditions took place in the rodl and danube shear zones brittle deformation dominated in the vitis and diendorf shear zones 40 ar 39 ar dating of various size fractions of muscovite formed and or deformed during mylonitization yield ages of ca 287 ma the nw se trending system and ca 288 281 ma the ne sw trending system the shear zones are interpreted as a late variscan conjugate system 40 ar 39 ar age spectra of fine grained newly grown sericite or rejuvenation of ages give evidence for post variscan reactivation of the shear zones brittle deformation within the shear zones was probably associated with maintenance of very high fluid pressure during variscan deformation foreland deformation during the alpine orogeny also played a significant role leading not only to the development of the ceske budejovice graben but also to local reactivation of the shear zones at higher crustal levels

structural evolution of inverted basins in the dutch offshore abstract the structural evolution of the dutch central north sea graben and the fault bounded broad fourteens basin is discussed graben formation started during the early triassic and culminated in strong differential subsidence during the late jurassic early cretaceous narrow fault bounded grabens and troughs and broad intervening highs were formed as a result of crustal distension and associated transtensional deformations the thickness of the late jurassic to early cretaceous fill of these basins may have exceeded 3000 m concurrent with the filling of these basins the bordering highs became deeply truncated during the late cretaceous and early tertiary compressive stresses resulted in inversion of these basins whereby movements along their bounding normal faults were reversed giving rise locally to overthrusting as for instance in the broad fourteens and west netherlands basins the timing of these compressional deformations has been palaeontologically dated and coincides with major orogenic events in the alps

post variscan sedimentary record of the sw margin of the bohemian massif a review the late palaeozoic to cenozoic stratigraphic and structural record of the southwestern margin of the bohemian massif and its extension beneath the southward adjacent molasse basin shows that it is controlled by a system of basement involving faults which came into evidence during stephanian autunian times and which were subsequently repeatedly reactivated thick permo carboniferous clastics accumulated in fault bounded transtensional basins aligned with the southwestern bohemian border zone swbbz following late autunian deformation of these basins the swbbz was overstepped by late permian to late jurassic platform sediments reflecting tectonic stability during the early cretaceous the swbbz was strongly reactivated causing disruption and erosion of its mesozoic sedimentary cover sedimentation resumed in the area of the swbbz during late early and late cretaceous with clastic influx from the bohemian massif reflecting gradually increasing tectonic activity along the swbbz during the late senonian and paleocene transpressional deformations resulted in upthrusting of major basement blocks in the molasse basin such structures are sealed by transgressive late eocene marine strata mio pliocene uplift of the bohemian massif involving mild reactivation of the swbbz is related to the development of the volcano tectonic eger zone the structural configuration of the swbbz is largely the result of late senonian paleocene compressional intraplate tectonics which play a major role in the structural framework of the northern alpine and carpathian foreland

the tectonic evolution of the southern dutch north sea during the palaeogene basin inversion in distinct pulses abstract in this paper we discuss the response of a sedimentary basin to compressional reactivation of extensional faults in distinct pulses the inversion of the broad fourteens basin in the southern dutch north sea is used as a case study the first pulse of inversion occurred during the late mesozoic as a result of the sub hercynean phase a second pulse occurred during the mid palaeocene laramide phase a final inversion pulse occurred around the eocene oligocene boundary coinciding with the pyrenean tectonic event we reconstructed the stratigraphic and structural development of the area during the palaeogene in detail basic data are two 2d seismic surveys supported by 74 geophysical wireline logs on which newly constructed depth and thickness maps are based the reconstruction is aided by a quantitative subsidence analysis cessation of compression resulted in relaxation and tensional reactivation of faults caused differential subsidence inheritance of geological structures is a key element in the tectonic activity in the broad fourteens basin during the palaeogene tectonic movement during the palaeogene was always accommodated by reactivation of palaeozoic mesozoic faults the intensity of inversion in the southern north sea basin during the pyrenean phase appears much larger than previously noticed moreover the area affected by the inversion is much wider than during previous phases minor differences in the direction of the local stress field between the tectonic phases and by the deposition of a thick sedimentary succession during the periods of tectonic quiescence between the inversion phases can account for this

chemistry of hydrothermal quartz in the post variscan bavarian pfahl system f r germany abstract chemical analyses of hydrothermal quartz by means of instrumental neutron activation coulometric dewatering and decrepitation analysis are combined with previously published microthermometric and isotopic data in order to unravel the processes involved in the formation of the post variscan hydrothermal system bavarian pfahl the bavarian pfahl is interpreted as a fossil zone of tectonic activity and large scale channelized fluid movement in the upper continental crust the predominance of k relative to ca and na in quartz as well as in fluid inclusions strongly supports the hypothesis that incongruous dissolution of feldspar during wall rock alteration and k metasomatism during fluid ascent along the shear zone accompanied by intense silicification are characteristic features of important fluid pathways in the crust the element contents detected in quartz along a 70 km long profile can be correlated with variable wall rock compositions high concentrations of ba as rb sr and cs are found in the vicinity of sedimentary basins at the western margin of the bohemian massif elevated element contents in this part of the profile probably result from intense water rock interaction within the adjoining sedimentary basin high ba contents in the vicinity of the fluorite barite mining district of nabburg wolsendorf indicate a genetic relationship between both mineralizations low cl br ratios can be generated either by interaction with carbonaceous sediments in these basins or by interaction with graphite in basement rocks the calculated salinities of the fluid inclusions vary widely but correlate well with microthermometric data and indicate mixing of basement or sedimentary brines with high salinity and meteoric water with low salinity the effects of polyphase cataclasis a result of seismic pumping on the fluid inclusion population and the mechanical properties of quartz have been studied by combined dewatering and decrepitation analyses despite minor regional variations in the chemical composition of quartz along the profile the overall uniform element pattern supports homogeneity of the hydrothermal system over distances of at least 70 km and probably over the total length of about 150 km the fluid volume required for the formation of the bavarian pfahl is estimated to correspond to the volume of the baltic sea approx 23 000 km3 in analogy with hydrothermal springs in the vicinity of recently active shear zones and faults the lifetime of the hydrothermal system bavarian pfahl is estimated to be about 160 000 years

understanding the evolution of syn depositional folds coupling decompaction and 3d sequential restoration abstract the analysis of basin dynamics and burial evolution requires a good understanding of sediment compaction classically decompaction of sediments is performed in one dimension at a well location using either a simple compaction depth relationship or more complex elasto plastic models this paper presents a new approach combining sequential decompaction with 3d restoration to allow for a true 3d basin analysis decompaction is performed in 3d after each restoration step thus taking into account possible tectonic events and lateral thickness variations care is taken to apply decompaction to ensure volume continuity especially around faults this approach is particularly suitable for syn depositional folds whose growth strata constrain tectonic evolution through time the proposed approach is applied to the sand rich turbiditic reservoir analogue of annot se france where two fictitious wells are used to compare the new 3d technique to a well decompaction analysis coupling restoration and decompaction leads to an improved assessment of the basin history an uplift of the underlying units is identified which was not detected using decompaction on wells only such differences may have a significant impact on possible hydrocarbon maturation models of the basin moreover the geometry of the restored and decompacted models can better constrains the basin history and influence our understanding of potential hydrocarbon migration pathways

the late paleozoic felsic lava dominated large igneous province in northeast germany volcanic facies analysis based on drill cores in the deep subsurface of the northeast german basin products of extensive volcanism are present that formed during the waning phase of the variscan orogeny permian carboniferous boundary large volumes 48 000 km3 of dominantly felsic magma were emplaced in the northern foreland of the variscan mountains in a terrestrial semi arid environment most of these units were inferred by previous authors to represent the products of explosive volcanic eruptions such as ignimbrites however a detailed analysis of the volcanic texture and lithofacies association shows that most units are best interpreted as coherent lavas emplaced either as extrusive units or as shallow intrusions with important implications for the reconstruction of the paleo environment this study shows that detailed textural examination of drill cores provide important observations which can be applied as criteria for the interpretation of the mode of volcanic eruptions furthermore phenocryst logging and geochemical fingerprinting based on immobile element ratios can be employed for the classification and discrimination of individual emplacement units

burial history reconstruction and thermal maturity modeling for the middle cretaceous early miocene petroleum system southern dezful embayment sw iran abstract the middle cretaceous early miocene petroleum system is the most important hydrocarbon system in the zagros basin rock eval pyrolysis organic petrography and thermal 1d modeling were performed on wells located in the southern dezful embayment the results provide information on organic matter quantity and quality as well as burial and thermal histories of source rocks in the framework of the basin evolution a total of 98 cutting samples from bk 4 kk 1 si 4 and rs 2 wells were pyrolyzed by rock eval 6 also thermal maturity of organic matter derived from tmax of rock eval was interpreted in conjunction with vitrinite reflectance data 50 samples the toc values of the sequences mainly range from 0 5 to 2 5 wt the average values of tmax and vitrinite reflectance indicate that samples from the wells have reached maturities corresponding to early mid oil generation reconstruction of thermal history suggests that various steady heat flow values 62 54 50 and 56 mw m2 for bk 4 kk 1 si 4 and rs 2 wells respectively resulted in the best fit between the calculated and the observed vitrinite reflectance and bottom hole temperatures in our modeling thus values of heat flow decrease from 60 mw m2 in the southern basin margin to about 50 mw m2 along the ne of the dezful embayment and the zagros basin according to our modeling results the onset of oil generation from source rocks in the studied area occurs well after deposition of the seal rock and formation of traps ensuring entrapment and preservation of migrated hydrocarbons

