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THE JOURNAL OF GEOLOGY. 



So far as my observations go, I have never found 

 an instance where two distinct seams of coal came together or, 

 conversely, where a seam became divided and its parts continued 

 to diverge for a long or indefinite distance. It is not uncommon 

 to find, in a seam of coal, the proof that the coal marsh had in 

 it local depressions, which were filled with sediments, making a 

 soil on which new vegetation grew, and thus the seam shows 

 two parts, separated by fire clay sometimes several feet thick ; 

 but in every instance when traced I have found the parts to 

 reunite. The two parts never diverge indefinitely. From these 



Fig. 2. Stratigraphy of Coal Beds. 



statements we may infer a general law of parallelism. Such law 

 is in harmony with the belief of the most careful observers, that 

 our productive Coal Period was characterized by great quietness 

 and freedom from violent local disturbances." 



This describes the apparent condition of things in Ohio. The 

 same with minor modifications and explanations may be regarded 

 as according fairly well with the facts observed in the Iowa-Mis- 

 souri coal field. 



On the other hand there are many who, with Newberry, have 

 directly opposed any approach to the recognition of the paral- 

 lelism of coal veins. Among the latest opinions on this side of 

 the discussion is one expressed by Winslow,^ who in considering 

 'Geol. Sur. Missouri, Rep. Coal, pp. 28-30. Jefferson City, 1891. 



