WORK OF WILLIAM SMITH. 
be on the same general horizon, and the term Inferior Oolite came 
to be applied. 
To William Smith we are mainly indebted for the first clear 
definitions of our strata. He determined the sequence of the 
Jurassic rocks in the west arid south-west of England, and pointed 
out their relations to the soils and physical features. His most 
important generalization was that the different strata are 
characterized by fossils more or less peculiar to them, thus 
establishing the fact that strata can be identified by their 
organic remains. Moreover he pointed out that many of the 
rocks had been in succession the bed of the sea, and that the 
fossils were remains of animals that had lived and died at or near 
the places where they are now embedded.* 
Hence the prominent names of many of our rocks veere taken 
from the south-western and western parts of England, either from 
terms in local use or from localities where the beds were exposed. 
It may be useful therefore to give the following Table showing 
the names successively adopted by William Smith : f 
TABLE SHOWING THE SUBDIVISIONS OF THE JURASSIC ROCKS 
ACCORDING TO WlLLIAM 
1799. 
1812. 
1815-10. 
Xamrs now adopted. 
Purbeck Stone 
Purbeck Beds. 
Portland Rock 
Portland Stone. 
Sand 
Portland Sand. 
Oaktrce Clay 
Kiineridge Clay. 
Coral Rag and Piso- 
lite : Sand 
j Corallian Beds. 
Clay 
Dark Blue Shale Clunch Clay and Shale 
Oxford Clay. 
Kelloway's Stone 
Kellaways Rock 
Sand and Stone 
Cornbrash Cornbrasli 
Cornbrash. 
Clay 
Sand and Sandstone 
Forest Marble Rock Forest Marble 
j Forest Marble. 
Forest Marble 
; Clay over Upper Oolite 
Bradford Clay. 
Freestone 
Great Oolite Rock 
Upper Oolite 
Great Oolite. 
Blue Clay, Yellow'} 
Clay, Fuller's Earth, f 
Fullers Earth and 
Fullers Earth and 
Bastard ditto and f 
Rock. 
Fullers Earth Rock. 
Sundries. ) 
Freestone 
Under Oolite ! Under Oolite 
Inferior Oolite. 
Sand 
Sand 
Midford Sand. 
Marlstone 
Upper Lias. 
Middle Lias. 
Marl Blue 
Blue Lias 
Blue Marl Blue Marl 
Blue Lias ' Blue Lias 
Lower Lias. 
White Lias 
White Lias 
White Lias 
) 
Marl stone, Indigo and 
[RlifeticBeds. 
Black Marls. 
J 
Red-ground. 
Red Marl and Rod Marl 
New Red Marl, &c. 
Gypsum. 
It will be seen by reference to this Table that the chief divisions have 
been confirmed by later observation. The Purbeck Stone was, however, 
associated by Smith with the Kentish Itag, &c., while the Upper Lias was 
omitted, doubtless because it is very inconspicuously developed in 
Somersetshire. The Alum Shale (Upper Lias) of Yorkshire was grouped 
by him with the Oxford Clay. 
* See Memoirs of William Smith, by John Phillips, p. 141 ; see also Fitton, 
op. cit., pp. 29, &c. 
f Memoirs of W. Smith, by John Phillips, pp. 30, 146. See also Table by 
Buckland (1818) in W. Phillips' Outline of the Geology of England and Wales ; 
and Table by Sedgwick (1821) in A Syllabus of a Course of Lectures on Geology. 
J See also Table given by C. Fox-Strangways, Jurassic Rocks of Yorkshire, vol. i. 
p. 20. 
