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Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska /Blair, Mehgan O'Hearn. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 48-52). Also available via the World Wide Web.
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The Fraser Glaciation in the Cascade Mountains, southwestern British ColumbiaWaddington, Betsy Anne 05 1900 (has links)
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
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The Neoglacial History of Mt. Thielsen, Southern Oregon CascadesLafrenz, Martin Dietrich 08 June 2001 (has links)
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.
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The abandoned glacial lake shorelines of southwest Labrador.Harrison, David Alan. January 1964 (has links)
No description available.
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Glacial geomorphology of the Churchill Falls area, Labrador.Morrison, Alastair. January 1966 (has links)
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). [...]
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Late Pleistocene glacial geology of the Hope-Waiau Valley system in North Canterbury, New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosopy in Geology in the University of Canterbury /Rother, Henrik. January 1900 (has links)
Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). "August 2006." Includes bibliographical references (leaves 289-292). Also available via the World Wide Web.
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The glacial geomorphology of the Shoal Lake area, Labrador /Cowan, William Richard January 1967 (has links)
No description available.
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The glacial geomorphology of the Shoal Lake area, Labrador /Cowan, William Richard January 1967 (has links)
No description available.
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A depositional model for the Muncie Esker, East-Central IndianaTerrell, Mark A. January 1997 (has links)
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
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Impacts of past glaciation events on contemporary fish assemblages of the Ohio River basinJacquemin, Stephen J. January 2010 (has links)
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
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