bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of instrumental observations of the Jesenice meteorite fall on April 9, 2009
Authors: SPURNÝ Pavel , BOROVIČKA Jiří , KAC Javor , KALENDA Pavel , ATANACKOV Jure , KLADNIK Gregor , HEINLEIN Dieter , GRAU Thomas
Published: November 2010

Abstract– We report an analysis of instrumental observations of a very bright fireball which terminated with a meteorite fall near the town of Jesenice in Slovenia on April 9, 2009, at 0h59m46s UT. The fireball designated EN090409 was recorded photographically and photoelectrically by two southern stations of the Czech part of the European Fireball Network (EN). Simultaneously, a part of the luminous trajectory was also captured by two all‐sky CCD systems and one video camera of the Slovenian meteor network. In addition to these optical recordings, the sonic booms produced by the Jesenice fireball were detected at 16 seismic stations located within 150 km of the trajectory. From all these records, we reconstructed the fireball’s atmospheric trajectory, basic geophysical data, the possible impact area, and the original heliocentric orbit of the meteoroid. Using a detailed fireball light curve, we modeled the atmospheric fragmentation of the meteoroid. Both the atmospheric behavior and the heliocentric orbit proved to be quite normal in comparison with other observed meteorite falls. The Jesenice orbit is markedly different from the Příbram and Neuschwanstein orbital meteorite pair, which fell on similar dates (April 7, 1959, and April 6, 2002, respectively). Three meteorites with a total weight of 3.6 kg (until April 2010) were found in a high mountain area near the town of Jesenice. They are classified as L6 ordinary chondrites (Bischoff et al. 2010).
A Methodology for Predicting the Response of Blades With Nonlinear Coatings
Authors: Filippi Sergio , Torvik Peter J.
Published: November 2010

Ceramic coatings applied by air plasma spray or electron beam techniques as thermal barrier coatings or to improve the erosion or corrosion resistance of blades in gas turbine engines are found to add damping to the system. However, such coatings display nonlinear mechanical properties in that the Young’s modulus and the measure of damping are dependent on the amplitude of cyclic strain. To account for the coating nonlinearity, a new methodology for predicting blade response was developed and applied to an actual component coated with a titania-alumina blend ceramic infiltrated with a viscoelastic material. Resonant frequencies, mode shapes, and the forced response of a one blade segment of an integrated disk from a fan stage rotor were computed and compared with results from bench tests. Predicted frequencies agreed satisfactorily with measured values; predicted and observed values of system damping agreed to within 10%. The results of these comparisons are taken to indicate that it is possible to use laboratory-determined material properties together with an iterative finite element analysis to obtain satisfactory predictions of the response of an actual blade with a nonlinear coating.
On a New Passive Scalar Equation With Variable Mass Diffusivity: Flow Between Parallel Plates
Authors: Gori Fabio , Boghi Andrea
Published: November 2010

The present work investigates mass conservation equations in turbulent flow between parallel plates with variable mass diffusivity. Species conservation equations are relative to the average concentration, as well as to the concentration variance. The product of fluctuating mass diffusivity and space gradient of concentration fluctuation is appearing in the equation of mean and concentration variance. A physical interpretation is given to the different terms. The assumption of a relation between mass diffusivity and concentration allows writing expressions for average and fluctuating mass diffusivity, which can be simplified on the basis of theoretical considerations. The new mass flux is expressed as a function of mass diffusivity and a gradient of concentration variance. Further considerations make it possible to model the new terms appearing in the concentration variance equation. The mass conservation equation can be solved when coupled to the equation of concentration variance. The equations are solved numerically for flow between parallel plates in order to evaluate the influence of the new terms.
A Contribution to Study on the Lift of Ventilated Supercavitating Vehicle With Low Froude Number
Authors: Kaiping Yu , Jingjun Zhou , Jingxin Min , Guang Zhang
Published: November 2010

A ventilated cavity was investigated using three-dimensional numerical simulation and cavitation water tunnel experiments under the condition of low Froude number. A two-fluid multiphase flow model was adopted in numerical predictions. The drag between the different phases and gravitational effect, as well as the compressibility of gas, was considered in the numerical simulations. By comparing the ventilated coefficient computational results of three different turbulence models with the Epshtein formula, the shear-stress-transport turbulence model was finally employed. The phenomenon of double-vortex tube gas-leakage was observed in both numerical simulations and experiments. Based on the validity of the numerical method, the change law of the lift coefficient on the afterbody was given by numerical predictions and accorded well with experimental results. The cause for the appearance of an abrupt increase in lift was difficult to get from experiments for the hard measurement, whereas the numerical simulations provided some supplements to analyze the reasons. The distribution of lift coefficient on the afterbody had important significance to the design of underwater vehicles.
Determination of Spread Activation Energy and Assessment of Wetting Behavior of Solders on Metallic Substrates
Authors: Prabhu K. N. , Kumar G.
Published: November 2010

The effects of substrate material, substrate surface roughness, and operating temperature on the wetting behavior of Sn–37Pb, Sn–3.5Ag, and Sn–9Zn eutectic solders on metallic substrates were investigated. Solder spreading kinetics was successfully represented by the exponential power law (EPL): ϕ=exp(−Kτn). The EPL parameter K has the significance of accelerating the kinetics of relaxation while the parameter n represents the resistance to spreading process (spread resistance parameter). EPL parameters exhibited a decreasing trend with an increase in surface roughness. Estimated activation energies for solder spreading were found to be in between those reported for inert and highly reactive spreading systems.
Fabrication and initial characterization of ultrahigh aspect ratio vias in gold using the helium ion microscope
Authors: Scipioni Larry , Ferranti David C. , Smentkowski Vincent S. , Potyrailo Radislav A.
Published: November 2010

Toward the end goal of creating transducers with nanometer scale sensing features, the helium ion microscope (HIM) has been employed to create and characterize high aspect ratio features in gold films. The HIM has a spot size less than 1 nm, uses a chemically inert noble gas (He), which does not deposit/implant any species that may contaminate the material being patterned, and is able to rapidly generate arrays of vias in Au. Hence, the HIM is an ideal tool to generate these ultrahigh aspect ratio features. The authors characterize the vias, also using HIM, by measurements of feature size, lateral milling resolution, sidewall angle, and fabrication speed. Two novel methods were employed to enable the characterization due to the very small size of the features. A significant reduction in via width is achieved, as compared with traditional focused ion beam milling.
More physics in the laundromat
Authors: Denny Mark
Published: November 2010

The physics of a washing machine spin cycle is extended to include the spin-up and spin-down phases. We show that, for realistic parameters, an adiabatic approximation applies, and thus the familiar forced, damped harmonic oscillator analysis can be applied to these phases.
Charged radial infall for spherical central bodies
Authors: Franklin J. , Morton-Park F.
Published: November 2010

A massive, charged, spherical body can be neutralized by attracting particles of opposite charge. We calculate the time it takes to neutralize such a body using Newtonian and relativistic mechanics and the “forced” trajectories of general relativity. We compare the classical and (special) relativistic times and find that the special relativistic neutralization time is longer. A comparison of these times with the general relativistic result is not as direct. We offer the final calculation as a demonstration of dynamics in the general relativistic setting, highlighting the structural similarity of this problem with the other two cases.
Plasticity of Animal Genome Architecture Unmasked by Rapid Evolution of a Pelagic Tunicate
Authors: Denoeud France , Henriet Simon , Mungpakdee Sutada , Aury Jean-Marc , Da Silva Corinne , Brinkmann Henner , Mikhaleva Jana , Olsen Lisbeth Charlotte , Jubin Claire , Cañestro Cristian , Bouquet Jean-Marie , Danks Gemma , Poulain Julie , Campsteijn Coen , Adamski Marcin , Cross Ismael , Yadetie Fekadu , Muffato Matthieu , Louis Alexandra , Butcher Stephen , Tsagkogeorga Georgia , Konrad Anke , Singh Sarabdeep , Jensen Marit Flo , Cong Evelyne Huynh , Eikeseth-Otteraa Helen , Noel Benjamin , Anthouard Véronique , Porcel Betina M. , Kachouri-Lafond Rym , Nishino Atsuo , Ugolini Matteo , Chourrout Pascal , Nishida Hiroki , Aasland Rein , Huzurbazar Snehalata , Westhof Eric , Delsuc Frédéric , Lehrach Hans , Reinhardt Richard , Weissenbach Jean , Roy Scott W. , Artiguenave François , Postlethwait John H. , Manak J. Robert , Thompson Eric M. , Jaillon Olivier , Du Pasquier Louis , Boudinot Pierre , Liberles David A. , Volff Jean-Nicolas , Philippe Hervé , Lenhard Boris , Crollius Hugues Roest , Wincker Patrick , Chourrout Daniel
Published: November 2010

Ocean Dweller Sequenced

The Tunicates, which include the solitary free-swimming larvaceans that are a major pelagic component of our oceans, are a basal lineage of the chordates. In order to investigate the major evolutionary transition represented by these organisms,

Denoeud
et al.

(p.
1381
, published online 18 November) sequenced the genome of
Oikopleura dioica
, a chordate placed by phylogeny between vertebrates and amphioxus. Surprisingly, the genome showed little conservation in genome architecture when compared to the genomes of other animals. Furthermore, this highly compacted genome contained intron gains and losses, as well as species-specific gene duplications and losses that may be associated with development. Thus, contrary to popular belief, global similarities of genome architecture from sponges to humans are not essential for the preservation of ancestral morphologies.
A New Focus on Plant Sciences
Authors: McCormick Steven J. , Tjian Robert
Published: November 2010

Plants are essential to the survival of our planet—to its ecology, biodiversity, and climate. They maintain human health by providing the basis for nutrition, shelter, clothing, and energy. The study of plants has yielded fundamental insights that have reshaped our understanding of the world and has enabled major human needs to be addressed. But the world population is expected to increase from six billion to nine billion people by the year 2050, challenging humanity to develop more efficient ways to harness plants for meeting growing global needs. Vigorous high-quality scientific research in the plant sciences will be crucial for the world's future. Yet basic plant science research has struggled to take root in the United States. For more than a decade, agricultural research writ large has received only 2% of total federal spending on R&D. Federal support for fundamental plant science research has been even less: The amount awarded on a competitive basis to academic and research institutions constitutes only about 2% of extramural spending for life sciences research ($382 million out of $17 billion in 2005).
African 2, a Clonal Complex of
Mycobacterium bovis
Epidemiologically Important in East Africa
Authors: Berg Stefan , Garcia-Pelayo M. Carmen , Müller Borna , Hailu Elena , Asiimwe Benon , Kremer Kristin , Dale James , Boniotti M. Beatrice , Rodriguez Sabrina , Hilty Markus , Rigouts Leen , Firdessa Rebuma , Machado Adelina , Mucavele Custodia , Ngandolo Bongo Nare Richard , Bruchfeld Judith , Boschiroli Laura , Müller Annélle , Sahraoui Naima , Pacciarini Maria , Cadmus Simeon , Joloba Moses , van Soolingen Dick , Michel Anita L. , Djønne Berit , Aranaz Alicia , Zinsstag Jakob , van Helden Paul , Portaels Françoise , Kazwala Rudovick , Källenius Gunilla , Hewinson R. Glyn , Aseffa Abraham , Gordon Stephen V. , Smith Noel H.
Published: November 2010

