Original Horizontality Relative Dating Superposition Original Horizontality Faulting Tilting/Folding Intrusions Unconformities Geologic Columns Rock Puzzles

I. RELATIVE DATING: Determining whether an object or an event is older or younger than other objects or events. Relative Age? Layer 1 Layer 2 Layer 3 Layer 4

II. SUPERPOSITION: Younger rock lie above older rock. A. Law of Original Horizontality – Sedimentary rocks form layers of horizontal strata. List the rocks in order from youngest to oldest!

III. Disturbed Rock Layers: Events are younger than the rock layers Faulting – a break in the Earth’s curst where one rock layers will slide Intrusions – when molten rock squeezes into existing rock and cools Folding & Tilting – When internal forces bend or tilt rock layers Unconformities – a surface that represents an area where there is a missing piece of geologic rock

Cross Cutting Faulting Folding Unconformity

Faulting Intrusions

IV. Geochronology - the science of dating and determining the time sequence of events in the history of the Earth.

IV. Geochronology - Key