| Computer Code: |
KHB |
Preferred Map Code: |
KHB |
| Status Code: |
Full |
| Age range: |
Holkerian Substage (CQ)
— Holkerian Substage (CQ) |
| Lithological Description: |
Porphyritic olivine-basalt lava. Neither top, nor base is exposed in the Langholm District. As described in the Langholm memoir it is unclear whether associated "sediments" are interbedded with or below the basalt at the type locality of Kershope Quarry, but they probably sit at the base of the basalt. The lithology of the KHB is therefore defined only as olivine-basalt. |
| Definition of Lower Boundary: |
Not seen but presumed to be conformable with sedimentary rocks of the Fell Sandstone Formation. Underlain by sedimentary strata, mainly sandstones of the Fell Sandstone Formation. |
| Definition of Upper Boundary: |
Not seen but presumed to be conformable with sedimentary rocks of the Fell Sandstone Formation. Overlain by sedimentary strata, mainly sandstones of the Fell Sandstone Formation. |
| Thickness: |
About 30m |
| Geographical Limits: |
Scattered outcrops east of Langholm, Dumfries and Galloway between 340000 583000 and 350000 583000. |
| Parent Unit: |
Fell Sandstone Formation (FELL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
In the base of Kershope Quarry, by Kershope Bridge, and downstream in Kershope Burn there are exposures of basalt and sediment close to the base. At the top of the quarry, the basalt is vesicular and slaggy, suggestive of lava, rather than a sill. Lumsden et al., 1967, p. 95 - 96. |
| Reference(s): |
| Lumsden G I, Tulloch W, Howells M F and Davies A. 1967. The geology of the neighbourhood of Langholm. Memoir of the Geological Survey, Sheet 11 (Scotland). |
| Day, J B W and others, 1970. Geology of the neighbourhood around Bewcastle. Memoir of the British Geological Survey, Sheet 12. (England and Wales). |
| Stephenson, D, Loughlin, S C, Millward, D, Waters, C N and Williamson, I. 2003. Carboniferous and Permian igneous rocks of Great Britain, north of the Variscan Front. Geological Conservation Review Volume 27. Joint Nature Conservation Committee: Peterborough. 374 pp. |
| Peach, B N and Horne, J .1903. The Canonbie coalfield: its geological structure and relations to the Carboniferous rocks of the north of England and central Scotland. Transactions of the Royal Society Edinburgh, 40, 835-77. |
| Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) |
| 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. 165pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S011
E012
|
