The BGS Lexicon of Named Rock Units — Result Details

Dobb's Plantation Member

Computer Code: DOBP Preferred Map Code: notEntered
Status Code: Full
Age range: Quaternary Period (Q) — Quaternary Period (Q)
Lithological Description: Marine, quartz- and quartzite-rich flint gravel and sand. This member is characterised by c.10 per cent far-travelled material comprising mainly white or colourless quartzose rocks and the presence of Carboniferous and Rhaxella chert.
Definition of Lower Boundary: Appears to be conformable on sand and gravel of the Norwich Crag Formation. Incoming of significant amounts of quartzose clasts defines lower boundary. The base of the formation is marked by a change from flint-dominated lithologies of the Norwich Crag Formation to an assemblage with Rhaxella chert and white/colourless quartroase clasts. The base of the member also coincides with the appearance of Macoma balthica.
Definition of Upper Boundary: At surface or overlain unconformably by Happisburgh Formation (previously known as Corton Formation) glacigenic deposits. Junction marked by change to fine-grained sands or stiff sandy till.
Thickness: Up to more than 10m - maximum thickness unknown
Geographical Limits: Restricted to northern East Anglia - probably restricted to area north and north-east of Norwich. Not shown separately on BGS maps - included in Wroxham Crag formation.
Parent Unit: Wroxham Crag Formation (WRCG)
Previous Name(s): Bure Valley Beds (-216)
Weybourne Crag (WCG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Small overgrown pit at eastern edge of Dobbs Plantation, Crostwick Funnell, 1980 
Reference(s):
Rose, J, Moorlock, B S P and Hamblin, R J O. 2001. Pre-Anglian fluvial and coastal deposits in Eastern England: lithostratigraphy and palaeoenvironments. Quaternary International, 79, 5-22. 
Funnell, B M. 1980. Palaeoenvironmental analysis of the Dobbs Plantation Section, Crostwick (and comparison with the type localities of the Norwich and Weybourne Crags). Bulletin of the Geological Society of Norfolk, Vol.40, 1-10. 
Cambridge, P G. 1978. Report on a field meeting at Dobbs Plantation, Wroxham (TG 273 158), September 1977. Bulletin of the Geological Society of Norfolk, Vol.30, 77-78. 
Cambridge, P G. 1978. A section in the 'Bure Valley Beds' near Wroxham. Bulletin of the Geological Society of Norfolk, Vol.30, 79-91. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable