Viscosity changes during crystallization of a shoshonitic magma: new insights on lava flow emplacement

• VETERE Francesco

  Institut für Mineralogie, Universität Hannover

• SATO Hiroaki

  Department of Earth and Planetary Sciences, Graduate School of Science, Kobe University

• ISHIBASHI Hidemi

  Earthquake Research Institute, the University of Tokyo Present address: Department of Geosciences, Faculty of Science, Shizuoka University

• DE ROSA Rosanna

  Dipartimento di Scienze Della Terra, Università della Calabri

• DONATO Paola

  Dipartimento di Scienze Della Terra, Università della Calabri

Abstract

Viscosity changes during the crystallization of a shoshonitic lava from the Vulcanello peninsula (Aeolian Islands, southern Tyrrhenian Sea, Italy) were measured by use of a electromagnetic rotational viscometer under Ni-NiO buffered conditions at temperatures ranging from 1539 K to 1381 K. Results showed an increase in effective viscosity from 131 Pa s to 15320 Pa s as the crystal content increased from 0 vol% to ∼ 14 vol%. The crystallization processes in the nominally dry shoshonite began at 1420 K with the formation of clinopyroxene, which was followed by the formation of plagioclase and olivine at 1401 K. Experimental observations differed from predictions derived from the use of the Einstein-Roscoe equation with the Marsh (E-R-M) parameter at crystal contents higher than 8 vol%. The relative viscosity of samples was larger than that calculated by E-R-M by a factor of up to 9.5 as the temperature decreased to 1381 K. The large departure of the experimental results from the E-R-M equation predictions was likely caused by the interaction of elongated pyroxene crystals. The measured viscosity data were used to estimate the potential for emplacement of shoshonitic lavas.

Journal

• Journal of Mineralogical and Petrological Sciences

  Journal of Mineralogical and Petrological Sciences 108 (3), 144-160, 2013

  Japan Association of Mineralogical Sciences

Keywords

• Viscosity
• Concentric cylinders
• Crystal morphology
• Shoshonite
• Vulcanello

Details

• CRID: 1390001206546432640
• NII Article ID: 10031173676
• NII Book ID: AA11460926
• DOI: 10.2465/jmps.120724
• COI: 1:CAS:528:DC%2BC3sXhsVSltb3K
• ISSN: 13493825
• ISSN: 13456296
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed