Paolo Sansò

LATE HOLOCENE EMERGENCE IN CALABRIA, ITALY

Abstract A field survey along the coasts of Calabria has found little evidence of Holocene emergence, the greatest being no more than 1.0–1.5 m in elevation. A former shoreline (a thick crust of calcareous algae in growth position at about + 0.6 m, capping an elevated beachrock slab) was dated 2990 ± 60 yr B.P. This emergence is recent, if compared to the time of the Climatic Optimum, and relatively slight, if Late Pleistocene uplift rates, which in some cases exceed 1 mm/yr, are considered. This apparent discrepancy can be explained by taking into account glacio- and hydroisostatic effects of the last glaciation, which have produced subsidence at decreasing rates during the late Holocene in a wide area around the former Scandinavian ice sheet which includes most of the Mediterranean. According to isostatic modelling, the average subsidence rate during the last 6000-5000 years was between 0.4 and 1 mm/yr near the coasts of Calabria. If global sea-level changes can be neglected, it is only when the subsidence rate of glaciohydro-isostatic origin became slower than the local uplift that emergence at a slower rate than that of the tectonic uplift trend could have begun. Such emergence is therefore a recent phenomenon, in the Holocene, and its rate is still much slower than that of tectonic uplift predominating in Calabria over a longer time scale.

Holocene coastal dune development and environmental changes in Apulia (southern Italy)

Abstract The coastal area of southern Apulia is characterised by marine deposits of Pleistocene and Holocene ages. It shows the effects of different phases of coastal morphology evolution. During the Middle and Upper Pleistocene, a number of marine terraces were shaped. In some places, they are characterised by thin beach deposits along with a dune belt and relative back dune deposits. Two important morphogenetic phases occurred during the Holocene. The former was characterised by deposition of beach deposits placed slightly above present mean sea level, and by formation of dune belts which were radiometrically aged about 6000 years BP. This event marks the end of the rapid postglacial transgression that occurred during the Holocene Climatic Optimum. During the younger phase, dated at about 2500 years BP, deposition of aeolian sands occurred. Archaeological and morphological evidences suggest that this phase should be related to a low sea-level stand followed by a slow sea-level rise up to the present position and by humid-temperate climatic conditions. The collected data about the Holocene dune belts occurring along the Apulian coastline suggest that main phases of dune development could be related to the effects of sea-level changes, climatic conditions, and in a subordinate way, to human activity.

Pleistocene sea-level changes, sapping processes and development of valley networks in the Apulia region (southern Italy)

Abstract The central area of the Apulia region is characterized by a network of valleys with peculiar features, locally called ‘gravine’ or ‘lame’. They are short, straight valleys, deeply incised in Plio-Pleistocene calcareous sandstones and in Mesozoic limestones. These characteristic valleys cut a staircase of marine terraces. A series of valley generations is recognisable, each one of them leading to the internal margin of a marine terrace representing its base level. Morphological features and hydrogeological conditions suggest that sapping processes were responsible for the development of the valley network. As the aquifer rests on seawater intruding from the nearby coastal area, sapping processes were enhanced during interglacial high sea-level stands so that each ancient coastline is marked by its own generation of valleys. However, the longest and deepest valleys formed at the Ionian side during OIS 7. This is due mostly to a fast sea-level rise accompanied by very humid climatic conditions that increased the hydraulic head at the springs and the intensity of sapping processes. Sapping valleys could be useful for regional correlation of marine terraces and as indicators of relict coastlines at present placed below sea level.

The Salento Peninsula (Apulia, Southern Italy): A Water-Shaped Landscape Without Rivers

The Salento peninsula is the ‘heel of the boot’ drawn by the perimeter of the Italian coastline. It is placed to the south of the alignment Brindisi-Taranto cities, between the Ionian and the Adriatic seas. Its geological structure is made of a thick Mesozoic carbonate sequence covered by Tertiary and Quaternary deposits. Landscape evolution is the result of the interaction between tectonics, karst and marine processes controlled by climate and sea-level changes. The landscape of Salento peninsula is mainly composed of landforms shaped by the action of waters, both continental and marine ones, notwithstanding it is known to be currently a region without extended surficial drainage catchments.