A Geological Description of the. Parish of Portishead. 271 



have, with one exception not to the purpose, more or less of a southerly 

 dip. 



Since, then, the rocks on different sides of tlie district dip in very dif- 

 ferent and nearly opposite directions, it is evident that they must be sepa- 

 rated by an anticlinal line. One part of this line is visible at the landing 

 place ; it must next be carried along somewhere between the old red hill of 

 the point and tlie coal seam by the mill, and it must emerge on the other 

 side of the peninsula, between the carboniferous limestone of the battery 

 and beach adjacent, and the appearance, at a short distance, of the old red 

 of Woodhill Bay. So that so much of the course of this anticlinal, which 

 arises from and passes into the sea, may be considered as satisfactorily 

 determined. 



But there are indications of a second convulsion in tliis district. It has 

 been observed, that the carboniferous limestone of the battery, after having 

 been much contorted, and laid for some yards in a nearly horizontal posi- 

 tion, ceases abruptly, and abuts against a bank of old red shingle, and a 

 triangular portion of alluvial marsh. 



Beyond the road, considerably to the south of this, are further indications 

 of an irregularity, in the occurrence of the dolomitic conglomerate upon 

 the summit of a somewhat elevated hill. Following up this track, we come 

 upon the point already described, between the Down Gate Farm and the 

 church ; here it becomes evident that the whole mass of Portishead Down and 

 Woodhill Bay has been cast down, that the edges of the dolomitic beds 

 have been turned up during their descent, and that thus the beds of the 

 old red sandstone have been brought once more into view, and a reduplica- 

 tion of the carboniferous series brought about. It would be difficult, with- 

 out more time and means than we had at our immediate disposal, to estimate 

 with any degree of accuracy the amount of the fall of the downcast portion ; 

 but it may be observed, that a bed of quartz conglomerate, occurring in the 

 Woodhill Bay Cliff, may apparently be identified in one occurring at the 

 bottom of the hill, just above the church. The hill lying iietween Capenor 

 and the church, has apparently been detached by the convulsion, and has 

 undergone a twist round towards the north, so that the bearing of its strata 

 is more nearly coincident with that of those on the northern side of the 

 anticlinal, than with that of the adjacent rocks. The limestone itself, 

 moreover, resembles closely that of the battery, and is very different from 

 the same rock in other places. From the summit of this hill, the line of 

 fault is indicated by the convexity of the zone of old red, and seems to pass 

 down towards the marsh, in the direction of Naish and Charlton Houses, 

 between which its existence has been pointed out by Messrs. Conybeare 

 and Bucklatid. 



It still remains to be accounted for how the dolomitic rocks came to fill 

 up the irregularity cansed by the downcast of the old red. At present, 

 the ordinary level of these horizontal rocks does not extend to so great a 



