| Computer Code: |
THQ |
Preferred Map Code: |
THQ |
| Status Code: |
Full |
| Age range: |
Comley Series (EC)
— Comley Series (EC) |
| Lithological Description: |
Pink to maroon, medium- to fine-grained glauconitic sandstone. Subordinate mudstone beds and near-ubiquitous mudstone drapes. Tabular-planar and compound cross-bedding common. Summary of typical lithologies in Type Section:(i) Sandstone, maroon, fine, glauconitic and micaceous. Smooth, flat-topped beds, parallel-sided with horizontal lamination. Many bed tops bioturbated (56m). (ii) Sandstone, pink to maroon, glauconitic. Undulatory, smooth-topped beds with mudstone drapes. Compound cross-bedding with highly lenticular bed forms (39m). (iii) Sandstone, maroon to pinkish grey, glauconitic. Parallel-sided, smooth-topped beds with horizontal or gently dipping lamination; mudstone beds locally constitute 50% of succession (10.5m). (iv) Sandstone, maroon to pale pink, glauconitic. In thick tabular-planar cross-bedded sets, showing unimodal current directions, or in lenticular compound cross-bedded sets. Ubiquitous mudstone drapes (39m). (v) Sandstone, grey, coarse to pebbly. In lenticular, thick beds with tabular-planar cross-bedding showing bimodal current directions. Mudstone interbeds are lenticular, locally to 0.7m thick (7.5m). (vi) Horizontally laminated sandstone, mudstone dominant at base (5.3m). |
| Definition of Lower Boundary: |
Base of beds with abundant mudstone-draped top surfaces. Sandstones beneath (of Park Hill Member) predominantly grey, with herringbone cross-bedding in main part. |
| Definition of Upper Boundary: |
Incoming of variegated fine-grained sandstone and siltstone beds of Jees Member. Bimodal cross-bedding and trough cross-bedding becomes well-developed. |
| Thickness: |
157m in type section. |
| Geographical Limits: |
From Nuneaton town centre, extending north-west for 5.2km to Worthington Farm, Mancetter.(SP 3541 9205-3192 9572). |
| Parent Unit: |
Hartshill Sandstone Formation (CQ)
|
| Previous Name(s): |
Tuttle Hill Quartzite [Obsolete Name and Code: Use THQ]
(-3725)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Southeast face of Hartshill Quarry, 600m west-north-west of Hill Farm. (SP 3425 9360). |
| Reference(s): |
| 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: |
|
E169
|
