NATURAL HISTORY. 
95 
they do not descend to any particulars respecting it. 
We conclude, however, that after the deposition of the 
coal strata, powerful volcanic eruptions took place in 
the antediluvian world/ and this is proved by the various 
trap rocks in England, and the grand basaltic columns 
of the Giant's Causeway in Ireland, and StafFa in the 
Hebrides. Now one of the hills near Dudley is also 
crowned with basaltic columns, and basalt appears in 
the Clee Hills and our own Abberley Hills. A 
violent heat, then, at that period acting from beneath 
has caused the crystallization of the salt, and the 
consolidation of the red marl, giving to it at the same 
time its red and white colour, while probably at the 
same time the bed has been upheaved from below. 
After these volcanic eruptions, however, a season 
of quiet ensued, as the strata deposited upon the marl 
is crowded with shells. 
From Droitwich the new red sandstone extends 
southwards down the valley of the Severn, abutting 
against the elevated escarpment of the sienitic or 
granitic chain of Malvern. This abrupt termination 
of the sandstone at the base of Malvern Hills is very 
curious ; for whilst over the whole of the plain of 
Worcestershire the recent formations of the new red 
sandstone prevail, we no sooner reach the eastern 
side of Malvern Hill than we find the very oldest, or 
primitive rocks. Mr. Horner, in his paper in the 
first volume of the Geological Transactions, describes 
this part as being composed of sienite, but later 
investigators consider it more properly a granite 
1 Dr. lire's New Sysiem of Geology. 
