the micromorphology of last glacial maximum sediments in the southern north sea abstract the terrestrial ice limits of the last glacial maximum ice sheets are well understood but areas submerged during postglacial sea level rise have proved more difficult to accurately map fine grained diamicts in the southern north sea have been variously interpreted as glacial glacioaqueous or periglacial in origin implying different sedimentary environments this has resulted in contrasting opinions regarding the position of the last ice sheets in this area micromorphology is presented as a useful technique to aid the analysis of such sediments using systematic description of the physical characteristics of the sediments related to an interpreted seismic stratigraphy results indicate that the british ice sheet deposited glaciomarine sediments during an early advance and then advanced over an extensive part of the southern north sea as terrestrial ice

natural and anthropogenic factors affecting groundwater quality of an active volcano mt etna italy abstract new geochemical data on dissolved major and minor constituents in 276 groundwater samples from etna aquifers reveal the main processes responsible for their geochemical evolution and mineralisation this topic is of particular interest in the light of the progressive depletion of water resources and groundwater quality in the area multivariate statistical analysis reveal 3 sources of solutes a the leaching of the host basalt driven by the dissolution of magma derived co2 b mixing processes with saline brines rising from the sedimentary basement below etna c contamination from agricultural and urban wastewaters the last process highlighted by increased concentrations of so4 no3 ca f and po4 is more pronounced on the lower slopes of the volcanic edifice associated with areas of high population and intensive agriculture however this study demonstrates that natural processes a and b are also very effective in producing highly mineralised waters which in turn results in many constituents b v mg exceeding maximum admissible concentrations for drinking water

palaeogeography of atlantic canada 13 0 kyr abstract we combine isobase maps with a digital terrain model of atlantic canada to map coastlines from 13 14c kyr bp to the present at 13 14c kyr bp there are ridges of high relative sea level rsl values over newfoundland and the maritime provinces and a re entrant of low values in the gulf of st lawrence this pattern persists well into the holocene and reflects crustal response to the slow wasting of ice caps that persisted in newfoundland and the maritime provinces for up to five millennia after the removal of ice from the gulf of st lawrence by a migrating calving embayment the palaeogeographic reconstructions reveal an archipelago on the outer shelf from grand bank to the continent that persisted from 13 14c kyr bp until ca 8 14c kyr bp much of the magdalen shelf was exposed but the magdalen islands were never connected to the mainland prince edward island was initially separated from the mainland became connected after 11 14c kyr bp and was separated again just before 6 14c kyr bp when northumberland strait formed the reconstructions are highly sensitive to relatively small changes in isobase values especially on the shallow banks on the continental shelf

the last glacial maximum in the north sea basin micromorphological evidence of extensive glaciation despite a long history of investigation critical issues regarding the last glacial cycle in northwest europe remain unresolved one of these refers to the extent timing and dynamics of late devensian weichselian glaciation of the north sea basin and whether the british and scandinavian ice sheets were confluent at any time during this period this has been the result of the lack of the detailed sedimentological data required to reconstruct processes and environment of sediments recovered through coring this study presents the results of seismic sedimentological and micromorphological evidence used to reconstruct the depositional processes of regionally extensive seismic units across the north sea basin thin section micromorphology is used here to provide an effective means of discriminating between subglacial and glacimarine sediments from cored samples and deriving process based interpretations from sediment cores on the basis of micromorphology critical formations from the basin have been reinterpreted with consequent stratigraphic implications within the current stratigraphic understanding of the north sea basin a complex reconstruction is suggested with a minimum of three major glacial episodes inferred on at least two occasions during the weichselian devensian the british and scandinavian ice sheets were confluent in the central north sea whilst micromorphology can provide much greater confidence in the interpretation of late quaternary offshore stratigraphic sequences it is noted that a much better geochronology is required to resolve key stratigraphic issues between the onshore and offshore stratigraphic records copyright 2006 john wiley sons ltd

geochemistry of fluoride rich groundwater in kolar and tumkur districts of karnataka groundwater is a significant water resource in india for domestic irrigation and industrial needs by far the most serious natural groundwater quality problem in india in terms of public health derives from high fluoride arsenic and iron concentrations hydrogeochemical investigation of fluoride contaminated groundwater samples from kolar and tumkur districts in karnataka are undertaken to understand the quality and potability of groundwater from the study area the level of fluoride contamination the origin and geochemical mechanisms driving the fluoride enrichment majority of the groundwater samples did not meet the potable water criteria as they contained excess 1 5 mg l fluoride dissolved salts 500 mg l and total hardness 75 924 mg l hydrogeochemical facies of the groundwater samples suggest that rock weathering and evaporation crystallization control the groundwater composition in the study area with 50 67 of samples belonging to the ca hco3 type and the remaining falling into the mixed ca na hco3 or ca mg cl type the saturation index values indicated that the groundwater in the study area is oversaturated with respect to calcite and under saturated with respect to fluorite the deficiency of calcium ion concentration in the groundwater from calcite precipitation favors fluorite dissolution leading to excess fluoride concentration

the fluoride in the groundwater of guarani aquifer system the origin associated with black shales of parana basin this work presents petrological and geochemical results of the black shales interval from permian and devonian strata of the parana basin brazil and its relationships with fluoride of groundwater from guarani aquifer system the guarani aquifer located in south brazil uruguay paraguay and argentine presents contents of fluoride higher than the brazilian accepted potability limits several hypotheses have been presented for the origin of the fluoride in the groundwater of the guarani aquifer microcrystalline fluorite was registered in black shales of ponta grossa and irati formations from parana basin the results shown in this work suggest that fluoride present in groundwater of guarani aquifer can be originated in deeper groundwater that circulates in ponta grossa and irati formations the interaction of the groundwater coming from deeper black shales with the groundwater bearing aquifer guarani system occurs through regional fragile structures faults and fractures that constitute excellent hydraulic connectors between the two sedimentary packages the microcrystalline fluorite registered in ponta grossa and irati formations can be dissolved promoting fluoride enrichment in groundwater of these black shales and guarani aquifer system

constraining the late pleistocene history of the laurentide ice sheet by dating the missinaibi formation hudson bay lowlands canada abstract well dated paleorecords from periods prior to the last glacial maximum lgm are important for validating models of ice sheet build up and growth however owing to glacial erosion most late pleistocene records lie outside of the previously glaciated region which limits their ability to inform about the dynamics of paleo ice sheets here we evaluate new and previously published chronology data from the missinaibi formation a pleistocene aged deposit in the hudson bay lowlands hbl canada located near the geographic center of the laurentide ice sheet lis available radiocarbon ams 44 conventional 36 amino acid n 13 uranium thorium u th n 14 thermoluminescence tl n 15 and optically stimulated luminescence osl n 5 data suggest that an ice free hbl may have been possible during parts of marine isotope stage 7 mis 7 ca 243 000 to ca 190 000 yr bp mis 5 ca 130 000 to ca 71 000 yr bp and mis 3 ca 29 000 to ca 57 000 while mis 7 and mis 5 are well documented interglacial periods the development of peat forest bed and fluvial deposits dating to mis 3 n 20 radiocarbon dates 4 tl dates 3 osl dates suggests that the lis retreated and remained beyond or somewhere within the boundaries of the hbl during this interstadial ice sheet models approximate the margin of the lis to southern ontario during this time which is 700 km south of the hbl therefore if correct our data help constrain a significantly different configuration and dynamicity for the lis than previously modelled we can find no chronological basis to discount the mis 3 age assignments however since most data originate from radiocarbon dates lying close to the reliable limit of this geochronometer future work on dating the missinaibi formation using other geochronological methods e g u th osl is necessary in order to confirm the age estimates and strengthen the boundaries of the lis during this period

the laurentide and innuitian ice sheets during the last glacial maximum the late wisconsinan advance of the laurentide ice sheet started from a middle wisconsinan interstadial minimum 27 30 14 c ka bp when the ice margin approximately followed the boundary of the canadian shield ice extent in the cordillera and in the high arctic at that time was probably similar to present ice advanced to its late wisconsinan stage 2 limit in the northwest south and northeast about 23 24 14 c ka bp and in the southwest and far north about 20 21 14 c ka bp in comparison to some previous reconstructions of ice extent our current reconstruction has substantially more late wisconsinan ice in the high arctic where an innuitian ice sheet is generally acknowledged to have existed in the atlantic provinces where ice is now thought to have extended to the continental shelf edge in most places and on eastern baffin island where ice probably extended to the fiord mouths rather than to the fiord heads around most of the ice margin the late wisconsinan maximum ice extent either exceeded the extent of earlier wisconsinan advances or it was similar to the early wisconsinan advance ice marginal recession prior to 14 14 ck a bp occurred mainly in deep water and along the southern terrestrial fringe however heinrich event 1 probably drew down the entire central ice surface at 14 5 14 c ka bp sufficiently to displace the labrador sector outflow centre 900 km eastward from the coast of hudson bay the onset of substantial ice marginal recession occurred about 14 14 c ka bp in the northwest southwest and south but not until about 10 11 14 c ka bp in the northeast and in the high arctic thus the period of maximum ice extent in north america generally encompasses the interval from b24 21 to 14 14 c ka bp or considerably longer than the duration of the lgm defined as occurring during a period of low global sea level as well as during a time of relative climate stability b18 14 c ka bp the interval of advance of much of the laurentide ice sheet to its maximum extent between b27 14 c ka bp and b24 14 c ka bp coincides with a suggested interval of rapid fall in global sea level to near lgmlevels r 2001 elsevier science ltd all rights reserved

micromorphological criteria for discriminating subglacial and glacimarine sediments evidence from a contemporary tidewater glacier spitsbergen abstract sedimentological and micromorphological evidence is presented from four sites within st jonsfjorden western spitsbergen sedimentological and geomorphological evidence is used to distinguish sites comprising undisturbed glacimarine sediments from glacially over ridden glacimarine sediments and subglacial diamicts impregnated thin sections are used to define associations of micromorphological characteristics that allow diamicts formed under these different conditions to be discriminated in situ glacimarine deposits display winnowed textures dropstone structures and distinct vertical orientations of sand grains whilst subglacial conditions result in structures indicative of deformation under moderate to high stress regimes these criteria may help to determine the origin of ancient and quaternary diamicts of questionable subglacial or glacimarine origin

wisconsinan glacial and sea level history of maritime canada and the adjacent continental shelf a correlation of land and sea events the wisconsinan glacial history of maritime canada records the interaction of land based glaciers with the sea which dissects the region along the deep embayments of the bay of fundy and the laurentian channel ice centers collectively termed the appalachian ice complex shifted in a clockwise manner across the varied bedrock terranes of the region producing cross striated bedrock outcrops and compositionally distinct till sheets on land offshore glacial sediments can be correlated to their terrestrial counterparts on the basis of provenance thus establishing crucial land sea links in the glacial record five glacier flow events have been recognized during the caledonia phase in early to middle wisconsinan time ice from eastern appalachian upland sources crossed nova scotia and extended to the continental shelf edge where a calving margin was established slumping at this margin produced proximal wedge shaped bodies of diamicton that interfinger with glaciomarine sediments the caledonia phase glacier retreated during middle wisconsinan time to the inner scotian shelf during the escuminac phase in late wisconsinan time 22 19 ka an ice center formed over the magdalen shelf escuminac ice center and transported large quantities of local red bed material southward to the outer shelf slope margin this glacier retreated about 18 ka to a tidewater margin at sable island bank and banquereau sea level during this time was falling as a result of isostatic recovery from earlier escuminac phase maximum ice loads just after 18 ka ice wasted back across the midshelf basins to the tidewater margin of the scotian shelf end moraine complex and was stabilized by falling sea levels escuminac ice was reorganized into the scotian ice divide scotian phase over mainland nova scotia and the continental shelf south of cape breton island between 15 and 13 ka another period of glacier retreat ensued and the margin settled close to the present day land areas between 13 and 12 5 ka an ice margin was established from local terrestrial ice centers in northern nova scotia chignecto phase into the bay of fundy and just beyond the present day atlantic coast responding to increasing climatic warming these smaller glaciers dissipated and their margins retreated landward a sea level lowstand of 65 m on the inner shelf occurred ca 11 7 ka isolated terrestrial remnants of chignecto phase glaciers were reactivated as a result of cooling during the collins pond phase younger dryas ca 10 8 ka enhanced ice rafting evident in the north atlantic deep oceanic record appears to correlate with periods of glacier retreat in the appalachian ice complex during melting and sea level rise both the quantity and thickness of icebergs increased due to grounding line retreat within the magdalen shelf thereby increasing the net flux of hematite stained quartz to the north atlantic

relative sea level changes and glacio isostatic adjustment on the magdalen islands archipelago atlantic canada from mis 5 to the late holocene abstract the magdalen islands quebec canada in the centre of the gulf of st lawrence are located in a strategic position for providing an overview of the relative sea level rsl history of the maritime provinces of eastern canada although data are available for the coastal terrestrial areas of the maritimes data from the gulf are very scarce and both the rsl and glacio isostatic adjustment gia models extrapolate for this central region this study provides new stratigraphic and chronological data from four outcrops and two coring sites on the magdalen islands in addition to the five samples used mainly for age control purposes nine new luminescence ages are presented with these new data added to the available literature a new rsl curve is reconstructed for the lgm to the late holocene period and a partial curve is proposed for the interval between the late mis 4 to the mis 3 data also indicate a few insights for the mis 5 period results reveal that for the lgm to the late holocene the curve corresponds to the j shaped curve scenario recognized in the literature the rsl changes during this period are the result of glacio isostatic rebound migration and collapse of the peripheral forebulge and eustatic sea level changes for the lgm to the early holocene glacio isostatic depression curves displaying a few local differences are also proposed for the late holocene the data constrain the curve between two types of indicators i e marine and terrestrial and indicate that the rsl has risen at least 3 m during the last two millennia sediments dated to the mis 5 and the interval between the late mis 4 and the mis 3 illustrate that the gia following the lgm also occurred for the mis 5 interglacial and the mis 3 interstadial finally recent gia models are discussed in light of the results of this paper

recharge history and controls on groundwater quality in the yuncheng basin north china environmental isotopes and water quality indicators e g tds and no 3 contents were used to characterize the age recharge history and controls on the quality of groundwater resources in the yuncheng basin north china where extensive extraction occurs for agriculture and domestic supply delta 18 o and delta 2 h values as low as 10 6 and 73 parts per thousand respectively together with low radiocarbon activities 70 pmc indicating a significant component of modern post 1950s recharge the shallow groundwater has higher delta 18 o and delta 2 h values up to 8 1 and 54 parts per thousand that are similar to those in modern summer monsoon rainfall indicating that current recharge is via direct infiltration and or leakage of ephemeral streams during heavy rain events historic recharge rates estimated using radiocarbon ages are between 1 and 10 mm year corresponding to 20 mg l in some deep wells 180 m preferential leakage has occurred near the linyi fault in the northern sushui river basin salinisation nitrate contamination and excessive drawdown of deep groundwater are major concerns for the future of the groundwater resources in this region c 2010 elsevier b v all rights reserved