tectonostratigraphy of the nieuwerkerk formation delfland subgroup west netherlands basin the nieuwerkerk formation is a major lower cretaceous synrift and postrift fluvial unit in the west netherlands basin southwest netherlands that attains thicknesses in excess of 1 km in places a strong tectonic overprint on its deposition and a large degree of facies heterogeneity have complicated correlation and greatly hampered understanding reservoir and seal distribution within the unit the integrated application of fluvial sequence stratigraphic concepts with biostratigraphic dating and the correlation of cycles of changing accommodation to sediment supply ratio a s cycles on three dimensional 3 d seismic well log and core data have allowed a much improved understanding of reservoir facies distribution within the nieuwerkerk formation a major intraformational unconformity divides the nieuwerkerk formation into two members the lower of these the alblasserdam member is predominantly nonmarine and has a significant tectonic depositional overprint correlation within this member is dependent on the identification of base level transit cycles probably induced by pulses of tectonism the inclusion of 3 d seismic isopach data facilitates mapping thicknesses and reservoir properties of the alblasserdam member in areas with no well control the upper member the rodenrijs claystone member was deposited during the postrift stage and is predominantly a coastal plain succession biostratigraphic correlation proved useful in subdividing this unit and correlating key seismostratigraphic markers use of biostratigraphic and cyclostratigraphic correlation techniques allowed chronostratigraphically consistent reservoir maps to be made of the constituent members of the nieuwerkerk formation these maps exhibit localized nonmarine syndepositional basins alblasserdam member sand depocenters followed by gradual southward landward stepping of facies tracts of the rodenrijs claystone member above the intraformational unconformity the rodenrijs claystone member is capped by a marine transgression that terminated fluvial deposition in this part of the basin interestingly no major lacustrine facies have been identified in the fluvial units in the west netherlands basin rendering it somewhat anomalous among rift basins

molecular nitrogen in natural gas accumulations generation from sedimentary organic matter at high temperatures the occurrence of natural gas accumulations with high percentages up to 100 of molecular nitrogen in various hydrocarbon provinces represents a largely unresolved problem and a serious exploration risk in this context a geochemical and basin modeling study was performed to evaluate the potential of sedimentary organic matter to generate molecular nitrogen the masses of nitrogen present in coals if converted into molecular nitrogen are sufficient to fill commercial gas reservoirs a calculation for gas accumulations in northern germany where percentages of molecular nitrogen range from less than 5 to greater than 90 reveals that the molecular nitrogen generated in underlying coal bearing strata is sufficient to account for the nitrogen gas even in the largest fi lds in addition much of the total nitrogen in clay rich rock types such as shales and mudstones is fixed in sedimentary organic matter and may add to the nitrogen generation capacity of the coals a kinetic interpretation of the nitrogen and methane generation characteristics of humic coals during laboratory pyrolysis indicates that nitrogen is generated from organic matter in sedimentary basins at higher temperatures than methane minimum temperatures for preferential nitrogen generation are in excess of 300 c for extremely low heating rates or isothermal conditions lasting over 300 m y thus nitrogen rich gases are mainly formed in the final stage of gas generation when sedimentary rocks grade into metamorphic rocks applications of the kinetic parameters for the generation of nitrogen and methane from coaly organic matter in carboniferous sedimentary rocks are presented for part of the northwest german basin in this area immense volumes of the methane rich gas gener ted during the late paleozoic and mesozoic were lost to the atmosphere the present gas composition mainly reflects the latest cenozoic gas generation this cenozoic gas is nitrogen rich where the carboniferous source rock sequences are highly mature and deeply buried

characterization and quantification of active faulting in the roer valley rift system based on high precision digital elevation models the roer valley rift system rvrs is located in the northern prolongation of the upper rhine graben during the cenozoic the evolution of the rvrs was influenced by two different rift systems situated in the north and in the south the north sea rift system and the west european rift system respectively during the last decades moderate seismicity revealed the continuous activity of the graben border faults the peel boundary fault zone pbfz and the feldbiss fault zone ffz we use a high precision digital elevation model dem to characterize and quantify the present day deformation along these faults the fault pattern shows similarity to a strike slip structure however analysis of the dem reveals that the recent to quaternary formations and landforms affected by the fault activity are only vertically offset this suggests a pure normal faulting mode for the main border faults and a direction of extension perpendicular to the graben i e ne sw quantification of the offset dated markers allows the determination of the displacement rates along the fault segments in the southeastern part of the rvrs the vertical displacement rates inferred for the ffz and the southeastern pbfz range between 55 and 65 mm ky and around 65 mm ky respectively in contrast the displacement rates determined for the northwestern segment of the pbfz are around 200 mm ky we explain these differences between the northwestern and southeastern parts of the rvrs by the large scale geometry of the graben the rvrs being symmetric in the south east and asymmetric half graben in the north west the deformation is accommodated by two border faults ffz and the south eastern part of the pbfz in the south east and by only one fault in the north west the north western segment of the pbfz in addition the thickness of the neogene main depocentre in the northwestern half of the rvrs indicates a larger amount of extension in this part of the graben than in the south east the combination of the graben geometry and the amount of extension can explain the differences in the displacement rate