investigating peatland stratigraphy and hydrogeology using integrated electrical geophysics hydrology has been suggested as the mechanism controlling vegetation and related surficial pore water chemistry in large peatlands peatland hydrology influences the carbon dynamics within these large carbon reservoirs and will influence their response to global warming a geophysical survey was completed in caribou bog a large peatland in maine to evaluate peatland stratigraphy and hydrology geophysical measurements were integrated with direct measurements of peat stratigraphy from probing fluid chemistry and vegetation patterns in the peatland consistent with previous field studies ground penetrating radar gpr was an excellent method for delineating peatland stratigraphy prominent reflectors from the peat lake sediment and lake sediment mineral soil contacts were precisely recorded up to 8 m deep two dimensional resistivity and induced polarization imaging were used to investigate stratigraphy beneath the mineral soil beyond the range of gpr we observe that the peat is chargeable and that ip imaging is an alternative method for defining peat thickness the chargeability of peat is attributed to the high surface charge density on partially decomposed organic matter the electrical conductivity imaging resolved glaciomarine sediment thickness a confining layer and its variability across the basin comparison of the bulk conductivity images with peatland vegetation revealed a correlation between confining layer thickness and dominant vegetation type suggesting that stratigraphy exerts a control on hydrogeology and vegetation distribution within this peatland terrain conductivity measured with a geonics em31 meter correlated with confining glaciomarine sediment thickness and was an effective method for estimating variability in glaciomarine sediment thickness over approximately 18 km 2 our understanding of the hydrogeology stratigraphy and controls on vegetation growth in this peatland was much enhanced from the geophysical study

spatial variability in biogenic gas accumulations in peat soils is revealed by ground penetrating radar gpr 1 we performed surface and borehole ground penetrating radar gpr tests together with moisture probe measurements and direct gas sampling to detect areas of biogenic gas accumulation in a northern peatland the main findings are 1 shadow zones signal scattering observed in surface gpr correlate with areas of elevated ch4 and co2 concentration 2 high velocities in zero offset profiles and lower water content inferred from moisture probes correlate with surface gpr shadow zones 3 zero offset profiles depict depth variable gas accumulation from 0 10 by volume 4 strong reflectors may represent confining layers restricting upward gas migration our results have implications for defining the spatial distribution volume and movement of biogenic gas in peatlands at multiple scales

a study of the geoelectrical properties of peatlands and their influence on ground penetrating radar surveying1 geophysical surveys and chemical analyses on cores were carried out in three ontario peatlands from which we have gained a better understanding of the peat properties that control the geophysical responses the electrical conductivity depends linearly on the concentration of total dissolved solids in the peat pore waters and the pore waters in turn bear the ionic signatures of the underlying mineral sediments the ionic concentration and thus the electrical conductivity increase linearly from the surface to basement the average bulk electrical conductivity of peatlands at ellice marsh near stratford and at wally creek area forest drainage project near cochrane are of the order of 25 ms m the mer bleue peatland near ottawa has extremely high electrical conductivity reaching levels of up to 380 ms m near the base of the peat the mer bleue peatland water has correspondingly high values of total dissolved solids which originate from the underlying champlain sea glaciomarine clays the dielectric permittivity in peats is largely controlled by the bulk water content ground penetrating radar can detect changes in water content greater than 3 occurring within a depth interval less than 15 cm the principal peatland interfaces detected are the near surface aerobic to anaerobic transition and the peat to mineral basement contact the potential for the successful detection of the basement contact using the radar can be predicted using the radar instrument specifications estimates of the peatland depth and either the bulk peat or the peat pore water electrical conductivities predicted depths of penetration of up to 10 m for ellice marsh and wally creek exceed the observed depths of 1 to 2 m at mer bleue on the other hand we observe that as predicted a 100 mhz signal will penetrate to the base of a 2 m thick peat but a 200 mhz signal will not

composition and geochemistry of clay sediments offshore the northeastern sicilian coast southeastern tyrrhenian sea italy abstract grain size mineralogical and chemical analyses were carried out on fine fraction of sediments collected in the gulfs of patti and milazzo two borderland basins in the southern tyrrhenian extending offshore the northeastern sicilian coast results of granulometric analyses on size fractions smaller than 63 m showed that the investigated samples can be classified mainly as clayey silts the coarse fractions 63 m examined by optical microscopy consist of a terrigenous component representing in some samples about 98 99 of the total sediment and by a biogenic component this latter is mainly made up of benthic foraminifera the mineralogical composition of the fine fraction determined by x ray diffractometry is represented by muscovite quartz clay minerals carbonates calcite and in some samples by calcium and sodium rich plagioclases the method of saturation with k and mg followed by ethylene glycol solvation and heating are used for a qualitative determination of the clay minerals clay mineralogical composition is characterized by the dominance of clinochlore and illite with minor amounts of smectite especially montmorillonite and vermiculite the chemical data reflect the main mineralogical composition showing a uniform quantitative composition with high al 2 o 3 and sio 2 values and very few variations in the relative abundance of the other components the cr th th sc th co and la sc ratios suggest a felsic nature of the source rocks finally the geochemical parameters such as v cr u th ni co and cu zn ratios indicate that examined sediments were deposited under oxic environments

metal organic associations in sediments i comparison of unpolluted recent and ancient sediments and sediments affected by anthropogenic pollution abstract the concentrations of 19 trace elements were determined by plasma emission spectrometry in organic fractions organic solvent extractables soluble humics protokerogen and kerogen concentrates separated from various recent and ancient sediments mangrove sediments algal mats oil shales phosphorites as well as sediments polluted by industrial metal emissions rhine river port pirie smelter effluent often the organic constituents were found to be enriched in trace elements especially b v mn co ni cu zn as mo ag cd sb hg and pb up to more than three orders of magnitude compared to the bulk sediments indicating the importancesof organic substances with respect to transport and fixation of trace elements within sediments the formation of metal organic associations was found to reflect the environment of deposition marine to terrestrial as well as diagenetic transformations recent to ancient against an unpolluted natural background increasing metal pollution led to increasing metal potake by organic substances especially for b cr fe co cu zn as cd and pb

intraplate stresses and dynamical aspects of rifted basins abstract intraplate stresses play a important role during the syn and post rift evolution of sedimentary basins deviations from long term thermal patterns of post rift subsidence as well as the development of unconformities within rifted basins reflect to a large extent the temporal fluctuations of the regional stress fields in the lithosphere it appears that incorporation of intraplate stresses in dynamical models for basin development together with a quantification of the role of petrological changes in the crust lithosphere system can explain some of the observed shortcomings of thermal models of post rift basin subsidence late neogene accelerations in tectonic subsidence in the deeper parts of rifted basins in the northern atlantic and mediterranean regions could reflect a change in the level of intraplate stress over large areas of the globe non thermal contributions to the subsidence record affect estimates of crustal extension and consequently influence the depth at which hydrocarbon source rocks enter the maturity window stress induced changes in basement topography have also important consequences for the budget of fluid flow in the deeper parts of the sediment fill of the rifted basins as well as on the dynamics of diapirism

trace element distributions in surficial sediments of the northern tyrrhenian sea contribution to heavy metal pollution assessment the trace element distributions in surficial sediment of tyrrhenian sea have been investigated as a part of a series of studies on the environmental quality of the area off the tuscany coast west central italy this research has focused on the presence of possible contaminated zones it also provides data for the identification and future monitoring and control of pollution sources the study of numerous surface sediments and core samples has made it possible to distinguish between heavy metal enrichments related to natural sources and other anomalies caused by anthropogenic contamination over much of the basin the surface pb cu zn and as contents appear considerably enriched relative to those below 15 cm among these metals pb shows the highest and most widespread enrichment only in the case of some coarse grained sediments close to the mouth of cecina river it is possible to relate anomalously high zn contents to natural sources in all other sampling stations the enrichments of pb cu zn and as are ascribed to man s influence the sediment distributions of co cr and ni do not seem to be related to anthropogenic activities rather they mirror influx of materials derived from sources of ophiolitic rock the distribution of barium shows only two significant positive anomalies and both are related to natural causes concentrations of vanadium are high in a zone close to an important smelting plant these are thought to be of anthropogenic origin

pool patterning in a northern peatland geophysical evidence for the role of postglacial landforms a hydrogeophysical study conducted in a 2200 ha peatland in central maine shows evidence that a laterally continuous esker deposit extends below the peat soil following the direction of glacier retreat and coinciding with the presence of a pool system ground penetrating radar gpr electrical resistivity er imaging and terrain conductivity measurements were constrained with limited hydrological measurements direct sampling of inorganic sediments and radiocarbon dating of peat soils to develop a conceptual model for pool formation that could explain the unique pool patterning observed in other northern peatlands gpr profiles revealed three dimensional images of two esker crests below the easternmost edge of the pool area gpr data was supported by er imaging and terrain conductivity data and allowed for facies differentiation to infer processes related to esker formation during the glacier front retreat hydrologic data showed preferential flow of groundwater towards the esker suggesting that pools may persist as a result of enhanced peat decomposition and carbon loss due to oxygenation and or upward supply of alternative electron acceptors from the mineral soil along narrow permeable inorganic esker crests variations in pool depths and radiocarbon dating of peat samples from the pool bottom support a model whereby pools originate at a focus centered along the two esker crests and subsequently spread laterally outwards

reconstructing the palaeoenvironment at the early mesolithic site of lake duvensee ground penetrating radar and geoarchaeology for 3d facies mapping we investigate the landscape development of the early mesolithic hunter gatherer sites of duvensee 10000 6500 cal bce based on ground penetrating radar gpr and geoarchaeological drillings we

compressional deformation at the ocean continent transition in the ne atlantic local zones of compressional deformation spatially coincident with the ocean continent transition occur in the ne atlantic off western iberia on the northern margin of the bay of biscay and in the southern rockall trough the deformation zones are typically broad oceanward facing monoclines several tens of kilometres in width the amount of shortening is small although the structures may also accommodate some strike slip motion deformation peaked during the mid late eocene in biscay off galicia bank and in rockall trough and in the mid miocene off western iberia these deformation pulses were contemporary with the pyrenean and betic orogenies in western europe and may have resulted from structural reorganizations within the evolving orogens driven by changes in plate motion possible mechanisms which might concentrate deformation at the ocean continent transition include slip within serpentinized peridotite underlying the transitional region and reactivation of a pre existing detachment fault within the thinned continental crust our observations may imply that rifted continental margins when reactivated can develop into new sites of plate subduction

controls of soil pipe frequency in upland blanket peat 1 soil pipes were surveyed in 160 british blanket peat catchments using consistent application of ground penetrating radar soil pipes were found in all catchments the mean frequency of piping was 69 per kilometer of surveyed transect land management moorland gripping appears to exert the most important control on hillslope pipe frequency in blanket peats management practice in peatlands may therefore induce more rapid subsurface erosion carbon loss and landform denudation via enhanced preferential flow topographic position is also important with topslopes having greater pipe frequencies than footslopes followed by midslopes with lowest frequencies slope gradient however is not a significant factor in controlling blanket peat pipe frequency i propose that peat structural properties inherited from the way a blanket peat develops on a hillslope strongly control pipe network development this is manifested in the way slope position appears to control pipe frequency aspect appears not to influence pipe frequency in blanket peats except that it does play a weak role in catchments with annual precipitation 1500 mm here southwesterly facing slopes tend to have more frequent piping

benthic foraminiferal turnover across the cretaceous paleogene boundary at agost southeastern spain paleoenvironmental inferences abstract we studied upper cretaceous and lower paleogene benthic foraminifera from the agost section southeastern spain to infer paleobathymetrical changes and paleoenvironmental turnover across the cretaceous paleogene k p transition benthic foraminifera indicate uppermost bathyal depths at agost during the abathomphalus mayaroensis biochron from about 400 kyr before the k p boundary through the early plummerita hantkeninoides biochron about 120 150 kyr before that boundary the depth increased to middle bathyal for the remainder of the cretaceous and remained so for the danian part of the studied section parasubbotina pseudobulloides biochron at least 200 kyr after the k p boundary there were no perceivable bathymetrical changes at the k p boundary where 5 of the species became extinct and the species composition of the benthic foraminiferal fauna changed considerably below the boundary infaunal morphogroups constitute up to 65 73 of the faunas directly above the boundary in the black clays of the lower guembelitria cretacea biozone benthic foraminifera are rare several opportunistic taxa e g the agglutinant haplophragmoides sp have short peaks in relative abundance possibly reflecting low oxygen conditions as well as environmental instability with benthos receiving food from short lived local blooms of primary producers above the clays through the end of the studied interval epifaunal morphogroups dominate up to 70 of the assemblages or there is an even mixture or epifaunal and infaunal morphogroups infaunal groups do not recover to pre extinction relative abundances indicating that the food supply to the benthos did not recover fully over the studied interval about 200 kyr after the k p boundary the benthic foraminiferal faunal changes are compatible with the direct and indirect effects of an asteroid impact which severely destabilized primary producers and the oceanic food web that was dependent upon them

