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Processing, interpretation, and modelling studies incorporating reflection seismic, VSP, and wireline data from onshore metamorphic basement in Aberdeen formed the basis for investigating the origins of unexpected sequences of coherent, laterally extensive seismic reflections, gently dipping to the NNE and occupying most of the crystalline upper crust. Wireline analysis from a vertical well drilled to 4800' in the metamorphic basement incorporated evaluation of formation lithology and fracturing. In absence of core, wireline characteristics were correlated with formation lithology using crossplots and histograms. Computed stratigraphy incorporating quartz-schist, mica-schist and igneous units agreed with cuttings analysis, outcrop geology, wireline characteristics, and known paleo-evironment of deposition. 1463 fractures counted on the FMS log showed significant NW-SE strikes and steep dips (40-50°) to the NEW. The significant fracture orientations may be an expression of the stress field affecting Scotland. Re-processing of the vibroseis seismic profiles using optimum parameters resulted in significant improvements despite limitations in the accuracy of RMS velocity estimations induced by survey characteristics. Two of the three profiles showed poor signal to noise ratio in consequence of traffic noise contamination of the data. Reflections were categorised into three kinds: (1) parallel, inclined, laterally extensive, sometimes weakly coherent, single packed reflections related to the syndepositional characteristics of the formation (metasedimentary and basic igneous units); (2) discordant, irregular, high amplitude, double or multiple peaked and usually short spaced reflections related to the post-depositional characteristics of the formation (fracture zone and acidic igneous units); and (3) two sequence boundaries, the upper of which was interpreted, on the basis of regional evidence, as both a stratigraphic boundary as well as a thrust plane. The NNE thickening and dip of the metasedimentary wedges defined by the sequence boundaries appeared to contradict inferred regional structure of the upper crust dictated by the recumbently folded Tay Nappe.

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The unique late Cretaceous to early Tertiary Great Tonalite Sill (GTS) of SE Alaska and British Columbia is a very long (c.1000km) and thin (<25km), orogen- parallel, composite batholith, which may separate two major superterranes in the western Cordillera: the Insular superterrane (including the Alexander and Wrangellia terranes) from the Intermontane superterrane (including the Stikine and Cache Creek terranes).The steeply NE dipping, sheet-like plutons of the Great Tonalite Sill are dominated by NW-SE striking concordant fabrics with steep lineations, which formed within a country rock shear zone of similar dimensions - the Great Tonalite Sill shear zone - prior to the complete crystallization of the calc-alkaline tonalitic magmas. The steep, multiple dyke like nature of this composite body and its emplacement during orogenic contraction, imply that ascent and emplacement have been achieved by dyke wedging mechanisms along the deep reaching, probably crustal scale, shear zone. The remarkable narrowness and yet persistence of the Great Tonalite Sill, is probably the result of petrogenesis associated with a very localised zone of crustal thickening, produced by the associated narrow shear zone extending along the orogen length. Deformation in the Great Tonalite Sill shear zone is dominated by NE-SW directed contraction orthogonal to the orogenic strike associated with a component of NE over SW high angle shear. Such a shear zone of late Cretaceous to early Tertiary age, lying along 800 km of the boundary between the Insular and Intermontane superterranes, strongly implies that it represents the actual boundary between them. That being the case, then terrane accretion during this interval was orthogonal and not obliquely dextral as in some current interpretations of paleomagnetic data. NE side up tilting of mid Cretaceous plutons may therefore be responsible for much of the anomalous palaeomagnetic data determined for these intrusions.

Kimberlites have been recently discovered beneath 100m of glacial sediment at Fort a la Come, Saskatchewan, Canada. Crater and extra-crater facies have been intersected in borehole core, interstratified with coastal and marine sediments of Cretaceous age. Extra-crater kimberlite is very rare, and particularly well preserved at Fort a la Come. It is encountered in five borehole intersections drilled by Rhonda Mining Corporation, sponsors of the Operation Fish Scale project, which included kimberlite research at the University of Leeds. The regional setting and geological description of six kimberlite borehole intersections are presented. In addition, the broad geodynamic conditions and the stratigraphic context are described, and from these a model for kimberlite eruption is constructed. The kimberlites are then described at a range of scales from stratal thickness and disposition, to ultra-fine diagenetic mineral growth. A textural classification is then applied to the deposits. The volcanology of the Fort a la Cone kimberlites are then discussed: these are unusual in that the craters are preserved, and are broad and flat, rather than steep sided tapering cones. A new term, pateran crater, and process of evolution is proposed for these and other kimberlites of similar morphology. The survival of these volcanic edifices in the sedimentary environment is also considered. The geochemistry of the kimberlites is presented, both bulk rock, and over 450 analyses of individual mineral grains by electron microprobe. These minerals are mostly gamet, ilmenite and pyroxene, of megacryst, kimberlite, crust, mantle peridotite and eclogite origin. The mineral chemistries are compared to those found in other kimberlites around the world, and the nature of the cratonic lithosphere is described. The P-T and compositional characteristics of the lithosphere are further refined from diamond and garnet trace element chemistry in collaborative works with Taylor and Griffin, described herein. Economic aspects of the kimberlites are reviewed, and all the conclusions are presented in time order, from diamond growth in the Archean, crustal evolution in the Mid-Proterozoic, Early Cretaceous magma generation and eruption, to Late Cretaceous reworking and burial.