OSMINGTON MEETING. xli. 



authorities on the geology of this neighbourhood, and whose addresses we have 

 often listened to with much interest and profit. He asks me to express his 

 regret at being unable to be present to-day, as he is detained in London by an 

 important engagement. In his absence I have endeavoured to put together 

 a few remarks on some of the geological features of this part of Dorset. 

 As some of my hearers are, no doubt, interested in archaeology more than 

 geology, I might perhaps most suitably begin by drawing your attention to 

 the fact that we are close to what is known as " The Burning Cliff," or Hoi worth 

 Cliff, situated west of Holworth House. The archaeological interest of this is, I 

 take it, that the substance that was burnt was that which is most dear to the 

 hearts of Dorset archaeologists, Kimmeridge shale (but there is plenty of it left), 

 out of which many ornaments and other articles were manufactured by our 

 predecessors, and of which you may see a good collection in the Dorset Museum. 

 It is not, I believe, known certainly how the fire in the burning cliff originated, 

 though it is supposed that it may have been caused by the spontaneous ignition 

 of the pyrites contained in the shale through the action of water ; but it began to 

 burn in the autumn of 1826, and continued to do so for some years, emitting 

 much smoke and a very offensive smell, which could be perceived at the distance 

 of several miles when the wind was favourable. I have never experimented 

 myself on the burning of Kimmeridge shale, but I imagine that its smell is 

 exceedingly like that produced by the burning of the lignite which occurs in the 

 Oxford clay at Chickerell, which I have tried ; and I can quite realise the 

 difficulties that those who have attempted to make the Kimmeridge shale produce 

 some combustible which should be commercially profitable have had to contend 

 with. Bluish flames ascended through the cracks caused by the heat, and were at 

 times even visible at Weymouth. The cracks became covered with deposits of 

 sulphur. There has been a landslip at the spot since the occurrence, but some of 

 the burnt portions, looking like badly burnt bricks, can still be seen below by the 

 beach, and I hope to point them out shortly. It is strange that such an interest- 

 ing phenomenon as the burning cliff seems to be nowhere alluded to in our 

 volumes of "Proceedings," except quite incidentally at one place, and there the 

 date is given as 1841 (Vol. XI., xxxiii.). Similar combustions took place in the 

 Lias at Charmouth, which contains pyrites, in 1851 and 1855. 



This district possesses stratigraphical peculiarities which, according to Mr. 

 Hudleston, are not exceeded in point of interest by any throughout the whole of 

 England. There have been two distinct periods of disturbance, causing folds in the 

 strata. In the first place, the Oolitic (otherwise called the Jurassic) Beds, together 

 with the Wealdeu, which Lies just above them and just below the Gault and Upper 

 Greensand, have been crumpled up by subterranean forces into ridges and 

 furrows, or, in geological language, into anticlinals and synclinals, before the 

 deposition of the beds above them. They have also, before this took place, been 

 more or less denuded, so that both anticlinals and synclinals have been planed 

 down to comparative flatness, and on the base thus constituted the Cretaceous 

 beds, viz. : Gault, Upper Greensand, and Chalk, have been subsequently 



