238 PLATEAU OF CAXAMARCA. 



with the roots of the alpine grasses, enormous masses of rich 

 red silver ore and threads of pure silver (in remolinos, clavos, 

 and vetas manteadas) . Another elevated plain west of the 

 Purgatorio, near the Quebrada de Chiquera, is called 

 "Choropampa" or the "Field of Shells" (churu, in the 

 Quichua language, signifies shells, and particularly small 

 eatable kinds, hostion, mexillon] . The name refers to fossils 

 which belong to the cretaceous group; and which are found 

 there in such abundance that they early attracted the atten- 

 tion of the natives. -This is the place where there was 

 obtained near the surface a mass of pure gold spun round 

 with threads of silver in the richest manner. Such an 

 occurrence shows how independent many of the ores thrown 

 up from the interior of the earth into fissures or veins, 

 are of the nature of the adjacent rock and of the relative 

 age of the formations broken through. The rock of the 

 Cerro de Gualgayoc and of Fuentestiana has a great deal 

 of water, but in the Purgatorio absolute dryness prevails. 

 I found to my astonishment that notwithstanding the height 

 of the strata above the level of the sea, the temperature 

 of the last named mine was 15.8 Keaumur (67.4 Fahr.) ; 

 while in the neighbouring Mina de Guadalupe the water in 

 the mine showed about 9 Eeaumur (5 2. 2 Fahr.) As in 

 the open air the thermometer only rises to about 4 

 Eeaumur (41 Fahr.), the miners, whose toil is severe, and 

 who are almost without clothing, call the subterranean heat 

 in the Purgatorio stifling. 



The narrow path from Micuipampa to the ancient city of 

 the Incas, Caxamarca, is difficult even for mules. The name 



