The BGS Lexicon of Named Rock Units — Result Details

Hyssington Volcanic Member

Computer Code: HYS Preferred Map Code: Hys
Status Code: Pending Upgrade
Age range: Abereiddian Stage (O2) — Abereiddian Stage (O2)
Lithological Description: Interbedded sequence of grey shales, vitroclastic acid tuffs and volcaniclastic sandstones and wackes.
Definition of Lower Boundary: Lower boundary is passage from Mytton Flags Formation into dark shales of the Hyssington Volcanic Formation shale.
Definition of Upper Boundary: No upper boundary because of unconformity.
Thickness: c.1000 metres, much variation.
Geographical Limits: Not defined.
Parent Unit: Hope Shale Formation (HOSH)
Previous Name(s): Hyssington Volcanic Formation (-3485)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Sheet 165, SO39SW. 
Reference(s):
Cave, R. 1985. Geological notes and local details for 1:10,000 Sheets : Sheet SO39SW (Hyssington and Lydham) : Part of 1:50,000 Sheet 165 (Montgomery) Aberystwyth. Report of the British Geological Survey. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E165 E151