Lamplugh Formation

updated to follow: Stratigraphic Guide to the Cromer Knoll, Shetland and Chalk Groups of the North Sea and Norwegian Sea. Felix M. Gradstein & Colin C. Waters (editors), Mike Charnock, Dirk Munsterman,  Michelle Hollerbach, Harald Brunstad, Øyvind Hammer & Luis Vergara (contributors). Newsletter on Stratigraphy, vol 49/1 pp71-280, 2016

Chalk Group


The term Lamplugh Formation was introduced for a unit of argillaceous, chert-bearing, chalky limestones which underlie harder relatively chert-free chalks of the Jukes Formation and overlie hard, chalky limestones of the Herring Formation (Lott & Knox, 1994; Table).


After the eminent geologist G.W. Lamplugh (1859В­1926) who carried out detailed studies of the Cretaceous successions in Yorkshire in the late 19th century.


The Lamplugh Formation consists of chalky limestones which are typically white to grey, soft to moderately hard, commonly argillaceous and characteristically chert-bearing. The presence of chert (flint) bands throughout the unit is a characteristic feature (Lott & Knox, 1994).


The Lamplugh Formation ranges up to 200 m (e.g. well 49/25-1), but may vary in thickness due to intra-basinal tectonic controls and post-Cretaceous erosion.

Geographical distribution

The Flounder Formation is confined to the southern part of the South Viking Graben and the extreme north of the Central North Sea.


Type well

Well name: 49/24-1

WGS84 coordinates: Lat. 53° 16’ 49.5”NВ В В В В  Long. 02° 41’ 30.4”E
UTM coordinates:
UTM zone: 31
Drilling operator name: Shell UK Exploration and Production Ltd
Completion date: 30.04.1972
Status: Suspended
Interval of type section & thickness in type well: 1060В­1242 m (3478В­4075 ft)

UK Reference Wells

38/24-1: 1585.5В­1670.5 m (5202В­5481 ft)
43/8a-2: 948В­1189 m (3110В­3901 ft)
49/5-1: 1679.5В­1987 m (5510В­6519 ft)

Lat. 55° 12’ 35.3”N
Lat. 54° 45’11.3”NВ В В В 
Lat. 53° 52’ 05.0”N
Long. 02° 37’ 33.1”E
Long. 1° 33’07.8”E
Long. 02° 49’ 04.0”E


Upper and lower boundaries

Upper Boundary

The upper boundary of the Lamplugh Formation is marked by a downward change from the chalky limestones of the Jukes Formation into harder, more argillaceous chalks (Lott & Knox, 1994).

Lower Boundary

The lower boundary of the Lamplugh Formation is characterized by a downward change from moderately hard, chalky limestones to the harder, clean, micritic limestones of the Herring Formation (Lott & Knox, 1994).

Well log characteristics

The top of the Lamplugh Formation is marked by a sharp downward increase in velocity accompanied in some sections by a slight increase in gamma-ray values e.g.В  49/24-1. In some wells the mid-part of the Lamplugh Formation is particularly argillaceous (e.g. well 42/29-C01 Panel 1; 53/4-2 Panel 2, Lott & Knox, 1994) giving the log profiles a 'waisted' appearance. At the base of the formation there is a corresponding downhole decrease in gamma ray and increase in sonic velocity responses (Lott & Knox, 1994).


The FDO of Stensioeina granulata granulata marks the top of the formation and two intraformational biomarkers are S. granulata levis and S. granulata kelleri. Palynomorph recovery in the Lamplugh Formation is generally relatively low.


Late Turonian to Coniacian


The Lamplugh Formation passes northwards into the lower part of the Mackerel Formation of the Central North Sea (Table). Onshore, in eastern England the formation equates largely with the Burnham Chalk Formation of Wood & Smith (1978; refer also to Whitham, 1991).

Depositional environment

The chalky limestones of the Lamplugh Formation were deposited in an open marine setting as pelagic carbonates and consist primarily of fine bioclastic skeletal debris (dominated by coccolith plates). Terriginous clay is present as thin beds and seams (Lott & Knox, 1994).


None in UK waters.