Images and videos of analogue centrifuge models exploring marginal flexure during rifting in Afar, East Africa

Zwaan, Frank; Corti, Giacomo; Keir, Derek; Sani, Federico;

2020-09 || GFZ Data Services

This data set includes images and videos depicting the evolution of deformation and topography of 17 analogue experiments c passive margin development, to better understand the ongoing tectonics along the western margin of Afar, East Africa. The tectonic background that forms the basis for the experimental design is found in Zwaan et al. 2019 and 2020a-b, and references therein. The experiments, in an enhanced gravity field in a large-capacity centrifuge, examined the influence of brittle layer thickness, strength contrast, syn-rift sedimentation and oblique extension on a brittle-viscous system with a strong and weak viscous domain.

All experiments were performed at the Tectonic Modelling Laboratory of of the Istituto di Geoscience e Georisorse - Consiglio Nazionale delle Ricerche (CNR-IGG) and of the Earth Sciences Department of the University of Florence (CNR/UF). The brittle layer (sand) thickness ranged between 6 and 20 mm, the underlying viscous layer, split in a competent and weak domain (both viscous mixtures), was always 10 mm thick. Asymmetric extension was applied by removing a 1.5 mm thick spacer at the side of the model at every time step, allowing the analogue materials to spread when enhanced gravity was applied during a centrifuge run.

Differential stretching of the viscous material creates flexure and faulting in the overlying brittle layer. Total extension amounted to 10.5 mm over 7 intervals for Series 1 models that aimed at understanding generic passive margin development in a generic orthogonal extension setting, whereas up to 16.5 mm of extension was applied for the additional Series 2 models aiming at reproducing the tectonic phases in Afar. In models involving sedimentation, sand was filled in at time steps 2, 4 and 6 (i.e. after 3, 6 and 9 mm of extension). Detailed descriptions of the experiments, monitoring techniques and tectonic interpretation of the model results are presented in Zwaan et al. (2020c) to which these data are supplementary.

Originally assigned keywords

Corresponding MSL vocabulary keywords

MSL enriched keywords

MSL enriched sub domains
  • analogue modelling of geologic processes
  • rock and melt physics
  • geochemistry
Source http://doi.org/10.5880/fidgeo.2020.020
Source publisher GFZ Data Services
DOI 10.5880/fidgeo.2020.020
License CC BY 4.0
Authors
References
  • Zwaan, F., Corti, G., Keir, D., & Sani, F. (2020). Analogue modelling of marginal flexure in Afar, East Africa: Implications for passive margin formation. Tectonophysics, 796, 228595. https://doi.org/10.1016/j.tecto.2020.228595
  • 10.1016/j.tecto.2020.228595
  • IsSupplementTo
  • Zwaan, F., Corti, G., Keir, D., Sani, F., Muluneh, A., Illsley-Kemp, F., & Papini, M. (2020). Geological data from the Western Afar Margin, East Africa [Data set]. GFZ Data Services. https://doi.org/10.5880/FIDGEO.2020.017
  • 10.5880/fidgeo.2020.017
  • References
  • Zwaan, F., Rudolf, M., Corti, G., Keir, D., & Sani, F. (2020). Rheology of viscous materials from the CNR-IGG Tectonic Modelling Laboratory at the University of Florence (Italy) [Data set]. GFZ Data Services. https://doi.org/10.5880/FIDGEO.2020.018
  • 10.5880/fidgeo.2020.018
  • References
  • Zwaan, F., Rudolf, M., Pohlenz, A., Corti, G., Keir, D., & Sani, F. (2020). Ring-shear test data of feldspar sand from the CNR-IGG Tectonic Modelling Laboratory at the University of Florence (Italy) [Data set]. GFZ Data Services. https://doi.org/10.5880/FIDGEO.2020.019
  • 10.5880/fidgeo.2020.019
  • References
  • Zwaan, F., Corti, G., Keir, D., & Sani, F. (2020). A review of tectonic models for the rifted margin of Afar: Implications for continental break-up and passive margin formation. Journal of African Earth Sciences, 164, 103649. https://doi.org/10.1016/j.jafrearsci.2019.103649
  • 10.1016/j.jafrearsci.2019.103649
  • Cites
  • Zwaan, F., Corti, G., Sani, F., Keir, D., Muluneh, A. A., Illsley‐Kemp, F., & Papini, M. (2020). Structural Analysis of the Western Afar Margin, East Africa: Evidence for Multiphase Rotational Rifting. Tectonics, 39(7). Portico. https://doi.org/10.1029/2019tc006043
  • 10.1029/2019TC006043
  • Cites
Contact
  • Zwaan, Frank
  • University of Bern, Bern, Switzerland
  • frank.zwaan@geo.unibe.ch, fzwaan@hotmail.com
  • Corti, Giacomo
  • CNR Italian National Research Council, Italy
  • giacomo.corti@cnr.it
Citation Zwaan, F., Corti, G., Keir, D., & Sani, F. (2020). Images and videos of analogue centrifuge models exploring marginal flexure during rifting in Afar, East Africa [Data set]. GFZ Data Services. https://doi.org/10.5880/FIDGEO.2020.020