sedimentology of the bondi main heavy mineral beach placer deposit murray basin southeastern australia abstract drilling and pit wall exposures at the southern end of the bondi main heavy mineral beach placer deposit provided access to the loxton parilla sands which are here divided into five lithofacies the depositional environment of each lithofacies is interpreted as shoaling zone breaker zone surf zone swash zone and backshore dune other units encountered include the duddo limestone loddon river group bookpurnong formation and shepparton formation the interpreted depositional environments for these units are respectively shallow marine fluvial shallow marine shelf and fluvio lacustrine a palaeogeographical model is presented which proposes that the bondi main deposit formed at the southern end of a north trending shoreline this shoreline was truncated to the south by the dundas tableland and is broadly analogous in its geomorphological setting to the modern geographe bay in western australia the deposit therefore appears to have formed in association with a heavy mineral trap at its southern end postdepositional weathering overprints include ferruginous mottling clay eluviation and possibly quartz fracturing and disaggregation the ferruginous mottles formed under spatially and temporally variable redoximorphic conditions with fe being derived from the weathering of fe bearing primary minerals particularly ilmenite postdepositional clays in the loxton parilla sands are interpreted as being derived from the overlying shepparton formation

lee mixing and nocturnal structure over gentle topography abstractthis study analyzes measurements from a network of sonic anemometers over gentle topography to investigate the possibility of nocturnal lee generated turbulence although the valley side slopes are less than 6 and extend only about 12 m above the floor of the valley the turbulence can be enhanced in the lee of one of the slopes significant lee turbulence develops downwind from an abrupt slope transition between a miniplateau and the modest valley side slope lee generated turbulence is not observed on the opposite slope where the slope magnitude gradually decreases with height with intermediate 1 m wind speeds of roughly 2 4 m s 1 the cold pool is advected up the downwind slope this downwind displacement of the cold pool and warming by lee generated turbulence when it occurs leads to significant horizontal asymmetry of the temperature across the valley for stronger winds the cold pool is eliminated by mixing for weak winds a more traditional cold pool forms centered on the valley floo

numerical simulation of katabatic flow with changing slope angle a large eddy simulation les model and the advanced regional prediction system arps model which does not resolve turbulent eddies are used to study the effect of a slope angle decrease on the structure of katabatic slope flows for a simple uniform angle slope simulations from both models produce turbulence kinetic energy and momentum budgets that are in good overall agreement simulations of a compound angle slope are compared to a uniform angle slope to demonstrate how a changing slope angle can strongly affect the strength of katabatic flows both arps and the les model show that slopes with a steep upper slope followed by a shallower lower slope concave shape generate a rapid acceleration on the upper slope followed by a transition to a slower evolving structure characterized by an elevated jet over the lower slope in contrast the case with uniform slope having the same total height change yields a more uniform flow profile with stronger winds at the slope bottom higher average slope in the uniform slope angle case generates greater gravitational potential energy which is converted to kinetic energy at the bottom of the slope analysis of the total energy budget of slope flows indicates a consistent structure where potential energy generated at the top of the slope is transported downslope and converted into kinetic energy near the slope base

a linkage among pangean tectonism cyclic alluviation climate change and biologic turnover in the late triassic the record from the chinle formation southwestern united states abstract high precision geochronology provides unprecedented insights into the depositional history of the upper triassic chinle formation of the colorado plateau as well as its paleoenvironmental and paleobiological records the chinle succession exposed in the petrified forest national park pefo and vicinity arizona includes two large scale alluvial composite sequences although each composite sequence fines upward the upper composite sequence is more dominated by coarser grained deposits petrographic analysis of sandstone lithic content indicates an upward decrease in the proportion of volcanic rock fragments in each composite sequence paleocurrent indicators in the lower composite sequence suggest a variable paleoflow direction whereas northward paleoflow dominated the upper composite sequence the change in paleoflow appears to coincide with a reorganization of alluvial depositional processes and associated source terranes and precedes a rapid acceleration in basin subsidence climate proxy records from paleosol geochemistry indicate a gradual shift from humid to dry conditions across the transition between the lower and upper composite sequences and the adamanian revueltian biotic turnover composite sequence depositional reorganization climatic shift and biologic turnover in turn appear to coincide with episodes of magmatism recorded in triassic granitoid plutons presently exposed in southern california taken collectively these observations suggest that the late triassic depositional climatic and ecologic history at pefo may be related to emergence of the incipient cordilleran magmatic arc along the convergent western margin of pangea a new u pb date for the lower part of the chinle formation suggests that most or all of the formation was deposited in the norian stage

katabatic wind in opposing flow abstract this paper presents a one dimensional model of katabatic winds in ambient flow and examines types of possible solutions results presented in dimensionless form indicate that 1 cooling along a slope with upslope ambient flow can lead to tranquil flow speed less than gravity wave speed solutions characterized by appreciable entrainment and 2 the onset time of katabatic winds is particularly sensitive to the retarding effects of opposing flow and reduced cooling rates model results present a plausible explanation for observed delays in the onset time of downslope flow of up to 8 h after sunset along certain humid tropical slopes

dynamics of iron and calcium carbonate redistribution and palaeohydrology in middle eocene alluvial paleosols of the southeast ebro basin margin catalonia northeast spain abstract paleosols in the alluvial middle eocene of the ebro basin exhibit both the redistribution of iron groundwater and surface water gley and calcium carbonate the hydrological dynamics are reconstructed through gley features and location of carbonate accumulation together these allow a sophisticated analysis of the seasonal palaeohydrology of ancient sedimentary environments this analysis is performed on paleosols developed in marginal and distal floodplain and delta plain deposits derived from the southeast ebro basin margin the most proximal part of the floodplain sediments had moderate mainly vadose calcite redistribution with surface water gleying and fairly deep groundwater the more distal sediments have stronger calcite redistribution both of vadose and surface water gley environments these were frequently overprinted by groundwater related calcite indicating shallow and fluctuating groundwater in the most distal alluvial sediments both calcite redistribution and further soil formation were weak while groundwater was shallow

