GREENE COUNTY. 669 
mile or two beyond, to the east and north, the horizon of the Dayton 
stone is shown in many exposures with perfect distinctness; but its 
place is occupied by light-blue shale, or soapstone, as it is popularly 
called, and a worthless shaly limestone, yellow in color, and generally 
covered with fucoidal impressions, which are frequently rendered green 
by the presence of silicate of iron. This phase is well shown on the 
Grinnell pike, opposite the farm of Mr. A. V. Sizer, a mile below Yellow 
Springs. . | 
By far the best known deposit of the Dayton stone in the county, how- 
ever, is found.on the McDonald farm, three and a half miles south of 
Xenia. The rock was originally exposed here along a tributary of 
Ceesar’s Creek. When the quarries were first opened, but a light covering 
of glacial Drift, or bowlder clay, was found; but as the lines have been 
extended, the stripping has become heavier. The surface of the rock 
has been planed and polished by glacier agency. From four to eight feet 
of workable rock are here found, divided into courses varying from four 
to twenty inches in thickness. The stone finds market in Xenia, being 
quite widely distributed from that point by railroad. 
The composition of the stone from the McDonald quarry is seen in the 
following analysis, made by Prof. Wormley: 
Carbonate ali lime Ree UN nee fal eh Hat 5 Seid nh alh UR aOR 84.50 
Carrey AL One lem A CST Aree wenn eee estes aie scares Alas gaveanidaasenesdieawomeliess weieek taste 1G 
PNUMINMITV ARTA UI O Munna stiten nares arcMan ashi teas scusn season sos avwocsnsecersonsoacseisectens 2.00 
DUMCIOU Seas somes ee Mem aue nea eac wa smac Me clinches bund Gueu cats danweMevesosuesecesve steepness saaede _ 2.20 
99.86 
(b.) The Niagara shale directly overlies the Dayton stone where the 
latter stratum is found, and'the Clinton formation, in case the Dayton 
stone is wanting. It is a normal constituent of the general geological 
scale of the country. Highty-five feet of it are found at the Falls of Ni- 
agara, and along the Appalachain Chain it is thickened to one thousand 
five hundred feet. Its maximum development in Greene county can be 
seen in the “Glen” at Yellow Springs, on the’ land of W. C. Neff, Esq., 
and at the locality already noted, in the cutting for the Grinnell pike, 
opposite the old water-cure gounds. It here attains a thickness of thirty 
feet. This member of the series increases rapidly as it is followed south- 
ward through the State, measuring in Adams county one hundred and 
six feet. 
In composition it is not perfectly uniform, the two elements that enter 
into it being found in varying proportions in different sections. These two 
elements have been already named—a light-blue calcareous shale, and 
