sandstonp: of north cayiga township 373 



make it evident that there is a rather geneial impression tliat the Onon- 

 daga and Oriskany faunas are mino-Ied in the dej^osils of tlie region 

 mentioned above. Hence some of the results of woi-k recently done in 

 that vicinity may be of interest. 



The Exposures in Haldimand County, Ontaiuo 



SANDSTONE OF NORTH CAYCdA TOWN Sill I' 



In Ontario the Oriskany sandstone is represented in Welland and 

 Haldimand counties (the two counties lying along the north shore of 

 Lake Erie immediately to the west of Buffalo ) by remnants of a much 

 more extensiA^e formation. The largest and most important of these 

 remnants lies under a very thin mantle of drift and covers a considerable 

 portion of several square miles just west of Decewsville, in North Cay- 

 uga township, Haldimand County. The center of the area thus desig- 

 nated is the location of the De Cew quarry of former days, but tlie 

 sandstone has been taken out at more than a do/en localities and, on a 

 small scale, is now quarried at three or four places. At the Oneida 

 Lime Company^s quarry, 2 miles west of Decewsville, the Oriskany 

 is composed of 20 feet of coarse grained friable white to yellowish 

 sandstone. At some horizons, especially in the upper part, there occur 

 occasional concretion-like bodies of sand which have been cemented into 

 masses resembling quartzite. This sandstone lies unconformably on a 

 weathered buff to yellowish brown, somewhat porous, magnesian lime- 

 stone of Silurian age, and the lowest layers often contain subangular 

 fragments of the underlying formation, while at other places the sand 

 has penetrated the cracks and crevices of the Silurian and now appears 

 as thin veinlike seams cutting the rock in all directions or filling pocket- 

 like holes in it. The thickness of the sandstone varies much from place 

 to place, owing to the marked unevenness of the surface on which it lies. 

 The Oriskany is overlaid unconformably by about 4 feet of arenaceous 

 chert and cherty limestone. These upper beds often contain a consider- 

 able amount of sand, which sometimes gives them the appearance of 

 mortar beds. Good sized pieces of the sandstone, containing character- 

 istic Oriskany fossils, may be found embedded in the lower part of the 

 cherty limestone, while at other places not far distant the Onondaga 

 rests directly on the Silurian, with only here and there remnants of the 

 Oriskany lying between. 



FOSSILS FROM NORTH CAYUGA TOWNSHIP 



The coarse sandstone carries an abundance of such forms as Spinfer 

 arenosus (Conrad), Spirifer murchisoni (Castelnau), Eatonia peculiaris 

 XXVII— Bull. Geol. Soc. Am., Vol. 23, 1911 



