Francisco Hervé, a pioneer in the study of the Chilean accretionary prism

Abstract

This paper presents a brief overview of the evolution of knowledge regarding the accretionary prism of the Chilean Pacific margin, with particular emphasis on the contributions of Francisco Hervé, who has been a leading figure for over fifty years in advancing our understanding of its formation processes. The early contributions of Félix González Bonorino and Luis Aguirre LeBert are highlighted in this evolution, as they brought about a profound shift in the interpretations of their time and, through their studies, paved the way for subsequent research. These studies were based on solid petrological foundations, complemented by geochemical and isotopic analyses that allowed the reconstruction of the metamorphic characteristics along the Pacific margin. The age of these fossil-bearing rocks, found in a few areas, not only established their age, but also the paleogeography and the environment of emplacement. In some cases, such as the fusulinid-bearing limestones of Madre de Dios, these fossils have revealed the complex late Paleozoic circum-Pacific paleogeography. Different geochronological analyses and various methods have allowed us to understand the evolution of these rocks over time. Complex trajectories of pressure and temperature conditions of the different sectors were established, leading to their present exhumation. A key result of this research is the identification of the collision of an allochthonous island arc, the Chaitenia terrane, and the impact this has had on some local communities, such as the town of Chaitén in the Los Lagos Region. The local people have proudly embraced the findings of these studies. This community acceptance of the geological explanation of the territory is one of the greatest honors a researcher can receive.