Size:  (not chosen)
How Geocaching Works
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If the weather has been kind, and your GPS has got you to the right spot, you should be standing on a pile of rocks in a small car park, looking at some of the most stunning scenery in Snowdonia. Snowdonia means mountains of snow, and contains fourteen peaks exceeding 900m.
The geology of the area is vast, with Anglsea having some of the oldest rocks ever found. There have been orogenies (mountain building events from continent-continent collision), volcanism (Snowdon is the remnants of an extinct volcano), marine floods forming vast oceans (fossils of sea organisms have been found on Snowdon’s summit) and glacial events.
It is intensive glacial erosion (during the last 2 million years) that has formed the scenery you see in front of you now. During the late Pleistocene glacial phase (aprox 18,000 years ago), a large British Ice Sheet developed in response to global cooling. The ice sheets fluctuated is size over time, with those found in high mountain areas last formed or modified during the last glacial event (Younger Dryas).
Snowdonia is an area which once supported local glaciers during this time. The glaciers emerged from the cwms and were channelled down existing valleys (carved during the previous glacial phases), and in a few cases carved out new ones.
To your front you should be able to see the Cwm, with a river incising down into the valley below. This cwm (from Welsh for valley, and another term for corrie, a hollow or cirque created by glaciation in high mountains) houses a large lake and is surrounded on three sides by the towering faces of Snowdon and Crib Goch.
If you look down the valley to your left, you will see the evidence of the glacial erosion. The classic glacial valley is U shaped, with gently rising sides.
Both the Cwm and the valley are excellent examples of glacial evidence.
To claim this cache you must post a picture of yourself with the cwm in the background.
You must also email me with the answer to these two questions.
1. What large feature can be seen at the end of the valley that might also indicate a glacier was once present.
2. Using the information above, and the internet or geological literature:
Approximately how many years ago was the last glacial event?
(No hints available.)