Abstract The Eastern Mediterranean is one of the most seismically active regions in Europe. Crete, located in the centre of the Eastern Mediterranean, should experience tsunamis resulting from large magnitude earthquakes or volcanic eruptions. At three locations, boulders were observed that may relate to tsunami or storm events. At Lakki, the size of the boulders slightly favours a tsunami origin for deposition. By contrast, at Kommos, boulder size and geomorphology are consistent with storm parameters in the Mediterranean. The most compelling evidence for tsunami transport is found at Diplomo Petris, where a lithologically varied grouping of large boulders (≤690 t) is exposed at sea level. The calculated storm wave heights (15 m) required to transport the observed boulders significantly exceeds winter averages: therefore, these accumulations are interpreted as tsunami deposits. Radiocarbon dating of encrusting biological material was undertaken to constrain periods of boulder motion. Encrustations from Diplomo Petris and Lakki predate the 365 CE earthquake, suggesting that this event transported the largest boulders; the first time that boulder deposits have been identified on Crete from this tsunami. Therefore, these data are important for developing local and regional hazard assessments but also to inform numerical models of tsunami propagation in the Mediterranean.

Abstract: The occurrence and distribution of minerals in modern sedimentary systems hold many clues to help unravel the origin and distribution of reservoir quality-controlling minerals in ancient and deeply buried sandstones, but few quantitative studies have been undertaken. Here we have used a range of techniques including X-ray diffraction, scanning electron microscopy and fully automated mineralogical QEMSCAN analysis to provide a comprehensive understanding of mineral composition and distribution within the post-glacial, clastic sediments of the Ravenglass Estuary, NW England. The Ravenglass Estuary is fed by two main rivers: one drains a granite-dominated hinterland, the other drains a hinterland that contains andesite and Triassic red bed sandstones. The granite-supplied arm has slightly more quartz-rich and Fe mineral-poor sediment than the andesite- and red bed-supplied sediment. The provenance signals are muted for feldspar and mica minerals heavy-mineral garnet populations seem to be sensitive to provenance. Detrital K-feldspar grains are preferentially associated with illite-dominated clay mineral coats, whereas all plagioclase mineral grains are preferentially associated with kaolinite-dominated clay mineral coats. This can be explained by rapid early diagenesis in the sediment with K-feldspar grain surfaces replaced by illite and plagioclase grain surfaces replaced by kaolinite. The andesite- and red bed-supplied sediment contains twice the amount of Fe minerals, which are dominated by chlorite, than the granite-supplied sediment. Chlorite rarely is associated with grain coatings on feldspar grains, possibly because it is predominantly a detrital mineral. Detrital Fe minerals seem to be locally replaced by pyrite due to bacterial sulphate reduction, suggesting that some early diagenetic processes may serve to lock away iron and prevent it from creating Fe-rich clay minerals.