THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



DECEMBER 1871. 



LI. On the Connexion of certain Phenomena with the Origin of 

 Mineral Veins. By J. Arthur Phillips, F.C.S., M. Inst, 

 C.E., #c * 



[With a Plate.] 



THE origin of mineral veins is a subject which has long oc- 

 cupied the attention of writers on natural history ; and 

 numerous theories have at different times been framed with the 

 object of explaining the nature of the causes by which they are 

 supposed to have been produced. 



An enumeration and classification of those which had been 

 brought forward previously to 1838 is given by Baron von 

 Herder in his work on the Meissen adit, published in that year. 



This may be briefly summarized as follows : — ■ 



1st. Theory of contemporaneous formation. — According to this, 

 lodes are not mineral matter occupying previously existing fis- 

 sures, but were formed either contemporaneously with the 

 enclosing rock, or were subsequently produced by metamorphic 

 action. 



2nd. Theory of lateral secretion. — Lodes are fissures filled 

 by various mineral substances derived from the rocks enclosing 

 them. 



3rd. Theory of descension, by which veins are explained as 

 being produced by the filling of fissures by materials introduced 

 from above. 



4th. Theory of ascension. — This teaches that veins are the 

 result of deposits of mineral substances which have been intro- 

 duced into fissures from below. 



Four distinct modifications of the last theory may be divided 

 into as many sub-classes. 



* Communicated by the Author, 

 Phil. Mag. S. 4. Vol. 42. No. 282. Dec. 1871. 2 D 



