Thesis (Ph.D.)--Memorial University of Newfoundland. / Restricted until October 1996. Typescript. Bibliography: leaves [223]-239. Also available online.

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 181-195. Also available online.

Thesis (M.S. in Earth and Environmental Sciences)--Vanderbilt University, May 2006. / Title from title screen. Includes bibliographical references.

The Ajax-Monte Carlo property is a small porphyry copper deposit located approximately six miles south of Kamloops, British Columbia on the south flank of the Iron Mask Batholith. The Batholith and successor intrusives were emplaced in a northwest-trending structural element named the Carabine Creek Lineament. Early phases of the batholith were basic and coarse-grained and form the core of the complex. Later phases, of intermediate to acidic composition, were emplaced along the structurally weak margins of the core. Three stages of fracturing were recognized at the property. The earliest brecciated the coarse-grained phases prior to the emplacement of the fine-grained intrusions. The second stage of fracturing was synchronous with the alteration; the final stage created the stockwork in which the mineralization was concentrated. The propylitic alteration facies developed at the property is typical of porphyry copper deposits except that only minor quantities of quartz are present. The potassic facies is distinctly different in that it lacks abundant red orthoclase and biotite. Pyrite and chalcopyrite are the most abundant sulfides; and bornite is occasionally observed. Magnetite is a common accessory in the basic intrusives. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Guichon Creek batholith is exposed within an elongate area of 400 square miles. Sedimentary rocks of Cache Creek group (Permian) and Nicola group (Karnian of Upper Triassic) are intruded by the batholith. In the few places where outer intrusive contacts are exposed, the older rocks have been metamorphosed to albite-epidote and hornblende hornfels and to epidote-chlorite skarn. Middle and Upper Jurassic sediments, Lower Cretaceous and Tertiary volcanic rocks and sediments unconformably overlie intrusive rocks. Pleistocene glacial and interglacial deposits mantle the batholith leaving less than 3% of the surface of the batholith exposed. The Guichon Creek batholith is a composite, upper mesozonal to epizonal, intrusive pluton consisting of seven major, nearly concentric phases. In shape it is an elongate, semi-concordant dome. The magma was emplaced as a crystal mush in a series of pulses and crystallized during a short period of geologic time. It is suggested that erosion of overlying sedimentary and volcanic rocks, as indicated by absence of Lower Jurassic strata, accompanied emplacement and crystallization of successive phases of the batholith. This may explain the association of mesozonal features of older phases at the batholith margin with epizonal features of younger inner phases. The batholith was emplaced by a combination of sidewall and roof stoping, forceful intrusion and assimilation of older rock. There is, therefore, a variety of contacts between phases including sharp intrusive contacts, intrusive contacts of dyke-like bodies and brecciated contacts. Contacts between two phases, although generally intrusive, may be gradational in some parts of the batholith. Contacts between varieties of a phase are gradational and were not observed in intrusive contact. Effects of assimilation are evident in outer contaminated margins of Hybrid and Highland Valley phases. Textures of these rocks are extremely varied and the rocks range in composition from diorite to quartz monzonite. Inner uncontaminated phases have orderly compositional and textural variations. The outermost uncontaminated rock is granodiorite and is thought to represent closely the composition of the original magma. Compositional differences within the inner phases are the result of differentiation within the magma chamber. The most effective process of differentiation was upward and outward movement of alkalis and silica accompanying diffusion of volatiles to regions of lower temperature and pressure. The differential material collected in cupolas and along the walls of the magma chamber. Pressure buildup at the roof of the magma chamber may have exceeded the confining pressure and resulted in fracturing which allowed emplacement of magma into older crystalline phases and into surrounding country rock. The number of phases may have been largely determined by rate of diffusion of volatiles. Emplacement of differential magma from the margin of the chamber into cooler wall rock produced dyke-like bodies of various textures and compositions. Undifferentiated magma remaining in the magma chamber crystallized more slowly and produced rock of more uniform texture and composition. Twenty-six potassium-argon age determinations for the various phases of the batholith are centered around 198 ± 8 my. It is not possible to differentiate among phases on the basis of potassium-argon apparent ages because variations are within analytical limits of uncertainty of techniques used. No interval of time can be given for period of emplacement. All phases began retaining argon at approximately the same time 198 ± my. ago. The batholith has undergone no significant metamorphism since that time. On the basis of isotopic and geologic considerations, it is probable that the Guichon Creek batholith was emplaced approximately 200 my. ago, after Karnian stage of Upper Triassic but prior to Middle Jurassic. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Tuzo Creek Molybdenite Prospect is in southern British Columbia approximately twenty air-miles east-southeast of Penticton within the Nelson-Valhalla batholithic complex. A stock of porphyritic quartz monzonite, approximately 1½ miles in diameter, and younger sub-volcanic sills, dykes and masses of quartz-albite-sanidine porphyry were eraplaced into a basement of Nelson granodiorite of probable Jurassic Age. Mid (?) Tertiary alkaline basic dykes are the youngest intrusions present. Porphyries were emplaced successively at three different times along structures developed either by subsidence of the stock or by regional deformation. Differentiation, level of crystallization of phenocrysts, level of emplacement and regional correlation of acid intrusions are discussed. Two phases of hydrothermal activity are recognized, separated in time by intrusions of porphyry. In both cases, alteration was controlled by fractures and local shear and breccia zones. The first phase resulted in widespread wallrock alteration, quartz veining and mineralization throughout most of the stock and bodies of pre-mineral porphyry. Zoning of argillization, potash feldspathization and silicification and of oxide or sulphide fields of mineralization occurs on a large scale throughout the alteration halo. A large zone of low grade molybdenite mineralization occurs in a zone of more intense wallrock alteration containing stockworks of quartz veins and pyrite. The chemical and physical aspects of wallrock alteration and mineralization are considered in light of experimental studies done by others. The second phase of hydrothermal activity only occurred locally and involved development of secondary sericite and quartz with associated Zn, Pb, Cu, Pe and Mo sulphides and calcite and fluorite. All structures can be explained either by periods of subsidence of the stock or by genetic relationship to forces developed by periodic movements along a nearby regional fault zone following the West Kettle River valley. Source rocks of hydrothermal fluids, paragenesis, zoning and exploration potential for molybdenite are discussed. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No description available.

No description available.

The Guichon Creek batholith is exposed approximately 200 miles N.E. of Vancouver, B.C. and is a zoned 'granitic' pluton of Lower Jurassic age (198±8my). The batholith consists of seven major intrusive phases. The predominant rock typo is granodiorite with lessor amounts of quartz diorite and quartz monzonite. Study of rock and mineral compositions has revealed a gradual variation in the relative proportions of mineral phases as crystallisation of the batholith proceeded. The chemical compositions, however, of the individual mineral phases show very little change. The relative roles of assimilation and magma convection in producing compositional variations in the early phases of the batholith are discussed. Alkali feldspars are microperthitic with bulk compositions in the range 71-86 Wt% Or and the compositions of the porthitic components approach pure end members. The potassic phases of the perthites have structural states equivalent to that of orthoclase. The plagioclase feldspars are oligoclases with low to intermediate structural states. Plagioclase from the early phases of the batholith (Hybrid and Highland Valley phases) show normal zoning whereas those from the later phases (Bethlehem and Bethsaida) show oscillatory zoning. Biotites from the major phases of the batholith have progressively lower Fe/(Fe+Mg) ratios with progressively increasing silica content of the host rocks. Plagioclase crystallized early in the older phases of the batholith whereas quartz was the early mineral to crystallize from the younger major phases. Evidence suggests that magma convectod during crystallisation of the older phases of the batholith but that the younger phases crystallised from a stationary magma. Comparisons with experimental systems suggest that the early magma crystallised under conditions of relatively low total pressures in the order of 1 or 2 kb but that the later phases may have been subjected to total pressures in the order of 4 or 5 kb during crystallisation. This increase in total pressures was most probably due to increasing volatile pressures during crystallisation / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No description available.