Title: A bone fragment of a probable aquatic vertebrate in the Serra Alta Formation (upper permian of Paraná Basin)
Abstract:COMMUNICATIONSmuch darker than the cores, variations due to varying Fe and Mg contents.A second generation of light green tourmalines also occurs in quartz veins of Quartzite.These are alkalideficient...COMMUNICATIONSmuch darker than the cores, variations due to varying Fe and Mg contents.A second generation of light green tourmalines also occurs in quartz veins of Quartzite.These are alkalideficient, Cr-and V-bearing tourmalines with higher Mg# than those of the schorl-dravite series.The occupancy of the X-site, according to X-ray fluorescence data, is δ 0,51 Ca 0.33 Na 0.15 , thus corresponding to foitite, considered as an alkali-deficient schorl.Raman studies also discriminated two groups of tourmalines, one belonging to the buerguerite-schorl series and the other to the dravite-buerguerite-uvite series.Read More