top bottom soil ratios and enrichment factors what do they really show abstract high top bottom soil ratios or high values of enrichment factors efs are used as a proof for major anthropogenic impact on the geochemistry of the earth surface the idea behind calculating such ratios is that soils taken at depth or average crust can provide the geochemical background for the soils collected at the earth surface however a soil profile is not a closed system element exchange between the different layers depending on and varying with the chemical properties of the different elements and their turnover in the biosphere is the essence of soil formation high top bottom soil ratios or efs may thus highlight the geochemical de coupling of the lithosphere from the biosphere rather than contamination this is demonstrated by using regional data from 258 soil o and b horizon samples collected from the czech republic 76 800 km2 results show no relationship between the ratios and the magnitude of anthropogenic emissions the visible relationship between element concentrations and sources in a map of the spatial distribution of the elements is lost when maps for the top bottom soil ratio or efs are constructed the value of the data lies in the spatial elemental distribution and not in ratios calculated based on misconceptions

evaluation of the anthropogenic influx of metallic pollutants into puck bay southern baltic abstract distributions of 15 elements with depth in two sediment cores from puck bay in the gulf of gdansk show that ag cd pb zn and possibly cu and ni are anthropogenically enriched in the sediments there the concentrations of these elements decrease sharply with depth in the sediment column and the elements are preferentially enriched in the m size fraction of the sediment the sequence of element enrichment depends on whether the enrichment factor ef and the anthropogenic factor af are used to calculate the element enrichment by contrast the anthropogenic elements show no systematic decrease in concentration with depth in a sediment core taken from near the mouth of the vistula river this reflects the higher sedimentation rate there such that the entire upper 20 cm of the core was deposited during the major post war period of industrialization in poland in addition these elements are enriched in the 2 63 m fraction compared to the m fraction in these sediments this suggests that the heavy metals are mainly adsorbed on fe oxyhydroxide particles with diameters greater than 2 m at the hydrological front where vistula river water mixes with brackish baltic water it appears that heavy metal pollution of sediments in parts of puck bay may be greater than that near the mouth of the vistula river which may reflect in part the higher sedimentation rate near the mouth of the vistula river the mode of incorporation of heavy metals into the sediments in the two areas may also be different

the mass balance of soil evolution on late quaternary marine terraces northern california mass balance interpretation of a soil chronosequence provides a means of quantifying elemental addition removal and transformation that occur in soils from a flight of marine terraces in northern california six soil profiles that range in age from several to 240 000 yr are developed in unconsolidated sandy marine and eolian parent material deposited on bedrock marine platforms soil evolution is dominated by 1 open system depletion of si ca mg k and na 2 open system enrichment of p in surface soil horizons 3 relative immobility of fe and al and 4 transformation of fe si and al in the parent material to secondary clay minerals and sesquioxides net mass losses of bases and si are generally uniform with depth and substantial in some cases approaching 100 however the rate of loss of each element differs markedly causing the ranking of each by relative abundance to shift with time loss of si from the sand fraction by dissolution and particle size diminution from 100 to 80 to 90 to 10 concurrently with an increase of ai in the organic sesquioxide and clay phases to 10 and 50 respectively while only minor increases occur in the nonorganic sesquioxide phases

weathering and evolution of soils formed on granitic glacial deposits results from chronosequences of swiss alpine environments abstract two soil chronosequences of mountainous ecosystems in switzerland served as the basis to calculate the accumulation of soil organic matter transformation of pedogenic fe and al and net losses of the main elements ca mg k na fe al mn and si by means of mass balance calculations elemental losses due to deglaciation and exposure to the weathering environment were calculated these mass balance calculations indicate that extensive mineral weathering resulted in significant leaching losses of si major base cations and al particularly from the upper horizons the losses are especially pronounced in the early stages of soil formation in most cases the exponential decay model incorporating an asymptotic or logarithmic regression model seems to provide a good description of weathering the greatest changes in the soil chemistry of these alpine soils on granitic host material occurred within the first 3000 4000 years of soil development later the weathering rates decreased rapidly and the overall depletion of elements nearly reached an asymptote we also found that the mean ratio of al t fe d al d fe t of the fine earth of the a e and b horizons is closely linked to the duration of soil development a very rapid decrease of this ratio also occurred at the beginning of soil evolution in order to reach asymptotic values after about 3000 years consequently this ratio could be a good indicator of the age of alpine soils furthermore there is a close relationship between the mass of organic c or n in the whole profile and the soil age the older the soil the higher the corresponding mass per unit area the chronofunctions presented give a first attempt of the chemical soil evolution in the alps however only little data has been available up until now regarding alpine soils and this fact inhibits a more detailed observation of the changes that have occurred over a period of 2000 8000 years of soil formation under similar climatic conditions

stratigraphy of the anthropocene the anthropocene an informal term used to signal the impact of collective human activity on biological physical and chemical processes on the earth system is assessed using stratigraphic criteria it is complex in time space and process and may be considered in terms of the scale relative timing duration and novelty of its various phenomena the lithostratigraphic signal includes both direct components such as urban constructions and man made deposits and indirect ones such as sediment flux changes already widespread these are producing a significant event layer locally with considerable long term preservation potential chemostratigraphic signals include new organic compounds but are likely to be dominated by the effects of co2 release particularly via acidification in the marine realm and man made radionuclides the sequence stratigraphic signal is negligible to date but may become geologically significant over centennial millennial time scales the rapidly growing biostratigraphic signal includes geologically novel aspects the scale of globally transferred species and geologically will have permanent effects

soil development along an elevational gradient in the southeastern uinta mountains utah usa abstract a silt mantle enriched in ca is important in buffering soils on quartzitic terrane in the southeastern uinta mountains we examined 32 pedons along an elevational gradient on the south slope of the eastern uintas to determine the amount of the silt and its importance to pedogenesis the pedons were in the upper montane forest 2700 3000 m subalpine forest 3000 3400 m and alpine tundra 3400 3850 m on stable sites there were no significant differences in silt cap thickness or in profile quantities of silt upper 100 cm by ecoclimatic zone similar soils were found in all three ecoclimatic zones including eutrocryepts dystrocryepts haplocryalfs cryorthents and haplocryolls in descending order of abundance profile quantities of clay exchangeable cations and extractable al and solum thickness are greatest in the alpine zone probably because the soils there are older than those at lower elevations and soil formation proceeds more rapidly base cycling is enhanced in alpine communities dominated by acomastylis geum rossii as evidenced by large profile quantities and high tissue concentrations of ca profile quantities of total n and organic c are significantly greater p 0 05 in the alpine zone reflecting greater below ground production and lower rates of organic matter turnover than in soils at lower elevations

can an anthropocene series be defined and recognized we consider the anthropocene as a physical chronostratigraphic unit across terrestrial and marine sedimentary facies from both a present and a far future perspective provisionally using an approximately 1950 ce base that approximates with the great acceleration worldwide sedimentary incorporation of a bomb derived radionuclides and light nitrogen isotopes linked to the growth in fertilizer use and other markers more or less effective recognition of such a unit today with annual decadal resolution is facies dependent and variably compromised by the disturbance of stratigraphic superposition that commonly occurs at geologically brief temporal scales and that particularly affects soils deep marine deposits and the pre 1950 parts of current urban areas the anthropocene thus more than any other geological time unit is locally affected by such blurring of its chronostratigraphic boundary with holocene strata nevertheless clearly separable representatives of an anthropocene series may be found in lakes land ice certain river delta systems in the widespread dredged parts of shallow marine systems on continental shelves and slopes and in those parts of deep water systems where human rafted debris is common from a far future perspective the boundary is likely to appear geologically instantaneous and stratigraphically significant