late glacial stratigraphy and history of the gulf of st lawrence reply the three dimensional configuration of the quaternary sediments in the gulf of st lawrence is described based on analysis of 8000 km of high resolution seismic reflection data complemented by anal

effect of land use and urbanization on hydrochemistry and contamination of groundwater from taejon area korea abstract taejon metropolitan city located in the central part of south korea has grown and urbanized rapidly the city depends heavily on groundwater as a water resource because of ubiquitous pollution sources the quality and contamination have become important issues for the urban groundwater supply this study has investigated the chemical characteristics and the contamination of groundwater in relation to land use an attempt was made to distinguish anthrophogenic inputs from the influence of natural chemical weathering on the chemical composition of groundwater at taejon groundwater samples collected at 170 locations in the taejon area show very variable chemical composition of groundwater e g electrical conductance ranges from 65 to 1 290 s cm most groundwater is weakly acidic and the groundwater chemistry is more influenced by land use and urbanization than by aquifer rock type most groundwater from green areas and new town residential districts has low electrical conductance and is of ca hco 3 type whereas the chemical composition of groundwater from the old downtown and industrial district is shifted towards a ca cl no 3 so 4 type with high electrical conductance a number of groundwater samples in the urbanized area are contaminated by high nitrate and chlorine and exhibit high hardness the epco 2 that is the co 2 content of a water sample relative to pure water was computed to obtain more insight into the origin of co 2 and bicarbonate in the groundwater the co 2 concentration of groundwater in the urbanized area shows a rough positive relationship with the concentration of major inorganic components the sources of nitrate chlorine and excess co 2 in the groundwater are likely to be municipal wastes of unlined landfill sites leaky latrines and sewage lines chemical data of commercial mineral water from other jurassic granite areas were compared to the chemical composition of the groundwater in the taejon area factor analysis of the chemical data shows that the hco 3 and no 3 concentrations have the highest factor loadings on factor 1 and factor 2 respectively factors 1 and 2 represent major contributions from natural processes and human activities respectively the results of the factor analysis indicate that the levels of ca 2 mg 2 na cl and so 4 2 derive from both pollution sources and natural weathering reactions

multivariate statistical analysis of geochemical data as indicative of the hydrogeochemical evolution of groundwater in a sedimentary rock aquifer system summary the study of groundwater hydrogeochemistry of the paleozoic basses laurentides sedimentary rock aquifer system in quebec produced a large geochemical dataset groundwater samples were collected at 153 sites over a 1500 km2 study area and analyzed for major and minor ions the large number of data can lead to difficulties in the integration interpretation and representation of the results two multivariate statistical methods hierarchical cluster analysis hca and principal components analysis pca were applied to a subgroup of the dataset to evaluate their usefulness to classify the groundwater samples and to identify geochemical processes controlling groundwater geochemistry this subgroup consisted of 144 samples and 14 parameters ca2 mg2 na k hco 3 cl so 4 2 fe2 mn2 br sr2 f ba2 hs seven geochemically distinct clusters c1 c7 resulted from the hca samples from clusters c3 c4 c6 and c7 are mostly located in preferential recharge areas the majority of these samples have ca mg hco3 recharge groundwater c3 c6 c7 and na hco3 evolved groundwater c4 samples from the other three clusters c1 c2 c5 are characteristic of an aquifer system under confined conditions the majority of these samples have na hco3 evolved groundwater c1 c5 and na cl ancient groundwater that exhibits elevated concentrations in br c2 in addition to recognizing the importance of hydrogeological conditions on groundwater geochemistry the distribution of clusters also showed the importance of the geological formations on minor and trace elements such as fe2 mn2 sr2 f and ba2 the first five components of the pca account for 78 3 of the total variance in the dataset component 1 is defined by highly positive loadings in na cl and br and is related to groundwater mixing with champlain sea water and solute diffusion from the marine clay aquitard the high positive loadings in ca2 and mg2 of component 2 suggest the importance of dissolution of carbonate rocks in this aquifer system from their characteristic loadings the first two components are defined as the salinity and hardness components respectively components 3 5 are related to more local and geological effects the integration of the hca and the pca with conventional classification of groundwater types as well as with the hydrogeological and geological contexts allowed the division of the region into four main geochemical areas providing an improved regional picture of the aquifer system dynamics and hydrogeochemical evolution of groundwater the following factors were recognized as influencing the evolution of groundwater identified in every geochemical area 1 geological characteristics including sedimentary rock type and till mineralogy 2 hydrogeological characteristics represented by the level of confinement and the hydraulic gradient and 3 the geological history including the latest glaciation and the champlain sea invasion with its integrated approach this hydrogeochemical study contributes to the characterization and understanding of complex groundwater flow systems and provides an example of the long term geochemical evolution of hydrogeological systems after a major perturbation in this case seawater invasion

