The fault system, active during more than 200 million years from the Triassic to recent, represents the ancient western continental margin of northwestern South America and forms the boundary between obducted oceanic crust to the west of the fault zone and continental crust to the east.

The Romeral fault system forms the structural boundary between the Western and Central Ranges of the Colombian Andes.

[6] The megaregional Romeral fault system represents the geological boundary between the Western and Central Ranges of the Colombian Andes.

The geology of the western domain consists of an ophiolitic belt with oceanic gabbroic, basaltic and sedimentary rocks of Cretaceous age.

The eastern domain consists primarily of continentalised metamorphic schistose, oceanic, and continental rocks, mainly of Paleozoic age.

The Romeral fault system forms a 20 to 40 kilometres (12 to 25 mi) wide deformed belt that is parallel to the western slope of the Central Ranges of the Colombian Andes; it extends from the Gulf of Guayaquil in Ecuador in the south through Colombia to the Caribbean Sea in the north.

The upper part of the easternmost major scarps forms the topographic divide of the Central Ranges of Colombia.

In the north, the segment bearing this name starts in Puerto Libertador, Córdoba, and extends southward into Antioquia.

[17] Farther south, the fault crosses the city of Armenia and displaces Pliocene to Pleistocene volcanic and volcano-sedimentary deposits of the Quindío Fan.

The faults extend through sheared cataclastic and undeformed basaltic and sedimentary Cretaceous oceanic rocks, cropping out on the eastern slope of the Central Ranges.

The fault displaces alluvial fans and debris flows on the eastern border of the department of Valle del Cauca.

[22] The Piendamó Fault is located at the base of the mountain front of the western slope of the Central Ranges, north of the city of Popayán, Cauca.

[25] The Buesaco-Aranda Faults, which are parallel, extend in a north-northeast to northeast direction from near the Galeras Volcano in southwestern Colombia.

On the western block of the fault are a group of low-grade metamorphic rocks which consist of greenschist, amphibolite, quartzite and black schist, all of Paleozoic age.

[28] Geometrically, the Romeral shear zone is characterised by an anastomosed arrange of faults yielding a block tectonic configuration, interpreted as an extensive shear zone (kilometric-scale) composed of multiple lithological units of varying ages, diverse origins, poly-deformed, and in faulted contact, which González (1980) named the Romeral Mélange.

[30] Regionally, the Romeral fault system separates the Central from the Western Ranges and corresponds to an extensive shear zone hosting a series of rocks; These older rock units are unconformably overlain by the Oligocene-Miocene coal-bearing Amagá Formation and the Mio-Pliocene volcanics of the Combia Formation.

[5] The western part of present-day Colombia was affected by a series of large-scale tectonic movements from the Mesozoic to Cenozoic.

The tectonic history of the Romeral fault system is determined by several phases of plate tectonic movements:[31] The fault system reached its "actual" configuration when the trans-American plate boundary (the fundamental pre-Aptian east-dipping subduction zone located to the west of the American margin) underwent a major transformation to a southwest dipping subduction zone beneath the future Caribbean Arc, impelling the closure of the Quebradagrande oceanic arc-back arc system.

[30] Initiation of this arc is likely constrained by HP-LT metamorphic rocks present in the circum-Caribbean subduction complexes, including examples from Colombia in the Barragán area (Valle del Cauca).

[35][36] Gómez Tapias, Jorge; Montes Ramírez, Nohora E.; Almanza Meléndez, María F.; Alcárcel Gutiérrez, Fernando A.; Madrid Montoya, César A.; Diederix, Hans (2015).