Julie TUGEND

Rift to Orogen: the record of peri-Iberian margins

Supervisors:
Sylvie Leroy & Laurent Jolivet (Sorbonne Université)

Major Results

The depth and nature of the décollement level of extensional faults evolves in rifted margins. The evolution of the rheological stratification and inheritance control 3D variations in structural style. The specific architecture of the Bay of Biscay passive margin may partly explain the modalities of inversion upon subduction initiation and collision.

Abstract

This project focused on investigating the 3D structural style and segmentation of the northern Bay of Biscay passive margin. Our results document a loose segment transition marked by a progressive lateral change in structural style. These changes seem controlled by 1) an evolution of the nature and depth of the main fault décollement level between the proximal and distal parts of the margin, 2) a different accommodation of extensional deformation across the transfer zone (Tugend et al., in prep1).

This segmentation occurs near major pre-existing structures identified further continentward, suggesting a role of inheritance. Documenting the architecture of the Bay of Biscay rifted margin and its rheological stratification was a start to investigate the modalities of the subduction initiation recorded in the North Iberian rifted margin and role of rift inheritance during the formation of the Pyrenean collisional orogen (Tugend et al., in prep2).

A case of ampferer-type subduction and consequences for the alps and the Pyrenees

McCarthy, A., Tugend, J., Mohn, G., Candioti, L., Chelle-Michou, C., Arculus, R., Schmalholz, S., M., Müntener, O. (2020) : A case of ampferer-type subduction and consequences for the alps and the Pyrenees. American Journal of Science 320(April):313-372.

keywords: Ampferer-type subduction, Benioff-type subduction, Alps, Pyrenees, rift basins, amagmatic subduction initiation

DOI: https://dx.doi.org/10.2475/04.2020.01

The role of serpentinization and magmatism in the formation of decoupling interfaces at magma-poor rifted margins

Gillard, M., Tugend, J., Müntener, O., Manatschal, G., Karner, G.,D., Autin, J., Sauter, D., Figueredo, P., H., Ulrich, M. (2019). The role of serpentinization and magmatism in the formation of decoupling interfaces at magma-poor rifted margins. Earth-Science Reviews, Elsevier, 2019, 196, pp.102882.

keywords: magma-poor margins, Serpentinization, Decoupling, Seismic, interpretation

DOI: https://doi.org/10.1016/j.earscirev.2019.102882

Role of rift structural inheritance in orogeny highlighted by the Western Pyrenees case-study

Gómez-Romeu, J., Masini, E., Tugend, J., Ducoux, M., Kusznir, N. (2019). Role of rift structural inheritance in orogeny highlighted by the Western Pyrenees case-study. Tectonophysics, Elsevier, 2019, 766, pp.131-150.

keywords: Western Pyrenees, Rift structural inheritance, Flexural isostatically and structurally balanced cross-section

DOI: https://doi.org/10.1016/j.tecto.2019.05.022

Thermal evolution of asymmetric hyperextended magma-poor rift systems: results from numerical modelling and Pyrenean field observations.

Lescoutre, R., Tugend, J., Brune, S., Masini, E. & Manatschal, G. (2019)
Thermal evolution of asymmetric hyperextended magma-poor rift systems: results from numerical modelling and Pyrenean field observations. Geochemistry Geophysics Geosystems 20(1)

keywords: Thermal evolution, Asymmetric rifting, Numerical model, Field analogue, Pyrenees, Heat flow

DOI: https://doi.org/10.1029/2019GC008600