distribution of soil taxa in antarctica a preliminary analysis abstract only 0 35 49 500 km2 of antarctica is ice free these areas are scattered around the periphery of the continent and in interior mountain ranges making soil mapping difficult here we compile the results of mapping in five of the nine ice free areas that account for 79 of the ice free area on a reconnaissance scale and interpret the distribution of soil subgroups in soil taxonomy soils of antarctica are contained in four orders dominantly gelisols 84 13 suborders 27 great groups and 76 subgroups forty five percent of the soils of antarctica are orthels gelisols that show minimal cryoturbation and occur in dry landscape positions 38 of the soils are turbels showing cryoturbation and occurring in more moist landscape positions only 16 of the soils of antarctica lack permafrost in the control section and are classified as entisols gel great groups inceptisols gelepts suborder or gelaquepts or histosols gel great groups these soils occur almost exclusively along the western antarctic peninsula and at elevations below 30 m in the south shetland islands ssi and south orkney islands soi typic anhyorthels are the dominant soil subgroup comprising nearly 15 340 km2 or 31 of the soils in antarctica these soils occur primarily in central and southern victoria land but also occur in the thiel and pensacola mountains and shackleton range the prince charles mountains and the mountains of queen maud land typic haploturbels and typic anhyturbels occupy 14 and 13 of the soils of ice free regions of antarctica respectively most abundant in central victoria land they are common in most mountainous regions of antarctica the dominant soil processes of maritime antarctica are cryoturbation gleization melanization podzolization paludization and phosphatization in coastal east antarctica the major soil processes are rubification salinization calcification pervection and gleization the predominant soil forming processes in the transantarctic mountains include rubification salinization desert pavement formation and permafrost development measures of pedodiversity will be valuable in the selection of protected areas in antarctica

morphological and sedimentological responses of streams to human impact in the southern blue ridge mountains usa abstract morphological and sedimentological responses of streams to basin scale impact have been well documented for intensively agricultural or urban areas sensitivity thresholds of streams to modest levels of disturbance however are not well understood this study addresses the influence of forest conversion on streams of the southern blue ridge mountains a region that has received little attention with respect to human impact on stream channels basins were chosen for this study to represent the end members of the range of human impact in the area with the forest cover of the basin used as a proxy for level of impact ranging from about 70 100 regionally two pairs of lightly impacted 90 forest and moderately impacted 70 80 forest sub basins of the upper little tennessee river were identified for comparison reach characteristics e g slope drainage area and riparian cover were aligned in each pair to isolate contrasting forest cover as the primary driver of any detected differences in morphology and sedimentology a suite of standard cross sectional and longitudinal data was collected for each reach for characterization of the sedimentology and morphology of the streams difference of means tests were conducted to identify parameters significantly differing between the lightly and moderately impacted streams in both pairs consistent and significant differences within both pairs were demonstrated in bankfull width depth ratios baseflow wetted width and particle size on the stream bed both in the thalweg and throughout the channel bed the moderately impacted streams are narrower than the lightly impacted streams and the bed texture of the moderately impacted streams is finer than that of the lightly impacted streams the moderately impacted streams contain a higher percentage of

morphological and sedimentological responses of small stream channels to extreme rainfall and land use in the darjeeling himalayas abstract three pairs of small fourth to sixth order catchments approximately 5 80 km2 draining the margin of the darjeeling himalayas into the piedmont were selected for a comparison of the land use impact on the morphology and sedimentology of their stream channels each pair experienced similar annual rainfall and comprised similar metamorphic bedrock steep topography and brown soils the members of each pair contrast with respect to their land use structure as they comprise large forest cover forest 90 and a significant contribution of agricultural land with tea plantations forest

coupling patterns between para glacial and permafrost degradation responses in antarctica the recently deglaciated environments in maritime permafrost regions are usually affected by very active paraglacial processes elephant point is an ice free area of 1 16 km2 located in the sw of livingston island south shetland islands antarctica between 1956 2010 the retreat of the ice cap covering most part of this island has exposed 17 3 of the land surface in this peninsula two geomorphological units were identified in this new ice free area a moraine extending from the western to the eastern coastlines and a relatively flat proglacial surface the glacier in 1956 sat in contact with the northern slope of the moraine but its accelerated retreat in parallel to the warming trend recorded in the antarctic peninsula left these areas free of glacier ice subsequently the postglacial evolution was controlled by the relaxation phase typical of paraglacial systems the typology and intensity of geomorphological processes show a significantly different dynamics between the southern and northern slopes of the moraine this pattern is related to the different stage of paraglacial adjustment in both slopes in the southern side on coarser sediments pronival ramparts debris flows and alluvial fans are distributed with a low to moderate activity of slope processes in the northern side mass wasting processes are extremely active on fine grained unconsolidated sediments ice rich permafrost is being degraded by thermokarst processes landslides and mudflows transfer large amounts of sediments down slope the surface affected by retrogressive thaw slumps in the moraine has been quantified in 24 172 m2 which accounts for 9 6 of its surface the abundance of kettle lakes is also indicative of the degradation of the ground ice paraglacial processes are expected to continue in the moraine and proglacial area in the near future although their intensity and duration will depend on the magnitude and rate of future climate trends in the northern antarctic peninsula copyright 2015 john wiley sons ltd

gully morphology hillslope erosion and precipitation characteristics in the appalachian valley and ridge province southeastern usa this study investigates gully erosion on an east tennessee hillslope in a humid subtropical climate the study area is deeply gullied in ultisols acrisol according to the world reference base for soil with thirty years of undisturbed erosional history with no efforts to correct or halt the erosion the objectives are 1 to examine how different gully morphologies channel sidewall and interfluve behave in response to precipitation driven erosion and 2 to identify an appropriate temporal scale at which precipitation driven erosion can be measured to improve soil loss prediction precipitation parameters total accumulation duration average intensity maximum intensity extracted from data collected at an on site weather station were statistically correlated with erosion data erosion data were collected from erosion pins installed in four gully systems at 78 locations spanning three different morphological settings interfluves channels and sidewalls kruskal wallis non parametric tests and mann whitney u tests indicated that different morphological settings within the gully system responded differently to precipitation p 0 00 for channels and sidewalls regression models relating erosion and precipitation parameters retained antecedent precipitation and precipitation accumulation or duration r2 0 50 p 0 00 for channels r2 0 28 p 0 00 for sidewalls but precipitation intensity variables were not retained in the models for interfluves less than 20 of variability in erosion data could be explained by precipitation parameters precipitation duration and accumulation including antecedent precipitation accumulation were more important than precipitation intensity in initiating and propagating erosion in this geomorphic and climatic setting but other factors including mass wasting and eolian erosion are likely contributors to erosion high correlation coefficients between aggregate precipitation parameters and erosion indicate that a suitable temporal scale to relate precipitation to soil erosion is the synoptic time scale this scale captures natural precipitation cycles and corresponding measurable soil erosion

the geology and palynology of lower and middle pennsylvanian strata in the western kentucky coal field abstract the western kentucky coal field is the southern tip of the eastern interior or illinois basin pennsylvanian rocks in this area which include conglomerate sandstone siltstone shale limestone and coal were deposited primarily in coastal deltaic settings at a time when western kentucky was located close to the equator this paper discusses temporal changes in regional sedimentation patterns and coal forming floras of lower and middle pennsylvanian strata in the western kentucky coal field lower pennsylvanian strata of the caseyville formation are characterized by paleovalley filling sedimentation patterns and extabasinal quartz pebbles caseyville formation coals are characteristically thin and discontinuous and were strongly influenced by subsidence within underlying paleovalleys and the dissected lower pennsylvanian paleotopography caseyville coals are commonly dominated by lycospora but can also have variable palynofloras which probably reflects variable edaphic conditions and edge effects within small patchy paleomires tradewater formation strata show increased marine influences and tidal estuarine sedimentation especially in the middle and upper parts coal beds in the lower part of the tradewater typically are thin and discontinuous although some economically important beds are present coals become thicker more abundant and more laterally persistent towards the top of the formation palynologically lower and middle tradewater formation coals are dominated by lycospora but begin to show increased amounts of tree fern spores middle and upper tradewater coals are thicker and more continuous and contain high percentages of tree fern spores in addition cordaite pollen is locally abundant in this interval carbondale and shelburn desmoinesian strata are much more laterally continuous and occur within classic cyclothems that can be traced across the coal field cyclothems have long been interpreted as being eustatically driven and glacio eustacy controlled not only sedimentation but also the formation of desmoinesian paleomires palynologically carbondale and shelburn coals are either dominated by lycospora or have heterogeneous palynofloras palynologic and coal quality data suggest that hydrologic base level may have been the primary control on desmoinesian paleomires rather than paleoclimate as the coals display rheotrophic rather than ombrotrophic characteristics

