The preservation of plant fossils hinges on preventing the organic material from decomposing, primarily achieved by rapid burial.
Plant fossilization is a complex process, but the key to preserving plant remains lies in shielding them from aerobic decomposition. This essentially means preventing oxygen and microbes from breaking down the organic material. The most effective way to do this is through quick burial.
Here's a breakdown of the factors and environments that contribute to plant fossil preservation:
- Rapid Burial: The faster a plant is buried, the less time it has to decompose. Sediment cover cuts off oxygen supply, inhibiting microbial activity. This is why areas like swamps, deltas, lakes, lowland flood plains, and volcanic areas are prime locations for finding plant fossils.
- Sedimentary Environments: These environments are characterized by high rates of sediment deposition.
- Swamps: Stagnant water in swamps limits oxygen, and accumulating plant debris is quickly covered by sediment.
- Deltas: River systems deposit large amounts of sediment at their mouths, burying plant life carried downstream.
- Lakes: Fine-grained sediments accumulate at the bottom of lakes, preserving delicate plant structures.
- Lowland Floodplains: Periodic flooding deposits layers of sediment, entombing plant material.
- Volcanic Areas: Ashfalls can rapidly bury and preserve plants, sometimes in exquisite detail.
- Mineralization: In some cases, minerals infiltrate the plant tissues, replacing the organic material with a durable mineral replica. This process enhances the long-term preservation of the fossil. Common minerals involved include silica, pyrite, and calcium carbonate.
In short, successful plant fossilization depends on a swift burial within oxygen-deprived, sediment-rich environments, possibly followed by mineralization.
