In the last Ice Age (and in all ice ages), there were cycles of glacial (when ice covered the land) and interglacial (relatively warmer temperatures) times. Corresponding with these times, the glaciers advanced or retreated. Scientists believe the last Ice Age—also called the Pleistocene Ice Age—had eight cycles. The following lists these stages for North America (stage names for northern and central Europe differ). All dates are approximate:
Giaclai/interqiacia! Periods
| Approximate Years Ago |
|
North American Stage |
| 75,000–10,000 |
|
Wisconsin* |
| 120,000–75,000 |
|
Sangomonian (interglacial) |
| 170,000–120,000 |
|
Illinoian |
| 230,000–170,000 |
|
Yarmouth (interglacial) |
| 480,000–230,000 |
|
Kansan |
| 600,000–480,000 |
|
Aftonian (interglacial) |
| 800,000–600,000 |
|
Nebraskan |
| 1,600,000–800,000 |
|
Pre-Nebraskan |
| * Note: During the Wisconsin glacial stage, an interstadial period occurred—a time not warm or prolonged enough to be called an interglacial period. |
