the velocity description of deformation paper 2 sediment geometries associated with fault bend and fault propagation folds abstract a general tectono sedimentary forward modelling equation is used to derive two dimensional numerical models of sediment geometries associated with developing fault bend and fault propagation folds these styles of folding are described in terms of velocity models of deformation and are linked with syn tectonic erosion transport and sedimentation the resultant two dimensional numerical models simulate pre growth and growth strata in both submarine and subaerial settings the geometries and relationships produced by the models are broadly similar to those seen in natural examples however complex stratal geometries may be generated which are significantly different to those produced by previous models growth strata associated with fault bend and fault propagation folds are also compared and the distinguishing features of each mode of folding discussed the forward models presented in this paper have predictive capabilities in terms of possible sediment geometries associated with fault bend and fault propagation folds and also in terms of the amount of deformation or erosion that a part of a structure may have undergone

cocorp profiling across the southern oklahoma aulacogen overthrusting of the wichita mountains and compression within the anadarko basin cocorp consortium for continental reflection profiling deep reflection profiles recorded across the wichita mountains and anadarko basin suggest that significant crustal shortening occurred in the final stages of the evolution of the southern oklahoma aulacogen the crystalline rocks of the wichita mountains were thrust in pennsylvanian time northeastward over sedimentary rocks of the anadarko basin along a series of faults with moderate average 30 to 40 and southwesterly dips these faults can be traced possibly as deep as 20 to 24 km listric thrust faults and hanging wall anticlines developed in the sedimentary rocks of the basin these features contrast with conventional interpretations of pennsylvanian structures as the result of predominantly vertical movements along high angle faults and they suggest that pennsylvanian downwarping of the anadarko basin was at least partially due to thrust loading truncations of reflections from cambrian ordovician rocks in the deepest part of the basin suggest normal faulting which would support ideas of an early extensional stage in the aulacogen cycle the distinctive precambrian layering seen on earlier cocorp data recorded south of the wichita mountains cannot be recognized under the anadarko basin and the proterozoic basin containing that layering may have been bounded on its north side by a precambrian fault this inferred fault was probably twice reactivated during formation of the southern oklahoma aulacogen once during late precambrian early cambrian extension and again during pennsylvanian compression the popular view that aulacogens originated from radial rifting of updomed homogeneous continental crust is probably too simplified and a more important constraint on their location and development may be the nature of pre existing lines of weakness

kinematic models of basement cover interaction insights from the malargue fold and thrust belt mendoza argentina abstract we investigate through natural examples from the malargue fold and thrust belt the manner in which the basement structures interact with the cover in a thick skinned fold and thrust belt our work suggests that there is a broad spectrum of basement cover interaction mechanisms with two end members coupled and uncoupled interactions the kind of bonding between basement and cover is related to the propagation to slip ratio p s because high values of this ratio indicate rapid forward propagation of shortening into the cover while low values favour welding between basement and cover structures we analyse the factors controlling the kinematics of basement cover deformation and find that not only the strength of the cover its thickness and its mechanical anisotropy control the p s and basement cover bonding but also the strain rate the thickness of synorogenic strata and the presence of pre existing faults

strains developed in the hangingwalls of thrusts due to their slip propagation rate a dislocation model reply abstract fault planes propagate radially from a point source and this failure propagation process is very similar to the movement of a dislocation through a crystal lattice an elastic strain represented by an extra half plane is necessarily imparted to the lattice at an edge dislocation and this is equivalent to the ductile bead which accompanies the propagating tip of a thrust fault this ductile bead migrates with the fault tip and imparts a characteristic internal strain to the thrust sheet a two dimensional model is presented to illustrate the inter relationship between fault plane slip fault tip propagation and internal strain in multilayered sequences internal strain is usually represented by asymmetric folds verging in the thrust transport direction a simple technique the displacement distance plot utilizes the fact that displacement dies out towards the fault tip this plot can be used to quantify the relative stretch measured parallel to the fault movement which is dependent on the slip propagation rate and it may be used to define exactly the position of the fault tip on a cross section examples of fold thrust structures from devon england and pembrokeshire wales are used to illustrate the technique

absolute dating of dedolomitization by means of paleomagnetic techniques paleomagnetic analysis in conjunction with petrographic studies is an approach whereby absolute dates can be placed on diagenetic events hematite is associated with dedolomite in the lower ordovician kindblade formation in south central oklahoma and is interpreted as a by product of the dedolomitization of ferroan dolomite paleomagnetic results date the time of dedolomitization as late pennsylvanian early permian dedolomitization was probably caused by oxidizing fluids with high calcium contents that migrated through the kindblade formation following uplift of the arbuckle mountains

probabilistic seismic hazard assessment for eritrea to date little is known about seismic hazard in eritrea despite its location in a volcanically and tectonically active region and the gathering pace of major infrastructure projects in response we report the findings of a comprehensive probabilistic seismic hazard assessment for eritrea and adjacent areas seismic source and ground motion models are constructed separately we use an adaptive spatiotemporal smoothing method to map expected patterns of seismicity to construct a consistent earthquake catalog from different data sets we use orthogonal regression to convert and unify different magnitude scales a sensitivity analysis of the different input parameters helps constrain them and disaggregation of site specific hazard estimates yields insights into the relative contribution from seismic sources of different magnitudes and distances the results highlight seismic hazard in proximity to the red sea gulf of aden afar depression and along the boundaries of the danakil microplate we estimate a 10 chance over 50 years of observing pseudospectral accelerations psas at 0 2 s exceeding 0 16g in the port city of massawa population 32 000 and the town of bada population 4000 for the capital asmara population 520 000 we calculate a psa of 0 11g at 0 2 s compared with previous studies our results provide greater spatial resolution use more recent ground motion models and benefit from a smoothed seismicity method our aims are to stimulate further studies and contribute to the safe development of the region in light of its exposure to seismic hazards

local seismic hazard assessment in areas of weak to moderate seismicity case study from eastern germany abstract generally the seismic hazard of an area of interest is considered independent of time however its seismic risk or vulnerability respectively increases with the population and developing state of economy of the area therefore many areas of moderate seismic hazard gain increasing importance with respect to seismic hazard and risk analysis however these areas mostly have a weak earthquake database i e they are characterised by relative low seismicity and uncertain information concerning historical earthquakes in a case study for eastern thuringia germany acting as example for similar places in the world seismic hazard is estimated using the probabilistic approach because of the lack of earthquakes occurring in the recent past mainly historical earthquakes have to be used but for these the actual earthquake sources or active faults needed for the analysis are imprecisely known therefore the earthquake locations are represented by areal sources a common practice the definition of these sources is performed carefully because their geometrical shape and size apart from the earthquake occurrence model influence the results significantly using analysis tools such as density maps of earthquake epicentres seismic strain and energy release support this oversizing of areal sources leads to underestimation of seismic hazard and should therefore be avoided large location errors of historical earthquakes on the other hand are represented by several alternative areal sources with final superimposition of the different results in a very similar way information known from macroseismic observations interpreted as source rather than as site effects are taken into account in order to achieve a seismic hazard assessment as realistic as possible in very local cases the meaning of source effects exceeds those of site effects very likely the influence of attenuation parameter variations on the result of estimated local seismic hazard is relatively low generally the results obtained by the seismic hazard assessment coincide well with macroseismic observations from the thoroughly investigated largest earthquake in the region

the velocity description of deformation paper 1 theory abstract there are several advantages in using velocities to describe the deformation of the crust and lithosphere induced by extension compression isostasy and other processes 1 the method is very general any deformation style can be described in this way simple examples are pure shear inclined or vertical simple shear bulk rotation airy or flexural isostasy and compaction 2 velocity fields can be combined to model more complex deformation 3 the syn tectonic evolution of parameters such as temperature pressure hydrocarbon maturity and porosity are easily modelled once the deformation velocities are specified 4 the syn tectonic evolution of sedimentary architectures can be modelled using a general tectono sedimentary forward modelling equation which incorporates the deformation velocities these advantages are illustrated by a computer model which simulates clastic sediments prograding into an active half graben formed by extension above a listric fault processes included in this model are compaction of the sediments hanging wall deformation by inclined simple shear and simultaneous footwall deformation to avoid space problems the velocity field for the hanging wall block above the non rigid footwall must obey a simple contact condition

