The role of inheritance in structuring hyperextended rift systems: Some considerations based on observations and numerical modeling

• Published in: Gondwana Research
• Main Authors: Manatschal, Gianreto, Lavier, L.L., Chenin, Pauline
• Other Authors: Dynamique de la lithosphère et des bassins sédimentaires (IPGS) (IPGS-Dylbas), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institute of Geophysics Austin (IG), University of Texas at Austin Austin
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Alpine Tethys; Hyperextended rifted margins; Rifting; Inheritance; Iberia–Newfoundland; Numerical modeling; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics; Newfoundland
• Online Access: https://hal.archives-ouvertes.fr/hal-01213225; https://hal.archives-ouvertes.fr/hal-01213225/document; https://hal.archives-ouvertes.fr/hal-01213225/file/Manatschal%26al2015_unformatted.pdf; https://doi.org/10.1016/j.gr.2014.08.006

International audience A long-standing question in Earth Sciences is related to the importance of inheritance in controlling tectonic processes. In contrast to physical processes that are generally applicable, assessing the role of inheritance suffers from two major problems: firstly, it is difficult to appraise without having insights into the history of a geological system; and secondly all inherited features are not reactivated during subsequent deformation phases. Therefore, the aim of this paper is to give some conceptual framework about how inheritance may control the architecture and evolution of hyperextended rift systems.In this paper, we use the term inheritance to refer to the difference between an “ideal” layer-cake type lithosphere and a “real” lithosphere containing heterogeneities. The underlying philosophy of this work is that the evolution of hyperextended rift systems reflects the interplay between their inheritance (innate/“genetic code”) and the physical processes at play (acquired/external factors). Thus, by observing the architecture and evolution of hyperextended rift systems and integrating the physical processes, one may get hints on what may have been the original inheritance of a system.We first define 3 types of inheritance, namely structural, compositional and thermal inheritance and develop a simple and robust terminology able to describe and link observations made at different scales using geological, geophysical and modeling approaches. To this, we add a definition of rift-induced processes, i.e. processes leading to compositional changes during rifting (e.g. serpentinization or decompression melting). Using this approach, we focus on 3 well-studied rift systems that are the Alpine Tethys, Pyrenean–Bay of Biscay and Iberia–Newfoundland rift systems. However, as all these examples are magma-poor, hyperextended rift systems that evolved over a Variscan lithosphere the concepts developed in this paper cannot be applied universally. For the studied examples we can show that:1) the ...