GEOLOGICAL SECTIONS OF THE REGION 179 



south. The inaxiniuin thickness of the Coal iNIeasures is about l,GUl) 

 feet, in the extreme southwest corner of tlie state. 



MISSOURI SECTION 



The typical section of Missouri has already been given in connection 

 with the general statement regarding the Carboniferous and its subdi- 

 visions in the Mississippi valley. Within the state limits, however, the 

 full sequence of the Missourian is not represented, the extreme ui)})er 

 part of the series not being found so far to the east. The maximum 

 thickness of the Coal Measures is the same as for Iowa-, and is found in 

 the extreme northwestern corner of the state. 



In southwestern Missouri the sandstone and conglomerate beds lying 

 at the base of the Coal Measures, and called the Graydon sandstone, in 

 Greene county,* for example, have been referred to the Des Moines series. 



In this part of Missouri the Coal Measures rest directly upon the Au- 

 gusta limestone. Over a considerable part of the region the latter also 

 forms the surf\\ce rock. Remnants of the Saint Louis limestone with 

 characteristic fossils have been observed. On the southern border of the 

 state the Kaskaskia beds have been recognized. f 



KANSAS SECTION 



In the extreme southern part of the state the Missourian series is con- 

 siderably thicker than it is along the Missouri river. A notable feature 

 is the thickening of the limestones toward the west and the introduc- 

 tion of new limestone beds. 



The great limestone formations are slightly tilted to the northwest, 

 and a succession of marked eastward-facing escarpments are prominent 

 features of the topography of the region. These escarpments continue 

 on southward well into Indian territory. 



INDIA N TERRITOR Y SECTION 



The three general sections of the Coal Measures given by Drake i in- 

 dicate a very great thickening to the southward. In his subdivision of 

 the Carboniferous above the Mississippian he recognizes (1) the Lower 

 Coal Measures, (2) the Upper Coal Measures, composed of the Cavaniol 

 and Poteau groups, and (3) the Permian. From his notes alone it would 

 be difficult to compare these sections with the Kansas section. Personal 

 observations in the field enable the two districts to be paralleled, so that 



* Missouri Geol. Survey, vol. xii, 1898, p. 124. 



t American Geologist, vol. xvi, 1895, p. 86. 



X Proc. Am. Philos. Soc, vol. xxxvi, 1898, p. 372. 



