344 ' NEW YORK STATE MUSEUM 



sandstone ; but it is thought probable, from some of the mineral 

 characters, no fossils having been seen, that they belonged to 

 the epoch of the Medina sandstone, and that the subjacent Shaw- 

 angunk grit is equivalent to the gray sandstone (=Oswego) 

 instead of the Oneida conglomerate." 



While it is known that Mather^ recognized and designated a 

 formation in eastern New York as " coralline limestone " which 

 recently has been shown to be identical with the Cobleskill 

 limestone, it is evident from the above citations that Mather 

 could not have regarded it as of Niagaran age, or he would not 

 even have suggested the possibility of the underlying red shales 

 being of Salina age. For many years following the publication 

 of Mather's report the section under consideration was not much 

 studied. The discovery, however, by Dr Barrett, of Cobleskill 

 fossils near Port Jervis in strata which lie above the red shales, 

 and the studies of Lindslay of the same formation at Rondout, 

 left little doubt as to the continuity of these rock masses in the 

 intervening section, and since the Cobleskill at that time was 

 correlated with and generally accepted as the equivalent of the 

 Niagaran formation as developed in western New York, it served 

 for the time being as apparently conclusive evidence that the 

 underlying shales could scarcely be correlated other than with 

 the Clinton and the Medina, or at least it was not thought they 

 could possibly represent the Salina. As we now know that the 

 Cobleskill Hmestone is of an age later than the Salina, the age 

 of the red shales together with the so called Clinton quartzite 

 lying above the Shawangunk grit again comes into question, 

 since both the Salina and the Medina are below the Cobleskill. 

 As no fossils have been found in the red shales, a feature which 

 contrasts them with the Medina of central New York, it is evi- 

 dent that in any attempt to correlate these red shales, evidence 

 must be had from other sources. 



It was early shown by Vanuxem^ and Hall^ that in central 

 New York the passage from the Oneida to the Medina was a 



iGeoL N. Y. ist Dist. 1843. p. 331. 

 2Geol. N. Y. 3d Dist. 1842. p. 71. 

 3Pal. N. Y. 1852. 2:15, 16. 



