Computer Code: |
AKB |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Asbian Substage (CR)
— Asbian Substage (CR) |
Lithological Description: |
Alternating limestones, calcareous mudstones and mudstones with some calcareous sandstones. The strata contain a marine fauna of polyzoa, corals, brachiopods and bivalves. |
Definition of Lower Boundary: |
Conformable contact with a thick seatearth lying c.90m above the Kinmont Limestone. |
Definition of Upper Boundary: |
Conformable contact with unfossiliferous sandstones and mudstones c.15m below the base of the Cornet Limestone. |
Thickness: |
c. 100 m. Limestones form up to 33% of the thickness. |
Geographical Limits: |
Confined to the Langholm district. |
Parent Unit: |
Tyne Limestone Formation (TYLS)
|
Previous Name(s): |
Archerbeck Limestone Formation [Obsolete Name And Code: See AKB And TYLS]
(ARLS)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Section |
Archerbeck Borehole from 520m to 621m depth from the surface; registered No. NY 47 NW/14, Langholm (1:50k Sheet 11 [Scotland], Langholm.) |
Partial Type Section |
In the Liddel Water, 0.7km southeast of Harelawslack, Langholm, Scotland. |
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). |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |