The mineralization at El Domo shares most of the features of a VMS deposit (Franklin et al., 2005; Franklin et al., 1981; Large, 1992; Large et al., 2001; Lydon, 1996; Lydon, 1988a; Lydon, 1988b). VMS deposits are major sources of Zn, Cu, Pb, Ag, and Au, and can contain trace metals such as Co, Sn, Se, In, Bi, Te, Tl, Ga, and Ge.
Pratt (2008) was the first to document and describe a Kuroko-type VMS environment on the Project concessions. He established a lithostratigraphy for the Las Naves/El Domo area in which massive sulphide mineralization rests on a footwall sequence of rhyolite and dacitic autobreccias. He divided the sulphide mineralization into five types:
- Massive sulphides with indistinct texture. In some places, a fragmental texture can be seen within the sulphides, suggesting that they may be formed by the replacement of lapilli tuff.
- Sulphide-altered lapilli tuffs and peperites.
- Transported sulphide fragments within polymictic lapilli tuffs.
- Sulphide “pseudo”-fragments within polymictic lapilli tuffs. Rare, thinly laminated siliceous chert with banded sulphides.
The mineralised zone at El Domo is an intact, upright and only mildly disturbed Kuroko-type VMS deposit. As such, it displays the characteristic zoning of the model type from the underlying feeder pipe area through vertical and lateral variations upward to the abrupt termination of the massive sulphides against the characteristic hanging wall grainstone mar ........
