Proeeeding$. cxlv 



RiK? excavatione for a sewer were made in a nearly direct line from the 

 SndmXrn sS rley road, past the Sandrock Hotel to 250 feet beyond 

 The Infan! School, near the top of the Addington Hills. These exca- 

 vations have a special interest. They give a continuous section from 

 he Sackheath to the underlying beds, and throw some light upon the 

 Ion-disputed question as to what formation the pebbly and sandy 

 bed^s which overlie the Woolwich and Reading series, belong to. Some 

 Soloists have classed them with the Oldhaven, others have grouped 

 fhem with the Woolwich and Reading, beds For years a controversy 

 upon this question has been carried on by Messrs. J. Starkie Gardner, 

 GF. Harris, Prof. Prestwich, and W. Whitaker. The arguments for 

 and against the different views are summarised m Whitaker s Geolo^ 

 of London ' vol. i., pp. 90—102 (1889). The section, 1636 feet long, 

 begins on the Addii^on Hills at a height of 418 feet above Ordnance 

 datum, and ends in Shirley Road, Croydon, at 320 feet. 

 " The excavations show : — 



FT. IN. 



On Addington Hills, 418 ft. above O.D. 



Flint pebbles in light coloured sand i^ u 



1 6 



At the Sandrock Hotel, 360 /t. above 0. D. 



Dark brown sand ----.-■■ , ^r, r 



Yellow sand, and grey sand with impure pipe clay 17 b 



At the Drinking Fountain, U7 ft. above O.D. 



FUnt pebbles " ° 



Yellow sand " ^ 



Grey sand with impure pipe clay » " 



Mottled clay, Reading bed •■■■•■-' ^j ^ 



Pebble rock with mottled clay and green sand - - 4 u 



Green sand, Woolwich and Reading bottom bed - 3 



At d^T ft. above 0. D. 



Woolwich blue and black clay on 



Reading mottled clay ^ " 



NeartheWindmill, Shirley Bead, S20 ft. above O.D. 



Pebbles, yellow and grey sand o J* 



Woolwich blue clay ■^ " 



"The sewer excavations afforded Uttle scope for detailed ex- 

 amination, but near the line of excavations there are pits at different 

 levels, where the pebbly and sandy beds can be conveniently examined. 

 The hic'hest bed of the Addington Hills is the Blackheath pebble bed, 

 consistmg of small and large flint pebbles in a fine sandy base ; the 

 sand is incoherent and without fossils, its colour reddish yellow, and 

 in long exposed sections yellowish grey. The exact thiclmess of the 

 bed could not be ascertained; in our section it begins at 380 ft. above 

 Ordnance datum, and is continuous to 481 ft., the highest point of the 

 hill, where bleached pebbles He exposed on the surface,' et. seq. 



The foregoing table, however, serves for oiur present purpose, but 1 

 hope we may be able to quote further from this interesting paper. 

 I understand that some of the Shii-ley villagers upon seeing the 

 lignite, which was discovered in the excavations, thought that coal 

 had been found, and took it home to burn ; but it was of little use, and 

 was moreover highly charged with pyrites. ,, , . 



The geological excursion of the year took place on Monday, Augu 

 4th, and was very well attended^twenty-seven members of the t . 



