The rock form shaped like a tornado was most likely produced by the weathering effect known as abrasion. Abrasion occurs when rocks are physically worn down and shaped by the scouring action of wind, water, or ice carrying particles or sediments that rub against the rock's surface. In the case of a rock form shaped like a tornado, it is likely that wind carrying abrasive particles had a considerable influence in shaping and sculpting the rock over time.
