Mount Washington rises abruptly to the west of the Coastal plain of Vancouver Island near Courtenay, British Columbia. It is ( -shaped possessing two cirques which face northeast. The basement rocks of the Mount Washington area consist of several thousand feet of massive basic to intermediate volcanics of the Triassic Vancouver group. A layer composed of gently dipping Upper Cretaceous shales, sandstones, and minor conglomerate and coal overlies the Triassic rocks on the Coastal plain, and outliers of this layer are present on the higher areas west of the plain. Dioritic intrusions cut the Triassic and Upper Cretaceous rocks. The higher portions of Mount Washington are composed mainly of Upper Cretaceous rocks. These, and the Triassic rocks underlying them have been domed by the intrusion of a centrally located quartz diorite stock. Numerous offshoots of this stock are present in the Upper Cretaceous rocks surrounding it. At its west border there are two breccia pipes. Copper-bearing quartz veins are present on the west side of the mountain in the vicinity of the stock. These were formed at high temperatures in a near-surface environment. The distribution of the breccias and sill-like intrusions at Mount Washington suggests that the development of the stock was highly restricted as it moved upward through the Triassic volcanics and that on reaching the Upper Cretaceous sediments it encountered much less resistance so that it spread laterally to form dykes, sills, and laccoliths(?). The present investigation provides, the only detailed geological mapping done in the Mount Washington-Constitution Hill area, and its contributions are as follows: (1) additions to the knowledge of the stratigraphy and structure of the rocks in the area; (2) information on the probable methods of emplacement of the dioritic intrusions, and the relationships among these intrusions; (3) the existence, extent, and nature of the breccias; (4) additions to the knowledge of the character of the mineral deposits, including the occurrence of the mineral wehrlite. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Granduc Mine is near the British Columbia-Alaska boundary in rugged mountainous country about 36 miles northwest of Stewart B.C. The writer participated in detailed surface mapping in the vicinity of the mine during the field season of 1959. Rock specimens were collected in the field and examined microscopically in the laboratory. The results of the latter investigation form the greater part of this thesis. The oldest rocks in the area are north trending, steeply dipping and isoclinally folded metavolcanic and metasedimentary rocks that are believed to be correlative with the Hazelton group. These consist of a basal andesite complex which is overlain by a large thickness of metasedimentary rocks. The Hazelton group rocks have been regionally metamorphosed and synkinematically intruded by small subconcordant bodies of foliated diorite and hornblende granodiorite. The metasediments are believed to have formed from greywackes, marls and sandstones that have been progressively metamorphosed to form schists that can be classified in the quartz-albite-epidote-biotite subfacies of the greenschist facies. Almost identical mineral assemblages are found in the altered dioritic and metavolcanic rocks, and it is concluded that these initially high temperature assemblages have retrogressed during regional metamorphism to attain or approach equilibrium in the same metamorphic facies. At a late stage in the metamorphism strong differential movement was localized in a quartz-rich member of the metasedimentary rocks in a zone near the contact with metavolcanic rocks. All rocks in this zone have undergone retrogressive metamorphism, and have attained equilibrium in the quartz-albite-muscovite-chlorite subfacies of the greenschist facies. Drag folds show that this dislocation metamorphism was related to the formation of an anticlinal structure that lies to the east of the map area. Some of the major structural ore controls appear to have formed at this time. The strongly-developed isoclinal folding was later flexed during or following intrusion of the Coast Range batholith. Ore bearing solutions are believed to have been derived from batholithic emanations and these were channeled along crumpled and brecciated zones that formed during the earlier period of regional metamorphism. Two mineralized zones are present and these are essentially conformable with the metasediments and consist chiefly of chalcopyrite, pyrrhotite and sphalerite. Mineralization has replaced the host rock along favourable lithologic horizons, but appears most heavily concentrated in brecciated zones. The deposit is classified as Mesothermal Replacement. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Fraser Valley from Hope to Emory Creek is underlain by mainly regionally metamorphosed Palaeozoic and (?) Mesozoic sedimentary and volcanic rocks. The Chilliwack group consists of iron- and magnesium-rich pelitic schists and minor basic schists of the staurolite-quartz subfacies and to a lesser extent of the sillimanite-almandine subfacies. Much of the femic component of the original sedimentary rocks was used in the early formation of a biotite-almandine-sericite-plagioclase assemblage. As a result, a later assemblage of minerals (kyanite, staurolite, sillimanite, and muscovite) developed even though they represent minerals too alumina-rich to form in rocks of these bulk compositions. The Hozameen group, which consists of cherts, phyllites and greenstones of the greenschist facies, is composed of schists and amphibolites of the almandine amphibolite facies at its western boundary. The Custer granite-gneiss is an ancient complex of sedimentary and volcanic rocks. During the regional metamorphism of the Custer, the complex formed gneisses and pegmatites, became mobile, and, limited by the structure of the surrounding rocks, moved into an area of less intense metamorphism. The movement caused a shearing of the Custer to form augen gneisses and of the adjacent rocks to form phyllonites. Later release of stresses along definite planes caused a closely spaced faulting of the Custer and the wall rocks. A band of sheared quartz diorite and gneiss separates the Hozameen group from the Custer. The quartz diorite intrudes both units. Unmetamorphosed conglomerates of the Jackass Mountain group unconformably overlie the Custer. A north-trending fault of largely dip-slip movement which formed between Lower Cretaceous to Miocene times has down-faulted the rocks east of the Chilliwack group. The fault extends from Spuzzum to Chilliwack River and possibly into northern Washington. Its trace south of Hope has been partly obliterated by the younger Chilliwack batholith. At least two periods of folding have occurred within the map-area. An early period of folding is associated with the movement of the Custer (Jurassic?) and a later (post-Lower Cretaceous) period with the formation of a northerly trending anticline that occupies the centre of the Fraser Valley. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

An area of 550 square miles between Lillooet and Big Bar, B.C. was mapped by the author using the scale of one mile to the inch. In the southern part of the Bowman Range four members are recognized in the Middle (?) and Upper Permian Marble Canyon formation which is partly composed of reefal limestone. This formation forms a northwesterly trending anticlinorium overturned to the northeast. The cherts, argillites, limestones, and volcanic rocks west of the Bowman Range, originally referred to the Permo-Pennsylvanian Cache Creek group are shown to be Permo-Triassic and are here assigned to the Pavilion group, a new group which is made up of two Divisions. Microscopic and stratigraphic evidence is given that the cherts of this group are of radiolarian origin. The Lower Cretaceous Lillooet group here is subdivided into three units. Divisions A and B are shown to form a northwesterly trending anticline. Three members are now recognized in Division A of the Lower Cretaceous Jackass Mountain group. The Lower Cretaceous Spences Bridge group is subdivided into several local and stratigraphic units. Two units previously assigned to the Spences Bridge group are correlated with the Kingsvale group on the basis of new fossil collections. Some volcanic and sedimentary rocks originally referred to the Miocene Kamloops group are here correlated with Miocene to Pleistocene rocks of the Quesnel map-area. West of Lillooet a belt of serpentinite was mapped that has structural and lithological similarities to the Upper Triassic ultrabasic intrusions of the Shulaps Range. Granitic rocks of three ages are recognized and range from early Lower Cretaceous or older to mid-Lower Cretaceous. It had earlier been shown that the Fraser River fault zone consists of several normal faults with relative downward movement to the east. East of these faults the author recognizes another fault with relative downward movement to the west. Lower Cretaceous and early Tertiary rocks thus occupy a graben between Permo-Triassic units to the northeast and to the southwest. This graben probably controlled the deposition of Divisions B and C of the Jackass Mountain group. The faulting may be related to the isostatic rise of adjacent granitic masses. Evidence is given that the latest movement on one of the faults took place in mid-Tertiary time. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The thesis represents a stratigraphical, structural and paleontological study of the Upper Cretaceous strata exposed on Hornby Island. The stratigraphy and structure were studied in some detail, but the main part of the work is the faunal description, revision and illustration of 24 species of cephalopods, 15 species of pelecypods, 9 species of gastropods, 1 coral and 2 scaphopods. The group of nostoceratids previously assigned to Anisoceras cooperi has been divided into five species, of which two are new ones. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The Summit Camp, now abandoned, is located seven miles north of the town of Greenwood in south-central British Columbia. Mineral deposits in skarn zones of the camp were mined for their copper, gold, and silver values. The oldest rocks in the Summit Camp are the contorted grey cherts of the Knob Hill Formation of Paleozoic (?) age. The Knob Hill Formation is overlain nonconformably by the Paleozoic Attwood Series, made up of the shales of the basal Rawhide Formation; the limestones, chert breccia, and limestone breccia of the Brooklyn Formation; and the pyroclastics, lavas, and greenstones of the Eholt Formation. The chert and limestone breccias of the Brooklyn Formation, interpreted by some earlier workers as the results of silicification and tectonic brecciation respectively, are considered to be of clastic sedimentary origin. There is a pronounced nonconformity between the Brooklyn and Eholt Formations. These sedimentary rocks were intruded in Mesozoic (?) time by the Emma Intrusive consisting of quartz diorite, diorite and minor gabbro. This event was followed by the emplacement of the Lion Creek Intrusive, which consists of quartz diorite and syenite. In Oligocene time the arkoses of the Kettle River Formation were deposited in fresh-water basins in the area. Earlier rocks were intruded by Miocene (?) phonolite and pulaskite, that also gave rise to flows of similar composition. Miocene (?) basic dikes are the latest rocks of the area. Mineral deposits of the camp contain magnetite, pyrite, pyrrhotite, chalcopyrite and tetrahedrite in a gangue of skarn minerals. Skarn has formed from Brooklyn limestone as a result of the addition of heat and large amounts of Si, Al, and Fe⁺⁺⁺ from the Lion Creek Intrusive. The intrusive assimilated large amounts of Ca and CO₂ in the process. Skarn zones are controlled by proximity to the Lion Creek stock, or by a contact of limestone with other rocks, or by the presence of channelways such as faults or permeable beds. Metallic minerals were introduced into the skarn zones along fractures and foliation planes with falling temperature. Epithermal precious metal veins that occur close to the Mesozoic (?) intrusives of the Boundary District are not found in limestone. It is believed that these veins were emplaced during a late stage in the cooling of the plutonic rocks. The earlier, higher temperature release of metals into the skarn deposits may be the result of the assimilation of CO₂ that locally prevented the solidification of the shell of the consolidated intrusive body. The mineralizing fluids responsible for the epithermal veins were trapped within the shell and released at a late stage by fracturing due to cooling. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

A granodiorite pluton near the southwest boundary of the Coast Range of British Columbia was examined by field and petrographic methods, with the object of determining the origin of the pluton. Field and petrographic characteristics are presented and descriptions of 42 of 65 thin sections studied are included. There are no field structures which can be explained solely by magmatic processes. Several field characteristics which should be associated with magmatic intrusion are absent. Petrographic examination revealed no features which can be explained only by magmatic processes. On the other hand, the replacement textures found by microscopic examination cannot be attributed to crystallization from a melt. The physical chemical system which produced the present form of the pluton was an open one. Potash was added and soda and lime were removed in the early stages of recognizable replacement. Later silica was added and potash, alumina, soda and lime were removed. The processes which developed the granodiorite pluton are most accurately described as granitization. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

This thesis represents a field and petrographic study of an elongate, tabular 'roof pendant' within the Cassiar Batholith. The general area lies between the headwaters of the Stikine and Finlay rivers in north-central British Columbia. Since no previous geological mapping had been carried out in this area, some details on the extent, lithology, and structure of the various formations are presented. These consist of the Takla Group of volcanics and marine sediments ranging from upper Triassic to upper Jurassic in age; the Cassiar Intrusions representing one general period of batholithic invasion; and the Sustut Group, composed of conspicuously bedded continental strata of upper Cretaceous and Paleocene age. Minor basic intrusives of probable Tertiary age are also present. The pendant occurs within intrusives of gabbroic composition. A wedge-shaped body along the western border consists of quartz gabbro. Bluish green hornblende, comprising some 25% of the rock, shows a lineation which is also visible in the orientation of the calcic plagioclase. Hornblende is the main mafic constituent, quartz comprises less than 10% of the total composition. The linear structures plus the presence of numerous foreign xenoliths within this more basic border phase, lead to the conclusion that the early intrusion was forceful, that emplacement was by piecemeal stoping, and that flowage of the magma occurred during crystallization. The main intrusive east of the pendant consists of massive granogabbro, composed of some 50% calcic plagioclase, 20% microcline, 20% quartz and 5% biotite. The emplacement of this intrusive was more passive. Phases intermediate to these two extremes are present, mainly along the eastern border of the pendant. These are of hornblende bearing granogabbro. The intrusives represent differentiated phases of a common magma. The pendant is composed of a conformable sequence of pyroclastics and calcareous sediments. The pyroclastics (tuffs) are predominantly of basaltic composition and form the flanks of the tabular structure. The calcareous sediments represent alternating deposition of tuffaceous and sedimentary material. The succession at three localities is presented in some detail. It is shown that thermal metamorphism of the basaltic tuffs has been negligible and that these beds have insulated the central portion of