학술논문

The Sardinia-Corsica Microplate and its role in the Northern Apennine geodynamics; new insights from the Tertiary intraplate strike-slip tectonics of Sardinia
Document Type
Academic Journal
Source
Italian Journal of Geosciences. 128(2):527-539
Subject
18|Geophysics - solid Earth (tectonophysics)
Adriatic Plate
Alps
Apennines
basin analysis
basins
Cenozoic
Corsica
deformation
Europe
fabric
faults
fold and thrust belts
folds
France
geodynamics
intracratonic basins
intraplate processes
Italy
Mediterranean region
Mediterranean Sea
microplates
Northern Apennines
Oligocene
orogenic belts
Paleogene
plate collision
plate tectonics
rift zones
Sardinia Italy
Southern Europe
strike-slip faults
structural analysis
syntectonic processes
tectonic wedges
tectonics
Tertiary
thrust faults
West Mediterranean
Western Europe
Language
English
ISSN
2038-1719
Abstract
The behaviour of Sardinia and Corsica within the Alpine-Apennine orogenic events has not been considered in a univocal way; different hypotheses have been proposed, disregarding any eventual effect on the internal structuration of this piece of European crust. Identifying the mechanism and age of the prominent strike-slip tectonics in Sardinia and Corsica allows us to bear new insights on the relationships between the south European crust and Adria plate. Syntectonic Oligocene-Aquitanian deposits fill some intracratonic basins in Sardinia. They developed in correspondence with releasing bends that affect the sinistral strike-slip faults, constraining the time span during which this tectonic regime was active. Thrusts and folds involving the Mesozoic and Lower Cainozoic cover are not ubiquitous in Sardinia, they are mainly localised along deformed corridors in the NE part of the Island where deeply shortened Cainozoic conglomerates were involved in the wrench-thrust faults which, in some case, led the basement to override the Mesozoic cover. The association of these structures to restraining bends is documented, so that they are the coeval transpressive counterparts of the strike-slip basins. Confining most of the Tertiary strike-slip tectonics of Sardinia and Southern Corsica within an Oligocene-Aquitanian time interval involves the following consequences: i) no E-W extension, leading to a N-S trending rift (in presentday coordinates), was active in Sardinia and Corsica during Oligocene-Aquitanian times; ii) the so-called Sardinia Rift is an assemblage of shallow asymmetric basins, trending N150, which developed during the late Burdigalian-Langhian, i.e. contemporary to the onset of the collapse of the North Apennine and Alpine Corsica orogenic wedge and to the opening of the North Tyrrhenian Sea; iii) the Oligocene-Aquitanian strike-slip tectonics in Sardinia is consistent with the deformation of a hinterland involved in collision; this was the collision between Adria and Europe that led to the building of the North Apennines; iv) the collisional event predates the drifting of the Sardinia-Corsica crust and the opening of the Liguro-Provencal basin.