High-resolution estimates of Nubia–Somalia plate motion since 20 Ma from reconstructions of the Southwest Indian Ridge, Red Sea and Gulf of Aden

Controls of inherited lithospheric heterogeneity on rift linkage: Numerical and analog models of interaction between the Kenyan and Ethiopian rifts across the Turkana depression

“…The numerical models predict a progressive narrowing of deformation within the preexisting Mesozoic rift, which is in agreement with the eastward migration of deformation from basins in the western portion of the Turkana depression to more central domains (e.g., Lake Turkana itself and surrounding areas) [ Ebinger et al , , and references therein]. However, the sedimentary basins west of Lake Turkana, which started developing prior to ~25 Ma, likely predate Nubia‐Somalia divergence [ Iaffaldano et al , ; DeMets and Merkouriev , ] and therefore were not strictly related to the Tertiary rifting event in a strict sense. Consequently, other processes, such as deep‐seated asthenospheric processes (plume impingement at the base of the lithosphere) [ Ebinger et al , ] or strain hardening between episodes of extension [ Morley et al , ], likely contributed to the observed evolution.…”

“…The amount of total extension, the velocity of plate motion in the past, and the timing of initiation of Nubia‐Somalia motion are not well constrained, as different plate motion models predict different values. Plate tectonic models that integrate seafloor spreading reconstructions into plate circuits indicate that divergence between the major plates started before 16 Ma [ DeMets and Merkouriev , ], likely at ~20 Ma [ Iaffaldano et al , ], with maximum values of extension of approximately 80 km [ Iaffaldano et al , ]. Geological data, however, seem to point to a later rift activation (at 10–12 Ma) [see Balestrieri et al , , and references therein] and lower amount of total extension (~30–40 km) [ Corti , , and references therein].…”

“…The tectonic setting of this area is controlled by long-term divergence between the Nubian and Somalian plates, which is currently occurring in a roughly E-W direction at rates of a few millimeters per year [Saria et al, 2014;Stamps et al, 2014]. Recent plate motion models [Iaffaldano et al, 2014;DeMets and Merkouriev, 2016] suggest that this direction of extension has likely remained steady during rift development (i.e., in the last 10-12 Myr).…”

Uncertainties in Trends of Young Hot Spot Tracks

“…For this test, the data are fit significantly better (p = 0.97) in the plate-by-plate analysis, validating the result obtained by Wang et al (2017) for an analysis with equally weighted trends. We also cannot categorically exclude the possibility that the misfits are due to errors in relative plate angular velocities or to nonrigidity of one or more plates or to a recent change in motion of one or more of the plates (e.g., the Pacific plate (Cox & Engebretson, 1985;DeMets & Merkouriev, 2016)). We also cannot categorically exclude the possibility that the misfits are due to errors in relative plate angular velocities or to nonrigidity of one or more plates or to a recent change in motion of one or more of the plates (e.g., the Pacific plate (Cox & Engebretson, 1985;DeMets & Merkouriev, 2016)).…”

Along‐Axis Variations of Rift Width in a Coupled Lithosphere‐Mantle System, Application to East Africa

“…We initiate a plume by seeding a 200‐km‐radius temperature anomaly at the base of the upper mantle, 300 K warmer than the surroundings. We simulate tectonic forcing by applying constant divergent velocity normal to two opposing model boundaries at a rate derived from Neogene plate kinematic reconstructions (DeMets & Merkouriev, ; Saria et al, ).…”