metamorphic evidence for tilt of the spuzzum pluton diminished basis for the baja british columbia concept to address the question of tilt versus translation as the mechanism responsible for discordance between paleomagnetic directions of cretaceous plutons in the british columbia coast plutonic complex and the north american reference direction metamorphic pressures around the margin of the spuzzum pluton have been determined pressures are derived from microprobe analyses and evaluation of exchange equilibria in the assemblage garnet biotite plagioclase aluminum silicate quartz samples studied come from eight localities in the contact aureole around the pluton and encompass the area of a previous paleomagnetic study the analyzed samples are coarse grained and exhibit textural features indicative of equilibrium crystallization following emplacement of the spuzzum pluton results of this study indicate a complicated tilt history for the spuzzum pluton with tilt first to the northeast then to the southwest the southwest tilt can fully explain the discordance of the paleomagnetic direction in the spuzzum but does not preclude translation however in view of the tilt history of this pluton the paleomagnetic data derived from it should not be used in an analysis of north south translation

matuyama brunhes polarity transition near bishop california summary exposed pleistocene lake sediments at three localities separated by as much as six kilometres near bishop california contain the change from reverse to normal palaeomagnetic polarity that occurred about 0 73 million years ago the matuyama brunhes m b transition a decrease in the relative field strength is used to define the length of the transition the width of that decrease exceeds by about one fifth the width where the palaeomagnetic directions show the switch in polarity because some of the usually six subsamples in a measured horizon in the central part of the transition have normal polarity while others have intermediate or reverse polarity the behaviour of the palaeomagnetic field in that region cannot be determined accurately there is however a short reversal within the upper quarter of the transition at one locality that can be documented at least 30 cm of normal polarity underlie reverse polarity at three sites spread over a distance of 150m taken as a whole the palaeomagnetic data for the full transition are a warning that some rapid short reversals within the transition that are reported in the literature might be caused by inaccurate recording of the palaeomagnetic field the palaeomagnetic polarity 17m beneath the m b transition at one locality places a minimum age of about 1 0 myr on the glass mountain d ash bed that is found in east central and southern california

magnetic susceptibility of the rock matrix related to magnetic fabric studies non ferromagnetic minerals constitute what is called the rock matrix whose susceptibility k1 is directly accessible using only high magnetic fields measurements on minerals and a wide range of rock types show that k1 is mainly due to paramagnetism and hardly exceeds 10 3 si with an anisotropy degree p less than 1 35 different methods to estimate the role of the matrix component in low field susceptibility k and its anisotropy include petrological and chemical analysis evolution of p vs k low temperature studies and comparison of k with remanent magnetizations

effects of experimental deformation on the remanent magnetization of sediments abstract changes in direction and in intensity of the remanent magnetization of sediments were studied during experimental deformation leading to an axial shortening of 20 30 the remanence was produced before shortening by anhysteretic magnetization in an alternating field of 90 mt superimposed on a parallel steady field of 1 mt at various inclinations with respect to the sample the samples were sandstones marls and volcanic sediments the results show that the direction of magnetization is stable during the deformation within the experimental precision the intensity of magnetization decreases during shortening by an amount which depends on the type of rock about 30 for sandstones and about 5 for marls and volcanic sediments the march model does not account for the data and a discontinuous deformation must be invoked the evolution of the young modulus of sandstones during cyclic loading and unloading shows first a decrease in relation to crack density growth then an increase showing a localization of the fracturation and finally a deformation by displacement of microblocks an interpretation is given after a discussion of the results obtained by other authors with plasticine and artificial clays the amplitude of the decrease and of the rotation of the remanent magnetization could be a function of the size of the magnetic grains compared with the scale of the fracturation during non homogeneous processes of deformation

intersecting intracontinental tertiary transform fault systems in the north american cordillera in central british columbia north trending dextral strike slip faults that cut late eocene granite also truncate northwest trending dextral strike slip faults the northwest trending strike slip faults bound the wolverine metamorphic complex wolverine complex which has been uplifted primarily by northwest southeast eocene crustal extension and somewhat by late eocene northerly extension the crustal extension is indicated by shallow dipping extensions faults dyke complexes and stretching lineations the wolverine complex and its bounding faults define a crustal pull apart in an en echelon dextral transform the northwest and north trending dextral strike slip faults in central british columbia are the continuations of faults that transect the interior of the north american cordillera and they represent at least two distinct plate boundaries intermittently active during the early to middle eocene and the late eocene to early oligocene each of these systems consists of en echelon strike slip fault

northward motion of the whitehorse trough paleomagnetic evidence from the upper cretaceous carmacks group reply the upper cretaceous carmacks group 70 4 2 4 ma comprises gently dipping basaltic and andesitic lava flows overlying volcaniclastic deposits of the intermontane belt in the whitehorse trough the sampling area is in southern yukon and northern british columbia it lies west of the tintina northern rocky mountain trench fault and teslin suture zone and east of the denali shakwak fault volcanic sections were sampled in three regions spread over 300 km providing the first paleomagnetic data from pre tertiary volcanic rocks in the northern canadian cordillera alternating field and thermal demagnetization revealed stable magnetization for 18 of the 27 sites collected the overall mean direction d 166 7 i 71 4 k 53 95 4 8 n 18 sites is pre folding and is most probably primary latest cretaceous this gives a paleopole at 109 4 e 82 1 n k 21 a95 7 8 a critical evaluation of north american cratonic data yields a reference paleopole for the latest cretaceous at 185 8 e 77

gradient irregularity in the herbert gorge of northeastern australia the seventy kilometre long herbert gorge of northeastern australia preserves a record of past floods in slackwater deposits and palaeostage indicators step backwater modelling of water surface profiles indicates that discharges ranging from 11000 to 17000 m3s 1 have occurred six times in the gorge during the last 900 years these flood reconstructions provide insight into the role of extreme flows in shaping bedrock channel morphology in particular the hydraulics of extreme flows can be related to boulder transport and to the location of large boulder bars large boulder bars occur throughout the herbert gorge being best developed at loci of stream power minima along the inside of bends at tributary junctions and at obstructions in the channel caused by bedrock highs only the flows exceeding approximately 8000 m3 s 1 are competent to transport the boulders which constitute the bars in the straight channel reaches the boulder accumulations and bedrock highs have a fairly regular spacing which appears to be independent of lithologic or structural controls the bars provide an efficient means of energy dissipation and they are interpreted as a result of the inherent high turbulence of flow in a steep channel the regular spacing of the bars and their correspondence with the hydraulics of large flows suggest that the bars and associated bedrock highs may represent a self regulating mechanism akin to the pool riffle sequence of alluvial channels it may therefore be appropriate to view bedrock channels as deformable on the timescale of extreme discharges

