Elevation of the last interglacial highstand in Sicily (Italy): A benchmark of coastal tectonics

摘要

Well-preserved MIS 5.5 terraces in Sicily are identified primarily by the index fossil Strombus bubonius, and dated by amino acid racemization (AAR), electron spin resonance (ESR), Uranium/Thorium (U/Th) and thermo luminescence (TL) methods. This review of published data and new results for the island of Sicily and neighbouring small islands of Egadi, Ustica and Lampedusa identifies areas of rapid uplift in the east (up to +175 m, elevation above sea level), slower uplift in the north (+ 29 m), and relative stability in the northwest (+ 2/ + 18 m). In contrast, about 250 km of the southern coastline of Sicily does not appear to contain MIS 5.5 outcrops. In eastern Sicily, correlation of MIS 5.5 highstands is based on Strombus bubonius, discovered at +86m, and correlated with the inner margin terrace at + 110 m, In the Taormina area, a fossiliferous miarine conglomerate on a terrace with an inner margin at + 115 m occurs in an area with undated terrace morphology and elevation data. Based on ESR methodology applied to fossils sampled at + 105 m in Taormina, we attribute this terrace to MIS 5, probably 5.5. This age allows us to constrain the date of one point along a very long coastline that is otherwise undated. A newly discovered fossil beach (between + 7 and + 9 m) at Cefalu (north-central Sicily) attributed to MIS 5.1/5.3 using AAR analysis, permits correlation of MIS 5.5 to a +29m-high tidal notch geomorphologically related to a terrace at the same elevation. Cefalu lies in an important position between the uplifted coastline of northeastern Sicily, and the more stable coastline of western Sicily. This compilation of MIS 5.5 data for all of Sicily reflects the active tectonics of eastern Sicily in contrast to the rest of the island.