effects of mass wasting on the stratigraphic architecture of a fjord valley fill correlation of onshore shear wave seismic and marine seismic data at trondheim norway abstract a combined record of onshore high resolution shear wave seismic and marine p wave seismic data shows the near shore stratigraphic organisation of a fjord valley fill at trondheim central norway the overall stratigraphy shows a typical fjord valley fill of up to 160 m in thickness that is composed of glaciomarine and fjord marine sediments overlain by deltaic deposits which in the onshore section are draped by an anthropogenic fill an interval characterised by low shear wave velocities below the onshore anthropogenic fills is shown by sampled drillings to comprise part clay and part organic deposits the seismic record reveals evidence of recurrent mass wasting events that include landslide debris turbidite deposits and channel features a chronological framework for the stratigraphy is provided by existing radiocarbon dates for local deglaciation and mass wasting events the combined onshore offshore datasets document the lateglacial to holocene development of an emerging fjord and delta system affected by major mass wasting events the architectural development of the younger part of the stratigraphy is interpreted as particularly affected by two known mass wasting events each involving several million m 3 of debris a thick layer of debris from a 3500 cal yr event probably resulted in a blockage of the subaqueous channels diversion of turbidity currents and deposition of lateral accretion packages whereby local fjord sedimentation temporarily increased a 2200 cal yr event resulted in a sudden reorganisation of the distributary system whereby distal delta sedimentation abruptly shifted north to northeastwards to an area temporarily subjected to marine erosion during fall of relative sea level the study adds to the understanding of landslides and low stiffness zones in the area of importance for near shore geohazard assessment the study also provides insight into the stratigraphic variability of fjord valley fills and highlights the interplay between fjord marine sedimentation marine abrasion delta progradation and mass wasting during late stages of fjord filling

controls on elevated fluoride and arsenic concentrations in groundwater from the yuncheng basin china chemical analysis of groundwater and sediments was carried out to investigate causes of elevated f 1 5 6 6 mg l and as concentrations 10 27 mu g l one sample affected by local contamination with 4870 mu g l as in groundwater from the yuncheng basin northern china groundwater from 9 out of 73 wells contains both f and as concentrations above world health organisation safe drinking guidelines 1 5 mg l and 10 mu g l respectively f concentrations above safe levels are more widespread than as 27 vs 12 wells the elevated as and f concentrations represent a significant health risk as groundwater is widely used to supply agricultural and domestic water in the region high f and as concentrations occur in shallow groundwater affected by agriculture and deep groundwater with long residence times 13 ka that shows little sign of anthropogenic influence the strong positive correlation between groundwater f cl and as cl ratios r 2 0 98 and 0 77 in shallow and deep groundwater respectively indicates that these elements are mobilized and enriched by common processes positive correlations between f and as concentrations and na ca ratios r2 0 67 and 0 46 respectively indicate that groundwater major ion chemistry plays a significant role in mobilizing f and as mobilization likely occurs via de sorption of as and f anions e g haso 4 2 and f from hydrous metal oxides moderate positive correlations between ph and as and f concentrations r 2 0 36 and 0 17 respectively indicate that high ph may favour de sorption while hco 3 may act as a sorption competitor high groundwater na ca ratios likely result from cation exchange while ph and hco 3 contents are predominantly controlled by carbonate weathering reactions sediments from the area were reacted with various water solutions producing f concentrations between 0 49 and 2 7 mg l and as concentrations between 0 51 and 16 7 mu g l up to 45 more f and 35 more as were released when sediments were reacted with a na rich ca poor solution compared to a ca rich solution this is consistent with increased mobilization of f and haso 4 2 by na rich ca poor groundwater increasing f and as concentrations across a wide area caused by high levels of pumping is a potential future health concern c 2011 elsevier ltd all rights reserved

the drift des demoiselles on the magdalen islands quebec canada sedimentological and micromorphological evidence of a late wisconsinan glacial diamict the deposits identified as being the drift des demoiselles which is the upper unit of the southern magdalen islands quebec canada belong to two units of different origin glacial and glaciomar

geochemical and isotopic evidence for palaeo seawater intrusion into the south coast aquifer of laizhou bay china this research aims to improve the current knowledge of groundwater salinisation processes in coastal aquifers using combined hydrochemical and isotopic parameters and inverse hydrochemical modelling field investigations were conducted in laizhou bay which is the area most seriously affected by seawater intrusion in north china during three sampling campaigns along a vertical transect in the changyiliutuan area 95 ground and surface water samples were collected for major ion and isotope analysis

