mineral magnetic record of late quaternary climatic changes in a high alpine lake the magnetic properties of a sediment core from a high altitude lake in the swiss alps were compared with palynological and geochemical data to link climatic and mineral magnetic variations according to pollen data the sediments extend from the present to the younger dryas i e they cover more than 10 000 years of environmental change in the alps the major change in magnetic properties corresponds to the climatic warming of the early holocene high coercivity magnetic minerals that characterize the late glacial period almost disappeared during the holocene and the concentration of ferrimagnetic minerals increased sharply the contribution of superparamagnetic grains also decreased in the holocene sediments similar variations in sp content and coercivity of smaller magnitude are found in the holocene and are interpreted to represent minor climatic variations comparison with the historical record of the last 1000 years confirms this interpretation the magnetic mineralogy the superparamagnetic contents and the irm intensity in the coarse grained late glacial sediments are similar to those measured in the catchment bedrock this indicates a detrital origin the different properties and the higher concentration of magnetic minerals in the holocene sediments are due to authigenic phases magnetic properties provide a high resolution record of climatic change they are sensitive even to small variations that are not recorded in the pollen or loi data magnetic parameters show fine scale variation and constitute a valuable supplement to conventional climatic indicators 1999 elsevier science b v all rights reserved

sediment yields and sources in a welsh upland lake catchment during the past 800 years estimates of suspended sediment yield over the past 800 years have been derived from a whole basin study of lake sediments in llyn geirionydd north wales magnetic and physical sediment properties were used to correlate a suite of cores to a master chronology based on 210pb and 14c dates the sources of sediment within the catchment were identified by comparing the magnetic and heavy metal properties of sediments soils and stream sediments mean suspended sediment yields range from 6 to 18 t km 2 yr 1 with high yields in the periods 1765 1830 and 1903 1985 corresponding to mining activities in the catchment the impact of earlier deforestation agricultural expansion or climatic change on sediment yields is low although there is evidence that agricultural activities increased levels of peak stream discharge afforestation in the 20th century does not appear to have significantly increased sediment yield sediment sources have remained fairly constant through time they appear to be widespread and dominated by stream channel sides rather than point sources except during the mining phases when spoil material has dominated the sediment load sediment loads to the lake today are still dominated by sediment derived from unvegetated spoil heaps

palaeclimatic significance of the xiantai fluvio lacustrine sequence in the nihewan basin north china based on rock magnetic properties and clay mineralogy summary here we report an increased cooling coupled with an intensified aridification for the xiantai fluvio lacustrine sequence of pleistocene age 1 9 0 1 ma in the nihewan basin north china known for the occurrence of several hominin sites the cooling is related to an up section decrease in propensity to chemical weathering as inferred from an increase in lowfield susceptibility after cycling to 700 c close to 700 c reacting chlorite is providing the iron source for newly formed very fine grained ferrimagnetic minerals which enhances the susceptibility signal the reactivity of chlorite after annealing at temperatures above 600 c is documented with x ray diffraction and the up section decrease in propensity to chemical weathering is confirmed by the up section declining illite chlorite ratios and increasing chlorite and illite contents based on x ray diffraction analysis on selected samples

magnetic properties of surface sediments from the pearl river estuary and its adjacent waters implication for provenance abstract environmental magnetism has been widely used as a rapid cost effective and non destructive method in various fields including sediment source identification nineteen surface sediments from ten transects in the pearl river estuary pre and its adjacent seas were studied for magnetic measurements combined with mineral analysis for representative samples magnetic implications for provenance are discussed the results indicate that concentration dependent magnetic parameters decrease gradually and change sharply between the pre and its adjacent waters the magnetic mineral assemblage is basically consistent at all sites i e consisting of magnetite and hematite however the grain size of magnetite particles is clearly different probably due to different material sources magnetic parameters allow separating the sediments from the pre and its adjacent seas into three groups more distinctively than deduced from clay mineral analysis these new findings indicate that magnetic properties of surface sediments bring complementary information of material source as well as marine geology

testing a logic tree approach for archaeoseismology to the ancient city of pinara sw turkey geologists seismologists as well as archaeologists increasingly apply archaeoseismological investigations to study possible natural causes of damage of a site and to assess the regional seismic hazard risks archaeoseismological investigations enable the obtaining of diverse data on past earthquakes and allow for an application of different methods furthermore archaeoseismology provides the opportunity to study past earthquakes in regions where limited instrumental and historical data are available therefore this approach contributes to a regional assessment of seismic hazard the increasing application and importance of archaeoseismology requires a comprehensive and systematic approach the logic tree methodology for archaeoseismology is an evaluation method which offers a standard procedure to identify and evaluate archaeoseismological information and to provide comparable values for seismic hazard assessment this study tests the logic tree methodology for archaeoseismology to pinara to assess the city s potential to have recorded earthquakes and the methodology s value the ancient city of pinara sw turkey 500 bc 900 ad is situated in the esen basin in the southern extremity of the seismically active fethiye burdur fault zone the present seismic quiescence of the esen basin contradicts the geological and historical records which indicate that fault and earthquake activity must have been recurrent with the application of the logic tree approach to pinara geological and archaeoseismological evidence of seismic activity is evaluated in six stages the end solution of the logic tree provides a value between 0 and 1 this archaeological quality factor aqf reflects the reliability and relative significance of pinara for archaeoseismological investigation and seismic hazard assessment respectively pinara s preferred end solution pes1 of 0 06 and the aqf of 0 12 are obtained by the logic tree method and reflect the high probability of recorded palaeoearthquakes in pinara in sum the logic tree for archaeoseismology provides a concept with reliable criteria to assess the earthquake hypothesis in general and the findings suggest the assumed low seismic hazard potential of this area needs serious reconsideration 2011 elsevier ltd and inqua

denudational isostatic rebound of intraplate highlands the lachlan river valley australia a range of evidence from the lachlan valley in the southeast australian highlands is consistent with neogene isostatic rebound in response to denudational unloading this evidence is found along the inland edge of the highlands in the transition zone between the highlands proper and the lachlan s inland alluviated valley and the intracratonic murray basin the amounts and rates of uplift indicated by offsets of suballuvium bedrock profiles and the long profiles of tertiary valley filling basalts are consistent with modelling of denudational rebound using known rates of highland denudation and basinal sedimentation and reasonable crustal properties the modelling shows that weak to moderately strong strong lithosphere effective elastic thickness te 1 25 km and strong lithosphere te 100 km are all consistent with the observed amounts of rebound strong lithosphere must be broken however to be consistent with the field data even in the australian setting which is characterized by very low rates of denudation isostatic rebound in response to denudational unloading must be a significant factor in maintaining highland elevation and must be incorporated in models of long term landscape evolution it would be expected that denudational isostatic rebound would be an even more significant component of long term landscape evolution in areas of higher denudation rates

the 1 october 1995 dinar earthquake sw turkey the dinar earthquake ms 6 1 usgs pde of 1 october 1995 occurred on the nwse trending dinar fault the earthquake is associated with a 10 km long surface rupture with predominantly normal faulting the mainshock was preceded by a series of foreshocks that started 6 days before the mainshock and included two md 4 5 events the mainshock source mechanism derived from the inversion of broad band p waves revealed that two sub events occurred on a nw se trending normal fault with a small strike slip component according to the source model estimated in this study the first rupture started at a depth of about 8 km and reached to a depth of about 12 km propagating north west the total seismic moment found from the inversion of p waveforms is 2 0 times 10 18 nm the seismic moment of the second sub event was about four times larger than the first one field observations gps measurements and slip vector obtained from the inversion of broad band p waveforms suggest that the nw se trending dinar fault is due to the internal deformation of sw anatolia moving south westwards

evidence for dynamic coupling of surface processes with isostatic compensation in the lower crust during active extension of western turkey western turkey in the eastern part of the aegean region is extending slowly with extension no faster than 0 5 mm yr 1 across any individual active normal fault up to 15 km of southward extension has occurred in the most active 100 km wide part of this region since 15 ma indicating a typical strain rate of 3 10 16 s 1 rivers carry a sediment flux of 4 106 m3 yr 1 westward to the aegean sea coast with offshore sedimentation at 1 mm yr 1 sediment loading causes coastal areas to subside much faster than would be expected from the extension alone most of this sediment is derived from regional erosion of inland areas to the east at a typical rate of 0 1 mm yr 1 this erosion being isostatically compensated by uplift it is suggested that the lower crustal material displaced by sediment loading near the coast flows east to isostatically compensate the erosion the average eastward velocity of this lower crustal channel flow beneath the aegean coast is estimated as 1 mm yr 1 the maximum velocity is 2 mm yr 1 this case study thus indicates the general point that isostatically compensated erosion and lower crustal channel flow can affect the evolution of sedimentary basins that are surrounded by eroding landmasses factors that are often neglected

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

introduction and background interpretations of landscape change research into the origins of landscape has a long and distinguished tradition in america landscape studies form the core of physical geology while elsewhere the study of landscape development has spread beyond the confines of geology to develop a firmer foothold in the geographical tradition particularly in geomorphology the development of ideas in landscape study has however been neither steady nor sequential it has been characterized instead by several major conceptual shifts interspersed with periods of reinforcement or neglect within geomorphology and certainly within the english speaking world the most important of these shifts occurred in the early 1960s with the move from denudation chronology of landscapes as a core activity to an emphasis on process based investigation of individual landforms in geology the 1960s also marked an important change in perspective publication of plate tectonic theories sea floor spreading continental drift subduction and mountain building had far reaching consequences for all earth science in particular plate tectonics made the study of apparently ancient processes billions of years old applicable to the present day with for example application to earthquake studies whilst the initial shift towards process studies was a response to the desire for a better understanding of the mechanisms driving landscape change it was not long before this goal became relegated in the eyes of many of its practitioners as a consequence process study became an end in itself rather than a means to an end this movement has been reinforced in recent years by a demand for greater relevance from for example research funding bodies resulting in an emphasis on problem solving and wealth generation that has moved away from studies at the landscape scale consequently within geomorphology process studies and applied geomorphology have come to dominate the literature a dominance reinforced by the increasing division and separation of the discipline into process domains such as fluvial and glacial studies this has reached the point where many researchers would now naturally identify themselves as specialists in a particular process rather than as geomorphologists a similar trend can be identified within geology whereby studies of uplift erosion and stability clearly fall into pre plate tectonics and post plate tectonics generations in the 1920s studies of denudation were popular as evidenced by the volume of work conducted in southern england and based largely on observations of palaeovaueys tilted strata and unconformities sediment provenance became important in the 1920s and 1930s and early works on the use of heavy minerals in studies of past erosion were developed by the 1960s geologists were standing back and viewing many processes in terms of their global plate tectonic significance however this emphasis on processes inevitably led to the development of more labour intensive analytical methods as a consequence of which the wider perspective began to be neglected through the 1970s and 1980s therefore studies of uplift developed using methods that determine heating or pressurization of the uplifted rocks thermal estimates of uplift including spore or conodont alteration indexes fluid inclusion studies and diagenetic models were developed together with estimates of pressurization including studies of mineralogy and sonic borehole logs however perhaps the most significant advance in the determination of uplift rates and amounts has been in the field of apatite fission track analysis afta carter 1999 the widespread use of afta in the oil industry has provided large datasets that encompass the offshore basins formerly ignored by those concerned with land erosion buchanan buchanan 1995 studies of erosion and palaeoerosion have also developed from the study of derived clasts to clay minerals and heavy minerals requiring increasingly labourintensive and hence specialist methods to derive local or even regional perspectives specialization clearly has many advantages if however it is allowed to proceed unchecked these advantages eventually come to be outweighed by the effects of an increasingly reductionist approach whereby concentration on small scale studies and the pursuit of ever greater detail detracts from appreciation of the largescale picture and ultimately fragmentation and loss of the subject core clearly the longer this reductionist segregationist approach persists the more difficult it is to define and to justify the existence of the original parent discipline

river profiles along the himalayan arc as indicators of active tectonics abstract longitudinal profiles along sixteen major transverse himalayan rivers add important constraints to models of active continental subduction and its evolution these profiles are characterized by a zone of relatively high gradient that cannot be associated with differential resistence to erosion in all cases the base of the zone of increased gradients correlates with 1 the topographic front between the lesser and high himalayas 2 the narrow belt of intermediate magnitude thrust earthquakes 3 the main central thrust zone mct these features define a small circle in the central portion of the himalayan arc these correlations suggest that the discontinuity in the river profiles and the other features are controlled by a major tectonic boundary between the rising high himalayas and the lesser himalayas no sharp increases in gradient are observed near the main boundary thrust mbt except on a few rivers such as the jhelum or kundar where the mbt lies close to both the mct and the seismic belt thus it is unlikely that the mbt is a major tectonic boundary the diversion of river courses along the mbt and around anticlines in the sub himalayas has probably been caused by aggradation near the rosion deposition boundary upstream of uplifts in the mahabharat range and sub himalayas a parallel is drawn between the himalayas and new guinea based on the hypothesis that continent arc collision of the type occurring in northern australia preceded continent continent collision in the himalayas the present sedimentary tectonic phase in new guinea resembles the subathu paleocene eocene phase in the himalayas incipient counterparts of the major himalayan structures including the mct and the mbt are recognized in new guinea the drainage patterns in the himalayas and in new guinea bear a similar relation to major structures this suggests that 1 the tectonic evolution of the himalayas has been rather uniform since early stages of collision and 2 the himalayan drainage was also formed at these early stages and is therefore antecedent to the rise of the high himalayas

210pb geochronology of sediment accumulation rates in mexico city metropolitan zone as recorded at espejo de los lirios lake sediments abstract a sedimentary sequence from the espejo de los lirios lake in the metropolitan zone of mexico city mzmc was analyzed in detail for 210 pb and 137 cs activities allowing to assess the evolution of the accretion rates in the lake during the last 84 4 years the core revealed the deposition of contemporaneously indigenous lake sediments to the site interspersed with eroded bedrock from the catchment evidencing episodic increases in sediment accretion which varied from 0 14 to 0 93 cm year 1 increasing trends in sedimentation rates were found to be closely related to demographic expansion of the metropolitan zone of mexico city and explained on the basis of the erosive processes produced as a result of deforestation created as a consequence of the urban and industrial development of the mzmc

normalized magnetic parameters and their applicability to paleomagnetism and environmental magnetism using simple theory one can show that normalized magnetic parameters i e one primary magnetic measurement divided by a second are not independent of the concentration of magnetic minerals in an assemblage except in a few special cases in the common situation when the number of minerals in an assemblage is unknown these parameters can only be used to show a lack of change in domain size or mineralogy

the identification of an active fault by a multidisciplinary study at the archaeological site of sagalassos sw turkey abstract the archaeological site of sagalassos sw turkey is located in a region characterized by the absence of any significant recent seismic activity contrary to adjacent regions however the assessment of earthquake related damage at the site suggests that the earthquakes that have been demonstrated to have struck this pisidian city in ca ad 500 and in the middle or second half of the 7th century ad are characterized by an msk intensity of at least viii and occurred on a fault very close to the city different investigation techniques archaeoseismology remote sensing and geomorphology surface geology and structural data 2d resistivity imaging and palaeoseismological trenching have been applied at the archaeological site and its direct surroundings in search for the causative fault of these earthquakes this multidisciplinary approach shows that each of the different approaches independently provides only partial non conclusive information with respect to the fault identification integration is imperative to give a conclusive answer in the search for the causative fault this study has indeed revealed the existence of a to date unknown active normal fault system passing underneath ancient sagalassos i e the sagalassos fault a historical coseismic surface rupture event on this fault could be identified this event possibly corresponds to the devastating sagalassos earthquakes of ca ad 500 and the middle or second half of the 7th century ad finally this study demonstrates that in the particular geodynamic setting of sw turkey archaeological sites with extensive earthquake related damage form an important tool in any attempt to asses the seismic hazard

southeast australian late mesozoic and cenozoic denudation rates a test for late tertiary increases in continental denudation throughout the tertiary average rates of erosion of southeast australia have been uniformly low about 10 3 mm yr of surface lowering indicating that this part of the australian continent did not contribute to a rapid increase in ocean basin sedimentation over the past 15 or 20 m y somewhat higher mesozoic rates may be the result of minor tectonism but explanation for the generally low cenozoic and mesozoic erosion rates may be sought in the forest cover and general tectonic stability of southeast australia over this time period australia9s gradually increasing aridity climatic seasonally over the past 20 m y has apparently not resulted in higher average rates of erosion of the continent except perhaps in the very latest tertiary and quaternary