We have identified a clonal complex of
Mycobacterium bovis
isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of
M. bovis
strains the African 2 (Af2) clonal complex of
M. bovis.
Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of
M. bovis
isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of
M. bovis
is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that strains of the Af2 clonal complex of
M. bovis
have, in general, four or more copies of the insertion sequence IS
6110
, in contrast to the majority of
M. bovis
strains isolated from cattle, which are thought to carry only one or a few copies.
In Vitro
Selection of Clinically Relevant Bevirimat Resistance Mutations Revealed by “Deep” Sequencing of Serially Passaged, Quasispecies-Containing Recombinant HIV-1
Authors: Knapp David J. H. F. , Harrigan P. Richard , Poon Art F. Y. , Brumme Zabrina L. , Brockman Mark , Cheung Peter K.
Published: November 2010

Initial
in vitro
studies of bevirimat resistance failed to observe mutations in the clinically significant QVT motif in SP1 of HIV-1
gag
. This study presents a novel screening method involving mixed, clinically derived
gag-protease
recombinant HIV-1 samples to more accurately mimic the selection of resistance seen
in vivo
. Bevirimat resistance was investigated via population-based sequencing performed with a large, initially antiretroviral-naïve cohort before (
n
= 805) and after (
n
= 355) standard HIV therapy (without bevirimat). The prevalence of any polymorphism in the motif comprising Q, V, and T was ∼6%, 29%, and 12%, respectively, and did not change appreciably over the course of therapy. From these samples, three groups of 10 samples whose bulk sequences were wild type at the QVT motif were used to generate
gag-protease
recombinant viruses that captured the existing diversity. Groups were mixed and passaged with various bevirimat concentrations for 9 weeks.
gag
variations were assessed by amplicon-based “deep” sequencing using a GS FLX sequencer (Roche). Unscreened mutations were present in all groups, and a V370A minority not originally detected by bulk sequencing was present in one group. V370A, occurring together with another preexisting, unscreened resistance mutation, was selected in all groups in the presence of a bevirimat concentration above 0.1 μM. For the two groups with V370A levels below consistent detectability by deep sequencing, the initial selection of V370A required 3 to 4 weeks of exposure to a narrow range of bevirimat concentrations, whereas for the group with the V370A minority, selection occurred immediately. This approach provides quasispecies diversity that facilitates the selection of mutations observed in clinical trials and, coupled with deep sequencing, could represent an efficient
in vitro
screening method for detecting resistance mutations.
Role of the Vacuolar-ATPase in Sindbis Virus Infection
Authors: Hunt Sabrina R. , Hernandez Raquel , Brown Dennis T.
Published: November 2010

Bafilomycin A
1
is a specific inhibitor of the vacuolar-ATPase (V-ATPase), which is responsible for pH homeostasis of the cell and for the acidification of endosomes. Bafilomycin A
1
has been commonly used as a method of inhibition of infection by viruses known or suspected to follow the path of receptor-mediated endocytosis and low-pH-mediated membrane fusion. The exact method of entry for Sindbis virus, the prototype alphavirus, remains undetermined. To further investigate the role of the V-ATPase in Sindbis virus infection, the effects of bafilomycin A
1
on the infection of BHK and insect cells by Sindbis virus were studied. Bafilomycin A
1
was found to block the expression of a virus-encoded reporter gene in both infection and transfection of BHK cells. The inhibitory effects of bafilomycin A
1
were found to be reversible. The results suggest that in BHK cells in the presence of bafilomycin A
1
, virus RNA enters the cell and is translated, but replication and proper folding of the product proteins requires the function of the V-ATPase. Bafilomycin A
1
had no significant effect on the outcome of infection in insect cells.
First‐choice therapy for dogs presenting with diarrhoea in clinical practice
Authors: German A. J. , Halladay L. J. , Noble P‐J. M.
Published: November 2010

Computerised referral histories were reviewed for dogs admitted to the University of Liverpool Small Animal Teaching Hospital between January 2000 and December 2008 with diarrhoea among the clinical signs. A total of 371 cases presenting to the referring veterinary surgeon were included in the study, and information was compiled regarding signalment, clinical signs and treatment given at the initial consultation. Various breeds, ages and sexes were represented. Antibacterials were used in 263 (71 per cent) cases, steroids in 71 (19 per cent) cases and miscellaneous antidiarrhoeal products (including probiotics, prebiotics, adsorbents and antimotility drugs) in 98 (26 per cent) cases. Other drugs used included antiemetics (48 of 371 [13 per cent] cases), gastric protectants (37 of 371 [10 per cent] cases) and sulfasalazine (26 of 371 [7 per cent] cases). Antibacterial administration was positively associated with hyperthermia (odds ratio [OR]=2.97, P=0.012) and anorexia (OR=2.17, P=0.0075), but negatively associated with both weight loss (OR=0.55, P=0.036) and tenesmus (OR=0.43, P=0.035). In contrast, use of antidiarrhoeal products was positively associated with the presence of faecal mucus (OR=1.77, P=0.043), and negatively associated with vomiting (OR=0.57, P=0.025) and weight loss (OR=0.52, P=0.033).
Gravity and magnetic interpretation of the Deer Lake basin, Newfoundland
Authors: Miller H. G. , Wright J. A.
Published: November 2010

Detailed reconnaissance gravity surveys in the Deer Lake Carboniferous basin have been conducted using a station spacing of 2.5 km. The digitized aeromagnetic data for the basin were reduced to a 1:253 440 scale composite map. These two data bases were used to determine the configuration of major features and the total sediment thickness at various locations in the basin. Preliminary seismic results from reflection and refraction seismic surveys planned on the basis of these results are discussed. Modelling of gravity and magnetic data indicates that the Humber syncline contains approximately 1.2 km of sediments underlain on the west by rocks similar to the Long Range Complex. The eastern limb of the syncline is underlain by rocks similar to the Gull Pond Igneous Suite. The Howley Formation is deduced to be approximately 1.5 km thick and floored by rocks similar to the Topsails Igneous Suite.
Mineralogy and oxygen isotope geochemistry of clays from surficial deposits in the Athabasca Tar Sands area
Authors: Spiers G. A. , Dudas M. J. , Muehlenbachs K. , Turchenek L. W.
Published: November 2010

Detailed clay mineralogical characterization was completed on four major glaciogenic surficial deposits in northeastern Alberta. The mineral species identified and quantified were mica, montmorillonite, beidellite, kaolinite, chlorite, and vermiculite. Although there were quantitative differences in the amounts of mica, kaolinite, and chlorite in the Legend unit, the similarity of the mineral species in all deposits precluded their use for a definitive assessment of sediment provenance.Oxygen isotopic data for the clay separates served as a useful criterion for differentiation of deposits. Differences in isotopic signature were related to the inclusion of materials from the underlying Cretaceous marine sediments and to the admixture of materials from preweathered Shield sediments. The difference in isotopic signature of the clay separates was specifically related to the formation conditions of the micaceous component.
Oxygen isotope–water relations in altered deep-sea basalts: low-temperature mineralogical controls
Authors: Böhlke J. K. , Alt J. C. , Muehlenbachs K.
Published: November 2010

Detailed analyses of oxygen isotope–water relations in <3, 13, and 109 Ma old mid-ocean ridge basalts reveal that, to a first approximation, the low-temperature alteration of deep-sea basalts in the upper few hundred metres of the igneous crust can be modelled as the partial conversion of basalt to smectite formed in isotopic equilibrium with seawater. Second-order variations in δ18O versus H2O+ plots are used to show that this approximation breaks down in detail because secondary mineral assemblages and mass transfer vary widely in response to subtle variations in temperature and (or) fluid flow. Strongly oxidized open systems can evolve relatively low δI8O hydrous oxide-rich assemblages if leaching is efficient (DSDP (Deep Sea Drilling Project) site 396), or relatively anhydrous high δ18O K-feldspar-rich assemblages if plagioclase breaks down (site 417), compared with the clay-mineral-dominated assemblages common in somewhat more restricted flow environments. Zonal distribution and common superposition of various alteration mineral assemblages within rock fragments cause significant small-scale isotopic heterogeneity. A simplified low-temperature alteration scheme involving (a) early-stage Fe–K–Mg clay minerals, (b) middle-stage K-feldspars, oxides, or smectites, depending on the duration, rate, and temperature (?) of fluid flow, and (c) late-stage zeolites and (or) carbonates, is recorded in rather complex time variations in δ18O versus H2O+ for individual rock parcels.
Paleomagnetic dating of the transformation of oolitic goethite to hematite in iron ore
Authors: Hodych J. P. , Pätzold R. R. , Buchan K. L.
Published: November 2010

We show that the oolitic hematite ores of Birmingham, Alabama, carry a remanence direction stable enough to have survived major folding. Nevertheless, this remanence was very likely acquired in the Pennsylvanian, about 130 Ma after the ore's Early Silurian deposition. This long delay is understandable if we accept the common hypothesis that the ore originated as oolitic goethite. We would then not expect acquisition of a stable remanence until deep burial in the Pennsylvanian raised the temperature to the ~80 °C probably needed to transform coarse goethite to hematite in water. Although the paleomagnetism of oolitic hematite may be of limited value in defining primary paleopoles, it may allow dating of when the ore's temperature was first raised to ~80 °C, perhaps aiding studies of sedimentary basin evolution and oil formation. Our results also support using caution in interpreting the paleomagnetism of more common red beds, emphasizing that a positive fold test is not necessarily evidence of primary remanence and that burial history may control the timing of remanence acquisition.
A detailed gravity profile across the English River Subprovince, northwestern Ontario
Authors: Gupta V. K. , Barlow R. B.
Published: November 2010

This paper presents the results of a detailed gravity profile measured across the two lithotectonic domains of the English River Subprovince from Vermilion Bay to Red Lake, a distance of 190 km, in northwestern Ontario. Along the profile 283 fresh rock samples were collected for density measurements. The density data clearly suggest that there is a measurable and significant density difference between the migmatized metasediments and plutonic rocks.A crustal model based on the seismic data, along the profile, has been used for computing a regional gravity field, which in turn has been used in isolating the residual anomalies from the Bouguer anomaly field. A strong correlation has been found to exist between the residual anomalies, the rock densities, and the surface lithologies. The Northern Supracrustal Domain, which is at its widest (60 km) along the profile, is dominated by a pronounced 15 mGal (150 μm s−2) positive residual anomaly believed to be caused by outcropping, anomalously dense metasediments extending to a modelled depth of approximately 10 km. In the Southern Plutonic Domain the residual anomalies along the profile are small (less than 5 mGal (50 μm s−2)) and limited in depth. The Mystery Lake dome extends to a modelled depth of approximately 2.5 km.
Paleogene geology and chronology of southwestern Umnak Island, Aleutian Islands, Alaska
Authors: McLean Hugh , Hein J. R.
Published: November 2010

The rocks of southwestern Umnak Island (Nikolski area) consist mainly of a slightly deformed marine sedimentary sequence intruded by hypabyssal quartz diorite sills and small plutons. Laminated and thin-bedded argillaceous and tuffaceous mudstone and siltstone reflect volcanic arc sedimentation from late Eocene to early Oligocene time. Zeolite facies minerals formed during diagenesis include heulandite, analcime, quartz, chlorite, and smectite. Radiometric dates from sill rock and plutons yield apparent ages of about 30 Ma, i.e, middle Oligocene. Chemical data from igneous rocks exhibit calc-alkaline and tholeiitic volcanic arc differentiation trends. Dikes of pyroxene basalt yield K/Ar apparent ages as old at 17 Ma, and a columnar-jointed plug of pyroxene basalt is as young as 1 Ma. The fossil ages and radiometric dates from southwestern Umnak Island are similar to those reported from other central and eastern Aleutian islands, and indicate uniformity in the chronology and tectonic development of the archipelago during the Paleogene. Paleomagnetic data suggest possible northward movement but remain equivocal and more work is indicated.
Geothermal energy from Penticton Tertiary outlier, British Columbia: an initial assessment
Authors: Lewis Trevor
Published: November 2010

Tertiary basins in south-central British Columbia may be economic sources of hot water for space heating. The heat flow, 72 mW m−2 for the Penticton Tertiary outlier, and the insulating layers of volcanic sediments produce particularly high temperatures within this basin. Underneath White Lake, the temperature at the bottom of a spectacular thickness of sediments may be 90 °C. The measured porosity, approximately 5%, and the water flows observed in boreholes indicate ample fluid and apparent permeability to extract significant heat from the rocks. However, a more qualitative assessment of these parameters can only come from a thorough hydrogeologic study involving several test wells.The regional heat flow indicates that Coryell-type intrusions having a high radioactive heat generation do not form a significant proportion of the upper crust.
In situ lingulids from deep-water carbonates of the Middle Ordovician Table Head Group of Newfoundland and the Trenton Group of Quebec
Authors: Pickerill R. K. , Harland T. L. , Fillion D.
Published: November 2010

Specimens of in situ lingulids have been discovered in carbonates of the Middle Ordovician Table Head Group of northwestern Newfoundland and Trenton Group of the St. Lawrence Lowland of Quebec. The discoveries have two important implications regarding Palaeozoic lingulid ecology. First, they represent one of the few recordings of in situ lingulids in carbonate substrates of Palaeozoic age and, second, they occur mainly in outer shelf and upper slope sediments (Grondines Member of Neuville Formation, Trenton Group, and Table Cove Formation, Table Head Group), deposited in presumed considerable water depths. Caution must be observed with the use in the fossil record of lingulids as palaeo-environmental indicators.
Ichthyornis (Aves) from the early Turonian (Late Cretaceous) of Alberta
Authors: Fox Richard C.
Published: November 2010

An isolated left humerus from the Cretaceous toothed bird Ichthyornis is described. The fossil comes from the Vimy Member of the Kaskapau Formation at Watino, Alberta, and is early Turonian in age. The Watino specimen is the oldest well authenticated record of Ichthyornis and the oldest Cretaceous skeletal fossil of a bird from the Western Hemisphere. The wide geographic distribution of Ichthyornis within the Western Interior of North America is in keeping with nomadic habits, as inferred from strongly flying modern marine birds.
An early Proterozoic volcanic arc succession in southeastern Wyoming
Authors: Condie Kent C. , Shadel Craig A.
Published: November 2010

The Green Mountain Formation of early Proterozoic age in the Sierra Madre Range of southeastern Wyoming comprises a bimodal mafic and felsic volcanic assemblage. The rocks, which are chiefly breccias, agglomerates, flows, and volcaniclastic sediments, represent both subaerial and submarine eruptions and in part were redeposited in fluvial and nearshore marine environments. Volcanic rocks are clearly calc-alkaline in character and share a large number of geochemical features in common with continental-margin arcs or evolved oceanic-arc systems.The low Mg numbers and Ni contents of the basalts require 30–40% olivine fractional crystallization, and the high contents of the most incompatible elements, high (La/Sm)N ratios, and low Zr/Nb ratios require an undepleted or enriched mantle source. Geochemical data are consistent with an origin for the felsic volcanics and associated Encampment River granodiorite by shallow fractional crystallization of calc-alkaline basalt in a tectonic setting similar to modern arc systems. The near absence of andesites may reflect the retention of andesitic magma in crustal reservoirs during fractional cyrstallization.
The Freemans Cove volcanic suite: field relations, petrochemistry, and tectonic setting of nephelinite–basanite volcanism associated with rifting in the Canadian Arctic Archipelago
Authors: Mitchell Roger H. , Platt R. Garth
Published: November 2010

