Last modified on 24 July 2010, at 02:38

Basic Geology/Volcanism

There are three types of lavas formed by volcanoes. Mafic, Intermediate, and Felsic

Mafic (Basaltic)Edit

  • %SiO2: < 50%
  • %FeMg: 4%
  • Temp: up to 1500C
  • Viscosity: Low
  • Eruptive Behavior: gentle
  • Distribution: divergent plate boundaries, hot spots, convergent plate boundaries

Intermediate (Andesitic)Edit

  • %SiO2: ~60%
  • %FeMg: ~3%
  • Temp: ~1000C
  • Viscosity: Intermediate
  • Eruptive Behavior: explosive
  • Distribution: convergent plate boundaries

Felsic (Rhyolitic)Edit

  • %SiO2: >70%
  • %FeMg: 2%
  • Temp: 700C
  • Viscosity: High
  • Eruptive Behavior: explosive
  • Distribution: hot spots in continental crusts (Yellowstone National Park), convergent plate boundaries