1.(76 D. F. Lincoln — Glacial Erosion of New York. 



drumlins are numerous, and intercept the drainage to such an 

 extent that the low grounds between them are largely filled 

 with alluvium, and often swampy. Hall, however, mentions 

 16 localities where the rock is exposed. A comparatively con- 

 tinuous series of exposures is seen along the line of contact 

 with the next following rock. 



The Corniferous limestone makes itself seen in many places 

 along the south side of the Auburn branch of the New York 

 Central railroad. It comes close to the surface at many quar- 

 ries ; and its low escarpment, resembling an old stone wall, 

 west of Geneva, has forced the railway to diverge four miles 

 to the north. Upon this escarpment, a mile south of the New 

 York Central, runs the new line of the Lehigh Valley road, 

 cutting through some low anticlinals of rock resembling those 

 mentioned in the case of the Niagara limestone, and with a 

 similar (N.-S.) axis. Both roads run for some miles west of 

 Geneva over broad levels of Corniferous limestone covered 

 with a little soil and occasionally swampy. The Lehigh road 

 has found it impossible to plant posts in the usual way, and 

 stone-laden cribs are used to support the fences. 



With the Corniferous begins the series of exposures belong- 

 ing to the lake-region proper. In this region no other escarp- 

 ment of equal development exists. Locally, however, we may 

 name that due to the Tully limestone, a sheet of rock a dozen 

 feet or more in thickness, surmounting the Hamilton group. 

 At its outcrop in the rising land between Seneca and Cayuga 

 Lakes, just north of Ovid, there is a shoulder or upward jog 

 in the landscape, quite well seen at a distance of eight miles. 

 The "basal limestone" (J. M. Clarke), which forms the lowest 

 layer of the Hamilton shale, parting it from the Marcellus, is 

 the cause of the bluff northerly termination of a certain de- 

 tached hill, four miles south of the outlet of Seneca Lake ; 

 the soil is very thin over a large tract, and the coral reef is 

 bare in spots. Many hundreds of little ravines, entering the 

 Finger Lakes from the sides, and cutting through the Devonian 

 series, have made the region classic ground for the collector of 

 fossils. The drift-coating, as shown in these cuts, is usually 

 thin (1-5 feet) at least within a mile or two of the lakes. In 

 many places, however, the delta-terraces are prominent, and 

 where cut through by the railways might mislead the observer's 

 estimate. It is fair to presume that these accumulations of 

 drift were not, for the most part, taken from the general sur- 

 face, but from those surfaces which have now been converted 

 into ravines and gullies. The general sweep and slope of the 

 country is not towards the ravines, as a rule ; the upland con- 

 tour is broken abruptly by the line of the gorge, and there 

 plunges at an angle of from 20° to 90°. Hence, little general 

 loss of drift has probably taken place through stream-action. 



