SciELO - Scientific Electronic Library Online

 
vol.48 issue2Local geological sections and regional stratigraphy based on physical geology and chemical stratigraphy of the Serra Geral Group from Araraquara to Avaré, SPGeochemistry of basaltic flows from a basalt ring structure of the Serra Geral formation at Água Vermelha dam, Triângulo Mineiro, Brazil: implications for the magmatic evolution of the Paraná-Etendeka Province author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Brazilian Journal of Geology

Print version ISSN 2317-4889On-line version ISSN 2317-4692

Abstract

SIMOES, Matheus Silva; LIMA, Evandro Fernandes de; SOMMER, Carlos Augusto  and  ROSSETTI, Lucas de Magalhães May. The Mato Perso Conduit System: evidence of silicic magma transport in the southern portion of the Paraná-Etendeka LIP, Brazil. Braz. J. Geol. [online]. 2018, vol.48, n.2, pp.263-281.  Epub May 14, 2018. ISSN 2317-4889.  http://dx.doi.org/10.1590/2317-4889201820170080.

The Mato Perso Conduit System is described from a ~ 120 km2 area in south Brazil exposing silicic volcanics of the Paraná-Etendeka LIP. A volcanic succession is defined by basaltic flows covered by flat-lying oxidized vitrophyres, banded vitrophyres cutting the lower lavas and grey flat-lying vitrophyres covering all the units. Flow morphologies determined by the recognition of structures, textures, and vesicle distribution were observed. Oxidized vitrophyres display massive flat-lying banded cores and flow tops from vesicular to frothy. Grey flat-lying vitrophyres have sharp contacts in the top of both basalt flows and oxidized vitrophyres, locally exhibit basal breccia and have a flat-lying foliation. Conduits are represented by banded vitrophyres and breccias, which outcrop in a 6 km wide, NW-SE oriented segment downthrown by normal faults towards the Antas River. The interpretation of the units on the geological map scale indicates intrusive contact relations. Recognition of dike-like structures in banded vitrophyres and dykes of oxidized vitrophyre are evidence of felsic magma transport. Based on field observations, we propose the emplacement of subaerial oxidized and grey vitrophyres fed by a fault-related conduit system. Sustained high temperature magmatic systems ensure the silicic lavas have a low viscosity and travel great distances.

Keywords : Large Igneous Province; magma transport; conduit system; Paraná-Etendeka LIP; Paraná Basin.

        · text in English     · English ( pdf )