Geochemistry of igneous silicic rocks of the Martín García Island, Río de la Plata Craton, Argentina

BENITEZ MANUELA; BALLIVIÁN JUSTINIANO, C.A.; LANFRANCHINI, M.E.; LAJOINIE, M.F.; SALVIOLI, M.A.

Malargüe

Conferencia; VI LASI 2019; 2019

THE PHYSICAL GEOLOGY OF SUBVOLCANIC SYSTEMS ? LACCOLITHS, SILLS AND DYKES COMITE

The Martín García Island (MGI, Buenos Aires Province, Argentina) is located in the Río de la Plata estuary, 44 km northeast of Buenos Aires city. The MGI is composed of basement rocks partially covered by modern fluvial sediments. Thebasement rocks crop out mainly along the southern and southwestern coasts of the island and are constituted by metaultrabasites, metabasites, metagranitoids, and basic and acidic dykes. They correspond to the Martín García Complex, definedby Dalla Salda (1975), which together with the Buenos Aires Complex (Marchese and Di Paola 1975) of the Tandilia System, constitute part of the Río de la Plata Craton, assigned to the Transamazonian Orogenic Cycle (Dalla Salda et al.2005 and references therein). The aim of this work is to determine the chemical features and petrogenesis of the silicic rocks of the MGI.