The BGS Lexicon of Named Rock Units — Result Details

Bangley Trachytic Member

Computer Code: BYTRC Preferred Map Code: notEntered
Status Code: Full
Age range: Visean Stage (CV) — Visean Stage (CV)
Lithological Description: The Bangley Trachytic Member consists of purple and blue-grey trachytic lavas with both feldspar-phyric (sodic plagioclase to sanidine) porphyritic and non-porphyritic types. Individual flows are known to be over 20m thick. Quartz-trachytes are also present. Red, brown and purple trachytic tuff and lapilli tuff with agglomerate and some sedimentary volcaniclastic rocks also are interbedded in units known to be at least 8m thick.
Definition of Lower Boundary: The base is apparently conformable on the Hailes Lava Member that consists of basaltic lavas and volcaniclastic rocks.
Definition of Upper Boundary: The Member is overlain by the siliciclastic sedimentary rocks of the Gullane Formation (Strathclyde Group). The contact is considered unconformable with volcaniclastic conglomerate recorded locally at the base of the overlying formation.
Thickness: 0 to 160m
Geographical Limits: East Lothian, outcrop of the Garleton Hills Volcanic Formation around North Berwick, East Linton, Garleton Hills, Stenton and in the subcrop farther west in the BGS Spilmersford Borehole near Pencaitland, but absent adjacent to the Lammermuir Fault.
Parent Unit: Garleton Hills Volcanic Formation (GHV)
Previous Name(s): Bangley Member (-3264)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  East Lothian around North Berwick, East Linton, Garleton Hills, Stenton and in the BGS East Linton and Spilmersford boreholes. (Davies, et al), 1986, figure 10; McAdam and Tulloch, 1985, figure 17). McAdam and Tulloch (1985). 
Reference(s):
McAdam, A D and Tulloch, W, 1985. Geology of the Haddington district. Memoir of the Geological Survey, sheet 33W (Scotland). 
Davies, A, McAdam, A D and Cameron, I B. 1986. Geology of the Dunbar district. Memoir of the British Geological Survey, Sheet 33E and part of Sheet 41 (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S033 S033