evolution of the eastern volcanic ridge of the canary islands based on new kar data the results of 64 new k ar age determinations together with 32 previously published ages show that after a period of erosion of the basal complex miocene volcanic activity started around 20 ma in fuerteventura and 15 ma in lanzarote forming a tabular succession of basaltic lavas and pyroclastics with a few salic dykes and plugs this series includes five separate volcanic edifices each one with its own eruptive history in fuerteventura several miocene eruptive cycles have been identified in the central edifice one around 20 17 ma followed by two others centred around 15 and 13 ma in the southern edifice the maximum of activity took place around 16 14 ma whereas in the northern one the main activity occurred between 14 and 12 ma in lanzarote a first cycle of activity took place in the southern edifice between 15 5 and 14 1 ma followed by another between 13 6 and 12 3 ma in the northern edifice three pulses occurred 10 2 8 3 6 6 5 3 and 3 9 3 8 ma an important temporal gap greater in fuerteventura than in lanzarote separates series i from the plio quaternary series ii iii and iv formed by multi vent basaltic emissions in fuerteventura the following eruptive cycles have been identified 5 2 9 2 4 1 8 1 7 0 8 0 4 and 0 1 ma in lanzarote the activity was fairly continuous from 2 7 ma to historic times with a maximum in the lower pleistocene eruptive rates in the series i edifices were on the average 0 1 0 01 km3 ka comparable but slightly smaller than in similar edifices in tenerife and la gomera but much lower than in gran canaria average post miocene eruptive rates were about 0 013 0 027 km3 ka in lanzarote and 0 003 0 007 km3 ka in fuerteventura all these volcanic edifices show a similar general sequence fissural eruptions erosion multi vent volcanism repeated at different periods in different parts of the eastern islands of the canaries the model of growth of the series i edifices is comparable to those in tenerife and la gomera long periods of activity sometimes greater than 6 m y with pulses separated by gaps however salic and intermediate differentiates frequent in tenerife and la gomera are very scarce in these islands the fuerteventura lanzarote ridge shows a decrease in volcanic activity with time and also a certain ssw nne polarity in the temporal development of volcanism

electron spin resonance esr techniques applied to mollusc shells from south america chile argentina and implications for palaeo sea level curve esr dating of marine mollusc shells gives no evidence for a so called mid wisconsin sea level high stand in argentina and chile the idea of this high stand around 30 000 40 000 bp is still alive especially in argentina but the evidence for it is in our opinion and that of others solely based on the misinterpretation of 14c dates all esr ages from southern south america belong either to the holocene or the last interglacial or older interglacial periods apart from the regional aspect this paper deals with some methodological problems in esr dating estimates have been improved by using only mollusc shells that are still closed and in living position and by introducing a plateau screening test for the determination of the accumulated dose ad the estimate of the environmental dose has been refined by analysing the infill sediments in the shells for their u th and k contents separately from the embedding matrix special interest has been paid to the debated problem of early or continuous u uptake the u contents of recent holocene molluscs support the early uptake model a probable solution to the problem of age overestimation of holocene shells is also presented present day shells are shown to possess frequently a fully developed signal and to give ad of 2 4 in one case up to 9 gy if the holocene ad values of 14c dated shells are corrected by subtracting these recent and spurious values the resulting age estimates are more consistent with radiocarbon ages

a comparison of modeling approaches for steady state unconfined flow abstract the dupuit forchheimer the fully saturated flow and the variably saturated flow models are compared for problems involving steady state unconfined flow through porous media the variably saturated flow model is the most comprehensive of the three and requires more parameters the performances of the three models are compared for different soil properties problem dimensions and flow geometries there are certain types of problems where the simpler models may yield satisfactory results for soils with large pores and or broad pore size density functions the variably saturated flow model solutions to steady state problems approach those of the fully flow model owing to the manner in which the soil water retention curve and relative permeability function respectively affect the variably saturated flow model solutions for problems of significant size the fully saturated flow model may be sufficient as the effects of the vadose zone are relatively diminished for problems with radial symmetry e g steady flow to a well the fully saturated flow model performs well because the variably saturated flow model is relatively insensitive to the parameters describing the soil properties as the amount of vadose zone flow compared with the total flow is relatively insignificant in such problems

uranium series ages of corals sea level history and palaeozoogeography canary islands spain an exploratory study for two quaternary interglacial periods abstract we present the first u series ages of corals from emergent marine deposits on the canary islands deposits at 20 m are 481 39 ka possibly correlative to marine isotope stage or mis 11 while those at 12 and 8 m are 120 5 0 8 ka and 130 2 0 8 ka respectively correlative to mis 5 5 the age elevations and uplift rates derived from mis 5 5 deposits on the canary islands allow calculations of hypothetical palaeo sea levels during the mis 11 high sea stand estimates indicate that the mis 11 high sea stand likely was at least 9 m relative to present sea level and could have been as high as 24 m the most conservative estimates of palaeo sea level during mis 11 would require an ice mass loss equivalent to all of the modern greenland and west antarctic ice sheets the more extreme estimates would require additional ice mass loss from the east antarctic ice sheet extralimital southern species of mollusks found in both mis 11 and mis 5 5 deposits on the canary islands imply warmer than modern sea surface temperatures during at least a part of mis 11 and much warmer sea surface temperatures during at least a part of mis 5 5 both mis 11 and mis 5 5 marine deposits on the canary islands contain extralimital northern species of mollusks as well indicating cooler than present waters at times during these interglacial periods we hypothesize that the co occurrence of extralimital southern and northern species of marine invertebrates in the fossil record of the canary islands reflects its geographic location with respect to major synoptic scale controls on climate and ocean currents previous interglacials may have been characterized by early insolation forced warming along with northward migration of the intertropical convergence zone itcz accompanied by weakened trade winds and diminished upwelling this allowed the arrival of extralimital southern taxa from the tropical senegalese faunal province during later parts of the mis 11 and 5 5 interglacials decreased insolation may have resulted in southward migration of the itcz strengthened trade winds and re establishment of upwelling such conditions may have brought about not only local extinction of the senegalese fauna but allowed southward migration of the cooler water mediterranean fauna to the canary islands in the later parts of interglacials a complex palaeoclimate record that is mirrored in the deep sea core record

the effects of oscillation period on groundwater wave dispersion in a sandy unconfined aquifer sand flume experiments and modelling summary this paper presents a new laboratory sand flume dataset on the propagation of groundwater waves in an unconfined sandy aquifer with a vertical boundary subject to simple harmonic forcing with a wide range of oscillation period from 10 7 s to 909 s the data is unique in that it covers a much wider range of non dimensional aquifer depths n d k where n is the porosity is the angular frequency d is the aquifer depth and k is the hydraulic conductivity than has been previously investigated both the amplitude decay rate and rate of increase in phase lag of the water table waves are observed to monotonically increase with increasing oscillation frequency increasing n d k this is in contrast to existing theoretical dispersion relations which predict 1 zero phase lag or standing wave behaviour and 2 an asymptotic decay rate as the frequency increases possible influences on the experimental data including sand packing measurement location finite amplitude wave effects unsaturated zone truncation and multiple wave mode effects are unable to explain the discrepancy the data was also compared against numerical solutions of richards equation with and without hysteresis and in both cases the same qualitative behaviour as the analytic solutions described above is found the discrepancy between data and predictions remains unexplained and highlights a knowledge gap that requires further investigation these findings relate directly to practical applications in the field of surface groundwater interactions such as the influence of wave forcing of coastal aquifers on contaminant transport sediment mobility and salt water intrusion all of which are influenced by the dispersion of the groundwater wave

pliocene palaeoclimates past climates as possible analogues of mid twenty first century climate abstract as a result of summarizing the data over 18 regional sections on the continents and those of deep sea drilling a preliminary chronological scale of global climatic events of the late miocene pliocene has been developed thirty superclimathems are determined which are the phases of mean global temperature varying with an amplitude of not less than 4 5 c and duration of 100 000 300 000 years the warm intervals thermochrons can be considered as palaeoanalogues of the possible future climatic conditions according to the widely suggested drastic warming of the world climates that may be impending due to carbon dioxide increase thus the climate of the warm interval of the pliocene the so called climatic optimum brunssum kamyshburunian 4 3 3 3 m y is taken as the palaeoanalogue of the mid twenty first century climate when doubling of the co2 content of the atmosphere might occur reconstruction of the temperature field of the northern hemisphere for july august and january february has been carried out for that time interval the mean annual temperature of the northern hemisphere at that time seems to have been 3 8 c higher than at present which coincides with calculations of manabe and wetherald based on their general circulation model for doubling the co2 concentration by the year 2050

dating of marine terrace sediments by esr tl and osl methods and their applicabilities abstract we present the results of a pilot study in which esr tl and optical dating are intercompared to assess their suitabilities for application to measurement of the uplift rates of the japanese islands samples used were known age marine ten ace sediments collected from three sites in central japan as a result of optical bleaching experiments it was found that the tl residual intensity was identified by uv lamp but we were not able to determine how the bleaching of the esr ti signal proceeded in antiquity esr tl and optical dating were performed using the ti signal the red tl emission and the uv emissions measured during stimulation by the waveband 500 40 nm respectively equivalent doses were estimated using the additive close method dose rates were calculated from radioisotope concentrations measured using neutron activation analysis it was found that variation in pore water content over time was of major significance in age determinations for these sediments on account of their history of deposition underwater with subsequent uplift and drainage it was concluded from the correspondence of ages estimated by tl and optical dating with geological expectation that the tl and optical dating methods are suitable for dating marine terrace sediments

relative sea level fall since the last interglacial stage are coasts uplifting worldwide the growing interest in quantification of vertical ground motion stems from the need to understand in detail how the earth s crust behaves for both scientific and social reasons however only recently has the refinement of dating techniques made possible the use of paleoshorelines as reliable tools for tectonic studies although there are many local studies of quaternary vertical motions of coastlines we know of no comprehensive worldwide synthesis here we provide a compilation of 890 records of paleoshoreline sequences with particular emphasis on the last interglacial stage marine isotopic stage mis 5e 122 ka the quality of dating mis 5e makes it a reliable marker to evaluate vertical ground motion rates during the late quaternary on a global scale the results show that most coastal segments have risen relative to sea level with a mean uplift rate higher than 0 2 mm yr i e more than four times faster than the estimated eustatic drop in sea level the results also reveal that the uplift rate is faster on average for active margins than for passive margins neither dynamic topography nor glacio hydro isostasy may explain sustained uplift of all continental margins as revealed by the wide distribution of uplifted sequences of paleoshorelines instead we suggest that only plate tectonic processes reconcile all observations of quaternary coastal uplift we propose that long term continental accretion has led to compression of continental plates and uplift of their margins therefore this study concludes that plate tectonics processes impact all margins and emphasizes the fact that the notion of a stable platform is unrealistic these results therefore seriously challenge the evaluation of past sea levels from the fossil shoreline record

chemical weathering of a marine terrace chronosequence santa cruz california i interpreting rates and controls based on soil concentration depth profiles abstract the spatial and temporal changes in element and mineral concentrations in regolith profiles in a chronosequence developed on marine terraces along coastal california are interpreted in terms of chemical weathering rates and processes in regoliths up to 15 m deep and 226 kyrs old quartz normalized mass transfer coefficients indicate non stoichiometric preferential release of sr ca na from plagioclase along with lesser amounts of k rb and ba derived from k feldspar smectite weathering results in the loss of mg and concurrent incorporation of al and fe into secondary kaolinite and fe oxides in shallow argillic horizons elemental losses from weathering of the santa cruz terraces fall within the range of those for other marine terraces along the pacific coast of north america residual amounts of plagioclase and k feldspar decrease with terrace depth and increasing age the gradient of the weathering profile bs is defined by the ratio of the weathering rate r to the velocity at which the profile penetrates into the protolith a spreadsheet calculator further refines profile geometries demonstrating that the non linear regions at low residual feldspar concentrations at shallow depth are dominated by exponential changes in mineral surface to volume ratios and at high residual feldspar concentrations at greater depth by the approach to thermodynamic saturation these parameters are of secondary importance to the fluid flux qh which in thermodynamically saturated pore water controls the weathering velocity and mineral losses from the profiles long term fluid fluxes required to reproduce the feldspar weathering profiles are in agreement with contemporary values based on solute cl balances qh 0 025 0 17 m yr 1 during saturation controlled and solute limited weathering the greater loss of plagioclase relative to k feldspar is dependent on the large difference in their respective solubilities instead of the small difference between their respective reaction kinetics the steady state weathering rate under such conditions is defined as r q h m sol m total 1 s v b s the product of qh and the ratio of solubilized to solid state feldspar msat mtotal define the weathering velocity the weathering gradient bs reflects the kinetic rate of reaction where sv is the volumetric surface area of the residual feldspar both this rate expression and the spreadsheet calculations produce similar plagioclase weathering rates r 5 14 10 16 mol m 2 s 1 which agree with those reported for other environments of comparable climate and age weathering dependent concentration profiles are commonly described in literature the present paper provides methods by which these data can yield a more fundamental understanding of the weathering processes involved

marine terraces of western sakhalin island abstract biostratigraphical and sedimentological studies of deposits of terraces with heights of 2 3 3 4 4 6 8 10 12 15 20 30 35 40 60 80 and 100 120 m on western sakhalin island have shown that they were all marine in origin the upper complex of terraces q i q ii formed during a period of slow tectonic uplift in this area to 120 m above modern sea level the lower complex of terraces q iii q iv may have formed in response to sea level oscillations without any influence of tectonic uplift

review of evidence for late tertiary shorelines occurring on south atlantic coasts abstract recognition of late tertiary shorelines on continental coasts is becoming increasingly common it is argued that the elevations of such features are central to their approximate dating and the demonstration of contemporaneity with similar features elsewhere south atlantic coasts have not had a long history of investigation yet there exist many diffuse observations in both time and space which are here drawn together into a preliminary synthesis and the case for widespread occurrences of late tertiary shorelines in the region reviewed this allows comparison with other areas from which tertiary shorelines are known the atlantic seaboards of the southeastern united states and northwest europe for example the coasts of oceanic islands are probably the best places to examine the legacy of late cenozoic sea level changes it is suggested that since many of the cliffed shores of these islands appear to be the result of a rapid emergence coastal features predating this event might be preserved on the cliff tops possible late tertiary shorelines from south atlantic islands are described as are those which have been positively dated to this period in the eastern canary islands for instance sedimentary and morphological indicators of tertiary high sea levels are described from antarctic coasts south american and african atlantic continental margins evidence from the latter two areas is most suspect owing to their generally more complex quaternary tectonic histories a summary of the evidence for tertiary shorelines on south atlantic coasts is tabulated methods which have been or could be used to date late tertiary shorelines are described minimum age can be deduced from that of deposits resting on an erosional surface maximum age from that of the youngest formation across which a surface is cut more precise age can be estimated where a marine surface is sandwiched between datable non marine formations or where periods of tectonic activity responsible for differential surface deformation can be dated elevations of surfaces can be used to estimate ages problems in both recognising and dating tertiary shorelines are discussed recognition of their origin is made more difficult by their degraded state and if they occur within a quaternary erosional sequence their antiquity may not be realised it is suggested that fluctuations in the antarctic ice sheet during the late tertiary induced substantial glacio eustatic changes of sea level which may have been most marked in adjacent areas this is considered to be the mechanism through which late tertiary shorelines in the area were formed yet considering the paucity of the morphological and sedimentary data these should not be used as the basis for a eustatic chronology

last interglacial sea surface warming during the sea level highstand in the canary islands implications for the canary current and the upwelling off african coast abstract the canary islands east of the north atlantic ocean 27 n 29 n are under the influence of the canary current the descending branch of the north atlantic gyre which is modulated by coastal upwelling off north west africa they constitute strategic sites for palaeoclimatic reconstructions especially for the last interglacial lig 129 to 116 ky bp estimated to be warmer than present seventy four carbon and oxygen isotope bulk analyses and time series measurements were performed on 32 aragonitic mollusc shells from the lig marine deposits on lanzarote and fuerteventura islands during a period of sea level highstand that we estimated to occur between 125 and 119 116 ky bp our sst calculations inferred from shell 18o values using available isotopic fractionation equations provide a seasonal sst amplitude ranging from 3 5 c to 6 0 c in agreement with the modern seasonal amplitude along with a mean sst comprised between 20 4 1 3 c and 22 2 1 2 c with respect to the pre industrial times we deduce a positive sst anomaly in the range of 1 0 1 4 c to 2 8 1 3 c consistent with the presence of the species persististrombus latus typical of warm ssts although this finding does not match with the zonal negative anomaly of a reconstructed sst at low latitudes of the north atlantic it is nevertheless corroborated by other climate reconstructions in the northeastern tropical atlantic region we attribute this trend to an excess of summer insolation during the lig which warmed the canary current enhanced by a weakening of the north african upwelling the entire north atlantic gyre was probably warmer during the lig

palaeoclimatic considerations of talus flatirons and aeolian deposits in northern fuerteventura volcanic island canary islands spain abstract fuerteventura volcanic island has been subject to considerable aeolian activity since the late pleistocene the aeolian record includes inactive aeolian deposits with interbedded entisols whose age by osl dating ranges between 46 and 26 ky bp the corralejo active dune field where sand sheets nebkhas coppice dunes blowouts barchans and transverse dunes have been described constitutes a more recent aeolian deposit here the age is about 14 ky bp on fuerteventura island aeolian dust has been deposited on valleys and slopes this last type of accumulation has been affected by gully incision producing talus flatirons samples taken on the apex of these palaeo slopes indicate an osl age of 30 and 50 ky bp a palaeoclimatic succession has been interpreted during which a prevailing arid period took place in ois 4 with the accumulation of aeolian dust a humid period occurred in ois 2 during which slopes were dissected and formed talus flatirons an arid period about 14 ky bp gave rise to the corralejo dune field which has continued until present with slight climatic oscillations

review of the chronology of marine terraces in the hawaiian archipelago abstract this chronology of marine terraces in hawaii includes 236 published dates most samples are from the emerged reef terraces on oahu the holocene record of transgression is outlined by the available data but further detailed work is needed a mid holocene high stand has been documented for kauai and is currently being resolved for oahu a double marine transgression during the last interglacial is suggested by stratigraphy and electron spin resonance dates from a newly studies site on oahu precise radiometric dates are needed to confirm this interpretation attention is called to the emerged terraces above 10 m in the hawaiian islands which initial studies indicate are older than the last interglacial a reevaluation of oahu age data suggests that oahu has undergone uplift during the last 500 000 years and may not be a suitable stable platform for eustatic sea level comparisons a promising set of deeply submerged terraces representing eustatic low stands has been discovered off the island of hawaii these drowned reefs offer potential for paleoceanographic and paleoclimatic studies

a review of amino acid racemization studies in quaternary mollusks stratigraphic and chronologic applications in coastal and interglacial sites pacific and atlantic coasts united states united kingdom baffin island and tropical islands abstract amino acid racemization aar studies of quaternary mollusks mostly marine mollusks from coastal deposits are reviewed data obtained in regional studies from the u s atlantic and pacific coasts baffin island the united kingdom and tropical islands are discussed as they relate to method evaluation kinetic model development and aminostratigraphic applications u s pacific coast studies have been employed for estimating tectonic deformation rates study of molluscan zonation patterns in the late pleistocene and in kinetic model evaluation u s atlantic coast studies have identified multiple aminostratigraphic zones in areas with complex morphostratigraphic relationships and have also revealed some important conflicts between aminostratigraphic temperature concepts and radiometric data studies in the united kingdom involving coastal sites and non marine interglacial sites identify some stratigraphic and kinetic conflicts but provide a preliminary chronostratigraphic model for the classical interglacial terminology of the u k middle to late pleistocene baffin island studies involving aar data and u th dating of shells have resulted in some significant revisions of previous chronologic models the arctic environment has also stimulated some novel approaches in the collection and interpretation of aar results tropical island studies though few in number aid in calibration of observed racemization and also aid in correlation of coastal deposits with late pleistocene isotopic ice volume records

a one million year long sequence of marine terraces on sumba island indonesia abstract an exceptional sequence of raised coral reef terraces is visible at cape laundi on the north coast of the island of sumba in the savu sea in which at least eleven terraces wider than 100 m six of them even being over half a kilometer wide are geomorphologically distinguishable between an ancient patch reef now at 475 m and the present sea level esr date estimations of almost unrecrystallized corals most of them in situ make possible a tentative identification of the terraces corresponding to isotope stages 15 ca 600 ka ago and 9 ca 330 ka ago when the uplift trend deduced from the present altitude of dated terraces 0 49 0 01 mm yr is extrapolated to the whole raised section most geomorphological features appear to correspond to interglacial stages of the astronomically calibrated oxygen isotope record up to stage 27 ca 0 99 ma beyond the matuyama jaramillo geomagnetic boundary the upper terraces would in this case be twice as old as previously estimated ca 0 5 ma main terraces seem to correspond to high sea levels at certain interglacial stages and substages but in some cases the action of low sea levels at glacial stages cannot be ruled out for terraces between 30 and 70 m in altitude th u and esr dates reveal that aragonitic corals at similar elevations may differ in age as much as 100 ka this can be explained by taking into account a polycyclic origin for several terraces reconstructions available of changes in the eustatic sea level during the last 250 kyr and the fact that coral reef development may have been scattered at some periods only without totally covering subjacent older formations the sumba sequence of marine terraces at cape laundi is among the longest and most complete for the past million years reported in the literature its relatively good state of preservation will probably give impetus to a number of new studies on the chemical physical isotopic morphological palaeoclimatic pedological ecological and diagenetic changes which have occurred during the past one million years

tyrrhenian coastal deposits from sardinia italy a petrographic record of high sea levels and shifting climate belts during the last interglacial isotopic substage 5e abstract detailed petrographic and sedimentological analysis of tyrrhenian coastal deposits from four sites in sardinia provides new data about climate and sea level changes during the early part of the last interglacial isotopic substage 5e and shows that facies analysis is not only useful for the identification of ancient depositional environments but also represents a powerful tool for evaluating past climatic conditions and sea level forcing mechanisms two shallowing upward sequences sensu ward w c brady m j 1979 strandline sedimentation of carbonate grainstones upper pleistocene yucatan peninsula mexico am assoc pet geol bull 63 362 369 commonly separated by an erosion surface and displaying complex geometric relationships occur above modern sea level at several locations along the shorelines of sardinia these sequences include upper shoreface to backshore deposits and were formed during separate sea level highstands attributed to isotopic substage 5e our recent revision of these deposits indicates that each sequence presents distinctive petrographic characteristics the older succession essentially contains mixed calcarenites rich in quartz grains and lithic fragments whereas the younger sediments are dominated by carbonate bioclasts such as red algae coral and mollusk fragments both units apparently accumulated in a similar depositional setting but during different climatic regimes the petrography of the lower unit reflects a temperate humid period characterized by increased weathering and continental erosion whereas the composition of the upper one suggests a dryer and possibly warmer climate favoring active carbonate production the disparity in petrographic composition between sequences probably records the migration of atmospheric circulation cells i e a shift of climate belts before and after the 128 ka insolation maximum our climatic data are coherent with the calculated insolation curves for isotopic substage 5e and thus support the milankovitch hypothesis for the origin of pleistocene climates in contrast our sedimentological data clearly show the occurrence of two distinctive highstands of sea level during this time period which does not agree with the hypothesis it follows that the relation between orbitally induced insolation variations climate and sea level is not necessarily straightforward

u series dates of pleistocene corals and their implications to the paleo sea levels and the vertical displacement in the central philippines abstract results of high precision alpha spectrometric 230th 234u dating of hermatypic corals in palawan in western philippines and cebu bohol and panglao islands in the central philippines confirm the presence of mis 5e reef terraces at 2 to 13 m above the present mean sea level similar to stable regions this suggests the relative vertical stability of the islands since the last interglacial period in panglao island the elevation of the 5e terrace increases to the northeast indicating tilting of the island to the southwest the continued sense of uplift since at least the last interglacial is indicated by the similarity in the spatial variation of middle holocene tidal notch a 5c terrace though less developed is also recognized in panglao island along the san isidro coast the inner margins of 5c and 5e terraces are at elevations of 5 and 7 1 8 m respectively and the difference in altitude between the terraces is only ca 2 3 m assuming that the sea level during mis 5e was 3 6 m above the present sea level sea level at mis 5c is estimated to be equal to or slightly higher than the present mean sea level

steady state analysis of unsaturated flow above a shallow water table aquifer drained by ditches the one dimensional pressure head profile above a fixed water table was studied for different steady infiltration rates as shown in previous studies when the infiltration rate qin is less than the soil saturated hydraulic conductivity ks this profile can be divided into two parts 1 from the water table surface z0 to an elevation z the pressure head varies from 0 to a value h such as k h qin 2 above the elevation z the pressure head is constant and equal to h above the water table the zone where the pressure head is variable has been called transition zone its height is shown to be highly variable and to depend on soil properties as well as on the infiltration rate this transition zone is not the capillary fringe as defined by gillham gillham r w 1984 the capillary fringe and its effect on water table response j hydrol 67 307 324 numerical experiments performed with hydrus 2d for the case of a water table drained by parallel ditches have shown that the height of the transition zone is similar in the one dimensional profile and in the two dimensional system as long as the local slope of the water table is small this result is important since in a two dimensional system the transition zone is the place where all the horizontal component of the unsaturated flow occurs the ratio of the horizontal component of the unsaturated flow vs the total horizontal flow in both the unsaturated and saturated zones has been computed for a given soil this ratio decreases as the infiltration rate increases for a given infiltration rate the soil with the thinnest transition zone transfers the largest amount of water above the water table

miocene rifting of fuerteventura canary islands 1 the older geological units of the volcanic island of fuerteventura canary islands i e the so called basal complex and the lower part of the subaerial volcanic rocks show abundant structures indicative of a long lived period of miocene tectonic activity these structures include faults dike swarms kilometer scale folds tilted sequences and fissural and central volcanic edifices a detailed structural study based on geological mapping and the use of fault slip inversion techniques and statistical analysis of dike orientation has allowed the identification of three separated miocene deformation phases m d1 m d2 and m d3 the average extension directions determined for these phases are nw se nne ssw and ene wsw respectively a model of oceanic lithosphere rifting is proposed to account for this deformation history a buoyant anomalous sublithosphere mantle triggered the extension in the lithosphere beneath fuerteventura isolating it during the early and middle miocene from the plate scale collision regime predominant in the nw corner of the african plate

mega tsunami conglomerates and flank collapses of ocean island volcanoes abstract marine conglomerates at high elevation on the flanks of ocean islands are usually interpreted as evidence of mega tsunamis generated by volcano flank collapses although their origin is sometimes debated elevated littorals vs tsunami in this review we introduce case studies of well documented examples of tsunami conglomerates in hawaii pacific ocean the canary and cape verde islands atlantic ocean and mauritius island indian ocean other less documented marine conglomerates are also presented as tsunami candidates then we build a comprehensive picture of the general characteristics of these conglomerates and the different methods that can be applied to date them different perspectives of research are proposed especially on the use of tsunami conglomerates as proxies for better constraining numerical models of ocean island flank collapses and associated tsunamis we also discuss the possible links between volcano growth flank instability and climate

drainage of recharge to symmetrically located downstream boundaries with special reference to seepage faces summary the seepage face is an important feature of the drainage process when recharge occurs to a permeable region with lateral outlets examples of the formation of a seepage face above the downstream water level include agricultural land drained by open ditches and the ballast beneath railway tracks the first part of the paper considers vertical section two dimensional analytical and numerical solutions for recharge to permeable regions above horizontal impermeable bases having two symmetrically positioned downstream boundaries with zero or specified external depths of water for vertical downstream boundaries with seepage faces above the downstream water level empirical relationships are developed relating the seepage face height on the downstream boundary to the downstream discharge the same problems are also analysed using the one dimensional dupuit forchheimer approximation improved estimates of the entire water table profile are achieved when the downstream boundary head is specified as a function of the downstream discharge using relationships derived from the two dimensional solutions instead of the customary assumption that the water table is drawn down to the ditch water level finally time variant simulations based on the dupuit forchheimer approximation are introduced for a single layer and for a system of two horizontal layers having different hydraulic conductivities

reconstruction of paleo wave conditions during the late pleistocene from marine terrace deposits monterey bay california the santa cruz coastal terrace fringes much of the northern monterey bay region california it consists mainly of a regressive sequence of high energy barred nearshore marine sediments deposited during the last sangamonian highstand of sea level this sequence can be sub divided into several depth dependent facies on the basis of paleo current data and vertical sequence of sedimentary structures these include a lower shoreface facies deposited in 10 16 m water depth an upper shoreface facies including both a storm dominated assemblage and a surf zone assemblage deposited in 0 10 m water depth and a foreshore facies deposited in the swash zone up to 3 5 m above high tide the magnitudes of the storm events responsible for depositing these sediments were estimated by calculating paleo wave heights using a variety of criteria e g critical threshold equations breaker depths berm heights in addition the climate and paleogeography during the deposition of these sediments were essentially the same as today allowing the use of present day wave statistics to estimate the frequency of these storm events the largest storms formed offshore flowing currents e g rip wind forced and possibly storm surge ebb currents that resulted in the deposition of approximately 30 of the sediments seaward of the surf zone however the magnitude and frequency of these events are unknown the remaining 70 of the sediment beyond the surf zone was deposited in response to smaller storm waves which were on the average at least 1 6 m high such waves presently occur no more than 15 of the time sediments deposited during fairweather conditions i e the remaining 85 of the time have a low preservation potential and are generally not preserved in this facies in contrast surf zone sediments were deposited by a variety of processes associated with waves whose maximum offshore heights were probably 2 2 m such waves presently occur up to 92 of the time sediments within the swash zone were deposited by waves up to 3 m high the largest of which presently occur approximately 2 of the time most of the sediments were deposited by storms of intermediate magnitude and frequency different facies however appear to preferentially record events of different recurrence intervals in particular surf zone sediments were deposited under relatively small storm and post storm conditions whereas sediments deposited farther offshore record increasingly larger less frequent storm events relatively rare events e g the 100 or 1000 yr events do not appear to have significantly affected sedimentation in these nearshore environments

on post glacial sea level i general theory summary modern analyses of sea level changes due to glacial isostatic adjustment gia are based on the classic sea level equation derived by farrell clark 1976 geophys j r astr soc 46 647 667 the connection between global sea level variations and changes to ocean height that is assumed within this equation breaks down in the presence of a time varying shoreline geometry we present a generalized sea level equation that overcomes this difficulty we also derive analytic expressions for and present schematic illustrations of the error in the ocean height change over finite time intervals introduced in published efforts to incorporate shoreline evolution into the theory of gia induced sea level change this comparison includes studies of shoreline migration due to either local sea level changes or the growth and ablation of marine based ice we conclude that the theories applied by johnston 1993 geophys j int 114 615 634 milne 1998 phd thesis university of toronto toronto and co workers are more accurate than the procedure advocated by peltier 1994 science 265 195 201 1998a geophys res lett 25 3955 3958 1998b rev geophys 114 615 634 although an improvement in the latter has recently been reported peltier drummond 2002 geophys res lett 29 10 1029 2001gl014273 our generalized theory is valid for any earth model in a companion paper we derive the equations necessary to treat the special case of a spherically symmetric linear viscoelastic and rotating earth and we quantify errors associated with previous work

radar interferometry and its application to changes in the earth s surface geophysical applications of radar interferometry to measure changes in the earth s surface have exploded in the early 1990s this new geodetic technique calculates the interference pattern caused by the difference in phase between two images acquired by a spaceborne synthetic aperture radar at two distinct times the resulting interferogram is a contour map of the change in distance between the ground and the radar instrument these maps provide an unsurpassed spatial sampling density 100 pixels km 2 a competitive precision 1 cm and a useful observation cadence 1 pass month 1 they record movements in the crust perturbations in the atmosphere dielectric modifications in the soil and relief in the topography they are also sensitive to technical effects such as relative variations in the radar s trajectory or variations in its frequency standard we describe how all these phenomena contribute to an interferogram then a practical summary explains the techniques for calculating and manipulating interferograms from various radar instruments including the four satellites currently in orbit ers 1 ers 2 jers 1 and radarsat the next chapter suggests some guidelines for interpreting an interferogram as a geophysical measurement respecting the limits of the technique assessing its uncertainty recognizing artifacts and discriminating different types of signal we then review the geophysical applications published to date most of which study deformation related to earthquakes volcanoes and glaciers using ers 1 data we also show examples of monitoring natural hazards and environmental alterations related to landslides subsidence and agriculture in addition we consider subtler geophysical signals such as postseismic relaxation tidal loading of coastal areas and interseismic strain accumulation we conclude with our perspectives on the future of radar interferometry the objective of the review is for the reader to develop the physical understanding necessary to calculate an interferogram and the geophysical intuition necessary to interpret it

