Justice League of America #113

After the JLA and JSA capture the Horned Owl Gang on Earth-2, a silent alarm is triggered inside of Sandman's old lab. When both teams arrive, they discover a sand monster has escaped. After further explanations by Sandman, it's revealed it was once his former partner, Sandy, who had been struck accidentally by an energy beam in his lab, that changed his body into pure silica. Both teams eventually reel him in, but the reason for his escape was that he was trying to quell several severe earthquakes that were about to occur, since in his new form he felt them.