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The Evolution, Recurrence and Behaviour of Monogenetic Volcanism in the Gegham and Vardenis Volcanic Highlands (Armenia)

Priya Minhas1 , Katie Preece1, Khachatur Meliksetian2, Gevorg Navasardyan2, Edmond Grigoryan2, Darren Mark3

  • Affiliations: 1 Department of Geography, Faculty of Science and Engineering, Swansea University, Swansea, UK; 2 Institute of Geological Sciences, National Academy of Sciences of Armenia, Yerevan, Armenia; 3 NERC Argon Isotope Facility, Scottish Universities Environmental Research Centre, East Kilbride, UK 

  • Presentation type: Poster

  • Presentation time: Friday 16:30 - 18:00, Room Poster Hall

  • Poster Board Number: 147

  • Programme No: 3.4.27

  • Theme 3 > Session 4

Abstract

The Gegham and Vardenis Volcanic Highlands (Central Armenia) consist of >200 Quaternary monogenetic vents, which are predominantly scoria cones, formed primarily during Strombolian eruptions. Seismic swarms in the Gegham Volcanic Highlands can be linked to an active magmatic system, indicating the possibility of future eruptions, which could pose a threat to Armenia's capital city Yerevan (~20 km SW of Gegham), and its population of 1.1 million people. However, the timing of volcanism in the region is currently poorly constrained and the age of the last eruption is unknown, limiting volcanic hazard estimation. Here we utilize 40Ar/39Ar geochronology, geochemistry and statistical modelling techniques to reconstruct eruption timings, recurrence rates and the spatio-temporal evolution of this potentially active monogenetic volcanic field. Field work and whole rock geochemical analysis reveal that past eruptions have produced extensive lava flows, scoria, and spatter, with predominantly basaltic trachyandesite and trachyandesite compositions (51.8 - 63.2 wt. % SiO2). 31 new 40Ar/39Ar ages for monogenetic vents, reveal the timing and recurrence rate of volcanism in the Gegham Volcanic Highlands and provide ages for the youngest volcanic activity in the Vardenis Volcanic Highlands. Results from kernel density estimation reveal areas most likely to experience future vent formation, based singularly on the distribution of previously formed volcanic vents. Spatio-temporal modelling will estimate the location and timing of possible future eruptions. Overall, the findings from this project will contribute to volcanic hazard assessment in Armenia and will improve our understanding of the evolution of monogenetic volcanic fields in post-collisional geodynamic settings.