IOWA ACADEMY OF SCIENCES. 
27 
SECTION OP ROCKS EXPOSED AT LOUISIANA— Continued. 
TEBBANES. 
43 
a 
0 
EOBMATIONS. 
+3 
CD 
fa 
Louisiana limestone. 
9 Limestone, buff to gray, compact, very fine-grained, in 
layers four to six inches thick, simiiar to lithographic 
stone in texture 
8 Limestone, similar to above 
7 Limestone, similar to above, layers thicker and sepa- 
rated by buff sandy partings 
6 Shale, buff, sandy, two to six inches 
31 
8 
6 
^4 
Western Hamilton. 
Niagara? 
5 Shale, green or dark blue 
4 Shale, black, fissile 
3 Limestone, magnesian, buff, massive, 
2 Oolite, white, massive 
Hudson, 
1 Shale, blue, with thin bands of limestone, near Louisi- 
ana 
2 
4 
2 
8 
40 
The basal member of the section is the Hudson shale. When 
fully exposed in the neighborhood it attains a thickness of 
about seventy feet. It rests on a heavy magnesian limestone 
carrying characteristic Trenton fossils. 
The next two higher members, Nos. 2 and 8, are provision- 
ally referred to the Niagara. The oolite appears to be some- 
what of a local phase, but is present not only in the vicinity of 
the town but all the way to Paynes ville, a distance of eighteen 
miles. The formation appears to be represented elsewhere in 
the vicinity by fossiliferous limestones which are not oolitic. 
The organic remains contained are rather abundant. The buff 
massive layer is very thin at Louisiana, being only two feet in 
thickness in the river bluff in front of the town. Two miles 
southward, at the mouth of Buffalo creek, it increases to 
nine feet, and still further southward, on both sides of the 
Mississippi river, and southwestward toward Bowling G-reen, it 
attains a measurement of twenty-five to thirty feet in a distance 
of fifteen to twenty miles. It is almost destitute of fossils. 
The next two, Nos. 4 and 5, belong to the Devonian. The 
lower black shale contains a characteristic fish fauna. 
Numbers 6 to 9 form the Louisiana division of the Kinder- 
hook. It is the lithographic limestone of the older state 
reports. For a long time the lithographic limestone has been 
regarded as the basal member of the Lower Carboniferous in 
the Mississippi valley. Recently* some doubt has been thrown 
upon the interpretation of the age of the formation. Regard- 
ing this question the following statements were made: 
^American Geologist, vol. X, pp. 380-384, 1892; also Missouri GeoL Sur., vol. IV, pp. 
54-55, 1894. 
