Lancashire Part 10

THE FOSSILS[47]

[47] One or two paragraphs condensed from the seventh chapter of _Summer Rambles_, 1866. Long since out of print.

Although the new red sandstone, so general in the southern parts, offers scarcely any attractions to the palaeontologist, Lancashire is still a rich locality in regard to fossils. The coal-fields and the mountain limestone, the latter so abundant near c.l.i.theroe, make amends. The organic remains found in the mountain limestone almost invariably have their forms preserved perfectly as regards clearness and sharpness of outline. The history of this rock begins in that of primeval sea; the quant.i.ty of remains which it entombs is beyond the power of fancy to conceive, large ma.s.ses owing their existence to the myriads, once alive, of a single species of creature. A third characteristic is that, notwithstanding the general hardness, the surface wears away under the influence of the carbonic acid brought down by the rain, so that the fossils become liberated, and may often be gathered up as easily as sh.e.l.ls from the wet wrinkles of the sands.

Access to the mountain limestone is thus peculiarly favourable to the pursuits of the student who makes researches into the history of the life of the globe on which we dwell. How much can be done towards it was shown forty or fifty years ago by the Preston apothecary, William Gilbertson, whose collection--transferred after his death to the British Museum--was p.r.o.nounced by Professor Phillips in the _Geology of Yorkshire_ at that moment "unrivalled." Gilbertson's specimens were chiefly collected in the small district of Bolland, upon Longridge, where also at considerable heights marine sh.e.l.ls of the same species as those which lie upon our existing sh.o.r.es may be found, showing that the elevation of the land has taken place since their first appearance upon the face of the earth.

The quarries near c.l.i.theroe and Chatburn supply specimens quite as abundantly as those of Longridge. Innumerable terebratulae, the beautiful broad-hinged and deeply-striated spirifers, and the euomphalos, reward a very slight amount of labour. Here, too, are countless specimens of the petrified relics of the lovely creatures called, from their resemblance to an expanded lily-blossom and its long peduncle, the crinoidea, a race now nearly extinct. A very curious circ.u.mstance connected with these at c.l.i.theroe is that of some of the species, as of the _Platycrinus triacontadactylos_, or the "thirty-rayed," there are myriads of fossilised _heads_ but no bodies.

The presumed explanation of this singular fact is, that at the time when the creatures were in the quiet enjoyment of their innocent lives, great floods swept the sh.o.r.es upon which they were seated, breaking off, washing away, and piling up the tender and flowerlike upper portions, just as at the present day the petals of the pear-tree exposed to the tempest are torn down and heaped like a snowdrift by the wayside, the pillar-like stems remaining fast to the ground. There is no need to conjecture where the _bodies_ of the creatures may be.

At Castleton, in Derbyshire, where the encrinital limestone is also well exhibited, there are innumerable specimens of these, and few or no examples of heads. The bodies of other species are plentiful at c.l.i.theroe, where the actinocrinus is also extremely abundant, and may be detected, like the generality of these beautiful fossils, in nearly every one of the great flat stones set up edgeways in place of stiles between the fields that lie adjacent to the quarries.

The organic remains found in the coal strata rival those of the mountain limestone both in abundance and exquisite lineaments. In some parts there are incalculable quant.i.ties of relics of fossil fishes, scales of fishes, and sh.e.l.ls resembling mussels. The glory of these wonderful subterranean museums consists, however, in the infinite numbers and the inexpressible beauty of the impressions of fern-leaves, and of fragments of the stems--well known under the names of calamites, sigillaria, and lepidodendra--of the great plants which in the pre-Adamite times composed the woods and groves. In some of the mines--the Robin Hood, for instance, at Clifton, five miles from Manchester--the roof declares, in its flattened sculptures, the ancient existence hereabouts of a vast forest of these plants. At Dixonfold, close by, when the railway was in course of construction, there were found the lower portions of the fossilised trunks of half a dozen n.o.ble trees, one of the stone pillars eleven feet high, with a circ.u.mference at the base of over fifteen feet, and at the top, where the trunk was snapped when the tree was destroyed, of more than seven feet. These marvellous Dixonfold relics have been carefully preserved by roofing over, and are shown to any one pa.s.sing that way who cares to inquire for them. Beneath the coal which lies in the plane of the roots, enclosed in nodules of clay, there are countless lepidostrobi, the fossilised fruits, it is supposed, of one or other of the coal-strata trees. Two miles beyond, at Halliwell, they occur in equal profusion; and here, too, unflattened trunks occur, by the miners aptly designated "fossil reeds." Leaves of palms are also met with.

The locality which in wealth of this cla.s.s of fossils excels all others in South Lancashire would appear to be Peel Delph. In it are found calamites varying from the thickness of a straw to a diameter of two or three feet, and as round as when swayed by the wind of untold ages ago. The markings upon the lepidodendra are as clear as the impress of an engraver's seal. In another part there is a stratum of some four feet in depth, consisting apparently of nothing besides the fossil fruits called trigonocarpa and the sandy material in which they are lodged. With these curious triangular nuts, no stems, or leaves, or plant-remains of any description have as yet been found a.s.sociated.

All that can be said of them is that they resemble the fruits of the many-sided j.a.panese tree called the salisburia.

At Peel Delph again a stratum of argillaceous shale, five or six feet in thickness, contains innumerable impressions of the primeval ferns, the dark tint thrown forward most elegantly by the yellow of the surface upon which they repose. The neighbourhood of Bolton in general is rich in fossil ferns, though Ashton-under-Lyne claims perhaps an equal place, and in diversity of species is possibly superior.

Thus whether considered in regard to its magnificent modern developments in art, science, literature, and useful industries, its scenery and natural productions, or its wealth in the marvellous relics which talk of an immemorial past, Lancashire appeals to every sentiment of curiosity and admiration.