Analog and Numerical Modeling of Rift‐Rift‐Rift Triple Junctions

Maestrelli, Daniele; Brune, Sascha; Corti, Giacomo; Keir, Derek; Muluneh, Ameha; Sani, Federico

doi:10.1029/2022tc007491

Cited by 10 publications

(4 citation statements)

References 66 publications

(147 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The combination of two tectonic phases, an orthogonal direction of extension imposed on the southern rift branch, as well as a high velocity ratio (R=4) make this model the best fit for comparison with the Afar triple junction (Maestrelli et al, 2022).…”

Section: Model Deformationmentioning

confidence: 99%

“…Analog models must be correctly scaled in terms of geometry/length, rheology, kinematic and dynamic evolution in order to be a realistic replica of the natural process under investigation (Hubbert, 1937;Ramberg, 1981;Weijermars & Schmeling, 1986). Specifically, for this model, the scaling follows the strategy adopted in Maestrelli et a. (2022).…”

Section: Model Scalingmentioning

confidence: 99%

See 1 more Smart Citation

Reconciling plate motion and faulting at a rift-rift-rift triple junction

Maestrelli,

Sani,

Keir

et al. 2024

Geology

Self Cite

View full text Add to dashboard Cite

Rift-Rift-Rift triple junctions are regions where three plates interact, generating complex networks of variably oriented faults. While the geometry of the fault networks is easily constrained from their surface expression, what remains unclear is how the kinematics of faults and their interactions vary spatially, and how these relate to the unusual crustal motions that result from three plates diverging from each other. The Afar depression lies at the triple junction between the African, Arabian, and Somalian plates (in the Horn of Africa), where the unique combination of observational data from structural mapping, seismicity, and Global Navigation Satellite System (GNSS) allows us to understand the link between fault kinematics and plate motions. We complement these observations with an analog model to gain insights into how the patterns and directions of faults relate to overall plate motions. A key finding in both the model and nature is that some adjacent normal faults form at high angles and generate T-shaped structures. These purely normal faults are synchronously active, which means that the extension direction varies ∼90° locally. These kinematic contrasts in our model and in nature occur despite the relatively smooth pattern of overall surface motions. The results indicate that normal faults interacting at high angles to form the T-shaped structures can evolve synchronously within a stress field that varies gently in magnitude but dramatically in orientation over a few kilometers.

show abstract

Section: Model Deformationmentioning

confidence: 99%

Section: Model Scalingmentioning

confidence: 99%

Reconciling plate motion and faulting at a rift-rift-rift triple junction

Maestrelli,

Sani,

Keir

et al. 2024

Geology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Outside of the two magmatic segments, relatively higher strain rates occur in a ∼ NW‐SE oriented region between the DMH and ASAL segments and at the southern tip of the DMH segment. While the strain localization at the southern tip of the DMH could be related to the formation of the triple junction in central Afar (Maestrelli et al., 2022), the higher strain rate between the DMH and ASAL segments clearly indicates incipient linkage between them.…”

Section: Deformation Rate From Geodesymentioning

confidence: 99%

To Rotate or to Link? The Connection Between the Red Sea and Gulf of Aden Rifts in Central Afar

Muluneh,

Brune,

Pagli

et al. 2024

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Central Afar is shaped by the interaction between the Red Sea (RS) and Gulf of Aden (GoA) rifts. While there have been several studies conducted in the region, we know surprisingly little about the mechanism of connection between these two rift branches. Here we use high‐resolution 3D lithospheric scale geodynamic modeling to capture the evolution of linkage between the RS and GoA rifts in central Afar. Our results demonstrate that the two rifts initially overlap and interact across a broad zone of faulting and vertical axis block rotation. However, through time, rift overlap is abandoned in favor of direct linkage which generates a series of localized en‐echelon basins. The present‐day direct linkage between the two rifts is supported by geodetic observations. Our study reconciles previously proposed models for the RS and GoA rift connection by considering spatial and temporal evolution of the rifts.

show abstract

“…; e.g., see review in Corti (2012)). Many analog studies have focused attention on the role of pre-existing fabrics on rift-related faults at different scales (e.g., Bonini et al, 2023;Chattopadhyay & Chakra, 2013;Corti, 2008;Corti et al, 2007;Maestrelli et al, 2020Maestrelli et al, , 2022McClay & White, 1995;Molnar et al, 2019Molnar et al, , 2020Morley, 1999a;Sokoutis et al, 2007;Sun et al, 2010;Tron & Brun, 1991;Wang et al, 2021;Withjack & Jamison, 1986;Zwaan et al, 2016Zwaan et al, , 2021aZwaan et al, , 2021b, with some examples focusing on the reactivation of inherited heterogeneities in the brittle crust (e.g., Bellahsen & Daniel, 2005;Bonini et al, 2016Bonini et al, , 2023Brun & Tron, 1993;Corti et al, 2007;Maestrelli et al, 2020;Zwaan et al, 2021b). These studies used 1g models (i.e., models under normal gravity) to reproduce either distributed extension or focused deformation above a velocity discontinuity (VD) of a purely brittle or brittle/ductile system, showing that the orientation of the inherited fabrics with respect to the extension direction has a significant influence on reactivation and the resulting rift-related fault pattern.…”

mentioning

confidence: 99%

Influence of Inherited Brittle Fabrics on Continental Rifting: Insights From Centrifuge Experimental Modeling and Application to the East African Rift System

Zou,

Maestrelli,

Corti

et al. 2023

Tectonics

Self Cite

View full text Add to dashboard Cite

The presence of pre‐existing fabrics at all lithospheric scales has been proven to be of primary importance in controlling the evolution of continental rifts. Indeed, observations from natural examples show that even in conditions of orthogonal rifting, when extension should result in simple fault patterns dominated by normal faults orthogonal to extension vectors, inherited fabrics induce complex arrangements of differently‐oriented extension‐related structures. This paper explored the influence of inherited fabrics on rift‐related structures by using a series of analog models deformed in a centrifuge. The models reproduced a brittle‐ductile crustal system and considered the presence of pre‐existing discrete fabrics in the brittle crust in conditions of orthogonal narrow rifting. These fabrics were reproduced by cutting the brittle layer at different orientations with respect to the extension direction. Modeling shows pre‐existing fabrics have a significant influence on rift‐related faults, provided that the angle between inherited fabrics and the rift trend is less than 45°. In these conditions, fabrics cause prominent segmentation of rift‐related faults and induce the development of isolated depocenters. Pre‐existing fabrics strongly influence the geometry of extension‐related structures, resulting in curved fault patterns and en‐echelon arrangement of oblique faults. These findings provide insights into the development of continental rift systems in nature: our modeling shows indeed significant similarities (i.e., peculiar fault architecture and geometries) with the faults in different sectors of the East African Rift System (e.g., the Magadi and Bogoria basin, Kenya Rift), testifying that reactivation of inherited fabrics is a paramount process in shaping continental rifts.

show abstract

Analog and Numerical Modeling of Rift‐Rift‐Rift Triple Junctions

Cited by 10 publications

References 66 publications

Reconciling plate motion and faulting at a rift-rift-rift triple junction

Reconciling plate motion and faulting at a rift-rift-rift triple junction

To Rotate or to Link? The Connection Between the Red Sea and Gulf of Aden Rifts in Central Afar

Influence of Inherited Brittle Fabrics on Continental Rifting: Insights From Centrifuge Experimental Modeling and Application to the East African Rift System

Contact Info

Product

Resources

About