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Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Morphological And Structural Mapping Of The Oudemans Impact Crater Layered Central Uplift, Mars, Bahareh Kasmai Dec 2014

Morphological And Structural Mapping Of The Oudemans Impact Crater Layered Central Uplift, Mars, Bahareh Kasmai

Electronic Thesis and Dissertation Repository

Central uplifts in large meteorite impact craters provide valuable information about the subsurface geology of planetary bodies. Compared to impact craters on Earth, Martian central uplifts can be well exposed and can be mapped in detail by using satellite imagery. Central uplifts preserve morphological and structural features formed as result of the combination of emplacement during the impact process, post impact modification, and erosion over time. In this study, the Oudemans Crater central uplift (the largest central uplift with layers on Mars) was investigated. Oudemans (9.89 S, 268.1 E) is 124 km in diameter and is located in the Sinai …


Controls On Syenite-Hosted Gold Mineralization In The Western Timmins Camp, Robert A. Campbell Nov 2014

Controls On Syenite-Hosted Gold Mineralization In The Western Timmins Camp, Robert A. Campbell

Electronic Thesis and Dissertation Repository

The Abitibi granite-greenstone belt has long been known for its’ world-class Archean

lode gold deposits. With exploration and production commencing in the early nineteen

hundreds and continuing into the twenty-first century, this prolific mining camp is rich

in history, research and precious/base metals. The Thunder Creek deposit and Hwy-144 gold prospect are two recently discovered and exploited syenite associated gold plays in the Timmins Camp. The research compares the Thunder Creek and Hwy-144 properties providing new observations on the variable mechanisms for gold mineralization that can change over a short strike distance (0.5-1.5 km’s) hosted in a geologically similar environment. …


Glacial Stratigraphy Of The Ridge River Area, Northern Ontario: Refining Wisconsinan Glacial History And Evidence For Laurentide Ice Streaming, Maurice Nguyen Sep 2014

Glacial Stratigraphy Of The Ridge River Area, Northern Ontario: Refining Wisconsinan Glacial History And Evidence For Laurentide Ice Streaming, Maurice Nguyen

Electronic Thesis and Dissertation Repository

Detailed field studies of Quaternary sediments were undertaken during the summer of 2012 in the remote Ridge River area of the Hudson Bay Lowland. Grain size, carbonate, stone lithologic analyses and stratigraphic relations of 31 sites were compiled and revealed two main till units likely deposited by the advance and retreat of the Laurentide Ice Sheet. Based grain size, carbonate, and lithologic data the tills cannot be distinguished and the abundance of distantly transported stones suggests rapid flux of glacial debris from Quebec over the Hudson Platform to the study area. Evidence from stone fabrics, striae, and glaciotectonic structures in …


Peat As An Archive Of Remote Mercury Deposition In The Hudson Bay Lowlands, Ontario, Canada, William James Goacher Aug 2014

Peat As An Archive Of Remote Mercury Deposition In The Hudson Bay Lowlands, Ontario, Canada, William James Goacher

Electronic Thesis and Dissertation Repository

Peat from the Hudson Bay Lowlands (HBL) in Northern Ontario, Canada was used to reconstruct historical accumulation of mercury (Hg) over more than 7000 years before present. Nine cores, many with previously published paleoclimate studies, were analyzed for Hg and accumulation rates were calculated. Anthropogenic Hg enrichment factors were calculated based on accumulation rates. A more exclusive calculation of the anthropogenic enrichment factor corroborates modelling efforts that have suggested re-cycling legacy Hg is a much greater contributor to present day deposition than previously thought, but not prior to ~500 cal yrs BP. An older pre-industrial record provides a better background …


The Development Of L-Tectonites In High-Strain Zone Settings: A Multiscale Modeling Investigation, Weiyin Chen Aug 2014

The Development Of L-Tectonites In High-Strain Zone Settings: A Multiscale Modeling Investigation, Weiyin Chen

Electronic Thesis and Dissertation Repository

Shape fabrics in high-strain zones are commonly used to constrain deformation processes in the lithosphere. Linear fabric, as a type of shape fabric, usually indicates constrictional strain and is an important feature in orogenic belts. Among all kinds of linear fabrics, the isolated L-tectonites, which are surrounded by strong planar fabrics, are poorly understood. The isolated L-tectonites are generally developed in heterogeneous high-strain zones. Their formation involves heterogeneous and multiscale deformation processes that current single-scale kinematic models cannot explain. To relate isolated L-tectonites in a high-strain zone with its boundary conditions, I apply a multiscale approach. Isolated L-tectonites are regarded …


Automated Image Interpretation For Science Autonomy In Robotic Planetary Exploration, Raymond Francis Aug 2014

Automated Image Interpretation For Science Autonomy In Robotic Planetary Exploration, Raymond Francis

Electronic Thesis and Dissertation Repository

Advances in the capabilities of robotic planetary exploration missions have increased the wealth of scientific data they produce, presenting challenges for mission science and operations imposed by the limits of interplanetary radio communications. These data budget pressures can be relieved by increased robotic autonomy, both for onboard operations tasks and for decision- making in response to science data.

This thesis presents new techniques in automated image interpretation for natural scenes of relevance to planetary science and exploration, and elaborates autonomy scenarios under which they could be used to extend the reach and performance of exploration missions on planetary surfaces.

Two …


Shock Metamorphic Effects In Lunar And Terrestrial Plagioclase Feldspar Investigated By Optical Petrography And Micro-X-Ray Diffraction, Annemarie E. Pickersgill Jun 2014

Shock Metamorphic Effects In Lunar And Terrestrial Plagioclase Feldspar Investigated By Optical Petrography And Micro-X-Ray Diffraction, Annemarie E. Pickersgill

Electronic Thesis and Dissertation Repository

Shock metamorphism, caused by hypervelocity impact, is a poorly understood process in feldspar. This thesis addresses: a) developing a quantitative scale of shock deformation in plagioclase feldspar; b) expanding the utility of plagioclase feldspar for determining shock level; and c) micro-X-ray diffraction as a technique with which to study shock in feldspar.

