The coal seams worked in the
South Yorkshire Coalfield
The South Yorkshire Coalfield is so named from its position within Yorkshire. It covers most of South Yorkshire, West Yorkshire and a small part of North Yorkshire. The exposed coalfield outcrops in the Pennine foothills and dips under Permian ...
lie mainly in the middle
coal measures
In lithostratigraphy, the coal measures are the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Co ...
within what is now formally referred to as the
Pennine Coal Measures Group. These are a series of
mudstones
Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from ''shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' ...
,
shales
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...
,
sandstones
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates) ...
, and
coal seam
Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron fro ...
s laid down towards the end of the
Carboniferous period between about 320 and 300 million years ago. The total depth of the
strata
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...
is about .
The list of coal seams that follows starts at the shallowest seam and proceeds downwards with the outcrops occurring progressively further west until the deepest coal seam, the Silkstone Seam which outcropped at the western edge of the coalfield.
The thicknesses and depths of each seam are not given as they vary across the coalfield.
Seams
Sources
*
*
Further reading
*
*
External links
Yorkshire Coalfield Geology- with depths of the seams at
Kiveton, and a map showing the depth of the Barnsley Seam across the coalfield; see also depths of the seams at
Dinningtonbr>
and
Thurcroftbr>
{{Coal mining in Yorkshire
Geology of South Yorkshire
Mining in South Yorkshire