Show:
The Position of Rock Layers
Determining Relative Age
Using Fossils to Date
100
The remains of organisms
What is a sediment rock
100
Lava that hardens on the surface
What is extrusion
100
How can a fossil be useful as an index fossil
What is a fossil must be widely distrubuted and represents a type of organism that existed only briefly
200
It is age compared to the ages of other rocks
What is the Relative Age of a rock
200
Magma that cools and hardens into a mass of igneous
What is intrusion
200
A type of organism that Geologists use as an index fossils
What is ammonitesm
300
To determine the relative age of sediment of rock layers
What is the Law of Superposition
300
A break in the Earth's crust
What is a fault
300
How are index fossils useful
They tell the relative ages of rock layers in which they occur
400
The number of years since the rock was formed
What is the Absolute Age of a rock
400
A gap in the geologic record
What is unconformity
400
To date rock layers, geologists first give a ____ ____ to a ____ __ ____ at one location and then give the same age to matching layers at other locations.
relative age; layer of rock
500
The oldest layer is at the bottom and it gets younger as it goes up
What is the order of the rocks work
500
A piece of rock that is contained in another rock
What is inclusion
500
Geologists look for ____ ____ in layers of rocks.
What is index fossils