palaeoecology and archaeology of the karlich seeufer open air site middle pleistocene in the central rhineland germany abstract the karlich seeufer archaeological site in germany s central rhineland was excavated between 1980 and 1992 the site provides evidence for hominid activity during a middle pleistocene interglaciation known up to now only from the karlich clay pit and therefore defined as the karlich interglaciation which is considered to be post cromer iv and pre holstein sensu stricto in age the site is characterized by acheulean artifacts a fauna dominated byelephas palaeoloxodon antiquus and a unique and outstanding preservation of wooden and other palaeobotanical remains assuming all finds are associated the site previously was interpreted as an elephant hunting camp with a wooden structure together with wood and bone implements preservedin situ recent analysis of the same features has shown that the site can also be interpreted as a reworked archaeological sample hominid occupation occurred in the vicinity of a small lake with prevailing meso oligotrophic conditions expanding boreal forests and fen vegetation characterized the landscape

late cretaceous paleomagnetism of the tombstone district and vicinity evidence for a rotational domain boundary in southeastern arizona paleomagnetic data are presented for late cretaceous volcanic and intrusive rocks in the tombstone district and dos cabezas mountains of southeastern arizona the resultant paleopole 73 n 224 e a95 8 is similar to a late cretaceous reference pole for north america 82 n 210 e a95 7 implying that these rocks have not been significantly rotated about vertical or near vertical axes relative to the continental interior generally concordant results have also been published for pennsylvanian terra rosa paleosols within the black prince limestone at localities in the nearby gunnison hills whetstone mountains and naco hills together however these carboniferous data indicate a 9 7 clockwise rotation with respect to north america similar to that determined for the colorado plateau 5 14 since the mid cretaceous published paleomagnetic data for rocks south and west of the tombstone vicinity indicate much larger clockwise rotations ranging from 25 to 60 implying that a rotational domain boundary runs between the mustang mountains and canelo hills to the southeast and between the silver bell and tucson mountains to the northwest this boundary roughly coincides in part with the sawmill canyon fault zone and is parallel to other northwest trending strike slip faults in the region that were active during the laramide orogeny the clockwise rotations in southern arizona are likely part of a larger pattern of dextral shear along the western margin of north america during the late cretaceous and early tertiary caused by northward oblique subduction of oceanic plates relative to the stable craton

an inverted double seismic zone in chile evidence of phase transformation in the subducted slab data from two microseismic field experiments in northern chile revealed an elongated cluster of earthquakes in the subducted nazca plate at a depth of about 100 kilometers in which down dip tensional events were consistently shallower than a family of compressional earthquakes this double seismic zone shows a distribution of stresses of opposite polarity relative to that observed in other double seismic zones in the world the distribution of stresses in northern chile supports the notion that at depths of between 90 to 150 kilometers the basalt to eclogite transformation of the subducting oceanic crust induces tensional deformation in the upper part of the subducted slab and compressional deformation in the underlying mantle

new discoveries at the middle pleistocene acheulian site of gesher benot ya aqov israel abstract the gesher benot ya aqov archaeological site in the northern dead sea rift of israel contains acheulian artifacts and middle pleistocene fossils initial results of a new interdisciplinary study have shown that fluviolacustrine sediments of the benot ya aqov formation which contains several archaeological occupations were deposited in an embayment of the hula basin they were subsequently deformed by tectonic activity associated with the dead sea rift biostratigraphy magnetostratigraphy and k ar dating serve to constrain the age of the benot ya aqov formation to between 240 000 and 730 000 yr b p archaeological excavation of three areas and two trenches at the new study area have produced abundant basalt flint and limestone artifacts mammalian and avian fossils and considerable plant material the lithic materials provide an excellent opportunity to study large assemblages of in situ acheulian artifacts a rare phenomenon in the middle pleistocene levantine record in addition the organic materials will facilitate paleoenvironmental reconstructions from an ecological floral perspective

large magnitude extensional deformation in the south mountains metamorphic core complex arizona paleomagnetic data are used to test controversial aspects of cordilleran metamorphic core complexes including the original dip of extensional structures origin of the mylonitic front and applicability of rolling hinge models we obtained paleomagnetic data 115 sites 82 accepted for analysis from the weakly deformed interior of a synkinematic footwall intrusive suite and proterozoic footwall rocks of the south mountains metamorphic core complex central arizona these rocks yield dual polarity high unblocking temperature and high to moderate coercivity magnetizations positive baked contact tests indicate that footwall rocks possess primary thermoremanent magnetizations trms or high temperature thermochemical remanent magnetizations tcrms acquired early in their cooling history and during ductile and brittle extensional deformation of structurally higher rocks this is consistent with thermochronologic data indicating rapid synkinematic cooling from crystallization through the range of laboratory unblocking temperatures for the magnetic mineralogy of these rocks between about 22 and 17 5 ma paleomagnetic data are considered as two populations based on the structural asymmetry of the south mountains metamorphic core complex 1 a front side characterized by northeast dipping 10 mylonitic fabrics and brittle extensional structures and 2 a back dipping side characterized by rollover of the mylonitic zone to form a southwest or back dipping 15 mylonitic front comparison of paleomagnetic data from these two sides suggests that the back dipping mylonitic front was synkinematically tilted about 10 down to the southwest the data support a folded shear zone hypothesis for origin of the mylonitic front and the interpretation that footwall rocks possess primary miocene age trms or tcrms a second regional fold test involved data from sites on both flanks of the topographically prominent northeast trending mountain range scale antiform the negative result from this fold test demonstrates that this structure formed early in the extensional history and prior to magnetization acquisition by the plutons we obtained a well grouped footwall grand mean from 62 front side and 20 back dipping site means n 82 d 1 0 i 51 7 k 41 8 95 2 5 we calculated this grand mean with the assumption that front side sites have remained structurally untilted whereas back dipping side sites require removal of 10 of southwest dip this grand mean is statistically indistinguishable 95 confidence level from time averaged miocene expected directions we thus conclude that the current gentle dip of front side mylonites and detachment faults is original therefore both ductile and brittle extensional deformations of the south mountains metamorphic core complex were accommodated along low angle structures dip of 15 our interpretation refutes the widespread applicability of models that predict metamorphic core complexes to represent tilted crustal blocks originally bounded by moderate angle normal faults and does not support rolling hinge models of metamorphic core complex evolution that require a moderate angle ramp

error analysis for the determination of tectonic rotation from paleomagnetic data appendix b is available with entire article on microfiche order from american geophysical union 2000 florida avenue n w washington d c 20009 document b83 001 2 50 payment must accompany order recent determinations of tectonic rotation and flattening from paleomagnetic data have exaggerated the size of the confidence limits or error bars by about 25 this has been caused by the misuse of conventional error propagation formulas to derive one degree of freedom error bars from a two dimensional cone of confidence 95 an analytical calculation which is valid when error bars are small shows that the correct error bars are 75 to 80 of the values derived in previous studies i have used numerical integration to check on the applicability of the analytical solution and to calculate error bars when the analytical approximation cannot be used the analytical approximation may be used whenever 95 is less than 10 and the mean inclination is not too close to vertical confidence limits given for tectonic rotation and flattening in recent literature are too large and should be reduced by 20 25 narrowing the error bars in this way permits a more accurate interpretation of paleomagnetic data

the river orontes in syria and turkey downstream variation of fluvial archives in different crustal blocks the geomorphology and quaternary history of the river orontes in western syria and south central turkey have been studied using a combination of methods field survey differential gps satellite imagery analysis of sediments to determine provenance flow direction and fluvial environment incorporation of evidence from fossils for both palaeoenvironments and biostratigraphy uranium series dating of calcrete cement reconciliation of palaeolithic archaeological contents and uplift modelling based on terrace height distribution the results underline the contrasting nature of different reaches of the orontes in part reflecting different crustal blocks with different histories of landscape evolution upstream from homs the orontes has a system of calcreted terraces that form a staircase extending to 200 m above the river new u series dating provides an age constraint within the lower part of the sequence that suggests underestimation of terrace ages in previous reviews this upper valley is separated from another terraced reach in the middle orontes by a gorge cut through the late miocene early pliocene homs basalt the middle orontes terraces have long been recognized as a source of mammalian fossils and palaeolithic artefacts particularly from latamneh near the downstream end of the reach this terraced section of the valley ends at a fault scarp marking the edge of the subsiding ghab basin a segment of the dead sea fault zone which has been filled to a depth of 1 km by dominantly lacustrine sediments of pliocene quaternary age review of the fauna from latamneh suggests that its age is 1 2 0 9 ma significantly older than previously supposed and commensurate with less uplift in this reach than both the upper and lower orontes two localities near the downstream end of the ghab have provided molluscan and ostracod assemblages that record somewhat saline environments perhaps caused by desiccation within the former lacustrine basin although they include fluvial elements the ghab is separated from another subsiding and formerly lacustrine depocentre the amik basin of hatay province turkey by a second gorge implicit of uplift this time cut through palaeogene limestone the ne sw oriented lowermost reach of the orontes is again terraced with a third and most dramatic gorge through the northern edge of the ziyaret dagi mountains which are known to have experienced rapid uplift probably again enhanced by movement on an active fault indeed a conclusion of the research in which these various reaches are compared is that the crust in the hatay region is significantly more dynamic than that further upstream where uplift has been less rapid and less continuous

geochronology paleogeography and archaeology of the acheulian locality of evron landfill in the western galilee israel a multidisciplinary study was conducted in a newly discovered paleolithic locality named evron landfill this locality is a part of the lower paleolithic complex of evron located at the western galilee israel examination of artifacts has enabled the cultural attribution of evron landfill to the early acheulian while detailed paleomagnetic stratigraphy places the hominin occupations near the brunhes matuyama transition 0 77 ma this age is constrained by cosmogenic isotope burial dating of the sediments overlying the paleolithic finds providing a minimum age of 0 66 0 11 ma for hominin activity at the site these results are further supported by the biochronological information derived from the faunal assemblage comparative analyses of faunal remains and lithic artifacts from evron landfill demonstrate similarities to the assemblages from the early acheulian site of evron quarry located 300 m to the south pedo sedimentological analyses indicate that hominin activity took place in a marsh environment in proximity to the mediterranean coast which probably fluctuated in both space and time with a fluvial environment in addition this study provides important data about ancient coastal activity during the early to middle pleistocene

model for late mesozoic early tertiary tectonics of coastal california and western mexico and speculations on the origin of the san andreas fault cretaceous and early tertiary arc and forearc rocks found along the coast in southern california and baja california have been shown by paleomagnetic measurements to have originated many hundreds or even several thousands of kilometers south of their current locations northward transport also is found in cretaceous batholithic rocks near the edge of the continent in washington and british columbia the consistency of this pattern suggests that slices of arc and forearc rock originating on the western edge of north america have been translated along the coast by strike slip faulting strike slip faults are shown to be an expected response to north oblique subduction of the farallon and or kula plates faulting and subduction probably were concurrent activities i e the arc and forearc grew and were displaced simultaneously because displacement was dominantly parallel to subduction related lithic belts arc and forearc rocks may have traveled large distances without producing either significant hiatuses in the rock record or conspicuous disruptions in the distribution of lithic belts subduction related strike slip faulting is shown to be favored by high angles of oblique convergence shallow dip of the subducting slab relatively easy slip on potential faults within the arc or forearc and the existence of a place for the moving sliver to go it is suggested that these conditions are not difficult to satisfy and that subduction related strike slip faulting may thus be a common feature of convergent orogens the location of the san andreas fault inboard from the continental margin may be attributable to localization of the pacific north american transform by a system of precollision subduction related faults

tilting history of the san manuel kalamazoo porphyry system southeastern arizona the laramide san manuel kalamazoo porphyry system of arizona has been pivotal in concepts of both extensional tectonics and alteration mineralization zoning this paper reexamines the tilting history in light of new work in the region and reinterprets the geometry of the deposit the porphyry mineralization occurs in and near an intrusion of laramide san manuel porphyry in precambrian oracle granite the area has an extremely complicated history of tertiary crustal extension and fanglomerate deposition but the blocks containing the two main fragments of the original orebody separated by the san manuel fault were involved in only the later parts of this history and are less tilted than other nearby blocks originally horizontal features of mid tertiary age are tilted about 30 degrees those of laramide age about 35 degrees and those of pre laramide age about 45 degrees to the northeast paleomagnetism of the porphyry intrusion itself suggests tilting of about 33 degrees the data thus suggest that postemplacement tilt of the laramide porphyry system was 30 degrees to 35 degrees and that virtually all of it was mid tertiary in age an earlier interpretation of greater tilt magnitude was apparently based in part on correlation with adjacent areas showing greater tilt magnitude as in the tar wash allochthon and in part on a choice of cross section that gives the impression of a nearly recumbent attitude however lowell9s sections are oriented along the strike of both the orebodies and the productive porphyry intrusion which are dipping tablo cylindroidal bodies ore forms a hollow envelope whose inner margin has an aspect ratio of about 4 3 length 2 5 downdip height l limb separation the productive intrusion around which ore is wrapped has a similar aspect ratio in the same plane strike n 58 degrees e dip 47 degrees se reconstruction of the original attitudes of intrusion and ore yields a common strike near n 759 e and a steep dip to the south this is a common attitude for undisturbed productive porphyry dikes of laramide age

exhumation with a twist paleomagnetic constraints on the evolution of the menderes metamorphic core complex western turkey 1 much remains to be understood about the links between regional vertical axis rotations continental extension and shortening in western turkey miocene vertical axis rotations have been reported that occur simultaneously with the extensional exhumation of the menderes metamorphic core complex which has been related to back arc extension in the eastern part of the aegean back arc in this paper we explore the spatial and temporal relationships between vertical axis rotations in southwestern turkey and extensional unroofing of the menderes massif to this end we provide a large set of new paleomagnetic data from western turkey and integrate these with the regional structural evolution to test the causes and consequences of oroclinal bending in the aegean region the lycian nappes and bey daglari are shown to rotate 20 between 16 and 5 ma defining the eastern limb of the aegean orocline this occurred contemporaneously with the exhumation of the central menderes massif along extensional detachments and after the latest oligocene to early miocene exhumation of the northern and southern menderes massifs exhumation of the latter two was not associated with vertical axis rotations the lower miocene volcanics in the region from lesbos to usak to the north of the central menderes massif underwent a small clockwise rotation insignificant with respect to eurasia this shows that exhumation of the central menderes massif was associated with a vertical axis rotation difference between the northern and southern menderes massifs of 25 30 this result is in excellent agreement with the angle defined by the trends of buyuk menderes and alasehir detachments as well as the angle defined by the regionally curving stretching lineation pattern across the central menderes massif these structures define a pivot point rotation pole for the west anatolian rotations the rotation of the southern domain including the southern menderes massif the lycian nappes and bey daglari must have led to n s contraction east of this pole the eastern limit of the rotating domain is formed by the transpressional couple of the aksu thrust and kirkkavak fault in the center of the isparta angle previously reported clockwise rotations in the volcanic fields near afyon may be the result of distributed n s shortening east of the pivot point the precise accommodation of this shortening history remains open for investigation late oligocene to early miocene extension in the eastern part of the aegean back arc was ne sw oriented and likely bounded by a discrete transform this transform may be associated with an early evolution of the eastern aegean subduction transform edge propagator fault oroclinal bending in the west anatolian region is likely related to a reconnection of the eastern part of the aegean orocline with the african northward moving plate in tandem with roll back in the aegean back arc comparable to a recently postulated scenario for western greece

evidence of marine isotope stage 5 5 highstand in liguria italy and its tectonic significance abstract the quaternary shoreline displacements in liguria are still poorly known this paper completely revises and reinterprets the literature on this topic taking into account only those markers that allow precise estimates of altitude and age of sea level highstands among the sites showing geomorphological evidence of mis 5 5 present in liguria three were considered reliable in eastern liguria a beach deposit with a terrace inner margin at 28 m a s l villa monteverde was dated by osl in western liguria in a site close to the french border balzi rossi a notch present inside two caves indicating a sea level altitude of 12 m is associated with a deposit containing a faunal assemblage with strombus bubonius this gastropod appeared in the italian seas only during the last interglacial highstand and provides a unique marker of the mis 5 5 horizon eastward near imperia another site madonna dell arma shows similar evidence but in this case the notch is not preserved because the cave is carved in a very soft oligocene conglomerate late quaternary tectonic movements along the different tracts of the ligurian coast seem to have occurred apparently with different although rather low uplift rates the connection between the alpine and apennine chains sestri voltaggio line divides the ligurian arch into two parts the alpine sector can be considered stable whereas the apennine relief displays in its central part an uplift rate of 0 16 mm yr

sea level and climate changes during ois 5e in the western mediterranean palaeontological geomorphological and sedimentological data supported by isotopic dating on oxygen isotopic stage ois 5e deposits from the spanish mediterranean coast are interpreted with the aim of reconstructing climatic instability in the northern hemisphere data point to marked climatic instability during the last interglacial ois 5e with a change in meteorological conditions and consequently in the sedimentary environment the oolitic facies generated during the first part of ois 5e ca 135 kyr shift into reddish conglomeratic facies during the second part ca 117 kyr sea surface temperature sst and salinity are interpreted mainly on the basis of warm senegalese fauna which show chronological and spatial differential distribution throughout the western mediterranean present hydrological and meteorological conditions are used also as modern analogues to reconstruct climatic variability throughout the last interglacial and this variability is interpreted within the wider framework of the north atlantic record all the available data indicate an increase in storminess induced by an increase in the influence of northwesterlies a slight drop of sst in the northern western mediterranean and an important change in meteorological conditions at the end of ois 5e 117 kyr these changes correlate well with the decrease in summer insolation and with the climatic instability recorded in north atlantic high latitudes

the biface assemblage from gesher benot ya aqov israel illuminating patterns in out of africa dispersal abstract this article presents the main characteristics of a lithic assemblage in particular its biface component from the acheulean site of gesher benot ya aqov israel we endeavor to demonstrate that this tradition did not evolve locally within the levant but was rather a result of a diffusion of ideas and or population from africa into the levant during the end of the lower beginning of the middle pleistocene the fact that other acheulean industries present in the northern dead sea rift resemble corresponding african traditions rather than each other may indicate that the gesher benot ya aqov occurrence was not an isolated event this phenomenon may be interpreted as representing a dynamic system in which populations and or ideas dispersed out of africa during the lower and middle pleistocene in repetitive distinct and separate waves

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

kinematics of pre miocene ductile deformation in the santa catalina core complex and adjacent regions this paper describes structures within mylonites and metamorphic rocks from the santa catalina and tortolita suizo metamorphic core complexes southeastern arizona united states in these areas mylonitic rocks constitute an easterly low dipping slab more than 4 km thick mapping of principal strain directions and analysis of shear sense have been carried out through the whole pile of mylonites it is shown that although the stretching lineation appears to have a uniform mean sw ne trend three successive shearing events are involved the first shearing event is toward the west and is accompanied in part by the emplacement of the leatherwood quartz diorite dated at 64 ma the second shearing event is toward the ne and is accompanied by the emplacement of the wilderness granitic suite dated at 49 ma the third shearing event is localized and directed toward the sw the top to west shearing and top to ne shearing are possibly related to laramide thrusting the last ductile shearing is related to post eocene extension

active normal faulting and crustal extension a world wide review of fault plane solutions and focal depths for large normal faulting earthquakes on the continents shows that the overwhelming majority of such earthquakes nucleate in the depth range 6 15 km on faults dipping between 30 and 60 in the few cases where levelling or seismic data are good enough these normal faults are shown to be approximately planar from the surface to their nucleation depth at the base of the brittle crust there is evidence that in some cases as a result of the enormous transitory increase in strain rate during large earthquakes rupture continues into the normally ductile lower crust on surfaces with substantially gentler dips these low angle surfaces may be analogous to some of the detachments seen in metamorphic core complexes of the western usa but the nature of the motion on them depends on strain rate as well as on rheological contrasts between the detachments and the blocks on either side such contrasts however are unlikely to introduce substantial curvature to an originally planar shear zone if the observed spread in active normal fault dips is caused by rotation of the faults and the blocks they bound during extension then a maximum value of 1 7 can be accommodated by seismic activity on a single generation of normal faults with continued extension either a new generation of steeper faults cutting the rotated first faults is likely to form or the deformation will continue aseismically on faults dipping at less than 30 large earthquakes have not been observed to nucleate on very low angle 20 normal faults within the continental crust anywhere in the world such faults can of course move aseismically but are unlikely to do so on a large scale within the upper crust in areas where steep normal faults are seismically active thus extensional models that require concentrated simple shear on large sub horizontal faults within the brittle upper crust will also require a spatial separation between aseismic very low angle faulting and seismic highangle faulting since seismogenic high angle faults dominate the topography of extending regions upper crustal very low angle faulting if it occurs on a large scale presumably does so in areas that are relatively fiat

two layer tidal modeling of the yellow and east china seas with application to seasonal variability of the m2 tide 1 the baroclinic response of tide and tidal currents in the yellow and east china seas is investigated using a two layer numerical model seasonal variability in the m2 tide especially the smaller summer amplitudes prevailing along the korea tsushima strait kang et al 1995 is investigated by a series of numerical experiments with varying degrees of stratification specific to winter and summer model results show that the summer amplitudes of the m2 tide around the southwestern tip of the korean peninsula and korea tsusima strait decrease with a peak decrease of about 14 cm off the southwestern tip of the korean peninsula while the summer amplitudes in other coastal regions tend to increase this seasonal variability generally coincides with the observations these models results indicate that seasonal stratification has several noticeable effects on the tides including varying degrees of current shear varying frictional dissipation and varying barotropic energy flux in particular it drives complicated seasonal variability in the m2 tide with a peak amplitude modulation of nearly 5 off the southwestern tip of the korean peninsula the seasonal variation of barotropic m2 energy flux through the eastern entrance of the yellow sea is thought to induce the corresponding variability in the m2 amplitude in the korea tsusima strait with smaller amplitudes found in the summer

tilt and rotation of the footwall of a major normal fault system paleomagnetism of the black mountains death valley extended terrane california paleomagnetic data have been obtained from miocene intrusions including crosscutting mafic and felsic dikes and proterozoic crystalline rocks to evaluate deformation during miocene and younger extension and unroofing of the black mountains death valley california synrift intrusions contain a well defined and at the site level well grouped magnetization interpreted to be of dual polarity the in situ direction of which is discordant in declination and inclination with an expected late cenozoic reference direction the oldest of these intrusions 11 6 0 2 ma gives a magnetite dominated remanent magnetization of high coercivity and high laboratory unblocking temperatures about 550 to 580 c that is interpreted to predate unroofing from midcrustal depths in situ site mean directions of this magnetization are directed toward the west and west northwest with moderate to shallow positive down and negative up inclinations the variation in direction of magnetization particularly inclination with site locality around the turtleback structures along the western flank of the black mountains is interpreted to result from folding of the intrusion after remanence acquisition younger intrusions 8 7 ma generally give magnetizations with inclinations similar to expected miocene values two populations of in situ site means are identified one with southwest declination and negative inclination the other with northward declination and positive inclination a preferred interpretation for footwall deformation involves from oldest to youngest 1 southwest side down tilting of the entire range block of some 20 to 40 to possibly 70 and at least locally folding of the crystalline rocks on a trend parallel to the death valley turtlebacks between 11 6 and 8 7 ma 2 progressive east to west footwall unroofing between 8 7 and ca 6 5 ma and 3 clockwise rotation 50 to 80 of much of the black mountains after the core detached from stable terrane to the west we interpret late rotation of the black mountains as oroflexure related to right lateral shear along the death valley fault zone

beach deposits containing middle paleolithic archaeological remains from northern israel abstract beach deposits of the last interglacial maximum mis 5e are common on the mediterranean coasts however only a few of them contain archaeological remains four beach deposits containing paleolithic remains were previously identified on the carmel coast of northern israel which relate to the mis 5e sea level high stand of the last interglacial maximum here we report on a newly identified outcrop of beach deposit containing archaeological remains from rosh haniqra on the northern galilee coast termed the rosh haniqra railway hill section this beach deposit is in the form of a tilted lens 12 5 m long and 1 5 m thick and is composed of seven layers containing limestone pebbles and cobbles crushed and whole marine shells flaked flint implements and a mammalian bone cemented by calcite while the previously known carmel coast beach deposits are embedded above or in kurkar deposits aeolian calcareous cemented quartz sandstone the rosh haniqra railway hill beach deposit lies directly on cretaceous bedrock and is overlain by a 5 m thick layer of kurkar based on the typology of the lithic artifacts and their similarity to other middle and late mousterian flint assemblages found in beach deposits and loamy red soils along the northern israeli coast the rosh haniqra railway hill beach deposit probably dates to the mis 5e high sea stand however its attribution to the earlier mis 7 stage dating to ca 200 ka cannot be entirely discounted future absolute dating of the deposits may clarify this issue

paleomagnetism of late jurassic rocks in the northern canelo hills southeastern arizona the canelo hills volcanics are exposed in the canelo hills a northwest trending range in santa cruz county southeast arizona the formation is composed of silicic tuffs and flows as well as volcaniclastic conglomerates and sandstones strikes of the rocks are generally to the northwest with moderate dips to the southwest and northeast apparent age results from the sequence studied paleomagnetically include two published isotopic dates of 147 6 ma k ar biotite and 149 11 ma whole rock rb sr and a rb sr isochron age reported here which indicates an age of 151 2 ma paleomagnetic samples were collected from 17 cooling units in the northern canelo hills samples from most of these units responded to alternating field af demagnetization and secondary components were generally erased by peak af between 10 and 50 mt samples from five sites showed no response to af demagnetization thermal demagnetization of samples from these units produced no significant changes in direction of natural remanent magnetization nrm although within site clustering of nrm directions was improved data from two sites were rejected because of failure to isolate a well determined characteristic nrm of the remaining 15 sites 10 sites were of normal polarity while five sites showed reversed polarity intensities of the characteristic nrm ranged from 4 10 3 to 3 10 1 a m the data from these 15 cooling units yield a formation mean direction of i 29 9 d 334 9 with k 33 4 and 95 6 7 the resulting paleomagnetic pole is at 62 2 n 130 3 dp 4 1 dm 7 4 this pole is between poles obtained from the summerville and lower morrison formations the canelo hills pole is thus consistent both in position and age with the late jurassic episode of rapid apparent polar wander originally defined by paleomagnetic data from the summerville and morrison formations

neogene tectonic rotation of the san gabriel region california suggested by paleomagnetic vectors previous paleomagnetic work in the western transverse ranges and the islands offshore of california has suggested that these regions have experienced large clockwise rotations since middle miocene time this study is aimed at testing how far east these rotations extend into the continent neogene volcanic rocks from the region bounded by the san gabriel and san andreas faults were selected for paleomagnetic study the sampled units are lavas from the late oligocene to early miocene continental vasquez formation and water laid tuff beds from the middle to late miocene mint canyon formation these rocks possess a stable remanent magnetization which was acquired soon after deposition and is believed to be primary seventy four lava flows from eleven locations in the vasquez formation were studied the average direction for seven locations near the center of the study area suggests that this area has rotated a net clockwise amount of 37 1 12 2 since the early miocene there is no suggestion of north or south translation a location west of the central region is rotated almost 90 clockwise although this is believed to be a local effect detailed magnetic stratigraphy at the western and central location can be correlated over 6 km locations in the east near the san andreas fault yielded highly dispersed directions which cannot now be interpreted in terms of rotation the mean paleomagnetic direction from six sites four different beds in the mint canyon formation west of the vasquez study area is deflected in a counterclockwise sense by 16 30 these data are consistent with a proposed model in which the san gabriel region first was rotated clockwise 53 37 16 in the early miocene and later rotated 16 counterclockwise as it slid northward into the leftward bend region of the san andreas fault the clockwise rotation is believed to be due to dextral shear within the pacific north american plate shear zone counterclockwise rotation in the mojave region is believed to be responsible for the bend in the san andreas fault

fault and fault rock characteristics associated with cenozoic extension and core complex evolution in the catalina rincon region southeastern arizona cenozoic extensional deformation in southern arizona included 1 a neogene phase of basin and range deformation recorded by high angle normal faults and 2 an earlier phase of detachment faulting and brittle ductile crustal shearing associated with tectonic denudation of metamorphic core complexes in the catalina rincon region exposed fault zones produced at different crustal depths during successive extensional episodes display differing fault geometries and types of fault rocks formed during progressive crustal extension detachment faults are associated with both mylonites produced by ductile shear and cataclasites produced by brittle shear younger faults formed at shallower depths are associated with less intense cataclastic deformation and with brittle fracturing that includes transtensile phenomena at the shallowest crustal levels represented qualitative measures of net displacement along individual fault zones are provided by 1 the nature of contrasts among successively overprinted fabrics and internal structures in the footwall and 2 the degree of contrast between fabrics and structures of footwall and hanging wall rocks footwalls of the oldest structures display varied brittle overprints of ductile fabrics and are juxtaposed across gouge zones along detachment surfaces with stratal successions cut by multiple brittle shear surfaces footwalls of younger structures formed at shallower depths display multiple generations of cataclastic features including brecciation of variable intensity and cataclasite dikes but are juxtaposed against hanging wall strata that are only moderately deformed by subsidiary faults the shallowest fault zones lack either structural overprints in their footwalls or any significant contrasts between footwall and hanging wall deformation exposures of mid crustal rocks within the core complexes reflect successive exhumation and uplift of fault footwalls during sequential episodes of deformation the present high elevation of mylonitic rocks in the catalina rincon metamorphic core complex reflects dip slip and isostatic footwall flexure during basin and range deformation as well as tectonic denudation during detachment faulting net uplift of core rocks resulted from multiple phases of deformation

northward migration of the southern diagonal fault of the hula pull apart basin dead sea transform northern israel abstract the hula valley located in northeastern israel is a 4 million year old pull apart basin bounded by two left stepped segments of the dead sea transform basic models of pull apart basins suggest four faults at all sides of the basin a situation which is not always the case in the hula pull apart basin the longitudinal n s faults are clearly evident while the transversal e w faults are less explicit an nw oriented lineament expressed as a north facing continuous scarp 1 3 m high was recognized in the southern part of the valley morphological seismic and sedimentary considerations suggest that this scarp is the surface expression of a deep seated fault this fault termed the yesod hama ala fault forms the present southern boundary of the hula pull apart basin and appears to be the southern diagonal fault which links the jordan fault in the east with the yammunneh fault in the west it is suggested that this fault scarp formed a shallow morphological barrier that partly blocked the southern outlet of the valley enabling a permanent lake in the southern part of the hula valley thus the uplifted southern block determined the sw shoreline of the lake it is proposed that the hula basin is a version of the classic pull apart model it is also suggested that in the absence of upwelling mantle material and extension along the length of the basin a crustal thinning and subsidence might have occurred through normal faulting of the upper brittle crust the thick depositional sequence within the southern part of the basin shows that the present margins have been a major depositional site for a long time and that the hula valley has thus developed as an asymmetric pull apart rhomb shaped basin bounded by steep north striking boundary normal as well as strike slip faults w nw striking and northward dipping normal faults and a south facing bending flexure as activity within the basin continued and northward migration of the faulting occurred a new fault developed according to this perception the present active fault is the yesod hama ala fault while the future fault will be located northward as can be presumed from the present micro seismic activity in the valley

flexural rotation of normal faults a conceptual model is proposed for the generation of low angle normal faults in metamorphic core complexes the model is based on three assumptions 1 the isostatic response to normal fault motion is of regional extent 2 when a fault segment is significantly rotated from the optimum angle of slip relative to the crustal stress field it is replaced by a new planar fault oriented in the optimum direction and 3 the fault cuts the entire upper crust and fault motion always nucleates in the same region at the base of the upper crust the stress field is considered to be uniform through the crust and the regional isostatic response of the crust to loads is computed using the thin plate flexure approximations active low angle normal faults are difficult to reconcile with rock mechanics theories earthquake focal mechanism studies and geochronologic results indicating rapid cooling of core complex rocks the model does not require active fault slip on low angle faults the flexural response to normal faulting is shown to be significantly affected by anelastic behavior of the crust and by loading due to sedimentation the anelastic response to large bending stresses results in significant reduction in the effective elastic rigidity of the upper crust this can explain the observed short wavelength of topographic response to normal fault loads the model results in 1 a nearly flat lying abandoned normal fault or detachment below slices of upper plate rocks and sedimentary infill 2 a strong contrast in metamorphic grade across the abandoned detachment 3 rapid movement of lower plate rocks from midcrustal depths to shallower depths these results are qualitatively in agreement with geologic observations for core complexes

detachment and rotation of a metamorphic core complex during extensional deformation palaeomagnetic study of the catalina rincon core complex basin and range province arizona abstract the catalina rincon complex exposes a metamorphic core of mid crustal rocks exhumed by extensional tectonism along a major detachment exposed along the southeast side of the catalina rincon mountains near tucson arizona the juxtaposition of core complexes against high level crust segmented into rotated and tilted fault blocks is an important component to models for crustal extension and key questions surround the way s that cores are exhumed we report palaeomagnetic results from rocks beneath the detachment in the catalina rincon core and additional data from lavas and tuffs in adjoining hanging wall rocks immediately above the detachment magnetic remanence in the metamorphic core is carried predominantly by magnetite with a dominant wnw ese dual polarity direction a1 d i 288 50 n 59 components r 55 60 95 4 6 this remanence is interpreted to have been acquired through a broadened blocking temperature spectrum during protracted exhumation and cooling in oligocene times since the magnetic inclination accords with the mid cenozoic field it is difficult to explain this magnetization in terms of large later tilting and it appears to be the record of near vertical axis ccw rotation of 63 5 relative to cratonic north america although magnetic inclination identifies no significant horizontal axis rotation this could be fortuitous and hide the influence of magnetic anisotropy and resultant inclination shallowing to assess this contribution both anisotropy of magnetic remanence amr and anisotropy of magnetic susceptibility ams have been investigated ams resolves only weak fabrics comparable with the top ne mylonite deformational fabric near the detachment which probably dates from a mid eocene high temperature event amr shows that deflections of magnetic remanence of up to several tens of degrees into the foliation may be anticipated although weak alignment of the magnetite is likely to reduce this effect the full importance of horizontal axis tilting remains unresolved although a possible relict component in the core a2 d i 269 9 n 24 components r 22 91 95 6 6 is rotated 20 more ccw than a1 and also of presumed mid cenozoic cooling related origin it suggests that segments of middle crust comprising the exposed core might have been rotated by large amounts into their present position highly faulted early oligocene pantano formation volcanic rocks in the hanging wall immediately above the detachment zone appear to have rotated by a much smaller amount ccw on the south west side d i 161 45 6 sites and by larger variable amounts on the northeast side movements of the upper plate immediately above the detachment are difficult to resolve with precision due to complex fault block rotations although the underlying core complex has clearly undergone large differential slip relative to these cover rocks the magnitude of inferred vertical axis rotation of the catalina rincon core implies that it is not rooted into adjoining crust as proposed in classical simple shear models instead the core exposed below the detachment may be part of a fault carapace that has decoupled and rotated over a ductile lower crust

mis 5e relative sea level changes in the mediterranean sea contribution of isostatic disequilibrium sea level indicators dated to the last interglacial or marine isotope stage mis 5e have a twofold value first they can be used to constrain the melting of greenland and antarctic ice sheets in response to global warming scenarios second they can be used to calculate the vertical crustal rates at active margins for both applications the contribution of glacio and hydro isostatic adjustment gia to vertical displacement of sea level indicators must be calculated in this paper we re assess mis 5e sea level indicators at 11 mediterranean sites that have been generally considered tectonically stable or affected by mild tectonics these are found within a range of elevations of 2 10 m above modern mean sea level four sites are characterized by two separate sea level stands which suggest a two step sea level highstand during mis 5e comparing field data with numerical modeling we show that i gia is an important contributor to the spatial and temporal variability of the sea level highstand during mis 5e ii the isostatic imbalance from the melting of the mis 6 ice sheet can produce a 2 0 m sea level highstand and iii a two step melting phase for the greenland and antarctic ice sheets reduces the differences between observations and predictions our results show that assumptions of tectonic stability on the basis of the mis 5e records carry intrinsically large uncertainties stemming either from uncertainties in field data and gia models the latter are propagated to either holocene or pleistocene sea level reconstructions if tectonic rates are considered linear through time

underwater geomorphology of the rocky coastal tracts between finale ligure and vado ligure western liguria nw mediterranean sea abstract the western part of the liguria region nw mediterranean sea has been reported as tectonically stable to slowly uplifting since the late pleistocene despite good knowledge of the coastal geomorphological features above sea level very little information is available on the characteristics of the underwater coastlines direct and indirect underwater surveys carried out in the area between vado ligure and finale ligure western liguria allowed the identification of several surfaces of marine origin in four sites at three depth intervals 8 13 m 17 23 m and 27 30 m these values appear to be in bathymetric analogy with those reported by other authors along the italian coastlines in areas where the tectonic movements along the late quaternary are considered negligible on the basis of the elevation of the mis 5 5 shoreline although few chronological constraints are possible due to the lack of dateable material the marine morphologies identified in this study constrain their ages to the middle and late quaternary

on the role of isostasy in the evolution of normal fault systems the footwalls of west dipping normal faults that separate the west central colorado plateau from the basin and range province record at least 5 7 km and perhaps as much as 15 20 km of west side up neogene uplift with an axis just 10 20 km west of undeformed plateau strata the uplift is expressed as folding and steep faulting in pre tertiary cratonic and disconformably overlying neogene strata forming a basement cored anticline and coincident topographic high on the western margin of the plateau the authors interpret the uplift as a nonelastic response of the crust to buoyancy forces accompanying the tectonic denudation of the plateau margin profound isostatically driven deformation of the footwalls of major normal faults may be common in extensional terrains calling into question several assumptions fundamental to existing models of the evolution of normal fault systems

metamorphic and stratigraphic constraints on the evolution of the santa catalina mountains metamorphic core complex arizona contact metamorphic mineral assemblages in the santa catalina mountains metamorphic core complex constrain the emplacement depth of the metaluminous late cretaceous leatherwood quartz diorite to between 7 5 and 14 km 2 3 8 kbar the peraluminous eocene wilderness granite is constrained to have been emplaced at depths of less than 14 km stratigraphic and tectonic considerations are consistent with emplacement of both the leatherwood quartz diorite and wilderness granite at upper crustal levels published igneous thermobarometry anderson et al 1988 although in approximate agreement with the metamorphic and tectonostratigraphic estimates for the depth of emplacement of the wilderness granite suggests that the leatherwood quartz diortite was emplaced at depths of 21 km 5 6 kbar or greater the discrepancy between the different emplacement estimates may reflect ambiguities associated with interpretations of the results from each technique igneous barometric assemblages may reflect conditions experienced during a period of crystallization during ascent of the magma through the crust i e ponding of the magma alternatively emplacement of the voluminous wilderness granite and associated plutons may have entirely overprinted earlier leatherwood related contact metamorphism the proposed upper crustal emplacement of the leatherwood quartz diorite is consistent with the observation that lararrade age crustal thickening in southeast arizona probably did not exceed 8 km

evidence for a local crustal root beneath the santa catalina metamorphic core complex arizona we used data from the tucson arizona broad band seismic station to analyze crustal and mantle structure under and adjacent to the catalina metamorphic core complex the data can be modeled with a simple two layer crust having an average moho depth of 30 km and seismic velocities consistent with a felsic composition the lower crust thickens under the catalina mountains depressing the moho by 4 2 km the crustal root can isostatically compensate the average topography of the catalina mountains indicating that the depth of isostatic compensation is at or below the moho and that the catatina mountains act as a coherent block bounded by high angle normal faults the presence of the crustal root is not consistent with models that predict upward bowing of the moho under the catalina metamorphic core complex the presence of the root cannot rule out models of lower crustal flow during the formation of the core complex however the presence of a root favors a model of metamorphic core complex development described by crustal thickening in shortening episodes crustal welt model followed by collapse of the crustal welt through extension

reconstructing the history of sediment deposition in caves a case study from wonderwerk cave south africa we applied cosmogenic isotope burial dating magnetostratigraphy and grain size distribution analysis to elucidate the history of the sedimentary sequence composed of fine quartz sands and silts of wonderwerk cave located on the southern edge of the kalahari desert south africa the source for the quartz sand is the kalahari sand dunes presently located 100 km to the north of the cave field observations and grain size analysis suggest a sediment transport scenario that includes eolian transport of kalahari sand abraded to a size of 70 100 m to the kuruman hills temporary storage on the hill slopes and valleys surrounding wonderwerk cave and later transport and deposition inside the cave our results suggest simple burial ages for sediments from both the front and back of the cave that range between 2 63 0 17 ma and 1 56 0 10 ma following initial exposure of 310 620 k y however 26 al 10 be ratios of 3 98 0 24 and 4 08 0 22 measured in a sand sample collected from the surface outside the cave may imply an initial burial signal equivalent to 0 78 0 15 ma thus reducing the possible age range of the buried samples to between 1 85 0 23 and 0 78 0 18 ma the paleomagnetic results for the front of the cave gave a polarity sequence of n r n n where n indicates normal polarity and r indicates reverse polarity this sequence can be correlated with both the older and younger cosmogenic burial age ranges the correlation suggests that in the cave front cosmogenic burial ages and the acquisition of stable remanent magnetization were not significantly affected by chemical and physical processes and that postburial production of cosmogenic isotopes was insignificant in contrast at the back of the cave the paleomagnetic polarity sequence of r n cannot be correlated with the cosmogenic burial ages since the temporal gap between the initial penetration of the sediment into the cave and the final acquisition of a stable remanent magnetization may have been long 10 5 yr and the single polarity transition can be correlated to any reverse normal transition that occurred during the quaternary this highlights the need for caution when cosmogenic burial ages and paleomagnetic sequences are compared the buried sediments in wonderwerk cave show similar grain size distributions to the fine sand sediment presently exposed at the surface in the vicinity of the cave furthermore calculated preburial 10 be concentrations for the buried sediment are similar to those measured in sediment outside the cave these similarities suggest that the environmental conditions and rates of geomorphic processes that persisted during sand deposition in wonderwerk cave during the late pliocene and early pleistocene may have been similar to those currently experienced in the southern kalahari the kuruman hills and the western ghaap plain these conditions favor the transport of fine grained quartz sand to the vicinity of the cave

continental lithospheric thinning and breakup in response to upwelling divergent mantle flow application to the woodlark newfoundland and iberia margins abstract depth uniform stretching is not the dominant deformation process for thinning continental lithosphere leading to breakup it cannot explain the observed depth dependent lithosphere stretching and mantle exhumation at rifted continental margins depth dependent lithosphere thinning in which stretching of the lower crust and lithosphere mantle greatly exceeds that of the upper crust has been observed at many non volcanic and volcanic rifted continental margins including conjugate margin pairs passive continental margins show a paucity of brittle deformation in the upper crust during continental lithosphere thinning leading to breakup and sea floor spreading initiation a new model of rifted continental margin formation has been developed that assumes that deformation and thinning of continental lithosphere leading to breakup occurs in response to an upwelling divergent flow field within continental lithosphere and asthenosphere and that this deformation evolves into sea floor spreading the new model successfully predicts depth dependent stretching of continental margin lithosphere for both non volcanic and volcanic margins and mantle exhumation at non volcanic margins both of which are observed but are not explained by existing depth uniform continental lithosphere stretching models the new model provides a balance of extensional strain supplies an explanation for the paucity of synrift brittle deformation and offers a simple transition from prebreakup lithosphere thinning to sea floor spreading the observed diversity of rifted continental margin structure and width of the ocean continent transition can be explained by variability in the form of the upwelling divergent flow field the new upwelling divergent flow model of continental lithosphere thinning leading to continental breakup successfully predicts the observed bathymetry and margin geometry for the most recent segment of sea floor spreading initiation in the woodlark basin in the western pacific and the observed bathymetry and free air gravity anomaly for the newfoundland and iberian margins

the reliability of uranium series mollusc dates from the western mediterranean basin abstract fossil mollusc shells from western mediterranean raised beach deposits have been dated using u series techniques sub sampling has allowed intra shell isotopic variability to be assessed although most of the calculated ages appear plausible and some internal consistency exists closer scrutiny of the data reveals that the shells have behaved as geochemically open systems and all the ages therefore must be considered suspect some previously published u series mollusc data from the same region may also contain evidence of open system behaviour and are considered equally unreliable simple modelling suggests considerable variation in isotopic uptake behaviour both within and between shells

the dead sea rift lateral displacement and downfaulting phases abstract a sinistral strike slip of 105 km along the dead sea rift is confirmed by the continuity in the restored trend of eocene sedimentary belts yet the similar characteristics on either side of the rift between the upper miocene conglomerates mudstones and lithographic limestones particularly the kefar gil adi fm and the pliocene marls oolitic limestones and basalts e g bira fm gesher fm cover basalt raise doubts as to whether a major lateral slip occurred after the end of the upper miocene or even during that epoch the master fault along which motion took place runs through the middle of the jordan valley on the western side of the hula valley through the metulla saddle and the ayoun valley and merges with the yammunneh fault major phases mainly of downfaulting occurred 1 during the middle and at the beginning of the upper miocene hordos fm and post hordos 2 subsequent to deposition during the upper miocene and pliocene and 3 towards the end of the lower pleistocene post ubediye and mishmar hayarden fms when tilting and folding within the rift marked the last significant stage of its formation

early and middle pleistocene faunal and hominins dispersals through southwestern asia abstract this review summarizes the paleoecology of the early and middle pleistocene of southwestern asia based on both flora and fauna retrieved from a series of windows provided by the excavated sites the incomplete chrono stratigraphy of this vast region does not allow to accept the direct chronological correlation between the available sites and events of faunal and hominin dispersals from africa it also demonstrates that hominins survived in a mixed landscape of open parkland with forested surrounding hills in addition the prevailing environmental conditions are not sufficient to explain successful adaptations to new ecological niches away from the african savanna of the bearers of core and flake and the acheulian industries the differences in knapping and secondary shaping of stone artifacts probably reflect the learned traditions of different groups of hominins the current distribution of lithic industries across eurasia is undoubtedly incomplete due to lack of cultural continuities as well as paucity of field research in several sub regions this observation supports the contention that what we view as a constant stream of migrants was actually interrupted many times the continuous occupation of southwestern asia by the makers of the acheulian is in contrast with neighboring regions such as the iranian plateau and eastern europe a more complex model is required to explain the recorded eurasian archaeological cultural mosaic

paleomagnetism of miocene volcanic rocks from southwestern arizona tectonic implications paleomagnetic data were acquired from 58 miocene volcanic units exposed in five mountain ranges in southwestern arizona unlike results of similar paleomagnetic studies west of the san andreas fault no clockwise rotations of the paleomagnetic vectors are observed in fact the data indicate a statistically significant counterclockwise rotation of 13 7 12 2 this counterclockwise rotation is consistent with garfunkel s tectonic model for the mojave block the paleomagnetic data from southwestern arizona could indicate that a similar counterclockwise rotation during basin and range crustal extension has also occurred in southwestern arizona

structural position of the pleistocene gesher benot ya aqov site in the dead sea rift zone abstract newly discovered outcrops of the middle pleistocene benot ya aqov formation are strongly disturbed due to recent tectonic activity along the dead sea rift the lacustrine fluviatile sediments of this formation comprise the littoral facies of a paleo lake that occupied the adjacent hula basin acheulian artifacts found embedded in the formation have typical african characteristics the geographical position of the site the northern extension of the east african red sea rift system is important for understanding hominid diffusion from africa to eurasia

implications of paleomagnetic data on miocene extension near a major accommodation zone in the basin and range province northwestern arizona and southern nevada paleomagnetic data from volcanic and crystalline rocks elucidate the evolution of a major miocene accommodation zone in the northern colorado river extensional corridor the accommodation zone is a 10 km wide belt of intermeshing conjugate normal faults that facilitates reversals in the dominant tilt direction of fault blocks and dip direction of major normal fault systems tilt corrected means e g n 28 sites d 353 4 i 61 3 95 6 7 k 17 4 from miocene volcanic strata overlap expected miocene directions at the 95 confidence level these data and geologic relations suggest that at exposed structural levels the accommodation zone did not facilitate distributed strike slip displacement between opposing tilt block domains vertical axis rotations are probably negligible in most of the corridor as the miocene structural grain generally mimics that in the zone discrepancies between characteristic remanent magnetizations chrm in crystalline rocks and expected directions are therefore attributed to rotations about horizontal i e tilting or flexing axes chrms from cretaceous and miocene intrusions suggest 50 90 of tilting of large crystalline terranes on either side of the accommodation zone the magnitude of tilting inferred from the paleomagnetic data is similar to that of tertiary strata in nearby fault blocks implying that these crystalline terranes are parts of highly tilted fault blocks rather than flexed lower plate rocks major low angle normal faults that bound highly tilted parts of these crystalline terranes probably nucleated at steep dips and were rotated to gentle dips by block tilting paleomagnetic data indicative of negligible tilting e g miocene intrusions northern black mountains crystalline terrane n 13 sites d 359 i 55 95 9 k 24 and geologic relations imply that lower plate rocks may surface in both the east and west tilted domains 35 50 km away from the zone the trend toward shallower structural levels with respect to miocene extension and tapering of highly extended terrane toward the accommodation zone imply that the magnitude of upper crustal extension decreases toward the zone temporal patterns of major extension especially an apparently continuous northward younging across both the east and west tilted domains further suggest that the accommodation zone served as a long lived rupture barrier between conjugate normal fault systems rather than as a short term boundary between opposing systems that propagated toward and converged at the zone

