The BGS Lexicon of Named Rock Units — Result Details

Hereford Till Member

Computer Code: HDTI Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Generally stiff, structureless, stony, sandy and silty diamict and clayey gravel, characteristically containing abundant Old Red Sandstone clasts (derived from Black Mountain, Fforest Fawr and the Brecon Beacons), nodular calcrete and relatively few Lower Palaeozoic clasts. Subordinate stratified sand and gravel are locally present. Colour and dominant clast composition are variable and generally reflect the local bedrock geology.
Definition of Lower Boundary: Overlies mudstone of the Raglan Mudstone Formation (Downton Group) at type locality
Definition of Upper Boundary: Ground surface or overlain by fluvial deposits of the Severn and Avon Catchments Subgroup
Thickness: Generally less than 4 m
Geographical Limits: Herefordshire and the Brecon Beacons west of the River Lugg
Parent Unit: Brecknockshire Glacigenic Formation (BNOCK)
Previous Name(s): Herford End-Moraine [Obsolete Name and Code: Use HDTI] (-2842)
Newer Till [Obsolete Name and Code: Use HDTI] (-2843)
Alternative Name(s): Hereford Formation
Stratotypes:
Partial Type Section  2.5 m of red-brown stony silt (till) on bedrock, 100 m N of Knapp Farm, Bishopstone, North of Garnon's Hill Brandon, 1989 and Field map SO44SW 
Reference(s):
Richards, A.. 2005. Herefordshire. In Lewis, CA and Richards AE. (eds) The glaciations of Wales and adjacent areas. Logaston Press. 
Charlesworth, J K. 1929. The South Wales end moraine. Quarterly Journal of the Geological Society, London, Vol. 85, 335-358. 
Luckman, B H. 1970. The Hereford Basin. 175-196 in The Glaciations of Wales. Lewis, C A (editor). (London: ) 
Bowen, D Q, 1999. Wales. Chapter 7 in Bowen, D Q (Editor), A revised correlation of Quaternary deposits in the British Isles. Geological Society of London Special Report, No.23. 
Brandon, A. 1989. Geology of the country between Hereford and Leominster. Memoir for 1:50 000 Geological Sheet 198. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable