Earth Science Conservation Review
| Copney Hill | Tyrone |
| Site Type: | Crags |
| Site Status: | ESCR |
| Grid Reference: | H600777 |
| Google maps: | 54.64434,-7.07061 |
| Rocks | |
|---|---|
| Rock Age: | Ordovician |
| Rock Name: | Tyrone Volcanic Group, Copney Pillow-lava Formation |
| Rock Type: | Feldspar porphyry, Pillow lava, Porphyry, Quartz porphyry |
| Interest | |
| Other interest: | Caledonian, pillow lava, Extrusion |
Introduction:
Copney Hill is a prominent feature in otherwise flat ground lying directly south of the main Omagh to Cookstown Road (A505), ~3km west southwest of Creggan. Access to the site is via a farm lane to the dwelling at [36025 37800] henceforth over poorly drained bogland and fenced rough pasture. This is an extensive site with outcrops of interest on several crags extending from the partially exposed stone circles at the foot of the northern face of Copney to the summit of Copney Hill.
On Portlock's geological map of the area, (1843) the rocks at Copney are classified as "metamorphic rocks of hornblendic type". Portlock used lithological qualifiers on the map to differentiate porphyritic rocks, "traps" and granitic rocks.
On the first edition of the one-inch to the mile geological map Sheet 26 (Draperstown, Geological Survey of Ireland, 1882) the rocks at Copney Hill were represented as "pyroxenic rocks" and were loosely classified as being of "Lower Silurian age". In the accompanying memoir, Nolan (1884) described a variety of rock types in the vicinity of Copney including quartz porphyry and "compact green rock".
When Hartley (1933) published the first detailed lithological map and description of the central Tyrone Ordovician volcanic plutonic terrane, he included the rocks at Copney Hill within a broad belt of tuffs and andesites which he referred to as the Tyrone Igneous Series.
On the second edition of Sheet 26 (Draperstown, Geological Survey of Northern Ireland, 1995), various lithologies are mapped on Copney Hill including quartz porphyry and feldspar phyric andesitic intrusions. Stratigraphically these lavas and tuffs form part of the Copney Pillow Lava Formation (Tyrone Volcanic Group). The Tyrone Volcanic Group is a major component of the Tyrone-Girvan Sub-Terrane of the Midland Valley Terrane (Bluck, 1992) and is broadly equivalent in age to the ophiolitic-volcanic associations at Girvan-Ballintrae (Scotland) and Clew Bay (County Mayo)
On Portlock's geological map of the area, (1843) the rocks at Copney are classified as "metamorphic rocks of hornblendic type". Portlock used lithological qualifiers on the map to differentiate porphyritic rocks, "traps" and granitic rocks.
On the first edition of the one-inch to the mile geological map Sheet 26 (Draperstown, Geological Survey of Ireland, 1882) the rocks at Copney Hill were represented as "pyroxenic rocks" and were loosely classified as being of "Lower Silurian age". In the accompanying memoir, Nolan (1884) described a variety of rock types in the vicinity of Copney including quartz porphyry and "compact green rock".
When Hartley (1933) published the first detailed lithological map and description of the central Tyrone Ordovician volcanic plutonic terrane, he included the rocks at Copney Hill within a broad belt of tuffs and andesites which he referred to as the Tyrone Igneous Series.
On the second edition of Sheet 26 (Draperstown, Geological Survey of Northern Ireland, 1995), various lithologies are mapped on Copney Hill including quartz porphyry and feldspar phyric andesitic intrusions. Stratigraphically these lavas and tuffs form part of the Copney Pillow Lava Formation (Tyrone Volcanic Group). The Tyrone Volcanic Group is a major component of the Tyrone-Girvan Sub-Terrane of the Midland Valley Terrane (Bluck, 1992) and is broadly equivalent in age to the ophiolitic-volcanic associations at Girvan-Ballintrae (Scotland) and Clew Bay (County Mayo)
| Enlander, I., Dempster, M. & Doughty, P., 2024. Copney Hill, County Tyrone, site summary. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/summary.php?item=584. Accessed on 2024-12-26 |
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