Peculiarities of the Mystic Coal Seam. — Bain. 407 
practically unstratified, the proportion of known drumlin sec- 
tions in which stratified drift is found is significantly large. 
The conclusion is, therefore, that this theory must be kept as 
a working hypothesis, even if it is not accepted as the most 
probable theory. 
PECULIARITIES OF THE MYSTIC COAL SEAM. 
By H. Foster Bain, of the Iowa Geological Survey, Des Moines, Iowa. 
The great simplicity of structure exhibited by the Paleo- 
zoic formations of the Mississippi valley has been frequently 
emphasized. The earlier workers in the coal fields of this 
region, influenced largely by the then preconceived ideas of 
the close parallelism of beds, sought to find this same sim- 
plicity in the minutiae of the coal-bearing strata. A high 
stratigraphic value was given to the different coal seams upon 
the supposition, in part at least, that the individual veins were 
practically co-extensive with the Coal Measure area. Thus 
Owen* mentioned the finding of five coal seams in Iowa and 
doubted whether more Mould be found. Hallf regarded a 
certain limestone band in the Lower Coal Measures as recog- 
nizable from northeastern Ohio to Kansas. Worthen* corre- 
lated the coals found at Peoria, Illinois, with those of the 
Kentucky section established by Owen,§ and found, as he 
thought, a close agreement. 
Owen's scheme was the first attempt to classify the coal 
beds of the western basin and it was more or less extensively 
adopted by later writers. ( 'ox || discussed these correlations 
and showed that much confusion had resulted from them. 
The numbering or lettering of the different seams early at- 
tempted was of little value and led to such titles as A, A 1 , 
A 2 , A 3 . White in Iowa attempted rather to name them, and 
in 1870 gave six coal seams as occurring in the "Middle" Coal 
Measures,^" some of them being considered to extend from 
Guthrie county to Lucas comity. 
*Geol. Sur. Wisconsin. Iowa. Minnesota, p. '.»;. 1852. 
fGeology of Iowa. vol. i, p. 134, 1858. 
!<>co|. Sur. Illinois, vol. i. p. 53, 1866. 
j^Geol. Sni'. Kentucky, vol. in. pp. 18-24, 1857. 
JGeol. Sur. Indiana. Ann. Rept. 1870, p. His. L871. 
■JlGeology of Iowa, vol. n. p. 273, 1870. 
