BAGSHOT BEDS. 44 1 



The Lower Bagshot beds of Surrey (loo to 150 feet in 

 thickness) may be studied near Wokingham and Virginia Water, 

 between Woking and Weybridge, at Ash, Aldershot, and other 

 places, where they rest on the London Clay. Irregular lines of 

 pebbles occur at different horizons.^ Mr. W. H. Herries mentions 

 that at St. Anne's Hill, near Chertsey, the beds contain Sarsen 

 stones, and some of the pebble-beds are solidified.^ Mr. W. H. 

 Hudleston has drawn attention to a railway-cutting through Walton 

 Common which exhibits symptoms of slight local unconformity 

 between the London Clay and Lower Bagshot Beds. 



At Ramsdell, north-west of Basingstoke in Hampshire, a bed of 

 brown clay, nearly 30 feet thick, occurs in the lower part of the 

 Bagshot Beds. This clay, termed the Ramsdell Clay by INIr. 

 Bristow, is separated from the London Clay, which it much re- 

 sembles, by beds of sand ; and the structure, which favours the 

 conformity of the formations, is similar to that at Brentwood.^ 



The Lower Bagshot beds are exposed in Alum and Whitecliff 

 Bays in the Isle of Wight ; at the former locality they attain a 

 thickness of upwards of 660 feet, and at the latter 140 feet. They 

 are described by Mr. Bristow as a series of variously-coloured 

 (white, yellow and crimson) unfossiliferous sands and clays, with 

 seams of lignite and iron-sandstone. The clays at Alum Bay have 

 yielded many land-plants of subtropical genera, which were 

 described by Dr. P. De la Harpe ; ^ but the plant-bearing beds are 

 no longer well exposed. 



Mr. Bristow observes that the flora of Alum Bay (Alum Bay leaf- 

 bed) is more especially distinguished by the number and variety of 

 its Leguminacese {CcEsalpina, etc.). Fig-trees of lofty proportions 

 with long thick leaves, fig-sycamores with more delicate heart- 

 shaped leaves, an Aralia with palmated leaves, must from their 

 abundance have imparted a singularly majestic aspect to the vegeta- 

 tion of the period. Ferns, Parasitic Fungi, Reeds and Rushes have 

 also been found. 



A still richer series of plant-remains has been found at Bourne- 

 mouth, and Poole. (See p. 439.) The Bournemouth leaf beds imme- 

 diately underlie the Bracklesham series ; and they have yielded 

 about 20,000 specimens to the labours of Mr. Gardner. They 

 include Polypodiiim, Acrostichum, Osvuuida, Nipaditcs, Sequoia, 

 Eucah'ptus, Araucaria, Alnus, Populus, Ulmus, Plataniis, etc. ; trees 

 and hard-wooded shrubs are most prevalent. The occurrence of 

 Insect-remains and also of a Bird's feather has been noticed.* The 

 beds consist of variously-coloured sands and clays, the latter 



1 H. W. Monckton and R. S. Herries, Q. J. xlii. 402. 



2 Geol. Mag. 1881, p. 174 ; see also Rev. A. Irving, P. Geol. Assoc, viii. 143 ; 

 Q. J. xli. 492 ; G. Mag. 1886, p. 402. 



2 Geol. parts of Berks and Hants, by H. W. Bristow and W. Whitaker, p. 39 ; 

 Mem. Geol. Surv. iv. 312; see also J. S. Gardner, G. Mag. 1882, p. 469 ; and 

 \V. H. Hudleston, Q. J. xlii. 162. 



* Prestwich, Q. J. ii. 223 ; Bristow, Geol. I. of Wight, p. 38. 



* Rev. P. B. Brodie, G. Mag. 1885, p. 384. 



