Lansing Pleistocene Geology. — Winchell. 297 
4a. At the same time, with a sHght swell upward in the limerock 
floor, begins another horizontal layer, differing in appearance from No. 
4, and thicker, and with a gentle southward ascent. This looks more 
like Carboniferous shale, but it is not in place as shale, and its lamin- 
ation is somewhat disturbed. Its composition may be very much that 
of shale. The commencement of No. 4a is two feet below the general 
level of No. 4. There is therefore an open interval between the two 
through which No. 2 seems to come down onto No. ic. 
No. IC. Underneath No. 4a is the continuation of No. la (or its 
stratigraphic analogue) of station A. But here it appears quite dif- 
ferent. It is about eight inches thick, and it suggests by its dark color 
that it is stained by carbon and iron, perhaps also by manganese, as 
if it had been an ancient geest soil. In this the small limestone frag- 
ments, so far as can be seen, are much rotted and roughened by decay, 
quite in contrast with the condition of those in No. la of station A. 
What the manner of transition may be from No. la to ic could not be 
seen* readily, but it is to be presumed that No. la disappeears coinci- 
dently with No. 4 or grades into No. 2 above No. 4a. 
Sample No. 6 was taken from the darker part of No. ic, at the 
point indicated. 
No. 2 appears homogeneous and loess-like, rising to the roof of the 
tunnel. 
Station C. This station is twenty-five feet from the en- 
trance. It is illustrated by fig-. 3, plate XVII. 
Here No. 4a is sixteen to twenty inches thick, and its upper and 
lower surfaces undulate. It is nicely horizontally laminated, but at its 
southern limit, in this station, the laminae are somewhat disturbed. 
Sample No. 7 illustrates this member at Station C. 
No. IC is red or brown-red, and only four or five inches thick. Its 
color contrasts with the light clayey color of No. 4a. It lies directly 
on the limestone, and near its upper surface are masses of much rotted 
limestone. 
Sample No. 8 is from No. ic; sample No. 9 is a rough and rotted 
limestone piece four inches across, from No. ic. 
Station D. This adjoins station C toward the south 
Here No. 4a becomes confused and thinner, and while it lies dis- 
tinctly and continuously on No. ic at the bottom its upper surface 
descends to the south, causing it to run to a point so that No. 2 again 
comes in contact with No. ic. Angular pieces of No. 4a are mixed 
in the bottom of No. 2, showing some disturbing action that brought 
on No. 2. 
Station E. Thirty-five feet south of the entrance. 
No. ic here is thin, say four inches, and is overlain by No. 4b. 
No. 4b consists of debris from No. 4a, and of limestone pieces not 
so much rotted as general!}' in No. la, and of debris of much finer 
* The wall of the tunnel was hid by boxes which had to be removed in 
order to get these sections. 
