Bulletin of Volcanology

, 77:102

The hydrothermal alteration of cooling lava domes

  • Jessica L. Ball
  • Philip H. Stauffer
  • Eliza S. Calder
  • Greg A. Valentine
Research Article

DOI: 10.1007/s00445-015-0986-z

Cite this article as:
Ball, J.L., Stauffer, P.H., Calder, E.S. et al. Bull Volcanol (2015) 77: 102. doi:10.1007/s00445-015-0986-z

Abstract

Hydrothermal alteration is a recognized cause of volcanic instability and edifice collapse, including that of lava domes or dome complexes. Alteration by percolating fluids transforms primary minerals in dome lavas to weaker secondary products such as clay minerals; moreover, secondary mineral precipitation can affect the porosity and permeability of dome lithologies. The location and intensity of alteration in a dome depend heavily on fluid pathways and availability in conjunction with heat supply. Here we investigate postemplacement lava dome weakening by hydrothermal alteration using a finite element numerical model of water migration in simplified dome geometries. This is combined with the rock alteration index (RAI) to predict zones of alteration and secondary mineral precipitation. Our results show that alteration potential is highest at the interface between the hot core of a lava dome and its clastic talus carapace. The longest lived alteration potential fields occur in domes with persistent heat sources and permeabilities that allow sufficient infiltration of water for alteration processes, but not so much that domes cool quickly. This leads us to conclude that alteration-induced collapses are most likely to be shallow seated and originate in the talus or talus/core interface in domes which have a sustained supply of magmatic heat. Mineral precipitation at these zones of permeability contrast could create barriers to fluid flow, potentially causing gas pressurization which might promote deeper seated and larger volume collapses. This study contributes to our knowledge of how hydrothermal alteration can affect lava domes and provides constraints on potential sites for alteration-related collapses, which can be used to target hazard monitoring.

Keywords

Hydrothermal alteration Lava dome Lava dome collapse Numerical modeling 

Supplementary material

445_2015_986_MOESM1_ESM.docx (76 kb)
ESM 1(DOCX 75 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Jessica L. Ball
    • 1
    • 2
  • Philip H. Stauffer
    • 3
  • Eliza S. Calder
    • 4
  • Greg A. Valentine
    • 1
  1. 1.Department of GeologyUniversity at BuffaloBuffaloUSA
  2. 2.United States Geological SurveyMenlo ParkUSA
  3. 3.Los Alamos National LaboratoryLos AlamosUSA
  4. 4.School of GeoSciencesUniversity of EdinburghEdinburghUK

Personalised recommendations