H. F. Bain — Limestone at Bethany, Missouri. 433 



Art. L1IL — The Bethany Limestone at Bethany, Missouri / 

 H. Foster Bain. 



The Coal Measures of the Iowa-Missouri coal field are made 

 up of the well-marked series of beds known respectively as 

 the Des Moines and the Missourian. As originally used* 

 these terms were considered to rank as stage names, but as the 

 work of geologic mapping has progressed in the two states it 

 has been found that both the Des Moines and the Missourian 

 formations are really series of quite well-marked beds. Keyes 

 has already proposedf that the terms be considered as serial 

 and many of the minor divisions or stages have been made out 

 in Iowa,;j: Missouri,! and Kansas. || 



The complete section of the Missourian series has not been 

 published, though individual formations falling within its limits 

 have been made out by Haworth,T Prosser,** Keyes and others. 

 Among the minor division the basal member of the Missourian 

 has been often referred to. It is a heavy bed of limestone, or 

 really a group of limestones with their intercalated shale beds, 

 and its outcrops have been mapped, in part in detail and in part 

 by reconnoissance work only, in Iowa, Missouri and Kansas. 

 The limestone is of considerable economic importance, not 

 only because, it furnishes stone for building and lime-burning 

 but also because it marks the upper limit of the productive 

 Coal Measures throughout most of the region. It is accord- 

 ingly particularly important that there should be no mistake in 

 its correlation. There has been some controversy as to the 

 proper name to be applied to the bed,ff but the term Bethany 

 or Bethany Falls seems to have priority. In the present paper 

 it will be shown that it is not the particular limestone which 

 forms the falls which is of significance, but a whole group of 

 limestones, all of which are well shown within the limits of 

 the town of Bethany, Missouri. In view of this fact the sug- 

 gestion already made, that the latter portion of the name as 

 first used be dropped, seems particularly good. 



In the recent work of the Iowa Geological Survey detailed 

 sections of the Bethany limestone have been made out at inter- 

 vals from the central portion of the state, where it passes 

 beneath the Cretaceous, to the southern border, where it is well 



* Keyes: Mon. Rev. Iowa Weather Service, vol. iv, p. 3, 1893. 



f Amer. Geol., vol. xviii, pp. 22-28, 1896. 



% Iowa Geol. Surv., vol. v, pp 378-398; ibid, vol. vii, 443-450, 509-520, 1897. 



§ Missouri Geol. Surv, vol. x, pp. 29-71, 1896. 



|| Univ. Geol. Surv. Kansas, vol. i, pp. 145, 193, 1896. 



^[ Loc. cit. 



** Jour. Geology, vol. iii, p. 800, 1895. 



ff This Journal, IV, vol. ii, pp. 221-225, 1896. 



