Sediments from a living shelf-edge reef and adjacent area off central eastern Florida

Jeff's Reef (27º 32.5' N; 79º 58.3' W), a 16m high Oculina coral bank on theshelf-slope break, is the site of modem carbonate sedimentation mixed withrelict carbonate and quartz. Surficial sediments from the 94 km2 surroundingarea of outer shelf, shelf edge and upper slope are significantly different fromreef sediments as judged by wt.% gravel, sand, silt, clay, mud, sorting,skewness and normalized kurtosis. Sand grain types (ooid +pellet+ carbonaterock fragments, barnacles and coral) are also different for reef and non-reefareas. Sediments of non-reef origin in the adjacent areas have significantlylarger between-station variance than within-station variance for the above grainsize descriptors. These sediments have significant changes in grain sizedescriptors E-W, and no significant changes N-S.