Basalt scoria


Basalt scoria

Basalt scoria

Extrusive igneous rock of mafic composition.
Fine-grained, dark-gray volcanic cinder block displaying abundant gas bubbles (vesicles).
Quaternary or older volcanic source.
From alluvial fan in volcanic area along Colorado River near Parker, AZ.

https://gotbooks.miracosta.edu/rocks/igneous/8.html

2/2/2021