The LOHAFEX experiment studied the environmental impacts of a sulfate of this element before being halted by the German government. John Martin’s “hypothesis” named for this element suggests that wind-blown addition of this element strengthens the biological pump during ice ages. Because it is limiting in HNLC regions, Russ George’s Haida Salmon Restoration Corporation controversially dumped this element to trigger blooms off the coast of British Columbia. Fertilizing oceans with this micronutrient (-5[2])has been suggested as a (10[1])route to sequester carbon, since this metal is required by photosynthetic cofactors in plankton. The oxygenation of the oceans is recorded by “banded” formations of this metal, which include ores like hematite. For 10 points, name this element alloyed with nickel in the Earth’s core. ■END■ (10[1])