geochemical control of magnetite dissolution in subarctic lake sediments and the implications for environmental magnetism geochemical and mineral magnetic studies of lake sediments from the karsa valley in north sweden demonstrate that down core variations in magnetic properties have been determined by post depositional magnetite dissolution rather than by sediment source changes a low sediment accumulation rate during times of climatic amelioration combined with a higher organic carbon content produced intense reducing conditions with almost complete magnetite loss an increase in the sedimentation rate and a reduction in the organic carbon content primarily due to glacier reformation allowed magnetite preservation thus the mineral magnetic profiles record lake sediment palaeoredox conditions brought about by climate change this new interpretation of mineral magnetic transformations in freshwater sediments may have far reaching implications for other mineral magnetic studies concerned with the alternation between glacial stadial and interglacial interstadial episodes during the quaternary period

magnetic mineralogy and its implication of contemporary coastal sediments from south china magnetic parameters have been widely used as a rapid cost effective and non destructive method to assess whether their magnetic properties reflect the development history in the pearl river delta three sediment cores collected from south china coastal waters were selected for magnetic research the results indicate that the predominant ferrimagnetic mineral is magnetite with an additional smaller amount of surprisingly high coercive greigite fine grained superparamagnetic and single domain particles of magnetite and the relative contribution of greigite are increased when the total concentration of ferrimagnetic minerals is higher three well known stages of the chinese history i e iron smelting cultural revolution and the latest phase of opening and reforming were identified in the vertical variation of magnetic concentration parameters although the record of the three cores is not completely consistent the results point out that magnetic concentration parameters can reflect the development and pollution history in surrounding coastal areas

source mechanisms of three moderate california earthquakes of july 1986 abstract we studied the source processes of three moderate size earthquakes in california the m s 6 0 event of july 8 1986 near palm springs the m s 5 8 shock of july 13 1986 offshore of oceanside and the m s 6 2 event of july 21 1986 in the chalfant valley on the east side of the sierra nevada the centroidal source parameters are estimated by inversion of long period p and sh waves recorded at teleseismic distances by seismographs of worldwide networks a more detailed description of the source is then obtained by analyzing broadband seismograms the north palm springs earthquake had a simple rupture process most of the seismic moment was released in the first 3 sec in a single step the strike of the source fault plane follows the average trend of the banning fault and its dip agrees with the dip of the fault plane delineated by the aftershocks the faulting mechanism of the main shock is right lateral strike slip with a sizable reverse component that is consistent with uplift north of the banning fault the earthquake offshore of oceanside had a slightly more complex rupture process the far field source time function consists of two pulses that represent the release of most of the moment in the first 3 sec the source mechanism indicates reverse faulting with the compressional axis trending northeast almost perpendicular to the trend of mapped faults offshore the event does not appear to be associated with major mapped faults in the area but the strike of one of the nodal planes agrees with the trend of the major mapped faults offshore and its mechanism is consistent with the missing component of plate convergence not taken up by the onshore strike slip fault systems and the idea of a weak san andreas fault system the rupture process of the chalfant valley earthquake was yet more complicated the source time function indicates that in a 4 sec time window three asperities were broken the source mechanism indicates right lateral strike slip faulting with a small normal faulting component on a fault that dips approximately 50 southwest earthquake activity suggests that presently the deformation in the northern part of the owens valley which includes the chalfant valley is dominated by conjugate strike slip faults which strike obliquely to the main range bounding normal faults the waveforms indicate the presence of a low velocity zone at a depth of about 20 km in the crust in the chalfant valley a synthesis of information from waveform modeling first motion fault plane solutions and aftershock distributions indicates that the nucleation and or termination of rupture for the north palm springs and the chalfant valley events were controlled by preexisting fault geometry

from palaeotectonics to neotectonics in the neotethys realm the importance of kinematic decoupling and inherited structural grain in sw anatolia turkey abstract in order to asses young i e neotectonic fault kinematics and the relation with plate tectonic processes in sw turkey we focused on the questions 1 what produced the structural grain i e how and when are faults generated 2 what was is the kinematic behaviour of these faults and 3 during which period s were these faults active firstly the distribution of faults has been investigated using a lineament analysis performed on satellite imagery and digital elevation models we define five main tectonic domains in sw turkey 1 and 2 the northern and southern western anatolian extensional provinces 3 the eastern hellenic arc including rhodes island and the submarine anaximander mountains 4 the lycian taurides and 5 the western limb of the isparta angle lineament analysis reveals dominance of three lineament groups i e nne ene and wnw trending in all identified domains variations in the relative importance of lineament groups exist and are attributed to the specific tectonic evolution of each domain a synthesis of recently published field data shows that the onset of activity of related fault groups is neither synchronous nor uniform the structural grain for the neotectonic deformation in sw turkey is formed during the last stage of palaeotectonic deformation stage 1 which is dominated by the onset of the menderes massif exhumation along a top n major detachment the datca break away fault seyitoglu g isik v and cemen i 2004 complete tertiary exhumation history of the menderes massif western turkey an alternative working hypothesis terra nova 16 358 364 and related se ward sliding of the lycian nappes in the footwall of this fault this stage is characterized by spatially variable types of deformation that are delineated by from nw to se the datca fault around the menderes lycian contact zone and the lycian frontal thrust zone respectively the kinematic decoupling along these structures explains the co existence of top n detachment type extension in the western anatolian extensional province and ongoing nappe emplacement and piggy back development in the lycian taurides the decoupling also explains the lateral complexity of deformation associated with later neotectonic deformation from late miocene onward stage 2 nne ssw extension dominated the western anatolian extensional province influenced by combined anatolian extrusion and hellenic subduction roll back contemporaneously bidirectional ese wnw and nne ssw extension controls the lycian taurides due to the effects of hellenic arc expansion superposed on extrusion roll back extension the zone of kinematic decoupling is characterized by structural complexity with local transpressional features during stage 3 post late pliocene the same types of extension prevail in the western anatolian extensional province and the lycian taurides although a third tectonic regime becomes gradually more important this regime is associated with a tectonic escape in the hellenic arc that induced forearc slivers to be sheared of the expanding arc along mostly sinistrally displacing ene trending strike slip zones several of these zones have been identified in the coastal zones of sw turkey either through recent seismicity or field observations and are especially focused in the lycian taurides domain here they form what is classically referred to as the fethiye burdur fault zone which becomes gradually penetrated from the sw by oblique or strike slip zones exemplifying the time transgressive nature of the tectonic escape mechanism zones of kinematic decoupling remain persistent throughout the entire early miocene recent tectonic evolution of sw turkey and explain the existence of differently deforming tectonic domains

reassessment of earthquakes 1900 1999 in the eastern mediterranean and the middle east summary we have reappraised locations and surface wave magnitudes of earthquakes this century in the eastern mediterranean and the middle east between 10 and 44 n and 18 and 70 e the results are presented in an improved parametric catalogue of shallow earthquakes h 40 km large enough ms 6 0 to be of interest in seismotectonics and earthquake engineering a considerable number of early events of 6 ms 7 2 not included in other catalogues have been identified and their magnitudes assessed we find that iss isc locations are systematically shifted by 10 30 km to the north or northeast of their macroseismic epicentres also we derived a regional average relationship between log m0 and ms we show that the correlation of magnitude with epicentral intensity is very weak as is expected and a source of error in frequency relations

the use of engineering seismological models to interpret archaeoseismological findings in tolbiacum germany a case study archaeological excavations carried out from 2001 to 2003 at the vicus tolbiacum site located in the present day city of zulpich germany unearthed heavily damaged and destroyed late roman fortification works damage includes 0 17 m wide tensile cracks in a 3 1 m wide wall tilted walls and fortification towers horizontal displacement of wall sections of 0 95 m and rotation of wall fragments engineering seismological models are used to test the hypothesis that the observed building damage is of seismogenic nature the site is located at the western edge of the lower rhine embayment lre in the northern part of the rhine rift valley more than 20 damaging earthquakes occurred in the area over the past 300 years several paleoseismic events with magnitudes of at least 6 4 occurred during the holocene site specific strong motion seismograms are modeled for assumed large earthquakes at active faults in the lre using stochastic methods and calibrated q models and duration models nonlinear site amplification is calculated based on an s velocity model from refraction seismic experiments and downhole measurements finite element simulation of the dynamic behavior of a fortification tower shows a natural period of the soil building system of about 3 0 sec horizontal and vertical displacements at the top of the 8 m tall tower reached 0 12 m and 0 06 m respectively for the simulated event no indications of man made activity exist that could explain the damage running water can also be excluded as a threat to the buildings due to the orographic situation and slow acting gravitational causes can be excluded due to the damage structure the destruction and damage is regarded as most probably seismogenic and site intensity is assessed at ix on the european macroseismic scale ems98 grunthal 1998 this result marks the first time an intensity above viii is described for a tectonic earthquake in germany preliminary dating results from three carbon 14 14c accelerator mass spectometry ams samples lead to the second half of the fourth century a d

a simple model for the interpretation of magnetic records in lacustrine and ocean sediments abstract many sources of magnetic minerals have been implicated as potential influences on the magnetic record of lake and ocean sediments the state of the art of our knowledge of these sources and their properties has been used to define a model which indicates those sedimentary environments where specific magnetic mineral sources may influence the magnetic record authigenically formed magnetic minerals are only likely to be found in estuaries and eutrophic lakes cosmic deposition eolian deposition and magnetic bacteria may be important in low accumulation rate deep ocean sediments whereas catchment derived material is only likely to be the sole source of the magnetic record in high accumulation rate low productivity lakes fly ash is only likely to be a dominant source in very low accumulation rate lake and ocean sediments

late alpine evolution of the central menderes massif western turkey the central menderes massif western turkey is characterized by an overall dome shaped alpine foliation pattern and a n nne trending stretching lineation a section through the southern flank of the central submassif along the northern margin of buyuk menderes graben has been studied there asymmetric non coaxial fabrics indicate that the submassif has experienced two distinct phases of alpine deformation a top to the n nne contractional phase and a top to the s ssw extensional event the former fabrics are coeval with a regional prograde barrovian type metamorphism at greenschist to upper amphibolite facies conditions this event known as the main menderes metamorphism is thought to be the result of internal imbrication of the menderes massif rocks along south verging thrust sheets during the collision of the sakarya continent in the north and the anatolide tauride platform in the south across the izmir ankara suture during the palaeocene eocene top to the s ssw fabrics represented by a well developed ductile shear band foliation associated with inclined and or curved foliation asymmetric boudins and cataclasites were clearly superimposed on earlier contractional fabrics these fabrics are interpreted to be related to a low grade greenschist retrogressive metamorphism and a continuum of deformation from ductile to brittle in the footwall rocks of a south dipping presently low angle normal fault that accompanied early miocene orogenic collapse and continental extension in western turkey a similar tectono metamorphic history has been documented for the northern flank of the dome along the southern margin of the gediz graben with top to the n nne extensional fabrics the exhumation of the central menderes massif can therefore be attributed to a model of symmetric gravity collapse of the previously thickened crust in the submassif area the central submassif is thus interpreted as a piece of ductile lower middle crust that was exhumed along two normal sense shear zones with opposing vergence and may be regarded as a typical symmetrical metamorphic core complex these relationships are consistent with previous models that the miocene exhumation of the menderes massif and cycladic massif in the aegean sea was a result of bivergent extension

incipient continental collision and plate boundary curvature late pliocene holocene transtensional hellenic forearc crete greece u ring t c brachert write in their recent paper ten veen kleinspehn 2003 proposed that the western messara graben of central crete underwent transtensional deformation since about 3 4 ma transtension is supposed to be dominantly resolved along 070 striking sinistral faults and that the 070 striking faults have strike slip normal slip ratios of 10 100 1 ten veen kleinspehn 2003 then use their results from the western messara graben to propose that sinistral transtension should represent tectonic escape of central and eastern crete during incipient collision of the libyan passive margin the interpretation of the kinematic data on which ten veen kleinspehn 2003 base their tectonic model is in contrast to earlier studies which have attributed the young i e pliocene to recent kinematics of crete largely to radial extension angelier et al 1982 fassoulas 2001 ring et al 2001 ten veen kleinspehn 2003 p 167 argued that onshore structural assemblages is critical to deciphering forearc kinematics and therefore we present our kinematic data from onshore faults in the western and central messara graben and compare our data together with the fault slip data of fassoulas 2001 from the heraklion graben and microseismicity data hatzfeld et al 1993 delibasis et al 1999 with the fault slip data of ten veen kleinspehn 2003 fig 9 for discussing the kinematics of the young faults we believe that fault slip data directly reflect the kinematics of the faults from which they were collected and therefore allow testing the proposition often veen kleinspehn that sinistral transtension is supposed to be mainly resolved at the 070 striking faults the latter of which are known to be an integral part of the youngest set of faults on crete fassoulas 2001 and are in part seismically active delibasis et al 1999 in general

westward propagation of the north anatolian fault into the northern aegean timing and kinematics we present new evidence for the propagation processes of the north anatolian fault folding in the dardanelles straits region allows us to document the timing of the deformation preceding and the finite displacement after the passage of the propagating tip of the fault the accuracy of the observations is due to interplay between deformation and the sea level changes in the mediterranean the well known messinian regression followed by the pliocene transgression the long term kinematics around the sea of marmara pull apart total displacement of about 85 km over the past 5 m y is similar to the present day kinematics deduced from space geodesy at a larger scale westward propagation of the north anatolian fault over nearly 2000 km in the past 10 m y appears to be associated with strain recovery suggesting that the continental lithosphere retains long term elasticity

earthquakes and archaeology abstract this article examines the use of archaeological evidence for the assessment of historical earthquakes in the eastern mediterranean region and middle east long before the advent of modern seismology we ask the questions when and where have large earthquakes happened in the past how can this evidence contribute to our scientific understanding of earthquake activity is it possible on literary and archaeological grounds to distinguish between earthquake damage and damage from other causes it is found that archaeological evidence for an earthquake is not always clear or unambiguous and that there is a need for collaboration between archaeologists historians geologists engineering seismologists and workers in other disciplines to evaluate the traces of earthquakes in excavations both for understanding their effects at the site and for the information they can provide about the nature of the earthquake implicated

morphological drainage and eolian controls on the microtidal patara beach sediments eastern mediterranean textural geochemical and mineralogical investigations abstract the effects of dominant hydrodynamic morphological fluvial and hinterland geological source conditions on the texture and composition of the microtidal and dissipative patara beach mediterranean coast of sw turkey sediments were investigated at 47 locations patara beach sediments are composed entirely of sand fine sand 5 94 was more abundant in the northwestern section while medium sand contents 2 94 increased in the central and southeastern sections moderately to well sorted mostly 0 3 0 7 o sediments tend to show overall better sorting towards the southeast in the net longshore current direction terrigenous carbonate grains derived from the hinterland constituted 6 50 as caco3 with varying tendencies to increase or decrease within sections alongshore total heavy mineral concentrations in bulk sediments 1 17 mostly

mineral magnetic properties of holocene lake sediments and soils from the karsa valley lappland sweden and their relevance to palaeoenvironmental reconstruction a mineral magnetic study of lacustrine sediments and soils from the karsa valley in lappland sweden was undertaken to estimate the potential of mineral magnetic techniques in elucidating the variability of climate recorded by glacier fluctuations and soil development sediment cores from two lake basins receiving sediment input from a glacial outflow stream and their respective catchments show a mineral magnetic record that can be interpreted in terms of glacial activity and soil development dissolution of magnetite is indicated during periods of climatic amelioration and causes a high s ratio during periods of glacial advance and colder wetter climate the minerogenic sediment supply is increased and magnetite is preserved in the sediment resulting in a low s ratio variations in the s ratio can then be used as a proxy climate indicator

future trends in paleoseismology integrated study of the seismic landscape as a vital tool in seismic hazard analyses this paper forms the introduction to this special issue of tectonophysics devoted to selected scientific research presented during events sponsored by the inqua subcommission on paleoseismicity in the past few years in this note we summarize the contents of the contributed papers and use the issues they raise to review the state of the art in paleoseismology from a quaternary geology perspective in our opinion the evolution of paleoseismological studies in the past decade clearly demonstrates that in order to properly understand the seismic potential of a region and to assess the associated hazards broad based multidisciplinary studies are necessary to take full advantage from the geological evidence of past earthquakes a major challenge in future paleoseismic research is to build detailed empirical relations between various categories of coseismic effects in the natural environment and earthquake magnitude intensity these relations should be compiled in a way that is fully representative of the wide variety of natural environments on earth in terms of climatic settings quaternary tectonic evolution rheological parameters of the seismogenic crust and stress environment for instance available data indicate that between earthquake magnitude and surface faulting parameters different scaling laws exist and they are a function of the local geodynamic setting including style of faulting typical focal depths heat flow in this regard we discuss in some detail the concept of seismic landscape which provides the necessary background for developing paleoseismological research strategies the large amount of paleoseismological data collected in recent years shows that each earthquake source creates a signature on the geology and the geomorphology of an area that is unequivocally related with the order of magnitude of its earthquake potential this signature is defined as the seismic landscape of the area e g serva l vittori e ferreli l michetti a m 1997 geology and seismic hazard in grellet b mohammadioun b hays w eds proceedings of the second france united states workshop on earthquake hazard assessment in intraplate regions central and eastern united states and western europe october 16 1995 nice france 20 24 ouest editions nantes france michetti a m hancock p l 1997 paleoseismology understanding past earthquakes using quaternary geology

neotectonic intersection of the aegean and cyprus tectonic arcs extensional and strike slip faulting in the isparta angle sw turkey abstract the isparta angle and adjacent antalya bay areas constitute an important segment of the eastern mediterranean region located at the intersection of the southward convex aegean and cyprus arcs some recent tectonic maps show the isparta angle as a nw se compressional lineament extending eastwards into the kyrenia range of northern cyprus however fault data from the onshore isparta angle together with offshore shallow seismic reflection data show that the present morpho tectonic setting is dominated by extension the last phase of compression to affect the area studied in the late miocene was accompanied by regional nappe emplacement lycian nappes onshore fault planes measured from fault zones bounding both the limbs and the core of the isparta angle are oriented predominantly ne sw nw se and n s superimposed slickenfibres show that reverse faults were succeeded in turn by right lateral faults then by normal faults the fault phases are dated by stratigraphical and geomorphological evidence reverse faults date from the late miocene or earlier compressional deformation whereas the right lateral faults mainly developed during latest miocene early pliocene normal faulting dominated from the late pliocene recent an interpretation of shallow seismic reflection data shows that antalya bay is characterised by a nw se trending asymmetrical graben system that has continued to be active during the late miocene early pliocene right lateral strike slip resulted from shear along the eastern termination of a zone of extension and rotation that characterises the western aegean this shear was focused in a n s direction by inherited zones of structural weakness in the basement antalya complex the switch to ne sw extension in the late pliocene quaternary relates to a regional change in stress direction throughout the aegean region and was accompanied by strong uplift of the bey da lari region of the taurus mountains bordering the isparta angle in the west the isparta angle is the link between a the extensional province of western turkey bounded to the south by the actively subducting hellenic arc and b the uplifted anatolian plateau bounded to the south by the cyprus subduction zone understanding the miocene to recent tectonic development helps elucidate the kinematics of the region the new structural data presented lend no support for recent suggestions that the isparta angle and antalya bay represent parts of a regional compressional zone related to plate collision

active tectonics of the alpine himalayan belt between western turkey and pakistan summary over 80 new fault plane solutions combined with satellite imagery as well as both modern and historical observations of earthquake faulting are used to investigate the active tectonics of the middle east between western turkey and pakistan the deformation of the western part of this region is dominated by the movement of continental material laterally away from the lake van region in eastern turkey this movement helps to avoid crustal thickening in the van region and allows some of the shortening between arabia and eurasia to be taken up by the thrusting of continental material over oceanic type basement in the southern caspian mediterranean makran and black sea thus central turkey bounded by the north and east anatolian strike slip faults is moving west from the van region and overrides the eastern mediterranean at two intermediate depth seismic zones one extending between antalya bay and southern cyprus and the other further west in the hellenic trench the motion of northern iran eastwards from the van region is achieved mainly by a conjugate system of strike slip faults and leads to the low angle thrusting of iran over the southern caspian sea the seismicity of the caucasus shows predominantly shortening perpendicular to the regional strike but there is also some minor elongation along the strike of the belt as the causcasus overrides the caspian and black seas the deformation of the eastern part of this region is dominated by the shortening of iran against the stable borders of turkmenistan and afghanistan the north east direction of compression seen in zagros is also seen in north east iran and the kopet dag where the shortening is taken up by a combination of strike slip and thrust faulting large structural as well as palaeomagnetic rotations are likely to have occurred in ne iran as a result of this style of deformation north south strike slip faults in southern iran allow some movement of material away from the collision zone in ne iran towards the makran subduction zone where genuinely intermediate depth seismicity is seen within this broad deforming belt large areas such as central turkey nw iran azerbaijan central iran and the southern caspian appear to be almost aseismic and therefore to behave as relatively rigid blocks surrounded by active belts 200 300 km wide the motion of these blocks can usefully be described by poles of rotation the poles presented in this paper predict motions consistent with those observed and also predict the opening of the gulf of iskenderun ne of cyprus the change within the zagros mountains from strike slip faulting in the nw to intense thrusting in the se and the relatively feeble seismicity in se iran baluchistan this description also explains why the north south structures along the iran afghanistan border do not cut the east west ranges of the makran within the active belts surrounding the relatively aseismic blocks a continuum approach is needed for a description of the deformation even though motions at the surface may be concentrated on faults the evolution of fault systems within the active zones is controlled by geometric constraints such as the requirement that simultaneously active faults do not in general intersect many of the active processes discussed in this paper particularly large scale rotations and lateral movement along the regional strike are likely to have caused substantial complexities in older mountain belts and should be accounted for in any reconstructions of them

the tempo of geomorphological change evidence from southeastern australia a revised denudational chronology based on k ar dating of basalts for much of southeastern australia shows that many major topographic features are far older than was previously realized some upland surfaces originated in the mesozoic and others in the early tertiary in some areas the last major uplift and onset of canyon cutting occurred prior to the mid oligocene apart from the slow headward extension of canyons and localized high level stripping much of the region had taken on approximately its present day form by the mid miocene paradoxically however none of the mechanisms that have been proposed to explain the survival of paleoforms hold here these instances may well be typical of large parts of the interior of tectonic plates and a revision of widely held estimates of modal rates of denudation seems required

regional analysis of bedrock stream long profiles evaluation of hack s sl form and formulation and assessment of an alternative the ds form the equilibrium form of the fluvial long profile has been used to elucidate a wide range of aspects of landscape history including tectonic activity in tectonic collision zones and in continental margin and other intraplate settings as well as other base level changes such as due to sealevel fluctuations the hack sl form of the long profile which describes a straight line on a log normal plot of elevation normal versus distance logarithmic is the equilibrium long profile form that has been most widely used in such studies slope area analysis has also been used in recent years we show that the sl form is a special case of a more general form of the equilibrium long profile here called the ds form that can be derived from the power relationship between stream discharge and downstream distance and the dependence of stream incision on stream power the ds form provides a better fit than the sl form to river long profiles in an intraplate setting in southeastern australia experiencing low rates of denudation and mild surface uplift we conclude that if an a priori form of the long profile is to be used for investigations of regional landscape history the ds form is preferable in particular the ds form in principle enables equilibrium steepening due to an increase in channel substrate lithological resistance parallel shift in the ds plot to be distinguished from disequilibrium steepening due to long profile rejuvenation disordered outliers on the ds plot slope area analysis and the slope distance ds approach outlined here are complementary approaches reflecting the close relationship between downstream distance and downstream catchment area copyright 2006 john wiley sons ltd

