Question

The composition of which one of the following reservoirs closely matches with that of iron meteorites?

• A. Primitive Mantle
• B. Earth's Core
• C. Depleted Mantle
• D. Bulk Silicate Earth

Hint:

- Iron meteorites → Analogues for Earth’s core (metallic Fe-Ni).
- Stony meteorites → Analogues for Earth’s mantle and crust (silicate).
- Carbonaceous chondrites → Represent primitive solar system material.

Answer 1

The Correct Option is B

Step 1: Nature of iron meteorites.
Iron meteorites are composed predominantly of metallic iron-nickel alloys, mainly kamacite and taenite. They are considered remnants of the cores of differentiated planetesimals that formed early in the solar system. Step 2: Comparison with Earth’s reservoirs.
- Primitive Mantle: Represents the silicate portion of the Earth before differentiation, rich in Mg-silicates, not metallic.
- Earth’s Core: Composed mainly of iron-nickel alloy with minor light elements (S, Si, O), similar in composition to iron meteorites.
- Depleted Mantle: Silicate reservoir left after partial melting, not metallic.
- Bulk Silicate Earth: Includes mantle + crust (silicate-dominated), not metallic. Step 3: Conclusion.
The composition of iron meteorites matches closely with the Earth’s Core. Final Answer: \[ \boxed{\text{Earth’s Core}} \]