354 h. Pumpelly—Paragenesis of Copper, ete. 
raneous with it, and they may be looked upon as having been 
formed under the influence of this reduction. Where cop 
predecessor, as in the pseudomorphs after some mineral (clay?) 
after laumontite. 
e 
, and in some places, as in portions of the Hecla — sare 
umet mines, it is wholly replaced by it; copper forming “shiel 
50 per cent, by weight, of the rock. In these instances ¢1 
ckel, etc., from the deposits of the trappean series, while they 
are present in the less metamorphosed rocks o 
ted; an intensity which m vy t 
which the process of concentration has been carried. pa 
tration is a process of removal relatively speaking and wee nid 
trated deposits are accumulated masses of material arres : 
the drainage channels of rock masses by the action of compe 
hoe th s . 
