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Joseph R. Desloges 《The Canadian geographer》1990,34(2):98-109
Changes in the grain-size distribution and the lithologi-cal I mineralogical properties of sandy-gravel sediments are used to discriminate between sources for the alluvial valley-fill of Bella Coola River, coastal British Columbia. Spatially variable bedrock sources, ranging from highly resistant quartz monzonites to easily weathered basalts, yield sediments that reflect parent rock characteristics. Local increases in the D95 fraction of bulk gravel samples and the D50 fraction of sand samples can be related to inputs from steeper, heavily glaciated tributaries, or those underlain by fractured basalts of the Fraser Plateau. Where there are similarities in the grain-size properties of the source and the sampled deposit, however, grain-size information alone cannot be used to discriminate between sources. The lithology of Bella Coola alluvium shows a close correspondence with the general distribution of rock types in the basin, suggesting proportional contributions from most tributary sources over the long term. However, sand samples from the floodplain have a mostly volcanic affinity, indicating the dominance of sediment derived from headwater tributaries underlain by this rock type. Admixture of plutonic source sediments is evident in lower Bella Coola River adjacent to alluvial fans, heavily glaciated tributary creeks or rock walls comprised mainly of quartz monzonite. Les changements dans la granulometrie et les proprietes lithologiques et mineralogiques des sediments de gravel sablonneux servent d differencier les sources des depéts alluviaux de la Riviere Bella Coola sur la céte de la Colombie-Britannique. La variation spatiale des sources fondamentales donnent des sediments qui refletent les caracteristiques de la roche-mbe variant des quartz rnonzonites très résistants aux basaltes superficiellement altérés par les agents atmospheriques. Les augmentations locales dans la fraction D95 des echantillons de gravel et la fraction D50 des echantillons de sable peuvent être reliees la contribution des tributaires aux pentes plus escarpees et fortement glaciaires ou ceux qui traversent les basaltes fractures du Plateau Fraser. Cependant, quand il y a des similitudes dans la granulometrie de la source et le dépôt-échantillon, l'information granulometrique seule ne peut pas 6tre employee pour differencier les sources. La lithologie des alluvions de Bella Coola montre une correspondance avec la distribution générale des types de roches dans le bassin, suggérant des contributions proportionnelles des sources tributaires a long terme. Cependant, les échantillons de sable des plaines sujettes à inondations ont en grande part une affinité volcanique, indiquant que la dominance du sédiment provient des tributaires qui traversent ce type de roche. Une addition de sediments de sources plutonique est evidente dans le bas de la Riviere Bella Coola adjacent aux eventails alluviaux, aux ruisseaux tributaires affect& par une forte glaciation, ou aux murs de roches qui comprennent principalement des quartz monzonites. 相似文献
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Hudson Mark J. Bausch Ilona R. Robbeets Martine Li Tao White J. Alyssa Gilaizeau Linda 《Journal of World Prehistory》2021,34(2):121-158
Journal of World Prehistory - From northern China, millet agriculture spread to Korea and the Maritime Russian Far East by 3500–2700 BC. While the expansion of agricultural societies across... 相似文献
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Debates about the future of small municipalities in Canada are set against a backdrop of economic, political, and social restructuring processes that have displaced former state investment policies in favour of neoliberal public policy approaches. Small municipalities struggle with outdated financial and governance structures and a provincial public policy agenda that asks them to become more creative, innovative, and “entrepreneurial” in their approach and responsibilities. Drawing upon key informant interviews with eight case studies in British Columbia, Canada, this research examines the tensions between municipal reforms mandated by the provincial government over the past 30 years and commensurate fiscal levers and capacities in place to address these broadening responsibilities for small municipalities in volatile staples-dependent regions. Our findings demonstrate how successive provincial governments have mobilized New Public Management objectives through a host of legislative and regulatory changes that have increased the responsibilities and requirements on local governments without commensurate fiscal or jurisdictional capacity. 相似文献
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In Westminster systems, governments enjoy a privileged position in the lawmaking process that they can use to deliver on their campaign promises and achieve their policy goals. What policy areas do governments seek to affect through lawmaking? How stable is the executive lawmaking agenda? How responsive is that agenda to changes triggered by elections or by transitions in prime minister? This study uses a dataset of 3982 Australian bills introduced between 2000 and 2017 to answer these questions. While it finds considerable stability in the policy content of executive lawmaking agendas, the analysis also indicates that Australia's executive lawmaking agenda is more responsive to changes in prime minister than to changes in the party in power. As the first application of the comparative policy agendas approaches to government bills in Australia, this article offers new insights into executive lawmaking priorities during an especially turbulent period in Australian politics. 相似文献
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