Quantifying Exhumation History Across the Northern Apennines
Abstract
Exhumation of Northern Apennines has been investigated through low-temperature geochronometric data (apatite fission-track analysis, AFT; U-Th/He on apatite and zircon). Results show a different thermotectonic evolution for the drainage divide area (Mt. Falterona, MF) and the metamorphic complex of the Apuane Alps (AA) on the Tyrrhenian side. Throughout the late Middle and Late Miocene, the AA were exhumed at a constant rate of 1.5 mm/y, whilst the MF area was rapidly subsiding, buried by foreland turbidites and eventually by the Ligurian unit. Exhumation in the AA abruptly dropped to 0.5 mm/y at the Early Pliocene. At that time, the MF started to be exhumed at a rate of 0.7 mm/y. No evidence for pronounced topography exists. With those rates, erosion could keep the pace with uplift. From Middle Pliocene onward, coarse-grained sedimentation in intramontane basins documents growing relief, with the final development of the present-day topography. The uplift rates increased to values of 1.4 mm/y in the MF and 0.8 mm/y in the AA. The MF became the most elevated area, therefore creating the present watershed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.T52B0928B
- Keywords:
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- 8109 Continental tectonics: extensional (0905);
- 8110 Continental tectonics: general (0905)