Sea-level highstands over the last 500,000 years; evidence from the Ironshore Formation on Grand Cayman, British West Indies

The Ironshore Formation (up to 19 m thick) in the Rogers Wreck Point area of Grand Cayman is divided into the unconformity-bounded units A, B, C, and D. The unconformities are highlighted by caliches and/or terra rossa. Th/U dates from aragonitic corals indicate that unit A formed at >400 ka, unit B approximately 346 ka, unit C approximately 229 ka, and unit D approximately 131 ka. These ages correlate with the highstands of the last four …