the impact of pipe flow in riparian peat deposits on nitrate transport and removal the effect of preferential flow in soil pipes on nitrate retention in riparian zones is poorly understood the characteristics of soil pipes and their influence on patterns of groundwater transport and nitrate dynamics were studied along four transects in a 1 to 3 m deep layer of peat and marl overlying an oxic sand aquifer in a riparian zone in southern ontario canada the peat marl deposit which consisted of several horizontal layers with large differences in bulk density contained soil pipes that were generally 0 1 to 0 2 m in diameter and often extended vertically for 1 to 2 m springs that produced overland flow across the riparian area occurred at some sites where pipes extended to the peat surface concentrations of no3 n 20 30 mg l 1 and dissolved oxygen do 4 6 mg l 1 observed in peat pipe systems and surface springs were similar to values in the underlying sand aquifer indicating that preferential flow transported groundwater with limited nitrate depletion low no3 n concentrations of 15 mg l 1 extended over a larger zone low dissolved organic carbon values at these locations suggest that supplies of organic carbon were not sufficient to support high rates of denitrification despite low do conditions these data indicate that it is important to develop a greater understanding of pipes in peat deposits which function as sites where the transport of large fluxes of water with low biogeochemical reaction rates can limit the nitrate removal capacity of riparian zones copyright 2011 john wiley sons ltd

analysis of dynamic sedimentary environments in alluvial fans of some tributaries of the upper yellow river of china based on ground penetrating radar gpr and sediment cores abstract there are ten ephemeral tributaries of the yellow river in the inner mongolia of china as their catchments are covered by loose materials and are dominated by an intense interaction between wind and water erosion these tributaries have had a high sediment yield and alluvial fans have been formed at the confluences of the tributaries with the yellow river however there is a lack of understanding in the deposition model of the alluvial fans and the roles of fluvial and aeolian processes in sediment accumulation in this paper we used ground penetrating radar 100 mhz and sediment cores to investigate the sediments in channels and alluvial fans of four out of the ten tributaries radar reflection profiles of sedimentary strata are dominated by horizontal or sub horizontal layers with a large scale showing that the fluvial deposition on the alluvial fans has been dominated by a vertical accretion pattern the reflection features like reflection free inclined reflections discontinuous undulate chaotic sinuous reflections and channel fill exist to a lesser extent a few gpr profiles send signs of intense erosion and the one near the apex of an alluvial fan reveals that erosion had been active likely during the early holocene and the channel position should be relatively fixed the information extracted from this profile and the widely exposed late pleistocene strata in the upper parts of the alluvial fans according to the geological map of the study area indicates that sediment accumulation has been slow in the upper alluvial fans since the early holocene the sediment cores indicate that sedimentary strata under the alluvial fans are mainly composed by sand and silt deposited in a fluvial environment and rarely reworked by wind actions also according to the core data the sediment deposits in the west fans were coarser than those in the east fans likely suggesting that the hydrodynamic force of the western tributaries was stronger than that of the east ones the hydrodynamic environment of the tributaries was usually unstable historically and hyperconcentrated flows might occur with a higher frequency in one of the tributaries in history

tectonics and global change inferences from the late cenozoic subsidence and uplift patterns in the atlantic mediterranean region summary quantitative subsidence analysis for a number of rifted basins in the northern atlantic mediterranean region provides evidence for rapid phases of plioquaternary subsidence the observed acceleration in tectonic subsidence occurs after a phase of general quiescence in subsidence in these basins and deviates from predictions of stretching models the latter indicate a decay of subsidence with time after mesozoic tertiary basin formatioh and a slow tectonic subsidence in plio quaternary times a possible explanation for the observed patterns of anomalous subsidence could be an increase in the level of intraplate compression in the northern atlantic region intraplate stress changes in the plio quaternary are related to the dynamics of african eurasian collision processes and a reorganization of spreading directions in the atlantic possibly reflecting a plate reorganization of global nature it seems that the plio quaternary record reflects a period of increased levels of neotectonic activity interplaying with periods of de glaciation stress induced topography in the onshore parts of continental margins coupled with the stress induced subsidence in the offshore deeper parts of the basins could have contributed to recent phases of uplift in fennoscandia augmenting the uplift induced by glacial unloading estimates of ice thicknesses are directly inferred from the observed uplift ignoring other driving mechanisms whereas topography plays a crucial role in the dynamics of glaciation it is therefore important to quantdy the interplay of rapid tectonic uplift and subsidence phases with climatic effects during the plio quaternary

origin of the permian triassic iberian basin central eastern spain abstract the iberian basin was an intracratonic rift basin in central eastern spain developed since early permian times the basin boundary faults were normal listric faults controlling an asymmetric extension propagating northeast with time hercynian or older lineaments controlled the orientation of the iberian basin and extension was accommodated basically in the hanging wall block by the formation of secondary grabens and a central high the basin was related with the coeval ebro catalan and cuenca mancha basins and their connections are discussed subsidence curves show that the early permian early jurassic period of extension can be subdivided into three rifting episodes and a flexural one extension factor increases from 1 17 in the northwest to 1 29 near the mediterranean coast the increasing extension rate was accommodated by transfer faults trending nne ssw more important in the levante area the rift evolution is intermittent and seems to reflect distinct stress fields the collapse of the late hercynian orogen and related increased heat flux extension and rifting is the most probable origin of the iberian basin and related basins the origin of the catalan and the valencia prebetic basins is related to the southwards migration of the hesse burgundy rift along the eastern margin of the iberian microplate

recent salt marsh development and natural regeneration of reclaimed areas in the plentzia estuary n spain the distribution of benthic foraminifera a range of elements and 137cs and 210pb were studied in surface sediments and 0 5 m cores from the plentzia estuarine marshes northern spain to determine the recent development of these previously reclaimed coastal areas these marshes receive abundant calcium carbonate from regional rocks and this allows calcareous foraminifera to colonize all marsh subenvironments good preservation of the original foraminiferal assemblages in the buried sediments is also favoured by high regional background carbonate benthic foraminifera are shown to be sensitive to both elevation above mean sea level exposure and salinity results from the chemical analyses indicate moderate anthropogenic pollution in the estuary and maximum input seems to have occurred in the 1960s recent marsh foraminiferal assemblages are good analogues for the palaeoenvironmental interpretation of historical and holocene cores and the combined micropalaeontological geochemical approach is demonstrated to be successful for the identification of short term anthropogenic impacts on this coastal region

palaeostress evolution of the iberian peninsula late carboniferous to present day abstract three main stages can be differentiated in iberia from the upper carboniferous to the present the end of the variscan orogeny late carboniferous the permian early cretaceous rifting and the alpine orogeny late cretaceous to present in this contribution the main features of the stress fields determined in each of these stages are compiled and revised from the analysis of the brittle deformations mainly microfault population stresses are related to the development of the principal structures of each stage in the late variscan fracturing stage sinistral strike slip faults prevailed in a stress field with ne sw subhorizontal compression in the permian to early cretaceous rifting stage the extensional trends varied in each sector during the alpine orogeny primarily the margins of the iberian massif the betic and pyrenee mountain chains were deformed however numerous deformations are also identified in its interior where large mountain chains such as the central system and the iberian chain developed these deformations occurred in a complex stress field where zones of nw se to nne ssw horizontal compression prevailed albeit predominantly extensional zones existed as well at present the stress field in most of iberia has a nw se compressive trend associated with active deformations in the betic cordillera where a continental subduction developed however simultaneously there are zones in which extensional settings predominate such as the internal zones of the betic cordillera and the gulf of valencia region making for quite a complex current stress field

