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Science chap. 15-16

Science chapters 15-16

What 3 things do fossils tell us? 1. relative history2. environment3. way organisms lived
Name 3 conditions that support fossil development... 1. hard bones2. quick bury3. preserved over a long time
Describe how petrification occurs... proccess in which minerals replace organisms tissues
How do index fossils work... you look at one fossil and then use it to see if another fossil is older or younger than it.
What does extinct mean? no more of a certain species alive
What 2 hypotheses were discussed about landform evoulution? 1. catastrophism2. uniformitarism
Describe the principle of superposition... younger rocks on top of older rocks
What is relative dating... estamating if the rock is older or younger than the rock saround it
Describe the 3 unconformities... 1. disconformity2. nonconformity3. angular unconformity
What elements have half-lifes... radio-active material
What is half-life... time it takes for half the radio-acrive material to decay
What happens to parent and daughter materials during radio-active decay... p- smallerd- larger
What are the 5 main subdivisions of geological time scale? eonera periodepochages
Phanerozoic PaleozoicMesozoicCenozoic
Paleozoic fish
Mesozoic dinosaurs
Cenozoic mammals
What are cyanobacteria? 1st known life 3.5 billion years ago
What affects survival? predators, food, shelter, and climate
Natural selection... The species/animal with a better trait lives while the others die
5 things fossils can be preserved in are... 1. amber2. ice3. asphault4. sediment (rock)5. petrification
uniformitarianism the events that happend in the past will happen again in the future
catastrophism bad event
paleontology study of the past using fossils
superposition the younger layers on top and the older are on the bottom
unconformity break in geological layers
fault fracture in layers
intrusion when magma goes through layers of existing rocks.
folding when a layer of rock bends
disconformity layer of rock is missing
non-conformities when layer of rock forms on top of a layer of pre-existing magma
angular unconformities a layer of horizontal sediment is deposited on top of tilted layers of sediment
isotope same number of protons and different nuetrons
half-life the time it takes for half of the parent material to decay
trace-fossil impressions such as footprints that are preserved from the past
mold outer part of something
cast mold filled
ammonites really good species of index fossils
trilobites Paleozoic time like snails (anthropods)
Created by: numnum