granitoid diapirism during protracted tectonism in an archaean granitoid greenstone belt yilgarn block western australia abstract the bullfinch parker dome area is an archaean granitoid greenstone terrain in the yilgarn block of western australia affected by a complex protracted tectonic event the majority of the deformation history was progressive rather than multiple discrete events finite strain patterns and structural and metamorphic zonation suggest that deformation in the greenstones was caused by regional ene wsw shortening and broadly simultaneous upward movement of granitoids by solid state diapirism and or ballooning plutonism rather than by core complex formation or multiple folding evidence for pluton related tectonism includes the foliation trends steeply plunging radial mineral lineations indications of upward movement of plutons increase of strain towards the batholith margins concordant structures in the pluton and the surrounding rocks such as lineation and foliation patterns constrictional tectonics near east west trending granitoid greenstone contacts syn to post kinematic peak metamorphism contact metamorphic zoning and pressure differences metamorphism largely of amphibolite facies was probably related to uprise of the granitoids at moderate crustal depths 10 12 km p 3 kbar causing both regional and contact metamorphism as a single thermal event relative and absolute timing defines an overlapping sequence of metamorphism progressive deformation and plutonism in this part of the yilgarn craton during the late archaean

experimental observations of tsunami induced scour at onshore structures tsunami inundation of the coastal environment can induce scour at structure foundations leading to failure a series of experiments are made using a unique pneumatic long wave generator to generate tsunami wave periods of 25 147 s equating to 3 17 3 min at 1 50 froude scale the waves propagate over a sloping bathymetry and impinge upon a square structure founded onshore in a flat sediment bed flow velocity height and scour depth are recorded as a function of time during tsunami inundation the rate of scour is observed to be time dependent equilibrium which is not attained is argued to be an inappropriate measure for time dependent transient flows such as tsunami in which the flow velocity depth and direction are variable the maximum scour depth is recorded and critically is observed not to be equal to the final depth due to significant sediment slumping when flow velocities reduce in the latter stages of inundation current and wave scour predictor equations over predict the scour while the asce 7 16 method under predicts comparisons with available data in the literature show longer inundation durations increase the amount of scour

metamorphic and structural setting of archaean amphibolitehosted gold deposits near southern cross southern cross province yilgarn block western australia abstract the southern cross archaean greenstone belt comprises dominantly low to mid amphibolite facies high strain domains which show evidence of a complex deformational and metamorphic history aeromagnetic field and petrographic data suggest that this complex structural metamorphic history was related to a single progressive deformation event which was broadly synchronous with granitoid emplacement between 2 68 and 2 62 ga lode gold deposits at corinthia hopes hill fraser s and polaris south occur in sequence from north to south along the fraser s corinthia shear zone in the southern cross greenstone belt corinthia and hopes hill are situated along a sheared granitoid greenstone contact whereas fraser s and polaris south occur within the greenstones about 200 m west of the contact gold mineralisation along the fraser s corinthia shear zone is associated predominantly with variably deformed quartz pyrrhotite pyrite plagioclase and or pyroxene calcite quartz plagioclase apatite veins with zoned alteration haloes of quartz plagioclase pyroxene calcite apatite and amphibole biotite chlorite there are accessory amounts of scheelite chalcopyrite arsenopyrite and galena with the fe sulphides bismuth and gold a variety of evidence including structural timing p t conditions deduced from critical metamorphic 550 c 2 5 3 7 kbars and metasomatic alteration assemblages 520 c 3 4 kbars the high thermodynamic variance of the metasomatic mineral assemblages and the zoning of individual alteration minerals indicates that gold related wallrock alteration occurred during or immediately after peak metamorphism there is some evidence for a sympathetic decline in metamorphic grade and the temperature of gold related alteration from south polaris south to north corinthia along the mineralised shear zone the shear zone acted as a major conduit for ore fluids at a depth of about 12 14 km 3 3 5 kbars lithostatic pressure in the crust gold mineralisation along the shear zone is related to large and small scale extensional crenulation cleavages the gold deposits might thus represent a relatively deep section of the crustal continuum of lode gold deposits proposed for the yilgarn block

significance of composite lineations in the mid to deep crust a case study from the north cascades washington abstract the origin of broadly orogen parallel nw se mineral lineations in cretaceous and paleogene arc plutons and amphibolite facies metamorphic rocks paleodepths of

granites built by sheeting in a fault stepover the sanabria massifs variscan orogen nw spain the sanabria region central iberian zone variscan belt of spain shows an asymmetric thermal dome marked by migmatites accompanied by the ribadelago and the sotillo plutons these small plutons display pronounced mineralogical variations biotite granodiorites and tonalites prevail and granites and gabbros are common both plutons are confined in the releasing stepover of a transpressional shear zone that strikes 120 e and dips 70 sw most of the igneous rocks form sheets parallel to the shear zone magnetic foliations and lineations in the igneous rocks are parallel respectively to the shear bands and stretching lineations observed in the shear zone the formation of these igneous sheets at high angle to the main axis of the regional field stress is explained by a combination of the fault valve behaviour of the shear zone with the power of melt overpressure to open and ascend through previously formed planar structures like s or c planes

deformation partitioning and porphyroblast rotation in meta morphic rocks a radical reinterpretation abstract most porphyroblasts never rotate during ductile deformation provided they do not intern ally deform during subsequent events with the exception of relatively uncommon but spectacular examples of spiralling garnets instead the sur rounding foliation rotates and reactivates due to partitioning of the deformation around the porphyroblast consequently porphyroblasts commonly preserve the orientation of early foliations and stretching lineations within strain shadows or inclusion trails even where these structures have been rotated or obliterated in the matrix due to subsequent deformation these relationships can be readily used to help develop an understanding of the processes of foliation development and they demonstrate the prominent role of reactivation of old foliations during subse quent deformation they can also be used to determine the deformation history as porphyro blasts only rotate when the deformation cannot partition and involves progressive shearing with no combined bulk shortening component

the role of ductility contrast and basement architecture in the structural evolution of the crystal creek block mount isa inlier nw queensland australia abstract the leichhardt river fault trough of the mount isa inlier comprises fault blocks which exhibit different local deformational histories and structural orientations many structural patterns in the stratigraphically highest cover sequences do not occur in adjacent fault blocks that expose older and mechanically stronger rocks within the mount isa group sediments of the crystal creek block for example tight e trending upright folds appear to be at odds with the surrounding north south regional trends in this paper it is proposed that an inherited extensional fault geometry played a significant role in controlling the structural patterns developed during later shortening through the integration of detailed surface mapping and forward magnetic modelling an inverted half graben was identified beneath the crystal creek block exposing the underlying origin of local structural complexities structural inversion and buttressing against pre existing faults simultaneously removed extensional displacement across pre rift rocks and induced folds and faults in overlying sag phase sediments this led to the development of two structural levels characterized by different deformational styles and apparently distinct deformational histories

deformation and metamorphism in the bard area of the sesia lanzo zone western alps during subduction and uplift the structure microstructure and petrology of a small area close to the village of bard in val d aosta italy has been studied in detail the area lies across the contact between the gneiss minuti gm and the eclogitic micaschist ems complexes of the lower element of the sesia portion of the sesia lanzo zone western alps both complexes have undergone high pressure metamorphism but the metamorphic assemblages indicate a sudden increase in pressure in going across the contact from the gm to the ems therefore we interpret the contact as a thrust dividing the lower element of the sesia into two sub elements this interpretation is supported by structural evidence the early alpine 90 70 ma metamorphic history is best preserved in the ems and is one of increasing pressure associated with thrusting the maximum p t recorded in the ems is 1500 mpa 15kbar and 550 c and in the gm is 1500 1300 mpa 15 13 kbar and 500 550 c we suggest that the rocks were probably in an active benioff zone during this time from then on the histories of the gm and ems are the same deformation continued and the thrust and thrust slices were folded during decreasing pressure we interpret the first postthrusting deformation in terms of uplift associated with continued shortening of the crust and underplating after the benioff zone had become inactive and a new benioff zone had developed further to the north west a still later deformation and the lepontine metamorphism 38 ma are related to continued uplift much of this deformation is characterized by structures indicative of vertical shortening and lateral spreading as the mountains rose above the general level of the surface

full scale cfd simulation of tsunamis part 1 model validation and run up abstract this paper presents numerical simulations of the propagation shoaling and run up of full scale tsunami waves the simulations are performed with a model solving reynolds averaged navier stokes equations with k turbulence closure and is one of very few studies involving cfd simulations at full tsunami scale involving full resolution of small scale dispersive effects as well as wave breaking it is demonstrated that a combination of previous analytical and empirical expressions for run up heights and inundation speeds match those simulated well this indicates that these are reasonable first approximation even in cases where the underlying assumption of linearity of the incoming tsunami is violated as well as in cases where breaking occurs though they generally slightly underestimate both run up height and inundation speed it is shown that the run up of tsunamis can manifest in different ways depending on the initial wave shape and slope of the coast and three qualitative run up types previously identified in the literature are described in detail it is further shown that the shorter waves of an undular bore which appear during lengthy propagation in shallow water can either maintain their shape the entire distance to shore or break far offshore creating a breaking bore it is demonstrated the front of the breaking bore will not appear as steep for n waves as single waves because these need to re wet the drawn down region before reaching the original shoreline finally the importance of shorter waves riding on the front of the tsunami is discussed it is shown that they have little impact on the run up height and inundation speed but are important in terms of local flow velocities the results presented here are part 1 of a larger study where part 2 involves details of the tsunami induced boundary layer dynamics bed shear stresses and implication for sediment transport

the development of a single cleavage in an area of repeated folding abstract structural investigations in the variscan fold interference pattern of sw sardinia italy document an intriguing example of the relationship between cleavage folding and finite strain although palaeozoic sediments were affected by two major folding events both under identical low grade metamorphic conditions only a single penetrative cleavage formed which is not unambiguously correlated with either of these events cleavage orientation changes smoothly along sigmoidally curving trajectories throughout the interference pattern thus the same cleavage can be axial planar to either the first or the second phase folds or transect both when curving from one set into the other the singularity of the cleavage is supported by microscopic studies which show no evidence of a pre existing or overprinting tectonic cleavage finite strain determinations and numerous field observations demonstrate that cleavage always parallels the principal plane of finite strain even though local strain varies according to the relative position in the fold interference pattern similar strain patterns were achieved by forward modelling of superposed buckle folds based on our findings we propose i that the finite strain pattern is due to the superposition of the heterogeneous strain fields associated with the individual folding events and ii that cleavage reflects the cumulative deformations that effected the rock this has consequences for the regional interpretation of cleavage in our study area and elsewhere and for the distinction between deformation phases in general

extensional flow produces recumbent folds in syn orogenic granitoids padron migmatitic dome nw iberian massif this contribution provides a case example on the generation of large scale recumbent folds in syn orogenic granitoids we analyze the progressive reworking of extension related structures into later ones after a period of crustal thickening the padron migmatitic dome formed after the climax of the gondwana laurussia collision in the late paleozoic petrostructural analysis carried out in the eastern flank of this dome reveals that extensional flow resulted in progressive exhumation of mainland gondwana which rested under peri gondwanan allochthonous terranes and a suture zone during maximum crustal thickening exhumation proceeded up to upper crust levels andalusite stability field along with partial melting of the middle lower crust and with the generation of granitoid laccoliths during an early extensional stage newly formed lithological and mechanical anisotropies such as the presence of variably sized sheet shaped bodies of syn orogenic granitoids provided a favorable rheological setting for fold nucleation during the intermediate stages of extension in extending orogenic crust whether recumbent folds occur after significant melt production depends on the lateral vertical flow ratio and on the orientation of deforming bodies with regard to kinematic strain axes we suggest that subhorizontal extensional flow dominated over vertical flow during the early and intermediate stages of the evolution of the padron dome a component of vertical diapiric flow caused progressive tilting of the sheet like bodies and obliquity respect to strain axes this resulted in the development of regional scale folds at the expense of syn orogenic granitoids such as in the case of the portomouro recumbent synform extensional ductile flow was oblique to the trend of the orogen during the whole process and directed to the nnw during the formation of recumbent folds non coaxial shearing favored an nnw sse elongate shape for the syn kinematic granitic massifs as well as the subsequent nucleation of recumbent folds deformation concentrated along discrete detachments during the late stages of extension

steady streaming and sediment transport at the bottom of sea waves the flow and sediment transport in the boundary layer at the sea bottom due to the passage of surface waves are determined by considering small values of the wave steepness and of the ratio between the thickness of the boundary layer and the local water depth both the velocity field and the sediment transport rate are determined up to the second order of approximation thus evaluating both the steady streaming and the net wave averaged flux of sediment induced by nonlinear effects the flow regime is assumed to be turbulent and a two equation turbulence model is used to close the problem the bed load is evaluated by means of an empirical relationship as function of the bed shear stress the suspended load is determined by computing the sediment flux once the sediment concentration is determined by solving an appropriate advection diffusion equation the decay of the wave amplitude which is due to the energy dissipation taking place in the boundary layer is taken into account the steady streaming and the sediment transport rate at the bottom of sea waves turn out to be different from those which are observed in a wave tunnel u tube because of the dependence on the streamwise coordinate of the former flow in particular in the range of the parameters presently investigated the sediment transport rate at the bottom of sea waves is found to be always onshore directed while in a water tunnel u tube the sediment transport rate can be onshore or offshore directed

kinematic and metamorphic aspects of cleavage formation in very low grade metamorphic slates abstract fabric studies on first cleavages in very low grade metamorphic slates from the rheinisches schiefergebirge and other very low grade metamorphic fold belts reveal two types of slaty cleavage 1 1 cleavage without syntectonic phyllosilicate recrystallization these are generally crenulation cleavages 2 2 cleavage with syntectonic phyllosilicate recrystallization with increasing syntectonic metamorphism the crenulation fabric is modified by solution of grains along cleavage planes and precipitation of material within the cleavage lamellae with further increase of metamorphism the crenulation fabric is gradually obliterated the finite fabric results from progressive solution crystallization and recrystallization superimposed with bending kinking and internal rotation achieved by slip parallel to the basal planes of phyllosilicates

structural boundaries and biotite and garnet isograds in the otago and alpine schists new zealand the otago and alpine schist belts of southern new zealand have traditionally been treated as structurally continuous metamorphic belts with minor modification by brittle faulting mapping of biotite and garnet isograds has been hindered by rock types unfavourable for index mineral growth closer examination of well exposed boundaries between metamorphic zones shows that they juxtapose rocks of different type and structural history apparent structural continuity across these zones is due to development of a locally pervasive boundary parallel foliation on both sides of the boundary in a broad boundary zone up to 2 km wide this feature has implications for mapping and metamorphic petrology in other metamorphic belts where structural continuity has traditionally been assumed true metamorphic isograds may be rare and metamorphic zones may more commonly represent structural slices of complex tectonically disrupted metamorphic piles

on the runup of long waves on a plane beach 1 using the records of free surface fluctuations at several locations during the 2011 japan tohoku tsunami we first show that the leading tsunami waves in both near field and far field regions are small amplitude long waves these leading waves are very different from solitary waves we then focus on investigating the evolution and runup of non breaking long waves on a plane beach which is connected to a constant depth region for this purpose we develop a lagrangian numerical model to solve the nonlinear shallow water equations the lagrangian approach tracks the moving shoreline directly without invoking any additional approximation we also adopt and extend the analytical solutions by synolakis 1987 and madsen and schaffer 2010 for runup and rundown of cnoidal waves and a train of multiple solitary waves the analytical solutions for cnoidal waves compare well with the existing experimental data and the direct numerical results when wave amplitudes are small however large discrepancies appear when the incident amplitudes are finite we also examine the relationship between the maximum runup height and the leading wave form it is concluded that for a single wave the accelerating phase of the incident wave controls the maximum runup height finally using the analytical solutions for the approximated wave forms of the leading tsunamis recorded at iwate south station from the 2011 tohoku japan tsunami we estimate the runup height

