RELATIVE DATING: WHICH CAME FIRST?

Brainstorm Questions 1.Why do think the Grand Canyon looks the way it does? 2. Which layers of rock are the oldest?

WHAT IS RELATIVE DATING? ANY METHOD OF DETERMINING WHETHER AN EVENT OR OBJECT IS OLDER OR YOUNGER THAN OTHER EVENTS OR OBJECTS.

WHAT ARE SOME METHODS FOR RELATIVE DATING? THE PRINCIPLE/LAW OF SUPERPOSITION THE GEOLOGIC COLUMN

THE PRINCIPLE/LAW OF SUPERPOSITION A PRINCIPLE THAT STATES THAT YOUNGER ROCKS LIE ABOVE OLDER ROCKS IF THE LAYERS HAVE NOT BEEN DISTURBED. ANALOGY??

THE GEOLOGIC COLUMN AN ARRANGEMENT OF ROCK LAYERS IN WHICH THE OLDEST ROCKS ARE ON THE BOTTOM. CONTAINS ALL THE KNOWN FOSSIL AND ROCK FORMATIONS ON EARTH. THIS HELPS SCIENTISTS INTERPRETE ROCK SEQUENCES.

EVENTS THAT DISTURB ROCK LAYERS SOME FEATURES CUT ACROSS EXISTING ROCK TO FORM NEW ROCK. UNDERSTANDING THESE FEATURES HELPS SCIENTISTS IN RELATIVE DATING.

FAULT A FAULT IS A BREAK IN THE EARTH’S CRUST ALONG WHICH BLOCKS OF THE CRUST SLIDE RELATIVE TO ONE ANOTHER.

INTRUSION AN INTRUSTION IS MOLTEN ROCK FROM THE EARTH’S INTERIOR THAT SQUEEZES INTO EXISTING ROCK AND COOLS.

FOLDING FOLDING OCCURS WHEN ROCK LAYERS BEND AND BUCKLE FROM EARTH’S INTERNAL FORCES.

TILTING TILTING OCCURS WHEN INTERNAL FORCES IN THE EARTH SLANT.

UNCONFORMITIES A BREAK IN THE GEOLOGIC RECORD CREATED WHEN ROCK LAYERS ARE ERODED OR WHEN SEDIMENT IS NOT DEPOSITED FOR A LONG PERIOD OF TIME.

GaggleTube Video Law of Superposition- Bozemanbiology 6:22