Geological Reports on the State of Neio York. 47 



" The floor of a mill, or factory, immediately at the falls of Oak Orchard 

 creek, Medina, consists of a thick gray layer of sandstone, about forty 

 feet deep in the rock. This layer presents an extensive surface, covered 

 with large and remarkably distinct furrows. Direction east 20^ north. 



" On the shore of Lake Ontario, north of Yates' center, and ten miles 

 from Medina, the sandstone is red and variegated, and contains similar 

 marks or furrows, whose direction is north and south, and also north 30° 

 east. These layers are at a depth of more than five hundred feet in the 

 sandstone. 



" Similar appearances are presented at Holley, on a layer of sandstone, 

 which also contained an individual of the Fucoides Harlani, which had 

 evidently bent and followed the irregularities. Direction of the furrows 

 not ascertained. 



"I have examined similar furrowed surfaces, or water-worn surfaces, 

 of the graywacke at Saugerties, on the Hudson river ; they are common 

 in the shales and sandstones of the Catskill mountain ; and I have also 

 observed them on layers of a dark, compact limestone, which is quarried 

 at Glasco, three miles west of Saugerties." 



" Limestone. — Thin layers of limestone are extracted from the bed of 

 Oak Orchard creek, between Medina and Shelby, and used at the former 

 place for flagging. They appear to be of a siliceous character, occur in 

 large slabs, and the surfaces are frequently covered with fossil vegetables 

 of the family of Fucoides ; they strongly resemble the petrified stems of 

 vegetables." 



In Niagara county, "in descending the terrace on the north, we find 

 hills of diluvial matter, extending from the top and sloping gradually off 

 to the surface below. Where the northern extremities of the hills have 

 been excavated, we find large rounded masses of limestone and shale, 

 from the rocks south, with masses of granite. These are all mixed to- 

 gether in confusion ; and the masses of limestone are worn and scratched, 

 as having been tumbled along with blocks of harder rock. From these 

 appearances, and the form of the hills, it is very evident that a current of 

 water flowed from the south. But again, on the summit of this terrace, 

 we find masses of sandstone from the north, often wedged into fissures of 

 the limestone, as if driven there by violent force. Although traces of op- 

 posing currents are not so apparent on the surface, their effects are more 

 evident on the rock beneath. In every case where I examined the lime- 

 stone in this county, it was worn and scratched from diluvial action. This 

 appears to have been effected by a force from the south, but in some places 

 there is undeniable evidence that a powerful force was exerted from a 

 northern direction. The following facts corroborate this opinion. We 

 often find fissures in the limestone having an east and west direction ; the 

 rock forming the southern edge of this fissure is broken up in a manner 



