ROCKS TELL A STORYMonday, May 16th

-Stratigraphy….what do cliffs tell us?Rock Test WEDNESDAY!!!!!

If you want to study rock I.D, stop after or before school.

QUESTIONS TO PONDER

•What is one of the three types of rocks

we just learned?

QUESTIONS TO PONDER

•If you found that rock in your backyard, what would that tell you?

3 RULESNatural LAWS

geologist use to “see under the ground”

1st RULE•LAW OF SUPERPOSITION

-the oldest rocks are on the bottom

2nd RULE•LAW of Horizontality –sediments occur in

horizontal layers

3rd RULE•LAW OF CROSS CUTTING

- Any rock melting through another rock

must be younger

WHATS UNDER US?

ROCKS TELL A STORY

AHH!

•INTRUSION?•EROSION?

•WEATHERING?Deposition?

ANGULAR UNCONFORMITY

•The erosion of tilted rock with new

deposits on top

DISCONFORMITY

•Horizontal Layers are removed and new layers take

their place

IGENOUS INTRUSION

•Interruption of rock layers by igneous rock

–Ex. BATHOLITHS, DIKES, SILLS,