Bimodal fissural volcanic suites from the Paraná basin (Brazil): k-'AR' age, 'SR'-isotopes and geochemistry - Piccirillo, Enzo Michele; Raposo, Maria Irene Bartolomeu; Melfi, Adolpho José; Comin-Chiaramonti, P.; Bellieni, Giuliano; Cordani, Umberto G.; Kawashita, Koji (Geochimica Brasiliensis, 1987)