Role of thermochemical and biogenic sulfate reduction in the formation of the El Porvenir sediment-hosted stratiform copper deposit, Neuquén, Argentina

RAINOLDI A. L.; FRANCHINI M.; BOYCE A.; GIUSIANO A.; CESARETTI N.; PONS M. J.; RÍOS J. F.

Salta

Simposio; 15th Quadrennial IAGOD International Association on the Genesis of Ore Deposits Symposium; 2018

International Association on the Genesis of Ore Deposits-SEGMAR

The El Porvenir deposit is one of the numerous sediment-hosted stratiform copper (SSC) occurrences and deposits of the Neuquén Basin (Argentina). It is located in the west sector of the Huincul High structure, near hydrocarbon fields, and is hosted in the Huincul Formation (Late Cenomanian-Early Turonian) of the Neuquén Group. The mineralization at El Porvenir occurs in bleached sandstone, associated with bitumen, whereas fine-grained sandstone and siltstone remain red, reflecting a strong control of porosity and permeability in both alteration and ore formation. In the last decades, several hypotheses on the formation of these SSC deposits have been proposed, however, a comprehensive genetic model for the deposits of the Neuquén Basin is currently lacking. In this contribution, we present the summary of a petrographic and geochemical study of the El Porvenir deposit anddiscuss the processes responsible for the copper mineralization.