A detailed field mapping, coupled with structural analyses and morphological investigation, has been carried out along the northern andwestern borders of the Hyblean Plateau (SE Sicily), in order to define the nature and the kinematics of a major Quaternary fault belt. This, heredesigned as the Scicli Line Fault Belt, is composed of two N50 oriented extensional basins that, linked by a regional N10 trending transfer zone,originated during the Early Pleistocene and experienced, since the Late Quaternary, a positive tectonic inversion. In both the two stages ofdeformation, the Scicli Line Fault Belt has been characterised by displacement-rate comparable with the relative velocities measured between thedistinct plates composing the central Mediterranean region. In the period going from 1.5–1.2 to 0.85 Ma, the fault belt accommodated the entiredivergence between Adria and Nubia. At present, the Scicli Line Fault Belt absorbs most of the Nubia–Eurasia convergence, while the westerndivergent margin of the Adria microplate has jumped to the eastern and the southern margins of the Hyblean Plateau, along the Late QuaternarySiculo–Calabrian Rift Zone. The off-shore prolongation of the two tectonic boundaries of the Hyblean Plateau has been recognised in the SicilyChannel, where they are both interrupted by a WNW-ESE oriented dextral fault. According to our reconstruction, the Hyblean Plateau representsan isolated lithospheric block, whose evolution can be related to the propagation of the western divergent margin of the Adria microplate,accompanied with the southward migration of the triple junction between Eurasia, Nubia and Adria. In this new large-scale kinematic picture, theGPS velocity measured in the Hyblean region, at the permanent site of NOTO, is actually representative of the local kinematics, rather than of theentire African promontory of southern Italy. This implies a correction of previous regional kinematic models based on combination of GPSvectors. In particular, our data constrain a new interpretation both for the kinematics along the E–Woriented Nubia–Eurasia margin, dominated byprevalent dextral deformation rather than reverse motions, and for the intraplate deformation in the Sicily Channel, within the Africa promontory,which would be dominated by a roughly N110° oriented extension. This conclusion has implication also on the mechanism and the origin of thePantelleria–Linosa–Malta Rift that is here interpreted as a transtensive feature developed along a major transform fault, rather than the result ofpassive rifting induced by the Nubia–Eurasia collision, as it is currently interpreted.

The migration of plate boundaries in SE Sicily: influence on the large-scale kinematic model of the African Promontory in southern Italy

CATALANO, Stefano;DE GUIDI, GIORGIO;ROMAGNOLI, GINO;TORTORICI, GIUSEPPE;
2008-01-01

Abstract

A detailed field mapping, coupled with structural analyses and morphological investigation, has been carried out along the northern andwestern borders of the Hyblean Plateau (SE Sicily), in order to define the nature and the kinematics of a major Quaternary fault belt. This, heredesigned as the Scicli Line Fault Belt, is composed of two N50 oriented extensional basins that, linked by a regional N10 trending transfer zone,originated during the Early Pleistocene and experienced, since the Late Quaternary, a positive tectonic inversion. In both the two stages ofdeformation, the Scicli Line Fault Belt has been characterised by displacement-rate comparable with the relative velocities measured between thedistinct plates composing the central Mediterranean region. In the period going from 1.5–1.2 to 0.85 Ma, the fault belt accommodated the entiredivergence between Adria and Nubia. At present, the Scicli Line Fault Belt absorbs most of the Nubia–Eurasia convergence, while the westerndivergent margin of the Adria microplate has jumped to the eastern and the southern margins of the Hyblean Plateau, along the Late QuaternarySiculo–Calabrian Rift Zone. The off-shore prolongation of the two tectonic boundaries of the Hyblean Plateau has been recognised in the SicilyChannel, where they are both interrupted by a WNW-ESE oriented dextral fault. According to our reconstruction, the Hyblean Plateau representsan isolated lithospheric block, whose evolution can be related to the propagation of the western divergent margin of the Adria microplate,accompanied with the southward migration of the triple junction between Eurasia, Nubia and Adria. In this new large-scale kinematic picture, theGPS velocity measured in the Hyblean region, at the permanent site of NOTO, is actually representative of the local kinematics, rather than of theentire African promontory of southern Italy. This implies a correction of previous regional kinematic models based on combination of GPSvectors. In particular, our data constrain a new interpretation both for the kinematics along the E–Woriented Nubia–Eurasia margin, dominated byprevalent dextral deformation rather than reverse motions, and for the intraplate deformation in the Sicily Channel, within the Africa promontory,which would be dominated by a roughly N110° oriented extension. This conclusion has implication also on the mechanism and the origin of thePantelleria–Linosa–Malta Rift that is here interpreted as a transtensive feature developed along a major transform fault, rather than the result ofpassive rifting induced by the Nubia–Eurasia collision, as it is currently interpreted.
2008
Plate boundaries; Kinematics; Active tectonics; Sicily; Scicli Line
File in questo prodotto:
File Dimensione Formato  
catalano et al 2008 The migration.pdf

solo gestori archivio

Tipologia: Versione Editoriale (PDF)
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 5.59 MB
Formato Adobe PDF
5.59 MB Adobe PDF   Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/4968
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 77
  • ???jsp.display-item.citation.isi??? 72
social impact