The Eocene volcanic suite of the Freemans Cove area of Bathurst Island, Canadian Arctic Archipelago, consists of dikes, sills, small plugs, and agglomeratic vents. Lavas are preserved only as clasts in the vents. The bulk of the magmatism consists of nephelinite or larnite-normative nephelinites and basanites. Subordinate members of the suite include olivine melilite nephelinites, phonolites, and tholeiitic and alkali basalts. The magmatism is bimodal and intermediate rocks are absent. Many of the nephelinites and basanites have the geochemical characteristics of primary magmas, and it is proposed that these members of the suite represent an integrated series of primary melts erupted in an essentially unmodified state from the upper mantle. Other members of the suite are generated by the combined effects of high- and low-pressure differentiation of the primary melts. The igneous rocks are confined to the grabenlike Southeast Bathurst Fault Zone and were emplaced during uplift and compression of the region by the Eurekan rifting episode. The magmatism has the petrological characteristics of intraplate continental magmatism of the type commonly associated with rifting and doming.
Fractionation in the feeder system at a Proterozoic rifted margin
Authors: Bedard Jean H. , Francis Donald M. , Hynes Andrew J. , Nadeau Serge
Published: November 2010

In the Proterozoic Cape Smith Foldbelt of Ungava, Quebec, basal basalts of continental affinity are succeeded upward and basinward by cyclic sequences of MgO-rich (≤ 19 wt.% MgO) to MgO-poor submarine basalts of oceanic affinity belonging to the Chukotat Group. The more primitive komatiitic basalts of the Chukotat Group evolved via fractional crystallization of olivine within a crustal feeder system that is represented by large, layered sills and discordant dyke – sill complexes. These intrusions occupy horizons of mechanical weakness such as sedimentary or hyaloclastite-rich horizons within the volcanic stratigraphy. Peridotite and peridotite – gabbro sills predominate at the base of the Chukotat volcanic pile, whereas gabbroic sills are more common higher in the stratigraphy, reflecting the progressive fractionation within the feeder system. Gravitationally controlled settling of crystals or crystal clots is thought to be the dominant process responsible for fractionation in these crustal sills. Fractional crystallization of olivine within the feeder system produced the olivine-phyric to pyroxene-phyric evolutionary trend observed in the coexisting volcanic rocks. Continuing extraction of clinopyroxene, plagioclase, and iron – titanium oxides in subcrustal sills or magma chambers is thought to have generated the MORB-like upper plagioclase-phyric Chukotat basalts. The compositional gap between the pyroxene-phyric and plagioclase-phyric basalts is a by-product of the fractional crystallization mechanism: liquids with compositions typical of the gap are so highly charged with suspended plagioclase crystals that they resist extrusion.
U–Pb geochronology of minerals from the Midwest uranium deposit, northern Saskatchewan
Authors: Baadsgaard H. , Cummino G. L. , Worden J. M.
Published: November 2010

Analyses of U/Pb ratios in 30 microsamples of pitchblende and coffinite from the Midwest uranium deposit in northern Saskatchewan, as well as two altered zircons from host rocks, indicate an age of mineralization for primary pitchblende of 1328 ± 17 Ma. The primary material was remobilized at 1110 ± 28 Ma, forming the second generation of pitchblende and coffinite. First-generation pitchblende appears to have lost Pb either by diffusion or by a series of episodic losses at 300–100 Ma, whereas the secondary material proved more susceptible to Pb loss in the recent past.There is evidence of migration of pitchblende downwards into the basement rocks under the deposit at least as recently as 700 Ma ago, but we have been unable to date with certainty any late stages in the paragenetic sequence because of sampling problems associated with the small size of material clearly identifiable as stage 3 or 4 of the paragenetic sequence of Wray et al.
The allochthonous origin of the reefal facies of the Stuart Bay Formation (Early Devonian), Bathurst Island, arctic Canada
Authors: Polan Kevin P. , Stearn Colin W.
Published: November 2010

Blocks of limestone and dolomite up to tens of metres across occur near the base of the Lower Devonian (Siegenian–Emsian) Stuart Bay Formation at six sites on eastern Bathurst Island. These blocks occur in groups of up to 30. At the two localities with the greatest number of blocks they are disposed in two or three roughly linear groups reflecting their occurrence on bedding planes. The blocks are mostly wackestones and floatstones and they contain abundant fossils of the reefal biofacies of which stromatoporoids and corals are most prominent.The blocks have weathered from a matrix of finely laminated deep-water siltstone. Most of the blocks are unbedded but where bedding attitudes can be measured they are discordant with that of the siltstone and those of neighbouring blocks. Although they have been described as bioherms that grew in place, the evidence indicates that they are allochthonous blocks derived when several catastrophic events such as earthquakes disturbed a Devonian reef tract developed on the western flank of the Cornwallis Fold Belt.
Why do the Smoking Hills smoke?
Authors: Mathews W. H. , Bustin R. M.
Published: November 2010

