446 Prosser — Sir atigraphic Position of Ilillsboro Sandstone. 



Total 

 Thickness Thickness 

 No. Ft. In. Ft, In. 



1. Cedar mile dolomite. — Light gray to buff, 

 porous rock, part of which contains 

 numerous large specimens of Pentame- 

 rus oblongus Sowb. Fifteen feet ex- 

 posed according to the barometer 15 15 



Dr. Orton stated that the sandstone is shown at this locality 

 "in its proper place as crowning the Niagara series,"* with a 

 thickness of 30 feet. It appears at present impossible to say 

 whether all the summit of the hill above the top of the exposed 

 Cedarville dolomite (No. 1) is sandstone or not. If it is, how- 

 ever, then as leveled by Mr. Miller it is only 16£ feet from the 

 top of the outcropping Cedarville dolomite containing numer- 

 ous specimens of Pentamems oblongus Sowb., to the summit 

 of the hill. 



SECTIONS NEAR TURKEY. 



Dr. Orton stated that " other localities at which it [Hillsboro 

 sandstone] occurs are principally to be found at the foot of the 

 slate hills on the eastern side of the county. The following 

 named points give good exposures : The Marshall and Sinking 

 Spring road near the house of John Bell, Esq.; the farm of 

 Hon. J. L. Hughes; the foot of Stult's Mountain ; the Caves 

 of Rocky Fork."f All of these localities, with the exception 

 of the Hughes farm, were located, and the outcrops on and 

 near the farm formerly owned by John Bell, now owned by 

 D. E. Stewart, were found to be the best. This locality is 

 about 5 miles southeast of Marshall and 1 mile southeast of 

 Turkey on the pike from Marshall to Sinking Spring, and 3 

 miles northwest of the last-named place, in Brush Creek Town- 

 ship. At the first four corners southeast of Turkey is the 

 house of A. L. Rhoads, and on the eastern side of the north 

 and south road on the Stewart farm, a short distance south of 

 the Rhoads house, is a small quarry in the so-called "marl" of 

 this region, which has been worked for the highway. In this 

 quarry is a sandstone which is lithologically like the Sylvania 

 sandstone ; but apparently does not extend entirely across the 

 quarry. The following section of this outcrop was made : 



Section on the P. P. Stewart farm. 



Total 

 Thickness Thickness 



No. Feet Feet 



3. Drab limestone lithologically like the 

 Monroe and rather harder than the 

 lowest zone in the quarry. No fossils 

 were seen ._ 5 ± 9i 



* Idem, p. 283. f Idem, p. 283. 



