Computer Code: |
HBW |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Llandovery Epoch (SL)
— Llandovery Epoch (SL) |
Lithological Description: |
Red-brown mudstones, typically massive, but with thin horizons of paler brown calcareous nodules. |
Definition of Lower Boundary: |
At the lowest appearance of red coloured mudstones above the green-grey mudstones and siltstones of the lower part of the Browgill Formation. |
Definition of Upper Boundary: |
At the top of the last red mudstone, in the transition to the pale grey mudstone of the overlying Far House Member. |
Thickness: |
0-20m |
Geographical Limits: |
Unit extends intermittently across the Howgill Fells inliers, and is known in several Lake District sections, (Ingham, J K, et al, 1978). |
Parent Unit: |
Browgill Formation (BRW)
|
Previous Name(s): |
Red Beds [Obsolete Name And Code: Age And Synonymy Unrecorded]
(RBD)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Section |
Hebblethwaite Hall Gill, 200m southwest of Hebblethwaite Hall. |
Reference(s): |
Rickards, R B, 1970. The Llandovery (Silurian) graptolites of the Howgill Fells (northern England). Monograph Palaeontological Society, London, 1-108. |
Rickards, R B, 1973. On some highest Llandovery red beds and graptolite assemblages in Britain and Eire. Geological Magazine, Vol.110, 70-72. |
Ingham, J K, McNamara, K J and Rickards, R B, 1978. The Upper Ordovician and Silurian rocks. 29-44 in Moseley, F (editor) "The Geology of the Lake District". Yorkshire Geological Society, Leeds. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |