Ambergate and Ridgeway Quarries
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SK358513 | — | Destroyed | 0.6 | 2013-10-03 |
| SK361516 | — | Favourable | 0.41 | 2013-05-02 |
Geology & landscape
Mining / Industrial: Quarry · Geological Period: Carboniferous · Rock Type: Sandstone
Landscape processes: Fluvial
Description
Area, 1.02 ha. 2.52 ac. Description These two quarries provide very important exposures in rock of Westphalian age Upper Carboniferous. The section exposed at the largely infilled Ambergate Quarry displays the best available exposure of the Belperlawn Coal and the sediments associated with that unit, the lowest economically viable seam in the Pennines coalfields. This section is principally of interest because it shows sediments originally laid down in front of the delta, whose sands formed the Crawshaw Sandstone Formation. This Formation is present in the nearby Ridgeway Quarry and is the lowest major sandstone body in the Westphalian rocks of the southern Pennines. The Crawshaw Sandstone Formation also has considerable economic importance as a gas and oil reservoir. Ridgeway Quarry shows the sandstone lying with an erosive base on the Gastrioceras subcrenatum Marine Band, the internationally recognised base of the Westphalian Series. The sandstone body itself has strongly developed planar crossbedding and is interpreted as a fluvial channel deposit. Both Ambergate and Ridgeway Quarries provide a valuable insight into the patterns of deposition of these economically important Carboniferous sediments.