wall of mud

As soon as Kamijou got behind the buses, a line of the ground in front of him burst
upward to block him from the washing machines. The wall of earth stretched five meters
high, then came crashing toward the three of them like an avalanche. The wall of earth
stretched from one end of the service facility to the other. They couldn’t avoid it, and if
they hid behind the buses, they’d be crushed along with them. Above all, if the metal
pillars supporting the roof broke, the entire facility could come toppling down on them.
“Kami-yan, you’re up! It’s made of temporary matter, like ectoplasm—your hand can
wipe out the whole thing!!”
As Tsuchimikado called out, Kamijou jumped in front. He felt his teeth start to chatter
at the enormous opponent, but he couldn’t run away crying in this situation. He dove
toward the root of the mudslide and shoved his right hand into it without a second
thought.

With a loud sound of glass shattering, the five-meter-high wall of earth came crumbling
down. It appeared to melt into thin air, and after it vanished nothing was left. The
asphalt below them returned to normal, too. Before Kamijou could pull back his right
arm, Tsuchimikado ran by him and disappeared behind the big washing machines.
Kamijou followed, rounding the obstacles in a single burst.

- Toaru Majutsu no Index Volume 9, Chapter 2 Part 8