Control of Terrigenous-Carbonate Facies Transitions by Baroclinic Coastal Currents - Nicaragua

摘要

The cross-shelf movement of fine-grained terrigenous sediments has received considerable attention in recent geological literature. Of perhaps greater interest is the spatial relationship with other sediment types and the processes that control facies segregation. Studies of sediment types and the processes that control facies segregation. Studies of sediment have revealed a 20- to 30-km-wide (12- to 19-mi) band of terrigenous sediment of confined near the cost. The band grades abruptly into an area of carbonate deposition that is composed principally of the disintegration products of calcareous green algae. Detailed studies of watershed runoff, structure of nearshore currents, and density gradients indicate the existence of a well-organized band of currents that run essentially parallel to the coast. An analytical model is formulated that successfully predicts the strength and location of this coastal boundary current system as a function of wind speed and direction, water depth, and local density gradients. Keywords: Cross shelf movement, Fine grained, Terrigenous sediment, Watershed runoff, Density gradients, Carbonate deposition, Seaward migration, Particulates.