Succession of the Ozark Series. — Broadhead. 263 
limestone appears nearl}' 200 feet in thickness and is capped by 
the first sandstone. 
A section one-half mile east Of Augusta shows the following: 
1 — Beds of Lower Silurian — Black River limestone. 
2 — 94 feet of first Magnesian limestone. 
f a-1 foot of greenish white calca- 
3 — 5 feet Beds of passage 1 | reous oolite, 
between limestone above J- including | b-1 foot soft yellow sandstone, 
and sandstone below. J c-1 foot drab oolite, calcareous. 
[d-2 feet brown calcareous oolite. 
4 — 130 feet of Saccharoidal sandstone — mostly white. 
5—2 feet of chert. 
6 — Second Magnesian limestone, with some chert and some beds of "cot- 
ton'' rock. 
The beds of passage (No. 3) are also found at several places in 
Warren and Montgomery counties. On Charette creek in Warren 
county we find: 
1 — 25 feet of Lower Silurian — Black River beds. 
2 — 59 feet of first Magnesian limestone. 
3 — 70 feet of Saccharoidal sandstone. 
4 — 22 feet of second Magnesian limestone. 
Westwardl}' in Warren county the sandstone becomes thinner, 
becoming still less in Montgomery and occurring mostlj' in pock- 
ets farther west resting in eroded valle3S of the second Magnesian 
limestone. On Loutre creek, near the mouth of Whetstone, 
the upper portion consists of about 3 feet presenting a columnar 
appearance perpendicular to the bedding plane very much resem- 
bling the sides of a piece of ice while melting. 
I have examined the Missouri bluffs at most of the outcrops of 
these on both sides of the river from St. Charles county 
to beyond Jefferson City and am satisfied with the correctness 
of my conclusions concerning them. The first sandstone is 
always soft and generally of a white color and remarkably pure, 
in silica generally over 99 per cent. At Crystal City, in Jefferson 
county, we find exposed 75 feet of this sandstone of a white color 
and soft consistency, and overl3'ing it is the first Magnesian lime- 
stone. Nearly 200 miles north and at West Point, Illinois, the 
first sandstone lies along the river for a mile or more with about 
75 feet thickness exposed, while overlying it is the first Magne- 
sian limestone with scarcely an}' trace of fossils, and also about 75 
feet thick. Upstream a quarter of a mile the Black River lime- 
stone beds overlie the Magnesian limestone with Trenton limestone 
still higher containing typical fossils. 
