geology and structure of the continental margin off northern israel and the adjacent part of the levantine basin abstract the continental margin off northern israel and southern lebanon is characterized by a narrow coastal plain in places it is absent a narrow shelf a narrow slope which is incised by numerous submarine canyons and by a complex topography of the adjacent deep sea levantine platform detailed seismic reflection surveys have revealed the development of the area since the late miocene during the messinian when the level of the mediterranean sea dropped the present continental slope area was exposed eroded and covered by thinly scattered sediments in the deep basin evaporite bearing series accumulated reaching 1 km in thickness about 60 km offshore during the pliocene quaternary the area was covered by a fine clastic sequence up to 1 5 km thick that forms the present continental margin basinward gravitational slumping of these sediments over the messinian evaporites which acted as a lubricant resulted in a complex topography and many shore parallel rootless growth faults along the base of the continental slope and the adjacent deep sea young faults which are exposed in northern israel and extend seaward comprise the most important structural feature of the study area these faults were active during the pliocene and quaternary possibly also during the miocene the major nw trending young yagur carmel fault and e w trending rosh hanniqra fault extend to the base of the continental slope where they converge enclosing the complex western galilee graben the relief of the base of the pliocene quaternary sequence was affected by motions of these faults and of smaller faults inside the graben farther seaward a horst like block is developed along the extension of the carmel fault still farther basinward there is a group of diapiric ridges trending nw to e w they were formed by flowage of messinian evaporites in some cases these ridges seem to be aligned along underlying faults this group of diapirs is unique in the area the diapir ridges are interpreted as expressions of deeply rooted faults

effect of wind scouring on climatic records from ice core oxygen isotope profiles removal of winter snow by wind explains why the annual mean oxygen isotope ratio at an ice divide is 2 5 less negative than it is 1 2 km downslope cores from two sites on an ice cap ellesmere island canada show past variations in the difference depending on where the ice originated relative to the scoured zone some ice core climatic records may need correction for scouring

holocene paleoclimatology of the queen elizabeth islands canadian high arctic abstract a wide variety of evidence reflecting in different ways the changing climate of the queen elizabeth islands during the holocene is reviewed all proxies pertain to summer conditions many sources of information provide weak or equivocal paleoclimatic signals but a general pattern of events can be discerned temperatures in the early to mid holocene were highest comparable with or higher than temperatures prevailing for much of this century although much evidence points to a mid holocene thermal maximum there is also considerable evidence that conditions were warmer in the early holocene possibly related to orbitally induced radiation anomalies the apparent mid holocene thermal maximum may reflect lags in the response of the environment and of some proxies in recording paleoclimatic conditions more direct indices point to warmest conditions in the early holocene before 7500 bp temperatures declined from 3000 bp culminating in exceptionally low temperatures from 100 400 bp this may have been the coldest period of the entire holocene resulting in glacier advances to post glacial maximum positions the period since 1925 has witnessed a pronounced increase in temperature leading to negative mass balances on glaciers and ice sheets throughout the archipelago this period is the warmest for at least 1000 years and perhaps for several thousand years modern climate in the queen elizabeth islands may thus be characteristic of the early to mid holocene and atypical of conditions which prevailed for much of the last few thousand years

permian early mesozoic tectonism and continental margin formation in israel and its implications for the history of the eastern mediterranean summary the early mesozoic tectonic reorganization of the tethys region also affected the levant area here two processes were superimposed a the pattern of long wavelength vertical motions of the arabo nubian platform changed in the late permian when israel and nearby areas began to subside b rifting occurred in this subsiding area probably in several phases late anisian and ladinian carnian norian and liassic differential movements reached 2 3 km and magmatism occurred in the liassic and perhaps also in the triassic the tectonism was strongly felt up to 50 km landward of the present coast the crust was thinned and modified under the present continental margin and in the main rifts passive margin conditions were established in late liassic times over the previously faulted area later in the jurassic a carbonate shelf was constructed along this subsiding margin its basinward edge was 1 1 5 km high which shows that the adjacent se mediterranean was already a deep sea hence this basin and its passive margin are considered to have been shaped by the early mesozoic rifting which is recognized in israel the rifting process probably signifies oblique separation of the tauride block from the levant part of gondwana

sea surface conditions in northernmost baffin bay during the holocene palynological evidence the analysis of cores collected in northernmost baffin bay from within the area of the north water polynya permits definition of a composite sedimentary sequence ca 12 m thick spanning the last 10 000 14 c yr with only a few discontinuities palynological analyses were performed in order to reconstruct changes in surface water conditions and biogenic production transfer functions using dinocyst assemblages were applied to estimate sea surface temperature sst and salinity as well as the seasonal duration of sea ice cover at the base of the record prior to 9300 14 c yr bp dinocysts and organic linings of benthic foraminifers are sparse indicating harsh conditions and low productivity after ca 9300 14 c yr bp the increased concentration of benthic foraminifers up to 10 3 linings cm 3 and dinocyst fluxes 10 2 10 3 cysts cm 2 yr 1 reveals high biological productivity related to open water conditions the early to middle holocene from ca 9000 to ca 3600 14 c yr bp is marked by relatively high species diversity in dinocyst assemblages and the significant occurrence of autotrophic taxa such as spiniferites elongatus pentapharsodinium dalei and impagidinium pallidum this assemblage suggests conditions at least as warm as at present from ca 6400 to ca 3600 14 c yr bp transfer functions indicate warmer conditions than at present with sst in august fluctuating up to 5 5 c after 3600 14 c yr bp the dinocyst record suggests a trend of decreasing temperature toward modern values marked by recurrent cooling events copyright 2001 john wiley sons ltd

