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Eoliska avlagringar och vindriktningar under holocen i och kring Store Mosse, södra Sverige

Bjermo, Tim LU (2019) In Examensarbeten i geologi vid Lunds universitet GEOL01 20191
Department of Geology
Abstract (Swedish)
Eoliska sanddyner är en sällan undersökt resurs ur ett paleoklimatperspektiv. Genom att undersöka dynernas geomorfologi och strukturer kan de klassificeras som olika dyntyper. Eoliska sanddyner kräver speciella omständigheter och förutsättningar för att bildas och agerar värdefulla klimatarkiv för de tidperioder då de avsatts. Dessa klimatarkiv kan berätta om den lokala miljön gällande bland annat vindregim, materialtillgång, fuktighet och temperatur.

Det undersökta området Store Mosse är beläget i södra Sveriges inland, Småland. De vindavsatta dynerna är bildade som allra tidigast då platsen blev isfri för ca 14 400 år sedan och åldersbestämd avsättning av sandprover täcker in varierande aktivitet mellan ca 10,5 – 3,29 ka. Som... (More)
Eoliska sanddyner är en sällan undersökt resurs ur ett paleoklimatperspektiv. Genom att undersöka dynernas geomorfologi och strukturer kan de klassificeras som olika dyntyper. Eoliska sanddyner kräver speciella omständigheter och förutsättningar för att bildas och agerar värdefulla klimatarkiv för de tidperioder då de avsatts. Dessa klimatarkiv kan berätta om den lokala miljön gällande bland annat vindregim, materialtillgång, fuktighet och temperatur.

Det undersökta området Store Mosse är beläget i södra Sveriges inland, Småland. De vindavsatta dynerna är bildade som allra tidigast då platsen blev isfri för ca 14 400 år sedan och åldersbestämd avsättning av sandprover täcker in varierande aktivitet mellan ca 10,5 – 3,29 ka. Som klimatarkiv berättar dynerna för oss om utvecklingen av den lokala miljön och klimatet kring Sydsveriges inland i en upptorkad issjö som sedan övergått till myrmark och slutligen södra Sveriges största högmosse idag. Ur ett större perspektiv kan studien kopplas ihop med andra likartade studier på regionalt spridda platser i Sverige och ge en klarare bild över hur miljö och klimat förändrades efter isavsmältningen och under holocen i Sverige.

Lokalen är undersökt genom fjärranalys av baserad på framförallt LiDAR-data. Dynernas geomorfologi och lutningen på deras sluttningar har analyserats för att utröna dynernas stöt- och läsida och därefter vilken typ av dyner det rör sig om. Dessa typer av dyner har sedan knutits till tidsperioder för deras avsättning genom insamling av sandprover vars deposition sedan åldersbestämts med hjälp av optiskt stimulerad luminiscensdatering.

Ett stort antal av de eoliska dynerna inom Store Mosse är klassade som parabeldyner. Parabeldyner är hästskoformade eller u-formade dyner vars armar sträcker sig mot den avsättande vinden. Detta sker då vegetation börjar stabilisera en aktiv och migrerande sanddyn och de beväxta delarna av dynen börjar släpa efter likt armar efterhand som dynens kropp migrerar framåt. Parabeldyner förknippas med miljöer där viss fuktighet är tillgänglig och växtlighet är närvarande och materialtillgången är god.
Då flera av dynerna har bildats fritt utan betydande topografisk inverkan från exempelvis dalgångar tolkas den nordvästliga vindregimen som avsatt flera av dynerna som representativ för de regionala vindmönster som rådde i södra Sveriges inland under åtminstone två tredjedelar av holocen. (Less)
Abstract
Aeolian sand dunes is a seldom studied resource from the perspective of paleoclimates. By analysing the dunes geomorphology and structures they can be classified into different type of dunes. Aeolian dunes require special circumstances and conditions to be met to enable their deposition. The sand dunes can then act as precious climate archives for the time periods during which they were formed. These climate archives can tell us about the local environment regarding wind regime, availability of material, humidity and temperature.

The examined site Store Mosse is situated in the inland of southern Sweden, Småland. The wind-deposited dunes have been formed at their earliest when the site became free from ice around 14 400 years ago.... (More)
Aeolian sand dunes is a seldom studied resource from the perspective of paleoclimates. By analysing the dunes geomorphology and structures they can be classified into different type of dunes. Aeolian dunes require special circumstances and conditions to be met to enable their deposition. The sand dunes can then act as precious climate archives for the time periods during which they were formed. These climate archives can tell us about the local environment regarding wind regime, availability of material, humidity and temperature.

The examined site Store Mosse is situated in the inland of southern Sweden, Småland. The wind-deposited dunes have been formed at their earliest when the site became free from ice around 14 400 years ago. Deposition of taken sand samples indicates varying aeolian activity between 10.5 – 3.29 ka. As a climate archive the dunes tell us about the local environment and climate of a dried up ice lake in the southern Sweden inland that turned into a mire and later into the largest raised peat bog of Sweden today. From a larger perspective this study can be connected to other similar studies performed in different regions of Sweden and give a more complete picture of how the environment and climate changed after the deglaciation and during the Holocene in Sweden.

The locale is analysed by remote sensing mainly based on LiDAR data. The geomorphology of the dunes and the steepness of the dune slopes have been analysed to determine the windward and leeward sides of the dunes and thereafter the type of dune. These dune types have then been tied to a specific time period for their formation by collecting several samples of sand from which time of deposition was determined through optically stimulated luminescence dating.

Several of the aeolian dunes in Store Mosse were classified as parabolic dunes. Parabolic dunes are horseshoe shaped or u-shaped dunes where the dune arms are reaching towards the direction of the dune forming wind. This happens due to vegetation stabilising parts of an active and migrating sand dune and the vegetated parts start trailing behind like arms as the main body of the dune continues to migrate forward. Parabolic dunes are associated with environments with some humidity and presence of vegetation and abundant sediment.
As several of the dunes in the area have formed freely without inferred topographic influence, like valleys, the north-westerly wind regime that formed the dunes is inferred to represent the regional wind patterns that prevailed in the southern Sweden inland during at least two thirds of the Holocene. (Less)
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author
Bjermo, Tim LU
supervisor
organization
course
GEOL01 20191
year
type
M2 - Bachelor Degree
subject
keywords
Store Mosse, optiskt stimulerad luminiscens (OSL), kvartsdatering, flygsand, eoliska dyner, holocen, fjärranalys, LiDAR, optically stimualted luminiscence (OSL), quartz dating, aeolian sand, aeolian dunes, Holocene, remote sensing.
publication/series
Examensarbeten i geologi vid Lunds universitet
report number
563
language
Swedish
id
8983090
date added to LUP
2019-06-13 14:46:33
date last changed
2019-06-13 14:46:33
@misc{8983090,
  abstract     = {Aeolian sand dunes is a seldom studied resource from the perspective of paleoclimates. By analysing the dunes geomorphology and structures they can be classified into different type of dunes. Aeolian dunes require special circumstances and conditions to be met to enable their deposition. The sand dunes can then act as precious climate archives for the time periods during which they were formed. These climate archives can tell us about the local environment regarding wind regime, availability of material, humidity and temperature.

The examined site Store Mosse is situated in the inland of southern Sweden, Småland. The wind-deposited dunes have been formed at their earliest when the site became free from ice around 14 400 years ago. Deposition of taken sand samples indicates varying aeolian activity between 10.5 – 3.29 ka. As a climate archive the dunes tell us about the local environment and climate of a dried up ice lake in the southern Sweden inland that turned into a mire and later into the largest raised peat bog of Sweden today. From a larger perspective this study can be connected to other similar studies performed in different regions of Sweden and give a more complete picture of how the environment and climate changed after the deglaciation and during the Holocene in Sweden. 

The locale is analysed by remote sensing mainly based on LiDAR data. The geomorphology of the dunes and the steepness of the dune slopes have been analysed to determine the windward and leeward sides of the dunes and thereafter the type of dune. These dune types have then been tied to a specific time period for their formation by collecting several samples of sand from which time of deposition was determined through optically stimulated luminescence dating.

Several of the aeolian dunes in Store Mosse were classified as parabolic dunes. Parabolic dunes are horseshoe shaped or u-shaped dunes where the dune arms are reaching towards the direction of the dune forming wind. This happens due to vegetation stabilising parts of an active and migrating sand dune and the vegetated parts start trailing behind like arms as the main body of the dune continues to migrate forward. Parabolic dunes are associated with environments with some humidity and presence of vegetation and abundant sediment.
As several of the dunes in the area have formed freely without inferred topographic influence, like valleys, the north-westerly wind regime that formed the dunes is inferred to represent the regional wind patterns that prevailed in the southern Sweden inland during at least two thirds of the Holocene.},
  author       = {Bjermo, Tim},
  keyword      = {Store Mosse,optiskt stimulerad luminiscens (OSL),kvartsdatering,flygsand,eoliska dyner,holocen,fjärranalys,LiDAR,optically stimualted luminiscence (OSL),quartz dating,aeolian sand,aeolian dunes,Holocene,remote sensing.},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbeten i geologi vid Lunds universitet},
  title        = {Eoliska avlagringar och vindriktningar under holocen i och kring Store Mosse, södra Sverige},
  year         = {2019},
}