aeolian sand sea development along the mid cretaceous western tethyan margin spain erg sedimentology and palaeoclimate implications the existence of a mid cretaceous erg system along the western tethyan margin iberian basin spain was recently demonstrated based on the occurrence of wind blown desert sands in coeval shallow marine deposits here the first direct evidence of this mid cretaceous erg in europe is presented and the palaeoclimate and palaeoceanographic implications are discussed the aeolian sand sea extended over an area of 4600 km2 compound crescentic dunes linear draa and complex aeolian dunes sand sheets wet dry and evaporitic interdunes sabkha deposits and coeval extradune lagoonal deposits form the main architectural elements of this desert system that was located in a sub tropical arid belt along the western tethyan margin sub critically climbing translatent strata grain flow and grain fall deposits pin stripe lamination lee side dune wind ripples soft sediment deformations vertebrate tracks biogenic traces tubes and wood fragments are some of the small scale structures and components observed in the aeolian dune sandstones at the boundary between the aeolian sand sea and the marine realm intertonguing of aeolian deposits and marine facies occurs massive sandstone units were laid down by mass flow events that reworked aeolian dune sands during flooding events the cyclic occurrence of soft sediment deformation is ascribed to intermittent marine flooding of aeolian dunes and associated rise in the water table the aeolian erg system developed in an active extensional tectonic setting that favoured its preservation because of the close proximity of the marine realm the water table was high and contributed to the preservation of the aeolian facies a sand drift surface marks the onset of aeolian dune construction and accumulation whereby aeolian deposits cover an earlier succession of coastal coal deposits formed in a more humid period a prominent aeolian super surface forms an angular unconformity that divides the aeolian succession into two erg sequences this super surface formed in response to a major tectonic reactivation in the basin and also marks the change in style of aeolian sedimentation from compound climbing crescentic dunes to aeolian draas the location of the mid cretaceous palaeoerg fits well to both the global distribution of other known cretaceous erg systems and with current palaeoclimate data that suggest a global cooling period and a sea level lowstand during early mid cretaceous times the occurrence of a sub tropical coastal erg in the mid cretaceous of spain correlates with the exposure of carbonate platforms on the arabian platform during much of the late aptian to middle albian and is related to this eustatic sea level lowstand

solution methods of hydraulic conductivity in low permeable saturated soil during liquid releasing solution methods of hydrogeological parameters in saturated zones for certain geological behaviors have been presented in many studies traditional solution methods of hydrogeological parameters such as hydraulic conductivity and storage coefficient were acquired by in situ hydrogeological experiment or seepage control equations however those two methods obtain a constant value of hydrogeological parameters which is not very suitable in practical cases this study assumes that hydrogeological parameters to be a variable value because the properties of soil were changed during liquid releasing an analytical solution for liquid releasing from saturated soil was deduced based on the existing seepage control equation and the analytical value of hydrogeological parameters was obtained moreover analytical expression for hydraulic conductivity was developed and variable hydraulic conductivity was gained by analyzing flow quantity during seepage different calculation methods were used to get constant and variable conductivity coefficient respectively a laboratorial test model of saturated soil under designed conditions was also established to verify the analytical solutions of both constant and variable parameters by fitting the calculated value and measured value curve seepage tests and case studies showed that variable hydraulic conductivity value presents higher agreement with the measured data for flux versus time than constant hydraulic conductivity in order to prove the fact that variable parameter is more reasonable in real cases we also conducted a group of comparative tests by rising and falling the hydraulic head of seepage model in three periods three different hydraulic conductivities were obtained and then they were substituted to seepage equation for the sake of curve fitting the correlation coefficient between measured flow versus time curve obtained from hydraulic conductivity vs time curve and calculated flow versus time curve is higher than flow versus time obtained from hydraulic conductivity versus periods solution methods suggested in this paper are generally applicable to problems involving the hydraulic conductivity specific storage and other related hydrogeological parameters calculation of low permeable saturated soil

continental shelf freshwater water resources and improved oil recovery by low salinity waterflooding this study assesses the feasibility of utilizing offshore freshwater for improved oil recovery in passive margin marine environments low salinity water flooding 5 km3 1 89x1011 barrels of fresh 3 of fresh brackish water 9 to 8 7x1010 barrels mile of shoreline most within 20 to 100 km from the coast in water depths of 10 to 50m because the majority of the offshore oil platforms are located less than 100 km 60 miles from the shore these resources could be utilized for low salinity recovery cross sectional aquifer models of offshore fresh brackish production indicate that a single 1000m 3280 ft long horizontal well could produce 19 200 m3 day 120 764 barrels day from a relatively permeable aquifer 10 11 to 10 12 m2 10 000 to 1000 md overlain by a moderately tight 10 15 m2 1 md confining unit for the typical life span of a well 30 years

climate and vegetation history of western portugal inferred from albian near shore deposits gale formation lusitanian basin the late early cretaceous greenhouse climate has been studied intensively based on proxy data derived essentially from open marine archives in contrast information on continental climatic conditions and on the accompanying response of vegetation is relatively scarce most notably owing to the stratigraphic uncertainties associated with many lower cretaceous terrestrial deposits here we present a palynological record from albian near shore deposits of the lusitanian basin of w portugal which have been independently dated using sr isotope signals derived from low mg oyster shell calcite 87 sr 86 sr values fluctuate between 0 707373 0 00002 and 0 707456 0 00003 absolute values and the overall stratigraphic trend match well with the global open marine seawater signature during albian times based on the new sr isotope data existing biostratigraphic assignments of the succession are corroborated and partly revised spore pollen data provide information on the vegetation community structure and are flanked by sedimentological and clay mineralogical data used to infer the overall climatic conditions prevailing on the adjacent continent variations in the distribution of climate sensitive pollen and spores indicate distinct changes in moisture availability across the studied succession with a pronounced increase in hygrophilous spores in late early albian times comparison with time equivalent palynofloras from the algarve basin of southern portugal shows pronounced differences in the xerophyte hygrophyte ratio interpreted to reflect the effect of a broad arid climate belt covering southern and southeastern iberia during early albian times

timing of early angiosperm radiation recalibrating the classical succession new stratigraphically controlled pollen data from the late early cretaceous of portugal allow a recalibration of the classical continental succession of the potomac group usa which has long been used to demonstrate the gradual morphological changes of angiosperm leaves and pollen the portuguese record represents the best dated succession of angiosperm pollen assemblages of the interval between the late barremian and the mid albian comparison of the angiosperm pollen record of the potomac group with the pollen assemblages from portugal and with other independently dated records indicates that the distinct differences in the angiosperm pollen assemblages between the three formations of this group the patuxent formation arundel clay formation and patapsco formation are related to discontinuities our revised age model for the potomac group implies a major discontinuity between the arundel clay of early albian age and the patapsco formation of mid albian early cenomanian age the portuguese record reveals a so far undocumented radiation phase of angiosperms within the early aptian to mid albian in which monocolpate angiosperm pollen of monocot and or magnoliid affinity appear as a highly diversified group these new findings imply that the onset of the radiation of monocots magnoliids preceded the radiation of eudicots by at least 10 ma

ice sheet load cycling and fluid underpressures in the eastern michigan basin ontario canada strong fluid underpressures have been detected in paleozoic strata in the eastern michigan basin with hydraulic heads reaching 400 m below land surface 4 mpa underpressure and 200 m below sea level in strata where unusually low permeabilities 10 20 10 23 m2 were measured in situ multiple glaciations including three with as much as 3 km of ice cover at the site in the last 120 ka suggest a causal link with the underpressures we examined this possibility using a one dimensional groundwater flow model incorporating mechanical loading from both ice weight and lithospheric flexure because hydrologic and mechanical changes during glaciation are not well characterized and subsurface properties are imperfectly known the model was used inversely to estimate flexural loads and loosely constrained permeabilities by matching observed pressures acceptable matches were obtained for a surprisingly wide range of scenarios with permeabilities close to measured values and plausible flexural loads matches were not obtained when too many parameters were preselected or when permeabilities were constrained to be significantly larger than measured values in successful model runs groundwater expulsion under glacial mechanical loads caused the underpressuring and flexural loads were important if aquifer and sub glacial pressures were significantly elevated during glaciation simulated fluid pressures in the low permeability strata fluctuated by 30 40 mpa during glacial cycles but resulted in advective transport of only tens of meters or less although other mechanisms cannot be ruled out we conclude that glacial mechanical forcing of a water saturated system can explain the observed underpressures

contaminant transport in a small deformation aquitard affected by the delayed drainage phenomenon this paper presents a formulation accounting for the effect of delayed drainage phenomenon ddp on the breakthrough of contaminant flux in an aquitard by considering the movement of soil particles porosity variation hydraulic head variation and transient flow during the consolidation the water flow equation in an aquitard was based on the terzaghi s consolidation theory and the contaminant transport equation was derived on the basis of the mass balance law two cases were used to illustrate the effect of ddp on the contaminant transport in an aquitard of small deformation it is found that the breakthrough time of contaminant in an aquitard is very long which is mainly ascribed to the low permeability of aquitard and sorption of soil particles it is also found that the increase of depletion which is in general induced by the increase of thickness and specific storativity and the decrease of hydraulic conductivity enhance the impact of ddp on the contaminant transport in an aquitard a larger delay index 0 of ddp gives a greater delay breakthrough time dbt of solute transport in an aquitard which controls the difference of the breakthrough time of contaminant transport in aquitards with and without the occurrence of ddp for the cases where advection plays a dominant role during the process of solute transport 0 is almost linearly correlated with dbt and the ratio of dbt over the breakthrough time without consideration of ddp also approximately shows a linear relationship with the ratio of specific storativity to porosity given a fixed drawdown in the adjacent aquifer with the sorption being ignored

overpressures in the anadarko basin southwestern oklahoma static or dynamic fluid pressures were estimated from mud weights and wellhead shut in pressures along a north south linear trend through the anadarko basin in southwest oklahoma fluid pressures above hydrostatic start at a depth of about 2 5 km on a normalized scale where hydrostatic pressure equals 0 and lithostatic pressure equals 1 estimates of fluid pressures were found to range from 0 4 to 0 8 over a depth range of 4 7 km using scale analyses and a simple numerical model we evaluated two end member hypotheses compaction disequilibrium and hydrocarbon generation as possible causes of overpressuring in the anadarko basin if compaction disequilibrium is the primary cause of present day overpressures in the anadarko basin the anadarko basin is required to have an average permeability of 10 23 m2 10 8 md or lower if geopressures in the anadarko basin result from hydrocarbon generation average basin permeabilities can be as high as 10 21 m2 10 6 md scaling these average permeabilities down to thicknesses of 100 m or less implies permeabilities lower than 10 25 m2 10 10 md are required in the most optimistic scenario the lowest permeabilities ever measured on sedimentary rocks are in the neighborhood of 10 22 10 23 m2 10 7 10 8 md thus it is not possible to reconcile the existence of overpressures in the anadarko basin with classic hydrodynamic theories that maintain that aquicludes do not exist either some unknown process is generating excess fluid pressures or the anadarko basin contains pressure seals geopressure models that invoke compaction disequilibrium and are commonly applied to cenozoic basins undergoing rapid sedimentation e g the gulf coast basin of the southeastern united states do not appear to apply to the anadarko basin the anadarko basin belongs to a group of cratonic basins that are tectonically quiescent and characterized by the association of abnormal pressures with natural gas begin page 146

a method to estimate groundwater depletion from confining layers 1 although depletion of storage in low permeability confining layers is the source of much of the groundwater produced from many confined aquifer systems it is all too frequently overlooked or ignored this makes effective management of groundwater resources difficult by masking how much water has been derived from storage and in some cases the total amount of water that has been extracted from an aquifer system analyzing confining layer storage is viewed as troublesome because of the additional computational burden and because the hydraulic properties of confining layers are poorly known in this paper we propose a simplified method for computing estimates of confining layer depletion as well as procedures for approximating confining layer hydraulic conductivity k and specific storage ss using geologic information the latter makes the technique useful in developing countries and other settings where minimal data are available or when scoping calculations are needed as such our approach may be helpful for estimating the global transfer of groundwater to surface water a test of the method on a synthetic system suggests that the computational errors will generally be small larger errors will probably result from inaccuracy in confining layer property estimates but these may be no greater than errors in more sophisticated analyses the technique is demonstrated by application to two aquifer systems the dakota artesian aquifer system in south dakota and the coastal plain aquifer system in virginia in both cases depletion from confining layers was substantially larger than depletion from the aquifers

a review of mesozoic climates there is overwhelming evidence based on the distribution of distinctive sediments and fossils and oxygen isotope data that the climate of the mesozoic world was appreciably more equable than that of today with no polar ice caps but precise quantitative data are not available except for an episode of late cretaceous cooling there is no good documentation of any significant change in global temperature distributions through the era the distribution of coals and evaporites together with other criteria indicates a pattern of humid arid and zones appreciably different in important respects from that of today during the triassic and jurassic western pangaea in low to middle latitudes was largely arid but in the early cretaceous the lands on the margin of the newly opening central atlantic and western tethys experienced a humid climate by late cretaceous times arid zones had become very restricted in extent because of insufficient suitable data attempts at climatic modelling have had only modest success and only to a limited extent can the major long term changes in climate between the permian and the present be explained in terms of changing geography the most probable explanation of mesozoic equability is an increased atmospheric co 2 content a number of enigmas remain such as the existence of flourishing forests in polar palaeolatitudes whereas for the late cenozoic short term climatic changes can be related successfully to variations in the geometry and mechanics of the earth sun system there is a long way to go before comparable success can be claimed for the mesozoic

recognition of cyclic and non cyclic environmental changes in the mediterranean pliocene a palynological approach the interval between 2 8 and 2 3 ma b p from the south italian singa section has been investigated for its dinoflagellate cyst and sporomorph contents in order to facilitate palaeoenvironmental interpretation the following curves are derived from the data the ratios sporomorphs dinoflagellate cysts protoperidinioid gonyaulacoid dinoflagellate cysts warm cold water indicating dinoflagellate cysts inner neritic oceanic dinoflagellate cysts outer neritic oceanic dinoflagellate cysts and the reworked dinoflagellate cysts per gram of sediment furthermore the already available 18o curve has been used calibration of changes in the sporomorph dinoflagellate ratio against the computed astronomical insolation curve leads to an improved age assessment for the section frequency analysis on the curves shows the 23 41 and 100 ka frequency components to be most important phase and amplitude differences between the filtered 23 41 and 100 ka frequency components are used for environmental interpretation the 23 ka frequency band is best explained by changes in runoff induced transport the 41 ka frequency components are classified in a group with short response time to orbital forcing and a group with longer response time those signals having a short response time are attributed to local precipitation induced changes in runoff those signals having a longer response time are mainly attributed to changes in global temperature and to a lesser extent to changes in global ice volume finally longer term cyclic and non cyclic changes are mainly attributed to temperature and sea level variation

mineralogy geochemistry and genesis of clays interlayered coal seams succession in the neogene lacustrine seyitomer coal deposit kutahya western turkey abstract the seyitomer coal deposit is an important source of energy in turkey this study aims to determine mineralogical geochemical characteristics and genesis of clays associated with coal seams in order to identify their precipitation environment the late miocene pliocene units comprise organic rich shale organic rich marl marl coal seam siltstone and sandstone deposited in a fluvial and lacustrine environment with associated tuff and tuffite in the seyitomer coal deposit serpentinite sandstone organic rich shale and tuffaceous host rocks of the coal deposit are partly to completely argillized and partially carbonate cemented having also stockwork type silica in fill fissures smectite illite and kaolinite are associated with quartz feldspar olivine gypsum and pyrite oriented flaky illite with irregular outlined kaolinite and smectite flakes edging and coating relict feldspar and volcanic glass grains developed by a dissolution precipitation mechanism in an alkaline micro environment during deposition and diagenetic process the occurrence of subrounded microorganisms on resorbed feldspar and the coexistence of smectite illite flakes with organic matter pyrite and siderite indicates that degradation of feldspar and devitrification of volcanic glass is biologically mediated the slight enrichment of heavy rare earth elements hree compared to light rare earth elements lree with a positive eu and ce anomalies reflects fractional crystallization of feldspar and amphibole alteration of feldspar biotite serpentine and volcanic glass resulted in the concentration of al fe mg and k in a stagnant environment and precipitation of beidellitic smectite and illite in an alkaline environment kaolinite precipitated in an acidic open hydrological system an increase in ni co and v v ni ratios in altered units also suggest anoxic and anoxic to dysoxic conditions occurrence of pityosporites microalatus pinus laevigatosporites haardti pityosporites spp polyvestibulopollenites verus alnus compositae and graminae in the seyitomer coal deposit suggest subtropical to warm temperature humid climate during late oligocene middle miocene period association of argillization and silicification with coal microorganisms pyrite and gypsum indicates a swampy environment and partial hydrothermal processes this interpretation is corroborated by the calculated formation temperatures from stable isotope analysis of 30 463 c for smectite and 140 156 c for illite the high 34s isotope values 16 8 33 3 indicate a mixed diagenetic and hydrothermal origin for the sulphide and sulfate minerals

climate and sea level variations along the northwestern tethyan margin during the valanginian c isotope excursion mineralogical evidence from the vocontian basin se france a high resolution mineralogical study bulk rock and clay fraction was carried out upon the hemipelagic strata of the angles section vocontian basin se france in which the valanginian positive c isotope excursion occurs to investigate sea level fluctuations and climate change respectively a detrital index di phyllosilicates and quartz calcite and a weathering index wi kaolinite illite chlorite were established and compared to second order sea level fluctuations in addition the mineralogical data were compared with the high nutrient index hni based on calcareous nannofossil taxa data obtained by duchamp alphonse et al 2007 in order to assess the link between the hydrolysis conditions recorded on the surrounding continents and the trophic conditions inferred for the vocontian basin it appears that the mineralogical distribution along the northwestern tethyan margin is mainly influenced by sea level changes during the early valanginian pertransiens to stephanophorus ammonite zones and by climate variations from the late early valanginian to the base of the hauterivian top of the stephanophorus to the radiatus ammonite zones the sea level fall observed in the pertransiens ammonite zone early valanginian is well expressed by an increase in detrital inputs an increase in the di associated with a more proximal source and a shallower marine environment whereas the sea level rise recorded in the stephanophorus ammonite zone corresponds to a decrease in detrital influx a decrease in the di as the source becomes more distal and the environment deeper interpretation of both di and wi indicates that the positive c isotope excursion top of the stephanophorus to the verrucosum ammonite zones is associated with an increase of detrital inputs under a stable warm and humid climate probably related to greenhouse conditions the strongest hydrolysis conditions being reached at the maximum of the positive c isotope excursion from the verrucosum ammonite zone to the base of the hauterivian radiatus ammonite zone climatic conditions evolved from weak hydrolysis conditions and most likely a cooler climate resulting in a decrease in detrital inputs to a seasonal climate in which more humid seasons alternated with more arid ones the comparison of the wi to the hni shows that the nutrification recorded al the angles section from the top of the stephanophorus to the radiatus ammonite zones including the positive c isotope shift is associated with climatic changes in the source areas at that time increased nutrient inputs were generally triggered by increased weathering processes in the source areas due to acceleration in the hydrological cycle under greenhouse conditions this scenario accords with the widely questioned palaeoenvironmental model proposed by lini et al 1992 and suggests that increasing greenhouse conditions are the main factor that drove the palaeoenvironmental changes observed in the hemipelagic realm of the vocontian basin during the valanginian positive c isotope shift this high resolution mineralogical study highlights short term climatic changes during the valanginian probably associated to rapid changes in the c cycle coeval massive parana etendeka flood basalt eruptions may explain such rapid perturbations c 2011 elsevier b v all rights reserved

