72 H. Bury — The Chines and Cliffs of Bournemouth. 



changing so rapidly tliat plants have no chance of establishing 

 themselves on it, and the same is true of the mouths of the chines, 

 where readjustment to the changing coastline is constantly going 

 on ; but the heads of all the principal chines are (or were before 

 man interfered) covered with rank vegetation, and afford no evidence 

 at all of rapid erosion. 



Secondly, the form of the chines must be taken into consideration. 

 If we examine the valley of the Bourne (not usually accounted a 

 " chine ") we find the sides rather steep, but the bottom wide and 

 fairly fiat ; in fact, in section it has the form of a broad letter U • 

 In Durley Chine, on the other hand, the sides are exceedingly 

 steep and the bottom narrow, so that a section takes the form of 

 a V. Passing next to Branksome Chine (or Branksome Glen ') 

 we find both these forms represented, the upper portion of the valley 

 (i.e. that furthest inland) being wholly of the U type, while the 

 lower (from just above All Saints Church down to the sea) has 

 a V-shaped ravine carved in the floor of the U (Fig. 1). Clearly, 

 then, we have two valleys of different ages, a newer and steeper one 



Fig. 1. — Transverse section of Branksome Chine. 



which alone contains water, and an older one which is more than 

 twice as wide and as long, being traceable inland almost as far as 

 Parkstone Station, where it is truncated by the slope leading down 

 to Poole Harbour ; while at the other end, after forming a well- 

 marked terrace on each side of the newer valley, it ends somewhat 

 abruptly about 50 feet above sea-level. It is, in truth, a hanging 

 valley, but its relation to the cliff is obscured partly by alterations 

 due to man, and partly by the fact that it curves towards the east 

 at this point, and was formerly continued for some distance in that 

 direction almost parallel to the present clifi'. The latter is 

 exceptionally low ojiposite Branksome Tower Hotel ^ for this very 

 reason, namely, that it is here a section of the old valley floor (valley 

 gravel, though not shown on the geological map, can be seen capping 

 it), and not, as elsewhere, a section of the plateau (Fig. 2). This 

 double structure can be traced in all the principal chines of Bourne- 

 mouth Bay, as well as in the " Bunnies " of Christchurch Bay;' 



^ The latter name is used by Mr. Starkie Gardner, the former by the Ordnance 

 Survey, by vi^hich wh&t used to be knovifn as " Branksome Chine " is called 

 " Branksome Dene Chine ". 



^ See Mem. Geol. Surv., Bournemouth, 2nd ed., p. 23, fig. 5. 



3 Quart. Journ. Geol. Soc., vol. xxvi, 1870, p. 532. 



