Publication Date:
2015-06-09
Description:
A multi-method approach (palaeothermal and thermochronological analyses; thermal modeling) is applied to reconstruct the exhumation history of the Altotiberina Fault (ATF), a representative example of crustal-scale active low-angle normal faulting in the Northern Apennines (Italy). Thermal maturity and thermochonological data yield similar burial histories but different exhumation patterns for the sedimentary successions in the hanging-wall and the foot-wall of the ATF. Since 3.8 Ma , the ATF foot-wall has exhumed at rates of 0.90 mm/yr. Exhumation led to bending and deactivation of the ATF uppermost portion as a result of tectonic unloading and isostatic adjustment, followed by migration of extension and the development of a set of domino-like, east-dipping normal faults, rooting on the buried portion of the ATF. ATF activity and isostatic rebound exhumed Triassic rock units from depths of about 4 km. We suggest that isostatic instability is accommodated at shallow crustal levels, in a similar way to what is observed on larger structures at mid-low crustal levels. This article is protected by copyright. All rights reserved.
Print ISSN:
0954-4879
Electronic ISSN:
1365-3121
Topics:
Geosciences
Permalink