Clay Minerals; March 2006; v. 41; no. 1;
p. 395-416; DOI: 10.1180/0009855064110201
© 2006 Mineralogical Society of Great Britain and Ireland
Clay mineralogy of onshore UK Carboniferous mudrocks
D. A. SPEARS
Centre for Analytical Sciences, Department of Chemistry, University of Sheffield, Dainton Building, Sheffield S3 7HF, UK
* E-mail: d.a.spears{at}sheffield.ac.uk
The Carboniferous in Britain is diverse and this is reflected in the clay mineral assemblages. Several factors affecting the assemblages are identified including climate, rates of weathering and erosion, source rocks in the hinterland, preservation of palaeosols, whether the source rocks are nearby or distant, sorting during transportation, the presence of altered volcanic ash-falls in the depositional environment and the extent of burial diagenesis. There are temporal and geographic variations in the clay mineral assemblages in the mudrocks as a result of these controls. There are also clay-rich rocks that differ from the normal mudrocks and a knowledge of the clay mineralogy of these is a necessary prerequisite to a full understanding of their origins. Mudrocks falling in this category, and described below, include bauxitic clays, flint clays, fragmental clay rocks, tonsteins and K-bentonites and various palaeosols.
KEYWORDS: clay minerals, Carboniferous, UK, mudrocks
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