Atoll-scale comparisons of the sedimentary structure of coral reef rim islands, Huvadhu Atoll, Maldives

Abstract

Maldivian coral reef rim islands host the majority of the nation's population, land area and infrastructure. However, understanding of the controls on rim island development and their accretionary histories is poor. Here, we present the first detailed sedimentary study of Maldivian rim islands through analyses of core logs from windward and leeward sites around Huvadhu Atoll. Island composition was dominated by a very restricted range of grain producers, with sediment dominated by coral (76.6 ± 0.6%). Material was predominantly rubble and sand-sized, the former likely generated by low-frequency high-magnitude events and the latter as a by-product of parrotfish grazing. While consistencies were found between windward and leeward sites, we highlight intra-regional diversity in reef island development at the scale of an individual atoll.