Vocab
Law of Superposition
Fossils
Absolute vs. Relative Dating
History of Planet Earth
100
A technique used to determine the chronological order of species without knowing the absolute date or age.
Relative Dating
100
Where will the youngest rock layer be found in a core sample?
The top of the rock strata
100
How many index fossils are shown?
3 index fossils
100
Which is more exact - absolute or relative dating?
Absolute
100
How old is planet Earth?
~4.5 billion years
200
The mineralized remains of organisms, showing how long-dead organisms lived and how their bodies were structured.
Fossils
200
Put the rock formations in chronological order based on their position in the rock strata.
Slate
Sandstone
Limestone
Basalt
Siltstone
200
If you find a rare, one-of-a-kind fossil in a remote part of the world, would it be a good index fossil? Yes or no?
NO! Index fossils need to be abundant (lots of them) and widespread (all over the world).
200
Is carbon dating a method of absolute or relative dating?
Absolute
200
Which is the longest era of Earth?
Precambrian era
300
Fossils that are used to find the relative date of rock layers. They are abundant, widespread, and found in one rock layer.
Index fossil
300
Define the Law of Superposition
In a rock strata, older layers will be found at the bottom of the strata, while younger layers will be found at the top.
300
Draw the shape of the most abundant index fossil.
300
Is the Law of Superposition a method of relative or absolute dating?
Relative Dating
300
How was Earth's moon formed?
The planet Theia collided with Earth, and the debris combined into the moon.
400
The layers of sedimentary rock having approximately the same composition throughout.
Rock strata
400
If the horse ancestor lived 55-100 mya and the fish ancestor lived 301-440 mya, what is the relative age of the dinosaur fossil?
101-300 mya
400
What are the 3 characteristics of index fossils?
Abundant
Widespread
Only found in one layer
400
Absolute and relative dating will both tell you what information about geologic events?
The chronological order of events
400
Which time period is older - Triassic or Jurassic?
Triassic
500
A technique used to determine how old a rock is by analyzing the amounts of radioactive isotopes and their decay products in the rock.
Radioactive Dating or Radiometric Dating
500
Draw a 6 layered rock strata with:
-an intrusion within the oldest and second oldest layers
-an intrusion within the second youngest and third youngest layers
500
How do scientists use index fossils
Narrow the time frame when using relative dating of rock layers.
Help scientists align rock layers from different digsites.
500
Pakicetus, the whale ancestor, was alive 50 mya.
Write how you could use both relative and absolute dating to determine that number.
Relative dating: if Pakicetus fossil was found between two layers with index fossils, making the relative age about 50 mya
Absolute dating: by carbon dating the rocks around the Pakicetus fossil
500
According to our geologic timeline activity, when did modern humans evolve?
200,000 years ago