Relative Dating
- Principle of Original Horizontality
- Principle of Superposition
- Principles of Cross-cutting and Inclusion
- Unconformities
Absolute Age
- Radioactive parent to radiogenic daughter
- Principle of half-lives
- Age of the Earth
Geologic Time Scale
- Cenozoic: 66 million years
- Mammals and flowering plants
- Mesozoic: 245 million years
- Paleozoic: 570 million years
- Invertebrates and land plants
- Precambrian: 4600 million years
Dino Death - What happened 66 million years ago?
- Gubbio outcrop
- limestone with clay at extinction bed
- Iridium
- Spherules
- Shocked quartz
- Soot
Interpretation
- 10 km meteorite
- Creates 100 km crater (10000x all nuclear weapons)
- Killing mechanisms
- Darkness
- Cold
- Greenhouse
- Acid Rain
- Fires