loess stratigraphy in central china abstract the loess deposits in central china record world wide climate changes of the last 2 5 ma numerous climatic oscillations are marked by alternating loess and soil units with continuous coverage of the matuyama and brunhes epochs magnetic susceptibility of the deposits correlates closely with the oxygen isotope record of the deep sea sediments and provides an independent measure of climate and time the key marker bed of the chinese loess sequence is the paleosol s5 the time equivalent of the mid brunhes oxygen isotope stages 13 14 and 15 it marks a prolonged interval of warm humid climate lasting from approximately 615 to 470 thousand years ago several episodes of river downcutting coincide with deposition of the exceptionally thick loess units l1 oceanic oxygen isotope stages 2 to 4 l2 stage 6 l5 stage 12 l6 stage 16 l9 stage 22 l15 stage 38 about 1 15 ma and ws4 about 2 3 ma these erosional events are interpreted as a result of episodic uplift of the loess plateau the deposition of the earliest loess layers between 2 5 and 2 3 ma ago marks a first order shift from warm and humid environments toward harsh continental steppes comparable to those of the middle and late pleistocene little if any lithologic or paleontologic changes were noted within or above the olduvai magnetozone so that the proposed plio pleistocene boundary at approximately 1 65 ma has no lithostratigraphic and biostratigraphic representation in the chinese loess series comparison with the deep sea drilling program core 552a in the north atlantic and with the santerno river section near bologna shows that the occurrence of the earliest loess in china coincides with the timing of the first significant ice rafting in the north atlantic and with the appearance of cold water foraminifers in the marine deposits of northern italy an extension of the stage system of the oxygen isotope signal extended back to the gauss matuyama boundary is proposed

application of an iterative least squares waveform inversion of strong motion and teleseismic records to the 1978 tabas iran earthquake an iterative least squares technique is used to simultaneously invert the strong motion records and teleseismic p waveforms for the 1978 tabas iran earthquake to deduce the rupture history the method solves for both slip amplitudes and rupture times on a finite fault several inversions of the data are done to determine the best fitting hypocenter average rupture velocity and source time function within the range of our parameter search the effects of using different data sets and different parametrizations of the problem linear versus nonlinear are also considered teleseismic body waves are shown to be essential to obtain a reliable solution due to the sparse coverage of the fault plane by strong motion stations a simple triangular source time function is compared with a modified kostrov source time function for a circular rupture and a constant propagating stress drop although the waveforms used in the inversions can not resolve between these two time functions the kostrov source time function gives a moment estimate and maximum fault displacement more consistent with long period surface waves and field observations the results of the iterative inversion for slip amplitudes and rupture times are compared with the results of a linear inversion for slip amplitudes in which the rupture velocity is fixed flexibility in the sequence of faulting for the linear inversion is obtained by allowing multiple rupture intervals a consensus of all the inversion runs indicates a complex multiple source for the tabas earthquake with four main source regions over a fault length of 90 km and an average rupture velocity of 2 5 km sec

mineral magnetic characterization of sediment sources from an analysis of lake and floodplain sediments in the catchments of the old mill reservoir and slapton ley south devon uk research on suspended sediment transport in the catchments of the old mill reservoir and slapton lower ley south devon has attempted to discriminate changing catchment sources on the basis of downcore variations in the mineral magnetic properties of lake reservoir and floodplain sediments here we examine these downcore variations and also explore the variability in catchment sources and the influence of topographic controls on mineral magnetic signatures of topsoils and subsoils particle size controls on the mineral magnetic signatures are explored by an analysis of a fractionated sediment sample whilst the possible impact of diagenesis is assessed by an examination of the mn profiles in the lake and reservoir sediments from this analysis it is evident that the mineral magnetic signatures of well sorted floodplain deposits are more likely to reflect the particle size composition of the transported material by contrast the mineral magnetic record in the sediment of slapton ley appears to be most strongly influenced by dissolution of magnetic minerals the sediment of the old mill reservoir provides the only suitable record for the application of a simple mixing model which is developed in order to quantify changes in the relative contribution of topsoil and subsoil through time the research has important implications for attempting to reconstruct sediment sources in highly eutrophic lakes and emphasizes the uncertainty in the application of simple mixing models 1998 john wiley sons ltd

environmental and depositional controls on laminated freshwater carbonates an example from the roman aqueduct of patara turkey abstract carbonate deposits in aqueducts are a new high resolution data source for environmental changes during the time of the roman empire notably in the fields of palaeoclimate and spring hydrology in order to distinguish environmental effects from those related to depositional setting laminated carbonate deposits were compared along the entire length of an ancient aqueduct channel at patara turkey the carbonate deposits up to 80 mm in thickness are composed of lamina couplets up to 1 mm thick of alternating porous microspar and dense columnar sparite the former formed in the dry warm season and the latter in the wet cool season the presence of biofilms seems to play a role in the development of the porous laminae the relative importance of both lamina types depends also on the location within the aqueduct dense coarse crystalline laminae dominate in steep sections of the aqueduct while porous fine crystalline laminae are mostly found on gentle slopes this is attributed to the flow velocity of the water since fast flow on steep slopes hampers the development of biofilms carbonate microstructures can vary considerably down the line of a specific aqueduct hence multiple sampling is needed along the channel in order to collect specimens suitable for detailed research 18 o profiles show oscillations with increasing amplitude downstream reflecting rising water temperatures in the channel while evaporation plays a minor damping role on these oscillations the periodicity of the 18 o values can be used to recognise annual layering in order to establish the number of years an aqueduct was operating 13 c values are higher in open masonry channel sections than in ceramic pipes probably due to stronger degassing of co 2 in the open channel carbonate deposits in roman aqueducts hold high promises as seasonally resolved archives of hydrology and climate and possibly of earthquakes

environmental magnetism past present and future environmental magnetism involves the application of rock and mineral magnetic techniques to situations in which the transport deposition or transformation of magnetic grains is influenced by environmental processes in the atmosphere hydrosphere and lithosphere the first explicit description of environmental magnetism as a distinct field was in 1980 since that time environmental magnetism has become a broad field that is finding application in an ever increasing array of scientific disciplines in this review of the present state of environmental magnetic studies we divide the field into three broad but arbitrary categories the first involves the use of mineral magnetic assemblages in the geological record to study physical processes in depositional environments this category includes the correlation of sediment cores using magnetic susceptibility measurements studies of geomagnetic field behavior the analysis of depositional and postdepositional mechanical processes that affect sediments and the examination of magnetic parameters that might represent proxies for paleoclimatic variation the second category encompasses studies of the processes responsible for variations in the magnetic minerals brought into a sedimentary environment these provenance investigations include studies of changes in catchment derived sediment in lakes fluctuations in contributions from terrigenous aeolian and glaciogenic components in deep sea sediments and the origin of atmospheric particulates the final category addresses in situ changes and transformations of magnetic minerals in sedimentary environments including pedogenesis authigenetic diagenetic formation of ferrimagnetic phases dissolution of magnetic minerals due to reductive diagenesis and contributions of biomagnetism to sedimentary magnetism because environmental magnetism can address problems in so many disciplines and because many of these problems may be inaccessible to other techniques it is likely that the scope of environmental magnetism will continue to expand rapidly environmental magnetism is capable of providing important data for studies of global environmental change climatic processes and the impact of humans on the environment all of which are major research initiatives in the international scientific community these factors suggest that environmental magnetism has a bright and diverse future

neotectonic evolution of the anaximander mountains at the junction of the hellenic and cyprus arcs abstract the anaximander mountains occupying an outer arc position at the junction of the hellenic and cyprus arcs have been studied using a suite of geophysical data including multibeam swath bathymetry backscatter images seismic reflection profiles and gravity and magnetic data which support an improved description of its deformation history lithologically the western mountains can be correlated with the neritic limestones of the bey daglar unit of sw turkey the eastern mountains relate to the ophiolitic antalya nappe complex in addition to this lithological contrast a deep seated crustal difference which is best reflected in gravimetry relates to the mid tortonian aksu thrust phase after the early middle miocene eastward emplacement of the lycian nappes the serravallian tortonian stage was characterized by the development of an array of grabens with n120 e strikes which occupied a vast continental area that extended from southern aegean to southwestern turkey during the mid tortonian the last phase of thrusting marked the onset of a different kinematic regime related to the westward rotation of the anatolian platelet this late miocene change marked the start of differential subsidence that resulted in the formation of the anaximander mountains and which is reflected by an unconformity surface between the lower middle miocene and plio quaternary units the messinian quaternary period in the western part of the anaximander mountains was characterized by distributed sinistral shear parallel to n70 e which was marked by the onset of an extension on n20 e striking normal faults that formed long graben like depressions during the pliocene these basins were transected by n70 e striking sinistral strike slip fault zones although continued crustal extension suggests deformation in transtension the eastern part of the anaximander mountains is instead characterized by n150 e striking normal and or oblique normal fault zones which lack significant evidence of strike slip deformation close examination of newly calculated predicted relative plate motions between africa from nuvel 1a and anatolia from gps measurements indicates that plate motion vectors change rapidly at the junction between the hellenic and cyprus arcs because of the close proximity to the pole of anatolian rotation these calculations indicate that along both the eastern hellenic arc and the western cyprus arcs the florence rise the relative motion between the anatolian and african plates is sinistral on the southern florence rise deformation is characterized by pure left lateral faulting whereas farther northwest in the eastern anaximander mountains the component of strike slip decreases although arc normal convergence predicts the occurrence of thrust faulting southwestward trench retreat also causes an extension internal to this outer arc domain such that the preexisting n120 e striking thrust faults of the aksu phase have been reactivated as normal to oblique normal faults during the pliocene and quaternary the observed sinistral faulting on faults striking n70 e in the western mountains is consistent with the relative plate motion along the eastern hellenic arc and merges with the extensional domain in the eastern mountains

