Computer Code: |
CGD |
Preferred Map Code: |
CGD |
Status Code: |
Pending Upgrade |
Age range: |
Llandovery Epoch (SL)
— Llandovery Epoch (SL) |
Lithological Description: |
Greywackes (beds dominantly less than 0.5 metres thick) with interbedded mudstones including some red mudstone beds. Includes few thicker massive arenite beds to east. Distinguished from 'underlying' Kirkmaiden Formation by presence of red mudstone beds. Distinguished from overlying Riccarton Group by presence of red mudstone beds and absence of dark grey finely laminated siltstone beds. |
Definition of Lower Boundary: |
'Lower' (i.e. Northern boundary) - gradational from Kirkmaiden Formation. |
Definition of Upper Boundary: |
Upper - faulted contact with Riccarton Group at Burrow Head (NX 4528 3414). |
Thickness: |
c 4000 metres section of vertical strata but some folding and locally intense faulting renders accurate assessment of stratigraphical thickness impossible. |
Geographical Limits: |
Not defined. |
Parent Unit: |
Hawick Group (HWK)
|
Previous Name(s): |
Carghidown Beds [Obsolete Name and Code: Use CGD]
(-3920)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Section |
Port of Counan to Burrow Head Coastal section, Sheet S02. |
Reference(s): |
Rust, B R. 1965. The stratigraphy and structure of the Whithorn area of Wigtownshire, Scotland. Scottish Journal of Geology, Vol.1, Part 2, p.101-133. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
S002
S001
S003
S004
S006
|