66 
THE GEOLOGIST. 
SuBDiTisioNS OF Beitish Rocks. — We find space for the following 
list of the subdivisions of British rocks, as recognized by the Geological 
Survey, believing it will prove useful to many of our readers. 
Blown sand. 
Alluvium. 
Peat. 
Raised beaches. 
Cave-deposits. 
Valley, or low-level gravel. 
Brick-earth. 
High-level gravel. 
Glacial drift. 
Till and boulder clay. 
Cave-deposits. 
Mammaliferous (Norwich) crag. 
Eed crag. 
Coralline crag. 
Leaf bed of Mnll. 
Lignite of Antrim. 
Bovey beds. 
Hempstead beds 
AVight). 
Bembridge beds. 
Osborne beds. 
Headen beds. 
Upper Bagshot sands. 
Barton clay. 
Bracklesham sands and 
clays. 
Lower Bagshot sands and 
clays. 
London clay. 
Bognor beds. 
^Yoohvich and Reading beds (plas- 
tic clay, with sand, pebble-beds, 
etc.). ' 
Thanet sands. 
Upper chalk. 
Lower chalk. 
Chalk marl. 
Chloritic marl. 
Upper green sand. 
Gault. 
Folkestone beds, 
Sandgate beds. 
Hythe beds, or Kentish 
rag. 
Atherfield clay. 
"NVeald clay. 
Upper Tuubridge Wells 
sand. 
Grinstead clay. 
Lower Tunbridge Wells 
sand. 
W^adhurst clay. 
Ashdown sands. 
Ashburnham beds. 
u-2 
Upper 
Cretaceous. 
s S 
V- 
Low 
eens 
J <s 
taceous 
\ 
a 
■Crel 
tings Sa 
Lower 
CO 
S3 
w 
Upper Purbeck beds. 
]Middle Purbeck beds. 
Lower Pui-beck beds. 
Portland stone. 
Portland sands. 
Kimmeridge clay. 
Upper Calcareous grit. 
Coral rag. 
Lower Calcareous grit. 
Oxford clay and 
Kelloways rock. 
J Ch «^ 
J 
1 11 
11 
1 
beds. 
Cornbrash. 
Forest marble 
Bradford clay. J g 
Great, or Bath Oolite. 1 ^ 
Stouesfield slate. I « |^ 
CoUyweston slate. [ u q 
Northampton sands. J 
Upper Fuller's earth 
Fuller's earth-rock. 
Lower Fuller's earth 
Inferior Oolite. 
Lias junctiou-sands. 
Upper Lias clay, or shale. 
Marlstone. ^ 
Lower Lias clay, shale, | 
and limestone. J 
Westbury beds (or white^ Koessen' 
limestone). }- 
Bone-bed. J 
Red maii and 
Upper Keuper sandstone 
Lower Keuper sandstone, j 
Marl (waterstones). J 
Mi'schelkalk, absent in~\ 
Britain. 
St. Cassian beds. \ 
Dolomitic conglomerate [ 
(Somerset and Glou- 
cestershire). 
Upper red and 
sandstone. 
Pebble beds. 
Lower red and 
sandstone. 
Upper red marl. 
Upper magnesian lim 
stone. 
Lower red marl. 
Lower magnesian lime 
stone. 
Red marl, sandstone. 
Breccia and 
Condomerate. 
J 
mottled"! 
mottled i 
J 
\ i 
J ^ 
Roth- 
j liegende. 
