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Origin, source and hazard of young intraplate volcanism in Saudi Arabia.

Evelyn R. Garcia-Paredes1, Froukje van der Zwan1, Alican Aktağ2, Kaj Hoernle2, Konstantinos Thomaidis1, Murtadha Al Malallah1, Thor H. Hansteen2, Folkmar Hauff2.

  • Affiliations: 1Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology KAUST, Thuwal, Saudi Arabia 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany

  • Presentation type: Poster

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

  • Poster Board Number: 9

  • Programme No: 3.7.16

  • Theme 3 > Session 7

Abstract

Saudi Arabia hosts 13 small-scale intraplate volcanic fields, the so-called Harrats, covering a total area of ~90,000km². They are distributed along the western margin of the country at varying distances from the Red Sea spreading axis and the Afar mantle plume[1]. Magmatism of the Harrats began at ~30Ma, contemporaneous with the initiation of the Red Sea rifting, and has continued until historical times, with the most recent eruption in 1256AD, next to the holy city of Medinah[2,3]. The origin and source of the Harrats have been debated and are attributed to two endmember processes: 1) Upwelling of hot asthenospheric mantle from the Afar plume[4,5]; 2) Decompression melting caused by Red Sea extension and thinning of the lithosphere[6,7]. However, most studies investigated samples covering a large range of ages and thus may not be representative for the most recent volcanism. In this study, we focus on the youngest volcanic phase (<10,000ky) to assess the current origins, sources and hazards. We present whole rock major and trace elements, and radiogenic isotope data, along with mineral chemistry of the youngest volcanic products collected from 9 different Harrats throughout the country, to clarify why and how volcanism persists in this tectonically complex region and to evaluate the associated hazards of these small-scale volcanic fields. [1]Coleman et al.,1983,USGS Publications [2]Bosworth et al.,2016,Canadian Journal of EarthSciences [3]Downs et al.,2018,Geosphere [4]Bertrand et al.,2003,Chemical Geology [5]Lim et al.,2020,Journal of Geophysical Research:SolidEarth [6]Sanfilippo et al.,2019,Geological Setting, Paleoenvironment and Archaeology of the Red Sea [7]Sanfilippo et al.,2021,Frontiers in Earth Science