Publication Date:
2022-06-14
Description:
In the past few years, a wealth of paleomagnetic
data gathered from Neogene
sediments consistently showed that since
ca. 10 Ma the Calabria terrane coherently
drifted ~500 km ESE-ward from the Sardinian
margin, and rotated 15 –20 clockwise
(CW) as a rigid microplate between 2 and
1 Ma. Here we report on a high-resolution
paleomagnetic investigation of the Crotone
forearc basin of northern Calabria. The
integrated calcareous plankton biostratigraphy
indicates early Pliocene (Zanclean)
to late early Pleistocene (Calabrian) ages
for 29 successful paleomagnetic sites and/or
sections. Unexpectedly, four domains undergoing
distinct rotations are documented.
Two blocks have undergone a CW rotation
statistically undistinguishable, for both timing
and magnitude, from the rigid Calabria
rotation documented in the past. Two additional
~10-km-wide blocks yielded a 30.8 ±
22.5 and 32.0 ± 9.2 post–1.2 Ma counterclockwise
rotation, likely due to left-lateral
shear along two NW-SE fault zones. We infer
that since advanced early Pleistocene times,
after the end of the uniform CW rotation,
left-lateral strike-slip tectonics disrupted
the Calabria terrane, overwhelming a widespread
extensional regime accompanying
the Calabria drift since late Miocene times.
Seismological evidence reveals that only the
southern part of the Ionian slab subducting
below Calabria is continuous, while beneath
northern Calabria a slab window between
100 and 200 km depth is apparent. We suggest
that the partial breakoff of the Ionian
slab after 1 Ma induced the fragmentation
of the Calabria wedge, and that strike-slip
faults from the Crotone basin decoupled
“inactive” northern Calabria from southern
Calabria, still drifting towards the trench.
Description:
Published
Description:
925–933
Description:
2.2. Laboratorio di paleomagnetismo
Description:
JCR Journal
Description:
restricted
Keywords:
Calabria
;
Crotone basin
;
paleomagnetism
;
rotations
;
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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