| Computer Code: |
GRWC |
Preferred Map Code: |
GRWC |
| Status Code: |
Full |
| Age range: |
Wenlock Epoch (SW)
— Early Devonian Epoch (DL) |
| Lithological Description: |
Conglomerate of cobbles and boulders up to 250mm diameter but most clasts are less than 70mm, mostly subrounded, consisting of greywacke, minor chert and quartzite, with a few sandstone beds. |
| Definition of Lower Boundary: |
In the type section, defined as the lowest bed of conglomerate with predominant greywacke clasts overlying the Quarry Arenite Formation. Elsewhere generally unconformable on Lower Palaeozoic rocks. |
| Definition of Upper Boundary: |
The upper surface of the highest bed of greywacke conglomerate below the overlying Swanshaw Sandstone Formation. |
| Thickness: |
From 25 m to 560 m thick. |
| Geographical Limits: |
Overlies the Lower Palaeozoic inliers in the southern part of the Midland Valley from Girvan to North Esk, on 50k sheets 14W, 14E, 15W, 23W, 23E, 24W, 32W. |
| Parent Unit: |
Lanark Group (LNK)
|
| Previous Name(s): |
Greywacke Conglomerate [Obsolete Name and Code: Use GRWC]
(-1575)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Monk's Water/Douglas Water section, near Monksfoot Farm. |
| Reference(s): |
| Rolfe, W D I, 1961. The Geology of the Hagshaw Hills Silurian Inlier, Lanarkshire. Transactions of the Edinburgh Geological Society, Vol.18, Part 3, 240-269. |
| Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. |
| Browne, M A E, Smith, R A, and Aitken, A M. 2002. Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. British Geological Survey Research Report RR/01/04. 67 pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S015
S024
S015
S033
S023
S023
S008
S007
S008
S032
S032
S014
S014
S022
|
