HR: 1340h
AN: T53B-0495    [Abstracts]
TI: Vertical Tectonics in the Calabria-Apennine Arc-Continent Collision Orogen from Geomorphic Features (CATSCAN Project)
AU: Seeber, L
EM: nano@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964 United States
AU: Taramelli, A
EM: ataram@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964 United States
AU: Dewez, T
EM: t.dewez@brgm.fr
AF: BRGM, Natural Risks Dept. 3 av. C. Guillemin, Orleans, 45060 France
AU: Stark, C
EM: stark@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964 United States
AU: * Commins, D
EM: dcommins@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964 United States
AU: Steckler, M
EM: steckler@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964 United States
AB: Calabria is an exotic continental fragment that forms a ridge parallel to the Aeolian volcanic arc and separates accretion and rollback-subduction of Ionian lithosphere from forearc extension on the Tyrrhenian side. Along-strike, the Calabria ridge merges into the Apennines and the Maghrebides, which formed in the progressive collision and emplacement of the arc onto Apulian and African passive margins. Flights of marine terraces in Calabria and adjoining parts of Sicily and southern Italy indicate rapid late-Pleistocene uplift along both collisional and rollback portions of the chain. The pattern of uplift appears to vary along- and across-strike as well as through time during the late evolution of the orogen, suggesting multiple causes and a time-transgressive pattern. We seek further constraints from river and ridge profiles and slope distribution using the SRTM 90m-DEM. The following results are preliminary: 1. The Calabrian ridge is a broad antiform. A bowed erosional paleosurface is preserved in crestal regions where chemical weathering and denudation may be relatively uniform. In this region slopes are gentle and drainage valleys are wide and low grade. A sharp boundary separates this region from the flanks of the antiform, which are gouged by energetic rivers into upwardly concave slopes and deep canyons. The western flank is also cut by longitudinal basin-forming dip-slip faults. Western rivers profiles exhibit sharp concavities suggesting fault-controlled uplift. Eastern river profiles are systematically smoother, as expected in response to seaward tilting. Regarding the pattern of uplift, morphology and structure are generally consistent, suggesting a steady-state regime. 2. The foredeep between the southern Apennines and the Apulian foreland is characterized by a set of longitudinal rivers, draining along the Apennine mountain front into the Gulf of Taranto. These rivers have narrow closely spaced drainage basins with little concavity and seem remarkably immature. This suggests rapid uplift of the foredeep in the Gulf of Taranto, where the Apennine collision is still incomplete. About 100km north of the gulf, drainage shifts to the NE and crosses the foredeep into the Adriatic Sea. This transverse drainage is more deeply incised and tends to capture the longitudinal drainage, thus moving the divide between them to the SE. This suggests that the transition from longitudinal to transverse drainage is tracking the collision to the SE.
DE: 8107 Continental neotectonics
DE: 1824 Geomorphology (1625)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting