Geological Guide

Geology and landscape around the Arctic Circle in Norway – Part II

GEOLOGICAL GUIDE

Saltfjellet

Between Svartisen and the Swedish border there is an extensive mountain area with varying scenery, ranging from barren mountains to fertile valleys. Saltfjellet lies furthest east. Here mountain plateau, broad valleys and rounded summits characterize the landscape which is developed in mainly granitic rocks. Further west, the height differences are accentuated and lofty mountain summits and narrow valleys prevail. The largest valleys, Saltdalen, Beiardalen, Bjøllådalen and Stormdalen extend in a mainly north-south direction and are aligned along the main structures of the bedrock which is here dominated by mica-schist and marble. The valleys usually follow marble belts and therefore have quite a luxurious and species-rich vegetation.

The bedrock on Saltfjellet is characterized by light-coloured granitic gneisses. The main minerals are quartz, feldspar and a little mica. A special type of gneiss., containing the aluminium-rich mineral kyanite, is also found among the rocks on Saltfjellet. The mineral topaz is also found in the same zone. There are few exposures along the road over Saltfjellet, but on the northern slope, through Lønsdalen, there are several outcrops of these rocks in road-cuts.

The great ice-sheet covering Scandinavia began slowly to release its grip on Saltfjellet a little over 9,000 years ago. The mountain tops were the first to become ice-free, and afterwards more and more of the mountain areas emerged as the glacier surface melted down and the ice-front retreated into the valleys. The ice mass was still enormous further east and extended to the Gulf. of Bothnia. Its highest part (ice divide) was far inside the Swedish border. The climate was quite warm at this time and melting proceeded relatively rapidly. Much melt water ran westwards from large areas as far as the ice divide.

The ice and melt water have left distinct traces on Saltfjellet and the trained eye can read the ice melt story almost like an open book in this forest-free, open terrain. In the final phase, the ice masses moved northwards through Lønsdalen and down towards Saltdalen. The ice surface sloped to the north and melt water, which ran along the ice edge, formed channels and flowed in this direction. When buried ice relics later melted there were many depressions ('dead ice hollows') on the land surface which today may be water-filled. Hills or ridges of sand and gravel are common in such a terrain and formed in cavities, joints or tunnels where the melt water sought passageways between the last ice remnants.

The view northwards through Lønsdalen towards Solvågtind and Båtfjellet (in the background to the right). In the foreground, forested sand terraces, formed between the mountain side and the glacier during melting of the inland ice 9,000 years ago, can be seen. Photo: Asbjørn Rune Aa.

Reconstruction of the melting of the inland ice in the area north of the Arctic Circle Center about 9,000 years ago (Figure on the next page). A: Only the highest summits are exposed above the ice. The ice movement and drainage of the melt water are northwards. B: The glacier has melted down further. Channels form in the moraine cover where the melt water follows the contact between the ice and valley sides to the north. The ice is only 100-200 m thick at Semska-Sørelva. C: The Lønsdal stage. The Semska-Sørelva area is now ice-free. The retreat of the ice is halted and from Junkerdalen in the northeast there is a slight advance of the ice to the north which dams up Lønsdalen. Marginal ice terraces, small marginal moraines and melt water channels form. Today these are 'casts' of the ice margin. The ice tongues to the south remain stable. The melt water carries much gravel, sand and silt into a glacier dammed lake between Semska and Sørelva. The water finds an outlet to the north, at the foot of Kjemåfjellet. D: The ice disappears from the mountain pass, but relics may still be present along Lønselva. Melt water from the south drains northwards until the water divide at Stødi becomes ice-free so that water from the southerly glacial tongue flows southwards to Dunderlandsdalen. In the north the ice dams up small glacial lakes at a lower level at Sørelva and Dypenåga. Here sand and silt terraces are formed between the ice and valley sides. The small frame shows the area shown on the map of the superficial deposits on page 36.

Locality 1 - The Arctic Circle Centre

The Centre is situated close to E6 on sand and gravel deposited by glacial rivers during the last ice age.l,700 million years old, underlie the superficial deposits and are their source, here two extremes of the geological time-scale meet old gneisses. All the rocks in the mountains near the Centre are Precambrian, but the superficial deposits here are younger than 100,000 years old.

On Nasafjellet, which lies southeast of the Arctic Circle Centre, one can see the basement on which the Caledonian mountain chain rests. Here, weathering and erosion have carved down through the stack of nappes forming a so-called window. Through and within this window one can see the rocks over which the nappe units of the Caledonian mountain chain have been transported. The rocks around the Arctic Circle Centre originally belonged to this basement, but were detached by the thrust processes and now form the lowermost nappe unit.

The Arctic Circle Centre is beautifully located in the mountainous terrain of Norway. View to the west towards Bolnatind.

Section through the upper part of the crust from the Arctic Circle Centre to the southeast towards the mountain area west of Krokstrand (to the left). The section shows how the rock units (nappes) are stacked up on each other by thrusting and subsequently folded, and how weathering and erosion have carved a "window" through them, so that the basement on which they rest is exposed at the present land surface.

Locality 2 - Offersteinan. A Lappish sacrifical site 2 km north of the Arctic Circle Centre

On Saltfjellet there are numerous so-called erratic blocks which were transported and deposited during the last ice age. Most are small and of local origin, but some are quite large. Some have been transpol1ed for long distances. As the ice melted and lost its capacity for transport, the blocks were left stranded. The largest of these are now prominent landmarks.

Locality 3 - Saltfjellet at Stødi-Semska

The 4 largest parking places (marked with P on the map) are located 8-16 kilometres north of the Arctic Circle Centre. A good view of the extensive superficial deposits can be obtained from all these places. The deposits are very thick and only occasionally can the bedrock be seen.

Old Lappish sacrificial site in the vicinity of three large erratic blocks at Stødi. The blocks are of the same rock as the bedrock on which they rest. They may however, have been transported many kilometres by the ice since this rock type is present many kilometres to the east and south-east.

Locality 4 - Semska

Large terraces are present on the valley floor east of the road. These were built up of gravel and sand carried by glacial melt water which flowed northwards during the Lønsdal stage (see fig. C, pages 31-32). The terraces terminate at the south end of a 10-20 m slope which is the 'cast' of the ice margin (ice contact-slope). The grave1 was transported to this place upon, within, or along the margin of the glacier and later washed forwards and deposited in terraces.

Locality 5 - Semska-Sørelva

Two large, north-south trending drumlins are present on this section, west of the road. They form marked ridges 20-40 m above their surroundings, and have a width of several 100 m. The largest is about 2 km long.

Superficial deposits and other traces of glaciation. Part of NGU's Quaternarygeological map Lønsdal 2128 III, scale 1:50,000 (each square on the map is 1 km2). The valley floor is covered by sand and gravel deposited during melting of the ice (orange), as terraces, ridges and hills. Fine grained glacial lake deposits (pale yellow) are also present. The valley sides and mountain plateau are characterized by thick till deposits which were earlier deposited under the sole of the inland ice (green). Elongate, streamlined ridges in the till surface (drumlins), reflect the direction of ice movement (black arrows). The whole area has numerous channels which are traces of melt water drainage 9,000 years ago (red symbols).

The gravel terraces on the valley floor were deposited about 9,000 years ago in front of a glacier tongue which dammed up the valley to the south (to the right). In the background, on the mountain side, some north-trending channels (towards the left) in which the water flowed at an early stage of the ice age melting can be seen. Photo: Harald Sveian.

The largest and most prominent drumlin on the Saltfjellet, located near Sørelva close to E6. This is an elongate, streamlined moraine ridge oriented parallel to the ice movement direction. Photo: Harald Sveian.

Linear melt water channels in the till cover can be seen in the easterly valley slope north of Semska, the mountain in the background. In the foreground, large melt water deposits of sand and gravel are present. These form pronounced hills and ridges with depressions in between. Photo: Harald Sveian.

Below Dypen-nasen glacial river deposits and a large melt water channel formed during the Lønsdal stage, c. 9,000 years ago. View eastwards from Sørelva road-maintenance station. Photo: Harald Sveian.

Section through one of the ice margin terraces formed in the glacier-dammed lake at Sørelva during the Lønsdal stage about 9,000 years ago. The glacial lake was almost filled up with clay and fine-grained sand arranged in horizontal layers. Photo: Harald Sveian.

Locality 6 - Sørelva and Dypen-nasen

From the E6 and the railway at Sørelva a good view can be obtained of the glacial margin deposits formed during the Lønsdal stage on the easterly valley slope beneath the Dypennasen mountain. Large gravel deposits were formed at the contact between the glacier and the mountain side. These, and a wide melt water channel show that Lønsdal, at this stage, was dammed up to the northeast by a glacial tongue from the inland ice. At this time the inland ice was still thick in Junkerdalen and in nearby Sweden.

Locality 7 - Parking area at Heimervatnet

The grey granitic gneisses are here exposed on the western side of the road. On the mountainside, east of the road, one can see the boundary between the old, light-coloured Precambrian gneisses and the rusty, black schists of presumed Cambrian age. There is a great time interval between the rusty schists and the gneiss, probably more than 1,000 million years. During these millions of years the old Precambrian landscape was worn down by weathering. On the worn down surface layers of clay were deposited. These later became argillaceous schist. The remains of animals and plants which lived in the sea at that time are now represented by black graphite in the schist. All the fossils have been destroyed during the folding and metamorphic (alteration) processes.

The boundary between "young" Cambrian schist and "old" Precambrian gneiss is readily visible in the mountain slope above the parking area at Heimervatn in Saltdal. At several places the rusty schist has given rise to fan-like rock avalanches which extended far down over the underlying gneiss. Photo: Svein Gjelle.

Locality 8 - Junkerdalsura

We follow state highway 77, from Storjord through Junkerdalen to the border with Sweden at Graddis. The first part of the road follows the narrow valley which the river, Junkerdalselva, has excavated before entering Saltdalen. Even the narrowest gully at the exit from Junkerdalen is clearly shaped by running water and almost certainly formed initially by melt water from the ice. We leave the Precambrian gneisses a kilometre from the E6, and enter the 1,000 million year younger rocks of the overlying nappe, the Junkerdalen nappe.

Once again we meet the Precambrian gneisses where Junkerdalen opens out towards the east and has the shape of a broad U-valley. The valley is here excavated by water and ice in schists along the nappe boundary which, generally speaking, follows the north side of the valley. Southwards, all the nappe rocks are worn down and the landscape is sculptured in hard, granitic rocks. Solvågtind lies on the north side of the valley with Junkerdalsura at its foot. It is known for its luxuriant plant life which includes several rare species. Arctic plants which have their southernmost extent here, are present in the surrounding high ground. Many heat-loving, southerly species also grow in this area. The lime-rich bedrock together with suitable local climate are important requirements for this. Plants in the blocky terrain ('ura') were protected by law as far back as 1928 and the area of protection has later been extended to encompass an area of 440 km2. Along the old track between Saltdalen and Junkerdalen a nature trail has been marked out and is well worth following. The trail begins at Storfjord, uppermost in Saltdalen.

View towards Ørfjellet (1,751 m) the highest summit on Saltfjellet from the parking place on the Junkerdalen road. Ørfjellet consists of granitic basement gneisses. Storjord in Saltdal can be seen down to the right in the picture. The Nordland National Park Centre is located here. Photo: Terje H. Bargel.

Junkerdalsura lies in the steep valley slope on the northern side of Junkerdalselva, at the foot of Solvågstind. Photo: Terje H. Bargel.

Solvågtind (1,559 m) is one of the most beautiful and characteristic peaks in the area. It was most likely formed by ice polishing its slopes during several, prolonged ice ages. This is how it looks from the east, from the road through Junkerdalen. Photo: Terje H. Bargel.

Tjårrisdalen lies on the north side of Junkerdalen and is a typical V-shaped valley. It is for the most part excavated by running water. The ice movement has largely been across this valley so that the ice has not excavated downwards significantly. Photo: Terje H. Bargel.

Locality 9 - Turn off 2.7 kilometres east of junkerdalen Tourist Centre

In road-cuts here one can see a lava rock (rhyolite porphyry) of Precambrian age. This is a light- coloured, grey, finegrained rock with millimetre-sized mineral grains, so-called phenocrysts, of feldspar and quartz. The phenocrysts are best seen on weathered surfaces. It is more difficult to see them on fresh rock surfaces, for the inexperienced eye. At the roadside, however, there are many loose stones in which the phenocrysts can easily be seen. This is a volcanic rock, a lava, which has been altered. On the opposite side of Junkerdalselva we can see Cambrian black schists which were deposited on the Precambrian rocks about 1,000 million years after the lava was formed.

Locality 10 - Parking place 3.6 kilometres east of Junkerdal Tourist Centre

A kilometre further up the valley, the border between the Precambrian gneisses and the black Cambrian schists crosses the road. Here, one can, in a single step, span 1,000 million years of geological history. At the contact between the two rocks there is a thin quartzite which is exposed on the south side of the road. It is an altered sedimentary. rock which consists almost entirely of quartz. The contact follows the little hollow up and southeastwards on the south side of the road.

In that part of the rhyolite porphyry which lies just under the quartzite one can see deformation structures which are probably related to thrusting of the nappes. One can also see cracks filled with quartz. The rusty, graphite-bearing schists have acted as an excellent lubricant during thrusting of the nappes.

The geological processes are still active. The yellowish coating, which can be seen on the rusty schists at many places, consists of small crystals of gypsum which have crystallized out after the road-cut was made.

Scetch of the contact relations between Precambrian rhyolite porphyry and Cambrian schist and quartzite at locality 7 in Junkerdalen.

Locality 11 - Turn-off about 1.5 kilometres from the Swedish border

We continue towards the Swedish border. After driving about 5 km through rusty schists similar to those we saw at the last stop, we enter a pale grey, fine-grained gneiss which lies in the lowermost part of the overlying nappe. This is a gneiss considered to be similar in origin to the rhyolite porphyry at the previous parking place, but here it is torn from its original substrate and forms the sole of the overlying thrust sheet.

Saltdalen

Saltdalen was a fjord at the end of the last ice age. At Storfjord we descend to about 120 m above present-day sea-level which is the level where the highest shore line lay about 9,000 years ago. All the superficial deposits downwards in the valley were deposited in the old ice-age fjord. They constitute the main basis for plant. arid animal life today, the prerequisites for agriculture and settlement. When the fjord extended as far as Storjord a large glacial river deposited sand and gravel where it met the sea. At the end of the ice-age the uppermost part of the large gravel heath was also deltaic at the beach margin. Finegrained material was deposited in quiet water further out in the old fjord and formed thick layers of silt and clay. As the land rose, the floor of the fjord gradually became dry land and the river eroded down in the sediments, thereby altering the landscape. The old fjord bottom was then leveled off. On top of the clay deposits the river formed sand terraces and plains at many levels. Today it is hardly possible to see clay at the surface in Saltdalen.

Section at the roadside at Graddis showing Precambrian rhyolite porphyry which is thrust over younger quartzite and graphitic schist.

Locality 12 - Storjord

A nature walk, with some geological information, starts from the National Parc Centre. A sign has been erected at a dead-ice hollow in the glacial river deposit. A sign-posted path shows the way to a pot-hole high up on the valley slope at the entrance to Junkerdalsura. This feature is carved in the rock by swirling melt water. Storjord is the starting point for the area of plant conservation in the Junkerdalsura.

The entrance to the Nordland National Park Centre at Storjord. Photo: Terje H. Bargel.

Some glimpses inside the Nordland National Park Centre at Storjord. Photo: Terje H. Bargel.

The first 10 km northwards from Storjord pass through Precambrian gneisses, but just northeast of the road we find the contact with the schists. In the valley slope, just above the rusty and graphite-bearing schists, lies the contact with the far-transported Seve-Køli nappe complex. This is the same nappe complex which we only just entered close to the Swedish border. In the slope on the west side of the valley at Bleiknes, about 10 km from Storjord, we can see a railway tunnel. Here the nappe boundary crosses the valley and continues up the slope on the west side. From about here, and northwards, Saltdal is developed along a major zone of marble, whilst the upper part of the valley is the same as in Junkerdalen, i.e. the valley is excavated along the nappe boundary between granitic rocks to the southwest and an overlying nappe of mica-schist and marble to the northeast.

A big glacial river deposit, now flat, pine-clad heath lands forms the valley floor at Storjord. This was the innermost embayment of the former Saltdalsfjord c. 9,000 years ago. Photo: Harald Sveian.

The state highway 812 from Saltdalen to Saltstraumen

The first 13 km of state highway 812 westwards from Medby in Saltdal to Ljøsnehammaren are dominated by marble of different types, but in the most westerly part there is also much limebearing mica schist. The lime-rich rocks give rise to a luxurious vegetation. At several places, in road-cuts, we can observe weathering of the rock to a depth of several metres.

Here the rocks are so crumbly that they can be dug out by hand.

Locality 13 - Ice-marginal moraine ridge at Trollhaugan

On the mountain section, 6-7 km from Medby, the road cuts through a 10 m high ridge of sandy moraine. A number of large blocks of rock, transported many kilometres, are present in the ridge itself. These, together with other material in the ridge, were deposited in front of the ice when it 1ay here shortly before 9,000 years ago. The marginal moraine is part of an ice-marginal zone which can be followed for long distances both northwards and southwards from the road-cut. At this time Saltdal was filled by a valley glacier, the front of which lay at the mouth of the valley at Rognan.

Locality 14 - Ljøsnehammarseter

View southwards to the quarry in colour-banded marble. The marble is strongly folded with pink, yellow, white and grey bands. Attempts have been made to utilize it for, among . other things, decorative tiles. Green fields on the hillside at Ljøsnehammer farm testify to the abundant growth of grass. The basis for mountain farming is the lime-rich mica-schist which weathers easily and provides good nutritious soil.

The road from Ljøsnehammar to Misvær passes through different types of mica-schist with intrusive bodies of granite and gabbro. In the floor of the Misvær valley there are large heath-like areas of sand and gravel which were deposited by melt-water from the ice during the melting period about 9,500 years ago.

Beiarn

Five to six km west of Løsnehammarseter a road branches off westwards to Beiarn. From the mountain pass there is a fine view of Beiardalen. Here, where the road descends, the valley turns sharply westwards and opens out a little in its continuation down to Beiarfjord. The lowermost part of the valley is clearly shaped by glaciers which moved along it in time past. The upper part is narrow, straight and about 30 km long. It is oriented southwesterly along the strike of the rocks. This part of the valley is developed along a limestone zone and follows both the strike and joint directions of the bedrock. It is one of the most clearly defined, strike-determined valleys in Nordland. In Beiarn there are a number of limestone caves.

The lowermost part of Beiardalen with the high coastal mountains in the background. View to the west. To the left is Høgtinden (1,405 m) made up of granite 430 million years old, and the youngest known rock in the area. Beiarfjorden extended up this part of the valley during deglaciation 9,500 years ago, and all buildings and cultivated ground are now located on sediments (clay) deposited on the floor of the fjord and river terraces (sand) of younger age.

Locality 15 - Misvær

A marginal ice delta lies in front of the entrance to the valley. This was formed at the end of the last ice-age when the ice-front lay on the rocky threshold inland from Misvær. Melt water flowing from the glacier transported much sand and gravel to the ice-front and out in the fjord. A large delta accumulated up to the prevailing sea level. This was then 116 m above present day sea level. Later, during land uplift, the river gradually dug down and removed large parts of the deposit. Lower river terraces mark different stages in the development of the valley floor. In the gravel pit west of Misvær one can see alternating layers of sand and gravel which are inclined northwards towards the fjord. In one of these layers shells are found and when dated by the radiocarbon method give an age of about 9,500 years.

Large bodies of intrusive rocks, mostly granitic, are present along the west shore of Misvær fjord. From Skjerstadfjorden towards Saltstraumen there is a broad belt of mica-schist and mica-rich gneisses.

Locality 16 - Støvset bridge, Misvær

A sculpture in white granite, forming apart of Sculpture Landscape Nordland, has been raised at the turn-off to Skjerstad. The road-cut on the south part of Sandøya consists mainly of black gabbro. This rock is intersected by dykes of both dark, fine-grained diabase and thin, white granite veins. Langholmen, a low-lying island of superficial deposits, lies close to Sandøya. This is a small ice-marginal deposit, formed when the ice-front was retreating in the fjord, and for a time stranded here on this distinct threshold.

Continuing on the road towards Saltstraumen, there is a view towards the entrance to Misvær fjord where marginal moraines lie on both sides of the fjord. Skjerstad church lies on a morainic ridge which is partly covered by marine clay and beach sand. Beneath these deposits is a distinct ridge of bedrock which almost closes the fjord entrance. This rocky threshold explains why the glacier front hung over Misvær fjord just here.

Locality 17 - The Tuv area

The bedrock in the whole of this area consists largely of grey, calcitic marb1e and white, granitic veins. From the road in the Tuv area, on Knapplundsøya to the north large granitic veins intruding the marble layers are very conspicuous. The veins are easily distinguished on account on their light colour and sparse vegetation.

Locality 18 - Saltstraumen

The strong Maelstrom is due to the fact that during the ebb and flow of the tide, the sea has to pass a narrow, rocky threshold between Saltfjorden and Skjerstadfjorden. The flow is strongest at times of full and new moon when the difference of sea level between high and low tide is greatest.

The bedrock in the area is, as at the previous locality, distinguished by calcitic marble with layers of mica-schist and cross-cutting, white granitic veins.

The 1,100 m high Børvasstindan, mainly made up of mica-rich gneisses, towers to the south of Saltstraumen.

Saltstraumen. The tide is on its way out northwards towards Saltfjorden. Photo: Terje H. Bargel.

Saltstraumen seen westwards from the bridge. The area is surrounded by fertile, undulating landscape (background). Photo: Terje H. Bargel.

The coastal road (state highway 17) from Saltstraumen to Holandsfjorden

In terms of bedrock geology this section is characterized by alternations between basement areas consisting mainly of granitic gneisses of Precambrian age and younger, mainly altered sedimentary rocks such as mica-schist, micaceous gneisses and calcitic marble. Locally, in areas with sedimentary rocks, there are intrusions of gabbro, diorite and granite. The bedrock occurs in large, dome-like areas and is folded together with the younger rocks. It lies mainly under the altered sedimentary rocks and emerges from these as 'windows'. It is probable that the granitic gneisses are continuous between the windows, under the sedimentary rocks. They have taken part in the Caledonian folding, but it is un-certain if they have also been thrust.

The coastal landscape along this route is distinguished by deep fjords and high mountains. The coastal road runs only slightly above sea level for most of the way and most of the road-section between Saltstraumen and Nesna passes through areas which were part of the sea-floor less than 10,000 years ago.

The islands along the coast can be seen from several places along the road. The strandflat forms the large, flat areas on, and around the islands. This landform is characteristic for the district. Morainic ridges, raised beaches and other landforms from the melting period of the inland ice, 10,000-12,000 years ago, are numerous along this section. There are also views towards the western part of Svartisen.

The section from Saltstraumen to Skauvoll (50 km) passes through an area in which the bedrock is characterized by lime-rich rocks (calcitic marble and dolomitic marble) invaded by numerous veins of granite. A quarry in dolomite is located close to the road at Ertenvåg, 20 km from Saltstraumen. At Kjøpstad there is a branch road and bridge to Sandhornøya. At Marnes (Sandhornøya) there is a quarry in quartzite from which quartz is produced for the ferrosilicon industry at Salten Verk. At Holmsundfjord the road passes through a massif of intrusive rocks, in part porphyritic granites.

Deep section showing the main features of the structure of the bedrock along the coast. Sedimentary rocks are thrust over a basement substrate of granitic rocks and both the nappe rocks and basement rocks are folded together. Windows are eroded through the nappe rocks at many places so that the basement appears at the surface. It is not known what lies under the basement gneisses.

Locality 19 - Skauvoll

Parking at the kiosk at the road junction (state highway 17/turn-off to Sund in Gildeskål). 250 m along highway 17, strongly folded micaceous gneiss with thin layers of greyish white calcitic marble can be seen in road-cuts. The marble contains a few large calcite crystals. The micaceous gneiss contains, in some places, needle-shaped blue crystals of kyanite up to 5 cm in length, and dark red garnets. Some layers consist almost entirely of garnet crystals. A few pale quartz veins with black tourmaline crystals occur in the gneiss.

Furthest north in the road-cut, about 400 m from the road junction a dark diorite is present. This is an igneous rock which has intruded the gneiss.

Slightly over 10,000 years ago a glacier tongue from the inland ice hung over the mountain area to the east and just reached the fjord at Skauvoll. The sea level at that time reached about 95 m above present day sea level. Dating of shells from the clay, deposited near the ice margin, indicates that the inland ice calved in the fjord outside Skauvoll more than 11,700 years ago.

Between the tunnel above Skauvoll and the road junction, the road cuts through fans of scree which lie on the mountain side to the east. This material probably avalanched from the mountain side just after the inland ice retreated, about 10,000 years ago.

Inndyr

From Skauvoll state highway 838 branches off northwards to Sund. The road passes through Inndyr, the centre of Gildeskål municipality. The rocks on this peninsula consist of mica schist, quartzite and marble. In the Inndyr area the rocks are mainly calcitic marbles. In older times they were much utilized for building purposes. Gildeskål church, which dates from 1130 AD, is built of this rock. The vegetation at Inndyr clearly shows the presence of lime-rich bedrock, several species of orchid being present.

Scetch-map with ice margins from the A-, B- and C-phases in a part of the coastal area north of the Arctic Circle. The age of these phases is shown in years before the present day.

Locality 20 - Oterstranda

The large Laksådalsvatnet was also a fjord arm 11,700 years ago. The shore line at that time is cut into the moraine cover on the south and west sides of the lake and in bedrock to the northwest. The beach now lies about 90 m above sea level. It is cut by a marginal moraine southwest of Laksådalsvatnet. The morainic ridge was deposited in front of a cirque moraine late in Younger Dryas time, over 10,000 years ago.

The fact that the shore line is intersected means that most of it was formed before the cirque glacier advanced and deposited its till.

From the old road, at the top of Storvikskardet, there is a fine view towards the shipping channel and the Norwegian Sea to the west. (This concerns the road as it is in 1994. From 1995 it will be tunneled from Oterstrand to Storvika, but plans exist to keep the old road open during the summer).

Locality 21 - Storvika

West of Storvikskardet lies Storvika with its large sand deposits. These are specially noticeable in a zone above the present day beach and also upwards in the terrain where they are several metres thick. The bay is open towards the sea from the west, and here westerly winds have been able to rearrange the sand either directly or by wave action. Storvikbukta is shallow and the superficial sediments on land are assumed to continue on the sea-floor, out into the bay. Much of this material was probably deposited at the glacial margin 12,300 years ago. At that time the edge of

66 the inland ice lay over this area. The subsequent land uplift, with strong wave-washing and redeposition, makes it impossible to reconstruct the form of the original deposits exactly.

The very large stone blocks which are present down towards the beach zone around the boundary between Gildeskål and Meløy have probably avalanched from the mountain side a short time after the inland ice melted and perhaps particularly in Younger Dryas time. Only a few of these are thought to be from younger periods and most of the younger blocks probably avalanched in particularly cold periods, as for example, in the 'little ice age' (1400-1900 AD).

Locality 22.-.Skogreina

Parking near road-junction (state highway 17/side road to Kunna). Glacial margin deposit (terminal moraine) with gravel pit on the seaward side of the branch road. The upper parts of the deposit were laid down in front of a glacier tongue extending from the valley to the southeast

67 during ice melting, probably at least 12,300 years ago (see map page 65). This deposit rests on sediments which were washed out into the fjord when the area was previously ice-free, 38,000 years ago. At the very top, there is a young beach deposit formed 4,000-5,000 years ago.

Locality 23.-.Reipå-Markavatnet

The side road to Markavatnet from state highway 17 at Reipå. From the melting of the ice up to about 7,000 years before the present day, the whole of this valley was a shallow arm of the fjord. About 2 km from Reipå there is a view of a terminal moraine deposited in front of a cirque glacier on the south side of the valley, about 10,700 years ago.

The morainic ridge dams up a small lake 71 m above sea level, southwest of Markavatnet. On the north side of Markavatnet the 10,500 years old main shore line indents the morainic cover almost 90 m above the present day sea level.

Location of the ice front in the Reipå-Ørnes-Glomfjord area during the deglaciation about 10,000 years ago. The marine limit is also shown on the map.

View towards Asmoen sports ground from turning-point on west side of Mosvolldalen. River excavation in the foreground. The uppermost houses in the background are located close to the marine limit, about 90 m above sea level.

Locality 24 - Torsvik

Turn-off, road to Torsvikskogen, about 2 km west of Ørnes. First road-cut on this road. The rock exposed here is a sagvandite, a rare igneous rock consisting of pyroxene and magnesite (magnesium carbonate). At Torsvik this rock is very coarsely crystalline and also contains a little olivine. The most striking features are rosettes, 5-10 cm across, of grey pyroxene crystals. Veins cutting the rock contain minerals such as anthophyllite, talc and chlorite.

Sketch of the stratigraphic sequence which can be seen in the river section in the foreground of the picture of Åsmoen. During the long period between deposition of layer C and layer B the inland ice advanced over the area and across the continental shelf before it retreated once again with the ice front high up in Mosvolldalen. Layer B was then deposited during a short-lived readvance of the ice during the following period of melting.

Locality 25 - Ørnes-Asmoen (Ørnes sports ground)

About 500-600 m northeast of Ørnes ferry-quay the main shore line is incised in bedrock about 90 m above sea level.

A side road to Mosvolldalen starts at the Esso petrol station at Ørnes. After about 1 km along this road there is a view of the sports ground which lies on a river terrace about 75 m above sea level. The uppermost (youngest) part of the river terrace, which is believed to be almost 10,000 years old, conceals superficial deposits from the ice age. At 2 m depth there is a 2.5 m thick layer of till (layer B) deposited about 12,300 years ago. The inland ice then advanced over the 0rnes area for the last time. The sea level 28,000 years ago was, for a period, at least 75 m above the present level. The area on the fjord-facing side at Asmoen was ice-free and shell-bearing gravel and sand (layer C) which now lie 4.5 m under the surface of the terrace, were washed out and deposited at

72 the mouth of the Mosvollelv of that time. The present day river has dug a channel through the moraine and 2 m down into the shell-bearing sediments beneath.

Ørnes -Vassdalsvik -Bjærangsfjorden -Forøy

Alternative route to the road from Ørnes to Forøy: Car-ferry Ørnes -Vassdalsvik (about 25 minutes), afterwards about 30 km driving to Forøy ferry-landing where state highway 17 continues southwards (see roadmap page 61).

Locality 26.-.Vassdalsvik

Vassdalsvik is situated on till deposited by the inland ice between 34,000 and 12,000 years before the present. A road leads to the uppermost farm (upper Vassdal) where the main shore line is distinct and cut into the moraine about 90 m above sea level. From here there is a good view towards the fjord landscape to the west and north.

Continuing to Forøy, the road passes through Engavågen where one can take a detour of almost 20 km to Grønøya and Åmøya (bridge connection).

Fjord landscape at the mouth of Glomfjorden, seen from Vassdal. The farm in the foreground, to the left in the picture, lies on flat terrain which extends up to the main shore line. This terrain was formed by washing and excavation by the sea in the morainic material more than 10,000 years ago. The highest farmhouses lie on a terminal moraine which dams up Vassdalsvatnet (114 m above sea-level). The terminal moraines were deposited in front of a cirque which was existing during Younger Dryas time (11,000-10,000 years before the present.

Locality 27 - Old mica mine on Grønøy

The bedrock in the northerly part of Grønøy consists of altered sedimentary rocks, mainly micaceous gneisses, with large bodies of peridotite and serpentinite. The strike direction is eastwards. Pegmatite veins striking north-south cut the micaceous gneiss and ultramafic rocks. Northwest of the quay area there are several small, old quarr.ies on both sides of the road. The light-coloured veins which are up to 5 m wide consist of feldspar, quartz, white and dark mica and tourmaline. Mining was based on extraction of mica. Large flakes of mica have been used, among other things, as insulating material for electrical purposes. Among other minerals in the veins can be mentioned quartz which is usually grey in colour. Rose quartz is present locally. The tourmaline is generally black, but both red and green varieties have been found.

Locality 28 - Skardalsvatnet on Åmøya

The inland ice calved further up in the fjords and retreated past Grønøya and Åmøya as far as Engavågen a little under 12,000 years ago (see map page 65).

At the north end of Skardsvatnet (13 m above sea level) there is a view westwards up towards a terminal moraine over 200 m above sea level. The moraine was deposited in front . of a local cirque glacier during Younger Dryas time.

In a sand-pit west of the north end of Skardsvatnet one can see, in the upper part of the sand, a layer with small and larger rounded stones. This marks a 7,000 year old storm beach formed when the sea level lay about 35 m above the present sea level. Above the storm beach lies 1-2 m of sand. Some of this sand may have been washed up on to the land from the sea, but most of it is wind-blown and thought to be several thousand years old also.

Locality 29 - Risneset

Marginal moraine on the north side of the island, about 800 m west of the place where the road crosses the sound from Grønøya. The morainic ridge is easily seen from the road returning from Skardsvatnet. It extends down towards the beach line where it sticks out as a short, blunt nose of land with a continuation on the sea-floor (see map page 65). Blocks and stones are numerous at the surface. The ridge is thought to have been deposited at the edge of the inland ice about 12,300 years ago.

Locality 30 - Breidvikhøgda

Viewing point with parking place at the red brick monument which forms part of Sculpture Landscape Nordland.

På Breidvikhøgda, tett inntil veien, står Meløys bidrag til Nordland skulpturlandskap. Herfra kan en bl.a. betrakte Bjærangsfjorden med omkringliggende isskurte dalsider, mens fjelltoppene har preg av mindre iserosjon. Foto: Terje H. Bargel.

The end of Bjærangsfjord is seen in an easterly direction. A few alpine-like mountain summits, over 1,000 m high, tower up on the north side of the fjord. The main shore line is cut into the till cover at about 100 m above present day sea level and is especially clear on the south side of Bjærangsdalen. A part of Svartisen can be glimpsed between the mountain summits to the east.

The main shore line can also be seen as a break in the terrain on the north side looking outwards over the fjord (page 79, upper part). A mountain slope can be seen in this direction. Over the years numerous snow avalanches have gone here, some of them right down to the fjord. The last time was in 1956 when two farms with cattle and people were swept away and destroyed by the snow. Three persons lost their lives.

Ørnes - Glomfjord - Holandsfjorden - Forøy

About 10,700 years ago glacier tongues from the inland ice lay in Spilderdalen, Neverdalen and other valleys in the area (See map page 70). Terminal moraines and other marked glacial margin deposits are visible evidence of these events today. Spildervatnet (44 m above sea level) and Selstadvatnet (46 m above sea level) are dammed up by such marginal deposits.

Locality 31 - Spilderhesten

Continuing southwards one comes to Sandå, about 5.5 km from Ørnes. From Sandå there is a view to the east-northeast where a large avalanche cone covers the foot of Spilderhesten (719 m above sea level). Frost-shattering is a frequent triggering mechanism for starting such an avalanche. Other causes can be, e.g., strong sound or noise effects, heating up of the rocks by the sun followed by rapid cooling, or even earthquakes. Periodically, many small earthquakes have been registered in this area, with values up to 3.5 on the Richter scale but it is not known whether the rock avalanche at Spilderhesten can be related to earthquake activity. The oldest part of the avalanche can just as well be related to pressure release on the mountainside when the inland ice melted.

Locality 32 - Neverdalen

A side road from the main road leads to Neverdalsvatnet (61 m above sea level).

From the road southwest of Neverdalsvatnet there is a view towards a marginal moraine which is crossing the valley c. 0.5 km northeast of the lake. There is also a view towards a marginal moraine which is related to a local cirque glacier from Yngre Dryas time at Storskardet to the southeast.

Locality 33 - Bjernneset, south of Neverdal

The rocks here belong to the Glomfjord window which consists of Precambrian gneisses most of which are granitic. Their age is 1,700 to 1,800 million years.

At this place there are small bodies of dark diorite which are surrounded by granite on all sides. There are also bands and veins of red, fine-grained granite in the diorite. On joint surfaces a little haematite is discernible.

Locality 34 - Rørneset

On Rørneset, 2 km south of Neverdal there is a good view towards the south side and out of Glomfjord. To the west emerges the island of Bolga with its characteristic hat form surrounded by a brim of low-lying terrain (strandflat). On the south side of the fjord, towards the southwest, there is a marked marginal moraine 70-80 m above the present day beach deposited outside a cirque glacier during Younger Dryas time. The highest mountain in the background is Kjelddalstinden, the summit of which is 1,027 m above sea level.

The area was affected by a series of earthquakes in the years 1978-1979. These were readily discernible but no serious damage was done. The centre for the earthquakes (epicentre) was a little further out in the fjord, at a calculated depth of 8-10 km in the crust.

