Abstract
The Main Ethiopian Rift (MER) represents an area where volcanism and tectonics interact to create closely linked volcano-tectonic features. This linkage is paramount in the axial portion of the rift, where magmatic segments localize several large peralkaline eruptive centres. Many of them evolved into caldera collapse (the best preserved of which are younger than <1Ma) generating large ignimbrites and registering the interaction between magmatism and tectonics along the MER. In this work we review the structure of the main collapsed calderas along the axial portion of the MER, to summarize the relationships between volcanism and tectonics proposed in the literature explaining their structural evolution. By doing this, we infer that tectonics had a strong influence in controlling the elongation of the majority of examined calderas. This control was induced by reactivation of inherited crustal fabrics or by stretching of the magma reservoirs under the MER regional stress field.
Highlights
We have reviewed the structural characteristics of the main collapsed calderas that occur along the axis of the Northern, Central and Southern sectors of the Main Ethiopian Rift
These perakaline calderas bear a strong linkage with the tectonics of this continental rift, showing several features suggesting a tectonic control on their development
Most of the examined calderas have a moderate to marked elongation and some of them (e.g., Fantale, Kone, Gedemsa and Corbetti calderas) have experienced a tectonic control exerted by preexisting faults reactivated during the collapse
Summary
The collapse of calderas is a volcano-tectonic process associated with the eruption/depletion or the lateral migration of magma from a magmatic chamber [e.g., Williams, 1941, Roche and Druitt, 2001, Druitt and Sparks, 1984, Lipman, 1997, Gudmundsson et al, 2016, Neal et al, 2019, Sigmundsson, 2019], causing. The volume of rock overlaying the latter to subside and form circular to elliptical depressions that may span from hundreds of meters to tens of kilometres in diameter This process implies the eruption up to thousands of km of magma, leading to a subsidence of the topographic caldera floor up to few kilometres [e.g., Druitt and Sparks, 1984, Lipman, 1984, 1997]. The Main Ethiopian Rift (MER), in the East African Rift System, does not make exception, showing hundreds of major volcanic centres along its whole length (and surrounding areas) Some of these volcanic systems eventually evolved into caldera collapse, leading to the emplacement of large ignimbritic sheets and plinian pumice fallout deposits with a peralkaline composition that cover the rift floor and a large part of the surrounding areas [Peccerillo et al, 2003 and reference therein]. We aim to summarise in which cases tectonic structures may have influenced the development of the examined caldera collapse systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