In the Smoking Hills area of the Canadian Arctic coast active areas of fire-baked rock or "bocannes" occur in Cretaceous mudstones along sea cliffs and in areas of recent slumping. Extinct and active bocannes are marked by bleaching, baking, and reddening of otherwise dark mudstones. Active bocannes are characterized by fumes of hot sulfurous gas and high ground temperatures. Petrographic, mineralogical, chemical, and calorific analyses indicate that the bocannes are fueled by oxidation of pyrite and (or) organic matter. With heating of the strata by oxidation, combustible gases are driven off that may burn in restricted areas, resulting in localized melting of the strata. The zone of active bocannes is restricted to areas of glacially(?) disturbed strata and landslides, indicating that disruption, rapid exposure, and access to atmospheric oxygen are required to generate the high temperatures. Spontaneous combustion of the exposed strata is facilitated by the very fine particle size and thus large surface area of pyrite, which is framboidal, and organic matter.
Structural and sedimentary history of the Quaco Head area, southern New Brunswick
Authors: Plint A. G. , Poll H. W. van de
Published: November 2010

Remapping of the Quaco Head area of southern New Brunswick has revealed a more complex structure than had been previously documented. The structure is dominated by two major thrust faults that dip to the south and southeast at between 35 and 45°. The lower (younger?) thrust emplaces Precambrian basalts and tuffaceous siltstones (Coldbrook Group) over alluvial sediments of the Boss Point and Tynemouth Creek formations (Westphalian A–B). Resting unconformably on the upper surface of the basalt is a thin layer (≤ 10 m) of marine, basal Windsor Group limestone, disconformably overlain by alluvial conglomerates of inferred Hopewell Group age. This sequence is truncated by an older, southeast-dipping thrust fault, to the southeast of which lie Hopewell conglomerates overturned towards the west and northwest. The latter sequence probably forms the lower limb of a large recumbent fold. Folding and thrusting in the Quaco Head area may have begun during Westphalian B times, although major movement was probably post-Westphalian C and occurred contemporaneously with dextral strike-slip movement on the Minas geofracture. Following this Alleghenian–Variscan deformation, the area underwent deep erosion prior to the deposition of a thick sequence of Triassic alluvial sediments. The more southerly reverse fault was reactivated as a normal fault during a phase of late Triassic or Jurassic faulting along the Bay of Fundy that was probably related to early Atlantic rifting.
Late Devonian – Early Carboniferous volcanism in western Cape Breton Island, Nova Scotia
Authors: Blanchard Marie-Claude , Jamieson Rebecca A. , More Elizabeth B.
Published: November 2010

The Fisset Brook Formation of western Cape Breton Island and its equivalents at MacMillan Mountain and the north Baddeck River are examples of Late Devonian and Early Carboniferous volcanic sequences associated with the formation of post-Acadian successor basins in the northeastern Appalachians. They consist of bimodal basalt–rhyolite suites interbedded with alluvial fan, lacustrine, and rare fluvial sediments. The earliest volcanic products are rhyolites and somewhat evolved basalts associated with coarse sediments, followed by tholeiitic to transitional basalt flows interlayered with lacustrine-type deposits. Geochemical studies on the Fisset Brook Formation indicate extensive remobilization of alkalies, Ca, Rb, and Sr, making these elements inappropriate for determining tectonic setting or magmatic affinity. Use of less mobile elements (Ti, Nb, Y, and Zr) suggests that the basalts are tholeiitic and that the apparent alkalinity of the type section lavas is a result of alteration. We conclude that volcanism in western Cape Breton Island started at MacMillan Mountain and migrated westwards, probably towards the centre of the deepening Magdalen Basin.
Basement-controlled structural fronts forming an apparent major refold pattern in the Yellowknife domain, Slave Province
Authors: Fyson W. K.
Published: November 2010

Trend lines of tight folds (F0 and F1) in Archean metasediments curve across the Yellowknife supracrustal domain to form an apparent major refold pattern. "Hinge traces," marking pronounced changes in trend, extend up to 50 km. More locally, F1 folds are discontinuous and markedly discordant in trend, suggesting that the major hinge traces, rather than simply following axial surfaces, denote structural fronts where fold sets with distinctive initial trends have interacted.Cleavages grouped as S2 and S3, each with subsets, postdate the F1, folds. A regional S3 cleavage strikes parallel to major hinge traces, whereas discontinuous S3 subsets are oblique, some terminating along well defined cleavage fronts. For example, one subset replaces another along a front generally parallel to a hinge trace, or fold front, but offset 1–2 km.The development of the apparent refold pattern and the parallelism of various generations of structural fronts and cleavages can be explained by the response of cover rocks to recurrent strike-slip movements and stress reorientations by faults in the basement.
Bison remains from a Lake Agassiz spit complex in the Swan River valley, Manitoba: depositional environment and paleoecological implications
Authors: Nielsen Erik , Gryba Eugene M. , Wilson Michael C.
Published: November 2010

Fossil bison remains have been recovered from gravels on an extensive spit complex situated between the Upper and Lower Campbell levels of Lake Agassiz in Swan River valley, western Manitoba. Three bone samples yielded radiocarbon dates of 10 300 ± 200 years BP (BGS-617), 9500 ± 150 years BP (BGS-840), and 9400 ± 125 years BP (BGS-887). These are the first dates obtained outside the southern basins of Lake Agassiz for the beginning of the Campbell phase.Local geomorphological evidence and the radiocarbon dates indicate that both Campbell beaches formed within a relatively short time during the Campbell phase. Aside from their geological significance, the bison remains and their depositional context are important for interpreting early Holocene ecology and Paleo-Indian occupation of the Swan River valley.
Ordovician rocks in the Eastcan et al. Freydis B-87 and other wells in offshore Atlantic Canada
Authors: Jenkins W. A. M.
Published: November 2010

Acritarchs and Chitinozoa from the lower 1300 ft (400 m) of the Eastcan et al. Freydis B-87 well, Labrador Shelf, indicate that these strata accumulated in a marine setting during Late Ordovician time. Five or more other exploratory wells on the Labrador Shelf and the Grand Banks of Newfoundland also have encountered Ordovician rocks.
The groundwater hydraulics of seasonal frost mounds, North Fork Pass, Yukon Territory
Authors: Pollard W. H. , French H. M.
Published: November 2010

Seasonal frost mounds occur in the North Fork Pass area in response to increased hydraulic potentials in perennial, spring-fed groundwater systems. Geochemical and isotope analyses indicate that local precipitation is the source of water for flow systems discharging from the springs. The direct measurement of pressure potentials in a number of frost blisters and icing blisters, undertaken in March 1982, gave values ranging from 30 and 81 kPa for mounds approximately 2.0 m high. These pressures exceed theoretical, calculated values and are attributed to the tensile strength of the soil and (or) ice overburden. In genetic terms, seasonal frost mounds should be clearly differentiated from other morphologically similar features such as palsas.
Age of rocks, structures, and metamorphism in the Nagssugtoqidian mobile belt, West Greenland—field and Pb-isotope evidence
Authors: Kalsbeek Feiko , Taylor Paul N. , Henriksen Niels
Published: November 2010

Two kinds of structural domains can be distinguished in the Nagssugtoqidian mobile belt: "Nagssugtoqidian" shear belts, which wrap around large areas in which "pre-Nagssugtoqidian" fold structures are preserved. It has been generally held that nearly all rocks in the Nagssugtoqidian mobile belt and the pre-Nagssugtoqidian fold structures are of Archaean age. We describe field and lead-isotope evidence suggesting that (1) some of the gneisses in the Nagssugtoqidian mobile belt are indeed Archaean, but that gneisses derived from Proterozoic intrusive rocks also occur; (2) most of the supracrustal rocks in the area are probably of Proterozoic rather than Archaean age; (3) the main phase of metamorphism took place at 1880 ± 50 Ma; and (4) most of the structures recognised in the Nagssugtoqidian mobile belt, including the pre-Nagssugtoqidian fold structures, developed during a Proterozoic orogeny that can be broadly correlated with the Hudsonian orogeny in the Canadian Shield.
Thermoluminescence studies on a 14C-dated marine core
Authors: Berger Glenn W. , Huntley D. J. , Stipp Jerry J.
Published: November 2010

We have applied previously proposed methods for the measurement of equivalent radiation doses in sediment to a marine core from off the gulf coast of Florida for which accurate 14C dates are available up to 25 ka. We observe that the thermoluminescence (TL) from the 4–11 μm grains shows two glow peaks throughout the upper 350 cm of core and that accurate TL apparent ages are obtained from only one of these peaks. Two major difficulties encountered were radon loss from dry powders and overestimation of paleodoses for two samples through inappropriate "sunlamp" exposures. The problem of radon loss was overcome by glassing the samples prior to alpha counting; the overestimated paleodoses were reduced by blocking the < 420 nm spectral component of the sunlamp and by using the R–Γ technique.
Freshwater shark teeth as paleoenvironmental indicators in the Upper Pennsylvanian Morien Group of the Sydney Basin, Nova Scotia
Authors: Masson A. Guy , Rust Brian R.
Published: November 2010

Algal limestones in the coal-bearing upper part of the Pennsylvanian Morien Group in the Sydney Basin, Nova Scotia, contain abundant fish fragments. A wide variety is present, including remains of bony fish, lungfish, and sharks. Of these, the most significant environmentally are the lungfish and the teeth and skeletal fragments from freshwater xenacanthid sharks. Their presence confirms the earlier diagnosis of nonmarine conditions derived from the nature of the sedimentary succession and the other biota present. Lithologic and faunal associations suggest that the xenacanthid sharks lived mainly in shallow, alga-bearing lakes on alluvial plains, whereas the bony fish were also tolerant of more restricted swampy environments marginal to the lakes.
Bergstroemograptus n. gen. crawfordi (Harris) from the Ordovician of western Newfoundland
Authors: Finney Stanley C. , Xu Chen
Published: November 2010

Specimens of Cardiograptus crawfordi Harris from the middle Table Head Formation on Port-au-Port Peninsula display a partially monopleural arrangement of the two thecal series. This feature and the rhabdosome size and shape make C. crawfordi so different from the genotype of Cardiograptus that it can no longer be retained in that genus. The Port-au-Port specimens are identical to isolated specimens from the middle Table Head Formation at Daniel's Harbour previously identified as Skiagraptus sp., especially with regard to the partially monopleural construction. However, Australian specimens of the genotype of Skiagraptus probably have a dipleural arrangement. Thus, the Newfoundland specimens cannot be assigned to that genus. The proximal-end development of C. crawfordi is very different from that of Apoglossograptus and Kalpinograptus, the other graptolites with partially monopleural arrangements. Therefore, a new genus, here named Bergstroemograptus, is defined for it. Bergstroemograptus represents an independent line of graptolite evolution in which a partially monopleural rhabdosome is attained.