Locality 35 - Fykan

Stop between the Fykan tunnel and the 7.7 km long Svartis tunnel. In the mountain section between Fykanvatnet (92 m above sea level) and Glomfjorden there are numerous grooves or flutings on the rock surface. These are formed by erosion beneath a glacier. The flutings are developed in granite, partly by the glacier which had moved forwards, partly by melt water under high pressure. These processes were active at this place during ice melting in Glomfjord, just before and during Younger Dryas time (11,000-10,000 years before the present). Between the

83 main road and the flutings is a knoll of dark amphibolite. This is a dyke rock which cuts through the granitic gneiss. Its continuation in the mountain slope north of Fykan can be seen.

Grooves or flutings in granite at Fykan. The direction of the grooves indicate a glacial movement which was directed obliquely towards the inner end of the fjord, not along the fjord as expected. The grooves were therefore formed when the ice-front was situated at, or near the end of the fjord. Photo: Terje H. Bargel.

Locality 36 - Fykanvatnet

A side road follows Fykanvatnet and continues up into the mountains. From the northern end of the lake a marked trail crosses light-coloured granite as far as some rock carvings from the Stone Age, 4,000-6,000 years old. On the rock surfaces one can see ice striae (stripes), parabolic markings and sickle marks formed by glacial movement. From a viewpoint erected here there is a view towards the rock carvings. Note that the carvings are often found on granite slabs which have a relatively smooth surface because of the massive character of the rock. The granite is usually very resistant to weathering and this has helped to preserve the carvings. The rock has a reddish colour and is of Precambrian age. In addition to feldspar and quartz the granite contains a

little magnetite (black) and numerous small dots of a red mineral (hematite). Green beryl has also been found.

At the east end of the lake there is an idyllic little deltaic fan. Upon this, a parking place has been made and a notice board set up giving information about nearby areas. From the parking place there is a view towards a glacial river fan on the southwest side of the lake. The last time this fan was supplied with much material was during the 'little ice-age' when all the glaciers in the country, including Svartisen, had their greatest development after the inland ice had melted. The 'little ice-age' culminated in about 1750 but extended from the 15th century until about 1900.

In late summer and early autumn it is possible to drive further towards Storglomvatnet. Here there is a view, among other things, of the glacier tongues from Svartisen.

Locality 37 - Sneland

From the cafeteria at Sneland there is a good view towards the south side of Nordfjorden, the innermost part of Holandsfjorden. Storøyra is a large glacial river fan deposited by melt water from Svartisen. Little material has been added to the fan after the 'little ice-age' ended at the end of the 19th century. Most was deposited during, and just after the Younger Dryas (11,000-10,000 years before the present).

Directly south, traces of a glacier tongue can be detected on the north side of Helgelandsbukken (1,454 m above sea level). This takes the form of a marginal moraine above Storøyra. Several such curved marginal moraines can be seen above Tenøyra to the southwest, Botteløyra to the southeast and Hindsøyra to the east-southeast. These are all from the Younger Dryas.

For the first kilometres westwards from Sneland the main road follows the main shore line, which is here developed in bedrock, a little over 100 m above sea-level telling us that this fjord was ice- free 11,000-10,000 years ago.

Engabreen - a glacier tongue extending from Svartisen. Photo: Terje H. Bargel.

Locality 38 - Bratsetvik -Engabreen

Stopping place with viewing point along the road. Boat departures for Engabreen are from the quay close by. Departure times about once an hour.

The glacier tongue hangs on the mountain side, a few hundred metres behind Engabrevatnet. The glacial front of the inland ice reached the fjord 10,000 years ago. In 1750 the tongue from Svartisen reached almost as far. In 1920 the glacier front did not extend so far but sufficient for 'Engabrevatnet' to be completely filled by glacial ice, i.e. about 2 km further forward than today. The lake, as we see it now, came into existence after the 19205 (1930-1945) but it has almost certainly existed for long periods before the 18th century.

The Svartis pavilion lies on the northwest side of Engebrevatnet a little over 1 km walking distance from the port of call. The pavilion lies on the marginal moraines from the turn of the

90 century with an open view towards Engabreen. By walking along the road to the south-east end of the lake it is possible to reach a point a few hundred metres from the glacier front. Before approaching the front more closely it is advisable to consult personnel in the pavilion who will advise on possible hazards from ice falls which occur from time to time. Guided walks on the glacier are arranged on request.

Even though Engabreen and Fonndalsbreen both lie well within the place where the glacier front lay in the 1920s, and before that time, the extent of the ice today is not the smallest since the ice- age. We presume that most of Svartisen, perhaps all of it, melted in the period 8,000-4,000 years ago. This is based, for the most part, on studies of climatic history and investigations of glaciers in the southern part of the country but is also thought to apply to Svartisen.

From the main road east of Brasetvika there is a good view towards Holandsfjord's south side where one can seethe main shoreline as a marked line in the landscape about 100 m above sea level.

In the mountain area above are several marginal moraines deposited in front of cirque glaciers during the Younger Dryas.

West of Fonndalen, on the fjord, lies the Rendalsvik mica mine. White mica was produced here from a mica-rich schist, but the operation is now closed down. Before and during World War II, a deposit located a short distance above Rendalsvik was worked for graphite.

At the church on Halsa the coastal road meets the alternative route Ørnes-Forøy. From Forøy there is a car ferry to Ågskardet. The crossing takes 10 minutes.