370 THE GLACIAL LAKE AGASSIZ. 



Creek. It evitleutly marks, at least approxiuiatel}', the liigliest sliore of 

 the glacial lake; but it bears no distiuct beach ridge nor line of erosion, 

 partly because the lake was so shallow on the adjoining delta area, and partly 

 because the prevailing trends of the inequalities in the till surface run 

 nearly from east to west, transverse to the course of the shore currents and 

 drift by which beaches would be formed, thus intercepting the scanty 

 deposits of beach gravel and sand in their hollows, instead of permitting 

 them to be accumulated in a distinct ridge. 



The Manitoba and Northwestern Railway crosses two beach ridges at 

 3f miles and 3 miles west of Neepawa, the crests of which are respectively 

 1,323 and 1,304 feet above the sea. These elevations indicate that they 

 belong to subdivisions of the second Herman stage, in the same manner 

 that this stage is represented by three beach lines at Treherne. Each of 

 thes'e ridges has a height of about 7 feet above the adjoining surface and 

 a width of 30 to 40 rods. They consist of sand and gravel, and the rail- 

 way company has therefore purchased a considerable tract occupied by 

 the lower one of them for its excavation and use as railway ballast. This 

 lower beach probably marks the same lake level as the beach observed at 

 Brandon, having tliere an elevation of 1,260 to 1,269 feet. Gravel and 

 sand brought into Lake Agassiz by Stony Creek seem to have contributed 

 to the conspicuous developuient of beach deposits here, while they are 

 wanting or less distinct upon most of the shore southward to Brandon and 

 also northward through the next 12 miles to where the Herman and Nor- 

 cross shores pass into the steep escarpment that forms the eastern face of 

 Riding Mountain. 



DELTA OF THE ASSINIBOINE RIVER. 



(plate XXXIII.) 



At Brandon the Assiniboine enters the area of Lake Agassiz, and thence 

 the gravel and sand delta of this tributary extends eastward 75 miles to 

 Portage la Praiiie, northeastward 50 miles to Gladstone, and east-south- 

 eastward 80 miles to Almasippi post-office, 9 utiles west of Carman. On 

 the northwest this delta is Ijordered by an expanse of moderately undu- 

 lating or rolling till which rises slowly above the ancient lake level and 



