Extrinsic growth, also known as accretion, refers to growth resulting from the accumulation of deposits from outside a body.
Understanding Extrinsic Growth
Extrinsic growth contrasts with intrinsic growth, which involves expansion from within. Think of it like this: a snowball growing larger as you roll it in the snow versus a living organism growing by cell division. The key defining factor is that the material causing the growth originates from an external source.
Examples of Extrinsic Growth
The reference provides several excellent examples:
- Sand Dunes: Wind carries sand particles, depositing them on existing dunes, causing them to increase in size and change shape.
- Mountains: While tectonic uplift is a primary driver of mountain formation (and can involve internal processes), deposition of sediment eroded from other areas contributes to their overall growth.
- Boulders: Mineral deposits on the surface of the existing rocks.
- Glaciers: Snow accumulates and compresses into ice, increasing the glacier's mass and size. The snow comes from atmospheric precipitation, an external source.
Table Summarizing Extrinsic Growth
| Feature | Description |
|---|---|
| Definition | Growth due to deposits originating outside the body or object. |
| Mechanism | Accumulation of external materials. |
| Examples | Sand dunes, mountains (through sediment deposition), glaciers, mineral deposits on boulders. |
| Contrast | Intrinsic growth (expansion from within). |
| Also Known As | Accretion |
