3D GEOLOGICAL MODELLING AND ISOTOPIC CHARACTERIZATION OF A GROUP OF PB-ZN-CU-AG MINERALIZATIONS RELATED TO EXTENSIONAL FAULTS IN THE SOUTHERN BORDER OF THE OSSA MORENA ZONE (VARISCAN MASSIF, SPAIN)

GUMIEL, Pablo, Recursos Minerales, Instituto Geológico y Minero de España (IGME), Departamento de Geología, Universidad de Alcalá, Rios Rosas, 23, Madrid, 28003, Spain, MARTÍN-IZARD, Agustín, Departamento de Geología, Universidad de Oviedo, C/ Arias de Velasco s/n, Oviedo, 33005, Spain, PALERO, Fernando, Departamento de Geología e Ingeniería de Minas, Universidad de Castilla- La Mancha, Almadén, 13400, Spain and ARIAS, Mónica, Departamento de Geología, Universidad de Alcalá, Facultad de Ciencias, Alcalá de Henares, 28871, Spain, pablo.gumiel@uah.es

This contribution presents a study of a group of Pb-Zn-Cu-Ag mineralizations structurally controlled by and associated with extensional faults, and hosted in Precambrian-Lower Cambrian volcaniclastic rocks located at the southern border of the Ossa Morena Zone.

One of the selected groups is the Pb-Zn-Cu-Ag mineralization of Casiano del Prado, which was the largest producer of lead-silver in the area in the nineteenth century. The vein-type mineralization is associated with a NE-SW trending extensional fault hosted in tuffs and volcaniclastic rocks belonging to the Malcocinado Formation (Upper Precambrian-Lower Cambrian age). The other group is the Pb-Zn-Cu vein-type mineralization of Montenegro which is related to a NW-SE trending extensional fault conjugate of the previous set, and ENE-WSW trending faults acting as pinnate veins.

Preliminary isotopic Pb/Pb data (²⁰⁶Pb/²⁰⁴Pb=18.220; ²⁰⁷Pb/²⁰⁴Pb=15.652; ²⁰⁸Pb/²⁰⁴Pb= 38.377) are very close to those from Alcudia Valley type "E" group, Linares-La Carolina, Castuera and peribatholitic from Pedroches (Palero & Martín-Izard, 2003; García-Medinabeitia, 2003).

3D geological modelling has been carried out on the basis of the old mining mapping and the structural interpretation of the available exposures. This 3D modelling has been generated using 3D GeoModeller© (www.geomodeller.com). In this software, lithological units are described by a pseudostratigraphic pile, intended to image the geology and structural relationships as well as possible. A major original feature of this modeller is that the 3D description of the geological space is achieved through a potential field formulation in which geological boundaries are iso-potential surfaces, and their dips are represented by gradients of the potential.

The models are built in a georeferenced system in a GIS, and use the digitized old mine workings maps, from which we have utilized the orthogonal projection of the mining stopes which were mineralized zones exploited at the time of mining. This has led to a three-dimensional representation which is a realistic approximation to the geometry of the mineralized bodies at depth.

Project CGL2008-03046/BTE funded by the Science and Innovation Ministry of Spain (MICINN)

Session No. 246--Booth# 19

Economic Geology (Posters)

Wednesday, 3 November 2010: 8:00 AM-6:00 PM

Hall D (Colorado Convention Center)

Geological Society of America Abstracts with Programs. Vol. 42, No. 5, p.580

© Copyright 2010 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.

Back to: Economic Geology (Posters)

<< Previous Abstract | Next Abstract >>