rates of soil erosion in his report decreased rates of alluvial sediment storage in the coon creek basin wisconsin 1975 93 20 aug p 1244 1 stanley w trimble presents the significant findings that there is a relatively constant supply of sediments released to the mississippi river from coon creek and

compilation of non annually resolved holocene proxy climate records stacked holocene peatland palaeo water table reconstructions from northern britain abstract the number and range of holocene palaeoclimate reconstructions from various regions of the world have increased dramatically over the last decade the data density for many regions and proxies now offers the potential of robust regional scale reconstructions that avoid the problems of records from individual sites and improve communication between palaeoclimate subdisciplines and climate modellers however there are problems with chronological uncertainties and quantification of proxies which make compilation of multiple records difficult here we explore a stacking and tuning approach to the derivation of regional records from peatland climate proxies to test its applicability to non annually resolved terrestrial records twelve individual records from northern britain based on water table reconstructions from testate amoebae analysis were divided into four regions records were detrended normalised and compared within regions to identify clear correlative events the original chronologies of the records were tuned using both these events and independent age markers the stacked record for northern britain indicates pronounced changes to wet conditions at 3600 2760 and 1600 cal yr bp with more minor changes at 3060 2050 1260 860 550 and 260 cal yr bp the main wet phases are highly correlated with mid european lake highstands wider north atlantic climate change inferred from ocean and ice core records and solar variability tuning and stacking of non annual terrestrial palaeoclimate records is a new approach to the compilation and reconciliation of individual records within coherent climatic regions and provides a tool for upscaling of palaeoclimate records for climate model data comparisons

fluvial development and the sediment regime of the lower calder ribble catchment northwest england in the lower reaches of the calder lancashire tributary of the ribble catchment northwest england five river terraces set into the surrounding glacial terrain have been mapped and their underlying sediments radiocarbon dated the earliest terrace t1 reflects sandur style deposition during deglaciation and it aggraded in a reach cut into glacial diamict and glaciolacustrine muds incision below t1 spanned the start of the holocene driven by a combination of reduced sediment supply under a stabilising landscape and lower base levels t2 had aggraded and was being abandoned by 4000 bc its formation latterly involving a period of comparative stability in terms of channel migration perhaps a function of extensive forest cover and sea levels reaching above present day levels the last 3000 years were marked by substantial changes in the sedimentary regime with increased and varying sediment supply driving cycles of cut and fill and greater lateral channel migration these changes coincided with the first widespread and substantial reductions in forest cover and a progression towards an agricultural landscape between the aggradation of terraces t3 and t4 there was a substantial increase in sediment supply which is broadly in keeping with the erosion history in the surrounding uplands this sediment slug appears to have induced a switch from highly sinuous meandering to lower sinuosity channels characterised by lateral scroll style migration late holocene vegetation changes particularly woodland removal driven by anthropogenic land pressure appear to have rendered the floodplain prone to channel migration and the landscape more susceptible to erosion

modeling of multicomponent reactive transport in groundwater 2 metal mobility in aquifers impacted by acidic mine tailings discharge the mobility of potentially toxic dissolved metals discharged from a mine tailings source into an aquifer is investigated by using the multicomponent reactive transport model mintran a generic aquifer resembling a site in northern ontario is used as a basis and a scenario analysis is performed to determine the effect of terminating the source input of acidity and dissolved metals after a finite time it is found that for most metals the buffering reactions in the carbonate aquifer lower the dissolved metal concentrations substantially often by several orders of magnitude in the case of a 12 year source duration most metals are effectively immobilized by precipitation and the concentrations of metals remaining in solution are well below drinking water limits the risk of contamination of water resources by toxic metals can thus be controlled

links between bulk sediment particle size and magnetic grain size general observations and implications for chinese loess studies using a combination of particle size analysis magnetic measurements scanning electron microscopy and transmission electron microscopy imaging this study shows that in a wide range of depositional environments there is a strong link between particle size classes and magnetic response especially below the upper limit of stable single domain magnetic behaviour ferrimagnetic grain assemblages dominated by stable single domain magnetosomes regularly have peak susceptibility and remanence values in coarser grades than do those containing finer grained viscous and superparamagnetic secondary magnetic minerals formed during pedogenesis this effect is despite the fact that there is a one to two orders of magnitude size difference between the particle size boundaries at 1 or 2 m and key domain state transitions mostly below 0 05 m the implications of these results are explored using samples spanning 22 myr of loess accumulation on the chinese loess plateau the results from the loess sections complemented by data from low temperature magnetic experiments show that there are subtle distinctions in mean ferrimagnetic grain size between the pleistocene and miocene parts of the record thus allowing more refined rock magnetic interpretations of the fine grained ferrimagnetic mineral assemblages arising from the effects of weathering pedogenesis and possibly diagenesis in the sections studied

mid holocene charcoal fall in southern scotland temporal and spatial variability abstract four securely 14 c dated pollen and microscopic charcoal stratigraphies and measures of peat humification from sites representing a range of environmental settings and altitudes within one small region of southern scotland are examined for the period 7000 5000 cal bp to identify the consistency of representation spatial patterning and temporal variability of the mid holocene charcoal fall charcoal falls are identified at three lowland sites but not in the upland sequence the charcoal falls at these sites may reflect an increase in fire regime in the later mesolithic determined in part by a shift to drier regional climate rather than a subsequent reduction in burning the charcoal fall is not synchronous within the region but differs between sites over c 1000 cal years each fall is associated with one of two shifts to drier soil conditions at c 6100 or 5400 cal bp at two sites the charcoal fall also coincides with ulmus declines

dating of post glacial landforms in the central howgills little is known of holocene landform development in upland britain this paper describes a site at middle langdale in the howgill fells of cumbria where large but now stabilized and inactive gullies cut through periglacial material at the base of the gullies large debris cones have buried earlier alluvial sediments on the valley floor on these sediments and buried by the debris cones is a well developed organic soil from which two 14c dates have been obtained in an attempt to estimate the age range of the soil these dates range from 2580 55 years bp for the fine particulate fraction from the base of the organic horizon to 940 95 years bp for fossil rootlets from the uppermost organic layer immediately below the overlying debris cones the pollen evidence suggests that the valley floor site was initially dominated by alder carr and later by a juncus marsh with birch alder and hazel nearby the pollen from the surrounding upland area suggests woodland on the valley sides dominated by oak and elm that was later replaced by a more open environment rich in heath species and in which disturbed ground species were present the magnetic evidence indicates a stable local environment during soil formation but shows a sudden inwash of unweathered debris at the top of the buried soil the evidence suggests that the valley floor was geomorphologically stable throughout the period of soil formation although there was a local change in valley floor vegetation and a reduction of woodland cover on the valley sides at sometime during the period the evidence then points to major geomorphological changes a wave of soil erosion gully development and debris cone deposition perhaps following the scandinavian introduction of sheep farming in the tenth century a d

river response to rapid holocene environmental change evidence and explanation in british catchments macklin m g jones a f lewin j 2010 river response to rapid holocene environmental change evidence and explanation in british catchments quaternary science reviews 29 13 14 1555 1576 sponsorship welsh assembly government and the higher education funding council for wales for funding this study through its support of the centre for catchment and coastal research at aberystwyth university

holocene alluvial fan and terrace formation in the bowland fells northwest england in the bowland fells lancashire northwest england in the headwater valleys of the hodder river system is a suite of holocene fluvial landforms debris cones and alluvial fans at tributary junctions and river terraces along the main valleys post date late pleistocene forms and pre date the modern valley floor alluvial forms eight 14c dates from wood samples incorporated within the terrace and fan deposits have allowed two main phases of holocene erosion to be identified with debris cone fan deposition taking place after c 5400 bp but before c 1900 bp and again at c 900 bp some of the fans and cones are complex with deposits attributable to both phases others are simple and attributable only to the later phase in the headwaters an upper terrace at c 5400 bp pre dates the cones and a lower terrace is contemporaneous with the first debris cone phase lower downvalley the youngest of three terraces date from c 5000 bp or earlier indicating that the sequence is less complex downstream

mire development pathways and palaeoclimatic records from a full holocene peat archive at walton moss cumbria england plant macrofossil data have been used to identify the successive mire communities occupying both central and marginal locations in the walton moss peatland complex during the last 10 500 years the reconstructed pathways of mire development indicate that early holocene fen and fen carr communities were succeeded by species indicative of deep mire water tables and oligotrophic conditions the character of the fen bog transition fbt is compared with similar records of peatland development from britain and scandinavia and with independent climate data for the early holocene the pseudohochmoor of central europe is suggested as an approximate modern analogue for the dry pioneer oligotrophic mire type and alternative explanations for its presence are explored the first major increase in ombrotrophic sphagna occurred at c 7800 cal bp overlying sphagnum peats provide a continuous record of climate change inferred from fluctuations in raised mire surface wetness the proxy palaeoclimate record reconstr

role of underground fissure flow in near surface rainfall runoff process on a rock mantled slope in the karst rocky desertification area abstract because of the complex near surface double layer geologic structure i e surface and underground fissures of slopes in karst regions it is difficult to collect data on all flows especially the flows generated in underground fissures this lack of information leads to a poor understanding of the rainfall runoff process associated with soil loss in karst landscapes the goal of this study was to determine the output characteristics of surface subsurface and underground fissure flows and their conversion relationships as well as the role of underground fissure flow in the near surface rainfall runoff process using rainfall experiments the results revealed the following findings light rainfall intensities 15 and 30 mm h generated subsurface lateral flow and underground fissure flow whereas greater rainfall intensities generated surface runoff in addition to subsurface and underground flows ii the runoff drainage depths of all the above flows increased with increasing rainfall intensity while the runoff drainage coefficient exhibited no obvious regular change except for the surface runoff moreover the distribution ratio of surface runoff to total flow also increased with increasing rainfall intensity but decreased with increasing underground fissure degree while the distribution ratio of underground fissure flow exhibited the opposite trend iii underground fissure flow with distribution ratios of 27 8 78 0 dominated the total flow yield this study has significance for controlling soil erosion and water shortage in the karst rocky desertification region and also improves the understanding of the near surface rainfall runoff process in this region

sulfide mineral oxidation and subsequent reactive transport of oxidation products in mine tailings impoundments a numerical model a versatile numerical model that couples oxygen diffusion and sulfide mineral oxidation pyrox has been developed to simulate the oxidation of pyrite in the vadose zone of mine tailings a shrinking core oxidation model and a finite element numerical scheme are used to simulate the transport of oxygen and oxidation of pyrite grains the rate of pyrite oxidation is assumed to be limited by the transport of oxygen to the reaction site the model determines the spatially variable bulk diffusion coefficient for oxygen on the basis of moisture content porosity and temperature all of which are variable input parameters the model pyrox has been coupled to an existing reactive transport model mintran which uses a finite element scheme for transport of contaminants and minteqa2 to solve for the equilibrium geochemistry the reactions described by mintran are subject to the local equilibrium assumption the resulting model mintox is capable of simulating tailings impoundments where the oxidation of pyrite or pyrrhotite is causing acidic drainage and where acid neutralization and attenuation of dissolved metals can be attributed to equilibrium reactions because mintox uses realistic boundary conditions and hydrogeological properties the potential benefits of various remediation schemes such as moisture retaining covers can be quantitatively evaluated

environmental magnetism a practical guide j walden f oldfield j and smith eds technical guide no 6 quaternary research association london 1999 243 pp price 17 00 9 00 to qra members isbn 0 907780 42 3

the late holocene history of gormire lake ne england and its catchment a multiproxy reconstruction of past human impact sedimentary evidence spanning the last 3500 years from cores taken from the centre of gormire lake cleveland northeast england points to two periods of deforestation and catchment erosion the first mainly late iron age romano british phase began c 200 bc and ended c ad 600 the second began c ad 1200 the time of early monastic activity and continued into the nineteenth century the chronology for the core rests on 137cs 210pb and 14c measurements and on the history of lead accumulation in the sediments the majority of the ams 14c dates are shown to be too old to varying degrees depending on the source of the organic matter in the sediments the record of vegetation change is derived from pollen analysis evidence for changes in sediment composition and source and for catchment erosion comes from magnetic measurements element analyses using xrf and organic biogeochemical analyses there is a high degree of coherence between all these lines of evidence interpretation of the magnetic record

