Revisiting the crystalline basement of the Central Cordillera (Colombia): Implications for terrane models and crustal evolution

The crystalline basement of the Central Cordillera of Colombia has traditionally been interpreted within a terrane framework that delineates distinct crustal blocks, such as the Chibcha and Tahamí terranes, separated by major fault zones like the Otú–Pericos fault. This review critically evaluates the validity of this model by integrating U–Pb geochronology, whole-rock Pb isotope geochemistry, and field relationships from key segments of the Central Cordillera.

New and compiled data challenge the existence of a Proterozoic terrane west of the Otú–Pericos fault and reveal substantial overlap in magmatic ages, metamorphic histories, and isotopic compositions on both sides of the proposed boundary. For instance, the Ibagué and Mariquita plutons intrude basement rocks across the fault and display similar Jurassic–Early Cretaceous crystallization ages and Pb isotopic signatures, undermining the interpretation of a fundamental terrane boundary. In addition, previously assumed Grenville-age exposures, such as the Tierradentro Gneisses and Amphibolites, lack reliable high-grade metamorphic evidence and are better explained as Permo–Triassic mylonitic units.

These findings suggest that the terrane model, while historically useful, is no longer adequate to explain the complex crustal architecture of the Central Cordillera. Instead, an accretionary-margin framework with lateral crustal growth, punctuated by localized strike-slip displacements, offers a more robust and parsimonious explanation for the tectonic evolution of the northern Andes. This study underscores the need for updated interpretations based on modern analytical datasets and a more integrative tectonic approach.