28o 5. L. POWELL 



This appears to be a basal conglomerate. It is comjposed of frag- 

 ments ranging in size from an eighth of an inch to pieces 6X15 

 inches. They consist of angular grains and pebbles of quartz, 

 pieces of dark chert 4X6 inches, large blocks of magnesian lime- 

 stone, and angular fragments of all sizes from the underlying cherty 

 magnesian limestone of the Chazy and Beekmantown formations. 

 The fossils, among them Ophileta, are imbedded in such a manner 

 with the fragments as to indicate that they were fossils when 

 inclosed. The conglomerate is from 6 to 8 feet thick. This evi- 

 dently is the conglomerate referred to by Mather as occurring at 

 Mount Moreno. It is in all probability the basal conglomerate 

 described by Weller from New Jersey. The writer has noted its 

 occurrence in Maryland and at several places here in southwestern 

 Virginia. It has been observed here at two points, in the same 

 stratigraphic position, 12 miles apart at right angles to the strike, 

 showing that the sea was encroaching upon the land, beating down 

 the ancient Chazy-Beekmantown limestone cliffs, and scattering 

 the fragments along the shore from Canada to Tennessee^ as the 

 sea advanced. 



Enough of the section has now been described to locate defi- 

 nitely the stratigraphic position of the shales carrying the Norman- 

 skill graptolite fauna. It is evident that the position assigned them 

 here, below the Trenton and above the Black River, is correct for 

 Virginia and Tennessee, and is in harmony with the statement of 

 Mather for part of New York. It is also in general accord with the 

 views entertained by Ami, Lapworth, and Gurley, who, on paleon- 

 tologic evidence only, thought the fauna should be placed in lower 

 Trenton if not below the Trenton. 



Dr. Ruedemann^ admits the essential identity of the Alabama 

 fauna with the Normanskill, but says it is open to question whether 

 this upper Trenton of Alabama is exactly equivalent to that of 

 New York. In the light of the manifestly clear section in south- 

 western Virginia, it is difficult to see how these same shales could 

 be upper Trenton in Alabama. Furthermore, the section as given 



' Keith describes a similar conglomerate "of unknown age" from that state, which, 

 from his description {U.S. Folio 16), is in all probability the same. 



^Mem. II, N.Y.S.M., p. 12. 



