Geology of Seneca County. 77 



Each stream has cut through its own terraces successively in 

 seeking lower levels, carrying away large amounts of drift to 

 add to the new delta. 



It is probable that, during the latter -part of this (third) stage, 

 toward its close, there was one rather protracted period of rest 

 or equilibrium, with the water 100 feet above its present level, or 

 not much higher. For this view there are several coinciding 

 bases. 1. The clay at Geneva rises to the level of 100 feet, 

 scarcely more, and then thins out or disappears. Traced west- 

 ward along the Lehigh Yalley railroad, it rises to about the same 

 height, .giving place to sand hills about half a mile S. E. of Oaks 

 Corners station. (This station is 564.3 A. T.; that at Geneva is 

 491.1, making a rise of 7.3 feet; Oaks Corners is 123 feet above 

 Seneca lake.) 2. The elevation of the kame deposits is very near 

 100 feet above Seneca lake. These deposits represent the dis- 

 charge of a glacial river at a late period into the conjoined 

 Seneca-Cayuga lake. 3. The lowest terrace at Lodi is 110 feet 

 above the lake. 



The delta-terraces are confined to the southern half of the 

 county. On the west side of Seneca lake they run much farther 

 north ; there is a well-marked one four miles south of Geneva 

 (mouth of Slate Eock Glen). 



Lines of beach connecting the delta terraces have been sought 

 for by various observers with little or no success. Wave action 

 is of subordinate effect in narrow waters. Beach ridges fringing 

 delta-terraces are not found, as far as 1 know, in Seneca county 

 but are handsomely shown at Kashong creek, eight miles south 

 of Geneva. Elevated lines of cliff have not been found as yet. 

 A study of the terraces, limited to Seneca county, would have 

 comparatively little value. In their best development they 

 occupy the upper half of both lakes and extend south up the val- 

 leys of inlet. Their relations to each other and to the points of 

 outflow require much study, based on complete and accurate 

 measurements, which have yet to be made. 



The section of the Lodi terraces is based on hand-level measure- 

 ments, the total error of which was small, the estimate being 347 

 feet of elevation above the lake, while that of the L. Y. K. K. is 

 344. 



