Volcanic Rock (Igneous)

Volcanic Rock (Igneous) Definition

A “Volcanic Rock” is an igneous rock that is finely crystalline and glassy (or aphanitic). To illustrate, volcanic rocks result from volcanic action at the earth’s surface. Typically, this also includes igneous intrusions that are “near-surface,” which may otherwise be considered plutonic. This action results in a final rock that is different in consistency, texture, and formation, comparing to other igneous rocks that crystalize underground. Moreover, most volcanic rocks are violently ejected or calmly extruded in the form of lava (liquid phase rock).

Examples of Volcanic Rock Types in Igneous Rock Classification

  • alkali-feldspar rhyolite
  • rhyolite (liparite)
  • dacite
  • quartz-alkali (-feldspar) trachyte
  • alkali (-feldspar) trachyte
  • foid-bearing alkali (-feldspar) trachyte
  • quartz trachyte
  • trachyte
  • foid-bearing trachyte
  • quartz latite
  • latite
  • foid-bearing latite
  • andesite
  • calc-alkaline andesite
  • andesite
  • mugearites
  • basalt
  • tephritic phonolite
  • phonolite tephrite (basanite)
  • tephrite
  • basanite
  • phonolitic foidite
  • tephritic foidite
  • foidite

Similar Posts

  • Contact Metamorphism

    ByGeo Forward

    Contact Metamorphism Contact Metamorphism – Metamorphism is associated with the intrusion of an igneous mass. Metamorphic changes are caused principally by heat, but also by magma composition and deformation related to the intrusion. Pressures are relatively low (<3000 bars) while temperatures range from 200°C to 1000°C.

  • Underground Storage Tank (UST)

    ByGeo Forward

    Underground Storage Tank (UST) Underground Storage Tank (UST): An underground storage tank (UST) is a confined container occupying any volume of space within the subsurface, for the purposes of storing liquid. Underground tanks typically support commercial and residential services and have filling ports, ventilation pipes, and connecting product pipelines. Underground storage tanks (USTs) come in different…

  • Type Section

    ByGeo Forward

    Type Section Geologic Definition In geology, the term “type section” refers to a specific stratigraphic unit, that can be compared to other parts of the geologic unit. For a type section, it’s preferred to describe the location where the geologic unit has the maximum thickness, and where the top and bottom units are observable.

  • Growth Fault

    ByGeo Forward

    Growth Fault Growth Fault: In geology, a growth fault is a strike-slip fault or dip-slip fault that moves contemporaneously with deposition. This causes the throw (amount of vertical displacement) to increase with depth and the strata to be thicker on the downthrown side as compared to the upthrown side.

  • Regression

    ByGeo Forward

    Regression Regression: In geology, regression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water withdrawing from the land. To illustrate, when regression occurs over millions of years, geologists find a layer of limestone, overlain by shale, and overlain again by limestone. The opposite of regression is…

  • Consolidation

    ByGeo Forward

    Consolidation “Consolidation” in geology refers to the gradual or slow reduction in the volume of a soil sample (representing a larger soil mass), and the increase in density in response to an applied increasing load, or compressive stress.