LOWER CARBONIFEROUS 43 



CALLA.WAY LIMESTONE. 



In southeastern Missouri, rocks containing the typical 

 fauna of the Western Hamilton are sparingly represented in 

 Perry and Cape Girardeau counties, in connection with the 

 limestones mentioned above. In this region the limestones 

 belonging to this group are dark-colored, shaly rocks, quite 

 different from the associated strata. 



North of the Ozark uplift the Devonian rocks referred to 

 the Hamilton extend westward along the Missouri river as far 

 as Jefferson City, having their most typical development in Cal- 

 laway county. In several places abundant fossils of this for- 

 mation have been obtained from strata having lithological 

 characters not very unlike the beds of the eastern Ozark 

 region referred to the same age. 



At Wintield, in Lincoln county, near the line of the so- 

 called Cap-au-Gris fault, the Western Hamilton limestone con- 

 taining numerous characteristic fossils, is inclined at a high 

 angle, about 75°. The beds lean against beds of the great 

 Magnesian limestone series. 



The limestone beds at Louisiana, near the probable north- 

 ernmost surface extension of the Devonian rocks in Missouri, 

 have already been discussed under the Niagara group. The 

 thin beds of clay-shales at the same place, particularly the up- 

 permost sandy layers containing abundant fossils, are con- 

 sidered at length further on, in connection with the remarks on 

 the Lithographic limestone. 



CARBONIFEROUS. 



Lower Carboniferous, or Mississippian, Series. 



In the great interior basin of the Mississippi the basal se- 

 ries of the Carboniferous is exposed more or less continuously 

 over broad areas, extending from northern Iowa to Alabama, 

 and from Ohio to New Mexico. In lithological characters the 

 rocks contrast sharply with the overlying members of the sys- 

 tem — the first being chiefly compact, highly fossiliferous lime- 

 stones ; the second principally clay-shales and sandstones. 



