The surface exposure of weathered sulfide deposits that has a distinctive color of the soil at the surface is called

The surface exposure of weathered sulfide deposits that has a distinctive color of the soil at the surface is called

• A. Limonite
• B. Goethite
• C. Gossan
• D. Hematite

Answer: (C)

Gossan refers to the oxidized, weathered cap that forms above sulfide mineral deposits when exposure to air and water drives oxidation. As sulfides like pyrite oxidize, iron is weathered into iron-oxide/hydroxide minerals such as limonite and goethite, which give the surface a distinctive yellow-brown to orange-brown color. This durable crust sits atop the unweathered ore and serves as a classic surface indicator of buried sulfide mineralization. While limonite and goethite contribute to the color of the oxidized zone, the term for the surface exposure itself is gossan. Hematite can also color soils red, but it isn’t the term used for the weathered sulfide cap.

Gossan refers to the oxidized, weathered cap that forms above sulfide mineral deposits when exposure to air and water drives oxidation. As sulfides like pyrite oxidize, iron is weathered into iron-oxide/hydroxide minerals such as limonite and goethite, which give the surface a distinctive yellow-brown to orange-brown color. This durable crust sits atop the unweathered ore and serves as a classic surface indicator of buried sulfide mineralization. While limonite and goethite contribute to the color of the oxidized zone, the term for the surface exposure itself is gossan. Hematite can also color soils red, but it isn’t the term used for the weathered sulfide cap.