198 Fi'ank Carney 



washed deposits, they were formerly called "serpentine kames." 

 In general shape and sometimes in position , they resemble morainic 

 loops, but can be easily distinguished by examining their material. 



1 alleys leading away from the ice. In some parts of the country, 

 ice-borne material is found hundreds of miles south of the margin of 

 the continental glacier. The Delaware, the Susquehanna, and the 

 Ohio rivers carried out wash from the ice sheet, far to the south. 

 In this state, the Muskingum and its various tributary vallej's, 

 the Scioto, the Hocking, and the Miami river valleys, are flood- 

 plained and terraced by waters that issued from the glacier. The 

 abundance of this outwash, and its great distance from the mar- 

 gin of the ice, furnish convincing proof of the turbulent condition 

 of streams that flowed from the ice sheet. 



Lake deposits. The drainage from glaciers does not always 

 flow away freely. When the land slopes towards the ice front, the 

 water accumulates. If the area is a plain, the resulting lake will 

 be long, with its greater axis parallel to the ice margin ; if the area 

 is a valley, this axis will be transverse to the ice margin. The 

 depth of such a lake depends upon the altitude of the outlet which 

 eventually its waters will find. The present-day evidences of 

 these former lakes is dependent upon their duration; the longer 

 a lake stood at a particular level, the more sharply developed 

 became its shorelines. The duration of ice-front lakes is contin- 

 gent on the time during which the ice held its stationary position. 

 Some lakes that bordered the front of the recessional ice must have 

 endured for many centuries; others were relatively evanescent. 



In nearly all respects, these ice-front lakes were like the lakes 

 of today. Rivers flowed into them, bays varied their outlines, 

 winds made waves on their surface, currents doubtless existed, 

 just as in the Great Lakes. Cliffs were cut by wave work, and 

 beaches constructed. At the mouths of rivers, deposits accu- 

 mulated as deltas. Spits, bars and cusps varied the shoreline. 

 Away from the shore, fine material was deposited as lake clay. 

 But, in these lakes, the quantity of clay w^as greater than in non- 

 glacial lakes; along the entire margin of the ice, which always 

 formed a part of the shoreline, debris gathered from the wasting- 

 glacier; this contained much fine clay, which was disseminated in 

 suspension through the lake, gradually settling to the bottom. 

 For this reason, clay is found more commonly on the beds of glacial 

 lakes. 



