View source for Alnön

{{Short description|Island in Sundsvall Municipality, Sweden}}
{{Infobox islands
| name                            = Alnön
| native_name                     = <!-- or |local_name= -->
| native_name_link                =
| native_name_lang                =
| sobriquet                       = <!-- or |nickname= -->
| image_name                      = Alnö.png
| image_caption                   = [[False color]] satellite image of Alnö outside Sundsvall in the Gulf of Bothnia.
| image_map                       =
| map_caption                     =
| pushpin_map                     =
| pushpin_relief                  =
| pushpin_map_caption             =
| coordinates                     = {{coord|62|24|N|17|28|E|display=inline,title}}
| etymology                       =
| location                        = [[Gulf of Bothnia]]
| archipelago                     =
| waterbody                       =
| total_islands                   =
| major_islands                   =
| area_km2                        = 67.79
| area_footnotes                  = <ref name=scb />
| rank                            =
| length_km                       =
| length_footnotes                =
| width_km                        =
| width_footnotes                 =
| coastline_km                    =
| coastline_footnotes             =
| elevation_m                     =
| elevation_footnotes             =
| highest_mount                   =
| country                         = [[Sweden]]
| country_admin_divisions_title   = County
| country_admin_divisions         = [[Västernorrland County|Västernorrland]]
| country_admin_divisions_title_1 =
| country_admin_divisions_1       =
| country_admin_divisions_title_2 =
| country_admin_divisions_2       =
| demonym                         =
| population                      =
| population_as_of                =
| population_footnotes            =
| population_rank                 =
| population_rank_max             =
| density_km2                     =
| density_rank                    =
| density_footnotes               =
| languages                       =
| ethnic_groups                   =
| timezone1                       =
| utc_offset1                     =
| timezone1_DST                   =
| utc_offset1_DST                 =
| website                         =
| additional_info                 =
| footnotes                       =
}}
'''Alnön''' is an island in the [[Gulf of Bothnia]] just outside [[Sundsvall]] in [[Medelpad]], Sweden. It has an area of 67.79&nbsp;km<sup>2</sup> and a permanent population of 8,417 (as of 31 December 2010), 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&nbsp;km long and 6&nbsp;km wide on the widest spot.  It is connected to the mainland by a {{convert|1042|m|ft|adj=mid|-long|sp=us}} 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 [[Tumulus|tumuli]] on the island from that period. The [[Alnön old church|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.
As result of decreased foreign trade during [[World War II]] [[apatite]] was mined in Alnön from 1943 to 1945.<ref name=Almq>{{Cite book|title=Nyttosten i Sverige|last1=Lundegårdh|first1=Per H.|publisher=[[Almqvist & Wiksell]] |year=1971 |isbn=|location=Stockholm |language=Swedish|pages=70|chapter=Apatit}}</ref> Apatite was separated by [[Froth flotation|flotation]] but results were meager.<ref name=Almq/> While the separation process had improved in 1945 the end of the war the same year meant also apatite mining became unprofitable.<ref name=Almq/>
==Geology==
{{main|Alnö Complex}}
Alnö was affected some 570 million years ago by a massive [[Volcano|volcanic eruption]]. The northeastern part of the island is rich in [[carbonate]] minerals, and it is one of few areas in the world with a [[carbonatite]] volcanic complex.<ref>{{Cite journal|last1=Andersson|first1=Magnus|last2=Malehmir|first2=Alireza|last3=Troll|first3=Valentin R.|last4=Dehghannejad|first4=Mahdieh|last5=Juhlin|first5=Christopher|last6=Ask|first6=Maria|date=2013-04-17|title=Carbonatite ring-complexes explained by caldera-style volcanism|journal=Scientific Reports|language=en|volume=3|issue=1|pages=1677|doi=10.1038/srep01677|pmid=23591904 |pmc=3628075 |issn=2045-2322|doi-access=free}}</ref> Its chemistry is very different from the ordinary granitic rock that form the rest of the island, resulting in a number of unusual minerals, such as [[baryte]] and [[aegirine]].<ref name="von Eckermann">{{cite book|last=von Eckermann|first=Harry|title=The Alkaline District of Alnö Island|publisher=Sveriges geologiska undersökning|location=Stockholm|date=1948|series=Ca, Avhandlingar och uppsatser|volume=36|pages=3–176}}</ref>
The most famous of the [[Rock (geology)|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.<ref>{{Cite journal|last1=Kresten|first1=Peter|last2=Troll|first2=Valentin R.|date=2018|title=The Alnö Carbonatite Complex, Central Sweden|url=https://link.springer.com/book/10.1007/978-3-319-90224-1|journal=GeoGuide|language=en-gb|doi=10.1007/978-3-319-90224-1|isbn=978-3-319-90223-4 |s2cid=135266142 |issn=2364-6497}}</ref>
[[File:Alnöbron.jpg|thumb|600px|left|''Alnöbron'' connects Alnön with the mainland, and was Sweden's longest bridge when it opened in 1964.]]{{-}}
==Sport==
*[[Alnö IF]]
==Notable citizens==
*Vilma Abrahamsson, Football player
*[[Gunnar Hellström]], Director
*[[Tina Nordlund]], Football player
*[[Hjördis Schymberg]], Opera singer
*[[Andreas Yngvesson]], Football player
*[[Helen Sjöholm]], Singer and actress
==References==
{{reflist|refs=
<ref name=scb>{{cite web|url=http://www.scb.se/statistik/_publikationer/OV0904_2011A01_BR_02_A01BR1101.pdf |title=Statistisk årsbok 2011 |publisher=[[Statistics Sweden]] |language=Swedish |page=12 |archiveurl=https://web.archive.org/web/20120113135944/http://www.scb.se/statistik/_publikationer/OV0904_2011A01_BR_02_A01BR1101.pdf |archivedate=13 January 2012 |accessdate=5 July 2011 |url-status=dead }}</ref>
}}
==External links==
* [https://web.archive.org/web/20081026044845/http://www.geology.neab.net/locality/alno.htm Rock samples from Alnön]
{{DEFAULTSORT:Alnon}}
[[Category:Sundsvall Municipality]]
[[Category:Islands of Västernorrland County]]