| Computer Code: |
SHOM |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Thanetian Age (GT)
— Ypresian Age (GY) |
| Lithological Description: |
In the type section, the Shorne Member comprises a 2 m thick bed of laminated or blocky, black or dark brown lignite with thin pale clays (the Cobham Lignite Bed), overlying non-marine sands and clays containing some woody debris. These were not included with the Cobham Lignite Bed by Collinson et al. (2003) but are here included in the Shorne Member. Elsewhere the member is probably represented by fine-grained sands and clays, commonly with detrital lignite, or by grey organic clay or sand.
The Shorne Member was deposited under non-marine conditions, probably on a fluvial flood-plain. The upwards change to the dark grey shelly clays of the Lower Shelly Clay represents a transgression that introduced lagoonal conditions.
Latest Thanetian to earliest Ypresian. |
| Definition of Lower Boundary: |
The Shorne Member lies on an erosional surface (marking the mid-Lambeth Group Hiatus) of the Lower Mottled Clay (Reading Formation), or of the Upnor Formation. The underlying deposits are generally pale and bleached (pedogenically altered). |
| Definition of Upper Boundary: |
The top of the Shorne Member is marked by the sharply-defined planar base of the overlying dark grey shelly clay of the Lower Shelly Clay (Woolwich Formation). |
| Thickness: |
Up to about 3.5 m in the type section. |
| Geographical Limits: |
The Shorne Member is known principally from the Shorne Outlier in north-west Kent but occurs more widely but discontinuously, for example in the Swanscombe Outlier (north-west Kent) and at Aveley (south-west Essex) (Collinson et al., 2009; Ellison et al., 2004, fig. 15). Lignite-bearing beds also occur at the base of the Woolwich Formation elsewhere in the London Basin, and in Sussex (Dupuis and Gruas-Cavagnetto, 1985). |
| Parent Unit: |
Woolwich Formation (WL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Temporary exposure in railway cutting at Scalers Hill, Cobham, Kent exposed in 1998 to 2000 (Collinson et al., 2003; Collinson et al., 2007; Ellison et al., 2004, fig. 15). |
| 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. |
| Collinson, M.E., Steart, D.C., Harrington, G.J., Hooker, J.J., Scott, A.C., Allen, L.O., Glasspool, I.J., Gibbons, S.J., 2009. Palynological evidence of vegetation dynamics in response to palaeoenvironmental change across the onset of the Paleocene-Eocene Thermal Maximum at Cobham, Southern England. Grana 48, 38-66. |
| Collinson, M.E., Steart, D.C., Scott, A.C., Glasspool, I.J., Hooker, J.J., 2007. Episodic fire, runoff and deposition at the Palaeocene-Eocene boundary. Journal of the Geological Society 164, 87-97. |
| Dupuis, C., Gruas-Cavagnetto, C., 1985. The Woolwich Beds and the London Clay of Newhaven (East Sussex): new palynological and stratigraphical data. The London Naturalist 75, 27-39. |
| Collinson, M.E., Hooker, J.J., Gröcke, D.R., 2003. Cobham Lignite Bed and penecontemporaneous macrofloras of southern England: a record of vegetation and fire across the Paleocene-Eocene Thermal Maximum, In: Wing, S.L., Gingerich, P.D., Schmitz, B., Thomas, E. (Eds.), Causes and consequences of globally warm climates on the Early Paleogene. Geological Society of America Special Papers 369, pp. 339-349. |
| 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). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
