Pre-AP Geophysical Science
Unit 6: Earth History
TOPIC: Age of the Earth…How do we know?
Main Ideas/ Questions
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Details and New Information
It is estimated that the age of the Earth is:
How do we measure this???
Relative Time
vs.
Examples
Using the Rock Record to determine Relative Time….
Law of Superposition
Unconformities
Summary
Absolute Time
Pre-AP Geophysical Science
Main Ideas/ Questions
Unit 6: Earth History
Details and New Information
Nonconformity
Angular Unconformity
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Disconformity
Law of Crosscutting relationships
Law of Included Fragments
Faulted and Folded Layers
Summary
Label the diagram A through M… A being the oldest, M being the youngest
Pre-AP Geophysical Science
Main Ideas/ Questions
Unit 6: Earth History
Barlow2014
Details and New Information
Rock Correlation
Outcrop-
Key Bed-
Geologic Rock Symbols
Sandstone
Limestone
Conglomerate
Granite
Using the Rock record to determine Absolute Age…
Rates of Erosion and Deposition
Tree Rings
Varve Count
Summary
Shale
Metamorphic
Pre-AP Geophysical Science
Main Ideas/ Questions
Unit 6: Earth History
Details and New Information
Radioactive Dating
Radioactive isotope:
Radioactive decay:
Half-Life
Parent isotopeDaughter isotope-
Carbon dating
Other Methods:
Summary
Barlow2014