The magnitude and rate of Late PleistoceneeHolocene vertical tectonic movements offshore of the CapoVaticano Promontory (western Calabria, southern Italy) have been measured on the basis of the presentdaydepth variations of the edges of submerged depositional terraces (and associated abrasion platforms)that formed below the storm-wave base, during the sea level stillstand of the Last Glacial Maximum(LGM). These depositional features, represented by submerged prograding wedges and an associatedterrace-shaped upper boundary, have been identified in high-resolution seismic reflection profiles acquiredalong the continental shelf and the upper slope of the promontory, and are referred to in thisstudy as “Lowstand Infralittoral Prograding Wedges (LIPWs)”. Our new data and methods provide evidencethat LIPWs can be used as geomorphological indicators of vertical movements in offshore settingswith well controlled uncertainty. Removal of the non-tectonic component of vertical changes using anice-volume equivalent eustatic sea level compilation indicates w11 ( 3.2) m of uplift and w25 ( 3.2) mof subsidence, from southwest to northeast, along the promontory, over a distance of w22 km, duringthe post-LGM. The resulting uplift and subsidence rates (including both regional and local components)for the last 20.350 ( 1.35) years are 0.54 ( 0.2) mm/y and 1.23 ( 0.25) mm/y, respectively. These resultsare consistent with longer-term estimates based on uplifted 215e82 ka old coastal terraces and LateHolocene shorelines. This integration of offshore and coastal markers indicates a pattern of verticalmovements characterized by a marked asymmetry associated with a northeast down tilt of the CapoVaticano Promontory. The calculated tilt rate increases by one order of magnitude during the post-LGMin respect to the time interval from 215 to 82 BP. Displacement associated with the NWeSE strikingnormal fault that bound the Capo Vaticano Promontory to the Gioia Tauro Basin ended in the (?)Pleistocene, and thus does not contribute to the tilt of the promontory at least during the last 215 ka.
|Numero di pagine||14|
|Stato di pubblicazione||Published - 2014|
All Science Journal Classification (ASJC) codes
- Earth-Surface Processes