the role of biological weathering in periglacial areas a study of weathering rinds in south iceland the importance of biogeochemical processes in the morphogenic system of periglacial environments has been underestimated for decades weathering rind studies help to characterise and quantify biogeochemical weathering over time experiments using fungi strains isolated from basaltic boulders allow one to decipher biological weathering a historical approach using heterochronous moraines provides the opportunity to follow the life of weathering rinds and helps to build a chronology of dominant processes of weathering during the first century of exposure it appears that exfoliation of weathering rinds commonly observed on boulders is the result of a combination of both biogeochemical and physical processes

holocene glacier fluctuations in south america and antarctica abstract glacial geologic evidence indicates that glaciers throughout the andes and antarctica fluctuated during the holocene radiocarbon dating and other age determinations suggest that glaciers readvanced significantly only during the last 5 ka reaching positions from several 100 m to a few kilometres beyond their present limits in south america tenuous evidence from radiocarbon dates with dendrochronological data and environmental interpretations from pollen analyses indicate four main periods of neoglacial advance culminating 5000 4000 bp 3000 2000 bp 1300 1000 bp and 15th late 19th centuries smaller advances may have occurred at ca 8400 bp ca 7500 bp and ca 6300 bp the meagre data are consistent in indicating broad synchrony throughout the andes during the last 5 ka suggesting response to global climatic changes anomalies exist in patagonia where some tide water glaciers reached their maximal holocene limits recently this century the broad spectrum of differing antarctic environments produces interesting contrasts some local glaciers in the mcmurdo sound area of the east artarctic continent are more extensive now than during the global glacial maximum ca 18 ka bp when they were starved of precipitation consistent agreement among 14 radiocarbon dates from the south shetland islands indicates two main holocene glacier advances the most extensive 2 3 km peaking in the 12th century the other culminating in the 18th 19th century glaciers in south georgia reached their most advanced holocene limits before 2200 bp moraine fjord glacier which culminated as a 6 km advance between 1460 1700 radiocarbon bp may have lagged 400 650 years behind the climatic forcing because it could only advance in its deep water fjord by building a moraine bank smaller advances in south georgia culminated in the 17th 19th centuries and during the 1920s 30s there is no firm evidence of glacier advances before 3 ka bp in the southern ocean sub antarctic domain but broad synchrony in glacier advances during the last ca 3000 years appears to have occurred throughout the andes antarctic transect caution is required in the interpretation and correlation of moraines associated with calving glaciers and of those with poorly constrained dating

windows on antarctic soil landscape relationships comparison across selected regions of antarctica abstract this paper brings together topographic cross section windows from across antarctica to illustrate soil landscapes from the margins of the polar plateau in the transantarctic mountains and mcmurdo dry valleys through east antarctic coastal areas to the northern antarctic peninsula region soils identified range from gelisols in the ross sea region through gelisols and entisols in coastal east antarctica to a mixture of gelisols entisols spodosols and inceptisols in the northern antarctic peninsula region where permafrost is not ubiquitous the relative impacts of the soil forming factors are considered at a continental scale climate is the main driver of the differences observed between soils in different areas at local scales strong soil topographic relationships are observed organisms time and parent material are dominant influences on soil properties only in relatively localized situations organisms dominate in areas of organic matter or guano accumulation and time is a dominant influence on exceptionally old upland surfaces in the mcmurdo dry valleys the us department of agriculture s soil taxonomy gives a useful overall appraisal of antarctic soils however for detailed work there is a need to introduce some new categories at subgroup level to better capture the range of soils described

geomorphic responses of lower bega river to catchment disturbance 1851 1926 abstract prior to significant european settlement of the area in the 1850s lower bega river on the south coast of nsw had a narrow relatively deep channel lined by river oaks the river had a suspended or mixed load with platypus habitat available in pools banks were fine grained and relatively cohesive silts and clays as was the floodplain which graded to a series of valley marginal swamps and lakes extensive evidence from maps and portion plans archival photographs bridge surveys and anecdotal sources complemented by field analysis of floodplain sedimentology including radiocarbon dated samples and vegetation remnants are used to document the dramatic metamorphosis in the character and behaviour of lower bega river in the latter half of the nineteenth century by 1926 the channel had widened extensively up to 340 and shallowed in association with bed aggradation by coarse sandy bedload floodplain accretion was dominated by fine to medium sands with some coarse sand splays in contrast with most other studies of channel metamorphosis in australia which have emphasised river responses to climatically induced flood histories relegating human impacts to a secondary role the profound changes to the geomorphic condition and behaviour of bega river reflect indirect human disturbance of bega catchment and direct but non point source disturbance to the channel extensive clearance of catchment floodplain and channel marginal vegetation occurred within a few decades of european settlement altering the hydrologic and sediment regime of the river and transforming the geomorphic effectiveness of floods although this study is situated in a relatively sensitive granitic catchment catchment clearance is likely to have induced equally significant responses in many other river systems in eastern australia in some instances the diffuse aspects of human disturbance on landscapes induce impacts on river character that are just as profound as major direct disturbances of river channels this may have profound implications in understanding and hence managing the geomorphic consequences of river behaviour in australia and elsewhere

stream capture and the geomorphic evolution of the linville gorge in the southern appalachians usa abstract the linville river in the blue ridge of north carolina flows across the blue ridge escarpment and through linville gorge a unique topographic feature within the southern appalachians the upper portion of the drainage effectively shifts the eastern continental divide away from the escarpment crest this shift is similar to other locations along the escarpment where streams flowing towards the piedmont have captured drainage area from low relief streams that drain towards the west here we examine the upper linville river for evidence of drainage captures that would have shifted drainage area away from the toe river and into the linville river we used lidar data to reconstruct stream profiles for possible drainage pathways and examined cobble deposits near the headwaters of the north toe river within those deposits on the west side of the linville river we found quartzite cobbles that must have been sourced from bedrock exposed only on the east side of the modern linville river this indicates that portions of the linville valley above linville falls historically drained to the west into the north toe river headward erosion above linville falls resulted in downcutting and multiple stream captures these captures more than tripled the drainage area of the linville river which would have significantly increased discharge downstream this increase in discharge likely drove the geomorphic evolution of the modern linville gorge including resultant downcutting and associated hillslope processes and helps to explain the prominence of linville gorge

pool and riffle characteristics in relation to channel gradient abstract the depths of pools relative to the dephts of runs and riffles were correlated with reach scale channel gradient along three rivers in coastal northern california the sample included 122 pools formed in channels with gradients from 0 172 to 0 002 relative pool depth on these rivers and relative distance between pools increase as channel gradient decreases mean pool riffle depth is 2 8 1 at the highest channel gradient and 6 2 1 at the lowest gradient while mean pool riffle length is 1 0 8 at high channel gradient and 1 1 8 at low channel gradient we hypothesize that these trends reflect changes in energy expenditure with decreasing gradient as a result of the flow s ability to erode its channel boundaries channel reaches with high gradients are characterized by resistant channel boundaries coarse material and relatively low discharge and total stream power channel reaches with low gradients have less resistant channel boundaries finger grained bed material and higher values of discharge and total stream power these changes in channel and flow characteristics with decreasing gradient result in flows in high gradient reaches expending a greater proportion of their energy in overcoming boundary and internal resistance with less energy available for channel bed scour and the formation of pools in their relatively resistant channels in contrast with less energy available for channel bed scour the channel bed creating deeper pools because the channel boundaries are less resistant and the proportion of flow energy available for sediment entrainment and transport should be greater

hydrogeochemistry of sulfate affected landscapes in keller peninsula maritime antarctica abstract keller peninsula located in king george island has a typical maritime antarctica climatic regime with higher temperatures and rainfall than other areas in continental antarctica the main outcropping rocks are pyritized andesites volcaniclastics and basalts recent pedological investigation indicated that the presence of sulfides in keller peninsula accelerates the weathering process the aim of this work was the determination of the geochemical background in water channels following geomorphological gradients in keller peninsula maritime antarctica we delimited and mapped all catchments in keller peninsula using gis techniques and field observations water samples were analyzed for twenty nine elements by icp oes and iec after the proper treatments eight catchments were identified as sulfide affected although water ph was nearly neutral the ionic concentration in solution was high both in non affected and sulfide affected catchments with a trend of greater values in the latter and changing downslope concentration values are above the range of other hydrogeochemical studies from elsewhere in antarctica the values of molar ratio hco3 ca mg 2 and na cl indicated the absence of carbonate bearing rocks local precipitation of evaporites as gypsum and epsomite was confirmed by the ca2 so42 and mg2 so42 molar ratios the high ionic concentration in sulfide affected areas illustrates the role of sulfate soil formation in this part of antarctica

high resolution u pb ages from the upper triassic chinle formation new mexico usa support a diachronous rise of dinosaurs abstract though the late triassic preserves major paleoenvironmental fluctuations and is key for understanding the evolution of mesozoic and modern terrestrial ecosystems comparisons of late triassic non marine sedimentary and fossil records are difficult because global correlations lack precise radioisotopic ages and have instead been based upon unconstrained biostratigraphic ranges of palynomorph and vertebrate fossils the chinle formation in southwestern north america preserves a major late triassic record of paleoenvironmental and biotic change including significant early dinosaur fossils previous high resolution radioisotopic age constraints for the formation are limited to a single u pb zircon age from the upper third of the formation the extraction of a geologically meaningful age is challenging from these redeposited units and preference is given to considering the youngest age of a deposit as a maximum age and closest approximation of the depositional age because calculating a weighted mean age or median age from a group of ages from such deposits is often not adequate the precision of our two new ca tims single crystal zircon u pb ages from the chinle formation of new mexico is limited to ca 0 3 or 0 7 ma of the youngest crystal age our 206 pb 238 u age of 218 ma from the blue mesa member in six mile canyon western new mexico demonstrates that strata palynomorphs and vertebrate fossils previously considered to be late carnian in age are actually middle norian in age our new age of 212 ma from the hayden quarry within the petrified forest member at ghost ranch northern new mexico provides the first maximum age for important vertebrate assemblages from this area that record the rise of dinosaurs and demonstrates that basal dinosauromorphs dinosaur precursors co existed with dinosaurs for at least 18 ma these new radioisotopic data allow a new correlation of the chinle formation to the late triassic timescale suggesting that most if not all of the lower chinle is norian in age this new correlation has global implications as it allows us to make more precise comparisons with early dinosaur assemblages from the ischigualasto formation of argentina indicating that chinle dinosaur assemblages are significantly younger than those from south america the revised age of the chinle formation also demonstrates that dinosaurs were much rarer in north america at a time when they were abundant in south america supporting hypotheses of paleolatitudinal variation during the rise of dinosaurs

the upper pennsylvanian duquesne coal of ohio usa evidence for a dynamic peat accumulating swamp community abstract an outcrop of the duquesne coal conemaugh cyclothem has the only significant occurrence of coal balls in upper pennsylvanian stephanian b equivalent sediments of the appalachian basin excellent preservation of plant debris within autochthonous peat has permitted a more refined reconstruction of the source plant community than reported in published studies of other coals coal balls were quantitatively sampled for whole plant species and mineralogical content shoot root ratios were extremely high compared with values reported for other coals the samples were analyzed using cluster analyses and non metric multidimensional scaling mds in order to differentiate microhabitats and stages of ecological succession within the general flora cluster analysis produced 5 stable clusters which agreed with the sequence of ecological succession as determined in a previous study and with microhabitat differentiation in contemporaneous seral stages three dimensions of the mds analysis provided the best fit to the data the dimensions are interpreted as representing 1 ecological time or succession 2 increasing dominance of psaronius tree ferns in the plant community and 3 an increase in microtopological variation probably hummock formation the initial stages of succession oldest layers of permineralized peat are characterized by aerial debris from mesoxylon sigillaria and calamites followed by an assemblage dominated by chaloneria this was succeeded by more species diverse assemblage dominated by neuropteris seed ferns and psaronius tree ferns with numerous subcanopy plants including lianas epiphytes and ground herbs late seral stages youngest layers of permineralized peat were dominated by psaronius tree ferns

sediment production from forest road surfaces erosion on roads is an important source of fine grained sediment in streams draining logged basins of the pacific northwest runoff rates and sediment concentrations from 10 road segments subject to a variety of traffic levels were monitored to produce sediment rating curves and unit hydrographs for different use levels and types of surfaces these relationships are combined with a continuous rainfall record to calculate mean annual sediment yields from road segments of each use level a heavily used road segment in the field area contributes 130 times as much sediment as an abandoned road a paved road segment along which cut slopes and ditches are the only sources of sediment yields less than 1 as much sediment as a heavily used road with a gravel surface

semi arid soils from a topolithosequence at james ross island weddell sea region antarctica chemistry mineralogy genesis and classification abstract climate and parent material have a significant impact on the development of antarctic soils and areas dominated by basaltic andesitic volcanic rocks sedimentary rocks and metamorphic rocks have been widely studied james ross island located in the semi arid transition between east antarctic peninsula weddell sea sector receives both continental and maritime climatic influences resulting in distinct transitional soil formation process in antarctica there is little research on semi arid soils formed on volcano sedimentary rocks as well as their pedogenetic processes in this study a topolithosequence of volcanic and sedimentary rocks in this semi arid transitional climate was investigated nine profiles three on marine terraces four on sedimentary rocks and two on volcanic rocks were described sampled and analyzed for morphological physical chemical and mineralogical properties soils are predominantly gelisols cryosols and present cryoturbation features despite the current dry climate vegetation is scarce and nesting birds are absent so that most soils can be characterized as ahumic all profiles have a skeletic character with a high percentage of coarse materials the soil ph varied from neutral to alkaline and the potential acidity values were null the mineralogy of the clay fraction presented kaolinite which was likely inherited from warmer and wetter paleoclimatic conditions during sedimentation the soils have intergrade properties between maritime and continental antarctic such as cryoturbation and redoximorphism side by side with desert pavements and ahumic character soil properties were more sensitive to the variations in parent material than to the topographic position in the landscape

geomorphological mapping of ice free areas using polarimetric radarsat 2 data on fildes peninsula and ardley island antarctica satellite borne synthetic aperture radar sar has been used for characterizing and mapping in two relevant ice free areas in the south shetland islands the objective has been to identify and characterize land surface covers that mainly include periglacial and glacial landforms using fully polarimetric sar c band radarsat 2 data on fildes peninsula that forms part of king george island and ardley island polarimetric parameters obtained from the sar data a selection of field based training and validation sites and a supervised classification approach using the support vector machine were chosen to determine the spatial distribution of the different landforms eight periglacial and glacial landforms were characterized according to their scattering mechanisms using a set of 48 polarimetric parameters the mapping of the most representative surface covers included colluvial deposits stone fields and pavements patterned ground glacial till and rock outcrops lakes and glacier ice the overall accuracy of the results was estimated at 81 a significant value when mapping areas that are within isolated regions where access is limited periglacial surface covers such as stone fields and pavements occupy 25 and patterned ground over 20 of the ice free areas these are results that form the basis for an extensive monitoring of the ice free areas throughout the northern antarctic peninsula region

distribution and characterization of soils and landform relationships in byers peninsula livingston island maritime antarctica abstract this paper presents the spatial distribution of soils from the northern part of byers peninsula livingston island which is the largest ice free area of the south shetlands archipelago maritime antarctica physical and chemical characteristics are presented for 23 soil profiles soil parent materials vary from marine sedimentary to volcanic and volcanoclastic rocks intruded by igneous bodies to assess soil landscape relationships twenty three soil profiles were described and sampled soil samples of selected horizons were submitted to chemical physical and mineralogical analyses soil mapping was based on the soil profiles integrated with the existent topographic map 1 25 000 scale a digital elevation model the geological map and a satellite image twenty different soil units were identified and mapped according to the world reference base for soil resources wrb system soils were classified as fluvisols regosols leptosols or cryosols which correspond mostly to fluvents orthents psamments inceptsols and gelisols respectively according to the soil taxonomy soils from northern byers peninsula are generally shallow and coarse textured with low organic matter content three soils from the rocky platforms of the northern coastal region possess ornithogenic character with lower ph higher p al 3 and organic c values when compared to soils not influenced by sea birds in non ornithogenic soils the presence of easily weatherable minerals in the clay fraction indicates that physical weathering occurs with limited chemical alteration of primary minerals the influence of penguin and other birds on coastal soils alters clay mineralogy with formation of poorly crystalline p rich phases a better understanding of the depth of the permafrost table and the spatial distribution of permafrost is necessary for a more conclusive classification of cryosols or gelisols

soil and landform interplay in the dry valley of edson hills ellsworth mountains continental antarctica abstract the main relief units from the dry valley of edson hills ellsworth mountains antarctica 79 49 12 4 83 40 16 1 were assessed emphasizing the analysis of soil and landform interplay soil morphological physical and chemical properties salinity surface boulder weathering frequency and feature classification and weathering stages were analyzed three distinct landforms summarize the geomorphology of the dry valley of edson hills ellsworth mountains i periglacial features like slightly creeping debris mantled slopes steep debris mantled slopes patterned grounds and thermokarst ii glacial features like hummocky moraines lateral moraines supraglacial lakes kettle hole proglacial cirques infill subglacial horn and arete erosional glacial and iii nonglacial features like scree slopes and talus deposits all these glacial and periglacial features are related to the west antarctica ice sheet variations soils in the dry valley of edson hills are pedologically poorly developed however the degree of development in soils associated with patterned ground and moraine systems is remarkable all soils present desert pavement owing to the action of severe aeolian erosion in addition soils accumulate salts depending on the local drainage conditions the most expressive soil classes among the studied soils were typic haploturbel and typic anhyorthel especially because of i a general trend of ice cemented permafrost occurrence in lower portions of the landscape particularly in the patterned ground area and in the hummocky moraine and ii the presence of dry permafrost in higher positions of the landscape in relief units such as in debris mantled slopes and talus deposits thus a close relationship among soil characteristics and landforms were observed in the dry valley of edson hills

geomorphological change detection of an urban meander loop caused by an extreme flood using remote sensing and bathymetry measurements a case study of karoon river iran abstract flooding and flood inundation are key hydrological characteristics of meander loop rivers however the effects of extreme floods on river morphology and spatial patterns of erosion and deposition are poorly understood a detailed geomorphologic change detection and sediment erosion process caused by an extreme flood more than 100 year recurrence interval discharge on 14 apr 2016 was surveyed for a single urban meander loop of the karoon river iran the studied meander loop is located next to the city of the ahavz and has a centerline length of about 14 km the bathymetry in 8892 stable points was measured also the detailed bathymetry layers for before 8 apr 2016 and after 24 apr 2016 the extreme flood event were compared geomorphological change detection gcd results show that in the studied reach about 106 ha of bank erosion was detected with a total volume of approximately 450 600 m3 furthermore total volume of surface lowering and the total volume of surface rising volumes that were obtained were 95421 6 m3 and 98619 0 m3 respectively the talweg length of the studied meander loop decreased about 126 m and the average depth decreased from 3 71 m to 3 14 m after the flood event channel widening as a consequence of the extreme flood was found to be about 21 m 17 the findings of this study indicate that extreme floods play an important role in the sediment budget and morphological evolution of meandering rivers

soil landscape interplays at harmony point nelson island maritime antarctica chemistry mineralogy and classification abstract soils and landforms of nelson island remain one of the least studied in the south shetlands archipelago despite that it is one of the oldest ice free areas and is strongly vegetated in this paper we examine the main processes and factors of soil formation at harmony point and the relation of soils to landforms vegetation and lithology to achieve the goals 26 pedons were collected and studied from a 4 km2 ice free area at harmony point s62 18 w059 10 on the southern area of nelson island maritime antarctica the soils were sampled on all representative local landforms including three levels of uplifted marine terraces up to cryoplanated plateau waterlogged depressions rock felsenmeer debris slopes and patterned ground and a paraglacial border of the ice cap 270 m a s l sampling along the cryoplanated plateau was carried out along a gradient extending inland from the margins of the ice cap and sampling of the marine terraces was performed along a chronosequence under varying bird nesting influence and age the main pedogenetic processes observed in this area are marked phosphatization melanization from the accumulation of organic matter and cryoturbation soil development varies from weakly developed shallow stony and cryoturbated to well developed and organic rich phosphate soils with colors ranging from grayish to brown the mineralogical composition of the clay fraction contains secondary minerals indicating the active role of chemical weathering ornithogenic soils have mature phosphate minerals such as vivianite and taranakite as well as poorly crystalline leucophosphite intensively cryoturbated soils are underlain by permafrost and are classified as typic haploturbels polygonal soils are widespread on the cryoplanated plateau areas without permafrost were classified as typic gelorthents phosphatization is a dominant soil forming process in this area and is associated with past and present day guano accumulation by bird nesting and has led to the the development of deeper ornithogenic haplorthels the ornithogenic soils occur at different topographic levels on the cryplanated platform and marine terraces high p concentrations can be used as a proxy of the past nesting birds activities with far reaching implications especially with regards to vegetation growth and microbial activity and diversity

patterns of spatio temporal paraglacial response in the antarctic peninsula region and associated ecological implications abstract the antarctic peninsula ap constitutes the warmest region of antarctica although 98 of the surface is still covered by glaciers the region shows contrasting geographic and climatic properties which have conditioned past and present glacial activity this paper constitutes a review of the spatial and temporal patterns of paraglacial activity across the ap bridging the geomorphological and ecological perspectives the number and extent of ice free environments has increased since the last glacial maximum particularly during the early holocene and the 20th century following deglaciation the redefinition of coastlines and the uplift of landmasses proceeded differently in the three sectors of ap with maximum uplift in the western sector 40 m a s l the minimum on the north 20 4 m a s l and intermediate in the eastern sector 30 m there are also differences in the levels of raised beaches with the highest complexity in the northern ap 5 7 levels and the lowest in the eastern ap 3 levels the transition from glacial to periglacial conditions paraglacial stage also differed greatly between the three sectors with the absence of rock glaciers in the western sector the development almost exclusively of glacier derived rock glaciers in the eastern ap and the majority of talus derived rock glaciers in the northern ap the development of protalus lobes block streams and other periglacial features was highly dependent on the cold warm based character of individual glaciers this characteristic determines the existence or absence of permafrost following deglaciation which in turn conditions the type and intensity of geomorphic processes in newly exposed ice free areas more recently following the post 1950s regional warming there have still been important differences between the three sectors in the development of paraglacial environments permafrost degradation has occurred in newly exposed areas accelerating mass wasting and sediment redistribution and changing hydrological processes especially in the northern and western ap while sudden glacial outburst flooding has occurred in the eastern ap the most apparent major ecological response to this recent warming is greening due to vegetation expansion which is more evident where paraglacial and periglacial processes are less intense the accurate characterization of the different paraglacial responses existing in the ap enables a better understanding of future environmental responses in this climatically sensitive region where climate models forecast significant environmental change for during forthcoming decades

permian phytogeography in gondwana abstract phytogeographic patterns based on multivariate techniques multidimensional scaling are proposed for the permian vegetation of gondwana this approach requires a data set with broad geographic coverage based on generic composition and with good time control in general strong phytogeographic differentiation can be observed throughout the permian in order to identify short term phytogeographic patterns the permian period was informally divided into five time slices in the permian stage i earliest permian the vegetation was strongly influenced by glacial conditions a very impoverished vegetation is seen except in patagonia and parts of south america four units were identified patagonia nothosouthamerica australia and indo africa by far patagonia was the most diverse and had the most favourable climatic conditions perhaps as a result of palaeogeographic separation from western gondwana nothosouthamerica which included plant assemblages from nw argentina and brazil perhaps as two subunits is a mid latitude area with glacial influence in the brazilian sector indo africa had a much lower diversity occupying high latitudes whereas australia had the lowest diversity of all the vegetational regions in stage i the early permian stage ii shows a more diversified and expanded plant cover vegetation of eastern and western gondwana was differentiated patagonia and south america including a brazilian and nw argentinean unit had the richest plant assemblages whereas africa indo australia and antarctica as separate units are less diverse probably due to late glacial influence by the late early permian stage iii gondwana shows much more ameliorated climatic conditions basically due to drifting into more temperate latitudes as well as increased moisture resulting in expansion of peat forming areas this is immediately reflected in the vegetation as shown by diversified plant assemblages even in antarctica nonetheless a differentiation is again observed between eastern gondwana patagonian and south american units and the western sector indo australian and antarctic units whereas africa would probably represent an ecotone beginning in the late permian stage iv there was a decrease in the number of plant assemblages and diversity indicating a deterioration in climate resulting from generally drier conditions latitudinal differentiation can be observed with antarctica as a polar unit afro australia at high latitudes whereas the south american indian and patagonian units are located in middle latitudes finally in permian stage v latest permian a south american unit can be differentiated clearly from the rest africa and indo australia antarctica is interpreted again as a discrete unit in the stage v time slice eastern gondwana returns to more humid climatic conditions allowing the formation of extended peat swamps whereas the western sector is affected by seasonal and strong droughtness this kind of phytogeographic approach has proven useful for detecting some palaeogeographic problems such as those involving the patagonian subcontinent in this regard palaeogeographic reconstructions and palaeoclimatic models should be tested against these phytogeographic patterns

soil formation in seymour island weddell sea antarctica abstract the antarctic peninsula marks the climatic transition between maritime and continental antarctica ice free areas at the western side of the peninsula maritime antarctica have been increasingly studied in the last 10 years whereas soils on the eastern coast have been relatively less studied the objective of the present study is to analyze the properties of soils developed on seymour island in the weddell sea sector eastern coast of the antarctic peninsula in order to identify the main factors and processes involved in soil formation under semi polar desert conditions in this part of antarctica twenty one pedons were described sampled and analyzed for their physical chemical and mineralogical attributes most of the soils were classified as gelisols and cryosols by the soil taxonomy and wrb fao respectively three soil groups were found immature alkaline soils on sandstones and siltstones acid sulfate and ornithogenic soils soils have little cryoturbation and are all affected by salinization with natric and salic characters acid sulfate soils are the most weathered soils in seymour island due to the dry climate phosphatization is still incipient with p rich ornithogenic layers with little interaction with the mineral substrate the soil taxonomy and wrb fao systems lack adequate classification criteria to classify all soils developed in transitional areas that are affected by a combination of salinization sulfurization and phosphatization

channel reach morphology in mountain drainage basins a classification of channel reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types colluvial bedrock and five alluvial channel types cascade step pool plane bed pool rime and dune ripple coupling reach level channel processes with the spatial arrangement of reach morphologies their links to hillslope processes and external forcing by confinement ripar ian vegetation and woody debris defines a process based framework within which to assess channel condition and response potential in mountain drainage basins field investigations demonstrate character istic slope grain size shear stress and roughness ranges for different reach types observations consistent with our hypothesis that alluvial channel morphologies reflect specific roughness configurations ad justed to the relative magnitudes of sediment supply and transport ca pacity steep alluvial channels cascade and step pool have high ratios of transport capacity to sediment supply and are resilient to changes in discharge and sediment supply whereas low gradient alluvial channels pool rime and dune ripple have lower transport capacity to supply ra tios and thus exhibit significant and prolonged response to changes in sediment supply and discharge general differences in the ratio of transport capacity to supply between channel types allow aggregation of reaches into source transport and response segments the spatial distribution of which provides a watershed level conceptual model linking reach morphology and channel processes these two scales of channel network classification define a framework within which to in vestigate spatial and temporal patterns of channel response in moun tain drainage basins

active layer thermal monitoring of a dry valley of the ellsworth mountains continental antarctica abstract the ellsworth mountains are located along the southern edge of the ronne filchner ice shelf and are subdivided by the minnesota glacier into the heritage range to the east and the sentinel range to the west figure 1 the climate of the ellsworth mountains is strongly controlled by proximity to the ronne filchner ice shelf and elevation the entire ice free area is underlain by continuous permafrost of unknown thickness most in the form of dry permafrost active layer depths in drift sheets of the ellsworth mountains range from 15 to 50 cm detailed knowledge on antarctic permafrost is patchy especially at the continent two adjacent active layer monitoring sites were installed at mt dolence ellsworth mountains in the summer of 2012 two dry valley soils at mt dolence area on quartzite drift deposits were studied i a convex slope site exposed to the wind lithic haplorthel 886 m asl 5 cm 10 cm 30 cm and a sheltered concave slope site protected from winds lithic anhyorthel 850 m asl 5 cm 10 cm 30 cm data was recorded at hourly intervals from january 2nd 2012 until december 29th 2013 the soil climate temperature at 5 cm reaches a maximum daily mean in late december reaching a minimum in mid july at both sites active layer thickness reaches a maximum of 48 4 cm at p1 on january 17th 2013 and 47 8 cm at p2 on january 7th 2012 the soil thermal regime at the dry valley of mt dolence ellsworth mountains is characteristic of cold desert affected by dry frozen permafrost although air temperature does not reach elevated positive values variations in soil temperature are intense showing the soil s response to solar radiation the origins of typical surface periglacial features and landform on the widespread ellsworth drifts may be inherited from past events of warmer climates since liquid water is unlikely to play any significant role under the present climate

late quaternary climates and river channels of the atlantic coastal plain southeastern usa abstract late quaternary river patterns and sedimentation styles reflect past climate changes in atlantic drainages of eastern georgia and the carolinas past climate episodes for the region are summarized from pollen and eolian sedimentary records that exhibit correlation to major changes in river channel patterns records of past river responses are derived from luminescence and radiocarbon dated landforms and strata slow tectonic uplift does not explain temporal changes in channel patterns drainage networks have not received meltwater from continental or mountain glaciers eustatic influence would have been most pronounced on the now submerged continental shelf prior to 6 ka and currently manifests only within 60 80 km of the present highstand shoreline human impact overshadows climatic changes during historic time but was negligible during prehistoric time the late quaternary fluvial system primarily responded to climatic fluctuations that drove changes in vegetation precipitation and runoff patterns prehistoric meandering paleochannels of the holocene stand as important references to guide natural channel rehabilitation efforts during the coldest climate phases of the late wisconsin stage ca 30 16 ka when forest vegetation was sparse and interspersed with grasses and herbs many rivers and streams were braided with eolian dunes on the floodplains the terminal wisconsin stage ca 16 11 ka exhibited rapid warming and forest expansion characterized by pronounced change from braided to meandering patterns with intermediate forms of sandy scroll bar patterns the younger dryas cold excursion is not readily apparent in the regional fluvial record unusually large meandering channels of the terminal wisconsin stage continue into the first half of the holocene and indicate significantly larger bankfull flood discharges during those times than during the last half of the holocene bankfull channels during the last half of the holocene retained meandering patterns but decreased to modern like dimensions suggesting more modern like flood regimes no clear fluvial response occurs to the presumed middle holocene climatic optimum hypsithermal the medieval warm period and little ice age or to recent instrumentally observed fluctuations in climate but little research has been done in these realms

role of debris flows in long term landscape denudation in the central appalachians of virginia four major storms that triggered debris flows in the virginia west virginia appalachians provide new insights into the role of high magnitude low frequency floods in longterm denudation and landscape evolution in mountainous terrain storm denudation in the blue ridge mountain drainage basins is approximately an order of magnitude greater compared to basins located in the mountains of the valley and ridge province this difference is probably the result of higher storm rainfall from the blue ridge storms radiocarbon dating of debris flow deposits in the blue ridge indicates a debris flow return interval of not more than 2 4 k y in mountainous river basins this finding combined with measurements of basin denudation suggests that approximately half of the long term denudation from mechanical load occurs episodically by debris flow processes although floods of moderate magnitude are largely responsible for mobilizing sediment in lowgradient streams our data suggest that high magnitude low frequency events are the most significant component in delivering coarse grained regolith from mountainous hollows and channels to the lowland floodplains

paleobotanical and paleoecological constraints on models of peat formation in the late carboniferous of euramerica abstract the dominant plants of the late carboniferous lowland tropics were taxonomically and structurally distinct from those of any later time periods dominance was distributed among lycopsids ferns sphenopsids pteridosperms and cordaites and each of these groups had distinctive and different ecological preferences and amplitudes peat forming habitats were dominated by lycopsids throughout the westphalian with a significant cordaitean element in the middle westphalian during the stephanian tree ferns were dominant following major extinctions near the westphalian stephanian transition each of the major plant groups had distinctive architectures and tissue composition trees contributed up to 95 of the peat biomass and tree forms of lycopsids psaronius and medullosa lack good modern analogues the cordaites were the only woody plant group to contribute significantly to peat and then only during the mid westphalian structurally wood like lycopsid bark is the major woody tissue encountered in most westphalian coals tree ferns and pteridosperms were largely parenchymatous in construction the stigmarian root systems of lycopsids also were largely parenchymatous the tissue structure of these dominant plant suggests the need for extreme caution in the inference of mire ecological conditions or vegetational structure from coal petrographic data peat formed under arborescent ferns or pteridosperms or peat repeatedly exposed to decay and rerooting by stigmarian root systems of lycopsids would have a distinctly non woody signature and yet would have formed in a forested environment a summary is presented of the autecology and synecology of mire plants emphazing the structural framework provided by lycopsids during the westphalian certain constraints in the links between peat biomass and miospore palynology are discussed in terms of over representation under representation and non representation the formulation of smith s four phase hydroseral model is discussed and compared with more recent data available from plant paleoecology the current debate over an ombrotrophic vs rheotrophic origin of late carboniferous peats relies in large part on paleobotanical data almost entirely palynological in combination with petrographic analyses ecological studies of miospores and of coal ball and compression macrofossils and the linkage of miospores to source plants permit the re evaluation of mire successional models evidence for tree lycopsids sphenopsids pteridosperms and cordaites suggests growth mainly in rheotrophic mires tree ferns are likely candidates for growth in domed mires although evidence is ambiguous and some tree ferns clearly grew under rheotrophic conditions densospores produced by at least sporangiostrobus lycopsid subtrees have been considered diagnostic of ombrotrophic conditions abundant evidence refutes this simplistic interpretation and suggests broad ecological amplitudes for densospore producers including growth under rheotrophic conditions although plant fossils alone can not resolve most of the major debates in modern coal geology paleobotany does contribute significantly to our understanding of ancient mires an approach combining paleobotanical data with petrography sedimentology and geochemistry on a case by case basis is most likely to produce a clear picture

channel response to sediment wave propagation and movement redwood creek california usa redwood creek north coastal californa usa has experienced dramatic changes in channel confguation since the 1950s a series of large floods in 1955 1964 1972 and 1975 combined with the advent of widespread commercial timber harvest and road building resulted in extensive erosion in the basin and contributed high sediment loads to redwood creek since 1975 no peak flows have exceeded a 5 year recurrence interval twenty years of cross sectional survey data document the downstream movement of a sediment wave in the lower 26 km of this gravel bedded river at a rate of 800 to 1600 m a i durng this period of moderately low flows higher transit rates are associated with reaches of higher unit stream power the wave was initially deposited at a site with an abrupt decrease in channel gradient and increase in channel width the amplitude of the wave has attenuated more than i m as it moved downstream and the duration of the wave increased from eight years upstream to more than 20 years downstream channel aggradation and subsequent degradation have been accommodated across the entire channel bed channel width has not decreased significantly after initial channel widening from large 25 year recurrence interval floods three sets of longitudinal surveys of the streambed showed the highest increase in pool depths and frequency in a degrading reach but even the aggrading reach exhbited some pool development through time the aggraded channel bed switched from functioning as a sediment sink to a significant sediment source as the channel adjusted to high sediment loads from 1980 to 1990 sediment eroded from temporary channel storage represented about 25 per cent ofthe total sediment load and 95 per cent of the bedload exported from the basin

