Evolution of the northern Main Ethiopian rift: birth of a triple junction

Wolfenden, E.; Ebinger, C. J.; Yirgu, Gezahegn; Deino, Alan L.; Ayalew, Dereje

doi:10.1016/j.epsl.2004.04.022

Cited by 393 publications

(490 citation statements)

References 37 publications

Supporting

Mentioning

471

Contrasting

Order By: Relevance

“…South of ∼ 7°N border fault stratigraphy shows that faulting was well established by ∼ 18 Ma (Bonini et al, 2005;Ebinger et al, 1993;WoldeGabriel et al, 1990). Between 7°N and 10°N, however, syn-rift growth of sedimentary and volcanic sequences, constrained by fission track thermochronology on exposed basement, indicates that rapid growth of border faults may have started somewhat later, between 6 and 11 Ma (Abebe et al, 2010;Bonini et al, 2005;Ukstins et al, 2002;Wolfenden et al, 2004) (Fig. 2).…”

Section: Rift Initiationmentioning

confidence: 99%

The development of extension and magmatism in the Red Sea rift of Afar

et al. 2013

View full text Add to dashboard Cite

Despite the importance of continental breakup in plate tectonics, precisely how extensional processes such as brittle faulting, ductile plate stretching, and magma intrusion evolve in space and time during the development of new ocean basins remains poorly understood. The rifting of Arabia from Africa in the Afar depression is an ideal natural laboratory to address this problem since the region exposes subaerially the tectonically active transition from continental rifting to incipient seafloor spreading. We review recent constraints on along-axis variations in rift morphology, crustal and mantle structure, the distribution and style of ongoing faulting, subsurface magmatism and surface volcanism in the Red Sea rift of Afar to understand processes ultimately responsible for the formation of magmatic rifted continental margins. Our synthesis shows that there is a fundamental change in rift morphology from central Afar northward into the Danakil depression, spatially coincident with marked thinning of the crust, an increase in the volume of young basalt flows, and subsidence of the land towards and below sea-level. The variations can be attributed to a northward increase in proportion of extension by ductile plate stretching at the expense of magma intrusion. This is likely in response to a longer history of localised heating and weakening in a narrower rift. Thus, although magma intrusion accommodates strain for a protracted period during rift development, the final stages of breakup are dominated by a phase of plate stretching with a shift from intrusive to extrusive magmatism. This late-stage pulse of decompression melting due to plate thinning may be responsible for the formation of seaward dipping reflector sequences of basalts and sediments, which are ubiquitous at magmatic rifted margins worldwide.

show abstract

Section: Rift Initiationmentioning

confidence: 99%

The development of extension and magmatism in the Red Sea rift of Afar

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Individual large mantle plumes have commonly been linked to magmatism, rifting and triple junction formation in flood basalt provinces like the Afar Volcanic Province (Garfunkel & Beyth, 2006) and the NAIP (Section 3), but other authors have argued that the East African rift system in general developed in response to global plate reorganizations (e.g. Wolfenden et al 2004). The common occurrence of dissimilar geochemical and isotopic signatures in rift-related basalts, within confined areas from, for example, the East African rift system (Barrat et al 1998;Orihashi, Al-Jailani & Nagao, 1998;Rogers et al 2000 (Blatt & Tracy, 1995).…”

Section: C the Naip In The Context Of Rift Geometry And Triple Junmentioning

confidence: 99%

“…The association between enhanced magmatism and rift geometry, that is, triple junctions (Sears, George & Winne, 2005) or kinks in rifting trends (Abdel-Rahman & Nassar, 2004;Wolfenden et al 2004), is well known. In this context the evolution of the protoIceland region may be of relevance for the Early Palaeogene NAIP magmatism, as the great increase in the volume of magma production in that area in Middle Palaeogene times (Foulger & Anderson, 2005) coincided with the establishment of the ridge-ridgetransform triple junction (Reykjanes ridge-Kolbeinsey ridge-Faroe transform fault) recorded by Bott (1985).…”

Section: C the Naip In The Context Of Rift Geometry And Triple Junmentioning

confidence: 99%

The onset of the North Atlantic Igneous Province in a rifting perspective

et al. 2009

View full text Add to dashboard Cite

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract -The processes that led to the onset and evolution of the North Atlantic Igneous Province (NAIP) have been a theme of debate in the past decades. A popular theory has been that the impingement on the lower lithosphere of a hot mantle plume (the 'Ancestral Iceland' plume) initiated the first voluminous outbursts of lava and initiated rifting in the North Atlantic area in Early Palaeogene times. Here we review previous studies in order to set the NAIP magmatism in a time-space context. We suggest that global plate reorganizations and lithospheric extension across old orogenic fronts and/or suture zones, aided by other processes in the mantle (e.g. local or regional scale upwellings prior to and during the final Early Eocene rifting), played a role in the generation of the igneous products recorded in the NAIP for this period. These events gave rise to the extensive Paleocene and Eocene igneous rocks in W Greenland, NW Britain and at the conjugate E Greenland-NW European margins. Many of the relatively large magmatic centres of the NAIP were associated with transient and geographically confined doming in Early Paleocene times prior to the final break-up of the North Atlantic area.

show abstract

“…In addition to being one of the rare examples of RRR junction, the Afar region is above water and thus an accessible case study to understand the short-term evolution of a triple junction. At the regional scale, the kinematics of this RRR junction has been the target of many studies focusing on the Neogene-Pliocene deformation that points out the importance of overlapping spreading axes generating a complex transfer zone with deformation distributed over a wide region (Manighetti et al 1997;Wolfenden et al 2004). However, dense measurements of the present-day deformation field are missing to draw the current kinematics of the triple junction, where active divergent plate boundaries and transfer zones are susceptible to rapid changes due both to the youth of the structures and to the discontinuous availability of magma supply Patriat & Courtillot 1984).…”

Section: Introductionmentioning

confidence: 99%

Current deformation in Central Afar and triple junction kinematics deduced from GPS and InSAR measurements

Doubre¹,

Déprez²,

Masson³

et al. 2016

Geophys. J. Int.

View full text Add to dashboard Cite

S U M M A R YKinematics of divergent boundaries and Rift-Rift-Rift junctions are classically studied using long-term geodetic observations. Since significant magma-related displacements are expected, short-term deformation provides important constraints on the crustal mechanisms involved both in active rifting and in transfer of extensional deformation between spreading axes. Using InSAR and GPS data, we analyse the surface deformation in the whole Central Afar region in detail, focusing on both the extensional deformation across the Quaternary magmato-tectonic rift segments, and on the zones of deformation transfer between active segments and spreading axes. The largest deformation occurs across the two recently activated Asal-Ghoubbet (AG) and Manda Hararo-Dabbahu (MH-D) magmato-tectonic segments with very high strain rates, whereas the other Quaternary active segments do not concentrate any large strain, suggesting that these rifts are either sealed during interdyking periods or not mature enough to remain a plate boundary. Outside of these segments, the GPS horizontal velocity field shows a regular gradient following a clockwise rotation of the displacements from the Southeast to the East of Afar, with respect to Nubia. Very few shallow creeping structures can be identified as well in the InSAR data. However, using these data together with the strain rate tensor and the rotations rates deduced from GPS baselines, the present-day strain field over Central Afar is consistent with the main tectonic structures, and therefore with the long-term deformation. We investigate the current kinematics of the triple junction included in our GPS data set by building simple block models. The deformation in Central Afar can be described by adding a central microblock evolving separately from the three surrounding plates. In this model, the northern block boundary corresponds to a deep EW-trending trans-tensional dislocation, locked from the surface to 10-13 km and joining at depth the active spreading axes of the Red Sea and the Aden Ridge, from AG to MH-D rift segments. Over the long-term, this plate configuration could explain the presence of the en-échelon magmatic basins and subrifts. However, the transient behaviour of the spreading axes implies that the deformation in Central Afar evolves depending on the availability of magma supply within the well-established segments.

show abstract

Evolution of the northern Main Ethiopian rift: birth of a triple junction

Cited by 393 publications

References 37 publications

The development of extension and magmatism in the Red Sea rift of Afar

The development of extension and magmatism in the Red Sea rift of Afar

The onset of the North Atlantic Igneous Province in a rifting perspective

Current deformation in Central Afar and triple junction kinematics deduced from GPS and InSAR measurements

Contact Info

Product

Resources

About