The spatial and volcanic evolution of Ayelu, Abida and Yangudi volcanoes in the Northern Main Ethiopian Rift – Southern Afar, Ethiopia

Abstract

The region between the Northern Main Ethiopian Rift and Southern Afar is a key link between two important sectors of the East African Rift System. Recent volcanism in this area occurs as a chain of NNE-SSW trending axial Quaternary volcanoes and volcanic fields, segmented and offset laterally by WNW-ESE trending right-steps. Here, we present the first whole-rock major element geochemical dataset from volcanoes in one such volcanic segment, the Adda'do Magmatic Segment (AMS). We combine these geochemical data with detailed remote sensing mapping of the region, to produce a relative chronology of the volcanic units. We investigate the volcanic evolution and composition of these volcanoes and find that all three volcanoes in the AMS exhibit similar evolutionary patterns, beginning with a base of older (presumed Plio-Pleistocene age) lavas, followed by a period of large-volume evolved magmatism, and recent basaltic-intermediate eruptions. Our results show evidence for at least three cycles of mafic-to-felsic evolution in the southern AMS, in agreement with earlier studies, indicating that the AMS has long been a site of volcanic activity.