China Clay mining has historically been concentrated in and around Cornwall, Dorset and Devon. Over the years this has steadily declined and the main areas that have continued China Clay mining are the areas around St. Austell and Dartmoor. Any prospective purchaser buying a property in these areas should carry out a China Clay search to determined whether the property is likely to be affected by clay deposits, and if these areas are likely to be worked in future or if past workings pose a threat of subsidence.