Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Neiva, Silva, Antunes, Ramos

Phosphate minerals of some granitic rocks and associated quartz veins from Northern and Central Portugal

Journal of the Czech Geological Society, volume 46 (2001), issue 1-2, 35 - 44

Phosphate minerals are common in northern and central Portuguese granitic rocks. Childrenite, eosphorite and intermediate compositions in this solid-solution series occur in muscovite granites at Paredes da Beira and Penamacor-Monsanto, muscovite-biotite granites at Penamacor-Monsanto and in aplite veins at Vidago. The compositions of childrenite and eosphorite are similar in each of these localities. Gormanite occurs in a muscovite granite at Segura. Triphylite is altered to strengite in the muscovite granite at Paredes da Beira, and to manganoan vivianite from (Fe_2.4Mn_0.4Mg_0.5) to (Fe_1.9Mn_0.9Mg_0.2), blue ludlamite, phosphoferrite and mitridatite in Vidago aplite. Green ludlamite and brushite were also found in aplite at this locality. Montebrasite and natromontebrasite were found in Li-aplite-pegmatite veins from Gonçalo and Segura. Mimetite with As/P ratio of 1.04 and a kintoreite-like phase are alteration products of galena in quartz veins at Segura.