This thesis investigates the origin of large-scale sandstone intrusions.  A new approach combining seismic, well data, core and outcrop observations with numerical modelling has been undertaken. Two possible end members of saucer-shaped, seismic-scale sandstone intrusions from the North Sea were identified on the basis of seismic data and core observation.  Diagnostic criteria were proposed to differentiate between fully and only partially injected sand bodies.  Outcrop and core data presented in this thesis provide a direct example and analogue for seismic and sub-seismic scale sandstone intrusions, highlighting the brittle nature of the host rock deformation at all levels within the examined intrusion complexes.  On this basis, the rheological behaviour of the host strata at the time of sand injection is inferred to be elastic with brittle fracturing.  This outcome is used as an input condition for Finite Difference and Finite Element modelling that aim to test hypotheses describing triggering mechanisms and estimate their regional extent, depth and overpressures present during sand injection.  The results of numerical modelling indicate that formation of the North Sea sandstone intrusions could potentially be triggered by catastrophic event(s) such as a meteorite impact or earthquakes, leading to sand liquefaction and remobilization.  It has also been shown that depths at which sand injection can take place reach 1 km.  Only supra-lithostatic pressures generate bodies composed of lower, bedding concordant part of intruded or depositional origin feeding inclined dykes at its marginal parts resembling those observed today on seismic data from the North Sea and in outcrops.

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The Spuzzum Batholith underlies an area northwest of Hope, B.C. It is nearly 60 km. long in a northerly direction and 10 to 20 km. across. The southern part of the body is zoned from pyroxene diorite in its core, through hornblende diorite, to biotite-hornblende tonalite. Tonalite forms about two thirds of the pluton's area, forming a nearly continuous rim. The pluton intrudes upper Paleozic Chilliwack Group, the Cretaceous (?) Giant Mascot Ultramafic Body, and Settler Schist of unknown age. K-Ar ages for tonalite and diorite range from 76 to 103 m.y. Diorite consists of subhedral orthopyroxene and plagioclase (An₆₂ to An⁴¹), with variable amounts of hornblende and clinopyroxene. Tonalite is largely composed of anhedral quartz and biotite, and subhedral hornblende and plagioclase (An⁵⁰ to An₃₂). Tonalite and some diorites are foliated. These rocks are locally hornblendized, resembling hornblende gabbro. Pods of directionless hornblendite are common in hornblendized rocks. Foliations and mineralogical zonation outline a crude tongue-like structure, modified by later deformation. Spuzzum diorite appears to have intruded the main part of the Giant Mascot Ultramafic Body but some hornblendites are younger than diorite. The Giant Mascot Ultramafic Body, 2 by 3 km., is zoned from dunite or peridotite, through pyroxenite, to a rim of hornblendite up to 100 m. across. Hornblendite occurs also as dykes. Orthopyroxenes of Spuzzum diorite are weakly aluminous hypersthene; those of the contact with Giant Mascot pyroxenite are bronzite. Clinopyroxenes of the same rocks are somewhat more aluminous salites and diopsides. Hornblendites from Spuzzum diorite and the Giant Mascot Ultramafic Body resemble alkali basalt in composition. Hornblende analyses fall into three categories: edenite, pargasite-common hornblende, and thirdly, more iron-rich common hornblende. It is concluded that Spuzzum diorite and tonalite originated by crystal settling from quartz diorite magma at depth, followed by diapiric rise of a zoned pluton composed of residual tonalite liquid cored by drawn-up dioritic cumulate. A mathematical test shows the compositions of diorite and tonalite to be consistent with this hypothesis. The rising pluton subsequently engulfed the Giant Mascot Ultramafic Body. Hornblendites may have formed by metasomatism of these rocks and adjacent diorite or tonalite as a consequence of the second boiling of tonalite and the coursing of resultant hydrothermal fluid through the nearly solid pluton. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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Thesis (M. Sc.)--University of Adelaide, Dept of Geology and Geophysics, 1986. / 1 map in pocket. Includes bibliographical references (leaves 150-160).

Thesis (Ph. D.)--University of Adelaide, Dept. of Geology and Geophysics, 1992. / Maps on 2 folded leaves in pocket. Includes bibliographical references (25 leaves ).

Thesis (M.S.)--University of Wyoming, 2008. / Title from PDF title page (viewed on Mar. 25, 2010). Supplemental map available as a PDF file. Includes bibliographical references (p. 159-165).

Thesis (Ph. D.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.Sc.)--Memorial University of Newfoundland. / Typescript. Bibliography: leaves 192-211. Also available online.