distribution timing and causes of andean deformation across south america the andean orogeny in south america has lasted over 100 ma it comprises the peruvian incaic and quechuan phases the nazca and south american plates have been converging at varying rates since the palaeocene the active tectonics of south america are relatively clear from seismological and global positioning system gps data horizontal shortening is responsible for a thick crust and high topography in the andes as well as in se brazil and patagonia we have integrated available data and have compiled four fault maps at the scale of south america for the mid cretaceous late cretaceous palaeogene and neogene periods andean compression has been widespread since the aptian the continental margins have registered more deformation than the interior for the peruvian phase not enough information is available to establish a tectonic context during the incaic phase strike slip faulting was common during the quechuan phase crustal thickening has been the dominant mode of deformation to investigate the mechanics of deformation we have carried out 10 properly scaled experiments on physical models of the lithosphere containing various plates the dominant response to plate motion was subduction of oceanic lithosphere beneath continental south america however the model continent also deformed internally especially at the margins and initial weaknesses

goringe alboran tell tectonic zone a transpression system along the africa eurasia plate boundary neotectonic structures distributed from the goringe bank to the tell atlas mountains show that the africa eurasia plate boundary in the western mediterranean corresponds to an east west trending deforming zone goringe alboran tell main pliocene and quaternary tectonic structures of the northern atlas mountains are northeast southwest striking fault related folds similar to that of el asnam and are related to north south to northwest southeast compressional movements active tectonics in agreement with the main seismicity distribution and focal mechanisms also support an oblique plate convergence and the existence of a 50 100 km wide transpression zone from goringe across alboran to the tell atlas mountains a kinematic model shows the interaction between dextral transcurrent faults and left lateral faults with block rotations and no lateral extension pinned model shortening and lateral movement rates during the quaternary are estimated to be 1 0 2 3 mm yr and block rotation rate is estimated as 2 5 3 9 m y the plate boundary may correspond to a transpression zone active thrust faults being controlled by deep seated dextral transcurrent faults

reconstruction of sea surface temperatures in the canary islands during marine isotope stage 11 the study of paleoclimates enables us to improve and better constrain climate models in order to forecast future climate variations marine isotope stage 11 mis11 which began around 425 000 yr bp and lasted about 65 000 yr is a warm isotope stage of paramount importance because the astronomical configuration was similar to the one characterizing the holocene therefore this warm isotope stage is the most appropriate analog to present day climate known to date this study aims to provide new data on sea surface temperatures ssts inferred from the carbon and oxygen isotope compositions of skeletal carbonates of marine invertebrates preserved in two marine deposits of the canary islands located at piedra alta lanzarote and arucas gran canaria according to published isotopic fractionation equations the marine deposit from arucas recorded ssts of 15 9 2 2 c on average while the tsunamite from piedra alta recorded ssts of 21 2 1 9 c on average absolute dating mollusc assemblages and calculated marine temperatures suggest that the arucas marine deposit corresponds to the beginning of mis11 while the piedra alta tsunamite was formed during mis11c these results show that low latitudes also experienced sizable sst changes during interglacial stages

pleistocene sea levels from raised coral reefs of haiti the elevations and ages of a sequence of three uplifted pleistocene coral reefs on the northwest peninsula of haiti have been determined with the assignment of a sea level of 6 meters relative to the present day at 130 000 years before present and constant uplift of the reefs the data indicate that sea level stood 10 and 13 meters at 108 000 and 81 000 years before present respectively these results are in substantial agreement with those reported for barbados and new guinea and support the hypothesis of constant uplift for each area sea level data from raised reefs indicate that the interglacial marine oxygen isotope oscillations during oxygen isotope stage 5 are a result of 30 percent ice volume effects and 70 percent temperature effects

tectonic eustatic and climatic significance of raised beaches of val de saire cotentin normandy france detailed mapping morphostratigraphical and geochronological analyses were undertaken in the val de saire cotentin normandy northern france these studies have identified a series of middle and upper pleistocene age deposits overlying four wave cut platforms pf iv pf i which can be associated with temperate high sea level events and equated with mis 11 9 7 and mi substage 5e a sea level stand recorded at 20 m ngf at the la mondree site seems to correspond to mi substage 5c or 5a the completeness of the val de saire record and particularly the width of platform iv mis 11 has so far no equivalent on the south coast of the english channel this study provides contribution to an understanding of the impact of the interglacial glacial cycles in a coastal intraplate situation the cyclicity of the morphogenesis is explained by interaction between eustatic variations and strongly expressed activity of slow uplift ca 60 mm kyr through the middle pleistocene several osl dates from the gravel to sand sequence of the eemian weichselian cycle indicate that these deposits represent the marine regression of the end of the last interglacial

raised marine sequences of lanzarote and fuerteventura revisited a reappraisal of relative sea level changes and vertical movements in the eastern canary islands during the quaternary abstract systematic mapping and morphosedimentary analysis of fuerteventura and lanzarote islands supported by laboratory techniques u series mostly by tims 14c analysis and allo isoleucine measurements on biogenic carbonates from raised marine deposits paleomagnetic and a few k ar measurements on volcanic formations related to marine deposits provide a basis for constraining the age of late cainozoic marine units the most complete sequences of raised marine terraces are found at similar elevations in both islands they include up to 12 marine terraces episodes at elevations between 0 m and 70 m above mean sea level asl at least six terraces should be of quaternary age and more recent than 1 2 myr throughout the whole marine sequence with the exception of the holocene terrace the warm fauna assemblage is characterized by the presence of ostrea virleti nerita emiliana and strombus s cf coronatus s cf bubonius however there is a major change highlighted by the disappearance of the first two species below the 8 10 m terrace that could possibly correspond to mis 11 k ar measurements allow an estimate for mean uplift rate of 1 7 cm ka during the last million years the present elevation of the last interglacial deposits about 1 and 2 m asl shows discontinuous vertical movements with possibly a reverse trend since mis 9 in eastern canary islands

three dimensional streamlines in dupuit forchheimer models an approximate method is presented for determining streamlines in three dimensions using two dimensional dupuit forchheimer models the latter models of horizontal flow which may comprise several aquifers are based on the assumption that the resistance to flow in the vertical direction is neglected this assumption does not preclude the occurrence of flow in the vertical direction vertical components of flow are determined in an approximate fashion by requiring continuity of flow the problem of leakage from a shallow pond above an unconfined aquifer is discussed as an example of determining streamlines in three dimensions the errors induced by the approximation are determined for a few idealized flow problems that can be solved exactly

soil forming processes and rates on uplifted marine terraces in southwestern oregon usa soil chronosequences were examined on flights of tectonically uplifted marine terraces near cape blanco and cape arago southwestern oregon all of the soils contain abundant organic c and are strongly acidic ph in h2o 30 of the exchange sites saturated with al the soils in the two areas show a progression in development from spodosols to spodosols with clay enriched horizons and eventually to ultisols although the spodic and argillic horizons appear to be forming concurrently in the soils evidence is presented to support the concept that the spodic horizon is eventually masked by clay accumulation because of weathering in situ neoformation of clays and clay translocation the primary age related trends include increases in 1 the relative abundance of silt and clay 2 the ratio of quartz to feldspars in the very fine sand 100 50 m fraction and 3 the amounts of dithionite extractable fe and al and crystalline forms of fe in the profile

phreatic surface flow from a near reservoir saturated tongue steady and transient 2d darcian flows in a saturated tongue adjacent to a reservoir are studied analytically first a stable tongue receiving water from an inclined equipotential reservoir bed and losing moisture through a phreatic surface is considered the hydraulic head is governed by the laplace equation and the complex potential and complex coordinate are determined explicitly by the polubarinova kochina method at an arbitrary bank slopes and evapotranspiration rates in a particular case of a vertical slope the tongue becomes a right angled triangle extending into the layer for the same distance as the dupuit forchheimer model predicts second a saturated dupuit forchheimer flow in the tongue is analyzed under the assumption of evaporation exponentially and linearly decreasing with the depth of a phreatic surface the corresponding non linear ordinary differential equation is integrated twice and predicts the length of the tongue as a function of the reservoir water level third a transient regime is modelled by the boussinesq equation with evaporation uniform in space but varying cyclostationary with time a straight line water table translating upward downward is found to be located always below the water table for steady regimes with an average evaporation

characteristics of seismic activity of the upper silesian coal basin in poland summary the upper silesian coal basin uscb in poland is one of the most seismically active mining areas in the world seismic observations supported by the central mining institute date back to the 1950s and include an extensive mine tremors data bank which has been in operation since that time more than 55 900 mine tremors of energy e 105 j local magnitude ml 1 5 occurred over the period 1974 2005 in the uscb two types of tremors can be distinguished these are the so called mining tectonic seismicity and mining seismicity the mining tectonic seismicity results from the interaction between mining and tectonic factors these seismic events appear to be located in tectonically disturbed zones and their sources are visibly more energetic the mine tremor source mechanism can mostly be the normal dip slip fault with a marked strike slip component in the source region the rupture plane azimuths and dips of these seismic events correlate well with the strike and dip of the pre existing local faults in the vicinity of which the mine tremor sources have been located the generalized mine tremor source mechanism of the events under consideration contributed a less than 15 per cent implosion component an about 15 per cent uniaxial compressional component and an about 70 per cent shear component to the total seismic moment tensor solution the second one mining seismicity is strongly associated with the mining activity and seismic events that occur in the vicinity of active mining excavations these events are energetically weak and their source mechanism can be of explosive type the total seismic moment tensor is composed of 20 50 per cent explosive component practically the same amount of uniaxial compressional component and a very small amount of shear component less than 10 per cent

an updated and refined holocene uplift history of southern tenerife canary islands and the possible consequences for future volcanic activity various uplift markers suggest asymmetrical uplift of tenerife island with stable conditions in the north but significant uplift of up to 45 m in the south over the past 42 ka fossil shells in beach deposits uplifted by 7 5 9 m were 14 c dated at a holocene age of 2460 35 bp 1 this confirms earlier results and documents very young and probably still ongoing uplift of southern tenerife potentially caused by ascending magma this underlines that southern tenerife is probably undergoing a further cycle of volcanic activity that started 95 ka ago

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

the canary record of the evolution of the north atlantic pliocene new 40ar 39ar ages and some notable palaeontological evidence abstract two new 40ar 39ar ages and previously published k ar ages of basaltic pillow lava flows are coeval with closely related fossiliferous marine layers allowing us to establish the beginning 5 8 5 0 4 8 ma at ajui fuerteventura island and 4 8 0 03 ma 2 at tamaraceite and a middle stage 4 20 0 18 ma 2 at la esfinge in gran canaria island of early pliocene marine deposits in the canary islands here the presence of tropicopolitan fossils megaselachus megalodon janthina typica suggests the influence of a possible central american circumtropical current during the pliocene and in the north atlantic basin the presence of both janthina typica and the argonauta argo also indicate the occurrence of tropical storms in the area of the canary islands around that time in addition the pillow lava flow at la esfinge overlies a submarine pyroclastic layer containing ostrea offreti that was preserved in its life position a fossil from the terminal miocene and commonly found on the south eastern iberian peninsula at la cruz on fuerteventura island a dune formed above marine deposits lies beneath a palaeosol and a basaltic lava flow that was k ar dated at 2 9 ma near el marmol in gran canaria the corresponding palaeosol lies between lava flows k ar dated at 3 ma based on these observations we argue in this paper that the first appearance of the canary current the eastern boundary current of the north atlantic sub tropical gyre occurred between 4 2 ma and 2 9 ma ago this was followed by a major sea level drop of about 40 m and the formation of a first fossil bearing palaeosol which indicate that major climate change that took place around 2 95 2 82 ma

mapping small elevation changes over large areas differential radar interferometry a technique that uses synthetic aperture radar sar images to measure very small 1 cm or less surface motions with good resolution 10 m over large swaths 50 km is presented along with experimental results the method could be used for accurate measurements of many geophysical phenomena including swelling and buckling in fault zones residual displacements from seismic events and prevolcanic swelling the method is based on sar interferometry where two images are made of a scene by simultaneously flying two physically separated antennas then the phases of corresponding pixels are differenced and altitude formation is deduced from some simple computation and image rectification it is also possible to use one antenna flown twice over the same scene then if the second flight exactly duplicates the track of the first an interesting possibility occurs there would be no phase changes between the images at all unless there was a physical change in the scene such as ground swelling that would alter the distance from some resolution element to the antenna since the phase changes all occur at the short carrier wavelength the basic limitation on sensitivity is only the phase noise in the system when the two imaging passes are made from flight tracks that are separated which is the case with the seasat images used here it is no longer possible to distinguish surface changes from the parallax caused by topography however with some additional computation a third image made at some other baseline may be used to remove the topography and leave only the surface changes this method was applied using seasat data to an imaging site in imperial valley california where motion effects were observed that were ascribed to the expansion of water absorbing clays phase change images of this area are shown along with associated ground truth about the presence of water problems with the technique are explored along with a discussion of future experimental possibilities on upcoming sar missions like earth observing system eos earth resources satellite ers 1 sir c and the venus imaging radar magellan

morphometric analysis and its relation to tectonics in macaronesia abstract for an investigation of the relation between the morphology and the tectonics in the macaronesian islands i e the geographical group of middle atlantic islands between 10 n and 40 n orientation studies have been made of steeply dipping joints and where possible of the trends of valleys and ridges a coincidence of the preferred directions of these features indicates a probable genetic relation between them the results are 1 joint strikes stream directions and ridge trends where available generally agree with each other on each individual island indicating a common genetic tectonic origin of these features thus the main result of this study is that the morphology of all macaronesian islands although surficially of volcanic origin has been significantly codesigend by tectonic processes 2 the direction data for corresponding geomorphic features are essentially the same across each individual archipelago certainly with regard to the joints somewhat less so with regard to the links and ridges 3 the canary and the madeira islands archipelago yield the same values for the direction maxima of joints and streams 4 the compression 1 axis indicated by the fault plane solution of the canary earthquake of 9 may 1989 lines up with one of the bisectrices and not with one of the strike maxima of the surrounding joints this indicates that the joint directions may be indicative of the shear lines rather than of the principal stress directions of the neotectonic stress field in the area 5 there is a steady anticlockwise rotation of corresponding morphotectonic directions as one moves from africa westward from the canary islands through madeira and the cape verde islands to the azores this may be due to a general rotation of the area whilst drifting n africa has been subject to an anticlockwise rotation pole west of madeira owing to the drag caused by the eastward spreading atlantic ocean floor 6 the mid atlantic ridge seems to have no influence on the orientation of the joints streams ridges on the islands in the plate tectonic model this lining up of joint orientations may be the consequence of the mirror reflection of the displacements away from the ridge on its two sides 7 the situation at the triple junction of the eurasian african and american plates is not clear additional microplates azorean iberian might even be present the azores might i have arisen around the triple junction from basaltic lava upwelling from a mantle hot spot to be carried away as islands on the moving plates or ii they may represent a hot spot trace on moving plates since trachytic andesitic lava flows have been found on the islands iii a tectonic control model has been proposed in the literature without recurrence to basaltic plates the results of our morphometric studies would be able to conform to all three models

fault reactivation in the central indian ocean and the rheology of oceanic lithosphere the intraplate deformation in the central indian ocean basin is a well known example of a deviation from an axiom of plate tectonics that of rigid plates with deformation concentrated at plate boundaries here we present multichannel seismic reflection profiles which show that high angle reverse faults in the sediments of the central indian ocean extend through the crust and possibly into the uppermost mantle the dip of these faults which we believe result from the reactivation of pre existing faults formed at the spreading centre is 40 in the basement which is consistent with the distribution and focal mechanisms of earthquakes on faults now forming at spreading centres this style of deformation coupled with the observation of large earthquakes in the mantle lithosphere indicates that brittle failure of the oceanic lithosphere may nucleate in the vicinity of the brittle ductile transition and propagate through the crust

the distribution of 230th234u ages in corals and the number of last interglacial high sea stands abstract the 104 available 230 th 234 u analyses of unrecrystallized corals from stable emerged terraces indicate that the last interglacial period occurred approximately 125 000 yr ago an estimate is made of the exact duration of this period by accounting for the surprisingly small distribution width observed among the 80 most reliable analyses this distribution width is compared with those obtained for model populations generated by assuming various characteristic analytical errors and various lengths of the last interglacial period the results show that 1 if there was only a single rise in sea level it probably lasted no more than 12 000 yr in agreement with previous estimates and 2 if there were two separate rises of sea level the gap between them must have been less than 7500 yr and not 12 200 as proposed by some authors

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

crustal extension from exposed sheet intrusions review and method proposal abstract sheet intrusions are probably the most widespread magmatic features on earth they create a space for themselves by dilating the host rock the exposed sheet intrusions allow an estimate of a minimum value of the extension to which the crustal layers and the volcanic edifices are subject the correct evaluation of the contribution of sheet intrusions to the crustal extension is of great importance in various geologic settings the current methods used to evaluate the extension due to exposed sheet intrusions are reviewed in this paper the effect of the dip of sheet intrusions on the evaluation of horizontal crustal extension is analysed if the dip effect is neglected and the intrusions are sub vertical the error due to the dip effect in the extension evaluation is small if the intrusions are shallow dipping the error may be great and varies as a function of the dyke dip for dykes with dip range 45 65 the error due to neglecting the dip effect is 30 to 15 increasing discrepancies of more than 25 are produced on the computed dilation when the intrusions progressively dip less than 50 a simple method based on structural field measurements of exposed sheet intrusions and on trigonometric considerations is presented as an improvement of pre existing methods to estimate the horizontal component of the crustal extension using this method field data of 1154 dykes from different geodynamic contexts are analysed the horizontal component of extension is computed using dyke data from the tertiary massifs of lanzarote and tenerife and from the active stratovolcanoes of monte somma vesuvius and etna since the analysed dykes are steeply dipping the cumulative difference between the extension computed neglecting and taking into account the dip effect remains less than 10 for all the data sets the percentage difference is nearly constant and cumulatively higher for monte somma where the mean dip of the intrusions is smaller in lanzarote 237 dykes emplaced between 15 5 and 3 7 ma give a peak extension of 276 m in direction n135 and a time averaged minimum extension rate of 1 9 10 2 to 2 3 10 2 mm a 1 in tenerife an extension of 562 m is computed in the direction n65 from 563 dykes emplaced from 7 4 to 3 3 ma the time averaged minimum rate of extension for the tertiary massifs of tenerife ranges from 0 14 to 0 25 mm a 1 the peak extension computed for monte somma is 81 7 m in the direction n90 based on 96 exposed sheets very likely most of monte somma sheets intruded within 12 ka giving a time averaged minimum extension rate of 7 mm a 1 from 184 exposed dykes of etna a minimum extension rate of 6 2 mm a 1 is computed peak extension is 212 m in direction n35 the poor resolution of age constraints may affect deeply the reliability of the extension rates however from the examples presented it appears that the extension rates of pre erosional successions from intraplate volcanic islands can be smaller than those of active stratovolcanoes this may suggest a more active dynamics in the stratovolcanoes

new results on ground deformation in the upper silesian coal basin southern poland obtained during the doris project eu fp 7 this paper presents application of satellite interferometric methods persistent scatterer interferometric synthetic aperture radar psinsar and differential interferometric synthetic aperture radar dinsar for observation of ground deformation in the upper silesian coal basin uscb in southern poland the presented results were obtained during the doris project ec fp 7 grant agreement n 242212 www doris project eu several insar datasets for this area were analysed most of them were processed by tele rilevamento europa t r e s r l italy datasets came from different sar satellites ers 1 and 2 envisat alos palsar and terrasar x and cover three different sar bands l c and x they were processed using both insar techniques dinsar where deformations are presented as interferometric fringes on the raster image and psinsar where motion is indentified on irregular set of persistent scatterer ps points archival data from the c band european space agency satellites ers and envisat provided information about ground movement since 1992 until 2010 in two separate datasets 1992 2000 and 2003 2010 two coal mines were selected as examples of ground motion within inactive mining areas sosnowiec and saturn where mining ceased in 1995 and 1997 respectively despite well pumping after closure of the mines groundwater rose several dozen meters returning to its natural horizon small surface uplift clearly indicated on satellite interferometric data is related to high permeability of the hydrogeological subregion and insufficient water withdrawal from abandoned mines the older 1992 2000 psinsar dataset indicates values of ground motion ranging from 40 0 to 0 0 mm the newer 2003 2010 dataset shows values ranging from 2 0 to 7 0 mm this means that during this period of time subsidence was less and uplift greater in comparison to the older dataset this is even more evident in the time series of randomly selected ps points from both coal mines the presence of bentonite deposits in the saturn coal mine can also have influence on the ground surface uplift analysis of interferometric l and x band data in upper silesia has enabled observation and monitoring of the underground mining front for several months it was indicated by the example from the halemba wirek coal mine analysis of the terrasar x dataset processed by squeesar algorithms proved to be the most effective for this purpose x band persistent scatterer interferometry psi time series can help to indentify small seemingly negligible movements and are successfully supplemented by fringes when displacement becomes significant differential interferograms from the l band dataset detect similar displacement values but thanks to longer wavelength are characterized by better coherence especially in the middle of the subsidence trough results on ground deformation proved that ground motion above abandoned mines continues long after their closure therefore existing regulations stating that abandoned mines are considered fully safe five years after mine closure should change moreover it should be emphasised that construction in these areas should be avoided due to existing potential risks

interpreting quaternary uplift rates at the mendocino triple junction northern california from uplifted marine terraces analysis of the altitudinal spacing of 14 flights of marine terraces indicates a spatial pattern of varying uplift rates that agrees with that determined from previously dated terraces for the past 3 81 ka and temporal changes in uplift rates from 1 m ka to 3 5 m ka that may reflect response to changes in tectonic regime during passage of the mendocino triple junction mtj a possible mechanism for regional uplift is growth of a slab window south of the mtj the region of most rapid uplift is 25 43 km south of the mtj immediately south of the northern boundary of the slab window the coastline is tilted upward to the south in the region directly above the southern edge of the subducted gorda plate at point delgada 55 km south of the present mtj where the northern edge of the slab window passes approximately 300 ka uplift rates have been 1 2 m ka for at least 330 ka more than 1 4 m y after passage of the southern edge of the subducted slab at the mendocino coast uplift rates have been less than 0 4 m ka for at least 330 ka

the antiquity of the sahara desert new evidence from the mineralogy and geochemistry of pliocene paleosols on the canary islands spain abstract the sahara is the largest warm desert in the world but its age has been controversial with estimates ranging from miocene to holocene mineralogical and geochemical data show that paleosols of pliocene to mid pleistocene age on fuerteventura and gran canaria in the canary islands have developed in part from inputs of dust from africa these paleosols contain quartz and mica minerals that are abundant in african dust but are rare in the basaltic rocks that dominate the canary islands trace elements with minimal mobility sc cr hf th and ta as well as the rare earth elements show that paleosols have compositions that are intermediate between those of local rocks and african derived dust thus results reported here and in a recently published study by others indicate that 9 paleosols record delivery of african dust to the canary islands between 4 8 2 8 ma 3 0 2 9 ma 2 3 1 46 ma and 0 4 ma a long term paleosol record of african dust input agrees with deep sea records off the coast of western africa that imply increased dust fluxes to the eastern atlantic ocean at 4 6 ma it is concluded that the sahara desert has been in existence as an arid region dust source at least intermittently for much of the pliocene and continuing into the pleistocene

signature of cryptic sedimentary basin inversion revealed by shale compaction data in the irish sea western british isles 1 inversion is one of the most common modes of intraplate deformation and a primary mechanism of sedimentary basin exhumation the key criterion for identification of basin inversion is the contractional reactivation of extensional faults reverse displacement associated with inversion is focused along the upper segments of faults so the evidence for inversion may be removed in deeply exhumed basins we believe this is the case in the irish sea western british isles previous authors have attributed the severe exhumation of this basin to plume related uplift and have ruled out inversion as a cause of uplift we present a method for identifying tectonic inversion in a basin where exhumation has removed evidence of reverse displacement on the upper segments of faults we utilize compaction based mapping of erosion patterns recorded by anomalously high sonic velocities in upper triassic shales we show that the amount of section removed during exhumation in the irish sea varies between 1 3 and 3 3 km and that exhumation patterns are markedly heterogeneous neither the heterogeneity of exhumation nor its focusing over hanging wall blocks of major faults is consistent with solely plume related uplift and we believe that our results record cryptic basin inversion that is superimposed on epeirogenic exhumation some of which may be plume related the direct evidence for this inversion has been removed because erosion has proceeded beneath the null lines of reactivated faults and we propose erosion of reactivated fault segments as one of the major reasons why shortening is frequently underestimated in inverted basins

a warm interglacial episode during oxygen isotope stage 11 in northern chile abstract combined paleontological morphostratigraphic and geochronologic data from emerged middle pleistocene coastal deposits in mejillones peninsula 23 s northern chile strongly suggest that climatic conditions were particularly warm during the particularly warm during the oxygen isotope stage 11 high seastand episode an anomalous warm water molluscan assemblage from localities assigned to that interglaciation included several extralimital species presently living only north of 6 s or 14 s that were not present in the area during subsequent middle and late pleistocene or holocene interglacial episodes only two of these extralimital species may be found nowadays at the 23 s latitude in a protected locality immediately after the occurrence of strong el nino events many of the species of the thermally anomalous molluscan assemblage tama are the same as those which lived in a closed shallow lagoon near santa north central peru 9 s during a brief mid holocene episode the new findings thus indicate that lagoonal and protected embayments were significantly warmer than the open marine environment ca 400 ka actually the co occurrence of cool water fauna in exposed sectors of the coastline at that time suggests that the coastal upwelling activity and the humboldt current effects were not strongly reduced the warm water conditions prevailing in lagoons and protected bays during the mid brunhes episode may reflect particularly warm air temperatures and distinct ocean atmosphere relationships than those prevalent nowadays these data support the hypothesis that the oxygen isotope stage 11 was the warmest interglaciation at least in the southern hemisphere

ecoulement sature et non sature de l eau souterraine vers des drains en aquifere a nappe libre the drainage of sports fields highways farm lands and covers for wastes corresponds to the drainage of a shallow unconfined aquifer resting on a horizontal or sloping impervious substratum the seepage partly saturated and partly unsaturated is thus described by nonlinear equations that are not easy to solve a few analytical solutions exist they were obtained after several simplifying assumptions are they realistic in this paper comparisons are made between predictions from analytical solutions and those from numerical resolutions for saturated and unsaturated seepage under steady and transient states the analytical solutions predict a water table and flow rates that differ significantly from those of the numerical resolutions and are sometimes unrealistic corrections to the analytical solutions have already been proposed to account for the vadose zone despite such corrections the published solutions to drainage problems may be inaccurate in engineering projects where the duration of dra

eemian crustal deformation in the eastern baltic area in the light of the new sites at peski russia and pohja uhtju estonia abstract several eemian mikulino marine deposits are known from the northwestern part of russia and from estonia the best known deposits are situated at mga russia and at prangli estonia two new sites with clayey and silty deposits covered by till were studied for pollen and diatoms at peski russia and pohja uhtju estonia at peski the deposit representing the eemian interglacial is 3 8 m thick at the depth of 13 4 9 6 m above present sea level at pohja uhtju the deposit representing the eemian is 3 5 m thick at the depth of 47 9 51 4 m below present sea level although peski is situated at a higher altitude than pohja uhtju at present the diatom stratigraphy at these sites indicates deeper and more saline conditions in the peski area than at pohja uhtju during the eemian this result is similar to some previous studies which indicate that although the russian deposits e g peski mga are now at a higher altitude than those in estonia pohja uhtju and prangli the diatoms in the russian deposits are indicative of a considerable depth of water during the time of deposition these deposits suggest that the eemian shore levels ascend from estonia eastwards while the late weichselian and holocene shorelines tilt downwards in the same general direction the present material from estonia and northwestern part of russia shows marked differences between the eemian and late weichselian holocene crustal deformations which probably resulted from different ice loads during the final glaciation phases and probably also from different deglaciation patterns during the saalian and late weichselian

growth structure instability and collapse of canarian volcanoes and comparisons with hawaiian volcanoes recent onshore and offshore investigations in the canarian archipelago especially in the western islands of la palma and el hierro have greatly improved the understanding of the genesis and evolution of these islands and allow interesting comparisons with other hotspot induced oceanic island volcanoes especially the hawaiian archipelago genesis induced by hotspot activity and consequently shield and post erosional stages of growth allow the definition of similar main stratigraphic units the canarian and hawaiian volcanoes show common constructional and structural features such as rift zones progressive volcano instability and multiple gravitational collapses however the canaries present some important geological differences from the prototypical hotspot volcanoes of the hawaiian islands particularly the absence of significant subsidence the canarian volcanoes remain emergent until completely mass wasted by gravitational collapses and erosion volcanic formations over 20 million years are observable in outcrop in the canaries including the seamount stages of growth in several of the islands

variably saturated modeling of transient drainage sensitivity to soil properties abstract numerical analysis of a transient two dimensional rectangular symmetry unconfined drainage problem using a variably saturated flow model shows that the location of the phreatic surface and the height of the seepage face are functions of the capillary forces exerted in the vadose zone a sensitivity analysis investigating the effects of independent variations in the saturated hydraulic conductivity and the two van genuchten parameters is compared to one performed where the saturated hydraulic conductivity is functionally related to the van genuchten parameters the relationship between these descriptive soil parameters which may be used to describe the pore size density function of a porous medium and the saturated hydraulic conductivity is surmised based upon limited empirical evidence expressing the permeability as a function of these soil properties reverses the sensitivities of the variably saturated model to the van genuchten parameters from the preliminary work performed herein consideration of the number of degrees of freedom used when performing a sensitivity analysis is shown to warrant great care if the predicted sensitivities are to have meaningful physical interpretations

the quaternary marine terraces of santa cruz california evidence for coseismic uplift on two faults the coast parallel elevation pattern of marine terraces along 50 km of coast centered about santa cruz california provides an opportunity to assess the relative roles of candidate uplift mechanisms we assemble 130 existing latitude longitude elevation inner edge locations from three of these marine terraces to constrain elastic dislocation models of coseismic uplift uplift resulting from repeated oblique slip seismic events similar to the loma prieta earthquake m s 6 9 of october 17 1989 appears to explain well the portion of the terrace uplift pattern south of santa cruz depending on whether the lowest terrace is assumed to correspond to isotope stage 5c or 5e the calculated mean repeat time for loma prieta events is either 490 or 820 yr corresponding to either 4 1 or 2 4mm yr slip rates on the loma prieta fault residual uplift not explained by such events increases monotonically to the north toward ano nuevo where the san gregorio fault zone intersects the coastline we assess whether this residual uplift may result from repeated events on the san gregorio fault given only the strike of the san gregorio fault we use an extensive parameter search to determine the geometry of and the style of motion on the implied rupture plane that best explains this residual uplift the fault parameters that minimize the misfit between data and model imply activity of a moderately steep 70 north east dipping san gregorio fault that ruptures in oblique thrust slip from 15 km to the surface the thrust slip component dominates the uplift pattern resulting in uplift of the coastline from santa cruz northward these parameters match available geological geodetic and seismic data on the dip and sense of motion on strictures within the san gregorio fault zone the san gregorio fault has therefore been an active late pleistocene participant in north american pacific plate boundary motion we conclude that the complex pattern of uplift along this 50 km reach of coastline can be explained by coseismic mechanisms tied to san andmas bend related fault structures onshore and to the san gregorio fault zone offshore as both of these mechanisms result locally in considerable shore normal uplift gradients caution is warranted in applying common correlation techniques based solely on uplift rates in the assignment of terrace ages in this and other such settings in addition while it is tempting to use terrace culmination offsets as a means of estimating san andreas fault dextral slip rates we provide a formalism to determine under what conditions such calculations are meaningful we conclude that the terrace offsets along the santa cruz coastline result not from dextral slip on the san andreas but from differential indentation of the loma prieta uplift pattern by the various sea level highstand coastlines

anomalously shallow palaeomagnetic inclinations and the question of the age of the canarian archipelago summary extensive geological geophysical and geochronological data available from the canary islands establish conclusively that formation of the oldest subaerial volcanic structure of the islands began during the miocene a mid cretaceous age for these volcanic formations has been postulated in previous works on the basis of palaeomagnetic determinations the results obtained in the present palaeomagnetic study of lanzarote include analysis of the record of variations of magnetic inclination in boreholes that penetrate the whole of the oldest volcanic series they show that the excessive age previously assigned to these formations is due to the utilization of volcanic units with abnormally low 15 magnetic inclinations lgis in lanzarote lavas exhibiting lgis appear interbedded in a volcanic series that overall shows a typical miocene inclination 45 the units stratigraphically beneath and above the lgi horizons give in fact directions consistent with the middle upper miocene field direction d 359 i 45 with k 29 a95 6 7 and a palaeopole of 87 n 178 e thereby confirming the miocene age of the oldest subaerial volcanics of lanzarote short excursions of the geomagnetic field seem likely to be the explanation for these lgis since other factors such as tectonic tilting post eruptive modification of the primary remanence or errors in sample orientation can be disregarded the detection in the canary archipelago of volcanic units with abnormally low magnetic inclinations seems to be related to the relatively continuous record of the geomagnetic field in rapidly growing volcanic edifices as seems to be indicated by the presence of a few usually one or two short polarity events in volcanic suites of several hundred metres thickness

