No abstract included. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

No abstract included. / Arts, Faculty of / History, Department of / Graduate

Field and culture studies have been carried out with the epiphytic red alga, Ceramium codicola J. Agardh, with the objective of determining what factors in its biology cause it to be limited to growth on one host plant, Codium fragile (Suringar) Hariot. A survey of epiphytes of C. fragile and C. setcheIIii confirm the absence of C. codicoIa on C. setcheIIii and shows that C. codicola is the most abundant epiphyte on C. fragiIe. More species of epiphytes were present in wave sheltered areas. C. codicoIa was not present in samples from the Strait of Georgia. In culture, C. codicoIa grew to reproductive maturity apart from C. fragiIe from spores, but the life history was not completed. The presence of living or extracted C. fragiIe or C. setcheIIii did not promote germination, growth or reproduction of C. codicola, and typically inhibited it. C. codicoIa did not grow well at temperatures above 15°C in culture; C. fragiIe, Ceramium pacificum and C. gardner i grew weII at 10-18°C. Rhizoids of C. codicola have bulbous tips, which appears to be genetically determined. Substratum can affect later development of these rhizoids, which may obscure the bulbous nature of the rhizoid tips. C. codicoIa is unable to produce digitate holdfasts on its rhizoid tips, as was observed in other Ceramium spp. , and may only be able to attach by entangling its rhizoids in loosely constructed substrata such as Codium spp. C. setcheIIii is not suitable because it is too compact, and penetration of rhizoids is inhibited. Field studies show that C. codicoIa is reproductive throughout the year, although reduced in the winter. Thallus length was also reduced in the winter. In addition, thalIi were longer in wave sheltered sites, and longer in the upper regions of their intertidal distribution. Male and female gametophytes and tetrasporophytes of C. codicola exhibit a hetermorphism in branching pattern. Gametophytes differ from tetrasporophytes by having more primary branches and larger angles of branching. Females differ from males by having a higher degree of proliferous branching, resulting in a higher number of primary branches and a higher branching ratio. Branching pattern in females may be the result of continued growth of involucral ramuli, and it may optimize reproductive potential. / Science, Faculty of / Botany, Department of / Graduate

The 1965 Hope Slide is one of the largest rock avalanche to have occurred in recent historic time. Although this landslide is very well known, virtually no comprehensive investigation was undertaken. This study represents a first, but essential, step to begin a detailed evaluation of the mass movement; it is also part of a research program investigating the landslide hazards along strategic transportation corridors in southwestern British Columbia (Savigny, 1990, in prep.). The geology at the slide site was confirmed to consist of greenstone and felsite, however, two varieties of each of the rock type were found: the greenstone occurs in a massive and a slightly schistose form, and the felsite occurs in a buff coloured and a greyish-white coloured variety. Discontinuities at the study site include two steeply dipping faults, three dominant sets (Jl, J2 and J3) and a shallower dipping set of joints, the orientations of the latter set closely relate to those of Jl, and a number of gouge filled shear zones along the buff felsite and greenstone contacts. The 1965 failure surface was probably controlled by two mechanisms, in which the steeper upper portion of the slope was largely controlled by pervasive step-like discontinuities (Jl and the shallower joints); the shallower lower part of the slope was controlled by gouge filled buff felsite-greenstone contacts. These two mechanisms also support the two slide events hypothesis put forward by Weichert et al. (1990), who suggested that the seismic signals recorded on the day of the landslide were the results, rather than the cause, of the mass movement(s). Based on the evidence found in this study, it is proposed that the lower slope (below the upper northeast trending fault) failed first along the gouge filled lithologic contacts, due to the debuttressing effects of the lower slope and the existing weakness along the joints, the upper slope subsequently failed. Slope stability analyses indicate that-the slope was in critical conditions prior to the 1965 slide. The results also demonstrate that the inherent weakness withinjthe rock mass was sufficient to explain the occurrence of failure without external influences. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The northern Cascadia subduction zone has been the site of numerous geophysical studies during the past two decades. However, little is known of the deep structure (> 40 km) or S-velocities throughout this region. In this study, locally generated P-to-S conversions (Ps) contained in ~100 teleseismic P-wave coda have been analysed to determine the S-velocity structure to upper mantle depths. Prior to the analysis, the applications and limitations of this technique as applied to a dipping layer environment have been examined. It is concluded that strict stacking bounds (≤ 10° in ∆ and BAZ) should be applied. It is demonstrated that dipping boundaries which could not be detected using this technique (e.g. ∆Vs = 0.08 km/s), may significantly alter the amplitude and arrival time of reverberations from deeper interfaces. Therefore, such phases should not be quantitatively modelled. As reverberations are an important constituent of receiver functions, formal inversion of these waveforms is not justified in this environment. Only arrivals which exhibit the amplitude and arrival time characteristics of primary P-to-S conversions are considered in this study. Finally, most studies have normalised receiver functions to unit amplitude prior to modelling. However, synthetic data demonstrate that undetected dipping boundaries may alter Ps/P ratios and lead to inaccurate earth models. A recent modification to this technique (Ammon, 1991) which provides 'absolute' amplitudes is examined. In addition to providing information on the near-surface velocity structure and on dipping layers, this modification provides for a more accurate image of the earth structure. Three 3-component broadband event triggered seismic stations were deployed in a 90 km long linear array oriented perpendicular to the continental margin of southwestern British Columbia. Between December 1987 and October 1989 approximately 100 teleseisms covering a wide azimuthal and distance range were recorded and analysed. The two largest phases observed in data from the westernmost station ALB-B reveal a prominent low-velocity zone extending from 37-41 km depth beneath central Vancouver Island. This feature correlates well with the reflective 'E' zone, a region which also exhibits high electrical conductivity. Combining the S-velocity estimates with refraction P-velocities yields a high Poisson's ratio for this layer. The low P- and S-velocities and high Poisson's ratio and electrical conductivity are supportive of the recent interpretation of this feature as a fluid-saturated shear zone above the subducting Juan de Fuca (JdF) plate. Analysis of data at the mid-array and easternmost sites, LAS and EGM respectively, permits this zone to be mapped northeastward to a depth of 54 km beneath the British Columbia mainland, approximately 250 km from the locus of subduction. The subducting oceanic crust is imaged at 47-53 km depth dipping 15°±5° in the direction N30°E±20° beneath central Vancouver Island. The dip angle increases to 22° ±5° at a depth of 60-65 km beneath the Strait of Georgia. The results of this analysis provide the first definitive evidence for the location of the subducting plate in this region and indicates that the seismicity at depth occurs within the oceanic crust. Further, the dip direction of N30°E supports the theory (Rogers, 1983) that the JdF plate is arched upwards as it subducts in this region. Finally, the continental Moho is imaged at 36 km depth beneath LAS, and there is evidence at both this site and EGM for a low-velocity zone in the lower crust. A similar feature is imaged beneath Vancouver Island and coincides with the reflective ‘C’ zone. The depth estimated to the top of this layer denotes the lower limit of shallow seismicity suggesting a significant structural or compositional change at a depth of 20-26 km. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The purpose of this research is to construct and test a model of the organization of microcore technology, a standardized core technology, within the subsistence-settlement system of prehistoric, semi-sedentary hunter-gatherers. The study of technological organization involves investigation of why a society selects particular tool designs, and how it structures the manufacture, use, maintenance and discard of tools and associated debitage across the landscape. The model tested here associates the use of microcore technology with a design for a maintainable and transportable tool assemblage which conserves lithic material, and with a regional distribution focused on residential camps as the locus of microcore manufacture and microblade production and use. The model is tested through a comparative case study of archaeological tools and debitage from microlithic and non-microlithic sites in two upland valleys in the British Columbia Southern Interior Plateau. Research hypotheses and corresponding test implications are evaluated with data and analyses relating to core reduction and tool production stages, to tool use, and to activity area patterning within the sites. Results of hypothesis testing indicate that the model only partially explains the role of this particular standardized core technology in the study areas. Microcore technology is found to be associated with high residential and logistical mobility; a transportable, expediently-used tool assemblage; and the conservation of a specific raw material in one valley. Thus, this research proposes that microcore technology was a standardized technology which was variable in design goals and distribution, even within the same geographically and ethnographically defined region. / Arts, Faculty of / Anthropology, Department of / Graduate

The focus of this study is on means by which the spatial distribution of housing development can be explained. This involved firstly (I) identification of potential determinants of residential location and the verification thereof, and secondly (II) investigation into the applicability of the use of Clark's Theory of Exponentially Declining Densities as a predictor of housing unit completions. (I) Interviews with sixty-three developers in the Greater Vancouver Area were used to rank criteria used in their location decision-making. Regressions of some of the more important criteria were attempted with housing completions as the dependent variable. Analysis of the data demonstrates that housing unit completions of a subarea are strongly related to both its unused and total housing potential. The data does not support the developers’ contention that relative land price is an important locational determinant. Travel time from the central business district is not in itself a significant variable in explaining the spatial distribution of housing unit completions. (II) Less than 50% of the variation of population density is explainable in terms of distance from the CBD in the manner of Clark's relation: Population/Area = [formula omitted] here d is the distance from the central business district, and A and b are constants. Considerably better results (59% to 74% of the variation) are obtained with the inverse travel relations:Population/Area Zoned Residential =[formula omitted]and Housing Units/Area Zoned Residential = [formula omitted]where t is the travel time from the central business district. The existence of unused potential in a subarea as defined by the difference between the density observed and the density calculated (by Clark's Theory or by the Inverse Travel Time Relation above) is a significant predictor variable of whether or not residential construction will take place. However, the magnitude of the unused potential thus calculated is not a significant determinant of the actual number of housing unit completions. / Business, Sauder School of / Graduate

The objectives of this study were to obtain up-to-date statistics on the quantitative aspects of condominium development in Metropolitan Vancouver; to obtain a social profile of all condominium purchasers;' to obtain information on purchasers' reasons for buying condominiums rather than single-family houses, and their criteria for selecting a particular condominium development; to assess the extent of satisfaction expressed by condominium purchasers; to examine the past behaviour of condominium resale prices; and to obtain information on the conversion of rental apartments to condominiums. Information on the quantitative aspects of condominium development was obtained by examining records of condominium registrations in the Vancouver and New Westminster Land Registry Offices. This information was of interest in itself, and also provided the basis for a survey of condominium owners conducted to obtain information on the purchasers of condominium units. Ten per cent of the residents in each condominium project larger than nine units were surveyed to obtain data on purchasers' characteristics, their reasons for puchase, and the extent of purchaser satisfaction. Information on condominium resale prices was obtained by examining records of units sold through the Multiple Listing Service of the Real Estate Board of Greater Vancouver, and quantitative information on apartment conversion was obtained through a real estate consulting firm. The quantitative growth of condominium development was found to have been extremely rapid, with the annual increase in number of units registered averaging about 175 per cent between 1968 and 1971. Obviously such a growth rate could not be long sustained, and 1972 saw only 10 per cent more units registered than in 1971, but the high overall growth rate is indicative of substantial public acceptance of this new form of housing. The results of the purchaser survey are far too voluminous to be summarized here, but two general observations should be noted. The first is that there are substantial differences between purchasers of town house condominium units and purchasers of apartment type units. Apartment purchasers were found to be generally older, had fewer dependent children, more often considered their unit to be a permenent home, and placed different emphasis on the criteria for selecting a condominium. The second notable finding was the high degree of satisfaction expressed by condominium residents. Over 93 per cent indicated moderate or extreme satisfaction, and 86 per cent said that, based on their experience with condominium living, they would still have purchased their unit. Examination of condominium resale prices revealed that they had been quite static over much of the brief history of condominium development. However, a readily observable upward trend began in the latter half of 1972 and strengthened in 1973, which refutes earlier indications of a relatively slow rate of appreciation of condominiums. Some difficulty was encountered in obtaining information on apartment conversions, and essentially only the numbers involved were obtained. Since the City of Vancouver has at least temporarily frozen all conversions, the requirement for further research on this aspect of condominium development will depend on the resolution of the current political situation. Given the public acceptance of the condominium concept indicated by the rapid growth of condominium development, the degree of satisfaction expressed by condominium residents, and the recent strength observed in condominium resale prices, it is concluded that condominiums will continue to form an increasingly important segment of the Metropolitan Vancouver housing market. / Business, Sauder School of / Graduate

Nephrite is a compact, microfibrous variety of actinolite-tremolite in which bundles or tufts of minute fibers of the amphibole are twisted and thoroughly felted or interwoven with one another, producing a characteristic "nephritic" microstructure. In British Columbia, nephrite deposits, both in place and placer, are closely associated with a belt of alpine ultramafic rocks that extends for 1000 miles from the Hope area, east of Vancouver, northwestward to the Yukon border. The three major nephrite producing regions are the Bridge River - lower Fraser River area, the Takla Lake area and the Dease Lake area. The nephrite from British Columbia contains, in addition to essential tremolite, small amounts of chlorite, uvarovite, chrome spinel, diopside, talc, carbonate, sphene, phlogopite and pyrite. Grains of chrome spinel and uvarovite are usually visible in hand specimen. The colour of the majority of the specimens is yellowish green; this colouration is caused by the presence of iron in both the divalent and trivalent states. Polished surfaces of the nephrite have an average Vickers hardness of 950 Kg/mm² and an average Mohs hardness of 7. The average specific gravity is 3.00. The unit cell parameters of tremolite from British Columbia nephrite specimens are similar to those of nephritic tremolite from Siberia. X-ray diffraction data for the tremolite from these specimens are also in good agreement with those for nephritic tremolite from other localities. The nephrite specimens contain an average of 3.05 percent iron; small amounts of cobalt, nickel, manganese, copper, lead, zinc, chromium, titanium and vanadium are also present. Significant regional variations in the averages for iron, cobalt, manganese, copper, lead, zinc and vanadium are not observed when the specimens are grouped according to the area of origin; slight variations are observed in the average contents of nickel, chromium and titanium. The general similarity of the regional average values for these elements suggests that the nephrites have been formed in similar environments. At the O’Ne-ell Creek deposit in central British Columbia, nephrite occurs in a zone of tremolite-chlorite rock developed in serpentinite at the contact with metasomatically altered sediments. The nephrite has resulted from the metasomatic alteration, by addition of calcium and silica, of the serpentinite during the process of serpentinization. The calcium was derived from the pyroxenes contained in the original ultramafic rock; the source of the silica was the enclosing sediments. High concentrations of calcium and magnesium and relatively lower concentrations of sodium, iron, aluminum and silicon characterized the environment in which the nephrite formed. Calcium and sodium were perfectly mobile while the other elements were relatively inert. These conditions of mobility and concentration account for the fine fibrous nature of the nephritic tremolite. A temperature range of approximately 300°C to 500°C and a pressure in excess of 4 kilobars are suggested for the formation of the nephrite. / Arts, Faculty of / Geography, Department of / Graduate

Feeding habits of two coexisting species of Chaoborus, C.trivittatus and C.americanus, were investigated in lake and in laboratory experiments, and by an extensive survey of larval crop contents. The field study showed that C.trivittatus has a two year life cycle, migrates dielly during the summer season down to 20 m, and is the more abundant of the two Chaoborus species. C.americanus has a one year life cycle and migrates at most over a distance of only 5 m. Seasonal abundance and distribution of most plankton types found in Eunice Lake were monitored during 1971 and 1972. Zooplankton had a low standing crop and were mostly found above 6 m. Zooplankton size and swimming velocity and size of larval head parts were measured in the laboratory and, together with the above data on vertical distribution, were used to evaluate the availability of zooplankton as prey for Chaoborus. The lake and laboratory experiments showed that rates of larval feeding and digestion increase significantly with temperature. Temperature, however, does not seem to affect feeding rate of the 4th instar C.trivittatus larvae. Feeding rates increase with larval age and vary with prey type and density. From analysis of chaoborid crop contents, diet differences were found among all instars of the two species, and these were related to prey size, abundance, and distribution. The calculated percent of prey standing crop that the Chaoborus in Eunice Lake could potentially remove ranged from a minimum of 3% for nauplii to a maximum of 20% for Diaptomus kenai. Seasonal changes in Choaborus instar composition and in zooplankton species composition result in reduced predation on any single zooplankton group. The observed diet of Chaoborus larvae in Eunice Lake was shown to be closely related to the morphology of Chaoborus and their prey and to the relative distribution of predator and prey. / Science, Faculty of / Zoology, Department of / Graduate