304 PORTILLO PASS. tcii.\r. xv. 



to the thickness of many thousand feet, I have felt inclined to 

 exclaim that causes, such as the present rivers and the present 

 beaches, could never have ground down and produced such masses. 

 But, on the other hand, when listening to the rattling noise of these 

 torrents, and calling to mind that whole races of animals have 

 passed away from the face of the earth, and that during this whole 

 period, night and day, these stones have gone rattling onwards in 

 their course, I have thought to myself, can any mountains, any 

 continent, withstand such waste ? 



In this part of the valley, the mountains on each side were from 

 3000 to 6000 or 8000 feet high, with rounded outlines and steep 

 bare flanks. The general colour of the rock was dullish purple, 

 and the stratification very distinct. If the scenery was not beautiful, 

 it was remarkable and grand. We met during the day several 

 herds of cattle, which men were driving down from the higher 

 valleys in the Cordillera. This sign of the approaching winter 

 hurried our steps, more than was convenient for geologizing. The 

 house where we slept was situated at the foot of a mountain, on the 

 summit of which are the mines of S. Pedro de Nolasko. Sir F. 

 Head marvels how mines have been discovered in such extra- 

 ordinary situations, as the bleak summit of the mountain of S. 

 Pedro de Nolasko. In the first place, metallic veins in this country 

 are generally harder than the surrounding strata: hence, during 

 the gradual wear of the hills, they project above the surface of the 

 ground. Secondly, almost every labourer, especially in the northern 

 parts of Chile, understands something about the appearance of ores. 

 In the great mining provinces of Coquimbo and Copiapo, firewood 

 is very scarce, and men search for it over every hilt and dale ; and 

 by this means nearly all the richest mines have there been discovered. 

 Chanuncillo, from which silver to the value of many hundred 

 thousand pounds has been raised in the course of a few years, 

 was discovered by a man who threw a stone at his loaded donkey, 

 and thinking that it was very heavy, he picked it up, and found 

 it full of pure silver: the vein occurred at no great distance, 

 standing up like a wedge of metal. The miners, also, taking 

 a crowbar with them, often wander on Sundays over the moun- 

 tains. In this south part of Chile, the men who drive cattle into 

 the Cordillera, and who frequent every ravine where there is a little 

 pasture, are the usual discoverers. 



20^. As we ascended the valley, the vegetation, with the 



