| Site Type: | Stream section |
| Site Status: | ESCR |
| Grid Reference: | H671878 |
| Google maps: | 54.73415,-6.95833 |
| Rocks |
|---|
| Rock Age: | Ordovician, Precambrian (Dalradian) |
| Rock Name: | Mullaghcarn Formation, Southern Highlands Group, Tyrone Volcanic Group |
| Rock Type: | Phyllite, Psammite, Semi-pelitic rock |
| Interest |
|---|
| Minerals: | Chlorite, Epidote, Graphite |
| Other interest: | fault, slickensides, thrust, cleavage |
The site is located 1.5km NE of the chapel at Broughderg, County Tyrone. McNally's Burn is one of several streams, which drain the southern slope of Keraghbrien. Access is via the south bank of the stream (Fig. 13) which passes beneath the Broughderg Road at McNally's Bridge. The first outcrop is encountered in the burn bed and in the overgrown banks about 200m upstream from McNally's Bridge.
The Sperrin Fault is the regionally important thrust structure that separates the Grampian (Central Highland) Terrane and the Tyrone-Girvan Sub-Terrane in central Ulster. McNally's Burn offers unique access to both hangingwall and footwall of the Sperrin Fault and contains a range of associated brittle and ductile structures and microstructures.
