Brittle-ductile analogue models of fold-and-thrust belts developed during progressive archingthe effect of viscous basal layer pinch-outs
- Alejandro Jiménez-Bonilla 1
- Ana Crespo Blanc 1
- Juan Carlos Balanyá Roure 2
- Inmaculada Expósito 2
- Manuel Díaz-Azpiroz 2
- 1 Universidad de Granada, España
- 2 Universidad Pablo de Olavide, España
ISSN: 0213-683X
Année de publication: 2018
Titre de la publication: Comunicaciones presentadas en la LXIV Sesión Científica / Ávila, 1 de Junio de 2018
Número: 64
Pages: 15-18
Type: Article
D'autres publications dans: Geogaceta
Résumé
Two brittle-ductile analogue models of fold-and-thrust belts developed during progressive arching that include silicone pinch-outs either perpendicular or parallel to the backstop apex motion direction (AMD) have been performed to test their role in fold-and-thrust belt geometry and structural evolution. When the silicone pinch-out is oriented perpendicular to the AMD the deformation front stagnates at the silicone pinch-out and arc-parallel lengthening is accommodated by normal and strike-slip faults. When deformation progresses, the wedge thickens and collapses, developing dismantling units. In contrast, when silicone pinch-outs are parallel to the AMD, different structural styles appear along the fold-and-thrust belt: a foreland verging imbricate system where silicone is absent, and a doubly-verging system where silicone is present, both separated by transfer zones. Additionally, the absence of silicone gives place to fold and thrust belt segments relatively narrower in plan-view and vertically thickened. Both models could be useful to delve into both the deposition of dismantling units and the distribution of along-strike structural differences observed in the Gibraltar Arc fold-and-thrust belt.