Today’s Learning Goal: Wednesday, November 9th, 2011 Bell Ringer: Pull out your football field, and consider: Where does most of life fit into the geologic time scale? Humans? You? Today’s Learning Goal: We are going to learn 5 Principles of Relative Age Dating Original Horizontality, Superposition, Cross-Cutting, Inclusions, Fossil Succession Today’s Agenda: Football Field Conclusion Relative Age Dating Principles Begin Cross-Section Assignment

John Day Fossil Beds, Painted Hills Unit Relative Age Dating

Principle of Original Horizontality Layers (Strata) of sediment are generally deposited in a horizontal position. If these layers are not horizontal, they have been deformed through earth processes.

Mary’s Peak, Corvallis, OR

Principle of Superposition In an undeformed sequence of sedimentary rock, each strata is older than the one above and younger than the one below.

Mary’s Peak, Corvallis, OR

Principle of Fossil Succession Fossil organisms (Plants and Animals) show up in the geologic record in a definite and determinable order. Any period of geologic time can be recognized by its fossil content.

He always does this. He’s such a NERD! Oregon Coast, near Newport, OR He always does this. He’s such a NERD!

FOSSILS

Principle of Inclusions A rock body containing inclusions of pre-existing rocks is younger than the rocks from which the inclusions came.

Principle of Cross-Cutting Relationships When a fault or igneous intrusion cuts through other rocks, the fault and intrusion are younger than the rocks they affect.

Let’s Practice these 5 principles!

Figure A

John Day Fossil Beds, Sheep Rock Unit

Figure B

Figure 4

Design your own cross-section Start by writing out the geologic history, then drawing what it would look like! Requirements: At least 5 layers Intrusion Fault OR Folding w/ erosion

No exit card today  Exit Card: Today’s Learning Goal: We are going to learn 5 Principles of Relative Age Dating Original Horizontality, Superposition, Cross-Cutting, Inclusions, Fossil Succession Tomorrow’s Learning Goals: Continuing our journey through the 5 Principles of Relative Age Dating