cretaceous remagnetization in the sylvester allochthon limits to post 105 ma northward displacement of north central british columbia the sylvester allochthon of the slide mountain terrane in northern british columbia is a structurally interleaved assemblage of ocean floor lithologies ranging in age from late devonian to late triassic it is the most inboard of oceanic suspect terranes and rests as a vast klippe on miogeoclinal strata of the cassiar terrane the sylvester allochton and the cassiar terrane lie west of the northern rocky mountain trench fault both the sylvester allochthon and the cassiar terrane are intruded by mid cretaceous 105 ma granite of the cassiar batholith six oriented cores were collected at each of 12 sites in guadalupian parafusulina bearing limestone of the sylvester allochthon at a location 4 km from the batholith isothermal remanent magnetization irm acquisition and subsequent thermal demagnetization indicate that pyrrhotite is the dominant ferrimagnetic mineral least squares line fitting to four thermal demagnetization steps between 150 and 310 c was used to determine the characteristic natural re

determination of stress from slip data faults and folds a new technique is derived to invert slickenside data for the stress field that caused the faulting episode this inversion is simplified by the assumption that the magnitude of the tangential traction on the various fault planes at the time of rupture is similar study of three normal faulting regimes shows that the inversion derived with this assumption yields results that closely match older inversions that did not include the assumption hence the assumption may be valid and is shown to be justified by analyzing a simple fracture criterion application of slip data inversions is extended from faulting regimes to the slip on bedding plane faults in folding regimes comparison of the inversion results with the geometry of the folds shows this application to be successful greatly increasing the number of data sets that can be used to find the paleostress field

geometric test for late cretaceous paleogene intracontinental transform faulting in the canadian cordillera the tintina trench northern rocky mountain trench tt nrmt fault zone and the fraser river straight creek fr sc fault zone are separate en echelon concentric small circle fault segments of a composite intracontinental transform fault zone more than 2500 km long that cuts diagonally across the canadian cordillera from the outboard part of a tectonic collage of accreted foreign terranes in the south into the north american preaccretionary continental margin in the north most of the 450 km of right hand slip on the tt nrmt fault zone was transformed southward during the late cretaceous and paleocene into oblique convergence in the southern canadian rockies the remainder probably comprising less than 100 km was transformed southwestward during early and middle eocene time via a zone of distributed shear and east west crustal stretching into right hand slip on the en echelon fr sc fault zone these interpretations based on regional systematic mapping of geologic structures are in conflict with interpretations of paleomagnetic measurements that call for more than 1000 km of post mid cretaceous right hand displacement along the general locus of the tt nrmt fault zone involving foreign terranes and the parts of north america to which they had been accreted this paradox must be resolved

recent landscape history in arid western new south wales australia a model for regional change accelerated erosion by wind and water has taken place in arid western new south wales australia since the introduction of domestic and feral herbivores by europeans in the nineteenth century this action led to widespread soil loss by sheetwash rilling gullying and aeolian deflation upland creek systems formerly comprising shallow sinuous channels are now entrenched into alluvial fills on the valley floor radiocarbon dating of charcoal from aboriginal cooking pits exposed by this erosion indicates that the current phase of incision of the valley floor has occurred since grazing of domestic animals began about 140 years ago stratigraphic evidence is presented which suggests that this type of incision gullying or arroyo cutting in the valley floor may not have occurred before within the 20 000 year sedimentary history of the valley fills studied channel enlargement and knickpoint retreat initiated by these changes is ongoing and the implications of this for land and heritage management in the region are discussed a conceptual model is presented which summarises the hydrogeomorphic changes which have occurred in upland catchments in the region as a result of changes in landcover

paleomagnetism of the spences bridge group and northward displacement of the intermontane belt british columbia a second look the spences bridge group is a mid cretaceous 104 ma volcanic succession in the southern intermontane belt of the canadian cordillera 50 5 n 121 w it comprises the pimainus formation mafic to felsic lava volcaniclastic and interbedded epiclastic rocks and the overlying spius formation andesitic lava flows including previous work we have 55 sites distributed among 15 localities representing most of the 3000 m thickness forty seven sites 286 oriented cores 457 specimens mainly andesites yielded acceptable data the beds are gently to moderately tilted partly due to synvolcanic deformation samples taken from a sequence of flows at any one locality have with one exception well grouped magnetization directions polarities are all normal as expected for rocks laid down in the cretaceous normal superchron declinations always are clockwise of that expected of cratonic north america indicating 60 rotation of the spences bridge group as a whole however declinations differ from locality to locality implying relative interlocality rotations about vertical axes hence inclination only analysis has been used to estimate dispersion mean inclination and paleolatitude minimum dispersion for the spius formation 27 sites was achieved after 80 untilting but the changes between 80 and 100 untilting are insignificant indicating that magnetization was acquired predominantly before tilting by contrast minimum dispersion for the pimainus formation 20 sites was achieved after 50 untilting indicating that magnetization was acquired after synvolcanic tilting when buried beneath the overlying spius formation polished thin section studies show that magnetite in the pimainus formation has undergone extensive low temperature hydrothermal alteration whereas magnetite in the spius formation shows little alteration throughout the range of tilt correction from 0 to 100 the mean inclinations of both formations were less than expected from observations obtained from mid cretaceous rocks of cratonic north america the best estimate of paleolatitude from the spius formation is 50 8 5 0 p 0 05 which is 9 5 5 7 less than would be expected had the rocks had been rigidly attached to north america this corresponds to displacement from the south of 1100 600 km displacement between the northern intermontane belt and craton probably was accommodated along major strike slip faults northern rocky mountain trench finlay pinchi etc in the south our results require a major dextral fault the intra quesnellia fault to be situated during late cretaceous or paleocene time within or marginal to the omineca belt along which about 1000 km of dextral motion occurred this could be a southern extension of the pinchi fault whose trace is now obscured by eocene extension and tectonic denudation the results also indicate that the largest tectonic discontinuity in the canadian cordillera occurs not to the east of the intermontane belt as commonly assumed but to the west because the displacements relative to cratonic north america observed from the intermontane belt are only about one third of those observed from the coast belt

