Advanced

Vittring i en moränjord vid Farabol, NV Blekinge

Holmqvist, Johan (1994) In Examensarbeten i geologi vid Lunds universitet
Department of Geology
Abstract
The aim of this study was to determine the mineralogy and the weathering rate of till in NW Blekinge, south Sweden. The physical properties of the soil were analysed on samples taken in test pits. These samples were separated in different fractions and analysed with XRD- and chemical methods and thin sections. The computer program PROFILE was used as a tool to calculate the weathering rate. The physical properties of the soil were necessery to determine because they are needed for the calculation. The results display a well developed weathering profile. Vermiculite is dominant in the clay fraction of the A-horizon. The XRD-analysis suggests that a hydroxi-Al-interlayered vermiculite is present. This type of vermiculite indicates that the... (More)
The aim of this study was to determine the mineralogy and the weathering rate of till in NW Blekinge, south Sweden. The physical properties of the soil were analysed on samples taken in test pits. These samples were separated in different fractions and analysed with XRD- and chemical methods and thin sections. The computer program PROFILE was used as a tool to calculate the weathering rate. The physical properties of the soil were necessery to determine because they are needed for the calculation. The results display a well developed weathering profile. Vermiculite is dominant in the clay fraction of the A-horizon. The XRD-analysis suggests that a hydroxi-Al-interlayered vermiculite is present. This type of vermiculite indicates that the enviroment has been acid with an approximative pH of 4,0 -5,0. Biotite, chlorite, hornblende and epidote, which are easily weathered minerals, have low concentrations in the A-horizon but increase with depth. These minerals are the main contributors of K, Mg and Ca, elements which are important for forest growth. Plagioclase displays the same trend as the mafic minerals and increases with depth. In contrast, K-feldspar has higher concentrations in the A- and B-horizon than in the C-horizon. The results also suggest that the mineralogical composition varies with particle size. In the coarser fractions quartz is more frequent than plagioclase and K-feldspar. The grain-size distribution analysis indicates that the soil profile has coarser particles in the C-horizon than in the A-horizon. The observed weathering rate is around 2 keq/ha*year, which is higher than previously observed in southern Sweden. An explication for this may be that epidote has high concentrations in the soil. This fact could explain why the forest in this area shows high resistance against acidification. The results from the calculation also show rather high values for Al in the B-horizon. The ratio (Ca+Mg+K)/Al is close to one, which is critical for forest stands. (Less)
Please use this url to cite or link to this publication:
author
Holmqvist, Johan
supervisor
organization
year
type
H1 - Master's Degree (One Year)
subject
keywords
geografi, geologi, vittring, moränjord, Blekinge
publication/series
Examensarbeten i geologi vid Lunds universitet
report number
56
language
Swedish
additional info
Professor Gunnar Jacks, Kungliga Tekniska Högskolan, Stockholm.
id
2370097
date added to LUP
2012-08-14 11:52:48
date last changed
2012-08-14 11:52:48
@misc{2370097,
  abstract     = {The aim of this study was to determine the mineralogy and the weathering rate of till in NW Blekinge, south Sweden. The physical properties of the soil were analysed on samples taken in test pits. These samples were separated in different fractions and analysed with XRD- and chemical methods and thin sections. The computer program PROFILE was used as a tool to calculate the weathering rate. The physical properties of the soil were necessery to determine because they are needed for the calculation. The results display a well developed weathering profile. Vermiculite is dominant in the clay fraction of the A-horizon. The XRD-analysis suggests that a hydroxi-Al-interlayered vermiculite is present. This type of vermiculite indicates that the enviroment has been acid with an approximative pH of 4,0 -5,0. Biotite, chlorite, hornblende and epidote, which are easily weathered minerals, have low concentrations in the A-horizon but increase with depth. These minerals are the main contributors of K, Mg and Ca, elements which are important for forest growth. Plagioclase displays the same trend as the mafic minerals and increases with depth. In contrast, K-feldspar has higher concentrations in the A- and B-horizon than in the C-horizon. The results also suggest that the mineralogical composition varies with particle size. In the coarser fractions quartz is more frequent than plagioclase and K-feldspar. The grain-size distribution analysis indicates that the soil profile has coarser particles in the C-horizon than in the A-horizon. The observed weathering rate is around 2 keq/ha*year, which is higher than previously observed in southern Sweden. An explication for this may be that epidote has high concentrations in the soil. This fact could explain why the forest in this area shows high resistance against acidification. The results from the calculation also show rather high values for Al in the B-horizon. The ratio (Ca+Mg+K)/Al is close to one, which is critical for forest stands.},
  author       = {Holmqvist, Johan},
  keyword      = {geografi,geologi,vittring,moränjord,Blekinge},
  language     = {swe},
  note         = {Student Paper},
  series       = {Examensarbeten i geologi vid Lunds universitet},
  title        = {Vittring i en moränjord vid Farabol, NV Blekinge},
  year         = {1994},
}