Publication Date:
2021-09-08
Description:
We report new paleomagnetic and anisotropy of
magnetic susceptibility (AMS) results from upper Tortonian to middle Pleistocene sediments which were deposited upon and
adjacent to active thrust structures in southwestern Sicily. The data show that the Plio-Pleistocene sediments from the Belice
and Menfi basins (covering the Saccense shelf limestones) underwent any internal shortening after the early Pleistocene (Santernian), as well as any net rotation. Sediments around this area (which overlie basinal Meso-Cenozoic successions) record
systematic rotations: one upper Tortonian site to the west is ~30° counterclockwise rotated, while to the east, lower Pliocene to
middle lower Pleistocene sites within the Gela Nappe domain show 25° to 56° clockwise (CW) rotations. These data show that
the ductile basinal sediments were bent and rotated around the rigid Saccense carbonates during the thin-skinned southward propagation of the orogenic front. We document here that the coastal sediments from the southwestern Gela Nappe underwent both a post middle early Pleistocene ~30° CW rotation and a post middle Pleistocene E-W to ESE-WNW flattening (revealed by AMS). Our data then constrain to the late Pleistocene-Holocene the age of the last shortening episode occurring in the
southwestern Gela Nappe front. Pleistocene rotations of similar amount also characterize the Sicanian domain, implying that it
was incorporated in the Gela Nappe wedge during the recentmost episodes of deformation. This evidence allows us to better understand the very large (up to 114°) post Mesozoic rotations reported by Channell et al. [1980, 1990] for the Sicanian
limestones, as related to both Miocene (or older?) deformational episodes and the Plio-Pleistocene evolution of the Gela Nappe.
Description:
Published
Description:
1178-1197
Description:
JCR Journal
Description:
reserved
Keywords:
paleomagnetism
;
tectonic rotations
;
Sicily
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
;
04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
