Very interesting. Those first two are quite intriguing to my untrained eye.
Could the tracks in the first be from melting snow?
Good find. How long did it take you to find these?
Originally posted by Phage
reply to post by verylowfrequency
Ice forming in partially collapsed lava tubes is an excellent call.
There are alternative explanations for this mass concentration, such as formation by a mantle plume Mantle plume A mantle plume is an upwelling of abnormally hot rock within the Earth's mantle . As the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcano centers known as Hotspot and probably also to have caused flood basalts.... or other large-scale volcanic activity.
Lava tubes can be up to 14-15 metres wide, though are often narrower, and run anywhere from 1-15 m below the surface.
A lava tube system in Kiama, Australia, consists of over 20 lava tubes, many of which are breakouts of a main lava tube. The largest of these lava tubes is 22 m in diameter.