a stratigraphical basis for the anthropocene recognition of intimate feedback mechanisms linking changes across the atmosphere biosphere geosphere and hydrosphere demonstrates the pervasive nature of humankind s influence perhaps to the point that we have fashioned a new geological epoch the anthropocene to what extent will these changes be evident as long lasting signatures in the geological record to establish the anthropocene as a formal chronostratigraphical unit it is necessary to consider a spectrum of indicators of anthropogenically induced environmental change and to determine how these show as stratigraphic signals that can be used to characterize an anthropocene unit and to recognize its base it is important to consider these signals against a context of holocene and earlier stratigraphic patterns here we review the parameters used by stratigraphers to identify chronostratigraphical units and how these could apply to the definition of the anthropocene the onset of the range of signatures is diachronous although many show maximum signatures which post date1945 leading to the suggestion that this date may be a suitable age for the start of the anthropocene

combined use of relative and absolute dating techniques for detecting signals of alpine landscape evolution during the late pleistocene and early holocene article i nfo a combination of three relative and two absolute numerical dating techniques applied on nine soil profiles in an alpine environment located in val di rabbi trentino northern italy was used to improve the investigation methodology of alpine sites in response to climate change and to reconstruct the chronology of late pleistocene and early holocene landscape evolution the degree of podzolisation clay mineral evolution and the element mass balances of each site were investigated furthermore the stable fraction of the soil organic matter som was extracted with 10 h2o2 and 14 c dated the age of the organic residues was compared with the age of charcoal fragments found in one of the studied soils and with the age of rock boulders obtained by surface exposure dating sed with cosmogenic 10 be numerical dating and weathering characteristics of the soils showed a fairly good agreement and enabled a relative and absolute differentiation of landscape elements the combination of 14 c dating of som and sed indicated that deglaciation processes in val di rabbi were already far advanced by around 14000 cal bp and that glacier oscillations affected the highest part of the region until about 9000 cal bp the development of clay minerals is time dependent and reflects weathering intensity we found a close link between secondary clay minerals like smectite or vermiculite and soil age as obtained by the dating of the organic residues after the h2o2 treatment calculated element mass balances strongly correlated with the ages derived from 14 c measurements old soils have lost a major part of base cations up to 75 compared to the parent material fe and al which indicates a continuous high weathering intensity results of the chemical and mineralogical analyses were in good agreement with numerical dating techniques showing the dynamics of an alpine landscape within a relatively small area the combination of relative and absolute dating techniques is a promising tool for the reconstruction of landscape history in high elevation alpine areas on siliceous substrates

assessing the anthropocene with geochemical methods anthropogenic chemical contamination is one of the most evident signals of human influence on the environment the large amounts of industrially produced pollutants that have been introduced over decades into air soil and water have caused modifications to natural elemental cycling anthropogenic contamination usually leads to enrichment in many elements particularly in industrial areas thus certain elements and their isotopes can be used as geochemical tracers of anthropogenic impact some human induced changes in the environment may be regarded as a secondary effect of pollution such as acidification which causes increased geochemical mobility of several trace elements in surficial deposits methods used by geochemists to assess the scale of anthropogenic influence on the environment include calculations of anthropogenic influence on the environment via enrichment and contamination factors geoaccumulation index and pollution load index the use of geochemical background levels for delineating between natural and anthropogenic pollution is important a historical perspective of anthropogenic contamination allied with isotopic and geochemical signatures in dated sediment cores may be applied to help define the anthropocene human influence on the environment has been complex encompassing different environmental compartments air water soil and scales of changes local regional global the earth is a dynamic system and geochemical dynamics are best illustrated by consideration of element cycling although anthropogenic pollution sources have contributed to chemical changes in the atmosphere hydrosphere pedosphere and biosphere their impact on the total environment is best preserved in sediments which are often referred to as archives of contamination choi wania 2011 significant evidence of a distinctive anthropocene signal can be found in recent sedimentary deposits that have been impacted by anthropogenic activity and dated sediment cores can be used to reconstruct the chronology of contamination buckley et al 1995 in assessing the anthropocene it is important to quantify the human influence on the environment the results of this influence recorded in sediments can be evaluated using different approaches and criteria depending on the nature of the signal mechanical biological or chemical fig 1 zalasiewicz et al 2011a b price et al 2011 vane et al 2011 schrag 2012 geochemical methodology may help discriminate natural and anthropogenic sources of a given substance in the environment some of the methods and concepts e g anomaly background concentrations geochemical calculations and geochemical tracers traditionally used in geochemical exploration and further adapted to the needs of environmental geochemistry have found application in the study of anthropogenic contamination reimann de caritat 2005 reimann et al 2005 galuszka 2007 galuszka migaszewski 2011 these methods may be extended in assessment of the anthropocene anthropogenic anomalies and geochemical background concept geochemical anomalies can be defined as abnormal concentrations of elements in earth materials compared with background levels allaby allaby 1999 anomalous concentrations of elements are both of natural origin e g via oreforming processes weathering of ore bodies or mineralized rock formations sorption by mineral phases volcanic and hydrothermal activity and of anthropogenic origin mcqueen 2009 of the different types of geochemical anomalies fig 2 the positive anthropogenic anomalies of regional scale may provide a useful marker for the anthropocene selinus esbensen 1995 identification of geochemical anomalies requires knowledge of the normal or average distribution of elements in the environment which is usually referred to as a geochemical background lower and upper limits of the geochemical background from waters c n zalasiewicz j a williams m ellis m a snelling a m eds a stratigraphical basis for the anthropocene geological society london special publications 395 http dx doi org 10 1144 sp395 5 the geological society of london 2013 publishing disclaimer www geolsoc org uk pub ethics range are considered thresholds of negative depletion in an element and positive enrichment in an element anomalies fig 3 historically the search for positive anomalies has been essential to mineral exploration and in the 1960s geochemists established several methodologies for separating anomalies from the geochemical background hawkes webb 1962 miesch 1967 many fig 1 types of human induced changes their possible effects and sedimentary record fig 2 systematics of geochemical anomalies a ga uszka et al

distribution of natural and anthropogenic lead in mediterranean soils abstract the concentrations and isotopic composition of pb have been combined with a selective sequential dissolution procedure to track the distribution of anthropogenic and natural pb in the soil of semiarid climate and the penetration pathway of petrol pb within the soil profile soil samples were collected from soil profiles adjacent to a major highway 8 23 m and from soil profiles 500 m away from the same highway the selective sequential dissolution procedure was used to determine the distribution of pb between the different soil components soil carbonate organic matter fe oxides and hydrous oxides and aluminosilicates natural pb is associated mainly with aluminosilicates 60 and fe oxides 30 and only a small fraction with the soil carbonate and organic matter 10 in contrast to the distribution of natural pb the distribution of anthropogenic pb which accumulates mainly in the upper part of the soil profile is 40 with the soil carbonate 10 with organic matter 35 with fe oxides and only 15 with aluminosilicates on the basis of concentration and isotopic composition of total pb the deeper horizon of the roadside soil 10 30 cm and the soil sampled 500 m from the highway seem uncontaminated however the isotopic composition of the labile components in the soil pbcarb pborg and pbfe ox indicates that these soils are actually contaminated this contamination implies that over the period of vehicle pollution 40 yr petrol pb has penetrated through the entire roadside soil profile 25 30 cm furthermore pb isotopes in aluminosilicates of the upper part of the roadside soil indicate that this pb too is anthropogenic measurements of pb concentration and isotopic composition in roadside soil profiles sampled in 1997 and archived samples collected at the same location in 1982 provided a unique opportunity to trace petrol pb penetration into the soil

bed sediment associated trace metals in an urban stream oahu hawaii of the 117 stream and lake systems sampled nationwide fish from manoa stream on oahu hawaii have consistently shown the highest pb concentrations therefore a detailed study was conducted to examine total metal contents in bed sediments from a 5 8 km stretch of manoa stream a total of 123 samples 63 m were examined for 18 elements and 14 samples for 21 elements selected samples were also examined using different leach solutions to examine metal phase associations all trace metal data computations of enrichment ratios and the modified index of geoaccumulation point to mineralogical control for cr and ni minor anthropogenic contamination for ba cd cu hg and zn and a very strong contamination signal for pb maximum pb contents up to 1080 mg kg 1 were associated with anthropogenic material dumping in minor tributaries storm sewer sediments and sediments in the lower section of the basin proportionally pb had the highest non residual component of elements examined dominantly in the reducible phase associated with mn and amorphous fe oxyhydroxides the contamination signal was typically lowest in the undisturbed headwater reach of the basin above 5 1 km with significant increases throughout the residential and commercial institutional zones of the mid basin the spatial pattern of bed sediment contamination and evidence from storm sewer outlet sediments strongly indicates that pb and to a lesser degree some other metals is still being transported to the stream and the primary agent is soil erosion and transport of metals sorbed to sediments the primary source of sediment associated metals is considered to be the automobile though other minor sources can not be ruled out

