Resumen de Arrecifes de arenisca en el Golfo de Salamanca, plataforma continental del Caribe colombiano

Sven Zea, Gladys Bernal, Gloria López, Marion Weber, Rocío García Urueña

• español

  En los mares tropicales hay fondos duros sumergidos que albergan corales, pero que no son de origen coralino. En el sector del Banco de las Ánimas, en la plataforma continental del Golfo de Salamanca, mar Caribe colombiano, hay arrecifes de arenisca colonizada por biota coralina. Un primer análisis petrográfico muestra que las rocas están compuestas de arenas de grano muy fino, maduras en textura y cementadas por dolomita. Se propone que estos arrecifes fueron formados en un sistema playa – duna – laguna de un nivel del mar antiguo, similar a la barra costera de Salamanca actual. En este sistema, rocas de playa y / o eolianitas pudieron formarse por la cementación de aragonito, convertido posteriormente en dolomita, en ambientes supramareales salinos de alta evaporación.

• English

  In tropical seas there are submerged hard bottoms that harbor corals but that are not coralline in origin. This is the case for the “Banco de las Ánimas” sector in the continental shelf of the Gulf of Salamanca, Colombian Caribbean. In its upper portion (14–16 m in depth), there are low mounds of sandstone blocks and slabs, conforming reefs, colonized by coralline biota and sparse corals. To confirm their lithology an initial petrographic analysis was carried out, which showed the rocks are made up of fine-grained sands, mature in texture, cemented by dolomite. It is proposed that these reefs were formed in a beach–dune–lagoon system during an ancient sea level, similar to the recent coastal bar of Salamanca. In these high-evaporation, supratidal saline environments, they could have been formed as beach rocks or as eolianites, by aragonite cementation, modified later into dolomite. Whether the foundation of the deeper coral formations of the bankis also sandstone or in fact coralline, remains to be determined.