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Magma dynamics within a basaltic conduit revealed by textural and compositional features of erupted ash: the December 2015 Mt. Etna paroxysms.
Author(s)
Language
English
Obiettivo Specifico
5V. Dinamica dei processi eruttivi e post-eruttivi
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/7 (2017)
Pages (printed)
4805
Issued date
July 6, 2017
Subjects
Abstract
In December 2015, four violent explosive episodes from Mt. Etna’s oldest summit crater, the Voragine,
produced eruptive columns extending up to 15 km a.s.l. and significant fallout of tephra up to a hundred
km from the vent. A combined textural and compositional study was carried out on pyroclasts from
three of the four tephra deposits sampled on the volcano at 6 to 14 km from the crater. Ash fractions
(Φ = 1–2) were investigated because these grain sizes preserve the magma properties unmodified by
post- emplacement processes. Results were used to identify processes occurring in the conduit during
each single paroxysm and to understand how they evolve throughout the eruptive period. Results
indicate that the magmatic column is strongly heterogeneous, mainly with respect to microlite, vescicle
content and melt composition. During each episode, the heterogeneities can develop at time scales as
short as a few tens of hours, and differences between distinct episodes indicate that the time scale for
completely refilling the system and renewing magma is in the same order of magnitude. Our data also
confirm that the number and shape of microlites, together with melt composition, have a strong control
on rheological properties and fragmentation style.
produced eruptive columns extending up to 15 km a.s.l. and significant fallout of tephra up to a hundred
km from the vent. A combined textural and compositional study was carried out on pyroclasts from
three of the four tephra deposits sampled on the volcano at 6 to 14 km from the crater. Ash fractions
(Φ = 1–2) were investigated because these grain sizes preserve the magma properties unmodified by
post- emplacement processes. Results were used to identify processes occurring in the conduit during
each single paroxysm and to understand how they evolve throughout the eruptive period. Results
indicate that the magmatic column is strongly heterogeneous, mainly with respect to microlite, vescicle
content and melt composition. During each episode, the heterogeneities can develop at time scales as
short as a few tens of hours, and differences between distinct episodes indicate that the time scale for
completely refilling the system and renewing magma is in the same order of magnitude. Our data also
confirm that the number and shape of microlites, together with melt composition, have a strong control
on rheological properties and fragmentation style.
References
1. Behncke, B. et al. The 2011–2012 summit activity of Mount Etna: Birth, growth and products of the new SE crater. Journal of
Volcanology and Geothermal Research 270, 10–21 (2014).
2. Branca, S. & Del Carlo, P. Types of eruptions of Etna volcano AD 1670-2003: implications for short-term eruptive behaviour. Bulletin
of Volcanology 67, 732–742 (2005).
3. Taddeucci, J., Pompilio, M. & Scarlato, P. Monitoring the explosive activity of the July–August 2001 eruption of Mt. Etna (Italy) by
ash characterization. Geophys. Res. Lett. 29, 1230 (2002).
4. Taddeucci, J., Pompilio, M. & Scarlato, P. Conduit processes during the July–August 2001 explosive activity of Mt. Etna (Italy):
inferences from glass chemistry and crystal size distribution of ash particles. Journal of Volcanology and Geothermal Research 137,
33–54 (2004).
5. Andronico, D., Cristaldi, A., del Carlo, P. & Taddeucci, J. Shifting styles of basaltic explosive activity during the 2002–03 eruption of
Mt. Etna, Italy. Journal of Volcanology and Geothermal Research 180, 110–122 (2009).
6. Polacci, M., Corsaro, R. A. & Andronico, D. Coupled textural and compositional characterization of basaltic scoria: Insights into the
transition from Strombolian to fire fountain activity at Mount Etna, Italy. Geology 34, 201 (2006).
7. Corsaro, R. A. & Pompilio, M. Magma dynamics in the shallow plumbing system of Mt. Etna as recorded by compositional variations
in volcanics of recent summit activity (1995–1999). Journal of Volcanology and Geothermal Research 137, 55–71 (2004).
8. Vulpiani, G., Ripepe, M. & Valade, S. Mass discharge rate retrieval combining weather radar and thermal camera observations.
Journal of Geophysical Research Solid Earth 121, 5679–5695 (2016).
9. Rosi, M. et al. Stromboli volcano, Aeolian Islands (Italy): present eruptive activity and hazards. Geological Society London Memoirs
37, 473–490 (2013).
10. Houghton, B. & Wilson, C. A vesicularity index for pyroclastic deposits. Bulletin of Volcanology 51, 451–462 (1989).
11. Walker, G. & Croasdale, R. Characteristics of some basaltic pyroclastics. Bulletin Volcanologique 35, 303–317 (1972).
12. Corsaro, R. & Pompilio, M. Dynamics of magmas at Mount Etna. Geophysical Monograph 143, 91–110 (2004).
13. Armienti, P., Pareschi, M. T., Innocenti, F. & Pompilio, M. Effects of magma storage and ascent on the kinetics of crystal growth.
Contrib Mineral Petr 115, 402–414 (1994).
14. Morgan, D. J. & Jerram, D. A. On estimating crystal shape for crystal size distribution analysis. Journal of Volcanology and
Geothermal Research 154, 1–7 (2006).
15. Marsh, B. D. Crystal size distribution (CSD) in rocks and the kinetics and dynamics of crystallization. Contrib Mineral Petr 99,
277–291 (1988).
16. Higgins, M. D. Verification of ideal semi-logarithmic, lognormal or fractal crystal size distributions from 2D datasets. Journal of
Volcanology and Geothermal Research 154, 8–16 (2006).
17. Fornaciai, A., Perinelli, C., Armienti, P. & Favalli, M. Crystal size distributions of plagioclase in lavas from the July–August 2001
Mount Etna eruption. Bulletin of Volcanology 77, 70–15 (2015).
18. Armienti, P. Decryption of Igneous Rock Textures: Crystal Size Distribution Tools. Reviews in Mineralogy and Geochemistry 69,
623–649 (2008).
19. Le Maitre, R. W. et al. Igneous Rocks: A Classification and Glossary of Terms. (Cambridge University Press, 2002).
20. Kamenetsky, V. S. et al. Arrival of extremely volatile-rich high-Mg magmas changes explosivity of Mount Etna. Geology 35, 255–4
(2007).
21. Corsaro, R. A., Miraglia, L. & Pompilio, M. Petrologic evidence of a complex plumbing system feeding the July-August 2001
eruption of Mt. Etna, Sicily, Italy. Bulletin of Volcanology 69, 401–421 (2007).
22. Andronico, D. et al. A multi-disciplinary study of the 2002–03 Etna eruption: insights into a complex plumbing system. Bulletin of
Volcanology 67, 314–330 (2005).
23. Burton, M. R. et al. Etna 2004–2005: An archetype for geodynamically-controlled effusive eruptions. Geophys. Res. Lett. 32, (2005).
24. Ghiorso, M. & Sack, R. Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model
for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures.
Contrib Mineral Petr 119, 197–212 (1995).
25. Smith, P. M. & Asimow, P. Adiabat_1ph: A new public front-end to the MELTS, pMELTS, and pHMELTS models. Geochem.
Geophys. Geosyst 6, 1–8 (2005).
26. Mueller, S., Llewellin, E. W. & Mader, H. M. The rheology of suspensions of solid particles. Proceedings of the Royal Society A:
Mathematical, Physical and Engineering Sciences 466, 1201–1228 (2010).
27. Mader, H. M., Llewellin, E. W. & Mueller, S. P. The rheology of two-phase magmas: A review and analysis. Journal of Volcanology and
Geothermal Research 257, 135–158 (2013).
28. Giordano, D. & Dingwell, D. Non-Arrhenian multicomponent melt viscosity: a model. Earth Planet Sc Lett 208, 337–349 (2003).
29. Vona, A., Romano, C., Dingwell, D. & Giordano, D. The rheology of crystal-bearing basaltic magmas from Stromboli and Etna.
Geochim Cosmochim Acta 75, 3214–3236, doi:10.1016/j.gca.2014.04.007 (2011).
30. Cimarelli, C., Di Traglia, F. & Taddeucci, J. Basaltic scoria textures from a zoned conduit as precursors to violent Strombolian
activity. Geology 38, 439–442 (2010).
31. Houghton, B. et al. The influence of conduit processes on changes in style of basaltic Plinian eruptions: Tarawera 1886 and Etna 122
BC. Journal of Volcanology and Geothermal Research 137, 1–14 (2004).
32. Sable, J. E., Houghton, B. F., del Carlo, P. & Coltelli, M. Changing conditions of magma ascent and fragmentation during the Etna
122 BC basaltic Plinian eruption: Evidence from clast microtextures. Journal of Volcanology and Geothermal Research 158, 333–354
(2006).
33. Lautze, N. C. & Houghton, B. F. Physical mingling of magma and complex eruption dynamics in the shallow conduit at Stromboli
volcano, Italy. Geology 33, 425 (2005).
34. Pioli, L. et al. Explosive dynamics of violent Strombolian eruptions: The eruption of Paricutin Volcano 1943–1952 (Mexico). Earth
Planet Sc Lett 271, 359–368 (2008).
35. D’Oriano, C., Cioni R., Bertagnini, A., Andronico, D. & Cole, P. D. Dynamics of ash-dominated eruptions at Vesuvius: the post-512
AD AS1a event. Bulletin of Volcanology 73, 699–715 (2011).
Volcanology and Geothermal Research 270, 10–21 (2014).
2. Branca, S. & Del Carlo, P. Types of eruptions of Etna volcano AD 1670-2003: implications for short-term eruptive behaviour. Bulletin
of Volcanology 67, 732–742 (2005).
3. Taddeucci, J., Pompilio, M. & Scarlato, P. Monitoring the explosive activity of the July–August 2001 eruption of Mt. Etna (Italy) by
ash characterization. Geophys. Res. Lett. 29, 1230 (2002).
4. Taddeucci, J., Pompilio, M. & Scarlato, P. Conduit processes during the July–August 2001 explosive activity of Mt. Etna (Italy):
inferences from glass chemistry and crystal size distribution of ash particles. Journal of Volcanology and Geothermal Research 137,
33–54 (2004).
5. Andronico, D., Cristaldi, A., del Carlo, P. & Taddeucci, J. Shifting styles of basaltic explosive activity during the 2002–03 eruption of
Mt. Etna, Italy. Journal of Volcanology and Geothermal Research 180, 110–122 (2009).
6. Polacci, M., Corsaro, R. A. & Andronico, D. Coupled textural and compositional characterization of basaltic scoria: Insights into the
transition from Strombolian to fire fountain activity at Mount Etna, Italy. Geology 34, 201 (2006).
7. Corsaro, R. A. & Pompilio, M. Magma dynamics in the shallow plumbing system of Mt. Etna as recorded by compositional variations
in volcanics of recent summit activity (1995–1999). Journal of Volcanology and Geothermal Research 137, 55–71 (2004).
8. Vulpiani, G., Ripepe, M. & Valade, S. Mass discharge rate retrieval combining weather radar and thermal camera observations.
Journal of Geophysical Research Solid Earth 121, 5679–5695 (2016).
9. Rosi, M. et al. Stromboli volcano, Aeolian Islands (Italy): present eruptive activity and hazards. Geological Society London Memoirs
37, 473–490 (2013).
10. Houghton, B. & Wilson, C. A vesicularity index for pyroclastic deposits. Bulletin of Volcanology 51, 451–462 (1989).
11. Walker, G. & Croasdale, R. Characteristics of some basaltic pyroclastics. Bulletin Volcanologique 35, 303–317 (1972).
12. Corsaro, R. & Pompilio, M. Dynamics of magmas at Mount Etna. Geophysical Monograph 143, 91–110 (2004).
13. Armienti, P., Pareschi, M. T., Innocenti, F. & Pompilio, M. Effects of magma storage and ascent on the kinetics of crystal growth.
Contrib Mineral Petr 115, 402–414 (1994).
14. Morgan, D. J. & Jerram, D. A. On estimating crystal shape for crystal size distribution analysis. Journal of Volcanology and
Geothermal Research 154, 1–7 (2006).
15. Marsh, B. D. Crystal size distribution (CSD) in rocks and the kinetics and dynamics of crystallization. Contrib Mineral Petr 99,
277–291 (1988).
16. Higgins, M. D. Verification of ideal semi-logarithmic, lognormal or fractal crystal size distributions from 2D datasets. Journal of
Volcanology and Geothermal Research 154, 8–16 (2006).
17. Fornaciai, A., Perinelli, C., Armienti, P. & Favalli, M. Crystal size distributions of plagioclase in lavas from the July–August 2001
Mount Etna eruption. Bulletin of Volcanology 77, 70–15 (2015).
18. Armienti, P. Decryption of Igneous Rock Textures: Crystal Size Distribution Tools. Reviews in Mineralogy and Geochemistry 69,
623–649 (2008).
19. Le Maitre, R. W. et al. Igneous Rocks: A Classification and Glossary of Terms. (Cambridge University Press, 2002).
20. Kamenetsky, V. S. et al. Arrival of extremely volatile-rich high-Mg magmas changes explosivity of Mount Etna. Geology 35, 255–4
(2007).
21. Corsaro, R. A., Miraglia, L. & Pompilio, M. Petrologic evidence of a complex plumbing system feeding the July-August 2001
eruption of Mt. Etna, Sicily, Italy. Bulletin of Volcanology 69, 401–421 (2007).
22. Andronico, D. et al. A multi-disciplinary study of the 2002–03 Etna eruption: insights into a complex plumbing system. Bulletin of
Volcanology 67, 314–330 (2005).
23. Burton, M. R. et al. Etna 2004–2005: An archetype for geodynamically-controlled effusive eruptions. Geophys. Res. Lett. 32, (2005).
24. Ghiorso, M. & Sack, R. Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model
for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures.
Contrib Mineral Petr 119, 197–212 (1995).
25. Smith, P. M. & Asimow, P. Adiabat_1ph: A new public front-end to the MELTS, pMELTS, and pHMELTS models. Geochem.
Geophys. Geosyst 6, 1–8 (2005).
26. Mueller, S., Llewellin, E. W. & Mader, H. M. The rheology of suspensions of solid particles. Proceedings of the Royal Society A:
Mathematical, Physical and Engineering Sciences 466, 1201–1228 (2010).
27. Mader, H. M., Llewellin, E. W. & Mueller, S. P. The rheology of two-phase magmas: A review and analysis. Journal of Volcanology and
Geothermal Research 257, 135–158 (2013).
28. Giordano, D. & Dingwell, D. Non-Arrhenian multicomponent melt viscosity: a model. Earth Planet Sc Lett 208, 337–349 (2003).
29. Vona, A., Romano, C., Dingwell, D. & Giordano, D. The rheology of crystal-bearing basaltic magmas from Stromboli and Etna.
Geochim Cosmochim Acta 75, 3214–3236, doi:10.1016/j.gca.2014.04.007 (2011).
30. Cimarelli, C., Di Traglia, F. & Taddeucci, J. Basaltic scoria textures from a zoned conduit as precursors to violent Strombolian
activity. Geology 38, 439–442 (2010).
31. Houghton, B. et al. The influence of conduit processes on changes in style of basaltic Plinian eruptions: Tarawera 1886 and Etna 122
BC. Journal of Volcanology and Geothermal Research 137, 1–14 (2004).
32. Sable, J. E., Houghton, B. F., del Carlo, P. & Coltelli, M. Changing conditions of magma ascent and fragmentation during the Etna
122 BC basaltic Plinian eruption: Evidence from clast microtextures. Journal of Volcanology and Geothermal Research 158, 333–354
(2006).
33. Lautze, N. C. & Houghton, B. F. Physical mingling of magma and complex eruption dynamics in the shallow conduit at Stromboli
volcano, Italy. Geology 33, 425 (2005).
34. Pioli, L. et al. Explosive dynamics of violent Strombolian eruptions: The eruption of Paricutin Volcano 1943–1952 (Mexico). Earth
Planet Sc Lett 271, 359–368 (2008).
35. D’Oriano, C., Cioni R., Bertagnini, A., Andronico, D. & Cole, P. D. Dynamics of ash-dominated eruptions at Vesuvius: the post-512
AD AS1a event. Bulletin of Volcanology 73, 699–715 (2011).
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