| Computer Code: |
TRCK |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Maastrichtian Age (KM)
— Maastrichtian Age (KM) |
| Lithological Description: |
The Maastrichtian chalks have become known informally as the Trimmingham Chalk and are described in glacially deformed 'erratics' (of considerable size) on the coast between Overstrand and Trimmingham. A number of units were given names of informal member status in Johansen and Surlyk (1990). All of the succession was investigated in the Trunch Borehole (TG 23 SE/8) [TG 2933 3455] that was published in the Great Yarmouth Memoir (Arthurton et al., 1994). No firm conclusion has been reached regarding formal nomenclature for these beds since their distribution under a thick Quaternary cover has not been determined. Mortimore et al. (2001) give a comprehensive review of the Trimmingham and Norfolk chalks in Norfolk. It is recommended that reference to these units be made informally using the Trimmingham Chalk term until they can be more formally attributed. |
| Definition of Lower Boundary: |
none recorded or not applicable
|
| Definition of Upper Boundary: |
none recorded or not applicable
|
| Thickness: |
none recorded or not applicable
|
| Geographical Limits: |
none recorded or not applicable
|
| Parent Unit: |
White Chalk Subgroup (WHCK)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Trunch Borehole (TG 23 SE/8) [TG 2933 3455] (Arthurton et al., 1994). |
| Reference(s): |
| Mortimore, R N, Wood, C J and Gallois, R W, 2001. British Upper Cretaceous Stratigraphy. Geological Conservation Review Series. No. 23. (Peterborough: Joint Nature Conservation Committee.) |
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. |
| Arthurton, R S, Booth, S J, Morigi, A N, Abbott, M A W, and Wood, C J. 1994. Geology of the country around Great Yarmouth, Sheet Memoir 162, British Geological Survey. [London: HMSO.] 138pp. |
| Johansen, M B and Surlyk, F. 1990. Brachiopods and the stratigraphy of the Upper Campanian and Lower Maastrichtian Chalk of Norfolk, England. Palaeontology, Vol.33, 823-873. |
| Hopson, P M. 2005. A stratigraphical framework for the Upper Cretaceous Chalk of England and Scotland, with statements on the Chalk of Northern Ireland and the UK Offshore Sector. British Geological Survey Research Report RR/05/01 102pp. ISBN 0 852725175 |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
