Publication Date:
2017-10-06
Description:
We report on an extensive paleomagnetic study (36 sites) of the Tuscan Nappe succession from
the Northern Apennines Arc, aimed to reconstruct the tectonic evolution of the internal sector of this chain.
We analyzed Eocene pelagic foreland ramp deposits (Scaglia Toscana Formation) and Oligocene–lower
Miocene siliciclastic turbidites (Macigno and Falterona Formations). Paleomagnetic results show that the
internal sector of the Northern Apennines underwent large counterclockwise (CCW) rotations with respect to
the Adria-Africa foreland. A decrease in the rotation magnitude was observed from the southern to the
northern sector of the arc (from 91 to 36°). This trend is opposite to that observed in the more external units
of Northern Apennines and demonstrates that the oroclinal bending model, which has been proposed for
the external units of the chain, is not appropriate to explain the evolution of the internal sector of the arc. On
the basis of the observed paleomagnetic pattern, we propose a new tectonic model in which the Tuscan and
Falterona-Cervarola units in the southern area were first rotated CCW along with the Corsica-Sardinia block
during its lower Miocene rotational drifting and were later involved in the main phases of rotational
emplacement and translation toward the outermost sector (Umbria domain), thus yielding the final curved
shape of the Northern Apennines chain. Data from this study represent the first paleomagnetic evidence of
the influence of the Corsica-Sardinia CCW rotation in the Apennines orogenic wedge deformation, in the
general framework of the geodynamic evolution of the Central Mediterranean subduction system.
Description:
Published
Description:
374-392
Description:
1A. Geomagnetismo e Paleomagnetismo
Description:
JCR Journal
Description:
restricted
Keywords:
paleomagnetism, Apennines, Tuscany
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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