Here is a link to many copper mines in the general area of the Tesoro, probably within 25 km. As you can see, there are many, 15 listed here, just on this page. As you click on the names of the copper mines, it opens up to more and more around the one you are looking at. To simplify it, the place is riddled with copper mines. I believe this is very indicative of chargeable mineralization found in the area. You can also play with this map and look at the Tesoro close by, though this map is not as up to date as the accu weather satelite image.

http://travelingluck.com/South+America/Peru/Arequipa/_3960553_Mina+Huarato.html