seismological hazard assessment for a site in northern germany an area of low seismicity abstract potential sites of nuclear waste deposits in the federal republic of germany are situated in areas of low seismicity nevertheless seismic hazard assessment has to be performed for a very long time period in order to prove the facilities of the repositories able to withstand seismic induced loads even though there is a considerable debate whether or not it is possible to quantify the seismic risk in such an area a combination of deterministic and probabilistic methods is used to assess the seismic hazard for a site in northern germany fulfilling the standards of the german building code for nuclear power plants as an example the site of the former iron ore mine konrad is investigated the deterministic method is based on the assumption that the strongest earthquakes inside a tectonic region can happen everywhere there also near the selected site for the probabilistic method several models describing the seismicity in an area of 200 km around the site are used to show the influence of the variability in input parameters like the maximum intensity of each source region on the exceeding probability of the site intensity it can be shown that the seismic hazard of a site in an area of low seismicity is mainly caused by the effects of distant but strong source regions and the background seismicity for very low probabilities probabilistic evaluation has the advantage of quantifying the seismic risk but deterministic and probabilistic methods together seem a practical tool for mutual control of the results and to overcome the weakness of each approach alone the historical german earthquake catalog with an observation period of about 1200 years is the basis for the input data for a probabilistic model from a deep knowledge of geological development and structural geology the time history of the surrounding faults is developed indications were found that the nearest and most important fault was active at least 5 ma ago the combination of both seismicity and tectonics provides the basis for a long term prognostic with probabilities of exceedance in the order of 10 5 per year for the investigated site the following parameters were derived site intensity as a function of exceeding probability site acceleration strong motion duration site dependent response spectra for the surface and the underground inside the mine

evidence for a relationship between hydrocarbons and authigenic magnetite establishing a relationship between hydrocarbon migration and the precipitation of authigenic magnetite in sedimentary rocks is of significant interest with respect to 1 elucidating mechanisms for remagnetization and establishing the origin of secondary magnetizations residing in magnetite 2 developing a method to date hydrocarbon migration events by determining the time of remanence acquisition by palaeomagnetic methods and 3 evaluating whether searching for anomalous concentrations of diagenetic magnetic minerals and or aeromagnetic anomalies is justified as a relatively inexpensive exploration tool the direct association of hydrocarbon migration and the precipitation of authigenic magnetite has however not been established in this paper we report palaeomagnetic rock magnetic petrographic and geochemical results of a study of samples from permian spelebthems and gilsonite found in the ordovician arbuckle group in southern oklahoma the results indicate that there is a genetic relationship between hydrocarbon migration and the precipitation of authigenic magnetite

a velocity description of constant thickness fault propagation folding abstract the expression of the geometric model of constant thickness fault propagation folding as a velocity description of deformation allows the derivation of rates of displacement uplift and fault propagation the velocity model of fault propagation folding and sedimentation are combined in a finite difference scheme and two examples of growth strata associated with overturned fold forelimbs illustrate the application of the model

statistical significance of the fold test in palaeomagnetism summary the significance of the change in direction dispersion on applying the fold test in palaeomagnetism is used as the criterion for deciding whether or not the fold test has statistical significance a set of tables is compiled which can be used for quick application of the test

assessing uncertainties in balanced cross sections abstract balanced structural cross sections are models that are fit to incomplete data the models are under constrained with respect to any particular two dimensional line length model but enough data generally exists to yield a well constrained area balance solution furthermore the area balance encompasses all possible line length solutions therefore where the primary objective of section balancing is the determination of horizontal shortening magnitude area balancing provides an analytical solution we use this analytical solution to develop a comprehensive robust analysis of the uncertainty in shortening estimates resulting from cross section balancing the analytical solution allows us to propagate errors formally on the input parameters stratigraphic thicknesses depth to decollement eroded hanging wall cutoffs through the equations and produce the resulting uncertainty on the magnitude of shortening balanced cross sections from the subandean belt of the central andes are used to demonstrate the relative importance of stratigraphy and eroded hanging wall cutoffs in the contribution to the overall error

uplift rates of marine terraces as a constraint on fault propagation fold kinematics examples from the hawkswood and kate anticlines north canterbury new zealand abstract marine terraces on growing fault propagation folds provide valuable insight into the relationship between fold kinematics and uplift rates providing a means to distinguish among otherwise non unique kinematic model solutions here we investigate this relationship at two locations in north canterbury new zealand the kate anticline and haumuri bluff at the northern end of the hawkswood anticline at both locations we calculate uplift rates of previously dated marine terraces using dgps surveys to estimate terrace inner edge elevations we then use markov chain monte carlo methods to fit fault propagation fold kinematic models to structural geologic data and we incorporate marine terrace uplift into the models as an additional constraint at haumuri bluff we find that marine terraces when restored to originally horizontal surfaces can help to eliminate certain trishear models that would fit the geologic data alone at kate anticline we compare uplift rates at different structural positions and find that the spatial pattern of uplift rates is more consistent with trishear than with a parallel fault propagation fold kink band model finally we use our model results to compute new estimates for fault slip rates 1 2 m ka at kate anticline and 1 4 m ka at haumuri bluff and ages of the folds 1 ma which are consistent with previous estimates for the onset of folding in this region these results are consistent with previous work on the age of onset of folding in this region provide revised estimates of fault slip rates necessary to understand the seismic hazard posed by these faults and demonstrate the value of incorporating marine terraces in inverse fold kinematic models as a means to distinguish among non unique solutions

tectonic rotations within the rio grande rift evidence from paleomagnetic studies paleomagnetic studies on miocene pliocene volcanic rocks from the espanola basin of the rio grande rift new mexico reveal directions discordant from the expected mean direction for north america the paliza canyon formation tschicoma formation and lobato basalt all sampled in the jemez mountains west of the pajarito fault zone have mean declinations east of the expected mean the cerros del rio volcanics lying east of the pajarito fault zone have a westerly declination combined with published data on the santa fe group sediments east of the fault zone and the valles rhyolite west of the fault zone distinct rotations of the two areas are evident the western block has rotated clockwise 12 while the eastern block shows 16 of counter clockwise motion differential rotations of 25 30 are calculated between the two blocks 4 m y is the minimum differential rotation for the past 5 m y geologic explanations for these rotations include the opening of the rio grande rift in response to clockwise rotation of the colorado plateau and significant left slip along the rio grande rift

sycamore knoll a wave planed pop up structure in a sinistral oblique thrust system southern california continental borderland at the boundary between the western transverse ranges province and inner continental borderland of southern california strain is partitioned across the sinistral oblique anacapa dume fault system sycamore knoll a pop up structure 20 km west of point dume in the hanging wall of the north dipping anacapa dume fault stands out as an anomalous bathymetric high along the southern california coast we synthesize new and existing geophysical datasets including multibeam bathymetry backscatter and single multichannel seismic to understand the morphology and tectonic implications of sycamore knoll we identify a complete eustatic low stand submerged marine terrace package encircling sycamore knoll platform that corresponds to the last glacial maximum lgm the marine terrace deposits and wave planed surface of sycamore knoll require a late quaternary uplift rate of 0 55 0 5 0 3 mm yr relative to sea level by combining our uplift rate with previous estimates of basin subsidence and a revised structural model of the anacapa dume fault we determine a maximum slip rate in latest quaternary time of 1 50 0 5 0 3 mm yr and hence a post lgm rate of convergence across the anacapa dume fault of 0 60 0 2 0 1 mm yr

growth stratal records of instantaneous and progressive limb rotation in the precordillera thrust belt and bermejo basin argentina analysis of synorogenic deposits preserved near the thrust front zone of the precordillera fold and thrust belt and in the bermejo foreland basin in central argentina documents the evolution of deformation during the last 5 myr as well as the thrust system kinematics seismic lines across the area display examples of progressive and instantaneous limb rotations the easternmost thrust plate of the central precordillera the niquivil thrust experienced episodic motion in two main stages a first thrust movement as a fault propagation fold and a second movement as a high angle anticlinal breakthrough fault after a period of quiescence growth strata deposited in the la pareja intermontane basin and the las salinas and bermejo anticline recorded continuous growth of eastern precordilleran structures beginning at 2 7 ma with uplift rates of 0 3 mm yr for the niquivil anticline 1 08 mm yr for the las salinas anticline and between 0 6 and 0 38 mm yr during the last 2 myr for the bermejo anticline once the eastern precordillera began to grow the propagation of the niquivil thrust stopped restricting the deformation to the young vallecito out of sequence thrust the complex geometry of growth strata deposited on the back limb of the las salinas anticline can be explained by using a model of a two step fault propagation fold with constant layer thickness the bermejo anticline of the eastern precordillera is formed by the simultaneous propagation of a shallow fault responsible for the fold shape and a deep fault that produced vertical uplift a growth triangle that documents instantaneous forelimb rotation for a fault propagation fold is recorded for the first time in a published seismic line

the occurrence and origin of late paleozoic remagnetization in the sedimentary rocks of north america although it has been known for 25 years that some paleozoic sedimentary rock units in europe and north america were remagnetized during pennsylvanian or permian time it is only very recently that the complex and widespread nature of the late paleozoic remagnetization phenomenon has been generally acknowledged it is now recognized that many paleozoic paleomagnetic poles for north america that were once considered reliable are in fact the result of remagnetization and as a consequence the paleomagnetic data base for the paleozoic is undergoing rapid and drastic revision the causes of late paleozoic remagnetization in north america are currently the focus of much interest and active research the remagnetization can reside in either hematite or magnetite and different remagnetization mechanisms have been important in different settings chemical remagnetization processes some related to specific diagenetic events are dominant in hematite bearing sandstones and carbonates in magnetite bearing carbonates both chemical and thermoviscous remagnetization processes appear to have been important but it is difficult to determine which process is the dominant one in some settings some of the observed remagnetizations can be linked to the migration of chemically active and perhaps hot fluids during the mountain building events that affected much of the continent during the late paleozoic paleomagnetic studies promise to be important in assessing the role of orogeny in driving fluid migrations within sedimentary basins and in constraining the age of the migrations and the nature of the fluids

remanence in authigenic magnetite testing the hydrocarbon magnetite hypothesis paleomagnetic rock magnetic petrographic and geochemical studies of hydrocarbon saturated speleothems in southern oklahoma indicate there is a relation between hydrocarbons and a chemical magnetization that resides in magnetite the speleothems which are composed of light and dark calcite bands occur in caves of karst origin in the ordovician kindblade formation vertebrate fossils interbedded with the deposits indicate they are permian in age the dark bands contain primary hydrocarbon filled fluid inclusions the dark calcites possess over an order of magnitude stronger natural remanent magnetization than the lighter bands which do not yield stable decay during demagnetization alternating field af and thermal demagnetization of specimens of the dark bands reveal a permian direction of magnetization declination 160 inclination 3 k 17 95 5 n 56 the results of rock magnetic experiments and the fact that most maximum unblocking temperatures are below 580 c suggest that the dominant component resides in magnetite in some specimens stable decay to 640 c suggests the presence of a weak component residing in hematite the presence of authigenic magnetite spheres in magnetic extracts of the dark calcites supports a chemical origin for the magnetization shallow burial depths probably eliminate the possibility of a thermoviscous magnetization the occurrence of primary hydrocarbon inclusions suggests that hydrocarbons seeped into the caves during precipitation of the speleothems and were trapped in the calcite crystals the relationship between intensity of magnetization and hydrocarbon abundance leads us to propose that chemical conditions created by the hydrocarbons caused precipitation of authigenic magnetite and acquisition of the associated chemical remanence

paleomagnetic dating of liesegang bands abstract paleomagnetic analysis in conjunction with petrographic studies is used in this study to date the formation of hematite liesegang bands in the ordovician upper arbuckle group in southern oklahoma the hematite bands form symmetrical patterns on both sides of calcite filled fractures in dolomitic beds the bands decrease in abundance and become more diffuse away from the fractures paleomagnetic specimens from distinctly banded dolomite near the fractures contain a relatively strong chemical remanent magnetization crm with a southeasterly declination and shallow inclination samples farther from the fractures which are less distinctively banded or have no bands contain a weaker and less stable magnetization samples were collected from both flanks of the arbuckle anticline late pennsylvanian folding and a fold test indicates that the crm is postfolding the pole position for the crm corresponds to the permian 280 ma part of the apparent polar wander path for stable north america petrographic evidence stable demagnetization to above 600 c and rock magnetic experiments indicate that the crm resides i hematite these results suggest that the liesegang bands formed in the early permian probably by precipitation of hematite from fluids that emanated from the fractures the fluids also apparently caused dedolomitization and precipitation of calcite in intercrystalline pore spaces probable sources of the iron in the bands include these fluids as well as iron released from dedolomitization and from oxidation of pyrite

