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 16: Till and peat section
NGR: [275957, 630845] [NS 75957, 30845]
| Key category of interest | Rarity | Quality |
|---|---|---|
| 1. Quaternary deposits | 4 | 5 |
| 2. Economic geology | 3 | 3 |
Access: Good access to section, accessible from roadways.
Current safety: Deep ponds nearby, accessible by road surface.
Measures to enhance site: Clean up sections in entrance to locality to avoid danger of deep ponds.
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
Aerial
Site description
Geology
This locality's primary interest is in its excellently preserved Quaternary deposits within a cutting created during construction of the two man-made fining ponds in the area. Up to 2 m of dark brown peat overlies a sandy glacial till, with the boundary between marked by a conspicuous ~10 cm thick bleached zone. It is thought this bleached zone represents the formation of a podzol (a soil) in the till. This usually forms in cool humid climates where peat develops on top of sandy tills. Where the peat comes into contact with the till, organic compounds in the peat have been washed out by rainfall and combined with aluminium and iron in the layer below. The till layer below has a bleached appearance because it becomes higher in silicon and lower in aluminium and iron — i.e. the main mineral left following podzolisation is quartz. This section preserves the original Quaternary cover that is likely to have covered the site before mining.
This locality also provides a good viewing area for appreciating two generations of mine waste (related to surface mine operations) to the south, and the natural processes that evolved over each since. The older generation has a cover of sparse vegetation and trees, whilst plant life has just started to grow in the newer generation.
Access and enhancement suggestions
Access is very good as a road has been cut through the peat and till for access to the ponds. Another exposure of peat lying above till can be seen above the Swanshaw Sandstone Formation, see Locality 17 site photos. The site could be enhanced by cutting a new, clean section through the access road before reaching the fining ponds, as hands on access is restricted at the current exposure due to the water level.