contaminant transport at a waste residue deposit 2 geochemical transport modeling contaminant transport in an aquifer at an incinerator waste residue deposit in denmark is simulated a two dimensional geochemical transport code is developed for this purpose and tested by comparison to results from another code the code is applied to a column experiment and to the field site the ongoing geochemical processes and any unknown geochemical parameters are obtained through simulation of the column experiment that used soil and leachate from the field site the application of the code to the field site which has been monitored for more than 15 years use this geochemical information along with the flow and nonreactive transport parameters obtained by the inverse modeling procedure described in the first paper sonnenborg et al this issue of this two paper series the simulation results of the site model are compared with several measured component breakthroughs at monitoring wells contamination was first controlled by transport and later by transport and ion exchange in both the column and field site simulations the code is used to identify the controlling transport processes physical or geochemical ion exchange and mineral precipitation and to estimate the involved parameters primarily ion exchange selectivity coefficients

interpreting alluvial archives sedimentological factors in the british holocene fluvial record abstract a holocene alluvial archive of 506 dated units for great britain is analysed in terms of the sedimentation styles involved the database is classified by sedimentation unit channel sediments palaeochannel fills floodplain surface sediments floodbasins and colluvial deposits and alluvial ensemble fans and cones upland gullies and streams braided systems and active inactive meandering and anastomosing systems floodplain palaeochannel and floodbasin sediments dominate the record mostly from meandering anastomosing systems different sediment units show varied potential for recording environmental change some are relatively poorly dated with respect to the volumes of material involved whilst many dates float in periods of depositional activity which lasted for extended time periods much dated activity is autogenic and of relatively little value in interpreting external environmental influence ensembles and units are similar in age patterns in some respects commonly they exhibit sets of short term peaks in sedimentation activity but differ in others floodbasins and to an extent braided systems feature in the earlier holocene whilst dated fan deposition is more evident in the late holocene there is a general bias towards sediment units of late holocene age which probably reflects preservation factors previous british holocene alluviation models are reviewed it is suggested that the majority of earlier models reflect partial views imposed by limited regional coverage and available dating

the influence of particle size variations on the magnetic properties of sediments from the north eastern irish sea this paper considers the magnetic properties of a range of recent and contemporary sediments from the north eastern part of the irish sea principal component ordinations of the results show a close link between magnetic property variations and particle size the magnetic properties of a subset of samples particles sized by a combination of sieving and pipette analysis confirm that variations in ferrimagnetic magnetite grain size parallel those in particle size despite the fact that the magnetic grains in the fine grades have diameters 1 2 orders of magnitude smaller than those of the particle size fraction in which they occur this is best explained by postulating that the fine magnetic grains occur in the clay fraction but are present in declining concentrations in the coarser grades up to 4o as an artefact of the pipette method most samples have a biomodal distribution of magnetic minerals with a coarse mode associated with heavy minerals in the sands or coarse silts and a fine mode in the clays magnetic susceptibility x and saturation isothermal remanent magnetization sirm largely pick out the coarse mode where present anhysteretic remanent magnetization arm largely picks out the fine mode the results open up the possibility of normalizing samples from these environments for particle size and more specifically clay content by means of arm or arm x values the most likely source for the uniform and almost exclusive stable single domain magnetite which dominates the magnetic properties of the clays is thought to be bacterial magnetosomes the measurements as a whole do not appear to hold much promise for discriminating sediment source types

holocene environmental reconstruction of sediment source linkages at crummock water english lake district based on magnetic measurements to reconstruct lateglacial and holocene environmental changes in the british uplands two c 5 8 m long sediment cores from crummock water nw england together with several hundred soil samples from the crummock water catchment were studied using magnetic techniques optically stimulated luminescence osl dating using fine silt quartz and 14c dating of terrestrial plant macrofossils were used to establish a chronology for the lake sediments a good agreement between optical and 14c ages indicates first that the osl dating method can be used to date lake sediments in the british isles second that macrofossil based 14c dating can be used to avoid the problem of old carbon error associated with bulk sample 14c dating of lake sediments and third that the established chronology is robust the lake sediment magnetic properties indicate a series of changes in sediment composition during the holocene which correlate well with sediment lithology water content and weight loss on ignition the first change corresponds to the lateglacial postglacial climatic shift at around 11400 years ago the subsequent suite of changes corresponds to a probable regional onset of human activity at 2000 bc and particularly to the intensification of human activity at around ad 900 a comparison of the lake sediment magnetic properties and those of the catchment soils shows a clear linkage for the lateglacial period and for the period after ad 900 in contrast detailed magnetic measurements of the early through mid holocene sediments suggest that their magnetic properties are dominated by bacterial magnetosomes

molecular marker records of land use change abstract evidence of a changing environment in the catchment area of a small lake gormire yorkshire uk over the past 3000 years is provided by the mean carbon number of n alkanes and the ratio of lignin thermochemolysis products together with pollen analysis and bulk organic geochemistry periods of deforestation which commenced at 600 bc and ad 1200 display a significant decrease in organic carbon contents of the lake sediments which probably reflects dilution by enhanced influx of clastic material the mean carbon number of waxy c27 c31 n alkanes closely corresponds with the percentage of pollen derived from grass in the sediments a higher plant derived triterpenoid tentatively identified from its mass spectrum as 28 carboxyursen 12 enol appears exclusively in samples where tree and shrub derived pollen is dominant thermochemolysis of lignin confirms that there was a significant change in the nature of material deposited in the lake sediments from woody to grass dominated changes in both the sedimentary c n ratios and yields of lignin derived phenols suggest that deforestation events led to enhanced aquatic productivity initially through the development of reed swamp vegetation

measurement uncertainty in rainfall kinetic energy and intensity relationships for soil erosion studies an evaluation using parsivel disdrometers in the southern appalachian mountains abstract the increased use of observations of rainfall microphysics from disdrometers to produce more accurate rainfall kinetic energy estimates requires closer analysis of measurement uncertainty and in particular how the type of sensor influences rainfall kinetic energy estimates in different hydrometeorological regimes this study evaluates the performance of parsivel1 p1 and parsivel2 p2 in measuring rainfall dsds drop size distributions in terms of rain depth p rain rate i and kinetic energy ke at three locations in the southern appalachian mountains for warm season rainfall for the same storm system there is large spatial variability of rainfall dsds between ridges and valleys and between exposed upwind ridges and the inner region parsivel1 measures underestimate the number of small drops while all rainfall variables are overestimated for dsds with a large number of drops in the midsize range 1 2 mm in diameter for both p1 and p2 overall results show differences of 40 in ke estimates when p1 is used compared with the more recent p2 the uncertainty analysis clearly illustrates the dependence on hydrometeorological regime and the instrument proper relationships between rainfall ke and intensity i need to account for the instrumental influence towards better characterization of the rainfall erosion potential locally and regional scale studies must include spatially distributed observations to capture the dominant hydrometeorological regimes especially in regions of complex topography where the spatial variability of rainfall is very high

