rauk
{{short description|Landform in Sweden and Norway}}
File:Sweden 2018-08-05 (44113488995).jpgs) at Fårö Island, east of mainland Sweden]]
A rauk is a column-like landform in Sweden, often equivalent to a stack. Rauks often occur in groups called raukfält 'rauk fields'. The limestone rauks of Gotland in the Baltic Sea are among the best known examples.
Sweden
Rauks are common on the island of Gotland, Sweden and on the smaller islands belonging to Gotland County.{{cite encyclopedia |url=https://snl.no/rauk |title=rauk |encyclopedia=Store norske leksikon |language=no |publisher=Kunnskapsforlaget |last=Linge |first=Henriette |location=Oslo |date=2018-02-20 }} Fårö island in Gotland, is particularly rich in rauks.{{cite web |url=https://www.expressen.se/allt-om-resor/resmal/europa/sverige/glom-gotland-har-ar-okanda-svenska-platserna-som-har-raukar/ |title=Glöm Gotland – här är okända svenska platserna som har raukar |language=sv |last=van Luik |first=Colette |date=August 5, 2018 |website=Expressen |access-date=February 19, 2019}} While Fårö is on the northern end of Gotland Holmhällars raukfält at Vamlingbo in the southern end of Gotland is also rich in rauks.{{cite web |url=http://www.guteinfo.com/?id=123 |title=Holmhällars raukfält |language=sv |last=Enderborg |first=Bernt |website=guteinfo.com |access-date=March 20, 2019}} Rauks in Gotland often occur in groups or fields, so-called raukfält.{{cite web |url=https://fof.se/tidning/2001/6/artikel/sa-stiger-rauken-ur-havet |title=Så stiger rauken ur havet |last=Larsson |first=Kent |date=September 1, 2001|website=Forskning & Framsteg |access-date=February 28, 2019|language=sv }} Rauks can be found both near Gotland's many cliffs or far away from these.
Other localities with rauks include Byrum on northwestern Öland neighboring Blå Jungfrun island, Hovs Hallar and Kullaberg in northwestern Scania and Härnön in northern Sweden's High Coast. Rauks on Öland are made up of limestone. A few rauks are located in the Scandinavian Mountains in northern Sweden's Sarek{{cite web |url=https://www.utsidan.se/cldoc/sallsamheter-i-sarek.htm |title=Sällsamheter i Sarek |last=Norris |date=2014 |website=utsidan.se |access-date=February 12, 2019 |language=sv}} and Padjelanta{{cite web |url=https://www.swedishlapland.com/sv/stories/vandra-i-padjelanta-det-hogre-landet/ |title=Vandra i Padjelanta, det högre landet |language=sv |last=Wallin |first=Göran |website=swedishlapland.com |access-date=March 10, 2019 }} national parks.
Norway
File:Traenstaven.jpg is a rauk amidst the strandflat landscape of Norway's coast.]]
In Norway, there are rauks in Trollholmssund where, according to local lore, the rauks are petrified trolls.{{cite web |url=https://www.ngu.no/blogg/reis-til-en-rauk |title=Reis til en rauk |last=Dahl |first=Rolv Magne |date=July 23, 2015 |website=www.ngu.no |publisher=Norges geologiske undersøkelse |access-date=February 23, 2019|language=no}} In Trollholmsund, rauks are made up of dolomite rock. Varanger Peninsula in northern Norway is rich in rauks and they also occur elsewhere along the Finnmark coastline.
In Norway the term rauk is also applied to isolated residual mountains in the flat strandflat landscape along the coast.{{cite report |author-last=Motrøen |author-first=Terje |date=2000 |title=Strandflatens dannelse – kystlandskapet som spiser seg inn i landblokken |url=https://brage.bibsys.no/xmlui/bitstream/handle/11250/134104/rapp04_2000.pdf?sequence=1 |publisher=Høgskolen i Hedmark |access-date=September 6, 2017 |language=no |isbn=82-7671-104-9 }}
Geology
{{see also|Geology of Gotland}}
Rauks are usually formed by wave erosion. On Öland and Gotland, rauks are chiefly formed along or near the escarpment known as the Baltic Klint. Gotland rauks consist of limestone representing reefs that existed in the Silurian period.{{cite journal |last1=Nose |first1=Martin |last2=Schmid |first2=Dieter U. |last3=Leinfelder |first3=Reinhold R. |date=2006 |title=Significance of microbialites, calcimicrobes, and calcareous algae in reefal framework formation from the Silurian of Gotland, Sweden |journal=Sedimentary Geology |volume=192 |issue= 3–4|pages=243–265 |doi= 10.1016/j.sedgeo.2006.04.009|bibcode=2006SedG..192..243N |quote=At the Digerhuvud rauk field (rauk: erosional rock remnant) in the northwestern part of Fårö (Fig. 1), rauks appear to represent erosional remnants of larger patch reef complexes}} As waves batter against limestone cliffs, pre-existing vertical fractures begin to erode and widen. Eventually this leads to the formation of caves that merge, and the remaining central rock has now become rauks.
The rauks of Gotland formed after the last ice age. It is unclear to which extent different rauks in Gotland started to form from a cliffed coast, a dissected coast or from glacial landforms.{{cite journal |last=Rudberg |first=Sten|author-link=Sten Rudberg |date=1967 |title=The cliff coast of Gotland and the rate of cliff retreat |journal=Geografiska Annaler |volume=49 |issue=2 |pages=283–298 |doi= 10.2307/520895|jstor=520895}} A comparison of photographs from 1900 and from 1966 has shown that some rauks had been destroyed during that period.
Carl Linnaeus, who visited Gotland in 1741, was the first scientist to describe rauks. He called them stenjättar (stone giants) while also noting the ruiniform shape of same rauks.
In Sarek National Park rauks originate as aeolian landforms, thus, contrary to other rauks, they are shaped more by wind than by water. These rauks are made of sandstone that belongs to the Sierggavággenappe ({{langx|sv|Sierggavággeskollan}}) of the Scandinavian Caledonides.
See also
References
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