chap. xv. Metalliferous Veins. 583 



to this rule : at Paral (SE. of Coquimbo) silver is found 

 in the porphyritic conglomerate formation ; as I suspect 

 is likewise the case at S. Pedro de Nolasko in the 

 Peuquenes Pass. Bich argentiferous lead is found in 

 the clay-slate of the Uspallata range ; and I saw an old 

 silver mine in a hill of syenite at the foot of the Bell of 

 Quillota : I was also assured that silver has been found 

 in the andesitic and porphyritic region between the 

 town of Copiapo and the Pacific. I have stated in a 

 previous part of this chapter, that in two neighbouring 

 mines at Arqueros the veins in one were productive 

 when they traversed the singular green sedimentary 

 beds, and unproductive when crossing the reddish beds ; 

 whereas at the other mine exactly the reverse takes 

 place ; I have also described the singular and rare case 

 of numerous particles of native silver and of the chloride 

 being disseminated in the green rock at the distance of 

 a yard from the vein. Mercury occurs with silver both 

 at Arqueros and at Copiapo : at the base of 0. de los 

 Hornos (SE. of Coquimbo, a different place from Los 

 Hornos, before mentioned) I saw in a syenitic rock 

 numerous quartzose veins, containing a little cinnabar 

 in nests : there were here other parallel veins of copper 

 and of a ferrugino-auriferous ore. I believe tin has 

 never been found in Chile. 



From information given me by Mr. Nixon of Yaquil, 1 

 and by others, it appears that in Chile those veins are 

 generally most permanently productive, which consist- 

 ing of various minerals (sometimes differing but slightly 

 from the surrounding rocks), include parallel strings 

 rich in metals ; such a vein is called a veta real. More 

 commonly the mines are worked only where one, two, 



1 At the Durazno mine, the gold is associated with copper-pyrites, 

 and the veins contain large prisms of plumbago. Crystalli-ed car- 

 bonate of lime is one of the commonest minerals in the matrix of 

 the Chilian veins. 



