SECONDARY FORMATIONS.
_No. 1. The New Red Sandstone._
“There is a path which no fowl knoweth, and which the vulture’s eye hath
not seen; the lions’ whelps have not trodden it, nor the fierce lion
passed by it.”—JOB.
We now take our leave of the Palæozoic period, and enter upon the
investigation of other and more recent geological epochs in the history
of the crust of our planet. This division is known by the names
Secondary or Mesozoic,[64] and is inclusive of the New Red Sandstone,
Oolitic, Wealden, and Cretaceous groups. If, in our previous survey, we
have had our minds filled with wonder as we looked at the disinterred
relics of past creations, and have gazed at these fossil forms of
ancient life with almost a loving interest in their still remaining
beauty; so, as we now study higher types of life, and behold how “other
wonders rise, and seize the soul the prisoner of amaze,” we shall find
reason upon reason for the penetration of our minds with the profoundest
adoration of Deity. No man turning up a tumulus, and there finding
coins, weapons, beads, vases, or other such historical relics, would
venture to say such things were created there; on the contrary, he would
acknowledge that they were Roman, and that he had come to that
conclusion by perceiving their resemblance to other and similar ancient
Roman relics, discovered where there could be no doubt of their origin
and history. Or if a traveller were to visit the cities of Herculaneum
and Pompeii, and there find buried beneath the overwhelming torrent of
once burning lava, all possible kinds of human memorials, not only in
human _works_, but also in the skeleton remains of human _beings_, would
he not come to the conclusion that these were indubitable evidences of
those cities having once been inhabited by man, and that these skeletons
were once covered with warm flesh, and that they had lived, and moved,
and had their being, even as we do now, amidst the activities and
enjoyments of actual life? We apply this to geology. There are persons
who never judge by _evidence_, (though what else have we to judge by?)
but rashly jump to conclusions about geological facts, that have not a
particle of common sense to sustain them. They never think that every
rounded pebble they meet with has been so rounded by the action of
water; they imagine sand to have been created as sand, instead of taking
the geologist’s proof, that all sand has been produced by the action of
moving water on solid rock. They believe that fossils were created, and
that God put encrinital remains, and dead ammonites, and bones of
saurians, and teeth and bones of great mammals, in the earth, just as we
find them in the cliffs and caves of this and every country; and they
imagine that thus to account for the wonders of creation redounds to the
glory of that God whom thus they ignorantly worship. Even our great
publishing society in Paternoster Row,[65] that has published about
everything in natural history but geology, has acknowledged to me that
it declines to undertake a work on this science, because of the
_theological difficulties_ connected with the subject. Why, what is this
but the very way to breed infidelity? The man who studies nature and who
studies his Bible, is not ashamed to say he believes them both; though
two books, they are both given by inspiration of God. Man may be a liar,
but neither nature nor the Bible can lie; and while one tells us the
history of man, the other reveals to us the history of the creation, and
succession of those beings which preceded the advent of man.
We now come to the New Red Sandstone, which must occupy our attention
both on account of the unique fossil remains found in it, and also on
account of its economic use and value in commerce. Few formations, small
as it is, possess so many points of interest to the beginner as the new
red sandstone; for, lying just above the carboniferous, and between it
and the oolitic group, we find in it certain curiosities of very olden
time, that are full of marvellous power to fill us with amaze. Every one
remembers Robinson Crusoe’s surprise at finding “the print of a man’s
naked foot on the shore, which was very plain to be seen in the sand,”
and how he “stood like one thunder-struck, or as if he had seen an
apparition;” and then how he “went again to see if it might not be his
fancy, but there was no room for that, for there was exactly the very
print of a foot, toes, heel, and every part of a foot;” and then how,
after “innumerable fluttering thoughts, and out of himself,” he went
home terrified to his fortification.
Equally surprising are the discoveries made in the old red sandstone.
Large slabs of this rock have been discovered in England, in Scotland,
and in the United States, on which are left, as Robinson left the
impression of his foot, the undisturbed footmarks of _pre-Adamite_
animals; the ebb and flow of the tide of those distant ages; the
ripple-mark showing the direction of the wind; and casts of the
rainprints made by showers, long long ages ere man had taken possession
of the “deep places of the earth.” “Romantic nonsense!” says a grave
friend; “let us go to something practical, instead of losing ourselves
in such idle speculations.” Now, you are just the person whose ear we
want to catch; and to you we say, just listen to the evidence of these
assertions. “The casts of rainprints below project from the under side
of two layers; the one a sandy shale, and the other a sandstone
presenting a warty or a blistered surface, and affording evidence of
cracks formed by the shrinkage of subjacent clay on which rain had
fallen. The great humidity of the climate of the coal period had been
previously inferred from the nature of its vegetation, and the
continuity of its forests for hundreds of miles; but it is satisfactory
to have at length obtained such positive proofs of showers of rain, the
drops of which resembled in their average size those which now fall from
the clouds. From such data we may presume that the atmosphere of the
carboniferous period corresponded in density with that now investing the
globe and that different currents of air varied then as now in
temperature, so as to give rise, by their mixture, to the condensation
of aqueous vapour.”[66]
[Illustration:
CASTS OF RAIN-PRINTS.
]
Again, let us hear the words of Professor Ansted. “It may appear at
first sight that nothing can be more fleeting, or less likely to be
handed down to future ages, among the fossils of a bed of sandstone,
than the casts of the impressions of the footsteps of an animal, which
by chance may have walked over that bed when it existed in the condition
of loose sand forming a seashore. A little consideration, however, will
show that it is in fact a very possible occurrence, as, if the wet sand
should be immediately covered up with a thin coating of marl, and
another layer of sand be superimposed, such an impression will be
permanently preserved. In after ages, also, when the soft sands have
become sandstones, and are elevated above their former level, the stones
split asunder wherever a layer of different material occurs; and thus it
happens that the casts of the footsteps may be preserved and exhibited,
although all other traces of the former existence of the animal have
been lost.”[67]
[Illustration:
FOOTPRINTS OF A TRYDACTYLE BIRD, AND IMPRESSION OF RAIN.
(_Nat. size._)
]
If we go to the British Museum, on the north wall of room No. 1. we
shall find slabs of sandstone containing footprints of animals,
apparently bipeds and quadrupeds, of which we find the following notice
in the catalogue of the Museum; and when this description is compared
with the three drawings that follow, we make no doubt of carrying the
conviction of the reader along with our own, as to the origin of these
extraordinary _ichnites_,[68] as such petrified prints are termed:—“The
slabs of sandstone on the north wall of this room, with the supposed
tracks of an animal called Cheirotherium, are that on the left from the
quarries of Hildburghausen in Saxony, and that in the centre from those
of Horton Hill, near Liverpool, (the latter presented by J. Tomkinson,
Esq.) On the right hand are placed slabs from the same new red sandstone
formation, with equally enigmatical imprests of various dimensions,
called Ornithichnites,[69] being very like footmarks of birds; they
occur in the sandstone beds near Greenfield, Massachusetts, at a
cataract in the Connecticut River known by the name of Turner’s Falls.”
[Illustration:
FOOTPRINTS OF BIPEDS (BIRDS?) PROM TURNER’S FALLS.
(_Size of slab, 8 ft. by 6._)
]
The lines in this drawing are merely to indicate the direction, the line
of progress, of these bipeds, and the reader by following the lines will
find the illustration all the more interesting.
But the most remarkable footprints preserved on slabs of sandstone are
those of a quadruped, whose hinder feet were much larger than his fore
feet. Some of our marsupial[70] quadrupeds, such as the opossum and
kangaroo, and many species of batrachian[71] reptiles, are distinguished
by the same peculiarity. Below is a copy of this slab, which is in the
window recess of the same room of the British Museum.
[Illustration: Fossil]
The animal that left these impressions on the soft sandy shore, that are
now converted into hard stone, was originally named the
Cheirotherium,[72] and, indeed, this name is still retained by many
writers, the hand-like footprints being quite a sufficient reason for so
appropriate a name; but latterly the teeth of a fossil animal, supposed
to be the same as the Cheirotherium, having been examined, and
disclosing a peculiarly labyrinthine character, the animal has been
called Labyrinthodon.[73] Professor Owen, the great comparative
anatomist of geology, has fairly established the real character of this
animal. He says it is a huge frog, a gigantic batrachian, with hinder
feet at least twelve inches in length, combining a crocodilian with a
frog-like structure; and although the actual shape and proportions of
such an animal must remain greatly an enigma, it is one of the wondrous
marvels of geology to pause over these extinct huge creatures, and mark
in them the exhaustless resources of creative power.
“So reads he nature, whom the lamp of truth
Illuminates,—thy lamp, mysterious Word!
Which whoso sees, no longer wanders lost,
With intellects bemazed in endless doubt,
But runs the road of wisdom. Thou hast built
Worlds that never had been, hadst thou in strength
Been less, or less benevolent than strong.”
In Professor Ansted’s remarkable prose poem on geology, called, “The
Ancient World,” we have the following picture of the new red sandstone
period, which we quote for its vivid but faithful colouring:—“We may
imagine a wide, low, sandy track by the sea-side; the hills and cliffs
of limestone, which still rise boldly on the shores of the Avon, and in
Derbyshire and Yorkshire, having then been recently elevated, and
forming a fringe to the coast line. In some places, where footprints are
found in successive beds and at different levels, local elevation was
probably going on, and the line of coast was occasionally shifting. The
sandy fiats thus laid bare, and not reached by the ordinary level of
high water, were of course traversed by the ancient animals of that
period; but only a few faint records of them have been handed down for
our observation. Amongst these, however, we are able to enumerate
turtles and tortoises, a little lizard having a bird-like beak, and
probably a bird’s foot,—birds themselves, some larger than an ostrich,
others as small as our smaller waders. In some parts of the world there
were also large reptiles with powerful tusks, not surpassed in the
amount of their departure from the ordinary structure of reptiles by any
known aberrant forms of that strange and varied tribe.
“Amongst the most striking of these objects, at least on our own shores,
would be the numerous and gigantic Labyrinthodons. We may imagine one of
these animals, as large as a rhinoceros, pacing leisurely over the
sands, leaving deep imprints of its heavy, elephantine hind foot,
strangely contrasting with the diminutive step of its short fore
extremities. Another, a small variety, provided like the kangaroo, not
only with powerful hind legs, but also with a strong tail,[74] also
leaves its impress on the sand, although itself, perhaps, soon fell a
victim to the voracity of its larger congener. These and others of their
kind, passing over the sands, and marking there the form of their
expanded feet, marched onwards in their course, fulfilled their part in
nature, and then disappeared for ever from the earth, leaving, in some
cases, no fragment of bone, and no other indication of their shape and
size than this obscure intimation of their existence.
“It is strange that in a thin bed of fine clay, occurring between two
masses of sandstone, we should thus have convincing evidence preserved
concerning some of the earth’s inhabitants at this early period. The
ripple mark, the worm track, the scratching of the small crab on the
sand, and even the impression of rain drops, so _distinct as to indicate
the direction of the wind_ at the time of the shower,—these and the
footprints of the bird and the reptile are all stereotyped, and offer an
evidence which no argument can gainsay, no prejudice resist, concerning
the natural history of a very ancient period of the earth’s history. But
the waves that made that ripple mark have long since ceased to wash
those shores; for ages has the surface then exposed been concealed under
great thicknesses of strata; the worm and the crab have left no solid
fragment to speak to their form or structure; the bird has left no bone
that has yet been discovered; and the fragments of the reptile are
small, imperfect, and extremely rare. Still, enough is known to
determine the fact, and that fact is the more interesting and valuable
from the very circumstances under which it is presented.”[75]
But reminding ourselves of one part of the title of our book, which
professes not only to describe the crust of the earth, but also to point
out its uses, we must add a few words on the economic value of this
small but interesting formation. In this same new red sandstone are
found the salt mines of Cheshire, and the brine pits of Worcestershire,
which supply all the rock and table salt consumed in England, besides
vast quantities for exportation. The rock salt of Cheshire was first
discovered near Northwich, while searching for coal; but the largest
mine, called the Wilton Mine, is at Nantwich, and still yields about
60,000 tons of salt annually. The salt is generally found from
twenty-eight to forty-eight yards beneath the surface, in thick strata
varying from fifteen to thirty-five yards in thickness. Besides these
beds of salt, there are brine springs from twenty to forty yards in
depth. Our common table salt is almost exclusively derived from these
springs, which is produced by evaporating the water, and allowing the
salt to settle at the bottom of the pans, where, after being washed, it
is placed in moulds like the China clay, and comes to our grocers’ shops
in the blocks we frequently see. “So far as observation has yet gone,
the English supply is practically inexhaustible; no limit is known to
the extent of the beds or the springs; and it ought to be regarded as
one of the blessings which we owe to the mineral wealth of our country,
that the beautiful table salt of England may be obtained at such an
extremely low price as that now charged for it.”[76]
To this formation, with its fossil footprints, we owe doubtless the fine
fancy of Longfellow, in one of his sweet minor poems; and we shall bring
this chapter to a close by quoting the last three verses of this lyric.
If we can fulfil such a mission, we had better be frail and erring men
than huge Labyrinthodons:—
“Lives of great men all remind us,
We can make our lives sublime,
_And departing, leave behind us
Footprints on the sands of time_.
“Footprints, that perhaps another,
Sailing o’er life’s solemn main,
A forlorn and shipwreck’d brother,
Seeing, shall take heart again.
“Let us, then, be up and doing,
With a heart for any fate;
Still achieving, still pursuing,
Learn to labour and to wait.”