Ancient petroglyphs all over the world show shapes and structures that plasma discharges make. What you should take into consideration is that all electrical events are scaled. That means big or small they behave the same. This fenomenon can best be explained by watching these videos:
If you want the long version
https://www.youtube.com/watch?v=tRV1e5_tB6Y&t [Embed]
If you want the shorter version
https://www.youtube.com/watch?v=sH11EJRFcH0 [Embed]
There it basically explains much better than I can in any forum post why the surface of planet Mars shows signs of massive electric discharge. Such features can also be found on Earth. Compare the canyons of Mars with Grand Canyon and then compare those to shapes current makes when going through wood like shown here:
https://www.youtube.com/watch?v=knACZPQx54s [Embed]
It's a really good documentary. No bullshit just facts if this doesn't sell you the idea nothing will. A gamechanger video. Makes other parts of the puzzle fit in.