assessing the impact of natural and anthropogenic activities on groundwater quality in coastal alluvial aquifers of the lower liaohe river plain ne china abstract the lower liaohe river plain lrp is an economically and ecologically important area situated on an alluvial plain where anthropogenic activities are very intensive field investigations were conducted in the lrp and 15 water quality parameters surveyed at 216 wells during september and october of 2009 and 2010 these showed significant variation in the hydrochemistry of groundwater throughout the plain a piper plot was used to identify the major geochemical processes occurring in the entire plain principal components analysis pca was used to identify various underlying natural and anthropogenic processes that created these distinct water types the stuyfzand classification was used to subdivide and interpret the complex groundwater hydrochemistry of the liaohe river delta five principal components pcs were extracted in terms of pca which can be invoked to explain 82 of the total variance in water quality parameters the pca results can be categorized by five major factors 1 holocene transgression and mixing 2 surface water infiltration 3 multi factor processes 4 rainfall and agricultural fertilizer contamination and 5 geogenic f enrichment this study demonstrates that the great variation of groundwater hydrochemistry in the lrp should be attributed to both natural and anthropogenic processes

assessment of the impact of anthropogenic activities on the groundwater hydrology and chemistry in tarsus coastal plain mersin se turkey using fuzzy clustering multivariate statistics and gis techniques summary tarsus coastal plain tcp is an economically and ecologically important area situated in between the fertile fluvio deltaic plains of two rivers delicay and tarsus mersin se turkey where anthropogenic activities agricultural industrial and domestic are very intense twenty four water quality parameters were surveyed at 193 groundwater and 10 surface water sites during august 2008 the objective was to characterize the physico chemical properties of groundwaters in tcp assess the impact of anthropogenic activities on the groundwater hydrology and chemistry and identify the major hydrogeochemical processes occurring in the area groundwater samples were grouped into hydrochemically distinct and spatially continuous four water classes i e c1 c2 c3 and c4 using the fuzzy c means fcm clustering method where membership values were interpolated using the ordinary kriging technique principal components analysis pca was used to decipher various underlying natural and anthropogenic processes creating these distinct water classes four principal components pcs were extracted in pca which explained more than 73 of the total variance in water quality major factors responsible for the variations in chemistries of water classes are identified as 1 water rock interaction and nitrate contamination 2 salinization by seawater intrusion and evaporite dissolution 3 geogenic anthropogenic cr fe and mn and 4 anthropogenic zn pollution overexploitation of the aquifer is clearly evident especially at settlements located near the coastal zone where the water table is lowered 2 5 m below the sea level salinization is well known in the area and is attributed not only to seawater intrusion but also to dissolution of evaporitic series from the handere formation hydrochemical evidence also suggest that in the area subsurface paleo river channels and the deposits infilling the ancient lagoon area within quaternary recent alluvial deposits act as significant hydrological features where preferential groundwater flow occurs along them

till fabric patterns and significance particle response to subglacial stress abstract the analysis of particle arrangements within glacial sediments fabric has long been considered to reflect the behaviour of the ice that transported and deposited or deformed the sediment particles can develop specific fabric arrangements as a response to bulk sediment strain driven by effective stress at the bed of a glacier as such fabric analysis has been used to try and understand the complex relationship between glacier and ice sheet dynamics and the geological evidence of former glaciation developments have focused on the use of stereonet patterns and statistical measures vector and eigenvector analysis of clast fabric to infer the process of sediment deposition deformation and consequent ice flow directions and dynamics however as this study identifies fundamental processes of particle orientation march jeffery and taylor rotation mechanisms would suggest more complex explanations than have been previously reported this study reports the results of a detailed field and laboratory investigation of macro scale clast and microfabrics from a till sequence in central scotland the results suggest a systematic behaviour of different particle size fractions which may be interpreted in terms of the strain response of sediment three fabric patterns are identified that illustrate consistent progressively shifting and more complex particle behaviour it is suggested these orientation patterns indicate the degree to which subglacial sediment has undergone strain and the nature of the deforming bed erosional or accretionary it is concluded that this approach may yield fundamental information about the strain conditions underlying different ice masses providing critical data linking glaciological modelling with the sedimentary evidence of glaciation

quaternary stratigraphy paleoecology and glacial geology iles de la madeleine quebec on the iles de la madeleine a rock platform as much as 20 m asl locally with clam borings is correlated to the regional interglacial surface at 2 8 m its anomalous height may be a consequence of salt tectonics overlying lagoonal and paludal organic beds one with th u ages of 89 101 ka record the sangamonian climatic optimum substage 5e which culminated in forest more thermophilous than that of the holocene optimum overlying littoral gravel and sand considered analogous to sediments in present day tombolos and organic beds with less temperate pollen types were deposited during the marine transgressive climax of substage 5e and thus indicate that sea level remained high after the thermal optimum as in holocene time cold based early wisconsinan ice probably centred on the magdalen shelf tectonized bedrock and interglacial beds and deposited till upon them periglacial features indicate a subsequent long cold period an organic bed dating from 11 3 to 10 6 ka records a warm interval followed

