The coastal road (state highway 17) from Holandsfjorden to

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Locality 39 - Blokktinden, Tjong

On the road to Tjong and onwards to Reppa there is a good view towards Blokktinden and its very large avalanche cone. Blokktinden is carved in granitic gneiss and belongs to one of the Precambrian basement windows. Strong vertical jointing in the bedrock is one of the reasons for the large quantities of scree material which have accumulated here.

The main shore line forms a break in the avalanche slope and can be seen as a horizontal line. Here it represents the marine limit and is clearly developed in the fallen material. This means that most of the cone is a little older than the last part of the Younger Dryas. Probably most of the stoneblocks fell from the mountain wall a little after the mountain emerged from the ice masses 12,000-11,000 years ago. The climate during the first part of Younger Dryas time was very cold which enhanced fracturing of the rock walls and initiated stone-block production.

Blokktinden with its 400 m avalanche cone, looking south from Tjong. Photo: Terje H. Bargel.

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Locality 40 - Nordværnes

On a branch road, about 15 km from Straumsvika and only a few hundred metres from Nordværnes, is a body of peridotite (olivine/pyroxene rock). It is easily seen because of ifs reddish yellow alteration colour. Parts of this body, particularly the marginal zone and intersecting veins, are very special. In a groundmass which consists mostly of orthopyroxene there are olivine crystals 5 cm to 1 m in length and randomly orientated. The rock is igneous, but the special texture is the result of alteration processes (metamorphism).

Landscape with ochre-coloured weathered peridotite at Nordværnes. Blokktinden (locality 39) in the background. Photo: Terje H. Bargel.

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Locality 41 - Ferry trip Jektvika -Kilboghamn (60 min.)

The ferry quay at Jektvik lies approximately where the glacier margin of the inland ice lay 12,300 years ago (see map page 93). It is thought that the marginal zone crossed Åsen (202 m above sea level) southwest of Jektvika. From the ferry we can see Rødøyløva to the northwest, with its characteristic island profile in which the uppermost part of the mountain ridge resembles the head of a lion. Rødøyløva consists of red, granitic gneiss. Other islands to the west are Renga and Rangsundøy which consist partly of granitic gneiss, partly of altered sedimentary rocks such as micaceous gneiss and marble.

After passing Telnes there is a good view of Melfjorden to the east. The ferry crosses the here. The glacier margin crossed Melfjorden 12,300 years ago (A-glacier margin line, see map page 22). The route of the ferry between Jektvik and Kilboghamn may have been ice-free as early as 12,300 years ago. The was probably full of icebergs at that time and the only 'tourists' who visited the area must have been whales or other marine animals. In Nordfjorden, a branch of Melfjorden, there is a permanent seal colony today. This is a protected area.

Locality 42 - Kilboghamn

At Kilboghamn there are also indications of the glacial margin 12,300 years ago. just south of the ferry landing (800 m} there is a gravel pit opened in a glacial marginal deposit with large transported blocks on its surface. This deposit is thought to represent the A-glacier margin.

From Øresvika we can see eastwards and inwards to Gjervalen which is the innermost arm of Sørfjorden. About 10,000 years ago thick tongues of ice extended down to the fjord, 3-6 km from Øresvika.

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Map of the ice situation 10,000 years ago. Two glacial tongues from the inland ice extend down to the fjord and icebergs drift in the sea outside the ice margins, filling parts of the fjord basin. This is in sharp contrast to the situation prevailing today.

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Locality 43 - Tonnes

After passing 0resvika one can take a 15 km long side road to Tonnes before returning to, and continuing on the main road. From Tonnes there is a good view of a cave on the mountain side to the northeast. This cave lies about 100 m above sea level. Many fallen blocks and much rock cover the rocky threshold at the opening. The cave is 170 m long and must have been excavated and shaped by the sea. It follows the contact between mica-schist and banded gneiss which is parallel to the strike direction of the gneisses here. In the sand on the floor of the cave aluminium sulphate has been found. In former times this was used by the local population for tanning leather.

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From Tonnes there is a good view of Hestmannen (Hestmona). From the shipping channel this feature looks like a man riding a horse (hest), therefore the name. It can also be seen from highway 17 when driving along the northeast side of Aldersundet. Hestmannen consists of mica- schist, but the smallest of the two summits is granitic.

Hestmannen seen from Kvaroya.

Locality 44 - Aldersundet

The nearest island on the west side of Aldersundet is Aldra, its highest summit being 967 m above sea level. It consists for the most part of granitic gneiss, but there is a belt of mica-schist and marble in the low ground where the houses are located. A marked shore line is carved in thick till and is about 90 m above sea level.

Above the sports ground in Aldersundet, about 1 km from the road, there is a marginal moraine deposited outside one of the many cirque glaciers of Younger Dryas time. This cirque glacier extended down to the sea level at that time. This is about 90 m above the present level which corresponds to the marked shore line on Aldra.

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The strandflat seen from Grønsvika fort (fortress).

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The Træna islands seen from the east. Notice the almost flat-lying layers of gneiss in Trænstaven (to the right in the picture, 336 m a.s.l.), and also the contrast between the strandflat and the high mountains (relics of erosion). Photo Terje H. Bargel.

Island domain to the west

From Stokkvågen the ferry and express boat service goes to the islands to the west, including Lurøya, Lovunden and Træna. The islands consist of the same rocks as those on the mainland, i.e. gneisses and mica schists of Precambrian and Cambro-silurian age, Younger sedimentary rocks which make up most of the continental shelf are not present on the islands. Several islands rise above the strandflat and have characteristic topographic profiles. Lovunden (623 m above sea level), is well known and has a colony of puffins living in the scree on the north side: The mountains of Træna, including .Trænstaven (336 m above sea level) lie on the Island of Sanna, At the foot of the mountains there are several caves and rock surfaces developed when the sea level was higher than it is today. The most well known of these is Kirkhelleren where excavations have revealed traces of settlement in several periodes from both the Older and Younger Stone Ages and from the Age.

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Locality 45 - Grønsvika fort

Viewing point. Parking at cafe.

The fortress was in use during World War II. It is now being restored as a historical site from that time. The rock is a greyish white, quartz-feldspar-rich gneiss. It is of Precambrian age and belongs to the window. From the highest point within the fortress there is a view westwards to Lovunden, Lurøy and the distinctive strandflat.

Locality 46 - Bogen

Stopping place towards the sea at Silavågen.

The rock at this place is the usual, light-coloured, pinkish, bed-rock gneiss in the Sjona window. It consists of red feldspar, grey quartz and black hornblende as well as a little . These minerals are also present in small irregular pegmatites (coarse-grained intrusive rocks) and are easy to identify.

Locality 47 -

Stopping place in former quarry, about 3.5 km west of Flostrand.

The rock is a grey, hornblende-bearing basement gneiss. In the gneiss there are several light- coloured pegmatite veins. In connection with some of these veins there is a network of cracks. The cracks are filled with sulphide-bearing minerals and ankerite, CaFe(CO3)2. Weathering of these minerals gives the gneiss a rusty appearance for half a metre or so from the veins. The veins themselves are only a few decimetres wide.

A narrow, dark, biotite-rich vein can be seen in the road-cut. This follows the planar structure in the gneiss and is similar to that in the previous locality, an altered diabase dyke.

During the deglaciation 10,000 years ago there was a fjord connection between Sjona and Ranafjorden via . This lasted several thousand years, but 5,000-6,000 years ago the land uplift had progressed so far as to close the fjord connection and cause the Utskarpen area to be dry land.

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Locality 48 - Sjonfjellet

View point from the stopping place just below the former cafeteria. In good weather this is a very good view point. Lovunden and Træna can be seen far out to sea and to the north, and northeast there is a view to the almost naked terrain of the granite areas on the opposite side of Sjona. This shows how important the composition of the rock is for the vegetation. In the mountain side to the south a sharp boundary can be seen. This is considered to be the thrust boundary for the nappe complex which is the uppermost nap-pe unit preserved in the Caledonian mountain chain.

White, pegmatite gneiss in basement gneiss in the abandoned quarry west of Flostrand. Notice the rust zone on each side of the pegmatite vein.

On the north side of Sjona an elongate cirque-shaped can be seen. The has cut down through a threshold at the mouth of the valley. The height of the threshold is about 200 m above sea level and probably represents the approximate height of the valley floor in the original river valley. Later erosion by glaciers has given the valley its basin-like form, but before that, the

106 valley can have attained its 'hanging' character by glacial erosion which shaped and lowered the level of the fjord valley.

Sjona and Ranafjorden were connected when the area between Nesna and Utskarpen in the distant past was an island. The map shows this connection as it was about 7,000 years ago.

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Earthquakes and recent land uplift

The coast of is known as an area where earthquake activity occurs from time to time. The biggest earthquake, about 6 on the Richter scale, occurred in the Rana area in 1819. In recent years, several registrations have been made which indicate that in some areas at least, land uplift is not a reaction to relief of pressure following former loading by ice. These crustal movements are related to movements in the Earth's interior and are called neotectonics. Neotectonic movements involving land uplift of the order of 1-3 mm per year have been registered in some areas. Movements can also occur along old faults and joint zones. This can be of importance for technical installations in the bedrock.

The Båsmoen fault west and north of is a fault zone which is probably still active today. It can be seen as a pronounced escarpment cutting across the landscape (marked with arrows) form Utskarpen in the west to the mountain area southwest of in the east. Photo: Odleiv Olesen.

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The road section Mo i RanaSaltfjellet (E6) and Mo i Rana – Umbukta (E12)

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The road section Mo i RanaSaltfjellet (E6)

The road proceeds along the Rana River, through Dunderlandsdalen. This area is well known, geologically speaking, for its deposits and limestone caves. In road-cuts it is common to find mica-schist of different types. Even though Dunderlandsdalen is rich in marble there are not many places where good exposures of this rock occur along the E6.

During the Caledonian orogeny the rocks in this area were thrust over the Precambrian basement and little by little large nappe complexes were built up. These complexes cover large areas in central parts of Nordland. The orientation and shaping of Dunderlandsdalen is largely determined by the structure of the bedrock. For long sections the valley lies parallel to rock boundaries (strike direction). At some places, however, the valley cuts across the rock boundaries. This coincides with zones of weakness in the bedrock (joints) which have locally determined the direction of the valley. The valley is usually narrow at such places, as for example at Åenget (5 km east of Mo i Rana), Illhollia and Storvoll.

Karst landscape and caves

The area around the Rana drainage system together with Dunderlandsdalen contains much marble, limestone altered at high pressure and temperature during the Caledonian orogeny in the Paleozoic. The limestone is relatively easily dissolved by water containing carbon dioxide. Surface water wears down the marble to such an extent that it changes the appearance of the landscape (karst). The surface becomes very uneven and dissected by channels and deep holes. In joints and cavities the water eats away at the rock so that a network of underground channels develops. In Dunderlandsdalen there are many streams that flow through the marble zones. More than 30 such streams have been observed between Storforshei and Bjøllånes. Some of the underground channels are so narrow that they are unable to drain all the water during periods of flooding. The surplus water follows surface channels down to the valley floor where it reunites with the rest of the water masses. Such surface channels are usually dry for most of the year. Examples of underground channels are Litlåga in the western mountain side at and Pista near Krokstrand.

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Where and streams have taken new courses through the limestone the older underground channels are more or less dry. It can be exciting to explore such caves and they have a special attraction for people looking for adventure but who do not suffer from claustrophobia. The caves are often branched and very different both as regards size and shape. The passage-ways rise and fall, sometimes in steep cliffs. Proper climbing equipment is necessary to pass the obstacles. Many caves open high up in the mountain sides and at other places, which shows that they cannot have been water-filled as the drainage conditions are today. Age determinations show that some caves have existed for more than 350,000 years and must therefore have survived several ice- ages. It is difficult to decide to what extent the caves were formed during the ice-ages but many show signs of ice action. Several caves are filled with gravel and stones with a foreign origin, indicating ice transport.

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At the end of the ice-age the sea was 120-125 m higher in relation to the land areas than it is today. The was a fjord as far as Dunderland, 40 km from the present day fjord.

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Locality 49 - Mo i Rana

The central parts of the town are located on large river terraces of sand and gravel. The largest terraces are between 40-50 m above present day sea level. They were formed in front of the mouth of the Rana River 6,000-8,000 years ago. In this period (the Tapes period) rapid uplift of the land ceased and a period of stagnation or very slow uplift followed. Jernverket (the iron works) lies on one of the large terraces (53 m above sea level) where it was easy to build a large industrial plant. The superficial deposit beneath the plant is more than 100 m thick.

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The road section from Mo i Rana to Røssvoll passes through quartz-rich mica-schist, lime- bearing mica-schist and an area with volcanic rocks. Age determinations show the latter to be 450 million years old.

Locality 50 - Åenget

When driving eastwards along the E6 from Mo i Rana river terraces at several levels can. be observed on the opposite side of the Rana River. At Åenget, 4 km east of Mo i Rana, the Rana River turns sharply (90o) towards the NNE and the valley narrows (see photo page 112 top). River terraces of sand are deposited above the road in the bend. Some of the sand layers contain shells of different species which lived 8,000 years ago when the sea level was about 50 m higher than today.

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Locality 51 - Røssvoll

At Rossvoll the valley opens out and large river flats occupy the floor only a few metres higher than the river. From the northwest a large branch valley emerges from Raudvassdalen and in which large river terraces were deposited at several levels. The airport is built on such a terrace about 70 m above sea level corresponding to the sea level 8,500-9,000 years ago. The terraces represent the Rana River's deltaic plains from that time. A branch road from the E6 leads northwards past the airport to Langvatnet and Raudvassdalen. Signs point to the geological sites, Grønligrotta and Østerdalsisen.

Locality 52 - Grønligrotta

In the area north of Langvatnet there are several limestone caves. Gr0nligrotta is the best known cave in Scandinavia and more than 10,000 tourists visit it each summer. The guided walk for tourists is 400 m long and electrically lit.

Grønligrotta was discovered during the first settlement at Grønlia 250 years ago. The cave now has two openings in the steep mountain face, 200 m above the floor of Raudvassdalen but earlier there must have been several tunnels in from the valley. A network of tunnels falls downwards in the mountain and the deepest lies 107 m under the entrance. The total length is about 2,000 m. A stream flows through parts of the cave forming waterfalls and rapids. The cave is largely formed

117 at the boundary between the mica-schist and the underlying marble. The schist often forms the roof.

