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A lead isotope study of selected precious metal deposits in British ColumbiaAndrew, Anne January 1982 (has links)
Lead isotope analyses of galena from multiple ore deposits restricted to specific tectono-stratigraphic terranes can provide information on the age and origin of the lead. In this thesis, three separate studies of lead isotopes applied to the metallogenesis of parts of the Canadian Cordillera are presented.
Lead isotope data from quartz-gold vein deposits and volcanogenic and related deposits in the Insular Belt group plot in four distinct clusters on Pb-Pb plots. Each cluster corresponds to a specific deposit type and host rock category. Two parallel evolutionary trends in the lead isotopic composition exist: 1) Sicker-hosted volcanogenic deposits to Sicker-hosted veins, and 2) Karmutsen and Bonanza-hosted volcanogenic and related deposits to Karmutsen and Bonanza-hosted veins. The trends indicate a genetic relationship between host rock and isotopic composition. These observations favour a host rock source for the lead in vein deposits and, by association, a comparable source for the gold. Plutonic or abyssal direct sources of metals are not consistent with the lead isotopic data.
It is suggested that the gold was extracted from the country rock, and concentrated as veins by hydrothermal activity related to Tertiary plutons. Vein deposits are isotopically distinct from volcanogenic and related deposits, providing an empirical test for distinguishing syngenetic from epigenetic deposits. Karmutsen and Bonanza-hosted deposits are more
depleted in 207Pb than similar deposits in Sicker Group rocks, indicating significantly different sources for volcanic components of these two important rock units.
Lead isotope data from quartz-gold veins in the Cariboo area of the Omineca Belt, and from similar veins in the adjacent Intermontane Belt indicate that these two vein types are genetically unrelated. A mid-Mesozoic model age calculated for the Cariboo gold mineralisation event indicates that all of the deposits examined are clearly epigenetic, despite reported stratiform textures at the Mosquito Creek mine. K-Ar dates from a quartz-barite vein and from regionally metamorphosed phyllite support a synmetamorphic origin for the veins, but a distal plutonic origin is not ruled out.
Recent work by Godwin and Sinclair (1982) has shown that syngenetic, shale-hosted, sedimentary exhalative deposits in the autochthonous part of the Canadian Cordillera contain lead which has evolved in a high U/Pb environment. This 'shale' curve evolution model applies to deposits which have an upper crustal (host-rock) lead source. Ainsworth-Bluebell, Carmi and Slocan camps, and lead associated with the Moyie intrusions, all contain lead which plots substantially and variably below the 'shale' curve. Their departures from this curve provide evidence for a second, uranium poor, possibly lower crustal lead source, for which a growth curve, referred to as the Bluebell curve, can be constructed. The lead data are interpreted within the framework provided by these two growth curves.
Mixing of lead between these two lead reservoirs is
proposed to explain the linear array of data from Slocan and Carmi camps. Mixing lines, joining points of equal time on the two growth curves, provide a method for interpreting lead data from these deposits. Introduction of relatively unradiogenic lead into the upper crust via magmas which originated in the lower crust is invoked to explain the mixing.
The three studies considered here illustrate the differences in lead isotopic characteristics of different tectono-stratigraphic terranes and show that the development of local models for the interpretation of common lead isotope data has application to exploration. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
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The sedimentology, petrography and geochemistry of some Fraser Delta peat depositsStyan, William Bruce January 1982 (has links)
On the recent lobe of the Fraser River Delta, peat deposition is occurring in three distinct settings: the distal delta plain, the transitional upper delta to lower delta plain, and the upper delta plain to alluvial plain. Each de-positional setting contains a unique sequence of lithofacies and biofacies.
Distal lower delta plain peats, although widespread, form a thin, discontinuous peat network dominated by a sedge-grass facies. The peats contain numerous intercalations of silt and silty clay, with a moderate to high pH and a high concentration of sulphur values. The peats overlie a thin fluvial sequence, which in turn overlies a thick coarsening upward sequence of prodelta clay and silty clay. Peats from this environment will form thin lenticular seams of high ash and high sulphur coal. The coal maceral precursors in the peat suggest that the base of the coal will be comprised mainly of desmocol1inite, whereas near the top of the seam oxyfusinite, macrinite, and interlaminated cutinite and vit-rodetrinite would be common.
Initial lower delta plain-upper delta plain peats developed from interdistributary brackish marshes. High concentrations of sulphur and ash in these peats decreased in overlying freshwater sedge-grass facies as the delta prograded and the natural levees formed. Sphagnum dominated communities
eventually succeeded in areas where fluvial influence was minimal. Laterally, however, along active channel margins, sedge-grass peats intercalate with silty clay overbank and sandy splay deposits. A thin fluvial unit of fining upward sand, silt and clay and a thick sequence of coarsening upward prodelta clay and silty clay underly the deposit. These peats will form relatively thick, widespread coal seams. The seams will be thin and possibly discontinuous adjacent to channels and areas where extensive splaying has occurred. High sulphur concentrations will be confined to the base of seams. The maceral precursors suggest that interbanded telenite, cu-tinite and cerenite will be abundant in the base of the seam and will grade vertically into suberinite, telocollinite, and telenite rich coal. Stumps which will form massive telenite will occur locally.
Alluvial plain peats accumulated in freshwater backswamp environments. Earliest sedge-clay and gyttjae peats developed over thin fining upward cycles of silty sand, silt and clay and inter laminated silt, and silty clay of flood origin. Overlying sedge grass and Sphagnum peats are horizontally stratified and form sharp contacts with.bordering flood sediments, at active channel margins, sedge-grass peats intercalate with overbank silty clay to form well developed natural levees, these peats will form a thick seam of high quality coal. The microlithotype composition is comprised of vitritic carbar-gillites and liptites near the base of the seams, and will shift to a clarite and then primarily vitrite near the top.
Compared to delta plain peats, maceral distribution will be less complex. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
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The evolution of the Thor-Odin gneiss dome and related geochronological studiesDuncan, Ian James January 1982 (has links)
The Thor-Odin gneiss dome is one of several structural culminations along the eastern margin of the Shuswap terrain. The gneiss domes have previously been ascribed both to diapiric uprise of granitic gneisses and to interference of late-stage buckle folds. The ages of rocks in the gneiss domes have also been the subject of controversy. Age estimates range from Archean to Mesozoic. This study provides the basis for a detailed model for a new interpretation of the structural evolution of the Thor-Odin gneiss dome.
Prior to doming, this area was characterized by the formation of large-scale nappe structures and imbrication of Archean basement rocks with the cover rock sequence. The first period of deformation (Phase One) consisted of large-scale infolding of the cover rock sequence into the basement rocks. The Pingston fold in the core of the dome is a product of this event. The second period of deformation (Phase Two) was marked by the forcing of wedges of basement into the cores of northerly-moving nappes. The third period of deformation (Phase Three) was co-axial with Phase Two and consisted of imbrication and refolding of the upper levels of the stack of Phase Two nappes.
Strain analysis based on fold shape, distorted lineation patterns and elliptical strain markers demonstrate that finite strains are highest in the imbricated zone between the Basement Cored Nappe Domain and the Cover Rock Domain. Flattening strains are anomalously low in the Autochthonous Core Gneiss Domain. Analysis of Phase Two fold axes distorted into flattened small circles by Phase Three folds shows that Phase Three strain magnitude √(λ₂/ λ₁) varies from 0.81 to 0.49.
Rb-Sr whole rock geochronometry has revealed evidence for three Precambrian events within the basement gneisses. Unmigmatized metasedi-mentary basement gneisses form a six-point errorchron with an age of 2.73±0.20 Ga. Granitic gneisses previously dated at 1.96 Ga by the U-Pb zircon technique, give reset ages for gneiss/vein whole rock suites with ages in the range 750 to 860 Ma.
Common lead systematics of stratabound sulfide deposits in the cover rock sequence suggest that the cover rocks are Cambrian in age, in agreement
with earlier lithological correlations. The lead isotope ratios suggest the deposits were ultimately derived from an approximately 2.0 Ga basement terrain. The outcropping gneissic basement rocks of the Shuswap are dominantly granitic gneisses which give 2.0 to 2.2 Ga Rb-Sr whole rock dates.;
Ductile deformation in the terrain appears to have ended by 150 Ma, as this corresponds to the ages of several post-tectonic intrusions which crosscut Phase Three folds and impose a contact metamorphic overprint on the regional metamorphic pattern. The Nelson Batholith is a post-tectonic batholith which intrudes both the Shuswap terrain and the Kootenay Arc to the east. Two sample suites were collected from the different batho-lithic phases and analyzed by Rb-Sr whole rock methods with the following results:
Suite I - Porphyritic monzonite with alkali feldspar megacrysts from the West Arm of Kootenay Lake give a seven-point isochron with an age of 158 ± 16 Ma and an initial ratio of 0.7069 ± 0.0001. Suite I has a Rb-Sr feldspar,
date of 153 ± 26 Ma, a K-Ar hornblende date of
143 ± 5 Ma, and a K-Ar biotite date of 60 ± 2 Ma. It seems likely that the K-Ar dates have been disturbed by thermal events subsequent to emplacement of the batholith. Suite II- Medium grained granodiorite from the southern tail of the Nelson Batholith gives a nine-point whole rock isochron with an age of 162 ± 6 with an initial ratio of 0.7065 ± 0.0001.
Taken together, these data provide significant new information on the nature and timing of the events that formed the metamorphic core zone of the southern Canadian Cordillera. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
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The role of grass-legume communities in revegetation of a subalpine mine site in British ColumbiaYamanaka, Koji January 1982 (has links)
This study describes an investigation of the potential for pioneer grass-legume communities to stabilize and ameliorate geologically-fresh soil leading to the establishment
of a self-sustaining, progressive plant succession on a surface-mined subalpine site.
The study area is located 2,000 m above sea level in the Canadian Rocky Mountains. Field surveys at the site indicated extremely limited invasion of reclaimed areas (3-7 years old) by native species from the adjacent subalpine forest. Soils on revegetated sites were generally warmer and drier than soils of the associated forest and have less than half the content of fine soil fragments (<2 mm).
Field studies revealed chronological trends in grass-legume communities at four sites revegetated during 1974-1978 including: species composition, legumes (Trifolium repens L., T. hybridum L. and Medicago sativa L.) performing increasingly poorly on the older sites; biomass changes, a shoot to root ratio (S/R) decreasing from 2.3 to 0.2 as the communities aged; and litter accumulation which continued even on the oldest site.
Fertilizer (13-16-10) operationally applied at 150 -391 kg/ha enhanced the growth of Dactylis glomerata L. and litter degradation, and acidified the soil. Nitrogen fertilization
was also associated with two clear inverse relationships identified between D. glomerata and Festuca rubra L. biomass, and between soil pH and phosphorus levels.
In greenhouse tests grasses were revealed to be more efficient soil nitrogen consumers than were legumes and nitrogen fixation decreased significantly (P<0.01) and linearly with increasing grass seeding rates. In the presence of grasses, nitrogen fixation was positively correlated with aboveground legume biomass at all nitrogen fertilizer levels tested. The results further revealed that operational seeding and fertilizer rates at this site may not optimize plant productivity and the ability of legumes to fix nitrogen symbiotically. Field trials based upon the experimentaly derived combination (17.5 : 30 : 50 kg/ha grass seeding rate : legume seeding rate : nitrogen fertilizer rate) would be desirable to evaluate these data on the site.
Other potential practical implications from this study
are:
(1) The need for improved legume establishment, involving legume seed germination, species and variety selection, and selection of Rhizobium strains.
(2) Improved control of the operational fertilizer application.
(3) Alteration of grass and legume species composition of the present seed mix.
(4) Selective placement of initial material (overburden or spoil) handling.
A modification of the acetylene reduction assay, "the open system" technique, was developed for evaluation of legume nitrogen fixation of mine spoils. Although the unit developed is limited to detection of the presence or absence of ethylene, calibration with the closed system of ethylene
levels obtained by the open system appeared feasible. Further refinement of the system for quantitative use would increase its usefulness in nitrogen fixation studies of legumes on mine spoils, nitrogen fixing woody plants in forests, and legumes in grassland sods. / Land and Food Systems, Faculty of / Graduate
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Sedimentology of the lower cretaceous gates and moosebar formations, northeast coalfields, British ColumbiaCarmichael, Scott M. M. January 1983 (has links)
The Lower Cretaceous Gates and Moosebar Formations in the Northeast Coalfields of British Columbia comprise a 350-450 m thick interval of marine and non-marine, coal bearing clastic sediments. The Moosebar Formation and lowermost unit of the Gates Formation (the Torrens Member) consist of between 2 and 4 coarsening-upward marine cycles. In the northern part of the study area, non-marine sediments in the Gates Formation occur interbedded with 3 major marine tongues (the Sheriff member, Falher C and Babcock member) which pinch out towards the south. In the study area south of Duke Mountain, sediments in the Gates Formation above the Torrens Member are entirely non-marine.
The coarsening-upward marine cycles in the Moosebar-lower Gates interval were deposited mainly during regressions when the shorelines prograded northwards. The cycles are comprised of up to 3 main facies interpreted as offshore, transition zone and shoreface-beach (and locally distributary channel) deposits. Thin transgressive deposits are present at the base of the Sheriff member. Lower Gates shorelines are interpreted as high energy and wave dominated. Shoreline trends for the Torrens, Sheriff and Babcock Members are approximately E-W, and approximately NW-SE for the Falher C.
Non-marine deposits in the Gates Formation are interpreted as forming in lagoons, fluvial channels and overbank environments within a coastal plain setting. The channels are mainly braided river types with anastomosing or straight (non-braided) and meandering river channels also present. The rivers flowed towards the northwest, north, northeast and east with
northeasterly directions most common. Up to three separate very coarse fluvial conglomerates, interpreted as proximal braided river-alluvial fan deposits are present in the south near Mount Belcourt. Overbank sediments were deposited in levee, crevasse splay, lacustrine and well to poorly drained swamp environments The upper Gates marine unit (Babcock member) contains both transgressive and regressive deposits. Three types of transgressive deposits are recognised:
1. Thick (maximum 40 m) estuary mouth |shoal retreat massif) sandstones and conglomerates preserved in linear belts approximately 0.4-2 km wide trending NW-SE and N-S.
2. A thin (maximum 90 cm) but laterally extensive marine lag.
3. Lagoon-intertidal deposits.
Upper Gates regressive deposits include shelf to shallow marine sandstones overlain by estuarine subtidal channel and shoal deposits which in turn are overlain locally by tidal flat and coastal plain deposits with thin coal seams. Upper Gates shorelines appear to be strongly tidally influenced.
Thick (maximum 10 m), laterally extensive coal seams occur in the lower part of the Gates Formation. Coal seams in the upper Gates are thin (generally <1.0 m). With the exception of few very thin seams, the Gates coals appear to be entirely autochthonous and to have accumulated as peat in swamps in a coastal plain depositional setting. Some of the coals in the lower Gates were deposited in swamps which extended inland for at least 75 km from the shoreline. The maximum coal development in the Gates Formation (28 m total coal and 6 seams >1.5 m thick) occurs in the Foothills south of Kinuseo Creek, near the
boundary between transitional marine and non-marine facies belts.
Cross-sections based on closely spaced borehole and outcrop sections illustrate the occurrence and distribution of coal seams in the Duke, Honeymoon, Babcock, Frame and McConkey Pits. Thinning and pinchout of coal seams occurs adjacent to fluvial channel and splay deposits and near the landward pinchout of the Sheriff member. Draping of coal seams over fluvial channel deposits causes rapid variations in interseam thickness which may lead to correlation problems in the early stages of exploration and affect the potential mineability of coal seams.
The main detrital components in the Gates sandstones are quartz and chert with siliceous rock fragments, carbonate rock fragments, clastic sedimentary and metasedimentary rock fragments, igneous rock fragments and feldspar present in lesser amounts. Mesozoic to Cambrian sedimentary rocks of the Rocky Mountain Front and Main Ranges are interpreted as the principal source of the detrital components. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
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Partnerships for affordable housing: an examination of the barriers faced by municipalities and the non-profit housing sectorGarnett, Lee-Ann Gail 05 1900 (has links)
The changes in housing policy during the 1990s has been profound. With federal funds for
non-market housing no longer available, the Province of British Columbia has attempted to
involve municipalities to a greater extent in meeting the housing needs in their communities.
However, this has proved to be an immense challenge for many municipalities. Nevertheless,
many have reported that they use, or in the future will use, partnerships with other
organizations to obtain more affordable housing in their communities. Specifically,
partnering with non-profit housing organizations is seen as one means of achieving this. The
non-profit organizations, too, find building more affordable housing a challenge, and are
interested in working with municipalities where possible. The intent of this research, then, is
to analyze the relationships between local governments in B.C. and non-profit societies, and
identify some of the barriers that each party faces. The research also examines the roles of
some of the other participants in affordable housing.
