THE GEOLOGY.
[Illustration: The Barton Cliffs.]
I have endeavoured, whenever there was an opportunity, to point out the
natural history of the Forest, feeling sure that, from a lack of this
knowledge, so many miss the real charms of the country. “One green field
is like another green field,” cried Johnson. Nothing can be so untrue.
No two fields are ever the same. A brook flowing through the one, a
narrow strip of chalk intersecting the other, will make them as
different as Perthshire from Essex. Even Socrates could say in the
_Phædrus_, τὰ µὲν οὖν χωρία καὶ τὰ δένδρα οὐδέν µ’ ἐθέλει διδάσκειν. and
this arose from the state, or rather absence, of all Natural Science at
Athens. Had that been different he would have spoken otherwise.
The world is another place to the man who knows, and to the man who is
ignorant of Natural History. To the one the earth is full of a thousand
significations, to the other meaningless.
First of all, then, for a few words on the geology of the Forest; for
upon this everything depends—not only the scenery, but its Flora and
Fauna, the growth of its trees and the course of its streams. Throughout
it is composed of the Middle-Eocene, the Osborne and Headon Beds capping
the central portion, with their fluvio-marine formation. The Upper
Bagshot develops itself below them, and is succeeded by the Barton
Clays, so well exposed on the coast, and finally by the Bracklesham
Beds, which crop out in the valley of Canterton, trending in a
south-easterly direction to Dibden.
Here, then, where the New Forest stands, in the Eocene period, rolled an
inland sea, whose waves lashed the Wiltshire chalk hills on the north,
moulding, with every stroke of their breakers, its chalk flints into
pebbles, dashing them against its cliffs, as the waves do at this very
hour those very same pebbles along the Hurst beach. Its south-western
boundary-line between Ballard Head and the Needles was rent asunder by
volcanic action, and the chalk-flints flung up vertically mark to this
day the violence of the disruption.
Long after this the Isle of Wight was altogether separated by the Solent
from the mainland, but still ages before the historic period. The
various traditions, as to the former depth of the channel, how Sir
Bevis, of Southampton, waded across it, how, too, the carts brought the
Binstead stone for building Beaulieu Abbey over the dry bed at low
water, have been previously given. The passage, too, in Diodorus Siculus
has been already examined,[265] and there can be no doubt,
notwithstanding his also making it, like the traditions, a peninsula at
low water, that his Ictis is the Isle of Wight and not St. Michael’s
Mount. The mere local evidence of the mass of tin, the British road—more
like a deep trench than a road—still plainly traceable across the
Forest, the names along it corresponding with that of its continuation
in the Island, would alone, most assuredly, show that this was the place
whence the first traders, and, in after-times, the Romans, exported
their tin. We must, however, remember that the channel of the Solent was
caused by depression rather than by excavation; and that at this moment
an alteration in the levels, as noticed by Mr. Austen,[266] is going on
eastward of Hurst Castle.
The drift, which spreads over the whole of the New Forest, is not very
interesting. No elephants’ tusks, or elks’ horns, so far as I know, have
ever been discovered. A few species of _Terebratula_ and _Pecten_, some
flint knives, and the _os inominatum_, of probably _Bos longifrons_,
mentioned farther on, are the only things at present found. Still, in
one way, it is most interesting, as completely disproving the
Chroniclers’ accounts that, before its afforestation by the Conqueror,
the district of the Forest was so fertile. The fact is a sheer
impossibility. No wheat could ever be grown on this great bed of
chalk-gravel, which is varied only by patches of sand.
But nowhere, perhaps, in the world can we see the stratification of the
upper portion of the Middle-Eocene better than at Hordle and Barton, as
the sea serves to keep the different strata exposed. The beds dip
easterly with a fall of about one in a hundred, though, at the extreme
west, at High Cliff, it is much less, and here and there in some few
places they lie almost horizontally.[267] At Hordle they seem to have
been deposited in a river of a very uniform depth. There is but one
single fault in the whole series, just under Mead End, where all the
beds have alike suffered. Here and there, however, they are deposited
with an undulating line; and here and there, too, a rippled surface
occurs, caused by the action of small waves. The river appears to have
varied very much in the amount and force of its stream, as some of the
beds, where the shells are less frequent, have been deposited very
rapidly, whilst others, where the organic remains are more abundant,
have been laid on very slowly and in very still water.[268]
It will be impossible to examine all the beds. One or two, however, may
be mentioned. And since the beds rise at the east we will begin from
Milford. First of all, at Mineway, there runs a remarkable band of fine
sand, the “Middle Marine Bed,” discovered some twenty-five years ago, by
Mr. Edwards, and subsequently successfully worked by Mr. Higgins. It is
seldom, however, exposed for more than a few yards; but that is
sufficient to show, that after the elevation of the beds beneath they
once more subsided, and the sea came over them again, and after that
they were once again elevated.
Just below Hordle House rises the “Crocodile Bed,” running out of the
cliff about three hundred yards from Beckton Bunny. The lowest part of
it teems with fish-scales, teeth, crocodile plates, ophidian vertebræ,
seed vessels, and other vegetable matter, very often mixed in a
coprolitic bed, just beneath a band of tough clay, the specimens being
more frequent to the east than the west. The accompanying section (I.)
will, perhaps, not only serve to show the situation of the bed, but also
those above and below. My measurements will be found to differ slightly
from Sir Charles Lyell’s[269] and Dr. Wright’s;[270] but this is owing
to their having been taken in different places.
Immediately under the “Leaf Bed,” which, as seen in the opposite
section, rises from the shore to the west of Hordle House, comes the
lowest bed of the Lower Freshwater Series, formed of blue sandy clay
sixteen feet in thickness, from whence Mr. Falconer obtained so many of
his mammalian remains.[271]
[Illustration: Section I. _of Hordle Cliff, a little to the west of
Hordle House.—The beds here incline at an angle of 5°._]
Ferruginous flint gravel interstratified with sand—18 feet.
Light blue marl in the upper part running into sand—12 feet.
Ligneous bed—12 inches.
Bluish marl running into shades of light grey, caused by the
comminuted shelly matter—15 feet.
Ligneous bed—9 inches.
Green marl—3 feet 6 inches.
Limestone—4 inches.
Lignite—1 inch.
Green marl—5 feet 4 inches.
Grey sand—portion of Dr. Wright’s Crocodile Bed—4 feet.
Fossil bed—9 to 13 inches.
_a, b_—Bands of tough brown clay, not continuous.
_c_—Coprolite bed appearing here and there, and always full of
organic remains.
Sand bed, uncertain—1 foot 8 inches.
Light blue marl—4 feet 6 inches.
Grey sand—2 feet 5 inches.
Leaf bed, which here rises from the beach—18 inches.
The present sea-shore.
It is a bed, however, which is seldom open, and can be worked only at
particular tides. It may easily be recognized as lying between the Leaf
Bed and the well-marked Lignite Bed, which shows the first traces of
salt-water, and where, in the lower portion, _Neritina concava_ may be
abundantly found. This last bed may be well seen at Beckton Bunny
(Section II.). The lignite, however, though it will give a good deal of
heat, will not blaze. Locally it is sometimes used for making black
paint.
[Illustration: Section II. _of Beckton Cliff immediately to the west of
the Bunny_.]
Flint gravel—scarcely more than 3 or 4 feet, with an uncertain band of
white sand.
Lignite—3 inches.
Brown clay—3 inches.
Lignite—3 inches.
Marl and sand—2 feet 2 inches.
Ligneous bed, containing shells much broken—8 inches.
Grey sand—2 feet 4 inches.
Orange-coloured sand, with very few fossils at this point, though
plenty eastward—15 feet 9 inches.
Olive bed. Fossils abundant—27 feet 3 inches.
The present sea-shore.
Passing on to Beckton Bunny we reach the first true bed of the Lower
Marine Formation, which rises a little eastward of that ravine. I have
distinguished it as the Olive Bed, from the abundance of specimens of
_Oliva Branderi_, forming the equivalent to number eighteen in Dr.
Wright’s arrangement, and which, when worked, emits a strong smell of
sulphur.
Immediately under the Olive Bed, as seen in the opposite section (II.),
taken immediately on the west side of the Bunny, rises grey sand,
seventeen feet and a half in thickness, possessing only a few casts of
shells. The next bed, however, composed also of grey sand, rising about
three hundred yards farther on, is, perhaps, the richest in the whole of
this Marine series, and its shells the best preserved. It may at once be
recognized by the profusion of _Chama squamosa_, from which it has been
called the Chama Bed. Specimens of _Arca Branderi_ and _Solen gracilis_
may be found here as perfect as on the day they were deposited.
A little farther on, nearly under the Gangway, rises the Barton clay,
encrusted with _Crassatella sulcata_.[272] And here, on looking at the
cliff, we may notice how all the beds, as they rise westward, gradually
lose their clayey character, and run into sand, which will account for
this part of the cliff foundering so fast. The water percolates through
the sand down to the Barton Beds, and the loose mass above is thus
launched into the sea.
Below the Barton Coastguard Station rises another bed of green clay,
containing sharks’ teeth and the bones of fish. About a mile farther on,
the High Cliff Beds emerge rich with _Cassis ambigua_ and _Cassidaria
nodosa_. And below them, seen in the channel of the stream flowing
through Chewton Bunny, rises a bed of bright metallic-looking, green
clay, the _Nummulina Prestwichiana_ Bed of Mr. Fisher, containing
sharks’ teeth and some few shells. Beyond, a little to the west of High
Cliff Castle, occurs the well-marked Pebble Bed, the commencement of the
Bracklesham Series, containing rolled chalk flints, and casts of shells.
Next follow grey sands full of fossil wood and vegetable matter, marked
by a course of oxydized ironstone-septaria. Then succeeds another Pebble
Bed, and lastly appear the grey Bracklesham Sands.[273]
We have thus gone through the principal beds, both of the Freshwater and
Marine Series, as far as they are exposed in this section along the
sea-coast. The fluvio-marine beds stretch away eastward as far as
Beaulieu and Hythe, but their clays here contain very few shells. On the
other hand, the Bracklesham Beds trend away northward towards
Stoney-Cross, appearing in the valley, and cropping out again on the
other side of the Southampton Water.
Some few words must be said about them. The highest beds, known as the
Hunting Bridge Beds, occur in Copse St. Leonards, not far from the
Fritham Road.[274] In a descending order, separated by thirty or forty
feet of unfossiliferous clays, come the Shepherd’s Gutter Beds, to be
found about half a mile lower down the King’s Gairn Brook; and below
them, again, separated by forty or fifty feet of unfossiliferous clays,
and situated somewhat more than a mile lower down the same stream, rise
the Brook Beds. Still farther down, too, from some shells very lately
discovered at Cadenham, it is supposed that the _Cerithium_ Bed of
Stubbington and Bracklesham Bay will be found, but this is not yet
ascertained.
The Hunting Bridge Beds I have never examined, but subjoin their
measurements, as also their most typical shells,[275] and must here
content myself to give a general description of the Shepherd’s Gutter
and Brook Beds. The former, the equivalent to the _Nummulina_ Bed at
Stubbington, Bracklesham, and White-Cliff Bay, is so called from a small
stream at the foot of Bramble Hill Wood, about a mile due north of the
King’s Gairn Brook. The measurements are as follows:—(1) Gravel from one
to five feet; (2) light-coloured clay, with a few fossils sparingly
distributed, five to six feet; (3) _Turritella carinifera_ bed, one foot
and a half; (4) fossil bed, characterized by _Conus deperditus_, and the
abundance of _Pecten corneus_ within a few inches of the bottom, one
foot and a half.
[Illustration: Shells from the Shepherd’s Gutter Beds.]
It is worth noticing that these, like all the Bracklesham beds, roll. In
a pit which Mr. Keeping and myself dug we found there had been a regular
displacement of the gravel, and that the beds rose at an angle of thirty
degrees, whilst the fossil bed was three feet lower on one side than the
other of the pit. In another, after cutting through a foot of gravel, in
which we found the _os inominatum_, of probably _Bos longifrons_,[276]
and a bed of sandy clay about two feet in thickness, we came upon a
deposit of gravel about four inches thick, lying in the depressions of
the stiff brown clay which succeeded, and in which still remained roots
and vegetable matter. Thus we can plainly see that, after the clay had
been deposited, vegetable, and perhaps animal, life flourished. Then
came the gravel, carrying all before it, and in its turn, too, was
nearly swept away, and only left here and there in a few scattered
patches.
Perhaps, nothing is so startling as this insecurity of life. As was the
Past so will be the Future, guided, though, always by that Law, which at
every step still rises, moving in no circle, but out of ruin bringing
order, and from Death, Life.
The Brook Beds I can best describe for the general reader by an account
of a pit which Mr. Keeping and myself made. It was sunk about 20 feet
from the King’s Gairn Brook, and measured about 6 yards long by 4 broad.
We first cut through a loamy sand, measuring 3 feet, and then came upon
19 inches of gravel, where at the base stretched the half fossilized
trunk of an oak, and a thick drift of leaves mixed with black peaty
matter, the remains of some primæval forest. Three feet of
light-coloured clay, unfossiliferous, succeeded; and then came the
_Corbula_ Bed, with its myriads of _Corbula pisum_, massed together,
nearly all pierced by their enemies, the _Murices_. Stiff light-coloured
clay, measuring 18 inches, followed, revealing some of the shells, which
were to be found so plentiful in the next stratum. Here, at the
_Pleurotoma attenuata_ Bed, our harvest commenced, and since Mr. Keeping
has worked these beds, no spot has ever yielded such rich results. Every
stroke of the pick showed the pearl and opal-shaded colours of the
nautilus, and the rich chestnut glaze of the _Pecten corneus_, whilst at
the bottom lay the great thick-shelled _Carditæ planicostæ_. Inside one
of these were enclosed two most lovely specimens of _Calyptræa
trochiformis_. Mr. Keeping here, too, found a young specimen of _Natica
cepacea_ (?), and I had the good fortune to turn up the largest
_Pleurotoma attenuata_ ever yet discovered, measuring 4½ inches in
length, and 3¼ inches in circumference round the thickest whorl.
We were now down no less than 8 feet. And at this stage the water from
the brook, which had been threatening, began to burst in upon us from
the north side. We, however, with intervals of bailing, still pushed on
till we reached the next bed of pale clay, measuring from 7 to 8 inches,
containing _Cassidariæ_ highly pyritised, and sharks’ teeth, amongst
which Mr. Keeping discovered an enormous spine, measuring at least 10
inches in length, but we were unable to take it out perfect. The water
had all this time been gaining upon us, in spite of our continuous
efforts to bail it with buckets. We, however, succeeded in making the
_Voluta horrida_ bed, which seemed, at this spot, literally teeming with
shells. Each spitful, too, showed specimens of fruit, earbones,
fish-palates, drift-wood, and those nodular concretions which had
gathered round some berry or coral.[277]
At this point, the water, which was now pouring through the side in a
complete stream, and a rumbling noise, showed danger was imminent.
Hastily picking up our tools and fossils we retreated. In a moment a
mass of clay began to move, and two or three tons, completely burying
our bed, fell where we had stood. Founder after founder kept succeeding,
driving the water up to higher levels. We procured assistance, but
precious time was lost. Night began to fall, and we were obliged to
leave unworked one of the richest spots which, in these beds, may,
perhaps, ever be met.
As it was, we found no less than sixty-one species, including in all 230
good cabinet specimens, which, considering the small size of the pit,
and our limited time, and the great disadvantages under which we worked,
well showed the richness of these beds.
Merely, however, collecting fossils for collecting’s sake is useless.
The aim of geology is to enable us to understand how this world was
made—how form followed form, how type after type took life and then
passed away, and the higher organization ever succeeded the lower. The
Middle-Eocene ought to be to us particularly interesting, separating us,
on the one hand, from those monsters which had filled the previous Age,
and, on the other, presenting the first appearances of those higher
mammals which should serve the future wants of man. The pterodactyle no
longer darkened the air. The iguanodon now slept in its grave of chalk.
A new earth, covered with new types and new forms, had appeared. It is a
strange sight which the Hordle Cliffs unveil. Here, beneath a sun
fiercer than in our tropics, the crocodile basked in its reed beds. Here
the alligator crimsoned the stream, as he struck his jaws into his
victim; whilst the slow tryonyx paddled through the waves, and laid its
eggs on the sand, where its plates are now bedded.
The very rushes, which grew on the river banks, lie caked together, with
the teeth of the rats which harboured in them. The pine-cones still,
too, lie there, their surfaces scarcely more abraded than when they
dropped from the tree into the tepid waters. Along the muddy river shore
browsed the paloplothere, whilst his mate crashed through the jungle of
club-mosses. Groves of palms stood inland, or fringed the banks,
swarming with land-snakes. Birds waded in the shallows. But no human
voice sounded: nothing was to be heard but the screaming of the
river-fowl, and the deep bellow of the tapir-shaped palæothere, and the
wolf-like bark of the hyænodon.
This description is no mere fancy, but taken from the remains actually
discovered in the Hordle Cliffs. I have had no need to borrow from the
fossils of the Headon and Binstead Beds, or the caves of Montmartre. On
these cliffs, too, is scored the history of the past. Here lie the
little _Nuculæ_, still crimson and pink as when they first settled down
through the water into their bed of sand; and teeth of dichodons still
bright with enamel. The struggle of life raged as fiercely then as now.
And the pierced skull of the palæothere still tells where it received
its death-wound from its foe the crocodile.
But other things do they reveal. They plainly show, as was, I believe,
first suggested by Mr. Searles Wood, that in the Middle-Eocene period
Europe and America were connected. The pachyderms of Hordle are allied
to the tapirs of the New World. The same alligators still swim in the
warm rivers of Florida: and the same type of sauroid fish, whose scales
spangle the Freshwater Beds, is now only found in the West.
[Illustration: Shells from the Brook Beds.]