adjustments by the charwell river new zealand to uplift and climatic changes major climatic changes and rapid local and regional tectonic movements were common in new zealand during the late quaternary and caused a diversity of adjustments in the drainage basin and piedmont reaches of the charwell river which are separated by the hope fault the onset of semi arid frigid climates during the latest pleistocene probably greatly increased hillslope sediment yields in a periglacial environment and the piedmont reach aggraded as much as 42 m on top of a broad strath with the return of humid mesic climates in the holocene sediment yields decreased as dense forests again mantled the slopes and the piedmont reach degraded as mush as 81 m dating of eleven cut and strath terraces by radiocarbon calibrated weathering rind measurements on greyawake cobbles shows the degradation rates varied greatly during the last 14 ka 1 ka 1000 yr initial degradation rates of 4 m ka 1 increased to 30 m ka 1 by 6 ka ago during a mid holocene climatic optimum since 4 ka ago degradation rates have been only 1 2 m ka 1 comparable to uplift rates in the piedmont reach inferred from marine terrace studies and the river is again cutting a broad strath each broad strath represents equilibrium conditions attained by this powerful stream during interglacial times despite episodes of being overwhelmed by climatically induced sediment yield increases during full glacial climates and having to maintain a long term degradation rate equal to the uplift rate the 75 81 m of degradation since formation of the latest pleistocene fill terrace tread is the sum of the amount of late pleistocene valley floor aggradation and the amount of regional uplift that occurred between the estimated times of major strath formation at about 30 and 0 ka the 39 m of tectonically induced degradation below the pre aggradation strath is sufficiently large that post 30 ka uplift may have doubled holocene degradation rates each of the eleven degradation terraces represents pauses of a few centuries in holocene downcutting brief equilibrium conditions were attained by streambed armoring and concurrent growth of riparian plants both processes progressively increased hydraulic roughness and the shear stresses needed to entrain streambed materials occasional floods possibly from rare cyclones derived from tropical moisture sources destroyed streambed armor and channel downcutting was renewed thus the formation of eleven equilibrium terraces can be accounted for without postulating additional tectonic perturbations or secular climatic changes

diagenesis of magnetic minerals in the recent sediments of a eutrophic lake magnetic mineral assemblages in lake sediments are usulally interpreted as reflecting changing catchment erosion magnetic and chemical assemblages in a small eutrophic lake lough augher northern ireland suggest diagenetic dissolution of fine grained magnetite however probably as a result of changing redox conditions associated with eutrophication water column results show internal cycling of mn and fe from the sediments into the armxic hypolimnion calculations suggest that late summer hypolimnetic fe concentrations are controlled by formation of aulhigenic vivianite sedimentary pore water concentrations of total soluble fe and p suggest a similar process in the sediments the loss of mn from the lake by diffusion from the sediment and washout at overturn is indicated by mn budget calculations and by it marked decrease in its sedimentary concentration reflecting onset of eutrophication as indicated by diatom biostratigraph y the changes in the sediment mn profile are coincident with and in some cases identical to changes in several rnagnctic parameters the changes in magnetic stratigraphy suggest a coarsening of the magnetic grain size and reduction in the total concentration agreement with chemical profiles indicative of changing rcdox suggest that this coarsening results from dissolution of fine grained magnetite catchment stability together with other stratigraphic profiles of eutrophication and changing redox supports the conclusion that the magnetic profiles are reflecting in situ diagenetic changes rather than altered catchment processes with the data available it is not possible to identify the actual clissolution process involved or to determine whether it is chemically or bacterially controlled

experimental study of knickpoint and longitudinal profile evolution in cohesive homogeneous material a series of experiments were conducted in homogeneous bedrock to study knickpoint and longitudinal profile evolution knickpoints are created by successive drops in base level which simulate intermittent uplift channel morphology and flow characteristics vary systematically along a knickpoint reach as the knickpoint lip is approached width decreases but depth velocity and bottom shear stress increase as a result knickpoints are rapidly destroyed through the process of 1 knickpoint replacement and 2 subsequent knickpoint inclination knickpoint replacement consists of two morphologically distinct erosional reaches the knickpoint face below the knickpoint lip which decreases in slope and an incising reach above the knickpoint lip which increases in slope knickpoint replacement is a significant process in the evolution of knickpoints in homogeneous bedrock within experimental limits this study supports the notion that knickpoints do not undergo parallel head ward retreat in homogeneous bedrock given intermittent uplift except in those possible cases of extensive and pervasive bedrock jointing only the erosional sediment transport discontinuity above the knickpoint is developed in cohesive sediments below the knickpoint a steep bedrock channel slope low sediment load and rapid decrease in grain size of sediment load preclude development of the aggradational sediment transport discontinuity knickpoint evolution can be characterized by three general models parallel retreat replacement and inclination these models are based on the following criteria within the knickpoint reach 1 relationship between bottom shear stress 0 and critical shear stress needed to initiate motion c 2 nature of the bed load transport discontinuities and 3 spatial variability of bedrock resistance to fluvial erosion

rupture complexity of a moderate sized mb 6 0 earthquake broadband body wave analysis of the north yemen earthquake of 13 december 1982 abstract the occurrence of the north yemen earthquake of 13 december 1982 provides an important opportunity to study source properties of earthquakes in the southern arabian peninsula although moderate in size m b 6 0 this earthquake is the largest to have occurred in the region since the deployment of the global digital seismograph network p waves recorded at teleseismic distances can be obtained from stations of this network and of the graefenberg array that are flat to displacement and velocity in the frequency range from 0 01 to 5 0 hz the broad bandwidth of the data is necessary for deriving a dynamic description of the earthquake as well as the static properties of the source in contrast inversions using only long period data provide much less insight into the complexity of rupture by fitting the displacement pulse shapes with synthetics we find that the yemen earthquake was a complex rupture consisting of two events that occurred about 3 0 sec apart the depth of both hypocenters is estimated to be 7 km the focal mechanisms of the events each have a nodal plane that strikes 340 and dips 60 to the east however the slip directions of the focal mechanisms are in slightly different directions 230 and 300 respectively the total moment of the earthquake is 3 0 10 25 dyne cm with the second event having three times the moment of the initial event by inverting p wave arrival time differences at each station we find the second hypocenter is located 7 5 km from the initial hypocenter in a direction that is nearly colinear with the nnw striking nodal plane of the focal mechanisms of each event the trend of extensional ground cracks in the epicentral region and the predominant strike of composite focal mechanisms of locally recorded aftershocks are also in a nnw direction from the consistency of these observations we infer that the east dipping nnw striking nodal planes are the fault planes the static stress drop of the first and second events are 44 and 31 bars respectively inverting the energy flux in the velocity waveforms we find the energy radiated by the earthquake is 4 8 10 20 dyne cm this implies an average apparent stress of 4 bars at different times during the aftershock sequence seismicity tended to cluster about one or another of two different planes which although having roughly the same strike had conjugate dips one of these planes delineated late in the aftershock sequence coincides with the inferred fault plane for the main shock the complexity of the main shock and of the aftershock sequence suggests that strain accumulated on a system of strongly interdependent faults as the region became critically loaded the effect of a major rupture was to critically stress faults adjacent to the initial nucleation the second event of the main shock represents the rapid release of stress from the fault system while the ensuing aftershock sequence represents the gradual release of stress

recognition of earthquake related damage in archaeological sites examples from the dead sea fault zone abstract archaeological structures that exhibit seismogenic damage expand our knowledge of temporal and spatial distribution of earthquakes afford independent examination of historical accounts provide information on local earthquake intensities and enable the delineation of macroseismic zones they also illustrate what might happen in future earthquakes in order to recover this information we should be able to distinguish earthquake damage from anthropogenic damage and from other natural processes of wear and tear the present paper reviews several types of damage that can be attributed with high certainty to earthquakes and discusses associated caveats in the rare cases where faults intersect with archaeological sites offset structures enable precise determination of sense and size of slip and constrain its time among the characteristic off fault damage types i consider horizontal shifting of large building blocks downward sliding of one or several blocks from masonry arches collapse of heavy stably built walls chipping of corners of building blocks and aligned falling of walls and columns other damage features are less conclusive and require additional evidence e g fractures that cut across several structures leaning walls and columns warps and bulges in walls circumstantial evidence for catastrophic earthquake related destruction includes contemporaneous damage in many sites in the same area absence of weapons or other anthropogenic damage stratigraphic data on collapse of walls and ceilings onto floors and other living horizons and burial of valuable artifacts as well as associated geological palaeoseismic phenomena such as liquefaction land and rock slides and fault ruptures additional support may be found in reliable historical accounts special care must be taken in order to avoid circular reasoning by maintaining the independence of data acquisition methods

magnetic and chemical characterisation of a diagenetic magnetic mineral formed in the sediments of productive lakes abstract measurement of low frequency magnetic susceptibility in sediments from several lakes showed that a diagenetically formed magnetic mineral can contribute a significant amount to the intensity of bulk magnetic measurements on anaerobic sediments from productive lakes a single ferrimagnetic mineral containing stable single domains is responsible sequential chemical extraction showed that the mineral is not a carbonate phosphate or partially reduced oxide comparison of changes in magnetic properties with changes in sulphide concentrations suggests that the mineral concentration covaries with sulphide but is not actually a simple iron monosulphide

nickpoint recession in karst terrains an example from the buchan karst southeastern australia nickpoint recession in the buchan karst southeastern australia has resulted in the formation of an underground meander cut off system in the murrindal river valley three nickpoints have been stranded in the surface channel abandoned by the subterranean piracy and these can be correlated with river terraces and epiphreatic cave passages in the nearby buchan river valley the presence of palaeomagnetically reversed sediments in the youngest cave passage in the buchan valley implies that the topographically lowest nickpoint in the murrindal valley is more than 730 ka old and the other nickpoints are probably several million years old the nickpoints are occasionally active during floods but the diversion of most surface flow underground has slowed down their retreat to the extent that they have been effectively stationary for several million years underground nickpoint migration has been by both incision within major phreatic conduits and their abandonment for lower level passages the nickpoints are all present in the upstream part of the cave system but have not migrated past the sink in the river channel despite the long period of time available for this to happen the sink is characterized by collapsed limestone blocks these filter out the coarse bedload from the river channel as a result erosion within the cave passages is dominantly solutional and therefore slower than in the surface channel where it is mostly mechanical in addition to transmit a drop in base level the cave system requires the removal of a larger volume of rock than for the surface migration of a nickpoint because any roof collapse material in the subsurface system must be removed these factors have slowed the migration of the base level changes through the subsurface system and may be a general feature in caves that have diffuse sinks as their main inputs

strike slip fault geometry in turkey and its influence on earthquake activity the geometry of turkish strike slip faults has been reviewed and described from this data set it appears that fault geometry the distribution of discontinuities such as bends and stepovers along the main fault trace plays an important role in controlling the location of large earthquake rupture segments along the fault zones large earthquake ruptures generally do not propagate past individual stepovers that are wider than 5 km or bends that have angles greater than about 30 more important than the size of each discontinuity however is the total geometric pattern i e the distribution of adjacent bends and stepovers based not only on distance from one another but also on relative discontinuity size certain geometric patterns restraining single or double bends are particularly common and can be viewed as responsible for strain accumulation along portions of the fault zone fault geometry not only plays a role in the extent of earthquake rupture but also in characteristics of earthquake behavior for example large earthquake epicenters often occur near restraining bends or double bends furthermore aftershocks and swarm activity can often be associated with releasing areas areas along the strike slip fault that are undergoing a relatively large amount of extension

disequilibrium profile of the potomac river near washington d c a result of lowered base level or quaternary tectonics along the fall line longitudinal profiles of major rivers in maryland and virginia are generally closely adjusted to the resistance of the rocks over which they flow but they all show major discontinuities at or just above the fall line the amount of discrepancy at the fall line between the actual profiles and the projection of the profiles of the upstream reaches increases from about 27 m at the james river to about 50 m at the susquehanna river at the potomac river it is about 45 m detailed study of the terraces along the potomac in the piedmont above washington d c suggests that the discontinuity in longitudinal profile is the result of quaternary downcutting in response to a lowered base level changes in base level during sea level fluctuations in the pleistocene must have been an important factor but strong circumstantial evidence suggests that the discontinuities in river profiles may in part be due to differential uplift of the piedmont with respect to the coastal plain along a zone of flexure or distributed faulting near the fall line

key areas for alluvial diamond and sapphire exploration in the new england gem fields new south wales australia key areas for diamond and sapphire exploration may be defined within the new england gem fields of eastern australia through an understanding of the geologic and geomorphic processes that operated within the tertiary central volcanic province at least two distinct periods of volcanic activity one at 32 to 38 ma and the other at 19 to 23 ma were controlled by south southeast north northwest trending fracture sets revealed by landsat data the locus of volcanism stepped westward with time from the glen innes ben lomond guyra area the east central province to the area west of inverell and armidale the west central province drainage and prevolcanic topography indicate a radial pattern of drainage associated with east central province uplift and volcanism 32 38 ma this was modified by the later west central province volcanism 19 23 ma which established its own radial pattern the division of the central province defines broad regions suitable for sapphire and diamond exploration highly prospective diamond bearing deep leads associated with the paleo gwydir river can be traced under the younger basalts of the west central province via reconstruction of the prevolcanic topography in the east central province the posteruptive fluvial history is seen as vital in controlling the concentration of economic sapphire deposits from lower grade source rocks the sapphire bearing placer deposits occur as shoestring type accumulations occupying channels within broad flat basalt filled valleys higher grades generally correspond to areas where channels are deepest and sapphire grades in excess of 500 g per m 3 have been recorded heavy minerals associated with sapphire in the placer deposits are zircon pleonaste chromium spinel titanium magnetite magnetite ilmenite and rare chrysoberyl additional minerals found in nearby in situ basaltic soils are olivine clinopyroxene enstatite and amphibole with zircon and sapphire being extremely rare investigation of heavy mineral suites from 12 collection sites indicates significant variability in mineral species within and between particular drainage catchments visual characteristics of the sapphires also vary within and between catchments this implies that the sources are local to the placer deposits the similarity in composition of minerals from soil and placer sites indicates that the sapphire bearing placers have formed through extensive reworking of the immediately surrounding alkali basaltic and volcaniclastic rocks concentration was largely through vertical movement with fine or light material being winnowed downstream leaving behind a heavy gem bearing residue within low gradient low energy drainage systems

timescales and the role of inheritance in long term landscape evolution northern new england australia landscape evolution in northern new england is characterized by the persistence of landforms over long time periods the topography in the study area was initiated by paleozoic diapiric intrusion of granitic rocks as highs within metasedimentary and volcanic rocks this framework was probably reinforced by differences in the resistance of the massive igneous and the fractured metasedimentary rocks to erosion as a result both the tertiary and present day relief of the area consists of uplands developed on granitic rocks partly overlain by paleozoic volcanic rocks and lowlands developed on paleozoic metasediments extensive volcanism in the tertiary had only a minimal effect on this relationship a significant impact of tertiary volcanism however was the diversion of major streams across topographic highs despite 19 35 ma of incision these streams are still far from establishing equilibrium profiles and dissecting the highs the persistence of topography for a timescale of the same order of magnitude as that conventionally thought to be required for planation is due to reduced denudation rates in a passive tectonic setting and the presence of erosion resistant paleozoic igneous units the latter influence is indicated by knickpoint persistence for 19 35 ma on streams diverted across these rocks since it is generally considered that such disequilibria are short lived features formed by quaternary or ongoing deformation this knickpoint persistence has important implications for landscape analyses that use disequilibria to assess recent tectonism in a landscape