The BGS Lexicon of Named Rock Units — Result Details

Ascog Member

Computer Code: ASO Preferred Map Code: ASO
Status Code: Pending Upgrade
Age range: Tournaisian Stage (CT) — Tournaisian Stage (CT)
Lithological Description: Red brown siltstone and sandstone with pedogenic limestone.
Definition of Lower Boundary: At the lower boundary grey-white fine-grained calcareous sandstone of the Ascog member is interbedded with grey mudstone and dolomitic limestone (cementstone) of the Ballagan Formation.The boundary is picked where beds of dolomitic limestone (cementstone) are absent and sandstone becomes the predominant lithology.
Definition of Upper Boundary: Sharp change at the probably erosional base of the overlying Birgidale Formation, which comprises mudstone, sandstone, seatrock and coal.
Thickness: 86m
Geographical Limits: Isle of Bute in Strathclyde, Scotland.
Parent Unit: Clyde Sandstone Formation (CYD)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  BGS Ascog borehole, from 133.6m to 219 .8m depth. 
Reference(s):
Paterson, I B and Hall, I H S, 1986. Lithostratigraphy of the late Devonian and early Carboniferous rocks in the Midland Valley of Scotland. British Geological Survey Report, 18/3. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S029