Dating
Laws and Theories
Dating Continued
Fossils
Geologic Time
100

What 2 types of radio-dating are included in Absolute Age Dating?

1. Radiocarbon Dating

2. Radioactive Dating

100

Theory ends in "Y" so it explains________ a natural phenomenon happens.

Why

100

What is an isotope?

An atom of the same element that has a different number of neutrons but the same number or protons and electrons.

100

If an unknown fossil is found in a rock layer with a known fossil what does it indicate about the age of the unknown fossil?

The unknown fossil was probably from the same time period as the index fossil
100

The youngest, least dense rock layers are located where according to the Law of Superposition?

At the top

200

Relative Age Dating works under the condition that the rock layers are not affected by tectonic or volcanic activity. Therefore, these layers remain __________.

Undisturbed

200

What is the condition that allows the Law of Superposition to be considered a law?

The layers always remain undisturbed
200

Radioactive dating uses what element discussed in class to date disturbed rock layers?

Uranium, Plutonium, etc.

200
What are 3 characteristics of index fossils?

1. The species only lived for a short time

2. The species was abundant (lots of them).

3. The species was widely distributed across the world 

200

The oldest, most dense rock layers are located where according to the Law of Superposition?

At the bottom

300

Absolute Age Dating helps determine the age of very old rock layers. It works in ____________ rock layers than have experienced tectonic or volcanic activity.

Disturbed rock layers

300

What type of dating works with the Law of Superposition to determine how old rock layers are?

Relative Age Dating

300
Absolute Age Dating is not an estimate it is _________. It gives us a numerical value.

Exact

300

An example of an index fossil that was a plant is_________________. This was used to help determine how Pangea moved apart.

Glossopteris


300

Which represents the longest period of time?

Era, Period, Eon, Epoch 

Eon

400

Which type of dating uses isotopes to determine the age of archeological artifacts and rock layers?

Absolute Age Dating

400

Relative Age Dating is not exact, it ______________undisturbed layers to each other to estimate the age of the layers. 

Compares
400

Uranium is useful because it has a long 

_____-_____ and remains in rock layers for a long time. This makes it useful in dating very old rocks 

half-life 

400
An example of an index fossil that shares an ancestor with horseshoe crabs are _____________________. 
Trilobites
400

Is an Era a shorter or longer chunk of geologic time than an Period?

Longer

500

Which represents the shortest amount of geologic time?

Eon, Epoch, Period, Era

Epoch

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