The Beach-Water Interface
The
beach-water interface on the cay that we studied had an interesting lithological
composition. The beach where we started our reef transect is composed of
three major components; these are lithified breccia, beachrock and sand
to pebble size sediment and unlithified sediment. The breccia is volcanic
in origin and is composed of subangular mafic clasts surrounded by a fine
grained mafic matrix. The beachrock is dominantly lithified carbonate sand,
but does contain minor amounts of eroded mafic volcanic material. The unlithified
sediment is of the same composition as the beachrock except that the mafic
clasts are slightly larger (pebble size rather than sand size).
