Editing Kerrera (section)

== Geology ==
The oldest bedrock of Kerrera is black [[slate]] ascribed to the Easdale Subgroup of the [[Dalradian]] [[Argyll Group]].  Overlying this across half of the island are [[conglomerate (geology)|conglomeratic]] [[sandstone]]s and [[basalt]] and [[augite]]-[[andesite]] [[lava]]s of early [[Devonian]] age, the former being the local representative of the [[Old Red Sandstone]] and the latter constituting part of the [[Lorne plateau lavas|Lorne Plateau Lavas]]. [[Ripple mark]]s and [[mudcrack|sun cracks]] are preserved in  [[shale]] strata on the south coast, belying the subaerial environment in which deposition of these sediments took place. There are thin [[limestone]]s within both the Easdale Slate Formation and the younger sandstones. All of these strata are cut by NW-SE aligned [[igneous]] [[dike (geology)|dykes]] forming part of the [[North Atlantic Igneous Province|North Britain Palaeogene Dyke Suite]] associated with early [[Palaeogene]] [[volcanism]]. A number of [[fault (geology)|geological faults]] cut across Kerrera, the majority are aligned NE-SW.
Modern beach deposits and [[raised beach|raised marine deposits]] of [[Holocene]] age are found around the island particularly on the north coast and along the Sound of Kerrera.<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=5 February 2020}}</ref><ref>{{cite web |title= Lismore, sheet 44E (Scotland), Solid Edition |url=http://www.largeimages.bgs.ac.uk/iip/mapsportal.html?id=1002389 |website=BGS large map images |publisher=British Geological Survey |access-date=5 February 2020}}</ref>