Felsic volcanic rocks from Azinhalinho, Beja, Portugal: relationship with Iberian Pyrite Belt magmatism.

The Azinhalinho volcanic rocks are hosted in the Frasnian Gafo Formation and display very similar geochemical signatures to some volcanic rocks from the Iberian Pyrite Belt (IPB),
namely anomalously low HFSE concentrations, possibly caused by low temperature crustal melting, which translate into classification problems. Considering the lack of radiometric dates and clear field relationships, the similarity between the geochemistry of Azinhalinho volcanic rocks and IPB volcanic rocks can be explained in two possible ways. The Azinhalinho volcanic rocks can be considered the product of a volcanism that preceded the volcanism that occurred in the IPB, which is widely interpreted as being of late Famennian to Middle Visean age. In this case, the volcanism of Azinhalinho would have happened synchronously with the Late Devonian Phyllite-Quartzite Group sedimentation in the IPB basin, but already in a very similar setting to the one in which IPB volcanism would develop later. Alternatively or complementary, both volcanisms could have been approximately contemporaneous, in which case the volcanism of Azinhalinho would represent conduits or feeders to the volcanism of the IPB.