Earth magic

In the Series: Events
In 'White Night'', during the Battle of the Deeps, Harry cast a spell while fighting Ghouls—"Flammamurus!" fire ripped out of the stone of the floor, in a line from the point of contact in either diredtion, molten stone shot up in a fountain about ten-twelve, hot liquid ston poured over the ghouls and created a wall of stone and fire.