Dissertations / Theses on the topic 'Geology – British Columbia – Gambier Island'

Lead isotope compositions have been obtained from five major volcanic and intrusive rock suites and several ore deposits on Vancouver Island. Lead, uranium and thorium concentrations and strontium isotope ratios have been obtained for a subset of these samples. The rock suites examined are the Paleozoic Sicker Group, Triassic Karmutsen Formation, Jurassic Island Intrusions and Bonanza Group volcanic rocks, and the Eocene Catface intrusions. Isotope geochemistry of the Sicker Group is consistent with the interpretation that it formed as an island arc. Relatively high 207pb/204pb ratios indicate sediment involvement in the subduction process, which suggests that the Sicker Group formed close to a continent. Buttle Lake ore deposits display decreasingly radiogenic lead isotope ratios with time, suggesting that the associated magmas become increasingly primitive. This supports the hypothesis that these deposits formed during the establishment of rifting in a back-arc environment. Karmutsen Formation flood basalts display isotopic mixing between an ocean island-type mantle source and average crust. Isotopic evidence is used to support a Northern Hemisphere origin for these basalts. Mixing is apparent in the lead and strontium isotope signatures of the Island Intrusions and Bonanza Group volcanic rocks, between depleted mantle and crustal (possibly trench sediments) components. This is consistent with formation of these rocks in an island arc environment. Eocene Catface intrusions have relatively high 207pb/204pb indicating that crustal material was involved in their formation. There are two groups of plutons corresponding to an east belt and west belt classification. Galena from the Zeballos mining camp related to the Eocene Zeballos pluton indicates that the mineralization was derived from the pluton. Galena lead isotope data from Vancouver Island may be interpreted in a general way by comparison with data from deposits elsewhere of known age and origin. No single growth curve model can be applied. Lead isotope characteristics of Vancouver Island are clearly different from those of the North American craton, reflecting the oceanic affinities of this terrane. A new technique has been developed to compare 207pb/204pb ratios between samples with differing 206pb/204pb ratios. The procedure projects 207pb/204pb ratios along suitable isochrons until they intersect a reference value of 206pb/204pb. This technique can be used for interpreting lead isotope data from old terranes, in which lead and uranium may have undergone loss or gain, and if lead and uranium abundances have not been measured.
Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate

The Buttle Lake Camp is a major Paleozoic volcanogenic massive sulphide district in which the relationships between massive sulphide mineralization and associated volcanism are best explained if the ore deposits and associated lithologic units formed in a rift basin generated by rifting in an island arc system. This setting accounts for the marked linear distribution of the massive sulphide bodies, and the presence and distribution of volcanic products from four distinct source areas: a volcanic arc region, a back-arc (or intra-arc) rifting region, and two seamount areas. These interpretations were achieved largely through detailed mapping (1: 2400) of the Price Hillside and the relogging of pertinent drill core. Geology of the Buttle Lake Camp consists of newly proposed, four lowermost formations of the Paleozoic Sicker Group in the Buttle Lake uplift (in order of decreasing age): (1) the Price Formation, a thick sequence of basaltic andesite flows and related breccias; (2) the massive sulphide-bearing Myra Formation, consisting of mainly volcanic and volcaniclastic units; (3) the Thelwood Formations bedded sequence of siliceous tuffaceous sediments, subaqueous pyroclastic deposits and mafic sills; and (4) the Flower Ridge Formation, largely comprising coarse mafic pyroclastic deposits. Significant units within the Myra Formation are the lowermost, largely felsic H-W Horizon which hosts the large H-W deposit; the Lynx-Myra-Price Horizon, which contains two massive sulphide mineralized felsic volcanic units; the ultramafic G-Flow unit; and the uppermost, basaltic Upper Mafic unit. Zircon U-Pb dating yielded a Late Devonian age of 370 Ma for the Myra Formation. Volcanic units in the Price and Myra Formations are grouped into five volcanic series: two mafic to intermediate volcanic series, two felsic volcanic series, and an ultramafic to mafic volcanic series. These volcanic series are the result of at least three distinct and partly contemporaneous magmatic lineages. Source region for the ultramafic to intermediate parental magmas was an upper mantle peridotite variably enriched in large ion lithophile elements but depleted in high field strength elements (relative to N-type MORB). The felsic volcanic series were generated from two distinct sources. One series is from evolved andesitic magma whereas the other is from magma formed by partial melting of lower crustal material.' The Price and Myra Formations represent a general sequence of repeated events comprising: mafic to intermediate arc volcanism; rifting and sulphide mineralization; felsic arc.volcanism; ultramafic to mafic rift volcanism; and volcanogenic sedimentation. The sequence was repeated twice and formed two mineralized horizons (H-W and Lynx-Myra-Price). The Thelwood and Flower Ridge Formations indicate a major change in depositional style and environment from the two underlying units. The Thelwood Formation is a sediment-sill complex underlying mafic volcanic rocks of the Flower Ridge Formation.
Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate

Upper Triassic and Jurassic rocks in the central Graham Island area comprise shale, siltstone, sandstone, and conglomerate of the Kunga, Maude, and Yakoun Groups. Volcanic rocks are common in the Middle Jurassic Yakoun Group. The oldest unit exposed within the study area is the Lower Jurassic Sandilands Formation of the Kunga Group, a more than 250 metre thick sequence of interbedded organic-rich shale, tuff, siltstone, and sandstone. The Lower Jurassic Maude Group conformably overlies the Kunga Group and is divisible into four formations. The Ghost Creek Formation is an organic-rich black fissile shale, and is overlain by calcareous sandstone of the Fannin Formation. The Whiteaves Formation consists of fissile calcareous grey shale that grades upwards into fossil-rich medium- to coarse-grained, sandstone of the Phantom Creek Formation. The base of the Middle Jurassic Yakoun Group is marked by an angular unconformity. The unit is more than 1500 metres thick and is divided into four lithofacies. The lowermost shale and tuff lithofacies is a sequence of interbedded shale, tuff, siltstone, and sandstone, with shale dominating. The sandstone lithofacies overlies and partly interfingers with the shale and tuff lithofacies and comprises medium- to thickly-bedded lithic arenite interlayered with thinly-bedded shale. The conglomerate lithofacies exists within the sandstone lithofacies and consists mostly of thickly-bedded pebble and cobble conglomerate. The volcanic lithofacies interfingers with, and overlies the sedimentary rocks of the Yakoun Group, and includes lava flows, pyroclastic rock deposits, and lahars. The Kunga and Maude Groups record several relative changes in sea level. They formed in a progressively deepening basin. In Pliensbachian time, the basin shallowed and deposition, represented by the upper Fannin Formation of the Maude Group, was near-shore. Toarcian time is marked by an abrupt transgression. The upper part of the Whiteaves Formation and the Phantom Creek Formation of the Maude Group indicate a subsequent regression. The sedimentary rocks of the Yakoun Group were deposited in local shallow marine basins. Volcanic rocks are most abundant in the eastern parts of the map area, and indicate that an igneous source is located in that direction. All rock units in the map area are deformed by major northwest-trending faults and folds, reflecting at least four northeast-southwest oriented deformational events. The angular unconformity at the base of the Yakoun Group restricts one compressional phase to mid-Jurassic time. Abundant southwest-verging folds suggest development of northeast-dipping thrust faults during this compressional event. Northeast-trending normal faults cut through the thrust faults, postdating them and indicating a period of extension. Rocks of the Sandilands Formation are observed thrust on top of the Yakoun Group, thus indicating a second compressional event. Several small-scale strike-slip faults cut through all described rock units and overlying Tertiary sections, suggesting a late Tertiary deformational event. The Middle Jurassic compressional event may be a result of collision of Wrangellia with North America, or could have been caused by changes in relative plate motion between the North American and Pacific plates during the break-up of Pangaea. Lithologic similarities between the Jurassic and older units of Wrangellia on the Queen Charlotte Islands and coeval rocks of the Alexander terrane in southeastern Alaska suggest that there are no clear differences between the two, and that they were contiguous since Upper Paleozoic time.
Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate

Chemical and isotope characteristics of surface and ground waters were investigated within portions of the Myra Falls (Zn-Cu-Pb) mining camp, Vancouver Island (49° 35' N, 125° 34' W). This site was selected to characterize ground waters, investigate metal mobility, develop ground water exploration methods, and to elucidate ground water circulation in mountainous terrain with high rainfall. A broad spectrum of water characteristics were found and have been subdivided into water facies which correspond to hydrologic regimes within the mining camp: (1) local precipitation and surface runoff have Ca2+-HCO 3-- composition. (2) Ca2+-HCO 3-- shallow ground waters are of recent meteoric origin, contain tritium, have low total dissolved solids (TDS) (<200 ppm), and are nearly saturated with respect to dissolved oxygen (DO). These ground waters are mainly limited to the fractured rock carapace of the Myra-Price ridge, and shallow zones within Thelwood Valley. Many of these waters contact sulphide mineralization but have near neutral pH and SO4 2' remains subordinate to HCO3--. (3) Ca2+-Na+-HCO3-- and Na+-Ca2+-HCO3 -- are meteoric waters occurring within the central core of the Myra-Price ridge. They have gained Na+ by cation exchange in rocks previously saturated with Na+-Ca2+-Cl -- water. These ground waters have TDS similar to Ca2+ -HCO3-- ground waters. (4) Na +-Ca2+-Cl-- saline ground waters (TDS >30,000 ppm) were discovered in areas undisturbed by mining operations. These waters are reducing, have alkaline pH, contain very low HCO3 --, are most likely 14C-free, and contain a high volume of helium. The unique chemical and isotope character of the Cl -- waters imply they are exotic to this setting. (5) Na +-Ca2+-SO42-- and Ca 2+-SO42-- ground waters, of meteoric origin, occur at intermediate depth in areas underlying previously mined areas and in areas where dissolution of anhydrite has dominated the anion chemistry. (6) Mg2+- SO42-- runoff waters result from intense weathering of mined waste-rock. Thelwood Valley is unaffected by mine development. Ground waters in this area exhibit a narrow mixing interface between modern Ca 2+-HCO3-- and saline waters, and have little cation exchange. The pH of ground waters related to the Myra Falls mineral deposits is generally near neutral, and acidic ground waters with high metal loads are extremely rare. Amorphous oxy-hydroxides composed primarily of Fe oxy-hydroxides but also including Mn and Al. Zinc displays the strongest and most reliable anomaly contrasts for hydrogeochemical exploration in the dominantly bicarbonate and sulphate ground waters associated with the Zn-Cu-Pb mineralization of the Price ore-deposit. (Abstract shortened by UMI.)

Mapping at 1:25 000 scale on the central Graham Island has shown that Cretaceous strata are more widely distributed than previously known. This study examines the stratigraphy and structural geology of the Cretaceous rock sequence, and also addresses the petroleum potential of these units. At the base is the Cretaceous sandstone unit. This unit is divided into three lithofacies. The massive sandstone lithofacies is a coarse grained, dark green to greenish black, massive sandstone. Parts of this lithofacies contains up to 50 % glauconite. The grey sandstone lithofacies is finer grained and has better defined bedding than the massive sandstone. It is frequently found with interlayered sandstone, siltstone, and shale. The third sandstone lithofacies is characterized by pervasive bioturbation. All three lithofacies are texturally immature, contain angular quartz and feldspar, and are rich in chlorite clay. The Cretaceous sandstone unit is interpreted as a transgressive sequence deposited on a storm dominated shelf. Conformably overlying the sandstones are the massive friable shale and silty shale of the Cretaceous shale unit. Intervals with increased input of storm generated sandstone layers are found throughout the unit. Spherical and elliptical calcareous concretions up to over 1 m across are common. The Cretaceous shale unit represent a continuation of marine transgression with deepening of the sedimentary basin. Turbidites forming the Skidegate Formation are interbedded with the upper part of the shale unit. This formation consists of interbedded shale, siltstone, and fine grained sandstone. Sedimentary structures are often well developed on bedding surfaces. The rocks of this unit are distal turbidites and levee deposits of a submarine fan. Coarse clastic rocks of the Honna Formation are interbedded with the Skidegate Formation. This formation is dominated by pebbly conglomerates and coarse grained sandstones. The clast material in the conglomerate lithofacies is mainly derived from units present on the islands. The sandstone lithofacies consists of indurated, bluish, medium- to coarse-grained sandstone. This formation is richer in quartz and biotite than any other Cretaceous sandstones of the central Graham Island. The Honna and Skidegate formations are the result of deposition from a submarine fan system that was initiated in Late Cretaceous time. Deposition of shale continued after the deposition of the submarine fan-related formations terminated. The Cretaceous rock sequence is overlain by Tertiary volcanic and sedimentary rocks. Volcanic rocks occur throughout the area, and sediments of the Skonun Formation are exposed in north. Three major periods of deformation are recorded in the Cretaceous units. The first event was a Late Cretaceous to Early Tertiary northeast directed compression, resulting in northwest trending folds and thrust faults. The deformation was highly localized to areas were weakness zones existed in the older basement rocks. Two periods of Tertiary block faulting activity are recognized. The first resulted in northwest-trending faults, parallel to older structures. Later Tertiary block faulting developed northeast trending faults, which are the youngest macroscopic structures in the area. The Cretaceous rock sequence does not contain any promising hydrocarbon source or reservoir rocks. The TOC, S1, and S2 values from Rock-Eval® pyrolysis are low for all units, and the organic material present is mostly gas prone. Visual porosity is generally poor, as a result of chlorite pore-filling clay and calcite cement.
Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate

The thesis is intended to provide an alternative model for rural land use planning and environmental management. The project addresses the issue of settlement and development of sixteen hectares on Carmelo Point, Gambier Island. . The intent of the design is to initiate the development of the site within the determined development areas and to provide specific examples of integrating passive ecological technologies. Furthermore, the proposed development is to utilize the natural renewable energy systems while mamtaining the site's natural character and balance. The design program for the thesis is centred in and around a commons and is comprised of a lodge for cohabitation. The lodge is to include seven private chambers which share facilities in common. These facilities are the dining hall, sun rooms, washrooms, and the kitchen. The lodge is to incorporate a post and beam structure supporting a roof, which is used to catch and harvest rainwater. Additionally, the roof is designed to promote a stacking effect within the interior space. Once the harvested rainwater has been filtered and used, it is then treated via a garden solar aquatic septic system. The lodge is recognized as an initial incremental step in developing the site for human settlement. This project is intended as a prototypical ecologically sensitive intervention in a rural landscape which is experiencing development pressures due to its proximity to the Vancouver metropolitan area.

The Metchosin Igneous Complex, a partial ophiolite exposed on southern Vancouver Island, is the most northerly exposure of the Eocene Crescent Terrane. The role of the Crescent Terrane in crustal genesis and Cordilleran tectonics would be affected by its tectonic setting, however that setting is in debate. Analysis of trace element compositions of basalt from the Metchosin Igneous Complex by ICP-MS was used to determine the tectonic setting in which the complex formed. REE and HFSE compositions are transitional between N-MORB and E-MORB and do not suggest a unique tectonic setting. Strong enrichments of Nb and Ta relative to N-MORB are contrary to formation in a subduction zone. In conjunction with existing plate motion data, this makes a rifted-margin origin unlikely. Interaction at a distance between the Yellowstone hot spot and the Kula-Farallon ridge is proposed to satisfy all the geological and geochemical data. Many studies of ophiolites have interpreted high-temperature phases as hydrothermal in origin despite high permeability and low temperatures in sea floor volcanics. Metamorphic assemblages and compositions of metamorphic minerals were used to determine if alteration in the Metchosin Igneous Complex was related to sea floor alteration or obduction. Chlorite geothermometry and amphibole compositions show that peak metamorphic temperatures increase from east to west across the complex. The metamorphic facies increase from prehnite-actinolite and greenschist in the east to amphibolite in the west, corresponding with the temperatures inferred from mineral compositions. The temperature gradient is perpendicular to stratigraphy, whereas hydrothermal patterns are expected to be parallel to stratigraphy. Therefore the pattern of alteration in the Metchosin Igneous Complex is unrelated to sea floor alteration. Metamorphism during obduction has overprinted any hydrothermal alteration patterns. The east-west thermal gradient is attributed to tilting of the complex, either by tectonic forces or by unequal exhumation due to orographic effects.

The Queen Charlotte Islands represent the most outboard exposure of Wrangellia in the Canadian Cordillera. This study analyzes the structural and stratigraphic history of the central Moresby Island area, and correlates this history with ongoing and previous studies in the Queen Charlotte Islands. The stratigraphic succession preserved in central Moresby Island comprises marine volcanic and sedimentary rocks of the Triassic Karmutsen Formation and Kunga Group, Middle Jurassic arc volcanic rocks of the Yakoun Group, marine sedimentary rocks of the Longarm Formation and Queen Charlotte Group, and Tertiary volcanic rocks. The Karmutsen Formation and Kunga Group rocks exposed in central Moresby Island formed during a widespread Triassic volcanic event followed by marine carbonate and clastic sedimentation. Coarse clastic lithologies in the Kunga Group indicate a volcanic provenance as early as the Norian. The Early to Middle Jurassic marine sedimentary rocks of the Maude Group, present elsewhere in the Queen Charlotte Islands, are absent in central Moresby Island. Oldest rocks of the clastic Longarm Formation in central Moresby Island are of Hauterivian age, and the conformably overlying Queen Charlotte Group extends into at least the Turonian. Both field and petrographic evidence suggest two distinct suites of Tertiary volcanic rocks exist in central Moresby Island. Dominant megascopic structures in central Moresby Island are dominated by north, northeast and northwest-trending fault sets. Folding is common in stratified Kunga Group lithologies, and only of minor importance in younger successions. The deformational history outlines five events: Middle Jurassic shortening, Middle to Late Jurassic extension, post-Cretaceous and pre-Tertiary shortening, post-Cretaceous and pre-(syn ?) Tertiary extension, and a syn (?) to post-Tertiary extension. The structural history outlined for the central Moresby Island area provides several refinements to pre-existing models. It provides evidence that Middle Jurassic shortening continued into and possibly outlasted Yakoun Group arc volcanism. Cretaceous block faulting, documented on Graham Island and northern Moresby Island, extended into central Moresby Island. Asymmetric south-directed Tertiary extension, documented on southern Moresby Island, also extended into central Moresby Island, and has implications to the offset history of regional faults.

Five lake and one soil sediment record from six mountainous sites on Vancouver Island, British Columbia, Canada, were examined for changes in pollen, macrofossils, charcoal, and mineral clasts to reconstruct late Quaternary history of vegetation, fire and climate. The results provide insights into the history and dynamics of the Mountain Hemlock biogeoclimatic zone and highlight the role of several species and species groups not previously recognized. During the early Holocene, Alnus crispa expanded throughout the region following deglaciation, playing a more important role in these ecosystems than today. Abies lasiocarpa was the dominant Abies species at these sites during the late glacial and early Holocene until it was replaced by A. amabilis between about 10,500 and 7300 calBP, perhaps due to changes in regional atmospheric circulation and greater seasonal variability in insolation than we experience today. A. amabilis increased during the mid Holocene and was later replaced at the sites by increased abundance of T. mertensiana while T. heterophylla became much more abundant at nearby low elevations. Ericaceous-heath communities were established soon after deglaciation at the moister sites but not until about 7000 calBP at drier sites. These drier sites show more variation in vegetation throughout their records than the wetter sites. High charcoal and clast concentrations coincident with rapid vegetation shifts during the early Holocene suggest that these changes were probably the result of large stand-clearing fires that exposed mineral soils. A peak in charcoal at several of the sites occurs at ca. 4000 calBP suggesting more frequent fire at that time. During the late glacial and very early Holocene, P. contorta was an important seral species until A. crispa became well established. In the mid to late Holocene when Ericaceous-heath became established, A. crispa was unable to predominate, possibly because of reduced fire activity or because the heath communities hindered the exposure of fresh mineral soil surfaces. As a consequence, conifer-dominated stands were favoured. Basal sediments from these sites are not as old as they are at lower elevations, suggesting that deglaciation may have happened later at higher elevations.

Volcanogenic massive suiphide deposits within the Buttle Lake mining camp are associated with andesitic and felsic rocks of the Price and Myra formation in the Paleozoic Sicker Group. The Battle zone occurs within H-W horizon, the lowest member of the Myra formation. H-W horizon is a 15 to 200 m thick felsic package that occurs throughout the camp, immediately above the Price andesite, which is the lowest known unit within the Sicker Group in the Buttle Lake area. H-W horizon consists of seven members, two of which represent periods of massive sulphide deposition. From the stratigraphic base to top these members are: Battle and Gap zone massive suiphide lenses, fine rhyolitic tuffaceous deposits, H-W mafic sills, coarse rhyolite pyroclastic deposits, rhyolite tuffaceous sediments, upper zone massive suiphides, and the rhyolite flow-dome complex. Thin section petrography and Pearce element ratio analysis of lithogeochemical data from samples of least altered rocks from the Price formation and rhyolite flow dome complex support the following conclusions: (i) lavas in the Price andesite are comagmatic and are related by sorting of plagioclase feldspar, pyroxene, olivine and Fe-Ti oxides, and (ii) the quartz porphyritic rhyolite (QP), quartz feldspar porphyritic rhyolite (QFP) and green quartz feldspar porphyritic rhyolite (GQFP) units of the rhyolite flow dome complex are comagmatic and are related by sorting of quartz and feldspar. Alteration in the Battle zone is marked by addition of silica in both the footwafi and immediate hangingwall. A signfficant amount of iron in the form of stringers and disseminated pyrite has also been added in the footwall. A broader zone dominated by sericite alteration that occurs both above and below the orebody corresponds to loss of sodium and calcium, and addition of potassium, barium and rubidium. Magnesium does not show any systematic spatial trends that clearly are related to hydrothermal alteration. The first cycle of mineralization was the most voluminous, and formed main Battle massive suiphide lens, the H-W main lens and probably the Gap lens. The main Battle massive sulphide lens is localized in a fault-bounded basin developed in the Price formation andesite. From a laterally extensive footwall stringer zone, it varies upwards through: (i) massive pyrite and chalcopyrite, (ii) banded massive suiphide in the central region, to (iii) pale yellow massive sphalerite at the top and periphery. This zonal distribution appears to have formed by a process of progressive zone replacement as a result of continued reaction between upweffing fluid and previously deposited suiphides. A second cycle of upper zone mineralization is represented by small, discontinuous lenses of baritic sphalerite and tetrahedrite rich massive sulphide lenses above the rhyolite tuffaceous sediments. Galena lead isotope data from the Buttle Lake mining camp indicate that lead evolved in an orogene or island arc environment. The linear trend in the galena lead data can be explained as a mixing line. Positions of data along this trend do not relate to age differences among the ore lenses, but appears to represent either: (i) varied mixing of upper crustal and mantle components, as might be expected in an orogene or island arc environment, or (ii) variable selective leaching of lead isotope components from footwall source rocks. A combination of these processes is not excluded. The less radiogenic end member appears to be spatially related to rhyolitic host rocks. The more radiogenic deposits occur immediately above major discharge stockworks in andesite. In H-W horizon, markedly radiogenic lead is characteristic of deposits that define the main lens trend (i.e. the H-W and Battle main lenses). Lenses in the main trend are among the largest; consequently a more radiogenic lead isotopic composition may identify favourable exploration targets.

Heteromorph ammonites and dinoflagellate cysts from the Upper Cretaceous Northumberland Formation on Hornby Island, British Columbia, Canada are examined. The collection and preparation of new material has enabled the recognition of eleven species of which only three have been reported from the locality. Of these taxa represented from three heteromorph ammonite families in the study area, five are new occurrences and three are new to science. This expansion of the Hornby Island ammonite fauna is presented alongside a pioneering taxonomic survey of dinoflagellate cysts from the same rocks. Together, these macro- and microfossils reinforce a late Campanian age for the Northumberland Formation with the upper extent of the section approaching the Campanian-Maastrichtian boundary (CMB) interval. The palaeoecology and evolutionary relationships of these heteromorph ammonoids are considered with new insights into their ontogenetic development and neritic palaeoenvironmental circumstances. The dinoflagellate cysts and associated terrestrial palynomorphs have also allowed for enhanced palaeoenvironmental reconstruction and depositional setting inference. The scope of the studied material, and the presence of key index taxa, enables refined biostratigraphy and a stronger basis for correlation of the Hornby Island succession with neighboring coeval biotic provinces.
Graduate
2018-08-10

This study involved a regional hydrogeological assessment of the Comox Coalfield on Vancouver Island, British Columbia. Two site-specific geological and hydrogeological investigations were conducted. The first involved generating a 2.5 dimensional hydrostratigraphic model of part of the Quadra Sand Comox-Merville Aquifer using lithology information from 196 drilled domestic-use groundwater wells. Well logs were standardized with respect to lithologic and hydraulic characteristics. Contact surfaces were created for identifiable hydrostratigraphic units employing an iterative geostatistical interpolation process that incorporated contact points from well logs and interpreted points based on the regional hydrogeology. Modeled hydrostratigraphic surfaces were compared to logged contacts and to exposures at Willemar and Lazo bluffs at Comox. Six lithostratigraphic units were identified in the coastal exposures. Hydraulic conductivity values, estimated from grain size data using the Hazen method, for the lowermost 4 units were: 2.3 x 10-3 cm/s, 9.1 x 10-6 cm/s, 9.4 x 10-3 cm/s, and 4.7 x 10-6 cm/s, respectively. The hydrostratigraphic model was verified using statistical variance analysis, field reconnaissance data, and the identification of a separate surficial aquifer within the study area. The model identified all units mapped in the field and two units below sea level, inferred to be the Cowichan Head Formation. The Comox Bluff model successfully predicted, within 2 m vertically, subsurface hydrostratigraphic boundaries 80% of the time. The second component of the study included a hydrogeological investigation of stacked Quaternary and Late Cretaceous bedrock aquifers at Oyster River. This investigation incorporated drilling logs, borehole geophysics, aqueous geochemistry, pumping and recovery test data, and hydrostratigraphic interpretation of surficial exposures. The potential for hydraulic communication between the Late Cretaceous Nanaimo Group fractured sedimentary bedrock and the overlying unconsolidated Quaternary aquifers was examined. Two adjacent groundwater observation wells were drilled; one completed in bedrock (146.9 m) and one in the surficial sediments (7.3 m). The deeper well penetrated the Trent River and Comox Formations of the Nanaimo Group. A water-bearing fracture zone approximately 3 m wide was encountered at 135 metres below ground surface, coincident with the Comox Y and Y Lower coal seams. Dissolved methane gas was detected in the bedrock aquifer, with an initial concentration of 2,123 mg/L. Schoeller diagrams reveal that the gas in bedrock is coal related. A pumping and recovery test in the deep well suggests that there is unlikely any hydraulic communication between the bedrock and surficial aquifers encountered at Oyster River. This assessment is based on infrequent water level measurements in the shallow well, which did not consistently draw down during pumping of the deeper well. However, the pumping rate was not sustainable for this test and it could not be held constant. Fracture transmissivity and hydraulic conductivity for the bedrock aquifer were estimated using the Theis Recovery method at 7.06 x 10-7 m2/s and 2.29 x 10-7 m/s, respectively. The hydrogeological research conducted at Comox and Oyster River highlights the effectiveness of a multidisciplinary approach for subsurface investigations. This study contributes site level data upon which regional inferences can be built for the Comox Coalfield.

The submarine geomorphology of Goletas Channel - Hardy Bay - Shusharti Bay is a record of environmental change, defined by sediment deposition since the late Pleistocene draped over glacially sculpted physiography. Sea level change, contiguous with waning ice extent at the termination of the Fraser Glaciation, triggered an oceanographic transition within Goletas Channel from a low energy closed embayment to a higher energy open channel environment. Morphologic evidence of lower sea level position is observed from sequence stratigraphy in Hardy Bay and suggests regression to 74 m below present. Stratigraphy also shows a correlation between sea level transgression and turbidity current flows in northwest Goletas Channel, and although triggering mechanisms remain elusive, they are likely related to reworking of glacial sediments concomitant to initial open channel conditions. Holocene sediment accumulation has been highest in southeast Goletas Channel, represented by mud with interstitial gas, and has been reworked by tidal currents into contourite structures. A combination of high-resolution multibeam bathymetry, seismic and core samples are used to study the geomorphology of the region.