Global sea level stratigraphy: An appraisal

Although Pleistocene sea level concepts were first developed in the Mediterranean Basin, research has been revolutionized during the past 15 years by massive dating programs applied in other world areas. reappraisal of four key sequences nonetheless shows that the chronometric framework is imperfect. As a result, available paleosea level traces continue to depend on deep-sea stratigraphy for confirmation rather than the reverse; they do not provide independent support for the Milankovitch radiation cycles, nor do they invite deductive-hypothetical ‘dating’ by means of such astronomical reconstructions. Inferred ‘initial’ sea levels, based on uplift assumptions or δ¹⁸O determinations on coral and mollusca, show considerable divergence but broadly agree that sea levels assigned to isotope stages 5a and 5c were lower than today. Systematic studies should be expanded in environments that allow lithostratigraphic resolution of interdigitated marine and continental sediments, meticulously complemented by biostratigraphic work. Direct information on the complexity and significance of regressional hemicycles helps place sea level stages recorded by transgressive facies into a multidimensional context essential for comprehensive interpretation.