Editing Coll (section)

== Geology ==
Coll is formed largely from [[gneiss]] forming the [[Lewisian complex]], a suite of [[metamorphic rock]]s of [[Archean|Archaean]] to early [[Proterozoic]] age.<ref>{{cite web |title=Tiree and Coll, Scotland sheet 42 and 51W (Solid and Drift) |url=http://www.largeimages.bgs.ac.uk/iip/mapsportal.html?id=1002385 |website=BGS large map images |publisher=British Geological Survey |access-date=3 February 2020}}</ref> The eastern part of the island is traversed by numerous [[normal fault]]s most of which run broadly northwest–southeast.  [[Dolerite]] and [[camptonite]] [[dike (geology)|dykes]] of [[Permian|Permo]]-[[Carboniferous]] or [[Tertiary]] age are also seen in the east of the island. 
[[Quaternary]] [[sediment]]s include [[raised beach]] deposits which are frequent around Coll's coastline whilst stretches of [[alluvium]] occupy some low inland areas. There are considerable areas of blown sand in the west and along stretches of the north coast and of [[peat]] southwest from [[Arinagour]].<ref>{{cite web |title=Onshore Geoindex |url=https://mapapps2.bgs.ac.uk/geoindex/home.html |website=British Geological Survey |publisher=British Geological Survey |access-date=3 February 2020}}</ref>