GEOLOGIC MAP OF THE TULLY QUADRANGLE 



47 



Ludlowville shale 



A large part of this division consists of beds of sandy olive shale 

 and laminated sandstones which appear on the sides of the Onon- 

 daga valley south of Cardiff as escarpments or terraces. There are 

 alternations of soft dark shales like the Skaneateles beds but the 

 sedimentation taken as a whole is much coarser than in that division 

 or in the horizon of the typical Ludlowville shales on Cayuga lake 

 and westward. The thickness of the mass is 350 feet at its maximum, 

 thinning toward the west. The upper limit is marked by an uneven 

 layer of hard bluish encrinal limestone at some exposures quite com- 

 pact and about 1 foot thick but at others in the eastern part of the 

 quadrangle concretionary or coarsely nodular. It is continuous to- 

 ward the west, appearing in the cliffs along Cayuga lake south of 

 Aurora and in Ontario county. The entire section is exposed in the 

 Fellows falls ravine but is not accessible except at times of low 

 water. There are many escarpments, ledges, field outcrops and 

 ravines on both sides of the Onondaga valley south of Cardiff that 

 afford favorable exposures of all parts of the formation. There are 

 extensive outcrops Y\ mile northeast of the village of Lafayette, and 

 2 miles north and northeast of the village of Pompey ; also along* 

 the highway on the hillside i l /> miles northeast of Apulia station; 

 and the terminal limestone with the underlying shales may be seen 

 in the bed of the small stream that crosses, 1 mile from the corner, 

 the road leading north from the Apulia- Fabius highway 3 miles east 

 of Apulia station. This limestone is also seen in the road leading 

 north on the east side of Kingsley hill; 1% miles west of Maple 

 Grove, in the town of Otisco. The sandy layers arc exposed at the 

 mouth of Bucktail ravine at Spafford valley and in an escarpment 

 on the east side of .the Otisco valley. 



These rocks are the most profusely fossiliferous of any in the 

 quadrangle and some of their localities and specially the exposure 

 in the ravine at Pratts falls just to the east of the quadrangle, have 

 furnished extensive collections for many years, for paleontologic 

 study. The series of species is not an extensive one but the pre- 

 dominating forms are the lamellibranchs and brachiopods. Beds of 

 cyathophylloid or so called staghorn corals are found in it, an ex- 



