| Computer Code: |
LBED |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Ypresian Age (GY)
— Ypresian Age (GY) |
| Lithological Description: |
The Laminated Beds typically consists of thinly to thickly laminated silts and clays, but can also include laminated fine- to medium-grained sand. Some shells can be present and the beds may contain lignite and pyritised plant material. Sporadic burrows occur throughout, and bioturbation is more common in the higher beds in which glauconite occurs sparsely. These deposits are typically pale grey but may be olive to brown; they tend to be paler than those of the Lower Shelly Clay. Beds of sand, where present, tend to form broad sheet-like deposits, in contrast to the channel-like deposits found in the Reading Formation, although some cross-bedding is present (Ellison, 1983, citing F G Berry, personal communication). Locally, the Laminated Beds can comprise the entire local representation of the Woolwich Formation.
King (in prep.) notes that un-named channel-filling sand or clay bodies occur at the top of the Laminated Beds in places.
The Laminated Beds were deposited in estuarine and other marginal marine environments.
Early Eocene (earliest Ypresian). |
| Definition of Lower Boundary: |
The base of the Laminated Beds is a sharply-defined contact with the underlying Lower Shelly Clay or locally on the Lower Mottled Clay. |
| Definition of Upper Boundary: |
The top of the Laminated Beds is a sharply-defined contact with the overlying Upper Mottled Clays or the Upper Shelly Clay. |
| Thickness: |
Up to 6 m but more generally 2 to 3 m. |
| Geographical Limits: |
The Laminated Beds occur in central and south-east London, extending east as far as the Swanscombe outlier (Ellison et al., 2004, fig. 18). |
| Parent Unit: |
Woolwich Formation (WL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Charlton Pit (or Gilbert's Pit), just south-west of Maryon Park, Charlton, London Borough of Greenwich (Daley, 1999b; Ellison et al., 1994; Hooker, 2010; Whitaker, 1889). |
| Reference Section |
BGS Crystal Palace Borehole (TQ37SW 671) 134.65 to 136.42 m depth (Ellison et al., 2004, p. 32). |
| Reference Section |
The Lower Upnor Pit (Daley, 1999b; Ellison et al., 1994; Kennedy and Sellwood, 1970). |
| Type Area |
The type area is the Stratford district of East London where numerous boreholes, especially those drilled for the Channel Tunnel Rail Link, have demonstrated a typical succession. |
| Reference(s): |
| Aldiss, D T. 2014. The stratigraphical framework for the Palaeogene successions of the London Basin, UK. British Geological Survey Open Report OR/14/008. 95 pp. |
| King, C. in prep. A revised correlation of Palaeogene and Neogene deposits in the British Isles. Geological Society of London Special Report. |
| Hooker, J J. 2010. The mammal faunas of the early Eocene Blackheath Formation of Abbey Wood, London. Monograph of the Palaeontographical Society, London, 164, 1-162. |
| 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). |
| Daley, B. 1999. London Basin: eastern localities, In: Daley, B, Balson, P (Eds.), British Tertiary Stratigraphy. Geological Conservation Review Series 15, pp. 23-72. |
| Ellison, R A, Knox R W O'B, Jolley, D W and King, C, 1994. A revision of the lithostratigraphical classification of the early Palaeogene strata of the London Basin and East Anglia. Proceedings of the Geologists' Association, Vol.105, 187-197. |
| Whitaker, W., 1889. The geology of London and part of the Thames Valley (Explanation of Sheets 1, 2 and 7). Memoir of the Geological Survey of the United Kingdom Vol. 1. Descriptive geology. |
| Ellison, R.A., 1983. Facies distribution in the Woolwich and Reading Beds of the London Basin, England. Proceedings of the Geologists' Association 94, 311-319. |
| Kennedy, W.J., Sellwood, B.W., 1970. Ophiomorpha nodosa Lundgren, a marine indicator from the Sparnacian of south-east England. Proceedings of the Geologists' Association 81, 99-110. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
