242 A Geological Description 



from Bristol. It is wanting on the south-east, in the distance 

 between Bath and Elm near Mells, where it reappears and 

 constitutes the whole of the Mcndip Hills, which run east aiul 

 west to the south of Bristol. On the west it runs in a wide 

 ridge whicii commences ahout three miles to the north-east 

 of Langford, and continues to within about two miles of 

 Bristol. On the north-west it is seen at Clifton and West- 

 bury. Independent of this limestone ellipsis there is a sub- 

 ordinate range which begins from Leigh and Asrhton Downs, 

 and runs towards the Channel above Belmont, Wraxal, and 

 Tickengham. The inclination of the limestone wherever seen is 

 always at a considerable angle, being never less tlian 35°. At 

 Week the strata arc elevated to an angle of at least 65°. At the 

 Mendips near Langford, and on the road near Westbury, thw 

 dip is seventy; and in some parts of Blais Castle grounds th« 

 'strata may be said to be completely vertical. It is very remark- 

 able that the direction of the dip varies as we observe it at dif- 

 ferent parts of the basin. At the north the, inclination is to- 

 Avards the south. On the east, at Sodbury, due west. On the 

 ■south, at the Mendips, they incline towards the north. This, 

 however, is only to be said of that ])art of the range which lias 

 a northern aspect; for that portion of the south part at Cheddar 

 Cliffs, and the hills above Wells and Axbridge, are observed to 

 incline towards the south. The Langford road passes along the 

 westward ridge, and wherever the dij) is seen, it is towards the 

 east ; and at Barrow, where there is a large quarrv, it is due east» 

 There are some places, however, where we find that the inclina- 

 tion does not conform to this arrangement. If \ve diverge froni 

 the Langford road, and come any where upon the brow of tlie 

 lidge above Brockley, Backwell, or Bourton, we find the dip 

 completely altered ; instead of its being as it is on the Langford 

 road eastwards, we find it almost due north. This part of the 

 range forms, in fact, the southern boundary of the Nailsea coal- 

 field, which lies between it and the oj)posite range, passing above 

 Wraxal, Belmont and Tickengham, v,here the dip is always tend- 

 ing towards the south. We therefore find the Nailsea coal^ 

 iield shut in by two barriers, each dipping towards the other. 

 From Clifton to Westbury the limestone sinks towards the south- 

 east, but about half a mile beyond Westbury the inclination i» 

 to the north. If we go from this point westward towards King- 

 weston Hill and Pinfield Point, we find the same dip to prevail. 

 It is probable that this variation in the dip is connected with 

 some coal formation in the plain be!o\v. I am confirmed in this 

 idea by having observed at Patishead along the point the mica- 

 ceous sandstone or Pennant stone, which is always in this coun- 

 try an unerring index of co^, 



The 



