Late Neogene evolution of the western South Aegean volcanic arc: sedimentary imprint of volcanicity around Milos

Abstract

The distribution and stratigraphy of volcanic rocks around the island of Milos has been interpreted from seismic reflection profiles. A consistent seismic stratigraphy can be recognised in the major basins, which contain mostly hemipelagic to low-energy gravitative sedimentation interrupted only locally by mass-transport deposits, despite the proximity to volcanic islands. Volcanic rocks have a distinctive rather incoherent acoustic signature and in places overlie stratified marine sediment. Their age is inferred from position relative to the Messinian seismic marker and by correlation with volcanic episodes dated on land. Volcanic rocks underlie an area five times larger than the present outcrops of volcanic rocks on Milos and adjacent islands. The main phase of volcanism was of late Pliocene age. It locally overlies folded lower Pliocene strata. In places the volcanic rocks have been planed off by Quaternary coastal erosion surfaces and have subsequently subsided, at rates of 0.2–0.35 mm/yr. Basin margins appear to have been generally stable, probably as a consequence of the relatively shallow water depths. Volcano flank failure deposits do not appear to be a major component of the sedimentary architecture.