Sediment Hosted Ore Deposits – Blog Part 14a – Pucara Basin Junin/Pasco Region, Peru

Three very different styles of base metal deposit within the same stratigraphic unit! The Upper Triassic – Lower Jurassic carbonates of the Pucara Group are important host rocks for Zn, Pb, Ag, Cu deposits in central and northern Peru. Collaborators and myself were able to visit the Ayawilica Sn – Zn deposit (the most unique deposit I’ve seen in awhile), Attachocha scarn, intermediate-sulphidation Zn-Pb-Ag-Cu-Au mine and the Shaplipayco Mississippi valley style Zn-Pb-Ag deposit. The Pucara Groups rocks contain a variety of different styles of traps that highlight the need for the field geologist to be observant and not to settle for model-based exploration. When the right plumbing system meets the right porosity and permeability, sometimes with a little igneous activity, and a serious amount of fluid-flow, a well endowed metalifferous basin is born.

Beautiful textures, minerals and scenery everywhere to be found in a district where I am sure there will be many more discoveries to come. I gratefully acknowledge the aid of Nexa Resources and the participation of colleagues Gustavo Diniz-Oliviera and Watson Flores who made for great field trip companions! Saludos!