Final answer:
Iron minerals that emerge from the ocean floor primarily undergo oxidation, forming rust, a hydrated form of iron (III) oxide. This process, known as rusting, requires the presence of both oxygen and water.
Step-by-step explanation:
When iron minerals pour out of the ocean floor, they primarily undergo a process known as rusting or oxidation. This involves iron being oxidized to iron (II) ions by oxygen. The iron (II) ions are subsequently oxidized and react with water and oxygen gas to form rust, which is a hydrated form of iron (III) oxide. The presence of both oxygen and water is necessary for rust to form. In an oxygen-rich environment such as the ocean, these conditions are met, allowing the process of rusting to occur. The formed red-brown hydrated metal oxide, called rust, does not form a protective film and instead, flakes off to expose more metal to corrosion. Therefore, the correct answer to what happens to iron minerals as they pour out of the ocean floor is A. They rust, or oxidize.