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Karah
Earth History
Crust | composed of igneous, metamorphic, &sedimentary rocks |
Mantle | silicate rocky shell with an average thickness of 2,856 kilometers |
Outer core | thick and composed of iron and nickel |
Inner core | solid ball made of metal |
Theory of the Continental Drift | States that parts of the Earth's crust slowly drift atop a liquid core |
What was the name of the single continent involved in plate tectonics | Africa |
petrified fossils | forms when minerals soak into the buried remains, replacing the remains, and changing them into rock |
preserved fossils | preserved remains of a prehistoric organism |
trace fossil | provides evidence of the activities of ancient of ancient organisms |
Mold fossil | a hollow area of a fossil |
cast fossil | copy of a fossil |
index fossil | only existed for a short period of time, easy to identify and small |
Law of Superposition | states that the oldest will be at the bottom |
What kind of rock are fossils usually found? | Sedimentary rock |
Precambrian | One of the 4 Geological ERA's. Began about 4.5 billion years ago and ended 543 million years ago. This started with the formation of Earth and ended at the first sign of complex life. |
Paleozoic | One of the 4 Geological ERA's. Ran from about 542 million years ago to 251 million years ago. |
Permian | One of the 4 Geological ERA's. Ended with the permian extinction. |
Mesozoic | One of the 4 Geological ERA's. started from about 245 million years ago to about 65 million years ago. Began with the largest mass extinction and ended with the asteroid that killed the dinosaurs. |
Ice Cores | cylinders of ice drilled out of an ice sheet or glacier. |
Where can Ice Cores be found? | Antarctica and Greenland |
What can be learned from Ice Cores? | They allow us to go back in time and to sample accumulation, air temperature and air chemistry from another time |
Most important things we can learn from fossils | how long life has existed on Earth and how different plants and animals are related to each other |
Relative dating | determining the relative order of past events |
absolute dating | determining an age on a specified time scale |