In Kapellet ( «the chapel» ), on the tourist route, a block of granite has become wedged between the cave walls. Since granite has not been found in the marble and schist rocks at Grønlia the block must have come from some distance. The nearest granite areas lie east of , almost 10 km away. The block must have been transported to the cave by the glacier and washed into it by melt water from the ice. This may have taken place during the last glaciation, 10,000-30,000 years ago, or even in an earlier ice age since the cave was probably formed several hundred thousands of years ago.

Map of Grønligrotta. (According to Oxaal 1913). The dotted line shows the tourist trail and the blue line where the stream is visible in the cave.

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Locality 53 - Østerdalsisen

If we continue northwards in Raudvassdalen and in Svartisdalen we arrive at Svartisvatnet. A boat operates on the lake during the tourist season. From the end of the lake there is a walk of 2-3 km to Østerdalsisen which is one of the best known and most visited glacier tongues from Svartisen.

This glacier has an interesting history as regards climate and extent during the last 250 years. Its maximum extent was around 1750. The outer limit shows clearly in the terrain, especially on the south side of Østerdalsvatnet where there is a marked morainic ridge. The rock surface inside this limit is washed and scoured and almost free of vegetation.

The border is easy to see from the boat on Svartisvatnet. The glacier lay in the same position for more than one hundred years. In 1890 the glacier front began to retreat slightly from Svartisvatnet. In the west, melt-water from the glacier drained towards Glåmdalen.

At the turn of the century the westerly part of the glacier tongue shrunk so that a small lake was formed in front of the ice-front. As the glaciation continued over the next 40 years this glacier- dammed lake became larger and larger and was called 0sterdalsvatnet. Gravel, sand and mud were deposited on the floor of the lake. A thick succession of layered sand and gravel accumulated at the outlet to the west, towards Glåmdalen.

In 1941 a sudden tapping of the water took place under the ice towards the east and down into Svartisvatnet. Fortunately, this tapping took place during a period of two weeks and no catastrophic situation arose. But the tapping became a yearly event and increased in extent such that the level of Østerdalsvatnet, by the middle of the fifties, fell by 60 m and 50 million m3 of water flowed across to Svartisdalen. Calving icebergs filled the whole lake and a very dramatic situation became apparent. A tunnel was driven eastwards from Østerdalsvatnet in 1959 to avoid the risk of a catastrophe and to keep the water level constant.

The glacier continued to diminish during the following years. By 1987 it was so thin that large pieces of the ice-front floated upwards and the whole lake became filled with large icebergs. Today the ice-front has begun to retreat up onto the land but calving still continues at the front. The steepness of the front means that calving and avalanching of iceblocks is even more dramatic. In the summer of 1989 a block of ice with a volume of several hundred cubic metres

120 became detached from the glacier. It fell into the water and gave rise to a huge flood wave which swept far in over the land. One person was caught by the wave and died. It is therefore important to keep well away from the water. Warning-signs have now been erected to indicate the danger zone.

Belemnites (fossils) have been found in glacial lake deposits in Østerdalsvatnet and in the river fan in Svartisvatnet where the river from the glacier emerges. Belemnite is the name of a group of cuttlefish (squids) which lived in the Mesozoic, especially in the Cretaceous, but which died out in the Tertiary. If these fossils have been washed out of till from Østerdalsisen it opens up a very interesting geological perspective since no rocks younger than the Cambro-Silurian have been found in the Svartis area.

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Road-map for the area Mo i Rana -Østerdalsisen -Melfjordbotn.

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Locality 54 - Melfjellet

From the road junction at Langvatn a road goes along the north side of Melfjellet to Melfjordbotn. Langvatnet lies in a terrain of marble and mica-schist whilst the mountain area to the west consists of Precambrian granitic gneiss.

From the highest point on the road on Melfjellet there is a view towards Høgtuva (1,268 m) to the south and to Svartisen to the north. The westerly part of Svartisen also lies on hard Precambrian gneisses. Along the valley between Høgtuva and Svartisen occur mica-schists and flagstones which are easily broken down by weathering and erosion. It is easy to see where the boundary towards the younger, overlying rocks goes since the latter are much darker in colour. Flagstones are exposed in road-cuts from Melfjellet down to Melfjordbotn. Close to the road several cylinder-like pot-holes occur in the flagstone. The largest are 2-3 m in diameter and 4-5 m deep. The pot-holes are formed by melt water from the inland ice. Swirling streams of water caused stones to rotate and excavate the holes.

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Background radiation

The bedrock can contain minerals which are radioactive. This gives rise to a natural background radiation, the intensity of which is related to the radioactive minerals present and their volume. In general it can be said that rocks with a sedimentary origin have lower background radiation. One exception is black schist which often gives higher radiation than other common sedimentary rocks. Granites and granitic gneisses are often more radioactive and the area around Høgtuva is such an area. However, the radiation is not high enough to constitute a health risk for people travelling in the area.

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Several pot-holes can be seen in the bedrock close to the road over Melfjellet. The pot-hole shown in the picture is c. 4 m across and is partly cut by the road. Photo: Terje H. Bargel.

View northwards from the road to Melfjord, Flat-lying rocks give rise to a special type of landscape with flat, plateau-like areas bounded by vertical cliffs. Here we see Øverloftet which consists of mica-schist and amphibolite whilst Svartisheia in the background to the right consists of granitic gneiss of Precambrian age. Photo: Svein Gjelle.

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Locality 56 - The Jordbru area in Plurdalen

From Røssvoll a side road leads eastwards to Plurdalen. This valley is parallel to the strike direction of the rocks. Long, narrow zones of marble alternate with lime-bearing micaschist. These rocks weather easily giving a good soil and lush vegetation. The farm Jordbrua is reached 26 km from Røssvoll. From here, a private road continues a further 6 km to Kaldvassdammen. A little over a kilometre from Jordbrua is Steinugleflåget (signposted at the road side). A path leads up to the edge of this circular, crater-like depression with a diameter of about 30 m. In the bottom of the depression there are openings to a system of underground passages.

It is 500 m from Steinugleflåget to Trollkjerka which is also a large collapse structure with steep walls and which opens out in a semicircle towards . The road runs just along the cliff edge. There is an entrance to the cave in the floor of the structure and this probably represents the entrance (gully) to Plurals underground channel as it was far back in time. Plura flows underground for about 3 km today.

Sprutforsen lies a further 2 km along the road. It lies where the underground stream-channel of Sprutbekken emerges in the valley side and gushes profusely when the flow of water is great. The cave system in which this stream runs is over 1 km long and part of Jordbrugrotta, a system of over 3000 m, with several entrances.

The road continues past Sprutforsen and a further 2.5 km up to Kaldvatnet. A walk starting from the parking area at Sprutforsen can be recommended. Follow the road a little way past Sprutforsen to the marked path to Sauvasshytta. The path starts off in mica-schist but soon passes into marble terrain. Here one can see how the streams alternate between underground and surface channels.

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The Jordbru area with Steinugleflåget, Trollkjerka and Sprutforsen. The extent of the marble is shown by the blue colour and other altered sedimentary rocks are shown in green.

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Locality 56 - Illhollia

From Røssvoll and 3-4 km along the E6 and Ranaelva (Rana River) the road enters a very narrow part of the valley. The river has dug deeply into the bedrock along a zone of weakness here. The V-shaped cross-section of the valley shows that river erosion has dominated and that the inland ice has not participated in the erosion. An explanation for this is that the ice moved more or less across this part of the valley instead of along it.

Locality 57 - Road-cut 500 m east of Storli camping

A garnet mica-schist invaded by a white intrusive rock (trondhjemite) is found here. The mica- schist has beautiful red garnets and is rich in white mica. A little black mica together with greyish quartz and white feldspar are also present. The veins contain white quartz and feldspar and sparkling white mica (muscovite). The trondhjemitic veins have invaded the mica-schist along the schistosity planes. At some places they can be seen to cut the schistosity. The rocks here lie in

131 the lower part of an old thrust sheet (nappe) and the associated zone of thrusting follows approximately the river.

From Storlia and further up the valley to Storvoll the road passes through a terrain with abundant marble. Calcitic marble, dolomitic marble and lime-bearing schists alternate with each other but there are very few good exposures easily accessible from the main road.

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Locality 58 - Storforshei

Rana Gruber's plant is located at Storforshei. The largest iron ore deposit in Rana mined in large, 'open pits. The ore is transported by-rail to the beneficiation plant in Mo i Rana where iron concentrates are produced and supplied to the international market.

The iron ore is an altered sedimentary deposit. It has been known for over 200 years but has been commercially exploited only in the present century. Up to 1940 it was in production in three separate periods, the longest of which was 4 years. An English company mined the deposit and the last period of operation ended when World War II began. After the war the Norwegian state took over all shares in the company and production on a large scale began in the mid-sixties.

Since then Rana Gruber has mined about 2 millions tons of ore a year. Norsk Jernverk in Mo i Rana was purchaser of the ore when they produced pig-iron, and at that time Rana Gruber was a part of Norsk Jernverk. Today the mines are a separate, independent company.

Rana Gruber produces an iron concentrate which is sold to smelters in Europe and the USA. In recent years some of the iron concentrate has been refined by micronization and the product used as black pigment in car tyres and concrete, among other things.

Locality 59 - Eitråga

The farms above the road lie on soil derived by weathering of the rock while those below the road lie on river sand. Here there is a road-cut in the calcareous mica-schist which is typical for Dunderlandsdalen. It consists for the most part of calcite, quartz, muscovite, biotite and garnet together with characteristic thin slivers of yellowish-white, fine-grained dolomite. It weathers easily, has a reddish-brown weathering colour and gives a fertile soil.

A little less than 3 km further up the valley from Eitråga, the road passes the railway used by Rana Gruber for transport of their products. The railway crosses the E6 and the Rana River by a bridge and enters a tunnel leading to an ore silo inside the mountain. The rock taken out during tunnelling has been used to build the railway track.

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Locality 60 - Litlåga, Dunderland

The area at Dunderland is characterized by zones of marble and mica-schist which strike parallel to the valley. Tributaries to the Rana River cross rock boundaries and many flow in underground channels through the marble zones. One of these streams is called Litlåga and it flows for several hundred metres below the surface in the lower valley side. It emerges again from several tunnel openings just above the E6 and unites to form a surface flow down to the Rana River. In periods of flooding the underground channels cannot handle all the water and the surplus is forced to follow a channel on the surface (flood channels).This channel is usually dry throughout the rest of the year.

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Map of Litlåga's drainage pattern.

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Locality 61 - Storvoll

Storvoll is a good starting point for walks in the terrain. Here four other valleys open out into Dunderlandsdalen. Stormdalen, a lush and beautiful valley with much lime-bearing bedrock and glacial till, enters from the west. At the opening of the valley, at Granneset, lies Nordland's most northerly natural forest of spruce.

Tespdalen and Bjøllådalen come from the north where the traffic between and Rana went before the road and the railway across were built. From the south comes Messingadalen.

The valley floor at Storvoll is filled with sand and gravel deposited by glacial rivers during deglaciation about 9,000 years ago. At Storvoll we leave the Rødingsfjell nappe complex and enter the Seve-Køli nappe complex (see drawing on page 34). Here the degree of alteration is lower, that is to say the rocks have not been exposed to such high temperatures and pressures during the mountain-building processes as was the case for the Rødingsfjell nappe complex. It is easier to break down weakly metamorphosed rocks than those more highly metamorphosed. This has caused the valley to be parallel with the front of the Rødingsfjell nappe. The upper part of Dunderlandsdalen starts about 3 km from Storvollen and just after the road has passed under a railway bridge. This is developed in low metamorphic mica-schists, phyllites and marbles. The nappe front with the high metamorphic rocks can be seen above the timber-line on the southwest side of the valley. Hard granitic rocks make up the mountains of the east side of the valley.

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The Nasa silver mine

About 8 km from Krokstrand there is a side road to the east. When the snow has disappeared it is usually safe to drive along it for a short distance. From this road an old, marked track leads to the Nasa silver mine which lies about 1,000 m above sea level and just across the border to . It is about 10 km from the E6 and involves climbing 500-600 m. silver-bearing galena and zinc blende were the most important minerals in the deposit. It was in production from 1635 to 1659 and from 1770 to 1810. At the time the deposit was found there was disagreement regarding the course of the state boundary between Sweden and /. At the most there were almost 100 men permanently employed at Nasafjell. The ore was transported about 50 km to a smelter at Silbojokk where a small community grew up. On Nasafjell itself a church was built.

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Here we find probably Scandinavia's highest burial site. Both the Silbojokk community and the mine on Nasafjell were destroyed by a Norwegian military force in 1659.

Traces of mining on Nasafjellet are still visible in the terrain almost 200 years after the mine was abandoned. The trench to the right in the picture cuts the remains of an ore vein that has been exploited. Here one can still find ore minerals such as silverbearing galena (the small picture). Photos: Ingvar Lindahl and Lars Petter Nilsson.

The road section Mo i Rana -Umbukta (E12)

This road section (E12, see map page 110) lies entirely in the Rødingsfjell nappe complex. The area is rich in ore deposits and several have been mined though none are in operation today. Mofjellet Gruber which was mined for zinc and lead lies in the mountain on the south side of Mo i Rana. It was closed as late as 1987 after having been in operation for about 100 years, admittedly with several periods of closure.

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Locality 62 - Bertelsberget (Sølvgruva)

Just outside Mo i Rana a road branches off to the south to Mofjell Gjestegard (Inn). Follow the signs further on to Bertelsberget about 2 km past the road to the inn. From here, a path 800 m long, leads to a 300 years old mine from which silver-bearing galena was produced. The mine adits are water-filled about 20 m from the portal. The deposit lies in a muscovite and pyrite- bearing gneiss.

From here there is a good view of Mo i Rana and the large river terraces on which the town is mainly built. Jernverket lies on the largest of these terraces. One can see two other mines from here. In a west-northwest direction, on the outskirts of Mo i Rana lies Bosmogruva. This pyrite mine was closed in 1937 after being in operation more or less continuously since 1894. In a north-northeasterly direction lies Rana Gruber's open pit where iron ore has been mined as well as calcite and dolomite. The mine is still in operation.

