| Computer Code: |
ULHLA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Arundian Substage (CJ)
— Asbian Substage (CR) |
| Lithological Description: |
The Upper Lecket HIll Lava Member consists generally of relatively evolved lavas, including trachybasalt (hawaiite), basaltic-trachyandesite (mugearite), trachyte and rare plagioclase-microphyric basalt transitional to trachybasalt (of 'Jedburgh' type). The member is generally poorly exposed, but at least seven platy-jointed and rather slaggy lavas are present. North-east of the summit of Lecket Hill [NS 6445 8121], lapilli-tuffs and agglomerates predominate locally over lavas. Craig (1980) has inferred that the source of the member was the nearby Waterhead Centre ('Waterhead Central Volcanic Complex'). |
| Definition of Lower Boundary: |
The basal basaltic-trachyandesite (mugearite) lava of the member is conformable or disconformable on underlying plagioclase-macrophyric trachybasalt (hawaiite) lava of the Boyd's Burn Lava Member. |
| Definition of Upper Boundary: |
The Upper Lecket Hill Lava Member is overlain apparently conformably or disconformably by the Kilsyth Hills Lava Member, which has a similar geographical distribution. The lithological change is to plagioclase-macrophyric transitional to plagioclase-microphyric basalt and trachybasalt (hawaiite) lavas (of 'Markle' type transitional to 'Jedburgh' type). |
| Thickness: |
65 m |
| Geographical Limits: |
The member is restricted to the Campsie Block and has a limited geographical extent, (reflecting the proximal character of the lava flows) in the eastern Campsie Fells and westernmost Kilsyth HIlls, north of Glasgow. |
| Parent Unit: |
Clyde Plateau Volcanic Formation (CPV)
|
| Previous Name(s): |
Upper Lecket Hill Lavas [Obsolete Name and Code: Use ULHLA]
(-4383)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The eastern Campsie Fells, and westernmost Kilsyth HIlls, north of Glasgow. Forsyth et al., 1996, after Craig, 1980. |
| Reference Section |
Back Burn. Craig, 1980. |
| 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. |
| Forsyth, I H, Hall, I H S, and McMillan, A A. 1996. Geology of the Airdrie district. Memoir of the British Geological Survey, Sheet 31W (Scotland). |
| Craig, P M. 1980. The Volcanic Geology of the Campsie Fells area, Stirlingshire. Unpublished Ph.D thesis, University of Lancaster. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S030
|
