Dr. FiTTON on the Strata below the Chalk. 



139 



:} 



Inclined Strata, near the bottom of the Lower Green-sand, Tilburstow Hill. 



Feet. In 

 Soil and loam (marked a a in the cut). , 



1. Soft nearly uniform sand ; when dry of a bright bufF colour / g ^ 



This has the appearance of havirig slid or subsided upon the next bed below. 

 Immediately above 2. the sand is green. 



2. FuUer's-earth; very like that in the upper part of the pits at Nutfield, hereafter 



mentioned, and also like that which occurs in the lower green-sand at Brill in 

 Buckinghamshire. This clay becomes soft and is diffused in water, but does 

 not break down with the rapidity of common Fuller's-earth. The bed varies in r to 

 thickness from 6 inches to 12: the masses of which it is composed have 

 smooth surfaces and a saponaceous feel, with the aspect and lustre of bee's 

 wax, probably produced by compression and motion on each other .... 



3. A bed consisting of chert and soft sandrock (" Hassock "), intimately mixed 



and passing into each other ; about 



This and the beds 4. 5. and 6. end abruptly above, as represented in the 

 sketch. 



4. A course composed of almost continuous bands of brownish grey chert, from 3 



to 6 inches thick, alternating with, and passing into, soft sandrock. This chert 

 is like that on the northern surface of the hill, where it is much used for re- 

 pairing the roads. By exposure it becomes divisible into slaty portions, ap- 

 proaching to a rhomboidal figure 



5. Soft sandrock (" Hassock"), including green particles : the hue is various where l about 



exposed. In some places tinged with oxide of iron J 3 6 



6. Sand ; green while it is moist, but when dry and exposed nearly white, containing -> 



layers which consist of stem-like or vermicular portions of white, translucent, 

 quartzose sand, surrounded by sand of a green colour. This contrast of 

 colour becomes indistinct in dry specimens, but is very conspicuous when 

 they are moistened. The white vermicular portions have a border of darker 

 green than the rest : they are generally about |^th of an inch in diameter, 

 somewhat curved, and in some cases have short lateral branches with round 

 extremities. This remarkable structure is very characteristic of several parts 

 of the lower green-sand, and is probably connected with the former presence 

 of organized bodies 



7. Coarse yellowish sandrock 



8. Here ferruginous matter is more abundant, and the sand is concreted irregularly 



into nodular masses nearly continuous. 7 and 8 together are about 1 5 feet thick. _ 



9. Ferruginous bands, like 8: a conglomerate of quartz grains, cemented by oxide 



of iron, with adhering sand, which in some places is white, and looks like 



mortar, but does not effervesce 



10. Sand, with dark particles, and irregular tortuous seams of a ferruginous com- 

 pound, like the carstone of Norfolk, consisting of fine rounded grains of 

 quartz, cemented by hard, dark reddish brown, oxide of iron. This passes 

 at the bottom into a less ferruginous sand, which is apparently continued down 

 to the Weald clay, 9 and 10 together are about 15 feet thick 



varymg 

 from 



to 



6 



15 



15 



Total thickness. . . .about 60 feet. 



T 2 



