BEDFORD AND BEREA FORMATIONS IN CENTRAL OHIO 601 
Farther down the run are outcrops of the chocolate-colored, 
argillaceous, Bedford shales.» Below these are excellent ones of the 
black Ohio shale, which in places form banks from 30 to 4o ft. in 
height. An earlier description of this section was given in the 
American Geologist.* 
The least thickness of the Berea sandstone noted on this run 
occurs in the small fall on the Enos Zwayer farm, where the ‘follow- 
ing section was measured at the fall’s northern angle: 
SECTION OF FALL ON SLATE RUN 
Total — 
No. os Thickness Thickness 
Inches Feet, Inches 
3. Sunbury shale—Basal portion of black, tough shale, 
the lower layers of which are rather arenaceous, pyriti- 
ferous, and tough; but containing near the base speci- 
mens of Lingula melie Hall and Orbiculoidea newberr yi 
(TB tei) 18 Reveal au AOS i ee a enone Ree ene 7 2 
. Berea sandstone-—Upper part not massive and con- 
taining much marcasite or iron pyrite. The sandstone 
in general is composed principally of white, quartz 
sand of moderate coarseness. The lower surface is 
rough, conforming closely to the inequalities in the 
upper surface of the underlying Bedford. At this 
point the Berea is thinnest and on the southern bank 
near that angle of the fall it is 2 ft. to 25 in. thick. This 
difference in thickness of the Berea is at the expense of 
the upper part of Bedford, since the upper surface of 
the Berea is even and regular with a dip up stream 
upon which the Sunbury black shale rests uniformly. 
Evident line of disconformity at the base........... 135 2 
1. Bedford formation.—Bluish, argillaceous shale with an 
occasional, sandy layer, approximately % in. thick. 
Wevelhomsirediniitaps ite oo eis nea ae shone 104 103 
“I 
to 
_ A view of this angle of the fall is shown in Fig. 4, in which the 
lower hammer marks the disconformable contact of the Bedford and 
Berea formations, and the upper one the conformable contact of the 
Berea and Sunbury shale. The entire thickness of the Berea sand- 
stone is shown, which is only 135 in. at the corner or angle. It also 
clearly shows the thickening of the lower part of the Berea on the 
XXXIV (December, 1904), 346-48. 
