204 
IOWA ACADEMY OF SCIENCES 
If this be the case then the limestone at Peru is the equivalent of that 
found at Winterset (See Geol. Mad. Co. la. Geol. Surv. Vol. VII, p. 512). 
The writer has gone over the ground alone and in company with Mr. 
Herman Mueller, and he agrees with the writer that the Peru section 
should be assigned to the Winterset. 
Now the top of the uppermost beds exposed in the Reed uarry, which 
is one-half mile west of the Peru quarry, is about 10 or 12 feet above No. 
9 of the Peru quarry section, which is also exposed in Reed quarry. 
As neither Mr. Mueller, Mr. T. E. Savage, nor the author have found 
any Fusulina while examining the Reed quarry beds above No. 9 of the 
Peru section and since there is thickness of 28 feet of strata between the 
top of the Winterset limestone and the base of the Fusulina limestone, ac- 
cording to Tilton and Bain, it seems probable that the Fusulina limestone 
is not exposed at the Reed quarry (See Mad. Geol. la. Geol. Surv. Vol. 
VII, pp. 525-529). 
The writer does not hope to offer much that is new concerning the 
geology of Madison county, but he would call attention to a vein of coal 
of fair quality eleven inches thick, a short distance below the Earlham 
limestone (Nos. 3 and 5 of the general section). 
Another feature not formerly mentioned is the glacial striations on 
the ledge in the Peru quarry. The striae run, as near as could be deter- 
mined with a pocket compass, north 27° west, and a level board laid 
across the top of the ledge at right angles to the striations would per- 
haps show some of them to be two or more inches deep in the center 
and as much as two or three feet in width. 
In some places the grinding has been carried on until the surface is 
almost as smooth as glass, again it is barely perceptible. There is a 
fair sample of this glacial work in the office of the Iowa Geological Sur- 
vey at the Capitol. 
The glacial deposits at Peru carry a very great number of limestone 
bowlders varying in size from small ones weighing one or two ounces to 
large ones weighing as much as two tons. Many of them are rounded 
and others show marks of glaciation. There are also the usual number 
of fossils of different kinds in that drift. 
The writer has found a small specimen of Rhombopora hardly one- 
inch long and as large as a small knitting needle, also a Derbya crassa 
scarcely one-half inch in diameter, which came out of the clay lying 
directly above the limestone at Peru. 
An amethyst crystal one inch long, a specimen of iron ore and a spec- 
ies of favositid coral also were found in the gravel above the clay just 
mentioned. 
Some small fish teeth were picked up from me sands of Middle river 
west of Winterset, but it may be that they were brought there, by the 
river from the Cretaceous farther north and west, rather than by the ice. 