The first 11-12 km of the E12 eastwards from Mo i Rana pass through calcareous mica-schist. This has white quartz lenses with pale brown eyes of calcite in them. The main minerals in the rock are calcite, quartz and mica, but there is also a significant content of zoisite (a calcium aluminium silicate) and garnet. Further towards the road passes through gneisses and amphibolites.

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Locality 63 - Mosgruva

About 20 km from Mo i Rana, at the northwest end of Raudvatnet, a narrow gravel road branches off to the north. This road, about 1 km long, leads to Mosgruva, a pyrite deposit which has been mined, but is no longer accessible. Signs have been erected to warn the public about the danger of mine openings in the area. Be careful! The mine was operated for a few years around the time of World War I. Lumps of pyrite can be found lying around on the ground. Many of these have a rusty surface but gold-shimmering interiors. The rock frequently has a reddish surface on account of the sulphide which rusts easily.

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Locality 64 - Raudvatnet

Just after Mosgruva, Raudvatnet appears on the southern side of the road and Raudfjellet on the northern side. The rusty weathering colour of the bedrock is the reason for these names (raud=red). The circular form of Raudvatnet has given rise to speculations as to whether it was formed by meteoritic impact. So far no proof of this has been found.

Part of the bedrock map Storforshei, scale 1:50,000. Mosgruva lies in the upper left corner of the map, northwest of Raudvatnet.

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Locality 65 -

The road continues south and southeastwards through amphibolites, gneisses and micaschists. The highest point on the road, about 650 m, is at Umskaret. A narrow gravel road branches off to the south here and leads to an area with beautiful mountain scenery. The road is 47 km long and was built in connection with regulation of the drainage system. Along the north side of Storakersvatnet it passes through limestone terrain where both grey-blue calcitic marble and yellow-white dolomitic marble are present. In the dolomitic marble crystals of white tremolite 10-15 cm long can be found. It is probably possible to find other calc-silicate minerals such as diopside. It is especially easy to find minerals by the lake when the water level is lowered. The height of adjustment/regulation is 43 m.

The road continues via Akervassdammen southwards along the west side of Storakersvatnet, passing by Kjennsvatnet and finishing at the dam at the west end of Grasvatnet. The road is

143 narrow and often badly maintained. At Kjennsvatnet there is an unmanned tourist hut called Kjennvasshytta. This is very convenient as a departure point for hiking in the Okstind area. (Keys to the hut can be obtained from the tourist office in Mo i Rana or in ).

The highest mountain in north Norway, Oksskolten (1,916 m), and Nordland's third largest glacier, Okstindbreen, are found here. (NB! It is not recommended to walk around on the glacier without a qualified guide! The local hill walking association arranges walks on the glacier during the summer). The bedrock in Okstindan is not so very well studied. Most of the area around the glacier and the highest summits consist of garnet and quartz-rich mica-schists. They are the same rocks as those at the dam at Grasvatnet.

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Locality 66 - Ice-polished rock surface at Umbukta mountain lodge

North of the lodge (250 m) we find rocks from the same zone seen in the area at Storlia in Dunderlandsdalen. A garnet-bearing micaceous gneiss cut by dark amphibolite dykes and white tonalitic veins and lenses characterizes the area. The youngest rock here is a white pegmatite vein consisting of quartz and feldspar, and which can be seen close to the road. It has sent thin white veinlets into the amphibolite, and these are therefore the youngest.

The rocks are strongly deformed and folded and also cut by several steep faults oriented about north-south. Faults are joint surfaces along which there has been some movement. On one side of the joint the rock is displaced in relation to the opposite side. Here it is only a question of small movements from a few centimetres to a few decimetres. On some of the fault planes there has been some mineral growth since movement took place. One can also find thin, black, stretched slivers of biotite.

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Locality 67 - National border (Norway -Sweden)

From Umbukta mountain lodge to the border there are a number of road-cuts in gabbro. This is a dark rock which originates as a melt or magma and which forces its way up from depth and solidifies. It is normally an excellent rock for road construction since it is durable and suitable as aggregate for road surfacing. From the border and 300 m inside Norway there are several exposures of gabbro which are cut by a light-coloured rock. This rock has the appearance of an intrusive breccia with dark fragments of gabbro in a lightcoloured matrix. It is possible to find joints filled with yellowish brown carbonate minerals, black biotite and gold-shimmering pyrite in the gabbro.

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Is it growing?

The glaciers of today give us an immediate feeling of closeness to the past and to a colder climate.

The part of geological history nearest to us in time is the Quaternary. It covers the last 2-3 million years and includes several ice-ages and relatively rapid climatic variations without any form of human interference.

Part of the key to predicting our future climate lies in an understanding of the ice-ages and the natural climatic variations which have taken place over the last hundreds of thousands of years. As is evident from the chapter on glaciations in this book Nature follows its own rules as regards climate. So far natural processes have exercised complete control on the amount of ice on our planet. There are now clear signs that we are between two ice-ages and that in the distant future the country will once again be enveloped in ice as long as Nature alone determines the climatic conditions. But today human pollution and the greenhouse effect threaten to disturb the delicate balances in Nature. To what extent the human entry Into the arena will change the natural course of climatic events remains to be seen. But one can justifiably question the behavior of the glaciers in the future and, like the tourist in the picture with a distant view of Svartisen, ask oneself: Is it growing? -or shrinking?

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Mines and quarries in the Arctic Circle area

Altermark

The Altermark talc mine lies west of Mo i Rana on the north side of Ranafjorden, Rana municipality. The mine was started in 1932 and is still in operation. The mineral talc is removed from a soapstone and used today as filler in paint, stopper, plastics and paper.

Bertelsberget

Silver-bearing galena deposit which lies just southeast of Mo i Rana, the Rana municipality. The occurrence was found and production started in the latter half of the 17th century. There is a signposted road and path to the mine.

Brenne

A marble quarry in Saltdalen, 7-8 km south of , municipality. A colourful calciferous banded marble in shades of red, yellow and blue is worked here. The marble is schistose and splits easily. It is used in the first instance for headstones and floor tiles.

Båsmoen

A pyrite mine at Båsmoen just northwest of Mo i Rana, Rana municipality. The period of operation extended from 1894 to 1937 with a few pauses. In all about 15 million tons of pyrite ore were mined.

Ertenvågen

A dolomite quarry on state highway 17 in Gildeskål municipality. This dolomite is white, medium grained and of sedimentary origin. It has a number of uses, for example, as an additive in

149 metallurgical processes, in glass production, and as a filler in paint and plastics. It is also used in the manufacture of magnesium oxide and magnesium metal and also for soil improvement.

Evja

A granite quarry in municipality. This is a light-coloured granite used mostly for tombstones and sculptures as, for example, for the sculptures at the Arctic Circle Centre, Saltfjellet.

Ljøsnehammaren

A marble quarry at Ljøsnehammaren on the road between Saltdal and Beiarn, municipality. A colourful calciferous marble with pink, yellow and white bands is found here.

Malmhaugen

Pyrite mine in Plurdalen east of Mo i Rana, Rana municipality. The occurrence was test-mined by Båsmoen Gruber in the period 1915-1923 and 5,000-6,000 tons of pyrite taken out.

Misvær

Old granite quarry in Misvær, Skjerstad municipality. White granite was mined here and used mainly for tombstones.

Mofjellet

A zinc/lead mine on the southern boundary of Mo i Rana, Rana municipality. The occurrence was found in 1688 and the first attempt at mining carried out in the second half of the 19th century. The mine was closed in 1987 when the ore reserves were exhausted. " Zinc, lead and copper were produced.

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Mosgruva

The pyrite mine northwest of Raudvatnet, 1 km from the highway E12, Rana municipality. The mine was worked for pyrite in the period 1911-1919. About 53,000 tons of pyrite were mined. The mine openings are now closed.

Mårnes

A quartzite quarry on Sandhornøy, Gildeskål municipality. Quartzite is mined here and shipped to Salten Verk in Sørfold where it is used in the production of ferrosilicon.

Nasa

A lead/silver/zinc mine on Nasafjell, Sweden. Silver-bearing galena and zinc blende were mined here from 1635 to 1659 and from 1770 to 1810.

Oterstrand and Kattvassfjell

The molybdenum mines at Laksådalsvatnet, Gildeskål municipality. Molybdenum sulphide was mined here from 1918 to 1920 and from 1937 to 1945. About 260 tons of molybdenum concentrate was produced. Molybdenum is used in steel alloys, electric light bulbs and in the electronics industry.

Rana gruber

The iron ore deposits in Dunderlandsdalen, Rana municipality. The deposits are mined by open pit methods and production has taken place in several periods between 1904 and the present day. Over 70 millions tons have been mined. Iron has many uses in our society.

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Rendalsvik

Mica and graphite mines.on the south side of Holandsfjorden, Meløy municipality. The mica mine was operated in the period 1970-1980 for white mica from a mica-schist. The graphite mine was in production before and during World War II.

Stolplia

Soapstone quarry in Misvær, Skjerstad municipality. Soapstone is a very soft rock, easy to work. It has therefore been used from time immemorial for the manufacture of articles in i every day use such as weights for fishing nets, bowls, ovens etc. It has also been used as building stone, particularly In our old stone churches. Today, talc is the most Important product from this rock in Norway, but attempts to restart production from this deposit have foundered on conservation regulations.

Storvika

Marble quarry in Storvika, Skjerstad municipality. A conglomeratic marble with white dolomite pebbles in reddish calcite is found here.

Øyjord

Limestone quarry northwest of Mo i Rana, Rana municipality. The quarry supplied limestone to Norsk Jernverk from 1953 to 1977 for the production of iron. 2,600,000 tons were used.

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Solvågtind in Junkerdalen with its characteristic peak in late evening sun. Photo: Terje H. Bargel.

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