54 THE IRON ORE DISTRICT OF EAST TEXAS. 



The European lignites vary in physical and chemical qualities according to 

 the more or less complete decomposition of the original material from which 

 they are derived. Principally, however, their vegetable origin is well pre- 

 served, and can be easily traced in the woody structure of the different varie- 

 ties, which very frequently contain the stems, leaves, and branches of trees 

 and plants in a good state of preservation. The coals form compact, brittle 

 masses, with conchoidal fracture, or they exhibit an earthy or woody tex- 

 ture, and, according to their appearance and qualities, they are distinguished 

 as pitch coal, fibrous coal, woody coal, paper coal, wax coal, and common 

 brown coal. Their existeDce has exerted a marvelous influence upon the in- 

 dustry and prosperity of European countries. They belong to the class of 

 mineral fuels, and, with iron, are the most useful minerals found on our globe, 

 upon the development of which modern civilization is based. 



In Europe, as well as on this continent, in Texas, the lithological material 

 which composes the beds containing the brown coal deposits consists mainly 

 of loose sands, various colored clays, and sandstones. 



Profile der Oligocaenformation in der Gegend von Halle a. d Saale nach Laspeyres. Credner 



Elemente d. G-eologie, p. 641. 



Germany. G. Aelteres Gebirge Porphyry. 



1. Kapselthon Clay. 



2. Knollensteine Shingle. 



3. Unterfloetz Lignite. 



4. Stubenoder Quarzsand • Sand. 



5. Oberfloetz Lignite. 



6. Magdeburger sand Sand. 



7. Septarienthon Clay. 



8. Glimmersand Sand with mica. 



D. Diluvium • • .Diluvium. 



COMPARISON OF LIGNITES. 



The economic value of lignites can only be estimated correctly from a 

 comparison of the analyses of Texas brown coal with coals worked advan- 

 tageously for many years in Europe. Their analyses must therefore be of 

 the highest interest. 



