340 The American Geologist. December, i904. 
the base of the sandstone as exposed in the 
bed of the stream to its top 4 feet 8 inches 
is shown. 
2. Very soft argillaceous shale, of drab color 3' 5' 
which probably is at the top of the Bedford 
shale. 
1. Covered to stream level. 2' 2 
Several important stratigraphic facts are brought out by a 
study of the LithopoHs glen and others to the southwest of thai 
town which will now be discussed. In the first place it will 
be noted that there is a remarkable thinning in the Berea sand- 
stone when this section is compared with the one on Rocky fork, 
where it has a thickness of 37 feet,* as shown in a vertical sec- 
*In my former descriptions of Rocky fori? there has been some uncer- 
tainty regarding the base of the Berea grit and its thicliness (See Journal of 
Geologii, Vol IX, 1901. pp. 217. 218 and Vol. X. 1902, pp. 276-278, 328.) In 
the latter paper a concretionary layer of sandstone — No. 2 of the section on 
page 278 — was described, which showed a lithologic change from the clay 
shales of the Bedford, regarding the stratigraphic position of which there 
was uncertainty as to whether it should be included in the Bedford forma- 
tion or regarded as forming the base of the Berea. In going up the stream 
this concretionary layer is clearly shown in the next cliff, on the same side 
of the stream as the one mentioned above, and then may be found at the 
base of the lower end of the cliff on the opposite bank and somewhat farther 
up the stream. Formerly the lower part of this cliflf was covered with debris 
but the floods of the winter and spring of 1004 have swept it clean so that 
the bed rocks are shown to water level. The stratigraphy of this portion 
of the three cliffs is in harmony : the concretionary layer was carefully lev- 
eled from the middle to the upper cliff and found to occur at the same ele- 
vation ; while the concretionary layer at the middle of the upper and lower 
cliff is so nearly at the same level that no difference could be noted in the 
barometric readings. It might be considered better by some to regard the 
base of the Berea as beginning with the sandstone No. 5 of the section on p. 
278 : but the tuickness of the shale zone. Nos. .S and 4 decreases as it is fol- 
lowed up the stream, apparently by the lithologic change of the upper arena- 
ceous shales into thin sandstones, and hence it is believed preferable to con- 
sider tlie concretionary sandstone — Xo. 2 — as marking the base of the Berpa 
formation. The thickness of the shale zone is lOi/i feet in the lower cliff. 
7 feet 4 inches in the middle one. and 3 feet 4 inches in the upper. Near 
the lower end of the upper cliff an almost vertical wall gives 374- feet as the 
total thickness of the Berea formation. The section of the cliff is as follows : 
Total 
No. Thickness, thickness. 
7. Suiihvrif hlncJ< shale, only base shown. I'fi" 41'8" 
6. Top of Berea sandstone. Mainly fairly massive 1.5'8" 40'2" 
sandstone. 
5. Alternating shales and sandstones, the layers 14'11" 24'6" 
of the latter 6i inches in thickness. 
4. Arenaceous .shales with thin sandstone layers. 2'0" 9'7" 
lowest one with ripple mai-ks. 
3. Shale zone with quite arenaceous shales at the 
top. 
2. Sandstone stratum at base of Berea formation 
which is concretionary in places. 
1. Top of Redford shale, which is bluish-gray and 
quite arenaceous at the ton, 3-f- to the bed 
of the stream. 
This cliff is shown in Fig. 3 where the lower student stands on top of 
No. 2, while the upper students indicate the top of the Berea sandstone. 
The section published on page 27<> of the former paper was measured 
near the upper end of tltis cliff, when the concretionary stratum was cov- 
ered, and the shale at the bottom — No. 1 — is the continuation of No. 3 of 
the section at the lower end of ihe cliff and therefore belongs in the Berea 
formation instead of the Bedfoi-d. 
A later measurement near the upper end of this bank gave the following 
section : 
3'4" 
6'10" 
6"4: 
3'6" 
3'4. 
3' 
