The BGS Lexicon of Named Rock Units — Result Details

Tom Dubh Conglomerate Member

Computer Code: TDCO Preferred Map Code: TDC
Status Code: Full
Age range: Early Devonian Epoch (DL) — Early Devonian Epoch (DL)
Lithological Description: A poorly sorted, coarse conglomerate, with cobble-sized clasts of vein quartz and quartzite.
Definition of Lower Boundary: A sharp, diachronous contact with poorly sorted mudstones and sandstones of the undivided Cromlix Mudstone Formation.
Definition of Upper Boundary: A transitional, diachronous contact with sandstones and pebbly sandstones of the Teith Sandstone Formation.
Thickness: Measured as 110 m thick near Tom Dubh [NN 64 09], 300m north of Port of Menteith.
Geographical Limits: The north-west limb of the Strathmore Syncline, between Lake of Menteith and Meall Leathan Dhail [NN 667 117].
Parent Unit: Cromlix Mudstone Formation (CXF)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Reference Section  Crags above tributary of Redrock Burn, 400m east of Beinn Dearg. 
Type Section  Trackside cutting 400m north of Bridge of Brackland. 
Phillips, E R and Aitken, A M. 1998. The petrology and composition of the Lower Old Red Sandstone exposed in the Aberfoyle Area (Sheet 38E), Central Scotland. British Geological Survey, Technical Report, WG/98/10. 
Browne, M A E, Smith, R A and Aitken, A M. 2001. A lithostratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. Version 3. British Geological Survey Research Report RR/01/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: