Geography of Ohio 219 



cially, this part of North America must have had a much higher 

 altitude. Such an hypothesis would make it much easier to under- 

 stand this relationship of deep channel-cutting. At the same time, 

 to accept a genetic association between canj'ons across the conti- 

 nental shelf and those farther inland would require our altering 

 the accepted idea of river and valley development. While, in 

 its headwater area, a river may occupy deep gorges, contem- 

 poraneously, its down stream section is found in wider valleys, 

 and eventually, before reaching the ocean, the river's course should 

 regularly be very old and flat. If, then, the submerged canyons 

 and buried channels represent stream-cutting due to an uplift, 

 they cannot be contemporaneous in origin. Many students are 

 of the opinion that along all our continents the buried channels 

 need not imply former greater altitude of the land areas, but in- 

 stead a tendency of the continents to creep seaward, thus carrying 

 with them the drainage patterns existing. 



Just what is the origin of the buried channels about the pres- 

 ent Great Lakes is an unsettled question. Before any conclusion 

 can be reached, it will be necessary to know more thoroughly 

 the extent to which buried valleys and channels exist; and since 

 such knowledge is established only through drillings, it will proba- 

 bly be a long time before this desired information is obtained. 



On one point, there appears to be complete agreement among 

 geologists: The present lake basins, preglacialh", were depressions 

 or valleys occupied by streams. When, however, these students 

 reconstruct that preglacial drainage, many opinions at once arise. 

 I will state, briefly, the more widely published reconstructed 

 drainage plans of this area. Among the early suggestions it was 

 stated that preglacially, part at least, of the area of the present 

 Great Lakes .was drained eastward through the jMohawk low- 

 land. This assumption appears to have been suggested by 

 the buried valleys south of Lake Ontario. To lead waters from 

 the buried gorges of the region south of Lake Ontario, that 

 could have been associated genetically with the continental-shelf 

 canyons, would require a deep valley through part of the Mohawk 

 lowland. No such valley has been found; furthermore it appears 

 to be well established that it never existed. In the vicinity of 

 Rome, N. Y., across the meridian of which, this hypothecated 

 valley or channel must have led, continuous rock exists. Bearing 

 on this point, however, and somewhat in harmony with the origi- 



