Optical dating of dune sand for the study of sea-level change

A new, widely applicable method to obtain well-constrained relative sea-lev el records, presented here, relies on optical dating of inorganic coastal l andforms and sediments. Eighteen optical ages of basal dune sand from a bar rier in Massachusetts, United States, indicate that local relative sea leve l rose 8 m during the past 5.5 k.y. A sea-level curve drawn from these opti cal ages shows good agreement with independent evidence from salt-marsh pea t sampled behind the barrier, demonstrating the reliability of the method. Optical dating will be particularly useful in analyzing coastal records tha t contain too few organic indicators to allow high-resolution, C-14-based a nalyses.