Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 48-52). Also available via the World Wide Web.

The objective of this study is to reconstruct the history of glaciation from the start of Fraser (Late Wisconsinan) Glaciation to the end of deglaciation, for three areas in the Cascade Mountains. The Cascade Mountains are located between the Coast Mountains and the Interior Plateau in southwestern British Columbia. The Coast Mountains were glaciated by mountain glaciation followed by frontal retreat, whereas the Interior Plateau underwent ice sheet glaciation followed by downwasting and stagnation. The Cascades were supposed to have undergone a style of glaciation transitional between these two. Terrain mapping on air photographs followed by field checking was used to locate surficial materials and landforms indicative of glaciation style and pattern. All three study areas were glaciated by mixed mountain and ice sheet glaciation. At the start of Fraser Glaciation, alpine and valley glaciers formed around higher summits as occurred in the Coast Mountains. At the glacial maximum the entire area was covered by the Cordilleran Ice Sheet. Deglaciation was largely by continuous downvalley retreat of active glaciers, contrasting with downwasting and stagnation in the Interior Plateau, and frontal retreat in the Coast Mountains. The scarcity of fresh moraines in the cirques suggests that, unlike in the Coast Mountains, most cirque glaciers were not active at the end of glaciation. Only the highest north facing cirques remained above the local snowline throughout deglaciation and, as a result, glaciers in these valleys remained active and retreated up valley. The pattern of glaciation in the Cascade Mountains was similar to that of other areas which underwent mixed mountain and ice sheet glaciation, such as the Presidential Range in New Hampshire, the Green Mountains in Vermont, mountain ranges in west central Maine and the Insular Mountains on Vancouver Island. However, deglaciation in al l areas was complex and depended strongly on local conditions. For this reason local patterns cannot be predicted easily on the basis of glaciation style. The value of an understanding of glaciation style to improve the accuracy of terrain mapping was also investigated. It was found that the model developed for the Cascade Mountains was of some use in predicting the presence of fine-textured material in valley bottoms and for the prediction of glaciofluvial material overlying till . However fine-textured sediments were not found in al l valleys which were predicted to contain them. The model appears to be most useful as an indicator of where to concentrate field checking in order to locate fine-textured sediments. / Arts, Faculty of / Geography, Department of / Graduate

Little Ice Age (LIA) deposits are recognized on Mt. Tbielsen, southern Oregon Cascades (43° 9' N, 122° 3' W), based on particle morphology and relative position. The initial advance, Lathrop 1, created a sharp-crested moraine and a protalus rampart within 200 m of the headwall. The retreat of the glacier and recent ice movement, Lathrop 2, is recognized by the deformation of the moraine and a mantle of "protalus till" creating a polygenetic "push-deformation'' moraine. Both the moraine and the protalus rampart have sparse vegetation, no lichens, and a lightly weathered Cox/C soil. This sequence is correlative with LIA Phase 1 and Phase 2 on Mt. Jefferson, central Oregon Cascades, and is broadly correlated with LIA deposits throughout the Cascades, Sierra Nevada, and Rocky Mountains. There is no evidence for pre-LIA deposits at Mt. Thielsen. The ELA on Lathrop Glacier (2450 m) is lower than ELAs on nearby glaciers. The glacier probably exists because of its preferential topographic position and extensive debris cover; thus, if annual snowfall decreases the glacier will persist longer than a similar sized bare ice glacier. Conversely, a growing protalus rampart may indicate an increase in annual snowfall but not necessarily a decrease in annual temperatures. The lack of older Neoglacial deposits on Mt. Thielsen may be a result of insufficient snowfall to maintain or advance the Lathrop Glacier. As such, the LIA may represent a period when climatic conditions were more severe than at any other time in the Neoglacial. Boulder size, shape, and orientation proved useful for classifying geomorphic features and assessing the relative ages of slopes. However, soils are the best method for correlating deposits in the cirque with other locations. Soils beyond the moraine are developed in Mazama ash and have moderately developed Bw horizons, depth to weathering over 70 cm, and Harden's PDI for B horizons of 2.10-3.64. Soils are Typic Vitricryands.

No description available.

The Churchill Falls are a second Niagara. They are situated in the interior of Labrador, about 200 miles from the nearest point of the open Atlantic coast, and about 225 miles north of the Gulf of St.Lawrence (figure 1-1). [...]

Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references (leaves 289-292). Also available via the World Wide Web.

No description available.

No description available.

The Muncie esker, a glaciofluvial ridged system, consists of three sharp-crested esker segments in the proximal and central sections, and a broad=crested, fan shaped distal segment. Grain size ranged from clay to boulders, although a larger presence of coarser material with high standard deviation values occurs in the proximal and central segments, while higher concentrations of finer sediment, primarily sand, exists in the distal segment. Field mapping and description included its geomorphic expression, stratigraphic relationships that consisted of facies identification, sedimentary structure , and paleocurrent direction. Sedimentological parameters, including downesker trends in grain size, sorting, a fractal analysis of grain size persistence, and clast roundness, was also investigated.The interpretation of the results provided us with detailed information allowing us to formulate a specific model of esker genesis. The depositional model consists primarily of nearly continuous, contemporaneous subglacial deposition that reulted in the formation of the proximal and central esker segments, and time-transgressive sedimentation, containing interlayered and randomly distributed ice rafted debris, in the form of a subaqueous delta that prograded beyond the ice-margin, forming the distal esker segment. Early stage deposition consisted of bed load transport from moderate flow velocities within a preglacial bedrock valley that served as an R-channel for preliminary subglacial meltwater drainage. Intermediate stage formation consisted of subglacial sedimentation from a hyperconcentrated deforming bed, induced by an outburst flood, and distal deltaic sedimentation as the subglacial flood discharged beyond the ice margin into an ice-marginal lake. Late stage deposition arises from bed load sedimentation of moderate fluvial activity reworking the upper portions of the hyperconcentrated flow deposits and upper deltaic facies. The finality of esker formation concluded with the ablation of the subglacial tunnel roof, sending a supraglacial debris flow that conformably covers the proximal and central esker segments in the form of a diamicton drape. / Department of Geology

I tested if spatial variation of Ohio River drainage basin fish assemblages, current habitat, water quality, and hydrology were concordant with historic glaciation boundaries. Assemblage analyses were organized using taxonomic and functional groups. Multivariate analyses, principal components analysis (PCA) and indicator species analyses, were used to test whether taxonomic and functional assemblages were distinct among regions with varying glacial histories. Principal components analysis was used to identify habitat and water quality as well as hydrologic gradients that could be discerned by glacial region. I identified significant differences in both taxonomic and functional fish assemblage structure and habitat variation among regions that had different glaciation histories. Recently glaciated Wisconsinan sites were characterized by assemblages of Cyprinidae and Catostomidae families, with high abundances of tolerant fishes that tended to occur in habitats with reduced current velocity. Sites in the Pre- Wisconsinan region were characterized by Cyprinidae, Catostomidae, Centrarchidae, and Percidae families, with increased abundances of intolerant fishes that tended to occur in habitats with coarser substrates and increased water velocity in streams of varying size. Sites in the unglaciated region were dominated by Cyprinidae and Percidae families but were not closely associated with any habitat-based functional group. Taxonomic and functional analyses explained 25% and 40%, respectively, of the variance in assemblage structure. Mean habitat PCA component scores in the unglaciated and Pre-Wisconsinan sites were significantly different than Wisconsinan sites, which were characterized by increased channel structure and reduced stream size. While a multitude of factors impact the distribution of fishes, these results suggest that historical influences such as glaciation may be used to further explain underlying mechanisms of spatial variation in fish assemblages. / Department of Biology