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Spectrum of magma sediment interactions intensity related to sediment properties and water confinement

Ivana Torres-Ewert 1,4, Alison Graettinger1,Ingo Sonder2, Susan Sakimoto2,3  and Alan Whittington5

  • Affiliations: 1University of Missouri Kansas City, Earth and Environmental Science, Kansas City, MO, United States. 2University at Buffalo, Department of Geology, Buffalo, NY, United States. 3Space Science Institute, Boulder, CO, United States 4 Millennium Institute on Volcanic Risk Research---Ckelar Volcanoes, Antofagasta, Chile. 5 University of Texas San Antonio, San Antonio, Texas, United states

  • Presentation type: Talk

  • Presentation time: Thursday 14:45 - 15:00, Room S160

  • Programme No: 3.7.3

  • Theme 3 > Session 7

Abstract

Magma sediment interactions occur at any interface between magma and sediment, including near-surface intrusions (0-500 m) or at the base of lava flows. The energy intensity of the interaction and the resulting contact shape are highly variable, and the interaction parameters are not well constrained. To understand the interaction parameters (calm through vigorous), 13 experiments using 7 different sediments, 15 to 30 l of remelted basalt, two water availabilities (confined and unconfined) and two different phases of water (liquidand solid) were run. The magma-dry sediment interactions form textures controlled by the heat transfer and the ability of the melt to move through the pore spaces. When magma interacts with wet highly porous and permeable material, the abundance of water does not affect the textures formed. However, when magmas interact with low porosity and permeability sediment, the water phase and availability affected the interaction. (1) Liquid water available between 0 to 11 vol % limits the interaction to baked sediment zones. (2) When the water available is liquid (unconfined), between 29 to 34 vol %, billowed textures and sediment trapped in the meltsediment interface are formed. (3) When the water available is 34 to > 40 % (liquid or solid) and confined, billowed textures, sediment is incorporated in the melt-sediment interface and top melt surface, and sediment paths through the melt can be formed. Detailed magma sediment interfacial textures in experiments resemble natural textures in 71 Gulch and Guffey Butte, suggesting that these experiments scale well to general magmasediment interactions.