Prosser — Stratigraphic Position of Ilillsboro Sandstone. 439 



land] . . The Samantha Hill [Quaker Hill] also shows them 

 in small extent. . . . 



The occurrence of sandstone and black slate in the Niagara 

 series marks the beginning of a great change in the condition 

 of the seas that prevailed here." * The lower shale zone appears 

 more nearly in place than those above and perhaps they were 

 deposited with the limestone. The writer is not certain that 

 the above explanation is correct and perhaps the black shale has 

 only slumped down the hill, for some was seen still lower in 

 the soil just above the Cedarville dolomite, as shown in the 

 rock wall of Benigar's cellar. 



To the east of the highway is the Charles Rogers farm, and 

 in the first gully about opposite the sandstone outcrops in the 

 road gutter, two layers of sandstone are exposed as shown in 

 the following section : 



Section hi gully on the Charles Rogers farm. 



Total 

 Thickness Thickness 

 No. Ft. In. Ft. In. 



4. Hillsboro sandstone. — Light colored sand- 

 stone composed of fine grains of quartz 



sand. Blocks with a thickness of at 



least 2 feet 2 inches as shown in small 



excavation east of old deserted house. 2 2 16 10 



3. Covered interval 11 1 14 8 



2. Layer of quartz sandstone outcropping in 



gully and on bank to the east, with a 



thickness of at least 10 inches 10 3 7 



1. Gray magnesian limestone, the top of 



which is apparently rather sandy 2 9 2 9 



The covered interval of 11 feet 1 inch between the two sand- 

 stone layers in the above section agrees closely in thickness 

 with that of the interval between the two sandstones on the 

 road (Nos. 5 and 10) which is 12 feet 3 inches. 



On the knoll to the east of this gully are fairly large blocks 

 of the Hillsboro sandstone which are apparently from a broken 

 down ledge. From the top to the bottom of these sandstone 

 blocks on the knoll is 7 feet 8 inches ; but the thickest indi- 

 vidual block is 2 feet 2 inches. In another gully just to the 

 east of the knoll, it is 3 feet 1 inch from the base to the top of 

 the sandstone blocks, or 6 feet 3 inches from the base in the 

 gully to the top of the highest sandstone block on the knoll. 



This section may be represented as follows : 



* Geol. Surv. Ohio Report of Progress in 1870, pp. 283, 284. 



