EOG Vocabulary Review

Law that states in undisturbed sedimentary rock layers, older layers of rock are beneath younger layers

• Intrusion
• Law of Superposition 
• Igneous rock

Measuring the age of materials by comparing the amount of radioactive form

• Radioactive dating
• Relative dating
• Radioactive decay

The actual age of a rock or fossil

• Absolute Age
• Relative Age
• Estimate

the age of rocks or fossils compared to other rocks and fossils

• Absolute age
• Radioactive dating
• Relative age

a sudden, severe change in conditions on earth

• Catastrophic
• Earth's climate
• Earth's weather

break in the geological record due to surfaces eroding

• Cracks
• Unconformity 
• Faults

fossil that is used for dating geologic layers

• Trace fossil
• Mold
• Index fossil 

a cylinder of ice from an ice sheet

• Ice Core
• Icicle 
• Glaciers

a crack in earth's surface

• Cracks
• Faults
• Continents 

a rock layer that collects and stores water

• Aquifer
• Aqua
• Sedimentary