We glanced in passing at some few features which could scarcely fail to
attract the attention of the tourist, and a brief notice only of others
will be needed for the geologist. In ascending the river we descend,
geologically speaking, from an upper to a lower series of rocks, which
rocks, in many instances, are covered over by fluviatile and marine
deposits of sand and gravel, containing shells of fish inhabiting our
modern seas. These show how recently the sea must have retired from a
surface so covered with its remains; whilst their position low down in
the valley, and but a little way above the present bed of the Severn,
proves how much more recently the arm of the sea, known as the Severn
Sraits, must have been succeeded by the river. The best places for
collecting these remains along the railway will be found to be in
embankments and cuttings near Buildwas and Coalbrookdale, the latter
having yielded as many as twenty-two distinct species. In cuttings along
the railway, and in their immediate vicinity, will also be found sections
of rocks, from the variegated marls of the New Red Sandstone, of the
Mesozoic, to the silurians, of the Palaeozoic, or Primary Formations. The
coal measures of Coalbrookdale, with their alternating beds of coal,
clay, and iron ore, are rich in specimens of the fauna and flora of the
carboniferous age; the best places for discovering them being the spoil
banks of the mines, where shale, and ironstone nodules, will be found the
most productive. One of the richest beds yielding fossils is the
Penneystone, which may be seen on the surface near Coalbrookdale and
Ketley; remains of the Megalicthys, Gyracanthus, and Holoptychus being
occasionally found there, whilst Conularias, Nautili, Spirifers aviculus,
Bellerophons, and others are numerous. The sand rock overlying it
contains Calamites, Lepidodendrons, Ulodendrons, Sigillarias, &c., &c.
Benthall Edge and Lincoln Hill yield characteristic fossils of the
Wenlock limestone and Wenlock shales in great numbers and variety, corals
being most abundant. Between the Severn and the Acton Burnell hills
fossils of the Caradoc may be found in drift, in old walls by the
wayside, and in strata dipping praidly beneath the Wenlock shales.