Fig. S4: Rapid changes from arid to humid conditions during the onset of the Paraná-Etendeka Igneous Provinces: can volcanic gas emissions from Continental Flood Basalts affect the precipitation regime?
journal contributionposted on 09.07.2021, 15:51 by V.G.P. Cruz, E.F. Lima, L.M.M. Rossetti, N.G. Pasqualon
Comparison between 'dry peperites' ( a, c and e ) cropping out in the locality of Torres (cf. Petry et al. 2007) and the Rio das Antas 'wet' peperites described in our work (c, d and f). Note that the 'dry' peperites only have sand-sized non-volcanic grains in the matrix, and that basaltic fragments have plagioclase phenocryst and microlite-rich groundmass. In contrast the Rio das Antas peperites have abundant silt–mud-sized non-volcanic material and a much higher presence of glassy angular basaltic fragments, interpreted as having formed by hydromagmatic quenching. All photomicrographs taken with parallel nichols.