the action of wind and water in a mid cretaceous subtropical erg margin system close to the variscan iberian massif spain aeolian processes and ephemeral water influx from the variscan iberian massif to the mid cretaceous outer back erg margin system in eastern iberia led to deposition and erosion of aeolian dunes and the formation of desert pavements remains of aeolian dunes encased in ephemeral fluvial deposits aeolian pods demonstrate intense erosion of windblown deposits by sudden water fluxes the alternating activity of wind and water led to a variety of facies associations such as deflation lags desert pavements aeolian dunes pebbles scattered throughout dune strata aeolian sandsheets aeolian deposits with bimodal grain size distributions mud playa ephemeral floodplain pebble sand and cobble sand bedload stream pebble cobble sand sheet flood sand bedload stream debris flow and hyperconcentrated flow deposits sediment in this desert system underwent transport by wind and water and reworking in a variety of sub environments the nearby variscan iberian massif supplied quartzite pebbles as part of mass flows pebbles and cobbles were concentrated in deflation lags eroded and polished by wind driven sands facets and ventifacts and incorporated by rolling into the toesets of aeolian dunes the back erg depositional system comprises an outer back erg close to the variscan highlands and an inner back erg close to the central erg area the inner back erg developed on a structural high and is characterized by mud playa deposits interbedded with aeolian and ephemeral channel deposits in the inner back erg area ephemeral wadis desiccated after occasional floods were mud cracked and overrun episodically by aeolian dunes subsequent floods eroded the aeolian dunes and mud cracked surfaces resulting in largely structureless sandstones with boulder size mudstone intraclasts floods spread over the margins of ephemeral channels and eroded surrounding aeolian dunes the remaining dunes were colonized occasionally by plants and their roots penetrated into the flooded aeolian sands upon desiccation deflation resulted in lags of coarser grained sediments a renewed windblown supply led to aeolian sandsheet accumulation in topographic wadi depressions synsedimentary tectonics caused the outer back erg system to experience enhanced generation of accommodation space allowing the accumulation of aeolian dune sands ephemeral water flow to the outer back erg area supplied pebbles eroded aeolian dunes and produced hyperconcentrated flow deposits fluidization and liquefaction generated gravel pockets and recumbent folds dune damming after sporadic rains the case of the namib desert monsoonal water discharge thar desert and meltwater fluxes from glaciated mountains taklamakan desert are three potential non exclusive analogues for the ephemeral water influx and the generation of hyperconcentrated flows in the cretaceous desert margin system an increase in relief driven by the aptian anti clockwise rotation of iberia led to an altitude sufficient for the development of orographic rains and snowfall which fed melt water fluxes to the desert margin system quartzite conglomerates and sands dominantly consisting of quartz and well preserved feldspar grains which are also observed in older cretaceous strata indicate an arid climate and the mechanical weathering of precambrian and palaeozoic metamorphic sediments and felsic igneous rocks unroofing of much of the cover of sedimentary rocks in the variscan iberian massif must therefore have taken place in pre cretaceous times

a new technique for obtaining high resolution pore pressure records in thick claystone aquitards and its use to determine in situ compressibility 1 laboratory tests are commonly used to determine properties vertical compressibility specific storage ss and vertical hydraulic conductivity kv of claystone aquitards however whether data representative of in situ conditions can be obtained from disturbed samples is questionable here we present a method to determine the in situ and ss of a thick sequence of cretaceous aged claystone by estimating the loading efficiency of a formation from pore pressure responses to barometric pressure fluctuations we installed 10 vibrating wire pressure transducers at different depths 25 325 m below ground in a thick claystone aquitard by placing them directly within the cement bentonite grout two years of continuous transducer records using this method appeared to provide pore pressure data with a resolution of better than one part in 105 equivalent to millimeter of hydraulic head change pore pressure responses to barometric pressure changes earth tides and precipitation events can be clearly identified and the barometric responses can be easily analyzed the resulting values of 0 6 0 93 2 5 10 7 to 2 2 10 6 kpa 1 and ss 2 6 10 5 to 4 5 10 6 m 1 all decrease with depth the results are comparable with the limited existing data for in situ estimates of ss and are as much as an order of magnitude smaller than laboratory estimates of ss for similar aquitard deposits our findings suggest that the fully grouted transducer method can provide an accurate and reliable means to monitor pore pressure changes and to determine in situ parameters for bedrock aquitard systems

mid cretaceous albian santonian sea surface temperature record of the tropical atlantic ocean paleoclimate records of geologic time periods characterized by extreme global warmth such as the mid cretaceous are important for a better understanding of the earth9s climate system operating in an exceptionally warm mode here we applied an organic geochemical proxy tex 86 on organic matter rich albian santonian sediments recovered from ocean drilling program leg 207 sites 1258 and 1259 on demerara rise to reconstruct sea surface temperatures ssts in the western equatorial atlantic preceded by a stepwise cenomanian warming trend 31 35 c the onset of the cretaceous thermal maximum coincided here with the cenomanian turonian boundary event once established this extreme warm climate regime characterized by averaged tropical ssts close to 35 c lasted up to the turonian coniacian transition two pronounced cooler intervals 2 3 c interrupt this otherwise remarkably stable record providing the first 18 o independent evidence for middle turonian cooling that previously has been attributed to glacioeustatic sea level lowering coniacian ssts decline stepwise reaching a minimum in the santonian 32 33 c where cooling is most pronounced presumably concomitant with the first progressive opening of a deep water passage through the equatorial atlantic gateway

geostatistical inverse modeling for the characterization of aquitard heterogeneity using long term multi extensometer data abstract the classical aquitard drainage model compac was used to simulate the deformation of a one dimensional vertically heterogeneous aquitard i e heter compac by coupling heter compac with the quasi linear geostatistical inversion approach the vertical heterogeneities of hydraulic conductivity k v elastic specific storage s ske and inelastic specific storage s skp fields could be characterized with the availability of long term multi extensometer data the methodology was first tested through a group of ten synthetic cases with randomly generated k v s ske and s skp fields results of the synthetic cases revealed that a geostatistical model could characterize the variability of aquitard hydraulic parameter fields and yields improved fits of simulated versus observed zone deformation than a geological model that treats each zone to be homogeneous subsequently the methodology was applied to a research site situated in changzhou city jiangsu province china where long term deformation behaviors of the strata within the aquifer aquitard system have been monitored vertical heterogeneities of k v s ske and s skp fields of the investigated aquitard at the site were characterized using the quasi linear geostatistical approach the correlation length of the three fields that yielded the best quality fit was assessed to be approximately 50 m and the fitting quality was slightly improved in comparison with that produced from calibrating a geological or zonation model through monte carlo analysis of aquitard deformation utilizing the inversed parameters and corresponding uncertainties the investigated aquitard is estimated to have compacted 914 8 42 6 mm before the rise in groundwater levels in adjoining aquifers

late cretaceous to early paleocene climate and sea level fluctuations the tunisian record abstract climate and sea level fluctuations across the cretaceous tertiary k t transition in tunisia were examined based on bulk rock and clay mineralogies biostratigraphy and lithology in five sections el melah el kef elles ain settara and seldja spanning from open marine to shallow inner neritic environments late campanian to early danian trends examined at el kef and elles indicate an increasingly more humid climate associated with sea level fluctuations and increased detrital influx that culminates at the k t transition this long term trend in increasing humidity and runoff in the tethys region is associated with middle and high latitude cooling results of short term changes across the k t transition indicate a sea level lowstand in the latest maastrichtian about 25 100 ka below the k t boundary with the regression marked by increased detrital influx at el kef and elles and a short hiatus at ain settara a rising sea level at the end of the maastrichtian is expressed at elles and el kef by deposition of a foraminiferal packstone a flooding surface and condensed sedimentation mark the k t boundary clay which is rich in terrestrial organic matter the p0 p1a transition is marked by a sea level lowstand corresponding to a short hiatus at ain settara where most of p0 is missing and a period of non deposition and erosion in the lower part of p1a 64 95 ma at seldja p0 and possibly the topmost part of cf1 are missing these sea level fluctuations are associated with maximum humidity these data suggest that in tunisia long term environmental stresses during the last 500 ka before the k t boundary and continuing into the early danian are primarily related to climate and sea level fluctuations within this long term climatic trend the pronounced warm and humid event within the latest maastrichtian zone cf1 may be linked to greenhouse conditions induced by deccan volcanism the absence of any significant clay mineral variations at or near the k t boundary and ir anomaly suggests that the bolide impact had a relatively incidental short term effect on climate in the tethys region

windblown desert sands in coeval shallow marine deposits a key for the recognition of coastal ergs in the mid cretaceous iberian basin spain introductionthe action of the wind in ancientsedimentary records is commonlybased on the direct observations ofdune and interdune deposits within ahierarchy of aeolian bounding surfa ces a direct observation of ancientaeolian systems is not always possibleas they are prone to erosion and to theremoval of sand into other uvial andmarine systems although the aeoliandeposits may no longer be present their former existence can be inferredon the basis of grain size characteris tics and aeolian features on grainsurfaces aeolian sediments indeedconstitute an important source formarine deposits kukal and saadal lah 1973 fryberger et al 1983 widespread ne grained very well sorted quartz sandstones characterizeshallow marine facies in the mid cre taceous of the eastern spain iberianbasin the good sorting and round ness of the grains hint at the presenceof a nearby erg system suggestive ofan arid climatic zone along the west ern tethyan margin during the mid cretaceous geological settingthe mesozoic iberian basin along thewestern tethyan margin has one ofthe more complete lower middle cre taceous sedimentary records in eur ope the iberian range is a nw sestriking intraplate fold belt generatedby the tectonic inversion of theiberian basin during the palaeogene fig 1a b salas and casas 1993 capote et al 2002 this basin wasformed by crustal thinning duringthe late permian triassic and latejurassic early cretaceous rift stages salas and casas 1993 arche andlo pez go mez 1996 during thesecond rift stage extensional sub basins were formed as part of thelarger maestrazgo basin i e the east ern sector of the iberian basin fig 1b soria 1997 sands of boththe last synrift unit of these sub basins the escucha formation and of the rst post rift unit of the iberian basin the utrillas formation were depos ited across the estuarine deltaic and uvial environments fig 1c quer ol et al 1992 the sands are domi nantly ne grained show excellentsorting and as they consist almostpurely of quartz they are mineralog ically very mature the escucha and the utrillasformationsthe upper aptian middle albian es cucha formation aguilar et al 1971 sole de porta et al 1994 fig 1c was formed during the last phases ofthe second rift stage that a ected theiberian basin salas and casas 1993 it is a tidally in uenced heterolithicunit dominated by very well sorted ne sand and clay with coal bearingdepositsinitslowerpart andlocallyinthe basal part coarse grained siliciclas tic levels it lies upon the limestonesand marls of the urgonian platform aptian and is covered by sandstonesof the utrillas formation fig 1c pardo 1979 querol 1990 the es cucha formation was interpreted as adeltaic estuarine succession querolet al 1992 with a barrier island sys tem in the northern part of the olietesub basin rodri guez lo pez et al 2005 it was deposited in extensionalsub basins bounded by palaeogeo graphic thresholds produced by listricand block rotation faults the utrillasformation overlies the escucha for mation and is late albian early cen omanian in age and represents uvialdeposits pardo 1979 however theabstract

contribution of global groundwater depletion since 1900 to sea level rise 1 removal of water from terrestrial subsurface storage is a natural consequence of groundwater withdrawals but global depletion is not well characterized cumulative groundwater depletion represents a transfer of mass from land to the oceans that contributes to sea level rise depletion is directly calculated using calibrated groundwater models analytical approaches or volumetric budget analyses for multiple aquifer systems estimated global groundwater depletion during 1900 2008 totals 4 500 km3 equivalent to a sea level rise of 12 6 mm 6 of the total furthermore the rate of groundwater depletion has increased markedly since about 1950 with maximum rates occurring during the most recent period 2000 2008 when it averaged 145 km3 yr equivalent to 0 40 mm yr of sea level rise or 13 of the reported rate of 3 1 mm yr during this recent period

six component seismic land data acquired with geophones and rotation sensors wave mode selectivity by application of multicomponent polarization filtering abstract multicomponent acquisition systems today record incomplete data because they do not measure rotations geophones or accelerometers provide linear motion and hydrophones provide pressure but no current commercial acquisition system includes sensors that measure rotations without rotations the data provide incomplete recording of the wavefield because in three dimensions there are six degrees of freedom three linear displacements and three rotations in two small 2d seismic surveys recorded with six components three component geophones were deployed and three component rotation sensors that measured pitch roll and yaw were deployed pitch was measured independently with closely spaced geophones measuring rotations with closely spaced geophones is not practical in production but it can be used in research and development to validate rotation sensor data a comparison of pitch measured by two independent methods finds that they fit after instrument designature data provided by rotation se

high latitude albian climate variability palynological evidence for long term drying in a greenhouse world abstract detailed quaternary style quantitative spore pollen counts with a pollen sum based on total non angiosperm seed plants from a southern high palaeolatitude 60 65 terrestrial sequence in gippsland southeast australia has revealed strong vegetation and climate variability during the albian this variability is more pronounced than previously suggested in global early cretaceous vegetation and climate reconstructions the quantitative spore pollen record shows drying throughout the albian based on upward decreasing total ferns and variation in podocarp and total alisporites vitreisporites pollen this record suggests that although global climate during the albian is considered to have been warm stable and equable regional factors such as water availability and continentality were the main drivers of this vegetation change

warm tropical ocean surface and global anoxia during the mid cretaceous period the middle of the cretaceous period about 120 to 80 myr ago was a time of unusually warm polar temperatures1 repeated reef drowning in the tropics2 and a series of oceanic anoxic events oaes that promoted both the widespread deposition of organic carbon rich marine sediments and high biological turnover3 4 5 6 7 8 the cause of the warm temperatures is unproven but widely attributed to high levels of atmospheric greenhouse gases such as carbon dioxide7 8 9 10 11 12 in contrast there is no consensus on the climatic causes and effects of the oaes with both high biological productivity and ocean stagnation being invoked as the cause of ocean anoxia3 4 5 6 7 8 here we show using stable isotope records from multiple species of well preserved foraminifera that the thermal structure of surface waters in the western tropical atlantic ocean underwent pronounced variability about 100 myr ago with maximum sea surface temperatures 3 5 c warmer than today this variability culminated in a collapse of upper ocean stratification during oae 1d the breistroffer event a globally significant period of organic carbon burial that we show to have fundamental stratigraphically valuable geochemical similarities to the main oaes of the mesozoic era our records are consistent with greenhouse forcing being responsible for the warm temperatures but are inconsistent both with explanations for oaes based on ocean stagnation and with the traditional view reviewed in ref 12 that past warm periods were more stable than today s climate

rainfall patterns and the distribution of coals and evaporites in the mesozoic and cenozoic abstract paleoclimatologists have adequately demonstrated over the last twenty years that the distribution of climatically sensitive sediments can be related to present day climatic zones that are roughly parallel to latitude for example coals were deposited at paleolatitudes that correspond to the present day rainy zones at the equator and at about 55 n and 55 s indicating that those zones were present in the past from this it can be concluded that atmospheric circulation has not been radically different from its present configuration despite some apparently great differences in some climatic parameters such as the equator to pole temperature gradient nevertheless the zonal model for predicting the distribution of climatically sensitive sediments is not wholly adequate although general atmospheric circulation may not have been radically altered from its present pattern it would have differed in some respects because the paleogeography was different from the present geography therefore we have constructed what we believe are more realistic maps of the distribution of rainfall through time these maps are based on maps of atmospheric circulation that have been successfully used to predict the distribution of some petroleum source beds and phosphorites we have compared the predicted distribution of rainfall to the distribution of coals and evaporites for each of seven geologic stages the circulation rainfall maps were more successful than the zonal model for predicting the distribution of evaporites and coals for times when the paleogeography would have maximized the development of a monsoonal circulation which most effectively disrupts the general zonal pattern for times when a monsoonal circulation would not have been important the zonal model adequately predicted the distribution of these rocks

interbed storage changes and compaction in models of regional groundwater flow water released from permanent compaction of compressible fine grained interbeds within confined aquifers may be a significant source of pumped water permanent or inelastic compaction of the interbeds occurs when head declines from pumping cause the effective stress or grain to grain load to exceed the elastic limits of the interbeds as a result the grains in the interbeds rearrange and excess water is expelled the amount of inelastic compaction generally is proportional to the increase in effective stress and the decrease in head a common approach for the simulation of elastic and inelastic compaction in groundwater flow models is to assume that head changes in the aquifer result in instantaneous storage changes in the compressible interbeds a term is added to the groundwater flow equation to account for the storage changes changes in specific storage may be computed explicitly from the results at the previous time step in the finite difference formulation of the groundwater flow equation a better approach is to implicitly apportion storage changes between elastic and inelastic components within a time step if storage changes cannot be considered to occur instantaneously with change in head in the aquifer another approach is taken equations for horizontal flow in the aquifer are coupled with equations for vertical flow in the compressible interbeds to simulate flow in half a representative doubly draining interbed storage changes and compaction are calculated for the representative half thickness and are extrapolated to the entire thickness of all interbeds within each cell this approach was applied to an existing model of groundwater flow in the central valley of california the simulation demonstrates that solving coupled systems of equations is feasible for a regional flow model

cretaceous forest composition and productivity inferred from a global fossil wood database abstractglobal patterns of cretaceous forest composition and produc tivity are analyzed using a comprehensive fossil wood database n 2238 to ascertain forest composition records were classi ed by botanical af nity plotted on georeferenced paleomaps and ana lyzed with arcgis tools results con rm previous conjecture that araucarioid and podocarpoid conifers were globally codominant in early cretaceous time especially in humid tropical and paratropi cal biomes but drastically reduced in numbers and range during the late cretaceous cupressoid conifers which were most common in seasonally dry mid latitudes and pinoid conifers which were asso ciated with temperate conditions at higher northern latitudes also declined at the same time though less markedly spatial analysis suggests that the loss of conifer forests especially araucarioids was linked to the rise of co occurring angiosperms our data also show that while angiosperms explosively diversi ed in mid cretaceous time they did not become forest dominants until the latest cretaceous 25 m y later by which time the modern relictual pattern of conifer distribution had been established to ascertain forest productivity mean tree ring width data were obtained from direct measurements and literature reviews n 284 and plotted by paleolatitude com parison with modern data shows that cretaceous forest productivity was signi cantly elevated 2 in mid and high paleolatitudes imply ing a poleward displacement of the temperate zone by 15 our data provide quantitative veri cation of cretaceous climate vegetation models and improve the understanding of the long term effects of future global warming introduction

groundwater flow in an arsenic contaminated aquifer mekong delta cambodia abstract to advance understanding of hydrological influences on as concentrations within groundwaters of southeast asia the flow system of an as rich aquifer on the mekong delta in cambodia where flow patterns have not been disturbed by irrigation well pumping was examined monitoring of water levels in a network of installed wells extending over a 50 km2 area indicates that groundwater flow is dominated by seasonally variable gradients developed between the river and the inland wetland basins while the gradient inverts annually net groundwater flow is from the wetlands to the river hydraulic parameters of the aquifer k 10 4 ms 1 and overlying clay aquitard k 10 8 ms 1 were determined using grain size permeameter and slug test analyses when coupled with observed gradients they indicate a net groundwater flow velocity of 0 04 0 4 ma 1 downward through the clay and 1 13 ma 1 horizontally within the sand aquifer producing aquifer residence times on the order 100 1000 a the results of numerical modeling support this conceptual model of the flow system and when integrated with observed spatial trends in dissolved as concentrations reveal that the shallow sediments upper 2 10 m of fine grained material are an important source of as to the underlying aquifer

short term warming events during the boreal albian mid cretaceous pronounced paleotemperature variations associated with the carbon cycle perturbations of oceanic anoxic events oaes 1b and 1d are known to have occurred during the early and latest albian however reliable paleotemperature data spanning the 12 m y between these two events are sparse here we present 18o 13c and mg ca data for the middle to early late albian based on analysis of unusually well preserved glassy foraminifers from a clay rich sequence drilled in the boreal lower saxony basin northwestern germany 45 n paleolatitude our records reveal pronounced variability in planktic 18o 1 5 2 5 on a 100 k y time scale that we interpret to indicate substantial changes in sea surface temperature to 7 c and 18o salinity to 3 psu our findings attest to the climatic sensitivity of marginal basins in these boreal latitudes during the mid cretaceous and suggest that the heat and salt budgets of the lower saxony basin were orbitally conditioned during the albian presumably through atmospheric or oceanic heat transport from lower latitudes where surface waters were warmer than today in response to strong greenhouse gas forcing

