Geology of the Parliament Buildings 5: Geology of the Manitoba Legislative Building

The Manitoba Legislative Building was designed by Frank Worthington Simon, assisted by Henry Boddington III, architects from Liverpool, England. The building style is neoclassical, incorporating Greek, Roman and Egyptian motifs and elements. Construction was completed early in 1920 and the building was dedicated July 15, 1920, on the fiftieth anniversary of the Province. The building is located in central Winnipeg, close to the north bank of the Assiniboine River and rests on 14 m of glacial Lake Agassiz clays over till and limestone bedrock. The mass of the building is supported by 421 concrete caissons that extend through the clays to indurated till or bedrock. Steel frames rest on the caissons and support bearing walls constructed of bricks manufactured from Manitoba shale and clay. Dimension stones decorate the bearing walls inside and outside, and the floors and stairways within. Each type of stone has its own decorative characteristics and each records geologic processes at different times in Earth history. The predominant dimension stone both outside and inside the building is Manitoba Tyndall Stone. Grey, pink and red Tennessee marbles are from the southern Appalachians. Botticino marble was quarried in the foothills of the Alps in northern Italy. Ordovician black marble and Verde Antique are from the Vermont-New York region in the northern Appalachians. Missisquoi marble is from quarries in southern Québec near Philipsburg, and also represents a northern Appalachian source. Bedford limestone, used for most of the statuary, is from south-central Indiana. Butler granite from Ignace, Ontario, was used for steps and floor surfaces of all four porticos. Red marble breccia, used to decorate most fireplaces, may have come from northern France. SUMMAIRE L'édifice du Palais législatif du Manitoba a été conçu par Frank Worthington Simon, assisté de Henry Boddington III, deux architectes de Liverpool en Angleterre. Il s'agit d'un édifice de style néoclassique comprenant des éléments et des motifs grecs, romains et égyptiens. Sa construction s'est achevé au début des années 1920 et son inauguration a eu lieu à l'occasion du cinquantième anniversaire de la Province, soit le 15 juillet 1920. L'édifice est situé au cœur de Winnipeg, non loin de la rive nord de la rivière Assiniboine, la géologie environnante consistant en une couche d'argile du lac Agassiz de 14 m d'épaisseur reposant sur du till et un socle calcaire. Le poids de l'édifice repose sur 421 caissons de béton qui s'enfoncent jusqu'au till consolidé ou jusqu'au socle. Des structures d'acier appuyées sur ces caissons supportent le poids des murs de briques fabriquées avec des schistes argileux et des argiles du Manitoba. Des pierres de taille parent les murs porteurs à l'extérieur comme à l'intérieur ainsi que les planchers et les escaliers intérieurs. Chaque type de pierre de taille présente des caractéristiques particulières, et chacun témoigne de processus géologique d'une époque particulière de l'histoire de la Terre. La pierre de Tyndall est celle qui prédomine tant à l'extérieur qu'à l'intérieur. Les marbres gris, roses et rouges du Tennessee proviennent du Sud de la chaîne des Appalaches. Les marbres de Botticino ont été extraits du piémont des Alpes dans le Nord de l'Italie. Les marbres noirs et les porphyres verts antiques proviennent des États du Vermont et de New York, au Nord des Appalaches. Les marbres de Missisquoi ont été extraits de carrières du Sud du Québec près de Phillipsburg proviennent aussi du Nord des Appalaches. Les calcaires de Bedford qui ont été principalement utilisés comme matériau statuaire proviennent du centre-sud de l'État d'Indiana. Les granites de Butler provenant de Ignace en Ontario ont été utilisés pour les marches et les planchers des quatre portiques. La brèche de marbre rouge qui a été utilisée pour la décoration de la plupart des foyers pourrait provenir du Nord de la France

Second-Order Nonlinear Mixing of Two Modes in a Planar Photonic Crystal Microcavity

Polarization-resolved second-harmonic spectra are obtained from the resonant modes of a two-dimensional planar photonic crystal microcavity patterned in a free-standing InP slab. The photonic crystal microcavity is comprised of a single missing-hole defect in a hexagonal photonic crystal host formed with elliptically-shaped holes. The cavity supports two orthogonally-polarized resonant modes split by 60 wavenumbers. Sum-frequency data are reported from the nonlinear interaction of the two coherently excited modes, and the polarization dependence is explained in terms of the nonlinear susceptibility tensor of the host InP.Comment: 7 pages, 8 Postscript figures, to be presented at Photonics West Jan. 2

Energy Deposition of Energetic Silicon Atoms Within a Silicon Lattice

The energy dependence of the ionization produced in silicon by recoiling silicon atoms was measured in the 4–54-keV energy interval. It is found that the fraction of the recoil energy that is dissipated as ionization follows an E1/2 dependence which agrees well with the predictions of the theory of Lindhard et al. [Mat. Fys. Medd. 33, 10 (1963)]

Spin diffusion in doped semiconductors

The behavior of spin diffusion in doped semiconductors is shown to be qualitatively different than in undoped (intrinsic) ones. Whereas a spin packet in an intrinsic semiconductor must be a multiple-band disturbance, involving inhomogeneous distributions of both electrons and holes, in a doped semiconductor a single-band disturbance is possible. For n-doped nonmagnetic semiconductors the enhancement of diffusion due to a degenerate electron sea in the conduction band is much larger for these single-band spin packets than for charge packets, and can exceed an order of magnitude at low temperatures even for equilibrium dopings as small as 10^16 cm^-3. In n-doped ferromagnetic and semimagnetic semiconductors the motion of spin packets polarized antiparallel to the equilibrium carrier spin polarization is predicted to be an order of magnitude faster than for parallel polarized spin packets. These results are reversed for p-doped semiconductors.Comment: 8 pages, 4 figure

BLAST: The Mass Function, Lifetimes, and Properties of Intermediate Mass Cores from a 50 Square Degree Submillimeter Galactic Survey in Vela (l = ~265)

We present first results from an unbiased 50 deg^2 submillimeter Galactic survey at 250, 350, and 500 micron from the 2006 flight of the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). The map has resolution ranging from 36 arcsec to 60 arcsec in the three submillimeter bands spanning the thermal emission peak of cold starless cores. We determine the temperature, luminosity, and mass of more than one thousand compact sources in a range of evolutionary stages and an unbiased statistical characterization of the population. From comparison with C^(18)O data, we find the dust opacity per gas mass, kappa r = 0.16 cm^2 g^(-1) at 250 micron, for cold clumps. We find that 2% of the mass of the molecular gas over this diverse region is in cores colder than 14 K, and that the mass function for these cold cores is consistent with a power law with index alpha = -3.22 +/- 0.14 over the mass range 14 M_sun < M < 80 M_sun. Additionally, we infer a mass-dependent cold core lifetime of t_c(M) = 4E6 (M/20 M_sun)^(-0.9) years - longer than what has been found in previous surveys of either low or high mass cores, and significantly longer than free fall or likely turbulent decay times. This implies some form of non-thermal support for cold cores during this early stage of star formation.Comment: Accepted for publication in the Astrophysical Journal. Maps available at http://blastexperiment.info

How Universal is the Relationship Between Remotely Sensed Vegetation Indices and Crop Leaf Area Index? A Global Assessment

Leaf Area Index (LAI) is a key variable that bridges remote sensing observations to the quantification of agroecosystem processes. In this study, we assessed the universality of the relationships between crop LAI and remotely sensed Vegetation Indices (VIs). We first compiled a global dataset of 1459 in situ quality-controlled crop LAI measurements and collected Landsat satellite images to derive five different VIs including Simple Ratio (SR), Normalized Difference Vegetation Index (NDVI), two versions of the Enhanced Vegetation Index (EVI and EVI2), and Green Chlorophyll Index (CI(sub Green)). Based on this dataset, we developed global LAI-VI relationships for each crop type and VI using symbolic regression and Theil-Sen (TS) robust estimator. Results suggest that the global LAI-VI relationships are statistically significant, crop-specific, and mostly non-linear. These relationships explain more than half of the total variance in ground LAI observations (R2 greater than 0.5), and provide LAI estimates with RMSE below 1.2 m2/m2. Among the five VIs, EVI/EVI2 are the most effective, and the crop-specific LAI-EVI and LAI-EVI2 relationships constructed by TS, are robust when tested by three independent validation datasets of varied spatial scales. While the heterogeneity of agricultural landscapes leads to a diverse set of local LAI-VI relationships, the relationships provided here represent global universality on an average basis, allowing the generation of large-scale spatial-explicit LAI maps. This study contributes to the operationalization of large-area crop modeling and, by extension, has relevance to both fundamental and applied agroecosystem research

New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary

Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous

Design of 280 GHz feedhorn-coupled TES arrays for the balloon-borne polarimeter SPIDER

We describe 280 GHz bolometric detector arrays that instrument the balloon-borne polarimeter SPIDER. A primary science goal of SPIDER is to measure the large-scale B-mode polarization of the cosmic microwave background in search of the cosmic-inflation, gravitational-wave signature. 280 GHz channels aid this science goal by constraining the level of B-mode contamination from galactic dust emission. We present the focal plane unit design, which consists of a 16$\times$16 array of conical, corrugated feedhorns coupled to a monolithic detector array fabricated on a 150 mm diameter silicon wafer. Detector arrays are capable of polarimetric sensing via waveguide probe-coupling to a multiplexed array of transition-edge-sensor (TES) bolometers. The SPIDER receiver has three focal plane units at 280 GHz, which in total contains 765 spatial pixels and 1,530 polarization sensitive bolometers. By fabrication and measurement of single feedhorns, we demonstrate 14.7$^{\circ}$ FHWM Gaussian-shaped beams with $<$1% ellipticity in a 30% fractional bandwidth centered at 280 GHz. We present electromagnetic simulations of the detection circuit, which show 94% band-averaged, single-polarization coupling efficiency, 3% reflection and 3% radiative loss. Lastly, we demonstrate a low thermal conductance bolometer, which is well-described by a simple TES model and exhibits an electrical noise equivalent power (NEP) = 2.6 $\times$ 10$^{-17}$ W/$\sqrt{\mathrm{Hz}}$, consistent with the phonon noise prediction.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 201