The submarine eruption of the Bombarda volcano, Milos Island, Cyclades, Greece

• Published in: Bulletin of volcanology Vol. 65; no. 4; pp. 282 - 293
• Main Authors: RINALDI, M, CAMPOS VENUTI, M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-05-2003; Springer Nature B.V
• Subjects: Breccia; Carapace; Crystalline rocks; Earth sciences; Earth, ocean, space; Exact sciences and technology; Explosions; Geology; Igneous and metamorphic rocks petrology, volcanic processes, magmas; Juveniles; Lava; Lava domes; Lithic; Obsidian; Pumice; Sea level; Seismic activity; Volcanic eruptions; Volcanic fields; Volcanism; Volcanoes; Volcanology; Greece; Cyclades; Southern Europe; Greek Aegean Islands; Milos; pumice; domes; Greece; lava; lava flows; Subaqueous explosive eruption; volcanic ash; emplacement; succession; models; Volcaniclastic mass flow; Europe; volcanic rocks; stratigraphic columns; boulders; explosive eruptions; Felsic monogenetic volcano; Milos Island; igneous rocks; transport; submarine volcanism; chemical analysis; magmatic breccia; volume; pyroclastics; volcanic fields; X-ray fluorescence; volcaniclastics; Lava dome; collapse; sea level
• ISSN: 0258-8900; 1432-0819
• DOI: 10.1007/s00445-002-0260-z

The Milos volcanic field includes a well-exposed volcaniclastic succession which records a long history of submarine explosive volcanism. The Bombarda volcano, a rhyolitic monogenetic center, erupted ∼1.7 Ma at a depth <200 m below sea level. The aphyric products are represented by a volcaniclastic apron (up to 50 m thick) and a lava dome. The apron is composed of pale gray juvenile fragments and accessory lithic clasts ranging from ash to blocks. The juvenile clasts are highly vesicular to non-vesicular; the vesicles are dominantly tube vesicles. The volcaniclastic apron is made up of three fades: massive to normally graded pumice-lithic breccia, stratified pumice-lithic breccia, and laminated ash with pumice blocks. We interpret the apron beds to be the result of water-supported, volcaniclastic mass-How emplacement, derived directly from the collapse of a small-volume, subaqueous eruption column and from syn-eruptive, down-slope resedimentation of volcaniclastic debris. During this eruptive phase, the activity could have involved a complex combination of phreatomagmatic explosions and minor submarine effusion. The lava dome, emplaced later in the source area, is made up of flow-banded lava and separated from the apron by an obsidian carapace a few meters thick. The near-vertical orientation of the carapace suggests that the dome was intruded within the apron. Remobilization of pyroclastic debris could have been triggered by seismic activity and the lava dome emplacement.