sedimentology of rocky shorelines 5 the marine samples at 326m from stearns swale lanai hawaiʻi and their paleo environmental and sedimentary process implications abstract fossiliferous gravels on lanai one of the smaller hawaiian islands are known collectively as the hulopoe gravel since 1984 several workers have attributed these gravels to deposition from the run ups and retreats of mega tsunami other workers before and since have interpreted the gravels as rocky shoreline deposits exposed by island uplift the existence of harold stearns makana paleoshoreline on lanai at 326 365 m elevation is particularly controversial in 1936 stearns collected some marine molluscan fossils from a site at 326 m elevation on the southern slope of lanai now known as stearns swale details of the site the fossils and his installed markers were recorded in his field note book now held by the us geological survey in honolulu the fossils were lodged in the national museum of natural history in washington d c during ww ii the 326 m site became a military installation and stearns markers and any remaining fossils were destroyed we have examined stearns notebook the 326 m site and the fossils two types of sediment adhere to the fossils a weakly cemented well rounded biocalcarenite grainstones with minor subrounded basalt fragments b calcite cemented sub rounded to well rounded volcanic litharenite or lithrudite with some bioclasts the fossil molluscs and the bioclasts in the adhering sands represent organisms typical of hawaiian rocky shorelines and adjacent submarine slopes these features are consistent with 1 deposition of the sediments on or closely overlying an unconformity surface cut in basalt bedrock in the vicinity of a rocky shoreline they are also consistent with 2 derivation of the materials from rocky shorelines or shorefaces at lower elevations and their transport up slope by waves generated by a category 5 hurricane or by a mega tsunami we prefer the first scenario as lanai s vertical mobility is indicated by at least ten topographically distinct shoreline related deposits located at various elevations on or adjacent to lanai including six submerged terraces on its western flank

two dimensional vertical moisture pressure dynamics above groundwater waves sand flume experiments and modelling this paper presents a new laboratory dataset on the moisture pressure relationship above a dispersive groundwater wave in a two dimensional vertical unconfined sand flume aquifer driven by simple harmonic forcing a total of five experiments were conducted in which all experimental parameters were kept constant except for the oscillation period which ranged from 268 s to 2449 s between tests moisture content and suction head sensor pairings were co located at two locations in the unsaturated zone both approximately 0 2 m above the mean watertable elevation and respectively 0 3 m and 0 75 m from the driving head boundary for all oscillation periods except for the shortest t 268s the formation of a hysteretic moisture pressure scanning loop was observed consistent with the decay of the saturated zone groundwater wave the size of the observed moisture pressure scanning loops decayed with increasing distance landward and the decay rate is larger for the shorter oscillation periods at the shortest period t 268s the observed moisture pressure relationship was observed to be non hysteretic but with a capillary capacity that differs from that of the static equilibrium wetting and drying curves this finding is consistent with observations from existing one dimensional vertical sand column experiments the relative damping of the moisture content with distance landward is higher than that for the suction head consistent with the fact that transmission of pressure through a porous medium occurs more readily than mass transfer this is further supported by the fact that observed phase lags for the unsaturated zone variables i e suction head and moisture content relative to the driving head are greater than the saturated zone variables i e piezometric head harmonic analysis of the data reveals no observable generation of higher harmonics in either moisture or pressure despite the strongly non linear relationship between the two in addition a phase lag of moisture content relative to the suction head was observed indicating that the response time of the moisture content to watertable motion is greater than that of the pore water pressure the observed moisture pressure dynamics are qualitatively reproduced using a hysteretic richards equation model however quantitative differences exist which are likely to be due to previous findings that demonstrated that the richards equation model is unable to accurately reproduce the observed watertable wave dispersion particularly at shorter period oscillations

investigating landslides with space borne synthetic aperture radar sar interferometry abstract this paper is addressed to readers without advanced knowledge of remote sensing it illustrates some current and potential uses of satellite synthetic aperture radar interferometry insar for landslide assessment data acquired by sar systems can provide 3d terrain models and be used to assist in regional scale investigations e g aimed at evaluation of susceptibility of slopes to failure under favourable environmental conditions the innovative permanent scatterers ps technique which overcomes several limitations of conventional sar differential interferometry dinsar applications in landslide studies is suitable for monitoring slope deformations with millimetric precision the ps technique combines the wide area coverage typical of satellite imagery with the capability of providing displacement data relative to individual image pixels with the currently available radar satellites however only very slow ground surface displacements can be reliably detected and measured the presented case study of a landslide from the liechtenstein alps indicates that the most attractive and reliable contribution provided by this remote sensing technique lies in the possibility of i wide area qualitative distinction between stable and unstable areas and ii qualitative relative hazard zonation of large slow landslides based on the identification of segments characterised by different movement rates since only the radar line of sight projection of the displacements can be detected a quantitative exploitation of the ps data is possible only where sufficient ground truth is available in site specific or single landslide investigations the ps data can represent a very useful complementary data source with respect to the information acquired through ground based observations and in situ surveying however the difficulties associated with the feasibility assessments of the applicability of sar data to local scale problems as well as with the interpretation of ps results require a close collaboration between landslide experts and specialists in advanced processing of radar satellite data the interpretation of the exact geotechnical significance of small radar sensed ground surface deformations is challenging especially where ground truth is lacking although any ground deformation is potentially of interest to an engineering geologist detection of movements in both vertical and horizontal directions is needed in the case of landslides to evaluate slope failure mechanisms with their high radar viewing angles however the current space borne systems can detect only a fraction of the horizontal component of movement it is expected that the upcoming sar dedicated missions with new sensors and different acquisition geometries combined with the rapid developments in the field of advanced radar data processing will allow a full 3d reconstruction of deformation data and help to further reduce the current limitations of the ps and similar dinsar approaches

tectonic evolution of the emergent part of a volcanic ocean island lanzarote canary islands abstract a reconstruction of the structural evolution of lanzarote confirms the existence of two principal stages of construction of the island separated by a main erosional event the first pre erosional is the shield stage miocene pliocene in age which is divided in three stratigraphic groups where different formations can be distinguished using unconformities mappable over the whole area of outcrop in the second post erosional stage developed during the quaternary nine stratigraphic levels are tentatively identified and are grouped in two phases of volcanic activity shields phase and pyroclastic cones phase data from 580 photogeologic lineaments as well as field data from 204 fault planes 195 with sense of movement 273 dykes and 45 volcanic alignments are presented the tectonic style of the deformations is brittle and polyphasic strike slip faults are dominant but normal and reverse faults are also present both the so called atlantic and african directions are well developed in trends of strike slip faults and volcanic indicators at least two deformation phases can be identified from the geometrical analysis of faults and from the stress tensor calculated using lineations on fault planes the reconstructed stress field responsible for the measured deformations changed orientation during the evolution of the island of lanzarote it is suggested that a permutation between principal stress axes 1 and 3 occurred subparallel to the length of the island between the pre erosional and post erosional stages

late pleistocene and holocene palaeoenvironments in golfo san jorge patagonia molluscan evidence palaeoenvironments suggested by molluscan assemblages preserved in late pleistocene and holocene raised marine terraces along the golfo san jorge central patagonia coastline argentina are reviewed in this work a better precision of the stratigraphical and geographical ranges of the molluscs through their systematic review shows that all taxa have living representatives mostly within the argentine and or magellanean zoogeographical provinces in general no significant taxonomic appearances or disappearances are evident along this coastal area since the last pleistocene highstand reinforcing that the modern palaeoceanographical pattern dominated by the cool malvinas falkland current has not been substantially modified and that the magellanean malacological province has lasted at least since the pleistocene although with varying boundaries the so called marine terrace v recently assigned to the last interglacial highstand oxygen isotope substage 5e showed in this area a molluscan assemblage characterised by very low diversity dominantly large shells of mulinia edulis and by cold water taxa in disagreement with higher sea surface temperatures within oxygen isotope substage 5e last interglacial maximum and suggesting softer substrates than in the modern adjacent littoral zone

soil development relative dating and correlation of late quaternary marine terraces in southwestern oregon abstract flights of tectonically uplifted late quaternary marine terraces are preserved at several localities along the oregon coast intervening coastal areas without marine terraces reflect net subsidence these gaps in the coastal terrace record make it difficult to correlate terraces along the pacific coast to test the utility of soils in relative dating and correlation two flights of marine terraces near cape blanco and cape arago were investigated the terraces could be distinguished in each area from soil morphological properties and a quantitative index of soil development derived from field descriptions the soils in the two areas show a progression in development from spodosols to spodosols underlain by clayey material to ultisols the lowest two terraces at cape blanco which have reported age estimates of 80 000 and 105 000 yr are correlative with the lowest two terraces at cape arago the fifth and oldest terrace at cape blanco has no equivalent at cape arago soil development indices for the third and fourth terraces at each area allow two alternative sets of correlations

contrasting styles and rates of tectonic uplift of coral reef terraces in the ryukyu and daito islands southwestern japan abstract coral reef terraces on kikai hateruma and yonaguni in the ryukyu islands on the eurasian lithospheric plate and those of kita daito and minami daito islands on the philippine sea plate indicate three distinct patterns of coral reef terrace formation and preservation primarily reflecting different uplift rates the kikai type which includes many terraces from oxygen isotope stages 5e to 1 is a result of high uplift rate of ca 1 8 m kyr on the fore arc rise of a chilean type subduction zone arcward westward tilting and faulting are also characteristic of the kikai type the hateruma type is characterized by two coral reef terraces younger than the stage 5e terrace and they are arranged in a concentric annular pattern slow uplift rate of ca 0 3 m kyr adjacent to a mariana type subduction margin is typical of the hateruma type the emergence of kikai and hateruma islands is recent younger than isotope stage 5e and 7 respectively reflecting the active deformations of the leading edge at the overriding eurasian plate in the daito type atolls surrounded by fringing reefs have been uplifted very slowly less than 0 05 m kyr but over a time period of at least several million years slow uplift and long history of daito type islands is the result of up bulging of the philippine sea plate as it migrates toward the ryukyu trench

emergent littoral deposits in the eastern canary islands abstract k ar ages a abdel monem p d watkins and p w gast 1971 american journal of science 271 490 521 this paper and revised paleontological determinations j meco 1977 los strombus neogenos y cuatenarios del atlantico euroafricano las palmas ediciones del excmo cabildo insular de gran canaria show that quaternary r crofts 1967 quaternaria 9 247 260 g lecointre k j tinkler and g richards 1967 academy of natural science of philadelphia proceedings 119 325 344 littoral deposits on lanzarote and fuerteventura are early pliocene and late pleistocene early and middle pleistocene strand lines are not represented early pliocene littoral and marine deposits contain a characteristic fossil assemblage strombus coronatus nerita emiliana gryphaea virleti patella cf intermedia and rothpletzia rudista differences in elevation record differential post pliocene uplift of the coastal platforms on which they lie late pleistocene beach deposits at low elevations belong to two groups an older with strombus bubonius and a younger without differences in elevation of early pliocene littoral deposits are reflected by differences in elevation of late pleistocene beach deposits nearby

