44 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JuilG 14, 



part of the Barton clays near Hordwell is well known, but in descend- 

 ing lower in the strata they become much scarcer, and almost entirely 

 disappear at the base of these clays. The strata also become gene- 

 rally more mixed with sand, much of which consists of greensand. At 

 the end of the cliif near High-cliff House, nearly one mile east of 

 Muddiford, we have the following section, fig. 1 . 



Section near the West end of Barton Cliff, 

 w. E, Fig. 1. 



Ft. in. 



Ochreous flint gravel. ] 



Dark grey sandy clays with imperfect vegetable re- I Lower part 



mains. ... I ^^ ^^^ 



Tabular soft septaria mixed with greensand. f Barton clay 



Clayey greensand with a few indistinct impressions series. 



of shells and a few pebbles. 

 Rounded flint pebbles in light-coloured sand. 



Light grey clayey sand full of car- 

 bonized small fragments of vege- 

 tables. 



Irregular band of sandstone. 



Same as above the sandstone, but 

 rather lighter and more sandy. 



Light brown and yellow clayey 

 sand with imperfect vegetable 

 ( impressions. 



The upper part of this bed 

 thins out as it trends 

 westward, whilst the 

 lower part loses its bitu- 

 minous clay and passes 

 into a fine whitish and 

 yellow sand full of the 

 same carbonized frag- 

 ments of vegetables. 



If the strata at the Barton cliffs and those at Hengistbury Head 

 were on the same line of strike, and no fault intervened, we might 

 expect to find at the latter place beds lower in the series than those 

 we left at the former ; but it will be perceived that Hengistbury Head 

 projects south in advance of the general line of coast, and conse- 

 quently is not in the same bearing of the strata as the Barton Cliffs. 

 At Hengistbury Head the strata are more in the trough of the syn- 

 clinal line of which the anticlinals of the Isle of Wight and Isle of 

 Purbeck form the southern edge. This may, I think, account, 

 without any disturbance, for the reappearance of the Barton clays on 

 the other side of Christchurch Harbour at Hengistbury Head. I 

 have little to add to Sir Charles Ly ell's description of the cliffs at 

 this place, and beg to refer to his paper for fuller details than I pur- 

 pose entering into. I would venture however to introduce the group- 

 ing shown in the section fig. 2. 



In examining this section we find a near lithological resemblance 

 to the cliff east of Muddiford. The difference is no greater than is 

 common at like distances in any beds of this varying series. The 

 same general characters are preserved, but some slight details vary. 

 The sands at the base of both sections are exactly alike in appearance, 

 and present in both places the same peculiar fragmentary and carbo- 

 nized appearance in their imbedded vegetable remains. Then we 



