48 research outputs found
Nickel and osmium isotope and trace element geochemistry of organic-rich sedimentary rocks: The first investigation of Ni isotope systematics in marine sediments
No full textUnderstanding the chemical composition of organic-rich marine sediments has the potential to: 1) allow evaluation of variations in ocean chemistry, enabling assessment of changes in global processes throughout geological time; and 2) provide an increased temporal and spatial understanding of petroleum systems. Herein two geologically distinct organic-rich sedimentary formations are explored utilising trace elements, and rhenium-osmium (Re-Os) and nickel (Ni) isotope systematics. Additionally, this thesis is the first study to investigate the behaviour of Ni isotope systematics in organic-rich marine sediments.
Osmium isotope profiling across the Sinemurian-Pliensbachian boundary GSSP indicates that there was a significant contribution of unradiogenic Os to the oceans at this time. Seawater 187Os/188Os(i) values range from ~0.20 – 0.48, becoming increasingly unradiogenic up-section. This progressive change in ocean chemistry is coincident with flooding of the Hispanic Corridor, formed during rifting of the Pangean supercontinent and creation of the Central Atlantic Ocean, evident from sudden levels of faunal exchange between the eastern Pacific and western Tethyan oceans. The Os isotope signal here reflects the onset of hydrothermal activity associated with formation of the Hispanic Corridor.
New Ni stable isotope data presented herein for the Sinemurian-Pliensbachian (S-P) GSSP and the Devonian-Mississippian Exshaw Formation, demonstrates that organic-rich marine sediments are characterised by δ60Ni values that are distinct to those of extraterrestrial and abiotic terrestrial samples. Further, the level of Ni isotope fractionation in organic-rich sediments (ranging from ~1.32 ‰ in the S-P sediments, and ~2.04 ‰ in the Exshaw Formation) is far greater than that seen in the other sample suites (ranges of ~0.17 – 0.37 ‰; Cameron et al., 2009). Although there are limited datasets available for comparison at present, the ranges of δ60Ni values for the S-P GSSP and Exshaw Formation are similar (0.28 ± 0.05 to 1.60 ±0.05 ‰ and 0.46 ± 0.04 to 2.50 ± 0.04 ‰, respectively), suggesting that such variation in Ni isotope fractionation may be characteristic of organic-rich sediments. This may be due to complexities that are ubiquitous to the sediment-seawater depositional environment. In addition, trace element ratios utilised to establish depositional paleoredox conditions demonstrate that redox did not exert control on the level of Ni isotope fractionation observed in these sediments. The study herein also demonstrates that thermal maturation of the Exshaw Formation has a negligible effect on Ni isotope systematics in mature source rocks, strongly suggesting that Ni isotopes may have the potential to be developed as an oil-source correlation tool
Structural Relationships between the Exshaw Thrust and Heart Mountain syncline, Exshaw, Alberta
No full text Displacement transfer between faults and folds has been extensively documented in the Rocky Mountains as an explanation for structural variability along strike producing seemingly similar overall shortenings. A series of subparallel imbricate thrusts and an associated syncline in the Southern Canadian Front ranges at Heart Mountain has been mapped at a scale of 1:16,667. Megascopic, mesoscopic and microscopic evidence supports the contention that the folding observed at Heart Mountain occurred synchronously with thrusting as the result of displacement transfer from the adjacent thrust. Numerical dynamic analyses (NDA) suggest that twinning of calcite grains occurred very early in the deformational history in response to a regional stress field orientation of 246/03, 340/02, and 159/84 for o 1, o2 , and 03 respectively in the Exshaw plate. Megascopic and mesoscopic fabrics indicate similar results. Ambiguous NDA results for the Heart Mountain Syncline are explained using neutral surface folding theories rather than flexural slip theories generally proposed for folding within the Front Ranges. Neutral surface folds are consistent with the deformational model (displacement transfer) proposed. An orthogonal fracture system is pervasive throughout the thesis area. Observations indicate that fractures are oriented parallel and perpendicular to the strike of the Rocky Mountains. Their development is inferred to have taken place in the same regional stress field thought to be responsible for twinning, with fracture opening occurring after the relaxation of tectonic stresses and the removal of substantial amounts of overburden. ThesisBachelor of Science (BSc
A Semi-Lumped Miniaturized Spurious Less Frequency Tunable Three-port Divider\Combiner with 20 dB Isolation Between Output Ports
No full textWe propose a new topology based on a semilumped
complex impedance transformer for the design of a
frequency tunable three-port power divider. A prototype has
been realized in a hybrid technology with commercially available
varactor diodes. Our design is based on an impedance
transformer in the input branch (with electrical length of 20.4°),
and a loop in the output branches (with electrical length of
2x24°). This leads to a miniaturized device, more than two times
shorter than a classical Wilkinson power divider. This divider
can be tuned over ±30% around 1.35 GHz (from 0.95 GHz to
1.75 GHz) with insertion loss lower than 0.3 dB, return loss better
than 20 dB and isolation between the two output ports better
than 20 dB. Moreover, the low-pass behavior of the input
impedance transformer leads to a good rejection of the second
harmonic
Searching For a Home - Hauzenberger, Edward and Frieda Family
No full textNotes - Freda Wood provides a brief history of her family, the Hauzenberqers, who immigrated to Alberta from Switzerland in 1912. Her father, Edward Hauzenberqer was born in Switzerland on April 22, 1883. Her mother, Frieda, was born on June 19, 1885, also in Switzerland. They were married in January of 1912 and immigrated to Canada the same year. They lived in Battle River County, St. Paul, Exshaw, and Calgary, before Edward, Freda (daughter) and family moved up to Athabasca. Freda married Emile Gosselin in 1933 and had two children. The family moved up to Athabasca, where Freda would teach at the South Athabasca School in 1945. Emile passed away that year, and Freda remarried Bill Wood the next year. Bill and Freda had three children together. Freda taught for 35 years in the Athabasca area. Freda's mother, Frieda passed away in 1960. After that, Edward discovered there were still homesteads available north of Athabasca. He purchased a piece of land for himself and moved a caboose up there to live in. While living out there Edward had many adventures with bears, deer and Athabasca nature. When living on the land got to be too much, he moved in with Bill and Freda. He died at the age of ninety-three (6 pages
Sedimentary record of Devonian-Mississippian carbonate and black shale systems, southernmost Canadian Rockies and adjacent Montana: Facies and processes
No full textAge-environment relationships and depositional conditions of uppermost Devonian and Lower Mississippian strata in the southernmost Canadian Rockies were evaluated.
During early and middle Famennian time, the region was the site of a westward-deepening carbonate ramp that was bordered to the west by a deep basin. The middle-late Famennian exhibited the termination of carbonate ramp sedimentation and the ultimate deposition of organic-rich sediments under oxygen-stressed conditions is shelfal to basinal environments (Exshaw Formation). Widespread oxygen deficiency in the late Famennian accompanied an aerially extensive transgression.
Sedimentation of anaerobic to marginally aerobic, deep-water, lower Banff facies occurred intermittently into the middle Tournaisian, and locally into the late Tournaisian prior to the westward progradation of ramp carbonates of the middle and upper Banff. Deep-water units include sequences of biogenic chert, black and gray shale, phosphatic and siliceous mudstone, and glauconitic and phosphatic clastics. The upper Banff bioclastic carbonates contain late Tournaisian bactrognathid-hindeodid faunas indicative of shallower ramp/shelf settings. Quartzofeldspathic clastics in the Exshaw and Banff reflect the periodic influx of detritus from a likely western orogenic source from the late Famennian into the late Tournaisian.
Degree of bottom water oxygenation during deposition of the low-oxygen facies of the Exshaw and Banff formations was recognized using ichnofabric, organic carbon and sulfur relationships, and degree of pyritization (DOP). Anaerobic, laminated, and amorphinite-rich black shales with high DOP values lack a macrobenthos with the notable exception of rare concentrations of inarticulate brachiopods on bedding planes. Dysaerobic to marginally aerobic facies have intermediate DOP values and a gradient of increasing degree of bioturbation. A framework model for the widespread deposition of these sediments entails the initial flooding of epicontinental/shelf seas with water derived from an expanded and intensified oxygen minimum zone during the late Famennian transgression. Within this framework, the complex interaction of factors such as increased shelf area, promotion of organic productivity, and relative sea level changes controlled the environmental gradients and distribution of low-oxygen facies. (Abstract shortened with permission of author.
Optoelectronic code division multiplexing using a dual drive external modulator for encoding
No full textInternational audienc
The dupe, [electronic resource] : A comedy. As it is now acting at the Theatre-Royal in Drury Lane. By His Majesty's servants. By the author of the discovery.
No full textAuthor of The discovery = Mrs. Frances Sheridan.With an epilogue.Epilogue reported by O, D & MRu.Electronic reproduction.English Short Title Catalog,Reproduction of original from British Library
A Compact Semi-Lumped Tunable Complex Impedance Transformer
No full textInternational audienceThis article describes the design and performance of a compact tunable impedance transformer. The structure is based on a transmission line loaded by varactor diodes. Using only two pairs of diodes, the circuit is very small with a total length of only λ/10. Both the frequency range and the load impedance can be tuned by varying the varactor bias voltages. Our design provides a tunable operating frequency range of ± 40% and an impedance match ranging from 20 Ω to 90 Ω at 0.8 GHz and from 30 Ω to 170 Ω at 1.5 GHz. In addition, a new approach that considers losses for the simulation and measurement of this impedance transformer was investigated. The measured performance of a 1 GHz prototype design confirmed the validity of this new approach
A Semi-Lumped Miniaturized Spurious Less Frequency Tunable Three-port Divider\Combiner with 20 dB Isolation Between Output Ports
No full textInternational audienceWe propose a new topology based on a semi-lumped complex impedance transformer for the design of a frequency tunable three-port power divider. A prototype has been realized in a hybrid technology with commercially available varactor diodes. Our design is based on an impedance transformer in the input branch (with electrical length of 20.4°), and a loop in the output branches (with electrical length of 2x24°). This leads to a miniaturized device, more than two times shorter than a classical Wilkinson power divider. This divider can be tuned over ±30% around 1.35 GHz (from 0.95 GHz to 1.75 GHz) with insertion loss lower than 0.3 dB, return loss better than 20 dB and isolation between the two output ports better than 20 dB. Moreover, the low-pass behavior of the input impedance transformer leads to a good rejection of the second harmonic
A new Roman history, by question and answer. [electronic resource] : In a method much more comprehensive than any of the Kind extant. Extracted from ancient authors, and the most celebrated among the modern, And Interspersed with such Customs as serve to Illustrate the History. With a complete index. Designed principally for Schools. By the author of the History of England by question and answer.
No full textAuthor of the History of England = John Lockman.Electronic reproduction.English Short Title Catalog,Reproduction of original from British Library
