Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/185

No. VII.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Oriskany, visible,	20′
		Stormville shale,	125′
No. VI.	Lower Helderberg limestone,		343′
No. Vc′	Salina, upper,		115′
	Total,		603′

Summary of section along Northern Central railroad; North side of anticlinal.

No. VIII.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Hamilton and Marcellus,	805′
		Selinsgrove limestone,	50′
		Selinsgrove shales,	170′
No. VII.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Oriskany sandstone,	57′
		Stormville shale,	110′
No. VI.		Lower Helderberg limestone,	413′
No. Vc’.		Salina upper,	115′
		Total,	1720′

It will be seen from these two sections that the rocks assigned to No, VI, the Lower Helderberg limestone, vary in thickness from 343′ to 413′; but only the bottom portion, from 100′–125′ thick, immediately overlying the Salina, and known east of the Susquehanna river as the “Bossardville limestone,” contain the massive good beds of the formation.

Limestone quarries.

S. Harmon’s quarry is the first opening in these lower limestone beds west of the river, about ½ mile from the bridge at Shoch’s mill, opened on a northwest dip of from 10°–15°.

The quarry is about 100′ long, east and west and 30′ wide, and shows an excellent section of the Bossardville beds from 85′ to 100′ thick. The exposure contains some little shaly limestone and some bands of lime shale, but shows several excellent blue beds. Nearly the same beds developed at Winfield in Union county, are developed here, and in many respects the exposures are identical, although the lowest Union county beds have evidently not been opened here as yet.

A bed of lime shale or “soapstone” as the quarrymen term it, 6′ thick, divides the quarry near the center. The good beds above this band show the same rough surfaces