212 GEOLOGY OF OHIO. 
the fac’ that the rock which composes them is more massive than that 
which connects and surrounds them. Hence, in the erosion to which 
this region has been exposed, these harder and more massive portions 
have best resisted the denuding action, while the softer rocks have been 
more deeply cut away. The light and uniform buff of the Amherst 
stone is undoubtedly due to the fact that these elevated cliffs, being 
freely drained, have been traversed by atmospheric waters, so that the 
iron the rock contains has been thoroughly oxidized. In localitie 
where the stone is beneath the water level, or is covered with a consider- 
able thickness of clay, it will be found to have a light blue color, as at 
Berea. This is well illustrated by the recent workings of the Amherst 
quarries, in which a stratum of very fine-grained, homogeneous blue 
stone has been found beneath the lighter beds, and where the rock was 
imperfectly drained. ‘This variety is called Blue Amherst, and is very 
handsome and highly esteemed. | 
No fossils have been found in the Berea grit of Lorain county, so far as 
lam informed. It has, however, yielded many interesting fossil fishes 
at Chagrin Falls (Palxoniscus Brainerdi), and some fish spines (Ctenacan- 
thus formosus), anda large Lingula at Berea, so that something of the kind 
may be looked for in the quarries of Lorain county. 
Bedford Shale.—Below the Berea grit comes in the Bedford shale, and 
this is exposed in all places where the sandstone is cut through. In 
Lorain county the upper part of the Bedford shale is generally red, and 
this will serve as a convenient guide in future explorations made in 
search of the Berea grit, it being understood that the only red shale in 
the county hes immediately beneath the sandstone. This red shale is 
well shown at the village of French Creek, in the gorge of Black River, 
at Elyria, in the railroad cut between Elyria and Amherst, in the quar- 
ries at Amherst, and in the cliffs bordering the Vermilion in Brown- 
helm. The best exposures of the entire thickness of the Bedford shale 
are on Black River, below Elyria, since the cliffs are chiefly composed of 
it for two or three miles. Here it is seen that the upper portion is deep 
red, the lower, bluish red and gray. It will be also noticed here that the 
upper surface of the shale is very irregular, showing that the currents of 
water which transported the sand—now the Berea sandstone—cut away 
the shale, then a red clay, in deep and broad channels. As these were 
filled with sand, the under surface of the sandstone is very uneven and 
its thickness variable. Several thin bands of impure limestone occur in 
the Bedford shale in the banks of Black River, and these contain a few 
fossils, the most abundant being a lammellibranch mollusk, called Mac- 
rodon Hamiltoniz, and a small Lingula not yet described. In one of 
