104 ME. T. LEIGHTON ON THE LOWER [May 1 89 5, 



division consists of sandy cherts which do not appear to have heen 

 formed in such deep water as the massive beds of the lower division. 



Local Group No. 3. — The clayey sands seen to the south of 

 Dorking. 



Local Group No. 4. — The ironsands which overlie the Atherfield 

 Clay at the base of the series, throughout the whole of this district. 



II. The Chert-beds of Leith Hill. 



In the light of Dr. Hinde's discoveries, 1 it has been open to any 

 reader of pp. 121-123 of the Weald Memoir to suggest the proba- 

 bility of anorth-and-south change in the so-called Hythe Beds, from 

 littoral to less littoral conditions, both being overlain by the Bargate 

 Beds ; but since the Geological Survey claims 2 that there is a chaDge 

 in composition on this horizon between Dorking and Leith Hill, it 

 appeared to me to be essential to controvert that statement before 

 proceeding to any suggestion whatever. 



There are several exposures of the various beds of the Lower 

 Greensand upon Leith Hill, 3 and I give the following vertical section 

 as a general collation of them all : — 



Folkestone Beds. Ferruginous sands, much false-bedded, 

 with layers of Carstone (usually most plentiful in the 



lowest beds 10 feet seen. 



Junction-beds, (a) Ferruginous sand with comparatively 



large pebbles (lydites, quartz, etc.) 1 foot ? 



(/;) Dark glauconitic sand, strongly false-bedded, with 

 layers of ferruginous sand, containing scattered smaller 



pebbles similar to those in (a) 3 feet. 



Bargate Beds. (a) Bark glauconitic, pepper-and-salt 

 coloured sands, pebbles rare ; at times clayey, and with 



thin layers of clay and clayey sandstone 3 to 6 feet. 



(b) Calcareous grit-beds of the usual Bargate character, 

 with pebbles (lydites, quartz, etc.) — the grit varies very 

 much horizontally and vertically in coarseness and in 

 hardness, and finally passes downward into coarse calca- 

 reous sandstone, interbedded with calcareous sands. 

 Fossils occur in the upper beds chiefly, and near the 

 top are some thin layers of greasy clay. (No loose beds 



of pebbles, properly so called.) 25 feet. 



Junction-bed. Ironstone and sandy chert 1 foot to 3 inches. 



Hythe Beds of the Geological Survey (Local Group 2). 

 Upper division. Bubbly beds of sandy chert inter- 

 bedded with layers of glauconitic quartz-sand — olive- 

 white in colour throughout — with occasional bands of 

 massive brown chert, thickening generally downward ... 60 feet to N. 



Lower division. Massive greensand and chert; vary- 

 ing in character, but generally containing thick beds of 

 hard rock, with softer beds of sandstone and sandy chert 

 in places ; sometimes sharply defined from the beds 



above, but at others passing into them 80 feet to S. 



Hythe Beds of the Geological Survey (Local Group 4). Fer- 

 ruginous sands 100 to 130 feet. 



1 Phil. Trans. Eoy. Soc. vol. clxxvi. (1885) p. 403. 



2 ' Geology of the Weald,' 1875, p. 121. 



3 [The name ' Leith Hill' is here applied to the whole physical feature, not 

 particularly to the southern point of that feature, which is a common resort of 

 pleasure parties. This application of the name is in accordance with local 

 usage, besides being scientifically and topographically correct. — January, 1895.] 



