110 ME. T. LEIGBTON ON THE LOWER [May 1895, 



appreciable increase of chert-debris until the Horsham Road is 

 passed. There is comparatively little chert-debris on the Holm- 

 wood slope of Leith Hill, more of course than on the common below, 

 but still less than might be expected from the steepness of the scarp. 

 It is to be remembered, however, that the ironsands of Local 

 Group 4 very largely form the escarpment on this side, rising over 

 Folly Lane, as has been stated, to the 700-foot contour, that is, 

 within 86 feet of the highest point of the easternmost ridge. 



III. The Pebble- and Cheet-beds East of Doeklng. 



About a mile east of Dorking the Lower Greensand ceases to 

 form an escarpment for a distance of between 2| and 3 miles, 

 owing to its line of strike being occupied by the valley of the 

 Mole. This stream, aided by atmospheric agencies, has planed 

 down the country to an average level of about 200 O.D., so that 

 sections are hardly to be expected. The Folkestone Sands are seen 

 at times towards the north of the outcrop, but there are unfortu- 

 nately no sections of the lower beds until the escarpment begins to 

 rise again at the east side of the gap, close to Reigate. 



At Trumpetshill, south of Reigate Heath, just where the escarp- 

 ment may be said to commence, the ironsands of Local Group 4 are 

 seen in a pit at 215 O.D. They are the usual false-bedded iron- 

 sands, but contain a few small scattered lydites and pebbles of 

 quartz. North of this place, at the south-western corner of Reigate 

 Heath, about 250 O.D., there is a second section, possibly also in 

 the same beds. It is impossible to say certainly from this isolated 

 section to which sub-stage these sands should be referred. They 

 are mapped as Hythe by the Survey, and their position certainly 

 appears to place them more probably on the horizon of Local 

 Group 4 than on that of the Folkestone Beds. 



At Reigate Park, however, we arrive on more certain ground ; 

 the surface here rises to about 400 O.D., and the following striking 

 section is exposed in Bell Street, opposite the New Road, at 

 317 O.D. Dip N. (about 5°) : — 



Sand, with layers of cbert, obscure as to the sand 4 feet seen. 



Pebble-beds, soft olive-wbite sandstone, giving a wall-like 

 section, with lydites, pebbles of quartz, etc., and pebbles 

 of clay 7 feet. 



Dark coarse sand, much false- bedded 2 1'eet seen. 



Great interest attaches to this section ; its position in the series 

 can be ascertained, and while it agrees in the main with the new 

 order of things seen at this horizon to the east, and all its divisions 

 can be traced there, it also bears strong resemblance to beds on the 

 same horizon to the west ; it serves, in fact, as a link connecting the 

 two. The beds of the Eell Street section almost immediately 

 underlie the Fuller's Earth, which again underlies the Folkestone 

 Sands ; this is clearly shown on the Geological Survey map, and on 

 the ground the correctness of that mapping can be demonstrated. 



In Reigate Park, to the south-west, the chert-beds may be seen in 

 the footpath ascending the hill at the escarpment, about, the 400-foot 



