58 NEW YORK STATE MUSEUM 



group in State Museum bulletin 63, and designated Grimes sand- 

 stone from its exposure in Grimes gully at Naples, N. Y. 



Other outcrops of these sandstones may be seen in several small 

 ravines west of Smoky Hollow and on the Silver lake outlet i^ 

 miles below Perry, also in the gullies north of Groveland station 

 and south of West Sparta. 



Gardeau flags and shale 



As considered in this bulletin, this formation consists of an ex- 

 tensive series of flags or thin sandstones and sjiales occupying that 

 part of the river section between the Grimes sandstone at the 

 mouth of Wolf creek and the base of the heavy sandstones at the 

 top of the Upper falls, with an aggregate thickness of 344 feet. 



These rocks constitute the most striking part of this famous 

 canyon. On the south side of the mouth of the Wolf creek ravine 

 the vertical cliffs rise 250 to 300 feet in which the bands of black, 

 blue gray and olive shales, and the greenish or blue sandstones of 

 varying thicknesses and in irregular succession are displayed in the 

 most effective manner. 



The lower beds, principally shales, are accessible in times of low 

 water in the lower part of the Wolf creek ravine, and some of the 

 lighter colored layers are fossiliferous. 



Midway in the cliffs for 2 miles south of Wolf creek the even 

 stratum of sandstone that is the platform of Table rock at the top 

 of the Lower falls, 70 feet high, is seen. Below this stratum down 

 to the bottom of the falls, there are five layers of black shale aggre- 

 gating 9 feet in thickness, intercalated at irregular intervals in 57 

 feet of gray shale and a few thin flags. Above it the sandstones 

 are more frequent and increase in thickness, and in the walls below 

 the Middle fall compose a considerable portion in the sedimentation. 

 They are mostly not more than a foot or two in thickness, however, 

 and layers of both light and dark shales recur up to the top of the 

 formation. 



In the broad slope of rock on the west side of the river extending 

 from the top of the Middle to the bottom of the Upper falls 19 

 feet of shales and flags are accessible and 20 feet more on the west 

 side of the waterfall can easily be reached. 



For 51 feet above the bottom of the Upper fall the rock is prin- 

 cipally soft with seven thin layers of dark or black shale inter- 

 stratified between light shales or thin flags. One stratum of rather 

 shaly sandstone 2 feet, 5 inches thick is 19 feet above the base of 

 the section and is separated from a similar but slightly more com- 