benthic foraminiferal faunal turnover across the cretaceous tertiary boundary at agost southeastern spain paleoenvironmental inferences we studied upper cretaceous and lower paleogene benthic foraminifera from the agost section southeastern spain to infer paleobathymetrical changes and paleoenvironmental turnover across the cretaceous paleogene k p transition benthic foraminifera indicate uppermost bathyal depths at agost during the abathomphalus mayaroensis biochron from about 400 kyr before the k p boundary through the early plummerita hantkeninoides biochron about 120 150 kyr before that boundary the depth increased to middle bathyal for the remainder of the cretaceous and remained so for the danian part of the studied section parasubbotina pseudobulloides biochron at least 200 kyr after the k p boundary there were no perceivable bathymetrical changes at the k p boundary where v5 of the species became extinct and the species composition of the benthic foraminiferal fauna changed considerably below the boundary infaunal morphogroups constitute up to 65 73 of the faunas directly above the boundary in the black clays of the lower guembelitria cretacea biozone benthic foraminifera are rare several opportunistic taxa e g the agglutinant haplophragmoides sp have short peaks in relative abundance possibly reflecting low oxygen conditions as well as environmental instability with benthos receiving food from short lived local blooms of primary producers above the clays through the end of the studied interval epifaunal morphogroups dominate up to 70 of the assemblages or there is an even mixture or epifaunal and infaunal morphogroups infaunal groups do not recover to pre extinction relative abundances indicating that the food supply to the benthos did not recover fully over the studied interval about 200 kyr after the k p boundary the benthic foraminiferal faunal changes are compatible with the direct and indirect effects of an asteroid impact which severely destabilized primary producers and the oceanic food web that was dependent upon them 2003 elsevier science b v all rights reserved

numerical modelling of salt diapirism influence of the tectonic regime abstract in the context of sedimentary basin mechanics salt diapirism has usually been described as a phenomenon initiated and driven by gravity instabilities associated with buoyant forces or differential loading this result holds essentially for an approximation of linear rheologies of both salt and overburden this has been contested by recent analog models and analytical studies buoyancy alone cannot drive salt diapirism through a brittle overburden regional extension or compression could be a necessary mechanism likely to promote salt diapirism numerical models are presented here to describe the relative effects of gravity and lateral forces on the dynamics of salt diapirism the numerical scheme is based on a viscoplastic approximation of deformations and an updated lagrangian description of kinematics which allows a study of large non linear deformations of salt bodies and the evolution of material interfaces this scheme takes into account brittle and ductile deformations of sediments moreover it describes the initiation and evolution of shear bands which play a crucial role in basin mechanics and especially in the dynamics of salt diapirism we show why extension is the most propitious driving mechanism of diapirism necking and faulting induced by extension promote and drive salt diapirism in the case of a brittle overburden this result holds with or without buoyancy forces this demonstrates that buoyancy which alone is not sufficient to break a brittle overburden is not a necessary mechanism either buoyancy however enhances diapirism induced by lateral forces in contrast with extension salt diapirism during compression is strongly constrained by the rheology of the overburden a brittle mode of deformation favours faulting rather than buckling induced thrusting and thickening of the overburden inhibit massive diapirism and favour the confinement of small salt plugs finally the post extension stability of a mature diapir produced by extension is presented

stratigraphy and soil properties of fens geophysical case studies from northeastern germany abstract the determination of the total carbon storage of peatlands is of high relevance in the context of climate change mitigation efforts this determination relies on data about stratigraphy and peat properties which are conventionally collected by coring ground penetrating radar gpr and electrical resistivity imaging eri can support these point data by providing subsoil information in two dimensional cross sections in this study gpr and eri were conducted at two groundwater fed fen sites located in the temperate zone in north east germany the fens of this region are embedded in low conductive glacial sand and are characterised by thick layers of gyttja which can be either mineral or organic the two study sites are representative of this region with respect to stratigraphy total thickness peat and gyttja types and ecological conditions ph value trophic condition the aim of this study is to assess the suitability of gpr and eri to detect stratigraphy and peat properties under these characteristic site conditions results show that gpr clearly detects the interfaces between i carex and brown moss peat ii brown moss peat and organic gyttja iii organic and mineral gyttja and iv mineral gyttja and the parent material glacial sand these layers differ in bulk density and the related organic matter content eri however does not delineate these layers rather it delineates regions of varying properties at our base rich site pore fluid conductivity and cation exchange capacity are the main factors that determine peat electrical conductivity reverse of resistivity whereas organic matter and water content are most influential at the more acidic site thus the correlation between peat properties and electrical conductivity are driven by site specific conditions which are mainly determined by the solute load in the groundwater at fens when the total organic deposits exceed a thickness of 5 m the depth of investigation by gpr is limited due to increasing attenuation this is not a limiting factor for eri where the transition from organic deposits to glacial sand is visible at both sites due to these specific sensitivities a combined application of gpr and eri meets the demand for up to date information on carbon storage of peatlands which is moreover very site specific because of the inherent variety of ecological conditions and stratigraphy between peatlands in general and between fens and bogs in particular

heavy metal and arsenic distributions in sediments of the elba argentario basin southern tuscany italy arsenic chromium cobalt copper lead nickel vanadium and zinc distributions in surficial and core sediments of the elba argentario marine basin southern tuscany central western italy are reported analysis of such distributions compared with grain size and mineralogical data allowed the identification of areas showing trace element enrichments with respect to natural background these enrichments are moderate and essentially restricted to pb and zn only as shows a widespread though not high positive anomaly this general pattern is in good agreement with the minor industrialization affecting the basin s watershed an unexpected anomaly concerning co pb and as as well as fe and ti has been pointed out close to montecristo island this has been ascribed to illegal local dumping of chemical waste

an application of ground penetrating radar to peat stratigraphy of ellice swamp southwestern ontario ground penetrating radar gpr has been applied to the mapping of stratigraphy and peat thickness of a large bog in southwestern ontario the gpr survey was undertaken in conjunction with a conventional coring survey and measurement of peat physical properties the results indicate that gpr responds to peat moisture content and bulk density which vary with stratigraphic changes in particular the acrotelm catotelm boundary and the basal clay are gpr reflectors the presence of gyttja above the clay is indicated by complex basal reflections ground penetrating radar is a viable alternative to an intensive coring survey for evaluating peat depth and extent

