Lake District Flashcards
what is the Lake District?
upland landscape in Cumbria
what are the three main groups of rocks found in the lake district?
skiddaw group
borrow dale volcanic
windermere series
the skiddaw group
the oldest, formed as black muds + sands settling on sea bed 500 mill yrs ago -> they have since been raised up + folded by tectonic forces, mainly found in the N + mountains formed = smooth, w many streams occupying deep gorges
borrowdale volcanic rock
consist of very hard lava + ash formed in eruption 450 mill yrs ago that have withstood erosion + make up the highest mountains eg Scafell, Helvellyn + great gable
the windermere series
sedimentary mudstones, sandstones, siltstones + some limestone about 420 mill yrs ago -> later folded + faulted, pushed up + eroded down to their present levels
what other two significant geologies are there?
- huge masses of granite were intruded 400 mill yrs ago -> erosion has revealed outcrops in eskdale, ennerdale + Shap
- shell + skeletal remains as 320 mill yrs ago a tropical sea covered the LD -> huge no.s of small marine animals formed the carboniferous limestone which crops out at whit barrow, scout scar in the south
the present landscape is a result of which glaciation period?
Pleistocene
what is the helvellyn range?
11km long ridge over 600 m high with numerous glacial erosional landforms
what is an example of a pyramidal peak?
helvellyn summit at 950m above sea level
-> lacks more than two corries on its flanks hence has been less sharply eroded on their back walls
what allowed valley glaciers to form ?
corrie glaciers
what is the tarn called?
Red Tarn
what is the very narrow arête called?
Striding edge
what did ice from the red tarn do?
flowed into the valley of glen ridding, forming a valley glacier large enough to create a small glacial trough
this then fed into much larger valley glacier + glacial trough occupied by ullswater today
why is ullswater floor irregular?
volcanic bands of rock
an example of a Roche moutonnee?
Norfolk island -> formed on an outcrop of the volcanic rock in the middle of the lake
what landforms are there on the west side of helvellyn range?
truncated spurs + hanging valleys
one of the spurs contains a stream , helvelllyn gill which has a series of small waterfalls as it drops 500m in just over 2km from low mod to thirlmere
how were the drumlins fields formed?
ice moved radially in all directions
eg south to Lancashire, east into n Yorkshire
they are extensive fields south of kendal
what are the characteristics of the drumlins?
lie on carboniferous rocks + range from 50m to 125m, they have broad rounded tops + freq steep sided, some drumlins rock cored while others consist entirely of till
rarely found above 300m above sea level
what is the average elongation ratio of drumlins?
3:1
where is an example of lateral moraine?
right bank of Langstrath valley -> distinctive appearance due to lack of mass movement process on the valley side
an example of medial moraine?
runs down the centre of Wythburn valley
example of recessional moraine?
Blea Water tarn in mardale
terminal moraine
the saddle valley SE of Keswick, 10 m - 15m high, 200-400m long
the saddle beck cut through it + today it is eroded + degraded
what depositional landform is common in the LD?
erratics, a no. of erratics from borrowdale volcanic group have been transported 30 km SE + deposited on carboniferous limestone at witherslack
best known lakeland erratics are those from Shapiros
