68 GEOLOGICAL FORMATIONS 



iferous strata, and extend around the iSedalia elevation into the 

 southwestern part of the State. 



In southwestern Missouri, however, although typical 

 Keokuk has been observed in a few places, the information is 

 not as satisfactory as would be desired. The encrinital lime- 

 stone of that region, which has been thought by some to rep- 

 resent both Keokuk and Burlington limestones of the more 

 northern localities, appears to be the latter alone. Extensive 

 collections of fossils made in various parts of the formation 

 show few species that can be regarded as belongingto the true 

 Keokuk. This is all the more remarkable from the fact that 

 the vertical section of the Kinderhook and Burlington beds of 

 this region is essentially identical lithologically, as well as fau- 

 nally, with the one in northeastern Missouri. The several 

 localities just referred to in which the Keokuk fossils have 

 been found, show the faunas of the two members of the 

 Augusta as well marked as in southeastern Iowa, and nowhere 

 has there appeared a mingling or mixture of species more 

 pronounced than at the typical places to the north. 



In Greene county, where the rocks of the Lower Carbon- 

 iferous have been more satisfactorily studied than in any other 

 district of the region, the Chouteau limestone and underlying 

 shales are exposed in nearly all the creek beds from the eastern 

 border to the western. At Ash Grove on the western line of the 

 county, the Chouteau and Lower Burlington are exposed near 

 the railroad station. On the hilltops a few miles to the west- 

 ward, in Dade county, the Upper Burlington with a large fauna 

 is found. As the rocks of the Lower Carboniferous in these 

 and the adjoining counties dip westward at a low angle, about 

 the same as the general slope of the present land surface, and 

 the Coal Measures appear a short distance beyond the last 

 named locality, there is evidently much ground for believing 

 that 'in its full and characteristic development, the upper mem- 

 ber of the Augusta may not be exposed here. Still, it may be 

 present, for the recent personal investigations were not con- 

 clusive enough to preclude its existence entirely ; and it may 

 be well rexjresented farther to the southwest. 



