A forty-year perspective on the Pampia and Cuyania terranes in the Pampean–Chilean flat slab region

Abstract

Forty years ago, in a groundbreaking application of plate tectonic principles, Victor Ramos and his collaborators proposed a disruptive concept regarding the geological history of Paleozoic rock sections uplifted over the modern Andean forelands. They intended a geodynamic model in which the southern South American plate’s continental crust grew through the sequential accretion of continental terranes against the margins of stable Precambrian cratons, fundamentally challenging prevailing geological paradigms. This conceptual shift moved away from describing geology in terms of distinct stratigraphic provinces toward observing them as a tectonic collage of terranes. The new perspective introduced terms such as the Cuyania composite and Pampia terrane (previously referred to as the Pampeanas or Pampean terrane). In this contribution, we reassess the Paleozoic history of central and western Argentina, situated above the Pampean-Chilean flat slab, to refine the geodynamic model. Extensive research and analysis have confirmed the existence of the Cuyania terrane. Instead, our geodynamic model ponders the concept of the Pampia terrane as inconsistent with a more streamlined tectonic model. We propose a revised geodynamic framework by reinterpreting the Neoproterozoic and Paleozoic tectonic evolution through the perspective of the Wilson Cycle. This geological background enhances our understanding of the regional Earth’s history and elucidates the underlying processes that have shaped it on a tectonic plate scale.