Earth Science Conservation Review
| Scalp Hill | Tyrone |
| Site Type: | Crags, Inland exposure |
| Site Status: | ESCR |
| Grid Reference: | H635745 |
| Google maps: | 54.61517,-7.0171 |
| Rocks | |
|---|---|
| Rock Age: | Ordovician |
| Rock Name: | Tyrone Volcanic Group |
| Rock Type: | Gabbro, Horneblende schist |
| Interest | |
| Other interest: | Caledonian, mineral layering, ophiolite |
Introduction:
Scalp Hill consists of a series of rocky knoll-like outcrops in semi-enclosed rough pasture ~3.5km northeast of Carrickmore in Co Tyrone. Vehicular access is via a farm track north from Devesky Road leading to a farmyard and thereafter by foot across fields and rough pasture.
Portlock's early geological map of the area, (1843) included all rocks in the vicinity of Scalp Hill within the category "metamorphic rocks of hornblendic type".
On the first edition of the one-inch to the mile scale geological map (Sheet 34, Pomeroy, Geological Survey of Ireland, 1877) rocks at Scalp Hill were referred to as "Hornblendic & Pyroxenic Rocks" and were part of the "Metamorphic and Igneous Rocks". In the explanatory memoir which accompanied the map (Nolan, 1878) the rocks at "the Scalp" were described as being pyroxenitic with an augitic variety prevalent and sometimes "developed in large crystals of hypersthene, glittering with the semi-metallic lustre so characteristic of that mineral". This early description contains no indication of the possible origins or the geological context in which these rocks were formed.
Hartley (1933) produced the earliest detailed geological map of the central Tyrone Ordovician volcanic plutonic terrane. On Hartley's lithostratigraphic map, Scalp Hill shown as gabbro and included within a plutonic subgroup of what Hartley referred to as the Tyrone Igneous Series.
There was renewed research interest in the Scalp Hill locality (Cobbing, 1969) following the resurvey and publication of the 1:50 000 second edition of Sheet 34 (Pomeroy, Geological Survey of Northern Ireland, 1979).
The stratigraphy of central Tyrone was revised following the resurvey and publication of the second editions of Sheet 34 (Pomeroy) (1979) and Sheet 26 (Draperstown) (1995). Hartley's Tyrone Igneous Series is now subdivided into two major components, the Tyrone Plutonic Group and the Tyrone Volcanic Group. The rocks at Scalp were assigned to the Tyrone Plutonic Group and have been interpreted as being part of an ophiolite complex (Hutton et al., 1985). On a regional scale, they form part of the Tyrone-Girvan Sub-Terrane of the Midland Valley Terrane (Bluck et al., 1992) and have broad lithological correlatives in the Girvan-Ballintrae ophiolite in Scotland and at Clew Bay in the west of Ireland.
Portlock's early geological map of the area, (1843) included all rocks in the vicinity of Scalp Hill within the category "metamorphic rocks of hornblendic type".
On the first edition of the one-inch to the mile scale geological map (Sheet 34, Pomeroy, Geological Survey of Ireland, 1877) rocks at Scalp Hill were referred to as "Hornblendic & Pyroxenic Rocks" and were part of the "Metamorphic and Igneous Rocks". In the explanatory memoir which accompanied the map (Nolan, 1878) the rocks at "the Scalp" were described as being pyroxenitic with an augitic variety prevalent and sometimes "developed in large crystals of hypersthene, glittering with the semi-metallic lustre so characteristic of that mineral". This early description contains no indication of the possible origins or the geological context in which these rocks were formed.
Hartley (1933) produced the earliest detailed geological map of the central Tyrone Ordovician volcanic plutonic terrane. On Hartley's lithostratigraphic map, Scalp Hill shown as gabbro and included within a plutonic subgroup of what Hartley referred to as the Tyrone Igneous Series.
There was renewed research interest in the Scalp Hill locality (Cobbing, 1969) following the resurvey and publication of the 1:50 000 second edition of Sheet 34 (Pomeroy, Geological Survey of Northern Ireland, 1979).
The stratigraphy of central Tyrone was revised following the resurvey and publication of the second editions of Sheet 34 (Pomeroy) (1979) and Sheet 26 (Draperstown) (1995). Hartley's Tyrone Igneous Series is now subdivided into two major components, the Tyrone Plutonic Group and the Tyrone Volcanic Group. The rocks at Scalp were assigned to the Tyrone Plutonic Group and have been interpreted as being part of an ophiolite complex (Hutton et al., 1985). On a regional scale, they form part of the Tyrone-Girvan Sub-Terrane of the Midland Valley Terrane (Bluck et al., 1992) and have broad lithological correlatives in the Girvan-Ballintrae ophiolite in Scotland and at Clew Bay in the west of Ireland.
| Enlander, I., Dempster, M. & Doughty, P., 2024. Scalp Hill, County Tyrone, site summary. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/summary.php?item=581. Accessed on 2024-12-26 |
| Previous Site | Next Site |