The BGS Lexicon of Named Rock Units — Result Details

Howe Of Byth Gravel Formation

Computer Code: HOBGR Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Gravel with subsidiary beds of diamicton and sand. Typically brown/dark brown and olive grey. Dominantly clast supported with a medium to coarse quartzose sand matrix. Clasts are subrounded and rounded and composed mainly of quartzite (probably reworked from Devonian conglomerates) with sparse metasedimentary rock, granites and grey/black ?Mesozoic mudstones. Red sandstone clasts are present in the lowest part of the formation where it directly overlies Devonian red sandstone bedrock. The gravels are crudely horizontally bedded and interbeds of sand show both horizontal stratification and local planar cross bedding. Both gravels and sands display locally strong staining and cementation by Fe and Mn. Palaeocurrent measurements from cross beds and imbricate clasts is towards the south. Common medium beds of yellowish brown gravelly silty sandy diamicton are present and are interpreted as debris flow deposits. The upper 1 to 2m of the deposit display crude involutions and erected clast fabric indicating disruption by periglacial soil processes. Interpreted as glaciofluvial outwash and debris flow deposits.
Definition of Lower Boundary: In the most recent exposures in Howe of Byth Quarry the lower boundary of te unit was a sharp, locally channelled, unconformity on weathered Devonian red sandstone.
Definition of Upper Boundary: The upper boundary of the formation is a sharp, planar, subhorizontal, unconformity overlain by reddish brown diamicton of the Byth Till Formation.
Thickness: To 13m
Geographical Limits: Buchan, northeast Scotland. The formation is currently only known from the vicinity of the Howe of Byth Quarry on Sheet 97 (Fraserburgh). The unit might be of regional significance and present locally across northeast Scotland.
Parent Unit: Banffshire Coast and Caithness Glacigenic Subgroup (BCD)
Previous Name(s): Howe Member (-2244)
Howe Of Byth Gravel Formation (HOBGR)
Byth Gravel (-322)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  North face (as at May 2002) of Howe of Byth quarry. 18km southwest of Fraserburgh, Buchan, northeast Scotland. Hall et al, 1995. 
Reference(s):
Duller, G A T, Wintle, A F and Hall, A M. 1995. Luminescence dating and its application to key-pre-Late Devensian sites in Scotland. Quaternary Science Reviews, Vol.14, 495-519. 
Connell, E R. 2002. Stratigraphical investigations at three key Quaternary sites in northeast Scotland. Quaternary Newsletter, 98, 29-32. 
Hall, A M, Duller G A T, Jarvis, J and Wintle, A G. 1995. Middle Devensian ice-proximal gravels at Howe of Byth, Grampian Region. Scottish Journal of Geology, Vol.31, 61-64. 
Merritt, J W, Connell, E R and Bridgland, D R (editors). 2000. The Quaternary of the Banffshire Coast and Buchan; Field Guide. (London: Quaternary Research Association.) 
Merritt, J W, Auton, C A, Connell, E R, Hall, A M and Peacock, J D. 2003. The Cainozoic geology and landscape evolution of north-east Scotland. Memoir of the British Geological Survey, Sheets 66E, 67, 76E, 77, 86E, 87W, 87E, 95, 96W, 96E and 97 (Scotland) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable