EARTH SCIENCE
Platte Canyon High
School
Bailey, Colorado
GEOLOGIC TIME SCALE
Ordovician
after Harland et al., 1982
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EARTH SCIENCE |
Platte Canyon High
School |
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GEOLOGIC TIME SCALE Ordovician after Harland et al., 1982 |
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| ========================================================= | ||
| Period | Epoch | Age | Ma age | Comments |
| 438 | ||||
| Ordovician | Ashgill | Hirnantian | ||
| Rawtheyan | ||||
| Cautleyan | ||||
| Psugillian | 448 | |||
| Caradoc | Onnian | |||
| Actonian | ||||
| Marshbrookian | ||||
| Longvillian | ||||
| Doudleyan | ||||
| Harnagian | ||||
| Costonian | 458 | |||
| Llandeilo | Late | |||
| Middle | ||||
| Early | 468 | |||
| Llanvirn | Late | |||
| Early | 478 | |||
| Arenig | 488 | |||
| Tremadoc | 505 |