GEOLOGY OF THE AUBURN-GENOA QUADRANGLES 25 



it is seen at the top of falls near the west line of the quadrangle 300 

 feet higher than the lake. 



On the east side the top of the Tully is at lake level at a small point 

 y2 mile from the south line of the Genoa quadrangle, but is covered 

 by beach sand and gravel for 35 rods, then appears between the lake 

 and the railroad, the lower layers submerged at the south end of the 

 exposure but above the water 25 rods farther north. It is displayed in 

 the cliff on the east side of the railroad for ^ mile and rises to 640 

 A. T. in the field Y^ mile north of Shurgers glen, in the vicinity of 

 which it is well exposed in the quarry of the Portland Cement Com- 

 pany and adjacent fields and ravines. 



It is at the top of the falls of Salmon creek at Ludlowville and ap- 

 pears at the top of the cliffs on the lake shore Yi mile north of Myers 

 point, and almost continuously for 3 miles, sinking with a northward 

 dip to partial submergence in the lake, then slowly rising, may be seen 

 in the shore cliffs and at the top of falls in several ravines near the 

 lake in an almost continuous exposure for 10 miles to King Ferry 

 (Clearview). 



The falls in some of the larger ravines are made exceedingly inter- 

 esting and picturesque by the disintegration of the soft Moscow shales 

 iDeneath the limestone which projects so far as to produce recesses or 

 caves of considerable extent. One near the railroad a mile south of 

 Lansing is 50 feet wide and 2.y feet deep and there are others not 

 much less extensive. Immense blocks of the limestone partly fill the 

 ravines below the falls producing different but equally striking and 

 rugged effects. The limestone rises rapidly and recedes from the lake 

 shore north of King Ferry outcropping at 800 A. T. on the Aurora 

 road and at the top of falls in two branches of Paynes creek. 



It is well exposed at 830 to 850 feet in the ravine at Chapel Corners. 

 This is the extreme northern outcrop of the limestone in the Cayuga 

 lake valley and from this point to an outcrop in the highway near the 

 four corners a mile north of Scipio its precise position is not known. 

 It produces a cascade at 1160 A. T. in the Ensenore brook i^ miles 

 farther south. 



The limestone is 14 to 15 feet thick in the Barnum and Groves 

 creek ravines, 17 feet 6 inches on Willow creek; 21 feet in Shurgers 

 glen; 18 feet in the Portland Cement Company's quarry and 15 feet 

 at Lake Ridge. 



The Tully is usually found to be only moderately fossiliferous but 

 there have been collected from the exposures in the Cayuga lake valley 

 70 species, of which 14 are corals, 26 brachiopods, 5 lamellibranchs, 15 



