Earth Science Conservation Review
| Carboniferous Subarea-9; Ballycastle | Antrim |
| Site Type: | Various |
| Site Status: | |
| Council area: | Moyle District Council |
| Grid Reference: | D119412 |
| Google maps: | 55.20563,-6.24234 |
| Rocks | |
|---|---|
| Rock Age: | Carboniferous (Brigantian, Namurian, Pendelian, Visean) |
| Rock Type: | Coal |
| Interest | |
| Fossil Groups: | Goniatite, Miospore |
Description:
INTRODUCTION
The geological mapping of the Ballycastle area has been completed by the Geological Survey of Northern Ireland and is published on One Inch to One Mile Sheet 8 (Solid and Drift editions) and described in the geological memoir for the area (Wilson & Robbie, 1966).
The description of the main geological features of the Ballycastle Coalfield was completed by H. E. Wilson in 1994. He wwrites that the coastline extending eastwards from Ballycastle to Fair Head and southeastwards, to include all of Murlough Bay, is not only one of the most important geological ASSI in Northern Ireland, valued for its scientific content and its educational potential, but is also an Area of Outstanding Natural Beauty.
The content of Wilson's report was derived almost exclusively from the published geological maps and memoir of the area. Since 1966 however much new data have been published regarding the age of the Ballycastle succession and the GSNI has recently resolved some of the remaining outstanding problems. This new information, which is not included in Wilson's report, is reviewed in an Appendix and the new biostratigraphical data held by the GSNI is published for the first time.
Two specific localities are described separately in the Appendix. One locality, which occurs in the coastal cliffs east of Ballycastle, contains a unique macrofauna and is described in Key Site 288. The other is an inland locality which exposes rocks containing an abundant and diverse miospore assemblage and is described in Key Site 289.
For site specific information see; Key Site 285 - Ballycastle Coalfield.
APPENDIX
Since publication of the Ballycastle geological memoir in 1966 new bio- and chronostratigraphical information has been obtained for the Carboniferous rocks. In particular George et al. (1976) correlated the Dinantian (Lower Carboniferous) part of the sequence with the Asbian and Brigantian stages; the stage boundary being located at the top of the tuffs and lavas that occur at least 250m above the unconformable base. In the later publication covering the Silesian Subsystem (Ramsbottom et al., 1978) all the Namurian strata were assigned to the Pendleian (E1) Stage and the Viséan-Namurian boundary was positioned, for convenience, at the base of the Main Coal (after Wilson & Robbie, 1966), about 570m above the base.
Whitaker and Butterworth (1978) published the results of a detailed miospore sampling programme based on outcrop samples and on core samples obtained from various GSNI boreholes at Ballycastle. Throughout the sequence the recovery of miospores was good although the lowest horizons sampled, between the Murlough Bay Coals and the top of the tuffs and lavas, produced only two poorly preserved assemblages. Species which could be regarded as stratigraphically significant in those two samples included Tripartites vetustus Schemel which is one of two index taxa for the VF Biozone, that correlates with the lowest part of the Brigantian Stage. None of their samples obtained from below the tuffs and lavas yielded miospores. Towards the top of the Ballycastle sequence their results supported the correlation of the Main Coal with the base of the Namurian Series. Spore assemblages from above the Main Coal most closely resembled those of Pendleian (E1) age from elsewhere in Great Britain. Although there was a superficial similarity with early Arnsbergian (E2) assemblages from Fife, in the eastern part of the Midland Valley of Scotland, the absence, from the higher Ballycastle assemblages of several distinctive species widely recorded from the Arnsbergian of Ireland and elsewhere do not lend support to this correlation.
The two specific localities described as Key Sites 288 and 289 were selected for the unique occurrence of goniatites, in the Ballycastle area, at the former locality and because miospores obtained at the latter locality indicate, for the first time, an unequivocal Brigantian age (not Asbian) for the basal strata in the Ballycastle area.
For site specific information see; Key Site 288 - North Star Colliery, Ballycastle Key Site 289 - Ballyberidagh North Townland lane.
The geological mapping of the Ballycastle area has been completed by the Geological Survey of Northern Ireland and is published on One Inch to One Mile Sheet 8 (Solid and Drift editions) and described in the geological memoir for the area (Wilson & Robbie, 1966).
The description of the main geological features of the Ballycastle Coalfield was completed by H. E. Wilson in 1994. He wwrites that the coastline extending eastwards from Ballycastle to Fair Head and southeastwards, to include all of Murlough Bay, is not only one of the most important geological ASSI in Northern Ireland, valued for its scientific content and its educational potential, but is also an Area of Outstanding Natural Beauty.
The content of Wilson's report was derived almost exclusively from the published geological maps and memoir of the area. Since 1966 however much new data have been published regarding the age of the Ballycastle succession and the GSNI has recently resolved some of the remaining outstanding problems. This new information, which is not included in Wilson's report, is reviewed in an Appendix and the new biostratigraphical data held by the GSNI is published for the first time.
Two specific localities are described separately in the Appendix. One locality, which occurs in the coastal cliffs east of Ballycastle, contains a unique macrofauna and is described in Key Site 288. The other is an inland locality which exposes rocks containing an abundant and diverse miospore assemblage and is described in Key Site 289.
For site specific information see; Key Site 285 - Ballycastle Coalfield.
APPENDIX
Since publication of the Ballycastle geological memoir in 1966 new bio- and chronostratigraphical information has been obtained for the Carboniferous rocks. In particular George et al. (1976) correlated the Dinantian (Lower Carboniferous) part of the sequence with the Asbian and Brigantian stages; the stage boundary being located at the top of the tuffs and lavas that occur at least 250m above the unconformable base. In the later publication covering the Silesian Subsystem (Ramsbottom et al., 1978) all the Namurian strata were assigned to the Pendleian (E1) Stage and the Viséan-Namurian boundary was positioned, for convenience, at the base of the Main Coal (after Wilson & Robbie, 1966), about 570m above the base.
Whitaker and Butterworth (1978) published the results of a detailed miospore sampling programme based on outcrop samples and on core samples obtained from various GSNI boreholes at Ballycastle. Throughout the sequence the recovery of miospores was good although the lowest horizons sampled, between the Murlough Bay Coals and the top of the tuffs and lavas, produced only two poorly preserved assemblages. Species which could be regarded as stratigraphically significant in those two samples included Tripartites vetustus Schemel which is one of two index taxa for the VF Biozone, that correlates with the lowest part of the Brigantian Stage. None of their samples obtained from below the tuffs and lavas yielded miospores. Towards the top of the Ballycastle sequence their results supported the correlation of the Main Coal with the base of the Namurian Series. Spore assemblages from above the Main Coal most closely resembled those of Pendleian (E1) age from elsewhere in Great Britain. Although there was a superficial similarity with early Arnsbergian (E2) assemblages from Fife, in the eastern part of the Midland Valley of Scotland, the absence, from the higher Ballycastle assemblages of several distinctive species widely recorded from the Arnsbergian of Ireland and elsewhere do not lend support to this correlation.
The two specific localities described as Key Sites 288 and 289 were selected for the unique occurrence of goniatites, in the Ballycastle area, at the former locality and because miospores obtained at the latter locality indicate, for the first time, an unequivocal Brigantian age (not Asbian) for the basal strata in the Ballycastle area.
For site specific information see; Key Site 288 - North Star Colliery, Ballycastle Key Site 289 - Ballyberidagh North Townland lane.
| Enlander, I., Dempster, M. & Doughty, P., 2024. Carboniferous Subarea-9; Ballycastle, County Antrim, site summary. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/summary.php?item=1182. Accessed on 2024-12-26 |
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