436 Expedition to the 



The graywacke^ which in this very general and hasty view 

 we have considered as in part, belonging to the clay slate of 

 transition appears to us to form the connecting link between 

 this clay slate, and the old red sandstone. In attempting to 

 give a more detailed account of these formations, we might 

 perhaps speak of the graywacke, as others have done, as a 

 distinct stratum. We have, however, usually found it so in- 

 timately blended either with the sandstone, or clay slate that, 

 in this enlarged view, we see no necessity for a separation. 

 We cannot agree in opinion with some who have considered 

 the graywacke as the substratum of the great secondary for- 

 mation of the valley of the Mississippi. We have found it 

 almost invariably overlaid by an inclined sandstone separating 

 it from the horizontal rocks towards the west. This may not 

 be as often the case at the north as in Pennsylvania, Mary- 

 land, and Virginia. Mr. Eaton, is of opinion that " gray- 

 wacke underlays all that district of country in the interior of 

 the state of New York, which would be bounded on the 

 north, by a line drawn from Albany, westward to the Onon- 

 daga salt springs, on the west, by a line running from the 

 salt springs by Bath to the Pennsylvania Hue, on the south, 

 by a line running thence to Newburgh, on the Hudson above 

 the Highlands, and from thence to Albany, by a line running 

 parallel to the river, at a few miles distance." We are in- 

 formed by governor Clinton,* that coal strata exist in the 

 western part of the state of New York, and we are induced, 

 from the analogy of the other parts of the same great secon- 

 dary formation, to believe that the brine springs of Onon- 

 daga, are situated not in graywacke, but in the sandstone of 

 that coal formation. According to Maclure,f old red sand- 

 stone appears from under the limestone, and other strata at 

 Lewistown, ten miles below the Falls of Niagara, and also 

 near the salines of Onondaga, in Genessee county. " This, 

 says he, would give some probability to the conjecture that 

 the old red sandstone is the foundation of all this horizontal 

 formation, and is perhaps attached to some series of rocks 

 laying on the primitive, north of the Great Lakes." 



IV. — Transition Sandstone. 



Old Red Sandstone? — Throughout the whole extent of the 

 transition formation, beforementioned, a sandstone occurs, 



* See his Speech at the openinjr of the Session of 1 022. Since the above 

 was written, we have been informed that coal has been discovered iu thp 

 interior of New York. 



f Observations on the Geology of the United States, p. 57. 



