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| Titel |
Seismogenic frictional melting in the magmatic column |
| VerfasserIn |
J. E. Kendrick, Y. Lavallée, K.-U. Hess, S. De Angelis, A. Ferk, H. E. Gaunt, P. G. Meredith, D. B. Dingwell, R. Leonhardt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 5, no. 1 ; Nr. 5, no. 1 (2014-04-09), S.199-208 |
| Datensatznummer |
250115265
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| Publikation (Nr.) |
 copernicus.org/se-5-199-2014.pdf |
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| Zusammenfassung |
| Lava dome eruptions subjected to high extrusion rates commonly evolve from
endogenous to exogenous growth and limits to their structural stability hold
catastrophic potential as explosive eruption triggers. In the conduit,
strain localisation in magma, accompanied by seismogenic failure, marks the
onset of brittle magma ascent dynamics. The rock record of exogenous dome
structures preserves vestiges of cataclastic processes and thermal
anomalies, key to unravelling subsurface processes. Here, a combined
structural, thermal and magnetic investigation of a shear band crosscutting
a large block erupted in 2010 at Soufrière Hills volcano (SHV) reveals
evidence of faulting and frictional melting within the magmatic column. The
mineralogy of this pseudotachylyte vein offers confirmation of complete
recrystallisation, altering the structure, porosity and permeability of the
material, and the magnetic signature typifies local electric currents in
faults. Such melting events may be linked to the step-wise extrusion of
magma accompanied by repetitive long-period (LP) drumbeat seismicity at SHV.
Frictional melting of Soufrière Hills andesite in a high velocity rotary
shear apparatus highlights the small slip distances (< 15 cm) thought to be required to bring 800 °C magma to melting point at upper conduit
stress conditions (10 MPa). We conclude that frictional melting is a common
consequence of seismogenic magma fracture during dome building eruptions and
that it may govern the ascent of magma in the upper conduit. |
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