RESTLESS EARTH
Chapter 3:
Uniformitarianism​
~ A principle that states that the same geologic
processes shaping the Earth today have been at work throughout
Earth’s history. These changes remain ​
uniform​
or do not change over
time. “The present is the key to the past”
Catastrophism​
~ A principle that states that all geologic change
occurs suddenly. Mountains, canyons, and seas can be explained by
rare, sudden events called ​
catastrophes​
.
Uniformitarianism VS. Catastrophism video
https://www.youtube.com/watch?v=zKBLp3AffRg
Video about relative dating, superposition, and geologic column
https://www.youtube.com/watch?v=VgeugxN217c
Relative Dating​
~ Geologists rely on rocks and fossils to determine
whether an object or event is older or younger than other objects or
events.
Absolute Dating​
~ The process of establishing the age of an object,
such as a fossil or rock layer, by determining the number of years it
has existed.
Relative Dating VS. Absolute Dating
https://www.youtube.com/watch?v=vLNA0qr8l3Q
Superposition​
~ The principle that younger rocks lie above older rocks
in undisturbed sequences. “younger over older”
Geologic Column​
~ Geologists combine data from all unknown
undisturbed rock sequences around the world. They create a ​
geologic
column​
which is an ideal sequence of rock layers that contains all the
known fossils and rock formations on Earth arranged from oldest to
youngest.
Fault​
~ A fault is a break in the Earth’s crust along which blocks of
the crust slide relative to another.
Intrusion​
~ Molten rock from the Earth’s interior (inside) that
squeezes into existing rocks and cools.
Folding​
~ This occurs when rock layers bend and buckle from Earth’s
internal forces.
Tilting​
~ This occurs when internal forces in the Earth slant rock
layers without folding them.
Geologic Time Scale​
~ A scale that divides Earth’s 4.6 billion-year
history into distinct intervals of time.