eudaemonema webbi sp nov mammalia mixodectidae from the late paleocene of western canada the youngest known mixodectid mixodectidae mammalia archonta are an unusual poorly known family of dermopteran like mammals that have been discovered at several north american localities of primarily early paleocene age among the three or four recognized mixodectid genera eudaemonema simpson is perhaps one of the least understood being known from only a few localities of late torrejonian and earliest tiffanian age this paper reports on a new species of eudaemonema from the late paleocene of alberta canada that significantly extends the geographic and stratigraphic ranges of the genus eudaemonema webbi sp nov is known from middle and late tiffanian localities in central and south central alberta and it represents the youngest and northernmost species of eudaemonema so far discovered e webbi differs from the genotypic species e cuspidata in being larger and in having a suite of dental characters e g molariform posterior premolars enlarged molar protocone and hypocone development of a second grinding platform on the

complex dielectric permittivity measurements from ground penetrating radar data to estimate snow liquid water content in the pendular regime 1 monitoring the snow water equivalent swe is critical to effective management of water resources in many parts of the world that depend on the mountain snowpack for water storage there are currently no methods to remotely sense swe with accuracy over large lateral distances in the steep and often forested terrain of mountain basins previous studies have shown that measurements of ground penetrating radar gpr velocity can provide accurate estimates of swe in dry snow introduction of liquid water into the snowpack results in a three phase system that cannot be accurately characterized with gpr velocity alone we show that measuring the frequency dependent gpr signal attenuation and velocity provides a direct estimate of the complex dielectric permittivity because the imaginary component is a function only of liquid water content we can utilize both the real and imaginary components of the permittivity to estimate liquid water content snow density and swe using existing empirical relationships that are valid in the pendular regime we tested this new method at two field sites and found that the estimates were accurate to within 12 of gravimetric methods in both a moist and a dry snowpack gpr has the potential to provide swe estimates across large lateral distances over a broad range of snow conditions

geological setting and paleobotany of the joffre bridge roadcut fossil locality late paleocene red deer valley alberta the joffre bridge roadcut locality paskapoo formation in south central alberta yields plant mammal fish and insect fossils a late paleocene tiffanian age is indicated by mammalian fossils supported by magnetostratigraphy and palynostratigraphy this paper summarizes the flora 28 taxa have been identified to date and describes the sedimentology to provide a paleoenvironmental context outcrops at the site are limited but seven stratigraphic units are recognized and are interpreted to represent five environments of deposition flood plain fluvial channel abandoned channel swamp and crevasse splay the flood plain mudstones lack identifiable plant material due to bioturbation and pedogenesis they are capped by a thin clay rich paleosol with scattered vertebrate bones an upward fining sequence interpreted as fluvial channel and channel abandonment sediments rests directly on the paleosol and includes remains of riparian trees carbonaceous mudstone interpreted as a swamp facies includes

georadar derived estimates of firn density in the percolation zone western greenland ice sheet 1 greater understanding of variations in firn densification is needed to distinguish between dynamic and melt driven elevation changes on the greenland ice sheet this is especially true in greenland s percolation zone where firn density profiles are poorly documented because few ice cores are extracted in regions with surface melt we used georadar to investigate firn density variations with depth along a 70 km transect through a portion of the accumulation area in western greenland that partially melts we estimated electromagnetic wave velocity by inverting reflection traveltimes picked from common midpoint gathers we followed a procedure designed to find the simplest velocity versus depth model that describes the data within estimated uncertainty on the basis of the velocities we estimated 13 depth density profiles of the upper 80 m using a petrophysical model based on the complex refractive index method equation at the highest elevation site our density profile is consistent with nearby core data acquired in the same year our profiles at the six highest elevation sites match an empirically based densification model for dry firn indicating relatively minor amounts of water infiltration and densification by melt and refreeze in this higher region of the percolation zone at the four lowest elevation sites our profiles reach ice densities at substantially shallower depths implying considerable meltwater infiltration and ice layer development in this lower region of the percolation zone the separation between these two regions is 8 km and spans 60 m of elevation which suggests that the balance between dry firn and melt induced densification processes is sensitive to minor changes in melt

melaniella timosa n gen and sp an unusual mammal from the paleocene of alberta canada a new genus and species of eutherian mammal having uncertain affinities is described from an incomplete lower jaw found in the late paleocene paskapoo formation of central alberta canada the new mammal is characterized by a shallow dentary no lower incisors an enlarged lower canine and a relatively long diastema between the canine and the first lower premolar which is premolariform and two rooted closest resemblance of this new mammal is to epoicotheriid palaeanodonts pholidota although it differs in several perhaps important features from known epoicotheriids if the paskapoo mammal is a palaeanodont it is the oldest known constituting the most northerly record for the suborder and the first from canada

emergence of the canadian rockies and adjacent plains a comparison of physiography between end of laramide time and the present day abstract the landscape of the canadian rockies in southern alberta is not a direct result of constructional processes that is the ridges and peaks have not been pushed into the positions in which we see them today tectonic activity provided original elevation but not mountains at the end of laramide time what are now the front ranges and foothills of the rockies comprised a high elevation upland of relatively low relief the present mountain physiography is the result of 55 60 million years of post orogenic differential erosion in which more resistant rocks have been left at higher elevations than less resistant rocks the canadian rockies and the foothills are developed in a thin skinned thrust and fold belt created during the laramide orogeny the adjacent interior plains cut across foreland basin sediments derived from the mountains the mountains currently consist of large parts of ridges of well indurated paleozoic and locally proterozoic rock alternating with valleys developed in soft mesozoic clastic rock in the foothills where the soft mesozoic rock is at the surface relief is subdued but ridges of more resistant sandstone rise above shaley lowlands the plains are relatively flat but also contain erosional outliers of higher paleo plains surfaces numerous lines of evidence suggest that the mountains and foothills have lost several kilometers of overburden since the end of the laramide orogeny while the western plains have lost at least 2 km requiring that the local relief of the mountains and foothills that we see is erosional in origin local physiography is adjusted to lithology the mountains have high relief because the exposed sub mesozoic rocks can hold up high steep slopes whereas the foothills have low relief because the underlying cretaceous rocks cannot hold up high steep slopes the east facing escarpment at the mountain front is a fault line scarp along a low angle thrust mesozoic rocks involved in the deformation originally extended all the way across the thrust and fold belt and physiography of the belt at the end of laramide time 60 55 ma depended mainly on whether mesozoic or paleozoic proterozoic rocks were exposed at the surface at that time a reconstruction using critical taper theory generally agrees with reconstructions from earlier stratigraphic and paleothermometry studies what are now the front ranges at the eastern edge of the rocky mountains were mostly or perhaps entirely covered with mesozoic rocks and despite that high elevation had a hilly not mountainous character the main ranges in the central rocky mountains were in part stripped of mesozoic cover by then and more mountainous treeline was higher then and the thrust belt may have been largely or entirely vegetated generation of modern relief in the front ranges including the escarpment at the mountain front had to await stripping of mesozoic rocks and incision of rivers into harder substrates in post laramide time the interior plains are an erosional surface that was cut 1 to 3 km below the aggradational top of the foreland basin sediments although some of the present low local relief of the plains results from weakness of underlying cretaceous tertiary rocks the low relief is probably largely related to the process of denudation

the relationship between the iridium anomaly and palynological floral events at three cretaceous tertiary boundary localities in western canada profiles illustrating the abundance of iridium and the changes in the relative abundances of major groups within the palynoflora are given for three localities from western canada the peak abundance of iridium ranges from 1 35 to 5 60 ppb and corresponds to the base of a coal and to a floral extinction event at the three localities immediately above the iridium peak anomaly angiosperm pollen is conspicuous in the assemblage in contrast to the fern spore spike described for sections in the mid continental united states and at the morgan creek locality in south central saskatchewan

orogenic pulses in the alberta rocky mountains radiometric dating of major faults and comparison with the regional tectono stratigraphic record radiometric ages from regionally distributed thrust fault gouge show that the eastward propagation of the southern rocky mountain fold and thrust belt in canada occurred in four orogenic pulses that correlate with tectonic events of the cordilleran interior and with depositional patterns in the adjacent foreland in the main ranges the pyramid 163 0 ma simpson pass 161 7 ma and johnson creek 145 7 ma thrusts were related to the initiation of thin skinned deformation from jurassic terrane accretion and were partly contemporaneous with development of the first clastic wedge in the foreland basin in the front ranges the emplacement of the greenock thrust 103 1 ma and broadview snake indian thrust 99 2 ma was contemporaneous with development of cenomanian deltaic deposits in the immediate foreland three thrusts in the front ranges rocky pass 74 8 ma sulfur mountain 75 6 ma and clearwater 74 2 ma thrusts define a campanian phase of tectonic loading that led to the last major transgression in the southern portion of the alberta foreland along the eastern margin of the front ranges the mcconnell thrust 54 0 ma together with the muskeg 52 4 ma brule 53 9 ma and nikanassin 52 1 ma thrusts in the foothills recorded the last phase of regional contraction the late jurassic mid cretaceous late cretaceous and early eocene deformation pulses are separated by relatively long periods 40 m y 20 m y and 10 m y of tectonic quiescence these spatially and temporally restricted fault motion pulses contrast with gradual forward fault propagation while regional eastward progression of deformation is preserved

coal rank and burial history of cretaceous tertiary strata in the grande cache and hinton areas alberta canada implications for fossil fuel exploration the present study discusses coal rank and burial histories for cretaceous tertiary coal measures and thermal maturity of associated source rocks coal rank ranges from subbituminous to semianthracite coalification maps for selected coal zones indicate a broad coalification maximum east of the deformed belt in the pocahontas brule and hinton areas rank levels appear to be elevated locally due to geothermal anomalies thermal modelling indicates that the westward decrease of coal rank in lower cretaceous strata is related to a westward decrease in the duration of burial beneath maastrichtian eocene foreland basin deposits upper cretaceous tertiary strata were subjected to relatively low geothermal gradients 20 c km whereas lower cretaceous strata were exposed to much higher gradients up to 46 c km tectonic loading in the foothills had only a minor impact on coalification at obed marsh alberta syncline thermal modelling suggests that deformation in the thrust belt continued for at least

propagation of a westward traveling surge and the development of persistent auroral features imaging instrumentation on board the spacecraft dynamics explorer 1 de 1 is used to observe the large scale motion of a surge over 7000 km along the auroral oval from near local midnight average speed of the surge is 2 2 km s ground based observations at fort yukon alaska show the classical looped multiple arc structure of a westward traveling surge as it passes overhead within the 6 min temporal resolution provided with de 1 the surge advances initially at a speed of about 8 km s followed by a steady decline to about 1 km s over a period of 17 min this sequence is then repeated a second time beginning with a significant intensification of the surge form this intense surge activity is not accompanied by significant auroral activity near magnetic midnight following passage of the surge persistent and localized bright emission regions remain along the auroral oval for several tens of minutes average separation distances are approximately 700 km if these persistent features identify the sites of individual stepwise advances of the surge the average time per advance is about 5 min

