What are the 2 methods of dating in Geologic Time?

__________ and _______________ studied features preserved in rocks & present-day geologic processes. Why is Sir Charles Lyell important? Uniformitarianism 

Seven principles of relative dating: . Who formulated these principles? Who expounded upon these principles?

Original horizontality  Superposition  Lateral continuity Grand Canyon, Ariz.

A B Inclusions In A & C, granite contains inclusions & is younger than the inclusions. In B, sandstone is younger than the granite b/c it contains inclusions of granite. Wisconsin C

Cross-cutting relationships  Ontario, Canada Castaic, Ca Cross-cutting relationships 

Principle of deformed rocks 

Types of Unconformities What are conformable contacts? Unconformities  What is a hiatus? Types of Unconformities

What is a Disconformity? How are disconformities recognized?

What is an Angular unconformity? James Hutton = 1st to recognize & understand the significance of an angular unconformity Siccar Point, Scotland

What is a Nonconformity?

What is correlation? Why do geologists use correlation? Factors: What are Key beds?

Why are fossils important? What are Index fossils?

What is Faunal succession?

Absolute-Dating ___________________________ discovered radioactivity in 1903. Radiometric dating  Radioactivity  Isotopes 

Radioactive decay  Alpha decay Beta decay Electron capture

Half-Lives

How was the Geologic Time Scale Developed? www.acs.appstate.edu/~hagemans/timescale.html How was the Geologic Time Scale Developed?

Can sedimentary rocks be dated radiometrically? Explain. How are they dated?