REGIONAL TECTONO-MAGMATIC OVERVIEW FOR COPPER PROSPECTIVITY ASSESSMENT OF THE JURASSIC MAGMATIC PROVINCE OF COLOMBIA

Porphyry copper deposits are formed in subduction settings at shallow crustal levels in felsic to intermediate rocks sourced by differentiated mantle related magmas that experience significant crustal interactions, in relatively thick crust.

The central and eastern Colombian Andes contains a wide Jurassic volcanic and plutonic record formed between 200 – 146 Ma interval. It contains intermediate to felsic arc-related rocks formed by mantle and crustal sources.

We review published geochronological and geochemical constraints to evaluate the potential controls on Cu mineralization in the Upper Magdalena Valley (Central Colombia), where at least 3 Cu-mineralizing events have been found: the north Payandé Skarn (165 Ma), the southern Mocoa Porphyry (170 Ma) and the central Natagaima district (183 Ma).

Field and thermo-barometric models have shown the preservation of shallow magmatic levels for the magmatic rocks formed between 186 and 165 Ma that will promote the preservation of porphyritic facies and related Cu-mineralization. Rocks formed within this interval are also highly enriched in LILE and characterized by high-K to calc-alkaline character compatible with high volatile contents into the melt increasing volumetric possibility of metals accumulation, whereas finally Sr/Y and La/Yb Mohometry suggest that magmas are associated with a relatively high crustal thickness.

Although this preliminary review shows that that the 165-183 Ma Jurassic province in central Colombia have lithostratigraphic and geochemical characteristics of common models for Cu mineralization, more detail geochronological and geochemical constraints within the mineralized regions will allow to understand in more detail additional controls for Cu formation.