John Seach, Volcano Live

 Lava Scratches - John Seach
Lava scratches are parallel marks on lava produced by two flows sliding against each other.
The scratches indicate the direction of flow.

Grooved Lava
Grooved lava is produced by lava moving past another lava flow of rock.
Grooves are deeper than scratches.

Lava Groove
Copyright John Seach