It has been known for some time that the drainage patterns of Alberta present some abnormal features which are rather difficult to explain by diversions caused by ice advance and retreat, or by the effect of preglacial stream courses (Bretz, 1943 and Warren, l944). Recently there has been found in the Alliance-Kinsella district of east-central Alberta a confused system of interconnected debris-filled channels which are intimately tied to the drainage problems of the larger stream courses of Alberta. Similar channels, or stream-trenches, have been noted on air photographs of the Stettler district, and it seems probable that the conditions which caused the stream trenches in the Kinsella district were widespread over central Alberta. The fact that most of the stream trenches are filled with moraine and stratified materials suggested to the authors that the trenches antedated the last glacial advance. A detailed examination of the Kinsella district, however, has provided evidence to suggest that these debris filled trenches are contemporaneous with the retreat of the last ice and formed in openings in stagnant ice. The realization of the age of these trenches does much to clarify some of the major problems of drainage in Alberta.
Gravenor, C.P. and Bayrock, L.A. (1956): Stream-trench systems of east-central Alberta; Research Council of Alberta, RCA/AGS Earth Sciences Report 1956-04, 15 p.