u pb geochronologic constraints on the age of thrusting crustal extension and peraluminous plutonism in the little rincon mountains southern arizona the little rincon thrust fault is a mylonitic shear zone that juxtaposes middle proterozoic continental granodiorite over metasedimentary rocks of proterozoic and early paleozoic age this fault is structurally beneath the san pedro detachment fault and associated ductile deformational fabrics which formed during early oligocene to early miocene time a syntectonic leucogranite sill within the little rincon shear zone yields a u pb concordia intercept age 66 plus minus 10 ma for zircon and a concordant age 51 plus minus 2 ma for fractions composed of monazite and xenotime this demonstrates that compressional deformation in the catalina and rincon mountains is generally coeval with laramide thrust faults that extend at least from southeastern california to southeastern arizona a peraluminous granite pluton that truncates the shear zone but displays extension related fabrics yields a lower intercept age 24 plus minus 12 ma for zircon and an age of 30 plus minus 6 ma for monazite this indicates that some peraluminous plutons in the region were emplaced during regional crustal extension

did the last interglacial sea penetrate mount carmel caves comments on the setting of the mt carmel caves reassessed by c vita finzi and c stringer

detachment faulting and the evolution of passive continental margins major detachment faults play a key role in the lithospheric extension process in the basin and range province and may also be important in other continental extension terranes such detachment faulting leads to an inherent asymmetry of extensional structure and of uplift subsidence patterns detachment models developed for the formation of metamorphic core complexes can also be applied to the formation of passive continental margins we therefore suggest the existence of upper plate and lower plate passive margins these give rise to a complementary asymmetry of opposing margins after continental breakup transfer faults offset marginal features and allow margins to switch from upper plate to lower plate characteristics along strike

late cretaceous paleomagnetism and clockwise rotation of the silver bell mountains south central arizona late cretaceous ash flow volcanism in the silver bell mountains of southern arizona 32 3 n 248 5 e was associated with caldera formation and porphyry copper mineralization oriented samples from 34 sites in volcanic volcaniclastic and intrusive units related to this episode of igneous activity 73 69 ma yield a mean paleomagnetic direction of i 61 2 d 24 0 95 7 6 primary remanent magnetizations are indicated by the presence of both normal and reversed polarities and by the significantly improved grouping 95 confidence level of site mean directions for a widespread tuff unit after structural correction a comparison of this direction with a direction at silver bell calculated from contemporaneous units for stable north america i 58 8 d 342 3 95 7 7 indicates a late cretaceous paleolatitude anomaly of 2 4 7 6 not significant at the 95 confidence level and a declination anomaly of 41 7 14 3 for the silver bell mountains previously determined paleomagnetic data for southeastern arizona suggest that this apparent clockwise rotation in the silver bell mountains is a local phenomenon although preliminary the average paleomagnetic direction for oligocene and lower miocene rocks in the silver bell area i 43 8 d 357 3 95 16 5 is similar to that calculated for stable north america i 50 2 d 352 2 95 3 9 implying that the observed rotation in the silver bell mountains occurred before 26 ma and was most likely associated with dextral strike slip movement along the ragged top and related wnw trending faults bounding the silver bell mountain block these data in conjunction with plate reconstructions and other paleomagnetic data from southwestern north america imply that wnw trending strike slip faults may have played an important role during late cretaceous to early tertiary deformation in southern arizona

clockwise rotation of the western mojave desert paleomagnetic results from miocene volcanic rocks in the western mojave desert suggest about 25 of clockwise rotation for this region twelve sites 110 oriented cores were collected from the 20 ma saddleback basalt and seven sites 56 oriented cores from the red buttes quartz basalt around boron california structural corrections were made from the attitude of the basalt or the tropico group sedimentary rocks in which the sampled basalts are interbedded paleomagnetic directions are coincident for the two basalts and show both normal and reversed polarity after demagnetization to 40 or 60 mt application of structural corrections and inversion of reversed sites the data yield an average direction of i 51 6 and d 15 6 k 19 95 8 2 comparison with the expected direction for miocene rocks for stable north america shows a clockwise rotation of 23 8 11 3 and a flattening of 2 1 7 4 clockwise rotation of the western mojave agrees in direction with oroclinal bending of the southern sierra nevada due to right lateral shear along the western margin of north america most of this rotation is constrained by other paleomagnetic and structural information to have occurred soon after the sampled basalts were deposited about 20 ma and before about 16 ma these clockwise declination anomalies also indicate that any subsequent counterclockwise rotation of the mojave is small and or compensated by previous clockwise rotation

fission track analysis of the footwall of the catalina detachment fault arizona tectonic denudation magmatism and erosion new apatite and zircon fission track ages obtained from the footwall of the catalina metamorphic core complex record a complicated cooling history associated with mid tertiary extension zircon fission track ages record the progressive unroofing of the catalina metamorphic core complex along the catalina detachment fault zircon fission track ages range from 31 9 to 19 4 ma generally decrease in the hanging wall slip direction and yield slip rates along the catalina detachment fault ranging from 1 2 to 12 km myr 1 in contrast apatite fission track ages increase in the hanging wall slip direction samples from the main range of the santa catalina mountains yield apatite fission track ages of 20 5 to 14 6 ma samples from the santa catalina mountain forerange located closer to the detachment fault yield apatite fission track ages of 21 4 to 18 8 ma rapid cooling 40 to 60 c myr 1 related to detachment faulting is best recorded by zircon fission track ages and higher temperature thermochronometers in the main range and by nearly concordant zircon and apatite fission track ages in the forerange slower cooling 3 7 c myr 1 of the footwall is recorded by shortened mean confined fission track lengths 14 m and is related to erosional unroofing approximately 2 km of late tertiary erosion played a significant role in the unroofing of the footwall of the catalina metamorphic core complex in contrast to metamorphic core complexes in western arizona where detachment faulting is the dominant unroofing mechanism

late miocene to present exhumation in the ligurian alps southwest alps with evidence for accelerated denudation during the messinian salinity crisis detrital apatite u th he and fission track thermochronometry are applied to constrain the exhumation history of the ligurian alps southwest alps exhumation of the ligurian alps is recorded from ca 11 ma and continues until present more than 4 km of exhumation is recorded at an average rate of 0 4 0 2 mm yr exhumation is accommodated along a north dipping thrust at the foot of the ligurian margin combined u th he and fission track thermal modeling show a phase of accelerated denudation between 7 and 5 ma associated with the base level drop during the messinian salinity crisis

ostracod evidence for the acheulian environment of the ancient hula lake levant during the early mid pleistocene transition abstract ostracod shells from the archaeological site gesher benot ya aqov gby in the upper jordan river valley israel were investigated to improve the understanding of the environmental conditions of the acheulian occupation site during the early mid pleistocene transition 0 78 ma the diverse ostracod assemblage consists of 28 species the distribution of most of the recorded species in the region today shows that the hydrological conditions at the early mid pleistocene transition were not fundamentally different from the modern ones however the predominance of candona neglecta shells in the gby sequence probably indicates cooler climatic conditions than today shells of candona angulata in the artefact richer upper half of the sequence suggest a slight salinity increase in the ancient hula lake from pure freshwater to slightly oligohaline conditions this shift probably resulted from wetter conditions and a more stable lake environment with increased residence time of the lake water and stronger influence of evaporation shells of the brackish water ostracod cyprideis torosa and the slightly halophilic heterocypris salina and plesiocypridopsis newtoni were recorded only rarely suggesting that the lake maintained an outlet through the entire period represented by the gby sequence shells of gomphocythere ortali in gby cycles 1 and 2 imply that a permanent freshwater stream existed close to the site humphcypris subterranea shells in cycles 3 5 provide further evidence that a tributary entered the lake from the south in contrast to the modern setting with the north south flowing jordan river at gby statistical analysis of the quantitative ostracod data from gby identified a group of samples from layers containing more abundant stone artefacts and another group of samples from layers with scarce artefacts samples from layers containing more abundant artefacts have relatively high abundances of c angulata darwinula stevensoni and physocypria kraepelini shells and include rare shells of ilyocypris hartmanni ilyocypris salebrosa heterocypris incongruens and pseudocandona sp 2 which do not occur in the other samples the presence of p kraepelini and h incongruens shells in artefact richer sediments possibly indicates poor bottom water oxygenation in the ancient hula lake sometimes during the periods of acheulian occupation however more detailed studies are required to assess whether lower dissolved oxygen levels in the lake resulted from a slight lake level rise and possibly higher nutrient flux to the lake during wetter conditions or whether hominins already impacted lake s nutrient status by butchering at its shore or by burning of near shore vegetation

reappraisal of the 1887 ligurian earthquake western mediterranean from macroseismicity active tectonics and tsunami modelling summary early in the morning of 1887 february 23 a damaging earthquake hit the towns along the italian and french riviera the earthquake was followed by a tsunami with a maximum run up of 2 m near imperia italy at least 600 people died mainly due to collapsing buildings this ligurian earthquake occurred at the junction between the southern french italian alps and the ligurian basin for such a historical event the epicentre and the equivalent magnitude are difficult to characterize with any degree of precision and the tectonic fault responsible for the earthquake is still under debate today the recent malisar marine geophysical survey allowed the identification of a large system of active faults we propose that the rupture of some of the segments belonging to this 80 km long northern ligurian faults system connected to a shallow dipping major thrust plane at depth was the source of the 1887 ligurian earthquake we investigated the macroseismic data from the sisfrance 08 and dbmi 04 historical databases using several models of intensity attenuation with distance and focal depth the modelling results are consistent with the off shore location with an epicentre around 43 70 43 78 n and 7 81 8 07 e and with a magnitude mw in the range of 6 3 7 5 numerous earthquake source scenarios have been tested on the tide gauge record at genoa harbour as a result we present seven characteristic source earthquake scenarios for a shallow strong earthquake occurring below the northern ligurian margin the modelled tide gauge records were analysed with the help of basic statistical tools and a simple harmonic analysis to extract the wave spectrum characteristics this analysis indicates that scenarios of a magnitude mw of 6 8 6 9 along a reverse n55 e striking fault are the best candidates to explain the known characteristics of the tsunami that followed the best fitting scenarios comprise a 70 dipping southward fault plane with mw 6 8 and a 16 dipping northward fault plane with mw 6 9 both with reverse kinematics taking into account the geometry of the active faults the location of the macroseismic epicentre and the morphotectonic evolution of the continental slope we propose that the 1887 ligurian earthquake corresponded to the reverse faulting of a n55 e striking fault plane dipping to the north with a coseismic slip of 1 5 m

