high iron glaucony from the continental shelf of the yellow sea off the southwestern korean peninsula abstract massive fractured and porous types of glauconies are found in subtidal sand and semi consolidated sand mud deposits from the continental shelf of the southeastern yellow sea thermal treatments on powdered glaucony increase the x ray intensity near 10 a suggesting the presence of some expandable layers ferric iron and mg 0 35 0 54 atoms progressively substitute for al from porous to massive glauconies a higher proportion of expandable layers is also observed with apparent increases from porous to massive type the clay preserved is ordered disordered massive to fractured type and interstratified illite smectite porous type containing 7 27 expandable layers glauconies from the yellow sea apparently form after deposition in reducing environments at the interface between dissolving clay minerals and degrading biogenic debris

eof analysis and modeling of gps tec climatology over north america an empirical ionospheric model of the total electron content tec over north america 20 60 n 40 140 w is constructed using the gps tec data collected by massachusetts institute of technology mit haystack observatory during the years 2001 2012 this model is based on an analysis of quiet time monthly averages using the empirical orthogonal function eof decomposition technique allowing for separation of spatial and temporal variations the importance of different types of spatial temporal variations to the overall tec variability can be well represented by the characteristics of eof basis functions and associated principal components coefficients with various modes the mode one eof decomposition constitutes 97 5 of the total variance and therefore represents the essential feature of north america spatial and diurnal variation of the tec the mode two eof as reported in an earlier study reveals a large and significant symmetric longitudinal variation of the ionosphere organized with respect to magnetic declination the mode three eof decomposition shows midlatitude latitudinal structure that varies with season in a manner very similar to the so called winter anomaly because of the quick convergence of eof decomposition modes the first four eof modes are utilized for constructing a tec empirical model for each of the eof modes the temporal variations are expressed analytically in terms of local time season and solar activity and the spatial variations by cubic spline functions an analysis of accuracy and quality indicates that this regional empirical tec model can reflect the majority of the quiet time monthly means and represent characteristic temporal spatial variations in the north america

de glauconiarum origine the glauconitic facies is widespread on present day continental shelves from 50 s to 65 n and at water depths between 50 and 500 m and is in particularly great abundance on the upper slope and outer shelf between 200 and 300 m it is also common in many ancient rocks of post late precambrian age it occurs as sand to pebble sized essentially green particles granular facies but also as a surface coating on particles and hardgrounds and as a diffuse impregnation film and diffuse facies we suggest the replacement of the term glauconite which has been interchangeably used to designate a morphological form and a specific mineral by glaucony facies and glauconitic smectite and glauconitic mica as end members of the glauconitic mineral family the widely accepted model of burst and hower for glauconitization requires a degraded micaceous 2 1 layer lattice structure parent clay mineral however detailed analysis of numerous samples of recent glaucony reveals that such a parent substrate is exceptional the model therefore requires modification generally the parent material is carbonate particles argillaceous kaolinitic faecal pellets infillings of foraminiferal tests various mineral grains and rock fragments that pass gradually into the commonly occurring green grains we show that the process of glauconitization is achieved by de novo authigenic growth of automorphous crystallites in the pores of the substrate accompanied by progressive alteration and replacement of the substrate it is this two fold evolution that causes the verdissement of granular substrates macrofossils and hardgrounds the authigenic mineral is an iron rich and potassium poor glauconitic smectite while new smectites are growing into the remaining pore space the earlier smectites are modified by incorporation of potassium producing decreasingly expandable minerals with a non expandable glauconitic mica as the end member this mineralogical diversity of the glauconitic mineral family explains the highly variable physical and chemical properties of glaucony four categories nascent little evolved evolved and highly evolved glaucony are distinguished glauconitization appears to be controlled by a delicate balance between degree of physical confinement of a particle and the amount of ionic exchange between the micro environment and ambient open marine sea water the optimum conditions for glauconitization are those of semi confinement as a result the interior of a grain is more glauconitized than its less confined periphery similarly for identical substrate types large grains 500 m provide more favourable substrates for glauconitization than lesser confined small grains on a larger scale the formation of glaucony is governed by the availability of iron and potassium and the balance between detrital influx and winnowing low accumulation rates expose grains to the open marine environment for sufficiently long times 105 106 years for highly evolved glaucony

the geomagnetic storm time response of gps total electron content in the north american sector over the last two decades maps of gps total electron content tec have improved our understanding of the large perturbations in ionospheric electron density which occur during geomagnetic storms however previous regional and global studies of ionospheric storms have performed only a limited separation of storm time local time longitudinal and seasonal effects using 13 years of gps tec data we present a complete statistical characterization of the ionospheric response to geomagnetic storms for midlatitudes in the north american sector where dense ground receiver coverage is available the rapid onset of a positive phase is observed across much of the dayside and evening ionosphere followed by a longer lasting negative phase across all latitudes and local times our results show clear seasonal variations in the storm time tec such that summer events tend to be dominated by the negative storm response while winter events exhibit a stronger initial positive phase with minimal negative storm effects we find no discernable difference between spring and fall equinox events with both being equivalent to the average storm time response across all seasons we also identify a prominent magnetic declination effect such that stronger dayside positive storm effects are observed in regions of negative declination i e eastern north america on the nightside asymmetries in the tec response are observed near the auroral oval and midlatitude trough which may be attributed to thermospheric zonal winds pushing plasma upward downward along field lines of opposite declination

statistical behavior of the longitudinal variations of daytime electron density in the topside ionosphere at middle latitudes electron density in the topside ionosphere has significant variations with latitude longitude altitude local time season and solar cycle this paper focuses on the global and seasonal features of longitudinal structures of daytime topside electron density ne at middle latitudes and their possible causes we used in situ ne measured by demeter and f2 layer peak height hmf2 and peak density nmf2 from cosmic the longitudinal variations of the daytime topside ne show a wave number 2 type structure in the northern hemisphere whereas those in the southern hemisphere are dominated by a wave number 1 structure and are much larger than those in the northern hemisphere the patterns around december solstice ds in the northern hemisphere winter are different from other seasons whereas the patterns in the southern hemisphere are similar in each season around march equinox me june solstice js and september equinox se in the northern hemisphere and around me se and ds in the southern hemisphere the longitudinal variations of topside ne have similar patterns to hmf2 around js in the southern hemisphere winter the topside ne has similar patterns to nmf2 and hmf2 does not change much with longitude thus the topside variations may be explained intuitively in terms of hmf2 and nmf2 this approach works reasonably well in most of the situations except in the northern winter in the topside not too far from the f2 peak in this sense understanding variations in hmf2 and nmf2 becomes an important and relevant subject for this topside ionospheric study

the magnetic storms of 3 4 august 2010 and 5 6 august 2011 1 ground and space based observations we have used total electron content tec values from low middle and high latitudes recorded over the american continent and density and ion temperature measured in situ by the dmsp f15 and f17 satellites during the geomagnetic storms of 3 4 august 2010 and 5 6 august 2011 to study the formation and dynamics of plasma density enhancements that developed during these two storms common to both storms are the timing of the main phase that extends between 20 and 24 ut and their seasonality with both storms occurring near the end of the northern hemisphere summer solstice during both storms tec data show incipient equatorial anomalies lacking a poleward expansion beyond 20 magnetic latitude two large scale tec enhancements were observed at middle latitudes showing a complicated pattern of structuring and merging the first tec enhancement corresponds to a storm enhanced density sed seen between 21 and 01 ut on the following day the second tec enhancement was observed over central america located equatorward of the sed and apparently moving northward however careful analysis of the tec values indicates that this second tec enhancement is not transported from lower latitudes through a superfountain effect instead the enhanced plasma has a local origin and is driven by a southward directed meridional wind that moves plasma up the tilted magnetic field lines dmsp flights passing over the second tec enhancement show a reduction of the ion temperature confirming an adiabatic expansion of the plasma as it moves up the field lines it is concluded that the midlatitude tec enhancements do not arise from a low latitude ionospheric fountain effect

neoformation of micas in soils surrounding an alkaline saline lake of pantanal wetland brazil abstract the mineralogy and origin of micas were investigated in incipient soils surrounding a modern alkaline saline lake of nhecol ndia a sub region of pantanal wetland soils were sampled along a toposequence and analyzed by xrd tem eds and icp ms the studied micas mainly concentrated in a green horizon are dioctahedral strongly associated with fe 3 and al and interstratified with smectite layers classification of individual crystals shows that glauconite and fe illite are the dominant micas but one crystal of illite was recognized si rich amorphous materials are associated with small crystallites in the mica enriched horizon a recent study shows that water samples from the studied lake and the surrounding water table have high ph negative eh temperatures up to 40 c high concentration of k and low concentration of si oh 4 experimental studies of micas synthesis reported in the literature show that similar water conditions allow for dioctahedral mica crystallization from initial precipitation of amorphous hydroxides therefore water characteristics combined with presence of si rich amorphous materials in the mica enriched horizon suggest that the micas of the study area are neoformed the alternated origin of illite glauconite and fe illite mixed layer minerals probably occurs due to seasonal variations of ph temperature and chemical composition of waters in microenvironments since the changes at this scale are possibly faster and more extreme

unusual seawater composition of the late cretaceous tethys imprinted in glauconite of narmada basin central indiaunusual seawater composition of the late cretaceous tethysu bansal et al a detailed investigation of a glauconite bed within the late cretaceous bryozoan limestone formation of the bagh group in central india as well as the study of existing records reveals the existence of a glauconitic sea along the margins of the palaeo tethys ocean during the late cretaceous epoch the authigenic green mineral formed abundantly on shallow seafloors unlike in its modern deep sea counterpart we present an integrated petrographical geochemical and mineralogical investigation of the glauconite within late cretaceous transgressive deposits to highlight its unique geochemistry with moderate fe 2 o 3 and high al 2 o 3 sio 2 mgo as well as k 2 o contents x ray diffractional parameters identify the evolved to high evolved nature of the glauconite while mossbauer spectroscopic study reveals the dominance of fe 3 compared to fe 2 in the atomic structure the rare earth elements ree pattern of glauconite reveals moderate light ree heavy ree lree hree fractionation and weak negative eu anomaly the ce anomaly of the glauconite indicates a sub oxic diagenetic condition we propose that late cretaceous glauconites formed within a shallow marine depositional setting across the tethyan belt because of enhanced supply of k si al fe mg cations through continental weathering under the extant greenhouse climate

climatology and latitudinal gradients of quiet time thermospheric neutral winds over millstone hill from fabry perot interferometer measurements 1 midlatitude nighttime thermospheric neutral winds are strongly dependent on season solar activity and latitude we use an extensive database of wind measurements made during 1989 2001 by the millstone hill fabry perot interferometer to study the detailed climatology of quiet time neutral winds near an altitude of 250 km to facilitate the analysis of these data we develop a local time day of year solar flux and latitude dependent empirical model with the latitude dependence obtained by considering north looking and south looking observations separately our results show that the zonal winds are predominantly eastward after dusk and westward before dawn with the strongest eastward winds occurring in the winter and with an east to west transition that occurs earliest in the summer the zonal winds exhibit weak to moderate latitudinal gradients with more westward values to the north the zonal wind magnitudes decrease with increasing solar flux the strongest trends occur during winter the meridional winds are predominantly equatorward in all cases and exhibit strong latitudinal gradients with larger values to the north the maximum nighttime equatorward winds decrease with increasing solar flux except during summer when there is no significant solar activity variation they are largest during the summer except at solar minimum when a semiannual variation is observed and the peak winds occur during the equinoxes earlier studies of midlatitude wind measurements are generally consistent with our data with our results providing a considerably more detailed description of the nighttime wind climatology at midlatitudes

interpreting benthic oxygen levels in mudrocks a new approach quantified paleoecology and gamma ray spectrometry have been applied in the analysis of the kimmeridge clay a highly organic rich british jurassic mudrock decreasing benthic oxygen trends are reflected in decreasing species richness and dominance diversity values similarly the degree of fragmentation of the benthos reflects the benthic energy levels and covaries with benthic oxygen the calculation of authigenic uranium values from data gathered by gamma ray spectrometry shows enrichment in more oxygen deficient environments the good correlation between the independently derived paleoecological and authigenic u data indicates the importance of these techniques in environmental analysis of marine petroleum source rocks

east west differences in f region electron density at midlatitude evidence from the far east region the global configuration of the geomagnetic field shows that the maximum east west difference in geomagnetic declination of northern middle latitude lies in the us region similar to 32 degrees which produces the significant ionospheric east west coast difference in terms of total electron content first revealed by zhang et al 2011 for verification it is valuable to investigate this feature over the far east area which also shows significant geomagnetic declination east west gradient but smaller similar to 15 degrees than that of the us the current study provides evidence of the longitudinal change supporting the thermospheric zonal wind mechanism by examining the climatology of peak electron density nmf2 electron density ne of different altitudes in the far east regions with a longitude separation of up to 40 60 degrees based on ground ionosonde and space based measurements although the east west difference r ew over the far east area displays a clear diurnal variation similar to the us feature that is negative r ew west ne east ne in the noon and positive at evening night the observational results reveal more differences including 1 the noontime negative r ew is most pronounced in april june while in the us during february march thus for the late spring and summer period negative r ew over the far east region is more significant than that of the us 2 the positive r ew at night is much less evident than in the us especially without winter enhancement 3 the magnitude of negative r ew tends to enhance toward solar maximum while in the us showing anticorrelation with the solar activity the altitude distribution of pronounced negative difference 300 400 km moves upward as the solar flux increases and hence produces the different solar activity dependence at different altitude the result in the paper is not simply a comparison corresponding to the us results but raises some new features that are worth further studying and improve our current understanding of ionospheric longitude difference at midlatitude citation zhao b m wang y wang z ren x yue j zhu w wan b ning j liu and b xiong 2013 east west differences in f region electron density at midlatitude evidence from the far east region j geophys res space physics 118 542 553 doi 10 1029 2012ja018235

quaternary geology of eastern germany saxony saxon anhalt south brandenburg thuringia type area of the elsterian and saalian stages in europe abstract the characteristic feature of the quaternary geology of eastern germany location map fig 1 is a sequence of more than 50 horizons and complexes of glacial laminated clays tills glaciofluvial sediments and periglacial river gravels gelifluction sheets alluvium loess facies in the period between the younger tertiary and the first elsterian continental glaciation at least four gravel terraces were built up under cold climate conditions the youngest of these gravel bodies lacks scandinavian rocks and is interbedded with elsterian glaciolacustrine deposits pre elsterian temperate periods have been recorded at a number of places i e zeuchfeld untermassfeld voigtstedt sussenborn two major ice advances with additional minor oscillations have been identified of elsterian and saalian ages complete eemian and holsteinian sequences are represented showing vegetational development through each interglacial cycle cool temperate warm cool the weichselian glacial stage in eastern germany is represented by thick periglacial sedimentation including gravels gelifluction sheets alluvium debris covers and loess within these sediments is a wide variety of glaciotectonic structures and periglacial soil structures including classical involutions and ice wedge casts an outline of the present state of knowledge of the quaternary of eastern germany is given in tables 1 3 while table 4 presents a stratigraphical comparison with the neighbouring regions and countries the palaeogeography of the region during the periods of the european continental glaciation is depicted in fig 2

ironstones and green marine clays in the dongjeom formation early ordovician of korea abstract in the sino korean north china block the occurrence of ironstone is reported for the first time from the lower ordovician dongjeom formation korea the dongjeom formation comprises much quartzose sediment deposited on the extensive carbonate platform and is composed of three coarsening upward sequences ironstone beds are distributed on the tops of the lower two sequences suggesting that they mark approximately maximum flooding events during the relative lowstand of sea level when the dongjeom formation was deposited extensive weathering in the source areas coupled with higher order sea level rises resulted in the formation of the dongjeom ironstones the dongjeom ironstones include much green marine clays ironstones of the lowest sequence are characterized by glaucony facies and those of the middle sequence by chamosite facies chemical compositions of dongjeom glauconies reveal that they were originally nascent to slightly evolved 3 to 5 k 2 o wt and that they were affected by illitization after burial their immature compositions suggest that glauconies were formed in about 10 3 to 10 4 years or less on the seafloor the substrates for glauconitization are interpreted as detrital mineral grains regressions after glauconitization introduced iron oxides to the green grains eventually forming the iron oxide rich band under the most oxidizing conditions the distribution of glauconies in limited horizons suggests that the dongjeom glauconies are autochthonous in origin chamosites have granular shapes and are mixed with quartzose sand grains suggestive of reworking during storms the dongjeom chamosites were transformed from the precursor berthierines the occurrence of glauconies in correlative horizons in korea and north china may indicate that glauconitization in the host sediments which were deposited in far northern gondwana occurred under the influence of a coeval transgressive event

sea level changes an integrated approach sea level changes an integrated approach in october 1985 sepm sponsored a four day conference entitled sea level changes an integrated approach the purpose of the conference was to provide a forum for an interdisciplinary exchange of ideas on sea level changes and to provide an opportunity for integrating various types of evidence in approaching unresolved issues the conference was successful in bringing together scientists from industry academia and government representing all of the major geosciences disciplines presentations of many new papers plus significant releases of data that were previously held proprietary provided fertile ground for discussion this much cited volume represents the best of the material presented at the conference includes the early vail chart

magnetic declination and zonal wind effects on longitudinal differences of ionospheric electron density at midlatitudes 1 a prominent ionospheric longitudinal variation at midlatitudes in particular over the continental us was found recently this variation is characterized as a higher east side electron density in the evening and a higher west side electron density in the morning and with clear seasonal and solar activity dependencies a combined effect of geomagnetic declination and changing zonal winds was proposed to explain it this paper represents a comprehensive investigation of this effect by examining climatology for both electron density longitudinal differences and the nighttime zonal winds in the eastern us electron density is from incoherent scatter radar extra wide coverage experiments during 1978 2011 over millstone hill for which the spatial separation of the data can be up to 50 in longitude the thermospheric zonal wind is from the on site fabry perot interferometer measurements during 1989 2001 the observed zonal wind climatology is found to be perfectly consistent with the expectation based on the east west electron density differences in terms of local time seasonal and solar cycle dependencies the correlation between the zonal wind and the east west differential ratio is extremely high with an overall correlation coefficient of 0 93 the observed time delay of 3 hours in the response of electron density differences to zonal winds is a marked feature thus these results confirm positively the declination zonal wind mechanism and provide new insight into longitudinal variations at midlatitudes for other geographic sectors

pioneer vegetation as an indicator of the geochemical parameters in abandoned mine sites using hyperspectral airborne data a general problem that is associated with open pit mining is the total displacement of the former landscape s geocomponents overburden conveyor bridges have an irreversible impact on the environment the consequence of this is a completely new system the so called post mining landscapes these are characterized by extreme geochemical milieus especially acidity which is caused by weathering processes acid mine drainage these extreme environments are often left to natural succession because of the enormous costs and poor prospects of a successful reclamation this study investigated the relationship between pioneer vegetation e g calamagrostis epigejos and the geochemical properties of heap material using hyperspectral airborne hymap data in the west bohemian lignite district near sokolov czech republic thus a fully constrained linear spectral unmixing algorithm was applied to link the geochemical parameters with fractional abundances due to the limitation of pure surfaces in the data set of such fragmented and mixed areas a three stage semiautomated endmember extraction was developed the first stage included the selection of pure surface types using a decision tree with a self developed narrow band and normalized difference indices the second stage extracted the potential endmembers using the sequential maximum angle convex cone algorithm the third stage identified the final endmembers and eliminated the spectral outliers by comparing the extractions to field laboratory spectral libraries the abundance fraction image of the pioneer vegetation which was generated by the linear spectral unmixing showed the spatial distribution and density of the vegetation a linear regression model was used to calibrate the abundance image against the ph value the regression model successfully predicted the ph values of the soil r 2 0 67 rpd 1 42 this method demonstrated that hyperspectral remote sensing data could be used for ecological medium and long term monitoring as well as for spatial assessments in post mining areas in addition this approach works with a small amount of geochemical measurements and the sparse availability of endmembers

stratigraphic condensed deposition and diagenetic evolution of green clay minerals in deep water sediments on the ivory coast ghana ridge abstract green grains concentrations were studied through the 22 m pleistocene sedimentary column recovered from ocean drilling project site 959 in 2100 m water depth located on a small plateau on the northern flank of the cote d ivoire ghana marginal ridge the green clay material usually fills the chambers of pelagic foraminifers taking into account the variance in color and mineralogic composition of the bulk green grains fraction observed in each level a methodological approach was especially performed mineralogical and chemical analyses were done successively on the bulk green material then on hand picked white pale green medium green and dark green grains and lastly surface and spot analysis of nanno structures were obtained using an energy dispersive microprobe coupled with a scanning electron microscope green grains concentrations are evidenced showing both rising up of green white ratio and increasing abundance of cracked dark green grains these irregular concentrations are not consistent directly with a general climatic forcing as evidenced by 18 o isotopic curve but are the result of recurrent bottom current activity thus winnowing process is the cause of the long lasting ionic exchange and mineralogical evolution at the water sediment interface clay infilling composed of smectite 35 40 kaolinite 45 50 traces of mica calcite and quartz was a precursor material along with dissolution of kaolinite crystallochemical modifications of smectites were observed both to the sequential concentration scale bulk samples and to the individual grain scale from white to dark green increment of fe content associated decrease of al and increase of layer charge and k content in the layers with the highest green grain concentrations and in agreement with crystallochemical formulae fe 3 rich montmorillonite displays octahedral charge tetrahedral charge appears only when fe content increased 1 2 fe per formulae with the maturation process the growing of the closed layers is observed mixed layer smectite glauconite 80 20 nearly similar evolution patterns were recorded at various levels 0 01 0 85 2 2 ma of the pliocene pleistocene accumulation however the nontronite way is evidenced in the lowest green grains concentrations and remind the previously described shelf processes independently of the morphologically induced winnowing in these marine tropical deposits the glauconitization process was especially favored by abundant iron supply and was not affected by low temperature 3 c it is suggested that in deep water environment bottom current controlled iron deposition and disponibility strongly influencing the mineralogic evolution a too lengthy dispersal of iron microparticles played an ultimate role in the development of the montmorillonite way rather than the nontronite way this would be the most commonly found in shallow water environment

theoretical study of the ionospheric weddell sea anomaly using sami2 1 the ionospheric weddell sea anomaly wsa was first reported more than five decades ago based on ionosonde data near the antarctica peninsula the wsa is an ionospheric structure characterized by a larger nighttime electron density than daytime density recent satellite observations indicate that the wsa can extend from south america and antarctica to the central pacific the major physical mechanisms that have been suggested for the wsa formation are an equatorward neutral wind an electric field the photoionization and the downward diffusion from the plasmasphere on the basis of the theoretical modeling performed in this study using the sami2 model an equatorward neutral wind is identified as the major cause of the wsa while the downward flux from the plasmasphere provides an additional plasma source to enhance or maintain the density of the anomalous structure

non pelletal glauconite from the campanian qusseir formation egypt implication for glauconitization abstract glauconitization processes proposed in the literatures include the layer lattice theory in which glauconite formed through k uptake by a detrital smectite precursor and the neoformation theory that does not require a smectite like precursor the non pelletal glauconite bed in the uppermost part of the campanian qusseir formation at the abu tartur area and the underlying smectite rich beds provided a potential example for the glauconitization process the glauconite occurs as fine clayey moderately hard and homogeneous bed ranges in thickness from 2 to 3 m under the optical microscope glauconite occurs in a unique morphology as very fine green clayey matrix which differs from the typical pelletal shape of many glauconites under the scanning electron microscope it appears as dense uniform and very fine flakes that are composed of si al fe and k x ray diffraction analysis of both bulk samples and clay fractions indicates that the glauconite bed is composed entirely of glauconite geochemical analysis suggested that the investigated glauconites belong to the 2nd stage of the maturity scale i e moderate maturity or they can be alternatively ranked as evolved chondrite normalized ree patterns exhibit lree enrichment relative to hree la yb n ratios vary from 5 to 8 and slightly negative eu anomalies eu eu from 0 7 to 0 8 clay beds that underlie the glauconite bed are composed of two types of smectites smectite of low k 2 o and fe 2 o 3 contents and smectite of high k 2 o and fe 2 o 3 contents smectite of low k 2 o and fe 2 o 3 contents is considered in this study as the initial precursor of glauconite while smectite of high k 2 o and fe 2 o 3 represents the transitional phase between smectite and glauconite this in turns supports the layer lattice theory in which glauconite formed by k diffusion to a detrital smectite precursor from the sea water due to transgression absence of mixed layer minerals suggests that the diffusion process was active and continuous until reaction completion was reached i e formation of glauconite maturity and ree patterns suggest the possible formation of the studied glauconite probably at shelf environment at approximately 100 m water depth the occurrence of glauconite indicates a marine invasion of the upper part of the qusseir formation which was considered previously as non marine sediments

is burial velocity a master parameter for bioturbation abstract the intensity of biological mixing in a marine sediment is widely believed to be related to the flux of labile organic matter at the same time this flux has been shown to be strongly correlated to the burial velocity one would then expect a significant correlation between biological mixing coefficient d b and burial velocity a nonlinear regression of existing data with a power law eqns 2 and 3 of the text produces a statistically significant correlation the statistical significance of the regression in no way implies causation and in fact it accounts for only about 22 of the total variance in the dataset thus reducing its physical significance a number of additional processes contribute to the large observed variance including timing of mixing events temporal and spatial heterogeneity differences in temporal scales sampling artifacts and specific particle associations with due care the d b relationship may prove useful in defining the likely range of d b values in a particular environment a similar analysis of the tracer identified surface mixed depth shows that it is essentially independent of burial velocity with a worldwide mean of 9 8 4 5 cm depth of mixing is probably more closely related to the energetic costs of deep burrowing

analyses and monitoring of lignite mining lakes in eastern germany with spectral signatures of landsat tm satellite data abstract coal mining activities cause an increased acidity and an associated decrease of the ph value in mine waters this process is also known as acid mine drainage amd due to amd lakes that were formed in the post mining landscapes in the lignite mining area of central germany are characterized by specific limnological development changes remote sensing is a time and cost saving technique that enables the observation of the hydrological and limnological development of the lakes ranging from a small to a mid size scale the current research was based on landsat tm5 etm 7 satellite data collected between 1999 and 2004 in combination of satellite data surface waters of the post mining lakes in central germany were sampled and analyzed for their physicochemical properties the objective of this approach was to evaluate the environmental conditions and to develop a monitoring system on the other hand the research was conducted to assess the potential of the use of satellite data and to calibrate its content for monitoring the geochemistry of mining lakes correlation of hydrochemical parameters of lake water to spectral signatures detected by satellites was performed with multivariate statistical analysis methods the five determined clusters of spectral partitions described the actual data ground truth data within the visible range the statistically identified clusters were combined with expert knowledge in limnology geology and water chemistry of large scale lakes in open cast mining areas in order to analyze the spectral information of the satellite images scientifically the utilization of spectral signatures revealed an acceptable classification of hydrological and hydrochemical properties of mining lakes and established the basis for further investigation of open cast lignite mining concerning the environmental impact particularly in areas where lignite mining lakes usually form

a new geochemical classification of sedimentary environments because of the relative constancy of ph in most subaqueous sediments and the general lack of measurability of eh these parameters are not practically useful for classifying sedimentary environments in their place a new classification is offered which derived from studies of modern sediments is based on the presence or absence of dissolved oxygen and dissolved sulfide in the sediments at the time of authigenic mineral formation sedimentary environments are first of all divided into oxic and anoxic depending upon the presence or absence of measurable dissolved oxygen anoxic environments in turn are divided into sulfidic and non sulfidic depending upon the presence of measurable dissolved sulfide anoxic nonsulfidic environments are further divided into postoxic or resulting from oxygen removal without sulfate reduction weakly reducing and methanic or resulting from complete sulfate reduction with consequent methane formation strongly reducing the environments are shown to succeed one another during early diagenesis in the order oxic post oxic sulfidic methanic iron and manganese minerals characteristic and stable in each environment are listed and discussed so that they may be used to distinguish the environments when studying the ancient geological record

longitudinal variations of topside ionospheric and plasmaspheric tec the upward looking ionospheric total electron content tec from the metop a and tsx satellites during 2008 2015 has been used to systematically study the longitudinal variations of the topside ionosphere and plasmasphere the results of this study are summarized as follows 1 there are significant longitudinal variations in the topside ionosphere and plasmasphere at low latitudes the tec maximum during the june solstice over the western and central pacific ocean corresponds to a tec minimum at the same location during the december solstice but the opposite behavior occurs over south america and the atlantic ocean 2 during the solstices the relative longitudinal variations in the geomagnetic equatorial region do not have a strong dependence on local time and solar activity 3 the tec in the winter hemisphere decreases with increasing solar activity especially at higher altitudes and at night the topside tec depletion with solar activity depends on longitude 4 the solstice like longitudinal pattern lasts much longer than the equinox like patterns with the june solstice pattern lasting the longest furthermore the equinox like longitudinal patterns occur in march when expected whereas they extend from the autumnal equinox until the end of october 5 the longitudinal variations of upward looking tec are different from the corresponding longitudinal variations of electron densities around the f2 peak and orbital altitudes this indicates that the topside ionosphere structure is strongly influenced by the physical processes in the topside region rather than being a pure reflection of the ionospheric f2 peak structure

pathways of organic carbon oxidation in three continental margin sediments we have combined several different methodologies to quantify rates of organic carbon mineralization by the various electron acceptors in sediments from the coast of denmark and norway rates of nh4 and sigma co2 liberation sediment incubations were used with o2 penetration depths to conclude that o2 respiration accounted for only between 3 6 17 4 of the total organic carbon oxidation dentrification was limited to a narrow zone just below the depth of o2 penetration and was not a major carbon oxidation pathway the processes of fe reduction mn reduction and sulfate reduction dominated organic carbon mineralization but their relative significance varied depending on the sediment where high concentrations of mn oxide were found 3 4 wt mn only mn reduction occurred with lower mn oxide concentrations more typical of coastal sediments fe reduction and sulfate reduction were most important and of a similar magnitude overall most of the measured o2 flux into the sediment was used to oxidized reduced inorganic species and not organic carbon we suspect that the importance of o2 respiration in many coastal sediments has been overestimated whereas metal oxide reduction both fe and mn reduction has probably been well underestimated

theoretical study of zonal differences of electron density at midlatitudes with gitm simulation this study investigated various physical processes responsible for the longitudinal modulation of electron density ne at midlatitudes by employing the global ionosphere thermosphere model gitm the good agreements between gitm outputs and champ observations indicate that the model is a suitable tool to perform the theoretical study nine runs were carried out to determine the effects from geomagnetic field geometry zonal wind meridional wind high latitude activity migrating tides from the lower atmosphere and solar illumination in quantitative ways distinct features were discussed as follows it was crucial that the geomagnetic and geographical axes were offset for the development of the longitudinal difference of ne the zonal wind contributes to about 80 of the fraction of the observed longitudinal dependence of ne the meridional wind effect is out of phase with the zonal wind over north america and southern ocean regions which trims the fraction of the longitudinal difference to 65 over the south pacific ocean the nighttime ne maintains at a higher level because of in phase effects from both zonal and meridional winds the solar illumination was important in the formation of the background longitudinal pattern of the electron density the migrating tide from the lower atmosphere could enhance the longitudinal difference of ne by 15 over north america enhanced activities at high latitudes could alter the longitudinal pattern of ne by transporting thermospheric composition disturbances to midlatitudes

sulfur isotope studies to quantify sulfate components in water of flooded lignite open pits lake goitsche germany abstract a system of connected lignite mining pits part of the former goitsche mining complex germany was flooded with river water between 1999 and 2002 a considerable accumulation of acid associated with oxidized sulfides in sediments was seen as a critical point for the development of the lake water to characterize the components contributing to the supply of dissolved lake water so4 hydro chemical and isotope investigations with respect to groundwater pore water in the sulfide bearing sediments river water and lake water were performed 34s of pore water so4 that was dominated by oxidized pyrites ranges around 25 vcdt and differs strongly from river water so4 with about 4 4 thus interactions between lake water and sediments were particularly pronounced during the first phase of flooding for this period a more quantitative estimation of the so4 components in the lake water was difficult because of the heterogeneous so4 distributions between the different sub basins of the lake and according to the flooding process itself later a component separation was attempted following mixing of the whole lake which first occurred in spring 2002 a very heterogeneous groundwater environment with respect to highly variable so4 concentrations and 34s values and changing interaction with the forming lakes proved to be one of the most important limitations in the calculations of the mixing

weathering of glauconite in soils of temperate climate as exemplified by a luvisol profile from gora pulawska poland abstract the aim of the research reported herein was to study the weathering of glauconite taking place in a luvisol profile developed on quartz glauconitic sand in gora pulawska eastern poland using x ray diffractometry fourier transform infrared spectroscopy mossbauer spectroscopy sem eds and an optical microscope the bulk soil material contains quartz glauconite glauconite smectite mixed layered minerals rich in smectite layers and traces of feldspars when compared with the parent material the cg horizon the bt1 and bt2 horizons are enriched in clay minerals while the ap aeg and e horizons are depleted in clays the observed mineral distribution is most likely controlled by the weathering of clay minerals in the uppermost part of the profile and translocation of clay fractions down the profile lessivage however contamination with glaciofluvial and or aeolian material has to be taken into consideration according to the microscopic observations of the thin sections clay is present in the bcg and cg horizons in the form of clay coatings and clay infilings this indicates that initially the parent sand did not contain clay fraction the fraction was formed most likely in the upper part of the soil profile and was deposited in the lower horizons by percolating atmospheric water green pellets separated from all the soil horizons are composed of glauconite showing more or less uniform chemical composition while clay fractions from all the horizons contain glauconite and glauconite smectite fine clay fractions separated from ap and aeg horizons are enriched in glauconite smectite relative to the fractions separated from the lower horizons the presence of glauconite and glauconite smectite minerals in the clay fractions studied indicates that glauconite weathering in the soil studied involves formation of glauconite clay by the pellet disintegration and glauconite smectitization ferrous iron accounts only for

the distinctive compositional evolution of glauconite in the cretaceous ukra hill member kutch basin india and its implications abstract an integrated study involving sedimentology mineral chemistry and spectroscopy highlights a distinctive compositional evolution of cretaceous glauconite within the ukra hill member glauconite occurs at the top part of transgressive systems tract deposits built on a marine shelf the concentration of glauconite steadily increases towards the maximum flooding surface maximizing around 50 and sharply falls at the onset of progradation unlike most phanerozoic examples ukra glauconite forms by the variable degree of replacement of quartz feldspar and mica grains xrd feg sem and spectroscopy of glauconite pellets indicate an evolved stage of maturation mossbauer spectroscopy reflects a minor substitution of al3 fe3 total in tetrahedral sites and significant substitution of the same in octahedral sites a consistently high value of k2o as well as fe2o3 contradicts the two popular theories layer lattice and verdissement and support replacement origin of glauconite in a high asi and high ak pore water environment incipiently formed glauconite records a marginal increase in k2o content accompanied by release of al2o3 and sio2 to form evolved glauconite pellets those forming within quartz grains involve an addition of fe2o3 total content during maturation the minimal increase in k2o content of incipiently formed glauconite best exhibited by those formed within quartz grains is possibly related to stratigraphic condensation compositional evolution like this is exhibited by precambrian glauconites involving abiotic substrates but is unusual for the phanerozoic original k2o and fe2o3 total content of glauconites is reduced around peripheries and fractures during diagenesis adding to compositional variability

durability assessments of rare green andesites widely used as building stones in buca izmir turkey miocene volcanism was active in the city area of izmir turkey where volcanic deposits formed predominantly made of gray and pinkish colored andesite these rocks have been widely used in the construction of many buildings in the region in the northern part of izmir known as the buca region there is an area where andesite presents green color the occurrence of the green andesite is rather rare and historically this rock type has been used in the construction of ancient valuable architectonic structures including aqueducts historical buildings and mosques some of these structures date back to the beginning of the first century ad when the region was under the control of the roman empire interestingly the recent survey of these structures showed that after all of these years the green andesite still appears pretty much well preserved only showing slight deterioration in the form of limited crumbling although these rocks were used in this particular region in the past their material properties have not been investigated so far the purpose of this study was therefore to identify mineralogical chemical physical and mechanical properties of these rocks which eventually determine their durability the first phase of the research focused on detailed site investigation which resulted in the definition of the geological extent of the green andesite and the identification of two historical quarries from one of which representative samples was collected for laboratory investigation which was the main task of the second phase of the research the main cause for the green color of the andesite resulted the presence of celadonite which is also accompanied by cristobalite the presence of cristobalite in the pores as a secondary mineral appears to have contributed to the increased strength and durability of buca andesite laboratory evaluation of the durability was in general agreement with field observations although some test gave ambiguous results this discrepancy revealed some weakness of laboratory tests to precisely assess durability of building stones

midlatitude summer nighttime anomaly of the ionospheric electron density observed by formosat 3 cosmic 1 this paper presents monthly variations of the midlatitude summer nighttime anomaly msna of the ionosphere for the first time by global observations of the formosat 3 cosmic f3 c mission the anomaly is characterized by the greater nighttime 1800 lt 0200 lt ionospheric electron density than during daytime 0800 1800 lt at middle latitudes during months around june and december solstices the anomaly shown during december solstice was known as the weddell sea anomaly wsa occurring around the antarctica and nearby the pacific ocean this paper demonstrates that the wsa like feature also exists in the northern hemisphere and is most prominent near the northeast asia europe africa and central pacific longitudes around june solstice in both hemispheres the anomalies with similar electron density characteristics and variations caused by the similar mechanism prompts us to name this phenomenon the msna the monthly f3 c observations indicate that the anomaly appears as the most prominent structure of the global ionosphere around midnight hours

the genesis of glaucony in the oligo miocene torquay group southeastern australia petrographic and geochemical evidence abstract the oligo miocene torquay group at bird rock in southeastern australia comprises a sequence of fine grained skeletal carbonates and argillaceous and glauconitic sandstones which were deposited in a cool water mid shelf environment the bird rock glaucony consists predominantly of randomly interstratified glauconitic smectite which constitutes bioclast infills and faecal pellet replacements petrographic and geochemical evidence indicates that the glaucony is autochthonous and comprises chemical components derived primarily from argillaceous matrix material seawater is unlikely to be a significant source of ions the glauconitization of the bird rock sediments occurred under sub oxic partially reducing conditions in the very shallow burial environment and involved local iron redistribution sub oxic conditions favour glauconitization because iron is stable in the soluble ferrous state and can be fixed in authigenic silicates due to the negligible concentrations of hydrogen sulphide it is likely that localised acidic conditions were initiated during the glauconitization process this acidity appears to have been buffered by the dissolution of bioclastic carbonate the fact that glaucony predominantly occurs as bioclast infills and faecal pellet replacements implies that the physico chemical conditions appropriate for glauconitization develop preferentially in such biogenic detritus the development of appropriate micro environments within such sediments probably relates to their physical confinement and or high organic matter content the bird rock glaucony developed during intervals of slow sedimentation and environmental quiescence associated with marine flooding events these conditions facilitated glauconitization by allowing the favoured clay rich sediments to accumulate and remain in the appropriate physico chemical regime sufficiently long for the complex glauconitic structures to form

chemical composition of thalassinoides boxwork across the marine k pg boundary of central new jersey u s a thalassinoides isp burrow networks filled with green to dark bluish gray glauconite pellets occur in the cretaceous to paleogene hornerstown formation and in the uppermost 1 2 m of the underlying upper cretaceous navesink and new egypt formations at many central new jersey cretaceous paleogene k pg boundary sections near the base of the hornerstown formation is a renowned bonebed the main fossiliferous layer mfl which contains isolated to articulated cretaceous marine reptiles turtles birds and crocodiles interpreted as a thanatocoenosis we investigated the bulk chemical composition of the burrow fill and surrounding matrix in the largely unconsolidated sections of the k pg interval at two sites inversand and walnridge meirs farm new jersey using a niton xl3t xrf analyzer to place them in proper stratigraphic context bulk matrix zr and ti concentrations decrease up section as a result of transgression deepening and increased distance from source areas in contrast an increase in k is attributed to greater amounts and maturity of the glauconite due to decreasing sedimentation rates zr and ti concentrations in burrow fills below the mfl are virtually the same as in overlying sediments above the mfl and much less than in the surrounding matrix this suggests that burrows in the cretaceous strata were passively filled with paleogene sediments k concentrations of burrow fills are generally intermediate between the high values encountered in the paleogene matrix and the lower values of the cretaceous matrix although this may have resulted from removal of glauconite during bioturbation and burrow filling it is more likely that immature glauconite was sequestered in the burrow fills below the depth of glauconitization before it could attain full maturity therefore burrows originating above the formational contact at or above the mfl penetrate as much as two meters into underlying cretaceous sediments and are passively filled with paleogene sediment burrows originating above the mfl may translocate diagnostic danian microfossils shocked quartz and ir effectively diffusing the k pg boundary this research demonstrates that care must be taken in sampling pervasively bioturbated strata to avoid incorporating stratigraphically younger burrow fill sediments

calibration of the geologic time scale cenozoic and late cretaceous glauconite and nonglauconite dates compared revision of the 1982 time scale of harland et al has led to the compilation of 377 isotopic dates for calibration of the cenozoic to cretaceous time interval the results show that the ages of stage boundaries based on glauconite dates are on average about 2 m y younger than those based on nonglauconite dates but for many cenozoic and late cretaceous stages the differences are too small to require special consideration of glauconite dates future work may reveal an irreducible systematic difference between glauconite and nonglauconite time scales but the progress made so far in recognizing those glauconites likely to yield reliable dates for the cenozoic to late cretaceous interval may continue to provide useful time scale calibration points

more evidence that the chicxulub impact predates the k t mass extinction yaxcopoil 1 yax 1 drilled within the chicxulub crater was expected to yield the final proof that this impact occurred precisely 65 myr ago and caused the mass extinction at the cretaceous tertiary k t boundary instead contrary evidence was discovered based on five independent proxies sedimentologic biostratigraphic magnetostratigraphic stable isotopic and iridium that revealed that the chicxulub impact predates the k t boundary by about 300 000 years and could not have caused the mass extinction this is demonstrated by the presence of five bioturbated glauconite layers and planktic foraminiferal assemblages of the latest maastrichtian zone cf1 and is corroborated by magnetostratigraphic chron 29r and characteristic late maastrichtian stable isotope signals these results were first presented in keller et al 2004 in this study we present more detailed evidence of the presence of late maastrichtian planktic foraminifera sedimentologic and mineralogic analyses that demonstrate that the chicxulub impact breccia predates the k t boundary and that the sediments between the breccia and the k t boundary were deposited in a normal marine environment during the last 300 000 years of the cretaceous

monitoring of hydrochemical parameters of lignite mining lakes in central germany using airborne hyperspectral casi scanner data active and abandoned coal mines have a huge impact on the environment the most challenging problem is caused by acid mine drainage amd using traditional methods such as single point measurements to determine and analyze mining lakes over the period of a few years is difficult due to the lakes high dynamic and inner differentiation to overcome this difficulty a new method has been successfully tested to additionally monitor residual lakes using a manifold data set like images from the hyperspectral airborne scanner casi ground truth data spectral field and laboratory measurements the optical properties reflection absorption and scattering of acid mining lakes were defined for the first time ever furthermore hydrochemical parameters in quality and quantity were ascertained in a two stage process first optical properties of the mining lakes were analyzed and defined for each of the limnological stages of development second based on the lakes optical properties algorithms for classification of the hydrochemical parameters evolved and were reliably utilized the new algorithms enable the monitoring of mining lakes from acidic to alkaline as well as the quantification of the hydrochemical properties inside the lake water

sequential mineral transformation from kaolinite to fe illite in two brazilian mangrove soils abstract mangrove soils have peculiar chemical and physical conditions generated by the variable water salinity cyclic tidal changes and intense biological activity that produce complex clay suites in this study the crystal chemical characteristics of clay minerals from two mangrove soils were investigated in detail to further our understanding of the processes taking place the two brazilian mangroves are from zones of contrasting climatic type and continental sediment character 1 tropical wet climate area receiving highly weathered sediments braganca para state and 2 mild semiarid climate area supplied with a mixture of highly and moderately weathered sediments acarau ceara state the investigation of the 2 0 2 m and 4 ions abundant in the interstitial water superior fe rich illite contents in acarau mangrove compared to braganca mangrove are explained by high inputs of 2 1 clays from sediment source areas inland the above clay mineral reactions shed light on the role of clays and the interaction between minerals and biotic components in mangrove soils in addition these reactions may influence the cycle of major elements in coastal ecosystem surrounding mangroves

the process of glauconitization chemical and isotopic evidence sequential leaching experiments were made on recent glauconies and clay fractions of the associated mud from off shore africa near the estuary of the congo river analyses of major rare earth elements ree and nd isotopic compositions on the resulting leachate and residue pairs allow identification of at least three important and isotopically distinct components which contributed to the glauconitization process 1 a detrital component with relatively high 87sr 86sr and relatively low 143nd 144nd isotopic ratios 2 a phosphate phase rich in ree and sr with sea water sr and nd isotopic characteristics 3 a component rich in organic matter and ca with a sea water sr isotopic signature a relatively low nd isotopic composition and elevated sm nd ratios this latter component probably represents the suspended organic and carbonate rich river load the detrital and the river components were mixed up in the muddy off shore sediment ingested by worms and integrated into faecal pellets the resulting material has sr and nd isotopic signatures intermediate between those of the detrital and river components and represents the precursor of the glaucony minerals during the subsequent dissolution crystallization process the glauconitic pellets remain isotopically closed to any external supply but expulsion of sr and nd with increasing degree of maturation is observed without any effect on the sr and nd isotopic compositions at a higher maturation stage k2o 4 5 the sr and nd isotopic compositions tend to decrease and increase respectively approximating the isotopic composition values of the phosphate rich phase because the sr and nd concentrations decrease the evolution of the glauconies toward lower sr and higher nd isotopic compositions can only be explained by expulsion of sr and nd of the detrital component with high sr and low nd isotopic signatures dissolution of the chemically unstable wormdigested clay material from mud may be responsible for the liberation of these elements consequently the phosphate rich phase with sea water sr and nd isotopic signatures becomes increasingly important for the isotopic characteristics of the maturing glauconite grains and sea water isotopic signatures can be reached during the stage of mature glauconite k2o 6 5 without chemical exchange with the depositional environment

is the rarity of glauconite in precambrian bhima basin in india related to its chloritization abstract an integrated textural mineralogical and chemical investigation reveals the origin of authigenic glauconite within the mesoproterozoic rabanpalli formation in the bhima basin and its subsequent alteration to chlorite glauconite forms within the transgressive shallow shelf deposits in the rabanpalli formation it primarily occurs in two modes as thoroughly replaced form of detrital grains and as altered zones along cleavages and fractures of quartz k feldspar and mica all varieties of glauconites exhibit high contents of k2o the fe2o3 t content is highest in glauconite formed within mica while it is least in glauconite formed by the replacement of feldspars pseudomorphic replacement of substrates by glauconite best explains the origin of glauconite in the rabanpalli formation diagenetic chlorite mostly occurring as thick rims on grains and along the grain margin fractures replaces glauconite chloritization predominantly takes place in the glauconite variety forming within the mica the mineral chemistry of chlorite is characterized by high mgo and fe2o3 t chloritization involves the simultaneous removal of fe mg and si from the glauconite structure to form brucite type sheets the high contents of fe2o3 t and mgo reducing porewater and the high thermal maturation of sediments facilitate the formation of chlorite within the rabanpalli formation this study therefore indicates that the rarity of glauconite in the precambrian is related to its alteration to chlorite

daytime ionospheric longitudinal gradients seen in the observations from a regional beidou geo receiver network many studies have devoted to the longitudinal variations of the ionosphere globally however the ionospheric longitudinal variations in a small region are rarely reported in this paper we for the first time use tec data from a beidou geostationary orbit geo receiver network to observe and investigate ionospheric longitudinal variations within the zonal scale of 1000 km over central china 112 122 e 27 31 n 20 24 n magnetic latitudes during june 2015 december 2016 the beidou geo tec provides a good dataset to study longitudinal variations compared with non geo tec without contaminating the spatial variations and elevation changes due to satellite motion pronounced daytime longitudinal gradients within the distance of 1000 km are present in beidou geo tec it was found that the tec is generally larger in the west than in the east in some cases the tec gradient magnitude is larger than 45 tecu for most events the obvious daytime longitudinal gradients are accompanied by the tec enhancement the occurrence rate of daytime longitudinal gradients under different geomagnetic activities is similar whereas strong daytime longitudinal gradients mainly occur under the moderate and strong disturbance geomagnetic activities these observations suggest that the electric field disturbances could have significant effects on producing the observed ionospheric longitudinal gradients

