BAGSHOT BEDS. 447 



On the Dorsetshire coast the beds at Hengistbury Head have 

 been thus divided by Mr. J. S. Gardner:^ — 



Barton Beds. 



/ Upper Bracklesham and Highcliff Sands (white sands) 25 feet. 



I j 2. Sands and clays, with 



Bracklesham J Hengistbury Head Beds. I ironstone 45 ,, 



Beds. j ( I. Clay with green grains 12 ,, 



f Boscombe Sands (sands and shingle-beds) 140 ,, 



^ Bournemouth Marine Series (sands and dark clays) 40 ,, 



Bournemouth Freshwater Series. (See p. 439.) 



The Highcliff Sands take their name from a cliff in Christchurch Bay, and the 

 Boscombe Sands are so termed from Boscombe Chine, east of Bournemouth. Mr. 

 Gardner includes the Bournemouth Freshwater Series with the overlying strata. 

 The Bournemouth Marine Series contains numerous fossils, but there are few 

 organic remains in the higher beds beneath the Barton Clay. 



In Berkshire and Surrey the Bracklesham Beds have a thickness 

 of from 20 to 50 feet, and consist of grey clays, white pipe-clays, 

 greenish loamy sands, and white and yellow sands with pebbles. 

 Cardita planicosta has been met with in the beds, which contain 

 lignite, pyrites, etc. The beds are visible at Bagshot and near 

 Sandhurst, and they were exposed in a cutting at Goldsworthy Hill, 

 near Woking.^ 



The green sands of the Bagshot Beds owe their colour sometimes to silicate of 

 iron, and in other instances, according to the Rev. A. Irving, the green is due to 

 vegetable matter.^ 



Barton Clay. — The Barton Clay, so well exposed in the cliffs of 

 Barton and Hordwell (Hordle) in Hampshire, consists of grey and 

 bluish-green clay and sands with septaria, altogether attaining 

 a thickness of 300 feet. The beds are shown also in Alum Bay.* 



The Clays are very fossiliferous, and contain Rostcllaria rimosa, 

 Vohita luctatrix, Fusus {Clavtlla) longcEVus, F. pyrus {Leiostoma 

 biilhiforjnis). Typhis pun gens, Mtirex asper. Conns dorynitor, Phorus 

 agghititians, Calyptrcea tiiberculaia, Sangiiinolaria compressa, Crassa- 

 tella sulcata, Pectcn reco7iditus, Nummulina, Trionyx, Zaig/odon, etc. 



Clay-ironstone nodules from Hengistbury have been worked as 

 iron-ore.^ The clay is used for making bricks. 



1 Q. J. XXXV. 209 ; G. ]\Iag. 1879, p. 148 ; see also Lyell, T. G. S. (2), 

 ii. 279. 



2 Prestwich, Q. J. iii. 382 ; Bristow and Whitaker, Geol. parts of Berks and 

 Hants, p. 41 ; T. R. Jones, P. Geol. Assoc, vi. 433 ; W. H. Herries, G. Mag. 

 1881, p. 173 ; H. \V. Monckton, Q.J. xxxix. 349 ; Rev. A. Irving, Q. J. xH. 492. 



■' G. Mag. 1883, p. 404 ; P. Geol. Assoc, viii. 152 ; see also Prestwich, Q. J. 

 iii. 397. 



* Gustavus Brander, Fossilia Hantoniensia, 1766 ; see also T. Webster, 

 T. G. S. (2), i. 90; Prestwich, Q. J. iii. 354, v. 43; Bristow, Geol. I. of Wight, 

 p. 49. 



* T. Codrington, G. Mag. 1S70, p. 23. 



