461 



Somersetshire and the southern part of Gloucestershire form 

 one connected coal field, the anteclinal of Kingswood has separated 

 the latter into a subordinate basin, in which the strata dip towards 

 the centre from all points. It appears to me that the whole of this 

 northern part of the coal field, commencing at Kingswood, has been 

 raised to a higher elevation than the Somersetshire end of the 

 basin, and it has thus been more exposed to those powerful 

 denuding forces which have swept over the district. The Lias and 

 the Keuper marls have here been to a great extent removed, and the 

 highest Coal measure strata of which we have any evidence are the 

 red shales which intervene between the Kadstock and Farrington 

 groups, these having been proved in the sinking of Parkfield 

 colliery. 



We next pass on to the Nailsea basin, the extent of which is 

 little known. Only a small portion of its northern end is exposed 

 at the surface, and it speedily disappears under the alluvial deposit 

 which extends under Kenn Moor towards the Channel. So far as I 

 have been able to determine, the strata belong to the under part of 

 the Pennant and the lower division of Coal measures, chiefly the 

 latter. 



A little to the north of the Nailsea basin, between Clevedon and 

 Clapton, we find a curious little strip of Coal measures wedged in 

 between two ridges of limestone, and near to Clevedon it presents 

 the appearance of dipping beneath the limestone. This is caused 

 by a fault, which happens to be so nearly coincident with the 

 bedding of the strata as to deceive a casual obsei'ver. The Clapton 

 Coal measures doubtless belong to the under division, but they are 

 of small area and importance. 



Range of the Coal Measures under Secondary Rocks. 



I have dwelt with some degree of minuteness on those parts of 

 the carboniferous system which come to the surface, and which are 

 therefore open to examination. Much additional information has 

 been obtained from mining operations, but this being of too 

 technical a character to be of general interest, I will now endeavour 

 to define the probable range of the different members of the 

 productive Coal measures beneath the secondary rocks, taking them 

 in their ascending order fsee diagram). 



