The coal seams worked in the
South Yorkshire Coalfield 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 Coal ...
within what is now formally referred to as the
Pennine Coal Measures Group. These are a series of
mudstones,
shales,
sandstones, and
coal seams laid down towards the end of the
Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
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 ei ...
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
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Further reading
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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