Combining δ18O isotope data and in-situ LA-ICP-MS trace element analysis of magnetite as a proxy for ore genesis: Constraints on the formation of Fe deposits from Ossa-Morena Zone (SW Iberian Peninsula)

The Ossa-Morena Zone (OMZ, SW of the Iberian Peninsula) is a geotectonic domain that comprises a set of diversified ore deposits formed from Cambrian to Carboniferous-Permian ages. The Montemor-o-Novo – Ficalho Fe-Zn-(Pb) belt was a productive mining sector until the first half of the 20th century with potential for future mineral exploration, although the mechanisms responsible for ore deposition are, in some cases, poorly constrained. In this study the trace element composition of a large set of orebodies belonging to three iron deposits is examined, and the first δ18O analysis of magnetite from the Portuguese sector of OMZ is reported.