Physical Volcanology Christoph Breitkreuz, TU Bergakademie Freiberg Structure: – Introduction – Reology and deformation of magma and lava – Eruption processes and types – Volcano forms – Emplacement of lava flows, domes and subvolcanic bodies – Pyroclastic fragmentation – Pyroclasts: Types and classification – Pyroclastic transport und deposition – Subaquatic and phreatomagmatic processes and resulting textures – Cooling textures in SiO 2 -rich (sub-)volcanic bodies – Volcanic hazards: Assessment and monitoring exercises: Fridays 7:30 – 9:00h, GP Osteifel: 20.6.-22.6.08 Test 4.7.08 Recommended literature BRANNEY, M. & KOKELAAR, P. (2002): Pyroclastic density flows and the sedimentation of ignimbrites.- Geol. Soc. London, Mem., 27, 143 pp. CAS, R.A.F. & WRIGHT, J.V. (1987): Volcanic successions - Modern and ancient.- Allen & Unwin, London, 528S. CHAPIN, C. E. and ELSTON, W. E. (eds.)(1979): Ash-flow tuffs.- Geol. Soc. Amer. Spec. Pap. 180, 211S. CHESTER, D.K., DUNCAN, A.M., GUEST, J.E. & KILBURN, C.R.J. (1985): Mount Etna: Anatomy of a volcano.- Chapman and Hall, London, 404S. DRUITT, T.H. (1999): Santorini volcano.- Geol. Soc. London, Mem. 19, 165 pp. DRUITT, T.H. & KOKELAAR, B.P. (eds.)(2002): The eruption of Soufrière Hills Volcano, Montserrat, from 1995 to 1999.- Geol. Soc. Mem. 21, 645S. FISHER, R.V. & SCHMINCKE, H.-U. (1984): Pyroclastic rocks.- Springer-Verlag, Berlin, 472S. FISHER, R.V. and SMITH, G.A. (eds.)(1991): Sedimentation in volcanic settings.- Soc. Econ. Paleont. Mineral., Vol. 45. FRANCIS, P. (1993): Volcanoes - A planetary perspective.- Oxford Univ. Press, Oxford, 1-443. FREUNDT, A. & ROSI, M. (Hrsg.)(1998): From magma to tephra – modelling physical processes of explosive volcanic eruptions.- Developments in Volcanol. 4, Elsevier, 318S. GIFKINS, C. , HERRMANN, W. & LARGE, R. (2005): Altered Volcanic Rocks: A guide to description and interpretation.- Univ. Tasmania, Centre for Ore Deposits and Exploration Studies, Hobart, 275S. LATTER, J. (ed.)(1989): Volcanic hazards.- Springer, 625S.
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Physical Volcanology
Christoph Breitkreuz, TU Bergakademie Freiberg
Structure:– Introduction– Reology and deformation of magma and lava– Eruption processes and types– Volcano forms– Emplacement of lava flows, domes and subvolcanic bodies– Pyroclastic fragmentation– Pyroclasts: Types and classification– Pyroclastic transport und deposition– Subaquatic and phreatomagmatic processes and resulting textures– Cooling textures in SiO2-rich (sub-)volcanic bodies– Volcanic hazards: Assessment and monitoring
exercises: Fridays 7:30 – 9:00h,
GP Osteifel: 20.6.-22.6.08Test 4.7.08
Recommended literatureBRANNEY, M. & KOKELAAR, P. (2002): Pyroclastic density flows and the sedimentation of
ignimbrites.- Geol. Soc. London, Mem., 27, 143 pp.CAS, R.A.F. & WRIGHT, J.V. (1987): Volcanic successions - Modern and ancient.-
Allen & Unwin, London, 528S.CHAPIN, C. E. and ELSTON, W. E. (eds.)(1979): Ash-flow tuffs.- Geol. Soc. Amer.
Etna: Anatomy of a volcano.- Chapman and Hall, London, 404S.DRUITT, T.H. (1999): Santorini volcano.- Geol. Soc. London, Mem. 19, 165 pp.DRUITT, T.H. & KOKELAAR, B.P. (eds.)(2002): The eruption of Soufrière Hills
Volcano, Montserrat, from 1995 to 1999.- Geol. Soc. Mem. 21, 645S.FISHER, R.V. & SCHMINCKE, H.-U. (1984): Pyroclastic rocks.- Springer-Verlag,
Berlin, 472S.FISHER, R.V. and SMITH, G.A. (eds.)(1991): Sedimentation in volcanic settings.-
Soc. Econ. Paleont. Mineral., Vol. 45.FRANCIS, P. (1993): Volcanoes - A planetary perspective.- Oxford Univ. Press,
Oxford, 1-443.FREUNDT, A. & ROSI, M. (Hrsg.)(1998): From magma to tephra – modelling
physical processes of explosive volcanic eruptions.- Developments in Volcanol. 4,Elsevier, 318S.
GIFKINS, C. , HERRMANN, W. & LARGE, R. (2005): Altered Volcanic Rocks: Aguide to description and interpretation.- Univ. Tasmania, Centre for Ore Depositsand Exploration Studies, Hobart, 275S.
LATTER, J. (ed.)(1989): Volcanic hazards.- Springer, 625S.
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LIPMAN, P.W. & MULLINEAUX, D.R. (eds.)(1981): The 1980 eruptions of Mount St.Helens, Wash., USA.- U.S. Geol. Surv. Prof. Pap., 1250, ca. 850S.
MARTÍ, J. & ERNST, G.G. (eds.)(2005): Volcanoes and the environment.- Cambridge University Press, 471 pp.
McCLELLAND, L. et al. (eds.)(1989): Global volcanism, 1975-1985.- Amer. Geophys.Union, Wash. D.C., 655S.
McPHIE, J.M., DOYLE, M. & ALLEN, R. (1993): Volcanic textures - A guide to theinterpretation of textures in volcanic rocks.- Univ. Tasmania, Centre for OreDeposits and Exploration Studies, 1-196, Hobart.
SCHMINCKE, H.-U. (2004): Volcanism.- Springer, Heidelberg, 324 pp.SIGURDSON, H. et al. (eds.)(1999): Encyclopedia of volcanoes.- Academic Press.SIMKIN, T. and FISKE, R.S. (1983): Krakatau 1883 - The eruption and its effects.-
Smithsonian Inst. Press. 464S.THOMPSON, D. (2000): The volcano cowboys - The rocky evolution of a dangerous science.-
St. Martin‘s Press, New York, 326 pp.WHITE, J.D.L., SMELLIE, J.L. & CLAGUE, D.A. (eds.)(2003): Explosive Subaqueous
volcanism.- Geophys. Monogr., 140, 1-379.
Journal of Volcanology and Geothermal Research (Elsevier)Bulletin of Volcanology (International Association of Volcanology and Chemistry of
the Earths Interior, IAVCEI), www.iavcei.orghttp://vulcan.wr.usgs.gov/home.html
Fig. 1.1 Relationship between viscosityand temperature for some magmas. Therhyolite was glassy or liquid through theentire temperature range (From Cas & Wright 1987, after Murase & McBirney1973).
VISCOSITY depends on:
- composition(SiO2 , Al2O3 ↑)(H2O, other volatiles, Na, K etc. ↓)
Table 1.1 Estimates of eruption temperatures for some common magmas (After Cas & Wright 1987).
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Fig. 1.2 The effect of H2O on the viscosityof (a) granitic and (b) basaltic melts at varying temperatures (From Cas & Wright 1987, after Murase 1962).
H2O content and Viscosity:
e.g. foaming up of magma during ascent(first boiling)
Basalt
Rhyolite
Fig. 1.3 Densities of some molten volcanicrocks with varying temperature at atmosphericpressure (From Cas & Wright 1987, afterMurase & McBirney 1973).
Density depends on:compositiontemperaturepressurecontent of phenocrysts and vesicles
Fig. 1.5 Relation between super cooling (∆T) and crystal nucleation and growth rate in a granitic melt(Swanson et al. 1989)
∆T = supercooling(below liquidus)
Formation of crystals and vesicles depends on:- temperature- presuure- time (Nucleation and diffusion!)
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Fig. 1.6 Bubble growth and water oversaturation in an ascending rhyolitic magma. The curvesdefine oversaturation in % as a function of the depth in the system during magma ascent. Thelabels on the curves refer to the ascent or rise rates. The initial conditions are 4 km (a) and 1 km (b), which correspond to initial water concentrations dissolved in the magma of 3.72 and 1.86 wt.%, respectively. Reproduced from Proussevitch and Sahagian (1996) (From Dingwell 1998).
FIRST BOILING:- ascent rate- supersaturation (e.g., with respect to H2O)
(m)
Embayments in quartz phenocrysts
Embayments form by:- growth impediment- skeletal growth
(quenching)
Growth zonation
Cathodoluminescenceimage of a quartzphenocryst
Quartz broken during first boiling
Ignimbrite with crystal fragments
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Fig. 1.4 Relation between deformation rate and deformation style of magma or lava dependingon temperature; Tg = glass transition temperature
Fig. 1.7 Temperature profiles of the Ben Lomondflow at different time steps as derived by numericalmodelling with the emplacement temperature of 850°C; Tg = glass transition temperature, FVP = finely vesicular pumice, U.OBS = upper obsidian, TZ = transition zone, RHY = stony rhyolite, L.OBS = lower obsidian, BRX = breccia (from Stevenson et al. 2001)
Land surface
Tg = glass transition temperaturec. 2/3 of the liquidus temperature