Intraplate subsidence and basin filling adjacent to an oceanic arc–continent collision: a case from the southern Caribbean‐South America plate margin |
| |
| Authors: | Germán Bayona Camilo Montes Agustín Cardona Carlos Jaramillo Germán Ojeda Victor Valencia Carolina Ayala‐Calvo |
| |
| Institution: | 1. Corporación Geológica ARES, Bogotá, Colombia, Calle 44A N. 53‐96, USA;2. Smithsonian Tropical Research Institute, Unit 0948. APO AA 34002‐0948, USA;3. Corporación Geológica ARES, Bogotá, Colombia, Calle 44A N. 53‐96;4. ECOPETROL S.A., Bogotá, Colombia;5. School of Earth and Environmental Sciences, Washington State University, Pullman, WA 99164‐2812 85721, USA |
| |
| Abstract: | The upper Campanian–Lower Eocene synorogenic sedimentary wedge of the Ranchería Basin was deposited in an intraplate basin resting on a tilted continental crustal block that was deformed by collision and subsequent subduction of the Caribbean Plate. Upper Cretaceous–Lower Eocene strata rest unconformably upon Jurassic igneous rocks of the Santa Marta Massif, with no major thrust faults separating the Santa Marta Massif from the Ranchería Basin. The upper Campanian–Lower Eocene succession includes, from base to top: foraminifera‐rich calcareous mudstone, mixed carbonate–siliciclastic strata and mudstone, coal and immature fluvial sandstone beds. Diachronous collision and eastward tilting of the plate margin (Santa Marta Massif and Central Cordillera) favoured the generation of accommodation space in a continuous intraplate basin (Ranchería, Cesar and western Maracaibo) during the Maastrichtian to Late Palaeocene. Terrigenous detritus from the distal colliding margin filled the western segments of the continuous intraplate basin (Ranchería and Cesar Basins); in the Late Paleocene, continental depositional systems migrated eastwards as far as the western Maracaibo Basin. In Early Eocene time, reactivation of former extensional structures fragmented the intraplate basin into the Ranchería‐Cesar Basins to the west, and the western Maracaibo Basin and Palmar High to the East. This scenario of continent–oceanic arc collision, crustal‐scale tilting, intraplate basin generation and fault reactivation may apply for Upper Cretaceous–Palaeogene syntectonic basins in western Colombia and Ecuador, and should be considered in other settings where arc–continent collision is followed by subduction. |
| |
| Keywords: | |
|
|
