Abstract

This report deals with a copper-bearing zone of about 50 kilometers long by 10-12 kilometers wide, located on the western flank of the Serranía de Perijá, between San Diego, municipality of Robles (La Paz), department of Magdalena, and Molino, municipality of Villanueva, Intendencia de La Guajira. There are several titled copper mines in this region, with dimensions of two-by-two kilometers each, without exploitation works and without knowing their commercial value.

The deposits are of the "porphyry ore" type, which commonly offers large volumes of ores with low copper content. They had no commercial value in the last century but gained importance since the beginning of the present century and in Chile since 1915. Today they yield more than 30% of the world’s copper production, being ores with less than 1% Cu. These results are due to advances in mining and ore beneficiation techniques and modern large-scale mining. Deposits of other types require 3-6% Cu to be exploitable.

In the Serranía de Perijá, because the deposits are irregular and generally poor, but of large extensions, the probability of their economic exploitation on a small scale must be ruled out in advance. Proof of this concept is given by the unsatisfactory results obtained so far. The reason for this is that the utilization of such deposits requires large capital and adequate organization. Therefore, before exploitation can be considered, extensive studies and explorations of the surface and subsoil must be carried out to determine the available volumes of minerals with their average copper content, the conditions of mineralization at depth, the most appropriate methods of exploitation (open pit or underground workings), and the systems of mineral beneficiation (leaching, flotation). The numerous copper occurrences in the Serranía de Perijá indicate extensive mineralization whose value for modern exploitation is unknown.

Consequently, and in view of the importance that copper from this region could have for the country's economy in terms of internal and external consumption, it is advisable to define the exploitability of the copper area soon.

The area between San Diego and Molino seems to be the most interesting. Copper mineralizations are also known to the north and south of this area and in some points of the southern part of the Sierra Nevada de Santa Marta.