Skip to content

Role of External Processes in the Initiation and Modulation of Explosive Volcanism at Christiana-Santorini-Kolumbo. IODP Expedition 398 Hellenic Arc Volcanic Field

Abigail Metcalfe1 , Tim Druitt1, Katharina Pank2, Steffen Kutterolf2, Jonas Preine3, Christian Hübscher4, Paraskevi Nomikou5 and IODP Expedition 398 Participants

  • Affiliations: 1Laboratoire Magmas et Volcans, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1-3, D-24148 Kiel, Germany 3Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole MA, USA 4Institute of Geophysics, University of Hamburg, Bundesstrasse 55, D-20146 Hamburg, Germany 5Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, Athens, Greece

  • Presentation type: Poster

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

  • Poster Board Number: 61

  • Programme No: 3.11.21

  • Theme 3 > Session 11

Abstract

Large polygenetic volcanoes can produce catastrophic explosive eruptions with significant societal and environmental impacts. The drivers of such eruptions include interactions and feedbacks between internal magmatic processes and far-field tectonic stresses. Such processes operate on overlapping timescales, obscuring their relative contributions. IODP Expedition 398 deep-drilled the rift basin volcano-sedimentary fills around the Christiana-Santorini-Kolumbo Volcanic Field (CSKVF) in the South Aegean Volcanic Arc, in order to unravel volcano-tectonic links. Using major and trace element analyses of volcanic glass shards from marine tephras and the CSKVF onland record, we produce a high-resolution chronostratigraphy of the rift basins. The existing seismic stratigraphy allows us to correlate major eruption deposits to onlap surfaces. Calculation of the basin subsidence history allows us to recognize the contribution of multiple factors in the initiation and driving of volcanism at the CSKVF. Lithospheric rifting NE of Santorini began >2 Ma, and ultimately triggered a period of sustained caldera-forming explosive volcanism starting at ~250 ka (the Thera Pyroclastic Formation). At the CSKVF, rifting is inferred to have modulated the internal magmatic processes by increasing the flux of mantle-derived melts, fluids and heat into the crust. This unique dataset provides new insights into the volcanic history of the CSKVF and has implications for understanding volcanic processes at other rifted arcs.