What he said!

Its not the White man, Black or Brown,
Its the Rich man who keeps you down.©

I've been a welder for 35 yrs. That is an arc discharge track. See "The Electric Universe' for the explanation that the mainstream is ignoring.
By the way, I have personally reproduced these contours in miniature with my TIG welder at work, after I saw something similar, labeled as "proof of water erosion", and it looked too much like certain craters in steel that I had previously encountered.