LETTER TO THE EDITOR — More on Escondida discovery

I am writing with regard to the article “Arequipa eyes Peruvian copper” (T.N.M., Nov. 29/93) and the letter to the editor “Escondida find a team effort” (T.N.M., Dec. 20/93) about the Escondida discovery in Chile.

Escondida was one of a number of targets identified by the Utah-Getty joint venture but was not considered a high-priority target at the time; in fact, several other projects were drilled prior to Escondida between July, 1980 (when I became involved in the joint venture), and March, 1981, when Escondida was discovered.

The truth is that a proposal was made, following our fifth blank drill hole through the alluvium to the north, to drop the project. It was Harold Courtright’s report and recommendations that saved the day.

While basically agreeing to our proposal for the first five holes in the north, Courtright recommended that if these were not successful, we should consider drilling one or two holes on Cerro Colorado Grande Hill. The rest is history. Hole 6 intersected copper enrichment at a depth of 242 metres on March 14, 1981. Holes 7 and 9 also returned significant copper intervals. By the way, Hole 6 was almost shut down at 200 metres depth and it was not until a couple of days later that Nivaldo Rojas and I discovered the chalcocite enrichment in the rotary cuttings.

In summary, the Escondida discovery was indeed a team effort, combined with a little luck.

Patrick Burns

Santiago, Chile