Any information about fossils on stones, corals and leaves?

Question

indicate how it is formed

Answer 1

FOSSILIZATION
Most fossils are actually casts of animals or plants. Here's how they might be made:

The animal dies and sinks to the sea floor.
The body begins to decay and is buried under layers of sediment such as mud or sand.
These layers become rock.
The hard parts of the animal are replaced with minerals such as iron pyrites or silica.
These minerals form the fossil.
Usually fossils show the hard parts of the animal or plant - such as shell or bones. This is because the soft parts are destroyed quickly after death. Sometimes you will find the actual shells, e.g. the shells found in the Barton clay beds in Hampshire, England. Sometimes you find trace fossils, that is fossils not of the animals themselves but of evidence of living plants or animals, such as worm burrows or dinosaur footprints.


Most fossils are found in sedimentary rocks - rocks which were created when shells or small loose bits of rock are laid down in layers. Examples of sedimentary rocks are limestone, sandstone, clay and chalk. Fossils (from Latin fossus, literally "having been dug up") are the mineralized or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms. The totality of fossils and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology.

Using radiometric dating techniques, geologists have determined most fossils to be several thousands to several billions of years old. Yet there is no minimum age for a fossil. Fossils vary in size from microscopic, such as single cells, to gigantic, such as dinosaurs. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous exoskeletons of invertebrates. Preservation of soft tissues is exquisitely rare in the fossil record. Fossils may also consist of the marks left behind by the organism while it was alive, such as the footprint or feces of a reptile. These types of fossil are called trace fossils (or ichnofossils) as opposed to body fossils. Finally, past life leaves some markers that cannot be seen but can be detected in the form of biochemical signals; these are known as chemical fossils or biomarkers.