The Palestina Fault extends from the Serranía de San Lucas in the department of Antioquia in the north, to the Nevado del Ruiz volcanic zone in the south. The Otú Norte and Bagre Norte Faults splay off the Palestina Fault. It mainly extends along the eastern slope of the Central Ranges, displacing Paleozoic crystalline metamorphic rocks and, in lesser amounts, Mesozoic plutonic rocks. The oldest rocks are mainly in the western block, which elevates a probable Miocene erosion surface whose eroded remnants are characterized by aligned flat narrow benches and spurs.