Coral conglomerate platforms as foundations for low-lying, reef islands in the French Polynesia (central south Pacific): New insights into the timing and mode of formation

In French Polynesia, low-lying, reef islands, composed of unconsolidated skeletal material rest on cemented conglomerate platforms. These are regarded as mainly generated by storm activity during the mid-late Holocene. Field observations and coral sampling were carried out on conglomerates from three atolls located in the north-western Tuamotu, namely, Takapoto, Takaroa and Fakarava. There, fifty-seven samples were dated using the uranium‑thorium (U/Th) method. The lateral age distribution of clasts indicates that conglomerate platforms have accreted from lagoon sides seawards.