Tectono-thermal evolution of a long-lived Paleozoic accretionary margin: insights from the Famatinian orogeny, NW Argentina

This thesis contributes to the understanding of the structural and thermal evolution of a mountain belt in a tectonic plate margin. Our study case is the Ordovician Famatinian orogen, in NW Argentina. We found that the orogen reacted to both tectonic and gravitational forces by stretching laterally under constriction rather than growing vertically as its foundations were thermally weakened. Geochronology and thermometry from different minerals indicate that the core of this orogen was partially molten for ~100 million years, cooling slowly at a rate of ~1 ᵒC/Ma. These partially molten rocks undermined the stability of the edifice and ultimately caused its failure.