structural implications of strain localization towards a continental transform fault the example of the shift between the levant margin and the dead sea fault plate boundary abstract continental transform faults accommodate lateral motion between two adjacent plates often evidence for such motion is hard to detect due to onland processes of erosion investigation of a submerged passive continental margin adjacent to a transform plate boundary might provide indications for the developmental stages of the transform to examine this hypothesis we analyzed the messinian to recent stratigraphy and structure of the levant continental margin that resides ca 100 km from the dead sea fault dsf continental transform the analysis is based on interpretation of seismic reflection data 2d and 3d time migrated and pre stack 3d depth migrated and four boreholes it includes construction of structural maps tracking of stacking patterns and calculations of sedimentation rates data show that the levant margin developed through three phases 1 late miocene earliest zanclean 6 5 ma nne ssw left lateral strike slip faulting 2 zanclean late gelasian 5 1 8 ma syn depositional folding striking in the same direction the top gelasian surface marks an abrupt change which is expressed as 3 mass slumping that occurred due to regional basinward tilt continuation of differential subsidence is manifested by calabrian to recent progradation 1 8 0 ma while nile sediment flux peaked at 1 8 ma and decreased during the calabrian to recent our data shows an increase in sedimentation on the levant margin throughout the entire plio pleistocene this discrepancy is caused by the regional tilting of phase 3 which shifted the depocenter to the west correlations to onshore findings suggest that the faulting folding and tilting observed on the continental margin represent localization of strain towards the dsf during the pliocene gelasian 5 3 1 8 ma this is attributed to the consequent deepening of the dsf and the incipient collision of the eratosthenes seamount with the cyprus arc the continental margin records the development of the nearby active transform through structural and sedimentary modifications

late tertiary paleodepth reconstruction of the levant margin off israel abstract paleodepth reconstructions of the late tertiary levant continental margin off israel using one and two dimensional quantitative basin analysis reveals several interesting phenomena in the evolution of the margin such as tilting events of the deep basin in north south and east west directions westward progradation of the continental shelf in the southern levant and the variation in style along the levant margin this variation may be the result from the decreasing influence of the nile to the north and the increasing influence of the nearby plate boundaries in general the bathymetry of the margin from the deep basin to the base of the slope has become shallower since base neogene this reflects the general filling of the eastern mediterranean at a time when the sediment supply from the continental margin exceeds the subsidence the paleodepth reconstruction also suggests the existence of a deep basin in pre messinian time which resembles the present one thus implying that the deposition of the evaporites during the messinian desiccation of the mediterranean sea occurred in a deep basin

new age constraints on the evolution of the mt carmel structure and its implications on a late miocene extensional phase of the levant continental margin abstract the mt carmel structure is one of the most prominent topographical elements along the levant continental margin and is the surface expression of a deep tectonic structure the use of 3d seismic data allows us to set new constraints on the uplift of the carmel structure and define the or akiva fault as its southern boundary the or akiva fault was created during a late miocene extensional phase that had also created the carmel fault at the northern edges of mt carmel the different topographic expression across these two boundary faults reflects a change in the post miocene activity where activity along the or akiva fault ceased and its southern side began subsiding whereas its northern side bordered by the carmel fault continued to rise we conclude that the late miocene north south extension previously recognized only along branches of the dead sea transform in northern israel and lebanon affected larger areas than previously thought and can be related to regional kinematic changes during the breakup of arabia from africa and its collision with eurasia

the potential effects of percolating snowmelt on palynological records from firn and glacier ice the effects of meltwater percolation on pollen in snow firn and glacial ice are not fully understood and currently hamper the use of pollen in ice core studies of paleoclimate several studies have suggested that due to grain size pollen is not mobilized by meltwater transport however these findings contradict many ice core pollen studies that show pollen concentrations in snow and firn are much higher than concentrations found in the ice layers they eventually form this study addresses one aspect of this question by investigating whether meltwater percolation can effectively transport pollen within a snowpack we used nine styrofoam coolers filled by natural snow accumulation the coolers were tested in three groups of three replicates each to simulate different glacier snowpack conditions and spiked at the surface with a known amount of lycopodium marker spores the snow was melted to two thirds the original volume sampled stratigraphically and tested for spore concentrations meltwater effluent was also collected and examined results show substantial vertical and horizontal spore transport during the experiment peak spore concentrations were found in the bottommost snow layer or in the meltwater effluent in eight of nine coolers indicating that the majority of surface spores were transported through the snowpack via meltwater percolation and or runoff

stratigraphic evidence for shear in structural development of the triassic levant margin new borehole data on the epicontinental to deep marine transition in israel abstract triassic tectonic movements that include shear along a significant portion of the levant margin are evidenced from microfacies analysis of material recovered from the asher atlit 1 ga ash 2 meged 2 devora 2 and ramalla 1 onshore boreholes seismic studies showed that structural lineaments attributed to early mesozoic extension underlie coastal and central israel trending ne sw beneath southern israel and sub parallel to the then extensional palmyride basin of syria a more curved trend approximately nnw sse lies to the north beneath central israel coast parallel sedimentary domains formed above these lineaments which constitute the newly formed passive margin of the levant coast in the triassic the sedimentary history of these domains indicates that some were linked to each other and others disconnected the relative vertical movement between one domain and another is explained by activation of transpressional and trans tensional shear movements on the underlying curved faults these subordinate vertical movements also created the discontinuous barriers and small subsiding basins that separate the epicontinental sedimentary domain from the open tethys causing partial restriction necessary for the intermittent development of thick evaporites in the internal domains alternating with a regionally suppressed carbonate system this zone is here named the onshore levant margin shear zone olmsz shear was invoked theoretically in a number of models for the tectonic evolution of the eastern mediterranean as part of a neotethyan opening system this paper provides rock based evidence for such shear applicable to 20 of the eastern levant margin in the triassic

improved vacuum preloading method for consolidation of dredged clay slurry fill abstractan improved vacuum preloading method was developed to consolidate clay slurry fill that is hydraulically placed in seawater for land reclamation this method adopted both a vacuum and an air pressurizing system in the vacuum system a new connector to connect each prefabricated vertical drain pvd directly to a horizontal vacuum pipe is used in lieu of a horizontal sand blanket in the air pressurizing system compressed air is injected into the soil to accelerate consolidation field pilot tests using both the improved and the existing vacuum preloading systems were carried out at the same site the testing data showed that better consolidation results were achieved using the improved vacuum preloading method

tectonic processes in offshore northern israel and the evolution of the carmel structure abstract the carmel structure in northern israel is an elevated tilted block that extends from the land into the continental shelf and divides the levant continental margin into two distinct provinces its axis trends at a high angle to the levant margin and deflects mesozoic and cenozoic sedimentary and basement rocks the carmel structure is probably older than the levant margin itself and has been through several phases of activity most of the multichannel seismic profiles in the offshore of northern israel were reprocessed through time migration and then interpreted the resultant maps combined with gravimetric magnetic and bathymetric maps show a complex tectonic picture of the carmel structure and its vicinity four evolutionary stages can be recognized in this area a early mesozoic rifting along the present levant margin we speculate that the carmel was at that time a triple junction a thick mesozoic volcanic and carbonatic section of more than 6500 m indicates rapid subsidence probably accompanied by normal faulting b folding along the nne axis this is probably part of the syrian arc compressional system which was active from the late cretaceous until the eocene normal faults of the previous stage were probably reactivated becoming reverse faults c left lateral strike slips faulting this formed a north west fault system which resulted in a clockwise rotation of segments of the fold axis and was active from the late miocene to early pliocene d a tensional tectonic regime prevails since the pliocene and is probably still active at present the well pronounced kishon graben which extends from land to the continental shelf was formed during this period the first two stages are of regional extent whereas the latter stages are the reslt of local modification of the regional stress fields

intraplate deformation by block rotation and mesostructures along the dead sea transform northern israel combined analysis of mega and meso structures yield the strain inferred stress and tectonic history of the margin of the sinai sub plate in northern israel along the dead sea transform three major stress regimes were developed and have affected the region since the middle miocene one is regional and controlled the left lateral shear along the dead sea transform this one has been active since post early miocene is characterized by 1 trending c 345 and deformed the plate margin by horizontal shear and contemporaneous block rotation this style of deformation is similar to simple shear the second one was local and may be subdivided into distinct stress and strain domains it was characterized by 1 trending e w and 3 trending n s which produced a conjugate set of strike slip faults the region underwent n s elongation by horizontal shear and block rotation similar to the pure shear mechanism this stress regime was active in late miocene to early pliocene time the third and youngest stress regime is extentional with 1 vertical and 3 oriented n s this one has been active since post middle pliocene time producing e w normal faults and minor n s elongation the second and third stress regimes show local distribution and developed as a consequence of the bent geometry of the transform vis a vis the plate slip vector finite element and photoelastic models predict the development of local stress fields and elongation of the plate margin parallel and subparallel to the transform plate boundary the strain of the plate margin in northern israel and southern lebanon indicate remarkable elongation parallel to the dead sea transform by a factor of 1 5 2 1 since the miocene this process of intraplate deformation and the consequent strain is unique to the parts of the plate margin which are adjacent to the bent segment of the transform

palynostratigraphy and chronostratigraphy of baffin bay deep sea cores climatostratigraphic implications abstract palynostratigraphic considerations and 14c dates ams accelerator mass spectrometry on foraminifera samples from piston cores suggest sedimentation rates as high as ca 8 11 cm ka in deep baffin bay during the late pleistocene throughout this interval baffin bay experiences rigorous conditions and probably the extension of a dense sea ice cover unfavourable to phytoplanktonic productivity the dinocyst microflora indicates only brief episodes of higher productivity related to arctic conditions and to moderately low salinites ca 30 31 the abundance of reworked pre quaternary palynomorphs in the deposits is interpreted as a response to glacial and glacio marine activity in the northernmost areas surrounding baffin bay the dinocyst stratigraphy spanning approximately over the last ice age ca 100 ka reveals that baffin bay constituted a confined basin isolated from the north atlantic ocean prior to the present interglacial

late holocene environmental conditions in coronation gulf southwestern canadian arctic archipelago evidence from dinoflagellate cysts other non pollen palynomorphs and pollen boxcore 99lssl 001 68 0958 n 114 1868 w 211 m water depth from coronation gulf represents the first decadal scale marine palynology and late holocene sediment record for the southwestern part of the northwest passage the record was studied for organic walled microfossils dinoflagellate cysts non pollen palynomorphs pollen terrestrial spores and sediment characteristics 210 pb 137 cs and three accelerator mass spectrometry 14 c dates constrain the chronology three prominent palaeoenvironmental zones were identified during the interval ad 1470 1680 zone i the climate was warmer and wetter than at present and environmental conditions were more favourable to biological activity and northward boreal forest migration with reduced sea ice and a longer open water growing season the interval ad 1680 1940 zone ii records sea ice increase and generally cool polar conditions during the little ice age during ad 1940 2000 zone iii organic microfossils indicate an extended open water season and decreased sea ice with suggested amelioration surpassing that of zone i although more marine studies are needed to place this record into an appropriate context the succession from ameliorated zone i to cooler sea ice influenced conditions zone ii and finally to 20th century warming zone iii corresponds well with several terrestrial climatic records from the neighbouring mainland and victoria island and with lower resolution marine records to the west copyright 2011 john wiley sons ltd

transform margin of the northern levant eastern mediterranean from formation to reactivation 1 the levant continental margin eastern mediterranean is usually defined as a passive margin that developed between the late paleozoic early mid mesozoic previous studies suggest that the margin is composed of two segments with different structural characteristics the southern segment south of the carmel structure was formed by rifting whereas the origin of the northern segment is not known the present study focuses on the northern segment which is a key for understanding the tectonic history of the eastern mediterranean investigation is carried out offshore on two scales 1 deep crustal observations analysis of seismic refraction and magnetic data and their comparison with other continental margins worldwide and 2 shallow crustal scale observations of recent tectonic deformations based on multichannel and single channel seismic reflection profiles integration of the deep and shallow observations with reevaluation of geological data onland show strong structural resemblance between the northern levant segment and other transform margins a modified scenario is suggested for the formation and development of the levant basin and its margins combining all previous studies into one simple picture where a signature of older structures on more recent features is evident located in the midst of the progressive afro eurasian collision the northern levant presents a unique lifecycle for transform margins worldwide from formation to reactivation

segmentation of the levant continental margin eastern mediterranean 1 the levant continental margin is divided into two major segments by the carmel structure which extends from the dead sea fault into the eastern mediterranean new seismic reflection data over the unexplored northern segment are used for completing the structural framework of the levant area together with existing data south of it inclusive depth structural maps of the area were produced for the base pliocene and base messinian evaporites previous studies indicate that differences between the two segments are well expressed in the deep crustal structure the present study which focuses mainly on the shallow section shows that these differences are maintained throughout the accumulation of young sedimentary units and even in the bathymetry this preservation of segmentation both in the shallow and in the deep structure insinuates that the two segments were formed through different continental breakup processes which continue to dictate the style of sediment accumulation

tectonic isolation of the levant basin offshore galilee lebanon effects of the dead sea fault plate boundary on the levant continental margin eastern mediterranean abstract the continental margin of the central levant offshore northern israel and southern lebanon is characterized by a sharp continental oceanic crustal transition exhibited on the bathymetry as a steep continental slope at the base of the slope a narrow zone of faulting deforms the upper messinian recent sedimentary sequence further into the basin no major deformations are observed however onland a restraining bend along the dead sea fault plate boundary results in the formation of the lebanon and anti lebanon mountain ranges which exhibit a large positive isostatic anomaly not compensated at depth all these geologic features follow a nne ssw trend a dense network of multi channel and single channel seismic profiles covering 5000 km of ship track offshore northern israel and southern lebanon was analyzed for the purpose of characterizing the continental margin additional seismic surveys covering the area between the levant margin and the cyprean arc were examined data were then incorporated with magnetic gravity and earthquake measurements to reveal the deep crustal structure of the area and integrated with bathymetry data to describe the behavior of the young sedimentary basin fill results indicate that the levant basin offshore northern israel and southern lebanon up to beirut is more or less unaffected by the intense tectonic deformation occurring onland the transition between the deformed area onland and the undeformed levant basin occurs along the base of the continental slope along the base the upper messinian recent sedimentary sequence is cut by two sets of faults shallow growth faults resulting from salt tectonics and high angle faults marking the surface expression of a deeper crustal discontinuity the marine extension of the carmel fault zone the central levant continental margin is being reactivated by transpressional faulting of the marine continuation of the carmel fault at the base of the continental slope this fault system coincides with the sharp continental oceanic crustal transition and acts as an isolator between the levant basin and its land counterpart to the north this feature may initiate the formation of a new triple junction with the latakia ridge part of the eastern cyprean arc and the east anatolian fault

magnetic anomalies over the central levant continental margin abstract the magnetic field over the central levant continental margin off northern israel and southern lebanon and the adjacent levant basin has two distinct trends mount carmel and its offshore continuation carmel nose which are the surface expression of a large subbottom structure that extends from the land area across the continental shelf to the continental slope form a dividing zone between the two magnetic trends south of the carmel structure the magnetic field trends east west while north of the carmel structure it trends northeast and north northeast several pronounced magnetic anomalies exist mainly north of the carmel structure the majority of which trend north northeast and northeast parallel and sub parallel to the trend of the magnetic field in this area some also trend northwest perpendicular to the trend of the magnetic field in several cases the magnetic anomalies indicate large lithological elements which continue from land to sea gravity and seismic refraction data show that the two magnetic domains north and south of the carmel structure are associated with areas of different crustal structure south of the carmel structure the continetal oceanic crustal transition zone is located beyond the continental margin at the base of the continental slope while north of the carmel structure it is located under the continental shelf near the shore on land there are also differences in the structure of the crust north and south of the carmel structure the crust being much thinner north of the structure than south of it we suggest that some of the large magnetic anomalies off the central levant were formed during the rifting phase of the eastern mediterranean

stratigraphy and palaeoecology of a possible interglacial site northernmost ellesmere island canada an extensive stratigraphic section at cape alfred ernest on the wootton peninsula northwest ellesmere island contains six lithofacies which appear to record two glacial phases separated by an organic layer 1 a lower massive gravel records a pre ice advance outwash phase 2 massive fine grained sediments record a period of non glacial marine deposition when sea level was higher than present 3 a massive diamicton records the advance of ice across the site 4 intermediate stratified beds record supraglacial and proglacial outwash and include an organic layer 5 massive diamicton grading down valley to stratified diamicton and then massive sheared diamicton overlain by laminated fine grained sediments with dropstones recording the last late wisconsinan glaciation 6 upward coarsening sands and gravels record proglacial outwash and grade to raised marine deltas radiocarbon dates of 39270 640 and 51000 yr bp were obtained on samples from the organic layer by accelerator mass spectrometry and conventional radiocarbon dating respectively palaeoecological data suggest that the organics accumulated in a wet sedge meadow environment when the climate was warmer than present stratigraphic considerations suggest that the organic layer represents an interglacial interval which if valid indicates that the site constitutes the northernmost interglacial stratigraphy in the canadian arctic alternatively the organic layer may date to plio pleistocene times

the east coast magnetic anomaly a model is proposed for the east coast magnetic anomaly that for the first time incorporates an observed basement feature a normal fault that consistently lies below the landward flank of the anomaly the east coast magnetic anomaly is similar to slope anomalies found over passive continental margins in many parts of the world thus the proposed model can be used to interpret slope anomalies in general

a holocene ice core pollen record from ellesmere island nunavut canada abstract a holocene record of pollen deposition was obtained from an ice core drilled through the agassiz ice cap the pollen records long range atmospheric transport to the ice cap pollen concentrations were highest in the early holocene 15 grains l decreased in the mid holocene 6 grains l and increased in the late holocene 9 grains l in the early holocene the higher concentration of tree pollen at a time when large parts of canada were still ice covered and when forest was generally farther away implies that atmospheric circulation was stronger than at present following deglaciation as vegetation migrated north in central and eastern canada sources of pollen were closer to the agassiz ice cap however the concentration of tree pollen decreased on the ice cap this was followed by several relatively rapid changes after 3500 yr ago until ca 3500 yr ago the pollen concentration curves resembled the ice core 18 o and summer melt layer curves both regarded as temperature proxies

late tertiary seismic facies and structures of the levant passive margin off central israel eastern mediterranean abstract the late tertiary seismic facies and structures of the levant passive margin off central israel in the eastern mediterranean sea were studied by the interpretation of more than 3000 km of seismic reflection profiles most of them previously unpublished single channel profiles the neogene growth and evolution of this margin was influenced by the interaction of three main processes 1 the outbuilding and loading of the margin by the nile sediments since the pliocene 2 uplift and tectonic subsidence related to the tectonic activity along the dead sea transform and 3 the effect of the above processes on the thick messinian evaporites which caused many salt tectonic features including flowage piercement diapirs slumps and en echelon listric normal faults in the supra salt sediments we suggest that the study area may be divided into two segments north and south of caesarea these segments vary in their depositional environment the amount of sediment supply and load salt related features and tectonic activity we propose that the northern segment is affected by low sediment supply and by the continued uplift of the carmel structure and that this segment may even be a part of this structure the southern segment has been affected by the deposition and loading in the nile derived sediments since the pliocene three main depositional sequences were observed in the southern segment 1 sequence i early pliocene onlaps the top of the messinian evaporites representing a rise of sea level and renewed subsidence 2 sequence ii early pleistocene is lens shaped thinning to the north west and east and was derived during a relatively short time interval from the pre nile and 3 sequence iii since the pleistocene represents a major episode of continental shelf construction

seismic refraction profiles between cyprus and israel and their interpretation summary a long seismic refraction profile was carried out between southern israel and cyprus the seismic energy was generated by 33 sea shots each of 0 8 t explosives and was recorded by land stations in israel and cyprus and by ocean bottom seismographs deployed along the profile the results showed that the continental crust of southern israel thins towards the mediterranean underneath a northward thickening sedimentary cover cyprus is underlain by a 35 km thick continental crust thinning south wards and extending to mt eratosthenes between mt eratosthenes and the israel continental shelf the crystalline crust is composed of high velocity 6 5 km s 1 material and is about 8 km thick it is covered by 12 14 km of sediments and may represent a fossil oceanic crust

ptolemais basin the tectonic origin of a senonian marine basin underneath the southeastern mediterranean sea abstract the large litani anticline that was recently discovered in the se mediterranean basin sheds new light on the regional tectonic history of the levant in the late cretaceous the anticline is buried under 5 km of undeformed sedimentary series its apex was leveled by erosion and its folding can be dated to the early senonian the seismic reflection data suggest that shortly after the structural development of the anticline in a shallow marine environment and under compressional stresses the regional tectonic regime turned extensional and the anticline subsided into the open marine environment of ptolemais basin that subsidence can be dated to the senonian as well it is suggested that the litani anticline is a part of the syrian arc and its deformation and subsequence subsidence reflect the complex tectonic regime of southern anatolia where the continental collision with arabia and the subduction of the neo tethys oceanic crust took place concurrently the litani anticline and the ptolemais basin thus show that contrasting tectonic regimes and their structural derivatives could evolve at a very fast rate

a modern pollen spectrum from dye 3 south greenland ice sheet results of pollen analysis of a large firn sample from dye 3 southern greenland are reported the sample was divided into three sections all dominated by pine birch and ragweed pollen pollen concentration for the entire sample is 15 pollen grains per litre and the annual pollen deposition rate has been estimated at approximately 0 73 grains cm 2 year 1 7300 grains m 2 a 1 although these values are slightly lower than expected considering the relatively southern latitude of the site they are within the range of values obtained from other arctic ice caps

