Yol. 67.] WEST, MID, a:nd east somekset. 31 



(2) Mid Somerset. 



(A) The Polden-Hills Area. 



(i) Introduction. — The name Polden Hills is popularly applied 

 to the noticeable ridge which presents a steep face south-westwards, 

 but a gentle dip-slope north-eastwards, and, starting near Dunball, 

 about 2 miles north of Bridgwater, runs in a south-easterly 

 direction certainly as far as the Butleigh Monument. But, beyond 

 that, it is doubtful whether popular opinion would permit of its 

 extension. Considerable research and abundant enquiry have not 

 forwarded matters : so — in accordance with the precedent set in 

 the delimitation of the Cotteswold Hills — I may suggest that a 

 definite contour-line be taken, and in the present case the 100-foot 

 contour-line would answer the purpose best. The higher ground 

 thus contained extends from Dunball to the neighbourhood of 

 Charlton Adam, and is excellently shown on Bartholomew's ' Half- 

 inch-to-a-Mile' map of England & Wales — Dorset (Sheet 34). 



At Dunball at one end of the area, and near Charlton Mackrell 

 at the other, magnificent sections have been displayed in railway- 

 cuttings. The section at the former locality is still open, for its 

 steep sides afford but little roothold for vegetation ; but the section 

 at the latter locality, with its sloping sides, is — despite its recent 

 construction — almost wholly obscured. In the intervening district, 

 as at Windmill Hill, Butleigh, higher strata (belonging to the Lower 

 Lias) are well exposed. 



The stratigraphy of the Phaetic in this area presents several 

 points of difficulty, which additional detailed local work, aided, per- 

 haps, by purposely-made excavations, can alone thoroughly elucidate. 

 The main difficulty is encountered in connexion with the Langport 

 Beds. At Dunball they are only 4 feet 3 inches thick ; but at 

 Charlton Mackrell, 20 feet 8 inches. There is not sufficient evidence 

 available to show in precisely what manner this thickening has 

 taken place : whether it is due simply to overlap on the part of the 

 higher beds over the lower from east to west, or to some more 

 complex cause. 



In the Dunball- Ashcott portion of the Polden Hills, it would 

 appear that the Langport Beds do not differ widely from their 

 equivalents in the railway-cutting at Dunball. That is, they are 

 thin, and the bottom massive limestones of the Langport Beds, 

 or the ' Sizes ' as they are locally called, cannot be definitely 

 recognized. All the limestone-beds present appear to belong to 

 the upper portion of the Langport Beds : in other words, the 

 ' Sizes' may be wanting, or very poorly represented, in this Dunball- 

 Ashcott district. Their absence or poor development may be due to 

 the fact that this portion of the Polden Hills during the time of 

 deposition of these beds was rendered unstable, owing to movements 

 along an old anticlinal axis, which is now traceable at Blue Anchor 

 Point, enters the Polden Hills near Knowle Hall (to the west of 

 Bawdrip), is seen in the railway-cutting near Cossington, and 



