Compression and Impression Fossil Formation
Compressions and impressions most common insect fossil. Insects with organic matter are called compressions, and insects with no organic matter are called impressions.Lake deposits are the most common environment where leaf and insect fossils form. Insects and leaves become trapped in sediments and as the sediments gather the insects and leaves decompose leaving behind imprints. As the sediments compact and hardened into rock the imprints become impression fossils. If organic matter remains then a compression fossil has formed.
A Trace Fossil is a fossil of an activity of an organism (people and animals are examples of some organisms) For example, a trace fossil can be a fossil of a footprint, a fossil of a burrow, or something along those lines. They form when the uninterrupted footprint (for example) gets surround by sediment and the sediment hardens around the footprint forming a trace fossil.