GLACIAL FEATURES OF THE HEARST‐COCHRANE MAP‐SHEET AREA: An Aerial Photograph Reconnaissance

• Published in: Canadian Geographies / Géographies canadiennes
• Main Author: Dean, W.G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1956
• Subjects: Antevs; Hearst; Ice Sheet; James Bay
• Online Access: http://dx.doi.org/10.1111/j.1541-0064.1956.tb01777.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1541-0064.1956.tb01777.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1541-0064.1956.tb01777.x

A number of glacial landform features which are interpretable from aerial photographs are described for the area covered by the Hearst‐Cochrane 8 miles to 1 inch map sheet. These include both the drumlinoidal patterns created by moving ice sheets, and various glacio‐fluvial and outwash landforms associated with the recession of continental glaciers. Sequence of late‐Wisconsin events is postulated as a working hypothesis. In the subsequent discussion of the distribution and nature of these landforms a sequence of late‐Wisconsin events is postulated as a working hypothesis. The hypothetical series of events worked out mainly on the basis of the evidence provided by the aerial photograph interpretation, may be briefly enumerated as follows:‐ A late‐Wisconsin glacial advance from the northeast ‐ the Labradorean In the subsequent discussion of the distribution and nature of these landforms a The hypothetical series of events worked out mainly on the basis of the evidence glacier ‐ presumed to be correlated to the Mankato ice advance. Recession of the Mankato (?) ice‐sheet, along with the formation of a proglacial lake and a possible marine invasion. A second glacial advance from the northwest covering all but the southern sections of the map‐area and the complete o r partial destruction of mariy of the eskers and other landforms of the Mankato (?) advance. Recession of the second glacier and the creation of Lake Ojibway as well as the large eskers, with their associated esker deltas, of the northeastern area of the map. Continued recession of this ice sheet no doubt allowed the complete drainage of Lake Ojibway and possibly the beginnings of marine inundation in the James Bay area. A readvance took place (Antevs'‐ Cochrane readvance) from the region to the north of the area of the Hearst‐Cochrane map‐sheet. This readvance took a asymmetric lobate form, and in part moved southward as far as approximately the latitude of Iroquois Falls where it formed kame deposits. This readvance also left a thin mantle of silty till ...