WINCHELL S STl DIES OF BASIC IGNEOUS ROCKS 



327 



other kinds of sediment. These strata are much less contorted or nearly 

 straight and can be traced, without loss of their structural individuality 

 or their chemical composition, for considerable distances. This fact is 



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Figure 1. — CJiarttcteristir Siirf<irc of JasitHytc: Soinhiii 



illustrated by the above fioure, which is from a photogra]))! taken from 

 the north ridge at Soudan. Here the two kinds of jaspilyte are separated 

 by the irregular line of nonconformity running betv^een the two asterisks 