challenging intensification human environment interactions in the holocene geoarchaeological record from western new south wales australia an intensification theory was developed in australian archaeology in the early 1980s from a desire to make the study of australian hunter gatherers closer to theoretical developments in hunter gatherer studies elsewhere an apparent increase in the quantity and range of archaeological deposits was interpreted as demonstrating a combination of population increase and increased social complexity beginning 2 3000 years bp data were amassed in support of the theory but with only one or two exceptions they were not directly tested here we report on a series of studies that permit us to formulate a test for one aspect of the intensification theory chronologies constructed using osl determinations of sediments are combined with the results of age determinations obtained from hearth charcoal to develop an envelope of time for human occupation of the southeast margin of the australian arid zone the results indicate that the apparent increase in the quantity and range of archaeological materials in the late

late holocene major australian arid period revealed by direct sedimentological evidence from lakes in the coorong region of south australia sedimentological studies of six holocene lakes in the coorong region of south australia have revealed the presence of a calcrete layer at a similar stratigraphic level in all of these lakes the calcrete layer lies at

digital imaging technology and experimental archeology a methodological framework for the identification and interpretation of fire modified rock fmr abstract this paper presents the results of a series of experiments for the identification and analysis of fire modified rock fmr fmr is a common but frequently overlooked artifact type experiments were conducted simulating the effects of different hypothetical burning scenarios on rocks similar to those found in a south african middle stone age site a digital imaging method was then used to quantify fmr color values designed to limit intra analyst bias statistical tests and a blind test suggest that unburned rocks and experimental fmr can be separated statistically based on physical appearance two burning scenario models based on measured experimental data were applied to archaeological fmr from a south african middle stone age site named pinnacle point 5 6 pp5 6 and show that the archaeological samples are not statistically different from a simulated campfire and possibly a lithic raw material heat treatment fire

determination of position gradient tensor from strain measurements and its implications for the displacement across a shear zone abstract a method is proposed for determination of the position gradient tensor from conventional strain measurements the position gradient tensor can be multiplicatively decomposed into two components left stretch and rotation tensors the former is readily supplied by field strain data whereas the latter is generally unknown in nature in order to determine the position gradient tensor using strain data it is assumed that structures within a shear zone are symmetric about the plane common to the transport direction and the pole to the shear zone or alternatively that the shear strain in the direction parallel to the pole to the shear zone on the plane normal to the transport direction in a parallel sided shear zone is negligible with these assumptions the position gradient tensor is fully determined from the attitude and principal ratios of the strain ellipsoid determined from field data this method has been applied to the strain data from deformed fragments in a succession of late triassic volcanic breccias abutting a large strike slip shear zone in north central british columbia the resulting position gradient tensor is then used to constrain the displacement across the shear zone suggesting 39 shortening normal to and dextral displacement of about 1700 m along the shear zone

where were the hearths an experimental investigation of the archaeological signature of prehistoric fire technology in the alluvial gravels of the southern plains the interpretation that a rock has been subjected to cultural utilization is a basic element of hunter gatherer research the fracture mechanics of the flaked stone tool production process are well understood and the material residues are routinely identified during fieldwork conversely non percussion processes such as hot rock technology which can result in rock fracture are less well understood an experimental study has been developed to examine the fractured gravels observed at a prehistoric site on the southern plains usa the experiment has sought to determine whether cultural or natural agencies were responsible for the production of the angularly fractured rocks the positive results of the experiment indicate that not only were humans most likely responsible for the breakages but also that the fractured rocks often exhibit distinctive morphologies that may be identified during fieldwork this simple experimental methodology is applicable to other hunter gatherer sites where the depositional environment is not conducive to the structural preservation of features such as hearths

paleomagnetism and crustal rotations along a shear zone las vegas range southern nevada in southern nevada paleozoic isopachs mesozoic structures and mountain ranges trend north south but as they approach the right lateral west northwest trending las vegas valley shear zone lvvsz they are bent clockwise up to 90 in oroflexes 30 km long in the las vegas range the declination of the characteristic magnetization of the cambrian bonanza king formation has likewise been rotated clockwise more than 50 for samples from eight sites 13 23 samples per site in the las vegas range and in its extension south of the lvvsz stepwise thermal demagnetization to 600 c removed recent and tertiary overprints revealing a nearly horizontal late paleozoic viscous partial thermoremanent magnetization vptrm which predates both the tertiary oroflexural bending and the sevier thrusting in the area the declination of the characteristic magnetization after correcting for the dip of bedding varies from 133 2 at a site 24 km north of the shear zone to 196 4 13 km north of it and 204 4 11 km south of the shear zone this parallels a similar change in the structural trend the paleomagnetic data indicate that the las vegas range is broken into rather small blocks 5 km which rotate in response to more continuous deformation at depth this deformation of the upper crust can be modelled using a thin non newtonian viscous plate model which when applied to the las vegas valley shear zone predicts rotations similar to those seen in the las vegas range

bathozonal tilt corrections to paleomagnetic data from mid cretaceous plutonic rocks examples from the omineca belt british columbia the skelly creek batholith 49 4 n 116 6 w 94 99ma and summit stock 49 1 n 117 0 w 102 ma are intruded into the southern omineca belt of southeastern british columbia bathozonal mineral assemblages from contact aureoles of these plutons and others of the same age indicate that post emplacement tilting of the purcell anticlinorium has probably not exceeded about 5 whereas the summit stock has been tilted 24 down to the west the skelly creek batholith has a mean direction of magnetization d i with respect to present horizontal 349 74 13 sites k 53 95 6 the mean direction of magnetization of the summit stock is 48 72 nine sites k 290 95 3 and after correction for a westerly dip of 24 the mean direction becomes 318 74 directions of the skelly creek batholith and tilt corrected direction from the summit stock are in agreement with the reference field for cratonic north america evidently this part of the eastern omineca belt was close to the margin of ancestral north america in mid cretaceous time essentially where it is today

major dextral transcurrent displacements along the northern rocky mountain trench and related lineaments in north central british columbia the northern rocky mountain trench and a number of other prominent lineaments along and east of the eastern margin of the intermontane belt mark faults along which dextral transcurrent movements have been dominant offsets of shelf to off shelf facies boundaries in lower paleozoic rocks indicate a cumulative displacement of at least 750 km and probably 900 km within the system of faults related to those in the northern rocky mountain and the tintina trenches farther west another system of faults appears to offset plutons and stratigraphic assemblages along the eastern margin of the intermontane belt by as much as 300 km these faults including the kutcho and the pinchi connect in part with the teslin suture zone in yukon territory and probably with the fraser river straight creek fault zone in southern british columbia although dextral transcurrent faulting may have taken place between the middle jurassic and early cenozoic the most convincing evidence points to middle cretaceous and particularly to early cenozoic eocene displacements the eocene movements were temporally related to plutonism volcanism lamprophyre dike emplacement high heat flow sedimentation in grabens and rapid uplift of northwesterly trending elongate ranges climactic episodes of granite emplacement particularly in and near the northern omineca crystalline belt at 100 m y 70 m y and 50 m y ago may have been facilitated by changes from dominantly compressional to dominantly transcurrent and related tensional strain

