Late neogene fore-arc basin evolution in the Calabrian arc (Central Mediterranean); tectonic sequence stratigraphy and dynamic geohistory

Abstract

Depositional sequences and their relation to relative fluctuations in sea level is one of the main issues in present-day Eanh Sciences. The generation of depositional sequences is controlled by the interplay of tectonics, sediment supply and eustatic sea level fluctuations (e.g. Haug, 1900; Suess, 1906; Grabau, 1913; Stille, 1924; Kuenen, 1939; Krumbein and Sloss, 1956; Fisher and Brown, 1972; Frazier, 1974; Payton, 1977; Burton et aI., 1987; Cloetingh, 1988; Wilgus et aI., 1988; Galloway, 1989; Walker, 1989). In order to establish the relative importance of these factors in foreland areas, previous studies have focused on the relation between tectonic activity and facies migrations on one hand and subsidence patterns on the other (Allen, 1986; Kleinspehn and Paola, 1988; Hemmings and Jordan, 1989, 1990; Cross, 1990; Angevine et aI., 1990; Macdonald, 1991). Comparing such data with forward models created many controversies; these were probably mainly due to the variability in parameters used in geophysical models, and to the discrepancy in scale between geophysical and geological models. In the present study, detailed tectonic and stratigraphic data from the Calabrian fore-arc area (southern Italy) are used together in order to show the relations between the various parameters and their role in the genesis of depositional sequences. The Late Neogene of Central Calabria was chosen because of its interesting position along the external side of the Central Mediterranean Calabrian Arc (Finetti, 1982; Moussat, 1983; Boccaletti et aI., 1984; Mantovani et aI., 1985; Kastens et aI., 1988; Patacca and Scandone, 1989). Rapid facies changes, ranging from continental to open marine, complex tectonically-defined unconfonnities within very small sub-basins, and a wide range of phenomena reflecting syn-depositional tectonic activity were known to occur. Furthennore, there is a thick, heterogeneous pile of Messinian clastic evaporites and continental deposits, reflecting major eustatic sea level fluctuations in this time interval. During field campaigns from 1983 till 1990, a number of local geological problems related to complex stratigraphic relationships and tectonic defonnations of the area had to be overcome. Data are presented in the fonn of detailed stratigraphic colums, composite structural profJ.J.es and paleogeographical maps which display encountered reflections of syndepositional tectonics. Additional infonnation from literature includes maps of basement structure, seismic sections and borehole data. An extensive review of previous geological literature is provided.