Rock Cycle
Fossils
Relative Dating
Absolute Dating
Age of Earth
Bonus
1
This is what we call lava when it is inside the earth.
Magma
1
What is a fossil
Remains or traces over 10,000 years old
1
Found in layers of rocks these remains help us reconstruct earth history
Fossils
1
If I say the rock is 3 million years old, what type of dating is this called?
absolute
1
How old is the earth?
4.5 billion years old.
1
E
2
Rocks formed from sediment.
Sedimentary rocks
2
If a water fossil is found in a desert, what can you assume about the area when the fossil was formed
it was once underwater and changed over time
2
In general rocks on the bottom of layers are _______.
Older
2
Radiometric age is often referred to as __________ age.
Absolute
2
3 types of evidence used to determine Earth's age
Fossils
Earth’s surface features
Measuring the age of rocks
2
What formed the grand canyon?
Weathering and Erosion
3
A rock formed from pressure and heat.
Metamorphic Rock
3
What does the above illustration prove about todays horses
they have evolved to be come larger and only one main toe
3
C.
3
These special fossils help us determine the age of rock quickly.
Index fossils
3
What is a surface evvent
changes to Earth's surface usually mountain formation, earthquake faults, or volcanic eruptions
3
Uranium turns into
Lead
4
rocks formed from the cooling process and used in absolute dating
igneous rock
4
the same fossil on separate continents across an ocean tell us what
the continents were connected
4
A
4
the difference between absolute dating and relative dating
relative is a comparison of rocks, absolute is an age or number
4
How did the moon form?
Collision with another planet.
4
If a scientist has a theory that the age of the Earth is 40 million years old due to the cooling rate of molten lava, how could he make this into a law
theories cannot become laws, they are the why things happen while laws are the what happens
5
Why is igneous rock used in radioactive dating
it comes from deep in the earth and therefore has more radioactive material
5
Tropites lived 208-230 million year ago. So, if a layer of rock has a lot of these fossils in it, that layer was formed somewhere between
208-230 million year ago
5
What is the law of superposition
in undisturbed layers of sedimentary rock, the younger layers lie above the older layer.
5
How does half life help with absolute age of rocks
unstable isotopes compared to stable isotopes within the rock, then use the known, constant rate of decay (half-life) for that specific isotope to calculate how many half-lives have passed since the rock solidified
5
What era we in, in relation to the geologic time scale?
Cenozoic
5
Atoms of AA decay to atoms of BB with a half-life of 100,000 years. If there are 20,000 atoms of AA to begin with (and 0 atoms of BB), how long will it take for there to be 2,500 atoms of AA?
300,000 years
After 1 half-life: 20,000/2=10,000 atoms
After 2 half-lives: 10,000/2=5,000 atoms
After 3 half-lives: 5,000/2=2,500 atoms