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Evaluation of methods to characterise the geochemistry of limestone and its fracturing in connection to heating

Jennerheim, Jessica LU (2016) In Dissertations in Geology at Lund University GEOR02 20161
Department of Geology
Abstract
Abstract: In 2011 Vinnova funded a joint project between Nordkalk AB, Kalkproduktion Storugns AB (KPAB)
and the department of Geology at the University of Lund. The goal of the project is to increase the general
knowledge of limestone and in extension, facilitate for the industry. This thesis is a part of the project and consists
of two separate parts which look into the geochemistry and thermal properties of limestones. Part one focuses on a
29 m drill core from the Storugns quarry on Gotland consisting of calcarenite, calcilutite, marl/marlstone, stromatoporoid,
fragment and reef limestone. The drill core was scanned with a high resolution XRF (ITRAX) and the geochemistry
between the different types of limestones was compared.... (More)
Abstract: In 2011 Vinnova funded a joint project between Nordkalk AB, Kalkproduktion Storugns AB (KPAB)
and the department of Geology at the University of Lund. The goal of the project is to increase the general
knowledge of limestone and in extension, facilitate for the industry. This thesis is a part of the project and consists
of two separate parts which look into the geochemistry and thermal properties of limestones. Part one focuses on a
29 m drill core from the Storugns quarry on Gotland consisting of calcarenite, calcilutite, marl/marlstone, stromatoporoid,
fragment and reef limestone. The drill core was scanned with a high resolution XRF (ITRAX) and the geochemistry
between the different types of limestones was compared. Focus ended up on silica (SiO2) and calcium
oxide (CaO) as they were the most common elements in the core and a statistical comparison using a student’s t-test
was conducted. To get comparable data to other studies from the area, a handheld XRF was used on polished and
cut parts of the core which represent the different types of limestone (except the marl/marlstone). Samples from
each rock type (again except the marl/marlstone) were dissolved in acetic acid and the residual material was analysed
in a SEM, more specifically using EDS. The results show that beside calcite and dolomite, the rock mostly
contain pyrite and quartz. The ITRAX scan confirms that geochemistry varies between the rock types, especially
when looking at the CaO and SiO2. Therefore, the ITRAX scan was deemed a reliable method to distinguish different
types of limestone whereas the handheld XRF was not. Part two of the thesis focuses on the thermal properties
of limestone and more specifically if x-ray computed tomography (CT) is a viable method for distinguishing dolomite
from calcite and if it can be used to study heat related fractures. Four samples were collected from the
Storugns quarry on Gotland and after drilling six cores per sample, the sample containing the most magnesium was
determined by using an acid test, handheld XRF and SEM (EDS). Five cores from this sample were scanned with a
CT. After scanning, the cores were heated to 400, 500, 600, 650 and 700 ˚C respectively and then scanned in the CT
again. Using a program called Fiji ImageJ, five levels were chosen in the images from the unburnt samples and the
corresponding levels were located in the burnt cores’ images. The images were then compared and all fractures
were marked and measured. The results show that CT is a good method for studying fractures however additional
studies would be needed to modify the method in order to use it to distinguish dolomite from calcite. (Less)
Please use this url to cite or link to this publication:
author
Jennerheim, Jessica LU
supervisor
organization
course
GEOR02 20161
year
type
H2 - Master's Degree (Two Years)
subject
keywords
geochemistry, limestone, Gotland, thermal properties, x-ray fluorescence, x-ray computed tomography
publication/series
Dissertations in Geology at Lund University
report number
486
language
English
id
8881774
date added to LUP
2016-06-16 11:30:19
date last changed
2016-06-16 11:30:19
@misc{8881774,
  abstract     = {Abstract: In 2011 Vinnova funded a joint project between Nordkalk AB, Kalkproduktion Storugns AB (KPAB)
and the department of Geology at the University of Lund. The goal of the project is to increase the general
knowledge of limestone and in extension, facilitate for the industry. This thesis is a part of the project and consists
of two separate parts which look into the geochemistry and thermal properties of limestones. Part one focuses on a
29 m drill core from the Storugns quarry on Gotland consisting of calcarenite, calcilutite, marl/marlstone, stromatoporoid,
fragment and reef limestone. The drill core was scanned with a high resolution XRF (ITRAX) and the geochemistry
between the different types of limestones was compared. Focus ended up on silica (SiO2) and calcium
oxide (CaO) as they were the most common elements in the core and a statistical comparison using a student’s t-test
was conducted. To get comparable data to other studies from the area, a handheld XRF was used on polished and
cut parts of the core which represent the different types of limestone (except the marl/marlstone). Samples from
each rock type (again except the marl/marlstone) were dissolved in acetic acid and the residual material was analysed
in a SEM, more specifically using EDS. The results show that beside calcite and dolomite, the rock mostly
contain pyrite and quartz. The ITRAX scan confirms that geochemistry varies between the rock types, especially
when looking at the CaO and SiO2. Therefore, the ITRAX scan was deemed a reliable method to distinguish different
types of limestone whereas the handheld XRF was not. Part two of the thesis focuses on the thermal properties
of limestone and more specifically if x-ray computed tomography (CT) is a viable method for distinguishing dolomite
from calcite and if it can be used to study heat related fractures. Four samples were collected from the
Storugns quarry on Gotland and after drilling six cores per sample, the sample containing the most magnesium was
determined by using an acid test, handheld XRF and SEM (EDS). Five cores from this sample were scanned with a
CT. After scanning, the cores were heated to 400, 500, 600, 650 and 700 ˚C respectively and then scanned in the CT
again. Using a program called Fiji ImageJ, five levels were chosen in the images from the unburnt samples and the
corresponding levels were located in the burnt cores’ images. The images were then compared and all fractures
were marked and measured. The results show that CT is a good method for studying fractures however additional
studies would be needed to modify the method in order to use it to distinguish dolomite from calcite.},
  author       = {Jennerheim, Jessica},
  keyword      = {geochemistry,limestone,Gotland,thermal properties,x-ray fluorescence,x-ray computed tomography},
  language     = {eng},
  note         = {Student Paper},
  series       = {Dissertations in Geology at Lund University},
  title        = {Evaluation of methods to characterise the geochemistry of limestone and its fracturing in connection to heating},
  year         = {2016},
}