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ABSTRACT Many large calderas result from the eruption of substantial volumes (tens or hundreds of km3) of silicic pyroclastics. Such events often begin with an airfall phase and progress to

the generation of voluminous ignimbrites1–3. We propose here that many such eruptions involve two well-defined stages, based on a simple analysis of magma chamber pressure variations during

an eruption. The first stage begins when an overpressured magma chamber fractures the country rock and forms a conduit to the surface. The chamber pressure decreases rapidly to values less

than lithostatic pressure. We show that only small to moderate volumes of magma, representing a small fraction of the total chamber, can be erupted during this stage. In the second stage,

caldera collapse results from a further decrease in magma pressure, which causes the chamber roof to fracture catastrophically and deform. Subsidence of the roof attempts to re-establish

lithostatic pressures within the chamber and can drive substantial volumes of magma to the surface. Geological relationships in pyroclastic deposits associated with large caldera eruptions

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subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS MAGMATIC ADDITION RATES DIFFERENTIATE PERIODS OF STEADY-STATE VERSUS FLARE-UP MAGMATISM IN THE

CENTRAL ANDEAN ARC Article Open access 15 March 2023 NO SINGLE MODEL FOR SUPERSIZED ERUPTIONS AND THEIR MAGMA BODIES Article 27 July 2021 CRYSTALS REVEAL MAGMA CONVECTION AND MELT TRANSPORT

IN DYKE-FED ERUPTIONS Article Open access 15 July 2020 REFERENCES * Williams, H. _Univ. Calif. Dept. Geol. Sci. Bull._ 25, 239–346 (1941). Google Scholar  * Smith, R. L. _Geol. Soc. Am.

Spec. Pap._ 180, 5–27 (1979). ADS  CAS  Google Scholar  * Wilson, L., Sparks, R. S. J. & Walker, G. P. L. _Geophys. J. R. astr. Soc._ 63, 117–148 (1980). Article  ADS  Google Scholar  *

Smith, R. L. & Bailey, R. A. _Geol. Soc. Am. Mem._ 116, 613–662 (1968). Google Scholar  * Roberts, J. L. _Geol. J. Spec. Iss._ 2, 287–338 (1970). Google Scholar  * Christiansen, R. L.,

Lipman, P. W., Orkild, P. P. & Byers, F. M. Jr. _US Geol. Surv. Prof. Pap._ 545B, B43–B48, 1965. Google Scholar  * Christiansen, R. L. in _Explosive Volcanism, Inception, Evolution and

Hazards_, 84–95 (National Academy Press, Washington DC, 1984). Google Scholar  * Simkin, T. & Fiske, R. S. _Krakatau 1883. The Volcanic Eruption and its Effects_ (Smithsonian Institute

Press, Washington DC, 1983). Google Scholar  * Sparks, R. S. J. _et al._ _J. Volcan. Geotherm. Res._ (in the press). * Druitt, T. H. thesis, Univ. Cambridge (1983). * Bond, A. & Sparks,

R. S. J. _J. geol. Soc. Lond._ 132, 1–16 (1976). Article  Google Scholar  * Self, S. & Wright, J. V. _EOS_ 62, 1085 (1981). Google Scholar  * Walker, G. P. L. _J. Volcan. Geotherm. Res._

8, 69–94 (1980). Article  ADS  Google Scholar  * Lipman, P. W. _J. geophys. Res._ (in the press). * Francis, P. W. _et al._ _Nature_ 301, 51–53 (1983). Article  ADS  CAS  Google Scholar  *

Walker, G. P. L. _J. geophys. Res._ (in the press). * Shaw, H. R. in _Geochemical Transport and Kinetics_ (eds Hoffman, A. W., Giletti, B. J., Yoder, H. S. & Yund, R. A.) 139–170

(Carnegie Institute, Washington Publ. 634, 1974). Google Scholar  * Blake, S. _Nature_ 289, 783–785 (1981). Article  ADS  Google Scholar  * Murase, T. & McBirney, A. R. _Bull. geol. Soc.

Am._ 84, 3563–3592 (1973). Article  CAS  Google Scholar  * Reynolds, D. L. _Koninkl. Nederlandsch. Mijnb. Genootscap. Verh. Geol._ 16, 355–398 (1956). CAS  Google Scholar  * Bacon, C. R.

_J. Volcan. Geotherm. Res._ 18, 57–115 (1983). Article  ADS  CAS  Google Scholar  * Druitt, T. H. & Sparks, R. S. J. _J. Volcan. Geotherm. Res._ 13, 147–171 (1982). Article  ADS  Google

Scholar  * Lipman, P. W. _Bull. geol. Soc. Am._ 87, 1397–1410 (1976). Article  Google Scholar  Download references AUTHOR INFORMATION Author notes * T. H. Druitt Present address: US

Geological Survey, MS-910, Menlo Park, California, 94025, USA AUTHORS AND AFFILIATIONS * Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, UK T. H. Druitt & R.

S. J. Sparks Authors * T. H. Druitt View author publications You can also search for this author inPubMed Google Scholar * R. S. J. Sparks View author publications You can also search for

this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Druitt, T., Sparks, R. On the formation of calderas during ignimbrite

eruptions. _Nature_ 310, 679–681 (1984). https://doi.org/10.1038/310679a0 Download citation * Received: 13 March 1984 * Accepted: 08 June 1984 * Issue Date: 23 August 1984 * DOI:

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