| Computer Code: |
TDC |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Maastrichtian Age (KM)
— Maastrichtian Age (KM) |
| Lithological Description: |
Limestone (chalk) with flint bands. Divided into five "Beds" (A to E). Abundant belemnites in lower "Bed" A and by an acme of crinoid debris in "Bed" C. Elsewhere asteroid and crinoid debris common. |
| Definition of Lower Boundary: |
The lower bounday is conformable, on the Ballymagarry Chalk Formation, at a bedding plane immediately below the thick continuous tabulate Long Gilbert Flint Band where this exists. Or at the same bedding plane marking the faunal change from the Ballymagarry Chalk Formation fauna. |
| Definition of Upper Boundary: |
The upper bounday is conformable with the overlying Port Calliagh Chalk Formation, at a bedding plane below a belt of complex flints. |
| Thickness: |
7.63m at its type-site. |
| Geographical Limits: |
Outcrops in the Southern Uplands area of Northern Ireland, the North Antrim Basin and in the southern part of the Londonderry Shelf. Absent in the East Antrim Basin, the Highland Border High and northern Londonderry Shelf due to pre-Palaeogene erosion. |
| Parent Unit: |
Ulster White Limestone Group (UWLF)
|
| Previous Name(s): |
Tanderagee Chalk Member [Obsolete Name and Code: Use TDC]
(-3719)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Long Gilbert Quarry, Ballymagarry, south wall of western part of quarry. |
| Reference(s): |
| Hopson, P M. 2005. A stratigraphical framework for the Upper Cretaceous Chalk of England and Scotland, with statements on the Chalk of Northern Ireland and the UK Offshore Sector. British Geological Survey Research Report RR/05/01 102pp. ISBN 0 852725175 |
| Fletcher, T P. 1977. Lithostratigraphy of the Chalk (Ulster White Limestone Formation) in Northern Ireland. Report of the Institute of Geological Sciences, No. 77/24. |
| Fletcher, T P. 1967. Correlation of the Cretaceous exposures of east Antrim. Unpublished MSc Thesis, Queens University, Belfast. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
