Coal Formations in the State of New York. 23 



the quantity of coal embraced in this formation equal to the line of 



1 



borings or any artificial excavations of the same extent to the deptl 

 of from fifty to one hundred feet. Deeper borings or other excava- 

 tions would be of no use ; because we now inspect the carboniferous 

 slate rock to its base. 



From the preceding statement of facts it appears that all our hopes 

 of discovering valuable coal beds in the state of New York are ne- 

 cessarily limited to the second coal formation in which the coal beds 

 of Pennsylvania, destitute of bitumen, are embraced. It was stated 

 in a preceding part of this paper that the coal beds of Carbondale, 

 &c. were embraced in a slate rock, which is the lowest stratum of 

 the lower secondary series of rocks. Although I have traced this 

 rock from the Pennsylvania coal beds along the foot of Catskill moun- 

 tains, the Heldebergh mountains, and by the way of Utica to Big 

 Salmon river on Lake Ontario, and observed it, in passing laterally un- 

 der the rock wjiich contains all the salt springs of the west ; yet the 

 importance of this part of my subject demands a more detailed de- 

 scription. The lime rock which extends along the foot of the Cat- 

 skill mountains is the lower carboniferous lime rock of European ge- 

 ologists. It underlays the slate rock which embraces the Pennsylva- 

 nia coal beds last mentioned. It supports the same slate rock from 

 the south part of Pennsylvania to Sackett's Harbor on Lake Ontario* 

 It forms a kind of Gothic arch around the southern extremities of two 

 primitive spurs from M'Combs mountains ; one called Root's Nose 

 and the other Little Falls Hill. With these two exceptions it forms 

 a pretty uniform curve from near Harrisbugh in Pennsylvania to 

 Sackett's Harbor on Lake Ontario. Throughout its whole extent the 

 same continuous slate rock which embraces the Pennsylvania coal 

 beds reposes immediately on its upper surface. This is the slate 

 rock which Farey calls limestone shale, because it is always slaty 

 and always reposes on limestone. This is the slate rock which em- 

 braces all the great coal measures of Europe. I have denominated 

 this rock second graywacke slate. 



This slate rock may be seen passing laterally under a conglom- 

 erate rock, called millstone grit or rubble stone, from near Littl* 

 Falls to Lake Ontario ; a distance of eighty miles. The conglome- 

 rate rock underlays the saliferous rock which forms the floor of all 

 the salt springs of the state. That this slate is co-extensive with the 

 saliferous rock cannot be be doubted ; for to doubt would be to aver 

 turn every principle of the science founded on analog) . 



