Chalk Group Lithostratigraphy: East Anglia - Upper Orbirhynchia Band

Jeans (1980) identified two horizons characterised by an abundance of the brachiopod Orbirhynchia mantelliana in the Lower Chalk of northern England, named the Lower and Upper Orbirhynchia Band. Of these, the upper one has generally been more widely recognised in East Anglia. In the south of the region, White (1932) referred to a fossiliferous band a short distance above the Totternhoe Stone containing large O. mantelliana, and Gallois (1994) identifies a similar horizon in north Norfolk as the Upper Orbirhynchia Band; locally, the Lower Orbirhynchia Band is just below the Totternhoe Stone (Gallois, 1994), but in areas where basal Totternhoe Stone erosion was pronounced, this horizon could be incorporated into the Totternhoe Stone as a reworked fauna.

Macrofossil Biozonation: A. rhotomagense Zone

Correlation: see Correlation with other UK Chalk Group successions

References

GALLOIS, R W.1994. Geology of the country around King's Lynn and The Wash. Memoir of the British Geological Survey.

JEANS, C V. 1980. Early submarine lithification in the Red Chalk and Lower Chalk of eastern England: a bacterial control model and its implications. Proceedings of the Yorkshire Geological Society, Vol. 43, 81-157.

WHITE, H J O.1932. The Geology of the country near Saffron Walden. Memoir of the Geological Survey England and Wales (Sheet 205).

See: Totternhoe Stone