12 
Annual Reports of Academy of 
of Indians from various parts of the plateau and the montana. 
In southern Bolivia are the important silver mines of Pulacayo 
and Chocaya, and the tin, bismuth and tungsten mines of Chorolque 
and Tasna. The latter produces most of the world’s supply of 
bismuth. 
The Andes forming the boundary between Chile and Bolivia and 
Argentina include a large number of volcanoes. At Ollagiie is a 
volcano of the same name, alleged to have an altitude of 18,200 
feet. It exhibits fumarolic activity. The rock is largely andesite. 
From the fumarole the vapor rushes with a terrific roar. About 
the small vents the rocks are coated with beautiful deposits of 
greenish-yellow and orange-colored sulphur. 
A short distance south of Ollagiie is the great borax deposit of 
Ascotan. 
The volcano San Pedro also exhibits some fumarolic activity. 
At its foot is a small but symmetrical volcano which from the 
distance looks like a museum-sized specimen. This cone is of 
recent origin and the erupted material consists largely of olivine 
basalt. 
On the hills northeast of Calama are the extensive copper deposits 
of Chuquicamata, which are noted among mineralogists for the 
many rare sulphates produced. 
Further southeast is a small town in the desert called Sierra 
Gorda. Sierra Gorda is a collection of calamena shacks upon which 
the sun burns ceaselessly. The town appears to be largely deserted, 
and the few inhabitants remaining seldom venture out into the 
sandy stretches which form the few streets. In either direction 
across the desert are some low hills, in which there was formerly 
considerable mining. The district is of interest as having formerly 
produced some exceedingly rare sulphates. 
Not far from Sierra Gorda one meets the first nitrate oficina, the 
Oficina Aconcagua, and is well into the Atacama desert. There 
are but few oases in this great desert whose length is about a thous- 
and miles. Copiapo, the most important one, is situated in the 
southern part of the desert, and formerly was the center of a very 
important mining district. 
One may sail for clays along the coast which contains but a few 
towns whose existence is due solely to the nitrate industry. Ant- 
ofogasta is the most important of these. It obtains all its water 
