{{Short description|Geological formation in southern England}} {{Use dmy dates|date=April 2022}} {{Infobox rockunit | name = Teign Valley Group | image = Folds at Penally Point near Boscastle in Cornwall - geograph 3067867.jpg | caption = Folded slate at Penally Point near Boscastle in Cornwall, England | type = Group | age = Famennian (Devonian) to Marsdenian (Carboniferous) | period = Paleozoic | prilithology = mudstones, | otherlithology = cherts, sandstones, limestones, basaltic lavas, tuffs | namedfor = valley of River Teign | namedby = | region = England | country = United Kingdom | coordinates = | unitof = Culm Supergroup | subunits = Barras Nose Formation, Trambley Cove Formation, Teign Chert Formation, Dowhills Mudstone Formation, Boscastle Formation, Brendon Formation, St Mellion Formation | underlies = Holsworthy Group | overlies = Exmoor Group | thickness = 100 to 720m | extent = north Cornwall through Devon to west Somerset | area = | map = | map_caption = }}
The '''Teign Valley Group''' is a late Devonian to late/middle Carboniferous lithostratigraphic group (a sequence of rock strata) in north Cornwall through Devon and into west Somerset in southwest England. The name is derived from the valley of the River Teign. The Group comprises (in ascending order i.e. oldest first) the Barras Nose, Trambley Cove, Teign Chert and Dowhills Mudstone formations. It also includes the Brendon and St Mellion formations whose stratigraphical context is unclear since all known boundaries of these two unit are tectonic. The Brendon Formation slates extend from Tavistock west to Bodmin Moor.<ref>British Geological Survey 1993 ''Tavistock'', England and Wales sheet 337 Solid & Drift geology 1:50,000 provisional series (Keyworth, Nottingham: BGS)</ref><ref>{{Cite web|url=https://www.bgs.ac.uk/lexicon/lexicon.cfm?pub=BREN|title = BGS Lexicon of Named Rock Units - Result Details}}</ref> The St Mellion Formation sandstones, siltstones and mudstones are found from Holne northeastwards.<ref>http://mapapps.bgs.ac.uk/geologyofbritain/home.html {{Webarchive|url=https://web.archive.org/web/20161202013758/http://mapapps.bgs.ac.uk/geologyofbritain/home.html |date=2 December 2016 }} BGS map viewer</ref> The Teign Valley Group was formerly known as the Lower Culm Group or Lower Culm Measures.<ref>http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=TEVY (BGS on-line lexicon of rock units)</ref>
==References== {{Portal|Cornwall}} {{Reflist}}
Category:Carboniferous System of Europe Category:Devonian System of Europe Category:Geology of England Category:Geological groups of the United Kingdom Category:Mudstone groups Category:Chert groups Category:Sandstone groups Category:Limestone groups Category:Basalt groups Category:Tuff groups