3D Geological Model of the Touro Cu Deposit, A World-Class Mafic-Siliciclastic VMS Deposit in the NW of the Iberian Peninsula

Mónica Arias,Pablo Nuñez,Cesar Castañón,Pablo Gumiel,Jorge Fuertes-Blanco,Daniel Arias,Agustin Martin-Izard

doi:10.3390/min11010085

Abstract

The Touro volcanogenic massive sulfide (VMS) deposit is located in the NW of the Iberian Variscan massif in the Galicia-Trás-os-Montes Zone, an amalgamation of several allochthonous terrains. The Órdenes complex is the most extensive of the allochthone complexes, and amphibolites and paragneisses host the deposit, characterized as being massive or semimassive (stringers) sulfides, mostly made up of pyrrhotite and chalcopyrite. The total resources are 103 Mt, containing 0.41% copper. A 3D model of the different orebodies and host rocks was generated using data from 1090 drill core logs. The model revealed that the structure of the area is a N–S-trending antiform. The orebodies crop out in the limbs and in the hinge zone. The mineralized structures are mostly tabular, up to 100 m in thickness and subhorizontal. Based on the petrography, geochemistry and the 3D model, the Touro deposit is classified as a VMS of the mafic-siliciclastic type formed in an Ordovician back-arc setting, which was buried and metamorphosed in Middle Devonian.

Highlights

The Touro copper deposit is located in the NW of the Iberian Massif, which has been divided into four zones [1,2,3]
The copper ores identified in the NW of the Iberian Massif are hosted by the so-called allochthonous complexes of the Galicia-Trás-os-Montes Zone (GTOMZ) (Figure 1B) [1], which are emplaced over the Central Iberian Zone
In this work we present, for the first time, a 3D model showing the geometrical characteristics of the world-class volcanogenic massive sulfide (VMS) Touro deposit

Summary

Introduction

The Touro copper deposit is located in the NW of the Iberian Massif, which has been divided into four zones [1,2,3]. The copper ores identified in the NW of the Iberian Massif are hosted by the so-called allochthonous complexes of the GTOMZ (Figure 1B) [1], which are emplaced over the Central Iberian Zone. Badham and Williams [10] described the petrography and geochemistry of the Touro deposit and discussed its geological context. They suggested that Touro might be a metamorphosed Besshi-type ore (siliciclastic-mafic [14]). Serranti et al [12] indicate that the chemical composition of anomalous garnet-rich am-

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Discussion

Conclusion