investigation of the vertical uplift capacity of deep water mudmats in clay subsea mudmats are used in deep water oil and gas fields to support seabed structures such as pipelines manifolds and well heads on soft soil removing mudmats during maintenance or decommissio

present status of the astronomical polarity time scale for the mediterranean late neogene sedimentary cycles may reflect orbitally induced climate oscillations and can then be used to construct astronomical time scales following the initial tuning of the late pleistocene the anchored astronomical time scale was extended to the base of the pliocene using palaeoclimatic records from ocean drilling project odp sites in the eastern equatorial pacific and north atlantic and sedimentary cycle patterns in marine successions exposed onland in the mediterranean in this paper we present a review of the progress subsequently made in establishing a late neogene astronomical polarity time scale a p ts in the mediterranean region major steps forward are 1 the evaluation of the initial time scale using high resolution climatic proxy records different astronomical solutions and the additional influence of obliquity on sedimentary cycle patterns 2 the extension of the a p ts into the middle miocene i e back to about 12 3ma 3 the closure of the messinian gap in the a p ts 4 the incorporation of the continental record and 5 the intercalibration of astronomical and radioisotopic time

reconstructing paleoenvironment eruption mechanism and paleomorphology of the pliocene pula maar hungary abstract pula maar is a partially eroded pliocene maar diatreme volcano part of the mio pliocene bakony balaton highland volcanic field the surficial remnant of the maar diatreme volcano consists of 1 a distinct depression with a thick post eruptive lacustrine alginite sediment infill interbedded with coarse grained volcaniclastic sediments 2 a narrow marginal zone inside the depression consisting of primary pyroclastic rock units that are interpreted to be partly collapsed and subsided blocks of entire sections from the tephra ring formerly surrounding the maar crater depression and 3 coarse grained volcaniclastic debris flow deposits closely associated with the collapsed primary pyroclastic rock units in the marginal zone the presence of coherent lava rocks below the crater fill units their distribution pattern and their association with scoriaceous beds indicate that after the maar diatreme forming phreatomagmatic explosive activity small 100 m scale scoria and or spatter cones erupted in the maar crater these cones are the likely source of the lava flows that partially filled the maar crater basin the widespread dm to m thick basaltic sand and or silt units at the base of the post eruptive crater filling sedimentary succession are interpreted to be reworked volcaniclastic material from the intra maar scoria spatter cones as well as from the tephra ring based on comparative analyses of 53 core descriptions this study reveals that the original maar crater basin was larger than previously suggested the deep level of the maar crater is reconstructed to be a northeast southwest elongated depression currently forming a c 50 m deep basin geomorphological considerations suggest that most of the phreatomagmatic pyroclastic rocks are composed of base surge and tephra fall deposits around the deep maar depression these allochthonous rock units form a 50 400 m wide zone of proximal tuff ring sequences the formation of this zone is inferred to be a result of a combination of syn eruptive subsidence due to mass deficit in the rigid triassic dolomite basement caused by the phreatomagmatic explosions as well as post eruptive subsidence of the crater and diatreme filling successions due to diagenetic compaction the facies in the centre of the maar lake is a soft laminated alginite mainly botryococcus colonies diatom frustles calcium carbonate crystals clay minerals in the section exposed in the pula open cast mine a single turbiditic layer is present this layer originated in a landslide which possibly could have been caused by either syn eruptive earthquake and or a sudden post eruptive subsidence event of the diatreme fill

t bar to spudcan design approach in single layer clays and calcareous silts abstractdifficulties in obtaining high quality soil samples from offshore sites and heavy involvement of lab testing and engineering judgment have necessitated increasing reliance on in situ penetrometer tests giving continuous penetration resistance profiles this paper reports a framework for estimating spudcan penetration resistance directly from continuous resistance profile of a full flow penetrometer t bar test in single layer clays and calcareous silts the framework was validated chiefly against centrifuge test data supplemented by some reported field data

the evolution of the carpathians pannonian system interaction between neotectonics deep structure polyphase orogeny and sedimentary basins in a source to sink natural laboratory abstract the carpathians pannonian basin system provides a natural laboratory for analysing lithospheric to surface controls on tectonic topography development in a coupled source to sink environment to link processes taking place at depth and at the surface recent research focused on the interplay between basin evolution active tectonics topography evolution and intraplate folding mechanisms neotectonic processes control landscape development and natural hazards in particular the seismicity during the late stage late neogene quaternary evolution of both the carpathians pannonian basin system and its interaction with the adjacent dinarides and balkans the deep structure of the se carpathians exerts a strong control on the post collisional evolution of the system new constraints are available from seismic tomography deep seismic reflection and refraction profiling and detailed studies of the vreancea seismicity inherited orogenic fabric and structure of the active black sea sink has a strong influence on the localisation of the neogene sediment pathways a close relationship has been established between the timing and mechanisms of stress changes in the pannonian and transylvania basins and structural episodes in the surrounding thrust belts pointing to an intrinsic mechanical coupling with these basins the orogen and its foredeep basin inversion taking place during the pliocene quaternary times in the entire carpathians pannonian system is related to changes in the regional stress field leading to differential vertical movements associated with a laterally variable folding mechanism active in the entire system short crustal folding patterns alternate with lithospheric wavelengths in the se carpathians foreland east and south carpathians transylvania and pannonian basins the lateral variability is the result of a marked contrast in rheology between these areas directly related to the crustal configuration thermal properties and late stage collision kinematics with the carpathians foreland lateral variations in the properties of the downgoing plates largely control the collision mode in the carpathians and the post collisional evolution of the entire system

the role of external environmental factors in changing eruption styles of monogenetic volcanoes in a mio pleistocene continental volcanic field in western hungary abstract the occurrence shape structure and eruption style of monogenetic volcanoes such as maars tuff rings tuff cones and scoria cones are generally governed by several internal composition of the magma magmatic flux ascent rate viscosity volatile contents and external conditions regional and local tectonics topography and the presence of surfacial ground and meteoric water these controlling factors are together responsible for the eruption style distribution pattern volcanic facies architecture and morphology of the monogenetic volcanic landforms the late miocene to pleistocene bakony balaton highland volcanic field bbhvf in western hungary is a typical small sized at least 6 volcanic cycles have been identified by cluster analysis time gap between the cycles were vary from 1 66 up to 0 06 ma while the average eruption recurrence rate was 0 1078 ma event the time volume diagram of the volcanism of bbhvf have shown time predictive behavior combined with low magma flux total preserved volume 2 867 km3 and output rates 0 53 km3 ma for the entire volcanic field and 0 90 km3 ma for the last 5 cycles suggesting that volcanism was largely tectonically controlled and not magmatically controlled furthermore the topographic differences between the northern elevated and southern basin like parts of the volcanic field are also important in local differences in dominant fragmentation style because the elevated part of the field was prone to host large more magmatically evolved volcanoes than on the lower water saturated unconsolidated sediments which favored to the magma water interaction driven phreatomagmatic fragmentation the third controlling parameter which seems to play an important role in controlling the eruptive style of monogenetic volcanism at bbhvf was the paleoclimate fluctuation especially during the time interval of 3 0 to 2 5 ma thus mainly the long term environmental changes e g aridification have been response the shifting fragmentation style from phreatomagmatic to more magmatic ones

miocene phreatomagmatic volcanism at tihany pannonian basin hungary abstract a late miocene 7 56 ma maar volcanic complex tihany maar volcanic complex tmvc is preserved in the pannonian basin and is part of the bakony balaton highland volcanic field base surge and fallout deposits were formed around maars by phreatomagmatic explosions caused by interactions between water saturated sediments and alkali basalt magma carrying peridotite lherzolite xenoliths as well as pyroxene and olivine megacrysts subsequently nested maars functioned as a sediment trap where deposition built up gilbert type delta sequences at the onset of eruption magma began to interact with a moderate amount of groundwater in the water saturated sand as eruption continued phreatomagmatic blasts excavated downward into limestones providing access to abundant karst water and deeper to sandstones and schist both providing large amount of fracture filling water at the surface this wet eruption led to the emplacement of massive tuff breccias by fall surge mudflow and gravity flow deposition the nature of the tmvc maar eruptions and their deposits appears to depend on the hydrological condition of the karst and or fracture filling aquifer which varies seasonally with rainfall and spring runoff the west and east maar volcanoes of tmvc are interpreted to represent low water input from the karst and or fracture filling aquifer summer vent whereas the east maar is interpreted to have formed when abundant karst and or fracture filling water was available spring vent

in situ dynamic piezocone penetrometer tests in natural clayey soils a reappraisal of strain rate corrections cone penetration testing with pore pressure measurement cptu is a cost and time efficient way of collecting in situ geotechnical parameters of near surface marine soils for cable and pipeline tr

eruptive and depositional history of a pliocene tuff ring that developed in a fluvio lacustrine basin kissomlyo volcano western hungary abstract kissomlyo volcano is a pliocene erosion remnant of an alkaline basaltic tuff ring belonging to the little hungarian plain volcanic field late miocene shallow subaqueous fluvio lacustrine sand and mud units underlie sub horizontally bedded lapilli tuff and tuff beds with an erosional contact the pyroclastic units a sequence up to 20 m thick constitute a semi circular mound with gentle

