The BGS Lexicon of Named Rock Units — Result Details

Montrose Group

Computer Code: MONT Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Paleocene Epoch (GP) — Paleocene Epoch (GP)
Lithological Description: The Montrose Group is characterized by mudstones that are variable in character but that differ from those of the overlying Moray Group in containing an abundant microfauna and in being poorly bedded, non-pyritic and mostly non-carbonaceous. The mudstones of the Maureen Formation display a downward increase in the proportion of carbonate, culminating in chalky marls that grade downwards into the chalky limestones of the Ekofisk Formation. The sandstones of the Montrose Group were deposited as submarine fans (Parker 1975, Knox et al. 1981; Rochow 1981; Mudge and Bliss 1983; Stewart 1987).
Definition of Lower Boundary: The base of the Maureen Formation is taken at the upward change from chalky limestone or marl of the Chalk Group or Shetland Group to a more variable succession of thinly interbedded marl and limestone with local sandstone.
Definition of Upper Boundary: The upper boundary is marked by a downward change from grey to grey-brown, carbonaceous, pyritic, mudstones and siltstones of the Moray Group to greenish, non-pyritic mudstones with abundant microfauna of the Montrose Group.
Thickness: The Montrose Group reaches over 600 m in parts of the Outer Moray Firth.
Geographical Limits: The Montrose Group extends throughout the North Sea area (Knox & Holloway 1992; Lott & Knox 1994).
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
Knox, R W O'B and Holloway, S. 1992. 1. Paleogene of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable