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Basalt or Gabbro?

Basalt or Gabbro?

Based on visual inspection how can I classify the bedrock on a riverbed if it is Gabbro or Basalt?

RE: Basalt or Gabbro?

color and grain size?

RE: Basalt or Gabbro?

Gabbro is coarser grained - almost like granite.  Basalt is uniformly dark gray or black and fine grained.  Here's a chart on igneous rocks:


¡papá gordo ain't no madre flaca!

RE: Basalt or Gabbro?

basalt gray or black
gabro more green  

RE: Basalt or Gabbro?

fattdad your the best..Thank you for the information..

RE: Basalt or Gabbro?

fattdad - where did you access the chart?

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