82 NEW YORK STATE MUSEUM 



conglomerate also outcrops so near the overthrust fault of the 

 Georgian that it might well be a block caught in the fault, although 

 it is there underlain and overlain by shale of presumably Normans- 

 kill age. At the Moordener kill a few miles south from Rysedorph 

 hill, it is seen five times repeated in the section and apparently folded 

 in with Normanskill shales i to 2 miles away from the overthrust 

 fault. Another fine exposure of this conglomerate which also has 

 furnished Plectambonites pisum is seen in the shore 

 cliffs at Papscanee island, about 5 miles below Albany. This out- 

 crops is at least 2 miles away from the overthrust plane, and another 

 good exposure at Schodack Landing is equally distant. The typical 

 Rysedorph Hill conglomerate southeast of Albany is thus too far 

 away from the thrust fault on which the Georgian was brought 

 westward to be considered as having been brought along this plane, 

 and it is seen in a number of places clearly intercalated in the 

 Normanskill shale as an intraformational conglomerate. 



Whatever may be the origin of this remarkable rock, the charac- 

 ter and variety of the pebbles and the character of their faunules 

 indicate, as we have shown in the paper on the Rysedorph Hill 

 conglomerate, that they are derived from beds not now exposed in 

 the slate belt and probably brought from the east, especially since 

 the fossils are of Atlantic type. The age of the conglomerate 

 which in museum Bulletin 42 had been held to be lower to middle 

 Trenton, is from the aspect of the faunules of both the youngest 

 pebbles and the matrix, probably greater and corresponding to the 

 Black river. The Normanskill shale with which it is associated in 

 the Rysedorph hill and Moordener kill localities, has been found by 

 Ulrich in the Athens trough to be upper Chazyan in age. We have 

 therefore considered the conglomerate as originally overlying the 

 Normanskill shale and thus represented it in the diagram, text figure 

 15. Investigations, however, carried on since have brought out the 

 fact that the Normanskill shale embraces two formations, as is more 

 fully stated below (page 93) and that the Rysedorph Hill con- 

 glomerate is intercalated in the upper division of Black River age. 



The peculiar fauna which was described from this conglomerate 

 by the writer has been recognized in part in the Chambersburg 

 limestone of Pennsylvania of the Chambersburg-Massanutten and 



^ This exposure while then known to the author, was accidentally omitted 

 in Bulletin 42. 