a new multilayered model for intraplate stress induced differential subsidence of faulted lithosphere applied to rifted basins in plane horizontal stresses acting on predeformed lithosphere induce differential flexural vertical motions a high precision record of these motions can be found in the sedimentary record of rifted basins originally it was proposed that rifted basins experience flank uplift and basin center subsidence in response to a compressive change of in plane stress which agrees well with observed differential motions subsequently published models predicted that the vertical motions may be opposite because of the flexural state of the lithosphere induced by necking during extension however the total flexural and permanent geometry of the lithosphere underlying the rifted basin is the controlling parameter for the in plane stress caused vertical motions the largest part of this preexisting geometry is caused by faulting in the uppermost brittle part of the crust and ductile deformation in the underlying parts of the lithosphere we present a new multilayered model for stress induced differential subsidence taking into account the technically induced preexisting geometry of the lithosphere including faults in the upper crust as continental lithosphere may exhibit flexural decoupling due to a weak lower crustal layer the new multilayer in plane stress model discriminates the geometries of the separate competent layers at a basin wide scale the new model predicts that a compressive change of in plane force results in basin center subsidence and flank uplift confirming the original hypothesis compared to all previous models the new model requires a lower horizontal stress level change to explain observed differential vertical motions

lithosphere dynamics and tectono stratigraphic evolution of the mesozoic betic rifted margin southeastern spain abstract quantitative subsidence analysis demonstrates that mesozoic sediments in the eastern betic cordilleras have been deposited on a thermally subsiding rifted margin the dynamics of rifting are related to regional trans tension in the atlantic realm modelling of this phase of rifting at the southern iberian margin shows that the associated stretching of the lithosphere significantly altered its geometrical and mechanical structure and exerted a major control on subsequent convergence tectonics the mesozoic stretching led to the formation of a ramp at the margin due to strong lateral variations in the effective elastic thickness eet of the lithosphere and the thickness of the crust in a direction perpendicular to the margin the existence of a ramp structure in the late mesozoic at the iberian margin which is also supported by stratigraphic and structural data is important for the style of subsequent deformation of the lithosphere in late cretaceous tertiary times the lateral variations in eet inferred from forward modelling of rifted margin stratigraphy could explain the observed multiple collapse of the betic margin and the partitioning of deformation between the converging units involved in the betic orogeny modelling of depth dependent palaeo rheological profiles of the margin shows that the mechanical properties of the lithosphere after stretching differed distinctly from those before stretching lithospheric deformation in the betic cordilleras during the tertiary orogeny seems therefore to be largely controlled by the previous rifting phase a comparison of the palaeo and present day rheologies in terms of estimates for eet during late cretaceous and present times indicates that the mechanical properties of the lithosphere underlying the betic orogen were also affected by rifting during late oligocene aquitanian times this phase of rifting is coeval with extension in the valencia trough the gulf of lions and the west european rift system which supports a causal relation with regional lithospheric processes the lateral and spatial variations in thermo mechanical properties of the lithosphere underlying the betics therefore reflect the dynamics of lithospheric extension on a larger scale

origin of string patterns in boreal peatlands the detailed stratigraphical analyses supported by field observations on mires in labrador and northern minnesota reported here provide the basis for an explanation of the development of the surface pattern of alternating peat ridges strings and linear depressions or pools flarks in boreal fens the developmental sequence involves drainage impediment and the concomitant initiation of peat accumulation development of linear patterns as a result of changing hydrological conditions and differential rates of peat accumulation of hummock and hollow plant communities and subsequent enlargement and coalescence of pools through the degradation of the underlying peat and the intervening ridges we show here that many of the processes may be active in the development of the pool patterns on raised bogs as well as on fens

stream channels in peatlands the role of biological processes in controlling channel form while some aspects of peatlands are well studied understanding of the hydrology and geomorphology of the associated surface drainage networks is quite limited this paper attempts to describe some of the basic attributes of stream channels in peatlands and asks whether the form and the mechanisms behind development represent a significant departure from self forming alluvial streams we use three approaches to better understand these poorly studied systems an examination of the geomorphology of allequash creek wisconsin a survey of aerial photographs of similar peatland stream complexes in northern wisconsin and a review of the existing literature on peat influenced and wetland channels distinct features of allequash creek and other wisconsin streams in peatlands include absence of mineral substrates low width depth ratio presence of lateral pool like structures along the channel margin long straight reaches and acute angle bends further the lateral location of the thalweg was apparently independent of planform or cross sectional form and no flow zones often occurred along both edges of channel cross sections collectively these features represent a distinct departure from characteristic forms of alluvial channels deep peat samples from allequash creek and aerial photographs from other sites indicate that these streams represent remnant lake systems whose basins filled with peat thus we suggest that the processes responsible for channel form in these low energy peatland systems are largely governed by groundwater hydrology and the biology of peat accumulation and decomposition in this manner biological forces not just physical drivers such as channel discharge and sediment supply are central to the understanding of stream geomorphology in peatlands

soil maps of wisconsin legacy soil maps are an important input in digital soil mapping this paper traces how reconnaissance soil maps in wisconsin evolved between the 1880s and the present with some discussion on future directions the first soil map in the usa was made in wisconsin by the geologist t c chamberlin in 1882 the second soil map of wisconsin was made by a r whitson in 1927 and the third by f d hole in 1976 soil texture and physiography were the major diagnostic mapping criteria as more detailed county soil surveys were completed and knowledge of the soils increased a higher level of detail can be observed on statewide soil maps the detailed county soil maps were digitized in the 1990s and early 2000s and have been used in a wide range of studies and applications e g agriculture forestry landscape architecture and human health in the 1990s soil scientists transitioned from mapping on paper copy aerial photos to digital procedures this change coincided with the development of digital soil mapping and the introduction of several new observational techniques gpr emi and cone penetrometer these modeling and observational tools continue to be used to evaluate small areas but have not yet become widely used for current soil mapping activities

groundwater surface water interaction between an esker aquifer and a drained fen summary groundwater discharge from an esker aquifer to a fen was studied to understand relevant hydrological processes for groundwater surface water interaction in an esker peatland hillslope piezometric levels of the peat layer and esker sand layer were continuously monitored and compared to climate data groundwater exfiltration points were spatially mapped and related to peat depth the study showed a clear interaction between fen surface water and sand esker groundwater although the hydraulic conductivity of peat was low and the peat depth thick in the artesian aquifer beneath the fen the piezometric head showed a clear response to precipitation and evapotranspiration wetting of the peat is rapidly seen as pressure increase in the confined aquifer this provides new information on hydraulics of wetlands found in aquifer discharge areas groundwater exfiltrated through thick peat layers in vertical preferential point discharges demonstrating how double porosity provides flow through the peat layer with low hydraulic conductivity in the peat matrix the pipe flow channels were found in the deep peat area in the transition zones from deep peat to shallow peat diffuse seepage through the ditch bottom was found where ditches cut into the sand layer increased discharge through the ditch bed reduced the flow resistance at the aquifer boundary which can lower the groundwater level in the esker the results show new processes in the groundwater discharge zone that are useful for groundwater modelling and policy development for future groundwater protection

effects of the pyrenean collision on the paleocene stratigraphic evolution of the southern iberian margin southeast spain rapid sea level changes are generally interpreted in terms of glacio eustasy but they can also be explained by the lithospheric motions associated with changes in intra plate stress in eastern spain latest senonian paleocene time was characterized by a wide spread regression which culminated in the emergence of large parts of the carbonate platform new data indicate that the platform emergence was accompanied by slope faulting and a sudden appearance of olistostromes and sandy turbidites at the southern iberian margin of southeast spain these changes in basin geometry are the result of a tectonic event which is dated as middle paleocene ca 60 ma this tectonic event can be correlated with the onset of collision in the pyrenees regional geologic data and paleostress measurements provide evidence for far field transmission of the pyrenean compressive stresses through the iberian lithosphere it is concluded that the platform emergence and slope steepening at the southern iberian margin reflect the vertical lithospheric motions of a basin flank subjected to compression

geophysical evidence for peat basin morphology and stratigraphic controls on vegetation observed in a northern peatland vegetation patterns in peatlands suggest autogenic peatland development and hydrological processes are controlling factors in peatland evolution these processes regulate vegetation ordination by influencing ph and nutrient availability at the peat surface geophysical studies in caribou bog a 2200 hectare peatland in central maine indicate a close correlation between underlying geologic deposits and dominant vegetation type the location of pools within the bog also appears to be related to subsurface geologic materials electrical resistivity imaging along a 1 km transect across the central unit of caribou bog resolved underlying lake sediment and glacio marine clay thickness as well as variability in depth to glacial till ground penetrating radar precisely defined the organic rich lake sediment the glacio marine interface and elevated till surfaces where peat thickness is less than 10 m direct verification of peat and lake sediment thickness in addition to samples of the glacio marine and till deposits constrained the geophysical interpretation wooded heath wh interspersed with occasional sphagnum lawn occurs where lake sediment and glacio marine clay accumulation is thickest abrupt thinning of both layers such that peat rests directly on till in places correlates with a sharp transition to shrub heath dominated vegetation a major open pool area located within the wh coincides with a localized sandy mineral soil lake sediment contact at the base of the bog the geophysical data suggest the underlying double basin system influences peatland development and dictates vegetation patterning limited groundwater elevation data suggest that sub organic sediment stratigraphy mapped with geophysics regulates water levels at the peat surface exerting a control on vegetation patterning the major pool area located between the basins appears to reflect isolation of stagnant water at a point where peat development is incomplete and thus suggests that pools exist concurrent with peatland formation

consequences of thrusting and intraplate stress fluctuations for vertical motions in foreland basins and peripheral areas summary we present a conceptual model for short term and long term alternations in subsidence and uplift in foreland basins convergence of lithospheric plates produces forces at the plate boundaries generating stresses in the accretionary wedge the underthrusted crust and the lithosphere when the stresses reach the shear strength of the rocks in these units deformation which results in the redistribution of mass takes place contemporaneously with reduction of the stress level modelling of both the effects of this alternating building up and relaxation of stress and the effects of the resulting mass redistribution on foreland basin geometry employing an elastic rheology of the lithosphere demonstrates that these processes exert an important control on the shape of foreland basins vertical motions take place on different time scales dependent on the scale of thrusting and the style of deformation short term 10 104 yr vertical motions are related to small scale thrust events while long term vertical motions are induced by larger scale deformation in the overriding thrust wedge furthermore the geometry of faults influences the duration of the magnitude of stress fluctuations stress induced alternations of subsidence may lead to the deposition of alternating sequences in foreland basins on scales of centimetres e g cyclothems to scales of several hundreds of metres on lap and off lap sequences in this respect the mechanical coupling between convergent zones and peripheral areas is of particular importance as it induces simultaneous alternations in regional facies patterns the model also provides an explanation for vertical motions in the foreland basin previously attributed to visco elastic relaxation processes

early middle miocene stratigraphic turning points in the alicante region se spain reflections of western mediterranean plate tectonic reorganizations abstract the paper concerns the miocene deposits of the alicante region se spain which forms part of the prebetic and intermediate units representing the former southern passive margin of the iberian continent from the late jurassic up to the miocene the alicante region was the scene of a facies distribution with more continental lagoonal or shallow marine conditions in the north and northwest and more open or deeper marine in the south and southeast the early middle miocene deposits can be divided in three sedimentary cycles each one controlled by a different tectonic regime cycle i aquitanian is deposits after a block faulting phase at about 25 ma related to the formation of the ligurian and balearic troughs cycle ii burdigalian early langhian is separated from first cycle sediments by a complete reorientation of palaeogeography at 19 5 ma due to the collision of iberia with africa the southern part of the region is folded and uplifted and separated from a northern emerged area by a trough cycle iii late langhian serravallian is controlled by strike slip movements caused by the continuing convergence between africa and europe and resulting in the development of a new set of basins at 15 5 ma at the middle late miocene boundary the alicante region emerges thus younger important tectonics could not be dated our results are in conflict with several recent plate tectonic models for the miocene history of the western mediterranean where the internal betic zone is placed juxtaposed to the alicante region prior to the burdigalian

gpr and aerial imageries to identify the recent historical course of the obra river and spatial extent of obrzanskie lake altered by hydro technical works ground penetrating radar gpr measurements have been conducted to retrace the natural course of the obra river and changes of spatial extent of obrzanskie lake western poland the obra river valley was subjected to intensive anthropogenic transformation three artificial canals were constructed here in the beginning of the nineteenth century the gpr surveys were done using a georadar mala proex equipped with 250 mhz antenna the measurement was verified by coring and analyses of historical maps aerial photographs and satellite images the research has shown that there are at least three elongated depressions preserved in the modern land surface near the village of solec situated in the middle course of the valley several structures suggesting functioning of a multi channel pattern in the past have been detected inside and in the vicinity of the depressions filling the channels with silts and peats might have been the effect of flow deceleration caused by the construction of the obra canals moreover situation of two of the retraced depressions suggests that the landforms might be the remains of a river bed disappearing in wetlands further studies including groundwater flux measurements in the area between the depressions are needed to confirm such hypothesis furthermore the study allowed retracing the spatial extent of obrzanskie lake the sediment structures detected by the gpr measurements and calibrated with coring were interpreted to be the traces of the lake shoreline the interpretation was supported by the findings inferred from aerial and satellite images it was shown that obrzanskie lake had had at least three islands and had been directly connected with a network of braided channels before the anthropogenic intervention the spatial extent of the lake was significantly altered by the construction of the north obra canal disconnecting the lake from the canal resulted in more than 50 decrease of the lake surface

oblique aggradation a novel explanation for sinuosity of low energy streams in peat filled valley systems low energy streams in peatlands often have a high sinuosity however it is unknown how this sinuous planform formed since lateral migration of the channel is hindered by relatively erosion resistant banks we present a conceptual model of holocene morphodynamic evolution of a stream in a peat filled valley based on a palaeohydrological reconstruction coring ground penetrating radar gpr data and 14c and osl dating were used for the reconstruction we found that the stream planform is partly inherited from the late glacial topography reflecting stream morphology prior to peat growth in the valley most importantly we show that aggrading streams in a peat filled valley combine vertical aggradation with lateral displacement caused by attraction to the sandy valley sides which are more erodible than the co evally aggrading valley fill due to this oblique aggradation in combination with floodplain widening the stream becomes stretched out as channel reaches may alternately aggrade along opposed valley sides resulting in increased sinuosity over time hence highly sinuous planforms can form in peat filled valleys without the traditional morphodynamics of alluvial bed lateral migration improved understanding of the evolution of streams provides inspiration for stream restoration this article is protected by copyright all rights reserved

ground penetrating radar for high resolution mapping of soil and rock stratigraphy ground penetrating radar is a technique which offers a new way of viewing shallow soil and rock conditions the need to better understanding overburden conditions for activities such as geochemical sampling geotechnical investigations and placer exploration as well as the factors controlling groundwater flow has generated an increasing demand for techniques which can image the subsurface with higher resolution than previously possible the areas of application for ground penetrating radar are diverse the method has been used successfully to map ice thickness water depth in lakes bedrock depth soil stratigraphy and water table depth it is also used to delineate rock fabric detect voids and identify karst features the effective application of the radar for the high resolution definition of soil stratigraphy and fractures in bedrock is highlighted the basic principles and practices involved in acquiring high quality radar data in the field are illustrated by selected case histories one example demonstrates how radar has been used to map the bedrock and delineate soil horizons to a depth of more than 20 m two case histories show how radar has been used to map fractures and changes of rock type to 40 m range from inside a mine another case history demonstrates how radar has also been used to detect and map the extent of groundwater contamination the corroboration of the radar results by borehole investigations demonstrates the power and utility of the high resolution radar method as an aid for interpolation and extrapolation of the information obtained with conventional coring programmes with the advent of new instrumentation and field procedures the routine application of the radar method is becoming economically viable and the method will see expanded use in the future

background levels of potentially toxic metals from soils of the pisa coastal plain tuscany italy as identified from sedimentological criteria identification of reliable background values of potentially toxic metals in sediments requires detailed integration of geochemical data with accurate sedimentological studies through analysis of 60 soil samples from the pisa coastal plain this study shows to what extent sediment provenance and facies characteristics may influence the natural distribution of potentially toxic metals cr ni cu zn pb within alluvial and coastal sediments metals supplied to the alluvial plain are mostly concentrated within the finest sediment fraction floodplain clays while coarser crevasse and overbank deposits exhibit invariably lower metal contents beach ridge sands display the lowest metal concentrations transport of ophiolitic detritus by the longshore drift may account for locally high cr concentrations within beach deposits geochemical fingerprinting of individual facies associations in terms of natural metal contents results in the construction of a geologically based geochemical map this map offers a more reliable depiction of spatial distribution of background levels than interpolation techniques based uniquely upon statistical methods matching background values against metal concentrations from topsoil samples leads to the reliable assessment of the pollution status of pisa coastal plain metal contents exceeding the threshold values designated for contaminated areas cr simply reflect catchment geology and are not the product of artificial contamination on the other hand anthropogenic disturbance may be detected even where metal contents pb cu lie below the threshold values the use of sedimentological criteria is presented here as a pragmatic tool to enhance predictability of natural metal contents in sediments with obvious positive feedbacks for legislative purposes and environmental protection

application of ground penetrating radar to the identification of subsurface piping in blanket peat natural soil pipes are common and significant in upland blanket peat catchments yet there are major problems in finding and defining the subsurface pipe networks this is particularly important because pipeflow can contribute a large proportion of runoff to the river systems in these upland environments and may significantly influence catchment sediment and solute yields traditional methods such as digging soil pits are destructive and time consuming particularly in deep peat and only provide single point sources of information this paper presents results from an experiment to assess the use of ground penetrating radar gpr to remotely sense pipes in blanket peat the technique is shown to be successful in identifying most of the pipes tested in the pilot catchment comparison of data on pipes identified by gpr and verified by manual measurement suggests that pipes can be located in the soil profile with a depth accuracy of 20 to 30 cm gpr identified pipes were found throughout the soil profile however those within 10 20 cm of the surface could not be identified using the 100 or 200 mhz antennae due to multiple surface reflections generally pipes smaller than 10 cm in diameter could not be identified using the technique although modifications are suggested that will allow enhanced resolution future work would benefit from the development of dual frequency antennae that will allow the combination of high resolution data with the depth of penetration required in a wetland environment the gpr experiment shows that pipe network densities were much greater than could be detected from surface observation alone thus gpr provides a non destructive fast technique which can produce continuous profiles of peat depth and indicate pipe locations across survey transects copyright 2002 john wiley sons ltd

stratigraphic controls on pool formation in a domed bog inferred from ground penetrating radar gpr ground penetrating radar gpr and terrain conductivity measurements reveal a close correlation between the location of water filled pools and stratigraphic lithologic features in caribou bog a 2200 hectare peatland in central maine the geophysical profiles supported by coring define the general peatland stratigraphy as till underlain by glacio marine sediment overlain by organic rich lake sediment transitioning into terrestrial peat gpr measurements show that open pools coincide with abrupt thinning of lake sediment and glaciomarine clay such that elevated mineral soil surfaces are in direct contact with the base of terrestrial peat the width of these features the gpr reflection patterns the anomalously low terrain conductivity and the core samples obtained support the interpretation of these elevated mineral surfaces as the extension of buried eskers that outcrop on the periphery of caribou bog the geophysical results indicate that two parallel esker ridges are orientated n s and dip towards the south we suggest that the distribution of open pools is related to the distribution of depressions and beads associated with a beaded esker deposit the pools possibly being maintained by local groundwater flow cells associated with the esker gpr and em31 surveys across sphagnum pools defined here as sphagnum filled wet depressions suggest a continuous sequence of underlying lake sediment and glacio marine deposits devoid of elevated mineral surfaces we suggest that sphagnum pools developed after peatland formation secondary features due to changes in water table peat accumulation and or climatic controls q 2005 elsevier b v all rights reserved

piping and pipeflow in a deep peat catchment abstract natural pipes are common in many upland blanket peats yet little is known about pipe network morphology or pipeflow processes most information on soil piping comes from the shallow peaty podzols of the welsh uplands where monitoring suggests that pipes may be important contributors to streamflow this paper presents information on piping and pipeflow from a deep upland blanket peat catchment in the pennine hills of northern england pipe outlets are found throughout the soil profile ranging from the underlying substrate at 3 m depth to pipes which are within a few centimetres of the surface mean pipe diameters range from 3 to 70 cm some pipes are over 150 m long slopes in the catchment are less steep than those usually associated with soil piping continuous flow records were obtained from 15 gauging sites on 8 separate pipes the pipeflow response from deep blanket peat was found to be different to that reported in the shallow peaty podzols of the welsh uplands the distinction between ephemeral and perennial pipe types does not appear to be useful within the deep pennine blanket peat response times from all of the pipes are short even from pipes deep within the peat at the same time pipes have a prolonged recession limb such that they maintain low flow for longer periods than most other runoff production processes within the catchment pipeflow contributes around 10 of the streamflow volume but can at times contribute up to 30 soil pipes may therefore be far more important in some upland peat catchments than previous work has hitherto suggested

analogue modelling of a reactivated basement controlled strike slip zone sierra de albarracin spain application of sandbox modelling to polyphase deformation this paper presents the results of an analogue modelling study on the reactivation of riedel shears generated by basement induced sinistral strike slip faulting it is based on a natural example in the sierra de albarracin iberian range spain the area has a polyphase deformation history defined by the variscan and alpine orogenies late variscan deformation was concentrated in a wide nw se shear zone with accompanying kilometre scale e w riedel shears which divided the palaeozoic basement into large fault blocks alpine reactivation resulted in differential movements on the riedel shears as evidenced by a nw se chain of palaeozoic inliers surrounded by a mesozoic cover that generally shows minor deformations except near the e w riedel shears where strata locally appear in near vertical to overturned position sandbox analogue modelling was applied to improve insight into the structural history it focused on the kinematics of spontaneously developed en echelon riedel shears reactivated in a rotated stress field sand with a controlled added strength was used to form riedel shears in a first deformation phase to act as weak zones for a second phase the modelling showed that in the first deformation phase large pop up structures developed between the riedel shears in a basement induced sinistral strike slip zone later reactivation in the n060 e and n135 e shortening directions was taken up respectively by sinistral reverse and dextral reverse shear along the pre existing riedel shears but only if the sand on one side of the fault zone was allowed to move freely along the other scissor faulting along the riedel shears with their complex 3d geometry increased the height of the up squeezed blocks for experiments with fixed boundaries and no oil water emulsion layer between the base plate and sand pack thrusting at the backstop occurred rather than reactivation of the riedel shears this approach provided robust insights on the 4d development of the sierra de albarracin area the geological society of london 2006

measuring thaw depth beneath peat lined arctic streams using ground penetrating radar in arctic streams depth of thaw beneath the stream channel is likely a significant parameter controlling hyporheic zone hydrology and biogeochemical cycling as part of an interdisciplinary study of this system we conducted a field investigation to test the effectiveness of imaging substream permafrost using ground penetrating radar gpr we investigated three sites characterized by low energy water flow organic material lining the streambeds and water depths ranging from 0 2 to 2 m we acquired data using a 200 mhz pulsed radar system with the antennas mounted in the bottom of a small rubber boat that was pulled across the stream while triggering the radar at a constant rate we achieved excellent results at all three sites with a clear continuous image of the permafrost boundary both peripheral to and beneath the stream our results demonstrate that gpr can be an effective tool for measuring substream thaw depth copyright 2005 john wiley sons ltd

hydrological connectivity of soil pipes determined by ground penetrating radar tracer detection soil pipes are common and important features of many catchments particularly in semi arid and humid areas and can contribute a large proportion of runoff to river systems they may also signi cantly in uence catchment sediment and solute yield however there are often problems in nding and de ning soil pipe networks which are located deep below the surface ground penetrating radar gpr has been used for non destructive identi cation and mapping of soil pipes in blanket peat catchments while gpr can identify subsurface cavities it cannot alone determine hydrological connectivity between one cavity and another this paper presents results from an experiment to test the ability of gpr to establish hydrological connectivity between pipes through use of a tracer solution sodium chloride was injected into pipe cavities previously detected by the radar the gpr was placed downslope of the injection points and positioned on the ground directly above detected soil pipes the resultant radargrams showed signi cant changes in re ectance from some cavities and no change from others pipe waters were sampled in order to check the radar results changes in electrical conductivity of the pipe water could be detected by the gpr without data post processing when background levels were increased by more than approximately twofold it was thus possible to rapidly determine hydrological connectivity of soil pipes within dense pipe networks across hillslopes without ground disturbance it was also possible to remotely measure travel times through pipe systems the passing of the salt wave below the gpr produced an easily detectable signal on the radargram which required no post processing the technique should allow remote sensing of water sources and sinks for soil pipes below the surface the improved understanding of owpath connectivity will be important for understanding water delivery solutional and particulate denudation and hydrological and geomorphological model development copyright 2004 john wiley sons ltd

heavy metal origin and concentration in the sediments of the pointe a pitre bay guadeloupe lesser antilles sewage discharge chiefly waste waters into the pointe a pitre bay originates from the neighboring developing town 60 000 inhabitants a sampling campaign carried out in march 1984 permitted the assessment of both water and sediment quality in the bay as well as the evaulation of heavy metal contents industrial pollution appears insignificant whilst urban pollution dominates heavy metal contents lead pb zinc zn copper cu are high in the sediments of the inner end of the bay and eastern bank parallel to the urban agglomeration this anthropogenic origin is accounted for by comparison of heavy metal contents with those prevailing in the terrestrial environment

holocene relative shore level changes and stone age palaeogeography of the parnu bay area eastern baltic sea the shore displacement and palaeogeography of the parnu bay area eastern baltic sea during the stone age were reconstructed using sedimentological and archaeological proxies and gis based landsc

ground penetrating radar and spring formation in a groundwater dominated peat wetland summary ground penetrating radar gpr was used to identify the thickness and geometry of peat in a groundwater fed wetland in northern wisconsin the low electrical conductivity of the water saturated peat permitted high resolution imaging to a depth of 16 m the gpr survey results delineated a break in slope in the interface between peat and the underlying sand gravel springs and ponds are located above the break in slope suggesting that thinning of the sand and gravel may focus groundwater flow upward to the wetland surface with emergence as springs the results of the gpr surveys suggests a potential mechanism that controls the formation of large springs and pools above the break in slope