The BGS Lexicon of Named Rock Units — Result Details

Cochno Lava Member

Computer Code: CCLA Preferred Map Code: notEntered
Status Code: Full
Age range: Arundian Substage (CJ) — Asbian Substage (CR)
Lithological Description: The Cochno Lava Member includes a wide range of lava types but is characterised by more mafic varieties, particularly near the base. These include olivine-microphyric basalts (Dalmeny type), olivine-clinopyroxene-macrophyric basalts (Craiglockhart type) and olivine-clinopyroxene-plagioclase-macrophyric basalts (Dunsapie type). Localised plagioclase-macrophyric basalts (Markle type) and plagioclase-microphyric basalts (Jedburgh type) occur in the south-west, around Bowling [NS 445 738].
Definition of Lower Boundary: The Cochno Lava Member overlies the Greenside Volcaniclastic Member and represents the restarting of lava extrusion after a major break in activity.
Definition of Upper Boundary: The Cochno Lava Member is overlain by the Mugdock Lava Member.
Thickness: 100-250m
Geographical Limits: The Cochno Lava Member stretches north east from Bowling [NS 450 738] in the south-west of the Kilpatrick Hills to the south of Clachan of Campsie [NS 610 790] where the lavas are correlated with the Knowehead Lava Member of the Western Campsie Fells area. Associated vents are located at Burnside [NS 474 741], Black Loch [NS 500 765] and Craigton [NS 525 770].
Parent Unit: Clyde Plateau Volcanic Formation (CPV)
Previous Name(s): Cochno Lavas (Hall Et Al. 1998) (-756)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The Cochno Lava Member crops out between Cochno Loch [NS 500 760] and Craigton [NS 520 770]. Hall et al 1998 
Reference(s):
Hall, I H S, Browne, M A E and Forsyth, I H. 1998. Geology of the Glasgow district. Memoir of the British Geological Survey, Sheet 30E (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S030