CHAPTER V. 
CARBONIFEROUS SYSTEM. 
Carboniferous System of Northern and Central Russia the equivalent of the Mountain 
Limestone of Great Britain. — Divided into three Fossiliferous Zones. Lower Zone 
with seams of Coal in Sand and Shale described in the Valdai Hills. Extension 
of Limestone to Vitegra. — White Limestone of Archangel. Great Central Basin o f 
Carboniferous Limestone . — Lower Southern edge of, near Kaluga, Tula, fyc. White 
Limestone of Moscow. — •Extension of this central mass along the river Oka to 
Kasimof and Jelatma. — Upper or Fusulina Limestone at Kovrof and near Samara 
on the Lower Volga. 
We have now to treat of a system equally vast in horizontal extension with that 
which has been just described, and infinitely more important in mineral contents. 
In the older palaeozoic rocks of Russia we met with no signs of terrestrial fossil 
vegetables, still less with any traces of carbonaceous matter, but we no sooner 
ascended to the horizon of the strata under consideration, than coal beds occui, 
and we were surrounded by organic remains which characterize the great Caiboni- 
ferous epoch. 
Throughout the whole of the enormous area over which this system extends (see 
letter c upon the Map), the subsoil, whether in the northern or central govern- 
ments, or in the southern steppes, consists of limestones, with beds of sandstone, 
shale and marl, which are the undoubted equivalents of the Mountain Limestone 
or lower portion of the Carboniferous group of English geologists. The upper 
member of this system, which is so copiously developed in Western Europe under 
the names of coal-measures and “ terrain houiller”, has not, as will hereafter 
appear, any decided representative in Russia, where the rocks of this epoch are 
analogous to the carboniferous deposits of Ireland, which, though very largely 
developed, contain no representative of the upper and pioductive coal-fields of 
Great Britain 1 . 
i See Griffith’s Geological Map of Ireland. 
