From stretching to mantle exhumation in a triangular back-arc basin (Vavilov Basin, Tyrrhenian Sea, western Mediterranean)

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doi: 10.1016/j.tecto.2016.10.017
Author(s): Milia, Alfonsa; Torrente, Maurizio M.; Tesauro, Magdala
Author Affiliation(s): Primary:
CNR, Istituto per l'Ambiente Marino Costiero, Naples, Italy
Universita del Sannio, Italy
Utrecht University, Netherlands
Volume Title: Evolution of fore-arc and back-arc sedimentary basins with focus on the Japan subduction system and its analogues
Volume Author(s): Sato, Hiroshi, editor; Ishiyama, Tatsuya; Matenco, Liviu; Henri, Fadi
Source: Evolution of fore-arc and back-arc sedimentary basins with focus on the Japan subduction system and its analogues, edited by Hiroshi Sato, Tatsuya Ishiyama, Liviu Matenco and Fadi Henri. Tectonophysics, Vol.710-711, p.108-126. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0040-1951 CODEN: TCTOAM
Note: In English. 105 refs.; illus., incl. sketch maps
Summary: In this study, we describe the mode of extension of the Vavilov, a fossil backarc basin, triangle-shaped (approximately 240 km-wide and 200 km-long), located between Sardinia margin to the west and Campania margin to the east. We combine the analysis of recent geophysical and geological data, in order to investigate the relationship between the crustal/sedimentary structure and the tectonic evolution of both apex and bathyal parts of the basin. With this aim, we interpret a large data set of multichannel seismic reflection profiles and several well logs. We observe that the apex basin corresponds to a sediment-balanced basin, with a sedimentary infill recording the episodes of basin evolution. In contrast, the distal basin corresponds to an underfilled basin, characterized by localized volcanic activity and a thin sedimentary succession that covers the exhumed mantle. The basin architecture reveals the occurrence of rift and supradetachment basins in the Vavilov rift zone. We find that the rifting of the Vavilov triangular basin was synchronous from the apex to distal regions around a single Euler pole located in Latium, between 5.1 and 1.8 Ma. The kinematic evolution of the Vavilov basin occurred in two stages: initial pure shear mode (5.1-4.0 Ma) that produced high-angle normal faults and syn-sedimentary wedges, followed by simple shear mode (4.0-1.8 Ma) that caused supradetachment basins filled by a Transgressive-Regressive succession that documents high subsidence rates (1.22 mm/y) in the apex region. The final stage of extension in the distal region led to: (i) complete embrittlement of the crust; (ii) direct continuation of crustal faults to upper mantle depth; (iii) serpentinization and mantle exhumation. Based on constraints on the present-day crustal structure of the Vavilov basin, we obtain a stretching value (β = 3.5) and extension rates (3 cm/y) in the bathyal zone analogous to those reported for magma-poor rifted margins.
Year of Publication: 2017
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 16 Structural Geology; 20 Geophysics, Applied; Back-arc basins; Basement; Basement tectonics; Basin analysis; Basins; Campania Italy; Cenozoic; Continental margin; DSDP Site 373; Deep Sea Drilling Project; Deformation; Europe; Exhumation; Geophysical methods; Geophysical surveys; Italy; Latium Italy; Leg 107; Leg 42A; Lithostratigraphy; Mantle; Marine sediments; Mediterranean Sea; Models; Multichannel methods; Neogene; ODP Site 652; ODP Site 654; Ocean Drilling Program; Plate tectonics; Pliocene; Quaternary; Reflection methods; Rifting; Sardinia Italy; Sediments; Seismic methods; Southern Europe; Surveys; Tectonics; Tertiary; Tomography; Tyrrhenian Sea; Vavilov Basin; Volcanism; West Mediterranean
Coordinates: N402117 N402119 E0120836 E0120834
Record ID: 2017099770
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands