The BGS Lexicon of Named Rock Units — Result Details
Marehill Clay Member
| Computer Code: | MHC | Preferred Map Code: | MhC |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Aptian Age (KP) — Aptian Age (KP) | ||
| Lithological Description: | Dark grey, locally glauconitic, silty clay. | ||
| Definition of Lower Boundary: | The lower boundary is taken at the upward change from mostly well-sorted fine-grained sands (locally iron-cemented at top) of the Pulborough Sandrock Member to silty clay (or clayey sand) of the Marehill Clay Member. | ||
| Definition of Upper Boundary: | The top is taken where there is an upward change from silty clay of the member into well-sorted medium to coarse sands of the Folkestone Formation. The contact is generally sharp, but rarely exposed. | ||
| Thickness: | 2 to 35m. | ||
| Geographical Limits: | Southwestern and western Weald. | ||
| Parent Unit: | Sandgate Formation (SAB) | ||
| Previous Name(s): | Previously part of Undifferentiated Sandgate Beds [Obsolete Name and Code: Use MHC]
(-4794)
Mare Hill Clay [Obsolete Name and Code: Use MHC] (-4191) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Old sandpit at Pulborough, near Marehill. The most characteristic lithology is a dark grey, blocky weathering, silty clay, which is locally sandy or glauconitic, in places extremely glauconitic; dark grey and lilac clayey silts or waxy clays occur in places. Humphries (1964, p.31) noted yellow, white and brown sandy clay in the Marehill quarry, the type locality [TQ 0647 1864], where the clay was stripped off as overburden during extraction of sand from the Pulborough Sandrock. Humphries (1964, p.51) measured a section in this pit when both the Marehill Clay (about 3 m) and the Pulborough Sandrock (about 5.6 m) were better exposed. | ||
| Reference(s): | |||
| Humphries, D W. 1964. The stratigraphy of the Lower Greensand of the south-west Weald. Proceedings of the Geologists' Association, Vol.75, 39-59. | |||
| Kirkaldy, J F. 1933. The Sandgate Beds of the Western Weald. Proceedings of the Geologists' Association, Vol.44, 270-311. | |||
| Bristow, C R, and Wyatt, R J. 1983. Geological notes and local details for 1:10 000 sheets TQ01NW, NE, SW and SE (Pulborough and Storrington). British Geological Survey Technical Report WA/VG/83/03. | |||
| Bristow, C R. 1991. Geology of the Petersfield District, Hampshire. Explanation of 1:10,000 Geological sheets SU72NW, 72NE, 72SW, 72SE, 82NW and 82SW. British Geological Survey Technical Report WA/91/24. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E300 E316 E317 E332 | |||