464 L. 0. Wooster—The Copper-bearing Series. 
abundant, viz: (1) the middle of the formation, and (2) the 
middle of the upper third. 
t Osceola Mills, about four miles from the southernmost 
outcrop of the Copper-bearing or Keweenawan Series, the 
second of these two horizons is found at an elevation of about 
casts of Holopea Sweeti anda Bellerophon in great abundance. 
nawan series at the northward. The sandstone here became 
variable in color and hardness, being on the whole darker and 
in certain places exceedingly compact, or as Capt. Knapp 
expressed it, baked. But no fusion or evidence of heat from 
lying outcrops of Copper-bearing rock. Under the guidance of 
Capt. Knapp, the locality was visited late one afternoon, and 
the “most curious deposit” was found to consist of “ trap’ 
conglomerate. The conglomerate composed a ridge which 
stretched to the westward from the river bank to the bordering 
ledge of sandstone one-fourth of a mile back. The river end of 
the ridge is about fifty feet in height and one hundred feet in 
breadth at its base. mit e component bowlders, bowlderets and 
oes of the conglomerate varied in size from those at the 
7 
with an unchanged center of “trap.” The matrix of this con- 
ose consisted of the same material as the imbedded bow!l- 
