BUFFALO SOCIETY OF NATURAI, SCIENCES 27 



The Ludlowville shale is a heavy mass of bluish gray, 

 calcareous shale extending from Lake Erie eastward to beyond 

 Cayuga lake and at all points keeping the same characteristics of 

 color, texture and content. It is often without strong cleavage 

 planes but is somewhat fissile. It weathers into a sticky, gray 

 clay. It includes several rather constant layers of limestone and 

 abundant small concretions. Its upper beds lie in contact with 

 the Tichenor limestone. Its lower beds merge into the Skaneateles 

 below it. So gradual is its transition that no line of demarcation 

 can be set. Grabau has considered the line of division to be 

 immediately beneath a bed containing Strophalosia truncata, 50 

 feet below the Encrinal limestone. 



The Ludlowville is exposed in Eighteen Mile creek for the 

 first mile of its course, in the lake cliffs at its mouth and as far 

 north as Avery's creek. The whole formation is shown in the 

 south branch of Smoke's creek at Windom and in the north 

 branch at Town Line Road where it forms a cascade. In 

 Cazenovia creek it appears in cliffs from the bottom of the dam 

 at Springbrook to the Skaneateles cliff at the terminus of the 

 Buffalo Southern Railway. In Buffalo creek its upper beds show 

 at the bridge at the Bullis Road and the shales exposed in the 

 cliffs north of Springbrook station are probably in the middle 

 beds. 



The whole formation is characterized by an abundance of 

 fossils, and because of the softness of the matrix these may be 

 removed w T ith ease in perfect condition. A few thin beds are 

 exceptionally rich. The lowest of these, the Nautilus bed, yields 

 Nautilus magister of large size. Above this, within a vertical 

 distance of eight feet, are the Pleurodictyum beds and the 

 Trilobite beds, all exceedingly rich in fossils, many of which are 

 rare in other formations. At the top of the formation and 

 immediately below the Tichenor limestone are two beds, the 

 Stictopora bed and the Demissa bed which yield an immense 

 number of beautifully preserved fossils in great variety. 



Tichenor Limestone. 



Limiting the Ludlowville shale above is a thin but constant 

 bed of limestone which was named by Hall the Encrinal limestone. 

 This has been rechristened by Dr. Clarke the Tichenor limestone 

 from its exposure at Tichenor Point on Canandaigua lake. It 

 extends eastward to Cayuga county. 



