Snowdonia Flashcards
1
Q
Location
A
- Near Irish sea
- North west of wales
- Next to Lleyn peninsula
- Is a national park
- Part of cambrian mountain range
2
Q
Formation of glacier
A
- Small drop in temp = snow settle, little melting during summer
- Accumulation of snow (firn)
- Compresses into ice (nevé), then blue glacial ice, (forms ice sheets)
- Ice sheets cover landscape, flow via gravity
- Melt in warm environment or meet sea
- Sea level lower, water frozen, not part of water cycle
- Temp fell 2.4m years ago
- 10k years ago ice retreated
3
Q
Geological history
A
- Upland area
- Geological events occured, Cambrian times (500m years) to Ordovician & Silurian period (430m & 390m years)
- Experienced volcanic activity + sedimentry deposition
- End of Silurian period, majoir uplift (Caledonian earth movement), upland area today
- Eroded mountains
- Aerial (climatic) and fluvial erosion
4
Q
Landforms
A
- Cwms, arêtes, pyramid peaks, formed at glacier source
- U shaped valley upland area (Nant Francon Valley). Steep sides, flat valley floor, truncated spurs, remains of interlocking spurs
- Hanging valley mark old course
- Roche moutonnée from volcanic dyke
- Lyn Ogwen, ribbon lake, follows valley shape
5
Q
Change over millennia
A
- Ice reached furthest extent 20k years ago in the midlands finishing in East Anglia
- Followed by period of warming
- Snout of valley glaciers retreated back, small corrie glaciers left 12k years ago
- These then disappeared
