424 PLATEAU OF CAXAMARCA. 



chalk series at the Perte du Rhone, was collected by us, both at 

 Tomependa in the basin of the Amazons and at Micuipampa sta- 

 tions of which the elevations differ 9900 (10,551 English) feet. In 

 a similar manner, in the Amuich Chain of the Caucasian Daghestan, 

 the cretaceous beds rise from the banks of the Sulak, which are 

 hardly 530 English feet above the sea, to a height of fully 9000 

 (9592 English) feet on the Tschununi; while on the summit of the 

 Schadagh Mountain, 13,090 (13,950 English) feet high, the Ostrea 

 diluviana (Goldf.) and the same cretaceous beds are again found. 

 Abich's excellent observations in the Caucasus would thus appear 

 to have confirmed in the most brilliant manner Leopold von Buch's 

 geological views on the mountain development of the cretaceous 

 group. 



From the lonely grazing farm of Montan, surrounded by herds of 

 lamas, we ascended more to the south the eastern declivity of the 

 Cordilleras, and arrived as night was closing in at an elevated plain 

 where the argentiferous mountain of Gualgayoc, the principal site of 

 the celebrated silver mines of Chota, afforded us a remarkablo 

 spectacle. The Cerro de Gualgayoe, separated by a deep-cleft 

 ravine or valley (Quebrada) from the limestone mountain of Cor- 

 molatsche, is an isolated mass of silicious rock traversed by a 

 multitude of veins of silver which often meet or intersect, and 

 terminated to the north and west by a deep and almost perpen- 

 dicular precipice. The highest workings are 1445 (1540 English) 

 feet above the floor of the gallery, the Socabon de Espinachi. The 

 outline of the . mountain is broken by numerous tower-like and 

 pyramidal points ; the summit bears indeed the name of " Las 

 Puntas," and offers the most decided contrast to the " rounded out- 

 lines" which the miners are accustomed to attribute to metalliferous 

 districts generally. " Our mountain," said a rich possessor of mines 

 with whom we had arrived, ."stands there like an enchanted castle 

 (como si fuese un castillo encantado)." The Gualgayoc reminds 

 the beholder in some degree of a cone of dolomite, but still more of 

 the serrated crest of the Monserrat Mountains in Catalonia, which 

 I have also visited, and which were subsequently described in so 

 pleasing a manner by my brother. The silver mountain Gualgayoc, 

 besides being perforated to its summit by many hundred galleries 



