H. Bury — -Tlie Chines and Cliffs of Bournemouth. 71 



The Chines and Cliffs of Bournemouth. 



By Henry Bury, F.G.S. 

 I. The Chines. 



npHE country round Bournemouth consists of a wedge-shaped 

 -■- plateaii, lying between the Eiver Stour and the sea, and 

 ranging roughly from 100 to 200 feet above sea-level. Of the 

 numerous valleys which intersect it, those that join the Stour 

 present as a rule no special features, but most of those running 

 down to the sea are of exceptional character and are known as 

 chines — a term which does not admit of very accurate definition, 

 but is generally applied only to valleys of more than usual 

 steepness. 



It is somewhat remarkable that, although the Geological Survey 

 has published two editions of its memoir on Bournemouth,' in neither 

 of them is any attempt made to deal with either the form or the 

 origin of these chines. Several other writers, however, have noticed 

 them, and have made suggestions as to their origin ; Lyell,''^ for 

 example, thought that they originated as the result of landslips, 

 though he does not attempt any details of the process or explain 

 how the country was drained before they arose. Mr. Starkie 

 Gardner^ considered them as simply enlargements of the innumerable 

 furrows cut by the rain in the clili'-face, and even speaks of new 

 chines being formed in the course of a few days; while Dr. Ord* 

 takes practically the same view, for after describing in detail the 

 formation of these cliff-furrows, he adds : " These illustrate the 

 first step in the formation of our chines." It is clear, then, that 

 while these three authors differ somewhat in detail they are all 

 agreed in regarding these valleys as having started in comparatively 

 recent times in the face of the cliff, and having lengthened themselves 

 by growing rapidly inland. But although a few of the minor in- 

 dentations of the cliffs may possibly have been formed in this way, 

 yet with regard to all the principal chines — all, at least, that are 

 named as such in the 6 in. map of the Ordnance Survey- — there 

 are strong reasons for doubting whether this hypothesis is correct. 



In the first place, if the chines are actually growing longer, their 

 rate of growth must be greater than that of the recession of the 

 cliffs ; and since the latter is known to be in the neighbourhood 

 of a foot a year, the heads of the chines should exhibit signs of very 

 great activity. Now a rough measure of such activity can be 

 obtained ; first, from the angle of slope, which is far less at 

 the heads of the chines than in the cliffs ; and secondly, from a 

 study of the vegetation. The face of the cliff is so steep and is 



' The Geology of the Country round Bournemouth, 1st edition, 1898; 2nd 

 edition, 1917. 



2 Principles of Geology, 10th ed., vol. i, 1867, p. 533. 



3 Quart. Journ. Geol. Soc, vol. xxxv, 1879, p. 220. 



* The Natural History of Bournemouth and District, 1914, pp. 61, 321. 



