High precision Acceleration Mass Spectrometry (AMS) dates of corals, gastropods and smaller foraminifers from a coral-algal stratigraphical sequence, exposed 2.73 - 4.20 m above the present msl, near Mithapur on Dwarka-Okha coast, have been reported in the present paper. The age ranges from ca. 41.2 to 18.3 ka BP. The mineralogy, petrology and δ13C values of the samples indicate that the dates are reliable within the limitations of the dating method. Confirmatory U/Th dating will, however, be useful to strengthen the conclusion. Since the samples are from the intraplate area of the Saurashtra Peninsula, the present position of 41.2 and 18.3 ka old sea level recorders cannot be explained by a large-scale uplift. At the same time, they cannot be taken as the records of the sea level stands of ∼40 ka and ∼18 ka BP, as the generally accepted data suggest very low sea level stands of the periods. Therefore, an epeirogenetic model is to be evolved that satisfactorily explains not only the presence of ∼40 ka corals and stratigraphically superposed younger ∼18 ka sediments, but also the corals of 118 - 176 ka BP and 6 ka BP ages that co-exist at low altitudes at Mithapur. For this we need to generate more reliable dates of the area and integrate them with the geological and geophysical information.
|Number of pages
|Journal of the Geological Society of India
|Published - 09-2002
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