Effects of Magmatic Fluids in Coals of São Pedro da Cova Coalfield, Douro Carboniferous Basin, Portugal: Insights from Inorganic Geochemistry

The Douro Carboniferous Basin (DCB), aged from Gzhelian, is an important coal-bearing basin occurring in Northern Portugal. While the coals and sedimentary sequence of DCB have been deeply studied, inorganic geochemical data are scarce. This study intends to provide major trace element contents discuss their modes occurrence origins using a set twenty-four coal samples São Pedro da Cova Coalfield taken different sectors/outcrops. Thus, integrated approach petrographic, geochemical, both organic inorganic, mineralogical was used achieve these purposes. main results demonstrated that anthracite A vitrinite component. Most elements affinities associated with aluminosilicates, while other sulfides. Illite muscovite phyllosilicates pyrite most common sulfide. However, cinnabar, together phosphates (fluorapatite, monazite, xenotime gorceixite), were also identified. enrichment as well heterogenous rare earth (REE) distribution pattern tectono-sedimentary unit (TSU) related magmatic fluids. On hand, on Eastern Outcrop (EO), tectonic slice, subparallel trend REE patterns, depletion all contribution. cinnabar gorceixite epigenetic mineralizations interpreted action porphyry intrusion identified this area DCB, between TSU B1 D1.