State by State


  • Specimen Number


  • Description

    Block of highly vesicular basalt.  Vesicles unfilled and strongly aligned vertically as mounted, indicating highly gas-rich and hot magma during quick cooling.  Possibly some lobes to left. Identification by state survey staff.

  • Classification
  • Igneous. Volcanic. Extrusive. Basalt. Vesicular.

  • Location & Occurrence

    Lava flow of recent origin, likely in southeast part of of state where crustal extension, thinning, and normal faulting is occurring.

  • Geologic Age

    Quaternary (?)

  • Geoheritage

    Gas rich basalt magma is the dominant source of CO2 in the atmosphere, and thus a cause of climate change. This sample provides visual proof of that process.

  • Links

    Link to State Geological Map from USGS.  Link to California Geological Survey.

  • Other

    The specimen was mounted with vesicles pointing upward in their natural state. Was this deliberate or accidental?

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Specimen stone for Alaska.
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