Editing Snowdonia (section)

== Geology==
{{main|Geology of Snowdonia National Park}}
[[File:Slate_quarry_near_Penygroes.jpg|thumb|left|Slate quarry with [[Mynydd Mawr]] in the background]]

The geology of Snowdonia is key to the area's character. [[Glaciation]] during a succession of ice ages has carved a distinctive rocky landscape from a heavily [[fault (geology)|faulted]] and [[Fold (geology)|folded]] succession of [[sedimentary rock|sedimentary]] and [[igneous rock]]s. The [[Last Glacial Period|last ice age]] ended only just over 11,500 years ago, leaving features attractive to visitors, which have also played a part in the development of geological science and continue to provide a focus for educational visits. Visiting [[Cwm Idwal]] in 1841, [[Charles Darwin]] realised that the landscape was the product of glaciation.<ref>{{cite web |title=Darwin Discoveries at Cwm Idwal |url=https://www.nationaltrust.org.uk/carneddau-and-glyderau/features/darwin-discoveries-at-cwm-idwal |publisher=National Trust |access-date=2 June 2020}}</ref> The [[bedrock]] dates largely from the [[Cambrian]] and [[Ordovician]] periods with [[intrusive rock|intrusions]] of Ordovician and [[Silurian]] age associated with the [[Caledonian Orogeny]]. There are smaller areas of Silurian age sedimentary rocks in the south and northeast and of [[Cenozoic]] era strata on the [[Cardigan Bay]] coast, though the latter are concealed by more recent deposits. Low grade [[metamorphism]] of Cambrian and Ordovician [[mudstone]]s has resulted in the [[slate]]s, the extraction of which once formed the mainstay of the area's economy.