1. a rock or mineral that has been transported from its place of origin to a different location, typically by geological processes such as erosion, water flow, or tectonic movement
Usage: geology; technical
2. an organism or species that has migrated to or been introduced into a region where it is not native
Usage: biology; ecology

Examples

• The geologist identified the allochthon as granite that had been carried downstream by ancient glaciers.
• Allochthons in the rock formation indicated significant tectonic activity in the region's past.
• The invasive plant species was classified as an allochthon because it originated from South America.
• Marine allochthons found in desert regions suggest that these areas were once covered by water.
• Studying allochthons helps scientists understand the geological history and transport mechanisms of Earth's crust.