| Computer Code: |
LYM |
Preferred Map Code: |
LYM |
| Status Code: |
Pending Upgrade |
| Age range: |
Rhuddanian Age (SR)
— Rhuddanian Age (SR) |
| Lithological Description: |
[Obsolete: use LYMD] Interbedded silty mudstones, grey-buff, and thin fine-grained sandstones; some mass flow and slumped strata, including coarse sandstones and conglomerate. |
| Definition of Lower Boundary: |
Not seen, but probably unconformable upon strata of mid-Caradoc age. |
| Definition of Upper Boundary: |
Not seen. |
| Thickness: |
Unknown. |
| Geographical Limits: |
Western side of the Severn Valley around Berriew and Fron. Sheets 151 (Welshpool) and 165 (Montgomery). |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Behind large water tank, 90m, 080 degrees from Llwyn-y-Brain, Garthmyl. |
| Reference Section |
As type section, also Rose Hill where there is a basal conglomerate and mass flow pebbly mudstone (equivalent to Powis Castle Conglomerate). |
| Reference(s): |
| none recorded or not applicable |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E165
E151
|
