soil weathering and accumulation rates of oxalate extractable phases derived from alpine chronosequences of up to 1 ma in age abstract in this study we compare newly developed chemical weathering data with previously published data from soils developed along two chronosequences of glacial deposits in the european alps and the rocky mountains wind river range usa by combining these chronosequences we are able to present a comprehensive dataset that represents a time period of 1 ma we describe weathering trends of important elements using a number of weathering indices e g k ca ti ratio the weathering index b of kronberg and nesbitt 1981 and the open mass transport function further we describe the accumulation of al fe si and mn oxyhydroxides including partially organic phases as a function of time and derive the corresponding accumulation rates we calculated pedogenetically formed oxyhydroxides using an approach based on immobile elements our study represents one of only a few studies that describe rates of soil chemical weathering over a period as long as 1 ma results show that rates of chemical weathering clearly decrease along the chronosequences with increasing age of the soils we find weathering rates are nearly four orders of magnitude lower in the 1 ma old soils than in the young soils our results suggest that the older soils may be reaching a steady state for these chemical properties in their present environments a power function best explains the measured time trends of the index b and k ca ti ratios in the soils the best time trend model for pedogenic weakly to poorly crystalline phases and the relative losses gains based on the open system mass transport function were obtained with an exponential decay model function in terms of the soil system the decreases in the accumulation rate of the oxyhydroxides appears to be influenced not only by the factor of time but by climate as well increased precipitation at higher altitudes slows the decrease in weathering rate over time thus our 1 ma chronosequences also become pedogenic gradients since we describe variations in soil properties along biogenic gradients

weathering and the mobility of phosphorus in the catchments and forefields of the rhone and oberaar glaciers central switzerland implications for the global phosphorus cycle on glacial interglacial timescales abstract in this study we evaluate the dynamics of the biophile element phosphorus p in the catchment and proglacial areas of the rhone and oberaar glaciers central switzerland we analysed erosion and dissolution rates of p containing minerals in the subglacial environment by sampling water and suspended sediment in glacier outlets during three ablation and two accumulation seasons we also quantified biogeochemical weathering rates of detrital p in proglacial sedimentary deposits using two chronosequences of samples of fresh suspended material obtained from the oberaar and rhone water outlets little ice age lia moraines and younger dryas yd tills in each catchment subglacial p weathering is mainly a physical process and detrital p represents more than 99 of the precipitation corrected total p denudation flux 234 and 540 kg km 2 yr 1 for the rhone and oberaar catchments respectively the calculated detrital p flux rates are three to almost five times higher than the world average flux the precipitation corrected soluble reactive p srp flux corresponds to 1 88 1 99 kg km 2 yr 1 rhone and 2 12 2 44 kg km 2 yr 1 oberaar respectively these fluxes are comparable to those of tropical rivers draining transport limited tectonically inactive weathering areas in order to evaluate the efficiency of detrital p weathering in the rhone and oberaar proglacial areas we systematically graded apatite grains extracted from the chronosequence in each catchment relative to weathering induced changes in their surface morphologies grades 1 4 fresh apatite grains are heavily indented and dissolution rounded grade 1 lia grains from two 0 10 cm deep moraine samples show extensive dissolution etching similar to surface grains from the yd profile mean grades 2 7 3 5 and 3 5 respectively in these proglacial deposits the weathering front deepens progressively as a function of time due to biocorrosion in the evolving acidic pedosphere with mechanical indentations on grains acting as sites of preferential dissolution we also measured iron bound organic and detrital p concentrations in the chronosequence and show that organic and iron bound p has almost completely replaced detrital p in the top layers of the yd profiles detrital p weathering rates are calculated as 310 and 280 kg km 2 yr 1 for lia moraines and 10 kg km 2 yr 1 for yd tills during the first 300 years of glacial sediment exposure p dissolution rates are shown to be approximately 70 times higher than the mean global dissolved p flux from ice free continents after 11 6 kyr the flux is 2 5 times the global mean these data strengthen the argument for substantial changes in the global dissolved p flux on glacial interglacial timescales a crude extrapolation from the data described here suggests that the global dissolved p flux may increase by 40 45 during the first few hundred years of a deglaciation phase

erosional and climatic effects on long term chemical weathering rates in granitic landscapes spanning diverse climate regimes abstract we used cosmogenic nuclide and geochemical mass balance methods to measure long term rates of chemical weathering and total denudation in granitic landscapes in diverse climatic regimes our 42 study sites encompass widely varying climatic and erosional regimes with mean annual temperatures ranging from 2 to 25 c average precipitation ranging from 22 to 420 cm year 1 and denudation rates ranging from 23 to 755 t km 2 year 1 long term chemical weathering rates range from 0 to 173 t km 2 year 1 in several cases exceeding the highest granitic weathering rates on record from previous work chemical weathering rates are highest at the sites with rapid denudation rates consistent with strong coupling between rates of chemical weathering and mineral supply from breakdown of rock a simple empirical relationship based on temperature precipitation and long term denudation rates explains 89 95 of the variation in long term weathering rates across our network of sites our analysis shows that for a given precipitation and temperature chemical weathering rates increase proportionally with fresh material supply rates we refer to this as supply limited weathering in which fresh material is chemically depleted to roughly the same degree regardless of its rate of supply from breakdown of rock the temperature sensitivity of chemical weathering rates is two to four times smaller than what one would expect from laboratory measurements of activation energies for feldspar weathering and previous inter comparisons of catchment mass balance data from the field our results suggest that climate change feedbacks between temperature and silicate weathering rates may be weaker than previously thought at least in actively eroding unglaciated terrain similar to our study sites to the extent that chemical weathering rates are supply limited in mountainous landscapes factors that regulate rates of mineral supply from erosion such as tectonic uplift may lead to significant fluctuations in global climate over the long term

10be inventories in alpine soils and their potential for dating land surfaces abstract to exploit natural sedimentary archives and geomorphic landforms it is necessary to date them first landscape evolution of alpine areas is often strongly related to the activities of glaciers in the pleistocene and holocene at sites where no organic matter for radiocarbon dating exists and where suitable boulders for surface exposure dating using in situ produced cosmogenic nuclides are absent dating of soils could give information about the timing of landscape evolution this paper explores the applicability of soil dating using the inventory of meteoric 10be in alpine soils for this purpose a set of 6 soil profiles in the swiss and italian alps was investigated the surface at these sites had already been dated using the radiocarbon technique or the surface exposure determination using in situ produced 10be consequently a direct comparison of the ages of the soils using meteoric 10be and other dating techniques was made possible the estimation of 10be deposition rates is subject to severe limitations and strongly influences the obtained results we tested three scenarios using a the meteoric 10be deposition rates as a function of the annual precipitation rate b a constant 10be input for the central alps and c as b but assuming a pre exposure of the parent material the obtained ages that are based on the 10be inventory in soils and on scenario a for the 10be input agreed reasonably well with the age using surface exposure or radiocarbon dating the ages obtained from soils using scenario b produced ages that were mostly too old whereas the approach using scenario c seemed to yield better results than scenario b erosion calculations can in theory be performed using the 10be inventory and 10be deposition rates an erosion estimation was possible using scenario a and c but not using b the calculated erosion rates using these scenarios seemed to be plausible with values in the range of 0 57 mm ky the dating of soils using 10be has several potential error sources analytical errors as well as errors from other parameters such as bulk soil density and soil skeleton content have to be taken into account the error range was from 8 up to 21 furthermore uncertainties in estimating 10be deposition rates substantially influence the calculated ages relative age estimates and under optimal conditions absolute dating can be carried out age determination of alpine soils using 10be gives another possibility to date surfaces when other methods fail or are not possible at all it is however not straightforward quite laborious and may consequently have some distinct limitations

mineralogical evidence for eolian contribution to soils of late quaternary moraines wind river mountains wyoming usa abstract volcanic heavy minerals are found in the a and b horizons of soils on moraines of the western wind river mountains of wyoming volcanic minerals do not occur in the underlying moraine sediments derived from plutonic and metamorphic bedrock sources of the volcanics are the sedimentary rocks of the green river basin the presence of volcanic minerals in the green river basin and their patterns of distribution in the moraine soils indicate eolian sedimentation is an important factor of soil genesis in this region moraines affected by eolian sediments include the pinedale and temple lake indian basin type localities the presence of eolian sediments in both pinedale and holocene deposits suggests eolian addition is not simply a late glacial phenomenon but continues throughout postglacial time relations between eolian sediments and soil development must be accounted for when comparing soil development on moraine chronosequences in this and possibly all alpine regions of western north america

landscape evolution in val mulix eastern swiss alps soil chemical and mineralogical analyses as age proxies towards the end of the last glacial cycle repeated re advances of valley glaciers in the european alps combined with periglacial processes led to the formation of a variety of climate related landforms independent age measurements of moraines and rock glacier lobes using both in situ produced and meteoric 10be allows for the use of soil formation as an age proxy in this complementary study we present chemical and mineralogical data from five podzols from val mulix in eastern switzerland two of them developed on granitic lateglacial moraines 14 9 ka and 10 7 ka respectively and three were sampled on lobes of a morphostratigraphically connected relict rock glacier covering an age range of approx 10 7 ka to 8 6 ka besides the evaluation of the suitability of selected pedosignatures for a relative age separation we hypothesised that these pedosignatures should give further information about the evolution of the specific sites although the soils had a high skeleton content and the oldest soil started its development in a slightly colder climatic phase typical weathering trends could still be detected whereas weathering indices such as the k ca ti ratio or the b index reflect time trends reasonably well the mineralogical composition of the fine earth and clay fraction yielded a slightly more inconsistent picture to a lesser extent some inconsistencies were also exhibited when using the weathering mass balance approach this is especially true for the relict rock glacier and it supports the suggested complex development history of these soils as well as the presence of pre weathered material techniques that include several surface soil horizons and the soil skeleton such as the k ca ti ratio the b index and the mass balance approach gave more robust results in terms of the expected chronology than the ones that only referred to single horizons clay mineralogy errors or variations due to potential reallocation processes within the soil horizons but without a prominent change of the overall soil characteristics are minimised using such an approach weathering indexes and the clay mineral assemblage provided a differentiation of soils even within a relatively narrow time range and gave insight into processes that have occurred at the specific sites the combined relative numerical dating approach used here not only enables an extended interpretation and mutual control but ultimately leads to a better understanding of landscape reconstruction and evolution

relation between soil age and silicate weathering rates determined from the chemical evolution of a glacial chronosequence long term weathering rates rlt were determined from base cation depletion in soil profiles developed on six granitic glacial moraines varying in age from 0 4 to 297 ka in the wind river mountains wyoming weathering rates were found to decrease with soil age t according to the power law equation rlt 15 t 0 71 where rlt is in meq m 2 yr 1 and t is in ka comparable data from the literature are consistent with this function and it is similar to power law equations describing changes in laboratory weathering rates with time on the basis of our study we predict that for a catchment unaffected by anthropogenic inputs and in a steady state with respect to the organic and cation exchange pools rlt should be higher than present day weathering rates derived from stream fluxes rpd by a factor of about 3 4

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

cosmogenic nuclides and the dating of lateglacial and early holocene glacier variations the alpine perspective abstract based on cosmogenic 10 be data from four sites in the alps we discuss geological uncertainties associated with the dating of former cirque and small valley glacier margins at the early lateglacial gschnitz site trins austria a 3000 yr spread in 10 be exposure ages points to prolonged boulder instability three out of seven ages are not included in the mean age calculation which yielded 15 400 1000 yr indistinguishable from the oldest boulder age of 16 130 1040 yr as a result of the distinctive morphology at julier pass switzerland site we are able to exposure date the early 12 300 1300 yr and the late 11 300 600 yr egesen stadial glacier advances younger dryas equivalent not just final retreat at the kromer site austria 10 be exposure ages from five clast supported boulders are indistinguishable within the analytical uncertainties mean age 8400 500 yr in addition to moraine age key factors that may lead to too young ages include degree of matrix vs clast support of the boulders post depositional periglacial activity and tree coverage at the nagelisgratli bedrock site near grimsel pass switzerland exposure ages of 10 760 11 720 yr are consistent with early holocene cirque glacier retreat and underline the marked lack of nuclide inheritance in bedrock exposures in the alps

fast but spatially scattered smectite formation in the proglacial area morteratsch an evaluation using gis proglacial areas in the alps usually cover a time span of deglaciation of about 150 years time since the end of the little ice age in the 1850s in these proglacial areas soils have started to develop due to the continuous retreat of the morteratsch glacier swiss alps the corresponding proglacial area offers a continuous time sequence from 0 to 150 year old surfaces furthermore an optimal digital dataset about the development of vegetation and soils is available for this area the soils have been developing on glacial till having a granitoidic character we investigated the clay mineral assemblage at 35 sites within the glacier forefield smectite can be used as a proxy for weathering intensity in these environments in the proglacial area the smectite concentration in the topsoil steadily increased with time of weathering however this development displayed a strongly scattered trend the complex interplay of biological physical and chemical processes in pedogenesis and clay mineral evolution limits our ability to predict and interpret landscape dynamics we consequently tried to analyse the role of topographic and vegetation modifications on the smectite content sites not or only slightly prone to erosion flattening slope ridge steepening slope ridge or flat morphology promoted the formation of smectite in addition the texture of the soil material influenced soil moisture and hence the degree of weathering and the development of vegetation although vegetation is not a fully independent factor because it is interrelated to the surrounding environmental conditions it seemed to exert its influence on weathering and consequently the formation of smectite green alder stands and grass heath where moister soils develop that have a finer texture or where more organic acids are produced were correlated with a higher smectite content humus forms serve as a proxy for the soil biota and soil organic matter composition at sites having a eumoder and a higher soil organic matter content the smectite concentration was elevated at these sites the production of chelating compounds or organic acids in the soil is believed to promote the development of smectites via an intermediate stage of hydroxy interlayered minerals and the subsequent removal of the hydroxide polymers in this work we have demonstrated that the topographic signature and the effect of vegetation on the formation of smectite and consequent weathering are pervasive our results will serve as a basis for further spatio temporal modelling

dynamic pedogenesis new views on some key soil concepts and a model for interpreting quaternary soils abstract inasmuch as soils are open systems and rarely if ever achieve equilibrium with their environments it is philosophically sound to view all soils as expressing varying levels of polygenesis as that term has been redefined soil genesis and resultant morphology may then be viewed in a comprehensive framework of soil evolution that consists of two linked pathways one developmental and the other regressive that reflect interactions of both exogenous and endogenous vectors vectors are factors processes and conditions of pedogenesis following this philosophy a model of pedogenesis is framed in an evolutional paradigm that emphasizes the integrated effects of dynamic and passive pedogenic vectors in directing pathways and in controlling rates of soil genesis through time the dynamic vectors include energy and mass fluxes frequencies of soil wetting and drying water table dynamics organisms feedback processes and pedoturbation the passive vectors include parent materials soil chemical environment stability of geomorphic surfaces and various evolved soil properties and conditions accessions both sets of vectors vary spatially and the dynamic vectors more so than passive vectors fluctuate through time the model is expressed as s f d p dd dt dd dt where s is the state of the soil or degree of profile evolution d is the set of dynamic vectors p is the set of passive vectors and dd dt and dp dt denote change through time t the model helps explain the apparent minimal development and regressed character of some old soils and the rapid and strong development of some young ones

biogeochemical weathering in sedimentary chronosequences of the rhone and oberaar glaciers swiss alps rates and mechanisms of biotite weathering abstract we analysed the composition of phyllosilicate minerals in sediments deposited by the rhone and oberaar glaciers swiss alps in order to identify processes and rates of biogeochemical weathering in relation to glacial erosion the investigated sediments are part of chronosequences consisting of a suspended fresh sediment in melt water b terminal moraines from the little ice age lia approximately 1560 1850 and c tills of the younger dryas interval yd approximately 11 500y bp secondary weathering products associated with the suspended sediment have not been observed we therefore exclude intermittent subglacial storage and weathering of this material and assume that the suspended sediment is directly derived from mechanically abraded bedrock this implies that biogeochemical weathering processes started once the glacially derived sediment was deposited in the proglacial area the combination of a developing vegetation cover the generally high permeability allowing the percolation of precipitation and the chemical reactivity related to the dominance of fine grained material biotite weathering rates are calculated using the difference in the biotite content between unweathered and weathered glacial sediments within the investigated profiles the reactive mineral surface area is estimated geometrically both with regards to the total relative surface wr t as well as to the relative edge surface wr e wr t biotite weathering rates are estimated as 10 13 10 15 mol biotite m 2 biotite s 1 wr e biotite weathering rates are on the order of 10 13 10 14 mol biotite m 2 biotite s 1 biotite weathering rates obtained by this study are in the order of one magnitude higher in comparison to other published field based weathering rates using biotite as an indicator we therefore suggest that glacially derived material in the area of the oberaar and rhone glaciers is generally subjected to enhanced biogeochemical weathering starting immediately after deposition in the proglacial zone and subsequently continuing for thousands of years after glacier retreat

clay minerals oxyhydroxide formation element leaching and humus development in volcanic soils a weathering sequence with soils developing on volcanic trachy basaltic parent materials with ages ranging from 100 115 000 years in the etna region served as the basis to analyse and calculate the accumulation and stabilisation mechanisms of soil organic matter som the transformation of pedogenic fe and al the formation and transformation of clay minerals the weathering indices and by means of mass balance calculations net losses of the main elements although the soils were influenced by ash depositions during their development and the soil on the oldest lava flow developed to a great extent under a different climate leaching of elements and mineral formation and transformation could still be measured leaching of major base cations coupled with a corresponding passive enrichment of al or fe was a main weathering mechanism and was especially pronounced in the early stages of soil formation due to mineral or glass weathering with time the weathering indexes such as the k ca ti ratio tend to an asymptotic value chemical and mineralogical changes between 15 000 and 115 000 years in the a and b horizons were small in contrast to this the accumulation of newly formed itm imogolite type materials and ferrihydrite showed a rather linear behaviour with time weathering consisted of the dissolution of primary minerals such as plagioclase pyroxenes or olivine the breakdown of volcanic glass and the formation of secondary minerals such as itm and ferrihydrite the main mineral transformations were volcanic glass imogolite kaolinite clay fraction in the most weathered horizons a very small amount of 2 1 clay minerals could be found that were probably liberated from the inner part of volcanic glass debris the rate of formation and transformation of 2 1 clay minerals in the investigated soils was very low no major changes could be observed even after 115 000 years of soil evolution this can be explained by the addition of ash and the too low precipitation rates in general soil erosion played a subordinate role except possibly for the oldest soils 115 000 years the youngest soils with an age 2000 years had the highest accumulation rate of organic c about 3 0 g c m2 year after about 15 000 years the accumulation rate of organic c in the soils tended to zero soil organic carbon reached an asymptotic value with abundances close to 20 kg m2 after about 20 000 years in general the preservation and stabilisation of som were due to poorly crystalline al and fe phases pyrophosphate extractable kaolinite and the clay content these parameters correlated well with the organic c imogolite type material did not contribute significantly to the stabilisation of soil organic matter

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

pedogenic gradients for iron and aluminum accumulation and phosphorus depletion in arctic and alpine soils as a function of time and climate pedogenically significant chemical extracts of iron aluminum and phosphorus are related mainly to time in chronosequences from baffin island canadian arctic the alpine sierra nevada and wind river range western united states the alpine khumbu glacier area himalaya nepal and the alpine southern alps new zealand based on the accumulation index for fe and al and the depletion index for p in each region the following ranking of chemical pedogenic development is obtained southern alps khumbu glacier area wind river range sierra nevada coastal baffin island inland baffin island the ranking mainly follows regional climate with the greatest accumulation and depletion to the warmest and wettest environment and the least accumulation and depletion in the coldest and driest environment

chemical weathering mass loss and dust inputs across a climate by time matrix in the hawaiian islands we determined the total mass loss and rate of chemical weathering from three minimally eroded hawaiian lava flows that are 10 170 and 350 ka old using a backhoe we sampled the entire weathering zone at 28 sites and measured the depletion or enrichment of each major element in each soil horizon relative to parent material we were able to assess the influence of both climate and substrate age on chemical weathering because each flow crosses a precipitation gradient from 600 to 2500 mm yr 1 mass loss rates were highest for the 0 10 ka interval under the wettest climatic conditions 54 t km 2 yr 1 and decreased to near zero in the wet sites during the 10 170 and 170 350 ka intervals not surprisingly weathering rates were lower in drier sites 24 t km 2 yr 1 from 0 10 ka to b 2tk m 2 yr 1 thereafter however the effects of precipitation were non linear there was a precipitation threshold below which mass loss was relatively small and above which mass loss was substantial but insensitive to increased rainfall chemical weathering rates depend on tectonic uplift erosion climate rock type or some combination thereof by working on stable uneroded surfaces of a single rock type across a well constrained precipitation gradient we were able to identify another potential driver the rate of dust deposition although hawai i is one of the least dusty places in the northern hemisphere dust inputs reached 82 of the total mass loss from the weathering zone at some sites and averaged 30 on the 170 ka flow this highlights the potential importance of dust as a component of observed weathering fluxes from catchments worldwide

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

soil development on marine terraces near metaponto gulf of taranto southern italy abstract for decades the marine terraces in the metaponto area have been the subject of discussions concerning their number sedimentology genesis and age this paper contributes to landscape history reconstruction from a pedogenetic view the marine terraces are generally covered by loamy sediments which have been interpreted in previous works as lagoonal and or alluvial sediments deposited shortly after the emergence of the land surface above sea level pedogenetic investigation including field observations e g soil colour intensity of weathering precipitation of secondary carbonates and fed fet ratio silt clay ratio and carbonate content reveals that the usual sedimentation history on the terraces includes a period of soil formation between the deposition of the marine and that of the alluvial sediments most likely soil formation began after the relative sea level maximum within the same interglacial during which the marine terrace formed later alluvial sediments accumulated during a time of periodic flooding while soil development in the underlying marine sediments probably continued at reduced rates one central question of this study is whether soil formation indicates progressive ages of the terraces the complex landscape history involving several sedimentation and erosion phases makes the correlation of soil development stages with terrace ages difficult nevertheless maximum fed fet ratios and ca mg k na al ratios of the soils developed in the different sediments plotted vs assumed terrace age indicate increasing soil development the relationship between fed fet ratios and terrace age can be best described by power r2 0 89 or logarithmic functions r2 0 72 both describing a strong increase in pedogenic iron in the first 100 ka which slows down afterwards ca mg k na al ratios follow a logarithmic decrease with time r2 0 99 indicating progressive silicate weathering associated with element release and leaching

biogeochemistry of glacial landscape systems abstractglaciers affect biogeochemistry of landscapes through their sediments glacial erosion rates are high and the sediments produced are distinctively fine grained hence glaciers can be thought of as producers of mineral surface area although this mineral surface area is highly reactive temperature limits chemical weathering fluxes from glaciers and their surroundings more significant effects may be associated with silt deposited in loess and on continental margins thick deposits in both settings contribute to carbon cycling through both silicate weathering and organic carbon burial the impact of glaciers on biogeochemical cycles will be long lasting as the legacy of glacial erosion processes continues as long as sediment yields are elevated

lunar impact basins stratigraphy sequence and ages from superposed impact crater populations measured from lunar orbiter laser altimeter lola data 1 impact basin formation is a fundamental process in the evolution of the moon and records the history of impactors in the early solar system in order to assess the stratigraphy sequence and ages of impact basins and the impactor population as a function of time we have used topography from the lunar orbiter laser altimeter lola on the lunar reconnaissance orbiter lro to measure the superposed impact crater size frequency distributions for 30 lunar basins d 300 km these data generally support the widely used wilhelms sequence of lunar basins although we find significantly higher densities of superposed craters on many lunar basins than derived by wilhelms 50 higher densities our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains the transition from a lunar impact flux dominated by population 1 to population 2 occurred before the mid nectarian this is before the end of the period of rapid cratering and potentially before the end of the hypothesized late heavy bombardment lola derived crater densities also suggest that many pre nectarian basins such as south pole aitken have been cratered to saturation equilibrium finally both crater counts and stratigraphic observations based on lola data are applicable to specific basin stratigraphic problems of interest for example using these data we suggest that serenitatis is older than nectaris and humboldtianum is younger than crisium sample return missions to specific basins can anchor these measurements to a pre imbrian absolute chronology

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

distribution of some selected major and trace elements in four italian soils developed from the deposits of the gauro and vico volcanoes the vertical distribution of 21 elements k ca ti fe mn cr ni cu zn ga as se br rb sr y zr pb th u hg in four italian soils derived from volcanic materials has been investigated most of the elements and in particular lithogenic ones show little enrichment depletion indicating a low degree of weathering and a great similarity to the parent material in relative terms the degree of soil evolution horizon expression and weathering and the depletion of the more mobile elements k ca and sr seem to increase with increasing rainfall and soil age discontinuities in the soil profile due to the accretion of new volcanic material are detectable from the geochemical composition of the horizons some metallic elements such as hg pb cu mn and zn show enrichment in the organic rich horizons o and a but the intensity of enrichment suggests that besides biocycling and weathering processes human activity soil management fertilizing and atmospheric pollution may be significant sources of trace elements

the rhine linth glacier in the upper wurm a model of the last alpine glaciation abstract the wurmian glaciation of the alpine foreland has been reconstructed in different phases as a result of investigations in the rhine bodan region as well as in the linth area the whole high glacial is divided in four main phases ice advance into the piedmont basins building up of the foreland glaciation high stages and retreat into the inner alps this epoch took up perhaps less than 12 000 years during the period of building an average increase of ice thickness of about 12 cm per year was sufficient to form an extensive foreland glacier within 5000 7000 years the snow lines of the stades of the piedmont glaciation as well as of the local glaciers are calculated snow lines at about 1500 m a s l led to an inner alpine ice build up and an advance of glaciers towards the piedmont basins to produce the foreland ice sheet low snow lines of 900 1000 m a s l were necessary an interstadial phase before the maximum glaciation is evidenced by sediment sequences and a 14c date of 22 100 bp the chronology of ice retreat after 18 ka bp is still uncertain

rates of weathering and chemical depletion in soils across a chronosequence of lake michigan sand dunes abstract accumulation of soil organic matter and depletion of base cations and trace metals were measured in surface soils i e o horizon and upper 15 cm of mineral soil across a 4150 year soil chronosequence of dune capped beach ridges bordering northern lake michigan within 400 years of beach ridge formation coniferous forest develops soil c and n accumulate to steady state levels of 40 and 1 3 mg ha 1 respectively and the ph of the upper mineral soil decreases from 8 5 to 4 3 as carbonate minerals dissolve after substantial proportions of ca and mg have been removed an incipient spodic horizon can be observed the upper surface of which progressively deepens with increasing soil age analysis of soil strain of the upper mineral soil showed gradual dilation reaching 121 after several centuries of soil development after accounting for soil dilation quantities of ca mg p zn mn fe and v in the upper 15 cm of mineral soil decreased exponentially to low asymptotic levels representing quantities contained in weathering resistant minerals mass balance modeling indicated weathering and elemental losses in the order of decreasing decay constant as ca mg mn zn p v fe al k na ti this sequence is consistent with weathering of carbonates then ferromagnesian minerals then feldspars p levels are tightly coupled with ca losses in soils older than 200 years suggesting that ca rather than fe or al stabilizes p high concentrations of heavy metals in the organic horizon relative to the upper mineral soil indicate atmospheric inputs of industrial pollutants

scanning electron microscope method for rock varnish dating rock varnish coatings on cobbles from geomorphic surfaces and exposed deposits in arid environments are an effective medium for dating over a time range of several thousand to a few million years a new analytical method for dating of rock varnish is presented wherein the varnish cation ratio vcr is determined by a scanning electron microscope sem equipped with an energy dispersive x ray analyzer edax the experimental sem method is a nondestructive technique that has several potential advantages over the original method of analysis described by r i dorn that uses particle induced x ray emission pixe of varnish scraped from rock surfaces the sem method can potentially eliminate analytical errors due to contamination from rock substrate because variations in varnish thickness and irregularities on the substrate surface are examined before cation ratios are determined because varnish surfaces remain intact varnish sites that yield anomalous results may be reanalyzed or verified in addition the general accessibility of scanning electron microscopes will make rock varnish dating more widely available for use in quaternary studies cation ratios were calculated for rock varnish from espanola basin new mexico and the yucca mountain region nevada and were used to construct rock varnish dating curves for these areas

pedogenic processes and domain boundaries in a vertisol climosequence evidence from titanium and zirconium distribution and morphology abstract the occurrences of titanium ti and zirconium zr within eight vertisols formed in a climosequence on the upper beaumont formation of the texas gulf coastal plain were investigated in order to determine processes responsible for ti and zr redistribution during pedogenesis discontinuities defined by significant shifts in particle size distribution and the content in volume percent of zr are present at 160 to 260 cm depth in each pedon the discontinuities are interpreted to be functional boundaries i e physico chemical expressions of pedogenic domains between an upper soil domain dominated by open system pedogenesis and a lower more closed system domain dominated by chemical weathering the depth at which the functional boundary occurs is dependent on physical and hydrogeochemical influences which are largely a function of available water soil materials above the discontinuities are slightly coarser textured and enriched in zr whereas below the sediments are finer textured and have lower and more constant zr contents the zr is associated almost exclusively with zircon and zr contents correlate positively to the weight percent sand coarse silt with negligible zr present in the profile volume loss gain i e soil strain e a mass balance calculation that assumes zr or ti immobility during pedogenesis indicate ezr values nearly four times greater than eti large values of ezr within the upper soil domains are due primarily to sand and coarse silt additions to the vertisols and preclude use of zr as a basis of mass balance calculations in these soils despite its relative chemical stability by comparison ti is generally conserved within the clay rich soil profiles and is therefore better suited for mass balance calculations of volume change and mobile element translocation during pedogenesis

soil development on moraines of mendenhall glacier southeast alaska 1 the moraines and soil morphology abstract soils on a sequence of well drained neoglacial moraines up to 240 years old plus an older soil were sampled to investigate soil development through the initial stages of podzolization pebbles and cobbles in the moraines are about 75 to 80 granitic rock computations based on minerals observed optically and on chemical analyses indicate that plagioclase and quartz are the predominant minerals in the fine earth the climate is perhumid leaching of the moraines may have begun before they were free of glacial ice but little organic matter accumulated under the initial vegetative cover of sparse dwarf fireweed 10 year site as alder thicket developed organic matter accumulated rapidly in oi oe and a horizons 38 year site as spruce trees began to replace alder organic matter was lost from the surface mineral soil to form an e horizon and an incipient bs horizon formed below it an oa horizon formed and the a horizon disappeared 70 and 90 year sites organic acid leaching continued to form a spodic bhs horizon in spruce forest 240 year site and a spodic bh horizon in spruce hemlock forest 240 year site hornblende has been etched slightly within 240 years apatite has been lost from e horizons and free fe presumeably in ferrihydrite has accumulated in b horizons the younger moraine soils both with and without incipient bs horizons are typic cryorthents and the 240 year old and older soils with spodic bhs and bh horizons are typic haplocryods they are expected to accumulate more organic matter and become andic humicryods which is the most common subgroup of soils in the area

effects of climate change on soils in glacial deposits wind river basin wyoming abstract soil chronofunctions are often quasilinear but those relationships may be only gross fortuitous generalizations that ignore changes in soils resulting from climatic and other cyclic external influences that govern soil formation or soil degradation in the rocky mountains soil development has been extensively used to estimate the age of sediments but the number of soils is usually few and large ranges in values for soil data may be dismissed as normal variation in a detailed study of soils in the wind river range and wind river basin characteristics of near surface horizons do not follow age trends however the underlying carbonate bearing horizons do have age related characteristics this soil paradox may be related to glacial interglacial cycles in which 1 wind erodes near surface horizons and then provides new parent material and 2 cryoturbation disrupts carbonate horizons remobilizing carbonate and changing carbonate morphology but with only minimal loss of carbonate from the soil

cosmogenic nuclide derived rates of diffusive and episodic erosion in the glacially sculpted upper rhone valley swiss alps denudation rates of small tributary valleys in the upper rhone valley of the swiss central alps vary by more than an order of magnitude within a very small distance tens of kilometers morphometric data indicate two distinct erosion processes operate in these steep mountain valleys we determined the rates of these processes using cosmogenic beryllium 10 10be in pooled soil and stream sediment samples denudation in deep glacially scoured valleys is characterized by rapid non uniform processes such as debris flows and rock falls in these steep valleys denudation rates are 760 2100 mm kyr 1 in those basins which show minimal previous glacial modification denudation rates are low with 60 560 mm kyr 1 the denudation rate in each basin represents a binary mixture between the rapid non uniform processes and soil creep the soil production rate measured with cosmogenic 10be in soil samples averages at 60 mm kyr 1 mixing calculations suggest that the debris flows and rock falls are occurring at rates up to 3000 7000 mm kyr 1 these very high rates occur in the absence of baselevel lowering since the tributaries drain into the rhone trunk stream up stream of a knickzone the flux weighted spatial average of denudation rates for the upper rhone valley is 1400 mm kyr 1 which is similar to rock uplift rates determined in this area from leveling the pace and location of erosion processes are determined by the oscillation between a glacial and a non glacial state preventing the landscape from reaching equilibrium copyright 2010 john wiley sons ltd

soil development on late quaternary river terraces in a high montane valley in bhutan eastern himalayas we examined the geochemistry and micromorphology of the soils on a suite of morphologically well defined and visually distinct fluvial terraces up to 40 m elevation above the current riverbed at thangbi in the upper bumthang valley bhutan the alluvia forming each of the terraces are lithologically and structurally similar with shallow or moderately deep clast free sandy loam overbank deposits capping deep clast supported beds of rounded boulders and interstitial sand the topsoils on the 40 m terrace have more silt than those on the lower terraces the soils are interpreted mainly as a monoclinal post incisive chronosequence features that indicate progressive pedogenesis with increasing elevation include subsoil rubefaction crystallinity of free fe sesquioxides and weathering of susceptible primary minerals such as biotite and hornblende however other soil attributes show no systematic trends and the overall impression is of limited pedogenesis even in the soils on the higher terraces we examine possibilities that the immaturity of the soils is due to pedogenic rejuvenation by post incision additions to the soil parent materials

initial stages of weathering and soil formation in the morteratsch proglacial area upper engadine switzerland investigations in alpine soils indicate that mineral weathering is much faster in young soils 1000 yr than in old soils 10 000 yr however little is known about the initial stages of weathering and soil formation i e during the first decades of soil genesis in this study we investigated rock forming minerals weathering at very early stages of soil formation due to the continuous retreat of the morteratsch glacier upper engadine swiss alps the proglacial area offers a full time sequence from 0 to 150 yr old surfaces a low slope and the absence of glacier which might have interrupted soil formation processes contributed to the choice of the morteratsch proglacial valley for this case study the area is well documented regarding vegetation and soils the tectonic unit is the bernina crystalline which is mainly constituted of granitoid rocks consequently the glacial till has an acidic character mineralogical measurements were carried out on the soil fraction 2 mm using xrd and drift for qualitative and quantitative phase analysis in addition chemical analyses of the stream water from the main channel tributaries and of rainwater were performed with a special focus on ca sr and sr isotope ratios 87sr 86sr furthermore the accumulation of organic matter within the time sequence and physical soil properties were measured decreasing grain size with time shows active physical weathering processes soil organic matter has been accumulated during 150 yr at very high rates special emphasis has been given to chemical weathering and to the formation and transformation mechanisms of minerals of special interest were biotite chlorite epidote plagioclase and calcite biotite has been continuously transformed into illite like components within 150 yr the concentration of epidote significantly decreased the high ca sr as well as 87sr 86sr ratios in the stream and spring waters confirmed that ca bearing minerals are weathering and transforming at very high rates in the proglacial area also in cryic ice free environments chemical weathering rates are high leading to the formation and transformation of minerals disseminated calcite in granitoid rocks not confined to sedimentary carbonate rocks also plays a role in subglacial environments it is however not known for how long such an influence is significant and measurable the high ca na and ca sr ratio in the stream and tributary waters showed that calcite contributes to the supply of soluble ca although the ion activity product calculations clearly demonstrated that the waters were undersaturated with respect to this mineral

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

glacial stratigraphy of stough creek basin wind river range wyoming abstract multiparameter relative age ra techniques identify four post pinedale morphostratigraphic units in each of three cirque valleys tributary to stough creek basin wind river range wy soil development lichenometry boulder weathering characteristics and the geomorphic relations among morphostratigraphic units indicate glacial deposits here correspond to the sequence previously described in the temple lake valley arct alp res 6 1974 301 cirque deposits in stough creek basin correspond to the temple lake alice lake black joe and gannett peak alloformations gsa abs prog 32 2000 a 16 10 be ages from moraine boulders and polished striated bedrock assoc am geogr annu mtg abs 2000 155 support recent numeric age estimates from temple lake and titcomb basin that indicate the temple lake alloformation corresponds to the younger dryas climate episode geogr phys quat 41 1987 397 geology 23 1995 877 science 268 1995 1329 gsa abs prog 31 1999 a 56 soils described from pinedale recessional deposits here represent the first systematic description of pinedale alpine deposits in the wrr

formation rates of smectites derived from two holocene chronosequences in the swiss alps the formation rate of smectitic components in alpine soils is derived from two chronosequences in the swiss alps covering a time span of 11 500 years the soils developed on granitic parent material the lithologies between the two chronosequences investigation areas however showed some distinct differences with respect to the main mineralogy and to a lower extent to the chemistry the chronofunctions of smectitic phase formation g kgclay year were fitted to data using an exponential formation model extensive mineral weathering resulted in significant losses of chlorite and mica and the corresponding formation of smectite and regularly and irregularly interstratified mica smectite this formation is especially pronounced in the early stages of soil formation our investigations reveal that the greatest changes in soil clay mineralogy of alpine soils on granitic or gneiss host material occur within the first 1000 3000 years of soil development at both investigation sites the annual formation rates are in a similar order of magnitude with 0 1 g kg year or even higher at the start of soil formation and with values 0 01 g kg year after about 7000 years the pedogenetic smectites from the e or bs horizons included several populations with various interlayer charges this heterogeneity seems to be related to the nature of their precursors

soil chronosequences on quaternary marine terraces along the northwestern coast of calabria southern italy abstract two soil chronosequences representative of four orders of marine terraces from early to late pleistocene have been studied along the tyrrhenian coast of northern calabria in southern italy all soil profiles show a high degree of weathering although the degree of soil evolution varies according to the age of each terrace the soils are characterized by reddish to reddish brown colors clayey textures abundant clay coatings slickensides fe mn features or calcium carbonate concretions the dominance of kaolinite and illite among phyllosilicate clay minerals in all soil horizons the intense depletion in caco 3 na and k and the severe etching of quartz crystals in the older soils all record a highly leached pedogenic environment that is progressively more intense from younger to older soils despite the carbonate bedrock quartz feldspar and mica minerals also occur suggesting a partly allochthonous eolian origin of the parent material the major pedogenic features and their formative processes occurred polycyclically on the different orders of marine terraces and we interpret the soils to have mainly developed during repeated quaternary interglacials some surface a and bw horizons show quite different features suggesting a clear change in pedogenetic processes and possibly in climate and duration of soil formation these horizons have the typical field appearance of volcanic soils with andic properties brown colors loamy textures high porosity low bulk density high water retention thixotropy the occurrence of very small volcanic glass fragments and the possible presence of short range order aluminosilicate minerals confirmed some pyroclastic supply during soil formation

soil formation rates on silicate parent material in alpine environments different approaches different results abstract high mountain soils develop in particularly sensitive environments consequently deciphering and predicting what drives the rates of soil formation in such environments are a major challenge in terms of soil production or formation from chemical weathering the predominating perception for high mountain soils and cold environments is often that the chemical weathering portion of soil development is temperature inhibited often to the point of non occurrence several concepts exist to determine long term rates of soil formation and development we present three different approaches 1 quantification of soil formation from minimally eroded soils of known age using chronosequences known surface age and soil thickness sast 2 determination of soil residence times srt and production rates through chemical weathering using un stable isotopes e g 230 th 234 u activity ratios and 3 a steady state approach using cosmogenic isotopes e g 10 be for each method data from different climate zones and particularly from high mountains alpine environment are compared the sast and steady state approach give quite similar results for alpine environments european alps and the wind river range rocky mountains usa using the srt approach soil formation rates in mountain areas but having a temperate climate do not differ greatly from the sast and steady state approaches independent of the chosen approach the results seem moderately comparable soil formation rates in high mountain areas alpine climate range from very low to extremely high values and show a clear decreasing tendency with time very young soils have up to 3 4 orders of magnitude higher rates of development than old soils 10 5 to 10 6 yr this apparently is a result of kinetic limits on weathering in regions having young surfaces and supply limits to weathering on old surfaces due to the requirement for chemical weathering to occur soil production rates cannot be infinitely high consequently a speed limit must exist in the literature this limit has been set at about 320 to 450 t km 2 a our results from the sast approach show however that in alpine areas soil formation easily reaches rates of up to 800 2000 t km 2 a these data are consistent with previous studies in mountain regions demonstrating that particularly young soils intensively weather even under continuous seasonal snowpack and thus that the concept of temperature controlled soil development soil forming intervals in alpine regions must be reconsidered

pongkor west java indonesia a pliocene supergene enriched epithermal au ag mn deposit the pongkor gold silver epithermal deposit with reserves of at least 98 tonnes of gold and 1026 tonnes of silver average grades 16 4 g t au and 171 2 g t ag is one of the most recent and largest gold and silver discoveries in indonesia proven within a short period 1988 1991 40ar 39ar dating on adularia samples give an age of 2 05 0 05 ma the deposit is of the low sulfidation epithermal type and consists of four main mineralized quartz veins located close to the internal rim of a volcano tectonic depression caldera this resulted from an explosive ignimbritic eruption that produced pyroclastic flows and accretionary lapilli with rare intercalations of epiclastic rocks this volcanic unit unconformably overlies miocene subaqueous volcanic andesitic rocks with interbedded epiclastic rocks the mineralized bodies are thick average 4 2 m steeply dipping quartz carbonate adularia veins with a very low sulfide content 0 5 wt their genesis is related to an extensional episode within a tectonic corridor showing nw se and nne ssw conjugate strike slip faults the major vein being located on the inner rim of the caldera the vein fill reveals four successive stages of deposition marked by a specific facies 1 carbonate quartz breccia with dominant quartz and calcite and minor kutnahorite rhodochrosite and rhodonite cq facies 2 a network of banded quartz and former carbonate transformed into manganese oxides through supergene alteration moq facies 3 banded opaline milky quartz boq facies and 4 grey locally banded sulfide rich quartz breccia cutting all the other types gsq facies adularia was deposited at the same time as the quartz the mineralogy and internal structures of the veins crustiform banding vugs collapse breccia clearly indicate a dilational context which is common in low sulfidation epithermal systems gold and silver grades as well as sulfide mineral abundances increase steadily through stages 1 to 4 locally reaching 1 kg t in the gsq facies the sulfides are dominated by pyrite accompanied by common acanthite aguilarite polybasite pearceite and electrum in which the gold content ranges from 48 to 74 wt sphalerite galena chalcopyrite and hessite are fairly rare although present within the cq facies the fluid inclusions of the four facies show homogenization temperatures ranging from 150 to 382 c indicating boiling of a hydrothermal fluid with an initial temperature of around 205 c no marked difference is seen in the gsq facies which has the highest gold content salinities are low generally below 1 wt eq nacl lead isotope compositions of the associated volcanic rocks and the mineralization are very similar 206pb 204pb between 18 706 and 18 814 and between 18 744 and 18 801 respectively demonstrating a genetic link between the pliocene volcanism and the auriferous hydrothermal activity the isotopic signature suggests that the source of the mineralization and associated volcanic rocks is an underlying ancient continental crust that melted and remobilized during the pliocene volcanic and hydrothermal events these conclusions seem applicable to the entire bayah dome the existence of both a tectonic corridor and a caldera favoured channelling of the hydrothermal fluids and the deposition of primary ore in the veins late intense weathering of the ore deposit to depths of 250 m below the surface has given rise to manganese oxide layers limonite zones and silver micronuggets within the veins as well as to gold enrichment

application of a combination of dating techniques to reconstruct the lateglacial and early holocene landscape history of the albula region eastern switzerland landforms in val mulix and the albula region in eastern switzerland offer a detailed insight into the period between the oldest dryas until the early holocene to better understand lateglacial and holocene climate change in the central alps glacial moraines polished bedrock and periglacial rock glacier landforms were dated using a combined approach of numerical cosmogenic 10be and relative schmidt hammer weathering rind thickness dating techniques at high elevation sites near the last glacial maximum lgm trimline 10be exposure ages of glacially modified bedrock are between 11 2 ka and 13 5 ka this suggests the persistence of long lasting small local ice caps after the breakdown of the lgm ice domes or alternatively a reformation of ice perhaps during the younger dryas in val mulix we obtained one of the first ages for the daun stadial 14 7 ka moraines 14 9 1 8 ka supporting a pre bolling chronological position the age is in excellent agreement with the age of a boulder from an egesen i moraine located up valley which we postulate may be a daun moraine that was re occupied during the egesen stadial a boulder from an egesen ii moraine gave an age of 10 7 ka which is similar to ages of egesen ii moraines at other sites in the alps 10be ages from boulders found on a relict rock glacier in val mulix indicate that the main active phase lasted from the lateglacial until the early holocene the derived mean annual flow rate is of the order of decimetres which is in accordance with values stated in the literature based on measuring active rock glaciers in the alps exposure ages from a glacially polished rock barrier showed that this area was ice free at the end of the younger dryas 9 0 0 7 ka and 11 9 0 9 ka the polished bedrocks are located a few hundred meters down valley from the little ice age lia moraines this gives direct evidence of a fast ice retreat towards the end of the younger dryas with glacier length variations that did not exceed the 1850 ad extension little ice age maximum surface exposure dating is however limited by several methodological constraints the choice of suitable snow depths plays a crucial role in the calculation of the 10be ages shielding of surfaces from cosmic rays by snow can significantly influence the exposure age and variations in the estimated annual snowfall in the albula region since the lgm is therefore a potential source of considerable uncertainty in our measurements while the measurement of weathering rind thicknesses turned out to be an appropriate tool to support the reconstruction of lateglacial landscape evolution schmidt hammer r values were less helpful the r values enabled a temporal distinction of landforms within the holocene lia moraine active rock glaciers but not within the lateglacial from a methodological point of view the different dating methods enabled a cross checking an extended interpretation of the data and a more accurate estimate of the possible sources of error

soil catenas of calcareous tills whiskey basin wyoming usa abstract we describe catenas developed on calcareous moraines of pinedale 21 15 ka and bull lake 130 100 ka ages at whiskey basin on the eastern flank of the wind river range wyoming usa we sampled one catena of each age from each of two separate moraine fields the jakey s fork and torrey creek valleys soils of the bull lake catena at jakey s fork are more developed than those of the corresponding pinedale catena they have thicker sola more horizons more pedogenic clay and more pedogenic carbonate presumably because of their greater age the weighted mean profile development index does not distinguish between the torrey creek catenas pedogenic carbonate content is greater in the torrey creek pinedale catena than the corresponding bull lake catena and pedogenic clay is greater in the bull lake catena catenas on the jakey s fork moraines are generally more developed than corresponding catenas on the torrey creek moraines we suggest that differences in catena development mostly result from the differences in slope length between the jakey s fork and torrey creek catenas the jakey s fork catenas are shorter than those of the torrey creek which appears to lessen the role that topographic position plays in catena development

combining cosmogenic nuclides and major elements from moraine soil profiles to improve weathering rate estimates abstract previous studies of chemical weathering rates for soil developed on glacial moraines generally assumed little or no physical erosion of the soil surface in this study we investigate the influence of physical erosion on soil profile weathering rate calculations the calculation of chemical weathering rates is based on the assumption that soil profiles represent the integrated amount of weathering since the time of moraine deposition the weathering rate of a surface subjected to denudation is the sum of the weathering loss from the existing soil profile added to the weathering loss in the material removed by denudation divided by the deposition age in this study the amount of weathered material removed since moraine deposition is calculated using the denudation rate estimated from cosmogenic nuclide data and the deposition age of the moraine weathering rates accounting for denudation since moraine deposition are compared to weathering rates based on the assumption of no physical erosion and on the assumption of steady state denudation for the type pinedale moraine 21 ka and the bull lake age moraine 140 ka in the fremont lake area wind river mountains wyoming usa the total weathering rates accounting for denudation are 8 15 1 05 g oxide m 2 y 1 for the type pinedale moraine and 4 78 0 89 g oxide m 2 y 1 for the bull lake age moraine which are 2 to 4 times higher respectively than weathering rates based on the assumption of no physical erosion the weathering rates based on denudation since moraine deposition are comparable or smaller than weathering rates assuming steady state denudation we find the assumption of steady state denudation is not valid in depositional landscapes with young deposition ages or slow denudation rates the decrease in weathering rates over time between the type pinedale and bull lake age soils that is observed in the case of no physical erosion is decreased when the influence of denudation on the total weathering rates is taken into account fresh unweathered material with high reactive mineral surface area is continuously provided to the surface layer by denudation diminishing the effect of decreasing weathering rate over time

late glacial retreat and neoglacial advance sequences in the zillertal alps austria abstract late glacial terrain in the schwarzensteinkees hornkees and waxeckkees forelands of the zillertal alps is dominated by sediments deposited by readvancing ice emplaced in the little ice age starting approximately 550 70 cal 14 c yr bp late glacial ice scoured the massif with remnants of late glacial end moraines fronting lia end moraines and buried paleosols underlying lia end moraines providing scattered evidence of compositional change and weathering since the later dryas the amount of recovered wood from lia moraines indicates that the massif was forested for at least part of mid holocene times most likely during the atlantic chronozone when presumably soil morphogenesis was accelerated details of till composition and weathering history provide a pedostratigraphic reconstruction which includes mid lia readvances between 400 70 cal 14 c yr bp and 350 70 cal 14 c yr bp the heavily convoluted character of underlying early lia or older tills suggests either pre existing strongly active cryoturbation in a thin entisol regosol or active push moraine dynamics of advancing warm ice sem analysis documents differences in glacial dynamics that may be related to ice thickness stick slip motion or clastic load in the ice coupled with rate of movement