PM umHORS. ABSTRACTS. 
[Papers presented at the Philadelphia meeting of the Geological Society of 
America, December, 1895. ] 
Preglacial and Postglacial Valleys of the Cuyahoga and Rocky hovers. 
By WarrEN UpHaM, St. Paul, Minn. 
The Cuyahoga River, entering Lake Erie at Cleveland, occupies 
the same valley as before the Ice Age, but the rock-bed of the pre- 
glacial river is more than 200 feet below the present river and level of 
the lake. About eight miles farther west the mouth of the postglacial 
channel of Rocky River, eroded nearly 100 feet deep in the Erie shale, 
is three-fourths of a mile east of the drift-filled preglacial valley, in 
which a very interesting section of two deposits of till, with intervening 
stratified sand and fine silt, is seen along a distance of one mile of the 
lake shore. The glacial and stratified drift deposited in both these 
preglacial valleys give evidence of a recession and readvance of the 
ice-sheet during its general stage of formation of the numerous 
retreatal moraines of the district. 
Four shore lines, the highest belonging to the Western Erie glacial 
lake, and the lower ones to the ensuing Lake Warren, are described in 
detail in their course through Cleveland, crossing the Cuyahoga valley. 
The highest or Leipsic beach is traced several miles farther east than it 
was before known, and is thus found to be correlative with the marginal 
moraine which extends from Euclid eastward, closely parallel with the 
lake shore. 
In the closing part of this paper the glacial readvance shown by 
the Rocky River and Cleveland sections is compared with the glacial 
and interglacial deposits of Toronto and Scarboro’, Ontario, which 
were described by Professor A. P. Coleman in the last September- 
October number of the JouRNAL or Geouocy (Vol. III., pp. 622-645, 
with sections). Mr. Upham attributes the fluctuations of glaciation 
which are thus recorded on the north side of Lake Ontario to a time 
after the formation of the moraines, stratified drift, and upper till, in 
the vicinity of Cleveland. 
127 
