| Computer Code: |
CQ |
Preferred Map Code: |
HtS |
| Status Code: |
Full |
| Age range: |
Comley Series (EC)
— Comley Series (EC) |
| Lithological Description: |
Grey to maroon medium-grained sandstone, glauconitic in upper part. Mudstone present only as rare beds 0.10m thick, or as drapes to sandstone beds. |
| Definition of Lower Boundary: |
Sharp unconformable contact of coarse beds on weathered tuffaceous Precambrian rocks of the Caldecote Volcanic Formation. Basal beds are red breccias or grey conglomerates. |
| Definition of Upper Boundary: |
Sharp sedimentary break. Dark grey glauconitic sandstones of the formation are overlain by red mudstone of Purley Shale Formation. |
| Thickness: |
Thickness in the type area is 275m. |
| Geographical Limits: |
Known extent: from Nuneaton town centre, extending north-west for 5.2km to Worthington Farm (SP 3529 9197 - 3192 9572). |
| Parent Unit: |
Not Applicable (-)
|
| Previous Name(s): |
Hartshill Formation [Obsolete Name and Code: Use CQ]
(-3954)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Upper northern levels of Boons Quarry, 50m south-south-west of Grange Farm. |
| Partial Type Section |
Hartshill Quarry, south-east face and part of south-west face, 550m west-north-west of Hill Farm. |
| Reference(s): |
| Carney, J N. 1992. Geology and structure of the Lower Cambrian Hartshill Sandstone Formation: information from quarries north-west of Nuneaton. British Geological Survey Technical Report WA/92/08. |
| Brasier, M D, Hewitt, R A, and Brasier, C J. 1978. On the late Precambrian - Early Cambrian Hartshill Formation of Warwickshire. Geological Magazine, Vol. 115/1, 21-36. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |