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17 Cards in this Set
- Front
- Back
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Petrification
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A process in which an organism's tissues are completely replaced by minerals.
Pertrified wood are made of stone |
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Mold & Cast
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An object created when sediment fills a mold and becomes rock.
The ammonite cast formed when sediment filled the ammonite mold on the right and became rock. |
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Imprints
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two dimensional impressions of an organism that does not contain any organic material.
Occured in fine-grained. |
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Entire Preservation
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-Amber: Hardened tree sap
-Freezing: When animals freeze and is preserved until the glaciers thaws of thousands of years later. -Mummification: When organisms die in dry places, such as deserts, they can sometimes dry out so fast that here isn't enough time for even their sof parts to decay. |
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Trace Fossil
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Any naturally preserved evidence of an animal's activity.
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What is the difference betweeb relative and absolute dating?
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AB: the process of establishing the age of an object, such as fossil or rock layer, by determining the number of years it has existed.
RB: Determining the absolute age of a sample based on the ratio of a parent material to daughter material. |
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Explain what happens to the nucleus of fa radioactive element as it decays.
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It starts out as 100% parent material. Parent material is unstable. Then the parent material is 50% daughter/parent material, then 75% daughter material and 25% of parent material. So on and so on.
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What era and period did the dinosaurs appeared?
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Mesozoic and Trassic
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What era and period did the dinosaurs went extinct?
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Mesozoic and Cretaceous
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What era and period did the modern man appeared?
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Cenozoic and Quaternary
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What era and period did the reptiles appeared?
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Paleozoic and Carboniferous
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What era and period did the first fish appeared?
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Paleozoic and Ordovician
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What era and period did the bacteria appeared?
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Precambrian
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List the four eras in order from oldest to most recent.
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Precambrian, Paleozoic, Mesozoic, Cenozoic
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An object was found with 25%of its parent material remaining. How many half lives did it go through? If it has a half life of 15,000 years, how old is it?
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30,000 years old and it went through 2 half lives.
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If an object is found with 4 grams of element y (parent material) remaining, and it went through 3 half lives, how much did it start with?
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32 grams
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If an object starts with 16 grams of parent material, how many grams willbe left after 1 half life? 2 half lives? 3 half lives?
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8 grams, 4 grams, 2 grams.
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