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Bulletin Volcanologique

, Volume 41, Issue 2, pp 136–146 | Cite as

Relationship between the chemistry and axial dimensions of some shallow water pillow lavas of alkaline olivine basalt-and olivine tholeiitic composition

  • H. Furnes
  • I. B. Fridleifsson
Article

Abstract

The axial ratio of basalt pillows in some shallow water pillow lava sequences from Azores and Iceland, is defined as V/H, where V and H represent the vertical and horizontal axes in cross section perpendicular to the elongate direction of undisturbed pillows. The axial ratios show a great spread of overlapping values for pillows from different sequences. However, alkaline olivine basaltic pillows tend to be more flattened than the olivine tholeiitic pillows. Another, and probably more discriminative feature between the two, is the difference in the maximum size of V and H of a pillow body. The limit for V and H for alkaline olivine basalt pillows is significantly lower than that of the olivine tholeiite pillows. A lower viscosity for alkaline olivine basalt than for olivine tholeiite probably accounts for the differences.

Keywords

Lava Flow Axial Ratio Flow Unit Pillow Lava Olivine Phenocryst 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Intern. Association of Volcanology and Chemistry of the Earth’s Interior 1978

Authors and Affiliations

  • H. Furnes
    • 1
  • I. B. Fridleifsson
    • 2
  1. 1.Geologisk InstituttBergenNorway
  2. 2.National Energy AuthorityReykjavikIceland

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