Coastal morphology and late quaternary history,Cayman Islands,West Indies

Instrumental surveys of coastal profiles in the Cayman Islands, western Caribbean, reveal the presence of a horizontal erosional bench at +1.9 m on Grand Cayman and a deep horizontal notch at +6.4 m on Cayman Brac, but no raised erosional features on Little Cayman. Each island is surrounded by a horizontal constructional raised reef, usually below +2 m, here dated by U-series methods as 124,000 ± 8000 yr old, and hence broadly contemporary with other western Atlantic raised reefs of similar elevations. The different raised erosional features indicate independent vertical tectonic movement of the three islands, predating the formation of the raised reef. The accordance and horizontality of the raised reef indicates stability of the islands since the last interglacial times. An erosional notch at present sea level has formed since the sea reached its present level less than 2100 B.P., and algal benches on exposed coasts are also in equilibrium with present conditions.