The BGS Lexicon of Named Rock Units — Result Details

Aveley Member

Computer Code: AVLY Preferred Map Code: notEntered
Status Code: Full
Age range: Ypresian Age (GY) — Ypresian Age (GY)
Lithological Description: The Aveley Member comprises mainly homogeneous silty clay, which is, however, very silty and micaceous at some levels. There are regular discontinuous layers of claystone concretions. Thin beds or partings of clayey silt, very fine-grained sand or glauconitic clay are present at some levels. The basal part is sandier and finely glauconitic (King, in prep.).
Definition of Lower Boundary: The base of the Aveley Member is marked by a thin basal bed of sandy silty clay, some of which is glauconitic, above the silty clay with thin layers and partings of well-sorted, fine-grained sand of the Ockendon Member, and by a return to mainly homogeneous clay.
Definition of Upper Boundary: The top of the Aveley Member is marked by a change upwards to silty clay with common sandy clayey silt interbeds of the Sheppey Member.
Thickness: About 56m in the type area (King, in prep.)
Geographical Limits: The Aveley Member occurs throughout the centre and east of the London Basin.
Parent Unit: London Clay Formation (LC)
Previous Name(s): Division B And The Lower Part Of Division C (-5079)
Unit C of Ellison et al., 2004 (UNITC)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Staines 5 Borehole (TQ07SW156) from 40 to 81.0m (Ellison and Williamson, 1999, fig.6; Ellison et al., 2004, p.46) 
Reference(s):
Aldiss, D.T., 2012. The stratigraphical framework for the Palaeogene successions of the London Basin, UK. British Geological Survey Open Report OR/12/004. Available from http://nora.nerc.ac.uk/17121/. 
King, C. in prep. A revised correlation of Palaeogene and Neogene deposits in the British Isles. Geological Society of London Special Report. 
Ellison, R A and Williamson, I T. 1999. Geology of the Windsor and Bracknell district - a brief explanation of the geological map. Sheet Explanation of the British Geological Survey. 1:50 000 Sheet 269 Windsor (England and Wales). 
Ellison, R A, Woods, M A, Allen, D J, Forster, A, Pharaoh, T C and King, C. 2004. Geology of London. Memoir of the British Geological Survey, Sheets 256 (North London), 257 (Romford), 270 (South London), 271 (Dartford) (England and Wales). 
King, C, 1981. The stratigraphy of the London Clay and associated deposits. Tertiary Research Special Paper No.6. (Backhuys: Rotterdam). 
Williams, R J. 2002. Observations on the London Clay excavation, at Aveley Essex. Tertiary Research, Vol. 21, 95-112. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable