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Character of the Caribbean Crust Revealed: Initial Observations of New and Reprocessed Seismic Data

Abstract

Details of the tectono-sedimentary evolution of the Caribbean region are debated due to lack of modern and regional seismic data. Industry seismic surveys across the Caribbean area are acquired over individual basins and do not incorporate regional perspective. We present data in support of distinct tectonic provinces and regional stratigraphic suites that reveal the complex evolution of the Caribbean Plate from a combination of newly acquired 2D seismic data and recently reprocessed pre-1995 ODP and DSDP scientific cruise seismic data from the region. Stratigraphic age is constrained by published ODP/DSDP well reports. A Caribbean-wide 3,500+ km composite seismic line is presented from the Volcan Bank of western, offshore Panama to the Barbados Accretionary Prism over-riding the Central Atlantic Plate. In the west, an interpreted 320 km wide former volcanic spreading center shows opposing dipping reflectors that are analogous to those at the volcanic margins of the South Atlantic. The western Colombian Basin contains evidence of isolated basin development south of the Hess Escarpment and associated volcanic activity. The eastern Colombian Basin region comprises a structurally thinned basement (3 km) with internal dipping reflectors. The Beata and Taino Ridge complex contains Late Miocene east-dipping, thick-skinned back-thrusts and Mid-Miocene west-dipping overthrusts. Areas of gently dipping and fanning reflectors within the basement are common across the region and correlate to striped patterns and geometries within filtered magnetic data, indicating a strong magnetic signature within the interpreted igneous basement layers. Sharp boundaries along tectonic provinces and structured regions correlate to anomalous zones in the filtered magnetic data and allow for tentative mapping of regional features beyond the seismic control. Continued reprocessing of the legacy data will reveal valuable details of the tectonic evolution of the Caribbean crust and associated basins.