Southampton Geologists/Geophysicists study Boset-Bericha Volcano Complex, East African Rift

The G&G research group was recently (March 2015) joined by new PhD student Melanie Siegburg who will study the Boset-Bericha volcano complex in Ethiopia. Together with PhD supervisors Jon Bull, Tom Gernon and Derek Keir, and fellow PhD student Finn Illsley-Kemp, Melanie completed reconnaissance fieldwork, including some field sampling, in April-May 2015. “Boset” is the closest Holocene volcano to the population centre of Addis Ababa and its eruptive history and hazard is poorly constrained, although the presence of fumaroles and some fresh looking lava flows suggests it has been recently active. The fieldwork was completed in collaboration with Addis Ababa University.

Fieldwork focused on collecting rock samples that will allow the determination of the chronology of magmatic products (lavas and pumice) as well as tectono-magmatic interactions. The photograph below shows fieldwork on sections through pumice exposed within a dry river bed. Fieldwork was completed towards the end of Ethiopia’s dry season, which meant the landscape is parched, and the field party carried plenty of water.

Melanie’s PhD will focus on the interaction of magma ascent and eruption with crustal extension. Melanie will utilize recently collected LiDAR data over the volcano, as well as use 40Ar/39Ar geochronology and C14 dating of organic matter preserved between lava flows to construct a robust and accurate/precise eruption chronology, as well as constrain fault-magmatic interaction. High-resolution Pb isotopes will be used to determine the crustal and mantle contributions to rift magmatism.

melanie and ermius

Melanie Siegburg (Southampton PhD student) and Ermius (masters student from Addis Ababa University) completing logging of a sequence of pumice layers while overlooked by children from a local primary school.