Volcano‐Tectonic Evolution of the Christiana‐Santorini‐Kolumbo Rift Zone

Abstract

The interplay of volcanism and tectonism has shaped many volcanic systems across the world (Acocella, 2021). Regional tectonics weakens the crust through increased faulting and fracturing creating pathways for magmatic fluids to ascend to the surface, although the controlling mechanisms remain elusive (e.g., Hill et al., 2002;Manga & Brodsky, 2006). Our current knowledge of volcano-tectonic feedback mechanisms is based mostly on the interplay of earthquakes and volcanic eruptions on time scales ranging from minutes to decades by direct observations or historic records (e.g., Manga & Brodsky, 2006;Watt et al., 2009). These studies revealed that tectonic movements can change stress levels in the crust and the underlying mantle, influencing production and ascent rates, as well as sizes and explosivities of eruptions. In turn, volcanism can alter the stress of the crust by accommodating extensional strain and inhibiting the formation of faults (Faulds & Varga, 1998) highlighting complex feedback

Spatio-temporal evolution of the Kolumbo Volcanic Chain and its link to the volcanic plumbing system of Santorini

“…An important influence of the local tectonic system on the emplacement of volcanoes at the CSK field has been suggested by previous studies due to the overall linear alignment of volcanic edifices parallel to the NE-SW striking regional rift system (e.g., Druitt et al, 1999;Dimitriadis et al, 2009;Feulliet, 2013, Heath et al, 20192021;Preine et al, 2022c). The two most prominent volcano-tectonic lineaments are the Kameni and Kolumbo lines, which strike NE-SW intersecting the northern part of the Santorini caldera (Fig.…”

“…Formed by the partial melting of the subducting African slab beneath the Eurasian plate, volcanism along the CSK field evolved in four phases, which initiated in the Late Pliocene with the emergence of the Christiana Volcano southwest of present-day Santorini (Phase 1; Piper et al, 2007;Preine et al, 2022a). The subsequent formation of major NE-SW trending fault systems in Middle Pleistocene correlates with the emergence of the early Kolumbo and Poseidon centers (Phase 2), which deposited volcaniclastic material in the Christiana and Anhydros Basins, respectively (Hübscher et al, 2015;Preine et al, 2022a;2022c). The KVC is thought to have formed after a major tectonic pulse that triggered a cascade of large-scale mass-wasting events at Santorini and Kolumbo (Phase 3; Preine et al, 2022b;2022c).…”

“…The subsequent formation of major NE-SW trending fault systems in Middle Pleistocene correlates with the emergence of the early Kolumbo and Poseidon centers (Phase 2), which deposited volcaniclastic material in the Christiana and Anhydros Basins, respectively (Hübscher et al, 2015;Preine et al, 2022a;2022c). The KVC is thought to have formed after a major tectonic pulse that triggered a cascade of large-scale mass-wasting events at Santorini and Kolumbo (Phase 3; Preine et al, 2022b;2022c). This series of events marks the beginning of the third phase, which is thought to include not only the formation of the KVC, but also buried volcanic cones southwest of Santorini, and the evolution of the onshore exposed Akrotiri rhyolitic center, the Peristeria stratovolcano, and the Akrotiri cinder cones (Druitt et al, 1999;Preine et al, 2022a).…”

“…In the last phase (since ~360 ka; Phase 4), a major tectonic event occurred in the Santorini-Anafi Basin, followed by the onset of highly explosive volcanism at Santorini, which corresponds to a distinct change in the primitive melt diversity (Flaherty et al, 2022). This explosive volcanism formed the Thera Pyroclastic Formation, while Kolumbo remained active producing two major eruptions (Preine et al, 2022a(Preine et al, , 2022c). Kolumbo's five units (K1-K5) formed over the course of more than 1 million years (Hübscher et al, 2015;Preine et al, 2022a).…”

“…Since the entire CSK field lies in the same regional rift system, it is subject to a common external tectonic control (e.g., Heath et al, 2019;2021;Preine et al, 2022c). There is an ongoing discussion regarding the role of regional (> 10 km length) and local (< 10 km length) faults on the emplacement of volcanic features (Hübscher et al, 2015;Heath et al, 2021) and regarding the connection of the plumbing system between the different volcanic centers.…”