Stratigraphy of the Missouri Palaiozoic. — Broadhead. ~io 
Beds of coarse pebbly sandstone and of magnesian lime- 
stone are found reposing upon the Archaean without any 
alteration of the contact layers. We therefore conclude that 
there is unconformity between them, and there is a lost inter- 
val between the Arclnean and the superincumbent terrane. 
One mile northwest from Fredericktown a section of strata 
shows as follows : 
1 — 21 feet of dark ash colored magnesian limestone. 
2 — 18 feet of white siliceous limestone. 
3—23 feet of gritty dolomite. 
1 — 10 feet of sandstone in thick beds. 
5 — 2 feet of red shaly sandstone. 
6— Reddish gray granite. 
On Twelve-mile creek, in Madison county, the equivalent of 
No. 3 of the above section is seen resting upon two feet of 
variegated marble, which latter is separated from the porphyry 
below by five feet of shale. The unaltered strata dip east- 
wardly 15 ° . 
On the west side of St. Francois river, near the mouth of 
Leatherwood creek, we find : 
1—5 feet of magnesian limestone. 
2 — 13 feet of gray dolomite. 
3 — 11 feet of dolomite. 
1—20 feet of marble beds. Strata dip 22°. Course, S-, 65° W. The 
marble is of variegated red, buff, drab and gray. 
On the St. Francois river, in Sec. 33, T. 34. R. 5 E., we find 
65 feet of sandstone and conglomerate, containing rounded 
porphyry pebbles and resting on porphyrinic granite. On tin- 
Mine La Motte tract sandstone is found below the magnesian 
limestones. At the head of Black river, in Iron county, two 
feet of limestone was observed resting on porphyry, with 40 
feet of sandstone and conglomerate overlying it. Similar oc- 
currences may be seen at Iron Mountain. On Marble creek, 
Iron county, a bed of 2<> feet of reddish porphyry appears at 
the edge of the water with nearly 300 feet of unaltered mag- 
nesian limestone overlying it. Summing up. we find that the 
section of the older series in southeast Missouri is about 
this : 
1 — Magnesian limestone. 
2—20 to 10 feet of gritty dolomite. 
3 — 20 feet of Ozark marble and calcareous conglomerate. 
1—10 to 90 feet of sandstone. 
5 — 2 to 30 feet of red shales. 
6— porphyry. 
7— granite. 
