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Physical Volcanology
Christoph Breitkreuz,
TU Bergakademie Freiberg
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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: Wednesdays, even weeks, 11.00 – 12.30, CVT
GP Osteifel: 1. – 3.7.2011Test 18.7.2011
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): MountEtna: 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.
ORTON, G.J. (1996): Volcanic environment. - in: READING, H.G. (Hrsg.):Sedimentary Environments: Processes, facies and stratigraphy. - BlackwellScience, Oxford, 3. Aufl., 485-567.
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
www.geo.tu-freiberg.de/dynamo/Abbildungen_Lehre.htm
Physical volcanologyPetrology Sedimentology
Natural Hazards
Mineral depositse.g. VHMS
Raw material
Agriculture
EngineeringGeology
HydrologyHealth
Fields of work and position within Geosciences
History of volcanology –Historic eruptions
Encyclopedia of Volcanoes 1999
AristothelesPlatoA.G. WernerJ. Hutton
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Santorini, Ägäis
Forque 1879
Dietrich, ETH Zürich
1650 B.C...
Encyclopedia of Volcanoes 1999
History of volcanology –Historic eruptions
Vesuv 79 A.D.
Pompei
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Encyclopedia of Volcanoes 1999
History of volcanology –Historic eruptions
Krakatau 1883 in Indonesia: Tsunami caused by a shallow marine caldera eruption: 36 000 fatalities
Encyclopedia of Volcanoes 1999
History of volcanology –Historic eruptions
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Lacroix 1904
Mt. Pelee, Martinique: 1902-3
St. Pierre
Lassen Peak, 1915,California
Encyclopedia of Volcanoes 1999
History of volcanology –Historic eruptions
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Mt. St. Helens, WashingtonJune 1980
Pinatubo 1991
Smithsonian Institute
Schmincke 1986
Bahlburg & Breitkreuz 2004
Plate tectonics and magma generation
Irvine & Baragar 1971
Geochemicalclassification
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older classifications
Required: Norm calculation (e.g. CIPW)
Al2O3 content
Reology and Deformation of Magma
and Lava
Christoph Breitkreuz,
TU Bergakademie Freiberg
Sill, Estratos El Bordo, Chile
Mt. St. Helens
Glass Mtns, California
welded ignimbrite, St. Francis Mtns, Missouri, Proterozoic
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Reology, deformation and fragmentation are controlled by many parameters. The following are important:
- Ambient pressure (in the magmatic conduit system, in subaquatic environment)
- Viscosity of Magma/Lava
- Density of Magma/Lava
- Temperature
- Deformation rate
- Magma ascent rate
Just to remember…
Types of fluids:Newtonian Fluid: water, certain pyroclastic flows
Bingham Fluid:(with yield strength)Debris flows, lava / magmacertain pyroclastic flows
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. )
- temperature
- phenocryst content- microlith content,- vesicle content
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 atvarying temperatures (From Cas & Wright1987, 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:composition temperaturepressurecontent 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 1.86wt.%, 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 quartz phenocryst
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 depending on temperature; Tg = glass transition temperature
Fig. 1.7 Temperature profiles of the Ben Lomond flow at different time steps as derived by numerical modelling 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
Glass (above Tg) oozes out of a fracture plain
Panum Crater, Mono Lake, California
Soweit so gut!