Nodular Sulphides in Cerdeirinha Stratiform Metasomatic Deposit—LA-ICP-MS Composition of Typomorphic Minerals

In the northwest of Portugal, in Serra de Arga, a stratiform and metasomatic tungsten ore deposit known as Cerdeirinha is located in parautochthonous terrains attributed to Silurian. In its stratigraphic sequence, there are some horizons containing concentrations of spheroid suphide nodules. The composition and origin of these nodules were poorly constrained. Co, Ni and Ag contents obtained by laser-ablation inductively coupled plasma mass spectrometry in nodular pyrite-pyrrhotite suggest a metamorphic/hydrothermal rework of a primitive sedimentary nature.