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Stratigrafiska undersökningar i sjön Vuolep Njakajaure, Abisko

Holmqvist, Björn H. (1993) In Examensarbeten i geologi vid Lunds universitet
Department of Geology
Abstract
Summary: This is a studie of Holocene lake sediments. The investigated lake, Vuolep Njakajaure (68°20'N, 18°47'O) is situated in the Abisko valley in the northern parts of the Caledonides. In this study four marginal cores of nonlaminated algalgyttja have been studied with respect to magnetic concentration parameters (ie susceptibility(χ) and SIRM) and loss on ignition. Core correlations have been carried out based on SIRM/χ and S-ratio. The core correlations indicates a hiatus at the beginning of Holocene in two of the cores. One core was selected as a main core. This main core was analysed with respect to pollen composition and indirectly 14C-dated by correlation to Sonesson (1968). Thus the sedimentation-rates were calculated in all of... (More)
Summary: This is a studie of Holocene lake sediments. The investigated lake, Vuolep Njakajaure (68°20'N, 18°47'O) is situated in the Abisko valley in the northern parts of the Caledonides. In this study four marginal cores of nonlaminated algalgyttja have been studied with respect to magnetic concentration parameters (ie susceptibility(χ) and SIRM) and loss on ignition. Core correlations have been carried out based on SIRM/χ and S-ratio. The core correlations indicates a hiatus at the beginning of Holocene in two of the cores. One core was selected as a main core. This main core was analysed with respect to pollen composition and indirectly 14C-dated by correlation to Sonesson (1968). Thus the sedimentation-rates were calculated in all of the cores. Snowball (1993) has shown that the S-ratio can be an indicator to climatic changes, because dissolution of magnetitegrains is greater compared to hematite-grains during warmer periods. S-ratio and SIRM/χ where compared to the climatic changes, as described by the pollenzonation, in the main core to investigate if they reflect climatic changes. In the upper part of the main core a correlation of the climatic changes and the mineral magnetic parameters was found. This is a strong indicator to high representativity of climatic changes, because two independent parameters ie pollen and magnetics correlates. (Less)
Abstract (Swedish)
Populärvetenskaplig sammanfattning: Detta är en studie av Holocena sjösediment. Den undersökta sjön, Vuolep Njakajaure (68°20'N, 18°47'O) ligger i Abiskodalen i de norra delarna av Kaledoniderna. I denna studie har fyra borrkärnor av alggyttja jämförts med magnetiska analyser (susceptibilitet(χ), SIRM) och glödförlust. Borrkärnorna har korrelerats i huvudsak baserat på SIRM/χ och S-kvot. Korreleringarna indikerar en hiatus i början av Holocen i två av borrkärnorna. En av borrkärnorna valdes till huvudborrkärna och i den analyserades pollensammansättningen. Huvudborrkärnan 14C-daterades indirekt genom korrelering till Sonesson (1968). Därefter beräknades sedimentationshastigheter i alla borrkärnorna. Snowball (1993) har visat att S-kvoten... (More)
Populärvetenskaplig sammanfattning: Detta är en studie av Holocena sjösediment. Den undersökta sjön, Vuolep Njakajaure (68°20'N, 18°47'O) ligger i Abiskodalen i de norra delarna av Kaledoniderna. I denna studie har fyra borrkärnor av alggyttja jämförts med magnetiska analyser (susceptibilitet(χ), SIRM) och glödförlust. Borrkärnorna har korrelerats i huvudsak baserat på SIRM/χ och S-kvot. Korreleringarna indikerar en hiatus i början av Holocen i två av borrkärnorna. En av borrkärnorna valdes till huvudborrkärna och i den analyserades pollensammansättningen. Huvudborrkärnan 14C-daterades indirekt genom korrelering till Sonesson (1968). Därefter beräknades sedimentationshastigheter i alla borrkärnorna. Snowball (1993) har visat att S-kvoten kan vara en klimatindikator genom att magnetit upplöses i större utsträckning än hematit under varmare perioder. S-kvot och SIRM/χ jämfördes med klimatförändringar, så som pollenzoneringen beskriver dem, i huvudborrkärnan för att undersöka om de återspeglar klimatförändringar. I den övre delen av huvudborrkärnan finns ett samband mellan klimatförändringar och magnetmineralogin. Detta är en stark indikation på god representativitet för klimatförändringar pga överensstämmelse mellan två oberoende parametrar. (Less)
Please use this url to cite or link to this publication:
author
Holmqvist, Björn H.
supervisor
organization
year
type
H1 - Master's Degree (One Year)
subject
keywords
Vuolep Njakajaure, stratigrafisk undersökning, geografi, geologi, Abisko
publication/series
Examensarbeten i geologi vid Lunds universitet
report number
52
language
Swedish
id
2370135
date added to LUP
2012-08-14 10:40:35
date last changed
2012-08-14 14:10:34
@misc{2370135,
  abstract     = {Summary: This is a studie of Holocene lake sediments. The investigated lake, Vuolep Njakajaure (68°20'N, 18°47'O) is situated in the Abisko valley in the northern parts of the Caledonides. In this study four marginal cores of nonlaminated algalgyttja have been studied with respect to magnetic concentration parameters (ie susceptibility(χ) and SIRM) and loss on ignition. Core correlations have been carried out based on SIRM/χ and S-ratio. The core correlations indicates a hiatus at the beginning of Holocene in two of the cores. One core was selected as a main core. This main core was analysed with respect to pollen composition and indirectly 14C-dated by correlation to Sonesson (1968). Thus the sedimentation-rates were calculated in all of the cores. Snowball (1993) has shown that the S-ratio can be an indicator to climatic changes, because dissolution of magnetitegrains is greater compared to hematite-grains during warmer periods. S-ratio and SIRM/χ where compared to the climatic changes, as described by the pollenzonation, in the main core to investigate if they reflect climatic changes. In the upper part of the main core a correlation of the climatic changes and the mineral magnetic parameters was found. This is a strong indicator to high representativity of climatic changes, because two independent parameters ie pollen and magnetics correlates.},
  author       = {Holmqvist, Björn H.},
  keyword      = {Vuolep Njakajaure,stratigrafisk undersökning,geografi,geologi,Abisko},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbeten i geologi vid Lunds universitet},
  title        = {Stratigrafiska undersökningar i sjön Vuolep Njakajaure, Abisko},
  year         = {1993},
}