soil human society and the environment soils forming the top layer of the earth s crust are a mixture of mineral parti cles organic matter water air and living organisms processes between these components perform vital functions within ecosystems the soil forms an interface between the geosphere the biosphere the hydrosphere and the atmosphere and is a largely non renew able resource ugolini warkentin show the fruitful relationships which geology and soil science have established since the birth of soil science and how these two disciplines together could contribute to solve future problems the dynamic soil system delivers functions and services vital for human societies and the environment soil is the basis for food and biomass production and plays a central role as a habitat for biota and as a gene pool moreover it stores filters buffers and trans forms a large variety of substances including water inorganic and organic compounds and is a major sink and source for greenhouse gases soil provides raw materials for human use it also serves as the basis for human activities landscape and heritage and for our technical and socio economic infrastructure delivering materials for their implementation and maintenance

catchment hydro geomorphological responses to environmental change in the southern uplands of scotland lake sediment and geomorphic evidence from the loch of the lowes st mary s loch basin in the central southern uplands of scotland provide a multiproxy reconstruction of changing sediment availability and transmission through the catchment interrogation of magnetic geochemical and grain size parameters for lake and catchment materials suggests it is possible to identify independent proxies that reflect both supply availability and discharge capacity controls on the sediment signal chronological control for the lake sediment record is proposed by linking a 210pb 137cs chronology for the last c 120 yr to an age depth profile based on proposed temporal correlations between cyclic hirm lf variability and the north atlantic oscillation geochronological studies on debris cones and alluvial fans yield evidence for episodic hillslope gullying 2000 0 bc with more extensive region wide slope instability ad 700 900 1100 1300 and after ad 1450 1550 and gully stabilization over the last 150 years the latter two episodes coincide with the lake sediment evidence for increased sediment supply from ad 1600 declining after ad 1870 the capacity related lake proxies appear to identify phases of increased flooding ad 1625 1650 1680 1700 1730 1760 1800 1815 1850 1880 1910 1930 1960 1970 and possibly the 1990s close correspondence between the sediment flood archive and historical records of flooding in scotland suggests that lake catchment systems of this type have the potential to yield valuable information on past hydrological response

meteorological and land use controls on past and present hydro geomorphic processes in the pre alpine environment an integrated lake catchment study at the petit lac d annecy france a wide range of environmental records is integrated in order to reconstruct the mechanisms of flooding and sediment transport within the 170 km2 petit lac catchment annecy france over time scales of 10 1 to 102 years these records include sequential lake sediment trap samples and cores floodplain stratigraphies dated landform assemblages hydro meteorological records and documented histories of river channel and land use change mineral magnetic measurements are used as the basis for classifying catchment sediment sources and tracing sediment movements through time records of magnetic susceptibility for monthly sediment trap samples 1998 99 track seasonal discharge peaking in winter and spring magnetic records in lake sediment cores are compared against and tuned to precipitation records to provide dated proxy records for past discharge spanning sub annual to decadal time scales back to 1826 calculated sediment accumulation rates in lake sediment cores are used as proxies for time averaged catchment sediment load analysis of the results reveals that climate and land use controls on the hydrological and sediment system are complex and vary according to the time scale of observation in general cycles of agricultural expansion and deforestation appear to have been the major cause of shifts in the sediment system through the late holocene deforestation in the 18th century may have caused a number of high magnitude flood and erosion events as the time scale of observation becomes shorter changes in climate and hydro meteorological conditions become progressively more important since the mid 19th century smoothed records of discharge roughly follow annual precipitation this is in contrast to sediment load which follows the trend of declining land use pressures episodic erosion events during this recent period seem to be linked to geomorphic evidence for slope instability in the montane and sub alpine zones triggered by intense summer rainfall at the annual scale changes in seasonal rainfall become paramount in determining sediment movement to downstream locations the study demonstrates that the connections between forcings and responses span a four dimensional array of temporal and spatial scales with strong evidence for dominantly nonlinear forcing response mechanisms

river sedimentation and fluvial response to holocene environmental change in the yorkshire ouse basin northern england holocene alluvial sediment sequences and floodplain geomorphological histories from three valley floor sequences in the yorkshire ouse basin have been determined using a variety of field evidence and laboratory methods geomorphological mapping sediment coring and trenching physical and chemical analysis of sedimentary units and 14c dating the application of multiple methods has revealed contrasting phases of river erosion alluviation and depositional styles during the late quaternary at each of the individual study reaches the gravel bedded river swale at catterick has been characterized by progressive valley floor incision during the late holocene with major phases of incision occurring during the cooler and wetter phase of the little ice age within the last c 245 years substantial thicknesses up to 2 m of overbank alluvium contaminated by metalliferous mining have been deposited across thefloodplain in contrast floodplain development in the lower reaches of the river swale at myton and t

testing a cellular modelling approach to simulating late holocene sediment and water transfer from catchment to lake in the french alps since 1826 this paper describes the application of a hydrogeomorphological numerical model caesar to simulate at hourly time steps changes in the hydrological and sediment regime of the petit lac d annecy catch ment the outputs of the model were validated in three ways in the short term 5 years water discharge out puts were compared against observed instrumental data over the longer term modelled sediment discharge ad 1825 2005 was compared with proxies for detrital sediment influx environmental magnetism and accumu lation rates discerned from a 210 pb chronology for the lake sediments finally spatial validation of the modelled erosion and deposition of sediment was undertaken by comparison with a field and remotely sensed survey of catchment geomorphology the results suggest that while minor perturbations in forest cover during the last 180 years have partially conditioned the response of the sediment system the bulk of modelled sediment discharge and particularly the peaks in sediment discharge were controlled by flood duration and magnitude which in turn is driven by precipitation storms floods and snowmelt basin geometry and geomorphology of each sub catchment ire and tamie were also important in producing differences in the modelled sediment discharge in essence these differences were a function of sediment accommodation space and the ability of each system to store and release sediments modelled sediment discharge and para lake sediments display similar histories and thus are both interpreted as reflecting variations in detrital sediment supply intriguingly the style of mod elled sediment discharge from the ire a confined mountain torrent displays a greater similarity to and perhaps dominates the lake sediment record these results provide partial validation of the caesar model and indi cate that perhaps in the future it may be used as an exploratory and predictive tool in determining the impact of changes in climate meteorology and land use on lake catchment systems

quantitative sediment source ascription using magnetic measurements in a reservoir catchment system near nijar s e spain the magnetic properties of sediments from a dried out reservoir and its inflowing streams were measured to provide a basis for sediment source determination quantitative estimates of source component proportions in the reservoir sediments were made using linear programming procedures the study confirms that this type of research must be based on a detailed knowledge of the relationship between magnetic properties and particle size in both the sediments and the potential sources in the case of the site studied the isabel ii reservoir near nijar s e spain the sediments generated by contemporary surface processes within the reservoir catchment fail to reflect fully the 19th century material largely responsible for the rapid infill of the reservoir an additional source type namely unweathered schist derived material not represented in the fine sediments sampled within channels upstream from the reservoir has to be included in the model before calculations of source component contributions can be made it is inferred that one or more high magnitude low frequency event outside the amplitude of the most recently operating processes was largely responsible for the infilling of the reservoir

carbonate mineral water interactions in sulfide rich mine tailings the chemical composition and mineralogy of coatings on carbonate minerals from mine tailings have been studied using aqueous geochemical methods time of flight laser ionization mass spectrometry tof lims and transmission electron microscopy tem the goal is to study major and trace element partitioning between the aqueous and solid phase and to infer mechanisms that control the concentrations of elements in the pore water of sulfide rich mine tailings pore water samples and carbonate mineral grains were collected from four geochemically distinct zones within the tailings oxidation of sulfide minerals near the surface results in a large range in pore water ph 3 85 to 6 98 and aqueous concentrations of metals and sulfate with increasing depth in the tailings mineral water interactions lead to increasing ph and decreasing concentrations of metals and sulfate calculated mineral saturation indices trends in the abundance of ca fe mg and mn in tof lims profiles through the secondary coatings and electron diffraction patterns obtained from the coatings suggest that precipitation dissolution of jarosite group minerals gypsum goethite akaganeite amorphous fe oxyhydroxides and siderite control the aqueous ca fe na k and so4 concentrations the occurrence of secondary coatings on primary minerals is widespread and reactions with the secondary minerals rather than the primary mineral substrate probably represent the principal controls on trace element distributions in the pore water the data indicate that adsorption surface complexation and co precipitation reactions are important controls on the concentrations of trace elements in the pore water the occurrence of siderite coatings on the surface of ankerite grains suggests that fe bearing dolomite structure carbonate minerals dissolve incongruently this corroborates inferences made by previous workers that solubility differences between calcite and siderite lead to calcite dissolution and siderite precipitation during acid neutralization the accumulation of secondary coatings will diminish the rate of mineral dissolution reactions involving the primary minerals consequently the use of kinetic rate constants obtained from the literature for simulating the dissolution of primary mineral phases such as the carbonates and alumino silicates will likely overestimate the actual rates

the record of land use change and soil erosion in the late holocene sediments of the petit lac d annecy eastern france pollen chemical and magnetic analysis of a 6 m core from the petit lac d annecy provides a record of land use change and soil erosion spanning the last 2000 years variations in the magnetic properties of the sediments especially above 3 m in the core can be linked to the history of soil inwash over the last 1000 years these changes together with parallel ones in element concentrations and pollen frequencies both concentrations and percentages can be interpreted by reference to the land use history in the catchment during medieval and post medieval times peak deforestation and human impact on vegetation and soils is recorded from the eleventh to fourteenth centuries and again during the eighteenth century the present study suggests that future detailed analyses of the laminated sediments of the lake could provide a precisely datable fine resolution environmental history of the lake and its drainage basin

river entrenchment and terrace formation in the uk holocene abstract a meta analysis of a large database of 14c dated fluvial units is used to assess the chronology and controls of episodic holocene river entrenchment and terrace formation in the uk most holocene terraces are of a fill cut type developed in pleistocene sediments in places now reaching down to pre holocene bedrock holocene terraces are widespread in higher relief areas of the uk and peripheral higher energy rivers and include up to 7 levels in some valley floor reaches using 14c constrained data sub sets for incision episodes the onset vertical ranges formation times and rates of entrenchment are examined together with geographical distributions the height range of terrace separation is relatively small 0 5 3 5 m with a long term averaged incision rate over the late and mid holocene of 0 43 0 5 0 67 0 7 and 0 81 m ka in the tweed rheidol severn ouse and ribble catchments and a regional similarity in the scale of incision events the periods 4200 3700 3100 2900 2100 1900 1800 1500 cal bp and most notably the last 1000 years with prominent peaks at 900 800 and 700 600 cal bp were times of accelerated incision it appears likely that extreme flood events triggered the formation of incision slots rather than entrenchment being a direct response to glacio tectonic uplift or the result of incremental valley floor lowering by combined incision and lateral reworking river entrenchment has also been rapid in recent centuries reflecting the coupling of extreme events with anthropogenic effects on catchment hydrology incision results in changes of river channel flood power and overbank flood extent and improved data on the long term and large scale vertical tendency of uk rivers are needed for flood risk management purposes

coupling relationships hillslope fluvial linkages in the hodder catchment nw england abstract variations in the coupling of sediment transfer between different parts of a fluvial catchment e g hillslope to axial stream can hamper understanding but are an integral part of the geomorphological record depositional environments respond to a combination of land use climate storms floods and autogenic conditioning the distribution of sediment in the upland landscapes of nw england is out of equilibrium with contemporary climate and geomorphological processes more a function of peri and paraglacial mobilisation of glacigenic deposits soil and vegetation development after deglaciation have interrupted any progression toward sediment exhaustion with sediment release controlled largely by extrinsic perturbation with late holocene anthropogenic activity climate and extreme hydrological events the likely candidates this paper presents a new radiocarbon dated holocene geomorphological succession for the river hodder nw england alongside evaluating new palaeoecological and geoarchaeological data to discern the impacts of human activity these data show a late holocene expansion in human occupation and use of the landscape since the iron age 700 0 cal b c with more substantial changes in the character and intensity of upland land use in the last 1300 years the geomorphological responses in the uplands were the onset of considerable and widespread hillslope erosion gullying and associated alluvial fan development interpretation of the regional radiocarbon chronology limits gullying to four more extensive and aggressive phases after 500 cal b c the downstream alluvial system has responded with considerable valley floor deposition and lateral channel migration that augmented sediment supply by remobilising the existing floodplain terraces and led to the aggradation of a series of inset alluvial terraces the timing of these changes between states of aggradation and incision in alluvial reaches reflects the increased connectivity between the hillslope and alluvial systems aspects of both the regional climate and land use histories are conducive to increasing discharge and sediment flux but the region wide lowering of erosion thresholds appears a key driver conditioning these sediment rich conditions and producing a landscape that was more susceptible to erosion under lower magnitude flows

geochemical evolution of inactive pyritic tailings in the elliot lake uranium district geochemical data obtained between 1979 and 1983 from a network of piezometer nests and cores from three inactive uranium tailings impoundments in the elliot lake district indicate that oxidation of pyrite taking place in the shallow part of the zone above the water table is causing the chemistry of the pore water above and below the water table to change a two layer hydrochemical zonation has developed in which infiltration water from rain and snow has resulted in an upper zone of low ph water with high concentrations of so4 fe and heavy metals this zone is gradually expanding downward at rates generally between 0 2 and 2 m year causing displacement of the original mill process water which has neutral ph and low concentrations of heavy metals high concentrations of fe iii at shallow depth in the zone above the water table indicate that ferric iron is an important oxidizer of pyrite in the presence of free oxygen the pe of the groundwaters is controlled by the ferric ferrous redox couple and trend

splash erosion under natural rainfall on three soil types in ne spain article i nfo article history splash detachment and transport of soil particles by raindrops impacting a soil surface are the initiating mechanisms of water erosion the amount of splash depends on rainfall characteristics mainly kinetic ener gy and intensity and soil properties experimental results of rainfall and splash monitoring in three soil types under natural rainfall in ne spain are presented some 27 rainfall events were evaluated during which high rates of soil splash were measured 6 06 g per splash cup stressing its importance as an erosion process on bare soils sources of variation of soil splash were analyzed by a linear mixed effects lme model significant relationships were found between the splash erosion rates and the rainfall erosivity index ei30 no significant differences in erosion were found among the soil types analyzed the lme model explained 55 of variance in the erosion rates and most of the residual variability 74 was due to differences between splash cups within a single soil type and event i e random effects

hillslope gullying in the solway firth morecambe bay region great britain responses to human impact and or climatic deterioration abstract in the solway firth morecambe bay region of great britain there is evidence for heightened hillslope instability during the late holocene after 3000 cal bp little or no hillslope geomorphic activity has been identified occurring during the early holocene but there is abundant evidence for late holocene hillslope erosion gullying and associated alluvial fan and valley floor deposition interpretation of the regional radiocarbon chronology available from organic matter buried beneath alluvial fan units suggests much of this geomorphic activity can be attributed to four phases of more extensive gullying identified after 2500 2200 1300 1000 1000 800 and 500 cal bp both climate and human impact models can be evoked to explain the crossing of geomorphic thresholds and palaeoecological data on climatic change bog surface wetness and human impact pollen together with archaeological and documentary evidence of landscape history provide a context for addressing the causes of late holocene geomorphic instability high magnitude storm events are the primary agent responsible for gully incision but neither such events nor cooler wetter climatic episodes appear to have produced gully systems in the region before 3000 cal bp increased gullying after 2500 2200 cal bp coincides with population expansion during iron age and romano british times the widespread and extensive gullying after 1300 1000 cal bp and after 1000 800 cal bp coincides with periods of population expansion and a growing rural economy identified during norse times 9 10th centuries ad and during the medieval period 12 13th centuries ad these periods were separated by a downturn associated with the harrying of the north ad 1069 to 1070 the gullying episode after 500 cal bp also coincides with increased anthropogenic pressure on the uplands with population growth and agricultural expansion after ad 1500 following 150 years of malaise caused by livestock and human the black death plagues poor harvests and conflicts on the scottish english border the increased susceptibility to erosion of gullies is a response to increased anthropogenic pressure on upland hillslopes during the late holocene and the role of this pressure appears crucial in priming hillslopes before subsequent major storm events in particular the cycles of expansion and contraction in both population and agriculture appear to have affected the susceptibility of the upland landscape to erosion and the hillslope gullying record in the region therefore contributes to understanding of the timing and spatial pattern of human exploitation of the upland landscape

investigation of pyrite oxidation and acid mine drainage characterization associated with razi active coal mine and coal washing waste dumps in the azad shahr ramian region northeast iran acid mine drainage amd pollution is considered to be the most serious water pollution problem in mining areas amd containing iron sulfates and other components can affect the receiving water bodies pyrite oxidation and amd generation can be considered as important processes that may take place in the wastes produced by coal mining and coal washing operations in the golestan province northeast iran the study area is characterized by appropriate atmospheric conditions that favor pyrite oxidation and the presence of a large amount of water bodies this study attempts to consider pyrite oxidation and amd generation in the azad shahr ramian region the impact of amd on the quality of the surface water bodies was investigated by taking samples and analyzing them for hydro geochemical parameters stiff and piper diagrams were used to represent chemical analyses of water samples the coal samples taken from different depths at four points on two different coal waste dumps were analyzed to find the fraction of pyrite that remained in the waste particles to investigate the pyrite oxidation process a computational fluid dynamic package called phoenics was used to model pyrite oxidation process numerically the results obtained from the geochemical analyses of water and coal samples and numerical simulation show pyrite oxidation and acid generation in the region however the presence of carbonate rocks raised the ph of the water samples the drainages of the razi mine may be recognized as natural alkaline mine drainages

evidence for changes in holocene sediment flux in semer water and raydale north yorkshire uk article i nfo we present preliminary results from studies carried out in the lake and extensively gullied drainage basin of semer water in north yorkshire england the results obtained so far are limited by physical problems encountered during coring at the present day lake the complex nature of the sedimentary infill upstream in raydale and difficulties experienced in establishing a continuous holocene chronology for the site both magnetic measurements and organic geochemical analyses show that the bulk of the sediment sampled in semer water and in the alluvial area of raydale just upstream is derived from the catchment although in some cases the allochthonous magnetic signature is overprinted by contributions from bacterial magnetosomes growing in the lake or surface sediments significant traces of polyaromatic hydrocarbons pahs in sediments contemporary with the mesolithic occupation of the pennines reinforce evidence from elsewhere for the use of fire at this time several lines of evidence identify a mid holocene period of reduced allochthonous input rapid sediment accumulation during the period between 4200 and 3500 cal bp points to the likelihood of increased erosion during the bronze age geomorphological studies point to periods of alternating dissection and aggradation in the catchment during the last 2000 years the record presented gives some indication of the potential for uniting geomorphological palaeolimnological and organic geochemical research in an effort to trace the holocene evolution of a complex highly eroded system 2008 elsevier b v all rights reserved

the formation and potential importance of cemented layers in inactive sulfide mine tailings abstract investigations of inactive sulfide rich tailings impoundments at the heath steele new brunswick and waite amulet quebec minesites have revealed two distinct types of cemented layers or hardpans that at heath steele is 10 15 cm thick occurs 20 30 cm below the depth of active oxidation is continuous throughout the tailings impoundment and is characterized by cementation of tailings by gypsum and fe ii solid phases principally melanterite hardpan at the waite amulet site is only 1 5 cm thick is laterally discontinuous 10 100 cm occurs at the depth of active oxidation and is characterized by cementation of tailings by fe iii minerals principally goethite lepidocrocite ferrihydrite and jarosite at heath steele an accumulation of gas phase co2 of up to 60 of the pore gas occurs below the hardpan the calculated diffusivity of the hardpan layer is only about 1 100 that of the overlying uncemented tailings the pore water chemistry at heath steele has changed little over a 10 year period suggesting that the cemented layer restricts the movement of dissolved metals through the tailings and also acts as a zone of metal accumulation generation of a cemented layer therefore has significant environmental and economic implications it is likely that in sulfide rich tailings impoundments the addition of carbonate rich buffering material during the late stages of tailings deposition would enhance the formation of hardpan layers

chemical modelling of the groundwater composition in aquifers affected by lignite mine dumps discharge surface mine inden germany the oxidation of pyrite results in sulphate concentrations from 1 300 to 2 000 mg l in the dump water of the open cast mine inden which is located in germany under near neutral ph and reduced redox conditions precipitation of siderite feco3 retains up to 85 of the pre liberated ferrous iron so that iron concentrations in the dump water are relatively low as compared to the concentrations of sulphate the highly mineralised dump water will enter the aquifer system northwards of inden during the next centuries this area is used intensely for water extraction model calculations show that there will be no problem of acidification in the adjacent aquifer system and therefore no problem of high heavy metal concentrations during the next centuries the most important problem will be high sulphate concentrations in the groundwater besides dispersion and diffusion there are no chemical mechanisms that lower the sulphate concentrations downstream on the basis of the simulations sulphate plumes of about 1 2 km in width and up to 15 km in length are expected within the core of these plumes sulphate concentrations will be above the drinking water limits

characterisation of the sarcheshmeh copper mine tailings kerman province southeast of iran mineral processing operation at the sarcheshmeh porphyry copper mine has produced huge quantities of tailings materials containing sulphide minerals in particular pyrite these tailings materials were geochemically and mineralogically characterised to assess pyrite and chalcopyrite oxidation acid mine drainage generation and trace element mobility to lead development of a proper remediation plan five vertical trenches up to 4 2 m deep were excavated from the tailings surface and 70 solid samples were taken in 0 3 m intervals the samples were first mineralogically analysed pyrite was the main sulphide mineral found in the tailings the gangue minerals include quartz muscovite illite chlorite albite orthoclase halite the samples were geochemically analysed for total concentrations of 62 elements paste ph so4 2 co3 2 and hco3 the maximum concentrations of so4 2 1 300 1 170 1 852 1 960 and 837 mg l were observed at a depth of 0 9 m in profiles a b c d and e respectively the tailings have a high acid producing potential and low acid neutralising potential pyrite 4 6 wt calcite 1 wt fe2 so4 3 cuso4 mgso4 and mnso4 were the dominant secondary sulphate minerals in the tailings the lowest ph values 2 9 3 and 3 were measured at a depth of 0 3 m in the profiles a b and c 3 9 at a depth of 0 6 m in the profile d and 3 at a depth of 0 9 m in the profile e the upper portions of the profiles c 1 8 m and d 2 1 m were moderately oxidised while oxidation in the profiles a b and e did not extend more than 1 2 1 2 and 1 5 m beneath the tailings surface zn pb rb u hf nd zr and ga show almost a constant trend with depth cd sr th la and ce increased with increasing depth of the tailings materials while co v ti cr cu as mn ag mo and ni exhibit initially a decreasing trend from tailings surface to the depths that vary between 0 9 and 1 2 they then remained constant with the depth the results show pyrite and chalcopyrite oxidation at surface layers of the tailings and subsequent leaching of the oxidation products and trace elements by infiltrated atmospheric precipitation

toward the discrimination of fine grained ferrimagnets by magnetic measurements in lake and near shore marine sediments the magnetic properties of low field susceptibility frequency dependent susceptibility fd and susceptibility of anhysteretic remanent magnetisation arm are used to define sets of natural soil and sediment samples within which by the criteria of king et al 1982 and maher 1988 the modal ferrimagnetic grain diameter is less than 0 07 0 1 m within this sample set two distinct groups with low and high values respectively for the quotients arm and arm fd are defined the first group includes sediment samples from sites where published studies propose a detrital origin for the fine grained ferrimagnetic content where catchment samples are available for comparison they fall within the same envelope as do clays from palaeosol samples within chinese loess this envelope of low quotient values also overlaps with the values for the fine grained synthetic magnetite samples within maher s 1988 new mt series the high quotient envelope of values includes sediments from the adriatic sea and clays from saltmarsh and shallow water marine sediments in nw britain in these cases no catchment source is postulated for the fine grained magnetite the size range of magnetite in this set appears to be almost exclusively stable single domain ssd and a bacterial origin seems likely sample sets from estuarine environments between river inflow sites and the open sea show intermediate values which in the case of the potomac are ordered by distance down river although at this stage magnetic measurements alone cannot discriminate between bacterial and fine grained detrital ferrimagnets in sediments they hold out some promise of doing so provided the distinctions proposed here can be substantiated by transmission electron microscopy

modelling the effect of chemical heterogeneity on acidification and solute leaching in overburden mine spoils abstract the generation of acid mine drainage from overburden spoil piles at open pit lignite mines is impacting the quality of groundwater and surface water bodies in large parts of the lusatian mining area in germany values of ph as low as 1 have been observed in the groundwater after decommissioning mine pits are generally converted to lakes which may also be acidic owing to the acidic groundwater discharge the acidic effluent is generated by sulphide oxidation in the unsaturated zone of the spoil pile which generally extends to large depths as a result of dewatering the long term evolution of the acidification is still largely unknown our research focuses on the effects of physical and chemical heterogeneity caused by mixing of soil materials that may have already been oxidized to different degrees during the deposition of the spoil pile processes considered include variably saturated groundwater flow oxygen diffusion in the soil gas kinetic pyrite oxidation and acidic effluent generation advective dispersive transport of the aqueous components equilibrium geochemical reactions between the chemical components and the soil minerals and possible buffering and acid neutralization several existing numerical codes were coupled to represent the complete set of processes simulations were carried out in one and two dimensions using representative characteristics of mine spoil piles with the two dimensional representation being based on spatially heterogeneous random fields of hydraulic conductivity and sulphide mineral fractions results show the long term evolution of the oxidation front the mass flux of oxidation products and the effects of system heterogeneity under conditions of constant flow the system is found to return to neutral conditions over a time period on the order of several decades further work including sensitivity analyses with respect to the controlling parameters and model calibration using site specific field data will be necessary to obtain a full understanding of the complex interacting mechanisms the simulation approach shows promise as a potentially useful tool for predicting the effects of sulphide oxidation on the water quality of pit lakes

the pore water geochemistry and the mineralogy of the vadose zone of sulfide tailings waite amulet quebec canada low ph waters requiring treatment because of high concentrations of dissolved metals are being discharged from a decommissioned tailings impoundment at the former waite amulet zncu mine in northeastern quebec canada a detailed study of the vadose zone of the tailings comparing mineralogical and geochemical analyses of the tailings solids with geochemical analysis of the tailings pore water and pore gas indicates the presence of three zones within the tailings these zones include an upper sulfide depleted zone in which the sulfides have been extensively removed and oxidation is largely complete an intermediate zone where sulfide oxidation and acid neutralization reactions are occurring and an unoxidized zone below the depth of oxygen penetration where sulfides are unoxidized high aqueous concentrations of dissolved solids are being displaced downward from the sulfide depleted zone through the unoxidized zone toward the water table sulfide oxidation and acid neutralization reactions have generated concentrations of dissolved solids high enough to lead to the precipitation of a series of secondary solid phases precipitation dissolution reactions involving these solid phases control the concentrations of the major ions in the tailings pore water concentrations of dissolved metals are controlled by precipitation dissolution crystal structural replacement and adsorption coprecipitation reactions predictions based on the observed data and numerical simulations suggest that in the absence of an effective remedial program sulfide oxidation and h production will continue for several centuries

mid holocene charcoal stratigraphy fire history and palaeoecology at north gill north york moors uk abstract small peat mires are a favourable medium for the preservation of charcoal records that can be correlated more precisely with past fire history as part of multi proxy palaeoecological studies the north york moors upland has many suitable peat deposits with a well researched palaeoenvironmental history that offer the potential for high precision palaeofire studies we have examined the charcoal and pollen stratigraphy at the north gill site at a range of spatial and temporal resolutions for the mid holocene period between about 7k and 4 5k radiocarbon years ago in an individual core three size class charcoal records large small and microscopic reflect the scale and location of local fire events although the micro charcoal curve contains a background regional signal of about 10 of the charcoal pollen ratio most micro charcoal is generated locally and deposited close to its source at the site scale spatial comparison of four cores shows a variable relationship between tree pollen and micro charcoal concentrations which is an index of the size and intensity of local fire phases individual fires cannot be distinguished fine resolution sampling at the millimetre scale resolves major burning phases into discrete sub phases that may reflect the effects of individual fires at this fine temporal scale this multi scale research indicates that detailed charcoal stratigraphies at varying resolutions are capable of interpretation in terms of local regional and intermediate fire history

flood stratigraphies in lake sediments a review abstract records of the frequency and magnitude of floods are needed on centennial or millennial timescales to place increases in their occurrence and intensity into a longer term context than is available from gauged river flow and historical records recent research has highlighted the potential for lake sediment sequences to act as a relatively untapped archive of high magnitude floods over these longer timescales abyssal lake sediments can record past floods in the form of coarser grained laminations that reflect the capacity for river flows with greater hydrodynamic energy to transport larger particles into the lake this paper presents a framework for investigating flood stratigraphies in lakes by reviewing the conditioning mechanisms in the lake and catchment outlining the key analytical techniques used to recover flood records and highlighting the importance of appropriate field site and methodology selection the processes of sediment movement from watershed to lake bed are complex meaning relationships between measureable sedimentary characteristics and associated river discharge are not always clear stratigraphical palaeoflood records are all affected to some degree by catchment conditioning fluvial connectivity sequencing of high flows delta dynamics as well as within lake processes including river plume dispersal sediment focussing re suspension and trapping efficiency with regard to analytical techniques the potential for direct e g laser granulometry and indirect e g geochemical elemental ratios measurements of particle size to reflect variations in river discharge is confirmed we recommend care when interpreting fine resolution geochemical data acquired via micro scale x ray fluorescence xrf core scanning due to variable down core water and organic matter content altering x ray attenuation we also recommend accounting for changes in sediment supply through time as new or differing sources of sediment release may affect the hydrodynamic relationship between particle size and or geochemistry with stream power where these processes are considered and suitable dating control is obtained discrete historical floods can be identified and characterised using palaeolimnological evidence we outline a protocol for selecting suitable lakes and coring sites that integrates environmental setting sediment transfer processes and depositional mechanisms to act as a rapid reference for future research into lacustrine palaeoflood records we also present an interpretational protocol illustrating the analytical techniques available to palaeoflood researchers to demonstrate their utility we review five case studies of palaeoflood reconstructions from lakes in geographically varied regions these show how lakes of different sizes and geomorphological contexts can produce comprehensive palaeoflood records these were achieved by consistently applying site validated direct and proxy grain size measurements well established chronologies validation of the proxy process interpretation and calibration of the palaeoflood record against instrumental or historical records