 Coal was also worked on a very small scale in the rocks of the Clapton-in-Gordano inlier just to the south of the Severn Coalfield.In the small 'Nailsea Basin' to the west of Bristol, a sequence of Coal Measures rocks are preserved within a syncline.These rocks are connected at depth with those of the Somerset Coalfield; though it lies close to the main body of the Bristol Coalfield, it is not connected with it.