1. originating or formed in a place other than where it is found; not native to a region
Usage: commonly used in geology and biology
2. (geology) formed or deposited in a location different from its original source
Usage: technical; used in geology and paleontology

Examples

• The allochthonous species of fish were introduced to the lake by humans.
• Geologists identified allochthonous rock formations that had been moved by tectonic activity.
• Many allochthonous plants in the region threaten the survival of native species.
• The fossil was allochthonous, having been transported from its original depositional environment.
• Allochthonous organisms often struggle to adapt to their new ecosystems.
• The study examined allochthonous versus autochthonous populations in the watershed.