CONEMAtJGH FORMATION OF WESTERN PENNSYLVANIA BASINS 175 



Entering at the southeast, one finds the lower part of the section as 

 at Salzburg, but at 5 miles from the county line, near Apollo, the Brush 

 Creek (Black Fossiliferous) limestone is present at 134 feet above the 

 Upper Freeport and 76 feet above the Lower Gallitzin, which is accom- 

 panied by the Mahoning limestone as at Salzburg. Already the great 

 sandstone mass overlying the Brush Creek limestone has broken up and 

 the Cambridge limestone, at 40 feet above the Brush Creek, is greenish 

 gray, fossiliferous, and in many features much like the Ames, as at many 

 localities in Ohio. The Ames (Green Fossiliferous) is given in the 

 generalized section as about 215 feet below the Pittsburg coal bed. and as 

 resting on the Harlem coal. It is 24 feet below the Morgantown sand- 

 stone, which is 34 feet thick. The Pittsburg limestones are at 21 and 43 

 feet, but no trace of the Little Pittsburg and Clarksburg coals appears. 

 The highest red shales are between the Morgantown and the Ames. 



Northward from the Kiskiminitas the section is traced with ease 

 along the east side of the county, where the great sandstones prevail for 

 several miles. The Brush Creek coal bed is at 140 feet above the Upper 

 Freeport, underlying the Buffalo-Cowrun sandstone, on which rest 8 feet 

 of red shale. The Barton coal is shown in many places at about 75 feet 

 below the Ames limestone, or 225 feet above the Upper Freeport, and 

 the Gallitzin is represented by one or the other of its splits at several 

 localities. On the west side of the Allegheny river the Ames is at 260 

 to 270 feet above the Upper Freeport and the Pittsburg reds are con- 

 spicuous as at several localities east from the river.* 



Butler county is west from Armstrong and north from Allegheny. 

 In the northern half one rarely finds more than 100 feet of Conemaugh. 

 The Gallitzin (Millerstown of Chance) is at 35 to 55 feet above the 

 Upper Freeport and occasionally becomes thick, 5 feet 10 inches at one 

 locality, but the coal is inferior. Both divisions of the Mahoning are 

 present and vary from massive to shaly sandstone, f 



Entering southern Butler at the southeast, one has Doctor White's 

 section showing two massive conglomerates, each 60 to 70 feet thick, 

 separated by sandy shales, giving in all 160 to 170 feet. The Upper, 

 or Buffalo, is the coarser, the pebbles being as large as hickory nuts, and 

 its bottom at the type locality is 120 feet above the Upper Freeport. 

 There the interval between it and the other plate, the Lower Mahoning, 

 is concealed, but Doctor White's section on the Armstrong County border 

 shows the conditions: 



* W. G. Piatt: (H 5), pp. 5, 21, 36, 68, 90-91, 163, 280, 288. 

 t H. M. Chance: (V), pp. 56, 90. 