organic petrology of an early paleocene coal zone wabamun alberta palynology petrography and geochemistry abstract an interdisciplinary investigation of a section through the early paleocene ardley coal zone at wabamun alberta reveals that there are distinct vertical variations in the palynological petrographical and geochemical properties reflecting changes in the original depositional environment palynological assemblages are dominated by taxodiaceaepollenites hiatus revealing that the original coal accumulating mires were inhabited by taxodiaceous vegetation subordinate palynomorphs include varied gymnosperm pollen other than t hiatus laevigatosporites spp fern spores of polypodiaceous affinity stereisporites spp mosses including sphagnum and osmundacidites sp family osmundaceae coal petrography reveals that these coals are inertinite rich abundant fusinite pyrofusinite along with semi fusinite and inertodetrinite comprise up to 65 of the maceral assemblages huminite macerals are predominantly eu ulminite b with lesser eu ulminite a densinite and geli huminite gelified huminite lacking any remnant cell structure liptinite macerals include resinite sporinite and cutinite thinner stratigraphically lower seams at wabamun seams nos 6 3 consist predominantly of bright coal with high huminite contents palynofloral assemblages are comprised of t hiatus with few abundances of other palynomorphs suggesting that the original depositional environment was low lying dominated by taxodiaceous vegetation and frequently flooded as evidenced by numerous shale partings high ash contents and relatively high sulphur percentages the thick no 2 seam displays a distinct dulling up petrographic profile resulting from increasing inertinite contents coupled with increased abundances of stereisporites spp this may be evidence of localized ombrogeny within the original wabamun mires and may support a genetic relationship between stereisporites sp and inertodetrinite the no 1 seam consists of abundant fibrous fusain rich coal modes of origin of this fibrous coal include extreme oxidation due to prolonged drought and possibly forest fires elevated ash contents within the nos 1 and 2 seams may be a result of this oxidation of organic matter and concentration of the inorganics as well as airborne volcanic ash as evidenced by numerous bentonite bands within these coals sulphur contents are extremely low as low as 0 05 reflecting a terrestrial depositional environment

recent evolution of marmolada glacier dolomites italy by means of ground and airborne gpr surveys abstract a 10 year long evolution of ice thickness and volume of the marmolada glacier is presented quantitative measurements have been performed by using two different ground penetrating radar gpr datasets a ground based survey using two different ground coupled systems equipped with 100 mhz and 35 mhz antennas was performed in 2004 in 2015 the dataset was collected by using a helicopter borne step frequency gpr equipped with a 100 mhz antenna through a critical discussion of the two different methodologies we show how both approaches are useful to estimate the ice volume within a glacier as well as its morphological characteristics and changes with time even if datasets are acquired in different periods of the year the observed 2004 2014 ice volume reduction of the marmolada glacier is equal to about 30 while the area covered by ice decreased by about 22 the glacier is now splitted in several separated units it is very likely that the fragmentation of the marmolada glacier observed in the period 2004 2014 was accelerated due to irregular karst topography by applying the observed 2004 2014 ice melting trend for the future although the marmolada glacier might behave slightly differently compared to glaciers on non karstic terrains owing to dominant vertical subglacial drainage it will likely disappear by the year 2050 only few isolated very small and thin ice patches will eventually survive due to avalanche feeding and shading at the foot of the north facing cliffs

twenty years of cold surface layer thinning at storglaciaren sub arctic sweden 1989 2009 this paper presents the changes in the thermal structure of the polythermal glacier storglaciaren northern sweden over the 20 year period 1989 2009 derived by comparing maps of the depth of the englacial transition between cold ice permanently frozen and temperate ice which contains water inclusions the maps are based on interpreted ice penetrating radar surveys from 1989 2001 and 2009 complex thinning of the cold layer first identified between 1989 and 2001 is still ongoing a volume calculation shows that storglaciaren has lost one third of its cold surface layer volume in 20 years with a mean thinning rate of 0 80 0 24 m a 1 we suggest that the thinning of the cold layer at storglaciaren is connected to the climatic warming experienced by sub arctic scandinavia since the 1980s and we argue that repeated ice penetrating radar surveys over the ablation area of polythermal glaciers offer a useful proxy for evaluating glacier responses to changes in climate

the development of the substorm expansive phase the eye of the substorm the explosive onset and development of a clearly defined auroral substorm has been analysed using data from the ultraviolet imager aboard the viking satellite these data permit the evolution of the substorm to be traced with a time resolution as high as 40 seconds the envelope of the disturbed region the eye expands both poleward and azimuthally to the east and west reaching an azimuthal extent of almost six hours of magnetic local time after about 15 minutes the poleward expansion involves irregular poleward motion accompanying intensifications within the eye with the maximum poleward displacement being at the meridian of the center of the eye within the eye discrete regions of enhanced luminosity develop with a tendency for each newly disturbed region to be to the west of the previous ones it is however observed that a newly excited region can be to the east of the pre existing activated region each new intensification is accompanied by a brief further poleward expansion of the high latitude edge of the eye each region of enhanced luminosity within the eye remains relatively stationary and fluctuates in intensity over its lifetime we identify these regions of enhanced luminosity with westward traveling surges as defined from ground observations in the earlier literature our uv imager data demonstrate that these surges do not necessarily propagate although the overall envelope of the substorm disturbed region expands both eastward and westward during the lifetime of the event

basin scale stratigraphic architecture and potential paleocene distributive fluvial systems of the cordilleran foreland basin alberta canada abstract the paleocene paskapoo formation in western canada is composed of several hundred meters of fluvial strata that were deposited in an actively subsiding retro arc foreland basin adjacent to the southern canadian cordillera here we utilize newly available subsurface data from down hole gamma ray well logs to reconstruct the large scale fluvial stratigraphy and depositional history of the paskapoo formation in the central portion of the cordilleran foreland basin in alberta paleocene fluvial strata in this region contain several notable characteristics including variable degrees of channel sandstone amalgamation regionally variable stratigraphic architecture and a large fan shaped sandstone unit that emanated from the adjacent fold thrust belt fluvial channel sandstone bodies are abundant and amalgamated near the base of the formation in the southern portion of the basin but become less apparent in the northernmost 100 km of the basin the middle interval of the paskapoo formation characterized by abundant mudstone with isolated channel sandstone bodies is prevalent across the entire study area the upper portion of paskapoo formation is dominated by a large 5000 km2 north northwest trending laterally continuous sandstone in the northern portion of the basin that abuts against the fold thrust belt and fans outward into the basin this feature is interpreted as either a distributive fluvial system or a fixed outlet river system that experienced repeated avulsions this area of the fold thrust belt may be the site of a long lived fluvial outlet the variable degree of sandstone amalgamation in the paskapoo formation suggests two different modes in the relative ratio of accommodation to sediment supply periods of rapid subsidence likely associated with thrust emplacement in the adjacent fold thrust belt resulted in mudstone dominated successions with isolated sandstone bodies whereas tectonically inactive periods associated with less subsidence resulted in amalgamated sandstone units the principal stratigraphic features reconstructed from the data in this area can be used to better understand and predict fluvial stratigraphy within other foreland basins

a comparison of seismic and radar methods to establish the thickness and density of glacier snow cover we show that geophysical methods offer an effective means of quantifying snow thickness and density opportunistic efficient but non optimized seismic refraction and ground penetrating radar gpr

magnetostratigraphy of the canadian continental drilling program cretaceous tertiary k t boundary project core holes western canada the canadian continental drilling program ccdp cretaceous tertiary boundary project cored three holes to 160 188 and 170 m in southern alberta saskatchewan and manitoba respectively to int

effects of ionospheric recombination time scale on the auroral signature of substorms the magnetosphere ionosphere coupling model of substorms developed by kan et al 1988 is improved by including the realistic recombination time scale in the ionosphere and the quiet time convection prior to the enhancement of the magnetospheric convection one of the new features of the improved model is the appearance of highly localized structures of the discrete aurora along the poleward boundary of the diffuse aurora in the evening midnight sector this feature is consistent with the auroral image data of the viking satellite our results show that a discrete auroral arc suddenly brightens near midnight and starts moving westward when the auroral brightness increases to a certain level which is similar to the substorm onset scenario the bright discrete aurora has an initial velocity of around 2 km s 1 but gradually slows down and dims this feature is identified with the westward traveling surge following passage of the surge several localized auroral arcs remain along the auroral oval and the most active auroral region shifts from premidnight toward the evening sector

an ultra wideband microwave radar for measuring snow thickness on sea ice and mapping near surface internal layers in polar firn sea ice is generally covered with snow which can vary in thickness from a few centimeters to 1 m snow cover acts as a thermal insulator modulating the heat exchange between the ocean and the atmosphere and it impacts sea ice growth rates and overall thickness a key indicator of climate change in polar regions snow depth is required to estimate sea ice thickness using freeboard measurements made with satellite altimeters the snow cover also acts as a mechanical load that depresses ice freeboard snow and ice above sea level freeboard depression can result in flooding of the snow ice interface and the formation of a thick slush layer particularly in the antarctic sea ice cover the center for remote sensing of ice sheets cresis has developed an ultra wideband microwave radar capable of operation on long endurance aircraft to characterize the thickness of snow over sea ice the low power 100 mw signal is swept from 2 to 8 ghz allowing the air snow and snow ice interfaces to be mapped with 5 cm range resolution in snow this is an improvement over the original system that worked from 2 to 6 5 ghz from 2009 to 2012 cresis successfully operated the radar on the nasa p 3b and dc 8 aircraft to collect data on snow covered sea ice in the arctic and antarctic for nasa operation icebridge the radar was found capable of snow depth retrievals ranging from 10 cm to 1 m we also demonstrated that this radar can be used to map near surface internal layers in polar firn with fine range resolution here we describe the instrument design characteristics and performance of the radar

a new erinaceid mammalia insectivora from the late paleocene of western canada a new genus and species of erinaceid lipotyphlan mammalia insectivora from the late paleocene of western canada is described oncocherus krishtalkai gen et sp nov is known from three late tiffanian localities in central alberta and southeastern saskatchewan and is but one of several erinaceomorph and soricomorph taxa known from the late paleocene of western canada oncocherus possesses apomorphies that link it to other primitive erinaceids e g enlarged upper and lower fourth premolars lower molars markedly decreasing in size from m1 m3 talonid basins v shaped yet its affinity with any of the recognized erinaceid subfamilies is uncertain although oncocherus is phenetically and probably phylogenetically closest to litolestes jepsen the genus is clearly distinguished from litolestes and other erinaceid taxa by its proportionately larger and more inflated premolars and lower crowned molars features that were likely adaptations for durophagy oncocherus joins a number of endemic mammalian taxa that were apparently confined to more northerly latitudes of the western interior of north america during the late paleocene

palynology and palynofacies analyses of the gray fossil site eastern tennessee their role in understanding the basin fill history abstract the gray fossil site gfs includes multiple karst sub basins that are filled with lacustrine sediments early paleontologic work on one of the sub basins gfs 2 indicates a late miocene early pliocene age based on an assemblage of well preserved vertebrate fossils however detailed palynological analysis of the 38 7 m deep gfs 1 core recovered from another sub basin indicates an older age the presence of caryapollenites imparalis c inelegans and c prodromus association suggests a paleocene to eocene age for the gfs 1 core section this age is also supported by the absence of pollen of the poaceae the grass family that is not commonly present until the neogene age constraints from palynologic data suggest that the gfs has a more complex basin fill history than previously suspected and that multiple depo centers within the basin may have been periodically active through the cenozoic palynofacies analysis of the gfs 1 core indicates that phytoclasts and opaques are the most abundant organic constituents and have diluted both the palynomorph population and amorphous organic matter two possible scenarios can account for this observation 1 an oxidizing depositional paleoenvironment and 2 a localized high flux of charcoal following wildfires and subsequent increased runoff

end of winter snow depth variability on glaciers in alaska a quantitative understanding of snow thickness and snow water equivalent swe on glaciers is essential to a wide range of scientific and resource management topics however robust swe estimates are observationally challenging in part because swe can vary abruptly over short distances in complex terrain due to interactions between topography and meteorological processes in spring 2013 we measured snow accumulation on several glaciers around the gulf of alaska using both ground and helicopter based ground penetrating radar surveys complemented by extensive ground truth observations we found that swe can be highly variable 40 difference over short spatial scales tens to hundreds of meters especially in the ablation zone where the underlying ice surfaces are typically rough elevation provides the dominant basin scale influence on swe with gradients ranging from 115 to 400 mm 100 m regionally total accumulation and the accumulation gradient are strongly controlled by a glacier s distance from the coastal moisture source multiple linear regressions used to calculate distributed swe fields show that robust results require adequate sampling of the true distribution of multiple terrain parameters final swe estimates comparable to winter balances show reasonable agreement with both the parameter elevation relationships on independent slopes model climate data set 9 36 difference and the u s geological survey alaska benchmark glaciers 6 36 difference all the glaciers in our study exhibit substantial sensitivity to changing snow rain fractions regardless of their location in a coastal or continental climate while process based swe projections remain elusive the collection of ground penetrating radar gpr derived data sets provides a greatly enhanced perspective on the spatial distribution of swe and will pave the way for future work that may eventually allow such projections

palynostratigraphic zonation of paleocene strata in the central and south central alberta plains paleocene strata of the scollard and paskapoo formations in the central and south central alberta plains can be subdivided into five formal biostratigraphic zones based in part on a momipites cary

1 4 ghz radar penetration and evidence of drainage structures in temperate ice black rapids glacier alaska u s a we have tested the ability of a 1 12 1 76 ghz bandwidth airborne frequency modulation continuous wave fm cw radar with an effective pulse duration of 3 ns to penetrate temperate ice of the ablation zone of black rapids glacier central alaska u s a we used high gain horn antennas to suppress clutter and tested over cold and nearly ideal surface conditions englacial horizons dipping to at least 60 m depth were found along three sections of one axial profile more narrow band 1 21 1 29 ghz low resolution 24 ns pulse duration profiles from a fourth section detected events at about 100 150 m depth comparative profiles recorded with a 100 mhz short pulse type radar reproduce the horizons of two of the sections and verify the penetration in all cases all horizons are composed of diffractions we interpret voids from the phase of the 100 mhz diffractions within one of the horizons the diffraction nature of the horizons the void interpretation and the proximity to a nearby and up glacier pothole field lead us to conclude that the horizons within two of the sections are meandering drainage channels a more complex branching structure with near surface horizons profiled within the third section much farther down glacier may also be a complex drainage system fed by near surface melting the fm cw signal to clutter noise ratios of some of the targets predict that they could be detected at 200 m depth in the 1 2 ghz range significant performance improvements at maximum vertical resolution could be achieved with higher gain antennas

magnetostratigraphic and biostratigraphic correlation of late campanian and maastrichtian marine and continental strata from the red deer valley to the cypress hills alberta canada two stratigraphic sequences red deer valley and cypress hills sections in alberta spanning the late campanian to paleocene are magnetostratigraphically and biostratigraphically characterized the red deer valley section had previously been studied but additional material has allowed the extension of the magnetozonation downwards into the bearpaw formation higher sample resolution has allowed the identification of a number of magnetosubzones in 32n 32r and 33n four reversed magnetosubzones have been identified in magnetozone 32n in addition to the one presently recognized in geomagnetic polarity time scales one normal subzone in 32r and one reversed subzone in 33n have also been recorded the 32r 33n boundary is shown to occur in the baculites cuneatus zone the campanian maastrichtian boundary is indicated to be at or near the baculites eliasi baculites baculus boundary at the top of 32n comparisons of the biostratigraphy between the two areas indicate that palynomorph ranges differ from data p

paleobotany and paleoecology of gao mine a late paleocene fossil locality near red deer alberta canada in addition to having a rich assemblage of mammalian fossils the gao mine locality in the paskapoo formation of south central alberta has yielded numerous plant specimens of late paleocene late tiffanian or ti5 age the plant fossils are preserved in siltstones and fine grained sandstones interpreted as overbank sediments that were deposited on an aggrading floodplain the assemblage is dominated by the cupressaceous conifer metasequoia foxii and the cercidiphyllaceous dicot joffrea speirsiae including their well preserved seedlings the flora also contains foliage of the ferns onoclea and speirseopteris and the woody dicots palaeocarpinus aphananthe celtis aesculus beringiaphyllum trochodendron and wardiaphyllum as well as seedlings of unknown dicotyledonous angiosperms metasequoia foxii and speirseopteris are unique to the floras of gao mine and the nearby munce s hill site tiffanian ti4 the remainder of the taxa are common in late paleocene floras of north dakota montana and wyoming a

glacier facies of vestfonna svalbard based on sar images and gpr measurements abstract the warming climate of the arctic affects the mass budget of glaciers and changes in the distribution of glacier facies are indicative of their response to climate change the glacial mass budget over large land ice masses can be estimated by remote sensing techniques but selecting an efficient remote sensing method for recognizing and mapping glacier facies in the arctic remains a challenge in this study we compared several methods of distinguishing the facies of the vestfonna ice cap svalbard based upon synthetic aperture radar sar images and terrestrial high frequency ground penetrating radar gpr measurements glacier zones as determined using the backscattering coefficient sigma0 of sar images were compared against gpr data and an alternative application of internal reflection energy ire calculated from terrestrial gpr data was also used for differentiating the extent of glacier facies the ire coefficient was found to offer a suitable method for distinguishing glacier zones and for validating sar analysis furthermore results of analysis of fully polarimetric phased array type l band synthetic aperture radar alos palsar and european remote sensing synthetic aperture radar ers 2 sar images were compared with the ire coefficient classification especially promising method is h segmentation where the glacier zone boundaries corresponded very well with both gpr visual interpretation and ire classification results the ire coefficient s simplicity of calculation makes it a good alternative to the subjective gpr visual interpretation method where results strongly depend on the operator s level of experience we therefore recommend for gpr profiles to be used for additional validation of sar image analysis in studies of glacier facies on the high arctic ice masses

walker creek fault zone central rocky mountains british columbia southern continuation of the northern rocky mountain trench fault zone walker creek fault zone wcfz well exposed in the western rocky mountains of central british columbia near 54 comprises a 2 km wide zone of variably deformed neoproterozoic and cambrian strata in fault bounded slivers and lozenges extensional shear bands subhorizontal extension lineations slickensides mesoscopic shear bands and other minor structures developed within and immediately adjacent to the fault zone consistently indicate right lateral displacement offset stratigraphic changes in correlative neoproterozoic strata indicate at least 60 km of right lateral displacement across the zone wcfz is the southern continuation of the northern rocky mountain trench nrmt fault zone it shows a through going moderate displacement strike slip fault system structurally links the nrmt and the north central part of the southern rocky mountain trench strike slip motion on the wcfz occurred in the late cretaceous to early eocene at the same time as northeast directed shortening in the fold and thrust

a new calibration point for the late cretaceous time scale the 40 ar 39 ar isotopic age of the c33r c33n geomagnetic reversal from the judith river formation upper creataceous elk basin wyoming usa we present a new calibration point for the latest cretaceous time scale an interval that at present contains no well dated polarity reversals the magnetostratigraphy of campanian aged sediments in the northern bighorn basin of wyoming documents a geomagnetic reversal in the upper part of the judith river formation that occurs in direct association with ash fall layers dated by the 40 ar 39 ar method extrapolation based on three new 40 ar 39 ar laser fusion dates from sanidines extracted from the ash fall layers dates the reversal at 79 34 ma thus the geomagnetic reversal in the judith river formation can be confidently correlated to the c33r c33n boundary of the geomagnetic reversal time scale this age estimate is in good agreement with recent time scales that date this polarity interval by interpolation between few and widely spaced calibration points the judith river formation is nonmarine and cannot be correlated regionally by traditional ammonite biostratigraphic methods this st

statistical description of the bulge type auroral substorm in the far ultraviolet 1 using global auroral images at ultraviolet wavelengths during 116 substorms we have obtained quantitative measures of key features of the bulge aurora and oval aurora their temporal variations their locations rates and characteristics of gross expansion and decay and the variability of these parameters the expansion period identified solely from images varied primarily from 10 to 40 minutes with an average of 30 9 minutes to avoid mixing expansion data with recovery data we normalized the time of each substorm to one unit from onset to maximum expansion the average onset location was 22 6 magnetic local time mlt and 66 8 invariant latitude ilat in good agreement with previous analyses we found that the bulge aurora rapidly expanded out of the onset location approximately equally to the west surge and to the east so that the average center of the bulge remained close to the onset mlt this is also the case for average location of the maximum expansion in latitude of the bulge thus the bulge is offset about 1 1 2 hours west of midnight by half the expansion period the bulge has usually expanded poleward sufficiently to reveal a brightened portion of the original auroral oval this brightening expands less than 1 hour mlt to the west but rapidly to the east farther than the east end of the bulge thus the two auroras are offset in mlt the bulge expansion is fastest initially but slows for the second half of the expansion period the ends of the bulge continue a small expansion poleward during early recovery when the center of the bulge slowly retreats the large spreads of substorm expansion times the onset locations and in the locations in mlt and ilat of the key features of these auroras argue strongly for the need to normalize the time of expansion and location of key features of the substorm for any kind of superposed epoch analysis to be meaningful

terrestrial palynomorph biostratigraphy of the cypress hills wood mountain and turtle mountain areas upper cretaceous paleocene of western canada three cored test holes were drilled to study the stratigraphic interval spanning the cretaceous tertiary boundary one in the western cypress hills near elkwater alberta a second in the eastern portion of the wood mountain area near killdeer saskatchewan and a third on the western edge of turtle mountain near goodlands manitoba the terrestrial elements of the palynological assemblages are discussed the maastrichtian assemblages encompassed the scollardia trapaformis zone and two new subzones myrtipites scabratus aquilapollenites delicatus var collaris and porosipollis porosus aquilapollenites notabile within the wodehouseia spinata zone the paleocene zones encountered include the aquilapollenites reticulatus subzone of the w spinata zone the previously described wodehouseia fimbriata and momipites wyomingensis zones and the newly defined tricolporopollenites kruschii zone these provide a biostratigraphy for the cored intervals which can be related to polarity chrons the observations mad

maastrichtian paleocene foreland basin stratigraphies western canada a reciprocal sequence architecture palynological and magnetostratigraphic chronostratigraphic correlations of lower maastrichtian to paleocene strata along an east west western canada basin transect allow for the recognition of a reciprocal sequence architecture in nonmarine strata reference sections include three canadian continental drilling program cretaceous tertiary boundary project core holes and outcrops in alberta southern saskatchewan and north central montana the spatial and temporal position of the third order sequences provides evidence for the correlation of proximal sector regional disconformities and sedimentary wedges with distal sector sedimentary wedges and regional disconformities respectively the boundary between the two sectors is represented by a hingeline which separates the foreland basin syncline from the peripheral bulge the stratigraphies defined by reciprocal third order sequences are complicated by fourth order boundaries developed within proximal sedimentary wedges and with no correlative distal strata these results support tectonic control on foreland basin sedimentation a model for interpreting the various types of sequences in terms of foreland basin evolution vertical tectonics and orogenic cycles is provided it is argued that nonmarine sequence boundaries times of maximum uplift in the foreland region may be expressed as disconformities incised valleys top of mature paleosol levels or base of fluvial channels whereas nonmarine equivalents of marine maximum flooding surfaces times of maximum basinal subsidence may be indicated by extensive coal seams and or lacustrine sediments resume les correlations palynologiques magnetostratigraphiques et chronostratigraphiques des strates echelonnees du maastrichtien inferieur au paleocene le long du transect est ouest du bassin de la cordillere occidentale au canada permettent la reconnaissance d une ordonnance architecturale de sequences reciproques dans les strates continentales les coupes de reference incluent trois trous de forage carottes du canadian continental drilling program cretaceous tertiary boundary project et des affleurements localises en alberta dans le sud de la saskatchewan et dans le centre nord du montana la position spatiale et temporelle des sequences de troisieme ordre plaide pour la mise en correlation des discordances regionales et des depots sedimentaires en coin dans le secteur proximal avec les depots sedimentaires en coin et les discordances regionales dans le secteur distal respectivement une ligne de jonction represente la limite entre les deux secteurs qui separe le bassin d avant pays en forme de cuvette du bombement peripherique les stratigraphies definies par les sequences de troisieme ordre reciproques sont embrouillees par les limites de quatrieme ordre developpees au sein des depots sedimentaires en coin proximaux sans la presence de strates distales correlatives ces resultats appuient la these d un controle tectonique sur le bassin sedimentaire d avant pays on presente ici un modele interpretant les divers types de sequences en termes d evolution d un bassin d avant pays de tectonique verticale et de cycles orogeniques nous tentons de demontrer que les discordances les vallees entaillees les horizons sommitaux de paleosols matures ou la base des chenaux fluviaux peuvent aider a definir les limites des sequences continentales periodes de soulevement maximum dans la region de l avant pays tandis que les couches de charbon etendues et ou les sediments lacustres representent plutot les equivalents continentaux des aires d inondation maximale periodes de subsidence maximum du bassin traduit par la redaction catuneanu and sweet 703

airborne radar stratigraphy and electrical structure of temperate firn bagley ice field alaska u s a helicopter borne 135 mhz short pulse radar profiles of the bagley ice field southern alaska u s a have been analyzed to determine the nature of radio wave propagation through crevassed stratified wet and draining firn diffractions characterize the firn horizons along the trunk and reflections characterize those of overlying snow fields dynamic stacking was used to form and determine firn depths and unstacked diffraction analysis to determine firn layer properties refractive indices range from 4 1 to 4 5 for the near surface from 1 7 to 2 1 at about 13 17 m depth along the main trunk and to 2 6 to 58 m depth within a snowfield average trunk values correspond with volumetric water contents of about 0 09 which agree with values measured for other glaciers the analysis of the airborne recorded diffractions is confirmed by deriving the approximate refractive index of water from a supraglacial lake bottom diffraction the lack of snowfield diffractions suggests that crevassing and not firn structure caused the trunk diffractions the reasonable values of the indices imply that the diffractions originated from single points or edges orthogonal to the profile transect and they predict low interlayer transmission losses the snowfield penetration suggests that several hundred meters might be penetrated in uncrevassed accumulation zones with improved system design

cold ice in the ablation zone its relation to glacier hydrology and ice water content 1 cold ice within a polythermal ice body controls its flow dynamics through the temperature dependence of viscosity and affects glacier hydrology by blocking water flow paths lakes on the surface linked by persistent deeply incised meltwater streams are hallmark features of cold ice in the ablation zone of a glacier or ice sheet ice radar is a convenient method to map scattering from internal water bodies present in ice at the pressure melting temperature pmt consequently lack of internal scatters is indicative of cold ice we use a helicopter borne 30 mhz ice radar to delineate the extent of cold ice within grenzgletscher zermatt swiss alps the inferred thermal structure is validated with temperature measurements in 15 deep boreholes showing excellent agreement the cold ice occupies 80 90 of the total ice thickness in a 400 m wide flow band along the central flow line quantitative interpretation of ice radar scattering power indicates a decrease of ice water content between pmt and 0 5 k below pmt as predicted by theory and observed in the laboratory the cold ice which emerges at the surface in the lower ablation zone is impermeable to water and is thus devoid of moulins if not crevassed the surface water from melt and rain is routed through deeply incised persistent streams and lakes and cryoconite holes are frequent in stark contrast to the adjacent temperate ice from other tributaries the cold ice thus has a strong control on glacier hydrology but is likely to change due to continued warming

petrology of fibrous coal fusain and associated inertinites from the early paleocene of the central alberta plains abstract megascopic micropetrographic and scanning electron microscopic investigations of fibrous coal indicate that paleo wildfires were common occurrences in the mire which produced highvale coals at least 20 fibrous coal fusain horizons have been identified in corehole samples from the pit no 3 locality at highvale in the central alberta plains thicknesses of individual horizons vary and are not particular to any stratigraphic position within coal seams the majority of these fibrous horizons is within the two thick economic seams the highvale nos 1 and 2 which are characteristically megascopically dull the dullness of given lithotypes is largely related to inertinite content with fibrous coal containing 51 inertinite on average and selected horizons comprised of as much as 85 inertinite semifusinite and inertodetrinite are the predominant inertinites with a few horizons exhibiting highly reflecting fusinite macrinite is rare and micrinite is absent sem investigations reveal that certain fibrous coals exhibit excellent preservation of the original gymnospermous taxodium woody tissue features such as homogenization and swelling of the cell walls elimination of the middle lamellae and preservation of bordered pits are clearly indicative of charcoal formation as a product of paleo wildfires depending upon the nature of the fire temperatures obtained and the nature of the mire vegetation a wide range of inertinite precursors can be produced

