Coal measure
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The Coal Measures is a lithostratigraphical term used mainly in the British Isles for the coal-bearing part of the Upper Carboniferous System. It represents the remains of fluvio-deltaic sediment, and consists mainly of clastic rocks (claystones, shales, siltstones, sandstones, conglomerates) interstratified with the beds of coal. In most places, the Coal Measures are underlain by coarser clastic sequences known as Millstone Grit, of Namurian age. The top of the Coal Measures may be marked by a non-sequence, the overlying rocks being Permian or later in age. In some parts of Britain, however, the Coal Measures grade up into mainly coal-barren red-beds of late Westphalian and possibly Stephanian age..[1] [2]
The Coal Measures formed during Westphalian and earliest Stephanian times in the European ('Heerlen') chronostratigraphical scheme (which is approximately equivalent to the Middle Pennsylvanian Series of the IUGS global chronostratigraphical scheme).
The term coal measures has also historically been used in other parts of the world for coal-bearing successions of various ages, e.g. the Permian coal measures of Australia and the late Cretaceous and early Tertiary coal measures found in New Zealand. However, these useages are mostly informal.
[edit] See also
[edit] References
- ^ Rayner, D H & Hemingway, J E, The Geology and Mineral Resources Of Yorkshire, Leeds: Yorkshire Geological Society (published 1974)
- ^ Edwards, W & Trotter, F M, The Pennines and Adjacent Areas (Third ed.), British Regional Geology, London: HMSO. Natural Environment Research Council (published 1954)
[edit] Further reading
- CJ Cleal and BA Thomas, Plants of the British Coal Measures, The Palaeontological Association, 1994.
- CJ Cleal and BA Thomas, British Upper Carboniferous stratigraphy, Chapman & Hall, London, 1995.