On a tectonic mechanism for regional sealevel variations

Abstract

No satisfactory tectonic explanations have yet been offered for the apparent sealevel fluctuations of about 1 cm/1000 years and a magnitude of up to a few hundred meters that have been proposed by Vail et al. [1]. We propose a mechanism that does appear to be able to explain these changes if horizontal stresses of the order of a few kilobars occur in the lithosphere and if changes in these stress fields occur on geological time scales. The proposed model is one of an interaction between these stresses and the deflections of the lithosphere caused by sedimentary loading. Apparent sealevel changes of up to 100 m can be produced at the flanks of the sedimentary basins by this interaction. The mechanism is most effective for young margins that are subject to rapid sediment loading. By its nature, the tectonic model can explain contemporaneous fluctuations in apparent sealevel in neighbouring depositional environments. In principle, it implies the possibility of regional correlations in different basinal settings. Show more