reciprocal stratigraphy of the campanian paleocene western interior of north america abstract the claggett bearpaw and cannonball successions campanian paleocene of the western interior foreland system were deposited during a series of regional second and third order transgressions and regressions locally modulated by fourth and lower order cycles the reciprocal flexural behaviour of the foreland lithosphere in response to orogenic cycles of loading and unloading results in out of phase sequences on opposite sides of the basin which defines the concept of reciprocal stratigraphies the proximal and distal regions of the basin are separated by a few kilometre wide hinge zone of proximal to distal facies change with the mid point taken as a stratigraphic hinge line which defines the boundary between coeval marine transgressive and regressive systems tracts or between nonmarine sequences and correlative sequence boundaries hinge lines have been mapped in alberta saskatchewan montana and wyoming for consecutive time slices during the campanian paleocene interval areally the hinge line traces a semielliptical pattern outlining the region of maximum foreland basin subsidence it migrated at 10 km ma to the north in response to late cretaceous paleocene orogenic dextral transpression the hinge line also migrated eastward during the campanian and maastrichtian in response to thrust sheet advance and westward during the paleocene in response to the redistribution of orogenic load associated with a transition from transpression to transtension possibly accompanied by a visco elastic deepening and narrowing of the foredeep

auroral medium frequency burst radio emission associated with the 23 march 2007 themis study substorm 1 auroral medium frequency mf burst is an impulsive auroral radio emission associated with substorm onset detected by ground based instruments between 1 3 and 4 5 mhz on 23 march 2007 an mf burst emission was detected by the dartmouth radio interferometer located near toolik lake alaska this emission temporally coincides with the onset of the 23 march 2007 time history of events and macroscale interactions during substorms themis study substorm directions of arrival computed using the dartmouth radio interferometer for this event also coincide spatially with the location of the expanding auroral arcs to the south observed by the all sky imager at fort yukon alaska this observation represents the first example of a direction of arrival measurement for mf burst it strongly supports the association of mf burst with intense auroral arcs accompanying substorm onset the direction of arrival of the mf burst is consistent with the direction to the eastern edge of the substorm onset location determined by multiple data sets during this substorm and suggests that location of mf burst radio emissions may be an effective method of locating substorm onsets much as radio atmospherics are used to locate lightning

north south structures in the midnight sector auroras as viewed by the viking imager during auroral substorms active auroras involving field aligned electric fields appear at the poleward border of the auroral oval equatorward of these active discrete auroras a diffuse region of luminosity develops which often features imbedded localized structures which can have distinctively north south orientations in this paper we study the behaviour of such longitudinally confined northsouth oriented auroral arc structures which may turn on and off sporadically during the substorm lifetime in particular we show observations which suggest that these structures may be the projection on the ionosphere of the drift paths of energetic electrons as they drift from the magnetotail into the more dipolar inner magnetosphere our results suggest that injection of auroral particles into the central plasma sheet occurs in quite localized regions over lengthy periods of time the injected particles drift earthward in the central plasma sheet where those electrons with pitch angles close to the loss cone are sporadically caused to precipitate into the ionosphere causing the fingers of luminosity north south aligned structures near the equatorward edge of the oval are believed to represent precipitation of a spatially localized population of energetic electrons for which the westward convective drift velocity in the evening sector nearly balances the eastward gradient and curvature drift velocity thus leading to purely earthward convective drift of the energetic electrons

late cretaceous to early tertiary magnetostratigraphy of a continental sequence red deer valley alberta canada the red deer valley exposes a conformable 350 m thick late campanian to early paleocene fluvial deltaic coal bearing sequence named the edmonton group systematic sampling and paleomagnetic analysis of the dominant lithologies mudstones sandstones and shales were carried out over five sections correlated by coal seams to provide some 500 sites stratigraphic levels primary detrital remanent magnetization directions after alternating field cleaning produce a polarity reversal pattern correlatable to sea floor magnetic anomalies 29 33 the campanian maastrichtian boundary based upon the first appearance of wodehouseia and the maastrichtian paleocene cretaceous tertiary boundary based upon an ir anomaly associated with dinosaur and cretaceous palynofloral extinctions correlate closely magnetostratigraphically with the marine foraminiferal section at gubbio italy radiometric dating of bentonites has indicated the ages of these boundaries to be approximately 71 and 64 ma respectively

strong spatial variability of snow accumulation observed with helicopter borne gpr on two adjacent alpine glaciers the spatial distribution of snow accumulation plays an essential role for the mass balancedistribution on alpine glaciers traditional point measurements snow pits and probes are labour intensive and interpolation in between the points causes uncertainties airborne radar measurements have already been used for snow mapping innon glacierized terrain but not on alpine glaciers to enhance our understanding ofthe spatial distribution of accumulation and pin down reasons for observed variations we have conducted high resolution helicopter borne radar measurements on the temperatedglacier findel and neighbouring adler glacier in southwestern switzerland the radar sensor was mounted underneath a helicopter and operated at a centre frequencyof 500 mhz with a bandwidth of 400 mhz the results were validated withextensive ground based profiling of the snow cover the radar data allows a clearrecognition of the snow cover 6 of the total profile length of 10 km did not allowinterpretation due to missing or disturbed layering and agreed well with the groundbased measurements r2 0 85 reduced accumulation has been observed in allcrevassed zones statistical analysis of the correlation between observed accumulationand terrain characteristics have been performed in a gis environment revealing differingaccumulation patterns on the lower part of findel glacier accumulation showsa clear altitudinal trend while the upper part is dominated by strongly varying snowdepth without an altitudinal trend the accumulation characteristic on adler glacieris similar to the upper part of findel glacier but despite of their close vicinity accumulationis reduced by 40 compared to the same elevation on findel glacier thisstudy reveals a large potential of helicopter borne snow profiling for measurements ofaccumulation distribution on alpine glaciers