| Computer Code: |
TDL |
Preferred Map Code: |
TDL |
| Status Code: |
Full |
| Age range: |
Asbian Substage (CR)
— Asbian Substage (CR) |
| Lithological Description: |
[Obsolete: use LEEL]
Comprises interbedded skeletal limestones and distinctive porcellanous limestones; rests unconformably on cleaved Ordovician mudstones. The formation is capped by the widely recognised Bryn Tirion Member and overlain by the massive or rubbly skeletal limestones of the Penmon Limestone. |
| Definition of Lower Boundary: |
Contact with Ordovician rocks. |
| Definition of Upper Boundary: |
Top of uppermost porcellanous limestone of the Bryn Tirion Member. |
| Thickness: |
45m |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
Careg-Onen Limestone Formation [Obsolete Name And Code: Use LEEL]
(COLF)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Tandinas Quarry, Sheet 94. |
| Reference(s): |
| Power, G M. Not published. The Stratigraphy and Sedimentology of the Lower Carboniferous in Anglesey, with special reference to rocks of Asbian(DI) age. Ph.D. Thesis, Queen's University, Belfast, 1977. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E094
|
