Caribbean Arc Revised Geological History Affecting Circum-Caribbean Oil Exploration
Geoclastica Ltd, Marlborough, United Kingdom
Conventionally, a "Great Arc of the Caribbean" fronting the Caribbean Plate is interpreted to have been smeared along opposed passive margins of N and S America by eastward oblique obduction, driving diachronous, oil-prone foreland basins (Cretaceous-Neogene). This model requires sideways expansion of the passing Caribbean Plate into the Yucatan and Falcon reentrants. A literature review suggests a more plausible model. Rather than a "Great Arc", Cuban volcanics belong to two other arcs: (1) a Paleo-Cuban Arc (Cretaceous) bisecting a vanished Inter-Americas Ocean (IAO) produced by Jurassic-Cretaceous spreading (Pangea breakup). This NE-SW arc, formed by NW subduction, eventually (Campanian) obducted onto the Cuba microcontinent, newly detached from Venezuela-Trinidad by Proto-Caribbean spreading (Santonian-Campanian; see companion abstracts); and (2) a Neo-Cuban Arc (Maastrichtian-Paleogene), formed on continental Cuba by SE subduction of the rest of IAO (former marginal sea). Development of this arc, which included Yucatan Basin interarc rifting/spreading in the W, ended with diachronous Paleogene accretion of Cuba against N America (Yucatan-Bahama Platform). A third, "Caribbean Arc" (new formal name) began migrating E in Campanian time by Proto-Caribbean subduction. Resulting Caribbean interaction with N America was transtensional (Mosquitia-Cayos Basin; Cayman Trough), without arc accretion. In S America, undergoing Proto-Caribbean amagmatic subduction from Campanian time, Caribbean Arc relative motion was E along the NE-trending Colombia margin, causing Amaime-Ruma forearc nappe oblique obduction (Maastrichtian-Eocene), then SE along Falcon (sub-parallel), forming the Gulf of Venezuela-Falcon transtensional basin (Oligo-early Miocene), and SE along C Venezuela-Trinidad (ENE trend), causing Cura-Rinconada-Tobago forearc nappe diachronous obduction (Mio-Pliocene).
AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas