Answer:
The bottom most area of the volcano.
Step-by-step explanation:
If we talk about geo thermal sources like volcanoes there is the bottom portion of those volcanoes that is rich in sulfites or ores of black colored minerals like nickel,zinc,copper, iron and some other minerals called black smokers as well.
Iron metal is specifically abundant in the bottom most portion of volcanic rocks. This iron is found in the form of rocky or magma-laden paths in the bottom layers and is mostly present in fluid form. However if there is a favorable pressure and temperature, iron can be deposited in the layers forming mineral veins.
Hope it helps!