Io/U ages of corals from Saurashtra coast

Un-recrystallized fossil corals occurring at 2–6 m above the present mean low-tide level on the Saurashtra coast (Western India) have been dated by ²³⁰Th/²³⁴U and ²³⁴U/²³⁶U radiometric methods. The measured ages of the corals, which are in agreement with radiocarbon ages, fall in three groups, 6,000, 30,000 and 120,000 years before present. This observation, coinciding with the high sea-level stands reported in several locations in the world, in the absence of evidence in support of instability of Saurashtra coast, suggests that the coral reefs are remnants of one Holocene and two Quaternary high sea-level stands.