ABSTRACT: Zur Geomorphologie des Expeditionsgebietes Oobloyah Bay, N-Ellesmere Island, N.W.T., Kanada [Geomorphology of the expedition area Oobloyah Bay, northern Ellesmere Island, N.W.T., Canada]

CGRG Bibliography of Canadian Geomorphology
Search Results

Author :

Date :

Title :

Publication :

Issue :

Page(s) :

Abstract

The expedition area Oobloyah Valley is a broad syncline running E-W. The relief towards the N (Krieger Mtns.) is of a high alpine type with valley glaciers, steep slopes and arretes; towards south the lower mountains of the Neil Peninsula with icecaps and more or less gentle slopes are forming a mountainous type of relief. The floor of the syncline is an accumulation plain, which seems to be of a complex formation. There are indications, especially from C-14 dates, that the accumulation in these parts started well before the maximum ice advance at the southern fringe of the Wisconsinan ice sheet (ca. 18,000/20,000 B.P.). In addition, the walls of the Oobloyah valley do not show prominent glacial features. Therefore it seems that the Oobloyah Valley has not been glaciated around 20,000 B.P. That corresponds with the NE fringe of the Wisconsinan ice sheet (IVES, 1978), and it fits with the model of ENGLAND (1976 a, 1976 b); BRADLEY & ENGLAND (1977) for N Ellesmere. The deep fiords and the erratics on Neil Peninsula are perhaps only indications for at least one former bigger glaciation. The landforms in Oobloyah Valley (slopes etc.) are well adapted to a periglacial environment. This is probably due to the fact that their development took a longer time than hitherto assumed and not only to a very high periglacial activity. Following the dates for raised beaches of other parts of northern Ellesmere Island the valley plain (ca. 75 m a.m.s.l.) has been formed around 7,000 B.P. Even if the sedimentation of the sandy material started well before 20,000 B.P. it is possible that around 7,000 B.P. the uppermost part of this plain has been formed in relation to the sea level of this time. Therefore our old C-14 dates are related to the age of the sediment and not necessarily to the age of the form. According to the hypothesis of excessive valley formation in Polar regions (BUDEL) we have to expect regular long profiles for rivers. That is not the case in the Oobloyah Bay region. The lower parts of Heidelberg and Nukapingwa River are steep and irregular. Fluvial valley formation has been relatively slow, despite high transportation rates. The area can therefore be looked upon as a region formed by high arctic periglacial processes of a probably long duration with low intensity of fluvial downcutting, but partly strongly influenced by glacial activity.

Bibliography of Canadian Geomorphology