floodplain architecture of an actively meandering river the ploucnice river the czech republic as revealed by the distribution of pollution and electrical resistivity tomography abstract the aim of this study was to describe the floodplain architecture of the ploucnice river a naturally meandering river in the czech republic using manual drill coring the element analysis of sediments and electrical resistivity tomography ert the ploucnice river has received diffuse pollution since the early twentieth century mainly pb followed by a prominent temporally well defined pollution pulse from uranium mining in the 1970s and 1980s mainly u and 226ra the pollution created a chemostratigraphic temporal framework for overbank fines we used geographical information systems gis to describe the channel s dynamics and visualise fluvial landforms we sampled and analysed the finest floodplain sediments in the top 1 to 2 m of the floodplain fill silty and sandy deposits and we used ert to visualise bodies of coarser and deeper strata at depths down to 3 m several limits of ert imaging have been found by a comparison of the resistivity domains with lithological descriptions of the cores several decimetre thick strata were not revealed they are below the spatial resolution of that method and humidity affected the results that were obtained in the topmost strata the space for deposition of fluvial sediments in the ploucnice river is being created by 1 natural lateral shifts in the channel up to 0 5 m year 2 meander loop development and cutoffs at the timescale of decades to centuries and spatial scale of up to 1 4 of the floodplain width and 3 more substantial reorganisation of the channel structure by avulsions probably at the timescale of centuries these processes continuously create space for the deposition of overbank fines on the top of former point bars and in swales and abandoned channels as a consequence of the speed of the channel shifts at least 80 of the fine grained top of the floodplain fill overbank fines was reworked over approximately three centuries

chemical weathering in two adirondack watersheds past and present day rates rates of chemical weathering in two forested adirondack watersheds were determined from mineral and elemental depletion trends in soil profiles and from input output budgets based on precipitation and surface water chemistry long term rates of weathering have averaged about 500 to 600 eq ha yr for both watersheds since the glaciers retreated from the region about 14 000 yr ago present day denudation rates average 1679 eq ha yr in the panther lake watershed and only 198 eq ha yr in the woods lake watershed mineral weathering reactions in both watersheds involve primarily the dissolution of plagioclase potassium feldspar and hornblende mass balance calculations however indicate that hornblende weathers in disproportionately large amounts in the panther lake watershed relative to its abundance in soils and till cation exchange in the glacial till mantling the panther lake watershed may also play an important role in controlling surface water chemistry in the basin in the panther lake watershed the current rate of weathering which is about a factor of 3 greater than the long term average may reflect a recent adjustment for higher hydrogen ion fluxes brought about by acid deposition the capacity of the thick till deposits in the panther lake watershed to neutralize acidity is ultimately reflected by the circum neutrality of panther lake in the woods lake watershed the soils and thin till deposits cannot effectively neutralize current acid loadings and therefore woods lake is acidic with a ph below 5

multiple isotope h o n s and sr approach elucidates complex pollution causes in the shallow groundwaters of the taipei urban area summary deterioration of the quality of groundwater under urban areas has become a major environmental concern worldwide this paper presents a pilot case study in the taipei urban area using multiple stable isotopes d h 2 o and 18 o h 2 o 15 n no 3 and 18 o no 3 34 s so 4 and 18 o so 4 and 87sr 86sr with the aim of understanding the subsurface nature and environmental status of such areas a previous study has already characterized taipei shallow groundwaters as sulfate rich in comparison to other southeast asian metropolitan cities our chemical measurements clarified that the arsenic is the important environmental concerns in the aquifers dual isotope approaches for nitrate and sulfate suggested these ions were sourced mainly from municipal sewage leaking from sewer pipes in urbanized area while chemical fertilizers applied in the local agricultural fields partly contribute in the suburb area significant decreases in nitrate and sulfate concentrations due to denitrification and sulfate reduction were observed in some groundwaters which induced increases in isotope ratios up to 24 9 for 15 n no 3 and 27 2 for 34 s so 4 nitrate groundwater pollution in the taipei basin is not a subject of serious concern no 3 for all analyzed samples at the present time due to attenuation by denitrification however arsenic is preferentially released in groundwater 100 g l in anoxic environment under which sulfate reduction occurs the sr isotope data suggested that the arsenic is derived from alluvial deposits of oligocene miocene sedimentary rock origin this study disclosed the complex causes of environmental changes in taipei urban shallow groundwater it is also important as an excellent case study demonstrating the efficient use of multiple isotope diagnosis in the urban groundwater environmental field

investigations on the intensity of weathering of soils developed from glacial and fluvioglacial deposits and their relationship with the history of the landscape in the mt everest region abstract soils developed from glacial and fluvioglacial deposits in the mt everest region eastern nepal were differentiated analytically with regard to weathering intensity and age iron fractionation clay mineral analysis and the calculation of weathering indices resulted in a separation of the soils into two groups one group of young soils with their main weathering zone in the top horizons has developed from deposits of the last ice age or postglacial events this was supported by radiocarbon dating the other group of considerably older highly weathered soils was presumably derived from interglacial deposits based on these results and according to the soil geographical evidence indications on the pleistocene history of the landscape and the extent of the last major glaciation could be deduced

geochemical mapping in polluted floodplains using in situ x ray fluorescence analysis geophysical imaging and statistics surprising complexity of floodplain pollution hotspot abstract this study is focused on a pollution hotspot in a floodplain impacted by uranium mining in the second half of the 20th century to image the internal structure of the hotspot we performed surface gamma activity mapping in situ x ray fluorescence spectroscopic analysis xrf using a portable instrument and manually obtained sediment cores and electric resistivity imaging of the shallow subsurface with the help of electric resistivity tomography ert and dipole electromagnetic profiling demp we used two approaches aimed at deciphering the origin of the pollution hotspot i surface pollution mapping and ii identification of the deeper lying lithogenetic units the description of the floodplain subsurface was supported by optically stimulated luminescence osl dating the surface mapping approach was found insufficient to visualise the hotspot and understand its origin we recognised deposition non linear in time or temporally independent of younger overbank fines including mining pollutants over considerably older channel sediments our work documents the value of dense geochemical mapping for documentation of fluvial pollution accessible by portable xrf as well as the need to understand the structure of the floodplain subsurface accessible by electric resistivity imaging and thereby rationalise the hotspot internal structure

the application of time lapse electrical tomography in groundwater studies recently various techniques of electrical tomography have been refined and fast efficient commercial systems are now available new inversion algorithms produce electrical images that more accurately model a two dimensional or three dimensional subsurface than ever before over the past three years electrical tomography surveys in germany the u k and the u s have produced remarkable results

long term base cation weathering rates in forested catchments of the canadian shield abstract a number of methods exist for estimating mineral weathering rates yet quantifying this crucial biogeochemical reaction in the field has always been a challenge because mineral weathering takes place in open systems whose initial state conditions are not well known and where material inputs and outputs vary in time and space here using the soil profile mass balance method we estimated long term weathering rates of base cations bcs for a set of 21 watersheds and we investigated the links between environmental variables and soil properties and the spatial variation in bc weathering rates in the study area the watersheds are located in southern quebec and vary with respect to hydro climatic conditions soil properties and forest cover average long term estimates of annual bc weathering rates for the study area were 0 16 0 10 0 09 and 0 06 kmolc ha 1 year 1 for ca mg na and k respectively overall redundancy analysis rda indicated that soil surface area percent deciduous canopy cover elevation as well as soil albite content were the most significant variables explaining together 56 of the total variation in bc weathering rates consistent with previous findings our results showed that beside soil properties climate related environmental variables played key roles in determining the variability of bc weathering rates in the study area in the context of global climate change more insights are needed for a better understanding of the effects of discrete climatic variables on bc weathering rates

constitutive mass balance relations between chemical composition volume density porosity and strain in metasomatic hydrochemical systems results on weathering and pedogenesis relations characterizing the chemical physical and mechanical changes resulting from metasomatic hydrochemical processes are developed using mass balance models which formally link chemical composition to bulk density mineral density volumetric properties porosity and amount of deformation strain rigorous analysis of aqueous solute transport effects is then made possible in a variety of porous media flow environments including chemical weathering pedogenesis soil formation diagenesis ore deposition and enrichment and metamorphism application of these linear constitutive relations to chemical weathering profiles shows that immobile and locally mobile chemical elements with masses conserved on the scale of soil profiles can be accurately identified from analysis of appropriate data arrays and then used as natural geochemical tracers to infer the nature and extent of hydrochemical weathering processes and volume changes during pedogenesis assumptions commonly made in the past about the supposed immobility of certain elements e g ti and zr become unnecessary quantitative differentiation between the effects of residual and supergene fractionation is then easily made these methods are applied to ni rich laterites developed by weathering of ultramafic rocks showing that during ordinary residual enrichment ni is concentrated by as much as 4 protolith peridotite concentrations this occurs simply by silicate mineral dissolution and removal of chemical elements other than ni e g mg with a corresponding reduction in saprolite density and increase in bulk porosity without significant deformation in contrast laterites with mineable concentrations of ni which are similarly undeformed such as the nickel mountain mine in riddle oregon have experienced in addition to residual enrichment strong supergene enrichment by fractionation of ore elements between a leached zone from which ni is extracted and a complementary enriched zone positioned farther along the direction of ground water flow soil forming processes in podzol chronosequences developed on sandy beach terraces of the mendocino coast of california involved soil column collapse of 60 percent by dissolution of silicate minerals in the albic horizon of al and fe leaching and 70 percent dilation expansion in the overlying organic rich layer by root growth the amount of erosion based upon paleosurface reconstructions using the excess mass of fe al pb ga and cu in the zone of supergene enrichment spodic horizon below the ground water table indicates that subsurface erosion by dissolutional collapse is three times that of surficial erosion finally using published chemical data for ti zr and cr on major bauxite deposits in australia where erosion rates are thought to be low we infer that there may have been major amounts of dissolutional collapse to explain the upwards increase of detrital zircon and rutile in weathering profiles

weathering in three podzolized pedons on glacial deposits in northern sweden and central finland abstract chemical weathering losses were calculated for three conifer stands in relation to ongoing studies on chemical status soil solution chemistry and soil genesis weathering losses were based on elemental depletion trends in soil profiles since deglaciation and exposure to the weathering environment gradients in total geochemical composition were assumed to reflect alteration over time study sites were nyanget and heden in northern sweden and hyytiala in central finland the nyanget site is located on sandy loamy weichselian till at an altitude of 310 m a s l and the heden and hyytiala sites on water deposited coarse silt and out wash sand at an altitude of 175 and 150 m respectively volume determined samples from different soil levels were fused with lithium metaborate dissolved in hno 3 and analysed by icp aes results indicated highest cumulative weathering losses at heden and lower but similar values for nyanget and hyytiala the weathering losses for the elements are in the following order mg ca na k al fe mn si p total annual losses for ca mg k expressed in mmol c m 2 yr 1 amounted to 27 2 16 6 and 19 at heden nyanget and hyytiala respectively variations between study sites were consistent with differences in geochemistry and mineralogy the accumulated weathering losses after deglaciation were much larger in e than in b horizons for all elements studied for fe al and si this was partly due to the retention by precipitation of secondary minerals

soil formation in kettle holes from high altitudes in central apennines italy abstract kettle holes are relatively common features of glaciated landscapes and have been widely reported in the literature the work reported here documents the presence of kettle holes at high altitude and low latitude in the central apennines italy and describes the geomorphic and pedogenic processes that originated the soils infilling these depressions the areas selected for this study were located on three of the main massifs of the central apennines italy gran sasso majella and sibillini the kettle holes on these massifs formed at the end of the wurm glaciation appear smaller and shallower than those reported from elsewhere in the northern hemisphere are roughly circular in form and do not contain bogs or lakes in each area the dimensions of 40 kettle holes were measured and three kettle holes were excavated to examine the soils developed inside them the size of the kettle holes was highest in the sibillini massif where the glaciers reached altitudes as low as 1700 m in the very narrow low lying valleys it is hypothesised that at lower elevations the glacier receded more rapidly generating larger blocks of ice and consequently larger kettle holes once formed the kettle hole depressions were very effective as sediment traps and acted as sink for materials washed in from the surrounding slopes or from more distant wind blown sources in the kettle holes from gran sasso and majella massifs small fragments of woody charcoal were found the material filling the kettle holes accumulated inside them in the form of layers soils formed inside the kettle holes showed horizons whose thickness and properties appeared mostly inherited from the amassed layers the only pedogenic process common to the kettle holes of the three massifs was the incorporation of organic matter that as expected from the rather cold climatic conditions was subjected to slow dynamics in the kettle holes of the majella massif the horizons developed from layers rich of materials of volcanic origin and the formation of short range order minerals occurred we conclude that the soils inside the kettle holes are a repository of geomorphic pedogenic and in reference to the source of the charcoal paleo environmental information

clay mineral formation in soils of two different chronosequences in the swiss alps two chronosequences of soils developed from postglacial tills at two different sites in the swiss alps were studied with respect to their soil mineralogy and chemistry the age of these soils ranged between 0 and 11 500 years the parent material for both chronosequences was similar but differences were found in the clay fraction within the considered time span podzols developed at both sites however at one site already after about 3000 years and at the other a few years later especially trioctahedral minerals were strongly weathered within the time span of about 11 000 years smectite and regularly interstratified dioctahedral mica smectite could be found in the most weathered horizons at one site the origin of smectite could be traced back to both chlorite and trioctahedral mica which supports the fact that smectite is the end product of chlorite alteration and regularly interstratified mica smectite or even smectite the end product of mica weathering in strongly leached and acidified horizons at the other site smectite was already present in the parent material most presumably due to hydrothermal formation during the first 500 years of soil formation a kind of retrograde podzolisation was observed leading to the elimination of this smectite within the same time increased amounts of dioctahedral minerals were formed and after 11 000 years a small proportion of pedogenic smectite was discernible again main clay mineral transformations occurred at both sites within the first 3000 years of soil development weathering and transformation reactions were most advanced in the e horizon being almost complete after 3000 years at one site the presence of significant amounts of chlorite and or a minimal content of mica of ca 5 seems however to be compulsory in order to detect low charge expandable minerals already after a 3000 year duration of soil formation in the alps otherwise smectite formation is retarded

the role of climate driven chemical weathering on soil production climate plays an important role in controlling rates of weathering and weathered regolith production regolith production functions however seldom take climate parameters into account based on a climate dependent weathered regolith production model at low denudation rates relative regolith thicknesses are less sensitive to changes in precipitation rates while at high denudation rates small changes in climatic parameters can result in complete stripping of hillslopes this pattern is compounded by the long residence times and system response times associated with low denudation rates and vice versa as others have shown the transition between regolith mantled and bedrock slopes is dependent on the ratio of denudation to production here we further suggest that this is itself a function of precipitation rate and temperature we suggest that climatic parameters can be easily incorporated into existing soil production models and that such additions improve the predictive power of soil production models

estimating depth of investigation in dc resistivity and ip surveys in this paper the term depth of investigation refers generically to the depth below which surface data are insensitive to the value of the physical property of the earth estimates of this depth for dc resistivity and induced polarization ip surveys are essential when interpreting models obtained from any inversion because structure beneath that depth should not be interpreted geologically we advocate carrying out a limited exploration of model space to generate a few models that have minimum structure and that differ substantially from the final model used for interpretation visual assessment of these models often provides answers about existence of deeper structures differences between the models can be quantified into a depth of investigation doi index that can be displayed with the model used for interpretation an explicit algorithm for evaluating the doi is presented the doi curves are somewhat dependent upon the parameters used to generate the different models but the results are robust

stratigraphic expressions of the holocene anthropocene transition revealed in sediments from remote lakes stratigraphic boundaries are ideally defined by distinct lithological geochemical and palaeobiological signatures to which a chronological framework can be applied we present a range of observations that illustrate how the holocene anthropocene transition meets these criteria in its expression in sediments from remote arctic and alpine lakes removed from direct catchment scale anthropogenic influences in glaciated lake basins the retreat of glaciers commonly leads to lithological successions from proglacial clastic sedimentation to non glacial organic deposition sediments from the majority of lakes record marked depletions in the nitrogen stable isotopic composition of sediment organic matter reflecting anthropogenic influences on the global nitrogen cycle in all cases siliceous microfossil assemblages diatoms and chrysophytes change markedly and directionally with regional nuances these stratigraphic fingerprints begin to appear in the sediment record after ad 1850 but accelerate in pulses between ad 1950 and 1970 and again after ad 1980 our review indicates that recent environmental changes associated with humankind s dominance of key global biogeochemical cycles are sufficiently pervasive to be imprinted on the sediment record of remote lakes moreover these changes are of sufficient magnitude to conclude that the holocene has effectively ended and that the concept of anthropocene more aptly describes current planetary dynamics the synthesis of these observations pertains directly to ongoing discussions concerning the eventual formalization of a new stratigraphic boundary

mesolithic settlement and mobility patterns at high altitudes the site of staller sattel sts 4a south tyrol italy abstract this paper presents the results of an ongoing research aimed at reconstructing early mesolithic settlement strategies and mobility patterns at high altitudes of alpine area focusing on the interactions and possible mutual influence between human behavior and the geomorphological and environmental context due to the high altitude environment research had to face the effects of post depositional processes on anthropogenic remains investigations have been carried out on a terrace in the ackstall locality south of the staller sattel passo stalle italian austrian border central eastern alps covered by coniferous vegetation since the preboreal the terrace central with respect to the available resources and in a strategic position within a reconstructed route system conjoining different sites and adjacent hunting territories yielded several lithic findspots one of these the excavated open air site sts 4a lying at 2125 m a s l revealed human site frequentation dating at least between 7370 and 6590 cal bc human occupation was established on a forested soil subsequently buried indicated as paleo podzol stratigraphy micromorphology and artifact distribution this latter showing a ring shaped pattern suggest the preparation of the living space by manipulating the existing soil cover anthropogenic remains indicate on site activities as wood carving exploitation of rock crystal and chert for tool manufacture and the probable consumption of plants originating from lower altitudes several features some of which connected with fire use have been identified fuel was collected in the form of dead wood in the open larch and stone pine forests surrounding the site the comparison of multiscale data allowed to get insights on the living space of a mesolithic hunter gatherer camp integrating detailed data from the excavation of a single site with the wider territorial context investigated by surveys allowed to draw a multi facetted picture of early mesolithic lifeways and highlighted the potential of research on the ephemeral high altitude sites

the influence of weathering processes on labile and stable organic matter in mediterranean volcanic soils the relationship and mechanisms among weathering processes cation fluxes clay mineralogy organic matter composition and stability were studied in soils developing on basaltic material in southern italy sicily the soils were transitions between phaeozems and vertisols intense losses of the elements na ca and mg were measured indicating that weathering has occurred over a long period of time the main weathering processes followed the sequence amphibole mica volcanic glass or if ash was the primary source smectite interstratified smectite kaolinite kaolinite kaolinite formation was strongly related to high al mg and na losses the good correlation between oxyhydroxides and kaolinite in the soils suggests that macro aggregates have formed due to physical or electrostatic interactions between the 1 1 clay minerals and oxides the stability of organic matter was investigated with a h2o2 treatment that assumes that chemical oxidation mimics the natural oxidative processes the ratio of c after the h2o2 treatment to the total organic c ranged from 1 28 no correlation between clay content and organic matter labile or stable fraction was found the refractory organic fraction was enriched in aliphatic compounds and did not greatly interact with the kaolinite smectite or poorly crystalline fe or al phases a part of this fraction most probably proteins was bound to crystalline fe oxides in contrast the oxidisable fraction showed a strong relationship with poorly crystalline oxyhydroxides and kaolinite surprisingly smectite did not contribute to the stabilisation of any of the organic c fractions the stabilisation of organic matter in the soils has therefore two main mechanisms 1 the protection of labile oxidisable with h2o2 organic matter including also aromatic rich compounds such as charcoal by the formation of aggregates with oxyhydroxides and kaolinite and 2 the formation of a refractory fraction enriched in aliphatic compounds

when did the anthropocene begin a mid twentieth century boundary level is stratigraphically optimal abstract we evaluate the boundary of the anthropocene geological time interval as an epoch since it is useful to have a consistent temporal definition for this increasingly used unit whether the presently informal term is eventually formalized or not of the three main levels suggested an early anthropocene level some thousands of years ago the beginning of the industrial revolution at 1800 ce common era and the great acceleration of the mid twentieth century current evidence suggests that the last of these has the most pronounced and globally synchronous signal a boundary at this time need not have a global boundary stratotype section and point gssp or golden spike but can be defined by a global standard stratigraphic age gssa i e a point in time of the human calendar we propose an appropriate boundary level here to be the time of the world s first nuclear bomb explosion on july 16th 1945 at alamogordo new mexico additional bombs were detonated at the average rate of one every 9 6 days until 1988 with attendant worldwide fallout easily identifiable in the chemostratigraphic record hence anthropocene deposits would be those that may include the globally distributed primary artificial radionuclide signal while also being recognized using a wide range of other stratigraphic criteria this suggestion for the holocene anthropocene boundary may ultimately be superseded as the anthropocene is only in its early phases but it should remain practical and effective for use by at least the current generation of scientists

accumulation of contaminant metals in marine sediments of halifax harbour nova scotia environmental factors and historical trends abstract sediments in halifax harbour have accumulated contaminant metals hg cu zn and pb as a result of discharge of untreated sewage and industrial waste leaching of land fill waste and surface drainage concentrations of contaminants in210pb dated sediment cores became significant about 1880 and rose rapidly after 1900 reaching maximum concentrations in the decades between 1950 and 1980 mean concentrations of hg increased from 0 2 g g 1 in pre 1890 sediments to 1 6 g g 1 in the 20th century similar enrichments for cu changed the concentration from 26 to 88 g g 1 for zn from 90 to 250 g g 1 and for pb the increase was from 12 to 206 g g 1 statistical factor analyses of geochemical data have been used to identify 1 primary contaminants directly associated with waste discharge these include total and organic bound forms of cu zn and pb 2 secondary contamination attributed to leaching and modification of primary contaminants include acid labile forms of zn ni and cu 3 diagenetic modification of buried sediments are identified by total and labile forms of mn 4 dispersion of contaminants from land surface drainage are characterized by fine grained aluminosilicates historical trends in the changing dominance of these environmental factors reflect changes in industrial activity urban growth and changes in the use of metals in paints domestic and industrial chemicals and in the combustion of fuels

quartz as a natural luminescence dosimeter abstract luminescence from quartz is commonly used in retrospective dosimetry in particular for the dating of archaeological materials and sediments from the quaternary period the phenomenon of luminescence is related to the interaction of natural radiation with mineral grains by the activation of and subsequent trapping of electrons at defects within the quartz lattice the latent luminescence signal i e the trapped electrons is released when the grains are exposed to stimulation energy in the form of light or heat despite the fact that quartz is most nominally pure sio2 the mineral forms in several different geological settings i e under different pressure and temperature conditions the luminescence emitted from quartz is complex and shows a variety of different components with diverse physical properties this complexity is explained by the variety of defects in quartz that are either intrinsic e g si and o vacancies or related to impurity atoms e g al or ti the concentration of impurity related defects is dependent on the conditions of mineral formation or subsequent alteration experimental data have shown that the luminescence properties of quartz are highly variable with geological source and vary even at a grain to grain level within a sediment as a consequence caution is needed when making any general statements about the luminescence properties of quartz when using luminescence measurements as a dating technique it is necessary to adjust the measurement procedures for each geological provenance furthermore some quartz has luminescence properties that make it problematic or even unsuitable for certain applications these problems can arise from low and changing luminescence sensitivity thermal transfer of trapped electrons thermal instability of the trapped electrons and low saturation dose reviewing the present knowledge reveals that insufficient information is available either to unambiguously link distinctive lattice defects with characteristic luminescence components or even to explain problems observed in application studies by potential dynamics of the defects within the crystal this paper gives some ideas on how future research could utilise innovative analytical tools to identify or map the distribution of lattice defects and how practitioners could relate lattice defects to measured luminescence properties of quartz

investigation of clay mineralogy in a temperate acidic soil of a forest using x ray diffraction profile modeling beyond the his and hiv description abstract the crystal structures as well as the amount of hydroxy interlayered clay minerals resulting from the al hydroxylation process in temperate acidic soil developed in a forest were studied by modeling experimental x ray diffraction xrd patterns the

quantitative geochemical approach to pedogenesis importance of parent material reduction volumetric expansion and eolian influx in lateritization abstract using mass balance techniques we test the prevalent view that laterite genesis is dominated by in situ residual enrichment during chemical weathering of bedrock through calculation of net mass fluxes through the laterite soils in mali west africa we show that residual enrichment by removal of mobile elements with a corresponding increase in bulk porosity and decrease in bulk density contributes only a very minor fraction of the enrichment of al fe si and au instead we demonstrate that the abundance of these elements is due to the influx and accumulation by selective retention of chemically mature detritus of local and foreign origin clearly evident in micromorphological infilling features at the same sample depths that accumulation reaches extreme values we show that volumetric expansion in excess of 200 has occurred locally we infer that these spatially coincidental zones of mass influx of rock forming metals fe al si and also au with dilational hyperstrains result from a mutually reinforcing mechanical interaction between material influx and the effects of subsurface deformational processes such as shrink swell cycles and root growth and decay we propose that with progressive infilling of available connected voids by illuvial microsedimentary deposits of insoluble resistate and neoformed minerals the capacity for the combined skeleton and plasma to remain isovulumetric is exceeded we speculate that the resultant space problem is relieved by upwards expansion towards the overlying free surface continued translocation and void infilling occur and are limited to the depth where the size of translocational particles is smaller than that of the connected voids consequently progressive hyperstrains accumulate above this critical depth by the long term influence of a proposed translocational wedge of chemically resistant minerals against which numerous generations of plant roots have exerted stresses eclectic surficial contaminants involved are continuously derived from above leaving no indication of a relict source region within the present soil profile from which they might have been extracted instead the source region is largely the existing regolith column itself which releases local material and in addition is supplemented by deposition of colluvial detritus shed nearby by escarpment retreat

the oldest managed aquifer recharge system in europe new insights from the espino recharge channel sierra nevada southern spain abstract in sierra nevada southern spain the highest mountain range in southern europe the application of an ancestral integrated water resources management system iwrm based on the conjunctive use of groundwater and surface water provides water resources for irrigation and supply in the driest months of the year in this semiarid mountain region meltwater is derived from the headwaters of the mountain streams and rivers through a set of uncoated channels excavated in the ground locally known as acequias de careo to infiltrate at the upper part of the valleys water infiltrated along the acequias de careo slowly flows down the hillsides through the weathered zone of the hard rock aquifer and the glacial and periglacial sediments the recharge accomplished through this managed aquifer recharge technique mar activates numerous springs located halfway down the hillside and increases the base flow of the rivers in this study focused on a careo channel located on the southern slope of sierra nevada called acequia de el espino different archaeological sedimentological geophysical and hydrogeological techniques are applied to determine the age and the efficiency of this ancestral example of a mar and iwrm system results suggest that the acequias de careo may be the oldest mar system in europe and that this mar technique could be applied in other high mountain alpine watersheds to mitigate the effects of climate change

weathering rates as a function of climate results from a climosequence of the val genova trentino italian alps a soil sequence in northern italy along an elevational gradient ranging from moderate 950 m a s l to high alpine 2440 m a s l climate zones was investigated with respect to element losses ca mg k na fe al si mn and the development of clay minerals element losses were derived from mass balance calculations that are based on enrichment depletion factors using immobile element contents ti mass balance calculations indicated that extensive mineral weathering resulted in significant leaching losses of major base cations with losses up to 80 of the initial content in the parent material al particularly from upper horizons and si element denudation was greatest in subalpine forests near the timberline weathering rates decreased with both higher and lower altitudes the pattern of smectite distribution along the climosequence has strong similarities to the al si na and k losses while an inverse trend could be detected for clay minerals with a high amount of interlayered al highest smectite contents with up to 30 of the clay fraction and also highest weathering rates were found at sites in subalpine forest near the timberline higher precipitation rates and the production of chelating compounds in the soil are believed to promote the appearance of smectites weathering rates of na and k were additionally modelled as a function of precipitation and temperature the relationship between climate and element weathering is strongly nonlinear and is thought to be overshadowed by the pronounced podzolisation effect near the timberline

pervasive autocorrelation of the chemical index of alteration in sedimentary profiles and its palaeoenvironmental implications the chemical index of alteration has been used widely for reconstruction of the palaeoclimate however the mechanisms and environmental factors controlling the chemical index of alteration of sediments are not yet fully understood in this study autocorrelations of the chemical index of alteration in nine sedimentary profiles from both the land and the sea spanning different geological times are discussed the sediments of these profiles have different origins dust fluvial or ocean sediments and are from various climate situations and sedimentary environments autocorrelations of chemical index of alteration series are ubiquitously evident in all profiles it is suggested here that autocorrelations may be caused by post depositional changes such as persistent weathering and diagenesis as a result the chemical index of alteration may not reflect climatic conditions during the time of sediment deposition this study strongly recommends the confirmation of the reliability and veracity of the chemical index of alteration before it is adopted to evaluate the weathering degree of parent rocks and to reconstruct the past climate significant autocorrelations in loess profiles were specifically observed suggesting that the existing understanding of loess deposition in terms of climate conditions requires re examination and that previous reconstructions of rapid climate changes for example in centennial millennial scales should be treated with caution

mass fluxes and clay mineral formation in soils developed on slope deposits of the kowarski grzbiet karkonosze mountains czech republic poland abstract weathering mineral formation and transformation processes along slopes are complex in cool mountainous regions undisturbed soil development with a strong vertical leaching element may abruptly change as a result of erosion accumulation lateral water fluxes and aeolian input we investigated soils in the eastern karkonosze mountains that have developed on silicatic slope deposits to date illite vermiculite and chlorite are the minerals that have been detected in the clay fraction although the climate and parent material should be favourable for the formation of smectites expandable phases were not verified so far we investigated if expandable phases could be detected and how they related to elemental fluxes along a short slope sequence 1142 1268 m a s l on the border between the czech republic and poland mass balance calculations indicated intensive mineral weathering together with a significant leaching of mg al ca and mn on the shoulder and foot slope positions in the middle zone which has a concave or undulating surface shape however the mass balances of several elements na k al p revealed a less pronounced leaching corresponding to a lower degree of podsolization and in some cases even accumulation at all sites mass balance calculations and detected soil minerals e g the increase in illite towards the surface together with an increase in al and k indicate some aeolian input kaolinite was detected in all soil horizons its concentration slightly increased towards the soil surface together with the pronounced leaching of ca part of kaolinite originates from plagioclase weathering besides being a weathering product of primary minerals part of the kaolinite is inherited from the parent material and probably is also due to aeolian input in all soils illite was being transformed into vermiculite and smectites through regularly interstratified illite smectite phases in addition the content of chloritic components which increases with depth indicated their concurrent weathering and transformation into smectites amphibole also may have acted as a source of smectites not all smectite is being actively formed in the soil most likely due to slope processes cover beds that affected even the subsoil some smectite has been transferred along the slope part of the smectite also seems to derive from the parent material active formation of expandable clay minerals is related to convex and planar landscape forms this relationship suggests intense element leaching inheritance from the parent material and cover bed mixing processes have contributed to the presence of smectite along the slope zones with predominant vertical transport shoulder foot slopes may repeatedly be interchanged with zones dominated by lateral transport undulating slope concave forms

ancient maya impacts on the earth s surface an early anthropocene analog abstract the measure of the mayacene a microcosm of the early anthropocene that occurred from c 3000 to 1000 bp comes from multiple late quaternary paleoenvironmental records we synthesized the evidence for maya impacts on climate vegetation hydrology and the lithosphere from studies of soils lakes floodplains wetlands and other ecosystems maya civilization had likely altered local to regional ecosystems and hydrology by the preclassic period 3000 1700 bp but these impacts waned by 1000 bp they altered ecosystems with vast urban and rural infrastructure that included thousands of reservoirs wetland fields and canals terraces field ridges and temples although there is abundant evidence that indicates the maya altered their forests even at the large urban complex of tikal as much as 40 of the forest remained intact through the classic period existing forests are still influenced by ancient maya forest gardening particularly by the large expanses of ancient stone structures terraces and wetland fields that form their substrates a few studies suggest deforestation and other land uses probably also warmed and dried regional climate by the classic period 1700 1100 bp a much larger body of research documents the maya impacts on hydrology in the form of dams reservoirs canals eroded soils and urban design for runoff another metric of the mayacene are paleosols which contain chemical evidence for human occupation revealed by high phosphorus concentrations and carbon isotope ratios of c 4 species like maize in the c 3 dominated tropical forest ecosystem paleosol sequences exhibit maya clays a facies that reflects a glut of rapidly eroded sediments that overlie pre maya paleosols this stratigraphy is conspicuous in many dated soil profiles and marks the large scale maya transformation of the landscape in the preclassic and classic periods some of these also have increased phosphorous and carbon isotope evidence of c 4 species we synthesize and provide new evidence of maya period soil strata that show elevated carbon isotope ratios 13 c indicating the presence of c 4 species in typical agricultural sites this is often the case in ancient maya wetland systems which also have abundant evidence for the presence of several other economic plant species the mayacene of c 3000 to 1000 bp was thus a patchwork of cities villages roads urban heat islands intensive and extensive farmsteads forests and orchards today forests and wetlands cover much of the maya area but like so many places these are now under the onslaught of the deforestation draining and plowing of the present anthropocene

from a black to a gray box a mass balance interpretation of pedogenesis we utilize chemical elements as tracers in a mass balance analysis that provides functional relationships among soil chemical composition bulk density and volume change in relation to parent material these analytical functions are based on the principle of conservation of mass and include a term quantifying mass flux into out of the soil and between horizons we apply the technique to the oldest member of a chronosequence developed on marine terraces in northern california it is an alfisol that evolved from beach sand to its present state nearly one third of its weight is composed of secondary clay minerals in about 240 ky aside from large increases in organic carbon desilication is the dominant factor in soil evolution 29 50 83 g cm 2 si was leached from the beach sand during pedogenesis the rate of desilication is roughly 2 1 t km 2 yr 1 0 21 g cm 2 ky 1 an order of magnitude slower than that implied by the si denudation rate calculated for the mattole river watershed weathering of primary minerals and synthesis of secondary minerals is relatively well advanced suggesting that the rate of desilication may be declining the local beach is composed of quartz and sodic plagioclase with smaller amounts of chlorite mica and kaolinite the soil has substantially different mineralogy sand is dominated by quartz and clay is dominated by kaolinite halloysite chloritic intergrades and gibbsite bases are also leached though the total mass was much less 57 2 55 g cm 2 of na in the beach sand was lost as plagioclase weathered by focusing on elemental and mineralogical gains and losses we emphasize the essential connection between the pedologic environment and the external hydrochemical environment

mass balance of soil evolution on late quaternary marine terraces in coastal oregon mass balance analysis was used to quantify elemental losses gains and transformations for a soil chronosequence developed on elevated marine terraces in south coastal oregon the four soils analyzed in the study range in age from 80 ka to greater than 250 ka and are inceptisols spodosols and ultisols dominant soil forming processes include 1 desilication and loss of base cations from the solum 2 redistribution of iron and aluminum from surface to subsurface horizons 3 transformation of iron and aluminum from sand and silt size fractions to secondary clay and crystalline sesquioxide fractions and 4 accumulation of organic matter silica represents the largest mass loss of any element from the system and varies from 6 48 g cm2 11 loss from solum compared to original amount of si in parent material to 42 99 g cm2 22 with increasing terrace age losses of silica from the sand size fraction over time 2 to 17 are accompanied by increases of silica in the clay size fraction base cations represent only a small portion of the soil mass but up to 53 0 09 g cm2 of the sodium present in the parent material is lost due to weathering and leaching iron and aluminum are redistributed within the sola of younger terraces during podzolization but are lost from the older soils due to intense weathering and leaching over time the majority of iron is transformed from the sand and silt size fractions to the crystalline sesquioxide fraction in contrast the majority of aluminum lost from the sand and silt size fractions is transformed to the clay size fraction

effect of north and south exposure on weathering rates and clay mineral formation in alpine soils abstract a comparison was made between two soil climosequences on north and south facing slopes in northern italy to determine the influence of slope aspect on soil processes the climosequences span an elevational gradient ranging from moderate 1200 m a s l to high alpine 2420 m a s l climate zones on surfaces having an age of about 15 000 years the soils were investigated with respect to organic c oxalate and dithionite extractable fe al and si elemental losses ca mg k na fe al si mn and clay minerals the stocks of soil org c as well as of oxalate extractable fe and al was greatest in the subalpine zone near the timberline there are no clear differences in organic c content between the soils on north and south facing sites fe oxalate and to a lesser extent alo stocks were however greater on north facing sites indicating that weathering is greater there eluviation and illuviation of al and fe within the soil profile typical for podzolisation was more distinctly expressed on the n slopes the probability of itm imogolite type material formation in the soil seemed to be greater on south facing sites on the north facing sites element leaching was most intense in the subalpine zone close to the timberline while on the south facing sites this was only the case for the base cations the n slopes exhibited higher leaching of elements which generally indicates a higher weathering intensity on south facing sites typical podzolisation processes were measurable only above 2000 m a s l the development of smectites is also a reflection of the weathering intensity smectite was discernible in the surface horizon at all sites on n slopes but the highest amount was detected in the sub alpine climate zone for the south facing sites only in the alpine climate zone could smectite be detected higher temperatures and an increased number of freeze thaw cycles on south facing slopes should theoretically enhance rates of chemical weathering this could however not be confirmed with our measurements the degree of chemical weathering increases from the south to the north facing sites that are characterised by lower temperatures lower evapotranspiration and consequently by a higher humidity although precipitation in alpine regions is abundant the availability and flux of water through the soil is the prime factor in weathering intensity

thermomechanical stress strain numerical modelling of deglaciation since the last glacial maximum in the adamello group rhaetian alps italy abstract deglaciated areas in the valleys of the italian alps have recently exhibited a high potential for geomorphologic hazards from diffuse deep seated gravitational deformations dsgsds caused by rock mass creep processes that can evolve into rock falls and rock avalanches a multidisciplinary approach that integrated geomorphologic surveys and stress strain numerical simulations was used to investigate the effects of the stress release that was induced by the last glacial maximum lgm in the adame valley italian alps no evidence of dsgsds has been found in this area however data are available to develop a well constrained evolutionary model of the valley deglaciation the extent and thickness of the southern extension of the adamello glacier the widest glacier in italy during its primary growth phases including those of the lgm three late glacial stages and the little ice age lia were reconstructed using glacial geological surveys and were reproduced using a finite difference stress strain sequential model spanning from the lgm to the present a thermomechanical numerical configuration was developed based on geomechanical field measurements that were collected from rock outcrops and data from laboratory tests specifically performed on intact rock samples the numerical simulations demonstrate that thermomechanical viscous behaviour cannot be neglected because the resulting strains on the slopes are significantly higher than those resulting from conventional elastoplastic behaviour the last major thermal effect in the rock masses reproduced using the model occurred from 11 5 ka until the lia the resulting displacement rates are as much as several tens of mm ka which are consistent with the absence of dsgsds in the adame valley as these rates are significantly lower than those previously obtained from dsgsds and other large landslides in the alps based on thermomechanical numerical solutions these rates should persist for the next 1000 years assuming that no variations in current climatic conditions occur

