Radiocarbon dates from the Ulong site in Palau and implications for Western Micronesian prehistory

Recent excavations on Ulong Island in Palau recovered an early pottery assemblage that has not been recorded previously in the archipelago. Four AMS results on charcoal fragments and carbonised residues adhering to pot sherds ranged from 3150 ± 90 BP to 4330 ± 90 BP, and were consistent with palaeoenvironmental work which suggests that human arrival in western Micronesia might have occurred as early as 4500 BP. Redating of the Ulong samples that gave the earliest results put occupation instead around 3000-2650 BP, and an error during laboratory processing of the oldest AMS samples is suspected. Revision of the Ulong dates invites reconsideration of other archaeological radiocarbon ages from western Micronesia where convincing evidence for occupation deposits older than c. 3300 cal BP has yet to be obtained.