Thesis (Ph. D.)--University of Wisconsin--Madison, 1988. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 169-188).

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 304-316). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph.D.) -- Memorial University of Newfoundland. / Typescript. Bibliography: leaves 263-283. Also available online.

Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Restricted until June 1999. Bibliography: leaves 195-106. Also available online.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Six maps and diagrams on folded leaves in pocket. Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 380-389).

The northerly trending Hozameen, Yale and Hope faults transect the northwesterly trending Custer Gneiss and Hozameen, Ladner and Jackass Mountain Groups. Yale Fault separates gneisses of the Hozameen Group to the east from Custer Gneiss to the west. The Custer Gneiss, as herein restricted, is compositionally distinct from the Hozameen Group and shows a period of early deformation not present in the Hozameen Group. During the Cretaceous, regional deformation and greenschist facies metamorphism of the biotite zone affected rocks between the Yale and Hozameen faults. These rocks grade into gneisses of the hornblende hornfels facies within a few hundred yards of the Spuzzum Quartz Diorite and Yale Intrusions. This restricted contact metamorphism contrasts with the widespread, high temperature and pressure metamorphism found in this and other areas around the Spuzzum Quartz Diorite on the west side of the Hope fault. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Pelitic metasediments immediately southwest of Yale, British Columbia contain mineral assemblages characteristic of staurolite through sillimanite zones of the Barrovian facies series. Isograds are steeply dipping. Two phases of deformation are recognized with metamorphism being syn- to post-tectonic. Pseudomorphs after andalusite indicate that contact metamorphism preceded regional upgrading of the pelites. Microprobe analyses of major silicate phases in the pelites are combined with linear regression techniques in discussing possible kyanite- and sillimanite-forming reactions. A zone some 3 kilometers wide contains the assemblage staurolite-kyanite-garnet-biotite-muscovite-quartz which is univariant in AFM projection. Regression analysis of the staurolite-kyanite assemblage reveals the sensitivity of regression methods to error limits associated with the different minerals present. Precision of the analyses was not high enough for regression analysis to differentiate between stable, divariant equilibrium and a buffered, univariant reaction relation for this assemblage. Pelitic and calc-silicate assemblages from the metasediments restrict pressure-temperature conditions during regional metamorphism to 5½-8 kilobars and 550-700°C. It is suggested that deformation, emplacement of granitic intrusions, and regional metamorphism are all part of the Cretaceous orogeny which formed structures of the Cascades Mountains. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

D.Phil. / Please refer to full text to view abstract

To constrain the thermal histories of two complex L chondrite melt breccia samples (NWA 5964 and NWA 6580) we compare textures and chemical compositions of metal and sulfide to L melt rock (NWA 6454 and NWA 6579) and strongly shocked (shock stage S6) (NWA 4860) samples. The inferred thermal histories can be used to evaluate formation settings on the L chondrite parent body. The L melt samples probably formed as different melt units within warm but largely unmelted material relatively close to the surface of the parent body, and the same is true for the S6 sample, except it experienced less melting. The breccia samples likely formed deeper, below different impact craters, by the injection of shock melt into a cooler chondritic basement. Carbide grains in the melt breccias could have formed by a contact metamorphic process caused by heating of the chondritic basement in proximity to the melt. Within the melt regions of the various samples, inferred cooling rates are on the order of 1-10 °C/sec, whereas in the chondritic portions of the melt breccias, the inferred cooling rates are many orders of magnitude slower, ~1-100 °C/My. The complex intergrowths of metal and FeS (hereafter referred to as dendritic grains) within the melt are recording cooling rates above the metal-sulfide eutectic, while the metal grains outside of the melt regions are recording cooling rates at much lower temperatures. It is likely the melt regions in the breccias cooled substantially prior to coming to rest against the chondritic basement, and thereafter the melt-chondrite rocks cooled more slowly.

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