• Specimen Number

  4

• 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

  USGS Compilation: Search for California in upper right.  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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