| 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: |
100-250 m |
| 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
(-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): |
| Dean, M T, Browne, M A E, Waters, C N, and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report RR/10/007. 165 pp. |
| 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
|
