Submarine depositional terraces in the Tyrrhenian Sea as a proxy for paleo-sea level reconstruction: Problems and perspective

摘要: Abstract In the last decade great effort was put in study of relative sea-level changes on Mediterranean coastlines through integration geophysical modelling and proxy data paleo-shorelines. this paper, we show potential limitations using additional marine geomorphic/sedimentary markers for earlier lower sea levels. These are submarine depositional terraces (SDTs), i.e., deposits formed by a set small prograding sedimentary wedges, having terraced shape found at variable shallow-water depths (mainly first −150 m) continental insular shelves Tyrrhenian Sea. The shallowest (near-shore) have their edges between −10 m and −30 m, approximating modern, local storm-wave base level. Their formation is thought to be associated with modern highstand thus, can used as analogue deeper past when level middle outer shelf. Mid-shelf between −40 m and −90 m probably during rise. They patchy spatial distribution large variability internal structure, so that they not suitable correlation regional scale. Shelf-edge between −120 m and −170 m, which close or than Last Glacial Maximum (LGM) stand. remarkable lateral continuity structure similar those shallower depth and, represent position around 20 ka. However, SDTs' direct measure paleo positions because depends complex interplay several factors, such storm wave its variation response coastal physiography, well occurrence subsequent erosional processes. Depending mapping methods determine depth, error range also differ. Based analysis these complexities wide physiographic settings Sea, discuss ranges order assess limitation SDT analyses vertical mobility an area.