northward translation of baja british columbia along the late cretaceous to paleocene margin of western north america paleomagnetic data suggest that a large part of british columbia and southern alaska was at the latitude of baja california mexico in early late cretaceous time this allochthonous block baja bc includes the insular talkeetna in alaska and intermontane composite terranes the miniterranes between them and possibly part of the omineca metamorphic belt assuming that baja bc was adjacent to north america by middle cretaceous an analysis using plate kinematics of the pacific basin produces a model of northward movement of baja bc which is compatible with the known geology of the reconstructed margin of western north america baja bc moved north 2400 km as part of the kuia plate along a transform margin with north america from 85 to 66 ma this time interval is marked by the cessation of igneous activity in the sierra nevada development of wrench faults and basins along coastal california and initiation of laramide style tectonics to the east within baja bc diminished igneous activity to the west was coeval with possible wrench tectonic basins along its eastern margin by the end of the cretaceous baja bc was positioned from oregon to northern british columbia between 66 and 56 ma baja bc became attached to north america in a dextral transpressive stage during which the kula north america plate boundary expanded to encompass the whole block with a series of northwest trending strike slip faults a fold and thrust belt in the east and large scale uplifts and the formation of an incipient volcanic arc on the west southern alaska was the site of convergence during the whole of the period of northward translation of baja bc a late cretaceous subduction zone in alaska evolved into a major compressional belt as the basin and miniterranes on the northern margin of baja bc collided with interior alaska the collision culminated in the paleocene with formation of the mckinley granites and coeval dextral slip on the denali fault system

a 30 000 year record of extreme floods in tropical australia from relict plunge pool deposits implications for future climate change relict plunge pool sedimentary sequences provide much longer paleoflood records than normally provided by slackwater deposits and other previously reported paleoflood sedimentary signatures the only two relict plunge pool sedimentary sequences so far reported lie 300 km apart in tropical northern australia and provide a record of extreme floods for the last 30 000 years each of these sequences identify the early to mid holocene and the period immediately prior to the last glacial maximum as the two periods of greatest flood magnitudes of the late quaternary flood discharges at these times were up to five times greater than any floods experienced over the last 4 000 years most climate models predict that the magnitude and frequency of storms and rainfall events will increase under a warmer greenhouse climate the plunge pool sedimentary sequences however show that periods of greatly enhanced discharge compared to present can be associated with both warm wet and cool wet phases of climate

complexity and the australian continental narrative themes in the archaeology of holocene australia accounts of long term cultural change in australia have emphasised the late holocene as the period when complexity emerged amongst foragers in australia associated with increased economic productivity reduced mobility population growth intensified social relations and cosmological elaboration these reconfigurations have often been interpreted as the result of continent wide trajectories which began in the mid holocene often termed intensification these approaches have been found wanting as they homogenise diverse records of human adaptation into a single account which inexorably leads to the ethnographic present the archaeological record tells a rather different story with fluctuating occupational intensity and even regional abandonments featuring in well documented archaeological records instead variability documented in the ethnographic and archaeological records can be understood as a product of local adaptations reflecting the operation of historically situated systems of social organisation in diverse environmental settings

discordant paleomagnetic poles from the canadian coast plutonic complex regional tilt rather than large scale displacement stratigraphic petrologic and isotopic data indicate that parts of the coast plutonic complex and the north cascade range have been tilted northeast side up by angles of approximately 30 degree about north northwest trending axes these tilts can account for discordant paleomagnetic directions observed in mid cretaceous plutons from these regions without large scale displacement relative to north america

fabrics and kinematic indicators associated with the local structures along finlay ingenika fault mcconnell creek area north central british columbia structures associated with dextral transcurrent displacement on the finlay ingenika fault are characterized predominantly by subvertical to vertical faults intersections of the fault planes with planar fabrics are all subvertical this geometry together with the common occurrence of subhorizontal slickenlines and stretching lineations in some strongly deformed fault zones indicates their strike slip nature principal directions of the strain ellipsoids determined from the deformed volcanic fragments along one of the faults are in accordance with those of the magnetic susceptibility ellipsoids from the adjacent plutonic rocks indicating that the plutonic rocks experienced the same deformation as the late triassic takla group volcanics regional cleavage within the fault bounded blocks indicates that the blocks were nonuniformly rotated clockwise about subvertical axes in response to progressive dextral transcurrent displacement on the finlay ingenika fault the mode of deformation observed in the a

holocene palaeoecology of the northern flinders ranges south australia based on stick nest rat leporillus spp middens a preliminary overview eight stick nest rat leporillus spp middens from three locations in the northern flinders ranges south australia provide a discontinuous palaeoecological record spanning the holocene evidence from radiocarbon dates pollen plant macrofossils and animal macrofossils is presented both pollen and plant macrofossils show that in the early to mid holocene c 8 8 5 3 ka woodlands with grassy understoreys were more widespread than present this accords with other studies suggesting wetter conditions at this time samples dating of the pleistocene holocene transition 10 9 9 ka are dominated by halophytes it is not yet clear whether this is due to the continuation of pleistocene aridity changes in rainfall seasonality or local influences on vegetation

human response to palaeoenvironmental change and the question of temporal scale investigating past human environment interactions requires not only suitable environmental proxies and well dated archaeological records but also a uniform temporal resolution between the two in the arid interior of australia the archaeological record of human occupation is known only from relatively few locations and palaeoenvironmental records with resolution on timescales akin to human lifetimes are rare even where detailed archaeological and palaeoenvironmental studies have been undertaken concurrently it has proven difficult to match the temporal resolution of both the archaeological and sedimentary records one approach is to make use of the extensive surface archaeological record and match it to high resolution palaeoenvironmental records from elsewhere here we utilise radiocarbon age determinations on charcoal from the deflated remains of heat retainer hearths from surface archaeological contexts in western nsw correlations with two different but related sets of environmental proxy data sea surface temperature fluctuations from the western pacific south china sea and australian dust deposition records from southern new zealand allow investigation of human responses to global environmental changes at a common temporal scale the correlations suggest a relationship between rapid climatic changes occurring over the last 3000 years and occupation by aboriginal people in the arid region of western new south wales aboriginal people abandoned large regions during times of lower rainfall and increased dust transport with some but not all regions reoccupied during periods of increased summer rainfall environmental fluctuations during the late holocene are likely to have posed marked challenges for aboriginal populations who occupied the region the patterns of radiocarbon assays from hearths provide a window into the nature of their response