the coolgardie goldfied western australia district scale controls on an archaean gold camp in an amphibolite facies terrane archaean lode gold deposits in the coolgardie goldfield western australia occur in mafic and ultramafic rocks which have been metamorphosed to the amphibolite facies mineralisation was broadly synchronous with peak metamorphism the main phase of granitoid emplacement and regional deformation several different structural styles are represented by the deposits of the coolgardie goldfield mineralisation occurs along sheared felsic porphyry ultramafic rock contacts in gabbro hosted quartz vein sets in fault bounded quartzvein sets and in laminated quartz reefs sited in brittleductile shear zones the structures hosting mineralisation formed in response to a progressive deformation event related to granitoid emplacement in an east west compressional far field stress regime but with local heterogeneous stress orientations this occurred after an earlier period of thrust stacking with probable north south directed tectonic transport two contrasting styles of goldrelated wallrock alteration are associated with the auriferous lodes of the coolgardie goldfield a high temperature assemblage formation temperature 500 c characterised by the proximal alteration assemblage garnet hornblende plagioclase pyrrhotite contrasts with a medium temperature assemblage formation temperature 500 c consisting of calcic amphibole biotite plagioclase calcite arsenopyrite pyrrhotite the distribution of the two styles of gold related alteration is controlled by distance from voluminous syntectonic granitoids located to the west of the coolgardie goldfield with the high temperature style of alteration more proximal to the granitoid greenstone contact than the medium temperature style the occurrence of gold deposits that formed under amphibolite facies conditions throughout the coolgardie goldfield supports a crustal continuum model for archaean lode gold deposits which proposes that gold is deposited in metamorphic environments that range from the sub greenschist to granulite facies in addition the data from coolgardie suggest that syntectonic synmineralisation granitic plutons may play a significant role in controlling the style of gold associated wallrock alteration at deep crustal levels

heterogeneous constrictional deformation in a ductile shear zone resulting from the transposition of a lineation parallel fold abstract we use new micro structural petrofabric strain and vorticity data to analyze the deformation path in a mesoscopic quartz mylonite zone the mylonite zone resulted from the complete transposition of a stretching lineation parallel isoclinal fold symmetric cleft girdle quartz c axis fabrics were recorded in the middle domain which occupies the inner limbs of the precursor isoclinal fold while asymmetric cleft and crossed girdle fabrics were observed in the upper and lower domains that represent the outer limbs constrictional strain with increasing k values towards the middle domain is inferred from petrofabric and 3d strain data oblique grain shape fabrics yield vorticity estimates of 0 72 0 90 in the zone however in the middle domain pure shear dominated deformation is suggested by orthorhombic crystallographic fabrics strain rate is constant throughout the zone a strain decrease towards the zone center implies that deformation ceased earlier in the middle domain the data indicates that fold transposition and subsequent mylonitization started as pure shear dominated constrictional deformation and progressively changed to simple shear dominated plane strain during this flow path the asymmetric quartz c axis fabrics likely developed by depopulation of cleft girdle maxima rather than from the synthetic rotation of fabric maxima itself

run up of tsunamis and long waves in terms of surf similarity abstract in this paper we review and re examine the classical analytical solutions for run up of periodic long waves on an infinitely long slope as well as on a finite slope attached to a flat bottom both cases provide simple expressions for the maximum run up and the associated flow velocity in terms of the surf similarity parameter and the amplitude to depth ratio determined at some offshore location we use the analytical expressions to analyze the impact of tsunamis on beaches and relate the discussion to the recent indian ocean tsunami from december 26 2004 an important conclusion is that extreme run up combined with extreme flow velocities occurs for surf similarity parameters of the order 3 6 and for typical tsunami wave periods this requires relatively mild beach slopes next we compare the theoretical solutions to measured run up of breaking and non breaking irregular waves on steep impermeable slopes for the non breaking waves the theoretical curves turn out to be superior to state of the art empirical estimates finally we compare the theoretical solutions with numerical results obtained with a high order boussinesq type method and generally obtain an excellent agreement

regional scale foliation reactivation and re use during formation of a macroscopic fold in the robertson river metamorphics north queensland australia abstract the rocks defining a macroscale antiform 25 km2 in the proterozoic robertson river metamorphics have been affected by four deformations of distinctive style with the fourth deformation d4 being responsible for formation of the macroscale geometry of the fold redistribution of progressive shearing strain due to strain partitioning during progressive d4 deformation resulted in the accommodation of d4 shearing strain along s2 differentiated crenulation cleavages that had been synchronously rotated into favourable orientations on the antiformal limbs this commonly resulted in reactivation of s2 because shearing during d4 was in a sense that was antithetic relative to that on the bulk scale of the fold continued d4 deformation caused unfolding of d2 crenulations resulting in straightening of sigmoidally folded s1 and its rotation toward the axial plane of the synchronously forming macroscopic d4 fold in zones where the sense of shear during d4 was the same as that operating on the bulk scale of the fold i e synthetic d4 shearing strain was accommodated dominantly by the favourably oriented approximately axial planar s1 fissility in zones where the progressive shearing component of d4 deformation was relatively more intense the s2 cleavage was also rotated into parallelism with s4 and was also re used as opposed to reactivated detailed microstructural analysis particularly of porphyroblast matrix relationships combined with field observations have resolved the processes operating during folding and reveal that despite the intensity of d4 deformation a separate cross cutting s4 cleavage has rarely been produced at either the meso or microscale similar processes have probably operated at all scales in other orogenic belts

rans based simulation of wave induced sheet flow transport of graded sediments abstract a one dimensional vertical 1dv turbulence closure flow model coupled with sediment transport capabilities is extended to incorporate graded sediment mixtures the hydrodynamic model solves the horizontal component of the incompressible reynolds averaged navier stokes rans equations coupled with k turbulence closure the sediment transport description includes both bed and suspended load descriptions so called high concentration effects turbulence damping and hindered settling velocities are likewise included the sediment transport model treats the bed and suspended load individually for each grain fraction including effects associated with increased exposure of larger particles within a mixture the suspended sediment transport model also makes use of modified reference concentration approach wherein reference concentrations computed individually for each fraction are translated to a common level conveniently enabling use of a single computational grid for the simulation of suspended sediments parametric study shows that these two effects combine to help alleviate an otherwise systematic tendency towards over under predicted transport rates for fine coarse sand fractions the sediment transport model is validated against sheet flow experimental oscillatory tunnel measurements beneath velocity skewed wave signals and demonstrates similar accuracy transport rates generally within a factor of two for both graded and uniform sands the model is likewise validated against an extensive data set involving sheet flow transport beneath acceleration skewed wave signals limited to uniform sands it is then utilized to study potential effects of gradation on the net transport beneath such flows the simulations suggest that gradation effects can both increase as well as decrease the total transport rate depending largely on the behavior of the fine sand fraction the model is implemented within the matlab environment and is freely available upon request to the corresponding author

structural evolution of sulphide tectonites and their host rocks stratmat mine new brunswick the sulphide orebodies at the stratmat mine in new brunswick are treated as tectonites because their primary characteristics have been so modified by deformation recrystallization and vein injection that most of their original features have been obscured pb zn cu sulphide orebodies at the stratmat mine consist of sulphide and sulphide silicate tectonites gneisses schists phyllites and slates produced by the mixing of two sulphide precursors and silicate host rocks by polyphase deformation much of which relates to progressive non coaxial deformation quartz vein injection during and after this period of deformation and the intermixing of nonsulphide lithotypes led to dilution of the initial ore composition both the deformation of the orebodies and fluid migration manifested by vein injection reflect processes that were operative in a major shear zone no indisputable primary characteristics of the orebodies are preserved although a number of tectonic and or tectonically modified features m

extent of the nevadan orogeny central sierra nevada california the late jurassic nevadan orogeny has long been considered responsible for much of the deformation that occurred in the central sierra nevada on the basis of our recent work and that of other workers we suggest that the intensity of nevadan deformation in the central sierra nevada decreases eastward within the foothills belt is restricted to domainal deformation in rocks between the melones fault zone and the batholith and is virtually absent in the continental volcanic arc along the east side of the range these data and interpretations suggest that in the central sierra nevada nevadan deformation does not represent as intense and widespread an orogeny as originally supposed

full scale cfd simulation of tsunamis part 2 boundary layers and bed shear stresses abstract this paper presents results from numerical simulations of the propagation and run up of full scale tsunamis using a reynolds averaged navier stokes model with emphasis on the resulting boundary layers and bed shear stresses spatial distributions of the shields and rouse parameters during run up and draw down show that for the tsunamis considered with a sediment grain size corresponding to medium sand considerable sediment transport shields parameter o 10 o 100 can be expected during run up and that the sediment transport can be expected to be dominated by suspended load the results likewise show that the expected sediment transport during draw down will similarly be considerable and dominated by suspension the tsunami induced boundary layers are monitored in time and the observed boundary layer thickness ranges from spanning only a small fraction of the water depth to spanning the entire depth the velocity profiles beneath the tsunamis are shown to have good correspondence with a logarithmic profile within the boundary layer similarly the bed shear stresses beneath the tsunamis are investigated and a new and simple engineering model is developed for predicting the temporal variation of the bed shear stress based only on a free stream velocity signal the new engineering model is shown give better predictions for the bed shear stress than a standard manning approach and is likewise shown in the appendix to produce reasonable predictions for shorter wind scale waves it is finally also shown how the temporal evolution of the boundary layer thickness can be predicted based on the free stream velocity signal alone the results presented here are part 2 of a larger study where part 1 presents the model validation and detailed descriptions of the run up process

fabric reactivation an example from the hualapai mountains nw arizona usa abstract foliation reactivation involves renewed movement on preexisting fabrics and can lead to difficulty in determining temporal and spatial relationships of fabrics to larger structures as well as correlation of fabrics to tectonic events porphyroblasts that contain internal fabrics allow for interpretation of the structural history of an area including the potential for foliation reactivation in boriana canyon hualapai mountains nw arizona three vertical foliations s 2 s 4 are preserved in the contact aureole of the 1 40 ga boriana granite foliation s 2 strikes northeast and is parallel with regional foliation that formed post or syn 1 68 ga foliation s 3 occurs throughout the canyon but is most prevalent in the contact aureole where close to the pluton it forms the main cleavage andalusite and garnet porphyroblasts overgrew s 3 crenulations foliation s 4 is parallel to the s 2 regional fabric and in some outcrops deformation associated with s 4 has decrenulated the s 3 fabric although s 3 is preserved in garnet and andalusite porphyroblasts in these outcrops s 4 is also axial planar to f 2 folds recognition of fabric reactivation of this aureole allows for discrimination of foliation forming episodes that are separated by 250 m y and a better understanding of the proterozoic geologic history for this part of nw arizona

complex strain patterns developed at the frontal and lateral tips to shear zones and thrust zones abstract many of the complex strain patterns seen in shear zones and thrust zones such as variable fabric orientations refolded folds and fabrics together with folds with hinges almost parallel to the main transport direction can be explained in terms of differential movement within the shear zones these strains are developed at the frontal and lateral tips of the zones as they propagate examples are taken from the moine thrust zone of scotland which show variations in strains particularly at the lateral tips the form of differential movement described here may lead to complex strain paths and non plane strain ellipsoids and the spatial variations in finite strain may be used to delineate zones of extensional and compressional flow and differential movement in the shear zones or thrusts

structural evolution of a 1 6 ga orogeny related to the final assembly of the supercontinent nuna coupling of episodic and progressive deformation

strain fabric evolution within and near deformed igneous sheets the sudbury igneous complex canada abstract deformation structures differing in style and orientation within a given terrane are often attributed to distinct tectono metamorphic events however mechanical heterogeneities may locally cause strain perturbations that can have a profound effect on the geometry of such structures here we document highly variable orientations of planar structures metre to kilometre scale folds and shortening directions inferred from brittle fault analysis within the synclinal and layered sudbury igneous complex sic and its huronian host rocks nw se shortening during palaeoproterozoic deformation led to the formation of planar structures in the host rocks that are parallel to the ne sw striking contact of the southern sic during deformation local contact parallel shortening became more important than regional nw se shortening and generated contact orthogonal planar mineral fabrics and folds local contact parallel shortening is attributed to the shape change of the southern sic from a convex outward to a concave inward curvi planar geometry contact parallel shortening accounts for the formation of a previously unidentified kilometre scale buckle fold in the sic and respective axial planar mineral fabrics in huronian host rocks this buckle fold shares similar structural characteristics with known higher order buckle folds of the eastern sic we suggest that non cylindrical buckling and associated mineral fabric development accommodated the shape change of the sic this resulted in mutually perpendicular fabric orientations which are compatible with overall nw se shortening the original shape of the sic seems to have had a profound influence particularly on the geometry of metamorphic foliations our structural analysis supports earlier structural studies advocating that highly discordant planar strain fabrics can be generated by local strain perturbations near igneous sheets under uniform regional shortening

conjugate shear folding a model for the relationships between foliations folds and shear zones abstract microstructural mapping of whole thin sections cut from two samples of micaschist containing cm scale folds plus garnet porphyroblasts has provided new insight in the relationships between folding shearing and foliation development the garnets exhibit coherent inclusion trail patterns that place important constraints on the kinematic development of both samples which are shown to be representative of coaxial versus non coaxial deformation in rocks containing a pre existing schistosity a comparison of crenulations cleavages geometries in both samples and a review of the geometry of natural and experimental multilayer folds leads to the conclusion that folding involves conjugate shearing at different scales at microscopic scales crenulation cleavages nucleate as conjugate kink or shear instabilities and develop further as a function of the macroscopic partitioning of deformation in fold hinge domains bulk coaxial deformation results in equal development of conjugate crenulations that progressively coalescence into symmetrical crenulation patterns so that macroscopically parallelism is achieved between foliation fold axial planes and long axes of strain ellipses fold limb domains represent a system of conjugate shear zones where single sets of crenulation instabilities with synthetic shearing component preferentially develop producing oblique relationships between the aforementioned elements cleavage fanning is inferred as a direct consequence of this conjugate shear origin of folds the model implies that crenulation cleavages and s c fabrics in shear zones form by analogous processes in both cases involving a component of shearing along foliation planes the development of conjugate sets of foliation planes surrounding porphyroblasts during early relatively coaxial stages of deformation explains continued gyrostatic behaviour during more advanced non coaxial stages as indicated by consistently oriented inclusion trails in the studied samples

post nevadan deformation along the bear mountains fault zone implications for the foothills terrane central sierra nevada california southern parts of the foothills terrane sierra nevada california consist of western and eastern sequences of volcanic rocks and overlying slate gray wacke units separated by a multiply deformed and lithologically chaotic central belt structural and strain studies suggest that the intensity of regional ductile deformation decreased from greater than 50 shortening in the western belt to less than 30 shortening in the eastern belt and that much of this ductile deformation is younger than the timing usually assumed for the nevadan orogeny these structures are in turn deformed by a large ductile shear zone representing the southern continuation of the bear mountains fault zone this shear zone separates the western and central belts has an oblique east over west sense of movement and deforms the western margin of the guadalupe igneous complex these observations suggest that the eastern and western volcanic sequences are pieces of arcs amalgamated along the bear mountains fault zone during and after nevadan deformation

