598 Limestone Quarries and Petrifying Spring 



sands ; 3. Purbeck beds ; which last the strata hereafter to 

 be described are considered by Conybeare (Outlines of Geo- 

 logy of England and Wales, p. 148.) to be introductory to, if 

 not identical with; form one of the most remarkable geological 

 groups in England, containing some most extraordinary fossil 

 remains, and furnishing us with the most striking proofs of 

 the great extent of former revolutions in the position of sea 

 and land. One of the facts respecting this formation most 

 deserving of notice is its limited extent : Lullworth Cove in 

 Dorsetshire, to the Lower Boulonnois in France, or about 

 200 English miles, being its extremest limits from west to 

 east; while it extends from north-west to south-east, Whit- 

 church in Buckinghamshire, to Beauvais in the interior of 

 France, a distance of about 220 miles. (Fitton, GeoL of 

 Hastings.) This limited space, considered to have been for- 

 merly occupied by the Wealden ; the marked difference in 

 the character of its fossils, most of which are freshwater, from 

 those of the marine strata both above and below it ; the pecu- 

 liarity of these fossils themselves, few of which resemble those 

 found in any other formation ; as well as the change of climate, 

 and alteration of the earth's surface they are supposed to in- 

 dicate; have induced our most distinguished geologists to 

 conclude that the whole of this group had its origin in fresh- 

 water communicating with the sea. 



The clay of the Weald of Sussex is well defined by Martin 

 as I* a stiff clay, brown on the surface, and blue and slaty 

 beneath, containing concretional ironstone." (Martin, Geolog. 

 Mem. Western Sussex.) This ironstone was formerly in high 

 request : in the sixteenth century, before coke was used for 

 smelting iron ore, two thirds of the whole iron of England 

 were procured from the Sussex beds ; many of the roads on 

 the Ashburnham estate are still paved, as in Derbyshire, with 

 the slags, the refuse of the founderies ; though what is now 

 excavated is, I believe, but trifling in quantity, and very indif- 

 ferent in quality. Beneath this is an alternation of sands and 

 clays, including thin beds of the limestone, containing such 

 numbers of the Paludina vivipara, a freshwater shell, well- 

 known as the Petworth or Sussex marble. 



The following is the order, according to Dr. Fitton, of the 

 beds of Hastings sands, in Sussex: — 1. Ferruginous and fawn- 

 coloured sands and sandstone, including small portions of 

 lignite, with stiff grey loam ; 2. Sandstone ; 3. Sandstone, 

 containing concretional courses of calciferous grit ; 4. Dark- 

 coloured shale; 5. White sandstone of Hastings cliffs, 100 ft.; 

 -6. Clay, shale, and thin beds of sandstone, containing lignite 

 and silicified wood (Endogenites erosa, of which large pieces 



