Glacial Geology of Western Neio York. 535 



Pre-Lnurentian Lakes} 



Lake Warren. — The area of Western New York is involved in 

 only the later phases of the Laurentian glacial lake-history. The 

 first of these glacial waters that invaded our area were those of 

 Lake Warren. The beaches of this great lake have been traced 

 about the southern shore of Lake Erie and through Western New 

 York to beyond the meridian of Eochester,^ with an elevation of 

 883 feet at the northernmost point. 



The Warren waters were drained to a lower level by the ice-front 

 receding in the vicinity of Syracuse sufficiently to uncover laud 

 that permitted flow to the Mohawk-Hudson, at a level below that 

 of the former outlet across Michigan to Lake Chicago and the 

 Mississippi. 



Lake {unnamed ; Geneva Beach).^ — A well-defined beach, lying at 

 an elevation of about 700 feet, has been traced for 30 miles along 

 the western side of the Seneca lake valley and westward to Shorts- 

 ville, while evidences of the same static water have been noted 

 farther west. It is supposed that these phenomena belong to a long 

 pause in the irregular fall of the Laurentian glacial waters from 

 the Warren level to the Iroquois level; but the outlet correlating 

 with the level is unknown. 



Lake Iroquois. — This latest glacial water in the region has left 

 the strong, mature shoreline about the Ontario basin, correlating 

 Avith the ancient channel at Rome, N.Y., opening into the Mohawk.'' 

 The phenomena are strong, and the main facts in the history are 

 clear. The beaches, like those of the preceding waters, show 

 a decided northward uplift, amounting to five feet per mile between 

 Syracuse and Watertown. 



MoRAiNAL Lakes. 



Doubtless many lakes had a brief existence, due to raorainal dams, 

 bat only a few have been identified, these lying in the valley of the 

 Genesee river. A brief description may be found in a former 

 paper." These were drained by the cutting of rock gorges (see last 

 section of this paper). The largest of these morainal lakes was 

 above Portageville. Another was in the new valley of the river 

 above Mount Morris. Others occupied side or tributary valleys to 

 the Genesee. 



1 For the latest comprehensive statement of the lake-history in the Laurentian 

 basin as a whole, see article by F. B. Taylor, " X. A Short History of the Great 

 Lakes," in ' Studies in Indiana Geography,' edited by C. R. Dryer. Terre Haute, 

 Indiana, 1897. 



2 H. L. Faircliild, "Lake Warren Shorelines in Western New York and the 

 Geneva Beach" : Bull. Geol. Soc. Amer., vol. viii, pp. 269-86. 



2 Ibid., pp. 281-4. 



* G. K. Gilbert, "The History of the Niagara Eiver" : 6th Ann. Rep. Com. of 

 State Reserv. at Niagara. Albany, 1890. 



= H. L. Fairchild, "Glacial Genesee Lakes" : Bull. Geol. Soc. Amer., vol. vii, 

 pp. 449-62. 