For municipalities, the barriers faced by them to enter housing partnerships are great. A lack
of resources, the absence of staff dedicated to housing issues, the lack of staff expertise
required to analyze complex housing partnerships, and a lack of commitment on the part of
politicians all contribute to the difficulties in having these agreements. The non-profit
housing groups also face deterrents, such as small staff sizes, few resources, in some cases,
little expertise in development, or ageing board members who do not wish to build new
housing. These barriers, however, are not insurmountable, and recommendations are
provided to overcome them.
It is important to realize that although housing partnerships can be a very effective tool, they
are just one of many that municipalities use to meet the housing needs in their communities.
Ultimately, housing needs will best be met by having all levels of government, the private
and non-profit sectors working together towards common goals. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
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The impact of modernization on British Columbia electoral patterns : communications development and the uniformity of swing, 1903-1975Wilson, Robert Jeremy January 1978 (has links)
This study explores changes in British Columbia electoral
patterns during the twentieth century, and relates these changes to dimensions of societal and political modernization. It focuses on swing, the percentage point shift in a party's support between two successive elections, and examines constituency- arid sub constituency-level results in provincial elections between 1903 and 1975. The thesis tested is that development of the province's communications infrastructure was a central cause of the electoral developments
which took place.
The first part of the study clarifies the electoral developments by tracing changes in the level of swing uniformity
and the degree of swing patterning. It begins with evidence that swings became much more uniform as the century progressed. Analyses of electoral shifts in constituencies and nonmetropolitan communities both show that swings of parallel direction and magnitude were much more likely in elections after 1952. This trend to swing uniformity is taken to indicate a decline in the importance of local electoral
forces. It is hypothesized that the twentieth century communications revolution contributed to this decrease in electoral localism by facilitating the establishment of locality-arching patterns of political influence.
After demonstrating the increase in swing uniformity, we examine three developments which could explain the trend. The premise underlying this part of the study is that increased patterning of swing by the characteristics of constituencies or communities may account for increased uniformity. Tests for cross-election changes in the explanatory
power of three variables—electoral competitiveness, socio-economic composition, and region—show that the overall decline in swing variance was not accounted for by increased patterning. The trend to uniformity was unpatterned; voter aggregates with different characteristics and locations were simply more likely to produce parallel swings in later elections.
The second part of the study explores the reasons for these developments. The communications development interpretation
is tested and alternative interpretations are considered. The communications interpretation argues that improvements in communications infrastructure contributed to an increase in the uniformity of electoral forces operating on dispersed constituencies and communities, and thus helped to bring about increased swing uniformity. Chapters 7 and 8 test four propositions which are derived from this interpretation.
These state: (a) that there should be a detailed correspondence between the pace of communications development and the trend to swing uniformity; (b) that the appearance of intense regional communications patterns should predict the
regional swing patterns which marked the 1969, 1972 and 1975 elections; (c) that regional differences in the timing of the trend to uniformity should be explained by differences in the pace of communications development; and (d) that communications
isolation should explain the tendency of some contemporary communities to swing in ways which indicate that they are insulated from prevailing electoral forces.
The results of these tests enhance the credibility of the communications interpretation. In speculating about alternative interpretations we acknowledge that a complete causal map would have to grant other factors an important place. But the evidence supporting the test propositions, and the fact that the most plausible alternative interpretations
complement the communications interpretation, argue that communications change was a principal cause of the provincialization of British Columbia electoral politics. Communications modernization altered the relationship between geography and the spatial distribution of electoral results. / Arts, Faculty of / Political Science, Department of / Graduate
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The role of leadership in the "spotlight campaign's" community mobilizationLougheed Green, Elizabeth. 10 April 2008 (has links)
No description available.
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Wilderness or working forest? : British Columbia forest policy debate in the "Vancouver Sun", 1991-2003Stoddart, Mark Christopher John. 10 April 2008 (has links)
No description available.
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The disciplining (professional conduct) of registered nurses in British Columbia from 1918 to present day : an historical inquiryMilner, Cynthia Louise. 10 April 2008 (has links)
No description available.
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