A revised chemo-chrono-stratigraphic 4-D model for the extrusive rocks of the Parana Igneous Province

The statistical analysis of a lithogeochemical database from whole Parana Igneous Province (PIP), containing 5974 outcrop and drillhole samples, stresses natural gaps separating SiO2, Zr, TiO2 and P2O5 in high and low values. Their combination delimits 16 chemical types, which have been adopted to classify a sub-set of extrusive rocks with <2% LOI, comprising 3296 samples. The SiO2 x Zr diagram, where only extrusive rock samples were plotted, shows two major trends connecting low silica (LSi) with high silica (HSi) types. The set formed by Type 4 (LSi-LZr-HTi-HP) + Type 3 (LSi-LZr-HTi-LP) + Type 2 (LSi-LZr-LTi-HP) outcrop samples constitutes a continuous strip that contours the North-Central portion of the Parana Igneous Province - PIP, subdividing the Type 1 (LSi-LZr-LTi-LP) into Type 1 (Southern) and Type 1 (Central-Northern). The rocks of Type 9 (HSi-LZr-LTi-LP) are mainly exposed in the Central-Southern region and the Zr contents divide them into Type 9 (Central Southern) < 303 ppm Zr and Type 9 (South-East) 303 ppm Zr. Both Type 13 (HSi-HZr-LTi-LP) and Type 14 (HSi-HZr-LTi-HP) are exposed on the eastern rim of the PIP. Types are characterized and correlated by typical major and minor elemental associations as well as specific geographical locations throughout the province, composing a robust 3-D model. The combination of maps, cross-sections and 40Ar/39Ar and U/Pb ages found in the literature resulted in a 4-D model (spatial and temporal) for the province. Thus, it is proposed to subdivide the PIP into Southern Sub-province and Central-Northern Sub-province, each one with its own evolution, based on the chemo- and chrono-stratigraphy of its volcanic sequence. (C) 2016 Elsevier B.V. All rights reserved.