landforms construct past ice extent Flashcards
(5 cards)
terminal moraine
-give evidence of glaciers furthest extent
-glacial geologists compile data bases and maps of these moraines, interpolating between them and creating past ice extent maps
drumlins and crag & tail
-indicate direction of ice flow
- Drumlins in Vale of Eden (Cumbria) show ice moved eastwards
erratics
-give clues on direction of movement
-work out source = work out origin
corries, aretes, glacial troughs
-leaves relict glaciateed landscapes that show evidence of previous ice coverage e.g. Snowdonia, lake district show most of country covered in Devensian
-distinctive glacial features e.g. steep back wall and steep sided, narrow ridges (aretes)
striations and polished rock surfaces
-microscale features can help show extent of coverage
-despite small size, link between striations and process of basal slip means they can be used to infer former presence of a glacier, direction of ice flow, mechanism of flow, and thermal reigme of glacier