dynamic theories: rocks form at volcanoes, landscape affected by floods...

theories: catastrophism - 1600-1700 - series of catastrophes

uniformitarianism - late 1700s (Hutton), mid-1800s (Lyell). "present is the key to the past"

Steno's Principles: original horizontality, lateral continuity, superposition, cross-cutting relationships

Unconformities

Compare and contrast Catastrophism and Uniformitarianism. How do these two theories differ from the static view proposed by Bishop Ussher?

Describe the four basic principles proposed by Steno. How are these used to determine the relative ages of rocks?

Interpret geologic history from a block diagram