270 A Geological Dcucrijilion of /he Parish of Portishead. 



appearance of the latter at the landing place, the pennant dips in an oppo- 

 site direction. 



It is stated, that at low water the carboniferous limestone re-appears below 

 the landing place ; but owing to the mud with which the rocks are covered 

 up,this fact, though extremely probable, has not been satisfactorily ascertained. 



III. Unless the bed of quartz conglomerate, before described as overlying 

 certain calcareous strata near Down Gate Farm, be considered as the repre- 

 sentative of the millstone grit, nothing analogous to that rock has been ob- 

 served in the district. 



IV. The pennant sandstone clusters about the point, but is not elsewhere 

 exposed. It reposes conformably on the northern face of the limestone of 

 the point, is prolonged to the east of it to form an anticlinal line, and then 

 dipping in a contrary direction, and more or less covered up, it skirts the 

 northern bank of the pill, and, with an included seam of coal, crops out 

 through a thin mantle of dolomite, a little to the north of the mill. 



V. The horizontal rocks pass so subtlely into each other, that it will be 

 most convenient to consider them all under the common appellation of 

 dolomite. 



The rocks above enumerated may be divided under two distinctions, de- 

 rived from their locality. The first are strictly in situ, having apparently never 

 been disturbed since the period of their deposition. The second set are 

 slightly inclined, and seem to have been subjected to a greater or less 

 change of elevation. 



1. The first series extend from the eastern extreme of the point, along 

 its northern face, encircling its western end, capping the carboniferous lime- 

 stone of the battery, and covering up the depression between the ridge and 

 the old red hill, round which they pass, and skirt the left bank of the pill, as 

 far up as the mill. At the mill itself, the beds are not very distinctly seen j 

 but tliey become more apparent as they pass to the south-west, in which di- 

 rection they form a zone of irregular width, covering up the skirts of the 

 hills on the one side, and dying into the marsh on the otiier. 



2. The distinction between the undisturbed and the disturbed beds, is 

 only apparent at certain points. Of tiiese, the principal is above the fork 

 of the roads, between the Down Gate Farm and the church, where for some 

 distance the former are observed, reposing on the west upon the car- 

 boniferous limestone, with a slightly conformable dip, and towards the east 

 abutting against the abrupt edge of the old red, by which their edges appear 

 to have been upheaved. 



Let us next consider the dislocations to which this district has apparently 

 been exposed. 



It has been observed that the rocks of the point, and of the hill behind 

 the point, have a general dip, in a northern or north-easterly direction, 

 while the rocks on the east side of the point along the banks of the pill, 

 and all those lying to the south of a line drawn from the battery to the mill. 



