Alnön
Encyclopedia
Alnön is an island in the Gulf of Bothnia
just outside Sundsvall
in Medelpad
, Sweden. It has an area of 65 km2 and a permanent population of 8,298 (as of 31 December 2009), although its summertime inhabitants are about twice that number. Most of the island's inhabitants work in Sundsvall and other towns on the mainland.
The island is 15 km long and 6 km wide on the widest spot. It is connected to the mainland by a 1042 metres (3,418.6 ft) long bridge, which was the longest bridge in Sweden when it was opened in 1964.
Evidences of habitation on the island predate the Viking Age
, and there are several tumuli
on the island from that period. The old stone church near the modern bridge was built in the 12th century.
The island saw a population boom in the second half of the 19th century, due to the development of steam-driven sawmill
s. In 1850 the island had 950 inhabitants, mainly farmers and fishermen, but by 1900 the population had grown to almost 7,000, following the establishment of 18 sawmills between 1860 and 1897.
. The ground is lime
rich, and it is one of few areas in the world with an alkaline volcanic area. Its chemistry is very different from the ordinary granitic rock in the region, resulting in a number of unusual minerals, such as borengite, baryte and aegirine
.
The most famous of the rock
s of Alnön is the alnoite, named from the Island, which is a lamprophyre
chiefly composed of biotite
or phlogopite
and melilite
as essential minerals, commonly with olivine
, calcite
and clinopyroxene. Perovskite
, apatite
, nepheline
and garnet
may also be present. Diamond
s have also been found on Alnön, but only in very small amounts.
Gulf of Bothnia
The Gulf of Bothnia is the northernmost arm of the Baltic Sea. It is situated between Finland's west coast and Sweden's east coast. In the south of the gulf lie the Åland Islands, between the Sea of Åland and the Archipelago Sea.-Name:...
just outside Sundsvall
Sundsvall
-External links:* - Official site from Nordisk Familjebok - Sundsvalls tourist information bureau. - The alternative guide to Sundsvall. - Blog with photos from Sundsvall....
in Medelpad
Medelpad
' is a historical province or landskap in the north of Sweden. It borders to Hälsingland, Härjedalen, Jämtland, Ångermanland and the Gulf of Bothnia....
, Sweden. It has an area of 65 km2 and a permanent population of 8,298 (as of 31 December 2009), although its summertime inhabitants are about twice that number. Most of the island's inhabitants work in Sundsvall and other towns on the mainland.
The island is 15 km long and 6 km wide on the widest spot. It is connected to the mainland by a 1042 metres (3,418.6 ft) long bridge, which was the longest bridge in Sweden when it was opened in 1964.
Evidences of habitation on the island predate the Viking Age
Viking Age
Viking Age is the term for the period in European history, especially Northern European and Scandinavian history, spanning the late 8th to 11th centuries. Scandinavian Vikings explored Europe by its oceans and rivers through trade and warfare. The Vikings also reached Iceland, Greenland,...
, and there are several tumuli
Tumulus
A tumulus is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, Hügelgrab or kurgans, and can be found throughout much of the world. A tumulus composed largely or entirely of stones is usually referred to as a cairn...
on the island from that period. The old stone church near the modern bridge was built in the 12th century.
The island saw a population boom in the second half of the 19th century, due to the development of steam-driven sawmill
Sawmill
A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....
s. In 1850 the island had 950 inhabitants, mainly farmers and fishermen, but by 1900 the population had grown to almost 7,000, following the establishment of 18 sawmills between 1860 and 1897.
Geology
Alnön was formed some 570 million years ago through a massive volcanic eruptionVolcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
. The ground is lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...
rich, and it is one of few areas in the world with an alkaline volcanic area. Its chemistry is very different from the ordinary granitic rock in the region, resulting in a number of unusual minerals, such as borengite, baryte and aegirine
Aegirine
Aegirine is a member of the clinopyroxene group of inosilicates. Aegirine is the sodium endmember of the aegirine-augite series. Aegirine has the chemical formula NaFeSi2O6 in which the iron is present as Fe3+. In the aegirine-augite series the sodium is variably replaced by calcium with iron and...
.
The most famous of the rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
s of Alnön is the alnoite, named from the Island, which is a lamprophyre
Lamprophyre
Lamprophyres are uncommon, small volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions...
chiefly composed of biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
or phlogopite
Phlogopite
Phlogopite is a yellow, greenish, or reddish-brown member of the mica family of phyllosilicates. It is also known as magnesium mica.Phlogopite is the magnesium endmember of the biotite solid solution series, with the chemical formula KMg3AlSi3O102. Iron substitutes for magnesium in variable amounts...
and melilite
Melilite
Melilite refers to a mineral of the melilite group. Minerals of the group are solid solutions of several endmembers, the most important of which are gehlenite and åkermanite. A generalized formula for common melilite is 2[SiO7]. Discovered in 1793 near Rome, it has a yellowish, greenish brown color...
as essential minerals, commonly with olivine
Olivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
, calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
and clinopyroxene. Perovskite
Perovskite
A perovskite structure is any material with the same type of crystal structure as calcium titanium oxide , known as the perovskite structure, or XIIA2+VIB4+X2−3 with the oxygen in the face centers. Perovskites take their name from this compound, which was first discovered in the Ural mountains of...
, apatite
Apatite
Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, chlorapatite and bromapatite, named for high concentrations of OH−, F−, Cl− or Br− ions, respectively, in the crystal...
, nepheline
Nepheline
Nepheline, also called nephelite , is a feldspathoid: a silica-undersaturated aluminosilicate, Na3KAl4Si4O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatites...
and garnet
Garnet
The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...
may also be present. Diamond
Diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...
s have also been found on Alnön, but only in very small amounts.
Notable citizens
- Tina NordlundTina NordlundTina Nordlund is a Swedish football manager and former player, currently managing Umeå IK. She is one of the most well known Swedish female footballers. In 2000, she won the Diamantbollen, an award given the best female player in Sweden each year. She played for Alnö IF, Sundsvalls DFF and Umeå IK...
, Football player - Andreas Yngvesson, Football player
- Gunnar Hellström, Director
- Hjördis SchymbergHjördis SchymbergHjördis Gunborg Schymberg was a Swedish coloratura and lyric soprano active on the opera stage and in concert halls between 1934 and 1968...
, Opera singer