SMITHSONIAN EXPLORATIONS, I93I 



35 



The camp of Providencia clings to the steeps hanks of Temerosa, 

 and facing it is a high and rugged palisade of limestone up which a 

 burro trail zigzags its way to the pass and on to the copper camp of 

 Aranzazu across the range, where a second granitic mass is exposed. 

 At or near the contact of this rock with the surrounding limestones are 

 extensive deposits of copper of the contact type. The principal cop- 



Fir,. 31. — Patio of the Santa Maria de la Paz mine 

 with workmen breaking ore by hand. 



per minerals are chalcopyrite and hornite associated with bodies of 

 garnet, epidote, and related minerals. A long tunnel, two kilometers 

 in length, has been driven through the massive granite to intersect 

 the ore bodies, offering an exceptional opportunity to study this type 

 of ore occurrence. At Aranzazu is a small grove of pines and cedars, 

 the last remnant of the extensive groves that once covered all the 

 higher slopes of the range. A rocky trail, in places blasted out of the 



