The Zn-Pb Mineralization of Florida Canyon, an Evaporite-Related Mississippi Valley-Type Deposit in the Bongará District, Northern Peru

Abstract

The Florida Canyon evaporite-related Zn-Pb sulfide deposit, in northern Peru, is one of the largest Mississippi Valley-type deposits in South America. Triassic carbonate and former evaporite-bearing rocks of the Pucará Group host the orebodies that constitute two different styles: (1) predominantly stratabound ore associated with hydrocarbon-rich porous dolostones and evaporite dissolution breccias and (2) high-grade ore associated with evaporite breccias representing diapiric injections along faults. A dome structure that controls the location of the ore deposit was defined by drill hole spatial data; the dome likely resulted from halokinetic processes during Andean deformation. NNE-trending, steeply dipping secondary faults linked to major northwest structures appear to control the distribution of ore grades in the deposit. Mineralization postdated hydrocarbon migration and accumulation. Strontium, carbon, and oxygen data isotope signatures allow distinction between pre- and synmineralization carbonate stages. The sulfur isotope composition of sulfides in the deposit suggests they precipitated as the result of mixing of a metal-rich fluid with resident hydrogen sulfide in the dome. Local thermochemical sulfate reduction may have contributed to the reduced sulfur budget during mineralization.

Application of mineral norm calculation in the resource evaluation of the sulphide and non-sulphide Zn-Pb mineralisation of the Florida Canyon MVT deposit, Peru

“…For validation purposes, we also used the SEM/EDS-MLA results from 65 samples presented by de Oliveira et al (2019a). The 3D geological model, developed by the first author and provided by the company, considered the individualisation of Zn-Pb ore bodies taking into account both primary stratabound and fault-bound MVT mineralisation styles (de Oliveira et al 2019b). The mineral resource evaluation involved the generation of variograms and estimation of the Zn, Pb and S grades in each block of the model by ordinary kriging (Journel 1983) (Figure 1).…”

“…The Florida Canyon MVT deposit is located in the Bongará District, Amazon region, northern Peru. Studies on the hypogene MVT sulphide mineralisation comprise Reid (2001), Basuki et al (2008), Basuki and Spooner (2009), and de Oliveira et al (2019b). Other supergene non-sulphide Zn deposits occur in the same district, such as Mina Grande (Arfè et al 2017a; Arfè et al 2017b) and Cristal (Arfè et al 2018; Mondillo et al 2018a; Mondillo et al 2018b).…”

“…The sulphide MVT mineralisation is dominantly stratabound hosted in carbonate and former evaporite rocks and extends all along the dome structure that defines the deposit. A second mineralisation type is discordant from the stratigraphy and is characterised by evaporite breccias with sulphide in open-space filling texture (de Oliveira et al 2019b). The supergene minerals overprints the original sulphide ore bodies, sometimes with the complete alteration of the primary sulphide ores (de Oliveira et al 2019a).…”

Germanium- and gallium-rich sphalerite in Mississippi Valley–type deposits: the San Vicente district and the Shalipayco deposit, Peru

“…1). It includes the San Vicente, Shalipayco, and Florida Canyon deposits, as well as dozens of inactive artisanal mines, prospects, and mineral showings (Fontboté and Gorzawski 1990;Carlotto et al 2009;Fontboté 2018;Mondillo et al 2018a;de Oliveira et al 2019de Oliveira et al , 2020Chirico et al 2022). The iconic San Vicente deposit is operated by Compañía Minera San Ignacio de Morococha S. A.A.…”

3D structural control and spatial distribution of Zn-Pb-Cu grades in the Palmeirópolis VMS deposit, Brazil

“…3D geological modelling is often related to mineral resources evaluation, but this application is far away to be unique, with considerable examples in the literature using it to understand better the formation and genesis of mineral deposits (Basson et al 2016;Stoch et al 2018;de Oliveira et al 2019;Cowan 2020;de Oliveira et al 2020de Oliveira et al , 2021. The Palmeirópolis deposit is an interesting case study to be modelled in 3D because it is a deformed Mesozoic VMS deposit, with distinct ore bodies occurring in different host rocks, shapes, and structural controls, making it possible to compare them with each other and to other VMS deposits around the world.…”