soil formation and weathering in a permafrost environment of the swiss alps a multi parameter and non steady state approach spatially discontinuous permafrost conditions frequently occur in the european alps how soils under such conditions have evolved and how they may react to climate warming is largely unknown this study focuses on the comparison of nearby soils that are characterised by the presence or absence of permafrost active layer thickness 2 3 m in the alpine tundra and subalpine forest range of the eastern swiss alps using a multi method geochemical and mineralogical approach moreover a new non steady state concept was applied to determine rates of chemical weathering soil erosion soil formation soil denudation and soil production long term chemical weathering rates soil formation and erosion rates were assessed by using immobile elements fine earth stocks and meteoric 10be in addition the weathering index k ca ti the amount of fe and al oxyhydroxides and clay minerals characteristics were considered all methods indicated that the differences between permafrost affected and non permafrost affected soils were small furthermore the soils did not uniformly differ in their weathering behaviour a tendency towards less intense weathering in soils that were affected by permafrost was noted at most sites weathering rates the proportion of oxyhydroxides and the weathering stage of clay minerals were lower in permafrost soils in part erosion rates were higher at the permafrost sites and accounted for 79 97 of the denudation rates in general soil formation rates 8 8 86 7 t km2 y were in the expected range for alpine soils independent of permafrost conditions it seems that the local microenvironment particularly vegetation and subsequently soil organic matter has strongly influenced denudation rates as the climate has varied since the beginning of soil evolution the conditions for soil formation and weathering were not stable over time soil evolution in high alpine settings is complex owing to among others spatio temporal variations of permafrost conditions and thus climate this makes predictions of future behaviour very difficult this article is protected by copyright all rights reserved

discriminating between background and mine impacted groundwater at the phoenix mine nevada usa abstract differentiating between mineralized and non mineralized background groundwater chemistry at a mine site can be challenging if there is an overprint of past and or current mining on naturally mineralized conditions at the phoenix mine in the copper canyon mining district of nevada quantile quantile h so4 plots were used to segregate four wells clearly impacted by historical mining activity the mineralogy of rock at the elevation of the well screen interval was used to partition the 53 remaining wells into mineralized and non mineralized populations for each class groundwater chemistry was examined to identify if so4 and h trends were stable unimpacted or increasing impacted then each well was mapped as one of four resulting groundwater types across the mine site defining the spatial extent of the different groups several groundwater regions were identified a group of mineralized mine impacted wells type ii are located in philadelphia canyon adjacent to the cu leach facility with the anthropogenically impacted area bounded by several hydrologically downgradient mineralized unimpacted wells type i to the south and east there is a set of non mineralized impacted wells type iii downgradient from the tailings pond facility where a historical release of so4 is apparent in the well record however in some downgradient wells the tailings pond pump back mitigation system has resulted in recovery of the groundwater quality to a non mineralized background condition finally in the vicinity of the reona heap leach pad there is a group of non mineralized unimpacted wells type iv not surprisingly most mineralized wells types i and ii are located in or near mined areas while non mineralized wells types iii and iv tend to be in the southern portion of the facility in the alluvia of buffalo and reese river valleys once the well population was categorized phx f was identified with extremely mineralized background groundwater ph 3 8 so4 4600 mg l as 0 056 mg l cu 72 mg l zn 61 mg l which required further analysis the elevation of the phx f screen interval had up to 5 jarosite with mineralized fracture zones mapping directly to cavities in the adjacent iron canyon mine that originally contained a saturated ferrous sulfate solution explaining the anomalous chemistry in this well this study demonstrates that an empirical approach using mining history deposit geology hydrogeology well screen elevation mineralogy groundwater chemistry trends statistical analysis and geochemical modeling provides a technique to distinguish among different classes of groundwater at the operating phoenix mine site such an approach or a derivative may prove useful at other mines with different mineralogies and hydrogeologic settings

decoding potential effects of climate and vegetation change on mineral weathering in alpine soils an experimental study in the wind river range wyoming usa abstract climate change and a related increase in temperature particularly in alpine areas force both flora and fauna to adapt to the new conditions these changes should in turn affect soil formation processes the aim of this study was to identify possible consequences for soils in a dry alpine region with respect to weathering of primary minerals and leaching of elements under expected vegetation and climate changes to achieve this a field empirical approach investigating an altitudinal sequence was used in combination with laboratory weathering experiments simulating several scenarios the study sites are located in sinks canyon and stough basin of the wind river range wyoming usa the following sites from moist to dry with increasing temperature along the sequence were investigated 10 soil profiles typic haplocryoll in a tundra ecotone 10 soil profiles ustic haplocryoll in a pine fir forest and 20 soil profiles ustic argicryoll in sagebrush all soils developed on granitoid moraines soil mineralogy was analysed using cathodoluminescence and x ray diffraction this revealed that biotite and plagioclase were both weathered to smectite while plagioclase also weathered to kaolinite cooler wetter altitude dependent conditions promoted weathering of primary minerals furthermore the soils of the tundra and forest zone exhibited a higher acidity and more organic carbon in a series of wet laboratory batch experiments materials from topsoils a horizons and subsoils b horizons in each ecotone were examined alone or in combination with other samples in a first step aqueous extracts of the topsoil samples were generated in batch reactors and analysed for the main ions in a second and a third step the topsoil extracts were reacted with the subsoil samples of the same ecotone and with the subsoil samples of the ecotones at higher altitude the total duration of these batch experiments was 1800 h and the solutes were measured using icp oes and ion chromatography dissolved ca mg and k were mainly controlled by the chemical weathering of oligoclase k feldspar and biotite with increasing altitude the total concentrations of ca mg and k in the aqueous extracts decreased the relative ionic contribution from k decreased while the ionic contribution from ca increased climate change warming changed precipitation potentially will reduce weathering intensity soil acidity and the content of organic carbon an altitudinal shift in vegetation due to climate change seems to affect the ionic composition of the soil solution in the case of a shift from forest to sagebrush and tundra to forest or sagebrush the relative contribution from k would increase at the expense of ca we hypothesise that k will play an important role in future biogeochemical cycles under the assumptions of climate warming and subsequent vegetation shifts to higher altitudes

weathering rates and carbon storage along a climosequence of soils developed from contrasting granites in northeast brazil abstract i and s type granites comprise large areas and play a key role in global soil weathering patterns i type granites are originated from melting of igneous source rocks whereas s type granites result from melting of sedimentary sources this gives rise to differences in mineralogical and geochemical characteristics of the rocks the objective of this study was to address the effect of petrology and mineralogy of i and s type granites on weathering pedogenesis and total organic carbon stocks across a climosequence significant differences in morphological physical and chemical properties of soils derived from i and s type granites were observed and directly linked to petrological mineralogical and geochemical signatures of the underlying granites e g presence of more mafic minerals in the i type granite and therefore a higher clay and iron content in their derived soils in addition this higher iron content favored the hematite pathway and thus the red soil development despite the influence of the climate on weathering patterns i e higher soil development in humid areas parent material seems to play a decisive role in determining soils characteristics in the studied area the type of parent material also governed the rates of carbon accumulation in soils i type granites originated soils with higher toc stocks than soil profiles developed from s type granites this carbon accumulation is mainly due to soil chemical and physical characteristics driven by the type of granite notably soil fertility and clay content