modern pollen distribution in marine sediments from the northern part of the south china sea we analyzed the pollen and spore distributions in sediments from the northern south china sea to support reconstruction of the region s paleoenvironment 1 based on pca analysis in the two areas with water depths of 200 m pollen and spores found at water depths of 200 m wind transport is dominant 2 tree pollen was abundant on the continental shelves near guangdong and southeastern hainan island the center of the study area and deep basins in the south pinus pollen was abundant with the highest levels on the continental shelf near guangdong and in the marine area south of 15 degrees n pollen from tropical and subtropical broad leaved trees e g castanopsis quercus had low abundances castanopsis pollen appeared to originate near hainan island guangdong and the indochina peninsula herbaceous pollen was less abundant with pollen from the poaceae and artemisia scattered among the northern and southern regions with the highest levels near guangdong and a distribution that followed the rivers or sea surface circulation poaceae pollen was most abundant along the guangdong and vietnam coasts due to their proximity to tropical and subtropical grasslands and crops monolete spores and cyperaceae pollen were most abundant near the pearl river estuary southern hainan island and southwestern taiwan probably originating from fluvial river discharge trilete spores mostly dicranopteris were most abundant on the continental shelf of southeastern hainan island and the continental slope far from guangdong 3 pollen and spore assemblages from airborne sea surface water and sediment samples were compared from august to september airborne pollen and spores mainly belong to trees ulmaceae pinus and herbaceous pollen and have seasonal characteristics ocean surface waters in august september mainly contain d dichotoma rhizoma polypodiodis nipponicae and other trilete spores but no pinus pollen with clear seasonality characteristic pollen and spore assemblages in surface sediments are dominated by trilete spores pinus and herbaceous pollen and appear to integrate the pollen characteristics of the four seasons c 2014 elsevier b v all rights reserved

late quaternary pollen transport processes western north atlantic data from box models cross margin and n s transects abstract surface pollen assemblages in coastal and neritic sediments of the western north atlantic compare well with eastern north american vegetation zones and late quaternary pollen in marginal marine sediments clearly correlate with changes in terrestrial vegetation and paleoclimates in contrast offshore assemblages are strongly affected by differential adaptation of pollen to long distance transport by wind and water marine pollen transport processes were studied by measuring air and water inputs to a coast shelf box model and by study of surface samples from cross margin transects in three different climatic and oceanographic regions at approximately 38 45 and 55 n latitude the box model shows that aerial transport is the main process by which pollen moves across the continental margin off nova scotia two clear seabed distribution patterns were found betula quercus and herb pollen decrease rapidly offshore in abundance grains per cubic centimetre and in relative abundance percentage pinus and picea have abundance peaks on the continental margin but percentages increase further offshore distributions of the main pollen and spore taxa were compared for late wisconsinan glacial oxygen isotopic stage 2 12 28 ka terminal pleistocene 10 12 ka and holocene sediments at 5 continental margin and 3 deep sea sites the largest changes were found in percentages of pinus picea and herb pollen during the late wisconsinan glacial and terminal pleistocene intervals at subpolar latitudes these data can be related to shifts in paleo vegetation winds and hydrology that accompany global climate change

younger dryas pollen records from sverdrup island kara sea abstract sverdrup island in the kara sea is currently occupied by polar desert vegetation the analysis of allerod deposits indicates a climate drier than presently with increased summer and decreased winter temperatures the relative scarcity of distal pollen indicates that mainland source areas were located further south than at present younger dryas cooling and increased dryness resulted in an increase of the proportions of artemisia chenopodiaceae and salix pollen and in the extent of sphagnum mosses preboreal time was marked by warmer more humid conditions with dwarf birches ericales and possibly alnus fruticosa the increased proportions of distally derived arboreal birch pollen coupled with the local component of the assemblages indicates that the early holocene represented the climatic optimum initiated by the opening of the arctic ocean subsequent climate fluctuations were muted on sverdrup island due to the development of microclimatic conditions associated with an oceanic regime

ground improvement using vacuum loading together with vertical drains abstractthe use of vacuum as a preload together with vertical drains to reduce postconstruction settlement and increase the shear strength of soft ground is increasingly popular however conflicting views concerning preloading by vacuum consolidation continue to be disseminated a review and interpretation of case histories of vacuum loading together with vertical drains indicates that 1 with a novel definition of excess pore water pressure existing theories of consolidation solutions and associated computer programs that have been developed for fill loading can be applied without any modification to vacuum loading 2 vacuum that is available in the drainage blanket remains constant with depth within the vertical drains 3 for vacuum loading as for fill loading vertical drains may display well resistance 4 there is no difference in magnitude and rate of settlement for a vacuum load and an equivalent fill load 5 all empirical concepts of undrained shear strength that have originated from f

crustal structure of the levant basin eastern mediterranean abstract a seismic refraction wide angle reflection experiment was undertaken in the levant basin eastern mediterranean two roughly east west profiles extend from the continental shelf of israel toward the levant basin the northern profile crosses the eratosthenes seamount and the southern profile crosses several distinct magnetic anomalies the marine operation used 16 ocean bottom seismometers deployed along the profiles with an air gun array and explosive charges as energy sources the results of this study strongly suggest the existence of oceanic crust under portions of the levant basin and continental crust under the eratosthenes seamount the seismic refraction data also indicate a large sedimentary sequence 10 14 km thick in the levant basin and below the levant continental margin assuming the crust is of cretaceous age this gives a fairly high sedimentation rate the sequence can be divided into several units a prominent unit is the 4 2 km s layer which is probably composed of the messinian evaporites overlying the evaporitic layer are layers composed of plio pleistocene sediments whose velocity is 2 0 km s the refraction profiles and gravity and magnetic models indicate that a transition from a two layer continental to a single layer oceanic crust takes place along the levant margin the transition in the structure along the southern profile is located beyond the continental margin and it is quite gradual the northern profile north of the carmel structure presents a different structure the continental crust is much thinner there and the transition in the crustal structure is more rapid the crustal thinning begins under western galilee and terminates at the continental slope the results of the present study indicate that the levant basin is composed of distinct crustal units and that the levant continental margin is divided into at least two provinces of different crustal structure

dating of seasonal snow firn accumulation layers using pollen analysis reliable chronologies in ice cores and snow pits from many alpine glaciers in latitudes between 60 n and 60 s are often difficult to establish owing to problems with annual layer counting problems arise from melting wind erosion and the negligible amount of precipitation in some seasons all of which tend to obscure the seasonal variations in 18 o and chemical concentrations that are typically used to date ice cores however alpine glaciers contain many species of pollen grains that peak at particular times of the year we used the peaks in betulaceae pinus artemisia and a combination of abies and picea pollen species to determine the four seasonal layers of a snow pit on belukha glacier in russia s altai mountains comparing the pollen dated profiles with wind and precipitation records allows us to determine where a seasonal layer is missing thus the pollen dating method described here may be a useful tool to measure the annual snow deposition on alpine glaciers even when some seasonal layers are eroded by wind or missing due to negligible precipitation

a new approach of vacuum preloading with booster pvds to improve deep marine clay strata this paper presented a new approach for ground improvement of deep marine clay in which the conventional booster tube in the current air booster vacuum preloading technology was replaced by a boost

long distance transport of pollen to greenland 1 four pollen traps were recently placed at coastal sites in east and west greenland in order to assess long distance transport of pollen to the arctic domain by identifying potential vegetation source areas associated with air mass pathways we were able to produce the first detailed record of pollen transport from eastern north america to narsarsuaq southern greenland the record is based on observations and on a transport and dispersion model used to calculate back trajectories of the air masses the evidence points to the pollen being transported northward by the air mass over newfoundland and the labrador sea before reaching narsarsuaq at this point the air mass was at an altitude of 3000 m deposition of pollen grains occurred with downward air movements associated with a 0 5 mm h rain the source areas for these pollen grains differ from those of dust and certain other aerosols that reach the summit of the greenland ice sheet the results demonstrate the need for continued maintenance and analysis of the greenland pollen trap data in order to improve our understanding of atmospheric circulation and transport to high northern latitudes

reply to the discussion by mesri and kane on new approach of vacuum preloading with booster prefabricated vertical drains pvds to improve deep marine clay strata 1

pollen analysis of the 1973 ice core from devon island glacier canada abstract meltwater from a 299 m long ice core was filtered and analyzed for fossil pollen and spores pollen concentration was higher in the late holocene and interglacial intervals ca 7 liter 1 than in the early holocene and wisconsinan ca 1 2 liter 1 ones the late holocene and interglacial assemblages were dominated by alnus alder whereas the early holocene and wisconsinan ones were dominated by betula birch and artemisia sage during the holocene and probably the last interglaciation most of the pollen and spores were blown a minimum of 1000 km from low arctic shrub tundra and adjacent subarctic picea spruce forest these areas were dominated by the arctic air mass during the summer pollinating season during the wisconsinan early holocene glacier ice and arctic air were more widespread and pollen sources were more distant thus at this time relatively little pollen was incorporated into the ice the devon ice core data suggest that there should have been pollen in the continental ice sheet of wisconsin time when the ice sheet retreated this pollen would be carried by meltwater and redeposited with silt and clay together with contemporary pollen producing an ecologically anomalous assemblage

upper cenozoic history of the labrador sea baffin bay and the arctic ocean a paleoclimatic and paleoceanographic summary foraminifera palynomorphs and stable isotopes in planktonic foraminifera have been studied in piston cores from the northern labrador sea southern baffin bay and the alpha ridge region of the central arctic ocean foraminifera in cores from the labrador sea and southern baffin bay show glacial interglacial 18o values similar to those reported from the norwegian and greenland seas in contrast to the eastern north atlantic ocean however peaks of subarctic foraminifera and dinoflagellates in the western north atlantic cores show that relatively warm atlantic surface water continued to flow into the northern labrador sea during the early glaciation growth phases of isotopic stages 2 4 6 and 8 boreal and subarctic pollen suggest that warm atlantic air flowed into the northern labrador sea and baffin bay during the ice sheet growth phases the advection of warm air masses and the presence of open waters during the summer probably provided moisture for the growth of the laurentide innuitian and greenland ice sheets isotopic and microfossil records in arctic cores can also be tentatively correlated with major high latitude north atlantic glacial interglacial events magnetostratigraphic palynological and amino acid dating however shows that sedimentation on the alpha ridge has been very slow during the past 0 73 m y therefore events of less than 20 000 years duration cannot be clearly discerned interpretation of pre pleistocene paleoenvironments is further limited by the sparseness of calcareous and siliceous microfossils

internal configuration of the levantine basin from seismic reflection data eastern mediterranean abstract in the easternmost mediterranean the levantine basin is filled by up to 10 km of mesozoic to recent sediments next to the alpine deformation front of the cyprean arc near the junction between africa and arabia away from the deformation front the basin has undergone little deformation for the past 100 ma as evidenced by deep seismic reflection profiles mostly subhorizontal reflections image the undisturbed sedimentation above a possibly paleozoic basement two marked reflections are identified within the sedimentary fill m and k they correspond to unconformities near the deformation front and their laterally equivalent concordant surfaces basinward in the deepest part of the basin there are more than 4 km of tertiary to recent sediments within which the m reflection is well defined above the 1 5 km thick messinian evaporites and beneath the 500 m thick plio quaternary sedimentary sequence pre tertiary sediments reach up to 6 km thick beneath the k reflection and above the top basement reflection they are little deformed and possibly correspond to late jurassic cretaceous age the limit with the cyprean arc deformation front is a sharp tectonic boundary south of the hecateaus rise where the whole sedimentary fill terminates against a subvertical fault zone that can be followed down to more than 14 km depth to the east this limit changes into a 30 km wide zone of strike slip deformation that includes flower structures progressively buried basinward by tertiary to recent syntectonic sediments possibly since paleocene times the basin corresponds to the almost undisturbed part of a larger basin whose northern side has been incorporated within the alpine deformation of the cyprean arc and limited to the east by the dead sea transform system

paleoenvironments of the canadian high arctic derived from pollen and plant macrofossils problems and potentials abstract analyses of peat sections lake sediments and ice cores provide information about late quaternary arctic environments palynomorphs and plant macrofossils from each of these three types of sediments record different aspects of the environment with particular spatial and temporal scales of resolution in the arctic the limits to the interpretation of past environments are particularly significant problems of low pollen concentrations long distance transport stratigraphic inversions and contamination by fossils from older deposits are more serious in this region due to the biogeographic context that characterizes these high latitudes and influences the particular ecological and geomorphological processes however recent work has shown that past environments can be reconstructed from evidence preserved in high arctic sediments and ice cores if these problems are taken into account before their interpretation

international geomagnetic reference field 1980 a report by iaga division i working group i igrf 1965 the first international geomagnetic reference field was adopted by the international association of geomagnetism and aeronomy iaga in 1968 iaga commission 2 working group 4 1969 it consists of a model of the main field at 1965 0 along with a model of secular variation for use in extending the main field model in time both backward not earlier than 1955 0 and forward not later than 1975 0 igrf 1975 adopted later consists of igrf 1965 extended to 1975 0 along with a revised model of secular variation for use in extending the main field model up to 1980 0 iaga division i study group 1976

modern and late quaternary pollen spectra of fiord sediments eastern baffin island arctic canada abstract pollen spectra of thirty surface samples from baffin island fiords are dominated by abetula filicales cyperaceae gramineae association that is somewhat representative of local or regional vegetation however betula and filicales are over represented andsalix cyperaceae and ericales are under represented compared to their importance in the present vegetation two possible causes for this disparity related to the fluvial processes that furnish most pollen to fiords are 1 fluvial reworking of older sediment that contains abundantbetula and filicales and 2 greater resistance of these taxa to corrosion and degradation during fluvial transport the pollen stratigraphy of five piston cores from fiords contains two types of pollen assemblages in the lower portions of the cores exotic pollen types and pre quaternary palynomorphs are abundant the upper portions of the cores contain an assemblage roughly representative of the present vegetation in which cyperaceae and gramineae are abundant and exotic and pre quaternary types are reduced or absent the lower assemblage was deposited during the late glacial deglacial transition and deglaciation ca 12 000 to 6000 b p when eastern baffin island had little vegetation cover and long distance transport and reworking were virtually the only pollen sources a feature of several cores is a major peak in dinoflagellates about 5000 b p this event may be related to the postglacial marine climatic optimum in the eastern canadian arctic between 5000 and 3000 b p

modern and holocene pollen assemblages from some small arctic lakes on somerset island nwt canada abstract modern pollen samples from 15 lakes along a north south transect on western somerset island nwt canada show a decrease in pollen concentrations from the high arctic to the mid arctic zone but there are few differences in the pollen percentages between these sites long distance transport accounts for up to 50 of the pollen in these lake sediments cores from two lakes show few changes in the percentages of important pollen types except for an initial period before 6000 yr b p of increased salix the pollen concentration of lake rs36 from the mid arctic is twice that of lake rs29 from the high arctic and at both sites the concentrations decreased during the past 6000 yr b p this suggests a climatic deterioration during the past 6000 yr which has caused a decrease in the abundance of plants on the landscape

displaced terranes and crustal evolution of the levant and the eastern mediterranean geophysical data from the levant and the eastern mediterranean suggest that this area can be divided into distinct crustal units of different origins for example a marked difference in crustal structure and structural style exists in the levant between samaria and judea south of the carmel structure and the galilee and lebanon north of it on the other hand several microcontinental fragments such as cyprus and the eratosthenes and anaximander seamounts are embedded within the oceanic crust of the eastern mediterranean the present location of these units has resulted from complex tectonic processes which were active during the mid paleozoic mesozoic evolution of this area during this period several crustal units were accreted to the northern margin of africa while others were detached away from it the crustal evolution of the eastern mediterranean and the levant is intimately linked with the closure of the paleo tethys the formation of the neo tethys and its subsequent closure

application of pollen analysis to dating of ice cores from lower latitude glaciers 1 ice cores from temperate regions have long been expected to be useful for understanding local climate trends but a reliable dating method has proved difficult here we show that measurements of pollen using samples with only 10 ml of water can give an accurate measure of the annual ice accumulation in addition two major types of pollen allow us to estimate the summer ice accumulation as well as the annual accumulation