The BGS Lexicon of Named Rock Units — Result Details
Holme High Limestone Group
| Computer Code: | HOHI | Preferred Map Code: | HOHI |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Chadian Substage (CI) — Brigantian Substage (CX) | ||
| Lithological Description: | A pale to dark grey, typically darker towards the base, micritic to crystalline limestone, with subordinate partings and thin beds of dark grey shale, and locally abundant chert, crinoid and brachiopod debris. A thin vesicular brecciated basalt is present near the base of the type locality, and dolostone or dolomitic limestone is predominant in the basal 120 m above this. Shallow water platform to ramp carbonates. Chadian to Brigantian. | ||
| Definition of Lower Boundary: | The base of grey and grey-brown dolostone of the Holme High Limestone Group, resting unconformably upon Lower Palaeozoic green slate strata in the type locality. | ||
| Definition of Upper Boundary: | The sharply conformable base of overlying dark grey, carbonaceous, fissile mudstone of the Bowland Shale Formation, above the pale grey limestone of the Holme High Limestone Group. | ||
| Thickness: | Seen as 613 m in the type locality, though seismic surveys over the high suggest that the group may be up to 1250 m thick (Evans and Kirby, 1999). | ||
| Geographical Limits: | Not seen at outcrop, but proved in the subsurface over the Holme High, an E-W structure extending from Heywood [SD 80 10] to Holmfirth [SE 20 10], bounded to the north by the Holme and Heywood faults, and to the south by the Alport Basin. The group is extended to include equivalent platform carbonates present on the Heywood High, which represents the westward continuation of the Holme High. | ||
| Parent Unit: | Carboniferous Limestone Supergroup (CL) | ||
| Previous Name(s): | Carboniferous Limestone [Obsolete Name and Code: Use CL]
(-4550)
Carboniferous Limestone [Obsolete Name and Code: Use CL] (-4550) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Not seen at the surface, but present in the Wessenden-1 Borehole (SE00NE/7) from 489.5 to 1103.3 m depth, displaying the entire thickness of the formation (Evans and Kirby, 1999). | ||
| Reference Section | Heywood No.1 Borehole (SD80NW141) from the base of the borehole at 1619 m to 1460.9 m, displaying the upper part of the group, of Brigantian age (Waters et al., 2009). | ||
| Reference(s): | |||
| Waters, C N, Waters, R A, Barclay, W J, and Davies, J R. 2009. Lithostratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/09/01. 184pp. | |||
| Evans, D J, and Kirby, G A. 1999. The architecture of concealed Dinantian carbonate sequences over the Central Lancashire and Holme highs, northern England. Proceedings of the Yorkshire Geological Society, Vol. 52, 297-312. | |||
| Riley, N J. 1993c. Foraminiferal-Algal Biostratigraphy of Enterprise, Wessenden No.1 Borehole: Cores 1 and 2. British Geological Survey Technical Report, Stratigraphy Series, WH/93/009. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E085 E086 | |||