WEALD, OR OAK TREE CLAY. 65 



From the considerable depth in the Weald clay, at which this lime- 

 stone generally occurs, its geographical extent cannot be accurately de- 

 fined, our knowledge of its course depending, for the most part, upon 

 such sections as are accidentally exposed, by the sinking of weUs, or other 

 artificial excavations. The information thus obtained is, however, suf- 

 ficient to prove, that the beds traverse the county in a N.N.W. direc- 

 tion, extending from Kirdford, in Western Sussex, to Laughton, six miles 

 N.E. from Lewes, from whence it proceeds eastwardly, and is lost in the 

 alluvial marshes of Pevensey Levels. Wherever it approaches the sur- 

 face, it occupies moderately rising ground, generally on the north side of 

 a rivulet. The following list contains every locahty with which I am at 

 present acquainted : 



Localities of the Sussex Makble. 



Kirdford. In the quarries of the Earl of Egremont, lying on blue 

 clay, twenty feet below the surface. 



North Chapel. This locahty is mentioned by Da Costa. 



Petworth. The quarries are nearly four miles from the town, and the 

 marble occurs in a bed of blue clay, at the depth of twenty-five feet. 

 " The bed is horizontal, and is exposed to view in the ravines. It is 

 divided by fissures into large slabs, fit for tables and other purposes, 

 varying in thickness, from twelve to twenty-two inches, and is more or 

 less compact*." 



Wisborough Green. 



West Grinsted f . 



Friar's Oak Inn, on the Brighton road f. 



St. John's Common : in blue clay, at the depth of a few feet beneath 

 the surface, generally covered with a thin bed of loam. The limestone 

 is of a deeper blue than in most other places, and the slabs, where in con- 

 tact with the clay, are covered with a profusion of casts of univalves, lying 

 in relief The pathways leading to the cottages, situate on the road-side 



* I am indebted for this notice, to my excellent friend John Hawkins, Esq. F.R.S. &c. of 

 Bignor Park, near Petworth. 



t These localities were communicated by Richard Weekes, Esq. F.L.S. &c. of Hurstperpoint. 



K 



