Interactions between mantle upwelling, drainage evolution and active normal faulting: an example from the central Apennines (Italy)

Abstract

SUMMARY In this paper we show that the processes that have shaped the Quaternary surface development of the Apennines in central Italy are all consequences of a single subcrustal process, the upwelling of the mantle. The relationship between gravity and topography shows that mantle convection is responsible for a long‐wavelength (150–200 km) topographic bulge over the central Apennines, and stratigraphic evidence suggests this bulge developed in the Quaternary. Active normal faulting is localized at the crest of this bulge and produces internally‐draining fault‐bounded basins. These basins have been progressively captured by the aggressive headward erosion of major streams that cut down to the sea on the flanks of the regional bulge. The only surviving closed basins are those on the Apennine watershed most distant from the marine base level, where continued normal faulting is still able to provide local subsidence that defeats their capture by the regional drainage network. Understanding the competition between regional capture and local, fault‐related subsidence of intermontane basins is crucial for recognizing potentially hazardous active faults in the landscape and also for interpreting the sediment supply to adjacent offshore regions. Central Italy provides a good modern analogue for processes that are probably common in the geological record, particularly on rifted margins and intracontinental rifts, but may not have been fully appreciated.

New insights into the onset and evolution of the central Apennine extensional intermontane basins based on the tectonically active L’Aquila Basin (central Italy)

“…15) could indicate a partial decoupling of processes responsible for the migration of shortening and extension toward the foreland. These processes include (1) convergence and rollback of the subducting plate, responsible for the migration of the compressional front toward the foreland (e.g., Doglioni et al, 1997;Funiciello et al, 1999;Faccenna et al, 2001;Carminati and Doglioni, 2012), and (2) mantle upwelling, responsible for the development of the hinterland extensional domain, the uplift of the compressional tectonic wedge, and intermontane extensional basin formation (e.g., Dewey, 1988;Doglioni, 1995;Faccenna et al, 1996;Cavinato and DeCelles, 1999;D'Agostino et al, 2001;Fig. 16).…”

Two Tectonic Geomorphology Studies on the Landscape and Drainage Network of Chain and Piedmont Areas of the Abruzzi Region (Central Apennines, Italy)

“…Some of these elements will respond more rapidly to changes imposed on them than others, according to the combination of many factors such as lithology, local tectonics, rock uplift/subsidence and climate changes (Morisawa and Hack, 1985;Kühni and Pfiffner, 2001;Twidale, 2004). In tectonically active landscapes, changes in the incision/aggradation behaviour of the rivers are associated with the variations in climate and tectonics (Schumm, 1969;Bull, 1991;Merrits et al, 1994;Ascione and Cinque, 1999;Burbank and Pinter, 1999;Pazzaglia and Brandon, 2001;D'Agostino et al, 2001;Pazzaglia, in press). Such changes occur following a specific sequence involving incision, valley widening and aggradation, and tend to form a series of fluvial terraces.…”

Morphotectonic map of the Aventino-Lower Sangro valley (Abruzzo, Italy), scale 1:50,000

“…It is a thrust belt migrated north-east, that built up during the Neogene (Calamita, Esestime, Paltrinieri, Scisciani, & Tavarnelli, 2009;Carminati & Doglioni, 2004;Parotto & Praturlon, 2004;Patacca & Scandone, 2007). Since the Late Pliocene the Apennines have been affected by differential uplift and extensional tectonics with the emergence of the Apennine piedmont and the formation of intermontane basins (Ascione, Cinque, Miccadei, Villani, & Berti, 2008;Cavinato & De Celles, 1999;D'Agostino, Jackson, Dramis, & Funiciello, 2001;D'Alessandro, Miccadei, & Piacentini, 2003).…”