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

• Tipo: Artigo em Revista Científica Internacional
• Data: 2022

Autores

Costa, M (Autor) Outra; Moura, H (Autor) Outra; A. Pinto de Jesus (Autor) FCUP; Suarez-Ruiz, I (Autor) Outra; Flores, D (Autor) FCUP

Revista

Título: Minerals

Vol. 12

Página Final: 275

Editora: MDPI

Indexação

ISI Web of Knowledge - 2 Citações

Scopus - 3 Citações

Outras Informações

ID Authenticus: P-00W-6T9

DOI: 10.3390/min12020275

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

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 24