Manganese (Mn) exists as Mn(II), Mn(III), or Mn(IV) in soils, and the Mn oxidation state controls the roles of Mn in numerous environmental processes. However, the variations of Mn oxidation states ...

Here's What'll Happen When Plate Tectonics Grinds to a Halt. A new study says we may only have another 1.45 billion years to enjoy the dynamic action of Earth’s geologic engine.