DOMAIN III. ARGILLACEOUS. 



Guancavelica, behind Parcos, lie mountains of 

 weather-beaten argillaceous slate, mixed with 

 sand. The sections of these mountains consist 

 entirely of separate, more or less sharp-pointed, 

 pyramids of a flesh-coloured sand-stone. 



" The ridge of mountains covered with snow, 

 over which the road to the Pacific Ocean passes, 

 consists of simple sand-stone, through which 

 metallic veins, in some places with quartz or 

 felspar, in others with steatite and schorl, &c. 

 openly appear. On the contrary, the chain of 

 mountains to the north of Guamanga and Guan- 

 cavelica is said to consist, to the extent of one 

 hundred miles, of simple lime-stone, and equally 

 abounds with metallic ores, especially in the 

 province of Tarrna." 



" Behind Guancavelica the mountains gra- 

 dually become composed of less various mate- 

 rials, and at last consist only of simple sand- 

 stone, with layers of marl, lime-stone, and spar, 

 or of simple lime-stone ; they continue however 

 equally rich in gold, silver, quicksilver, rock- 

 salt, &c." 



It further appears from the original work that 

 the clay slate, which chiefly composes this mag- 

 nificent chain of mountains, is of various beauti- 

 ful colours ; blue, dark red, flesh colour, grey, 

 and yellow. 



