1. a rusty or weathered surface layer of rock containing iron oxides, typically found above a sulfide ore deposit
Usage: geology

Examples

• The geologist identified gossan at the surface, indicating potential mineral deposits below.
• Mining companies often look for gossan as a sign of underlying ore bodies.
• The reddish-brown gossan was clearly visible on the hillside.
• Prospectors use gossan formations to guide their exploration efforts.
• The gossan layer had formed over centuries of weathering and oxidation.