The BGS Lexicon of Named Rock Units — Result Details

Bryn Tirion Member

Computer Code: BTM Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Asbian Substage (CR) — Asbian Substage (CR)
Lithological Description: Porcellanous limestones (calcite mudstones) with spar filled fenestrae; intercalated thin dark grey shales.
Definition of Lower Boundary: Rests on skeletal and peloidal limestones of the lower parts of the Tandinas Limestone.
Definition of Upper Boundary: Overlain by the Penmon Limestone (massive and rubbly skeletal limestones).
Thickness: 4 metres; up to 11 metres at Tandinas Quarry and 8.5 metres at Flagstaff Quarry.
Geographical Limits: Not defined.
Parent Unit: Leete Limestone Formation (LEEL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Hillside below Bryn Tiriom Farmhouse, Sheet 94. 
Reference(s):
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E094