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What is Petrifaction?
The conversion of organic material into stone.
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What is resin
A sticky liquid substance that usually hardens when exposed to air.
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What does extinct mean?
A term applied to a species of plant or animal that was once living but now is not.
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When a plant or animal dies, what is the most likley thing that will happen to its remains?
they will decompose and form rich humas which will later be used by plants as a source of nutrition.
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Which forms first, a fossil mold or a fossil cast?
a fossil mold.
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Describe the process of a cast forming, indicating when the mold has formed and when the cast has formed?
a cast is formed when a object such as a seashell is encased by sedimentary rock forming a mold. Later other sediments can come and fill the mold forming a cast.
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what is required for petrifaction occur?
In order for petricaction to occur the bones must be exposed to water that contains a large amount of minerals. As minerealrich water swirls around the creatures remains the organic materials begin to Decompose and are replaced by minerals that are deposited into the remains.
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why does petrifaction usually produce fossils with more information then fossil casts
Because petrifaction preserves more the just the outside shape of the plant or animal
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what is the differance between a carbonate residue and an impression?
A carbonate residue has a film of carbon remnaining on it while an impression has none of the residue left
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How are carbonate residues and impressions similar?
Both apperear to be drawings of those remains inbstead of a replica of the whole creature.
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what is so nice about fossils which have beeen encased in amber or ice?
other fossils preserve mostly hard remains these fossils can preserve softer organs that would otherwise rot
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what are the 4 general features of the fossl record?
- 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 either water-dwelling creatures or insects.Only a tiny,tiny fraction of the fossils we find are of plants, reptiles, birds and mammals.
- 3. Many of the fossils we find 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 differant then the fossils found in another layer of the same stratified rock.
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what kind of creatures make up 95% of the fossil record?
clams and other hard shelled organisms.
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approximately how many species of plants and animals have gone extinct in the last 400 years: a hundred,a thousand,ten thousand, or a hundred thousand
484 species of animals and 654 species of plants.
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what is a trilobite? are trilobites extinct?
a crab like creature that lives in the ocean and is assumed to be extinct.
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what is a placoderm? are placoderms extinct?
a strange looking plated fish that is assumed to be extinct.
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what is the uniformitarian explanation for how most sedimentary rocks formed?
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.
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what is the catastrophist explanation for how most sedimentary rocks 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 flood waters determined what kind of sediments were laid down, which in turn determined the type of rock formed.
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what is the uniformitarian explanation for why different fossils are found in different strata?
the different fossils found in different layers result from the fact that different plants and animals existed at different times in any given region.
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What is the catatrophist explanation for why different fossils are found in different strata?
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.
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what major speculation must uniformitarians make when studying geology?
Uniformitarians must speculate how millions of years of time affect the processes that we see working today.
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what major speculation must catastrophists make when studying geology?
catastrophists must speculate about the nature of Noah's flood.
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