inverse modeling for possible rather than unique solutions abstract despite the implementation of several kinematic and mechanical models for fault related folding and the incorporation of structural uncertainty in geological models structural modeling is still too deterministic the current focus is on forward modeling of a unique fit we show the application of trishear inverse modeling global optimization and markov chain monte carlo mcmc methods to a clay model of basement involved compressional faulting from which we know both total and incremental deformation global optimization and mcmc methods provide a range of possible models rather than a unique fit total inversions give an average of the model s deformation while incremental inversions are more physically related to the model s evolution global optimization identifies the full range of possible models while mcmc characterizes expected parameter values and their uncertainties structural inversions without sound geology are meaningless a robust stratigraphy geomorphic markers mesoscopic structures analogue and mechanical modeling can all greatly improve the inversions

escarpment evolution on high elevation rifted margins insights derived from a surface processes model that combines diffusion advection and reaction experiments with a surface processes model of large scale 1 1000 km long term 1 100 m y erosional denudation are used to establish the controls on the evolution of a model escarpment that is related to the rifting of a continent the model describes changes in topographic form as a result of simultaneous short and long range mass transport representing hillslope diffusive processes and fluvial transport advection respectively fluvial entrainment is modeled as a first order kinetic reaction which reflects the credibility of the substrate and therefore the fluvial system is not necessarily carrying at capacity one dimensional and planform models demonstrate that the principal controls on the evolution of an initially steep model escarpment are 1 antecedent topography drainage 2 the timescale or equivalently a length scale in the fluvial entrainment reaction 3 the flexural response of the lithosphere to denudation and 4 the relative efficiencies of the short and long range transport processes when rainfall and substrate lithology are uniform a significant amount of discharge draining over the escarpment top causes it to degrade only when the top of the model escarpment coincides with a drainage divide can escarpment retreat occur for these conditions an additional requirement for retreat of a model escarpment without decline is a long reaction time scale for fluvial entrainment this corresponds to a substrate that is hard to detach by fluvial erosion and therefore to fluvial erosion that is not transport limited continuous backtilting of an escarpment due to flexural isostatic uplift in response to denudational unloading helps maintain the scarp top as a divide it is essential if the escarpment gradient is to be preserved during retreat in a uniform lithology low flexural rigidities promote steep and slowly retreating escarpments for given rainfall and substrate conditions the morphology of a retreating model escarpment is determined by the ratio of the short range diffusive and long range advective transport efficiencies a low ratio which is interpreted to correspond to a relatively arid climate and weathering limited conditions promotes steep sharp topped escarpments with straight main slopes and escarpment retreat occurs over a wide range of height scales a high ratio interpreted to correspond to a more humid temperate climate produces a convex upper slope and concave lower slope morphology and only major escarpments are predicted to preserve a high scarp gradient lithological contrasts in the model produce more complex morphologies and predict the formation of scarps crowned by an erosionally resistant caprock however resistant caprocks are not an essential requirement for model scarps to retreat we conclude that the inferred controls and model behavior are both consistent with the present day morphology of rifted continental margins and with modern conceptual models of landscape evolution

fault mechanics and the kinematics of block rotations in many strike slip tectonic settings large rotations up to 100 of crustal blocks have been inferred from paleomagnetic data these blocks are bounded by sets of parallel faults which accommodate the relative motion between the blocks as regional deformation progresses simple geometrical considerations require that the faults must also rotate in this paper we show that on the basis of mechanical considerations the amount of fault rotation permissible under a stationary stress field is limited to 20 to 45 consequently block rotations that are larger than 40 or 45 require more than one set of accompanying faults to accommodate the block rotation examples of such multiple sets with 40 to 45 between them as predicted by the model were recognized in sistan iran in yerington the lake mead area nevada and in southern california

paleomagnetism of the cambro ordovician arbuckle group and associated deposits in the southern oklahoma aulacogen evidence for block rotations the magnetization in hydrocarbon impregnated arbuckle group limestones from the southern margin of the southern oklahoma aulacogen limestone hills is secondary and resides in magnetite the magnetization declination inclination 128 2 95 7 6 k 79 fails a fold test and is post pennsylvanian the corresponding pole position 146 e 30 n however does not coincide with the post pennsylvanian apparent polar wander path apwp some permian speleothems that fill caves in these rocks contain magnetizations that are also anomalous shallow remanent inclinations from the folded limestones and speleothems suggest that the most likely time of remanence acquisition was the permian the directions are at least 30 in declination from the expected directions based on the inferred ages of the magnetizations this discrepancy can be explained by a horizontal counterclockwise rotation consistent with left lateral wrench faulting during deformation of the aulacogen