Geological relationships of basalts, andesites and sand injectites at the base of the Paraná volcanic province, Torres, Brazil

Reply to the Discussion by Duarte and Hartmann on "volcanic stratigraphy of intermediate to acidic rocks in southern Paraná Magmatic Province, Brazil" by Polo and Janasi (2014), geologia USP. série científica, 14(2), 83-100

“…The presence of unmistakable sedimentary (S 0 ) layering (Figure 2; point RS-73) does not leave doubt that in these cases they do not correspond to injectites. It must be stressed that we do not deny that sand injectites may be present in the region, and by no means we cast doubt on the importance of such deposits in the Paraná Magmatic Province, as properly described in several areas by Hartmann et al (2012aHartmann et al ( , 2012b.…”

Discussion: "Volcanic stratigraphy of intermediate to acidic rocks in southern Paraná magmatic Province, Brazil" by polo and janasi (2014), geologia USP. série científica, 14(2), 83-100

“…But the intrusive nature of the sand is clear in the province. The authors are presently directed to the detailed studies on the origin of the fine-grained sandstones intercalated with the volcanic rocks, because overwhelming genetic evidence for intrusion is displayed by Hartmann et al (2012aHartmann et al ( , 2012bHartmann et al ( , 2012c, Duarte et al (2014) and other chapters in Hartmann and Baggio (2014). These studies covered the Paraná volcanic province from Uruguay to Mato Grosso do Sul, including the intervening Brazilian states.…”

Stratigraphy of amethyst geode-bearing lavas and fault-block structures of the Entre Rios mining district, Paraná volcanic province, southern Brazil

“…Gilg et al (2003), Proust and Fontaine (2007) and Morteani et al (2010). The observation that the basalts attained brittle conditions (130°C) and were intensely altered to smectite and zeolites before AMETHYST-BEARING LAVAS FROM ENTRE RIOS, PARANÁ PROVINCE the protogeode formation led to a more accurate hypothesis of low-temperature, epigenetic origin of the cavities (Duarte et al 2009, Hartmann et al 2012a, also supported by Commin-Fischer et al (2010). The fluid that formed silica minerals in the geodes originated in the Guarani aquifer (Gilg et al 2003).…”