Question | Answer |
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 |
tilting | |
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) |