THE GEOLOGIST. 
DECEMBER, 1860. 
THE GEOLOGY OF THE SEVERIT VALLEY RAILWAY. 
A SKETCH BY 
GEORGE E. ROBERTS. 
AUTHOR OF "The Rocks of Worcestershiee." 
Deep cuttings and long tunnels are regarded by railway-contractors 
as tilings to be avoided, though lessons of the gTeatest instruction 
are derived from them by the student of geology. But as safety in 
transit demands the easiest gradients, and a line as straight as pos- 
sible, the lesser inequalities of the suiface have often to be cut into, 
so that no insignificant part of geological teaching is derived from 
railwaj^-work. And oft-times a way that puzzles the contractor to 
make " good," or a hill-slope that, lacking knowledge of its springs, 
he has cut into only to see it slip continuously upon his line, are 
great aids and helps to comprehending the natural formation of a 
district, and so, a contractor's poison becomes a geologist's meat. 
There are many such instructive points upon the Bridgnorth rail- 
way, which after briefly noting I hope will be looked at with pleasure 
by observers. In the mere name of the line there is a certain spice 
of geology — " The Severn Valley ;" its whole coui-se being along a 
narrow and in places deep valley, scooped out like a channel between 
England and Wales. Perhaps everyone knows that at no very dis- 
tant time, the tide which now laves the beaches of Cheshire, came 
rolling down this arm of the Irish sea, bringing shoal sand, and 
banking it in places about its course, and rolling the pebbles along 
its current till beaches, as well marked as those of Rhyl and Llan- 
dudno, were laid in lines parallel with the flow. Everybody sees 
evidence of this in the gravel-beds which lie upon the red sandstone 
in so many places in these border-counties, and specially to be noted 
in the neighbourhood of Bridgnorth, at Acleton and Worfield, where 
Terebrm, those slender trumpet-shells so abundant on the Welsh 
coast, may be picked up in sand ; at the Knowl — more firm sand, by 
VOL. III. 3 I 
