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"Geology may be regarded as
the science of landscape: it is to the landscape painter what anatomy is
to the historic one or the sculptor…. Landscapes are tablets roughened
with the records of the past; and the various features, whether of hill or
valley, terrace or escarpment, form the bold and graceful characters in
which the narrative is inscribed." – HUGH MILLER.
It may appear a truism to
say that the geological structure and history of a country are responsible
for its scenery; but it is not so long ago since it was recognised that
the present features of the land are due, not to the powers of
subterranean convulsions of nature which were supposed to have reared the
hills on high, and cleft open the valleys, but to the simple denuding
agencies of air, rain, and frost; agencies which grind slowly, persistent
and ruthless, more mighty in their effects than the greatest cataclysms of
which history relates. While of course we recognise the great earth:
movements, which in the ages have alternately raised and submerged the
land, plicating and crumpling the strata and giving the general trend to
the surface; it is to these simple agencies, acting upon the lines of
least resistance, taking advantage of the peculiarities of fault and
structure, that the diverse details of the land which constitute its
scenic features are due. The picturesque mountain chains of the Highlands
are but the relies of denudation; they have been sculptured out of a huge
tableland by the erosion of the valleys; the process is still going on,
and will go on until a "base level" is reached, when again a new series of
rocks composed of the ruins of the old may be upreared, to be subjected to
the same ceaseless waste, and a new configuration be given to the surface
of the land.
From the varied resistance
to erosion presented by different natures of rock, we find each rock
formation having a distinct type of scenery. Thus in quartzite regions the
hills assume conical forms- the paps or "ciche" of so many districts;
while the riven peaks or "stuc" of schist, and hummocky ridges of slate,
and the precipitous hills or "bidean " of basalt, are familiar features of
the places where these rocks predominate. Again, the character of the
underlying strata has its influence upon the vegetation which clothes the
surface; from the grassy covering of basalt or limestone regions, the
rugged and heathery slopes of gneiss, to the sterile bare peaks of
quartzite.
We would expect therefore
that where different geological formations succeed or alternate quickly in
a comparatively small area, the scenery would be of an agreeably
diversified nature.
Now from the shores of Jura
and Scarba to the waters of Loch Awe - a region embracing the district of
Netherlorn - an interesting sequence of the old metamorphic rocks of the
Highlands appears. On the west we find a great mountain chain of
quartzite, rising in Beinn-an-oir, one of the Jura paps, to over 2,500
feet; then great thicknesses of clay slate of perfect cleavage and great
hardness constitute the bed rock of the interesting group of slate
islands-Sell, Luing, Easdale, Shuna, Torsa, Belnahua, and many others: the
slate in its turn passing into the schists and conglomerates of Loch Awe
and Kilmartin. These stratified rocks are of immense antiquity: they are
pre-Cambrian in geological chronology. Subsequently, in the old Red
Sandstone and Tertiary times, there were periods of great volcanic
activity, when large sheets of igneous rock over-poured the country,
appearing as sills or ledges between the beds, or forcing their way across
the strata of the older rocks in the form of dykes or veins of intrusive
material, or overlying all in huge thicknesses. Many of the hills of the
district are built up of this rock. The terraced declivities show the
edges of the sills; while the dykes, easily traceable for many miles, and
seldom more than l00 yards apart, cross the country from south-east to
north-west: here, where they are of harder material than the surrounding
rock, standing in relief, grey lichen-covered ramparts, locally known as "stac";
there, where they are more easily eroded, leaving picturesque ravines or
dark gullies, the "sloc" of Gaelic phraseology. Sometimes we find a "soft"
and a "hard" dyke side by side, and then, especially if it so happen on
the sea-shore, where the enormous force of the waves aids the ordinary
sub-aerial agencies to more decisive and striking effect, we see "sloc"
and "stac," or gully and dyke, magnifying each other's proportions, making
a most striking feature in cliff scenery.
To this diversity of
structure and consequent diversity in scenery, the landscapes of the
district owe their charm. There is no monotony. Mountain, moor, glen and
fiord, river and loch blend fitly. The long, narrow and tortuous
indentations which pierce and embarb the rough bounds, stretching to the
foot of that mountain chain which for ages has been known as Druim Albain
(the ridge of Albain, Dorsum Britanniae), mellow as if by stealth the
solemn grandeur of the mountains and valleys: they add the contrast of the
ever-changing sea to the "everlasting hills": the freshness and warmth of
the ocean penetrate to the heart of the district. The shattered scalps and
riven precipices of the summits are succeeded by the heath-covered slopes
strewn with grey scars and boulders, which in their turn merge into broad
terraces of grassy alluvium bordering the edge of the fiord and river.
It is related that, during
a fear of foreign invasion, instructions were given to the Lord
Lieutenants of counties, should a descent by the enemy upon the coast be
imminent, the cattle and sheep were to be driven at least 12 miles from
the sea; so deeply, however, have these sea lochs been carved into the
heart of the country, that it was found that, with the exception of a
narrow strip of the Blackmount in the extreme north-east, no part of the
large county of Argyll was that distance inland.
Again, the peculiar trend
of the coast-line of south-western Argyllshire cannot fail to strike the
observer. The long narrow promonteries of land and chains of narrow
islands, alternating with valleys and arms of the sea, are arranged in
"echelon" of parallel lines passing from north-east to south-west, and
this direction has been determined, in the first instance at any rate, by
the effects of great earth movements. Some mighty squeezing force passing
from the south-east has thrust and thrown the rocks into billows of
contorted strata folding towards the north-west, and the valleys have been
subsequently cut out by the ordinary processes of sub-aerial denudation
along the axes of these plications.
These western sea lochs are
true fiords – submerged valleys - portions of the glen which passes down
from the "col" at the watershed or the corrie on the mountain-side to the
head of the loch. When the great ice sheet which rounded the hills and
ridges left by previous ages of denudation began to disappear, mighty ice
streams continuously fed by the snows were left in the valleys. These in
their resistless march seawards, carrying along with them sheets of
detritus, disrupted the subjacent rocks, pounding them into clay and mud,
broadening and deepening the valley. They increased in strength until a
point of maximum pressure was reached, where necessarily the power of
erosion would be greatest; and so we find the greatest depth in the fiord
much nearer the eastern termination at a point where the shadows of the
hills still darken the surface, shoaling gradually in its progress
westward until, as the loch debouches on to the general coast-line, the
lip of the submarine basin appears as a submerged reef or chain of bare
skerries. Loch Etive or Loch Craignish are types of such a fiord. At
Connel Ferry, the western end of the former, we find the waters at low
tide pouring in a surging cascade over the edge of a submarine cliff, so
that a rise of a few feet in the level! of the coast would convert that
splendid sheet of water into a fresh-water lake.
Fiord and glen then are the
product of the glacier, and on the hillsides we can trace the mark of its
burin, we can tell by the ice scratches the direction of its flow, while
the grass-covered moraines, and the tenacious clay which beds the fiords,
are further proofs of its once mighty presence.
The Netherlorn country
partakes in an eminent degree of this admixture of sea and landscape. It
stretches from the foot of mighty Cruachan to the western seas, a broad
plateau of land - attaining in Beinn-a-Chapull a height of 1,700 feet, but
seldom exceeding 1,000 - intersected by ravines and glens, leaving broad
ridges of moorland which are continued into the sea in tongue-like
promontories or nesses. But while the country lacks the Alpine character
of many parts of the Highlands, it gains, in the archipelago of emerald
islands which fringe its coasts, a peculiar beauty. Islands,
"Confusedly hurled, The fragments of an
earlier world," varying in size
from to square miles downwards, are scattered in profusion all over this
part of the Firth of Lorn. Bounding the whole on the south-west, the huge
truncated cone of Scarba, seldom without its hood of misty vapour, storms
the clouds; while further north, on the fringe of the sea, the grassy
slopes of the Holy Islands appear in isolated beauty, guarding the
entrance of the Firth of Lorn, the confines of the district in this
direction.
The western and
north-western aspect of these shores, exposed to the fury of the gales and
breakers, is generally rocky and precipitous; in many places the
precipices descending sheer into the sea, in others the crag line
retreating a hundred yards or so, leaving long stretches of flat raised
beach between it and the present shore. These raised beaches belong to the
"twenty-five feet" series, and are a prominent feature of the coast. Along
the sides of a defile or "bealach" landslips frequently lay bare the
strata and expose traces of a still higher beach, covered with water-worn
boulders, and strewn with the shells of the common limpet and other
existing species of mollusc.
From these heights the land
slopes eastward to the shores of the sea lochs and straits. The
declivities are dotted with farm homesteads, while tracts of brilliant
green pasture interspersed with thickets of broom and furze pass downwards
to the shore, where the absence of heavy seas allows a fringe of turf with
a dense coating of stunted grass to maintain a position well below
high-water mark. The heads of the promontories are coated with thick
coppices of hazel, and the steeper sides towards the heads of the inlets
are thickly covered with a natural growth of ash, rowan, thorn, oak, and
other indigenous trees. In some of the more inland lochs the scenery is
still further varied by the numerous plantations of spruce, fir, and
larch, stretching over the lower hummocky hills, along the dark ravines,
and high up the acclivities.
The insulous and indented
nature of the country is well seen if we ascend one of the higher hills of
the island of Seil. Gazing southwards it is possible to determine no less
than thirty-two isolated patches of sea. To the stranger it appears a
country abounding in fresh-water lakes and tarns; and it is difficult to
dispel the illusion, the scene being so devoid of evidences which indicate
the proximity of the ocean.
This intricacy of parts-the
juxtaposition of mainland, promontory, and island, with their diversified
covering, the varied expanses of land-locked ocean, and the sinuosity of
the narrow channels which connect these, often in the most unexpected way
- creates a series of land and seascapes of romantic arid unrivalled
beauty. On a summer day when the waters are still; when the vista of
shimmering islands appears stretching away into infinitude, their green
colouring fading into the grey mist of the distance; when the steep wooded
precipices of the mainland are reflected on a mirror of pellucid azure - a
diaphane of crag, copse, and fleecy cloud - we view a scene of that
subdued grandeur which arises from the contemplation of the uncertain and
infinite; a scene which, as it has nothing of the awesome monotony of
mountain scenery, has nothing of the commonplace of the plains. It is
scenery which causes the soul to long for deeper contemplation, which we
gaze upon with delight, from which we are unwilling to depart. |
