The Sierra Madre de Chiapas evolved in the vicinity of the triple junction between the Cocos, North America and Caribbean plates. The Sierra Madre de Chiapas tectonics reflects positive topographic growth along its main core and a northwards-directed collapse through a free border related to the Gulf of Mexico. Major exhumation and topographic growth occurred during the middle–late Miocene (16–10 Ma). Evidence for this deformational event is provided by fault activity, major stratigraphic unconformities along the Sierra Madre de Chiapas and the Tabasco coastal plain (i.e. southern Gulf of Mexico), major salt-related motion, northward progradation of the sedimentation and northward migration of the buried deformational front. During the Neogene, strike-slip deformation and its related exhumation migrated landwards from the western edge of the Chiapas massif complex to the Chiapas Sierra. Horizontal displacement along the main strike-slip faults in the Chiapas Sierra has been indirectly estimated to be between 30 and 43 km during the last 6–5 Ma, implying 0.5–0.8 cm a−1 of lateral accommodation. These values suggest that a significant amount of the motion transferred by the Caribbean and North American plates is currently being accommodated along the Chiapas area.
A geological map of the Sierra Madre de Chiapas is available at www.geolsoc.org.uk/SUP18507.