Creation of Loch Ness and the Great Glen Fault Line

Loch Ness and the Great Glen owe their existence to a shattering fissure in the earth’s crust that occurred many millions of years ago; perhaps 380 million years ago. This fault line, which clearly divides Scotland, stretches almost from the Shetland Isles down the North Sea, through the Great Glen and Loch Ness and into the Atlantic.

There is still controversy amongst geologist as to how this displacement took place. In 1946 W.Q. Kennedy proposed that the Great Glen Fault Line was the result of lateral movement (or strike slip). As evidence for this he pointed out the straightness of the fault, the shattered rocks on both sides and to the similarity between the granite at Foyers and Strontian. From this he suggested that there was a displacement of over 60 miles (97k) - this being the distance between Foyers and Strontian..

At the time of the fracture Loch Ness was filled with broken stones; there was no lake here. However during numerous Ice Age periods glaciers pushed the broken stones towards Inverness and Loch Ness filled with water. Loch Ness is in fact a very large example of a ‘glacier trough’. The true magnitude of the loch’s depth is not realisable because of glacial infilling.

It is also believed, with good reason, that Loch Ness was in former times a salt water lake. However alluvial deposits of sand and gravel left by glaciers eventually blocked up the Inverness end of the lake and now Loch Ness is a fresh water lake. In 1893 a three hundred foot (91m) bore hole was made in the Ness valley. It passed through fluvioglacial deposit without hitting bedrock. This would appear to indicate that the Loch Ness basin continues into the Beauly Firth.

Ice Age - Raised Beaches, Eskers, Kames and Gorges

During the last Ice Age, which ended about 10,000 years ago, this area was covered by an ice-field of up to 5000 feet (1524m) depth. Glaciers moved generally in a north easterly direction towards the sea crushing rocks and creating valleys on their way there. The heavy ice also depressed the land mass allowing, it is believed, the sea to flow back into Loch Ness. As the ice retreated the land started to rise again creating raised beaches along Loch Ness. Fine examples of raised beaches (or isostatic rebounds) are clearly visible at Drumnadrochit and on the directly opposite southern shore.

The erosive power of glacier melt water was also responsible for cutting out large gorges at Inverfarigaig and Foyers.

Further indications of glacial action is unmistakable between Dochgarroch and Inverness where  esker ridges, kettle holes and kame terraces are evident; culminating in the 200 feet (61m) eskers of Torvean and Tomnahurich.

Geology, Geomorphology and Topography.

This is a geologically complex area. However the major landscape characteristics that we see today were fashioned principally by water erosion during the last 60 to 100 million years and by recent glacial activity.

Rock-Ness

Moine Schist – mainly found on north side of Loch Ness, A82.

A little way south west of Inverness at about Loch Dochfour, following the A82 on the north side of Loch Ness, the rock composition is mainly Moinian. This rock has a complicated metamorphic history stretching back some 820 to 1200 million years. During that period massive pressure from the earth’s crust caused localised melting which resulted in the heated (i.e. metamorphic) crystalline rock of today. It is not a fossil bearing rock as any fossils that it may have contained in the past have been altered or destroyed by the massive heat and pressure that it underwent.

Red Sandstone – mainly found in Inverness and on the south side of Loch Ness.  

On the B852, Inverness to Foyers road, the rock that we see is principally composed of Middle Old Red Sandstone – (Devonian 350 – 400 million years). At Drumnadrochit, following the northern shoreline of the loch, the rock composition changes from Monian to  red sandstone - a few miles further west the rocks revert back once again to Moinian.

Mealfuarvonie, a distinctive pudding bowl shaped hill adjacent to Urquhart Castle, was in the beginning formed in the basin valley. However geological faults thrust it up and it is now one of the highest old red sandstone conglomerate outcrops in Britain.

Granite masses of Abriachan (A82), Foyers (B852) and Moy (A9).

About 400 million years ago additional mountain building resulted in the granite masses that outcrop at Abriachan (A82), Foyers (B852) and Moy (A9).

Sandstone and Shale - Inverness

It is believed that there was a gradual downward flexing of crustal rocks around the Moray, Beauly and Dornoch Firths. Extensive accumulations of eroded sandstone and shale were carried and deposited there by the forces of nature.
It is estimated that about 20 million years ago, for example, over 20,000 feet (6095m) of Moinian schists were stripped from the Foyers upland and eventually put down in the Inverness/Nairn area.

Wilder-Ness Flora

Trees

In the past much of the Highlands was covered in trees. However alterations in climate, burning, cutting and grazing has denuded much of the area. Listed below is a list of some of the principal trees that you will come across today.

Hybrid Larch, Norway and Sitka Spruce.

The coniferous forest plantations that can be seen on the hillsides running parallel to Loch Ness are mainly composed of Hybrid Larch, Norway and Sitka Spruce.

The Hybrid Larch came about by a chance cross-pollination of Japanese and European Larch. This hybrid survives well under poor conditions and changes colour in autumn.

Sitka Spruce (originating from Alaska) has now almost completely replaced the Norway Spruce (the Christmas tree) because of its higher yield.

Scots Pine.

The Scots Pine is Britain’s only coniferous native tree and once grew extensively throughout our ancient and long gone Caledonian Pine Forests. It arrived here some 6000 years ago but, for various reasons - such as burning or intensive grazing - only two percent of our original extensive Scots Pines forest, which is estimated to have covered 75% of the Highlands, now remains.  It is a rugged tree being able to thrive in poor soils. In the past it was used for ships masts etc. Turpentine, resin, tar and charcoal were also extracted from this venerable conifer. This tree can be seen growing on isolated patches around Loch Ness.

Along the shore line and hillsides of Loch Ness can also be found some of our other trees, for example:-

Willow	Used extensively throughout the Highlands for wickerwork i.e. baskets.
Hazel	An excellent coppice tree, the hazel nut is on the squirrels menu.
Oak	A tree sacred to the Druids, used for ship building, houses, furniture, tanning leather and for smoking food.
Ash	Its wood is a natural shock absorber and is used for tool handles, rackets, hockey sticks and for flooring.
Silver Birch	This tree was one of the first trees to colonise the area 8000 years ago; after the end of the ice age 10000 years ago.
Rowan	Can be found growing higher up the mountains than any other indigenous tree. Often found next to houses to ward off witches.
Sycamore	Introduced from France in the Middle Ages.
Wild Cherry	Fast growing, used for fine furniture, musical instruments, veneers etc.
Juniper	This tree is found in areas of low snowfall. Being an evergreen it cannot survive entombment under snow for long periods
Alder	Normally found in boggy ground, for example in Urquhart Bay.
Holly	Its fruit is of substantial importance to wildlife
Yew	This is a primitive form of conifer and one of the oldest living trees in Europe. It can often be found growing in churchyards.
Aspen	Its Latin name is ‘Populus tremula’ on account of its leaves trembling even in a light wind.

Other Bushes and Plants

The geology of an area influences the type of plants that can be found growing. The principle rocks in this area, for example, are mainly Devonian conglomerates, sandstones and acidic Moine schist. The town of Inverness sits on glacial deposits. Other factors also affect the type of plants that flourish such as human activity, weather and height above sea level.

Lowland

The lowland area around Inverness and Ness valley is farmed extensively. The hills around Loch Ness rise so steeply from the waterside that there is almost no lowland area other than small areas at Drumnadrochit and Foyers. Wild Hyacinth and Bluebells carpet the road sides and canal banks as do the magnificently conspicuous yellow of the Whin (Gorse) and Broom. The Whin was planted on the banks of the canal at the time of its construction to help stabilise it. Weld grows on Torvean next to the canal and Wall Lettuce and Jack-by-the-hedge can be seen on the canal banks. Growing on the shingle beach at Aldourie, Loch Ness, is sea campion, enchanter’s –nightshade and herb-Robert.

Woodland Undergrowth

Conifer Plantations

Other than paths and ditches the shaded nature of our conifer plantations results in the virtual absence of ground flora.

Open Pine Woods and Ravines

Depending on the nature of the soil and other factors the following are examples of the vegetation that can be found in our open pine woods or ravines - such as the Falls of Foyers and Inverfarigaig by Loch Ness–
bracken, ferns, mosses, lichens, ling, wood sage, blaeberry, bugle, wood sorrel, orchid, primrose, violets, ramsons, saxifrage, wood cranesbill, grass-of-parnassus, common and intermediate wintergreens, chickweed wintergreens, sanicle, white garlic. At the Falls of Foyers there can be seen Rose-root, Yellow Mountain Saxifrage, Mossy Saxifrage and Golden Saxifrage.

Hill and Moorland

Much of the Loch Ness area lies between 500 and 2500 feet (150m to 760m). Travelling along the higher roads in July the reddish shades of Bell-heather are conspicuous and are replaced in August by glorious swathes of purple coming from the flowering Ling heather. In March the Purple Saxifrage flowers here; to be followed by the Yellow Mountain Saxifrage and Mossy Saxifrage. On Mealfuarvonie can be found the Greater, Lesser Butterfly Orchids and the Frog Orchid. Purple Saxifrage, Alpine Cinquefoil, Alpine Saussurea, Scottish Asphodel and Holy Fern can also be seen growing on the hillside. We have three types of insectivorous plants; these being Bladderwort, Butterwort and Sundew.

Wilder-Ness Fauna

Birds

We have a rich and diverse bird population here in the Inverness area and throughout the Highlands. Some can only be found in mountain and moorland areas, whilst others are associated mainly with coniferous forests, broad-leafed woodland, fresh water or coastal areas.

I have omitted coastal bird habitats from this text and the following is only a small sample of the birds that are resident or breed in the neighbourhood of Inverness.

Eagle	Rarely, high above Loch Ness and on passage through.
Buzzard	Frequently above Urquhart Castle, A82 road, and Torvean (near Inverness).
Red Kite	Frequently seen on Dunain straight, A82(near Inverness).
Osprey	Spring and summer at Loch Dochfour and Loch Ness
Peregrine	Uplands of Blackfold to Abriachan, by Loch Ness.
Hen Harrier	Uplands of Blackfold to Abriachan, by Loch Ness.
Black Grouse	Can be seen at Corriemony, RSPB nature reserve, Glen Urquhart.
Heron	Often seen fishing on the River Ness at Dochfour weir.
Cormorants	Swimming and fishing on Loch Ness.
Mute Swan	Breeds on the shore line of Loch Ness.
Whooper Swan	Winter visitor, recorded at Drumnadrochit.
Sand Piper	Breeds on the shores of Loch Ness and River Ness.
Dipper	Found on the River Ness and other rivers flowing into Loch Ness.
Grey Wagtail	Feeding on the shores of Loch Ness and River Ness.
Pied Wagtail	Feeding on the shores of Loch Ness.
Kingfisher	Fishing on the River Ness and occasionally on other rivers.
Crossbill	Conifer Plantations in Abriachan, Balmacaan woods, Drumnadrochit.
Blackcap	Regular breeders, spring, at Whin Park, Inverness, Balmacaan woods, Drumnadrochit.
Whitethroat	Regular breeders, spring, at Whin Park, Inverness
Garden Warbler	Regular breeders, spring, at Whin Park, Inverness
Sedge Warbler	Regular breeders, spring, at Whin Park, Inverness
Willow Warbler	Path from Clansman hotel to Balchraggan, Loch Ness.
Treecreeper	Balmacaan woods, Drumnadrochit.
Chiffchaff	Balmacaan woods, Drumnadrochit.
Great Spotted Woodpecker	Woodland at Clansman hotel
Goosander	River Ness and Loch Ness, nests locally.
Merganser	River Ness and Loch Ness
Goldeneye	Loch Dochfour in winter.
Common Sandpiper	River Ness and other nearby rivers.
Dipper	River Ness and other nearby rivers.
Swift	In summer swooping around Loch Ness and Loch Dochfour
Swallow	In summer swooping around Loch Ness and Loch Dochfour
Sand Martin	In summer swooping around Loch Ness and Loch Dochfour
House Martin	Seen throughout the area in summer; often nesting under the eaves of the Clansman Hotel.
Tufted Duck	Loch Dochfour.
Mallard	Common throughout the area.
Redstart	Abriachan in spring and summer
Crested Tits	Abriachan, all year.
Ring-necked Pheasant	Dochgarroch area, not native, bread for sport.
Slavonian Grebe	These birds only nest in Britain within a radius of 40 miles from Loch Ruthven, by Inverness; where there is an RSPB nature reserve. Sadly in recent years the number of pairs have dwindled from 70 down to 29 in 2008, the lowest since records began in 1971. BBC ‘Springwatch’ filmed at Loch Ruthven in 2008.
Minnesota Blueback   Pheasant	Dochgarroch area, not native, bread for sport.

Inverness has two thriving ornithological societies - Scottish Ornithological Society (SOC) and the RSPB. Both of these excellent societies hold monthly talks and outings between autumn and spring and extend a cordial welcome to new members and visitors.

Butterflies

A new ‘Atlas of Butterflies in Highland and Moray’ was published in 2008 by members of the Highland Branch of Butterfly Conservation Scotland and the Highland Biological Recording Group. This atlas replaces an earlier one printed in 1998. There have been a number of changes recorded since then particularly noticeable is the spread of the Orange-tip, Ringlet and Speckled Wood. Perhaps the most strikingly obvious newcomer is the arrival of the colourful Peacock butterfly since 2002. The following is a list of butterflies that you may see in this area.

Green Hairstreak	May and June, widespread.
Scotch Argus	Mainly confined to Scotland it is widespread in the Highlands
Meadow Brown	June, July and August, common native species.
Peacock	Seen12 Sept 2008 at Clansman Harbour, this butterfly arrived from the continent in 2002 and is now hibernating here successfully.
Tortoiseshell	April to Sept - Sept 2008, Clansman Harbour
Red Admiral	June to October - common
Chequered Skipper	Rarely – May to June – mainly found in Lochaber area but has been seen near Drumnadrochit.
Large White	June to September, widespread.
Small White	May to September – common, gardens and river banks.
Green-veined White	May to August – common, damp areas near woodland
Orange Tip	Spread from the south, May, June, common, damp areas near woodland
Speckled Wood	Spread from the south.
Small Copper	May to September
Common Blue	June to August - widespread

There are many gaps in  distribution maps for animal and plant life in the Highlands. Often this is because the Highlands, though rich in wildlife, are thinly populated and hence poorly recorded. To try to remedy this the Highland Biological Recording Group (HBRG) was founded in 1986. They are delighted to receive records from residents and visitors alike for both the Highlands and  from outside their boundaries. This valuable information will be forwarded them to the appropriate centres. Their email address is as follows – info@hbrg.org.uk

Dragonflies and Damselflies

Loch Bran is one of the best locations in Britain for dragonflies and damselflies to breed. Approximately eleven species of these large insects can be found here. The golden ringed dragonfly is common around Inverness between June and September and is the largest dragonfly in Britain. The common hawker, the four-spotted chaser and the black darter are three other species of dragonflies that can be found. The large red damselfly and the common blue damselfly can also be seen.
Loch Bran is not only an important habitat for dragonflies and damselflies but also for plants and animals such as water lilies, rushes and char. Because of this the loch is a Site of Special Scientific Interest (SSSI) and is cared for by Scottish Natural Heritage (SNH).

Mammals

In the past there were giant Irish elk, great ox, lynx, brown bear, beavers, wild boar and wolves roaming our hills and forests. Attempts are currently being made to reintroduce beavers, boars and wolves back into the area but this has been met, understandably,  with considerable opposition particularly from the farming community and from those wishing to protect our freedom of access. The following is a list of the principal mammals currently living in this region. Many of these animals are timid and do not readily advertise their presence to the busy commuter or casual visitor.

Daubenton’s Bat	Can be seen flying just above the River Ness hunting for insects.
Pipistrelle Bat	The smallest but most widespread of our bats, occurring all round the Inverness area.
Long-eared Bat	The Inverness area is possibly its most northerly limit.
Rabbit	Ubiquitous, in 1956 myxomatosis reduced the rabbit population by 90%. This dramatic decline badly affected carnivorous animals such as the fox, wild cat, pine marten, stoat and weasel.
Brown Hare	Abundant in open ground up to 1000 feet (300m)
Mountain Hare	usually found in areas over 1000 feet (300m), slightly smaller than the brown hare and has shorter ears. It feeds on heather and in winter can change its coat from brown to white. They can be seen at the Slochd summit, just south of Inverness on the A9.
Red Squirrel	prevalent in the Inverness area mainly in coniferous forests but are also present in deciduous woods particularly if it contains Hazel; it is absent from Birch. Can be found in Inverness, Torvean and the Inverness/Foyers road where ropes bridges have been erected to allow safer passage for them across the road.
Fox	This nocturnal carnivorous animal predates lamb, poultry, rabbit, game, small mammals, birds and beetles.
Pine Marten	This is a woodland animal but has had to adapt to the disappearance of its natural habitat. It is related to the otter, badger, stoat, weasel and mink and is present over a wide area around Inverness.
Badger	This animal prefers sandy or gravely banks in which to burrow and can be found next to rivers and woodland. The Highland Council has provided underpasses to enable these animals to cross some of our roads safely.
Wild Cat	A genuine wild cat is considerably larger than a domestic cat, it fur is stripped and has a shorter bushier ringed tail with a black tip. It is a very shy nocturnal animal and frequently interbreeds with domestic cats.
Red Deer	This is our largest land animal and can be seen on open hillside and moorland. Progressive deforestation forced this woodland creature into open terrain causing it to become smaller over time.
Roe Deer	Frequent open woodlands and thickets, they are widely distributed throughout the Inverness and can be often seen grazing in fields around Dochgarroch.
Sika Deer	These animals were introduced to the south east side of Loch Ness at Aldourie in about 1900. They share the same birch and hazel habitat as Roe Deer. The sika deer and the red deer have the same annual breeding cycle and are interbreeding.
Otter	This is a secretive animal and seldom seen. They travel significant distances between rivers, the sea and loch. These animals are present on the River Ness and Loch Ness.
Common Seal	This animal swims up the River Ness chasing salmon and sea trout. They have been seen in Loch Ness at Urquhart castle.

Fish

The peat stained water of Loch Ness is poor in nutrients being classed as ‘oligotrophic’. It is therefore not rich in fish containing salmon, brown, ferox and sea trout, brook lamprey, pike, eel, three-spined stickleback, minnow and arctic char. The char is believed to be the first fish to colonise our lochs 8,000 to 10,000 years ago at the end of the last ice age. These fish rarely come to the surface to feed.

Climate

Inverness benefits from a generally agreeable climate and relatively mild winters. The average annual rainfall in Inverness is 25 inches (0.6m), at Fort Augustus it is 3 feet (1m) and at Fort William 6 ½  feet (2m).

It is interesting to note that for every 1000 feet (305m) that you climb in the Highlands there are equivalent alterations in temperature and vegetation that you would find by travelling 600 miles (965k) further north