paleomagnetic evidence for motions of parts of the canadian cordillera abstract paleomagnetic evidence from major terranes of the western cordillera in canada referred to collectively as baja british columbia indicates that they have moved as a whole about 2300 km from the south and rotated 60 clockwise relative to north america in the late cretaceous and earliest tertiary 85 50 ma sometime between the early jurassic and the mid cretaceous 190 100 ma these same terranes moved south over 1000 km and underwent irregular but where well constrained counter clockwise rotations the terranes amongst themselves seem to have shared much the same paleolatitude during and since the late triassic although they may have undergone relative rotations in the later jurassic and early cretaceous these motions are now known to be broadly consistent with the motions of oceanic plates to the west as calculated by independent procedures and indicate that the terranes of the western cordillera were for part of their existence coupled to oceanic plates first to the farallon plate during the late jurassic and early cretaceous and then to the kula plate during the late cretaceous and early tertiary it was this change of allegiance from farallon to kula that caused first the southerly and then the northerly motion the paleomagnetic evidence despite claims to the contrary is consistent with geologically inferred displacements along major faults in the canadian cordillera when due account is taken of the age constraints on those motions

bedrock benches and boulder bars floods in the burdekin gorge of australia the burdekin gorge of northeastern australia lies within the seasonal tropics and is characterized by high discharge variability slackwater sediments and paleostage indicators in the gorge record seven large floods that have occurred during the past 1 200 yrs these floods range in magnitude from 11 000 to 30 000 m 3 s 1 and are characterized by large downstream variations in hydraulics the floods generate high values of velocity boundary shear stress and stream power per unit area downstream fluctuations in these variables help to explain the location of boulder bars high flood levees small scale erosional features in the bedrock and the formation of inner channels boulder bars and flood levees form where shear stress and stream power decrease due to channel widening small scale erosional features such as potholes and troughs are best developed at sites of channel constriction and associated increases in shear stress and stream power the development of the inner channel appears to be controlled by complex interactions between bedrock lithology and structure and by flow hydraulics all of the channel features are related to the hydraulics of large floods which therefore are the dominant controls on many aspects of channel morphology in this bedrock gorge

stratigraphy sedimentology chronology and palaeohydrology of quaternary lacustrine deposits at madigan gulf lake eyre south australia abstract madigan gulf is a large bay at the southern end of lake eyre north a major ephemerally flooded playa in arid central australia at the southwestern margin of a vast 1 300 000 km2 internal drainage basin the stratigraphy and chronology of the quaternary sequence in the gulf is described from 8 cores and a cliff exposure at the gulf margin a number of depositional environments are recognised and their distinctive sedimentary components are described facies recognised include deep and shallow water lacustrine environments dominated by surface water processes and dry or ephemerally flooded playa environments dominated by groundwater controlled processes sedimentary components include terrigenous clastics from river inflow and shoreline erosion carbonates of detrital inorganic or biological origin and gypsum and halite evaporites carbonates and gypsum evaporites precipitated within the basin are frequently reworked as clastic components the establishment of a preliminary chronology for the sequence by the application of thermoluminescence uranium thorium disequilibrium amino acid racemization and radiocarbon dating techniques has allowed a reconstruction of the last 130 ka of lake eyre palaeohydrology the wettest phase occurred during the last interglacial early in oxygen isotope stage 5 when an enlarged lake eyre was up to 25 m deep subsequently there has been a number of dry periods separating successively less effective wet phases culminating in the deposition of a substantial halite salt crust around the time of the glacial maximum the dry interludes are characterised by deflation of salts and sediment from the basin a process controlled by lowering of the watertable the record from madigan gulf demonstrates the dramatic and repetitive impact of lake deflation on the quaternary record of lake eyre in the early holocene a minor but mostly perennial lacustrine event was terminated at about 3 4 ka when the modern ephemeral playa regime was established the major catchment of lake eyre is located in the monsoon watered areas of northern australia as demonstrated by large floodings of the modern ephemeral regime major lacustrine episodes must indicate enhanced monsoon precipitation in northern australia in the holocene the lake has not risen to levels achieved during the early stage 5 lacustral phase indicating a marked reduction in the effectiveness of the monsoon in the present interglacial by comparison with its predecessor

human environment interactions in australian drylands exploratory time series analysis of archaeological records exploratory time series analysis of radiocarbon data from archaeological contexts is used to reconstruct the population history of arid australia allowing this to be read in concert with records of climatic variability over the last 20 000 years probability distribution plots of 971 radiocarbon ages from 286 sites in five dryland regions the arid west coast pilbara and murchison nullarbor arid interior and the southeastern arid zone provide a proxy record of prehistoric population fluctuations in these areas there is regional variation but the radiocarbon density plots suggest a step wise pattern of population growth and expansion with significant thresholds at 19 8 and 1 5 cal kyr bp within this the plots suggest a saw tooth pattern of rapid population growth and decline on a 1 3 kyr frequency with a marked collapse of dryland hunter gatherer populations around 3 2 5 cal kyr bp affecting most regions comparison with climate data shows broad correlations with past temperature and rainfall

block rotations along the strike slip finlay ingenika fault north central british columbia implications for paleomagnetic and tectonic studies structure developed in association with oblique motions on the dextral strike slip finlay ingenika fault fif in the mcconnell creek area north central british columbia is dominated by subvertical to vertical strike slip faults some of the faults cut the area into discrete fault bounded blocks several kilometres wide stress tensors for 24 sites were inverted from the regional cleavage which predates the block bounding faults the site mean stress tensors indicate that the fault bounded blocks were rotated clockwise about a subvertical axis during progressive oblique motions on the fif rotation varies systematically being maximal 58 7 3 3 close to the fif and minimal 0 0 1 6 about 20 km away paleomagnetic samples were collected from 13 sites in the widespread early jurassic to cretaceous plutonic rocks interpretable magnetic components of presumed late cretaceous age were obtained from six sites the observed paleopole is significantly different from the late cretaceous reference pole for cratonal north america cna after corrections for the local block rotations the precision is much improved k increased from 48 to 383 and the paleopole moves closer to the reference pole but is not coincident with it rotation about the eulerian pole for the best fitting small circle to the tintina trench and northern rocky mountain trench fault zone however brings the observed pole into coincidence with that for cna and requires 670 km of dextral displacement on the fault zone it is evident therefore that local structures associated with large dextral strike slip faults could account for at least part of the paleomagnetic disparity between some western parts of the canadian cordillera and cna