Andesine and labradorite from the Mistastin Lake impact structure, Labrador, Canada, and anorthite from Earth’s moon, returned during the Apollo program, show shock effects such as diaplectic glass. Planar deformation features are absent in plagioclase, but abundant in terrestrial quartz. A pseudomorphous zeolite phase (levyne-Ca) was identified as …


Shear Zone Influence On The Emplacement Of A Giant Pegmatite: The Whabouchi Lithium Pegmatite, Quebec,Canada, Laurisha Bynoe Apr 2014

Shear Zone Influence On The Emplacement Of A Giant Pegmatite: The Whabouchi Lithium Pegmatite, Quebec,Canada, Laurisha Bynoe

Electronic Thesis and Dissertation Repository

The Whabouchi pegmatite is within a transpressional high-strain zone of a metamorphosed volcano-sedimentary belt. A well-developed subvertical transposition foliation and a subvertical stretching lineation are present in this zone. The main body of the Whabouchi pegmatite is parallel to the transposition foliation and branching veinlets from this body have been folded and boudinaged by shear zone deformation. Thus suggesting that the Whabouchi pegmatite intruded syn-kinematically during the deformation of the shear zone. Previously, the Whabouchi pegmatite gave a zircon age of 2577 + 14Ma. The Whabouchi pegmatite is linked geochemically and geochronologically to a large pegmatite body to the south …


The Aricheng Basement-Hosted Albitite-Type Uranium Deposit, Roraima Basin, Co-Operative Republic Of Guyana, South America., Jim A. Renaud Apr 2014

The Aricheng Basement-Hosted Albitite-Type Uranium Deposit, Roraima Basin, Co-Operative Republic Of Guyana, South America., Jim A. Renaud

Electronic Thesis and Dissertation Repository

The Kurupung batholith is situated in a west dipping mylonite zone within theTransamazonian-aged Mazaruni granite greenstone terrane. Mylonitic shearing is a result of regional sinistral strike-slip faulting during the post-collisional stage of the Transamazonian orogenic cycle. Deformation was active between 2103 +/- 3 Ma, the age of the batholith, and 1995 +/- 15 Ma, the age of hydrothermal uranium and zircon mineralization. Mineral chemical and geochemical characterization of the batholith identifies a uranium-enriched low-Ti sanukitoid generated by partial melting of slab metasomatized mantle which retained unresorbed Cr-bearing mantle inclusions. Rapid unroofing to greenschist facies conditions at approximately 2094 +/- 5 …


Micro-Computed Tomography Semi-Empirical Beam Hardening Correction: Method And Application To Meteorites, David R. Edey Feb 2014

Micro-Computed Tomography Semi-Empirical Beam Hardening Correction: Method And Application To Meteorites, David R. Edey

Electronic Thesis and Dissertation Repository

X-ray micro-computed tomography (μCT) is able to non-destructively provide high- resolution 3D images of the internal structures of dense materials such as meteorites. The widespread availability of instruments capable of biomedical micro-computed tomography means there is ample access to scanners for the investigation of geomaterials, but the scan data can be susceptible to artifacts such as beam hardening, a consequence of high X-ray attenuation in these dense materials.

A semi-empirical correction method for beam hardening and scatter that can be straightforwardly applied to available biomedical scanners is proposed and evaluated. This method uses aluminum as a single calibration material to …


The Latte Gold Zone, Kaminak's Coffee Gold Project, Yukon, Canada: Geology, Geochemistry, And Metallogeny, Eric Buitenhuis Jan 2014

The Latte Gold Zone, Kaminak's Coffee Gold Project, Yukon, Canada: Geology, Geochemistry, And Metallogeny, Eric Buitenhuis

Electronic Thesis and Dissertation Repository

The Latte Gold Zone is hosted within complexly tectonically imbricated metamorphic rocks of the Yukon-Tanana terrane. Snowcap assemblage psammitic schist and amphibolite with exotic Slide Mountain ultramafics overthrusts unidentified arc metavolcanics which in turn overthrust the Late Permian Sulphur Creek orthogneiss. Rapid unroofing of the Dawson Range during the Mid-Cretaceous culminated in dextral movement along the Coffee Creek fault system. A set of stacked, ESE–WNW trending, steeply dipping brittle fault structures served as conduits for gold-bearing fluids. Core-logging, detailed petrography, microprobe analysis, and PIMA investigations indicate that Latte is an epizonal orogenic gold deposit. Gold is hosted within arsenian pyrite …


A Detailed Metallogenic Study Of The Mcfaulds Lake Chromite Deposits, Northern Ontario, Jordan E. Laarman Jan 2014

A Detailed Metallogenic Study Of The Mcfaulds Lake Chromite Deposits, Northern Ontario, Jordan E. Laarman

Electronic Thesis and Dissertation Repository

The Black Label, Black Thor and Big Daddy chromite deposits are a series of chromitite layers that are hosted by the 2734.5 +/-1.0 Ma ‘Ring of Fire’ Intrusion in the McFaulds Lake greenstone belt of Northern Ontario. Over 4200 electron microprobe analyses and 142 laser ablation ICP-MS analyses were performed on chromite and record individual fractionation sequences of chromitite below the metre scale. In comparing results, the dunite-hosted Black Thor chromites are higher grade with 53 to 49 wt. % Cr2O3, more primitive than Black Label chromites at 50 to 46 wt. % Cr2O …