64 Cherty Lime-rock, or Corniferous Lime-rock. 



This generalization of our rocks requires extensive subdivisions 

 in some localities. But numerous reviews, since I proposed this 

 nomenclature in your Journal of January, 1830, have confirmed 

 me in its correctness. And I now ask state geologists to examine 

 these rocks, from the six proposed starting points, on the cornifer- 

 ous or cherty lime-rock. I have considered that as the upper rock 

 in the lower secondary class. If I am right in regard to it, as an 

 equivalent of the cherty lime-rock of English authors, its vast ex- 

 tent and the important disposition it holds among North American 

 rocks, will make it very useful to geological surveyors. If I am 

 not right, it will be equally useful, for examining the relative po- 

 sition of other rocks ; as they can take their true equivalent places 

 in European systems, after its character is demonstrated. For 

 example, all our salt springs are in a red (or variegated) sand-rock. 

 This rock is below the corniferous lime-rock, together with its pe- 

 culiar associate ; bb ferriferous rocks embracing the iron stratum, 

 liasoid, (water cement,) geodiferous or fetid lime-rock, all our gyp- 

 sum beds, &c. But there is on Catskill Mountain a red sand-rock 

 and conglomerate, resembling the red sand-rock and trap tuff under 

 the basaltic rocks on Connecticut River, and also on Hudson 

 River. As these red rocks all contain a fucoid, resembling that of 

 Mr. Conrad, found in our saliferous rock, I will refer the geologist 

 to these definite localities. On Catskill Mountain, twelve miles 

 west of the village of Catskill, about one mile south of the 

 Little Lake and mountain house, there is a round hill, about 

 two hundred feet higher than Little Lake. On ascending this 

 hill, alternations of red sand-rock and marble are found. This 

 red sand-rock contains a species of branching fucoid, resembling 

 in general appearance the fucoid of Oak-orchard Creek, on the 

 Erie canal, between Genesee River and Lockport. I have found 

 it on said creek, so uniformly articulated, that I called it an encrir- 

 nus, until Mr. Conrad corrected me. But they differ from those 

 on Catskill Mountain, in that the latter have no articulations, so 

 far as I have examined. I am at present a proselyte to the paleon- 

 tous method of reading out rocks. But, as the sand-rocks on the 

 loftiest peaks of Catskill and Alleghany mountains, are thousands 

 of feet above the corniferous lime-rock, and the saliferous rock 

 always below it ; my learned friend, Conrad, ought to examine 

 the locality just mentioned ; also a similar one at the southeast 

 foot of Mineral Hill in Blenheim, Schoharie county, and numer- 

 ous others. 



