how are plants fossilized?

Answer 1

Plants are covered with a layer of silt or muck that blocks oxygen and prevents complete drying or decay. The 3-D shape of the plant holds a space within the wet silt and minerals slowly replace the structure of the plant. The minerals are 'stained' by chemicals within the plant and later when the fossil is pure rock, the stains are still visible. The 'logs' in the Petrified Forest look just like fallen trees complete with annual rings. Ever try to get food stains out of your favorite shirt?

Answer 2

As has been mentioned one type of fossils are compression fossils where the specimen is trapped under layers of sediment and eventually over time is chemically altered and tissues are mineralized. Another type of fossils are amber fossils, is a piece of plant / plant tissue gets trapped in sap, it also gets chemically altered, the sap itself becomes almost like stone and you can see all sorts of things which were stuck in it, bits of plants, insects, even some small vertebrates have been preserved like this. There are also subfossils, plants which have been preserved for very long periods of time but haven't fossilized yet, this can happen in peat bogs for example were the anaerobic conditions, acidity, tannins, preserve tissue and delays decomposition.

Answer 3

very simply, the plant gets trapped between layers of mud/silt/sand; this gets compressed over time, and becomes a sedimentary rock imprinted with the shape of the plant.

Answer 4

The following links have the information--

1) http://www.zoomschool.com/subjects/dinosaurs/dinofossils/Fossiltypes.html

2) This would be better one for you--

http://www.ucmp.berkeley.edu/IB181/VPL/Pres/PresTitle.html