geology and tectonic evolution of the bear mountains fault zone foothills terrane central sierra nevada california the late jurassic early cretaceous bear mountains fault zone bmfz is the westernmost strand of the foothills fault system in the western metamorphic belt of the sierra nevada the tectonic significance of this 300 km long fault zone has been downplayed in the past but we contend that it is a major discontinuity within the foothills terrane the bmfz is an 5 km wide shear zone consisting of slate metagraywacke matrix melange that experienced intense polyphase deformation and metamorphism small scale structures indicate reverse slip along most of the extent of this steeply east dipping shear zone a host of lithologically diverse tectonic blocks are enclosed in the bmfz blocks of sandstone metavolcanic rocks and plutonic rocks of intermediate composition have counterparts in the adjacent eastern and western zones of the foothills terrane whereas other block types are exotic exotic blocks include ultramafites that locally contain pods of gabbro garnet amphibolite greenschist sedimentary breccia and volcaniclastic rocks the breccia is composed primarily of clasts of amphibolite and minor garnet bearing impure quartzite metachert it probably accumulated at the base of fault scarps the exotic blocks comprise a broadly ophiolitic assemblage similar to that inferred to form basement to the foothills terrane and they record a deformation prior to incorporation in the slate metagraywacke matrix amphibolite blocks and quartzite preserved as clasts within the breccia probably were deformed during overthrusting of oceanic lithosphere in a setting similar to that beneath the tuolumne ophiolite east of the bmfz the presence of exotic blocks implies large scale mixing and large displacements in the bmfz as do differences in stratigraphy across the fault zone metamorphic grade does not vary significantly across the bmfz however suggesting that dip slip did not exceed several tens of kilometers if the fault zone originally dipped gently eastward as we propose there is no direct evidence for major strike slip along the bmfz as has been proposed by others any such slip must have occurred before the reverse slip related structures of the zone we thus interpret the bmfz as an intra arc reverse fault of moderate to large displacement with possible earlier strike slip that incorporates ophiolitic basement showing an older complicated history

structural and geochronologic relations along the western flank of the coast mountains batholith stikine river to cape fanshaw central southeastern alaska abstract geologic and u pb geochronologic studies in central southeastern alaska provide constraints on the mid cretaceous to mid tertiary deformation west of the coast mountains batholith the ne dipping sumdum and fanshaw faults record the w directed emplacement of the ruth assemblage yukon tanana terrane and taku terrane over the subjacent gravina belt and alexander terrane ductile fabrics of the sumdum fanshaw fault system truncate early formed foliation and thrust faults in albian and older gravina belt strata u pb age data from syn and post tectonic plutons suggest that deformation was ongoing at 92 9 3 0 ma but had mostly ceased by 90 ma the sumdum fanshaw fault system marks the tectonic boundary between the alexander wrangellia terrane and inboard yukon tanana and stikine terranes and lies within a thrust belt that extends from southern alaska to northern washington mid cretaceous structures are truncated to the east by ne dipping ductile fabrics of the coast shear zone sheet like paleocene tonalites were emplaced into and deformed within the shear zone undeformed mid eocene dikes cross cut the tonalites kinematic relations in the coast shear zone suggest a complex displacement history that includes both east side up reverse and west side up normal shear the shear zone probably accommodated the collapse of overthickened crust developed during mid cretaceous shortening

propagation and amplification of tsunamis at coastal boundaries when tsunamis hit a coastal area they often cause substantial damage and loss of life at locations otherwise well protected from normal even severe wind generated waves an example of such a catastrophe took place on 12 december 1992 when an earthquake of magnitude ms 7 5 occurred in the eastern region of flores island indonesia1 2 one of the areas hardest hit by the resulting tsunamis was babi a small coastal island two villages on the island were completely destroyed even though both were located in sheltered areas where wave conditions are normally calm here we describe the results of numerical and laboratory experiments that show how unlike wind generated waves tsunamis are capable of penetrating into sheltered coastal areas without significantly losing their energy for the case of babi island the original tsunami wave was split into two with one wave propagating around each side of the island the two waves met in the sheltered region and the subsequent amplification of wave amplitude resulted in the destructive flow onto the beach

rans based simulation of turbulent wave boundary layer and sheet flow sediment transport processes abstract a numerical model coupling the horizontal component of the incompressible reynolds averaged navier stokes rans equations with two equation k turbulence closure is presented and used to simulate a variety of turbulent wave boundary layer processes the hydrodynamic model is additionally coupled with bed and suspended load descriptions the latter based on an unsteady turbulent diffusion equation for simulation of sheet flow sediment transport processes in addition to standard features common within such rans based approaches the present model includes 1 hindered settling velocities at high suspended sediment concentrations 2 turbulence suppression due to density gradients in the water sand mixture 3 boundary layer streaming due to convective terms and 4 converging diverging effects due to a sloping bed the present model therefore provides a framework for simultaneous inclusion of a number of local factors important within cross shore wave boundary layer and sediment transport dynamics the hydrodynamic model is validated for both hydraulically smooth and rough conditions based on wave friction factor diagrams and boundary layer streaming profiles with the results in excellent agreement with experimental and or previous numerical work the sediment transport model is likewise validated against oscillatory tunnel experiments involving both velocity skewed and acceleration skewed flows as well as against measurements beneath real progressive waves model capabilities are exploited to investigate the importance of boundary layer streaming effects on sediment transport in selected velocity skewed conditions for the medium sand grain conditions considered the model results suggest that streaming effects can enhance onshore sediment transport rates by as much as a factor of two moreover for fine sand conditions streaming and related convective effects are demonstrated to potentially reverse the direction of net transport i e from offshore to onshore relative that predicted in oscillatory tunnel conditions the developed model is implemented within the popular matlab environment and hence may be attractive for both research and educational purposes

effect of bed roughness on tsunami bore propagation and overtopping abstract the accurate modelling of overtopping of coastal defences by tsunami waves is of vital importance for the formulation of disaster management strategies to improve knowledge of this phenomena the authors conducted experiments on coastal structure overtopping using bores that were generated by a dam break mechanism three types of structures were tested namely a coastal dyke a wall and a wall of infinite height the results highlight the necessity to consider the energy present in a bore to determine if a structure will be overtopped or not as a result of these experiments an empirical formula to determine the height of overtopping given the incident bore height and velocity was validated the study highlights the importance of clearly modelling the velocity and froude number of a tsunami such experiments should be conducted on rough beds for which a suitable manning s n seems to be around 0 06 sm 1 3 the study also contrasted the results obtained to those of the asce7 method and concludes that the manning s n values recommended in asce7 are probably too low

40ar 39ar thermochronologic constraints on deformation metamorphism and cooling exhumation of a mesozoic accretionary wedge otago schist new zealand abstract structural thickening of the torlesse accretionary wedge via juxtaposition of arc derived greywackes caples terrane and quartzo feldspathic greywackes torlesse terrane at 120 ma formed a belt of schist otago schist with distinct mica fabrics defining i schistosity ii transposition layering and iii crenulation cleavage thirty five 40ar 39ar step heating experiments on these micas and whole rock micaceous fabrics from the otago schist have shown that the main metamorphism and deformation occurred between 160 and 140 ma recorded in the low grade flanks through 120 ma shear zone deformation this was followed either by very gradual cooling or no cooling until about 110 ma with some form of extensional tectonic exhumation and cooling of the high grade metamorphic core between 109 and 100 ma major shear zones separating the low grade and high grade parts of the schist define regions of separate and distinct apparent age groupings that underwent different thermo tectonic histories apparent ages on the low grade north flank hanging wall to the hyde macraes and rise and shine shear zones range from 145 to 159 ma n 8 whereas on the low grade south flank hanging wall to the remarkables shear zone or caples terrane range from 144 to 156 ma n 5 most of these samples show complex age spectra caused by mixing between radiogenic argon released from neocrystalline metamorphic mica and lesser detrital mica several of the hanging wall samples with ages of 144 147 ma show no evidence for detrital contamination in thin section or in the form of the age spectra apparent ages from the high grade metamorphic core garnet biotite albite zone range from 131 to 106 ma n 13 with a strong grouping 113 109 ma n 7 in the immediate footwall to the major remarkables shear zone most of the age spectra from within the core of the schist belt yield complex age spectra that we interpret to be the result of prolonged residence within the argon partial retention interval for white mica 430 330 c samples with apparent ages of about 110 109 ma tend to give concordant plateaux suggesting more rapid cooling the youngest and most disturbed age spectra come from within the alpine chlorite overprint zone where samples with strong development of crenulation cleavage gave ages 85 107 and 101 ma due to partial resetting during retrogression the bounding remarkables shear zone shows resetting effects due to dynamic recrystallization with apparent ages of 127 122 ma whereas overprinting shear zones within the core of the schist show apparent ages of 112 109 and 106 ma these data when linked with extensional exhumation of high grade rocks in other parts of new zealand indicate that the east gondwana margin underwent significant extension in the 110 90 ma period

thrust kinematics and transposition fabrics from a basal detachment zone eastern australia abstract emplacement of an upper crustal leading imbricate fan thrust belt in the lachlan fold belt of eastern australia was accomplished along a 0 5 1 km thick zone of heterogeneously deformed low grade phyllonite in pelitic rock continuous recrystallization and neocrystallization of mica in a zone of transposition layering has provided a weak zone at the base of a 100 km wide 150 km exposed length 10 km thick thrust system the basal deformation zone is characterized by a low moderately dipping strong intense transposition foliation enclosing elongate fault bounded slices up to 20 km long 5 km wide in map view of disrupted cambrian metavolcanics and upper ordovician black shales and slates these are derived from a structurally lower zone of duplexing or from the overturned limbs of anticlinorial structures the detachment zone is a 10 15 km wide zone of intense deformation showing a transition from open upright folds with weak cleavage to inclined tightisoclinal folds with strong axial surface cleavage the intensity of minor faults also increases into the zone leading imbricate fan thrust belts show maximum deformation effects along the basal detachment which forms the frontal or leading fault the leading imbricate geometry is due to emplacement of the basal detachment zone up the lowest and last formed imbricate thrust movement is along a relatively ductile low viscosity layer at the base where strain softening occurs with development of transposition layering this enables confined flow along the basal zone with transport and emplacement of the fold system and duplex zone to higher structural levels reaction enhanced ductility and grain boundary sliding may be important deformation mechanisms responsible for this flow localized polydeformation marked by mesofolds and crenulation cleavage reflects the interaction between thrust sheets and the movement on faults

nomenclature and geometric classification of cleavage transected folds abstract terms and measures for describing real and theoretical three dimensional cleavage transected folds are reviewed and clarified the geometrically possible range of cleavage transected folds is explored reappraisal and extension of published measures allows study of geologically realistic asymmetrical folds scale related description of cleavages and associated folds is formalized and sampling problems discussed the plot comparing axial with profile plane fold transection by cleavage is used to classify transected folds in a geometrical manner it helps reveal the constitutive geometry of cleavage transected folds and should help identify the most actively growing fold order during a cleavage forming episode plotted examples from welsh asymmetric cleavage transected folds of acadian age show complex transection geometries

factors constraining the geographic distribution of earthquake geochemical and fluid related precursors abstract earthquake precursors are elusive and this elusiveness has hampered earthquake prediction in this paper the available catalogues of historical and contemporary geochemical and fluid related precursors of earthquakes are considered the locations of recording sites are mapped and compared with data concerning volcanic locations heat flows crustal velocities and the depth of seismic events possible relations among the considered geophysical parameters and the occurrence of fluid related earthquake precursors are discussed only some geological and geophysical conditions may allow for the occurrence of fluid related earthquake precursory phenomena as a consequence the geophysical models utilized to explain the occurrence of earthquake precursors should be updated furthermore only some areas of the world are deemed suitable for earthquake fluid related precursor monitoring

tsunami induced scour around monopile foundations abstract a fully coupled hydrodynamic and morphologic numerical model is presented and utilized for the simulation of tsunami induced scour around a monopile structure representative of those commonly utilized as offshore wind turbine foundations at moderate depths i e for depths less than 30 m the model is based on solutions to reynolds averaged navier stokes equations coupled with two equation k turbulence closure with additional bed and suspended load descriptions forming the basis for sea bed morphology the model is first validated for flow bed shear stresses and scour within a steady current where a generally excellent match with experimentally based results is found a methodology for maintaining and assessing hydrodynamic and morphologic similarity between field and laboratory model scale tsunami events is then presented combining diameter based froude number similarity with that based on the dimensionless wave boundary layer thickness to monopile diameter ratio this methodology is utilized directly in the selection of governing tsunami wave parameters i e velocity magnitude and period used for subsequent simulation within the numerical model with the tsunami induced flow modelled as a long sinusoidally varying current the flow sediment transport and scour processes beneath up to ten tsunami waves are simulated in succession these illustrate a generally accumulative scour process i e a relatively rapid scour induced by the leading wave with an additional build up of the scour depth during additional trailing waves the resulting scour seems to approach an equilibrium value after sufficient time duration which corresponds reasonably to that predicted by existing steady current scour depth expressions after accounting for the finite boundary layer thickness induced by the unsteady tsunami wave i e it is important to incorporate both current like as well as wave like aspects of the long tsunami event based on the simulated results a simple methodology for predicting the tsunami induced scour depth in engineering practice is finally developed this methodology is demonstrated to match the predicted scour development for all of the simulated flows considered ranging from the series of transient tsunami waves to the steady current limit

numerical simulation of tsunami scale wave boundary layers this paper presents a numerical study of the boundary layer flow and properties induced by tsunami scale waves for this purpose an existing one dimensional vertical 1dv boundary layer model based on the horizontal component of the incompressible reynolds averaged navier stokes rans equations is newly extended to incorporate a transitional variant of the standard two equation k turbulence closure the developed numerical model is successfully validated against recent experimental measurements involving transient solitary wave boundary layers as well as for oscillatory flows collectively demonstrating the ability to reproduce accurate velocity profiles turbulence and bed shear stresses on both smooth and rough beds the validated model is then employed for the study of transient wave boundary layers at full tsunami scales covering a wide and realistic geophysical range in terms of the flow duration bottom roughness and associated reynolds numbers for this purpose three different synthetic idealised tsunami wave descriptions are considered i e invoking 1 single wave solitary like but with independent period and wave height 2 sinusoidal and 3 n wave descriptions the flow boundary layer thickness turbulence and bed shear stresses induced are systematically monitored and parameterised under both hydraulically smooth and rough bed conditions the results generally support a notion that the boundary layers induced by tsunami scale waves are both current like due to their long durations as well as wave like in the sense that the boundary layer will not necessarily span the entirety of the water column the results likewise suggest that there is a continuum connecting wind wave and tsunami wave scales as existing expressions commonly used for characterising boundary layer properties beneath wind waves maintain reasonable accuracy when extrapolated to full tsunami scales boundary layers driven by actual field measured tsunami signals are likewise simulated stemming from both the 2004 indian ocean as well as the 2011 tohoku events these results are reconciled with the various synthetic tsunami signals considered generally confirming their usefulness as idealised tsunami waves

regional structural and strain analyses of terranes in the western metamorphic belt central sierra nevada california abstract a comparison of total strains in 225 samples from the western metamorphic belt sierra nevada shows that strain types and intensities strongly depend on rock type greywackes and clast supported conglomerates are least strained whereas more intense strains occur in lapilli tuffs pebbly mudstones and slates large belts of volcanic rock record plane strain whereas nearby slate and greywacke sequences record flattening type strain suggesting that volume losses of 45 65 occurred in slates and 0 26 in greywackes lapilli tuffs record less than 11 volume loss the differences in volume loss and strain from one rock type to another require that discontinuities in total strain occur at most lithologic contacts independently of the lithologic control regional structural patterns and strain fields support the delineation of three terranes foothills merced river and northern sierra and two distinct domains western and eastern foothills terranes at these latitudes within the western metamorphic belt these terranes each bordered by large ductile shear zones differ in average strain intensity and orientation but not in strain type in the foothills terrane strain intensities decrease from moderate values in the western foothills terrane to low values in the eastern foothills terrane strain intensities in the study area are highest in the melones and bear mountains fault zones and in terranes east of the melones fault structures associated with regional deformation in each terrane do not extend far across terrane boundaries multiple generations of regionally developed structures are therefore rare in this part of the western metamorphic belt outside of fault zones we see one regionally developed cleavage in the foothills terrane a single but older cleavage in the merced river terrane and two still older cleavages in the northern sierra terrane however younger deformations may have reactivated and rotated older structures in adjacent terranes the timing and kinematics of the deformation in the foothills terrane suggest that faulting and rigid body rotations preceded pervasive shortening continued fault movement and rotation of faults to steep dips if orientations of ductile structures reflect plate motions structures in the merced river terrane suggest jurassic triassic orthogonal nne convergence whereas structures in the foothills terrane support late jurassic orthogonal ne convergence changing to oblique ene convergence about 150 ma ago

experimental study of tsunami induced scour around a monopile foundation abstract this paper presents an experimental study of the tsunami induced scour process around a monopile foundation representative of those commonly used for offshore wind farms the scour process is studied by subjecting the monopile to a time varying current which enables a properly down scaled experiment from the boundary layer and scour perspective it is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min it is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers by subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion with the final equilibrium scour depth tending to the depth limited steady current limit it is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model finally the experimental results are compared to a fully coupled hydrodynamic and morphologic cfd model and a good correspondence is obtained

progressive evolution from uplift to orogen parallel transport in a late acadian upper amphibolite to granulite facies shear zone south central massachusetts fabrics within a 1 km wide shear zone along the eastern margin of the bronson hill anticlinorium in central massachusetts provide important information on the regional tectonic development during the devonian acadian orogeny two distinct mineral lineations observed within the zone are each defined by alignment of coarse sillimanite needles and elongated quartz and feldspar grains and aggregates both lineations are associated with shearing and development of mylonitic fabrics the character of the two lineations and related fabrics differs mainly in orientation and in the relationship of each lineation to the local orientation of quartz c axis fabrics the interpreted earlier lineation has a steep west plunge and the later lineation has a shallow plunge and north south to southwest trend parallel to the regional trend of the orogen extensive dynamic recrystallization of feldspar the possible activity of prism slip in quartz and the mineral assemblages in apparent equilibrium during deformation suggest that both lineations probably formed under upper amphibolite facies conditions just after the thermal peak of acadian metamorphism a progressive change between the two deformation fabrics is suggested by evidence of overlap between the two by their striking similarity in style and metamorphic conditions of formation and by the similarity in orientation of their bulk strain axes with a change only in the transport direction between them kinematic indicators associated with each phase of lineation development are consistent throughout the shear zone the earlier phase has a west side up sense of shear and the later phase indicates west side north movement these phases are correlated with the regional backfold and dome stages of acadian deformation the kinematics and relationships between them suggest a revised tectonic model for the later part of the acadian orogeny and for development of orogen parallel lineations in this region in this model uplift and thickening of basement gneisses in the bronson hill anticlinorium during the backfold stage was impeded by gravitational instability in a thermally weakened crust this led to a change from subvertical to subhorizontal extension east west acadian shortening was still in progress constraining this extension to a north south direction parallel to the trend of the orogen

the runup of solitary waves this is a study of the runup of solitary waves on plane beaches an approximate theory is presented for non breaking waves and an asymptotic result is derived for the maximum runup of solitary waves a series of laboratory experiments is described to support the theory it is shown that the linear theory predicts the maximum runup satisfactorily and that the nonlinear theory describes the climb of solitary waves equally well different runup regimes are found to exist for the runup of breaking and non breaking waves a breaking criterion is derived for determining whether a solitary wave will break as it climbs up a sloping beach and a different criterion is shown to apply for determining whether a wave will break during rundown these results are used to explain some of the existing empirical runup relationships

multiply deformed terrains problems of correlation abstract the best tools available for carrying out a structural analysis in a complex area are overprinting style and patterns of orientation unfortunately all have limitations which are reviewed briefly and discussed in areas of continuous unfaulted outcrop the deformational history can be established purely on the basis of overprinting but even in such areas there can be problems since not all overprinting relationships are unambiguous most fold interference patterns are reliable overprinting relationships based on foliations however are commonly unreliable and various examples are cited and discussed even in areas where the sequence of deformational events can be established their temporal significance is unclear since the methods applied only determine local relative timing and absolute relationships must vary in space and time across an orogen

the partitioning of deformation in flowing rock masses abstract most geological structures owe their development to heterogeneous and or non steady flow flow partitioning refers to the division of the instantaneous velocity field into components related to translation strain and rotation flow partitioning during the development of a geological structure usually changes with time and different histories of flow are involved at different points in the developing structure heterogeneity leads to the development of flow domains with different characteristics notably the degree of non coaxiality of deformation and different partitionings of the rotational component of flow into shear induced vorticity and spin during non steady flow there is often continual repartitioning of vorticity between the spin and shear induced components spin is an important aspect of flow leading to the development of structure this paper discusses the partitioning of deformation in a flowing rock mass coaxial flow tends to occur in isotropic materials in regions near weakly constrained boundaries non coaxial flow is favoured by suitably oriented material anisotropy and or the presence of well defined boundary constraints involving parallel relative displacements a developing anisotropy e g a crystallographic fabric in a shear zone can induce a change from coaxial to non coaxial flow other effects are related to the scale of approximation for example bulk shear induced vorticity can be locally converted to spin flow in the crust and mantle of the earth produces geological structures on all scales and involves many different types of rheological response the factors that affect flow partitioning e g spin versus non coaxial deformation are therefore of interest

tsunami generation in a large scale experimental facility abstract experimental studies on tsunami are carried out since many years most of them by generating solitary waves with a piston type wave maker however today it is more and more appreciated that these kinds of waves actually do not represent a real tsunami very well as particularly for the shallow waters at the coast the wave length becomes comparably far too short recently new generation methods for scaled down real tsunami experiments were suggested as it was doubted that sufficiently long waves could be generated with a classical wave maker the present paper shall disprove these arguments by providing results of a study carried out in the large wave flume groser wellenkanal gwk where waves of periods between 30 s and more than 100 s at 1 m water depth were successfully generated with a piston type wave maker results for elongated solitary waves trough led n waves and real tsunami records as a combination of a different number of general solitons sech2 waves are presented finally the requirements and limitations to bring a real tsunami into the laboratory are discussed

stretching normal to the regional thrust displacement in a thrust wrench shear zone rehamna massif morocco the hercynian rehamna massif of morocco is located in the meseta belt on the sheared boundary between the weakly strained western meseta coastal block and an intensely deformed carboniferous basin deformation may be related to three superposed phases the most important phases d1 and d2 result in a main composite s1 2 foliation and are related to westward thrusting d4 is contemporaneous with the emplacement of syn to late tectonic granitic plutons fold asymmetry and microstructures rotated garnets s c tectonites suggest a dominant westward thrusting in eastern rehamna in central rehamna along the thrust zone front stretching lineations are almost normal to the regional coeval thrust displacement direction and microstructures rotated garnets shear bands asymmetrical pressure shadows observed along the 1 direction stretching lineation direction suggest dextral reverse southward wrenching this particular strain pattern is interpreted as a product of thrust wrench shearing combining ductile thrusting and wrenching during the progressive synmetamorphic shortening of the area along the frontal tip of the central meseta thrust units

sequential porphyroblast growth and crenulation cleavage development during progressive deformation abstract six stages of crenulation cleavage development during a single deformation event d2 can be recognised in both matrix and porphyroblast inclusion trails in the robertson river formation n e australia these stages progress from undeformed to crenulation and differentiated crenulation of s1 through development of differentiated crenulation cleavage s2 and differentiated schistosity s2 to homogeneous foliation s2 these rocks underwent prograde metamorphism during d2 and chloritoid garnet staurolite andalusite and sillimanite isograds have been mapped most rocks are rich in porphyroblasts which commonly contain well defined inclusion trails the geometry of these trails varies from one mineral type to the next depending on the timing of porphyroblast growth relative to the stage of crenulation cleavage development in the schistose matrix the deformation history involved progressive bulk inhomogeneous shortening and the strain is very heterogeneous on all scales partly as a consequence of this hence each of the six stages of crenulation cleavage development formed locally at various times during d2 therefore if a porphyroblast grew late in the deformation it could overgrow all stages of crenulation cleavage development including the very early ones the temperature increased during metamorphism in any one locality and consequently some porphyroblasts overgrew others that were unstable in the new conditions preserving them from destruction hence the precise timing of mineralogical reactions deduced from isograds and mineral chemistry relative to the stages in schistosity development can also be determined in the andalusite zone the sequence of porphyroblasts in decreasing order of age is biotite garnet biotite staurolite andalusite dissolution of garnet occurred during growth of staurolite and especially andalusite and dissolution of staurolite accompanied andalusite growth

