OLDHAVEN AND BLACKHEATH BEDS. 433 



thickness on the east and west coasts, yet the total thickness of the 

 series is much the same.' 



In Dorsetshire the Woolwich and Reading Beds are exposed on 

 the south of Studland Bay; and there are beds of plastic clay near 

 Corfe Castle, East Luhvorth and Dorchester, which have been 

 referred to the Series, as have also the pebble-beds and sands of 

 Bincombe Heath and Black Down, between Abbotsbury and 

 Dorchester. Mr. J. S. Gardner is, however, disposed to refer the 

 latter beds to the London Clay.^ Bride Bottom, west of Black 

 Down, a comb which forms the source of the River Bredy, contains 

 a number of blocks of puddingstone, breccia, and Greywether 

 sandstone, and is known also as the "Valley of Stones."^ (See 

 p. 449.) 



Economic products, etc. 



The clays near Reading and many other places are largely used for brickmaking, 

 also for coarse pottery ; and sometimes pipe-clay is found in the beds. Fire-bricks 

 have been made at Nonesuch Park, Ewell. Fuller's Earth is said to have been 

 found in the Reading Beds at Katesgrove Kiln, Reading, a pit which has been 

 worked for more than a century.'* 



Websterite (hydrous sulphate of alumina) occurs at the junction of the 

 Tertiary beds and Chalk at Newhaven in Sussex ; it was named after the dis- 

 coverer, Mr. T. Webster.^ 



Prof T. R. Jones and Major C. Cooper King have noted the occurrence at 

 Coley Hill, Reading, of clay-galls (rolled pieces of clay) in buff and grey sands. 

 IMany of these are stated to be "ferruginous and hard from change, and somewhat 

 septarian," while some nodules consist only of limonite crusts and ochreous cores.^ 



The pebble-beds are worked in places for road-metal, as at Bolter End, south- 

 west of West Wycombe. Eocene pebbles from Chittern Down, near Ileytesbury 

 have been used to form pavements for grottoes, etc." Beds of sand are some- 

 times employed for making mortar, and the purer kinds have been used in glass 

 works. 



OLDHAVEN AND BLACKHEATH BEDS. 



The name Oldhaven Beds was given by Mr. Whitaker in 1866 

 to the sands and pebble-beds that come between the London Clay 

 and Woolwich Beds in Kent ; these beds had previously been 

 classed by Prof. Prestwich with the basement-bed of the London 

 Clay, and to a small extent with the Woolwich Beds. The true 

 basement-bed of the London Clay may sometimes be seen over- 



' Q. J. xxiv. 520. * Q. J. xxxix. 208. 



' Damon, Geol. Weymouth, 1SS4, p. 139 ; Buckland and De la Beche, T.G.S. 

 (2), iv. 4. 



* J. Rofe, T. G. S. (2), V. 127 ; see also Buckland, T. G. S. iv. 277. Loam- 

 pits (lam-pyttes) were known in places in Saxon times. 



» See T. G. S. ii. 191. 



^ Q. J. xxxi. 453 ; see also P. Geol. Assoc, iv. 522, v. 514. 



' Benett, Cat. Org. Rem. Wilts. 



28 