the pendant from laterally spreading thermal and metasomatic effects. The thermal metamorphism of xenoliths of basaltic tuff in the quartz gabbro is shown to be insignificant, whereas sedimentary xenoliths have been converted to an amphibole hornfels assemblage in equilibrium with the magma. Dynamic metamorphism has been active within the intrusive and older rocks, rendering those within the pendant to a schistose condition. Effects of earlier, ascending thermal metamorphism have been largely obscured by dynamic metamorphism. Hydrothermal alteration of the fault and shear zones to aggregates of quartz-ankerite and chromian muscovite, represents the final stages of the crystallization of a granitic magma. Field and petrographic criteria of ‘granitization’ are presented and critically examined. The coarse grained gabbros are shown to represent crystallization from a true magma. Maps and plates illustrate the main features. The appendix includes determinative mineralogy and petrographic descriptions of the intrusives. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Bowen Island is situated within six and one-half miles of the University of British Columbia and is accessible at all seasons. The island contains a great variety of rocks and offers an excellent opportunity for the student geologist to study batholithic and minor intrusives, acidic to basic extrusives, pyroclastics and sediments. The writer studied the rocks and is submitting, for a Master's degree in Geological Engineering, this paper encompassing the results of his study. Roughly two-thirds of the island were visited in reconnaissance survey. Mapping was done by means of pacing, compass and barometer. A compilation map showing the writer's observations and those of earlier observers is presented. A small area, roughly half a mile square, was studied in detail and is the main basis of the paper. The area studied in detail was found to be composed of volcanics, sediments, quartz-diorite and minor intrusives. The earliest rocks in the detailed area are a series of volcanics with some interbedded sediments. The volcanics and interbedded sediments are highly metamorphosed and intruded by basic porphyry dykes which are in turn metamorphosed to a lesser degree. All the above are cut by quartz-diorite and minor acid intrusions. This places the basic porphyry dykes as later than the volcanics and earlier than the quartz-diorite and related rocks. Basic dykes of trachytic texture represent the closing period of intrusion. Pleistocene and post-pleistocene sediments lie unconformably on the earlier rocks. There are three types of metamorphism present: a) dynamic metamorphism; b) thermal metamorphism; c) contact metamorphism. In addition to these, paulopost juvenile action and propylitization have caused considerable alteration of the volcanics and related dykes. The age of the batholith is accepted provisionally as Upper Jurassic. Material which is believed to be from fossilized organisms but which has not yet proved identifiable, is found in limey inclusions in the volcanics of Wharf Point. The inclusions may indicate an earlier limestone formation or mud formation contemporaneous with the flow rocks. Structures in the pre-batholith volcanics are of questionable assistance in determining top from bottom of a formation. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Rocks of the Kobau Group occur between the Okanagan and Similkameen Valleys in southern British Columbia and northern Washington. The Group consists of quartzite, phyllite, greenstone and minor limestone deposited within a synorogenic, eugeosynclinal environment in pre-Cretaceous, possibly post-Devonian, time. Intrusion and extrusion of basic igneous rocks accompanied deposition. The observed succession has been divided into nine units with total original thickness under 5,000 feet. Earliest recognized deformation of the Group formed tight recumbent folds with easterly trending axes. Transposition of compositional layering to foliation and extensive shearing occurred at this time and was accompanied by regional dynamothermal metamorphism which attained the middle subfacies of the greenschist facies. Later (second phase) deformation produced overturned and normal folds with steep axial planes and south-easterly trending axes, and refolded early recumbent structures. Several quartz latite dykes cut the Group during or shortly after late folding. Emplacement of granitic and dioritic stocks with radiometric ages of 144 x 10⁶ years or less followed second phase folding. Contact metamorphic zones of varying extent are present around larger intrusive bodies and attain the hornblende-hornfels facies. A latest (third) phase of deformation about poorly defined northerly trending axes may be related to this intrusive episode. A number of dacite and basalt dykes intruded both stock and country rocks. Extensive fracturing during Tertiary time broke preexisting structures into numerous blocks and wedges. Fractures parallel axial planes of early and late folds as well as faults in the Okanagan Valley. Relationships between the Kobau Group and rocks in adjacent areas are unknown. The Group possesses lithologic and structural similarities to parts of the Shuswap Complex and may share some of the complex's history. Part of the southerly adjacent Anarchist Group may be correlative with the Kobau Group. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate