But because different iron minerals behave differently, scientists must know what iron minerals were present, according to Poulton.

MSN: What green rust did long ago to the big blue ocean

"Typically the concentrations are small in red mud and what is present is tightly bound to the particles of iron oxide, " he says.

BBC: How toxic is Hungary's red sludge?

The studios behind "Iron Man, " Paramount and Marvel, also will present a panel for "Captain America: The First Avenger, " even though it is still a year away from release.

CNN: The long rollout: Studios build early buzz at Comic-Con