fluoride concentrations in a crystalline bedrock aquifer marathon county wisconsin water samples from 2 789 private water supply wells in marathon county wisconsin reveal that fluoride concentrations in the crystalline bedrock range from 0 01 to 7 60 mg l with 0 6 of the values exceeding the environmental protection agency s epa s maximum contaminant level of 4 mg l and 8 6 exceeding the epa s secondary maximum contaminant level of 2 0 mg l roughly a quarter of the wells contain dissolve fluoride within the range considered optimal for human health between 0 5 and 1 5 mg l whereas 63 3 fall below 0 5 mg l consistent with studies conducted in other regions felsic rocks have significantly higher fluoride concentrations than mafic and metasedimentary rocks syenites yield the most fluoriferous groundwaters but the highest median concentration occurs in a sodium plagioclase granite a relationship between plagioclase composition and fluoride concentrations suggests that dissolved fluoride levels are controlled by fluorite solubility and that higher fluoride concentrations are found in soft sodium rich groundwater

microscopic evidence of subglacial deformation abstract subglacial deformation is by now a well established process however recognition of this process in pleistocene tills is not always clear studies of thin sections of pleistocene tills show that there are a variety of microscopic features caused by deformation this paper gives a review of microscopic evidence for subglacial deformation and starts with a case where deformation could be established macroscopically then traces the microscopic features through planar and rotational movements which are described and separated accordingly attention is also given to features caused by crushing of grains and sediment dewatering these studies indicate that almost all basal tills show evidence of subglacial deformation rather than sedimentary derivation this implies that if we want to understand subglacial processes such tills should be described in tectonic rather than sedimentary terminology

a conceptual model of the deglaciation of atlantic canada abstract we present a conceptual model for the deglaciation of atlantic canada in which a role is played by ice streams the ice margin lay close to the edge of the continental shelf at the last glacial maximum ice streams occupying shelf troughs comprised 1 a major ice stream in the laurentian channel 2 secondary streams in the bay of fundy gulf of maine trinity trough and notre dame channel and 3 lesser ice streams elsewhere early retreat in the northeast notre dame bay and in the southwest bay of fundy gulf of maine was mainly by calving along embayments by 18 ka radiocarbon years a calving embayment had opened on emerald basin scotian shelf retreat along channels marooned ice on intervening banks a major calving episode beginning just before 14 ka removed ice from the gulf of st lawrence triggering re advances down secondary troughs isolation of a newfoundland ice cap produced radial drainage via fiords and more extensive flow into the st george s bay lowlands on the west coast by 13 ka most ice was on land and was ablating by melting rather than calving shelf ice caps persisted until 11 ka

effect of different land use land cover on karst hydrogeochemistry a paired catchment study of chenqi and dengzhanhe puding guizhou sw china summary rainfall spring stage water temperature ph and conductivity in the paired karst spring catchments of chenqi and dengzhanhe which shared the same climatic condition but different land use land cover lulc at puding guizhou province sw china were monitored by two high resolution multi parameter auto recordable instrument of ctdp300 during the hydrological year of september 2007 september 2008 other monthly hydrogeochemical and carbon isotopic 13c variations in the paired karst catchments during the same hydrological year were also investigated a thermodynamic model was used to link the continuous data to monthly hydrogeochemical data allowing the calculation of co2 partial pressure pco2 and calcite saturation index sic on a continuous basis the primary study objective was to understand how the karst processes and karst hydrogeochemistry respond to different lulc which is essential to assessing the karst related carbon cycle marked seasonal and storm scale variations were found for ph conductivity pco2 sic and 13c of the two springs indicating that both springs were dynamic and variable systems however there were differences in the magnitude and direction of the variations of these features between the two springs the higher pco2 and hco 3 concentration and lower ph sic and 13c in chenqi spring than those in dengzhanhe spring tend to be related to the difference in lulc between chenqi and dengzhanhe spring catchments in the chenqi spring catchment there was larger soil cover and the paddy land was located in the discharge area both of which produced and kept more co2 a major driving agent for the karst processes and lower 13c in the soil aquifer system while in the dengzhanhe spring catchment area there was larger bare carbonate rock occurrence and the paddy land was located mainly in the recharge area moreover the ph increased and pco2 decreased generally in chenqi spring after rainfall possibly due to more carbonate dissolution in the larger soil cover rich in limestone fragments in the spring catchment while the ph decreased and pco2 increased generally in dengzhanhe spring after rainfall all these differences show that soil cover and land use pattern played important roles in the karst processes in other words the karst hydrogeochemistry and the karst related carbon cycle could be regulated effectively by different lulc in addition the higher concentrations of ca2 so 4 2 mg2 and conductivity of dengzhanhe spring were due to the dissolution of more gypsum and dolomite minerals in the strata of dengzhanhe spring catchment therefore the karst hydrogeochemical parameters including ph conductivity hco 3 ca2 mg2 so 4 2 pco2 sic and 13cdic could serve as good indicators of different lulc and the other environmental changes

the landform and sediment assemblage produced by a tidewater glacier surge in kongsfjorden svalbard abstract this paper describes the landform and sediment assemblage produced by a surge in 1948 of the kongsvegen kronebreen tidewater glacier complex in northwest spitsbergen the main geomorphological products of this advance are two large thrustmoraine complexes on opposite sides of the fjord and a system of geometrical ridges revealed on glacier decay the thrust moraines are composed largely of diamicton sandy and muddy gravel gravelly sand sand and mud with minor laminites all of these appear to be derived from the fjord floor and represent both fine fjord basin sediments and coarse grounding line fan deposits thrusting was the principal mode of emplacement of the sediment onto the adjacent land areas during the 1948 advance however the geomorphology of the thrust moraine complexes on either side of the fjord is quite different reflecting a transpressive regime on the southwest side mainly long ridges and a normal compressive regime on the northeast side short ridges and pinnacles of a hummocky nature the advance which produced the moraine complex has previously been attributed to a surge of kongsvegen but the glaciological and geomorphological evidence suggests that the advance involved both kongsvegen and kronebreen comparison of the landform assemblage produced by this event with that produced by other tidewater glacier surges demonstrates the diverse range of landform assemblages associated with glacier surges or other episodes of rapid flow within glaciomarine environments

subglacial till formation sedimentary characteristics and classification we review the major subglacial till forming processes as presently understood by glacial researchers and define the parameters within which tills are produced and reconcile them with sedimentary end members processes of deformation flow sliding lodgement and ploughing coexist at the base of temperate glacier ice and act to mobilize and transport sediment and deposit it as various end members ranging from glacitectonically folded and faulted stratified material to texturally homogeneous diamicton the dominance of any one subglacial process varies both spatially and temporally giving rise to the possibility that a till or complex till sequence contains a superimposed signature of former transportation deposition at the ice bed interface we recommend that while glacial geologists and geomorphologists should be able to recognize the sedimentary imprints of various subglacial processes genetic fingerprinting of subglacial tills should be less process specific and till classification must reflect the range of products encompassed by the subglacial till production continuum glacial geologists can presently unequivocally identify a glacitectonite rock or sediment that has been deformed by subglacial shearing deformation but retains some of the structural characteristics of the parent material b subglacial traction till sediment deposited by a glacier sole either sliding over and or deforming its bed the sediment having been released directly from the ice by pressure melting and or liberated from the substrate and then disaggregated and completely or largely homogenised by shearing and support the theoretical case for c melt out till sediment released by the melting of stagnant or slowly moving debris rich glacier ice and directly deposited without subsequent transport or deformation because observations on contemporary glaciers reveal that their beds are most likely to be mosaics of deformation and sliding and warm based and cold based conditions the patterns of which change temporally and spatially it is extremely unlikely that subglacial till end members in the geological record will be anything but hybrids produced by the range of processes operative in the subglacial traction zone

criteria to distinguish between subglacial glaciotectonic and glaciomarine sedimentation i deformation styles and sedimentology abstract this paper compares and contrasts the sedimentology and structural geology of a quaternary glaciomarine site melabakkar asbakkar iceland and a quaternary subglacial glaciotectonic site west runton uk research suggests that the glaciomarine environment is dominated by sedimentary processes related to sediment supply water content and distance from the glacier margin glaciotectonic deformation however is dominated by deformational processes related to effective pressure shear strain nature of the subglacial material and distance from the glacier margin from this study a series of criteria are suggested to distinguish both quaternary and contemporary glaciotectonic and glaciomarine environments in addition the paper also discusses the subsequent effects of glaciotectonic deformation on a primary glaciomarine site due to a glacial readvance

evidence of late glacial permafrost in newfoundland abstract structures interpreted as ice wedge pseudomorphs are developed in postglacial sediments at several locations in coastal areas of western central and eastern newfoundland the ice wedge casts indicate that permafrost was prevalent in exposed coastal locations following late wisconsinan deglaciation and marine regression due to isostatic uplift formation of the ice wedge casts indicates that the mean annual temperatures were colder than at present along the newfoundland coast and that snow pack depths were less and snow cover less persistent the environment following marine regression was marked by cold windswept conditions which permitted the development of permafrost in the coastal regions much of the interior of newfoundland remained covered by glacial ice and consequently did not support subaerial permafrost direct numerical dating of the ice wedge casts is not possible at present however the geomorphic settings and stratigraphic positions of the features indicate that they developed subsequent to latest wisconsinan glacial retreat and followed regression from the postglacial marine limit permafrost formation preceded climatic warming and establishment of arboreal vegetation in the early holocene the time of formation of the ice wedges therefore is constrained between the initiation of postglacial marine regression ca 12 300 11 000 bp uncal and the initiation of climate amelioration ca 10 400 bp uncal this chronological range corresponds to the combined duration of the initial postglacial cooling episode and the subsequent younger dryas cold climate event documented in palaeoenvironmental records from newfoundland as lasting from shortly before ca 11 200 to ca 10 400 bp