22 Relations of Trap-Bocks with Ores of Copper. 



We may perceive that there is here a law determining the 

 richness of veins, which may be explained by this fact ob- 

 served in the veins of other countries, namely, that the fis- 

 sures are ill developed in slaty formations, so that the veins 

 in them are narrow, and filled with stei'il debris ; while the 

 greenstone and schalstein, by the open and distinct nature of 

 their fractures, have presented wider and more durable inlets 

 to the metalliferous emanations. A second law, however, 

 comes to add to tlie importance of the first, and authorizes 

 us to attribute a more direct and decided metalliferous in- 

 fluence to these rocks ; namely, tliat these vein-fissures, which 

 from their origin have but little dependence on the enclosing 

 rocks, exist only in positions analogous to those we have de- 

 scribed, positions really subordinate to the trap-rocks. 



Accordingly, in the vast transition mass of the Rhenish 

 Provinces, the characteristics of mineral riches are sparry 

 iron, blende, and galena ; few copper mines, propei'ly so called, 

 exist there, unless it be some veins, forming an exception to 

 the general arrangement at Rheinbreitenbach. Throughout 

 the whole trap country of Dillenburg, we observe, on the 

 contrary, a multitude of veins, exclusively chai*acterized by 

 oligistic iron and copper pyrites, and the richest places there 

 are always in the relations of vicinity or contact with the 

 trajj-rock. When we leave the traps, for example, and re- 

 pair to the county of Siegen, so I'ich in ores, we find that the 

 copper pyrites becomes only an accidental mineral.* 



The constitution of the metalliferous formation of Dillen- 

 burg, and the relations Avhich regulate the richness of the 

 veins, give rise to a very intei'esting arrangement. 



The alternating beds which form the mass of Stangen- 

 waage, are highly inclined, and dip at angles from 55 to 75 

 degrees. Now, as the veins which cross these alternations 

 almost perpendicularly to their direction, become rich in the 

 greenstones and schalstein which dip under the same angles, 

 it follows that tne metalliferous zones of the veins are in- 

 clined as the vertical sections of these beds. Thus, then, by 



* I an) indebted to M. Ileusler, chief mining-engineer in tlie district of Siegen, 

 for tile communication of tliese results, attested by long praotico. iu llie minos 

 of the whole of that country. 