rock glaciers and protalus landforms analogous forms and ice sources on earth and mars 1 the basic features and terminology of terrestrial rock glaciers are reviewed together with associated forms termed protalus lobes and protalus ramparts two basic models of rock glacier formation and flow invoke either the creep of ice derived from permafrost or glacial former glacial activity a third possible mechanism invokes landslide emplacement observations on terrestrial rock glaciers and similar forms suggest that the ice component can be produced via ground ice or from a glacier system finite element modeling of simple slope systems containing 1 a continuous ice layer buried by debris and 2 a mixture of ice and rigid blocks can both show creep but with very low rates especially at low temperatures possible martian examples of rock glacier and protalus lobe features are identified from candor chasma by wide angle mars orbiter camera moc imagery although the topography does not allow unambiguous interpretation some possible ways in which moc and mars orbiter laser altimeter mola and other mars orbiter data could help future interpretation of rock glaciers related protalus landforms and ice presence are discussed

geomorphology and soils distribution under paraglacial conditions in an ice free area of admiralty bay king george island antarctica abstract the main pedological geomorphological and cryogenic features of keller peninsula part of admiralty bay king george island maritime antarctica were mapped and quantified with emphasis on the relationship between the ice retreat process melt out landform development and soil distribution moraines protalus scree slopes inactive glacial cirques uplift marine terraces biogenic landforms aretes and felsenmeer were mapped scree slope is the main landform covering approximately 25 of the peninsula indicating prominent paraglacial features inherited glacial landforms such as lateral moraines highland plateau and exhumed u shaped valleys are now being exposed in north keller by ice shrinkage of former ice protecting cover landforms influenced soil formation and stability cryosols and leptosols wrb roughly corresponding to gelisols and entisols sss respectively are the most common soil classes with an overall tendency of absent permafrost in the coastal areas changing to sporadic permafrost at mid slope and discontinuous permafrost with greater altitude and substrate stability

rock glaciers in the south shetland islands western antarctica rock glaciers are found in the peripheral regions of antarctica particularly in the antarctic peninsula region study of these features is relevant for the palaeoenvironmental reconstruction of maritime antarctica because they are indicators of permafrost and periglacial conditions this paper reports and analyzes the results of an inventory of rock glaciers and protalus lobes in the south shetland islands nine rock glaciers and eleven protalus lobes have been identified all of them are located in recently deglaciated zones between 300 m a s l and sea level and they cover an area of 497 103 m2 tongue shaped rock glaciers are more common than lobate types being in general of medium and small sizes they are talus rock glaciers 55 and debris rock glaciers 45 according to the genetic classification the lack of a preferred orientation suggests that there is no significant microclimate control on their distribution they are related to particular morphodynamic situations estimated annual velocities based on relationships with raised beaches and transported debris volumes range between 2 4 and 97 cm year 1 within the ranges reported for other rock glaciers three groups of rock glaciers can be recognised a those immediate postdating the last major ice recession b rock glaciers younger than 2000 years bp but pre dating the little ice age lia and c rock glaciers formed during the lia

fluvial responses to land use changes and climatic variations within the drury creek watershed southern illinois abstract fluvial responses to climatic variation and anglo american settlement were documented for the drury creek watershed southern illinois by examining stratigraphic geomorphic climatic and historical data regional analyses of long term precipitation records document a period of decreasing mean annual precipitation from 1904 to about 1945 and an increasing trend in annual precipitation from 1952 to the present the period between 1945 and 1951 experienced a large number of intense storms that resulted in high annual precipitation totals statistical relationships illustrate that changes in precipitation totals are transferred to the hydrologic system as fluctuations in stream discharge historical records of southern illinois show that a maximum period of settlement and deforestation occurred between the 1860s and 1920s this era ended in the 1940s when large tracts of land were revegetated in an attempt to curtail erosion which had caused extensive upland degradation in response to hillslope erosion at least two meters of fine grained sediments were deposited on valley floors average sedimentation rates determined using decdrochronologic techniques are estimated to be 2 11 cm yr for the period between 1890 and 1988 rates that are 1 to 2 orders of magnitude greater than pre settlement values calculated for other areas of the midwest however botanical data suggest that aggradation was episodic possibly occurring during three periods characterized by greater annual precipitation since the 1940s sedimentation rates have declined reduced rates of sedimentation are related to an episode of channel entrenchment that reduced overbank flooding entrenchment coincided with a period of 1 reduced sediment yields associated with watershed revegetation and the introduction of soil conservation practices and 2 intense storm activity that resulted in long periods of high discharge as a result of channel incision and hillslope erosion newly exposed bedrock in upstream areas currently provides a source of gravel load to the channels the distribution of coarse bedload material along tributary streams combined with downstream decreases in width depth ratios and tractive force estimates suggest that channels in the drury creek watershed are slowly adjusting their configuration to transport coarse bedload material the fluvial response to the increased influx of coarse sediment began more than 45 years ago and continues today

sampling methods for quantitative analysis of coal ball plants abstract three methods were used to collect data from the same coal ball peels and were compared for data comparability and for relative time efficiency although the data produced by the standardly used cm2 grid method and by the newly devised random mm2 method were of equivalent accuracy the newly devised method is estimated to be much more time efficient for abundant samples of coal balls containing numerous small plants in contrast the accuracy of the subdivided cm2 method is equivocal and the time efficiency of this method is minimal

late holocene paleofloods in the upper little tennessee river valley southern blue ridge mountains usa we derive a paleoflood chronology for the past 2000 years from three stratigraphic sections of overbank sediments with dates from radiocarbon luminescence 137cs techniques and historical records particle sizes were measured in 6 15 year intervals in post 1870 sediments and in 45 170 year intervals in pre 1870 sediments using an automatic laser analyzer the sedimentological characteristics of ad 1948 2009 deposits were compared with gaging records demonstrating that fine sand content and sorting discern time intervals of large floods but flood magnitudes are not well resolved this modern analog was applied to pre 1870 sediments and revealed two periods in the last 2000 years with large floods during ad 650 850 and ad 1100 1350 which are times when the regional tree ring record showed extreme wetness and no severe or extreme droughts our findings indicate flood prone phases of transitional climate at the beginning and end of the medieval warm period mwp and relatively subdued flooding during

confirmation of carboniferous clastic swamp communities tropical lowlands dominated by arborescent lycophytes are the principal foci for our understanding of carboniferous peat and non peat accumulating coastal swamps1 2 suggested palaeoeco logical interpretations of various lycophytes and accessory vegetation have been based on transported compression assemblages3 4 and palynomorphs5 6 or in situ permineralized peats7 where transported macrodetritus resulting in compression assemblages is used to reconstruct past vegetational patterns taphonomic factors tend to bias the preserved flora8 11 taken alone or out of depositional context the heterogeneity of an assemblage most probably bears little or no relationship to that of the original contributing communities gastaldo9 suggests that reconstructions should be based on the autecology of erect in situ plants because with peats permineralized in situ precise resolution in time of laterally equivalent vegetation is difficult here i document an erect in situ early pennsylvanian lycophyte swamp which provides the first confirmatory evidence for previously hypothetical ecological amplitudes

genesis properties and classification of cryosols from admiralty bay maritime antarctica abstract soils from maritime antarctica are different than those from other antarctic climatic zones and are among the least studied soils in antarctica we here present analytical and morphological data for the main soils found in admiralty bay king george island in the south shetland group fifty six 56 pedons were described sampled and analyzed according to standard international methods and classified according to both u s soil taxonomy and the wrb the soils are generally weakly developed and have chemical physical and morphological characteristics strongly influenced by the parent material we identify four main soil groups i basaltic andesitic ii acid sulfate iii weakly ornithogenic and iv ornithogenic soils small adjustments are proposed for both classification systems for allowing a more adequate classification for maritime antarctica greyish colored eutric lithic and typic haploturbels turbi leptic cryosols with neutral to alkaline reaction are the most common soils in admiralty bay and are usually developed from basaltic andesitic tills yellowish acid dystric sulphuric haploturbels turbi thionic cryosols are restricted to areas affected by pyritized andesites umbriturbels turbi umbric cryosols only occur at sites under bird influence ornithogenic soils are the most developed soils in admiralty bay and show pronounced chemical physical and morphological alteration of parent materials with formation of umbric epipedons and phosphatic b horizons fibristels organo turbic cryosols are restricted to hydromorphic areas under thick moss carpets

