58 F. T. THWAITES 
A few rods east of the Kroll quarry, on the side of the hill which 
slopes to the east, is a pit in soft St. Peter sandstone which is 
overlain, at the top of the exposure, by a few feet of disintegrated 
Trenton dolomite. Within the sandstone are crevices and pockets 
filled with glacial gravel. Excavations at the bottom of the pit 
show the shaly and cherty zone characteristic of the top surface 
of the underlying Lower Magnesian formation which here dips 
about 30 degrees to the east. 
In the Kroll quarry, on the hill to the west, 50 feet higher than 
the bottom of the pit, sandstone is seen at the entrance, overlain — 
Fic. 2.—Fold at entrance of Ripon limestone quarry, looking north 
by a few feet of dolomite at about the same level as that to the 
east. At the eastern edge of the quarry proper is the monoclinal 
fold shown in Figure 2. The displacement is from 8 to 1o feet, 
down to the west, and the strike is N. 5° W. Less than 4o feet 
west of this fold is a pit in the main floor of the quarry 40 feet deep, 
which shows no St. Peter sandstone. The quarry well reaches 
sandstone at a depth of 100 feet (Fig. 3). 
i In Figure 3, No. 1 is Lower Magnesian; Nos. 2 to 4 and 6 to 8, 
Trenton; and Nos. 5 and 9, Pleistocene; the sandstone in the well 
is Cambrian. 
