DUMAS B. & RAFFY J.
How eustatic raised marine terraces of Calabria can be connected with climate oscillations occurring over the MIS 5-MIS 4 period
Pages 11-31
Abstract
On the Calabria coast of the Strait of Messina, six major terraces (MT) have been shaped from the Late Pleistocene to the Holocene time. The four higher, stepped between about 180 m and 50 m a.s.l., are assigned to the MIS 5.5-MIS 4 period. Cross-sections and detailed mapping show that they consist of several terraces placed side by side: eleven for MT VI (MIS 5.5), four for both MT V (MIS 5.3) and MT IV (MIS 5.1) and finally three for MT III (MIS 4). The uppermost terrace of each series is termed head terrace. All over the study area, they were raised at a 1.3 m/ka mean uplift rate, without any important tilting or faulting occurring since the beginning of MIS 5. The characteristic thickness (CT) of the clastic marine deposits (= sea stacks) associated with each terrace is the vertical height between their top wall at the inner edge of the terrace (the coastline or shoreline angle) and their farthest seaward bottom (outer edge of their basal boundary). It clearly shows that the twenty-three studied terraces result from as many sea-level oscillations. So, a relative sea-level curve can be drawn. A comparison is attempted between sea level changes and millennial-scale climate oscillations recognised from ice and marine records. A good correlation exists between head terraces, high CT, large amplitudes of sea-level rises and climatic orbital events at 128 ka, 105 ka and 84 ka plus a significant suborbital event at about 72 ka. Minor terraces (between head terraces), with small CT, have been generated by low-amplitude and high-frequency sea-level fluctuations. Most of them can be connected with suborbital and rapid climatic oscillations over the MIS 5-MIS 4 period.