analysis and interpretation of composite foliations in areas of progressive deformation abstract in areas of progressive deformation where successive structures develop during a relatively continuous deformation within a geologically short time period traditional chronological notations of structural elements e g s 1 s 2 etc can give erroneous impressions of how large rock masses evolve in time and space we demonstrate from field examples that successive structures can develop which a are comparable in morphology and orientation but of different ages b are different in morphology but of comparable age and c show rapid morphological changes over short distances under such conditions correct identification of the relative age of structures is often difficult to impossible we consider the concepts of a composite foliation and of transposition cycles as vehicles to objectively evaluate the significance of different sets of structures in the evolution of larger rock masses we suggest that 1 structural elements be labeled using morphological notation adding numerical subscripts only when independent evidence is available 2 geologists more fully acknowledge and integrate the concept of deformation partitioning into their models and 3 when analyzing areas of multiple deformation more emphasis is placed on the relationship between domains of differing complexity integration of these three perspectives in the analysis will lead to a more realistic basis upon which to model the structural evolution of large rock masses

analytical solutions for tsunami runup on a plane beach single waves n waves and transient waves in the literature it has so far been common practice to consider solitary waves and n waves composed of solitary waves as the appropriate model of tsunamis approaching the shoreline unfortunately this approach is based on a tie between the nonlinearity and the horizontal length scale or duration of the wave which is not realistic for geophysical tsunamis to resolve this problem we first derive analytical solutions to the nonlinear shallow water nsw equations for the runup rundown of single waves where the duration and the wave height can be specified separately the formulation is then extended to cover leading depression n waves composed of a superposition of positive and negative single waves as a result the temporal variations of the runup elevation the associated velocity and breaking criteria are specified in terms of polylogarithmic functions finally we consider incoming transient wavetrains generated by monopole and dipole disturbances in the deep ocean the evolution of these wavetrains while travelling a considerable distance over a constant depth is influenced by weak dispersion and is governed by the linear korteweg de vries kdv equation this process is described by a convolution integral involving the airy function the runup on the plane sloping beach is then determined by another convolution integral involving the incoming time series at the foot of the slope a good agreement with numerical model results is demonstrated

polyphase deformation in the western mount isa inlier australia episodic or continuous deformation abstract the polyphase deformation history of the mount novit ranges western mount isa inlier australia involved the development of four generations of n s to nw plunging folds development of which alternated with movement on n s striking faults shear zones with west over east displacement the spatial relationships between successive structures and the distinct similarities in the kinematics style and asymmetry are all consistent with continuous deformation during e w to ne sw shortening additional support for this hypothesis is based on the development of the three major fold generations and the intervening faults and shear zones during low p high t metamorphism although the duration of this metamorphic event cannot be constrained recent studies have linked low p metamorphism to heat advection by migrating melts thermal modelling indicates that such metamorphic events will be short lived in comparison to those associated with thermal relaxation of over thickened crust low p metamorphism is unlikely to persist through two or more separate tectonic events therefore syn metamorphic polyphase deformation in the mount novit ranges apparently formed during a single continuous tectonic episode this structural history differs from both the regional scheme and that of previous workers in this area the main differences are i no evidence was found for early thrust faulting prior to n s folding ii there are four generations of n s to nw se folds as opposed to two and iii this study favors a single consistent tectonic regime in contrast to the interpretation of three discrete isolated tectonic events

flow and sediment transport induced by a plunging solitary wave 1 two parallel experiments involving the evolution and runup of plunging solitary waves on a sloping bed were conducted 1 a rigid bed experiment allowing direct hot film measurements of bed shear stresses and 2 a sediment bed experiment allowing for the measurement of pore water pressures and for observation of the morphological changes the two experimental conditions were kept as similar as possible the experiments showed that the complete sequence of the plunging solitary wave involves the following processes shoaling and wave breaking runup rundown and hydraulic jump and trailing wave the bed shear stress measurements showed that the mean bed shear stress increases tremendously with respect to that in the approaching wave boundary layer by as much as a factor of 8 in the runup and rundown stages and that the rms value of the fluctuating component of the bed shear stress is also affected by as much as a factor of 2 in the runup and hydraulic jump stages the pore water pressure measurements showed that the sediment at or near the surface of the bed experiences upward directed pressure gradient forces during the down rush phase the magnitude of this force can reach values as much as approximately 30 of the submerged weight of the sediment the experiments further showed that the sediment transport occurs in the sheet flow regime for a substantial portion of the beach covering the area where the entire sequence of the wave breaking takes place the bed morphology is explained qualitatively in terms of the measured bed shear stress and the pressure gradient forces

structures and fabrics in a crustal scale shear zone betic cordillera se spain abstract a broad zone of dominantly ductile high strain deformation lies beneath the aguilon nappe in the sierra alhamilla southern spain it forms part of a crustal scale movement zone traceable through much of the betic cordillera which separates the higher betic nappes from the underlying nevado filabride complex the zone is characterized in outcrop by a distinctive platy foliation and a strong nne trending stretching lineation microstructural characteristics include quartz ribbons mica fish augen of feldspar and other minerals in a matrix of dynamically recrystallized quartz and extensional crenulation cleavages narrow bands of ultramylonite and cataclasite occur within and on the margins of the movement zone deformation occurred under lower greenschist facies conditions and was accompanied by retrogression of earlier higher grade mineral assemblages structures in the movement zone developed in a temporal sequence beginning with isoclinal folding and transposition of older foliations this was followed by the formation of extensional crenulation cleavages and the progressive localization of strain into the ultramylonite bands mylonitic foliation in these bands is deformed by syn mylonite folds restricted to the bands all these structures were then deformed by s to se vergent small scale folds restricted to the movement zone as a whole cataclasis associated with alteration is localized along the ultramylonite bands and indicates a transition to late stage brittle deformation the lower boundary of the movement zone is gradational strain decreases recrystallized grainsize and the degree of recrystallization of quartz increases and pressure solution becomes the dominant deformation mechanism in mica schist asymmetric quartz fabrics in the movement zone indicate a nne sense of shear but variations in the degree of asymmetry suggest that flow was partitioned with the ultramylonite bands taking up much of the shear strain and the intervening rocks deforming more slowly and with a lower degree of non coaxiality diffuse fabrics in the fine grained ultramylonite bands may indicate a switch to a grainsize sensitive deformation mechanism and an overall downward increase in the opening angle of crossed girdle fabrics may reflect increased water activity at depth

deciphering the variscan tectonothermal overprint and deformation partitioning in the cadomian basement of the tepla barrandian unit bohemian massif the tepla barrandian unit tbu has long been considered as a simply bivergent supracrustal median massif above the saxothuringian subduction zone in the variscan orogenic belt this contribution reveals a much more complex style of the variscan tectonometamorphic overprint and resulting architecture of the neoproterozoic basement of the tbu for the first time we describe the crustal scale ne sw trending dextral transpressional krakovec shear zone ksz that intersects the tbu and thrusts its higher grade northwestern portion severely reworked by variscan deformation over a southeastern very low grade portion with well preserved cadomian structures and only brittle variscan deformation the age of movements along the ksz is inferred as late devonian 380 370 ma on the basis of structural microstructural and anisotropy of magnetic susceptibility data from the ksz we propose a new synthetic model for the deformation partitioning in the tepla barrandian upper crust in response to the late devonian to early carboniferous subduction and underthrusting of the saxothuringan lithosphere we conclude that the saxothuringian tepla barrandian convergence was nearly frontal during 380 346 ma and was partitioned into pure shear dominated domains that accommodated orogen perpendicular shortening alternating with orogen parallel high strain domains that accommodated dextral transpression or bilateral extrusion the synconvergent shortening of the tbu was terminated by a rapid gravity driven collapse of the thickened lithosphere at 346 337 ma followed by or partly simultaneous with dextral strike slip along the baltica margin parallel zones driven by the westward movement of gondwana from approximately 345 ma onwards