Mixed carbonate-silicicastic systems are common in the geologic record and numerous conceptual models have been proposed to explain their character. In this study, Mateu-Vicens et al. examine the role of seagrass on the surface sediment of an extant mixed carbonate-siliciclastic system in the northern Mediterranean. The results reveal that much of the sediment is poorly sorted siliciclastic skeletal sand, with a paucity of carbonate mud, interpreted to reflect the heterozoan association and in situ mixing in this temperate system. The data provide a contrast with well-documented examples in either photozoan or exclusively carbonate settings, and provide the basis for comparison with, and interpretation of, ancient analogs.
Seagrass-meadow sedimentary facies in a mixed siliciclastic–carbonate temperate system in the Tyrrhenian Sea (Pontinian Islands, Western Mediterranean) by Guillem Mateu-Vicens, Marco Brandano, Giovanni Gaglianone, and Alessio Baldassarre