 ASU |
 UTEP |
SWGEONET |  GEON |
 NSF |
 NASA |
SWGEONET Geologic Time Scale |
| Eon | Era | Period | Time (million years before present) |
|
| Phanerozoic | Cenozoic | (Q) Quaternary | 1.8 to now | |
| (T) Tertiary | 65 to 1.8 | |||
| Mesozoic | (K) Cretaceous | 146 to 65 | ||
| (J) Jurassic | 208 to 146 | |||
| (Tr) Triassic | 245 to 208 | |||
| Paleozoic | (P) Permian | 280 to 245 | ||
| (IP) Pennsylvanian | 325 to 280 | |||
| (M) Mississippian | 363 to 325 | |||
| (D) Devonian | 417 to 363 | |||
| (S) Silurian | 443 to 417 | |||
| (O) Ordovician | 495 to 443 | |||
| (C) Cambrian | 540 to 495 | |||
| Proterozoic | 2500 to 540 | |||
| Archean | 3900 to 2500 | |||
| Hadean | 4600 to 3900 | |||
Geology Topography |
Earthquakes Landslides |
ASTER NDVI |
Gravity |
Downloads Glossary Geologic Time |