mineralogical and sub microscopic aspects of iron oxides in polygenetic oxisols from minas gerais brazil iron oxides are known to be useful paleo environmental indicators and their properties may give information about past and present circumstances of weathering and soil formation iron oxides from polygenetic oxisols developed on saprolites of metamorphic rocks soil saprolite sequences and on sediments soil sediment sequences from minas gerais brazil were studied by x ray diffraction mossbauer spectroscopy micromorphology and electron microscopy to establish the connection between their properties and circumstances of formation hematite and goethite are the only iron oxides found in the clay and silt fractions micromorphology and mineralogy indicated the presence of three genetically different forms of hematite and four forms of goethite xrd and mossbauer spectroscopy indicate that these forms have differences in mean coherence length mcl and al substitution in soil saprolite sequences hematite is mainly formed during saprolite formation while goethite formed mainly during soil formation microscopic hematite formed in the saprolite has low al substitution and uniform mcl in response to soil formation it diminishes to submicroscopic size and goethite is formed towards toposoils goethite formed in yellow surface soils reflects recent soil formation and has high al substitution hematites and goethites related to gley phenomena have low al substitution and large mcls different coexisting forms of either goethite or hematite point to varying pedo environments either in time corroborating the polygenetic nature of the studied soils or at micron scale

facies analysis of a probable large fluvial fan depositional system the upper triassic chinle formation at petrified forest national park arizona u s a abstract the upper triassic blue mesa member and the overlying sonsela member of the chinle formation consist of paleosol bearing alluvial strata whose characteristics vary markedly strata exposed within a 4 km2 study area at petrified forest national park were evaluated using sedimentologic stratigraphic paleopedologic and petrographic criteria to formulate potential depositional models that may account for varying alluvial deposition the study succession records a progressive up section increase in grain size increase in channel depth and width increase in lateral and vertical connectivity of channel deposits decrease in overbank preservation and crevasse splay and or sheetflood deposition and increase in overbank drainage mean annual precipitation from the calmag paleosol weathering proxy suggests precipitation averages approximately 1300 mm yr 1 3 m yr throughout the succession despite changing paleosol drainage these features are consistent with deposition in a progradational fluvial system such as a large fan or splay complex sediment accumulation rates in the study interval suggest decreased subsidence in the upper blue mesa member reduced rates of accommodation gain may have promoted progradation of the fluvial system an up section decrease in sandstone mineralogical maturity may be related to increasing sediment bypass in proximal fan positions or increased rates of erosion and sedimentation increasingly better drained paleosols are attributed to deposition in more upland positions during fan or avulsion complex progradation rather than changing climate

evidence for biological and hydrological controls on the development of a paleoproterozoic paleoweathering profile in the baraboo range wisconsin u s a abstract we examined a complete late paleoproterozoic paleoweathering profile beneath the baraboo quartzite from south central wisconsin usa in order to interpret biological and hydrological controls on ancient terrestrial weathering processes detailed thin section investigations were used to identify characteristic pedogenic features associated with saprolitization and formation of an overlying regolith and the isocon method a geochemical mass balance technique was employed to characterize elemental gains and losses the age of the sub baraboo profile is well constrained by the youngest detrital zircon ages previously reported from the basal baraboo quartzite 1712 ma and the 1749 ma crystallization age of the underlying baxter hollow granite and rhyolite parent materials micromorphologic evidence of paleoweathering comprises clay illuviation features indicative of clay movement sepic plasmic fabrics formed by repeated wetting and drying cycles redoximorphic features redox related depletions and concentrations of fe indicative of variable drainage and redox conditions and dissolution and alteration of feldspars and mafic minerals now sericite and fe oxides geochemical evidence for weathering includes depth dependent whole rock losses of na ca mg si ba sr fe and mn and relative enrichment of several immobile elements there is also evidence for post weathering k metasomatism previously dated as 1456 ma that includes 30 net additions of k and rb geochemical patterns for the baraboo profile resemble those of the previously studied and older pronto 2 475 2 44 ga and ville marie 2 38 2 215 ga paleoweathering profiles but with important differences related to baraboo profile development beneath a regolith cover and under conditions of variable hydrology during weathering in spite of its age and greenschist facies metamorphism the baraboo paleoweathering profile is remarkably similar to some modern weathering profiles formed on granite

climate and landscape reconstruction of the arroyo chijuillita member of the nacimiento formation san juan basin new mexico providing environmental context to early paleocene mammal evolution abstract the sedimentologic stratigraphic and paleopedologic attributes of a laterally continuous outcrop exposure of the basal portion of the lower paleocene arroyo chijuillita member of the nacimiento formation located in the bisti de na zin wilderness area was examined to provide paleoenvironmental context for the puercan north american land mammal age nalma terrestrial ecosystems of the san juan basin new mexico the studied outcrop spans the middle and late puercan pu2 pu3 nalma and thus is an ideal location to assess the potential causes of faunal turnover between pu2 and pu3 the stratal succession consists of fluvial channel and laterally continuous sandstone and associated fine grained floodplain deposits including paleosols that document variability in drainage and maturity quantitative and qualitative reconstructions of paleoclimate from paleosols supplemented by analyses of fossil floras indicate no change in climate through the studied interval further there is no evidence that regional tectonics relate to changes in depositional environments given the lack of evidence for climate change or regional tectonics and the characteristics of the fluvial facies and the paleosols across the study locality we interpret the spatial and temporal variability in paleopedologic and sedimentologic characteristics to be the result of autocyclic channel avulsion and migration additionally the stable climatic conditions and lack of tectonic influence between the pu2 and pu3 biozones suggest that mammalian turnover is unlikely to have been caused by extrinsic environmental changes i e climate or tectonics and is instead probably the result of rapid evolution following the k pg boundary and or competition from the migration of new mammalian species into the basin

evaluating trace elements as paleoclimate indicators multivariate statistical analysis of late mississippian pennington formation paleosols kentucky u s a abstract the temporal and spatial distributions of trace elements in paleosols in relation to soil forming processes and climate have received little attention primarily due to their generally low concentrations 100 ppm and a fundamental lack of knowledge of their behavior in soil systems trace element concentrations of pennington formation paleosols spanning an 8 ma interval in the late mississippian chesterian were analyzed using linear and multivariate statistics of whole rock elemental data linear statistics of the elemental data set show that ti zr nb cs la hf ta w ce and th have the highest correlation through time with r values 0 75 nb served as the proxy trace element for comparison temporal trends in nb closely match trends in lessivage clay formation and accumulation by feldspar weathering mean annual precipitation map and chemical weathering map effectively controls soil hydrology and the accumulation of organic matter and clay map in conjunction with chemical we

the distinction between ground water gley and surface water gley phenomena in tertiary paleosols of the ebro basin ne spain abstract in studies of paleosols the distinction iron segregation due to either surface water or ground water fluctuatins is hardly ever made recognition of subsequent hydromorphic phases is even more rare nevertheless such distinctions can be made and are very useful in determining the paleoenvironment in this study we demonstrate that subsequent stages of hydromorphism and their sequence can be recognized in paleogene paleosols of the ebro basin it appears that in these carbonate rich hydromorphic oils goethite iron segregations are due to ground water influence while hematitic segregations are due to surface water the preservation of original mineralogy in this case is due to absence of late diagenetic transformations the results contradict the thesis that red colours in such paleosols would be the result of the late diagenesis in the studied samples mottledcolour patterns frequently indicate fairly advanced soil formation although weathering of primary minerals is almost absent detailed study of colour patterns gives much additional information on the post depositional environment

geochemistry and spatial distribution of heavy metals in oxisols in a mineralized region of the brazilian central plateau abstract the majority of the soils of the central plateau of brazil are product of long time development over stable surfaces usually associated with erosion and re deposition cycles in this context to successfully study the geochemistry and spatial distribution of heavy metals it is essential to understand the geology as well as the geomorphology of the landscape and the properties of the metals related to their mobility the main objective of this work was to evaluate contents of naturally occurring heavy metals co cu mn ni pb and zn in some highly weathered tropical soils as related to their geochemistry geology and geomorphology additionally it was aimed to interpret the spatial distribution patterns of these metals and of major elements al fe ti and mg evaluating the association and taking the influence of the geology and geomorphology into consideration in geo referenced sites ranging from 480 to 1040 m in altitude samples were collected at two depths 0 20 and 60 80 cm ground sieved and prepared for analysis heavy metals and major element contents were determined by extraction with aqua regia descriptive statistics pearson correlation coefficients principal components analysis pca and spatial variability analyses were conducted and soil metal concentrations for the whole area were predicted by kriging interpolation a close association between pb zn and mn was observed using pca and pearson s correlation highest concentrations of pb zn and mn were determined in soils between 650 and 550 m altitude surrounding the dolomite massif hills and ambrosia and fagundes mineral deposits copper and fe were found to be geochemically associated with highest concentrations observed in soils formed from carbonaceous phyllite with quartzite layers cobalt and ni concentrations were associated with areas characterized geomorphologically as alluvial colluvial deposits at the lowest altitudes within the region although there is a marked dispersive action of tropical weathering on metal distribution in the region cu pb and zn were found spatially associated with their geological source this probably happens because of greater affinity of those metals to fe and mn oxides formed predominantly under tropical conditions and present in higher concentrations near to the sources of these heavy metals on the other hand both the low affinity of ni and co for these oxide minerals and the region s geomorphology allowed for their migration towards the drainage network to the regions of sediment accumulation at lower altitudes during the landscape s evolution

the interaction of katabatic flow and mountain waves part i observations and idealized simulations abstract the mutual interaction of katabatic flow in the nocturnal boundary layer nbl and topographically forced gravity waves is investigated due to the nonlinear nature of these phenomena analysis focuses on information obtained from the 1993 atmospheric studies in complex terrain field program held at the mountain canyon plains interface near eldorado canyon colorado and idealized simulations perturbations to katabatic flow by mountain waves relative to their more steady form in quiescent conditions are found to be caused by dynamic pressure effects based on a local froude number climatology case study analysis and the simulations the dynamic pressure effect is theorized to occur as gravity wave pressure perturbations are transmitted through the atmospheric column to the surface and through altered horizontal pressure gradient forcing to the surface based katabatic flows it is proposed that these perturbations are a routine feature in the atmospheric record and represent a significant p

observations of flow and turbulence in the nocturnal boundary layer over a slope measurements were conducted on an eastern slope of the salt lake basin slb as a part of the vertical transport and mixing experiment vtmx conducted in october 2000 of interest was the nocturnal boundary layer on a slope in particular katabatic flows in the absence of significant synoptic influence extensive measurements of mean flow turbulence temperature and solar radiation were made from which circulation patterns on the slope and the nature of stratified turbulence in katabatic winds were inferred the results show that near the surface 25 50 m the nocturnal flow is highly stratified and directed downslope but at higher levels winds strongly vary in magnitude and direction with height and time implying the domination of upper levels by air intrusions these intrusions may peel off from different slopes surrounding the slb have different densities and flow at their equilibrium density levels the turbulence was generally weak and continuous but sudden increases of turbulence levels were detected as the mean gradient richardson number dropped to rig about unity with a short timescale fluctuated on the order of a few tens of seconds while modulating with rig a longer along slope internal waves sloshing timescale of about half an hour the mixing efficiency or the flux richardson number of the flow was found to be a strong function of similar to that found in laboratory rig experiments with inhomogeneous stratified shear flows the eddy diffusivities of momentum and heat were evaluated and they showed a systematic variation with when scaled with the shear length scale and the rms rig vertical velocity of turbulence

combined mine tremors source location and error evaluation in the lubin copper mine poland abstract a modified method of mine tremors location used in lubin copper mine is presented in the paper in mines where an intensive exploration is carried out a high accuracy source location technique is usually required the effect of the flatness of the geophones array complex geological structure of the rock mass and intense exploitation make the location results ambiguous in such mines in the present paper an effective method of source location and location s error evaluations are presented combining data from two different arrays of geophones the first consists of uniaxial geophones spaced in the whole mine area the second is installed in one of the mining panels and consists of triaxial geophones the usage of the data obtained from triaxial geophones allows to increase the hypocenter vertical coordinate precision the presented two step location procedure combines standard location methods p waves directions and p waves arrival times using computer simulations the efficiency of the created algorithm was tested the designed algorithm is fully non linear and was tested on the multilayered rock mass model of the lubin copper mine showing a computational better efficiency than the traditional p wave arrival times location algorithm in this paper we present the complete procedure that effectively solves the non linear location problems i e the mine tremor location and measurement of the error propagation

the role of static stress transfer in mining induced seismic events occurrence a case study of the rudna mine in the legnica glogow copper district in poland summary seismicity accompanying mining exploitation results from changes in the stress field in the rock mass near the mining excavations caused by human activity many studies of the temporal and spatial distribution of mining induced seismicity have provided evidence for interrelations among events although a variety of techniques have been applied to quantify the interdependences of mining induced seismic events the physical mechanism of interactions has not been unequivocally identified based on the premise that one possible cause of interactions among seismic events can be static stress transfer we have verified statistically the role of coulomb stress transfer in the generation process of mining induced seismicity using a series of seismic

early oligocene paleosols of the dagshai formation india a record of the oldest tropical weathering in the himalayan foreland abstract this study reports paleopedological features of the fossil soils that formed during the earliest phase of continental sedimentation in the himalayan foreland the fluvial sequence of the dagshai formation 31 6 3 9 ma to 30 3 3 9 ma exposed along the koshaliya river nw himalaya contains four pedofacies named pedofacies a d of ferruginous paleosol sequences contained within overbank sediments the dagshai formation unconformably overlies the marine subathu formation pedofacies a consists of 3 4 well developed ferruginous paleosols overlain by gray sandstone beds pedofacies b d are marked by a progressive decrease in pedogenesis these paleosols occur as 0 5 m to 1 5 m thick bw bt btk bk bss horizons that are marked by extensive development of rhizoliths pedogenic carbonate and iron rich clay pedofeatures that correspond to modern entisols inceptisols alfisols and vertisols based on early oligocene paleogeographic position of the northward drifting indian plate it is inferred that these paleosols were formed at 18 n paleolatitude in the dagshai sub basin in the himalayan foreland micromorphology geochemical analyses weathering indices and stable isotope composition of paleosols indicate tropical climate paleoprecipitation of 947 1256 mm and paleotemperature of 25 c with an initial phase of monsoonal conditions during pedogenesis these paleoclimatic conditions favored c3 paleovegetation immediately after the transition from greenhouse to icehouse conditions

evidence for multiple episodic mid holocene hypsithermal recorded in two soil profiles along an alluvial floodplain catena southeastern tennessee usa abstract floodplain soil paleosol successions are valuable archives for reconstructing pleistocene holocene climate changes but have been relatively unstudied in the southern appalachian region two soil profiles on a small floodplain in southeastern tennessee usa were described and sampled in detail using both pedological and geological approaches including stable carbon isotope analysis of soil organic matter som correlation between the 2 profiles was constrained by uncalibrated ams 14c ages of bulk humates and using som 13c values both mobile and immobile elements four distinct 2 5 4 shifts towards less negative 13c values for som suggest 300 yr cyclicity and transient warmer and drier climate events with either water stressed c3 vegetation or as much as 35 c4 plants present during the mid holocene these postulated multi episodic drier climate conditions have never before been documented in the southern appalachian region and are tentatively correlated with mid holocene warming and drying in the eastern us the nearly time equivalent mid holocene events documented in texas the us high plains and in the gulf of mexico high rates of floodplain sediment accumulation 0 5 3 mm yr high clay content and maintenance of poorly drained soil conditions favor preservation of high resolution climate archives in floodplain deposits by inhibiting oxidation and translocation of organic c

geogenesis pedogenesis and multiple causality in the formation of texture contrast soils abstract coarse over fine vertical texture contrasts vtc are common in soils and weathering profiles in a variety of environmental settings including many where inheritance or surficial processes alone cannot account for them a multiple causality model is presented here which shows that texture contrasts can form in response to a combination of ubiquitous phenomena there are six key elements downward translocation by water erosional winnowing soil mixing by bioturbation the tendency for surface clay additions to be mobilized while subsurface clays are more likely to remain in place and biological facilitation of moisture flux no element alone is sufficient to create a vtc but not all are necessary in any given regolith the model is illustrated by application to case studies in the ouachita mountains arkansas ridgetops in eastern kentucky the lower coastal plain of north carolina and the upper coastal plain of east texas the implications for interpretation of soils paleosols and weathering profiles is that the presence of a textural contrast by itself does not connote any particular set of geogenic or pedogenic processs or controls texture contrasts may be geogenic pedogenic or both given the widespread occurrence of the mechanisms of the multiple causality model vertical texture contrasts are inevitable

holocene environmental history at the treeline in the northern apennines italy a micromorphological approach the aim of this work is to investigate paleoenvironment at treeline quotas through the help of soil micromorphology it also assesses how the micromorphological approach can provide information in paleoenvironmental studies where paleosols are available as proxy archives nine soil profiles are described across the treeline between 1723 and 1860 m on mt cusna slope 2121 m a s l northern apennines italy undisturbed samples from selected soil horizons are collected in kubiena boxes from field observations all the profiles appear to be composed of two main pedogenetic units the upper one composed of a recent soil of colluvial origin and the deeper one consisting of an underlying more developed buried paleosol thin sections give detailed information about the nature and the origin of both pedological units four principal phases of paleosol development are detected a first period of temperate climate with forest cover and contrasted seasons is followed by a phase of change and then by a successive decrease of forest cover in a last phase the soil experiences frost action under the effect of a colder climate the final deposition of colluvium seems to be very recent historical time moreover multiple colluvial layers are identified colluvial material of different origins could be identified as part of dismantled soils similar to the preexisting paleosol in conclusion with the help of soil micromorphology it is possible to assess the existence of past stable forest at least 100 m above the present treeline the micromorphological approach represents a powerful tool in multidisciplinary paleoenvironmental studies due to its high level of resolution in outlining the individual and successive phases of soil evolution

palaeosols in westphalian coal bearing and red bed sequences central and northern england westphalian a c coal bearing strata and red beds in the pennine basin of central and northern england contain a wide variety of palaeosols in coal bearing facies associations alluvial gley semi gley organic and rare well drained palaeosols reflect the predominance of poor drainage conditions during deposition in red beds more evolved ferruginous and ferallitic palaeosols testify to free drainage conditions during deposition catenary relationships can be inferred between most of the palaeosols in both facies associations providing further information on the palaeogeomorphology of the depositional systems and assisting in the understanding of the environments and conditions of coal seam formation

weathering trends and parent material characteristics of polygenetic oxisols from minas gerais brazil i mineralogy in geologically stable areas in the tropics climatic changes and geomorphic cycles give origin to polygenetic soils polygenesis involves new soil formation phases taking place on preweathered materials from previous phases resulting in soils with rather similar chemical and mineralogical properties polygenetic soils from minas gerais brazil were investigated with the purpose of distinguishing mineralogical aspects in relation to polygenesis the soil materials were studied by micromorphology and electron microscope and analyzed by xrd all soils are strongly weathered and even show weathered grains of ilmenite and quartz the soils show two phases of kaolinite formation pseudomorphs after mica and precipitation from solution and of accumulation of iron compounds desilication causes gibbsite formation from kaolinite occasionally even in the deep saprolite superposed processes can be due to progressively deeper weathering or to changes of the external environment

reply to the comments by bromley et al of the paper reconnaissance of the upper jurassic morrison formation ichnofossils rocky mountain region usa paleoenvironmental stratigraphic and paleoclimatic significance of terrestrial and freshwater ichnocoenoses by stephen t hasiotis

eocene paleosols on king george island maritime antarctica macromorphology micromorphology and mineralogy abstract we investigated the origin of reddish layers between basalt flows in an early eocene volcanic succession in king george island maritime antarctica previous studies in the area classified these layers as regolith surfaces baked zones and paleosols but the properties of these layers and the reasons for their classification are not clarified since the early eocene epoch was one of the warmest phases on earth during the cenozoic a proper investigation of these layers is crucial to obtain additional regional information about the paleoenvironment the focus of this study is on three profiles located in the admiralty bay on king george island they were classified as paleosols based on field micromorphological and mineralogical properties main soil forming processes identified by micromorphological analyses were clay neoformation pedo bioturbation and a weak redoximorphosis the occurrence of plant residues in all profiles was a reliable indicator that these soils formed a land surface during the early eocene abundant weathered volcanic glass and pyroclasts may indicate andosolization although the main diagnostic features for andosols which are the presence of nanocrystalline minerals and organic matter accumulation were not detected or only in small amounts respectively the long term burial of the paleosol could be a reason for lacking of these diagnostic features clay minerals associated with moderately weathered volcanic soils smectite were detected in the x ray diffraction analysis a predominantly reddish colour of most of the soil horizons is given by hematite confirmed by the determination of pedogenic oxides nevertheless rubification was not solely a result of pedogenesis but also of reddening of oxyhydroxides by dehydration during diagenesis other diagenetic processes were burial compaction loss of organic matter and induration in the horizons directly buried by a basalt flow voids were filled by zeolite crystals an effect related to lava cooling another possible diagenetic effect was the geochemical rejuvenation and homogenization of the profiles despite the occurrence of these features the results are in agreement with previous studies indicating a humid temperate paleoclimate for king george island during the early eocene

alluvial fan and wetland interactions evidence of seasonal slope wetlands from the silurian of south central wales uk distal environs of the ludlow age trichrug formation from south central wales uk detail deposition on the outer fringe of an ephemeral debris flow dominated alluvial fan debrites and subordinate sheetflood deposits are interbedded with sporadic thin sandstone dominated heterolithic units deposited in shallow ephemeral ponds in the axial valley the latter slope wetland system fringed the permeable alluvial fan deposits being maintained by streamflow precipitation and ground water recharge a prolonged high water table is indicated by low chroma intervals interpreted as the result of gleying a variety of redoximorphic indicators including colour mottling and ferricrete concretions are evidence of iron mobilization and concentration associated with a seasonally fluctuating water table the slope wetlands were colonized periodically by skolithos generating organisms most likely to have been arthropods the widespread occurrence of redoximorphic indicators and ferricrete contrasts markedly with calcrete vertisols in penecontemporaneous continental deposits lower old red sandstone of the region it is likely that the alluvial fan toe area was the site of a wetland depression which maintained a high though fluctuating water table in contrast the alluvial channel reaches of the surrounding drainage network were significantly better drained with floodplains prone to wetting and drying and vertisol palaeopedogenesis

characteristics of cold pools observed in narrow valleys and dependence on external conditions observations from the recent cold air pooling experiment colpex field campaign are used to relate the intensity of cold pools within two small valleys o 100 m depth and o 1 km width to flow conditions within the airmass passing over the valley the temperature structure of the cold pools is examined using transects of ground based sensors through the valleys and radiosonde releases from within the valley in order to evaluate simple two dimensional concepts of cold pool formation due to sheltering the cold pool spatial and temporal structure is found to be consistent between different nights when strong cold pools occurred initially a sharp surface inversion occurs similarly at all points within the valley with isentropes roughly terrain parallel the inversion layer at the bottom of the valley then grows deeper spreading over the bottom portion of the valley and cross valley isentropes eventually become horizontal by defining appropriate measures of the relative temperature drop within the cold pool and non dimensional valley depth diagnosed with respect to the speed and stability of the approaching flow the measurements are shown to be consistent with previous relationships determined for simple two dimensional valleys

an idealized modeling study of nocturnal cooling processes inside a small enclosed basin 1 the advanced regional prediction system is utilized to examine the evolution of the nocturnal boundary layer observed within arizona s meteor crater a small enclosed basin on quiescent nights during the 2006 meteor crater experiment field campaign two aspects of the observed basin atmosphere are investigated a quasi steady state three layer temperature structure including an isothermal layer away from the basin floor and the intrusion of a regional scale cold air drainage flow into the basin in general the two dimensional numerical simulations are able to reproduce the salient features of the nocturnal boundary layer inside meteor crater a combination of increasingly cold air intruding into the basin and pooling near the basin floor and compensating adiabatic ascent yield an isothermal layer over a large depth of the basin atmosphere a series of experiments are then conducted in order to examine the sensitivity of basin thermal structure to upstream terrain slope basin width and the presence of a rim surrounding the basin in the case of a large basin of o 10 km in diameter the cold air intrusion process remains but the larger basin volume yields greater dilution of the cold air intruding into the basin and a weak inversion develops inside the basin away from the floor in the case of a small basin with the same dimensions as meteor crater but with flat upstream terrain the influence of the surrounding terrain on basin cooling is negligible last the presence of a rim surrounding the basin is found to not be necessary for isothermal layer development

origins and implications of soil layering abstract layering is common in soils due to a variety of pedologic and geologic processes and has important consequences for the interpretation of soils and landscapes layering can derive from original sedimentary layering depositional upbuilding episodic surface erosion deposition and stability soil production by weathering vertical or lateral translocation bioturbation and various combinations of these complex and polygenetic models incorporate both geogenic and pedogenic processes and allow for physical and biological processes as well as both vertical and horizontal movements we review these conceptual frameworks and synthesize them into a vertical contrast model vcm for interpreting layered surficial materials the vcm incorporates a variety of geologic and pedologic processes which may create destroy enhance or obscure vertical contrasts the model is illustrated via application to sites in the ouachita mountains usa and northwest saxonian lowlands germany the examples illustrate the importance of a comprehensive pedogeomorphic interpretation of layering since neither standard stratigraphic or top down pedogenetic principles necessarily apply the examples also show that the same process can sometimes contemporaneously both create and destroy vertical contrasts

profiles of katabatic flow in summer and winter over coats land antarctica observations from a novel autonomous doppler sodar wind profiling system are described and analysed these include the first continuous wintertime soundings of katabatic winds over antarctica a continent with which they are synonymous during 2002 and 2003 over 2600 wind profiles were taken during case studies of high resolution sounding lasting hours to days these case studies have been subjectively classified as synoptically driven katabatically influenced 28 days primarily katabatically driven flows a subset of 16 days or other flow types the doppler sodar observations were augmented by automatic weather station observations at the field site and further up the slope as well as synoptic and upper air observations at halley research station some 50 km distant on the brunt ice shelf in primarily katabatic flows there is a systematic change in the shape and depth of the low level katabatic jet with wind speed relatively strong katabatic flows maximum winds of typically 8 10 m s 1 have a jet maximum between 20 and 60 m above the surface and are relatively deep up to 200 m while moderate katabatic flows 4 8 m s 1 typically have a jet maximum between 3 and 30 m and are shallower 100 m although they can also be more diffuse in structure with a wind speed maximum at higher altitude in all katabatic flows there is backing of wind direction with height consistent with decreasing friction away from the surface during summertime katabatic flows there is a clear diurnal signature at all heights although this is less pronounced in the surface layer where there seems to be a persistent 2 4 m s 1 katabatic flow during all case studies where the diurnal forcing results in an abrupt katabatic flow deceleration i e what may be a katabatic jump there is a concurrent vertical acceleration wind profiles from a recent numerical weather prediction study of idealized katabatic flows at this site compare favourably with selected mean profiles the only significant difference is that the model s wind speed is too low over the lowest 10 m copyright 2006 royal meteorological society

spatial variability of soil hydraulic conductivity along a tropical rainforest catena abstract we investigate the spatial variability of saturated hydraulic conductivity ksat along a tropical rainforest catena which consists of a typic kandiudult latossolo vermelho distrofico argissolico and plinthic hapludox latossolo amarelo distrofico tipico the former soil type extends from midslope to interfluve and has a high clay content throughout the profile whereas the latter soil type extends from the midslope to valley bottom and only has a high clay content at depths 90 cm we measured ksat along a transect at depths of 20 30 50 and 90 cm with a compact constant head permeameter ksat is not significantly different 0 10 between these soil types at any depth except for 90 cm ordinary and robust linear regression models with distance from the interfluve as in the independent variable showed no significant change in ksat as a function of topography loess regression showed some dependency of ksat on topography only at the 90 cm depth semivariograms showed no apparent spatial structure in ksat at distances 25 m for all depths we conclude that the strong topography dependence of soil types along this catena and hence primary soil attributes is not reflected in a similar dependence of ksat and tentatively attribute this lack of dependence to the overriding influence of bioturbation controlled macroporosity we outline a framework for detecting possible ksat topography relationships based on the distinction between bioturbation controlled nonstructural macroporosity and mineralogy controlled structural macroporosity

dryland continental mudstones deciphering environmental changes in problematic mudstones from the upper triassic carnian to norian mercia mudstone group south west britain

the paleoecological and paleoenvironmental importance of root traces plant distribution and topographic significance of root patterns in upper cretaceous paleosols abstract rhizoliths are organosedimentary structures produced by plants and are an important proxy for paleoenvironmental reconstructions because the differences in the morphology of rhizoliths and their rooting depths can be used to interpret soil humidity regimes overall biomass at the soil surface and the behavior of the water table with the objective of advancing knowledge on rhizoliths a study was performed on the macromorphological and micromorphological characterizations of the rhizoliths preserved in the thirty one paleosols of the marilia formation in minas gerais southeastern brazil based on the topological and architectural attributes of rhizoliths and on their possible functional adaptations such as mycorrhizal associations three different types of rhizoliths are described in this study and represent at least three different plants rhizohaloes root casts and rhizocretions well developed paleosols with nodular horizons contain the higher density of long root casts indicating a seasonally dry environment because the root casts present two meters in length these adaptations are associated with an exploitation of a lowered water table during most times of the year the higher density of rhizoliths indicates an area with agglomerated arboreous arbustive vegetation cover paleosols with chalky horizons also show a high density of root casts indicating a landscape with high plant density that is adapted to drained soils but with a seasonally elevated water table or the influence of ephemeral flows given the proximity to the flow channels the poorly drained paleosols with redoximorphic features show the lowest density of rhizoliths thus indicating an incipient vegetation in response to near surface water table and waterlogged soils in a distal floodplain the rhizogenic laminar horizons have developed near fluvial channels with frequent sedimentary input resulting in a sequence of laminar horizons composed of rhizocretions that are separated by sandy deposits or poorly developed pedogenic horizons the micromorphological analysis on the rhizogenic laminar calcretes showed biogenic features such as alveolar septal structures calcified filaments microcodium calcified cells and pisoliths despite the scarce paleobotanical findings in the marilia formation the results obtained indicate an ecosystem that was composed of plants varying from herbaceous to arboreous with an environment similar to modern semiarid shrublands

