measuring winds from underneath the ocean surface by upward looking acoustic doppler current profilers upward looking acoustic doppler current profilers were deployed in the gulf of lions in the western mediterranean for winter convection studies during early 1987 the near surface doppler data which are dominated by sidelobe echo returns from the surface and which are therefore usually discarded for the analysis of subsurface current profiles were found to contain information useful for determining surface winds the horizontal doppler directions were highly correlated with wind direction measured by a research vessel in the vicinity wind speed while not correlated with the size of the doppler shifts was significantly correlated with the acoustic backscatter energy at 150 khz frequency and 20 main beam angle the wind speed exponent was determined as 1 32 and at 75 khz and approximately 24 sidelobe reception angle it was 0 76 at near vertical incidence where more and more energy is scattered sideways with increasing wind speed the exponent was found to be negative the wind data were too limited to determine whether a saturation limit of the wind dependence existed while bragg scattering seems to be primarily responsible for the surface doppler shifts their magnitude cannot be explained by the bragg effect alone the modulation of the bragg scattering ripple waves by longer waves of the surface wave spectrum also appears to be important

lithologic succession in the path fork coal bed breathitt formation middle pennsylvanian southeastern kentucky abstract the path fork coal bed breathitt formation middle pennsylvanian westphalian b on the pine mountain thrust sheet in southeastern kentucky and adjacent portions of virginia exhibits a lithologic succession which is traceable for about 25 km lateral continuity of lithotypes within the bed can be demonstrated using organic petrography palynology and ash geochemistry the lithologic continuity is a consequence of the initial levelling of the pre peat topography and the interaction of the peat with growing anticlines and synclines

coal modeling using markov chain and monte carlo simulation analysis of microlithotype and lithotype succession abstract markov chain analysis was applied to the description of the megascopic lithologic transitions in pennsylvanian age eastern kentucky coals coal lithology modeling can be problematic as individual lithotypes can represent near instantaneous events vitrain prolonged degradation durain or fire induced loss of previously deposited lithologies fusain each of the latter lithotypes potentially representing vastly different amounts of time could be of the same thickness therefore equal thickness does not necessarily imply equal time probability transform matrices that employ uniform lithotype thicknesses were used allowing transitions between like lithotypes embedded markov chains thereby only considering transitions between different lithotypes and continuous time markov chains were employed in the assessment of a section of the no 5 block coal pennsylvanian breathitt group martin county kentucky embedded markov chains could successfully simulate the lithologic transitions a monte carlo random process was programmed to simulate thickness variations of lithotypes between the transitions the proposed hybrid model of monte carlo markov chain was able to predict the random pattern that underlies lithotypes transitions and thickness the hybrid monte carlo markov chain technique proved to be effective in the case study in simulating both the lithologic thickness variations and transitions

the measurement of the synoptic scale wind over the ocean mesoscale and microscale features of the turbulent winds over the ocean are related to the synoptic xscale winds in terms of published spectral forms for the microscale a mesoscale valley and published values of u var u var v and z l as defined in the text and as obtained for moderate to gale force winds the frequencies involved correspond to periods longer than 1 hour and extend to the microscale which starts at a period near 2 min or so and continues to the kolmogorov inertial range nondimensional spectra that span both the mesoscale and the microscale are derived as a function of u f nz and z l where z is 10 m l is the monin obukhov stability length and is evaluated at 10 m for the same different values of z l produce a range of values of u which in turn result in variations of the eddy structure of the mesoscale and microscale spectra both conventional anemometer averages and remotely sensed winds contain a random component of the mesoscale wind in their values these components are differences and not errors when winds are compared and quantitative values for these differences are given ways to improve the measurement of the synoptic scale wind by transient ships data buoys and scatterometers on future spacecraft are described these ways are longer averaging times for ships and data buoys depending on the synoptic conditions and pooling spacecraft data to form superobservations design considerations for future remote sensing systems are given

palynologic petrographic and geochemical characteristics of the manchester coal bed in eastern kentucky the manchester coal bed in eastern kentucky is the stratigraphically lowest coal in kentucky that is both laterally continuous and of consistent mineable thickness the manchester coal bed occurs in the lower part of the breathitt formation in an interval between the underlying corbin sandstone and the overlying betsie shale both of which are also aerially widespread units the manchester is early middle pennsylvanian in age and is equivalent with the middle morrowan of the eastern interior basin and the late westphalian a of western europe increment samples were collected from the western and eastern outcrop and mining areas of the eastern kentucky coal field and were analyzed palynologically petrographically and geochemically to compare and contrast the two areas in the western part of the eastern kentucky coal field the manchester coal bed is uniform in occurrence and composition the bed is consistently 0 61 0 92 m 2 3 ft thick and generally is devoid of inorganic partings palynologically the coal in this area is largely dominated by lycospora the dispersed spore of many of the large lycopsid trees e g lepidodendron and lepidophloios and to a lesser extent granasporites medius representing diaphorodendron and synchysidendron petrographically the coal contains high percentages of vitrinite macerals and correspondingly low percentages of liptinite and inertinite macerals most of the increments from this area studied are generally low in ash yield 5 and sulfur content 10 and occasionally sulfur 1 in the eastern part of the coal field the manchester coal bed is typically thicker 3 ft 1 m but usually occurs as a coal zone with intercalated coal beds and clastic units palynologically the coal in this area contains increased percentages of small lycopsid small seed ferns calamites and cordaites petrographically the coal is higher overall in liptinite and inertinite macerals ash yields in the eastern sample area are generally low 10 an exception being some high ash durain bands overall sulfur contents also are low typically 1 the western samples are interpreted as having formed in a well protected generally flooded mire a consistent water cover would provide a favorable environment for arboreous lycopsid growth and proliferation and also inhibit oxidation of the peat surface thus promoting the formation of a high vitrinite content coal the eastern samples are also interpreted as having formed in a mire that was well protected most of the time giving rise to thick sequences of low ash low sulfur coal intermittent inundation by extra swamp waters carrying sediment in this area resulted in the development of a multiple coal zone i e several peat forming events with intervening clastic deposition in contrast to a single peat forming event in the western area surficial peat exposure was more frequent in the eastern area which allowed for increased microbial degradation of the peat and subsequent formation of inertinite macerals upon conversion to bituminous coal this condition might also accelerate charring of the peat surface by wildfire

the normalized radar cross section of the sea at 10 spl deg incidence measurements of the normalized radar cross section of the sea at k sub u band at an incidence angle of 10 spl deg were performed from a manned airship off the oregon coast in september and october of 1993 the cross section at this incidence angle is often assumed to have little dependence on windspeed and direction their measurements however indicate that at windspeeds below 6 7 m s the cross section is in fact dependent on these quantities and the azimuthal modulation can reach values on the order of 5 8 db comparisons of the measured values with the predictions of the quasispecular scattering model are presented the theory is shown to be accurate in predicting the azimuthal modulation and the strength of the backscatter if the effects of swell are included or if measured wind directions are ignored and the upwind direction is forced to be near the maximum cross section values of mean square wind wave slope and effective reflection coefficient required to obtain these fits are very close to those obtained by previous investigators in particular mean square wind wave slopes are about 70 80 of those of cox and munk 1954 because the radar responds only to facets larger than about 10 cm with smaller ripples acting to reduce the reflection coefficient if swell is included they find that mean square slopes in the direction of the swell that are as much as ten times the measured swell slopes are required to fit the model to the cross section data at low windspeeds they suggest that this may be due to high order effects of the hydrodynamic modulation of short waves by the swell they believe that this explanation is more likely than assuming that wind directions were incorrectly measured

fully and nonfully developed sea models for microwave remote sensing applications a new statistical description of the ocean surface is proposed and described classically it is assumed that the spectrum of the surface vertical displacements depends only on one external or forcing parameter the wind speed or the wind friction velocity this is true for fully developed sea states only in the more general case of nonfully developed sea states the spectrum should depend as well on internal parameters describing the characteristic features of the surface such a representation is discussed in this article for applications to active and passive microwave remote sensing of the oceans

invertebrate trace fossils and agglutinated foraminifera as indicators of marine influence within the classic carboniferous section at joggins nova scotia canada the sea cliffs at joggins nova scotia are the most extensive and continuous carboniferous section in eastern north america although the section has been considered to have formed within a nonmarine depositional basin paleobiological information indicates that parts of the section were deposited in brackish water the occurrence of a trace fossil assemblage which includes cochlichnus kouphichnium and treptichnus is part of an assemblage of biogenic structures that apparently reflects paleodeposition within fluvial systems that may have experienced distal marine influences presence of agglutinated foraminifera characteristic of brackish water environments supports this interpretation this information provides new evidence of brackish water conditions at joggins such as those now being widely recognized in other carboniferous coal bearing sections

the seasat a satellite scatterometer the geophysical evaluation of remotely sensed wind vectors over the ocean on the seasat a satellite a microwave scatterometer was used to determine the vector wind over the world s oceans the technique is based on the sensitivity of microwave radar backscatter to the centimeter length ocean waves created by the action of the surface wind this paper describes the algorithm used to convert the scatterometer s measurements of ocean normalized radar cross section to the neutral stability vector wind at 19 5 m height and the comparison of these winds with high quality surface observations the wind vector algorithm used an empirical model function to describe the dependence of the ocean 0 on the 19 5 m neutral stability wind vector two model functions developed from a limited base of aircraft and satellite measurements were evaluated by using an independent set of in situ surface wind observations from the joint air sea interaction experiment jasin although these model functions were found to have some weaknesses the results of these comparisons produced better results than the seasat specifications of wind speed accuracy of 2 m s and wind direction accuracy of 20 over the 0 16 m s range of winds observed during jasin an improved model function was later developed by tuning to these jasin data so that the remaining biases between the observed surface winds and the scatterometer derived winds were minimized results are presented for this model function compared against other surface wind observations from the gulf of alaska seasat experiment and the seasat storms hurricane experiment

wind direction alias removal studies of seasat scatterometer derived wind fields owing to the antenna configuration and the biharmonic nature of the anisotropic return of the probing radar the seasat scatterometer wind reports consist of as many as four wind directions at each point of observation a systematic methodology is proposed for selection of the true direction from among these in the absence of any in situ observations the techniques employed are those familiar to meteorological analysts they were subjected to rigorous testing for the jasin workshop with two teams performing independent analyses the agreement of the two analyses was striking comparison with wind directions from the jasin data set and those estimated from the analyzed pressure field show agreement largely within the seasat specifications it is concluded that the methodology employed is suitable for seasat scatterometer data users

comparison of seasat scatterometer winds with tropical pacific observations the seasat a satellite scatterometer sass observed near surface vector winds over the world ocean from an 800 km orbit by measuring radar backscatter from the wind roughened surface the early end of the mission in 1978 forestalled some of the planned ground truth validation experiments questions remain about the instrument s performance in particular away from mid latitudes to increase the geographical range of sass and in situ comparison experiments we have compared data from nine islands in the tropical pacific and contemporaneous scatterometer winds we used satellite winds derived from two different wind vector algorithms the signal processing that reduces the radar backscatter to wind speed and direction the sass 2 algorithm due to wentz provides clearly better agreement in wind speed than the earlier sass 1 algorithm sass 1 speeds tend to be higher than the island measurements by about 1 m s 1 while daily mean sass 2 minus island wind speed differences average 0 07 m s 1 the rms differences between sass 2 and the daily mean island data average 1 7 m s the sass 1 rms differences average 2 2 m s 1 because the seasat wind algorithms yield solutions with more than one possible direction a single direction can only be selected from the others using ancillary information we compared direction results from the objective selection method developed at the goddard laboratory for atmospheres as well as results from the somewhat artificial method of selecting the sass direction closest in agreement with the comparison island direction when averaged over tens of days the goddard directions agree closely with the island observations however goddard daily mean directions exhibit considerably higher variance than those measured at the islands the closest direction technique gives daily mean sass minus island rms direction differences averaging 20 the goddard rms differences average 52

the stratigraphic distribution of inertinite abstract the paper presents the results of an investigation into the stratigraphic distribution of inertinite in humic coals ranging from the silurian to the neogene periods this range equals the time span during which both land plants and atmospheric oxygen evolved the survey is based on a literature study of inertinite in coals covering a variety of depositional environments and climates in all continents the inertinite percentages listed in this paper have been arranged in stratigraphic order they are the mean values based on mineral free whole coal compilations maceral compositions listed in the literature for individual subsections have been averaged to represent complete coal seams beds although this might not have been always possible due to some ambiguity in the published record moreover not all of the published and unpublished information could be used because of poor sample description obscure geographic origin or insufficient stratigraphic information the results show that there have been times in the geological past e g during the late permian in which coals were particularly rich in inertinite compared with other times e g during much of the late tertiary in which many coals contained very little inertinite occasionally such primary global trends were modulated by a diffuse distribution of inertinite percentages that correspond to differences in climate depositional settings e g active orogenic margins versus tectonically inactive shelf margins and other local or regional variations although various mechanisms for the generation of inertinite have been proposed in the past the overall pattern in its stratigraphic distribution supports the notion of incomplete combustion as the main source of inertinite in coal this points to secular variations in the atmospheric oxygen content as an explanation for the global changes in the inertinite distribution while differential subsidence and climatically influenced reaction rates governed regional and local variations in inertinite percentages

paleoecology of the fire clay coal bed in a portion of the eastern kentucky coal field vertically continuous increment samples of the fire clay coal bed mid middle pennsylvanian late westphalian b collected from a portion of the central appalachian basin were studied palynologically petrographically and geochemically in order to partially reconstruct the paleoecology and processes associated with peat formation in the ancient fire clay paleomire results indicate that four compositional groups can be identified they are 1 a lycospora vitrinite dominant group characterized by high percentages of lycospora and vitrinite macerals and generally low but variable ash yields and sulfur contents 2 a mixed palynoflora high vitrinite group that petrographically is similar to group 1 except that it contains a more diverse palynoflora 3 a mixed palynoflora moderate low vitrinite group characterized by various admixtures of lycopsid fern and calamite miospores increased percentages of liptinite and inertinite macerals and low ash yields and sulfur contents and 4 a mixed palynoflora high ash yield group characterized by high percentages of small lycopsid fern and occasionally calamite and cordaite miospores high liptinite and inertinite contents high ash yields and moderate to high sulfur contents the fire clay coal bed contains a distinctive flint clay parting of probable volcanic origin that naturally divides the bed into two benches these two benches upper and lower are highly disparte in occurrence appearance and composition in the study area the lower bench generally is thin 0 5 m laterally discontinuous and mainly composed of dull mainly durain coal lithotypes ash yields typically are high sulfur contents generally are moderate to high compositional group 4 the mixed palynoflora high ash yield group defines all of the increments examined from the lower bench in contrast the upper bench is thick 0 75 m laterally continous and mainly comprised of bright mainly clarain coal lithotypes overall ash yields and sulfur contents for this bench are generally low although vertical variation is apparent all of the compositional groups occur in the upper bench in some columns notably those that are thick and uninterrupted by clastic partings groups 1 and 4 often occupy basal coal layers and groups 2 and 3 occur in higher layers other columns especially those taken in areas of thin 0 5 m fire clay coal are dominated by groups 1 and 4

quantification of crystalline mineral matter in some turkish coals using interactive rietveld based x ray diffractometry quantitative x ray diffractometry using a rietveld based computational method siroquant has been carried out for a series of coal samples from the various turkish mines standard proximate and ultimate analyses were carried out chemical compositions of the high temperature ash hta of coal samples were determined by x ray fluorescence xrf spectrometry technique crystalline mineral matter and amorphous content of raw coal samples were estimated the ca si al s and fe concentrations are higher than those of the other major elements ti mn mg na p k in the studied coal samples the percentage of crystalline mineral matter for each sample varies from 16 5 to 36 1 of the coal samples the minerals in the sampled coals consist mainly of quartz clay minerals calcite pyrite and gypsum percentages of crystalline mineral matter in ash content remarkably decrease for the elbistan orhaneli and tufanbeyli lower rank coals

analysis origin and significance of mineral matter in coal an updated review abstract the material classed as mineral matter in coal embraces crystalline mineral materials as well as a range of inorganic elements that occur in non crystalline form this review outlines the methods that may be used to evaluate the percentage of mineral matter for a coal sample as opposed to the ash yield and to identify the minerals their individual percentages and their modes of occurrence within the coal the principal techniques include low temperature oxygen plasma ashing quantitative evaluation of x ray diffraction data observation using optical microscopy and a combination of observation chemical analysis and in some cases mapping based on scanning electron microscopy and related methods a range of other techniques may also be used to provide additional information on particular mineral matter components processes responsible for mineral matter formation include detrital input biogenic activity and authigenic precipitation at different stages of the coal s depositional and post depositional history differential migration of non mineral inorganic elements may also occur in lower rank coals and expulsion of non mineral inorganics may take place with rank advance knowledge of the mineral matter may be of assistance in understanding the modes of trace element occurrence with implications for assessing possible environmental impacts and also the potential for recovery of economic products from coal the behaviour of different mineral matter components at high temperatures is also discussed as well as methods for mineralogical analysis of ashes and other coal utilization products information from mineral matter studies may provide an improved basis for understanding coal formation and for evaluating the response of particular coals to different combustion gasification and coking processes

petrology of the river gem coal bed whitley county kentucky abstract the river gem coal bed middle pennsylvanian breathitt formation in the hollyhill 7 1 2 minute quadrangle whitley county kentucky consists of a low to moderate sulfur lower bench followed by a high ash high sulfur bone and capped by a high ash high sulfur upper bench variations in the amount of total sulfur and pyritic sulfur as well as variations in the pyrite size and form point to the degree of syngenetic and epigenetic control on the pyrite emplacement the pyrite types particularly in the high sulfur upper benches are dominated by

studies of the location of azimuth modulation minima for ku band ocean radar backscatter an extensive data set of radar backscatter measurements at 14 ghz was used to evaluate the locations of the azimuthal modulation minima relative to the cross wind directions it was found that the minima were significantly offset from the cross wind directions toward the downwind direction for the horizontal polarization data these offsets were substantially smaller for the vertical polarization data simple scattering model calculations based on the two scale scattering approach also show similar offsets implications of these results for the geophysical model function are discussed

seasat scatterometer detection of gale force winds near tropical cyclones hurricane center advisories specifying the radius of gale force winds gfw in tropical cyclones are severely limited by inadequate data their accuracy is especially vulnerable in the data void tropical ocean regions the seasat a satellite scatterometer sass sensed surface winds associated with numerous tropical cyclones although instrument design ruled out retrieval of winds within the inner core of the storm surface truth studies indicate sass can detect the threshold of gale force winds 17 18 1 with an accuracy comparable to the original seasat specifications 2 ms 1 or 10 and 20 accurate and abundant sass observations were thus used as verification for advisories specifying the radius of gale force winds for tropical cyclones in the pacific and atlantic ocean basins advisories were found to consistently overestimate the radius of gfw often by a factor of two in the central pacific large asymmetries in the gfw distribution measured by sass were often in considerable disagreement with symmetric circular and semicircular advisory values however advisories that had access to low level aircraft data closely matched sass measured gfw values

validation and assimilation of seasat altimeter wave heights using the wam wave model the mutual consistency of the seasat global data sets of scatterometer winds and altimeter wave heights is investigated for the complete seasat period using the third generation wave model wam the wave model was driven by surface 1000 hpa wind and surface stress fields constructed by the goddard laboratory for atmospheres gla by assimilation of the scatterometer winds in an atmospheric model for the 10 day period september 7 17 the intercomparison was extended to two further scatterometer wind fields a 1000 hpa assimilated wind field from the european centre for medium range weather forecasts and a subjectively analyzed 19 5 m height surface wind field from the jet propulsion laboratory on the global average the modeled and observed wave heights agree reasonably well regional differences however can be large and sometimes exceed 40 the errors are attributed mainly to deficiencies in the forcing wind fields low wind speeds are found to be overestimated and high wind speeds underestimated by the seasat scatterometer algorithm the friction velocities of the gla model are found to be significantly underestimated in the high wind belt of the southern hemisphere the analysis demonstrates the diagnostic advantages of applying a wave model for the quality assessment of satellite wind and wave data a preliminary wave data assimilation scheme is presented in which the wave field is updated without changing the forcing wind field a considerable improvement of the computed wave field is achieved particularly in regions in which the wave energy is dominated by swell however a more general assimilation scheme including modifications of the wind field is needed to upgrade wind sea forecasts

the relationship between wind vector and normalized radar cross section used to derive seasat a satellite scatterometer winds the dependence of ocean normalized radar cross section nrcs or 0 on the 19 5 m neutral stability wind vector for the seasat a satellite scatterometer sass is described for the sass wind vector algorithm this dependence is specified in the form nrcs u where is the radar incidence angle is the angle between wind direction and radar azimuth and u is the neutral stability wind speed in meters per second at a height of 19 5 m the development of models to express this relationship and to provide the basis for inversion of nrcs to sass winds is traced from its initial form based on aircraft scatterometer measurements through the seasat field validation experiments goasex storms and jasin to its final form comparison of the model nrcs versus surface wind speed with sass data from these experiments are made

comparison of microwave signatures for fully and nonfully developed sea models the boundary perturbation method is applied to a numerical comparison of active and passive microwave signatures for fully developed sea conditions described by a classical sea surface displacement spectrum with one degree of freedom and for nonfully developed sea conditions described by a new displacement spectrum with three degrees of freedom it is shown that altimeters and scatterometers at low incidences are rather sensitive to the sea state development and in particular to the significant slope while scatterometers at high incidences and radiometers are much las except for wave tank conditions

geochemistry of the pond creek coal bed eastern kentucky coalfield the pond creek coal bed middle pennsylvanian breathitt formation is an important low sulfur resource in pike and martin countries in the eastern kentucky coalfield the mined area is crossed by the n20 e trending belfry anticline the pond creek coal bed has a higher sulfur content on the west side of the anticline the vertical trends in the ash geochemistry also vary across the anticline the sites to the east of the anticline represent deposition of peat through periods of relative stability with slow deposition bright lithotypes interspersed with periods of relatively rapid clastic deposition dull lithotypes both generally removed from marine influence comparison of elemental trends between the lowest bright lithotype and the second bright lithotype suggest that the swamp became less acidic with time an upward decrease in minor element concentration may be related to the influx of clays and other silicates present in the bone lithotype this bone may have acted as a relatively low nutrient soil for the growth of the plants which contributed to the overlying bright lithotype the sites to the west of the anticline were subjected to a greater marine influence than the eastern sites high k2o al2o3 ratios at the bottom and top of the coal bed and a high tio2 zr dull clarain near the bottom of the coal point to clastic influences on the geochemistry the relatively high cao percentages in the middle third of the coal bed suggest deposition at near neutral ph the upper third of the coal bed was dominated by syngenetic and epigenetic pyrite emplacement

40 ar 39 ar dating of fluid migration in a mississippi valley type deposit the gays river zn pb deposit nova scotia canada the gays river zn pb deposit of southern nova scotia canada represents an example of mississippi valley type mineralization reserves ca 2 4 million metric tons 8 6 zn and 6 3 pb the deposit is hosted by visean age dolomitized carbonate rocks bank and interbank facies that form part of a series of carbonate banks i e the gays river formation the banks developed on paleotopographic highs underlain by lower paleozoic metaturbidites of the meguma group but locally there is an intervening basal breccia unit which contains fragments centimeter to meter scale of meguma group lithologies within a mineralized pb or zn dolostone matrix petrographic examination of fragments in the breccia unit indicate traces of hydrothermal alteration which is considered to have been coincident with mineralization at gays river maximum temperatures associated with the alteration ranged from ca 300 degrees fluid inclusions to ca 350 degrees c chlorite geothermometry five 40 ar 39 ar step heating experiments of metasedimentary clasts in the basal breccia give nearly identical age spectra profiles with low temperature gas fractions indicating apparent ages of ca 300 ma followed by plateau ages of ca 380 to 400 ma for high temperature gas fractions whereas the latter ages are consistent with previously determined whole rock 40 ar 39 ar ages for regional deformation and metamorphism of the meguma group the ca 300 ma age is considered to reflect thermal overprinting and is consistent with recent palcomagnetic determinations suggestive of a mid mississippian to late pennsylvanian age for mineralization model calculations of the age spectra assuming degassing of micaceous phases and volume diffusion suggest that the most plausible interpretation is a reheating event of ca 250 degrees to 300 degrees c of ca 1 to 6 m y duration the anomalously elevated temperatures determined from this study in conjunction with the presence in maritime canada of late devonian carboniferous mafic felsic magmatism and the widespread resetting of radiometric systems in the meguma terrane at ca 300 ma suggest that the gays river mineralization may be related to the same broad scale tectonic processes that formed the martimes basin and involved regional scale structures and probably magma generation

petrology of selected carbonaceous limestones and shales in late carboniferous coal basins of atlantic canada carbonaceous limestones and shales are associated with coal in late carboniferous alluvial to coastal successions of nova scotia the units are thin 45 km they consist of micrite and or illitic and kaolinitic clay and some contain abundant bivalves ostracodes pyrite up to 11 vol and phosphatic and sideritic nodules trace fossils are scarce to absent the organic material 2 43 toc is characterised as type ii iii and is mainly of terrestrial derivation predominantly vitrinite and sporinite with lamalginite and telalginite as minor constituents vitrinite reflectance measurements indicate immaturity ro 0 5 but are lower than those of associated coals source rock and hydrocarbon recovery potentials are good to very good and the potentials of some units compare favourably with those of alginite rich carboniferous oil shales in adjacent basins the carbonaceous units were deposited in shallow lakes and or interdistributary bays with aerobic to anaerobic bottom waters at times of minimal detrial input

geologic fluid inclusion and stable isotope studies of the gays river lead zinc deposit nova scotia canada the gays river deposit is the largest carbonate hosted lead zinc deposit known in the mississippian windsor group of atlantic canada the orebody mainly occupies one flank of a porous dolomitized carbonate bank that unconformably overlies a basement ridge of the metasedimentary lower paleozoic megurea group the orebody consists of stratiform disseminated sulfides as open space fillings in primary and secondary pores of the dolomite and fault controlled veinlike bodies of high grade massive sphalerite and galena the carbonate bank is overlain by evaporite deposits of mississippian age underground mapping and laboratory studies suggest four main stages of evolution for gays river 1 deposition of the visean carbonate bank preore evaporite deposition pervasive dolomitization and growth of diagenetic marcasite 2 deposition of sphalerite galena chalcopyrite and calcite as a result of influx of hydrothermal metal rich saline brines into fractures and porous dolomite 3 postore deposition of calcite fluorite barite marcasite pyrite and selenite and 4 uplift localized dedolomitization of the mineralized carbonates and exposure by erosion in cretaceous times microthermometry of fluid inclusions yields the following mean homogenization temperatures sphalerite 215oc ore stage calcite 173oc postore calcite 142oc fluorite 142oc and barite 137oc pressure corrections should be minimal for these temperatures no evidence of boiling was observed in the inclusions salinity determinations from the ice melting temperatures of inclusions in postore fluorite and calcite yield a value of ca 20 4 equivalent wt percent naci for the hydrothermal fluid during the waning stages of mineralization isotopic analyses indicate that anhydrite and gypsum in the overlying evaporites and barite within the orebody are enriched in heavy sulfur t 34s 13 1 16 5 0 suggesting a mississippian seawater source ore stage sphalerite galena and chalcopyrite probably derived their sulfur b34s 8 0 13 65 0 from sulfates or possibly a homogenized basement source postore marcasite and pyrite are characterized by light probably biogenic sulfur ba4s 9 7 to 46 0 mineralized carbonates are significantly depleted in the heavier isotopes of oxygen and carbon with respect to their unmineralized equivalents preliminary lead isotope data for galena suggest that the metasedimentary basement was a source of lead this study disputes an earlier interpretation that the stratiform lead zinc ores are an early low temperature diagenetic cement of the carbonate bank the high grade zones are not residual concentrations related to sinkholes as originally thought instead both disseminated and massive ores are probably the result of the same mineralizing episode involving deeply convecting brines or brines expelled during basin dewatering under high geothermal gradients in the late paleozoic

response of late carboniferous tropical vegetation to transgressive regressive rhythms at joggins nova scotia fossil plant assemblages are described in their sequence stratigraphic context from the upper carboniferous langsettian joggins formation of nova scotia to elucidate ecosystem response to transgressive regressive rhythms results show that rising base level resulted in retrograding submerged coastal mires co dominated by lepidodendron and lepidophloios which were replaced by short lived paralycopodites communities immediately following mire drowning extensive brackish bays existed during early highstand distally fringed by gymnospermous and putative progymnospermous coastal and or upland vegetation late highstand bay filling generated prograding distributary wetlands dominated by flood disturbed lycopsid pteridosperm sphenopsid communities and locally by cordaite mangroves as base level fell well drained alluvial plains were dominated by fire prone cordaite and or sigillaria communities which persisted until the next phase of base level rise this rhythmic ecosystem succession repeatedly occurred on a c 50 200 ka time scale and was probably driven by glacial interglacial climate rhythms

tower based measurements of normalized radar cross section from lake ontario evidence of wind stress dependence we report here the dependence of the normalized radar cross section nrcs on incidence angle azimuth angle wind speed wind stress and atmospheric stratification for ku band microwave backscatter from a lake the measurements were made in autumn 1987 on lake ontario using a rotating microwave system mounted on a research tower operated by the canada centre for inland waters the results show that at intermediate incidence angles the nrcs on the lake generally increases faster with wind speed than it does on the ocean we attribute this to the larger atmospheric drag coefficients which exist on the lake compared with the ocean and we show that the results are more consistent with a dependence of the nrcs on wind stress than on wind speed near the surface we find a stratification dependence of the nrcs similar to that previously reported at c band and show that at 40 and 60 incidence angles this dependence can be removed by parameterizing the nrcs in terms of either the friction velocity or neutral wind speed at a 20 incidence angle the stratification dependence is not removed by this procedure

the dependence of ocean backscatter at k sub u band on oceanic and atmospheric parameters the jet propulsion laboratory nuscat k sub u band scatterometer successfully acquired ocean backscatter data over a wide variety of oceanic and atmospheric conditions during the surface wave dynamics experiment swade ten flights resulted in 30 h of data collection were conducted on the nasa ames c130 aircraft the swade experimental area was deployed with several buoys providing appropriate in situ measurements to correlate with the radar backscatter for incidence angles from 10 to 60 spl deg at both horizontal and vertical polarizations the nuscat swade backscatter data base was utilized in conjunction with buoy measurements to investigate ocean backscatter signatures over the range of conditions encountered during swade to account for modulations and fluctuations in incidence angles a backscatter analysis independent of a priori geophysical model functions was developed tested and implemented results for backscatter azimuth modulations in terms of upwind downwind and crosswind radar returns are compared to airborne radscat results and to sass i and ii geophysical model functions versus neutral wind speed u sub n nuscat swade results are closest overall to sass ii values fit best with sass i at 10 spl deg incidence angle and are significantly higher than radscat effects of friction velocity u wave age c sub o u and significant wave height h sub 1 3 on ocean backscatter are studied the backscatter shows a good positive sensitivity to u an inverse dependence on c sub o u and no systematic trend with h sub 1 3 excluding cases of large swells coefficients of empirical relations between backscatter and neutral wind speed friction velocity and wave age are derived for 10 40 spl deg incidence angles at both horizontal and vertical polarizations covariance studies of backscatter with the derived relations to winds show an overall deviation factor in the order of 1 db for ocean signatures including uncertainties in surface conditions

structure of the surface wind field from the seasat sar an intensive analysis of the vector wind field of one seasat data set pass 1339 is described wind speed and direction signatures are found in seasat sar synthetic aperture radar images and the resulting estimates are compared with the seasat a scatterometer system sass and simultaneous noaa p 3 aircraft measurements a power law is presented to relate sar measured backscatter to sass estimated wind speed and the sar estimates are shown to agree with the sass estimates to within a standard error of 0 7 m s over a range of wind speeds from 3 m s to 13 m s the surface expressions of atmospheric roll vortices are apparent in several of the sar images and may be responsible for the wind direction signature in these cases wind field estimates averaged over regions of variable sizes are possible because of the high resolution of sar imagery a method for extracting low wave number directionality and its variability from sar spectra is described and sar direction estimates obtained from spectra of 6 4 km square images are shown to have a precision of approximately 10 although a comparison data set that could validate these higher resolution estimates is lacking averages over 40 km square regions are in good agreement with the other wind field information the sar wind direction estimates yield a more complete interpretation in a region with a turning wind field near a front that is ambiguous with only sass observations in this region the flow patterns of the high resolution estimates appear consistent with our knowledge of the overall circulation considering all the observations however in another region the small scale variability is too large and random to represent real wind variability although averages derived from these estimates are still reliable

on a satellite scatterometer as an anemometer the seasat a satellite scatterometer sass wind algorithm was tested against surface wind fields three classes of surface wind fields were used point measurements an isotach field over an intensively measured triangle with 200 km sides and synoptic scale winds determined from pressure and temperature fields and a planetary boundary layer model these comparisons can verify optimal capabilities of sass at accuracies of 2 m s 1 and 20 sass ability to locate fronts accurately is also established complications in nonsteady highly variable fields indicate problems exist in unqualified application of the sass algorithm to all conditions

nscat high resolution surface wind measurements in typhoon violet nasa scatterometer nscat measurements of the western pacific supertyphoon violet are presented for revolutions 478 and 485 that occurred in september 1996 a tropical cyclone planetary boundary layer numerical model which uses conventional meteorological and geostationary cloud data is used to estimate the winds at 10 m elevation in the cyclone these model winds are then compared with the winds inferred from the nscat backscatter data by means of a novel approach that allows a wind speed to be recovered from each individual backscatter cell this spatial adaptive wind vector retrieval algorithm employs several unique steps the backscatter values are first regrouped in terms of closest neighbors in sets of four the maximum likelihood estimates of speed and direction are then used to obtain speeds and directions for each group since the cyclonic flow around the tropical cyclone is known nscat wind direction alias selection is easily accomplished the selected wind directions are then used to convert each individual backscatter value to a wind speed the results are compared to the winds obtained from the tropical cyclone boundary layer model the nscat project baseline geophysical model function nscat 1 was found to yield wind speeds that were systematically too low even after editing for suspected rain areas of the cyclone a new geophysical model function was developed using conventional nscat data and airborne ku band scatterometer measurements in an atlantic hurricane this new model uses the neural network method and yields substantially better agreement with the winds obtained from the boundary layer model according to the statistical tests that were used

the impact of climate change tectonism and hydrology on the formation of carboniferous tropical intermontane mires the springhill coalfield cumberland basin nova scotia abstract both climate and tectonism are influential in determining basin and mire hydrology in the rapidly subsiding intermontane basins of euramerica which formed in response to the variscan hercynian alleghenian orogeny however the record of climate change has been muted and may therefore go unrecognized the complex interplay of climate and tectonism in a tropical continental setting is recorded in the 4 km thick westphalian a b fill of the cumberland basin thick peat accumulation was favoured at the southern basin margin where rheotrophic forested mires 4 9 km wide flourished between basin axis rivers and coalesced alluvial fans derived from the cobequid highlands as a result of their geomorphic setting the thicker coals 4 3 m exhibit distinct areal zones piedmont inner mire and riverine evidence that the forest swamps were nourished both by rainfall and by groundwater discharge from alluvial fans includes the stratigraphic affinity of thick coals and basin margin conglomerates interfingering of distal fan sheetflood and mire deposits petrographic evidence of elevated ph partial gelification of tissues and predominance of the arboreous lycopsids lepidodendron and paralycopodites whereas such groundwater supply is crucial to maintenance of modern wetlands in drier periods a subhumid climate is implied coals at joggins further removed from groundwater discharge at the basin margin are less well developed a 600 m thick coal window within the fining and reddening upward basin fill sequence at springhill is inferred to represent a coincidence of optimal groundwater supply and net subsidence the ultimate decline of peat accumulation in the basin may reflect decrease in catchment area and fan size and loss of rainshadow as the cobequid massif was denuded and the basin filled the coal window ca 6 9 10 5 yr is punctuated by non marine cyclothems of coal grey sideritic mudrock and multistorey sandstone that share similar time frames with astronomic cycles of axial precession ca 1 4 10 4 yr the stress of related climate change is inferred to have caused peat accumulation to fall into disequilibrium with sediment flux and basin subsidence the late quaternary history of certain african mires illustrates the dramatic impact of climate change especially temperature and seasonality and orographic effects on tropical continental peat accumulation aspects of the groundwater recharge model may be applicable to the westphalian stephanian intermontane mires of spain and mesozoic coal basins of northern china

a c band scatterometer for remote sensing the air sea interface an airborne c band scatterometer system c scat has been developed to remotely sense ocean surface winds and improve upon the present understanding of the relationship between normalized radar cross section nrcs and ocean surface roughness influences such as wind speed and direction wave height and slope and the air sea temperature difference the scatterometer utilizes a unique frequency steered microstrip array antenna that is installed beneath the fuselage of an airplane the antenna is electronically scanned in elevation from 20 degrees to 50 degrees off nadir and mechanically spins in azimuth the system is capable of measuring ocean surface nrcs from altitudes as high as 25000 ft the system is divided into four subsystems the transmitter and receiver the spinning antenna the computer control and data acquisition subsystem and the digital and analog interface electronics

architecture of coastal and alluvial deposits in an extensional basin the carboniferous joggins formation of eastern canada abstract the joggins formation was deposited in the cumberland basin which experienced rapid mid carboniferous subsidence on bounding faults a 600 m measured section of coastal and alluvial plain strata comprises cycles tens to hundreds of metres thick the cycles commence with coal and fossiliferous limestone siltstone intervals interpreted as widespread flooding events these intervals are overlain by coarsening upward successions capped by planar based sandstone mounds up to 100 m in width that represent the progradation of small river generated delta lobes into a standing body of open water developed during transgression the overlying strata contain sand rich heterolithic packages 1 8 m thick that are associated with channel bodies 2 3 m thick and 10 50 m wide drifted plant debris calamites groves and erect lycopsid trees are preserved within these predominantly green grey heterolithic sediments which were deposited on a coastal wetland or deltaic plain traversed by channel systems the cycles conclude with red siltstones containing calcareous nodules that are interbedded with thin sandstones and associated with both single storey channel bodies 1 1 5 m thick and 2 3 m wide and larger multistorey channels 3 6 m thick with incised margins numerous channel bodies at the same level suggest that multiple channel anastomosed river systems were developed on a well drained floodplain many minor flooding surfaces divide the strata into parasequences with dominantly progradational and aggradational stacking patterns multistorey channel bodies are relatively thin fine grained and modestly incised and palaeosols are immature and cumulative the abundance and prominence of flooding surfaces suggests that base level rise was enhanced whereas the lack of evidence for abrupt basinward stepping of facies belts coupled with the absence of strong fluvial incision and mature palaeosols suggests that base level fall was suppressed these architectural features are considered to reflect a tectonic architectural signature in accordance with the high subsidence basinal setting evidence for restricted marine influence and variation in floral assemblages suggests modulation by eustatic and climatic effects although their relative importance is uncertain

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

tower based measurements of the ocean c band radar backscattering cross section continuous measurements of the c band normalized radar cross section nrcs at vertical vertical polarization as a function of wind speed and direction were carried out from a research platform in the north sea during a period of 11 months in 1984 the nrcss have been correlated with other environmental data routinely collected at the platform like air water temperature difference water temperature and ocean wave slope the wind speed exponent of the c band nrcs at 45 incidence angle was determined as 1 50 valid in the wind speed range 2 19 m s our data set shows that the c band nrcs depends strongly on the air sea temperature difference for example when the air sea temperature difference decreases from 5 c to 5 c the nrcs increases by 6 db at a wind speed of 8 9 m s and an incidence angle of 45 for stable air sea interfaces and low wind speeds the nrcs increases with increasing root mean square wave slope however no systematic dependence on water temperature was observed

fire ecology of a late carboniferous floodplain joggins nova scotia the facies distribution and palaeobotanical identity of fossil charcoal is described from the upper carboniferous westphalian a b joggins section nova scotia in order to examine the fire ecology of early westphalian floodplains three charcoal assemblages are noted assemblage 1 consists of channel sandstone bodies containing beds of calcrete breccia cordaite logs up to 3 m long and coniferopsid wood charcoal this assemblage records upland coniferopsid forest fires which altered basin hydrology and promoted flooding in downstream floodplain rivers assemblage 2 consists of thin 1 8 mm thick coals containing hollow sigillarian tree stumps and lepidodendrid and medullosan plant compressions fifteen of the 29 stumps observed have a 2 5 cm thick basal layer infilling the stumps composed entirely of sigillarian charcoal sigillarian and medullosan charcoal is also scattered around the outside of these stumps this assemblage represents fire in lowland peat forming communities dominated by sigillaria and medullosan pteridosperms these forest fire profiles were slowly buried in floodplain muds assemblage 3 consists of a heterolithic sheet sandstone body containing a 2 5 m high sigillarian tree trunk with an internal basal trunk deposit of sigillarian charcoal and a lightly charred bark rind this also records fire in lowland sigillarian forests but in contrast to 2 this forest fire profile was buried rapidly in a distributary lobe

metalliferous coals of the westphalian a joggins formation cumberland basin nova scotia canada petrology geochemistry and palynology abstract five coals of westphalian a early middle pennsylvanian age were sampled from the joggins formation section exposed along chignecto bay at joggins nova scotia coal beds along the bay were mined beginning in the early 17th century yet there have been few detailed published investigation of the coal beds of this classic section the lowermost coal the upper coal 28 upper fundy is a high vitrinite coal with a spore assemblage dominated by arboreous lycopsid spores with tree ferns subdominant the upper portions of the coal bed have the highest ratio of well preserved to poorly preserved telinite of any of the coals investigated coal 19 clam coal has 88 total vitrinite but unlike the fundy coal bed the telinite has a poor preservation ratio and half the total vitrinite population comprises gelocollinite and vitrodetrinite the latter coal bed is directly overlain by a basin wide limestone bed the lower kimberly coal shows good preservation of vitrinite with relatively abundant telinite among the total vitrinite the middle kimberly coal which underlies the tetrapod bearing lycopsid trees found by lyell and dawson in 1852 exhibits an upward decrease in arboreous lycopod spores and an upward increase in the tree fern spore punctatisporites minutus telinite preservation increases upwards in the middle kimberly but overall is well below the preservation ratio of the upper fundy coal bed the coals all have high sulfur contents yielding up to 13 7 total sulfur for the lower lithotype of the upper fundy coal bed the kimberly coals are not only high in total and pyritic sulfur but also have high concentrations of chalcophile elements zinc ranging up to 15 000 ppm ash basis is present as sphalerite in fusain lumens arsenic and lead each exceed 6000 ppm ash basis in separate lithotypes of the kimberly coals together these data are consistent with elevated ph in planar mires the source of the elemental enrichment in this presumed continental section is enigmatic

paleomagnetism of the gays river zinc lead deposit nova scotia pennsylvanian ore genesis the gays river zinc lead deposit is the largest known mississippi valley type deposit in the mississippian windsor group of atlantic canada thermal and af demagnetization show that both ore and host rock have very similar magnetic characteristics stability tests constrain the magnetization to be mid mississippian to late pennsylvanian the pole position from the ore and host rock sites falls next to the pennsylvanian apw path suggesting an 8 clockwise rotation of the meguma platform relative to the craton regional thermal history and geochemical evidence suggest that the zinc lead ore magnetization and host rock remagnetization are coeval

detection of glaciers displacement time series using sar abstract glaciers are sensitive indicators of climate change particularly glacier surface velocity constitutes a key parameter for estimating ice volume variations as response to global warming and its incidence in sea level rise several methodologies based in remotely sensed data have been employed for estimating ice velocity fields they are mostly based in cross correlating pairs of images in order to track features displacement between two dates high ice flux velocity which can reach more than 1 km year constitute a challenge for the existing methodologies in practice limiting to a few days the time span between useful data in this work we present an extension of the known pixel offset small baseline subsets po sbas technique that profit a set of successive synthetic aperture radar sar scenes for computing displacement time series and ice velocity fields the algorithm is guided by a preliminary ice velocity model estimated from the data itself which significantly improves the results reliability and reduces the overall computational cost furthermore it implements a processing scheme that considers the displacement estimations po quality in order to decide which pixels are included in the time series inversion the proposed technique is applied to 22 cosmo skymed sar images of viedma glacier southern patagonian icefield argentina spanning roughly a year the results obtained are robust and make profit of the whole available dataset resulting mean velocity field and displacement time series show the algorithm suitability for retrieving and characterizing complex ice motion patterns

the westphalian d fossil lepidodendrid forest at table head sydney basin nova scotia sedimentology paleoecology and floral response to changing edaphic conditions copyright c 1996 elsevier science b v all rights reserved strata of westphalian d age on the western coast of the sydney basin expose a fossil forest of approximately 30 lepidodendrid trees within one of several clastic splits of the harbour seam a mutidisciplinary approach was employed to interpret the origins of the coal bed the depositional history of the site and the response of the fossil forest to changing edaphic conditions the megaspore and miospore records indicate that the mire vegetation was dominated by arboreous lycopsids especially paralycopodites with subdominant tree ferns petrographic palynological and geochemical evidence suggest that the harbour coal bed at table head originated as a rheotrophic cf planarr mire eutric histosolr the mire forest is interpreted to have been engulfed by prograding distributary channel sediments sparse protist assemblages are suggestive of a freshwater delta plain lake environment occasionally in contact with brackish waters lepidodendrids persisted as site colonizers of clastic substrates even after burial of the rheotrophic peatland and influenced the morphology of deposited sediment but apparently were unable to colonize distributary channels equivocal taxonomic data compression fossilsr show the fossil forest to have been composed of both monocarpic lepidodendronr and polycarpic diaphorodendron paralycopodites sigillariar lycopsids genera recorded in the palynology of the uppermost ply of the underlying coal bed comparatively rare within the clastic beds of the fossil forest however is the stem compression of paralycopodites whose dispersed megapores and miospores dominate the underlying coal bed tree diameter data recorded equivalent to breast height indicate a forest of mixed age these data would appear to suggest that some lepidodendrids employing a polycarpic reproductive strategy were better able to cross the ecological barrier imposed between peat and clastic substrates foliar compressions indicate that an understory or stand of psaronius type tree ferns co existed with the lepidodendrids on clastic substrates which developed as incipient gleysol soils the entombment of the forest can be ascribed to its distributary coastal setting local subsidence and a seasonal climate that fostered wildfire and increased sedimentation

imaging of oceanic features by ers 1 synthetic aperture radar data from the european space agency s ers 1 satellite synthetic aperture radar sar covering the region of the east australian current during late 1991 have been analyzed in conjunction with ship and airborne data and infrared imagery apart from wind effects the largest differences in backscatter seem to be associated with different water masses these differences probably being caused by wave damping due to natural surfactants slicklike features in the tasman sea are common even in the deep ocean when the winds are light ocean currents are often visible but as relatively subtle features it is unlikely that changes in atmospheric boundary layer stability due to changing sea surface temperature are the dominant mechanism for radar imaging of ocean currents it is suggested that c band radar backscatter will prove to be more directly correlated with biological activity and ocean color than with sea surface temperature particularly at higher latitudes surfactants could cause errors of 20 or more in wind speeds derived from satellite scatterometers

vegetation induced sedimentary structures from fossil forests in the pennsylvanian joggins formation nova scotia vegetation induced sedimentary structures viss are primary structures formed by the interaction of detrital sediment with in situ plants viss provide physical evidence of vegetation s fundamental role in mediating sediment accumulation and erosion in clastic depositional systems despite the abundance of modern viss descriptions from the ancient record are surprisingly rare analysis of fossil forests in floodplain strata of the pennsylvanian joggins formation has identified seven types of viss five hydrodynamic types comprise simple forms developed around a single plant centroclinal cross strata scratch circles upturned beds and complex forms where structures have amalgamated between several plants coalesced scour fills scour and mound beds two types mudstone filled hollows downturned beds form by the decay of an entombed plant and represent infilling of an empty hollow and or soft sediment deformation hydrodynamic types are present in both dryland and wetland settings whereas decay related types occur only in dryland settings where the water table was perennially or periodically low viss represent significant accumulations of sediment and are present in a high proportion of joggins formation strata the paucity of descriptions from the ancient record suggests that these structures have been overlooked or misinterpreted as strictly hydrodynamic recognition of viss in early to middle palaeozoic strata may provide an important insight into the distribution of early land plants in oxidizing environments where organic material was not preserved

self consistency of marine surface wind vectors observed by ascat marine surface wind vectors observed by the advanced scatterometer on the metop a satellite are evaluated by assessing their self consistency global statistics on wind speeds and directions were calculated from the data for a period of one year the wind speed histograms exhibited a clear dependence on the cross track wind vector cell wvc location which corresponds to the incidence angle this trend was reflected in the higher order statistics standard deviation skewness and kurtosis of the wind speed distribution the histograms of the wind directions relative to the satellite flight direction clearly showed systematic errors relative to the antenna beam directions the number density of the wind directions exhibited a systematic pattern relative to the antenna beam directions and the pattern varied with wind speed and cross track wvc location these systematic errors in the wind speed and direction may affect the divergence convergence and rotation of the wind field the results of this study suggest the need for further refinements of the wind retrieval algorithms and the c band geophysical model function it was also confirmed that the evaluation technique based on the statistical distributions of scatterometer derived vector winds is effective for identifying systematic errors in the wind speeds and directions

vegetation ecology of early pennsylvanian alluvial fan and piedmont environments in southern new brunswick canada abstract the vegetation ecology of pennsylvanian upland dryland regions is poorly known despite its evolutionary significance here fossil plant assemblages are described from well drained alluvial fan piedmont deposits in the uppermost boss point and tynemouth creek formations late yeadonian langsettian southern new brunswick beds record the northward building of a large alluvial fan complex over alluvial plain deposits in response to near continuous sourceland uplift proximal alluvial fan environments characterized by sheetfloods and braided streams were dominated by large cordaitalean trees medullosan pteridosperms ferns and calamiteans distal alluvial fan environments where braided stream and levee splay sedimentation predominated were covered by similar vegetation together with lycopsids in localized poorly drained depressions calamitean thickets were particularly widespread in rapidly aggrading settings on the distal fan well drained alluvial plains beyond the fan toe were characterized by axial braided rivers containing cordaitalean trunks transported from proximal settings piedmont vegetation is otherwise poorly resolved all studied plant assemblages are of low to medium diversity and dominated by the remains of a single group cordaitalean seed plants such dominance diversity characteristics together with the presence of charcoal the product of wildfire imply that pennsylvanian upland dryland vegetation experienced water stress and that the seed habit was integral to successful colonization

notes on the methods of the combined maceral microlithotype determination in coal abstract both macerals and microlithotypes the microscopic assemblages of macerals reveal basic information on coal depositional environments and coal utilization the combined analysis of the full iccp suite of macerals and microlithotypes on oriented block samples provides a powerful synergistic technique in petrographic analysis an example applying a combined maceral microlithotype analysis of a nova scotia coal demonstrates the value of the technique in providing detailed information on the nature of the megascopically identifiable coal lithotypes

on satellite scatterometer model functions satellite scatterometer model functions are the empirical correlations between observed backscatter and geophysical parameters one problem is the choice of surface truth for the latter currently buoy data and general circulation model surface analyses have been used to establish 10 m neutrally stratified wind model functions the correlation between backscatter and surface winds has been the foundation of the scatterometers the backscatter is anisotropic with respect to wind direction allowing wind direction information to be derived from multiple looks at the same patch of ocean here the evolution of a model function for the pressure gradient hence surface geostrophic wind is given the european center for medium range weather forecasts surface pressure analyses are used to establish the pressure based model function there are limitations and advantages to both geophysical data sets

lower and lower middle pennsylvanian coal palynofloras southwestern virginia copyright c 1996 elsevier science b v all rights reserved lower and lower middle pennsylvanian coals recovered from an exploratory drilling program in southwestern virginia were analyzed for their palynomorph content results show them to be dominated by spores produced by arboreous lycopsids lycospora pellucida and lycospora pusilla generally are the most common species with others namely lycospora granulata l micropapillata and lycospora orbicula being locally abundant densosporites cristatisporites radiizonates and cingulizonates representing small lycopsids and granulatisporites produced by small ferns and perhaps some pteridosperms typically are sub dominant taxa the recovered palynofloras are similar in overall composition making individual coal bed identification and correlation very difficult if not impossible however the introduction and extinction of a few forms do assist the correlation of packages of strata on both an intra and interbasinal scale dictyotriletes bireticulatus is first observed in basal lee formation strata at about the level of the cove creek coal bed radiizonates aligerans and r striatus also appear more abundantly at this level although some forms have been observed in older pocahontas formation coals this level essentially coincides with the namurian c westphalian a boundary based on plant megafossil evidence laevigatosporites minor l vulgaris endosporites globiformis e zonalis and granasporites medius are first seen consistently just above the sewell coal bed radiizonates aligerans r striatus and densosporites irregularis are last seen in the early middle pennsylvanian at about the level of the splash dam coal bed schulzospora rara occurs throughout early and early middle pennsylvanian strata and is last seen in the manchester coal the manchester is directly overlain by the betsie shale a widespread marine unit the base of the betsie marks the westphalian a b contact when compared with palynomorph assemblage zonations published for the western interior and eastern interior basins early and early middle pennsylvanian palynofloras from the central appalachian basin compare most favorably with early morrowan strata analysis of bench samples indicates that lycospora typically dominates basal and middle portions of early and early middle pennsylvanian coals more terminal layers often contain higher percentages of granulatisporites and related trilete sphaerotriangular genera e g lophotriletes acanthotriletes deltoidsporar and densosporites and related trilete crassicingulate genera e g cristatisporites cingulizonates radiizonatesr this temporal change is consistently observed and may primarily reflect a water table change within the paleomires from consistently high covered with water or at least water logged most of the timer to intermittently low occasional substrate exposurer

removal of ambiguous wind directions for a ku band wind scatterometer using three different azimuth angles the seasat a satellite scatterometer sass sensor demonstrated very successfully that ku band scatterometers can make accurate synoptic measurements of surface wind speed over the ocean because sass provided normalized radar cross section nrcs measurements from only two azimuths however the harmonic relationship of nrcs with azimuth results in up to four ambiguous wind directions the primary improvement to be incorporated in a next generation scatterometer design such as navy remote ocean sensing system nross is the addition of a third azimuth look at each sampled cell with this and other instrument improvements preliminary studies indicate that wind direction ambiguities aliases could successfully be removed in at least 80 percent of the cases furthermore these studies show that in over 90 percent of the wind solutions the two most probable solutions correctly identify the wind streamlines methods were studied which could examine typical streamline patterns derived from scatterometers using continuity or pattern recognition techniques to determine which of the possible two wind directions was correct in addition unambiguous solutions were sought for cases where streamlines were not correctly defined this paper describes several approaches for such alias removal algorithms these algorithms were developed with the aid of simulated three beam scatterometer ambiguous wind solution data based on noss conditions over a known windfield the resulting algorithms were evaluated using a different set of simulated orbital data but withholding the true winds

palynologic and petrographic variation in the pond creek coal bed pike county kentucky abstract recent studies of the petrology and ash geochemistry of the pond creek coal bed middle pennsylvanian breathitt formation in pike and martin countries kentucky have defined vertical and lateral trends that are related to the development of the northeast trending belfry anticline contemporaneous with the deposition of the pond creek peat to the northwest of the anticline the coal bed has a high caco3 middle zone and a high fe2o3 high sulfur upper zone to the east of the anticline particularly in the lick creek and jamboree 7 1 2 quadrangles the coal bed exhibits a distinctive petrographic zonation in the latter area the usual megascopic sequence is a basal durain followed by a bright clarain durain dull the palynology of the pond creek coal bed was investigated in six sets of bench lithotype samples from the lick creek and jamboree 7 1 2 quadrangles the low vitrinite basal durain zone 1 has a palynomorph assemblage which reflects the importance of tree ferns and herbaceous lycopods the easternmost site has a bright clarain below the durain the latter lithotype has a fair diversity of palynormph groups and also has the highest percentage of arborescent lycopod forms of any bench below the bone zone 5 the bright zone 2 above the durain has the greatest maceral group range and the greatest floral diversity of any of the lithotypes the zone 3 dull lithotype has increased amounts of herbaceous lycopods and decreased amounts of arborescent lycopods sphenopsids and tree ferns the zone 4 bright lithotypes are generally over 80 vitrinite and in general exhibit a dominance of arborescent lycopods although sphenopsid tree fern and small fern forms exhibit varying importance the high ash bone zone 5 has 71 6 77 0 vitrinite this lithotype is marked by a dominance of herbaceous lycopods at the expense of arborescent lycopods and sphenopsids the zone 6 bright clarian is marked by an increase in arborescent lycopods and a large decrease in herbaceous lycopods the low vitrinite terminal durain has an assemblage with high percentages of herbaceous lycopods and low percentages of arborescent lycopods as well as increase in tree fern spores over zone 6 in general the petrology and palynology trends are predictable dull lithotypes have abundant herbaceous lycopod representation and bright lithotypes have abundant arborescent lycopod representation the greatest deviation from this simple pattern is within the zone 4 bright lithotypes where diverse palynomorph assemblages occur among the high vitrinite benches overall the greatest floral diversity appears to have occurred near the base of the coal bed

the diversification of paleozoic fire systems and fluctuations in atmospheric oxygen concentration by comparing silurian through end permian 250 million years myr charcoal abundance with contemporaneous macroecological changes in vegetation and climate we aim to demonstrate that long term variations in fire occurrence and fire system diversification are related to fluctuations in late paleozoic atmospheric oxygen concentration charcoal a proxy for fire occurs in the fossil record from the late silurian 420 myr to the present its presence at any interval in the fossil record is already taken to constrain atmospheric oxygen within the range of 13 to 35 the fire window herein we observe that as predicted atmospheric oxygen levels rise from 13 in the late devonian to 30 in the late permian so too fires progressively occur in an increasing diversity of ecosystems sequentially data of note include the occurrence of charcoal in the late silurian early devonian indicating the burning of a diminutive dominantly rhyniophytoid vegetation an apparent paucity of charcoal in the middle to late devonian that coincides with a predicted atmospheric oxygen low and the subsequent diversification of fire systems throughout the remainder of the late paleozoic first fires become widespread during the early mississippian they then become commonplace in mire systems in the middle mississippian in the pennsylvanian they are first recorded in upland settings and finally based on coal petrology become extremely important in many permian mire settings these trends conform well to changes in atmospheric oxygen concentration as predicted by modeling and indicate oxygen levels are a significant control on long term fire occurrence

probabilities and statistics for backscatter estimates obtained by a scatterometer methods for the recovery of winds near the surface of the ocean from measurements of the normalized radar backscattering cross section must recognize and make use of the statistics i e the sampling variability of the backscatter measurements radar backscatter values from a scatterometer are random variables with expected values given by a model a model relates backscatter to properties of the waves on the ocean which are in turn generated by the winds in the atmospheric marine boundary layer the effective wind speed and direction at a known height for a neutrally stratified atmosphere are the values to be recovered from the model the probability density function for the backscatter values is a normal probability distribution with the notable feature that the variance is a known function of the expected value the sources of signal variability the effects of this variability on the wind speed estimation and criteria for the acceptance or rejection of models are discussed a modified maximum likelihood method for estimating wind vectors is described ways to make corrections for the kinds of errors found for the seasat sass model function are described and applications to a new scatterometer are given

comparison of the petrography palynology and paleobotany of the little fire creek coal bed southwestern virginia u s a abstract two continuous cores that penetrated the lower pennsylvanian little fire creek coal bed in the southwestern coal field in southwestern virginia were sampled and x ray radiographed to determine subunit distinctions comparison of petrographic palynologic and paleobotanic data from the same sample sets from the two cores allowed for comparison of compositional data within the little fire creek coal bed the proximate petrographic palynologic and plant tissue data from two sets of samples indicate a high ash gelocollinite and liptinite rich coal consisting of a relatively diverse paleoflora including lycopsid trees small lycopsids tree ferns small ferns pteridosperms seed ferns and rare calamites and cordaites the relatively very high ash yields 3 80 wt the relatively thin subunits 1 28 cm and the large scale vertical variations in palynomorph floras suggest that the study area was at the edge of the paleopea forming environment as a result most of the compositional correspondences are among those components indicative of degradation or decomposition

the pennsylvanian tropical biome reconstructed from the joggins formation of nova scotia canada the pennsylvanian langsettian joggins formation contains a diverse fossil assemblage first made famous by lyell and dawson in the mid 19th century collector curves based on c 150 years of observation suggest that the joggins fossil record is relatively complete a key feature of the site is that fossils occur in par autochthonous assemblages within a narrow time interval