The BGS Lexicon of Named Rock Units — Result Details

Henfryn Formation

Computer Code: HEN Preferred Map Code: Hen
Status Code: Pending Upgrade
Age range: Telychian Age (ST) — Telychian Age (ST)
Lithological Description: Pebbly mudstones, conglomerates and sandstones. Rapid lateral facies changes common.
Definition of Lower Boundary: Disconformably overlies Ashgill Formation.
Definition of Upper Boundary: Gradational but taken at base of first thick mudstone unit above the sandstones and conglomerates of the formation.
Thickness: 15-80 metres.
Geographical Limits: Central Wales.
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Quarry, 300 metres north-north-east of Henfryn, Abbeycwmhir. 
Reference(s):
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E179