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Fontboté, L., & Moritz, R. (2000) New data on polymetallic and Cu ore deposits along a transect across the Andes of Central Peru and their implications on the Andean metallogenic evolution. International Geological Congress, Rio de Janeiro, Brazil, August 2000, CD-ROM abstract volume, 1 p.

New data on polymetallic and Cu ore deposits
along a transect across the Andes of Central Peru
and their implications on the Andean metallogenic evolution

Fontboté, L. & Moritz, R. Section des Sciences de la Terre, University of Geneva, Maraîchers 13, 1211 Geneva, Switzerland

Data from recent and ongoing investigations on polymetallic and Cu ore deposits in Central Peru oblige to revise some genetic hypotheses and open new exploration possibilities. The main findings can be summarized as follows, following a W-E transect.

- The Raul-Condestable Cu deposits show significant similarities with the class of iron oxide (Cu-U-Au-REE) deposits. The possibility that Candelaria style mineralization is related to the Cretaceous Peruvian Coastal Batholith is reinforced by the intersection in a prospect east of Lima in the Palma area of sulfide-oxide paragenesis with hematite replaced by magnetite.

- The volcanic-hosted masside sulfides of the Perubar Zn-Pb-Ba district, occuring in a submarine volcano-sedimentary sequence of mid-Cretaceous age, are related to a rapidly subsiding basins in a back-arc pull apart system showing analogies with the present day Eastern Manus back-arc basin (Polliand et al., 1999).

- The Zn-Pb-Ag mantos hosted by Lower Jurassic Pucará carbonates in the San Cristobal-Andaychagua district, Domo de Yauli area, appear to be related to the same Miocene intrusive events responsible for the vein (Pb-Zn-Ag ± W), skarn (Pb-Zn-Ag ± Cu) and porphyry copper (Cu-Mo ± Au) mineralization in the Domo de Yauli-Morococha area. Mineral zoning, hydrothermal alteration including hypogene argillic associations and fluid inclusion and isotopic data favor this hypothesis (Moritz et al., 2000, Beuchat et al., 2000).

- The carbonate-hosted Colquijirca Zn-Pb-Ag and the newly discovered San Gregorio Zn-Pb deposits are part of a same high sulfidation epithermal system centered in the Miocene Marcapunta stock (Fontboté and Bendezú, 1999). This finding makes necessary a reinterpretation of other Zn-Pb deposits as Hualgayoc, Azulcocha, Cercapuquio which also may belong to the new type "carbonate-hosted high sulfidation epithermal Zn-Pb deposits".

- The formation age of the MVT Zn-Pb deposit of San Vicente hosted in Lower Jurassic Pucará carbonate rocks may be as late as Miocene as suggested by ore textures indicating sphalerite deposition synchronous with the very first overthrust movements.

The implications of these new findings on the metallogenic evolution of the Andes in Central Peru are discussed.