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Geometry and kinematic evolution of a long‐living foreland structure inferred from field data and cross section balancing, the Sainte‐Victoire System, Provence, France

2012; Wiley; Volume: 31; Issue: 4 Linguagem: Inglês

10.1029/2011tc002988

1944-9194

Nicolás Espurt, Jean‐Claude Hippolyte, Marianne Saillard, Olivier Bellier,

Geological and Geophysical Studies Worldwide

The Sainte‐Victoire System (SVS) is a key area to understand how the shortening is accommodated in outer foreland of the Pyrenean‐Provence orogen between Late Cretaceous and Eocene. Structural data, growth strata and fault slip analysis, and four balanced cross sections are used to decipher the along‐strike geometry, deformational characteristics and kinematics of the SVS. The SVS is divided into two structural domains separated by a regional relay zone: the eastern domain is governed by a N‐vergent thin‐skinned tectonic style above Triassic series and the western domain, by a mixed S‐vergent thick‐ and thin‐skinned tectonic style with tectonic inversion of Late Paleozoic‐Triassic half grabens. Growth strata indicate that the eastern SVS grew during Danian as a result of shortening transfer from the southern Arc Basin. In contrast, the western SVS is an independent structure which has recorded the early stage (∼83 Ma) of shortening and focused continuous deformation during ∼40 Myr. The shallow N‐S shortening is ∼5 km (∼25%) and ∼8 km (∼34%) in the western and eastern SVS, respectively. At a regional scale, the tectonic inversion of the SVS and the Arc Basin recorded a deep shortening of the order of 15–18 km (∼34%). Although the shortening magnitude of the SVS remains small, other structures similar to the SVS were synchronously active across foreland basin, suggesting a significant amount of cumulated shortening. This outer foreland shortening may account for a non‐negligible amount of deformation at the Pyrenean‐Provence orogen scale.