stratigraphy and isotope records of middle and late pleistocene mollusks from a continuous corehole in the hula basin northern jordan valley israel morphological changes in melanopsis shells and the sudden disappearance of viviparus were observed in a continuous core representing about 700 000 yr taken from the l 12 corehole in the hula basin northern jordan valley israel two major events in 18o values are recorded the first at about 435 000 yr b p is accompanied by a shift in 13c values and indicates a shallowing phase with slightly higher evaporation this event is concurrent with the abundant occurrence of a monotypic distorted melanopsis suggesting an ecophenotypic event during deposition of the lake s pleistocene lower lacustrine beds the second major isotopic event is evidenced in the lower part of the section as a gradual depletion in 18o toward the bottom of the corehole minor shifts of 1 20 in the oxygen isotope content along the core may represent changes in the 18o values of the water from glacial to interglacial periods representing the major climatic cycles of the pleistocene five of these cycles were observed along the core

deformation of the 125 ka marine terrace in italy tectonic implications in peninsular italy marine terraces and shorelines created during oxygenisotope substage 5e known historically as the tyrrhenian highstand provide a reliable and homogeneous datum of vertical motions during the past 125 000 years published accounts of 121 locations on the tyrrhenian inner edge were reinterpreted and used to calculate both local and regional uplift rates the data show arching of southern italy between the tyrrhenian and the adriatic coasts and of the calabrian arc between the sangineto and the longi taormina tectonic lineaments at rates of up to 1 2 mm yr for the past 125 ka they also suggest that the present configuration of the southern apennines is the product of post early pleistocene regional uplift superimposed on tortonian to early pleistocene thrusting uplift patterns are characterised by different wavelength in different geodynamic settings suggesting a close link with the depth of the causative tectonic sources

coastal deformation between the versilia and the garigliano plains italy since the last interglacial stage the opening of the north central tyrrhenian sea is the result of the cretaceous paleogene alpine collision which triggered a series of regional uplift subsidence and transcurrent tectonic mechanisms along the coastal tyrrhenian sectors of peninsular italy these tectonic pro cesses in conjunction with the effects of glacio and hydro isostasy during the quaternary produced substantial crustal responses that in some cases reached metres in extent in the study of coastal neotectonics geomorphological markers of the last interglacial maximum corresponding to marine isotope stage 5 5 are generally used to quantify the magnitude of the vertical crustal displacements that have occurred since 125 kyr through altimetrical palaeoenvironmental and chronological reinterpretation of the most significant works published since 1913 combined with an additional set of data reported here a detailed reconstruction of the shoreline displacements evident along 500 km of coast between northern tuscany and southern latium is presented the reconstruction was carried out by quantifying the vertical movement since the last interglacial period and by identifying the tectonic behaviour of different coastal sectors this has been done by carefully choosing the eustatic marker among those available at each study site in order to minimize the margin of error associated with the measurements copyright 2003 john wiley sons ltd

a theoretical and experimental comparison of the anisotropies of magnetic susceptibility and remanence in rocks and minerals summary susceptibility thermo remanent magnetization trm and isothermal remanent magnetization irm anisotropy ellipsoids have been determined for several rock samples the results indicate that the ellipsoid of initial susceptibility is less anisotropic than the trm and low field irm ellipsoids which are found experimentally to be of identical shape this suggests that palaeomagnetic data for anisotropic rocks may be corrected by using the anisotropy ellipsoid determined from magnetically non destructive low field irm measurements such irm measurements can also be used to obtain anisotropy axes of samples which are inherently anisotropic but which have a susceptibility which is too weak to be accurately measured the results for a series of artificial anisotropic samples containing magnetite particles of different sizes in the range 0 2 90 m were very similar to those for the rocks in contrast a comparison of the susceptibility and irm ellipsoids for anisotropic samples containing particles from a magnetic tape gave very different results in accordance with theory such results imply that susceptibility and irm ellipsoids could be used to determine whether anisotropic rocks contain uniaxial single domain particles magnetization confined to the easy axis or whether the particles are essentially multidomain

uniform sense normal simple shear of the continental lithosphere geophysical studies suggest that the thin crust characteristic of the basin and range province extends eastward beneath the west margin of the colorado plateau and rocky mountain regions in arizona and utah zones perhaps over 100 km wide may be defined bounded on the west by the east limit of upper crustal normal faults that account for more that 10 extension and on the east by the east limit of thinning beneath the colorado plateau a discrepancy exists within these zones between the negligible extension measurable in the upper crust and the substantial extension apparent from crustal thinning assuming the discrepant zone crust was as thick as or thicker than the colorado plateau rocky mountain crust prior to extensional tectonism if various theories appealing to crustal erosion are dismissed mass balance problems evident in the discrepant zones are most easily resolved by down to the east normal simple shear of the crust moving lower and middle crustal rocks that initially were within the zones up and to the west to where they now are locally exposed in the basin and range province west of the discrepant zones in both arizona and utah east directed extensional allochthons with large displacement are exposed these geophysical and geological observations complement one another if it is accepted that the entire crust in both arizona and utah failed during extension on gently east dipping east directed low angle normal faults and shear zones over a region several hundred kilometres wide large scale uniform sense normal simple shear of the crust suggests the entire lithosphere may do the same such a hypothesis predicts major lithospheric thinning without crustal thinning will occur in plateau areas in the direction of crustal shear in the case of the arizona utah and red sea extensional systems and possibly the death valley extensional terrain a broad topographic arch typically 1500 2000 m higher than the extended terrain is present suggesting lithospheric thinning in areas predicted by the hypothesis

constraints on vertical crustal motion for long baselines in the central mediterranean region using continuous gps abstract gps determination of vertical crustal velocity relative to a globally defined reference frame is limited by the accuracy of the reference frame origin and scale however the precision of relative vertical rates at regional distance scales remains largely unexplored we investigated the precision of regional scale vertical velocity estimates using data from seven continuously operating gps stations located in the central mediterranean the stations form a network of aperture 500 km and each has been in operation for at least 5 yr we used published constraints on recent crustal uplift inferred from late quaternary shoreline data to aid in the definition of a local vertical reference frame for gps rates to facilitate an assessment of gps vertical precision we explored different methods of defining the local reference frame the simplest method involves the estimation of a single scalar translation parameter adjusting the reference frame by this simple method yields agreement between cgps and holocene shoreline data sets at the level of 0 2 to 0 4 mm yr relative rates determined using cgps are also consistent with tide gauge records and sea level determined by satellite altimetry at the level of about 0 2 mm yr these results suggest that regional scale relative velocity precision well below the mm yr level is now possible using continuous gps

modes of tilting during extensional core complex development crustal extension and formation of the mineral mountains core complex utah involved tilting of the mineral mountains batholith and associated faults during hanging wall and footwall deformation the batholith was folded in the hanging wall of the beaver valley fault between 11 and 9 million years ago yielding about 45 of tilt subsequently the batholith was unroofed along the cave canyon detachment fault and the batholith and fault were tilted approximately 40 during footwall uplift recognition of deformed dikes beneath the detachment fault establishes the importance of footwall tilt during formation of extensional core complexes and demonstrates that footwall rebound can be an important process during extension

crustal structure from three dimensional gravity modeling of a metamorphic core complex a model for uplift santa catalina rincon mountains arizona gravity modeling shows that the observed fluctuations in gravity over the catalina rincon metamorphic core complex of southeastern arizona are caused primarily by shallow crustal density contrasts the wilderness suite granites the probable source of a 20 mgal low over the central part of the core complex may extend to depths of 7 12 km below the surface seismic refraction information is consistent with the existence of a deep crustal root under the catalina rincon core complex we hypothesize that the voluminous wilderness suite granites are related to a crustal thickening event that built the root in early tertiary time modeling of flexural isostatic uplift resulting from an excess crustal root predicts two episodes of uplift for the catalina rincon metamorphic core complex 1 low relief flexural uplift in the middle tertiary and 2 complete uplift precipitated by high angle basin and range faulting at 10 15 ma the uplift and exposure of core complexes therefore can be an isostatically driven process that occurs in regions of locally thickened crust

geological setting and age of the middle paleolithic site of nahal mahanayeem outlet upper jordan valley israel abstract in this paper we present the sedimentary features and the luminescence chronology for nahal mahanayeem outlet nmo an archaeological open air site at the southern margin of the hula basin northern jordan rift valley israel the site is characterized by a lithic assemblage ascribed primarily to the middle paleolithic mousterian tradition and by an excellent preservation of floral and faunal remains six geological units forming the stratigraphic sequence of the site were distinguished unit 6 archaeologically sterile light colored limnic carbonates unit 5 conglomerates of rounded basalt boulders and cobbles forming a hill like topography unit 4 and unit 3 a sequence of similar dark silty sediments attached to and overlaying the conglomerates containing the archaeological horizons of the site unit 2 a number of channels cutting into the top of unit 3 filled with coarse sand and rounded basalt and limestone gravels of fluvial origin and unit 1 a thin sand layer laid down by the present day jordan river covering another unconformity as a result of heavy machinery drainage operations in 1999 the osl age for unit 6 yielded a minimum age older than 460 ka sedimentary features and the embedded fossils suggest that unit 1 can be linked to the early pleistocene gadot chalk unit 5 represents a local geological feature and could be an indicator for a period of increased erosion with formation of coarse grained sediments the archaeological horizons form the lower parts of unit 4 and yielded osl ages between 55 and 65 ka indicating an affiliation to the sediments called ashmura formation with an upper pleistocene age for the site the channel fills of unit 2 can be dated by the recovered artifacts these range in age from the upper paleolithic aurignacian to historic times unit 1 is recent the study of the complex nmo stratigraphy combined with coherent osl chronology has enabled us to reconstruct parts of the geological history of the hula basin during the late pleistocene it is this history that forms the background for the human migration and utilization of natural resources in the upper jordan rift valley

palaeomagnetic evidence for large magnitude low angle normal faulting in a metamorphic core complex controversy exists over whether large magnitude extensional deformation can occur along low angle master detachment normal faults1 16 large amounts of cenozoic extension occurred in the basin and range province of the western united states and master detachment faults related to this extension are currently exposed as subhorizontal structures along crustal arches known as metamorphic core complexes mccs 10 11 17 one set of models suggests that mccs represent crustal scale blocks bounded by originally high angle normal faults which have tilted to sub horizontal attitudes1 6 more dynamic models propose isostatically induced flexural tilting of an initial subhorizontal fault to an active high angle fault to final abandonment as a subhorizontal structure7 9 these models require mcc detachment faults and their footwalls to have been tilted by 30 60 alternatively mcc detachment faults may have originated as subhorizontal or low angle structures10 16 here we test these models with palaeomag netic data from undeformed portions of the south mountains a typical cenozoic mcc in the southern basin and range province18 24 comparison with time averaged expected directions of the geomagnetic field25 27 yields no evidence for tilting of the footwall we conclude that the south mountains master detachment fault was active as a low angle extensional structure with a dip of 10

assessing tectonic subsidence from estimates of holocene relative sea level change an example from the nw mediterranean magra plain italy new sedimentological sea level indicators are presented from the river magra coastal plain in nw italy chronologically well constrained paralic peats and organic sediments which had been deposited in a defined relationship with sea level were recovered in four of the seven boreholes considered in this work their evolution scatters in the time span of the past 6000 years since the cores are located within a single sedimentary basin it was possible to correct the elevation of marker horizons for the effect of sediment compaction by means of both a field and a geotechnical method thus seven reliable index points for the mid to late holocene sea level rise were obtained the age depth model derived from them was compared with that of sea level predictions from two different glacial isostatic adjustment gia models available for the area in both cases the modelled sea level estimates overlie the index points suggesting lower relative sea level elevation than the one predicted considering the combin

dating the lower paleolithic open air site of holon israel by luminescence and esr techniques abstract the open air acheulian site in holon israel was dated by the luminescence methods and by electron spin resonance esr situated in the coastal plain quaternary kurkar group the holon site was first excavated in the late 1960s when typical lower paleolithic lithics and middle pleistocene fauna were found in order to date the site new test pits were dug adjacent to the earlier excavations and the archaeological bed was exposed in a section comprising a series of paleosols and aeolianites alkali feldspars separated from the sediments were dated using the infrared stimulated luminescence and thermoluminescence signals and quartz was dated using the optically stimulated luminescence signal the age of the archaeological bed is constrained by two samples to 198 000 22 000 201 000 17 000 yr the age of the base of the section is 240 000 29 000 yr and the age of the top is 81 000 8000 yr two teeth from the archaeological bed recovered from the original excavation collection yielded an average esr age of 204 000 16 000 yr calculated using the linear uptake model which is in a very good agreement with the luminescence ages these dates place holon within the range of other late acheulian and acheulo yabrudian sites in this region such as tabun e younger chronology yabrud i archaeological level 18 and berekhat ram

evidence for climatic changes around the matuyama brunhes boundary mbb inferred from a multi proxy palaeoenvironmental study of the gby 2 core jordan river valley israel the acheulian site of gesher benot ya aqov gby in the upper jordan valley revealed important data on environment and material culture as well as evidence for hominin behavioural and cognitive patterns documented at the margins of the hula palaeo lake a 50 m long core gby 2 drilled at the archaeological site has provided a long pleistocene geological environmental and climatological record which expands the existing knowledge of hominin habitat relationships bracketed by two basalt flows dated by 40ar 39ar and based on the identification of the matuyama brunhes boundary mbb and correlation with the gby excavation site the sedimentary sequence provides the climatic history around the mbb multi proxy data including pollen and non pollen palynomorphs macro botanical remains molluscs and ostracods provide evidence for lake and lake margin environments during marine isotope stages mis 20 and 19 semi moist conditions were followed by a pronounced dry phase during mis 20 and warm and moist conditions with quercus pistacia woodlands prevailed during mis 19 in contrast to the reconstructed climate change from relatively dry to moister conditions the depositional environment developed from an open water lake during mis 20 to a lake margin environment in mis 19 generally shallower conditions at the core site in mis 19 resulted from the progradation of the lake shore due to the filling of the basin micro charcoal analysis suggests a likelihood of human induced fire in some parts of the core which can be correlated with artefact containing layers of the gby excavation site the hula palaeo lake region provided an ideal niche for hominins and other vertebrates during global glacial interglacial climate fluctuations at the end of the early pleistocene

strain and magnetic fabric in the santa catalina and pinaleno mountains metamorphic core complex mylonite zones arizona anisotropy of magnetic susceptibility ams is capable of recording finite strain in weakly magnetized rocks ams was measured for 228 samples from 20 sites in two mylonite zones with the same deformational history ams measurements were compared with finite strains determined from dike rotations and from foliation orientations in one zone the santa catalina mountains the orientations of susceptibility and finite strain ellipsoids are in excellent agreement and there is a logarithmic relationship between susceptibility difference ki ki k k and finite strain magnitude in the second zone the pinaleno mountains minimum susceptibility is perpendicular to the finite flattening plane but the maximum susceptibility does not parallel the maximum extension direction and there is no systematic relationship between susceptibility magnitude and strain magnitude oriented polished thin sections indicate that magnetite in the protolith of the santa catalina mylonite occurs as randomly oriented elongate grains with subsequent deformation the long axes are rotated into the maximum extension direction in the pinaleno mylonites both equant and elongate magnetite grains are present with deformation the elongate magnetite grains are rotated into the maximum flattening plane but show no preferred orientation within this plane ams in the two mylonite zones appears to be predominantly controlled by the orientation of elongate magnetite grains with respect to the megascopic fabric the final orientation of the elongate grains is a function of their initial orientation as well as the finite strain therefore despite similar deformational histories the two zones display different ams patterns due to the differences in occurrence initial orientation and shape of ferromagnetic grains

the structure and morphotectonics of the gesher benot ya aqov area northern dead sea rift israel abstract geological geomorphological and morphotectonic studies at the gesher benot ya aqov acheulean site northern jordan valley provide 1 a unique opportunity to establish the ecological background of hominid behavior during the early stages of widespread human occupation 2 crucial data for understanding the paleo environment and the various processes that affected the area near the gesher benot ya aqov site and 3 a basis for further comprehensive research in the region quaternary tectonic activity near the acheulean archeological site has produced a complex local setting that controls the surrounding landscape tectonic activity formed the benot ya aqov embayment which attracted hominids and a variety of other fauna sediments of the benot ya akov formation deposited in the embayment facilitated excellent preservation of the remnants of acheulean hominid activities and of abundant floral and faunal remains the formation was subsequently affected by faulting and folding local uplift ended the deposition of lacustrine sediments in the embayment of hula valley basin and caused erosion and vertical incision of the jordan river that resulted in the capture of the rosh pinna river and the exposure of the benot ya akov formation these deposits are found in different structural positions along the north south oriented morphotectonic embayment the outcrops contain numerous archeological sites giving the study area an unusually high potential for future hominid discoveries

beach deposits of mis 5e high sea stand as indicators for tectonic stability of the carmel coastal plain israel abstract ten beach deposits mainly beachrock on the carmel coastal plain northern israel are discussed six are reported for the first time the deposits are situated within or close to the following seasonal stream locally termed nahal channels nahal ahuza amiram ovadia galim megadim bir ibdawiya me arot and kebara the morphology and lithology of most of the deposits are similar their uppermost altitude varies from 0 to 9 m above the present sea level most of the deposits are composed mainly of fine quartz sand and marine mollusk shells carbonate cemented the dominant mollusk families are glycymerididae cardiidae and donacidae most of the beach deposits are situated between cemented aeolian sandstones locally termed kurkar layers on the carmel coast ridge in the nahal ahuza deposit a marine gastropod lentigo latus an index fossil for the mis 5e high sea stand in the mediterranean area was discovered according to lithology and chronostratigraphy the presence of lentigo latus th u aar and rtl dating and flint artifacts the beach deposits were related to the last interglacial maximum about 125 ka bp i e the mis 5e high sea stand these beach deposits are used to identify the palaeo sea levels and coastlines and to study the tectonics along the carmel coastal plain by comparing the elevations and characteristics of the beach deposits to known mis 5e deposits elsewhere and by analyzing archaeological data it is concluded that during the last 125 ka the maximum possible vertical displacement was less than 48 mm ka and the carmel coastal plain was relatively tectonically stable

thermal constraints on the tectonic evolution of a metamorphic core complex santa catalina mountains arizona abstract we present an analysis of the thermal evolution of the metamorphic core complex of the santa catalina rincon and tortolita mountains in south arizona the structural and kinematic data are briefly reviewed granite mylonites result from three successive shearing events respectively compressional top west during paleocene and top ne during mid eocene and extensional top sw after eocene in a preliminary part of the paper available radiometric data are reviewed in detail for both deformed and undeformed granites with closing temperatures from 565 to 105 c these data are then used to constrain the temperature history for three intrusions which were emplaced respectively during paleocene eocene and miocene times the general temperature time curve shows 1 rapid cooling for the three intrusions just after emplacement and 2 a large and rapid cooling of the entire complex between 35 and 22 ma from 530 to 100 c in the final part this thermal history is used to constrain the tectonic history of the metamorphic core complex the thermal effects of erosion tectonic denudation homogeneous and heterogeneous thinning are computed using a finite difference scheme in one dimension an analysis of the parameters involved in the models shows that the crust of the santa catalina metamorphic core complex has undergone mainly a thinning of its upper part of at least 15 km and more reasonably 20 25 km in less than 10 ma this estimation is discussed considering thermal effects of magmatism

pleistocene amphibians and squamates from the upper jordan rift valley gesher benot ya aqov and nahal mahanayeem outlet mis 20 18 and mis 4 3

evidence for large scale transport on the bullard detachment fault west central arizona the bullard detachment fault is a gently to steeply dipping normal fault that flanks the harcuvar and harquahala mountains of the basin and range province in west central arizona the stratigraphy of upper plate miocene conglomerates and the regional distribution of upper and lower plate pre tertiary units indicate that upper plate rocks were displaced about 50 km to the northeast with respect to the lower plate during middle to late tertiary time normal slip of this magnitude on the regionally northeast dipping bullard fault indicates that deep seated tertiary cretaceous mylonitic gneisses and mesozoic thrust faults of the lower plate were drawn out from beneath precambrian rocks along the margin of the transition zone of central arizona during middle to late tertiary crustal extension the transition zone was therefore affected by deep seated tectonism in both mesozoic and tertiary time