The taxonomy and distribution of Chitinozoa from Silurian (Llandovery) and Lower Devonian strata are reported from the Paraná Basin in southern Brazil and eastern Paraguay. The preCarboniferous sequences of the Paraná Basin in this area are present in three sub-basins viz., the Alto Garças (north) and Apucarana (south) sub-basins in Brazil, and the "East Paraguay Sub-basin" in east Paraguay. There is more similarity in the lithology between the Alto Garças and "East Paraguay" subbasins, than between the former and the Apucarana sub-basin. Llandoverian and Lochkovian to Pragian beds are present in all sub-basins. So far, no Emsian beds have been found in outcrops from the north-northwest margin of the Alto Garças Sub-basin, and no early Emsian beds in the outcrops on the northeast margin. Furthermore, Emsian beds could not be identified from the "East Paraguay Sub-basin" in the present study. The Early Devonian sequence is more complete in the Apucarana Sub-basin. It seems that the Apucarana Sub-basin endured a different evolution compared to the two other sub-basins during the Ordovician, Silurian and lower Devonian. Of the 39 chitinozoan species encountered, 24 species are left in open nomenclature, and the following five species are newly described: Ancyrochitina paranaensis, Angochitina daemoni, Sphaerochitina silurica, Spinachitina harringtoni, and Spinachitina wolfarti. A chitinozoan biozonation, with five zones and three subzones, is proposed for the investigated interval, and compared with the spore zonation. In addition we infer that the Furnas Formation could correspond to two chitinozoan zones found in Bolivia and Argentina (zones of Urochitina loboi and Angochitina aff. A. comosa), ranging in age from late Lochkovian to earliest Pragian. The zones are, from oldest to youngest: total range zone of Belonechitina postrobusta (upper Rhuddanian); total range zone of Conochitina elongata (Aeronian); concurrent range subzone of Spinachitina wolfarti n. sp. and Plectochitina sp. A (lower Aeronian); concurrent range subzone of Conochitina proboscifera and Spinachitina harringtoni n. sp. (upper Aeronian s.l.); concurrent range subzone of Conochitina proboscifera and Desmochitina cf. D. densa (lower Telychian s.l.); concurrent range zone of Salopochitina monterrosae and Conochitina proboscifera (upper Telychianlower Sheinwoodian); total range zone of Urochitina loboi (upper Lochkovian); total range zone of Angochitina aff. A. comosa (lowermost Pragian); total range zone of Ramochitina magnifica (Pragian s.l.), and total range zone of Ancyrochitina parisi (upper Emsian).

The end-Triassic is characterized by one of the largest mass extinctions in the Phanerozoic, coinciding with major carbon cycle perturbations and global warming. It has been suggested that the environmental crisis is linked to widespread sill intrusions during magmatism associated with the Central Atlantic Magmatic Province (CAMP). Sub-volcanic sills are abundant in two of the largest onshore sedimentary basins in Brazil, the Amazonas and Solimões basins, where they comprise up to 20% of the stratigraphy. These basins contain extensive deposits of carbonate and evaporite, in addition to organic-rich shales and major hydrocarbon reservoirs. Here we show that large scale volatile generation followed sill emplacement in these lithologies. Thermal modeling demonstrates that contact metamorphism in the two basins could have generated 88,000 Gt CO2. In order to constrain the timing of gas generation, zircon from two sills has been dated by the U-Pb CA-ID-TIMS method, resulting in 206Pb/238U dates of 201.477 ± 0.062 Ma and 201.470 ± 0.089 Ma. Our findings demonstrate synchronicity between the intrusive phase and the end-Triassic mass extinction, and provide a quantified degassing scenario for one of the most dramatic time periods in the history of Earth.

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Gondwana was an enormous supertarrane. At its peak, it represented a landmass of about 100 × 106 km2 in size, corresponding to approximately 64% of all land areas today. Gondwana assembled in the Middle Cambrian, merged with Laurussia to form Pangea in the Carboniferous, and finally disintegrated with the separation of East and West Gondwana at about 170 Ma, and the separation of Africa and South America around 130 Ma. Here we have updated plate reconstructions from Gondwana history, with a special emphasis on the interactions between the continental crust of Gondwana and the mantle plumes resulting in Large Igneous Provinces (LIPs) at its surface. Moreover, we present an overview of the subvolcanic parts of the Gondwana LIPs (Kalkarindji, Central Atlantic Magmatic Province, Karoo and the Paraná–Etendeka) aimed at summarizing our current understanding of timings, scale and impact of these provinces. The Central Atlantic Magmatic Province (CAMP) reveals a conservative volume estimate of 700 000 km3 of subvolcanic intrusions, emplaced in the Brazilian sedimentary basins (58–66% of the total CAMP sill volume). The detailed evolution and melt-flux estimates for the CAMP and Gondwana-related LIPs are, however, poorly constrained, as they are not yet sufficiently explored with high-precision U–Pb geochronology.