Details

Autor(en) / Beteiligte

• Mora, J. Alejandro
• Oncken, Onno
• Le Breton, Eline
• Ibánez‐Mejia, Mauricio
• Faccenna, Claudio
• Veloza, Gabriel
• Vélez, Vickye
• Freitas, Mario
• Mesa, Andrés

Titel

Linking Late Cretaceous to Eocene Tectonostratigraphy of the San Jacinto Fold Belt of NW Colombia With Caribbean Plateau Collision and Flat Subduction

Ist Teil von

• Tectonics (Washington, D.C.), 2017-11, Vol.36 (11), p.2599-2629

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2017

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Collision with and subduction of an oceanic plateau is a rare and transient process that usually leaves an indirect imprint only. Through a tectonostratigraphic analysis of pre‐Oligocene sequences in the San Jacinto fold belt of northern Colombia, we show the Late Cretaceous to Eocene tectonic evolution of northwestern South America upon collision and ongoing subduction with the Caribbean Plate. We linked the deposition of four fore‐arc basin sequences to specific collision/subduction stages and related their bounding unconformities to major tectonic episodes. The Upper Cretaceous Cansona sequence was deposited in a marine fore‐arc setting in which the Caribbean Plate was being subducted beneath northwestern South America, producing contemporaneous magmatism in the present‐day Lower Magdalena Valley basin. Coeval strike‐slip faulting by the Romeral wrench fault system accommodated right‐lateral displacement due to oblique convergence. In latest Cretaceous times, the Caribbean Plateau collided with South America marking a change to more terrestrially influenced marine environments characteristic of the upper Paleocene to lower Eocene San Cayetano sequence, also deposited in a fore‐arc setting with an active volcanic arc. A lower to middle Eocene angular unconformity at the top of the San Cayetano sequence, the termination of the activity of the Romeral Fault System, and the cessation of arc magmatism are interpreted to indicate the onset of low‐angle subduction of the thick and buoyant Caribbean Plateau beneath South America, which occurred between 56 and 43 Ma. Flat subduction of the plateau has continued to the present and would be the main cause of amagmatic post‐Eocene deposition. Key Points We linked Upper Cretaceous to Eocene tectonostratigraphic evolution of the San Jacinto fold belt of NW Colombia with plate kinematics Eocene major change in plate kinematics caused to the onset of flat subduction and cessation of arc magmatism in northwest Colombia The existence of a tear or STEP fault in the Caribbean Plate, located toward the western end of the Oca‐San Sebastián‐El Pilar Fault System is proposed