New detailed morphotectonic analyses of a well exposed flight of marine terraces along the Ionian coast of Southern Italy has been carried out. The area represents a key transect for investigating the middle-late Quaternary evolution of the Southern Apennines chain-foredeep-foreland geodynamic system. A major result of the research is the reconstruction of a virtually complete 3D geometry of the marine surfaces along a coastal sector of ca. 70 km, which i) documents the occurrence of 18 paleo-shorelines and ii) provide evidence for a strong regional uplift affecting the investigated area. Following a systematic critical review of literature relating to geochronological data, integrated with a morphogenetic model based on the interaction between tectonic uplift and eustatic sea level changes, the different terraces are correlated to as many highstand sea level peaks, dating the highest/oldest terrace to ca. 600 ka (MIS 15). The vertical and horizontal distribution of the terraces show a general convergence of the paleo-shorelines towards NNE, which indicates a decreasing trend in differential uplift in that direction ranging from almost 2 mm/a in the southwestern sector to about 0.2 mm/a in the north-eastern sector. Detailed mapping and 3D reconstruction also emphasize the partitioning of the area into three distinct sectors characterized by different tilting rates. This behavior is likely caused by the combined role and activity of three major tectonic structures working at different scales and rates including i) the reactivation of an out-of-sequence thrust, ii) sliding along the basal detachment of the external Apennines wedge and iii) a lithospheric-scale duplexing (crustal or deeper). As a major conclusion, within the external sector of the Southern Apennines chain and its foredeep, regional shortening and a contractional tectonic regime persisted throughout the whole Quaternary and it is probably still active.
Ionian marine terraces of Southern Italy: insights into the Quaternary tectonic evolution of the area.
CAPUTO, Riccardo;
2010
Abstract
New detailed morphotectonic analyses of a well exposed flight of marine terraces along the Ionian coast of Southern Italy has been carried out. The area represents a key transect for investigating the middle-late Quaternary evolution of the Southern Apennines chain-foredeep-foreland geodynamic system. A major result of the research is the reconstruction of a virtually complete 3D geometry of the marine surfaces along a coastal sector of ca. 70 km, which i) documents the occurrence of 18 paleo-shorelines and ii) provide evidence for a strong regional uplift affecting the investigated area. Following a systematic critical review of literature relating to geochronological data, integrated with a morphogenetic model based on the interaction between tectonic uplift and eustatic sea level changes, the different terraces are correlated to as many highstand sea level peaks, dating the highest/oldest terrace to ca. 600 ka (MIS 15). The vertical and horizontal distribution of the terraces show a general convergence of the paleo-shorelines towards NNE, which indicates a decreasing trend in differential uplift in that direction ranging from almost 2 mm/a in the southwestern sector to about 0.2 mm/a in the north-eastern sector. Detailed mapping and 3D reconstruction also emphasize the partitioning of the area into three distinct sectors characterized by different tilting rates. This behavior is likely caused by the combined role and activity of three major tectonic structures working at different scales and rates including i) the reactivation of an out-of-sequence thrust, ii) sliding along the basal detachment of the external Apennines wedge and iii) a lithospheric-scale duplexing (crustal or deeper). As a major conclusion, within the external sector of the Southern Apennines chain and its foredeep, regional shortening and a contractional tectonic regime persisted throughout the whole Quaternary and it is probably still active.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
