Explosive mafic volcanoes on Mars and Earth: Deep magma sources and rapid rise rate

Tracy K P Gregg, Stanley Williams

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

Volcanism on Mars is dominated by mafic or ultramafic products. On Earth, mafic volcanics are typically emplaced through small-scale pyroclastic activity such as lava fountaining or Strombolian eruptions, resulting in lava flows. Tyrrhena and Hadriaca Paterae, large, central-vent volcanoes on Mars, however, appear to be primarily constructed of mafic pyroclastic deposits (probably pyroclastic flows), and magma-water (or ice) interactions were not necessarily the cause of these explosive eruptions. The volcanotectonic conditions which generated highly explosive basaltic eruptions on Mars may exist on Earth as well: Masaya Caldera Complex, Nicaragua, has produced large-volume, basaltic ignimbrite, Plinian ash-fall and surge deposits, without overt magma-water interactions. Basaltic magma apparently originated ∼100 km beneath Masaya, and ascended faster than ∼100 cm s-1 through an established conduit, allowing the magma and exsolved volatiles to reach the surface simultaneously. The combination of deep-sourced magma and rapid rise rate may have also generated ignimbrite-like basaltic pyroclastic deposits at Zavaritski Volcano, Russia, and Ambrym, Vanuatu. Examination of these terrestrial volcanoes may further our understanding of large-scale mafic pyroclastic activity on Mars.

Original languageEnglish (US)
Pages (from-to)397-405
Number of pages9
JournalIcarus
Volume122
Issue number2
DOIs
StatePublished - Aug 1996

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ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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