GEOLOGY 



I. BORING AT RICHMOND WATERWORKS, 1 876-84. * 



Thickness 

 in feet 



Kind of Material 



Geological Classification 



10 

 160 



22* 



300 



150 



220 



16 



IO 



8 7 i 

 207^ 



Made ground and sandy gravel 



Clay 



Mottled clays with a bed of sand 



Light grey and greenish sand with green- 

 coated flints at base 



White chalk with flints 



Greyish and cream-coloured chalk without 

 flints 



Grey marly chalk passing downward into 

 chalk marl 



Calcareous sandstone 



Pale and dark blue clay with glauconitic 

 sand and phosphattc nodules at base 



Limestone, somewhat oolitic, with thin 

 bands of clay 



Limestones, more or less oolitic, with a thin 

 band of clay and some layers of calcareous 

 sandstone 



Alternations of red, white and mottled sand- 

 stone with red and variegated marls ; 

 dipping steeply 



Total depth 



Recent 



London Clay "j 



Reading Beds I Eocene 



Thanet Sands I 



Upper Chalk 

 Middle Chalk 



Lower Chalk 

 Upper Greensand 

 Gault 



Upper Creta- 

 ceous 



( ?) Lower Greensand. (?) Lower Cre- 

 taceous 



Great Oolite Series. Jurassic 



(?) New Red Sandstone. (?) Triassic 



II. BORING AT STREATHAM COMMON FOR THE SOUTHWARK AND VAUXHALL WATER 



COMPANY, 1 882-88.* 



Thickness 

 in feet 



10 

 153 

 43i 



35 



22l 

 2I 9 



188^ 

 38* 



138 



1,258 



Kind of Material 



Gravel and mud 



Blue clay, sandy and pebbly at base 



Black and mottled clay, sandy clay and 



thin beds of green sand 

 Green and grey sand, with flints at base 

 White chalk with flints 

 Hard greyish chalk without flints 

 Grey chalk passing downwards into chalk 



marl 



Greenish-grey calcareous sandstone 

 Firm clay with phosphatic nodules at base 

 Alternations of oolitic limestone, calcareous 



sandstone, sandy clay and clay 

 Greenish-grey, reddish and mottled sandstone, 



with bands of hard reddish clayey rock ; 



dipping steeply 



Total depth 



Geological Classification 



Recent 

 London Clay 

 Woolwich and Reading 



Beds 



Thanet Sands 

 Upper Chalk 

 Middle Chalk 



Eocene 



Lower Chalk 



Upper 

 ceous 



Creta- 



Upper Greensand 

 Gault 



Great Oolite Series ) ~ 



,, ,-, ,, , ,, > Jurassic 

 (( Forest Marble) ) J 



Triassic (?), or Devonian (?) 



1 For fuller details see Prof. J. W. Judd and C. Homersham, Quart. Journ. Geol. Sac., 

 vol. xl. (1884) pp. 724-783 ; and vol. xli. (1885) pp. 523-527. 



2 Mem. Geol. Survey, 'The Geology of London,' vol. ii. (1889) pp. 224-229. 



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