Salt tectonics and crustal tectonics along the eastern Sardinian margin, western Tyrrhenian; new insights from the METYSS 1 cruise

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doi: 10.1016/j.tecto.2013.12.015
Author(s): Gaullier, V.; Chanier, F.; Lymer, G.; Vendeville, B. C.; Maillard, A.; Thinon, I.; Lofi, J.; Sage, F.; Loncke, L.
Author Affiliation(s): Primary:
Université de Lille I, Unité de Formation et de Recherche des Sciences de la Terre, Villeneuve d'Ascq, France
Université Paul Sabatier, France
Bureau de Recherches Géologiques et Minières, France
Université de Montpellier II, France
Université Pierre et Marie Curie, France
Université de Perpignan, France
Volume Title: Tectonophysics
Source: Tectonophysics, Vol.615-616, p.69-84. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0040-1951 CODEN: TCTOAM
Note: In English. 91 refs.; illus., incl. sketch maps
Summary: The Tyrrhenian Sea is usually interpreted to be a Neogene back-arc basin that opened by continental rifting and oceanic spreading caused by the eastward migration of the Apennine subduction system during Miocene and Pliocene times. Rifting of the southern Tyrrhenian Sea started first along the Eastern Sardinian margin during the middle to late Miocene times, including the Messinian. The "METYSS" project aims at better constraining the relationships between crustal tectonics, salt tectonics and sedimentation from Messinian times to present-day. The "METYSS 1" cruise (2009) allowed to acquire about 1200km of HR seismic-reflection profiles along the Eastern Sardinian margin, Western Tyrrhenian Sea. This data set clearly illustrates that this area has been highly dissected during the rifting stage by N-S trending normal faults delineating ridges and basins, as previously described. The Messinian seismic markers (UU and MU) locally display fan-shaped stratal geometries, but the mechanism responsible for such geometries, salt tectonics or rifting, has yet to be carefully deciphered. We also mapped the spatial distribution of the mobile salt. The highly variable thickness of the small confined salt basins may be related to the initial pre-Messinian basin geometry, to the fact that salt deposition was syn-rift or to salt movement. Southeastward, salt tectonics is vigorous in unconfined basins and appears to have started early during the UU deposition. More surprisingly, our data demonstrate that some of the major faults have been significantly reactivated during the post-rift period, up to late Quaternary time, as shown by bathymetric scarps and associated debris flows. Moreover, some of this post-rift deformation can be evidenced within the Plio-Quaternary sequence by a regional unconformity. The post-Miocene deformation style varies greatly between different areas of the margin, and can also be strongly influenced by the presence or absence of mobile Messinian salt. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 16 Structural Geology; 20 Geophysics, Applied; Back-arc basins; Basement tectonics; Basin analysis; Basins; Cenozoic; Continental margin; Crust; Depositional environment; Europe; Faults; Geophysical methods; Geophysical surveys; Italy; Leg 107; METYSS; Marine sedimentation; Mediterranean Sea; Messinian; Miocene; Neogene; Normal faults; ODP Site 654; Ocean Drilling Program; Paleoenvironment; Paleosalinity; Plate tectonics; Rifting; Salt tectonics; Sardinia Italy; Sea-floor spreading; Sedimentation; Seismic methods; Southern Europe; Surveys; Syntectonic processes; Systems; Tectonics; Tertiary; Tyrrhenian Sea; Upper Miocene; West Mediterranean; Western Tyrrhenian Sea
Coordinates: N393000 N423000 E0120000 E0093000
Record ID: 2014065695
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands