Platforms of the Nicaraguan Rise: Examples of the Sensitivity of Carbone Sedimentation to Excess Trophic Resources

Hailock, Pamela
Hine, Albert C.
Vargo, Gabriel A.

December, 1988

BV No.123

The Nicaraguan Rise is an active tectonic structure in the western Caribbean. Carbonate accumulation on its platforms has not kept pace with relative Holocene sea-level rise, despite a tropical location remote from terrigenous sedimentation. Trophic resources apparently exceed levels favoring coral-reef development because sponge-algal communities dominate the drowning westerns platforms, in contrast to mixed coral-algal benthos on Pedro Bank and well developed coral reefs along the north coast of Jamaica. Concentrations of biotic pigment in sea-surface waters show a corresponding west-east gradient; oceanic waters flowing over the western banks carry nearly twice as much biotic pigment as oceanic waters north of Jamaica. Concentrations of biotic pigments in sea-surface waters show a corresponding west-eats gradient; oceanic waters flowing over the western banks carry nearly twice as much biotic pigment as oceanic waters north of Jamaica. Sources enriching the western Caribbean are terrestrial runoff, upwelling off northern South America, and topographic upwelling over the Nicaragua Rise.

GEOLOGIA; SEDIMENTACION; NICARAGUA;