geochemistry and tectonic development of cenozoic magmatism in the carpathian pannonian region this review considers the magmatic processes in the carpathian pannonian region cpr from early miocene to recent times as well as the contemporaneous magmatism at its southern boundary in the dinaride and balkans regions this geodynamic system was controlled by the cretaceous to neogene subduction and collision of africa with eurasia especially by adria that generated the alps to the north the dinaride hellenide belt to the east and caused extrusion collision and inversion tectonics in the cpr this long lived subduction system supplied the mantle lithosphere with various subduction components the cpr contains magmatic rocks of highly diverse compositions calc alkaline k alkalic ultrapotassic and na alkalic all generated in response to complex post collisional tectonic processes these processes formed extensional basins in response to an interplay of compression and extension within two microplates alcapa and tisza dacia competition between the different tectonic processes at both local and regional scales caused variations in the associated magmatism mainly as a result of extension and differences in the rheological properties and composition of the lithosphere extension led to disintegration of the microplates that finally developed into two basin systems the pannonian and transylvanian basins the southern border of the cpr is edged by the adria microplate via sava and vardar zones that acted as regional transcurrent tectonic areas during miocene recent times major trace element and isotopic data of post early miocene magmatic rocks from the cpr suggest that subduction components were preserved in the lithospheric mantle after the cretaceous miocene subduction and were reactivated especially by extensional tectonic processes that allowed uprise of the asthenosphere changes in the composition of the mantle through time support geodynamic scenarios of post collision and extension processes linked to the evolution of the main blocks and their boundary relations weak lithospheric blocks i e alcapa and western tisza generated the pannonian basin and the adjacent styrian transdanubian and z rand basins which show high rates of vertical movement accompanied by a range of magmatic compositions strong lithospheric blocks i e dacia were only marginally deformed where strike slip faulting was associated with magmatism and extension at the boundary of adria and tisza dacia strike slip tectonics and core complex extension were associated with small volume miocene magmatism in narrow extensional sedimentary basins or granitoids in core complex detachment systems along older suture zones sava and vardar accommodating the extension in the pannonian basin and afterward pliocene quaternary inversion magmas of various compositions appear to have acted as lubricants in a range of tectonic processes

40 ar 39 ar ages of tephras intercalated in astronomically tuned neogene sedimentary sequences in the eastern mediterranean we present new 40 ar 39 ar data for sanidine and biotite derived from volcanic ash layers that are intercalated in pliocene and late miocene astronomically dated sequences in the mediterranean with the aim to solve existing inconsistencies in the intercalibration between the two independent absolute dating methods 40 ar 39 ar sanidine ages are systematically younger by 0 7 2 3 than the astronomical ages for the same ash layers the significance of the discrepancy disappears except for the upper ptolemais ashes which reveal the largest difference if an improved full error propagation method is applied to calculate the absolute error in the 40 ar 39 ar ages the total variance is dominated by that of the activity of the decay of 40 kt o 40 ar f70 and that the amount of radiogenic 40 arp in the primary standard ga1550 biotite f15 if the 40 ar 39 ar ages are calculated relative to an astronomically dated standard the influence of these parameters is greatly reduced resulting in a more reliable age and in a significant reduction of the error in 40 ar 39 ar dating astronomically calibrated ages for taylor creek rhyolite tcr and fish canyon tuff fct sanidine are 28 53f0 02 and 28 21f0 04 ma f1 s e respectively if we start from the more reliable results of the cretan a1 ash layer the most likely explanation for the large discrepancy found for the younger ptolemais ash layers equivalent to fct of 28 61 ma is an error in the tuning of this part of the sequence d 2004 elsevier b v all rights reserved

intraplate volcanism in the danube basin of nw hungary 3d geophysical modelling of the late miocene pasztori volcano three dimensional geophysical modelling of the early late miocene pasztori volcano ca 11 10 ma and adjacent area in the little hungarian plain volcanic field of the danube basin was carried out to get an insight into the most prominent intra crustal structures here we have used gridded gravity and magnetic data interpreted seismic reflection sections and borehole data combined with re evaluated geological constraints based on petrological analysis of core samples from available six exploration boreholes the volcanic rocks consist of a series of alkaline trachytic and trachyandesitic volcanoclastic and effusive rocks the measured magnetic susceptibilities of these samples are generally very low suggesting a deeper magnetic source the age of the modelled pasztori volcano buried beneath a 2 km thick late miocene to quaternary sedimentary sequence is 10 4 0 3 ma belonging to the dominantly normal c5 chron our model includes crustal domains with different effective induced magnetizations and densities uppermost 0 3 1 8 km thick layer of volcanoclastics underlain by a trachytic trachyandesitic coherent and volcanoclastic rock units of a maximum 2 km thickness with a top situated at minimal depth of 2 3 km and a deeper magmatic pluton in a depth range of 5 15 km the 3d model of the danube basin is consistent with observed high z magnetic anomalies above the volcano while the observed bouguer gravity anomalies correlate better with the crystalline basement depth our analysis contributes to deeper understanding of the crustal architecture and the evolution of the basin accompanied by alkaline intraplate volcanism

towards a mechanical model for the formation of the pannonian basin abstract new maps showing crustal and lithospheric thickness variations in the pannonian basin and the surrounding east alpine carpathian and dinaric mountains have been prepared on the basis of recent seismic seismologic and electromagnetic data a map presenting miocene faults of regional significance has been also constructed for the same region by using a wealth of recently available national and or more local studies it is suggested that observed crustal and lithospheric structural contrasts have been controlled primarily by neogene kinematic history of the region kinematic history is characterized by the following main patterns 1 1 indentation by adria and large scale backthrusting in the southern alps 2 2 eastward escape and extension of the eastern alps 3 3 extensional collapse in the pannonian basin area 4 4 formation of broad wrench fault systems along strike in the dinarides and southern carpathians and the western carpathians with dextral and sinistral shear respectively 5 5 compression and accretion of the external thrust and fold belt in the eastern carpathians these kinematic patterns are thought to be interrelated and all are manifestations of the late stage evolution of an overthickened orogenic wedge in order to arrive at a better understanding of the mechanism of extension which formed the pannonian basin deep crustal seismic profiles hydrocarbon exploration reflection lines and borehole data have been analyzed in the little hungarian plain this plain represents the transition zone between the alps and the pannonian lowlands and the results are illustrated by eight interpreted cross sections one result of regional importance is the clear recognition that the transdanubian central range at the southeastern flank of the little hungarian plain is composed of alpine pre senonian thrust sheets this finding marks the end of a century of debate the allochthony of the substrata of the pannonian basin can be now considered proven another result of more general interest is that these cross sections document the mode of lithospheric extension preexisting compressional detachment planes reactivate as low angle normal faults and lead to tectonic unroofing of deeply buried metamorphic terranes characterized by ductile flow along subhorizontal lineation

displacement rate effects during t bar cycling in remoulded gulf of mexico clay the influence of the displacement rate of a t bar on the remoulded shear strength of a soft natural lightly overconsolidated marine clay is investigated a series of t bar cyclic tests was carried out in 12 box cores collected from the gulf of mexico one general equation relating the displacement rate to the remoulded strength is presented which provides insight on rate effects for remoulded clays and which can be used to correct for remoulded penetration resistance data for natural soft clays for a t bar recorded at displacement rates other than the commonly used displacement rate of 0 020 m s

radioisotopic dating of the tortonian global stratotype section and point implications for intercalibration of 40ar 39ar and astronomical dating methods in this paper we present new 40 ar 39 ar data of volcanic ash layers intercalated in the astronomically dated sections of monte dei corvi and monte gibliscemi italy to obtain better radioisotopic time constraints on the serravallian tortonian boundary and to confirm the intercalibration of radioisotopic and astronomical time proposed by kuiper et al 2004 fish canyon tuff fct sanidine at 28 21 0 03 ma the latter intercalibration is supported by astronomically calibrated fct sanidine ages for two ash layers at monte gibliscemi gif 1 28 28 0 04 gid 3 28 16 0 04 ma 1 se as a consequence our results support the astronomically calibrated age of 11 608 ma for the tortonian global stratotype section and point and hence the tuning of the serravallian tortonian boundary interval the ancona and respighi levels at monte dei corvi give a more diffuse picture possibly because of contamination with detrital or xenocrystic material and the inferior quality of biotite for intercalibration

mantle plumes and flood basalt stratigraphy in the parana south america geochemical studies of the parana continental flood basalts in brazil have led to the recognition of distinct magma types which have been used to infer the internal stratigraphy of the lava pile the overstepping of stratigraphic units toward the north and a similar compositional change in sills within the underlying parana basin sedimentary rocks imply that the site of magnatism migrated 750 km toward the north during this volcanic event this has important implications for recent plume related models that have argued whether fithospheric rifting must accompany the presence of a mantle plume in order to generate continental flood basalt magmatism it is difficult to ascribe the magnitude and direction of the shift in the locus of the parana magmatism to movement of the brazilian lithosphere relative to the underlying tristan mantle plume instead it is suggested that the observed lava distribution and internal structure of the parana etendeka flood basalt province were imposed by the intracacies of the rifting process during the initial opening of the south atlantic ocean

age of the el golfo debris avalanche el hierro canary islands new contraints from laser and furnace 40ar 39 ar dating abstract the life cycle of ocean island volcanoes is commonly punctuated by large scale flank collapse events which may generate far reaching tsunami estimates exist though are poorly constrained for worldwide recurrence time intervals of giant landslides however individual events are often difficult to date the el golfo debris avalanche on the island of el hierro canary islands is a young feature although its exact formation age remains elusive using both furnace and laser heating 40 ar 39 ar dating techniques on groundmass separates we obtained new ages for the altitudinally highest lava flows cut by the el golfo landslide headwall as well as a post collapse lava flow erupted from within the embayment the new data significantly improve limits on the age of the debris avalanche which we propose occurred between 87 8 ka and 39 13 ka ago this age range raises doubts on the previously proposed correlation between this event and the glacial to interglacial transition at 130 ka

tertiary mineralization and magmatism east greenland lead isotope evidence for remobilization of continental crust abstract well defined lead isotope signatures of sulphides from mineral occurrences associated with tertiary igneous rocks in east greenland fall in two distinct groups 1 sulphide samples from the region south of scoresby sund kangerlussuaq igneous complex have lead characterized by retarded uranogenic evolution and slightly elevated thorogenic isotopic ratios 2 sulphide samples from the region north of scoresby sund werner bjerge kap simpson and kap broer ruys igneous complexes have lead compositions typical of modern average terrestrial lead these distinct signatures in both conventional and 208 pb 204 pb 207 pb 204 pb diagrams lie within linear trends defined by previously published lead isotope data for unmineralized tertiary basalts and intrusive rocks the linear trends are mixing lines between the lead in the tertiary mantle derived magmas and lead remobilized from continental crust tertiary magmas in the region south of scoresby sund remobilized and incorporated lead from low high 208 pb 204 pb crustal sources similar in isotope composition to archaean high grade metamorphic gneisses exposed in the area non to sub parallel distinct lead mixing lines in the 208 pb 204 pb 206 pb 204 pb diagram for the tertiary igneous complexes in this region suggest strong heterogeneity of the remobilized crust more than one half of the lead from sulphide mineral occurrences within the kangerlussuaq alkaline intrusive complex may be derived from local continental crust in the region north of scoresby sund the tertiary magmas remobilized moderately radiogenic lead from local basement and sedimentary basins palaeoproterozoic mesoproterozoic gneisses neoproterozoic ordovician sediments caledonian granites and palaeozoic mesozoic sediments these crustal rocks lack the very low 206 pb 204 pb and 207 pb 204 pb ratios typical of the gneisses from the kangerlussuaq region and mixing trends between mantle derived and crustal lead are therefore much less extensive however because the mantle derived magmas had very low total lead contents even small additions of crustal lead are traceable sulphide mineralized alkaline intrusive complexes are shown to be highly contaminated with crustal lead and it is further shown that the pre tertiary rocks of north east greenland are likely local crustal sources of lead for contaminated tertiary plateau basalts many stratabound sediment hosted hydrothermal base metal occurrences in the palaeozoic mesozoic jameson land basin are thought to be tertiary in age but do not appear to contain tertiary igneous derived lead on the contrary the hydrothermal alteration zones associated with several of the mineralized tertiary igneous complexes attest to extensive fluid rock mass transfer lead and other base metals were leached from the country rocks homogenized and incorporated into sulphide minerals

scales of columnar jointing in igneous rocks field measurements and controlling factors columnar jointing is a common feature of solidified lavas sills and dikes but the factors controlling the characteristic stoutness of columns remain debated and quantitative field observations are few in number in this paper we provide quantitative measurements on sizing of columnar joint sets and our assessment of the principal factors controlling it we focus on 1 chemistry as it is the major determinant of the physical mechanical and thermal properties of the lava and 2 geology as it influences the style of emplacement and lava geometry setting boundary conditions for the cooling process and the rate of heat loss in our analysis we cover lavas with a broad range of chemical compositions from basanite to phonolite for six of which we provide new geochemical analyses and of geological settings our field measurements cover 50 columnar jointing sites in three countries we provide reliable manually digitized data on the size of individual columns and focus the mathematical analysis on their geometry 23 889 data on side length of which 17 312 are from full column sections and 3 033 data on cross sectional area and order of polygonality the geometrical observations show that the variation in characteristic size of columns between different sites exceeds one order of magnitude side length ranging from 8 to 338 cm and that the column bounding polygons average order is less than 6 the network of fractures is found to be longer than required by a minimum energy hexagonal configuration indicating a non equilibrium geologically quick process in terms of the development and characteristic sizing of columnar joint sets our observations suggest that columns are the result of an interplay between the geological setting of emplacement and magma chemistry when the geological setting constrains the geometry of the emplaced body it exerts a stronger control on characteristic column stoutness at unconstrained geometries e g unconfined lava flows chemistry plays the major role resulting in stouter columns in felsic lavas and slenderer columns in mafic lavas

an outline of neotectonic structures and morphotectonics of the western and central pannonian basin abstract neotectonic deformation in the western and central part of the pannonian basin was investigated by means of surface and subsurface structural analyses and geomorphologic observations the applied methodology includes the study of outcrops industrial seismic profiles digital elevation models topographic maps and borehole data observations suggest that most of the neotectonic structures in the pannonian basin are related to the inverse reactivation of earlier faults formed mainly during the miocene syn and post rift phases typical structures are folds blind reverse faults and transpressional strike slip faults although normal or oblique normal faults are also present these structures significantly controlled the evolution of landforms and the drainage pattern by inducing surface upwarping and river deflections our analyses do not support the postulated tectonic origin of some landforms particularly that of the radial valley system in the western pannonian basin the most important neotectonic strike slip faults are trending to east northeast and have dextral to sinistral kinematics in the south western and central eastern part of the studied area respectively the suggested along strike change of kinematics within the same shear zones is in agreement with the fan shaped recent stress trajectories and with the present day motion of crustal blocks derived from gps data

blocky versus fluidal peperite textures developed in volcanic conduits vents and crater lakes of phreatomagmatic volcanoes in mio pliocene volcanic fields of western hungary abstract volcanic fields in the pannonian basin western hungary comprise several mio pliocene volcaniclastic successions that are penetrated by numerous mafic intrusions peperite formed where intrusive and extrusive basaltic magma mingled with tuff lapilli tuff and non volcanic siliciclastic sediments within vent zones peperite is more common in the pannonian basin than generally realised and may be also important in other settings where sediment sequences accumulate during active volcanism hajagos hegy an erosional remnant of a maar volcano was subsequently occupied by a lava lake that interacted with unconsolidated sediments in the maar basin and formed both blocky and globular peperite similar peperite developed in kissomlyo a small tuff ring remnant where dykes invaded lake sediments that formed within a tuff ring lava foot peperite from both hajagos hegy and kissomlyo were formed when small lava flows travelled over wet sediments in craters of phreatomagmatic volcanoes at sag hegy a large phreatomagmatic volcanic complex peperite formed along the margin of a coherent intrusion all peperite in this study could be described as globular or blocky peperite globular and blocky types in the studied fields occur together regardless of the host sediment

early tertiary magmatism in ne greenland abstract between 73 and 74 n in ne greenland a lower series of quartz tholeiite lavas is overlain by an upper series which varies from quartz tholeiitic to basanitic the lower series basalts are attributed to large melt fractions produced east of the present outcrop where lithospheric thinning permitted the iceland plume to ascend to shallow levels relocation of eruption sites up to 150 km further west preceeded upper series activity in this small degree melts generated principally from garnet lherzolite facies sources were followed by products of more extensive shallower melting which gave rise successively to the upper series lavas a post upper series basaltic dyke swarm and its associated caldera complex palaeomagnetic observations and 40 ar 39 ar dating suggest that the lower series and part of the upper series erupted in c24r at 58 57 ma rejuvenescent activity at c 32 ma marking the termination of volcanism may relate to decompressive mantle melting associated with late regional uplift

paleogeographic evolution of the late miocene lake pannon in central europe abstract the paleogeographic evolution of lake pannon within the pannonian basin is reconstructed with eight maps ranging from the middle miocene to the early pliocene the maps are based on the distribution of selected biozones and specific fossils and on complementary sedimentological and seismic information our reconstruction shows that the history of lake pannon can be divided into three distinct intervals an initial stage with low water level which resulted in isolation from the sea at about 12 ma and might have led to temporary fragmentation of the lake an interval of gradual transgression lasting until ca 9 5 ma and a long late interval of shrinkage and infilling of sediments that persisted into the early pliocene the deep subbasins of the lake formed during the transgressive interval in more basinward locations than the deep basins of the preceding sarmatian age the southern shoreline running parallel with the sava and danube rivers along the northern foot of the dinarides changed very little during the lifetime of the lake while the northern shoreline underwent profound changes

pile and penetrometer end bearing resistance in two layered soil profiles the paper examines the influence of soil strength and stiffness on the end resistance mobilised by a cone or displacement pile in a two layered soil profile i e strong soil overlying or underlying weak soil the investigation involved a series of numerical analyses that idealise pile cone penetration assuming the spherical cavity expansion analogue it is shown how the end resistance mobilised by a penetrometer in a dense sand i e strong soil varies with the number of penetrometer diameters d from a weak soil assumed here to be either a loose sand or soft clay and depends on the ratio of the steady state penetration resistances of the strong and weak layers the penetrometer resistance in the weak soil is not affected by an adjacent strong layer at penetrations greater than 2d a design procedure based on a numerical parametric study is proposed and this is subsequently shown to compare well with centrifuge test data and with previous numerical research

volcanism and paleoenvironment of the pula maar complex a pliocene terrestrial fossil site in central europe hungary abstract we describe the late pliocene paleoenvironment and paleoclimate of the pula fossil site of the western pannonian basin hungary which occurs within a lacustrine succession deposited in a volcanic crater maar radiometric dating of adjacent volcanic bodies hosting the fossil bearing sedimentary assemblages gives an age of 4 25 0 17 ma k ar to date five articulated rhinoceros skeletons dihoplus sp have been recovered and a few fragmentary remains of artiodactyls and freshwater fishes perca sp leuciscus sp and gobius sp are also present an insect taphocoenosis comprises terrestrial groups that inhabited the former lake margins syrphidae heteroptera chalcidoidea tenebrionidae as well as aquatic insects dytiscidae baetidae and chironomidae deciduous broad leaved woody plants prevailed in and around the pula locality quercus ulmus zelkova acer salicaceae and are associated with some rare floral elements ginkgo sassafras and buxus deposition at the lake bottom seems to have taken place in oxygen depleted layers and taphonomic evidence indicates that fossil material underwent minimal if any weathering 13c values of one rhinoceros tooth suggest that this mammal consumed mixed c3 plants in a wooded environment the climatic conditions inferred from the reconstructed vegetation and stable oxygen isotope data from the tooth enamel support a cf type climate koppen classification with a mean annual temperature of 10 13 c with some dry periods during the year pula is comparable to other maar fossil sites of pliocene age such as camp dels ninots spain and hajnacka i slovakia

depositional architecture of a maar pitted playa sedimentation in the hopi buttes volcanic field northeastern arizona u s a abstract primary and reworked tephra in the mio pliocene bidahochi formation of northeastern arizona was produced by and partly preserved in maar volcanoes and related hydrovolcanic structures the temporal and geometric relationships among lithofacies of the bidahochi formation illustrate the dynamic interplay between volcanism and sedimentation in an essentially closed sedimentary system maar volcanism in the low relief basinal environments of the bidahochi appears to have resulted in little net aggradation both because the total amount of magma erupted was relatively modest and because the large maar volcano craters produced areas of lowered base level within the basin that formed sediment sinks for much of the newly erupted tephra the volcanically eroded maar craters commonly contain deposits of lakes multiple stream channels and eolian dunes they formed an integral part of the basin s overall depositional environment and affected sedimentation in the playa lake stream systems beyond the vents both during and following the major eruptive period

a release to rest model for dynamically installed anchors abstractdynamically installed anchors are torpedo shaped anchors that are installed by dropping them through the ocean such that they self bury in the soft seabeds typically encountered in deep wat

review of neogene and quaternary volcanism of the carpathian pannonian region abstract development of the pannonian basins as well as thrusting and folding of the carpathians was accompanied by widespread volcanic activity this volcanism can be divided into three main genetic types 1 1 early miocene mainly acidic volcanism tuffs and ignimbrites the recent spatial separation of these volcanics may be due to large right lateral displacement along the mid hungarian shear zone during the early miocene 2 2 middle miocene pliocene calc alkaline mainly intermediate stratovolcanic complexes in the inner western carpathians and in the east carpathians related to a subducted oceanic slab their geochemical compositions show a transitional character between active continental margin and island arc type magmatic rocks the thickness of the crust increased with time and from west to east beneath this volcanic arc 3 3 pliocene pleistocene alkali basaltic volcanism was related to an upwelling then cooling asthenospheric dome this is thought to have initiated the thermal regime from which these melts ascended the compositional difference in space and in time might reflect the existence of local individual small sized diapiric bodies as well as several processes e g fractional crystallization mixing which modified the original magma the eruption of these basaltic melts was temporally associated with the final phase of development of the pannonian basin this volcanism was associated with recent uplifts and tectonic rejuvenation of the area

calibration chamber tests of a cone penetrometer in sand the results of a series of tests using a cone penetrometer in sand in a large calibration chamber are reported sand at three different densities and a range of stress states was studied the principal finding from the tests is that cone resistance in sand depends primarily on the horizontal stress and the angle of friction but is relatively unaffected by the vertical stress a relationship between qc h and tc is proposed and compared with previous work in calibration chambers l article presente les resultats d une serie d essais effectues avec un penetrometre a cone dans du sable dans une chambre d etalonnage le sable a ete etudie avec trois densites differentes dans un intervalle d etats de contrainte les essais ont demontre surtout que la resistance au cone dans le sable depend d abord de la contrainte horizontale et de l angle de friction mais reste relativement peu influencee par la contrainte verticale on propose une relation entre qc h et tc et on la compare avec des recherches anteri

age of the cretaceous alkaline magmatism in northeast iberia implications for the alpine cycle in the pyrenees cretaceous magmatism in northeast iberia is related to the opening of the bay of biscay and counterclockwise rotation of iberia with respect to europe and predates the collision between iberia and europe that resulted in the formation of the pyrenees to better constrain the age of this magmatism we have undertaken a ar ar study on samples from the pyrenees and the catalonian coastal ranges in the basque cantabrian basin and the north pyrenean basins we have obtained albian ages ca 102 ma in the northern catalonian coastal ranges we have obtained campanian ages ca 79 ma we integrate our data with a review of previously published ages and discuss our results in terms of their geodynamic significance the cretaceous magmatism in the pyrenees is albian santonian mostly occurring between 105 to 85 ma and was emplaced in a tectonically unclear context after the opening of the bay of biscay and rotation of iberia the magmatism in the catalonian coastal ranges is well constrained to ca 79 ma and could mark the onset of alpine shortening in the pyrenean realm in northeasternmost iberia finally we describe a late triassic ca 232 ma early jurassic ca 180 ma phase of magmatism in the central pyrenees previously considered to be cretaceous that widens temporally and geographically the extent of the rift related alkaline magmatism in southwestern europe at that time key points new ar ar data update the age of the cretaceous magmatism in ne iberia magmatism in the pyrenees postdates the rotation of iberia magmatism in the catalonian coastal ranges could mark the onset of alpine shortening

generation and polybaric differentiation of east greenland early tertiary flood basalts major element trace element isotope and petrographic studies of magma diverentiation mantle melting the basal volcanics in the kangerdlugssuaq fjord region of the east greenland margin provide constraints on the generation and subsequent diverentiation and contamination histories of magmas during the early stage of continental rifting creating the north atlantic ocean basin most primitive lavas of the succession are introduction shown to have accumulated olivine corrections for crystal ac the distinctive geochemical features of continental flood cumulation yield estimates for erupted primitive liquids with mgo basalts cfbs are strongly controlled by the composition contents between 9 and 13 wt the occurrence of suspended and structure of the continental lithosphere and underfo88 olivine phenocrysts further requires the existence of parental lying mantle significant controversy remains concerning magmas with mgo contents up to 17 wt and feo contents up the balance of contributions from the lithosphere and to 14 wt quantitative modeling of fractionation indicates the mantle and the mechanisms by which the various that kangerdlugssuaq magmas primarily diverentiated at moderate source components contribute to basalt petrogenesis pressures 8 kbar to form dunitic and wehrlitic cumulates at how are basalt compositions influenced by generation depths of 25 km evolved east greenland flood basalts from the in anomalous regions in the deep mantle plumes by scoresby sund region record a more complex fractionation history interaction between rising magmas and the continental involving olivine clinopyroxene fractionation in the lower crust lithospheric mantle and by contamination with conas found for the lower basalts followed by olivine plagioclase tinental crust how are the diverentiation con clinopyroxene fractionation at shallow crustal levels cor tamination magma mixing and storage histories of cfbs relations between sio2 incompatible elements and sr nd isotopic controlled by the structure of the continental lithosphere ratios for the lower basalts are consistent with bulk assimilation and how do the thermal and chemical features of the of up to 15 20 archean leucogneiss with unradiogenic sr and mantle and the extensional history of the continental nd isotopic ratios characteristic of lewisian type lower crust lithosphere avect mantle melting and compositions of comparisons between inferred magma types for lower basalts and primary liquids estimated primary liquids from elsewhere in the north atlantic these questions are best addressed in the context of show complex relationships among feo mgo tio2 contents a geologically and geochemically well constrained cfb and cao al2o3 ratios that relate to regional and temporal changes province such as the north atlantic tertiary province in mantle temperatures lithospheric thickness and involvement of separation of east greenland from northern europe in at least two end member mantle sources we postulate that the the early tertiary at 60 myr ago was accompanied by lower basalts of east greenland were derived from iron poor voluminous volcanic activity the blosseville coast of mantle depleted by prior melt extraction and distinct from morb east greenland extending from kangerdlugssuaq fjord source mantle that was enriched in tio2 and lrees by a to scoresby sund fig 1 contains spectacularly exposed metasomatic event shortly before early tertiary magmatism we sections of lavas these sections begin at the basal contact associate this depleted mantle source with the ancestral iceland of the lavas with underlying cretaceous tertiary sediments and archean basement and continue to the plume anomaly

on the origin and fluid content of some rare crustal xenoliths and their bearing on the structure and evolution of the crust beneath the bakony balaton highland volcanic field w hungary rarely occurring clinopyroxene plagioclase bearing felsic granulite and skarn xenoliths were studied from the mantle and crustal xenolith bearing alkaline basaltic and pyroclastic localities of the bakony balaton highland volcanic field w hungary geobarometry and geothermometry of the xenoliths made it possible to categorise them in three groups according to their depth of formation the first group formed in the lower crust together with mafic and metasedimentary granulites the second group represents magmatic intrusions of the middle crust and the third one comprises contact metamorphic rocks of relatively shallow origin the calculated pressure difference from the core and rim compositions of plagioclase and clinopyroxene as well as garnet breakdown reactions in some xenoliths show evidence for pressure decrease due to crustal thinning both in lower crustal and middle crustal xenoliths during formation of the pannonian basin fluid inclusion studies reveal the dominance of the co2 rich fluids in the whole crustal section in contrast with fluids found in mafic garnet bearing xenoliths crustal stratigraphy was constructed for the periods prior to the extension and after the extension on the basis of geobarometry and geophysical data on the basis of mineral stabilities and geothermo barometry we estimated that the pre extensional thickness of the lower and upper crust may have been 27 34 and 26 28 km respectively comparison of pre extensional and present day thickness of the lower and upper crust indicate that thinning affected both the lower and the upper portion of the crust but on a different scale the calculated thinning factors are between 2 25 and 3 4 for the lower crust and 1 3 1 56 for the upper crust

