Primary. 
140 
TABLE OF STRATA. 
Table of British Strata. 
Quaternary or f Recent. 
Post-tertiary. Pleistocene* * * * 
Pliocene. \ 
(Cromer Forest bed and Crags.) 
Oligocene.^ 
Tertiary or J (Fluvio-marine beds! of the Hamp- 
CiENOZOlc.f ) shire basin.) 
Eocene.\ 
(Bagshot series, London Clay and 
Lower London Tertiaries.) 
Secondary or 
Mesozoic.H 
r Cretaceous .** * * §§ *** * * §§§ 
(Chalk, Upper Greensand, Gault „ 
Lower Greensand, W ealden 
series.) 
Jurassic, ff 
(Purbeek and Portland series, Kime- 
ridge clay, Corallian series, Oxford 
clay, Great Oolite series, Inferior 
Oolite, Lias.) 
Triassic.%% 
(Rh8etic,§§ Keuper,|| || Bunter.^F) 
f 
! Paleozoic* 
*# # 
[ Pre-Cambrian , 
^Permian, ftt 
Carboniferous. 
-<( Devonian and Old Red Sandstone, 
j Silurian.%%% 
(_ Cambrian. 
or Archaean. §§§ 
* Pleistocene , Gr. pleistos, most ; kainos, recent. 
f Caenozoic, Gr. kainos, recent ; zoe, life. % Pliocene, Gr. pleion, more. 
§ Oligocene, Gr. oligos, few. 
|| Eocene, Gr. eos, dawn. Most of the names of the groups of tertiary strata 
were given by Lyell to indicate the proportion of recent to extinct species of 
mollusca which they respectively contain. No miocene (Gr. meion, less), rocks 
are now recognized in Britain. The oligocene group was named by Beyrich, of 
Berlin. 
«[[ Mesozoic , Gr. mesos , middle. 
** Cretaceous, Lat. creta, Cbalk. 
ft Jurassic, from the Jura Mountains. 
Triassic, from its threefold character in Germany. 
§§ Bhaetic, from the Rhsetic Alps. 
DU Keuper , Ger. quarryman’s term, from local name of a checked fabric. 
ff Bunter, Ger. “ variegated.” 
*** Palaeozoic , Gr. palaios, old. 
fft Permian, from Perm in Russia. 
XXX Silurian from the British tribe of Silures. Prof. Lapworth’s term Ordovician, 
from the tribe of the Ordovices, is often used to indicate certain strata regarded by 
some as intermediate between the Silurian and the Cambrian. 
§§§ Archaean, Gr. archaios, ancient. 