evolution of middle to late cretaceous oceans a 55 m y record of earth s temperature and carbon cycle a new 55 m y global compilation of benthic foraminifera 13 c and 18 o for the middle to late cretaceous shows that there was widespread formation of bottom waters with temperatures 20 c during the cretaceous greenhouse world these bottom waters filled the silled north atlantic and probably originated as thermocline or intermediate waters in the tropical oceans carbon burial during the cretaceous oceanic anoxic events produced a positive 13 c shift in global carbon reservoirs but this is not particularly large especially by comparison with the remarkable late paleocene carbon maximum the interbasin 13 c gradient was unusually large during the cretaceous hot greenhouse probably because the north atlantic sills prevented the free exchange of waters in the deep basin the hot greenhouse ended when the equatorial atlantic gateway opened sufficiently to flood the deep north atlantic with relatively cool polar waters formed in the southern ocean

three dimensional imaging of aquifer and aquitard heterogeneity via transient hydraulic tomography at a highly heterogeneous field site abstract previous studies have shown that geostatistics based transient hydraulic tomography tht is robust for subsurface heterogeneity characterization through the joint inverse modeling of multiple pumping tests however the hydraulic conductivity k and specific storage ss estimates can be smooth or even erroneous for areas where pumping observation densities are low this renders the imaging of interlayer and intralayer heterogeneity of highly contrasting materials including their unit boundaries difficult in this study we further test the performance of tht by utilizing existing and newly collected pumping test data of longer durations that showed drawdown responses in both aquifer and aquitard units at a field site underlain by a highly heterogeneous glaciofluvial deposit the robust performance of the tht is highlighted through the comparison of different degrees of model parameterization including 1 the effective parameter approach 2 the geological zonation approach relying on borehole logs and 3 the geostatistical inversion approach considering different prior information with without geological data results reveal that the simultaneous analysis of eight pumping tests with the geostatistical inverse model yields the best results in terms of model calibration and validation we also find that the joint interpretation of long term drawdown data from aquifer and aquitard units is necessary in mapping their full heterogeneous patterns including intralayer variabilities moreover as geological data are included as prior information in the geostatistics based tht analysis the estimated k values increasingly reflect the vertical distribution patterns of permeameter estimated k in both aquifer and aquitard units finally the comparison of various tht approaches reveals that differences in the estimated k and ss tomograms result in significantly different transient drawdown predictions at observation ports

parameter estimation of an overconsolidated aquitard subjected to periodic hydraulic head variations within adjacent aquifers abstract extensometers provide long term records of deformation over a depth interval of interest an overconsolidated aquitard usually undergoes elastic deformation if the hydraulic head within adjacent aquifers remains higher than the preconsolidation head within the aquitard the vertical hydraulic conductivity k v and elastic skeletal specific storage s ske are two critical parameters that control the deformation behavior of an overconsolidated aquitard and they could be interpreted from valuable extensometer data an analytical solution for the elastic aquitard deformation caused by periodic hydraulic head variations phhv within adjacent aquifers is derived using the separation of variables method based on euler s formula the phase difference in phhv between adjacent aquifers is found to reduce the amplitude of periodic aquitard deformation meanwhile the phase difference is found to cause no influence on the growth pattern of the phase shift which is between the periodic aquitard deformation and phhv versus the period a new parameter estimation method is further proposed to interpret aquitard k v and s ske from periodic aquitard deformation data this new method yields robust k v and s ske estimates of a moderately thick aquitard whose deformation history has been recorded by an extensometer located in shanghai china the field study confirms that the phase difference in phhv between the aquifers adjacent to the overconsolidated aquitard of interest cannot be ignored

an analytical solution for leakage rate and depletion of aquitard influenced by the delayed yield phenomenon delayed yield phenomenon dyp occurs when the drawdown of an aquitard is no longer in equilibrium owing to previous changes in the level of water in adjacent aquifers in this study an analytical solution to determine the distribution of the drawdown at any time and at any point in an aquitard in which the water level was not in equilibrium at the initial time and the water level of the aquifers immediately above and below the aquitard was time dependent was developed the analytical solution for the flow rate at any time and location was presented based on variations in drawdown in the aquitard in addition the effects of the dyp on the leakage rate and depletion of the aquitard were studied subsequent comparison of the proposed analytical and numerical solutions revealed that they were in good agreement the results of this study will be useful to future studies of groundwater flow and environmental problems such as water budgets rising sea levels solute transport heat conduction and ground subsidence

vegetation dynamics angiosperm radiation and climatic changes in the lusitanian basin portugal during albian times abstract the mid cretaceous is characterised by significant evolutionary changes in terrestrial ecosystems during this period the typical vegetation consisting of ferns conifers and other gymnosperms was replaced by an angiosperm dominated flora long ranging and continuous records from the continental realm are mostly lacking due to the prevalence of sedimentary gaps here a comprehensive palynological and clay mineralogical dataset covering early albian to early cenomanian strata from the shallow marine sao juliao section lusitanian basin portugal is analysed to reconstruct the vegetation composition as well as climate and weathering conditions in the continental realm the palynological assemblage is dominated by non saccate classopollis and inaperturopollenites gymnosperm pollen with low abundances of spores and angiosperm pollen the clay mineralogical data is mainly composed of kaolinite and mica and shows two conspicuous intervals of high kaolinite abundances in the late albian based on the ecological preferences of the associated parent plants of the spore pollen assemblage a gradual relative temperature increase is inferred in the hinterland of the lusitanian basin during the early albian to early cenomanian interval the clay mineralogy and palynological record show that the climate in the continental hinterland of the lusitanian basin was semi arid to sub humid and punctuated by two distinct humid phases during the late albian multivariate statistical analyses and a comparison with the nearby guincho section demonstrate the significance and reproducibility of the spore pollen record furthermore the palynological assemblage implies that angiosperms and ferns occupied similar palaeo ecological habitats namely as understorey in cheirolepidaceae araucariaceae and cupressaceae conifer dominated forests

phase difference between groundwater storage changes and groundwater level fluctuations due to compaction of an aquifer aquitard system abstract drainage and deformation of intercalated confining layers due to internal stress change discharge recharge cycle in an aquifer aquitard system not only can have great effects on the groundwater storage gws but also can cause unsynchronized water level wl fluctuations the phase relationship between gws and wl is crucial for the accuracy and attribution of gws changes we identify the dominating episodic components of gws and wl through the singular spectrum analysis ssa analysis and harmonic analysis first we analyzed a generic aquifer aquitard system using numerical simulations which showed that the dissipation of overpressure from the aquitard and flow from it is the inherent cause of a phase shift between the gws and wl observations water released from confining layers with compaction time constant of zero no delay to century time scale results in detected phase shift between total gws and wl in the aquifer then we analyzed the complex and varied phase relationship between gws derived using the gravity recovery and climate experiment grace data and measured wl time series in the subsiding north china plain ncp aquifer the spatially varied phase relationship between gws and measured wl is reasonably related to varied land subsidence development features and may be related with the compaction time constant and thickness of the confining layers results of the generic numerical model and the ncp observations suggest that elastic inelastic response need to be considered in the interpretation and correction of gws changes for a compacted aquifer aquitard system

palynology of the circum mediterranean triassic phytogeographical and palaeoclimatological implications following a tentative evaluation of palynological information from ladinian and more particularly karnian successions there seems to be every indication that qualitative and quantitative compositional differences of palynological assemblages could well be applied in testing concepts of triassic phytogeography and palaeoclimatology

reply to comment by t n narasimhan on a method to estimate groundwater depletion from confining layers we thank t n narasimhan for his comment on ourpaper konikow and neuzil 2007 and for extending thediscussion with a historical perspective additional exam ples and some considerations we did not discuss includingimplications for water management we support and agreewith the thrust of his comments

the jurassic cretaceous transition of the fararp 1 core southern sweden sedimentological and phytological indications of climate change the 116m deep fararp 1 core drilled in the vomb trough in southernmost sweden is dated by integrated terrestrial and marine palynostratigraphy the lower part of the succession ca 84 m encompasses uppermost jurassic to lowermost cretaceous uppermost tithonian to valanginian strata an unconformity separates the valanginian strata from an overlying ca 1 m thick interval of upper albian to cenomanian arnager greensand formation the uppermost part of the core is a repetitive succession of lowermost cretaceous sediments during the jurassic cretaceous u k transition nw europe was located in mid latitudes and comprised an archipelago of large and small islands separated by deeper grabens and epicontinental seaways that connected the boreal sea to the north with the warmer tethys ocean to the south boundary strata in england france the netherlands and germany are characterised by relatively prominent climatic change from arid semi arid to subhumid humid conditions southernmost sweden was located on the margin of a large landmass comprising most of the fennoscandian shield bordering a large epicontinental sea to the west by combining sedimentology clay mineralogy and palynofacies the tithonian to valanginian cored succession of the fararp 1 core provides complementary information on how marginal deposits from the eastern part of the epicontinental sea reflect the climatological and environmental changes observed in other parts of nw europe the fararp 1 core shows that during the tithonian to earliest berriasian deposition took place in a terrestrial but near marine depositional setting in coastal lakes or lagoons with little marine influence a dry climatic regime favoured stagnant water conditions with common algal blooms of primarily bonyococcus and zygnemataceae palynofacies and sedimentology indicate limited transport of freshwater and material to the basin the stagnant depositional environment was terminated by a marine flooding in the early berriasian during the remaining berriasian and the early valanginian conditions shifted between near marine and marine settings in a dynamic coastal environment similar to contemporaneous assemblages reported from the danish island of bornholm a shift in clay mineralogy from a dominance of 10 a minerals to increasing amounts of mixed layer and kaolinite indicates a change to more humid conditions in the latest tithonian cheirolepidacean pollen classopollis are present but never common in the cored succession and a similar conspicuous decrease of these pollen as previously reported from england germany and france is not evident in the fararp 1 core instead a subsequent shift in both palynofacies and palynoflora marked by an increase in abundance of heavy terrigenous material i e wood and coal particles upland pollen grains and reworked palynomorphs is also observed in the uppermost tithonian lowermost berriasian interval at the same level spores and pollen classified as warmer drier elements decrease in abundance this is interpreted as representing a shift to more humid climatic conditions with increased runoff from the hinterland thus the combined sedimentological and palynological data from the fararp 1 core suggest that climatic conditions in the area changed from more seasonally dry semi arid to more humid semi humid across the j k boundary latest tithonian to earliest berriasian and hence earlier than the mid berriasian climatic shift recorded from e g england and the netherlands c 2011 elsevier b v all rights reserved less

analytical solutions for pressure perturbation and fluid leakage through aquitards and wells in multilayered aquifer systems 1 large scale groundwater pumping or deep fluid injection in a multilayered subsurface system may generate pressure perturbation not only in the target formation s but also in over and underlying units hydraulic communication in the vertical direction may occur via diffuse leakage through aquitards and or via focused leakage through leaky wells existing analytical solutions for pressure perturbation and fluid flow in such systems consider either diffuse leakage or focused leakage but never in combination with each other in this study we developed generalized analytical solutions that account for the combined effect of diffuse and focused leakage the new solutions solve for pressure changes in a system of n aquifers with alternating leaky aquitards in response to fluid injection extraction with any number ni of injection pumping active wells and passive leakage recharge in any number nl of leaky wells the equations of horizontal groundwater flow in the aquifers are coupled by the vertical flow equations in the aquitards and by the flow continuity equations in the leaky wells the solution methodology described in detail in this paper involves transforming the transient flow equations into the laplace domain decoupling the resulting ordinary differential equations odes coupled by diffuse leakage via eigenvalue analysis solving a system of nl n linear algebraic equations for the unknown rates of flow through leakage wells and superposing the solution of pressure buildup drawdown in aquifers and aquitards resulting from flow in the ni active and nl leaky wells verification of the new methodology was achieved by comparison with existing analytical solutions for diffuse leakage and for focused leakage and against a numerical solution for combined diffuse and focused leakage application to an eight aquifer system with leaky aquitards and one leaky well demonstrates the usefulness and efficiency of the approach and illustrates the pressure behavior over a spectrum of leakage scenarios and parameters

a new type curve method for estimating aquitard hydraulic parameters in a multi layered aquifer system summary we propose a new type curve method for estimating the hydraulic conductivity k and the specific storage s s of an aquitard in a multi layered aquifer system theoretical type curves of rate of aquitard compaction versus time are obtained through drawdown time series in the aquitard under a condition that the drawdown history of the underlying aquifer can be approximated as piecewise linear segments pls in each of which the drawdown shows a linear increase trend with time comparing with previous analytical solutions which are limited by the assumption of a constant head in the overlying unconfined aquifer the superposition principle can be called when water levels fluctuate with time in both upper and lower aquifers adjacent to the aquitard when applying the new pls method to estimate k and s s values of an aquitard the starting point of drawdown history at adjacent aquifers should be determined at first after that the drawdown history is approximated as pls to obtain drawdown rate of change for each linear stage and turning points of drawdown history the new pls method is demonstrated at a field site in changzhou city jiangsu province of china estimated results show that k and s s are respectively 9 80 10 10 m s and 4 46 10 4 m 1 for a thick aquitard and 2 34 3 50 10 10 m s and 2 28 10 4 m 1 for a thin aquitard estimated field k values as well as s s values through the new pls method are generally in accordance with the results obtained from the geologic method by konikow and neuzil 2007 they are also in agreements with the numerically calibrated results of shi et al 2008a at the regional scale and the laboratory experimental values of in situ soil samples collected by geological survey of jiangsu province of china