a review of charcoal analysis as a tool for assessing quaternary and tertiary environments achievements and limits abstract identification of charcoal fragments 2 mm using reflected light microscopy is routinely carried out to study former natural ecosystems assess changes in vegetation communities over time and identify the influence and patterns of behaviour of human populations on vegetation material studied comes either from archaeological horizons or soil profiles despite undeniable limits informative results have been obtained in the last 25 years mostly in southwestern europe where charcoal analysis has been widely applied in quaternary studies examples of these achievements are provided focusing on the major vegetation trends since the upper palaeolithic to the middle ages the techniques used for charcoal analysis in the reconstruction of quaternary vegetation are now being used to study tertiary charcoal and lignites the study of fossil charcoal can be a highly informative method for interpreting ancient ecosystems as species easily degraded may be preserved by charcoalification some results from the lower rhine embayment germany are presented here

paleoecology of the late pennsylvanian age calhoun coal bed and implications for long term dynamics of wetland ecosystems quantitative plant assemblage data from coal balls miospores megaspores and compression floras from the calhoun coal bed missourian of the illinois basin usa are used to interpret spatial and temporal changes in plant communities in the paleo peat swamp coal ball and miospore floras from the calhoun coal bed are dominated strongly by tree ferns and pteridosperms and sigillarian lycopsids are subdominant depending on geographic location within the coal bed although the overall composition of calhoun peat swamp assemblages is consistent both temporally and spatially site to site differences and short term shifts in species dominance indicate local topographic and hydrologic control on species composition within the broader context of the swamp statistical comparison of the calhoun miospore assemblages with those from other late pennsylvanian coal beds suggests that the same basic species pool was represented in each peat swamp landscape and that the relative patterns of dominance and diversity were persistent from site to site therefore it appears that the relative patterns of proportional dominance stayed roughly the same from one coal bed to the next during late pennsylvanian glacially driven climatic oscillations

do periglacial landscapes evolve under periglacial conditions polar and alpine periglacial areas are traditionally regarded as necessarily submitted to very efficient frost driven processes that control the holocene and ongoing geomorphic activity during the last decade the validity of this academic view has been increasingly questioned among the international scientific community the search for the real past and present processes responsible for landform evolution in cold nonglaciated areas is based mainly on more and more refined monitoring protocols relying upon sophisticated equipment to assess the representativeness and significance of monitoring data collected in restricted sites it appears necessary however to widen the perspective by adopting a twofold multiscale approach as proposed in the present paper 1 in space by integrating various scales from the general slope system to the bioclimatic nanoenvironment and 2 in time by taking into account the landscape history from tertiary inherited features to recent process changes induced by the contemporary warming reintegrating the historical approach should help both to place the ongoing processes within a succession and or combination of interoperating processes and to avoid misinterpretations of features considered wrongly as emblematic of frost action overall both the historical and monitoring approaches tend to reduce the geomorphic efficiency of frost derived processes instead the role of noncold related processes such as chemical thermal biogenic and rainfall induced ones is being emphasized of special interest would be an interdisciplinary discussion between geomorphologists and various disciplines of biological sciences including biochemistry and ecology studying processes of primary successions

geomorphological characteristics of small debris flows on junior s kop marion island maritime sub antarctic the geomorphological characteristics of small debris flows in a maritime sub antarctic environment are described the morphological and sedimentological characteristics of the debris flows are comparable to debris flows documented for other parts of the world their initiation appears closely linked to the unusual environment in which they are found sediment supply is generated by diurnal frost heave of loamy sediment associated with azorella selago the debris flows are triggered by sediment mobilization upon saturation of the frost heaved surface gravel and overland flow over the low permeability and frost susceptible slope materials morphological effects of the flows are short lived due to obliteration by subsequent frost heave activity copyright 2000 john wiley sons ltd

holocene ethnobotanical and paleoecological record of human impact on vegetation in the little tennessee river valley tennessee abstract human occupation and utilization of plant resources have affected vegetation in the lower little tennessee river valley of east tennessee for 10 000 yr changes in indian cultures and land use are documented by radiocarbon chronologies lithic artifacts ceramics settlement patterns and ethnobotanical remains from 25 stratified archaeological sites within the holocene alluvial terrace the ethnobotanical record consists of 31 500 fragments 13 7 kg of wood charcoal identified to species and 7 7 kg of carbonized fruits seeds nutshells and cultigens from 956 features pollen and plant macrofossils from small ponds both in the uplands and on lower stream terraces record local vegetational changes through the last 1500 to 3000 yr human impact increased after cultigens including squash and gourd were introduced ca 4000 yr b p during the archaic cultural period forest clearance and cultivation disturbed vegetation on both the floodplain and lower terraces after 2800 yr b p during the woodland period permanent indian settlements and maize and bean agriculture extended to higher terraces 1 5 km from the floodplain by the mississippian period 1000 to 300 yr b p after 300 yr b p extensive land clearance and cultivation by historic overhill cherokee and euro americans spread into the uplands beyond the river valley

discussion on origin of vanadium in coals parts of the western kentucky usa no 9 coal rich in vanadium special publication no 125 1997 273 286 scientific editing by peter haughton james c hower stephen f greb james c cobb david a williams write premovic et al 1997 following studies by zubovic 1966 maylotte et al 1981 and hower et al 1990 b discussed the origin of vanadium anomalies in the upper few centimetres of the springfield no 9 coal bed middle pennsylvanian carbondale formation in a limited area of the western kentucky coal field the vanadium enrichment is accompanied by high concentrations of other metals notably cr ni and zn their conclusions with regard to the origin of the vanadium enrichment and to the geology of the springfield coal bed conflict with the established geology of the coal the enrichment of v in the top few centimetres of the coal bed was established by zubovic 1966 hower et al 1990 b noted this trend at 42 of 44 western kentucky sites although their study sites did not in many cases have the vertical resolution of the previous study premovic et al examined the v enrichment in samples from the providence mine southwestern hopkins county kentucky a site where the upper 12 6 cm lithotype has 10 600 ppm v our analysis via xrf reported on ash basis 11 67 ash premovic et al state that it is quite unlikely that a source of v in the w ky no 9 coal was ordinary shallow 100 m swamp waters p 280 as the levels of metals in modern swamp waters are very low the springfield coal is overlain by a black phosphatic shale which yields a characteristically high gamma response on subsurface logs such shales are characteristic of many mid continent coal bearing cyclothems for example the colchester coal another desmoinesian coal of the illinois basin has a high gamma roof

common ground between two british pennsylvanian wetland floras using large first hand datasets to assess utility of historical museum collections abstract studies on the macrofloral record of the pennsylvanian palaeotropical peat forming wetlands coal swamps depend heavily on historical collections in museums this paper examines the robustness of such collections for macrofloral studies 110 000 individually recorded specimens from south wales field collected by david davies during the early 20th century were compared with the 6500 museum voucher specimens derived from them eventually intended for a representative teaching collection this showed that the voucher collections accurately reflect the order of abundances of the plant groups as documented in the field records but not their actual numerical abundances these welsh data were then compared with the available museum collections for similar aged macrofloras in the nearby bristol somerset coalfield cluster analyses and detrended correspondence analyses were performed 1 on the raw data recorded on the museum labels 2 on standardised data that were updated to reflect the currently accepted taxonomy for these fossils and 3 on standardised data in which single occurrences of taxa have been removed the results suggest that unstandardised museum collection data can reveal meaningful biostratigraphical and biogeographical patterns but that these become clearer with the standardised data the effect of removing the singleton taxa was less clear although it did provide a slightly enhanced resolution with cluster analysis whilst previous studies have considered these to be separate basins with the bristol somerset coalfield being proximal to south wales on the mid pennsylvanian variscan front results show an overall consistency between the two basins and suggest a common gene pool and vegetational physiognomy as well as a general stasis through time based on relatively stable environmental and growth conditions the study confirms that even unrevised historical collections can provide some data to help understand the dynamics of these systems however it also underlines the importance of taxonomy in such studies as it helps improve both the biostratigraphical and biogeographical resolution

response of bankfull discharge to discharge and sediment load in the lower yellow river this paper presents a study on the response of bankfull discharge to incoming discharge and sediment load based on long term hydrological and bankfull discharge data measured on the lower reaches of the yellow river the analysis indicated that the bankfull discharge was a function of the preceding 5 to 6 years flow regimes revealing that bankfull channel dimensions were a result of the accumulative effect of several consecutive years flow discharge and sediment load conditions in other words the mean relaxation time was about 5 to 6 years for channel adjustment theoretical methods for the prediction of bankfull discharge were developed in which the response time or the relaxation time was fully considered testing of the methods using data observed at five hydrologic stations in the lower reaches of the yellow river from 1960 to 2003 showed that the proposed methods can predict the variation of bankfull discharge in response to changes in the incoming discharge and sediment load the proposed methods hold promise for predicting the magnitude and trend of channel response to other rivers undergoing aggradation or degradation from changes in hydrologic or sediment regime

effects of aggradation and degradation on riffle pool morphology in natural gravel channels northwestern california after the flood of december 1964 12 gaging sections in northern california widened as much as 100 and aggraded as much as 4 m and then degraded to stable levels during a period of 5 years or more as channels aggraded bed material became finer and low to moderate flow through gaging sections in pools became shallower faster and steeper comparisons of longitudinal profiles also show the diminishment of pools as well as a decrease in bar relief accompanying the excessive sediment load as gaging sections degraded hydraulic geometries recovered to a limited degree full recovery probably depends on channel narrowing and further depletion of sediment supply the hydraulic changes with aggradation indicate an increase in the effectiveness of moderate discharges less than i to 2 year recurrence interval annual flood series to transport bed load and shape the bed bars become smaller pools preferentially fill and rimes armored with relatively small gravel tend to erode headward during falling stages and form a gentler gradient excess sediment can thus be more readily transported out of channels when additional contributions from watersheds are usuall slight

multi scalar controls on channel geometry of headwater streams in new zealand hill country abstract catchment reach and local scale controls upon channel geometry are examined for small headwater streams in adjacent sub catchments with variable land use histories in a typical hill country area of the north island of new zealand although systematic downstream increase in channel cross sectional area is evident in one sub catchment a result of catchment scale controls on geometry including discharge and slope marked local variability in channel geometry in the two other sub catchments reflects non systematic patterns of reach scale controls including the distribution of floodplain pockets and associated bank materials and local scale controls such as bedrock outcrops and wood land use change exerts a primary control upon these relationships for a given catchment area streams in native forest are wider and shallower than streams that flow within pasture or pinus plantations increased hillslope erosion following land clearance has instigated the accumulation of post settlement alluvium psa which has altered the boundary conditions and bank materials within which streams flow significant psa accumulation following native forest clearance in one of the sub catchments has allowed the stream to flow entirely within its own alluvial deposits in this instance catchment scale controls on channel geometry are dominant in contrast local scale controls on channel geometry are more important in the other sub catchments where lesser accumulation of psa reflects differences in land clearance these findings indicate that place based understandings which consider the spatial and historical contexts of landscape settings are required to interpret patterns of channel geometry and to inform river rehabilitation initiatives

anthropogenically accelerated mass movement kulu valley himachal pradesh india abstract a devastating landslide occurred on 12 september 1995 near luggar bhatti kulu himachal pradesh and killed 65 people an estimated 0 96 106 m3 of unconsolidated mass slid sse down the terminal part of a thick alluvial fan of quaternary age on the left bank of the beas river about 0 03 106 m3 of dislodged material formed a 15 m high and 150 m long hump at the bottom of the failed slope a shallow sag pond developed in the rear the slide occurred after heavy rains on 3 6 september in the region when the beas rose to a bankfull position factors involved in this toppling cum debris slide include steep slope continuous seepage with high pore water pressure in unconsolidated material a road cut obliterating the foot of the fan slope and impinging by the beas river during the flood a survey in the area showed that a variety of mass movement processes were triggered by the heavy rains in september the most predominant being a series of slope failures on the outside of meander loops and bank erosion caused by turbulence of the overflowing beas river extensive damage was sustained by national highway 21 nh 21 a bridge ramp near bhuntar a suspension bridge at kulu and two other bridges upstream most damage occurred in the manali area where massive buildings were washed away by the flash flood this paper examines the factors and processes responsible for triggering widespread mass movement and related damages in the kulu valley whereas some smaller events occurred in the early and middle part of this century the recurrence and intensity of mass movements are recent phenomena attributed mainly to escalating socio economic development growth of tourism and population pressure some long term policy is suggested for mitigation of landslides and other denudational processes in relation to impelling human factors

soils and landforms from fildes peninsula and ardley island maritime antarctica abstract fildes peninsula f p and ardley island a i are among the first ice free areas in maritime antarctica since the last glacial retreat in this part of antarctica 8000 to 5000 years bp the landscape in these areas evolved under paraglacial to periglacial conditions with pedogenesis marked by cryogenic processes we carried out a detailed soil and geomorphology survey with full morphological and analytical description for both areas forty eight soil profiles representing different landforms were sampled analyzed and classified according to the u s soil taxonomy and the world reference base for soil resources wrb soils are mostly turbic moderately developed with podzolization and strong phosphatization chemical weathering of rock minerals and formation of amorphous al and fe minerals in former ornithogenic sites while in areas with poor vegetation show typical features of cryogenic weathering nivation solifluction cryoturbation frost weathering ablation and surface erosion are widespread the most represented landform system by surface in fildes peninsula is the periglacial one and 15 different periglacial landforms types have been identified and mapped these features occupy about 30 of the land surface in which patterned ground and stone fields are the most common landforms other significant landforms as protalus lobes rock glaciers or debris lobes indicate the extensive presence of permafrost soil variability was high in terms of morphological physical and chemical properties due to varying lithic contributions and mixing of different rocks as well as to different degrees of faunal influence three soil taxonomy orders were identified whereas thirty four individual pedons were differentiated fildes peninsula experiences a south north gradient from periglacial to paraglacial conditions and apparently younger soils and landforms are located close to the collins glacier arenosols entisols and cryosols gelisols frequently cryoturbic are the most important soil classes leptosols entisols gleysols aquents and cambisols inceptisols also occur all with gelic properties and with varying faunal influences both soil classification systems are adequate to distinguish the local pedogenesis processes the wrb system is broader since it was designed to be applied in all polar regions the family classes adopted by the st were effective in separating soils with important differences with regard to texture and gravel content all important attributes accounting for the ecological succession and periglacial processes an altitudinal organization of landforms and processes can be recognized from geomorphological mapping periglacial features are dominant above 50 m a s l although are present at lower altitude

properties and processes of recently established soils from deglaciation of cierva point western antarctic peninsula abstract for more than sixty years the antarctic peninsula has experienced significant temperature increases that have accelerated glacial retreat glacial losses along with the relatively warm and moist climatic conditions of the region have increased the rate of soil development the objective of this study is to study the properties and genesis of soils at cierva point which is located in the zone of maximum warming along the western antarctic peninsula cierva point is a terraced steeply sloping ice free peninsula containing a small retreating glacier the peninsula contains a large penguin rookery and significant areas of moss buildup twenty seven soils were described physical and chemical properties from each horizon were analyzed four categories of soil were identified acidic ph 5 moss dominated high organic matter accumulations and ornithogenic high phosphorus accumulations neutral soils were newly formed soils which had undergone the least development and were located closest to the glacier margin acidic soils were located farthest from the glacier margin allowing for a greater nutrient leaching to occur these soils have extremely low ph values as low as 3 5 but did not have the high phosphorus accumulations found in ornithogenic soils or the high soil carbon content found in moss dominated soils in a region with rapidly retreating glaciers such as the antarctic peninsula proximity to the glacier margin becomes an important factor determining soil properties soils farther from the glacier have had more time to be affected by leaching penguin activity and moss buildup

changes in the channel bed level of the eastern carpathian rivers climatic vs human control over the last 50 years article i nfo this paper is focused on the changes over the past 50 years in the channel beds of seven major rivers that are part of the siret drainage basin located in eastern romania each river has been subjected to various degrees of human intervention assessed based on the morphological quality index mqi two rivers siret and bistrita have undergone complex human interventions on 40 and 60 respectively of their channel lengths two rivers suceava and moldova are 30 artificial and the remaining three rivers trotus putna and buz u have a good or moderate mqi the changes occurring in channel beds and data on water discharge qw and sediment load qs w ere assessed simultaneously for the last 50 years the bedload was indirectly evaluated as ranging between 5 and 15 of the total sediment load it was determined that incision was prevalent among the processes acting on the channel bed sections under investigation representing 62 of the altered area and changing bed level by between 0 25 and 2 70 m with aggradation accounting for the remaining 38 causing changes ranging from 0 15 to 1 25 m the magnitude of the processes incision or aggradation for sections with an mqi b 0 3 was four times higher than for sections with a moderate or good mqi 0 3 the pattern of change in the channel bed processes between 1960 and 2010 for all river categories was as follows a low rate of incision from 1960 to 1979 followed by a higher rate of incision from 1980 to 1989 and finally a tendency of recovery toward the river s initial state characterised by a decrease in the incision rate or slight aggradation after 1990 the variable that exhibited the strongest response to climate conditions was water discharge qw whereas the sediment load qs was highly responsive to both climatic signals and anthropogenic factors the sediment load has been instrumental in the adjustments of the channel beds by maintaining a balance between the two controlling factors nature and man

the maritime subantarctic a distinct periglacial environment recent research on slope processes and weathering on marion island has highlighted distinctive attributes of the maritime subantarctic periglacial environment compared to other periglacial environments this is reflected morphologically by sorted stripe characteristics and stratified solifluction forms but the wind factor and low diurnal temperature range also results in differences with other diurnal frost environments its hyper maritime setting at low mean annual temperatures results in very high frost cycle frequencies with associated effectiveness in surface sediment transport and patterned ground development in addition a high frequency of wetting and drying cycles is observed in rocks small seasonal temperature ranges and steep temperature profiles indicate a high sensitivity to climate change in the subantarctic as reflected in a rich relict periglacial record on most islands this sensitivity appears absent in high tropical environments of low annual temperature range