The BGS Lexicon of Named Rock Units — Result Details

Gwern Feifod Lava Member

Computer Code: GFL Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Costonian Substage (OO) — Harnagian Substage (OG)
Lithological Description: Flow-foliated and brecciated, vesicular felsic lava.
Definition of Lower Boundary: Conformably overlies volcaniclastic blue-grey mudstone of the Llangynog Formation.
Definition of Upper Boundary: Overlain by volcaniclastic mudstones and tuff [Gwern Feifod Tuff].
Thickness: 18m
Geographical Limits: none recorded or not applicable
Parent Unit: Llangynog Formation (LGF)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
none recorded or not applicable
Wedd, C B, Smith, B, King, W B R and Wray, D A. 1929. Geology of the country around Oswestry. Memoir of the Geological Survey of Great Britain, Sheet 137. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E136 E137