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First, what were the topographic cliaracteristics of tlie valley before the 

 laking stage; in other words, what was its preglacial history. Second, 

 what happened to the valley during the laking stage, its glacial history. 

 Third, what has happened since the disappearance of the lake, its post- 

 glacial history. 



DESCRIPTION OF TOPOGRAPHIC FEATURES. 



Valley Slofjcs. While the average slope of the valley side is some- 

 where between twenty-five and thirty degrees, it very rarely falls as 

 -low as fifteen and in many places attains a slope as high as forty de- 

 .grees. The variation in the slope bears a direct relation to the minuteness 

 ■of dissection, or the spacing of the streams crossing it. Observation bears 

 out the conclusion that the closer the streams to each other, the more sub- 

 dued the slope. For a number of stretches along the valley sides very few 

 • streams crossed them, and there the slope was invariably found to assume 

 the steepest angle. Moreover, the trend of the slopes appear to have a 

 .peculiar and persistent variation in direction, considered with reference to 

 the general direction of the valley. It is believed that these features afford 

 certain criteria by which something of the early history of Bean Blossom 

 may be determined. 



Valley Floor. The greater part of the valley is remarkably smooth 

 and flat. There is, however, some systematic variation from an abso- 

 lute plain. If We should construct a cross-section of the relief of the 

 valley, especially in the central or upper parts, we should lind that its 

 systematic departures from a plain are such as to suggest that such ag- 

 grading as occun-ed in the valley was governed to a very large degree, 

 ^t least on the present surface, by fiuviatile agencies and not to the pro- 

 miscuous distri))Ution of sediments over its bottom during a period, of 

 laking. 



It should also be noted that the present river channel throughout a 

 large part of its course persists iu keeping to the south and west side of 

 the valley floor. Only at a few points within the limits of :Monroe County 

 •do we find that the present Bean Blossom succeeds in meandering across 

 the entire width of the valley floor. In other words, this river is not appro- 

 priate to and does not fit the broad valley which it now occupies. 



The monotonous plain of the valley is broken at various places within 

 the limits of Monroe County by the projection of conical hills and elon- 



