The BGS Lexicon of Named Rock Units — Result Details
Glenelly Formation
| Computer Code: | GLLY | Preferred Map Code: | GY |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ) | ||
| Lithological Description: | Mixed series of quartz feldspar psammites and semi pelitic biotite schists with tourmaline. | ||
| Definition of Lower Boundary: | Conformable with Dart Formation. | ||
| Definition of Upper Boundary: | Conformable with Glengawna Formation. | ||
| Thickness: | at least 2.7km | ||
| Geographical Limits: | Sperrin Mountains, counties Tyrone and south Londonderry, Northern Ireland. | ||
| Parent Unit: | Argyll Group (ARGY) | ||
| Previous Name(s): | Glenelly Formation (A) [Obsolete Code: Use GLLY]
(DCGG)
Glenelly Formation (B) [Obsolete Code: Use GLLY] (DCGO) Glenelly Formation [Obsolete Code: Use GLLY] (-932) Tourmaline schists of Glenelly North [Obsolete Name and Code: Use GLLY] (-284) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | Top of formation. First conspicuous graphitic mica schist in Glengawna Formation, in Glendarragh Burn, Glenlark. | ||
| Partial Type Section | Bottom of formation. Oughtboy Burn, transition from medium-grained gritty psammites and graphitic mica schists (Dart Formation) to silvery green semi-pelitic, schistose flags with tourmaline and albite. | ||
| Reference(s): | |||
| Hartley, J J, 1938. The Dalradian rocks of the Sperrin Mountains and adjacent areas in Northern Ireland. Proceedings of the Royal Irish Academy, Vol.XLIV, section B, 141-171. | |||
| Arthurs, J W. 1976. The geology and metalliferous mineral potential of the Sperrin Mountains area. Geological Survey of Northern Ireland, Special Report No. 1, 119pp, 2app, 2 figs, 7 tables, 102 maps. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| N26 | |||