24 NEW YORK STATE MUSEUM 



With the increase of sand in the sedimentation toward the east, 

 a few brachiopods which are not found at Wiscoy appear. 



i 



CHEMUNG SHALE AND SANDSTONE 



About 450 feet of the lower beds of this formation compose 

 the surface rock on the high land in the extreme southern part 

 of the Wayland quadrangle. In lithologic character they are not 

 materially different from the Gardeau beds, except that the sand- 

 stones are lighter colored and more micaceous. 



Fossils are rare in the lower 300 feet but are in very great 

 abundance in the higher sandstones exposed on this quadrangle. 

 These may be seen to good advantage along the roadside three- 

 fourths of a mile northeast of Loon lake, where the rock is 

 crowded with large brachiopods. Hydnoceras nodosum 

 Hall occurs here also. 



The rock lies near the surface over this region and small field 

 exposures are frequent, but there are no extensive outcrops. 



DIP 



The average dip of the base of the Onondaga limestone be- 

 tween Honeoye Falls and the salt shaft at Livonia is about 33 

 feet per mile toward the south. . On an east and west line, though 

 made variable by frequent undulations of the strata, this lime- 

 stone is on the whole nearly level. 



As all of the formations above the Onondaga up to the Wis- 

 coy shale, except the Stafford limestone and the Rhinestreet black 

 shale, thin out more or less rapidly toward the west, the dip 

 in that direction varies also with the contact line used as a base, 

 but is nowhere appreciable except on careful measurement. The 

 deep and narrow valleys partly occupied by Conesus, Hemlock 

 and Honeoye lakes are blocked at the south ends by enormous 

 beds of gravel, sand and clay which compose a part of the great 

 moraine of the second glacial epoch. The areas intervening be- 

 tween the lakes and the moraine are level beds of rich alluvium. 

 The Genesee river valley in the northwest corner of the Honeoye 

 quadrangle ; the Canaseraga valley near Dansville ; the bed of a 

 small lake near Wayland and another at South Lima, are of 

 similar character. 



A striking exhibition of the force of glacial action occurs in a 

 small amphitheatrical valley of Stony brook at Five Corners, four 

 miles west of Honeoye Falls. The bed rock, Bertie waterlime, is 