paleomagnetism of the upper cretaceous strata of mount tatlow evidence for 3000 km of northward displacement of the eastern coast belt british columbia this study contributes the first paleomagnetic data from dated cretaceous units of the coast belt 51 3 n 123 8 w in which paleohorizontal bedding surfaces can be identified with certainty we sampled 38 sites through a 1 5 km stratigraphic interval of cenomanian silverquick sedimentary strata and cenomanian to campanian powell creek volcanics in the tatlow syncline in the tyaughton methow basin magnetizations at 21 sites have high unblocking temperatures tub and pass the tilt test precision k 5 before untilting maximum k 48 after 100 untilting magnetic minerals of volcanics show original textures mean declinations in volcanic and sedimentary rocks are statistically identical and polarity is consistently normal the mean inclination 55 4 3 4 probability p 0 05 of this pretilting magnetization is 20 1 4 0 shallower than that expected if the rocks were deposited in their present position relative to cratonic north america field and laboratory observations rule out other causes for these anomalous shallow inclinations these rocks therefore have been displaced northward by 3000 500 km relative to cratonic north america since mid cretaceous time this displacement is almost 3 times greater than that estimated from mid cretaceous volcanics in the now adjacent intermontane belt evidently the two belts were not amalgamated until latest cretaceous or early tertiary time these results are inconsistent with all previous geologically based tectonic reconstructions of the cordillera magnetizations at eight sites in silverquick and powell creek beds have low tub and directional characteristics similar to those in three younger diorite intrusions reversed and normal polarities occur the rocks are commonly highly altered and maximum precision occurs after 40 untilting the magnetizations therefore are interpreted as overprints of latest cretaceous age acquired during folding

paleomagnetic evidence for displacement from the south of the coast plutonic complex british columbia the mid cretaceous spuzzum and porteau plutons of the coast plutonic complex of british columbia have two magnetizations a and b the a magnetization eight sites 83 specimens d 30 3 i 56 7 95 4 9 paleolatitude 37 5 n paleopole 65 0 n 14 9 w a95 6 2 is considered to have been acquired in the age range 105 90 ma this result differs from the field established for cratonic north america in this time range the difference could be caused either by previously undetected tilting about a horizontal axis of the plutons or by their rotation about a vertical axis and lateral displacement relative to the craton previously observed mid cretaceous magnetizations from other rock units from the western canadian cordillera and the cascades of washington united states are similarly discordant with respect to the craton this similarity over such a large area indicates that although local undetected tilting could be partly responsible it is unlikely to be the prime cause and we argue ther

paleomagnetism of 122 ma plutons in new england and the mid cretaceous paleomagnetic field in north america true polar wander or large scale differential mantle motion a paleomagnetic study of cretaceous white mountains plutonic complexes in new hampshire and vermont yields high unblocking temperature dual polarity magnetizations in different types of igneous rocks the resulting pole position for three plutons 71 9 n 187 4 e a95 6 9 age 122 5 ma agrees with previously published mid cretaceous poles for north america which together give a mid cretaceous standstill reference pole slightly revised from globerman and irving 1988 at 71 2 n 194 1 e a95 3 7 n 5 studies we argue on the basis of the wide geographic distribution of these studies the variety in tectonic settings and rock types positive reversal tests and an overall reversal pattern consistent with geomagnetic polarity time scales that this mean pole represents the north american mid cretaceous reference field for nominally 36 m y 124 to 88 ma the standstill pole limits to within 4 the motion of the north american plate relative to the earth s spin axis during the same mid cretaceous interval the new england hotspot track 124 ma monteregian hills 122 5 ma cretaceous white mountains and 103 to 84 ma new england seamounts requires 11 4 of north poleward motion of north america in direct conflict with the paleomagnetic standstill a similar 13 discrepancy is independently demonstrated between the spin axis and the tristan da cunha hotspot track on the african plate during the mid cretaceous interval the hotspot spin axis discrepancies ended by 90 ma when it is shown that both atlantic hotspots agree with north american and african dipole paleolatitudes and present day locations nondipole fields are an unlikely explanation of the uniform motion of these two widely separated hotspots with respect to the spin axis leaving as possible interpretations true polar wander and large scale but differential mantle motion the southerly motion of the mid cretaceous louisville hotspot relative to the spin axis is ostensively at odds with what would be predicted under the true polar wander interpretation and points to differential mantle kinematics the motions of the three widely separated mid cretaceous hotspots with respect to the spin axis may be related to the recently proposed increase in global oceanic lithosphere production rates which gave rise to the mid cretaceous superplume

tilt and northward offset of cordilleran batholiths resolved using igneous barometry considerable controversy surrounds the suggestion based on palaeomagnetic evidence that large segments of the north american cordillera travelled long distances parallel to the coast during the latest cretaceous and early tertiary periods well after the amalgamation of exotic terranes discordant palaeomagnetic data from mid cretaceous plutonic rocks of the peninsular ranges batholith of coastal southern california and baja and the mount stuart batholith of the cascade range in washington play a pivotal role in the controversy the discordant data were originally interpreted to reflect northward transport of 1 000 km relative to cratonal north america after the batholiths cooled through their magnetic blocking temperatures1 5 more recently it has been argued that the discordances arise from local tilting of batholiths rather than northward offset6 7 here we present and implement new methods based on hornblende barometry8 for determining the palaeohorizontal in granitic batholiths and correcting palaeomagnetic data for tilting our results indicate that the peninsular ranges and mount stuart batholiths have undergone northward offsets of 1 000 450 and 2 900 700 km respectively and also significant tilting

variability in the chronology of late holocene aboriginal occupation on the arid margin of southeastern australia analysis of 28 radiocarbon determinations obtained from the excavation of heat retainer hearths from sturt national park in western new south wales indicates aboriginal occupation of the arid margin of australia during the last 1700 years the determinations show two phases of hearth construction separated by a period of at least 200 years and possibly 400 years when no hearths were constructed palaeoenvironmental and archaeological evidence is reviewed in an effort to account for the late holocene dates from the hearths and the existence of the hiatus in hearth construction despite the close match between the hiatus and the so called medieval warm period caution is required before extrapolating the results from an archaeological study of a small geographic region to the continent as a whole

