The BGS Lexicon of Named Rock Units — Result Details

Queensberry Formation

Computer Code: QBY Preferred Map Code: QBY
Status Code: Full
Age range: Llandovery Epoch (SL) — Llandovery Epoch (SL)
Lithological Description: Sandstone, typically medium- to coarse-grained but ranging from fine- to very coarse-grained, locally pebbly. Generally medium- to very thick-bedded or massive over thicknesses of tens of metres, units up to few metres thin-bedded. Interbedded siltstone or silty mudstone generally thin to medium beds but silstone units range up to several tens of metres locally. Rare conglomerate and intraclast-rich sandstone occur locally. Sandstone siltstone typically bluish grey when fresh, darker grey when weathered. Although of similar facies, the mid-Llandovery Queensberry Formation is younger then the adjacent early Llandovery Mindork Formation. Sandstone in both formations is predominantly quartzo-feldspathic, but is distinguished by accompanying volcanic debris; the Mindork Formation sandstone commonly contains sparse intermediate volcanic lithic debris and associated mafic crystal material (typically pyroxene); volcanic debris may be more common in the Queensberry Formation and tends to be more basic (spilitic) in character, mafic crystal material occurs locally but is relatively rare.
Definition of Lower Boundary: Sedimentological boundary with rocks of the Moffat Shale Group.
Definition of Upper Boundary: Faulted, no stratigraphical evidence preserved.
Thickness: minimum 100m, may be substantially more.
Geographical Limits: Southern Scotland.
Parent Unit: Gala Group (GALA)
Previous Name(s): Queensbury Grits (-4034)
Buckholm Grits (-3630)
Queensbury (Buckholm) Grits (-476)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Incised stream section and crags - Hang Gill to Black Craig (Black Hope, Moffatdale). 
Type Section  Quarry at Garpol Side, southwest of Moffat. 
Reference Section  Blaebeck and hillside to north of Black Craig, north of Moffat. 
Partial Type Section  Crags at Redgill Craig and Saddle Craigs (Black Hope, Moffatdale). 
Reference(s):
British Geological Survey. 1991. Moffatdale. Solid Geology. 1:25 000. Classical areas of British geology. (Keyworth, Nottingham: British Geological Survey). 
Peach, B N and Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoir of the Geological Survey of the United Kingdom. 
Webb, B C, Rushton, A W A and White, D E. 1993. Moffatdale and the upper Ettrick valley. Description of the solid geology of parts of 1:25000 sheets NT10, 11, 20 and 21. Classical Areas of British Geology. (London: British Geological Survey, HMSO.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable