Carboniferous of the Fintona Block, Northern Ireland

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Mitchell, W I (ed.). 2004. The geology of Northern Ireland-our natural foundation. Geological Survey of Northern Ireland, Belfast.

W I Mitchell

Fintona Block

Geological map of the western part of the Fintona Block. (P947817)
Fossils 1–6 Early Carboniferous miospores: 1–3: (Courceyan and early Chadian) from the Roe Valley and Tyrone groups in Co. Londonderry. 1 Schopfites claviger (x 275) 2 Auroraspora macra (x 250) 3 Lycospora pusilla (x 625) 4–6: (Brigantian-Pendleian) from the Kilskeery Group in the Fintona Block, Co. Tyrone: 4 Tripartites vetustus (x 350) 5 Savitrisporites nux (x 300) 6 Reticulatisporites carnosus (x 225) (P948072)
Fossils 7–10 Late Carboniferous (Westphalian A-B) miospores from the Slievebane Group in the Fintona Block, Co. Tyrone: 7 Dictyotriletes bireticulatus (x 550) 8 Laevigatosporites desmoinesensis (x 550) 9 Endosporites globiformis (x 400) 10 Vestispora pseudoreticulata (x 500) (P948073)
Litho-, bio- and chronostratigraphy of the Kilskeery Group of the Fintona Block. (P947931)
Distribution and classification of Carboniferous rocks in Northern Ireland. (P947927)
Location (A) and detailed geological map (B) of the stratotype of the Greenan Sandstone Formation. (P947818)
Litho-, bio- and chronostratigraphy of the Slievebane Group of the Fintona Block. (P947932)
The Drumlish Conglomerate Formation, Straduff quarry [H 343 666], Co. Tyrone, 16 km ENE of Kesh. Vertical bedding, youngs to the right. (P947998)

The Carboniferous rocks are restricted [1] to the fault-bounded and lithostratigraphically distinctive Milltown and Tempo-Lisbellaw segments (P947817) [2][3].

Tempo-Lisbellaw Segment

Kilskeery Group (P947931)

Green mudstones near the top of the basal Topped Mountain Sandstone Formation exposed on the east flank of Brougher Mountain [H 355 531] contain miospores of the VF Biozone (Brigantian) including the index taxon Tripartites vetustus and Savitrisporites nux (P948072) Fossils 4, 5. The hills of Largy, Ballyreagh and Brougher Mountain (316 m) are formed of the Ballyreagh Conglomerate Formation (P947817). Interbedded sandstone and conglomerate occur in Largy quarry [H 298 475], 5 km west of Tempo and are associated with ripple marks and desiccation cracks. The Ballinamallard Mudstone Formation is exposed in the Ballinamallard River [H 268 529]. Miospores, recovered from green mudstones in the stream (P947817) at the Hollow House [H 251 552], include Reticulatisporites carnosus (P948072) Fossil 6 an index taxon of the NC Biozone (P947931).

Milltown Segment

Greenan Sandstone Formation (P947927)

The basal unconformity with the Dalradian is exposed [H 316 668] on Greenan Mountain (P947817) and (P947818) . Green mudstone laminae in the sandstone contains miospores diagnostic of the VF and possibly NC biozones. Rhyolitic lava occurs towards the top of the Formation east of Omagh.

Slievebane Group (P947932)

The outcrop of this Group is fault-bounded (P947817) [1]. At the best exposure [H 218 616] of the Tullanaglare Mudstone Formation at Tullanaglare, green mudstones contain miospore assemblages (P948073) Fossils 7–10 with index taxa of the RA and NJ biozones (Westphalian A/B). The Drumgivery Limestone Member marks the top of the formation. The Drumlish Conglomerate Formation is exposed [H 343 666] in Straduff Quarry (P947817), (P947998). Volcanic rocks [1] in the Omagh Thrust Fault zone [H 432 712] may be the source of the lava clasts in the conglomerate.

References

  1. 1.0 1.1 1.2 Mitchell, W I, and Owens, B. 1990. The geology of the western part of the Fintona Block, Northern Ireland-evolution of Carboniferous basins. Geological Magazine, 127, 407 26.
  2. Geological Survey of Northern Ireland 1982. Enniskillen, Northern Ireland Sheet 45. Solid Geology. 1:50 000. (Southampton: Ordnance Survey for the Geological Survey of Northern Ireland).
  3. Geological Survey of Northern Ireland 1995. Omagh, Northern Ireland Sheet 33. Solid Geology. 1:50 000. (Keyworth, Nottingham: British Geological Survey).