the evolution and sensitivity of katabatic flow dynamics to external influences through the evening transition data collected over an arid shallow slope 2 4 during the mountain terrain atmospheric modeling and observations materhorn program are used to study the katabatic structure and onset of katabatic flow through the evening transition an unprecedented suite of instrumentation including a transect of five turbulence towers with 29 sonic anemometers is used for the investigation fifteen transition periods with well defined katabatic flow and relatively little synoptic forcing are used in the study the katabatic onset jet velocity and jet height all show a large degree of interdiurnal and intersite variance the slope aligned budgets of momentum and potential temperature are used to define time scales that describe the evolution of the katabatic flow composite wind velocity time series are used to show that 30 min elapses from the time when the katabatic flow initializes at 0 5 m to the point of initialization at 20 m a simple katabatic model utilizing surface energy budget modeling is developed and used to model the interdiurnal katabatic variance finally uni and multi variate statistical analysis are used to diagnose the influence of specific external variables valley wind speed turbulence structure soil moisture and shadow front speed are all found to influence the katabatic dynamics to varying degrees

the development of deep soil processes in ancient kurgans of the north caucasus abstract in the past four thousand years luvisols with a clearly differentiated profile have developed on kurgans of the bronze age under beech and oak stands in humid climatic conditions of the foothills of the north caucasus the great height of the kurgans up to 10 m and their homogeneous composition the kurgans were constructed of chernozemic soil and are underlain by chernozem make it possible to study the direction and rate of pedogenetic and diagenetic processes acting at a considerable depth in these kurgans the profiles of luvisols are underlain by the carbonate illuvial horizon that has been shaped by illuviation processes acting for about 4000 years the major part of this horizon lies at the depths of 110 350 cm though carbonates penetrate as deep as 9 m along the deep earthworm burrows at this depth they occur within the noncalcareous mass of the lower part of the kurgans bodies and in the upper part of the underlying chernozem at the depth of 5 9 m in the kurgans and in the buried chernozem gypsum and iron pedofeatures nodules and red brown films on ped faces have appeared humus clayey infillings are present in some of the earthworm burrows at this depth the formation of such a deep profile with the carbonate illuvial gypsiferous and ferruginated horizons is related to the local bioclimatic conditions characterized by high precipitation and the growth of forest vegetation deep washing of the soil with atmospheric precipitation is combined with the manifestation of illuviation processes and alteration of the soil mass at a considerable depth the mineralization of humic substances and some alkalization of the soil mass also take place in the deep horizons however these processes may occur at different depths independently from the illuviation processes and can be attributed to the group of diagenetic processes

late cretaceous to late eocene palaeogeographic evolution of southwest europe abstract a synthesis of personal research concerning the peri pyrenean region and previously published data is presented as a series of palaeogeographic reconstructions subsequent to the progressive regression at the end of the cretaceous the sea invaded three times parts of the earlier senonian marine domain on both sides of the eastern palaeo pyrenees pre cuisian climatic rewarming combined with cuisian continental epeirogenic deformations resulted in major biogeographic modifications during the cuisian local tectonics forced the sea from the northern pyrenean basin whereas in the southern pyrenean basin the sea retreated much later as a consequence of the pyrenean tectonic phase however the pyrenean tectogenesis seems to have affected a much larger region including the alps shoreline migrations are compared and related to the geodynamic behaviour of the meridional and septentrional european provinces in order to distinguish between tectonic and eustatic causes

anthropic pedogenesis of purple rock fragments in sichuan basin china abstract considerable amounts of rock fragments are found in many purple soils developed from purple rocks in the sichuan basin of southwestern china we describe the effects of anthropic pedogenetic processes on purple rock fragments associated with soil amelioration by determining changes in rock fragment size distribution transformation of p and k of purple rocks into soils and the complexing of purple rock particles soil mineral particles with organic matter during anthropic pedogenesis of purple soils in sichuan basin of southwestern china the pedogenetic capacity of rock fragments can be expressed by the content of r 0 891 0 961 n 16 digging simulated by sieving and crop planting facilitate pedogenesis of purple rock fragments and their mineral nutrient transformations the soil mineral particles preserve 18 36 of the organic carbon added as corn straw the organic carbon is complexed after corn straw is mixed with

space time clustering of seismic events and hazard assessment in the zabrze bielszowice coal mine poland the results of the statistical analysis of seismic activity recorded in the zabrze bielszowice coal mine in poland are presented in this article the monitoring was conducted by a small network consisting of four triaxial geophones deployed in vertical holes in the roof for over 1000 seismic events recorded during the two month s experiment the location of sources was realized the seismic sources were mostly located ahead of the active face of the longwall since the first day of the monitoring cluster analysis was sequentially performed for increasing number of sources at the end of the experiment 31 clusters were identified they consisted of different numbers of events and were separated in space about 40 of the events were not included in the clusters for each large cluster hazard analysis was separately performed the hazard function evaluated for the largest cluster was compared with hypocenters of high energy tremors e 1000 j recorded by the geophones in that area for some cases recorded tremors occurred after an abrupt decrease of hazard function but only one of them was located in the vicinity of the appropriate cluster we concluded that for the analyzed cluster a correlation between evaluated hazard function and time occurrences of the high energy tremors existed except for one case there is no space correlation between analyzed clusters and high energy tremors

erosion sedimentation and pedogenesis in a polygenetic oxisol sequence in minas gerais brazil the geomorphic evolution of the south eastern brazilian landscape is attributed to climatic changes coupled with tectonic activity soils developed on the resulting surfaces are mainly deep polygenetic oxisols the combination of stable landscapes with continuously exposed soils and neo cenozoic graben zones episodically filled with sediments that may have undergone soil formation offers the possibility to unravel the history of the soils that are found at the present day surface soil sediment sequences in the southern part of the state of minas gerais brazil were investigated by micromorphology and mineralogy in order to understand the genesis of the soils erosion profile thinning weathering biological activity clay accumulation and iron translocation are the main soil forming processes imprinted in the various pedosedimentary layers strong weathering is shown by dissolution of quartz and weathering of ilmenite bioturbation is ubiquitous even in older and deeper buried layers clay accumulation is observed as illuviation and precipitation features which were micromorphologically differentiated accumulation and movement of iron are represented by gley and pseudogley features related to groundwater and surface water saturation processes these features and the layering of sediments and soils play key roles in understanding the evolutionary phases undergone by the soils and sediments as main soil formation episodes the graben fillings show two phases of clay formation and illuviation separated by a phase of ferralitization interrupted by various episodes of erosion the whole material was eventually overprinted by a phase of ferralitization and plinthite formation apart from water saturation these processes also appear to have acted on the soils of the stable areas not affected by tectonic activity but overprinting and erosion prevents recognition of the separate evolutionary phases

high resolution numerical studies of stable boundary layer flows in a closed basin evolution of steady and oscillatory flows in an axisymmetric arizona meteor crater 1 we describe high resolution numerical simulations of flow within and over an axisymmetric approximation of the arizona meteor crater under stable boundary layer conditions motivations included guidance of and comparisons with observations during the meteor crater experiment metcrax performed in october 2006 modeling objectives were to assess the dynamical processes accounting for cold pool breakup various initial stable boundary layer sbl flows were considered on the basis of observed sbl flows and responses forcing conditions include impulsive sbl startups constant sbl accelerations and oscillatory sbl flows dominant responses include kelvin helmholtz shear instability at the top of the crater cold pool gravity waves arising from the crater geometry and seiches within the crater cold pool shear instability at the cold pool top exhibits a range of behaviors in response to different initial conditions including vortex shedding from the inflow crater lip vortex pairing strong mixing and erosion of the cold pool stratification and secondary vortex formation at the top of the mixing layer gravity wave responses depend on the flow speed are strongly three dimensional and time dependent and impact flow structure within and above the crater seiches arise from transient or oscillatory forcing and exhibit complex responses and spatial structures including upward phase progression multiple periods and vertical structures and sloshing that ejects cold pool air into the external sbl we conclude that both sloshing of cold pool air and mixing accompanying shear instability represent efficient dynamical mechanisms by which cold pool stratification can be eroded in response to external sbl motions

on the turbulence structure of deep katabatic flows on a gentle mesoscale slope a comprehensive analysis of the turbulence structure of relatively deep midlatitude katabatic flows with jet maxima between 20 and 50 m developing over a gentle 1 mesoscale slope with a long fetch upstream of the meteor crater in arizona is presented the turbulence structure of flow below the katabatic jet maximum shows many similarities with the turbulence structure of shallower katabatic flows with decreasing turbulence fluxes with height and almost constant turbulent prandtl number still stark differences occur above the jet maximum where turbulence is suppressed by strong stability is anisotropic and there is a large sub mesoscale contribution to the flux detecting the stable boundary layer top depends on the method used flux vs anisotropy profiles but both methods are highly correlated the top of the stable boundary layer however mostly deviates from the jet maximum height or the top of the near surface inversion the flat terrain formulations for the boundary layer height correlate well with the detected top of the stable boundary layer if the near surface and not the background stratification is used in their formulations however they mostly largely overestimate this boundary layer height the difference from flat terrain boundary layers is also shown through the dependence of size of the dominant eddy with height in katabatic flows the eddy size is semi constant with height throughout the stable boundary layer depth whereas in flat terrain eddy size varies significantly with height flux gradient and flux variance relationships show that turbulence data from different stable boundary layer scaling regimes collapse on top of each other showing that the dominant dependence is not on the scaling regime but on the local stability

an observational and numerical study of a regional scale downslope flow in northern arizona 1 boundary layer observations taken during the metcrax field study in october of 2006 near winslow in northern arizona revealed the frequent presence of a near surface wind maximum on nights with relatively quiescent synoptic conditions data from a sodar a radar wind profiler several surface stations and frequent high resolution rawinsonde soundings were used to characterize this boundary layer wind phenomenon and its relation to synoptic conditions and the ambient environment the data analyses are augmented by high resolution mesoscale numerical modeling it is found that the observed nocturnal low level wind maximum is part of a regional scale downslope flow converging from high terrain of the colorado plateau toward the little colorado river valley the depth of this downslope flow is between 100 and 250 m with a peak speed of 4 6 m s 1occurring usually within the lowest 50 m above ground opposing ambient winds lead to a longer evening transition period shallower slope flows and a smaller horizontal extent as compared to supporting synoptic winds a simple analytical solution based on local equilibrium appears to agree fairly well with the observed layer mean downslope wind speed but the classic prandtl solution for maximum downslope wind speed fails to match the observations the properties of the flow appear to be insensitive to changes in soil moisture land cover and surface roughness length the contribution to the low level wind maximum by inertial oscillation at night is found to be insignificant

numerical simulations of turbulent flow within and in the wake of a small basin 1 small terrain features such as small valleys basins sinkholes low hills and outcrops while generally associated with mountainous regions can also be found over plains in this study we present a numerical investigation of the effect of a small terrain feature a 30 m high rim on the mean and turbulent flows inside and downstream of an enclosed basin it surrounds results from high resolution numerical simulations 10 m isotropic spatial resolution indicate that small terrain features in the proximity of larger ones can induce relatively large modifications to the mean and turbulent flows the 30 m high rim is found to have an effect on the mean wind speeds at least 600 m upstream from the basin the main effect is a 10 reduction in wind speed up to 120 m above ground level due to the upstream blocking effect of the rim the presence of the rim can also double the turbulent kinetic energy tke both inside and downstream of the basin compared to an otherwise identical basin without a rim the slopes of the basin play an important role in first creating and then defining the wake and in intermittent wind regimes most of the scalar transport from near the slope of the basin happens through slope roll vortices that define the edge of the downstream wake region of the basin inside the basin the rim acts to limit momentum transfer in the lower half of the basin which suggests a mechanical forcing effect induced by the rim on lower basin environments that could interact with thermal buoyancy effects in heated or cooled basins some of the wake features resemble wind eroded surfaces in the wakes of martian craters results also reveal a critical height level 43 m below the rim height that acts as the most favored location for tke production and destruction which could be important for the top to bottom turbulence erosion of basin boundary layers these results stress the importance of resolving small scale terrain features as their effects can be nonlocal

floodplain palaeosols of the cenomanian dunvegan formation alberta and british columbia canada micromorphology pedogenic processes and palaeoenvironmental implications