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

• A. Laterite
• B. Saprolite
• C. Gossan
• D. Latite

Answer: (C)

Gossan is the surface expression of an oxidized sulfide ore body. When sulfide minerals near the surface react with oxygen and water, they weather to iron-oxide minerals such as goethite, hematite, and limonite. This creates a porous, iron-rich cap that often has a distinctive rusty red to yellowish color, giving the surface soils a telltale ochre hue. This reddish-orange to yellow staining signals underlying sulfide mineralization and is a classic indicator in exploration. By contrast, laterite refers to extreme tropical weathering with iron and aluminum-rich clays, saprolite is weathered rock that still preserves the original structure, and latite is a volcanic rock, not the oxidized cap over sulfides.