extralimital senegalese species during marine isotope stages 5 5 and 11 in the canary islands 29 n sea surface temperature estimates abstract the presence of harpa doris roding 1798 in marine deposits of the last interglacial period 130 120 ka marine isotope stage or mis 5 5 in the canary islands gran canaria lanzarote and fuerteventura enabled us to compare this occurrence with its present habitat in the gulf of guinea and the cape verde islands well to the south this comparison leads to the conclusion that sea surface temperatures ssts in the waters around the canary islands during the last interglacial period were at least 3 3 c higher than today h doris is found in association with the large gastropod persististrombus latus gmelin 1791 as well as the coral siderastrea radians pallas 1766 the presence of these extralimital southern warm water species in the canary islands during the last interglacial period also implies a northward expansion of plankton feeding larvae in seawater with a high chlorophyll a content such conditions would require a shortening of the southern arm of the cool canary current that dominates the waters around the canary islands at present marine deposits dating to 400 ka mis 11 are also found on the canary islands in these deposits the presence of saccostrea cucullata born 1778 allows a comparison with its present habitat in the gulf of guinea in this analysis we conclude that ssts in waters around the canary islands during this major interglacial period were at least 4 2 c higher than today middle pleistocene fossils of s cucullata have also been found in the western mediterranean sea and morocco as well as the cape verde islands if these deposits also date to mis 11 sst warming could have been a regional phenomenon including much of the eastern atlantic ocean and mediterranean sea

climatostratigraphic scheme of the black sea pleistocene and its correlation with the oxygen isotope scale and glacial events abstract new evidence from the asov sea black sea region shows that after the cobb mountain magnetic event 1 1 myr there were 8 saline water events with mediterranean molluscs penetrating into the asov sea five times farther than the western manych strait and 7 or 10 cold freshwater events during the freshening phase the caspian sea molluscan fauna penetrated into the black sea each time the caspian mollusc assemblage was characterized by a new species of didacna thus some 18 20 bioclimatostratigraphic units can be distinguished in the asov sea black sea section for the last 1 myr their numerical age is estimated by some dozen thermoluminescence dates and 12 magnetic polarity datum planes the karangatian s lato corresponds to the interval 300 000 50 000 yr the uzunlarian to 580 000 300 000 yr and the chaudian to 1 100 000 600 000 yr the karangatian and tyrrhenian marine terraces correspond to marine isotope stages 5 and 7 the uzunlarian and milazzian to stages 11 15 and the chaudian and sicilian to stages 16 28 the number and ages of glacial interglacial cycles in continental europe are identical to the climatic cycles in the black sea and mediterranean

last interglacial sea stands on barbados and an early anomalous deglaciation timed by differential uplift three major sea level maxima between 137 and 120 kyr b p are documented by surveys of pairs of wave cut notches and other features associated with the broadly defined last interglacial coral terrace on barbados regression analysis of elevation differences between notch pair members as a function of their uplift rates at seven sites yields the age difference between first and third sea stands and their eustatic sea level difference these results when combined with stratigraphic data from the bahamas bermuda and western australia and a chronology based on age limits of corals from the bahamas and western australia yield an endpoint age and eustatic low tide elevation of 136 7 kyr b p and 7 4 m respectively for the first sea stand 126 kyr b p and 5 6 m for the second and 120 5 kyr b p and 3 0 m for the third the first sea stand is the result of an anomalous deglaciation that was completed during low northern summer milankovitch insolation this is contrary to the milankovitch hypothesis that orbitally controlled insolation largely determines the variations of glacial ice volume it implies that internal factors within the earth s climate system can be much stronger than the effects of insolation variations

sea level cycles during the growth of atlantic type oceans abstract first order changes in global sea level are commonly thought to be the result of short term fluctuations in oceanic spreading rate however eustatic high stands have occurred only twice in phanerozoic time and in both cases have followed supercontinent break up by a lag period of 50 100 ma therefore if pulses in spreading rate were the primary control of eustasy then for some reason rate increases would have had to have occurred with predictable periodicity with respect to major rifting events alternatively we propose that the major control on first order sea level cycles is the formation of atlantic type oceans with its attendant changes in the area age distribution of the global ocean floor and the formation of extensional passive margins our calculations indicate that both the approximate magnitude and relative timing of sea level highstands relative to supercontinent break up are predicted by this mechanism thus the importance of short term spreading rate variations in eustatic cycles becomes secondary

the maximum warmings of the pleistocene world climate recorded in the canary islands abstract evidence of the warmest pleistocene climatic changes is preserved in the eastern canary islands although the existence of raised fossiliferous marine deposits in northern gran canaria has been known since the 19th century their chronology and significance with regard to past sea levels and temperatures have remained uncertain here we show three marine transgressions recorded by raised marine deposits the highest 85 m above sea level masl and oldest marine deposit is interbedded in basaltic lava flows and has been dated using both palaeomagnetic and radiometric methods the age of these deposits located on the northwest coast of gran canaria near the town of agaete places the marine transgression in a first pleistocene interglacial into the plio pleistocene limit the marine deposit at an intermediate altitude 35 masl has been dated using the unspiked k ar method on a pillowed basaltic lava flow the age of these deposits in arucas places the transgression in the penultimate european mindel riss sense interglacial the deposits at 12 masl in las palmas are attributed to the last pleistocene interglacial on the basis of their fossil content which is similar to that of the matagorda deposits in lanzarote and matas blancas in fuerteventura radiometric dating of a lava flow overlying similar deposits at el cotillo in fuerteventura has been carried out the molluscan fauna associated with the deposits permits an estimation of the sea temperatures by reference to their present biogeographical distributions the plio pleistocene boundary coincides at agaete end of olduvai event with a high sea level between 1 8 and 1 75 ma oxygen isotopic stage ois 63 the dated marine deposits at arucas 0 42 ma place an interglacial in ois 11 3 and finally we confirm that in the canaries with only one high sea level with a senegalese fauna ois 5 5 they are not an outpost for the mediterranean tyrrhenian deposits with strombus oscillations

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

the chronology palaeogeography and archaeological significance of the marine quaternary record of the west sussex coastal plain southern england u k abstract the quaternary sediments of the west sussex coastal plain have produced a wide range of floral faunal and archaeological remains these sediments consist of marine sands and gravels exhibiting transgressive and regressive trends which occur from present day sea level to c 43 0 m o d and are overlain by terrestrial silts and cold climate periglacial sediments at the present day coastline channel fill deposits occur below modern beach levels new field observations coupled with a re investigation of old sites and literature suggest that five discrete high stands of sea level may be preserved in the area of the west sussex coastal plain age estimates for these deposits suggest that they span large parts of the middle and upper pleistocene oxygen isotope stages 13 to 5 conformable relationships between many of the marine and terrestrial sediments suggest that the potential exists within the area to correlate the marine and terrestrial quaternary stratigraphic records in addition sediments associated with two of these high sea level stands are associated with extensive buried landsurfaces covering large areas of the coastal plain at some locations these intact landsurfaces are associated with evidence for human activity and represent stratigraphic and cultural resources of international importance

quaternary laminar calcretes with bee nests evidences of small scale climatic fluctuations eastern canary islands spain thick laminar calcrete profiles are common on the surface of the eastern canary islands of lanzarote and fuerteventura this paper reports the study of one profile from lanzarote macher profile and one from fuerteventura tef a profile these profiles are about 2 m thick the macher profile is developed on basaltic host rocks and consists of two main horizons a lower horizon in which white veins of laminated micrite penetrate cracks and an upper laminar horizon the tef a profile is cumulative and consists from base to top of massive laminar and massive and laminar brecciated horizons highlighted in the study of these profiles are the presence of ooids the complex structure of the laminar horizons and the occurrence of fossil bee nests celliforma ooids consist of a nucleus of clay micrite and etched grains coated with envelopes of micrite and clay mainly palygorskite organic films favoured both the precipitation of carbonate and the adhesion of clays when the ooids formed in the soil the laminar horizons consist of a centimetre scale alternation of massive micrite with varied amounts of ooids and detrital grains with laminated micrite this alternation indicates the small scale periods of sedimentation erosion and soil formation in the upper part of a relatively stable surface these small scale alternations may reflect climatic vegetation changes in which arid periods are represented by micrite with ooids while laminated micrite reflects a better developed vegetation of the wet periods celliforma occur as ovoid larval cells with more or less rounded bases and a flat top the cells are about 3 cm long and 1 5 cm in diameter their wall is about 5 mm thick and is commonly laminated celliforma is interpreted as fossil nests of solitary bees their presence in the laminar horizon is evidence for the existence of a vegetation cover containing angiosperms

subsidence versus natural landslides when dealing with property damage liabilities in underground coal mines abstract this paper presents a case study in the town of boo asturias spain where land subsidence due to underground coal mining has been observed in the past along with landslides and natural ground settling the confluence of these phenomena represents a liability for mining companies any property damage caused by ground movements is considered by those affected to be a direct result of mining induced subsidence this has led to numerous property damage liability claims against mining companies even many years after the mining activities have stopped based on the analysis of geotechnical studies subsidence simulations developed with hundef and 3dec software and ground movement measurements together with research developed within the research fund for the coal and steel merida project the authors investigated the landslide and slope instability phenomena that are occurring in the town of boo moreover they determined the geographical and temporal limits to distinguish damages for which mining activity may be responsible from natural or human induced damages unrelated to mining this research will allow underground coal mining companies to manage property damage liability claims from a clearer perspective and may help researchers reconsider some studies that focused only on mining induced subsidence to explain ground movements within similar environments

interaction between shallow groundwater saline surface water and contaminant discharge at a seasonally and tidally forced estuarine boundary this paper presents findings from a 2 year field investigation of a dissolved hydrocarbon groundwater plume flowing towards a tidally and seasonally forced estuarine river system in perth western australia samples collected from transects of multiport wells along the riverbank and into the river enabled mapping of the fine scale 0 5 m vertical definition of the hydrocarbon plume and its longitudinal extent spear probing beneath the river sediments and water table and transient monitoring of multiport wells electrical conductivity was also carried out to define the zone of mixing between river water and groundwater the hyporheic zone and its variability the results showed that groundwater seepage into the estuarine surface sediments occurred in a zone less than 10 m from the high tide mark and that this distance and the hyporheic transition zone were influenced by tidal fluctuations and infiltration of river water into the sediments the dissolved btexn benzene toluene ethylbenzene the xylene isomers and naphthalene distributions indicated the behaviour of the hydrocarbon plume at the groundwater surface water transition zone to be strongly influenced by edge focussed discharge monitoring programs and risk assessment studies at similar contaminated sites should therefore focus efforts within the intertidal zone where contaminants are likely to impact the surface water and shallow sediment environments