40ar 39ar geochronology of neogene phreatomagmatic volcanism in the western pannonian basin hungary abstract neogene alkaline basaltic volcanic fields in the western pannonian basin hungary including the bakony balaton highland and the little hungarian plain volcanic fields are the erosional remnants of clusters of small volume possibly monogenetic volcanoes moderately to strongly eroded maars tuff rings scoria cones and associated lava flows span an age range of ca 6 myr as previously determined by the k ar method high resolution 40 ar 39 ar plateau ages on 18 samples have been obtained to determine the age range for the western pannonian basin neogene intracontinental volcanic province the new 40 ar 39 ar age determinations confirm the previously obtained k ar ages in the sense that no systematic biases were found between the two data sets however our study also serves to illustrate the inherent advantages of the 40 ar 39 ar technique greater analytical precision and internal tests for reliability of the obtained results provide more stringent constraints on reconstructions of the magmatic evolution of the volcanic field periods of increased activity with multiple eruptions occurred at ca 7 95 ma 4 10 ma 3 80 ma and 3 00 ma these new results more precisely date remnants of lava lakes or flows that define geomorphological marker horizons for which the age is significant for interpreting the erosion history of the landscape the results also demonstrate that during short periods of more intense activity not only were new centers formed but pre existing centers were rejuvenated

distinct kimberlite pipe classes with contrasting eruption processes abstract field and scott smith field m scott smith b h 1999 contrasting geology and near surface emplacement of kimberlite pipes in southern africa and canada proc 7th int kimb conf eds gurney et al 1 214 237 propose that kimberlite pipes can be grouped into three types or classes classical or class 1 pipes are the only class with characteristic low temperature diatreme facies kimberlite in addition to hypabyssal and crater facies kimberlite class 2 and 3 pipes are characterized only by hypabyssal and crater facies kimberlite in an increasing number of class 1 pipes a new kimberlite facies transitional facies kimberlite is being found in most cases this facies forms a zone several metres wide at the interface between the hypabyssal and diatreme facies the transitional facies exhibits textural and mineralogical features which are continuously gradational between the hypabyssal and the diatreme types the textural gradations are from a coherent magmatic texture to one where the rock becomes increasingly magmaclastic and this is accompanied by concomitant mineralogical gradations involving the decline and eventual elimination of primary calcite at the expense of microlitic diopside both transitional and diatreme facies kimberlites are considered to have formed in situ from intruding hypabyssal kimberlite magma as a consequence of exsolution of initially co 2 rich volatiles from the volatile rich kimberlite magma the transitional facies is initiated by volatile exsolution at depths of about 3 km below the original surface with subsequent cracking through to the surface and resultant rapid decompression the further catastrophic exsolution of volatiles and their expansion leads to the formation of the diatreme facies thus diatreme facies kimberlite and class 1 pipes are emplaced by essentially magmatic processes rather than by phreatomagmatism distinctly different petrographic features characterize crater facies kimberlite in each of the three pipe classes in crater facies kimberlites of class 1 pipes small pelletal magmaclasts and abundant microlitic diopside are characteristic these features appear to reflect the derivation of the crater facies material from the underlying diatreme zone most class 2 pipes have shallow craters and the crater facies rocks are predominantly pyroclastic kimberlites with diagnostic amoeboid lapilli which are sometimes welded and have vesicles as well as glass possible kimberlite lava also occurs at two class 2 pipes in n angola the possible presence of lava as well as the features of the pyroclastic kimberlite is indicative of hot kimberlite magma being able to rise to levels close to the surface to form class 2 pipes most class 3 kimberlites have very steep craters and crater facies rocks are predominantly resedimented volcaniclastic kimberlites in some cases characterized by the presence of abundant angular magmaclasts which are petrographically very similar to typical hypabyssal facies kimberlite found in class 1 pipes the differences in crater facies kimberlite of the three classes of pipe reflect different formation and depositional processes as well as differences in kimberlite composition specifically volatile composition kimberlite forming pipe classes 1 and 3 is thought to be relatively water rich and is emplaced by processes involving magmatic exsolution of volatiles the kimberlite magma forming class 2 pipes is co 2 rich can rise to shallow levels and can initiate phreatomagmatic emplacement processes

40ar 39ar constraints on the temporal evolution of graciosa island azores portugal lava flows spanning the eruptive record of graciosa island azores archipelago and a gabbro xenolith were dated by 40ar 39ar in order to constrain the pleistocene and holocene volcanic evolution of the island the results range from 1 05 ma to 3 9 ka whereas prior published k ar and 14c ages range from 620 to 2 ka the formation of the serra das fontes shield volcano started at minimum 1 05 ma and the magmatic system was active for ca 600 ky as suggested by the formation of the gabbro xenolith by magmatic differentiation evolved magmas making up the serra das fontes serra branca composite volcano were generated at ca 450 ka after a period of ca 110 ky of volcanic inactivity and erosion of volcanic edifices volcanism was reactivated with the formation of the vitoria unit nw platform later the development of the vulcao central unit started with the formation of monogenetic cones located to the south of the serra das fontes serra branca vitoria unit this volcanism became progressively more evolved and was concentrated in a main eruptive center forming the vulcao central stratovolcano with an age older than 50 ka the caldera related to this stratovolcano is older than 47 ka and was followed by effusion of basaltic magmas into the caldera resulting in the formation of a lava lake which ultimately spilled over the caldera rim at ca 11 ka the most recent eruptions on graciosa formed two small pyroclastic cones within the caldera and the pico do timao cone within the vitoria unit at ca 3 9 ka

bearing capacity and stiffness of embedded circular footings on stiff over soft clay abstractthis technical note presents results from a series of undrained load tests performed at model scale on circular embedded footings founded in a two layered stratigraphy comprising uniform s

the auckland volcanic field new zealand geophysical evidence for structural and spatio temporal relationships abstract geophysical data from the monogenetic auckland volcanic field reveal complex structural and spatio temporal relationships at different scales the volcanic field is coincident with regional magnetic and gravity anomalies that mark a major crustal suture and with a discontinuity marking a significant structural asperity here the linear regional magnetic anomaly splays into a wide band of nnw trending lineaments arising from serpentinised shear zones in the upper crust that matches the extent of the volcanic field and that may reflect a region of crustal weakness creating preferential permeability however there appears to be no simple correlation between the locations of individual vents and these lineaments that might delineate more shallow structural controls with this orientation probably as a consequence of other structural influences high resolution aeromagnetic data over the volcanic field show that the volcanoes have a wide range of magnetic signatures indicating a variability of subsurface structure scoria cone volcanoes typically have strong anomalies up to several 100 nt whilst tuff ring volcanoes typically have weak anomalies less than 50 nt though the surface geology is not always an indicator of the nature and extent of the subsurface deposits both cone and tuff ring volcanoes in the auckland field appear to be underlain by subsurface bowl shaped bodies of basalt implying that their eruption histories commonly involve lava ponding into early excavated craters the present geophysical data give no evidence for subsurface dyke like structures or for substantial near surface volumes of basaltic rocks where there are no known eruption centres or buried flows aeromagnetic and palaeomagnetic data suggest that a number of adjacent vents with an implied structural linkage may be contemporaneous though other examples occur where vents of clearly different ages exploit the same apparent structure a unique feature of the auckland field is that at least 5 widely separated and structurally unrelated volcanoes are contemporaneous these observations highlight the spatial and temporal heterogeneities that can occur in monogenetic fields and have an important bearing on recurrence rates and temporally linked eruptions which are probably more common than is generally supposed and are key factors in statistically based hazard assessments

rate effects on the vertical uplift capacity of footings founded in clay this paper describes results from a series of uplift tests performed in a drum centrifuge on shallow square footings founded on clay and sand with an overlying sand backfill the test series investigated footings of various widths loaded at displacement rates extending over five orders of magnitude additional tests were performed to examine the influence on uplift capacity of the direction of load inclination the uplift tests performed on footings founded on sand enabled estimations to be made of the suction that developed at the base of the footings founded on clay it is shown that the suction mobilised at very fast rates may be assessed using existing undrained bearing capacity approaches and a rate corrected operational undrained strength similar to that measured in triaxial extension the uplift rates required to reach fully undrained conditions are almost two orders of magnitude higher than those for footings loaded in compression and the upward footing displacements required to generate maxim

strength of fine grained soils at the solid fluid transition deepwater offshore oil and gas developments require an assessment to be made of the risk of infrastructure damage from submarine slides the likelihood and magnitude of submarine slides and the co

maar diatreme phreatomagmatism at hopi buttes navajo nation arizona usa remnants of an extensive maar diatreme volcanic field are magnificently exposed at various depths of erosion in the hopi buttes volcanic field of northeastern arizona field and petrographic studies of both the maar and diatreme elements of a selection of volcanoes within the field show that 1 lower sections of the maar rim sequences are typically rich in sandy mudrock derived from the pre eruptive mio pliocene bidahochi formation and the muddy bidahochi sediment was soft and wet at the time of maar eruptions 2 beds higher within the rims contain generally increased proportions of sandstone clasts from the triassic wingate formation in the diatremes late emplaced breccia has deeper seated lithics than more marginal breccia emplaced earlier and 3 many vents are topped by megacryst enriched scoria and spatter and deep seated xenoliths are known only from upper diatreme and craterfilling tephra these observations show that 1 eruptions at hopi buttes involved interaction of magma with unconsolidated mudrock at shallow levels and the phreatomagmatic processes that provided the bulk of the energy involved in the violent eruptions were driven by the interaction of magma and wet sediment 2 the locus of explosive activity migrated downward as eruptions progressed and 3 the closing stage of many eruptions was characterized by rapid magma rise and relative depletion of water

