26 
IOWA ACADEMY OP SCIENCES. 
VERTICAL RANGE OP FOSSILS AT LOUISIANA. 
BY CHARLES R. KEYES AND R. R ROWLEY. 
Owing to peculiar phases in the erosion of the Mississippi 
river in northeast Missouri the basal portion of the Lower 
Carboniferous rocks is exposed to better advantage than per- 
haps anywhere else in the whole interior basin. In Pike county, 
Missouri, and in the contiguous parts of Illinois, not only does 
the lower part of the Carboniferous crop out along the streams, 
but vertical sections from the Hudson shales up to the Upper 
Burlington are obtainable in single exposures. In this locality 
the bluffs are high and the outcrops of the rocks under consid- 
eration are practically continuous along the great river for a 
distance of more than seventy- five miles. 
The section at Louisiana, which may be regarded as typical, 
is given below, essentially as when first published several 
yeas ago,* except that for the present purpose, smaller zones 
are recognized. 
SECTION OP ROCKS EXPOSED AT LOUISIANA, MISSOURI. 
TSRRANBS. 
Number 
FORMATIONS. 
Feet, 
Pleistocene. 
21 
Soil, and red residuary clay, with abundant chert frag- 
ments 
4 
Upper Burlington 
limestone. 
20 
19 
18 
17 
16 
15 
14 
13 
Limestone, brown, rather thinly bedded and cherty.. 
Limestone, compact, thin-bedded, encrinital, with 
much gray chert in bands and nodules 
Limestone, yellowish-brown, rather soft, encrinital... 
28 
18 
4 
Lower Burlington 
limestone. 
Limestone, bluish, fine-grained, siliceous 
Limestone, massive, white, encrinital, coarse-grained 
flipper whil.e ledp^ei 
4 
12 
20 
9 
6 
Limestone, brown, encrinital, with irregular chert 
bands and nodules, a^d occasional thin clay partings 
Limestone, white, very heavily bedded, encrinital, 
some white chert (lower white ledge) 
Limestone, brown, encrinital, heavily bedded 
Chouteau(?) limestone. 
12 
Limestone, yellow, massive, or heavily bedded, rather 
soft, fine-grained 
9 
Hannibal shales. 
11 
10 
Shale, brown, very sandy, passing into soft sandstone 
locally 
12 
60 
Shale, green, sandy above 
*Am. Jour. Sci., (3) vol. XLIV, p. 443, 1893. 
