538 Mines of Panuncillo, part m 



NE. by N., close up to the very foot of the Ciiesta de 

 Los Hornos, a crooked range of mountains formed of 

 intrusive rocks of the same nature with the above de- 

 scribed hillocks. Only in one or two places, on this 

 south-eastern side of the range, I noticed a narrow 

 fringe of the upper gypseous strata brushed up and 

 inclined south-eastward from it. On its north-eastern 

 flank, and likewise on a few of the summits, the strati- 

 fied porphyritic conglomerate is inclined NE. : so that, 

 if we disregard the very narrow anticlinal fringe of 

 gypseous strata at its SE. foot, this range forms a 

 second uniclinal axis of elevation. Proceeding in a 

 north by east direction to the village of Combarbala, 

 we come to a third escarpment of the porphyritic con- 

 glomerate, dipping eastwards, and forming the outer 

 range of the main Cordillera. The lower beds were 

 here more jaspery than usual, and they included some 

 white cherty strata and red sandstones, alternating with 

 purple clay stone porphyry. Higher up in the Cordillera 

 there appeared to be a line of andesitic rocks ; and 

 beyond them, a fourth escarpment of the porphyritic 

 conglomerate, again dipping eastwards or inwards. 

 The overlying gypseous strata, if they ever existed here, 

 have been entirely removed. 



Copper Mines of Panuncillo. — From Combarbala 

 to Coquimbo, I traversed the country in a zig-zag 

 direction, crossing and recrossing the porphyritic con- 

 glomerate and finding in the granitic districts an un- 

 usual number of mountain-masses composed of various 

 intrusive, porphyritic rocks, many of them andesitic. 

 One common variety was greenish-black, with large 

 crystals of blackish albite. At Panuncillo a short 

 NNW. and SSE. ridge, with a nucleus formed of 

 greenstone and of a slate-coloured porphyry including 

 crystals of glassy feldspar, deserves notice, from the 



