86 NEW YORK STATE MUSEUM 



Origin of the Gaspe sandstone 



We have noted that, so far as observations upon the faulting of these 

 rocks have extended, it would seem that displacements are of slight throw 

 and not sufficient in their totality to greatly qualify the thickness assigned 

 to them by Logan. So far as the sandstones alone are concerned we find 

 the most rational explanation in the deposition in a great coastal lagoon 

 receiving terrigenous sediment rapidly and in vast quantity from the highly 

 elevated old land. This was an Old Red lake in the same sense as those 

 of Scotland and that in which the Oneonta and Catskill sands of New York 

 were laid down. How slender was the barrier which cut off the lagoon 

 from the open sea is seen by the thin stratum with marine deposits which 

 we may fairly say represents the overwash in time of stress of the outside 

 water bringing in the marine organisms as we find them — dead shells from 

 the littoral. We have evidence of more than one such inrush of the sea, for 

 marine fossils have been found in more than one locality, and they prob- 

 ably lie at different horizons. The conglomerates, to which reference is 

 again made on a following page, are the evidence of deposit on a bold and 

 rocky coast; they indicate interruptions of lagoon conditions and imply such 

 a sea front as exists today, and has prevailed for ages along the face of the 

 Gulf about Perce. 



The list of marine fossils presented above shows that the original 

 determination of the age of these beds as practically equivalent to the 

 Oriskany of New York is insufficient. The assemblage presents a strange 

 and unusual combination. In majority of number the species are unques- 

 tionably those of the Hamilton fauna of New York,' but with these are 

 several pronounced Oriskany species and those customarily regarded as 

 indicial of that stage : Rensselaer ia ovoides gaspensis, Ortho- 

 thetes becraftensis, Leptocoelia flabellites, Eatonia 



'Professor Hall was the first to express the opinion that some of these fossils sub- 

 mitted to him by Sir Williana Dawson had a Hamilton expression and Dawson himself, on 

 several occasions, quoted and endorsed this view. 