subjacent crustal sources of sulfur and lead in eastern great basin metal deposits sulfide minerals in mesozoic replacement skarn porphyry and vein deposits in lower paleozoic rocks in central and eastern nevada have sulfur isotope compositions 10 34 s 206 pb 204 pb 19 that are elevated relative to the range of s and pb isotope compositions in eastern great basin metal deposits the s and pb isotope compositions of central and eastern nevada mesozoic metal deposits e g eureka are similar to the s and pb isotope compositions of pyrite disseminated in the thick is less than or equal to 8 km terrigenous detrital succession tds of siliciclastic rocks of late proterozoic early cambrian age subjacent to the deposits tds rocks are therefore a possible source for most if not all s and pb in these deposits to the south and east in southern nevada southeastern california and western utah progressively thinner tds rocks correlate with lower 34 s values 206 pb 204 pb ratios s and pb isotope compositions of sulfide minerals in metal deposits that are temporally related to middle tertiary granitic intrusions also vary geographically and are generally lower than isotope compositions of mesozoic metal deposits regardless of paleozoic host rock age compared to the mesozoic deposits middle tertiary deposits in central and eastern nevada apparently derived significant but mostly smaller amounts of s and pb from tds rocks and or paleozoic rocks tertiary metal deposits in western utah may have obtained nearly all their s and pb from older precambrian crystalline rocks or from magmas and virtually none from tds and paleozoic rocks semiquantification of source rock contributions of s and pb to metal deposits is based on average s and pb isotope compositions of possible source rocks and simple mixing calculations possible source rocks are somewhat isotopically inhomogeneous but their s and pb isotope compositional ranges largely bracket the s and pb isotope compositions of metal deposits in the eastern great basin thus facilitating determination of end member contributions geologic factors that cause isotope inhomogeneity in both source rocks and metal deposits include different source rock provenances particularly for pb isotopes isotope mixing and fractionation by unrecognized hydrothermal processes metamorphism and tectonism that has juxtaposed potential source rocks of differing ages and isotope compositions tds pyrite formed from processes that produced s with high 34 s values including diagenesis involving seawater sulfate and at higher temperatures and greater depths thermochemical sulfate reduction radiogenic pb in tds pyrite was derived from leaching of quartzofeldspathic sedimentary rocks granitic melts acquired s and pb and possibly other ore forming components by bulk assimilation of tds and or paleozoic sedimentary rocks proterozoic crystalline rocks and possibly older precambrian rocks by volatilization of disseminated pyrite in source rocks during ascent and by hydrothermal circulation near the sites of ore deposition the high density of eastern great basin metal deposits and the sources of s and pb for these deposits appear to be a function not only of the large number of granitic intrusions but also of intrusion age and the thickness and type of precambrian crust s and pb isotope compositions in eastern great basin metal deposits support a proposed origin for jurassic cretaceous and tertiary intrusions that involves generation of magmas at different crustal levels and variable amounts of magmatic contamination by precambrian rocks

effects of pile shape and pile end condition on the lateral response of displacement piles in soft clay a series of lateral tests conducted in a centrifuge on displacement piles in kaolin is used to examine the effects of pile shape pile end condition and clay overconsolidation on the lateral load t

interpretation of cone penetration testing in silty soils conducted under partially drained conditions abstractthe standard penetration rate used in cone penetration tests cpts is 20 mm s regardless of soil type which yields fully drained penetration in sand and fully undrained penetration in clay however for silty soils that represent an intermediate grain size composition and unique characteristics compared with sand and clay the standard rate of penetration results in partially drained penetration often leading to misinterpretation of this soil type in this study 15 cpts with penetration rates varying from 0 5 to 60 mm s were performed at a test site in northern denmark where the subsoil consisted primarily of sandy silt with clay bands the results illustrated that when the penetration rate is reduced the cone resistance increases but the pore pressure decreases the transition between undrained and fully drained penetration was determined by converting the results into a normalized penetration rate also evaluated and presented in this paper is how cone resistance obtained under parti

effects of reconsolidation time on holding capacity of deepwater dynamically installed anchors a dynamically installed anchor dia is a practical and promising type of anchor for deepwater offshore engineering currently very few research studies have reported the effects of reconsolidatio

birth life and death of the pannonian lake abstract the miocene pliocene pannonian lake formed in an extensional basin system behind the compressional arc of the carpathians its size and depth were comparable to those of the caspian sea subsidence began in middle miocene times forming deep pelagic basins separated by reef bearing ridges clastic influx filled the marginal basins during middle miocene time prograding deltas dissected the lake and completed the infilling of the basin system by the end of the pliocene basin plain prodelta delta front delta plain beach fluviatile and marsh environments can be recognized terminal miocene uplift of the carpathians isolated the pannonian region from the rest of paratethys the subsequent decrease of salinity resulted in the evolution of an endemic freshwater mollusc fauna rich nutrient influx from rivers supported high organic productivity dinoflagellates diatoms nannoplankton foraminifers ostracods etc yielding organic rich sediments preservation of organic matter was helped by a stratified water column and oxygen deficient bottom conditions deep burial continuing subsidence and high geothermal flux due to an extremely thin crust led to the formation of commercially exploitable oil and gas accumulations shallow lacustrine zones of basin margins provided suitable environments for a rich congeria melanopsis mollusc fauna wave action on beaches produced commercially exploitable pure quartz sand deposits taxodium and alnus forests flourished around the lake producing enormous lignite deposits besides a rich land snail and mammal fauna prehominids lived in the forests there was a warm temperate climate with probably frostfree winters basaltic volcanoes overlooked the landscape and maars hosted minor lakes with rich algal flora forming oil shale the catchment area included most of the carpathians and parts of the apls and dinarides the positive water balance resulted in a supposed overflow in the southern margin supplying exotic fauna to the south carpathian and dacian basins of the eastern paratethys the pannonian lake was completely filled by the end of pliocene recent lakes in the carpathian basin are not descendants of it

discrete element model dem simulations of cone penetration test cpt measurements and soil classification this paper presents a study on the simulation of cone penetration tests cpts using the discrete element model dem method this study s main objective is to investigate the effect of different m

structural and morphometric irregularities of eroded pliocene scoria cones at the bakony balaton highland volcanic field hungary abstract scoria cones of the mio pliocene bakony balaton highland volcanic field bbhvf are built up by wide range of volcanic rocks including intercalated lava flows dykes pyroclastic breccias and scoriaceous lapilli with various degrees of welding or agglutination according to k ar and ar ar dating ages of the fourteen scoria cones within the field span between 5 2 and 2 5 ma from these fourteen seven cones were selected which are suitable for morphometric analysis i e visible in the field and have identifiable boundaries the morphometric data were either derived by manual measurement on topographic maps and by digital elevation model based calculations using the same input contour line data from 1 10 000 maps basic cone parameters such as cone height basal and crater width have been measured in order to calculate parameters like h co w co ratio and average slope angle the results of these three parameter based manual calculations have been compared to the dem based results in order to highlight the controls of degradation pitfalls in morphometric parameterization and the differences between these two calculation methods based on the results three main controlling conditions have been identified that are together responsible for the preservation and erosion of the scoria cones located in the bbhvf 1 age of the cone 2 climate during the degradation and the 3 inner architecture of the edifice in terms of morphometric dating the traditional three parameter based method tends to give inaccurate results on 1 scattered and or truncated cones and 2 on the edifices characterised by highly effusive behaviour during the emplacement

the influence of recent lead loss on the interpretation of disturbed upb systems in zircons from igneous rocks in east greenland abstract a series of caledonian igneous rocks from east greenland have been dated by means of u pb isotope determinations on zircons all discordias obtained give too low intercept ages in one case more than 200 ma younger than the rb sr mineral isochron age from the same sample leach experiments show that recent or subrecent loss of lead is responsible for the geologically meaningless ages obtained further it is shown that the recent lead loss is not caused by laboratory treatment but must be related to natural processes x ray investigations combined with transmission electron microscope analyses show a correlation between recent lead loss and the chemistry of the investigated zircons

paleomagnetism in lake pannon problems pitfalls and progress in using iron sulfides for magnetostratigraphy dating of upper miocene sediments of the pannonian basin hungary has proven difficult due to the endemic nature of biota scarcity of reliable radio isotopic data and generally inconsistent magnetostratigraphic results the natural remanent magnetization nrm is mostly residing in greigite fe3s4 which complicates nrm interpretation we reinvestigate the viability of these sediments for magnetostratigraphy using samples from recently drilled well cores paet 30 and paet 34 from the paks region significant intervals of the cores contain composite nrm behavior thermal demagnetization results include multipolarity m type samples consisting of a low temperature lt above 120 c a medium temperature mt and a high temperature ht component within distinct temperature ranges and all exhibiting dual polarities the lt and ht components have the same polarity and are antiparallel to the mt component rock magnetic and scanning electron microscopy results indicate that all magnetic components reside in authigenic greigite the lt and ht components represent the characteristic remanent magnetization and are of early diagenetic origin the mt component records a late diagenetic overprint alternating field demagnetization cannot resolve the individual components it yields polarities corresponding to the dominant component resulting in erratic polarity patterns interpretation of lt and ht components allows a reasonably robust magnetostratigraphic correlation to the geomagnetic polarity time scale with the base of paet 30 at 8 4 ma and its top at 6 8 ma average sedimentation rate of 30 cm kyr the base of paet 34 is correlated to 9 ma and its top to 6 8 ma average sedimentation rate of 27 cm kyr

shallow penetrometer tests theoretical and experimental modelling of the rotation stage shallow penetrometers are a new type of device that measures the properties of surficial offshore sediments via multi phase tests involving penetration dissipation and rotation stages in fine gr

40ar39ar geochronology of tertiary mafic intrusions along the east greenland rifted margin relation to flood basalts and the iceland hotspot track abstract the east greeland tertiary igneous province includes the largest exposed continental flood basalt sequence within the north atlantic borderlands more than ten layered gabbro complexes including the 55 ma skaergaard intrusion and a large dolerite sill complex are the plutonic equivalents of flood basalts both lavas and intrusions have been regarded as synchronous with continental breakup at 57 54 ma we report ten new ages of the mafic intrusions determined by40ar 39ar incremental heating experiments demonstrating that the mafic intrusions formed in two distinct time windows only intrusion ii of the imilik gabbro complex the skaergaard intrusion and the sorgenfri glestcher sill complex formed at 57 55 ma coeval with the eruption of regional flood basalts and continental breakup other layered gabbro intrusions at imilik intrusion iii kruuse fjord igtutarajik nordre aputite q kap edvard holm and lilloise are distinctly younger and formed between 50 and 47 ma plate kinematic models indicate the axis of the ancestral iceland mantle plume was located under central greenland at 60 ma and subsequently crossed the east greenland rifted continental margin we propose that tholeiitic magmatism along the east greenland rifted margin largely occurred in three distinct pulses at 62 59 ma lavas and dykes 57 54 ma lavas dykes sills and some gabbros and 50 47 ma gabbros dykes and rare lavas related to discrete mantle melting episodes triggered by plume impact continental breakup and passage of the plume axis respectively this model implies northwestward continental drift of greenland relative to the plume axis by 3 9 5 0 cm yr between 60 and 49 ma consistent with estimates from seismic studies of submerged flood basalts

boron concentrations of volcanic fields in different geotectonic settings abstract whole rock boron and other mobile and immobile element concentrations are reported for the alkaline maar volcanic rocks from the bakony balaton highland volcanic field bbhvf hungary and for three other geographically distinct maar volcanic fields from diverse tectonic settings spain canary islands tenerife new zealand waipiata otago and mexico pinacate sonora and ceboruco cone field boron concentrations along with other fluid immobile and incompatible element concentrations are used to study the fluid enrichment of the above mentioned intraplate volcanic materials the fluid addition was the highest in the trans mexican volcanic belt ceboruco cone field which is associated with recent subduction the bbhvf also shows high fluid enrichment the average b content of the tenerife canary islands samples 6 4 g g is similar to that of the bbhvf 6 9 g g the fluid enrichment is higher in the bbhvf than in the waipiata volcanic field wvf the magmatic source regions for all the investigated volcanic rocks were affected by fluid components to different degrees and despite the distant relationship to subduction zones all show evidence of a subduction derived fluid component

40ar39ar dating of the skaergaard intrusion we report the first 40ar 39ar data for the skaergaard intrusion based on analyses of hornblende and biotite from a transgressive granophyre from upper zone a uza of the layered series hornblende separates heated in a resistance furnace and laser heated single crystals of biotite from the granophyre give plateau ages that are consistent with isochron ages of 55 48 0 30 and 55 40 0 14 ma respectively 2 internal uncertainty with initial 40ar39ar ratios of 292 4 19 0 and 291 1 7 2 if uncertainties in the ages of 40ar 39ar standard fluence monitors are considered external uncertainties 2 errors are 0 76 and 0 72 ma respectively resistance heating analysis of biotite separated from a gabbro from lower zone a lza of the skaergaard layered series indicates that the sample has been extensively contaminated by ar inherited from old crust and does not constrain the intrusion age apart from indicating that it is less than approximately 57 ma old the ar cooling ages are consistent within uncertainty with both pluton cooling models presented by norton and taylor 1 but the data agree best with their model s2 which assumes a smaller permeability 10 13 cm2 combination of the new ages and the norton and taylor cooling models constrains the emplacement and final crystallization of the skaergaard magma chamber to be at 55 75 0 30 ma and 55 65 0 30 ma respectively evidence for late crystallizing quartz and tridymite near the sandwich horizon sh combined with phase equilibria constraints on the near solidus crystallization temperature of the sh 975 25 c require the pressure of sh solidification to be 60 15 mpa this means that the tertiary basalts and sediments overlying the kangerdlugssuaq region were 3 2 0 8 km thick at 55 65 0 30 ma assuming that the 6 7 km thick tertiary section exposed further east along the east greenland coast is representative of that which accumulated above the skaergaard we infer that the skaergaard emplacement occurred during the main stage of the east greenland flood basalt event after approximately half of the tertiary section had erupted the onset of coastal flexure in the kangerdlugssuaq region was after 55 48 0 76 ma

estimation of soil strength in fine grained soils by instrumented free fall sphere tests the dynamic response of a sphere in soft clay is considered through field tests in which a 0 25 m dia steel sphere was allowed to free fall in water and dynamically penetrate the underlying soft soil the test data collected in a lake and a sea environment relate to sphere velocities of up to 8 m s reaching sphere invert embedments close to ten diameters an inertial measurement unit located within the sphere measured the motion response of the sphere during free fall and penetration in soil the resulting acceleration data were used within a simple framework that accounts for both geotechnical shearing resistance and fluid mechanics drag resistance but cast in terms of a single capacity factor that can be expressed in terms of the non newtonian reynolds number the merit of the framework is demonstrated by using it as a forward model in a series of inverse analyses that calculate the undrained shear strength profile from acceleration data measured in free fall sphere tests the good match between th

dynamic analysis of a smooth penetrometer free falling into uniform clay the finite element analysis of free falling objects penetrating soil deposits is one of the most sophisticated and challenging problems in geomechanics a robust numerical method will be described here for dealing with such complex and difficult problems the approach is based on the arbitrary lagrangian eulerian ale method of analysis the main features and challenges of which are described briefly in the paper the ale method is then employed to perform a parametric study of a perfectly smooth penetrometer free falling into a uniform layer of clay which deforms under undrained conditions the effect of the mechanical properties of the clay soil on the penetration characteristics is presented and an approximate closed form expression is derived for the dynamic penetration factor ndp comparisons are made between the deduced values of ndp and published values of the conventional cone factor nc and comparisons are made with experimental data to validate the approach

timing of basaltic volcanism along the mesa butte fault in the san francisco volcanic field arizona from 40ar 39ar dates implications for longevity of cinder cone alignments using high precision stepwise heating 40ar 39ar methods we dated volcanic products of at least 12 vents cropping out along the northern segment of the mesa butte fault in the san francisco volcanic field arizona where the relationship between fault and vent alignment is unambiguous the 40ar 39ar isochron dates indicate that the mesa butte fault hosted five episodes of volcanism over a 1 million year interval from 1400 to 300 ka the first episode occurred 1 km northwest of the trace of the mesa butte fault whereas the next two episodes were centered near the intersection of the mesa butte and cedar ranch faults the final two episodes produced red mountain 750 100 ka and shadow mountain 300 100 ka respectively ages of vents representing the third mesa butte episode of volcanism 760 50 ka to 900 80 ka indicate a systematic southwestward shift in the locus of volcanism along the mesa butte fault that contrasts sharply with overall eastward younging of volcanism within the field these data demonstrate that structures in basaltic volcanic fields are capable of hosting multiple episodes of volcanism over periods of time comparable to duration periods of composite volcanoes 106 years but at significantly lower recurrence intervals these results suggest that probability models of spatiotemporal recurrence of volcanism within basaltic volcanic fields should incorporate mapped structures particularly where these structures have either hosted previous volcanic activity or are proximal to population centers or sensitive installations such as nuclear power plants or waste repositories

effect of perforations on uplift capacity of skirted foundations on clay the retrieval of deep water subsea installations resting on soft soil such as mudmat shallow foundations can be a difficult and costly operation if significant resistance to uplift is experienc

relating shaft friction of buried piles and cpt resistance in clayey sands this paper examines factors controlling the ultimate shaft friction developed on buried piles in normally consolidated clay sand mixtures and explores the relationship between this friction and the

the age of earth s largest volcano tamu massif on shatsky rise northwest pacific ocean this study presents laser step heating 40ar 39ar age determinations of basaltic lava samples from tamu massif the oldest and largest edifice of the submarine shatsky rise in the northwest pacific and earth s proposed largest volcano the rocks were recovered during integrated ocean drilling program expedition 324 which cored 160 m into the igneous basement near the summit of tamu massif the analyzed lavas cover all three major stratigraphic groups penetrated at this site and confirm a late jurassic early cretaceous age for the onset of shatsky rise volcanism lavas analyzed from the lower and middle section of the hole yield plateau ages between 144 4 1 0 and 143 1 3 3 ma with overlapping analytical errors 2 whereas a sample from the uppermost lava group produced a significantly younger age of 133 9 2 3 ma suggesting a late or rejuvenated phase of volcanism the new geochronological data infer minimum average melt production rates of 0 63 0 84 km3 a over a time interval of 3 4 million years consistent with the presence of a mantle plume

