general science module 07

The conversion of organic material into stone

A sticky, liquid substance that usually hardens when exposed to air

A term applied to a species of plant or animal that was once living but now is not

The most likely thing that will happen to the remains of a dead plant or animal is that they will decompose. Fossilization is a rare exception to this general rule

A fossil mold forms first. If a cast forms, it forms later when the mold is filled with sediment.

The remains of a plant or animal are encased in sediment and the sediment eventually hardens into rock. As the remains of the plant or animal disintegrate, a hole is left in the rock, in the shape of the original remains. That is the mold. The mold might fill up with sediment later and when the sediment hardens, it forms a cast.

Petrifaction requires water that has a lot of minerals in it.

Petrified fossils have more information that fossil casts because fossil casts retain only the shape and outer details of the fossil. When a fossil is petrified, its components are replaced with minerals. This means the entire fossil is preserved, which gives us more information than just the shape and outer details of the fossil.

A carbonate residue still has a film residue of the original creature. In an impression, the film is completely gone, leaving only an outline that looks like it was etched in stone.

Both carbonate residues and impressions are formed by the same process. They also leave an outline of the creature.

Fossils encased in amber or ice do not decompose as quickly as other fossils. Thus, tissue and other soft parts which usually are not preserved tend to be preserved very well.

The four general features of the fossil record are: 1. Fossils are usually found in sedimentary rock. Since most sedimentary rock is laid down by water, it follows that most fossils were laid down by water as well. 2. The vast majority of the fossil record is made up of clams and other hard-shelled creatures. Most of the remaining fossils are of water-dwelling creatures and insects. Only a tiny, tiny fraction of the fossils we find are of plants, reptiles, and mammals. 3. Many of the fossils we fond are of plants and animals which are still alive today. Some of the fossils we find are of plants and animals which are now extinct. 4. The fossils found in one layer of stratified rock can be considerably different that the fossils found in another layer of the same stratified rock.

Clams and other hard-shelled animals made up 95% of the fossil record.

Approximately 100 species have gone extinct over the last 400 years, This is a stark contrast to the 10000 species which some "environmentalists" claim go extinct each year!

A trilobite is a creature that lived in the water and was covered in a hard outer covering. Typically, trilobites lived at the bottom of the ocean. They are now assumed to be extinct.

A placoderm is a kind of fish. It was much like the fish we see today, but its head was covered with hard plates rather than scales. Placoderms are considered to be extinct.

According to uniformitarians, sediments are laid down slowly over millions of years. Eventually, conditions change and the sediments harden to form rocks. The conditions during which the sediments were laid down determine the type of sediment, which in turn determines the kind of rock formed.

According to catastrophists,most of the sedimentary rocks we see today were formed in Noah's flood. The depth, speed, and direction of the sediments were laid down, which in turn determined the type of rock formed.

According to catastrophists, each layer of rock represents a period of earth's history. Thus, the different fossils found in different layers result from the fact that different plants and animals existed at different times in any given region.

According to catastrophists, most of the sedimentary rock we see today is the result of the flood. Thus, the different fossils in different layers are the result of the fact that different kinds of fossils were trapped and preserved during different stages of the flood.

Uniformitarians must speculate how millions of year of time affect the processes that we see working today. At best, we have viewed how these processes work over a few thousand years. The effect that millions of years will have on the processes can only be speculated.

Catastrophists must speculate about the nature of Noah's flood. The speculation is aided by the observation of local catastrophes. Nevertheless, Noah's flood would have been much different that a local catastrophe, so the details of the flood can only be speculated.