late quaternary lake level changes and climates of australia abstract spatial and temporal patterns in lake level data from 38 sites in australia and papua new guinea provide a basis for reconstructing changes in water balance and atmospheric circulation during the past 30 000 years the reconstructions are consistent with hydrological changes inferred from pollen analysis and palaeowind directions inferred from dunes generally wetter conditions between 30 000 and 24 000 bp are consistent with a strong walker circulation with the sta near its present position general aridity at the glacial maximum until 12 000 bp with higher than present lake levels in the southeastern interior of australia implies that the southern margin of the subtropical anticyclone belt was expanded southward and the southern westerlies were correspondingly displaced this southward shift appears in all gcm simulations of the 18 000 bp climate and may be a result of the increased vigour of the northern hemisphere circulation a northward migration of the belt of high lake levels between 11 000 and 6000 bp suggests that the sta shifted back equatorward to north of its present position relaxation to modern conditions occurred after 6000 bp interrupted by an unexplained dry phase 6000 5000 bp in tasmania and queensland

canadian cordilleran displacement palaeomagnetic results from the early jurassic hazelton group terrane i british columbia canada summary the early jurassic telkwa formation comprising the base of the hazelton group was sampled at three areas in the central part of the stikine terrane british columbia detailed alternating field and thermal step demagnetization on samples from nine sites from the red canyon area and 10 sites from the zymoetz river area both of which are in the bulkley ranges and eight sites from the telkwa range area isolate stable remanence magnetization components the components are interpreted to be primary magnetizations because of the presence of two polarities and the much improved agreement of their inclinations after full tilt correction of the sites from the bulkley ranges within locality declinations agree well between locality declinations are discordant the expected cratonic declination is 340 whereas declinations from this study are 265 227 and 328 for the red canyon zymoetz river and telkwa range areas respectively these results are similar to those of monger irving 1980 and we concur that the discordant declinations are the result of differential rotation about vertical axes between sample localities our observed mean inclination of 52 is in good agreement with monger irving s 1980 result of 54 they interpreted this to indicate 1300 km of northward displacement since the early jurassic and their interpretation was substantiated by several later studies however with revisions to the geologic time scale and the early jurassic reference pole for north america the early jurassic canadian cordillera palaeomagnetic data base appears latitudinally concordant this indicates that terrane i and southern wrangellia were in much the same latitudinal position relative to the north american craton as they are now tectonic displacement models developed in view of discordant cretaceous palaeomagnetic data from the canadian cordillera must now consider latitudinally concordant permian to early jurassic data and middle eocene to recent data this tectonic senario appears more reconcilable with the regional tilt hypothesis however this hypothesis cannot account for discordant cretaceous data from bedded volcanic rocks in terrane i it is therefore probable that cretaceous cordilleran tectonics were characterized by both regional tilting and moderate latitudinal displacement

changes in vegetation and seasonal climate since the last full glacial at lake frome south australia abstract results are presented from stratigraphy radiocarbon and pollen analysis from lake frome south australia close to the summer winter rainfall boundary at 30 south latitude the pollen sequence shows that tree vegetation was minor around 18 000 yr b p the landscape was dominated by chenopod low shrublands and ephemeral tubuliflorae vegetation by 17 000 yr b p callitris moved in and rose to 25 of the pollen sum values of casuarina myrtaceous shrubs acacia dodonaea and cyperaceae also rose at about the same time between 17 000 and 14 500 yr b p callitris and eucalyptus dominated the tree vegetation with callitris reaching its maximum values eucalpt woodlands were associated with undershrubs belonging to myrtaceae acacia dodonaea and gyrostemonaceae whereas callitris woodlands had probably supported only a sparse understorey chenopodiaceae today distributed mainly in the winter rainfall zone continued to show high values 25 gramineae today associated with high summer rainfall generally remained below 20 the sporadic presence of a number of taxa which now grow in temperate areas further south suggest that average annual temperatures were a little lower than at present from 14 500 to 13 000 yr b p there was a sudden decline in the values of callitris and a more gradual decline in chenopodiaceae and dodonaea the rise of ephemeral vegetation together with a fall in chenopodiaceae would indicate that winter precipitation had started to decline between 13 000 and 4500 yr b p chenopodiaceae and tubuliflorae ephemerals declined and gramineae rose to its highest values tribulus pollen a subtropical tropical taxon first appeared 13 000 yr b p overall plants from the summer rainfall zone became more prominent and taxa from the temperate south declined summer monsoon incursions apparently strengthened and temperature increased during this phase since 4500 yr b p both chenopodiaceae and tubuliflorae returned to high values whereas gramineae declined values of acacia and myrtaceous shrubs rose but those of casuarina declined and callitris remained extremely low these changes were accompanied by the onset of playa environments which have since persisted vegetation during this phase suggests that summer precipitation declined and summer monsoon incursions became rare during the late holocene

determination of the tectonic stress tensor from slip along faults that obey the coulomb yield condition a new method to calculate the stress tensor associated with slip along a population of faults is derived here the method incorporates two constraints first the stresses in the slip direction satisfy the coulomb yield criterion and second the slip occurs in the direction of maximum shear stress along the fault the computations provide the complete stress tensor normalized by the vertical stress and evaluation of the mean coefficient of friction and the mean cohesion of the faults during the time of faulting the present method is applied to three field cases dixie valley nevada wadi neqarot israel and yuli microearthquakes taiwan it is shown that the coefficieet of friction of the three cases varies between 0 1 to 0 8 further it is demonstrated that previous stress inversion methods implicitly assume zero friction along the faults

a fine resolution palaeoclimatic reconstruction of the last 2000 years from lake keilambete southeastern australia a fine resolution analysis of pollen charcoal magnetic susceptibility sediment fractions and total carotenoids was used to investigate the last 2000 years of environmental history at lake keilambete in western victoria australia the chronology of sedimentation was based on three radiocarbon dates supplemented by inferences from 22 previous radiocarbon ages from the site spanning approximately the last 7500 years changes in the analysed parameters infer a relatively higher effective moisture from approximately 2000 to 1800 cal bp increased instability in the lake keilambete catchment from 1750 to 1425 cal bp may reflect a decreased moisture availability and cooler temperatures at about 1450 cal bp a period of considerable environmental change is suggested at lake keilambete warmer temperatures or an increased moisture supply seem likely between 1415 and 1320 cal bp from around c 1150 until 800 cal bp overlapping the medieval warm period a series of changes in the composition of the la