pb isotopes during crustal melting and magma mingling a cautionary tale from the miki fjord macrodike central east greenland abstract pb isotopic data are presented for hybrid rocks formed by mingling between mantle derived tholeiitic magma of the eocene miki fjord macrodike east greenland and melt derived from the adjacent precambrian basement bulk mixing and afc processes between end members readily identified in the field fail to model the pb isotope systematics selective contamination during diffusional exchange which can explain the complex sr and nd isotope compositions of the hybrid rocks blichert toft et al 1992 cannot fully account for the variability of the pb isotopic data using the identified crustal end members the crustal anatectic end member although similar in sr and nd isotope composition has a markedly different pb isotopic composition than its source gneiss the differences are consistent with preferential incorporation of radiogenic pb from accessory phases such as metamict zircon or loosely bound pb from grain boundaries during disequilibrium melting of the host rock by the mafic magma the crustal melt involved in magma interactions was therefore heterogeneous with respect to pb isotopes on a metre scale these results illustrate the difficulties inherent in interpreting isotopic variations in contaminated mafic magmas even when the end members are well constrained by field relations we show that the pb isotopic composition of the crustal contaminants and contamination trajectories for the miki fjord hybrid magmatic lithologies are markedly different from regional basement gneisses and contaminated lavas of the associated flood basalt province that were contaminated by characteristically unradiogenic pb and sr lithologies resembling lewisian basement not exposed locally

chemical modification of east greenland tertiary magmas by two liquid interdiffusion the macrodikes of the east greenland tertiary igneous province partially melted precambrian basement along their contacts field evidence suggests that silicic liquid produced by partial melting of the basement buoyantly migrated roofward in the intrusions where it ponded and kinetic and or rheological barriers prevented the crustderived melt and mafic magma of the macrodikes from intimately mixing however extensive redistribution of mobile elements occurred locally between these reservoirs close agreement between element partitioning in the various lithologic units in the macrodikes and experimental observations involving liquid immiscibility and silicate liquid interdiffusion suggests that chemical equilibrium between the magma reservoirs was approached through diffusive element exchange

petrology and geochemistry of the kruuse fjord gabbro complex east greenland the kruuse fjord gabbro complex is a composite intrusion of layered gabbro and troctolite with subordinate ultramafic rocks and minor trondhjemitic bodies it was emplaced into archaean continental crust of east greenland during early tertiary rifting of greenland from eurasia the work to date has identified an outer gabbro series and an inner troctolite series and these are separated by a narrow zone of trondhjemitic intrusions in the southeast the partially crystallized cumulates of the gabbro series were intruded by a lenticular ultramafic pluton 800 m in thickness volumetrically minor syenite trachyandesite net veined dykes and later diabase dykes cross cut the plutonic rocks structural and topographic features suggest that the layered rocks were affected by synmagmatic subsidence and deformation but not by monoclinal coastal flexure the gabbro series is composed of a marginal gabbro unit about 20 m wide bordering more than a 2 km thickness of layered olivine and magnetite gabbro cumulates the marginal gabbro is interpreted to be chilled magma the layered cumulates are the product of repeated injections of magma that fractionated in an open system magma chamber anorthositic and troctolitic layers in the lower part of the sequence may represent inputs of magma and suggest that the order of cumulus mineral crystallization was 1 plagioclase an 39 85 2 olivine fo 46 82 3 augite wo 28 47 en 39 58 fs 8 18 and 4 magnetite the disappearance of cumulus magnetite and a reversal in mineral compositions at 1 5 km from the base of the succession suggests a major input of magma occurred at this height in the troctolite series the composition of cumulus minerals mineral crystallization sequence and style of emplacement are similar to those in the gabbro series the ultramafic pluton is composed of coarse grained wehrlite olivine melagabbro and troctolite that were formed by at least three injections of magma the typical mineral crystallization sequence was 1 cumulus chromite and olivine fo 84 88 2 poikilitic chrome diopside wo 29 51 en 43 63 fs 3 13 and 3 intercumulus plagioclase an 75 90 phlogopite apatite and localized disseminated sulphides containing au and platinum group elements comparison of crystallization sequences and the major and trace element compositions of clinopyroxene suggests that the gabbroic and troctolitic rocks formed from a magma represented by the chilled marginal gabbro a tholeiitic basalt magma similar to e morb whereas the ultramafic rocks formed from a magma that was relatively enriched in incompatible trace elements and volatiles the association of these two magma types is an example of bimodal mafic ultramafic magmatism in a rifting environment

some measurements of the permeability of kaolin this paper reports an experimental investigation of the vertical and horizontal permeabilities of speswhite kaolin clay the permeabilities were measured using falling head permeability tests a mo

rate effects on penetrometer resistance in kaolin this paper describes the results from a centrifuge investigation into the rate dependence of t bar and ball penetrometer resistance in kaolin four t bar diameters and two ball diameters were installed in kaolin with overconsolidation ratios of 1 2 and 5 at penetration velocities varying over five orders of magnitude the penetration resistances are compared with the properties of kaolin as measured in element tests to assist in the development of a framework that describes this resistance over the full velocity range consistent trends emerge when the soil viscosity is assumed to affect the penetration resistance in both the partially drained and undrained conditions enabling the dependence of the t bar and ball resistances on diameter velocity and soil characteristics to be quantified

testing the fixed hotspot hypothesis using ar 40 ar 39 age progressions along seamount trails abstract hotspots and their associated intra plate volcanism producing seamount trails have become an accepted fact in geology from a conceptual theory the azimuths and age progressions of these seamount trails provide the only means to determine absolute plate motions with respect to an independent reference frame of fixed hotspots however the presumed fixity of hotspots is in disagreement with recent paleomagnetic studies and global circuit plate reconstructions for the hawaiian emperor seamount trail in this study we provide independent evidence suggesting that hotspots are not fixed relative to each other we use a straightforward test that compares the observed 40ar 39ar age progressions along pacific seamount trails 0 140 myr with the pacific plate velocities as predicted by their poles of plate rotation i e euler poles in most of these comparisons the age progressions were found incompatible with published euler poles or with a new set of euler poles as derived in this study using discrete seamount locations digitized from the bathymetry maps of smith and sandwell eos 77 1996 315 science 277 1997 1956 1921 we conclude that the relative motion between hotspots may be required to reconcile the observed age progressions with the predicted plate velocities from their modeled euler poles on average the pacific hotspots may show motion at 10 60 mm yr over the last 100 myr partly attributed to individual hotspot motion whereas systematic motion of these hotspots due to true polar wander may account for the remainder

a deep seismic reflection transect across the irish caledonides new reflection profiles recorded to 18s c 60km along a 600 km north south transect west of ireland wire lines provide a cross section of the irish caledonides from lewisian basement in the north to the variscan fold and thrust belt in the south and constrain the offshore extrapolations of major caledonide structures we interpret the profiles as showing the great glen fault and associated ne trending strike slip faults as near vertical structures which cut the whole crust and the uppermost mantle beneath the surface trace of the fair head clew bay line we image a north dipping zone which soles into horizontal layers just above the reflection moho the north dipping zone separates south dipping reflections above and to the north from north dipping reflections below and to the south from the fair head clew bay line as far south as the iapetus suture the lower crust contains north dipping packages of reflectors possibly related to acadian accretionary underplating the iapetus suture zone can be identified as a zone more than 50 km wide dipping north at 30 from 5 km depth offshore dingle peninsula to sole into the moho at c 30 km depth west of the shannon estuary in the upper crust the shallow part of the iapetus suture zone appears to be transported to the north by late caledonian retrocharriage or by variscan thrusting the iapetus suture does not penetrate through the present day reflection moho but there are scattered reflectors in the mantle not continuous with crustal reflectors perhaps relics of a subducted slab we recognize lower crustal reflectivity and the reflection moho along almost all the wire profiles regionally the travel time to the reflection moho varies from 9 s c 28 km offshore donegal northwest of ireland to 12 s c 35 km offshore kerry and cork southwest of ireland apparent moho offsets rapid lateral changes in the travel time to the reflection moho north of donegal and north of mayo are probably due to the great glen fault and associated faults the lower crustal reflectivity varies considerably in thickness and prevalent dip direction along the wire profiles in donegal bay this reflectivity is observed at depths less than 5 km c 1 5s whereas west of kerry prominent reflectivity is only observed beneath 6s c 17 km though the age of crustal reflectors cannot in general be determined beneath central ireland from donegal to dingle the lower crustal reflectors mimic in dip direction the structural vergence of the exposed dalradian and early palaeozoic rocks so that the lower crustal reflectivity patterns and probably much of the crust must be caledonian in age

analysis of piezocone penetration under different drainage conditions with the two phase material point method abstractthe piezocone penetration test cptu is commonly used to identify a soil s profile and estimate its material properties depending on the soil type ranging from clay to sand undrained partially drained or drained conditions may occur during cone penetration in silt and sand clay mixtures the cptu penetration is characterized by partially drained conditions which are often neglected in data interpretation the effect of drainage on cptu measurements has been mainly studied experimentally numerical analyses are rare because taking into account large soil deformations soil water and soil structure interactions and nonlinear soil behavior is still a challenging task this paper presents and discusses numerical simulations of cptu in saturated soils with the two phase material point method soil behavior is described with the modified cam clay model this study investigates the effects of pore pressure dissipation during penetration cone roughness and horizontal stress state comparing the