Uranium-series dates on Overwash Deposit Corals from Anegada, British Virgin Islands

Uranium-series dates from coral boulders narrow the time window of a medieval tsunami from faulting in the Puerto Rico Trench. Previously reported traces of this sea flood include hundreds of coral boulders that came to rest hundreds of meters inland on Anegada, British Virgin Islands. Many of these retain the form of living coral colonies. U-series dates on coral boulders from Anegada now provide limiting dates for the tsunami. The narrowest limits were obtained from cored interior bands of a boulder that retains a life-like hemispherical form. By those limits, the tsunami dates between 1386 and 1391 C.E. and probably occurred in summer or fall.