past human populations and landscapes in the fuegian archipelago southernmost south america this contribution discusses possible relationships between human populations and holocene environmental deterioration phenomena cold arid pulses and volcanic eruptions in the fuegian archipelago south america based on summed probability distributions of archaeological dates paleoenvironmental information geospatial data and archaeological evidence during the first millennia after peopling only the hudson ca 7700 cal yr bp and the first monte burney ca 8600 cal yr bp eruptions might have played a role in human dispersion particularly a more intense human occupation around the beagle channel and long distance interactions are proposed as risk buffer strategies related to the hudson eruption a cooling phase and a demographic growth at ca 5500 cal yr bp might have favored more dispersed spatial occupations and a subsistence diversification in the beagle channel in the northern steppes the second monte burney eruption ca 4300 cal yr bp and an arid episode ca 2600 cal yr bp are proposed as the main triggers for changes in land use patterns long network interactions and subsistence strategies even though occupation changes in the fuegian archipelago coexist with environmental deterioration episodes after 1500 cal yr bp demographic processes and the european colonization most likely explain this trend similarities between the steppe ecotone and forest occupation curves suggest common behavioral patterns across the holocene

tectonic analysis of fault slip data sets using data that include the direction and the sense of motion on individual fault surfaces determined by slickenside lineations it is possible to reconstruct reduced stress tensors that correspond to the orientation of stress axes and to the ratio 2 3 1 3 between principal stress values 1 2 3 compression being positive no assumption is made concerning the orientation of fault planes relative to stress axes so that reactived faults are taken into account as well as newly created ones qualitative and quantitative methods for analysis of fault slip data were developed during the last 10 years the practical limitation of the methods and the necessity for critical field observations are emphasized these methods can be applied to focal mechanisms of earthquakes a more complex analysis of heterogeneous data sets involving an iterative separation of different stress systems is also discussed this analysis enables one to distinguish successive faulting events careful qualitative study in the field is in all cases essential

paleomagnetic and structural evidence for localized tectonic rotation associated with fault drag in the northeastern mojave desert implications for the late cenozoic tectonic evolution of the eastern california shear zone abstract paleomagnetic data coupled with detailed geological analysis of the southeastern goldstone lake region indicate that lower miocene volcanic and epiclastic rocks of the pink canyon area have been folded faulted and tectonically rotated 28 4 9 0 clockwise about a vertical axis identical rocks lying to the west across the goldstone lake fault east branch have been rotated 9 6 7 4 the coyote canyon fault is locally folded about a vertical axis 25 in a clockwise sense in the pink canyon area timing relationships indicate that rotation is post early miocene regional relationships imply that deformation is late miocene to holocene in age these relationships imply that tectonic rotation is local rather than regional in extent as proposed by some tectonic models the results of this study are generally consistent with the dokka and travis 1 model and the subsequently revised dokka model 2 of strain partitioning in the northeastern mojave desert block

paleomagnetic and inner diapiric structural constraints on the kinematic evolution of a salt wall the bicorb quesa and northern navarres salt wall segments case prebetic zone se iberia abstract paleomagnetism together with an analysis of the internal structure of the bicorb quesa and northern navarres salt wall segments prebetic zone in se iberia were used to constrain their kinematics and driving mechanisms paleomagnetic data from upper triassic red beds of the selected salt related structures and from the miocene rocks belonging to adjacent syn diapiric half grabens reveal 15 30 counter clockwise vertical axis rotations of the salt wall rocks and a 20 clockwise rotation of the jurassic miocene cover block located south of the salt wall this together with the salt wall structure indicates that the origin of the salt wall was linked to the motion of a late miocene thin skinned extensional fault system which detached on the upper triassic evaporites specifically the salt wall formed by the south southwest displacement with a 20 clockwise rotation component of a cover block bounded northwards by the detachment disruptions generated by the motion of pre existent basement faults the upper triassic detachment level was first affected by a counter clockwise vertical axis rotation and during the paleogene earliest miocene building of the iberian chain by tight wnw trending folds and sse directed minor thrusts this study also shows that paleomagnetism together with the analysis of the internal structure can successfully depict the geometry and kinematic evolution of complex salt wall structures

paleomagnetism and tectonics of the cretaceous mt stuart batholith of washington translation or tilt abstract the mt stuart batholith is a composite pluton of late cretaceous age that intrudes the crystalline north cascades terrane of northwestern washington its paleomagnetic direction d 10 0 i 45 5 95 4 9 is markedly different from the direction expected for cretaceous rocks from northwestern washington d 330 5 i 73 0 which means that the mt stuart batholith either has moved relative to the north american interior or has been tilted through a substantial angle or both since it acquired its magnetism either tilt or translation are possible geometrically but translation is more likely because 1 local geology apparently does not support tilt in the required direction 2 it probably is not possible for a panel of rock the size of the mt stuart batholith to tilt through the necessary angle ca 35 after its deeper parts have cooled sufficiently to retain remanent magnetization 3 the sense of paleomagnetic discordance found in the mt stuart batholith clockwise rotation of declination flattened inclination is identical to that found in nearly every other allochthonous terrane in the western north american cordillera including every other cretaceous batholith studied except the sierra nevada

multiple strike slip fault sets a case study from the dead sea transform in many strike slip tectonic settings large rotations of crustal blocks about vertical axes have been inferred from paleomagnetic data these blocks are bounded by sets of parallel faults which presumably accommodate the relative motion between the blocks as regional deformation progresses a mechanical model suggests that rotations greater than c 25 to 45 must be accommodated by more than one set of faults with the angle c between their directions consequently the sum of the angles between sets must be roughly equal to the total tectonic material rotation to test this model we investigated the fault geometry and field relationship of fault sets in the mt hermon area in northern israel where paleomagnetic declination data imply 69 13 counterclockwise ccw block rotation the statistical and field relationship analysis of over 315 faults shows that the faulting is predominantly right lateral strike slip consisting of three distinct sets the oldest set strikes 254 the second oldest set strikes 295 and the youngest strikes 331 this last direction is consistent also with the current north south direction of the maximum principal stress axis the angle c between the first and second sets is 41 and between the second and third sets 36 in good agreement with the c angle predicted from mechanical considerations the sum of the two angles is 77 ccw in good agreement with the 69 13 ccw paleomagnetically derived rotation the results suggest specifically that the sequential development of multiple intersecting fault sets is responsible for the faulting in the mt hermon area and generally that the model of block rotation with multiple faults provides very good simple rules for analyzing very complex fault patterns