Terminal and recessional moraines as glacial indicators. Terminal moraines mark the furthest extent of glacier advance Drumlins form beneath glaciers, not outside them, and are always found above terminal moraines When glaciers pause during retreat, they build recessional moraines
Terminal moraines mark the furthest extent of a glacier's advance — think of them as the "I was here" line. Drumlins, meanwhile, form underneath the ice as streamlined features molded by glacial movement. When glaciers pause during retreat, they build recessional moraines, which are similar to terminal moraines but form where the glacier temporarily stabilizes rather than at maximum advance. Glaciers really are like bulldozers piling material up in front of them, with internal conveyor-like systems transporting and depositing debris. Ancient geological construction crews!
Key Facts
- Terminal moraines mark the furthest extent of glacier advance
- Drumlins form beneath glaciers, not outside them, and are always found above terminal moraines
- When glaciers pause during retreat, they build recessional moraines
- Moraines are constructional features built by glacial movement and internal conveyor-like systems
- Glaciers act as bulldozers, piling up material in front of them
Source: Speak To The Earth and It Shall Teach Thee: Younger Dryas Series S1E4 by The Randall Carlson