| Ulster White Limestone Group | |
| Type: | Group |
| Period: | Maastrichtian |
| Prilithology: | limestones |
| Otherlithology: | flint, marl, conglomerates |
| Region: | Northern Ireland |
| Country: | United Kingdom |
| Subunits: | Post Larry Bane Chalk Subgroup, Pre-Larry Bane Chalk Subgroup |
| Underlies: | Palaeogene basalts / Quaternary deposits |
| Overlies: | Hibernian Greensands Group |
| Thickness: | Highly variable dependent on the basin, up to 120 m in composite |
| Extent: | throughout Northern Ireland |
The Ulster White Limestone Group is a late Cretaceous lithostratigraphic group (a sequence of rock strata) in Northern Ireland. The name is derived from the characteristic chalk rock which occurs particularly along the Antrim coast. The strata are exposed on or near to both the northern and eastern coasts of Antrim and also between Portrush and Dungiven within County Londonderry. Further outcrops occur between Belfast and Lurgan and between Dungannon and Magherafelt. The current names replace an earlier situation where the present group was considered to be a formation and each of the present formations was considered a 'member'. Several other stratigraphic naming schemes were in use during the nineteenth century and much of the twentieth century.[1] This group and the underlying Hibernian Greensands Group are the stratigraphical equivalent of the Chalk Group of southern and eastern England.
There is an unconformity (non-sequence) at the base of the Boheeshane Chalk Formation.