Ellen, R. and Callaghan, E. 2015. Geodiversity Audit of Spireslack and Mainshill Wood Surface Coal Mines. British Geological Survey Commerical Report CR/15/126. 70pp.
Spireslack Locality 12: Sedimentary section through Limestone Coal Formation
NGR: [274979 630606]–[274930 630564]
| Key category of interest | Rarity | Quality |
|---|---|---|
| 1. Sedimentary rocks | 4 | 5 |
| 2. Palaeontology | 3 | 3 |
Access: Good access to base of exposure, easily accessible from roadway.
Current safety: Uneven surfaces, potentially loose large blocks at top of exposure may pose hazard.
Measures to enhance site: Assess large blocks from above exposure, and assess any remedial measures necessary. Clean surface to enhance sedimentary structures.
Key categories in order of interest (1 = primary interest); Rarity, 5 = only example in Spireslack, 1 = many examples in Spireslack; Quality 5 = exceptional preservation in Spireslack, easy access/viewing potential 1 = average preservation in Spireslack, difficult access/viewing potential
Photograph overview with polygon boundary
© Getmapping: Licence Number UKP2006/01
Site description
Geology
A rare chance within the Spireslack void for an apparently safe, in situ sedimentary sequence to be examined is the focus of this locality. A 5 m section through part of the Limestone Coal Formation allows hands on access to a coarsening upwards sequence of sandstones, mudstone, siltstones, representing a deltaic environment. The sandstone in the section displays a distinct two tone appearance, a characteristic also observed in a sandstone higher in the sequence — the latter unit is traceable across the length of the scarp, and acts as a key marker bed when following the sequence across faults. The sedimentary rocks contain abundant bioturbation, crinoid fragments and organic remains.
Access and enhancement suggestions
There is good access to the section, but by providing a level base to view the sequence this would improve access, and cleaning the rock face would assist in the understanding of the depositional environment of these sedimentary rocks.