Andesite with flow banding


Andesite

Andesite (lava-rock)

Extrusive igneous rock of intermediate composition
Fine-grained flow-banded andesite lava rock. The flow-banding structure formed as the viscous, gas-free lava stretched as it flowed and cooled, similar with stretching taffy.
From Tres Pinos Creek, gravel bar, San Benito County, CA.

https://gotbooks.miracosta.edu/rocks/igneous/5.html

2/2/2021