substrate control on formation and maturation of glauconites in the middle eocene harudi formation western kutch india formation and maturation of glauconites within the early middle eocene harudi formation built up in a lagoon to shelf transition in western kutch india is addressed taking recourse to a combined sedimentological micropalaeontological and mineralogical investigation the glauconite is authigenic and its occurrence coincides with maximum flooding the glauconite is more matured within the fecal pellets and is less matured within the intra particle pores of bioclasts namely foraminifera ostracoda gastropoda and bryozoa sem eds xrd and geochemical studies clearly document that the infilling within the intra particle pores of bioclasts belong to nascent to slightly evolved glauconite 5 wt k2o while the pellet belongs to slightly evolved to evolved glauconite 5 7 wt k2o based on chemical characteristics and sem investigations the glauconitization process can be best explained by the verdissement theory the glauconite possibly formed as initial authigenic glauconitic smectite precipitates while the pellet matured subsequently by addition of k the process was hindered in case of infillings the maturation process also involved addition of si and release of al with or without release of mg the glauconite maturation was facilitated in case of fecal pellets because of higher porosity inter granular nature of pores and availability of necessary elements in semi confined micro environments in contrast the maturation was aborted at an early stage in case of infillings because of the minute closed nature of the pores and prevalent alkaline conditions not allowing dissolution of calcitic tests a low negative cerium anomaly suggests glauconite formation in sub oxic micro environments created by decay of organic matters within the fecal pellets and bioclasts a clear case of substratum control on glauconitization becomes apparent

east west coast differences in total electron content over the continental us 1 total electron content tec measurements made by a network of dense gps receivers over the continental us are used to investigate ionospheric longitudinal differences we find that the evening tec is substantially higher on the us east coast than on the west and vice versa for the morning tec the longitudinal difference displays a clear diurnal variation through an analysis of morning evening variability in the east west tec difference minimum variability is found to coincide with the longitudes of zero magnetic declination over the continental us we suggest that these new findings of longitudinal differences in ionospheric tec at midlatitudes are caused by the longitudinal difference in magnetic declination combined with the effects of thermospheric zonal winds which are subject to directional reversal over the course of a day this study indicates that longitudinal variations in tec measurements contain critical information on thermospheric zonal winds the proposed declination zonal wind mechanism may also provide a new insight into longitude ut changes at midlatitudes on a global scale as well as into some geospace disturbances

ionospheric climatology and variability from long term and multiple incoherent scatter radar observations climatology in eastern american sector 1 ionospheric climatology and variability studies are conducted using long term incoherent scatter radar isr observations from seven sites around the world these studies result in an empirical model system the isr ionospheric model isrim which represents local and regional ionospheric climatology and variability of the ionosphere this paper addresses some new climatological features revealed by the model for latitudes spanning 18 70 n over the eastern american sector the latitudinal change of the f2 layer electron density exhibits a clear depletion near millstone hill latitudes when solar activity is median or low accompanied by a te enhancement and electron density peaks at 10 both to the north and south of millstone hill possible explanations are discussed we also characterize several types of variation in plasma temperatures in this region including ion temperature elevation for quiet conditions in the auroral zone and electron temperature increases toward higher latitudes

longitudinal modulation of electron and mass densities at middle and auroral latitudes effect of geomagnetic field strength in this study the effect of a reduction in magnetic field strength on the longitudinal modulation of electron density ne and mass density is investigated we study conditions during the september equinox and june and december solstices at middle and auroral latitudes in both northern and southern hemispheres the global ionosphere thermosphere model was employed for the theoretical study simulations were performed with a realistic international geomagnetic reference field igrf model and an igrf model reduced in strength by 50 the reduction in field strength increased the longitudinal variations in ne by 2 34 in the nighttime sector but reduced the variation by 7 20 in the daytime sector at mid latitudes in both hemispheres conversely at auroral latitudes ne was reduced by 2 32 at all local times the changes during equinoxes are larger than those for the solstices the differences with local time in the response of ne to a reduction in magnetic field strength were mainly due to changes in the oxygen molecular nitrogen o n2 ratio in the northern hemisphere whereas the differences were due to the combined effects of vertical winds and changes in the o n2 ratio in the southern hemisphere both vertical winds and horizontal e b convection eliminated ne at high latitudes got enhanced at both middle and auroral latitudes which was related to the enhanced joule heating effect when the magnetic field was reduced

evolution patterns of glaucony maturity a mineralogical and geochemical approach abstract integrated mineralogical and geochemical analyses were carried out on a wide variety of glauconitic grains from 25 western european localities covering the whole range of glaucony maturity and ranging in age between the cretaceous and the pliocene a comprehensive data set documents the major evolution patterns of glaucony and the relationships between glauconitic minerals and their substrate components increasing glaucony maturity involves potassium and rubidium enrichment the progressive evolution from a k poor glauconitic smectite to a k rich glauconitic mica is accompanied by the overall decrease of distance between peaks 001 and 020 the width of basal reflection 001 however is proposed here as a more powerful tool for the discrimination of glauconitic minerals at different stages of maturity this parameter is especially efficient for the differentiation of evolved and highly evolved glaucony the range of initial substrate composition appears to control significantly major and trace element variations during glaucony maturation contrasting patterns are observed in glauconitic grains as a function of the proportion of carbonate versus siliciclastic substrate components particularly the distribution patterns of mgo and sio2 in glaucony associated with carbonate host rocks suggest progressive uptake of these elements in the structure of glauconitic minerals with increasing degree of maturation by contrast a decrease in sio2 and ai2o3 with increasing maturity may be observed when the substrate for glauconitization is represented by siliciclastic material fe shows a positive correlation with k2o in glaucony with low maturity but an opposite trend in evolved glaucony therefore fe cannot be regarded as a reliable indicator of glaucony maturity maturation of glauconitic minerals results invariably in ca and sr depletion irrespective of the original composition of the precursor material as a consequence the proportion of ca and sr may be considered as an inverse relative criterion of glauconitic mineral evolution for a given source area

first observations of the midlatitude evening anomaly using super dual auroral radar network superdarn radars 1 under geomagnetically quiet conditions the daytime midlatitude ionosphere is mainly influenced by solar radiation typically electron densities in the ionosphere peak around solar noon previous observations from the millstone hill incoherent scatter radar isr have evidenced the presence of evening electron densities higher than daytime densities during the summer the recent development of midlatitude super dual auroral radar network superdarn radars over north america and japan has revealed an evening enhancement in ground backscatter during the summer superdarn observations are compared to data from the millstone hill isr confirming a direct relation between the observed evening enhancements in electron densities and ground backscatter statistics over a year of data from the blackstone radar show that the enhancement occurs during sunset for a few hours from april to september the evening enhancement observed by both superdarn and the millstone hill isr is shown to be related to recent satellite observations reporting an enhancement in electron densities over a wide range of longitudes in the northern hemisphere midlatitude sector during summer time finally global results from the international reference ionosphere iri and the horizontal wind model hwm07 are presented in relation with previously published experimental results and proposed mechanisms of the evening enhancement namely thermospheric horizontal winds and geomagnetic field configuration it is shown that the iri captures the features of the evening enhancement as observed by superdarn radars and satellites

use of gis to discover potential coalfields in yatagan milas area in turkey abstract the study was aimed to produce potential coalfield map using geographic information systems gis in the milas yatagan basin frequency ratio model was used to define the relationships between the coal occurrences and the selected variables which are significant for coal prospection formation geologic age lithology rock types depositional environment distance to fault and slope data of the study area were used as variables frequency ratio values of the variables were calculated and assigned to variable s class attributes all variable maps were summed according to the frequency ratio values of superposed pixels to calculate the probability index the probability index values of the potential map were classified into five classes as very high high medium low and very low probability areas finally the potential map was compared with known coalfields in the milas yatagan basin and calculated distribution of the known coalfields on the probable areas

the summer evening anomaly and conjugate effects 1 the constellation observing system for meteorology ionosphere and climate cosmic gps occultation data have been analyzed in this study to provide a better understanding of the weddell sea anomaly wsa and to place it in the wider context of a general phenomenon that occurs near dusk in summer which we are calling the summer evening anomaly to better capture its global nature the terminator and the magnetically conjugate points for the terminator in the other hemisphere have been plotted on top of global maps of cosmic nmf2 and hmf2 for 2 months either side of the december and june solstices for 2006 2008 these plots show that there are distinct enhancements of nmf2 and increases in hmf2 as soon as the conjugate footprint of the field line on the winter terminator is seen at middle latitudes in the summer hemisphere this effect is most pronounced where the wsa is formed but it also occurs across the south pacific ocean in the southern summer and across much of the north atlantic ocean siberia and kamchatka during the northern summer an hmf2 increase occurs between the two terminators even at locations where there is no increase in nmf2 a similar but reversed effect occurs in hmf2 near dawn this behavior appears to be most consistent with upward and poleward ion drifts in the evening but neutral wind and downward precipitation may make important contributions to this effect

hyperspectral remote sensing monitoring of pyrite mine wastes a record of climate variability pyrite belt spain monitoring of mine waste on sulphide deposits through hyperspectral remote sensing data contributes to predicting surface water quality quantitatively estimating acid drainage and metal contamination on a yearly basis the mineralogy of surface crusts loaded with highly soluble salts is a record of available humidity and temperature along the year a temporal monitoring of salt efflorescence on mine wastes at a mine site in the iberian pyrite belt spain has been mapped in this work using hyperspectral airborne hymap data climate change estimations are made based on oxidation stages derived from well known sequences of minerals tracing sulphides oxidation intensity using archive spectral libraries therefore mine waste weathering products of sulphide mapped from airborne hyperspectral remote sensing data can be used as a short term record of climate change providing a useful tool for assessing environmental geoindicators in semi arid areas

regional and local ionospheric models based on millstone hill incoherent scatter radar data 1 local and regional statistical models to describe millstone hill incoherent scatter radar observations of electron density electron temperature and ion temperature since 1976 are developed using a bin fit technique the local models generate ionospheric variations with local time day number and altitude from 150 1000 km the prior day s f107 and the ap index from the previous 3 hour period are keyed inputs to specify solar and geomagnetic activity the regional models have a latitude coverage of 32 55 geodetic and an altitude coverage of 200 600 km these climatology models are capable of reproducing primary ionospheric variation features seen in previous studies as well as several newly revealed features such as the semiannual variation of electron density they are accessible through the world wide web at the url http www openmadrigal org

compositional variability of glauconites within the upper cretaceous karai shale formation cauvery basin india implications for evaluation of stratigraphic condensation abstract a detailed mineral chemical investigation of glauconite within the condensed section deposits of the cretaceous karai shale formation cauvery basin india reflects a wide spectrum in chemical composition related to origin and evolution in different substrates stratigraphic condensation and post depositional alteration fe and mg rich glauconite comprising up to 60 of the sedimentary rocks occurs as replaced forms of fecal pellets as infillings within pores and chambers of bioclasts including those of foraminifera ostracoda bryozoa and algae and as altered forms of mica exhibiting vermiforms authigenic precipitation of k and fe poor glauconite followed by addition of fe and k into the lattice and concomitant release of al and si explains the origin of glauconite pellets and infillings the origin of glauconite vermiforms in partly degraded mica involves only the second stage of fe and k addition glauconite pellets and vermiforms exhibit sharply defined alteration zones along peripheries to form rims and in proximity to cracks or cleavages with reduced k2o and fe2o3 total and enhanced al2o3 and sio2 related to late stage meteoric water actions cores of glauconite pellets and unaltered zones of vermiforms reflect evolved characteristics with 6 k2o typical of a condensed section while other glauconite varieties occurring at the same stratigraphic level exhibit slightly evolved nature not consonant with stratigraphic condensation increasing abundance of glauconite pellets from the bottom to the top of the transgressive systems tract accompanied by slight increase in k2o within their cores reflects the effect of stratigraphic condensation on the evolution of glauconite high fe2o3 total content of glauconite in the karai shale formation may be related to upwelling although the fe may be contributed partly by the biotite substrate mossbauer spectroscopy of glauconites reveals significant total fe substitution in both tetrahedral and octahedral sites detailed mineral chemical analysis enables us to distinguish stratigraphically significant glauconite within the karai shale formation from the rest of the glauconite notwithstanding its wide compositional range

meridional winds derived from cosmic radio occultation measurements 1 meridional winds at the magnetic meridian in the upper thermosphere are derived from the peak height and density of the ionospheric f2 layer as retrieved by the constellation observing system for meteorology ionosphere and climate cosmic satellites for 4 months from november 2006 to february 2007 these winds referred to as cosmic winds are first validated by comparison at multiple locations with winds obtained from ground based incoherent scatter radar isr and fabry perot interferometer fpi measurements then longitudinal variations of these winds are investigated and compared with simulations by the national center for atmospheric research thermosphere ionosphere electrodynamics general circulation model ncar tie gcm the results show generally good agreement between cosmic winds ground based measurements and the simulations significant longitudinal variations are presented in the cosmic winds at 40 n local winter around midnight the cosmic winds exhibit stronger and longer duration equatorward velocities within 110 w 20 w large negative magnetic declination sector than those in other longitudes during late morning hours the poleward winds show similar longitudinal variations at 40 s local summer during the daytime the poleward winds are stronger within 120 e 110 w large positive magnetic declination sector than in 60 w 90 e large negative magnetic declination sector while during the nighttime the maximum equatorward winds shifts about 2 h later in 60 w 90 e than in 120 e 110 w analysis of the tie gcm simulations suggests that the longitudinal variation of meridional winds is mainly induced by magnetic declination due to the contribution of geographic zonal wind

climatology of nighttime upper thermospheric winds from fabry perot interferometer 2011 2019 measurements over kelan 38 7 n 111 6 e china local time seasonal solar cycle and geomagnetic activity dependence

ionospheric symmetry caused by geomagnetic declination over north america 1 we describe variations in total electron content tec in the north american sector exhibiting pronounced longitudinal progression and symmetry with respect to zero magnetic declination patterns were uncovered by applying an empirical orthogonal function eof decomposition procedure to a 12 year ground based american longitude sector gps tec data set the first eof mode describes overall average tec while the strong influence of geomagnetic declination on the midlatitude ionosphere is found in the second eof mode or the second most significant component we find a high degree of correlation between spatial variations in the second eof mode and vertical drifts driven by thermospheric zonal winds along with well organized temporal variation results strongly suggest a causative mechanism involving varying declination with longitude along with varying zonal wind climatology with local time season and solar cycle this study highlights the efficiency and key role played by the geomagnetic field effect in influencing mesoscale ionospheric structures over a broad midlatitude range

glauconite composition and morphology shocked quartz and the origin of the cretaceous main fossiliferous layer mfl in southern new jersey u s a abstract the main fossiliferous layer mfl is a concentration of vertebrate and invertebrate fossils 20 to 30 cm thick preserved in a sequence of glauconitic sand at or near the cretaceous paleogene boundary in the new jersey usa coastal plain several hypotheses have been proposed to explain the origin and age of the mfl including marine transgression and formation of lag deposits of reworked bones and shells formation of a condensed section and attritional accumulation of fossil material and catastrophic collapse of late cretaceous ecosystems following the end cretaceous bolide impact at chicxulub we use new data on glauconite morphology concentrations geochemistry and presence of shocked quartz coupled with previous data on sedimentology taphonomy and rare earth element geochemistry of fossil vertebrates to interpret the genesis of the mfl glauconite concentration and maturity steadily increases from latest cretaceous sediments of the navesink new egypt formation through the mfl and into the paleogene upper hornerstown formation suggesting that marine transgression and decreasing sedimentation rates were a factor in the formation of the glauconite but not the mfl rare earth element patterns in fossil bones from the mfl which are acquired during fossilization are different from those of cretaceous and paleogene specimens indicating that vertebrate remains in the mfl fossilized in situ and were not reworked from older underlying units vertebrate fossils from the mfl are preserved as isolated to articulated specimens while isolated specimens would be common in a transgressive lag articulated specimens would not articulated specimens could be concentrated by attritional accumulation along a defined surface during a period of slow sedimentation but the lack of a distinct increase in glauconite maturity or concentrations of elements associated with heavy mineral accumulations at the navesink new egypt hornerstown contact or mfl which would be expected during a period of reduced sedimentation hiatus or unconformity are absent at the localities studied shocked quartz was identified in a burrow fill directly beneath the mfl at the contact of the navesink and hornerstown formations clay clasts with latest cretaceous microfossils along with reworked invertebrate fossils with infills of latest cretaceous sediment have been recovered from the mfl the association of shocked quartz mixture of isolated and articulated vertebrates with distinct rare earth signatures lack of a punctuated period of increased glauconite maturity and presence of reworked late cretaceous invertebrates and clay clasts with late cretaceous microfossils suggests that the mfl may represent a thanatocoenosis that was the direct result of environmental disturbance associated with the end cretaceous impact event at chicxulub