RAYMOND: CORRELATION OF THE ORDOVICIAN STRATA. 279 



in hollows in the sandstone below and the strata bend up 

 and down with the irregularities of the subjacent sur- 

 face. At the base is a bed of limonite two to three inches 

 in thickness. 18 to 13 ft. = 36 ft. 



3. Thick, irregularly cross-bedded sandstone with some 

 specimens of Obolus in the upper layer. Thickness 

 variable. 5 to 10 ft. = 23 ft. 



2. Thin strata of black shale alternating with layers of 

 yellow or red sandstone. The shale is in beds one to ten 

 inches thick and is similar in character to that above. 

 The basal portion consists of conglomerate with boulders 

 of sandstone from one to five feet in diameter, and also 

 small pebbles cemented together by limonite and pyrite. 



5 ft. = 13 ft. 

 Zones 2 to 4 represent the Packerort formation. 



1. Hard, white, coarse-grained sandstone. Base not seen. 



Top of Esthonia formation. 8 ft. = 8 ft. 



