Degree Project in Geology 15 hp
Bachelor Thesis
Stockholm 2016
Department of Geological SciencesStockholm UniversitySE-106 91 Stockholm
Sweden
Mineralogical characterisation of REE-bearing mineralisations in Knutsbo, Bergslagen
Karolina Mattsson
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Mineralogical characterisation of REE-bearing mineralisations in
Knutsbo, Bergslagen.
Karolina Mattsson
Abstract With a growing interest for rare earth elements (REE) and its industry, the EU has financed a project
called EUrare, regarding REE deposits in Europe with aim to safeguard and create a sustainable REE
industry. The Geological Survey of Sweden (SGU) has in relation to this project studied the so called
REE-line, located in west-central Bergslagen, along with other locations. Knutsbo lies at the northern
end of this extensive lens of 80 km of supracrustal rocks, with a bedrock of mainly granitoid-dioritoid-
gabbroid (GDG) mafic intrusive rocks. Previous studies and excursions have proved possibilities for
REE-bearing mineralisations in the area, which led to an undergraduate thesis with aim to further
investigate this cause. Through mineral observations in thin section collected from the area and SEM
analyses, the area proved to have mineralisations of mainly allanite, tremolite, quartz and actinolite.
A reoccurring mineral observed with pale brown-coloured pleochroism and high relief was of special
interest for analysis and proved to be REE-bearing. The REEs encountered in the samples were mainly
lanthanum (La) and cerium (Ce), with some traces of for instance yttrium (Y) which are more
uncertain. REE-bearing mineralisations are believed to be allanite, dollaseite törnebohmite and
västmanlandite. The analyses proves presence of REEs in the area and the results in this report will
hopefully encourage further studies regarding the subject.
Keywords: geology, rare earth elements, REE, mineralisations, ore deposits, volcanite, granites,
Fennoscandian Shield, Bergslagen, Knutsbo.
Supervisors: Joakim Mansfeld (Institution of Geology, Stockholm) and Magnus Ripa (SGU)
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Mineralogisk karaktärisering av sällsynta jordartsmetaller i
mineraliseringar i Knutsbo, Bergslagen.
Karolina Mattsson
AbstraktI samband med ett ökat intresse för sällsynta jordartsmetaller (REE) och dess industri har EU
finansierat ett projekt kallat EUrare, med syfte att skapa en säker och hållbar industri för sällsynta
jordartsmetaller i Europa. Sveriges Geologiska Undersökning (SGU) har i samband med detta projekt
studerat den så kallade REE-linjen i västcentrala Bergslagen, tillsammans med andra platser. Knutsbo
ligger på den norra änden av denna omfattande lins av 80 km ytbergarter, med en berggrund
bestående av huvudsakligen granitoid-dioritoid-gabbroid (GDG) mafisk, intrusiv berggrund. Tidigare
studier och exkursioner har bevisat möjliga REE-bärande mineraliseringar i området, vilket har lett till
möjligheten för ett examensarbete med syfte att studera detta område mer i detalj. Genom att
observera mineral i tunnslip från området och genomföra SEM-analys har området visat sig
framförallt innehålla mineral av allanit, tremolit, kvarts och aktinolit. Ett återkommande mineral med
svag brun pleochroism och hög relief observerades i proverna och var av speciellt intresse för analys,
som senare visade sig vara REE-bärande. De sällsynta jordartsmetallerna som upptäcktes i proverna
var framförallt lantan (La) och cerium (Ce), men även spår av yttrium (Y) som är mer osäkra. REE-
bärande mineraliseringar tros vara allanit, dollaseit, törnebohmit och västmanlandit. Analyserna
bevisar fyndigheter av sällsynta jordartsmetaller i området och resultaten i denna rapport
uppmuntrar förhoppningsvis vidare studier inom ämnet.
Nyckelord: geologi, sällsynta jordartsmetaller, REE, mineralisering, malmfyndigheter, vulkanit, granit,
Fennoskandiska skölden, Bergslagen, Knutsbo.
Handledare: Joakim Mansfeld (Geologiska institutionen, Stockholm) och Magnus Ripa (SGU).
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Table of Contents 1. Introduction ......................................................................................................................................... 2
1.1 Aims ............................................................................................................................................... 2
2. Background .......................................................................................................................................... 2
2.1 Regional geology ........................................................................................................................... 2
2.1.1 Fennoscandian Shield ............................................................................................................. 2
2.1.2 Bergslagen .............................................................................................................................. 4
2.2 Local geology ................................................................................................................................. 5
2.2.1 Knutsbo ................................................................................................................................... 5
3. Methods .............................................................................................................................................. 6
3.1 Field trip ......................................................................................................................................... 6
3.2 Rock samples ................................................................................................................................. 6
3.3 Thin sections studies ..................................................................................................................... 7
3.4 SEM analysis .................................................................................................................................. 7
3.5 Calculations of data ....................................................................................................................... 7
4. Results ................................................................................................................................................. 7
4.1 Mineralogy..................................................................................................................................... 7
4.1.1 Gruvhagen .............................................................................................................................. 7
4.1.2 Mörkens .................................................................................................................................. 8
4.1.3 Knutsbo ................................................................................................................................... 9
4.2 SEM analysis .................................................................................................................................. 9
5. Discussion .......................................................................................................................................... 10
5.1 Mineralogy................................................................................................................................... 10
5.2 SEM results .................................................................................................................................. 18
5.3 Local geology ............................................................................................................................... 19
6. Conclusions ........................................................................................................................................ 19
7. Acknowledgements ........................................................................................................................... 19
References ............................................................................................................................................. 20
Appendix ................................................................................................................................................ 21
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1. Introduction The bedrock of Sweden has gone through
several processes to eventually form the
geology present today. The composition and
age of the rocks differ from north to south but
are all part of the Fennoscandian Shield that
started to form around three billion years ago
(Andersson, 2004). As a result of the
geological processes that have occurred
during the formation of the Fennoscandian
shield in parts of Sweden, different rock types
have locally developed along with ore deposits
of various kinds. These deposits have been
explored and mined over a long period of time
and include important ore deposits like base
metal sulphide and iron oxide (e.g., SGA
Excursion Guidebook, 2013)
The area of Bergslagen in central Sweden has
been one of the regions where mining and
exploitation of mineral deposits have been of
great importance. The area is mainly rich in
iron oxides and base metals but also include
deposits of rare earth elements (REE) in west-
central Bergslagen (fig. 1). Because of this,
Sweden is included in the EURare project,
financed by the EU to set a basis for the
development of a European rare earth
element industry. The sectors of EU economy
deem it important to safeguard the supply of
REE materials and products to create a
sustainable, economically viable and
environmentally friendly industry of REEs in
Europe.
The exploration of REEs is done through
mapping in regions of interest, where the
Geological Survey of Sweden (SGU) has further
studied, among other areas, the REE-line in
Bergslagen (fig. 1). Through these previous
studies and collected samples, the Knutsbo
area have come of interest for REE deposits
that are to be further examined. In this report
its potential is reviewed in terms of samples
collected by the SGU.
1.1 Aims This report is an undergraduate (15 hp) thesis
in collaboration with the SGU and a part of the
EU-financed EURare project regarding REE
deposits in Sweden. The thesis aims to
investigate possible REE occurrences in the
Knutsbo area through already collected
samples (by SGU). Along with rock samples,
and analyses of thin sections and previously
gathered information from the SGU during
excursions and studies, the area of Knutsbo
have been described geologically and possible
REE-bearing mineralisations have been
identified. The framing of questions that are
examined and discussed in this report can be
summarised to the following bullet points:
Geologically describe the region of
Knutsbo.
Determine possible REE occurrences
in collected samples.
If present, what are the hosting
mineral(s) of the REEs?
2. Background
2.1 Regional geology 2.1.1 Fennoscandian Shield The following description is largely based on
the SGA Excursion Guidebook (2013). The
Fennoscandian Shield is one of planet Earth’s
ancient continental nuclei. It consists of a
collage of an Archean craton in the north-east
and towards the present day south-west
accreted magmatic domains. The major part is
composed of the Palaeoproterozoic
Svecokarelian orogeny (Stephens et al. 2009).
Large parts of the Shield are overlain by
platformal rocks which formed as sedimentary
basinal material in the south-east. The
magmatic domains amalgamated
progressively over time for more than one
billion years.
Juvenile crust was formed at 2.1-1.9 Ga in
numerous arc systems around the Archean
craton in the south-west which lead to
‘microcontinents’ in some regions, such as the
Bergslagen area (Andersson, 2004). The early
Svecokarelian rock-forming phase at 1.9-1.86
Ga resulted in thorough reworking, partly
including rift-related volcanism, of the earlier
3
Fig. 1. Geological map of the Bergslagen area (modified from Kampmann, 2015). The approximate extent of the REE line and position of Knutsbo are indicated.
4
arc systems in addition to the major formation
of newly formed juvenile crust between
microcontinents. Once accretion was
completed, subsequent east- and northward
subduction lead to reworking of the newly
formed crust during the late Svecokarelian
orogeny (1.85-1.75 Ga). In Bergslagen, this
resulted in granitoid magmatism and regional
metamorphism in the area (Andersson, 2004).
The Svecokarelian orogen hosts the largest
orogenic system. The bedrock was affected by
ductile deformation, metamorphism and
associated magmatic activity around 2.0-1.8
Ga, and started to react to crustal
deformation in a brittle manner around 1.8-
1.7 Ga. In addition to the Svecokarelian
orogeny, the part of the Fennoscandian Shield
located in Sweden is mainly composed of two
younger and spatially distinct orogens; the
Blekinge-Bornholm and Sveconorwegian
orogenies.
The orogenic processes locally lead to the
formation of an abundance of mineral
resources, and several ore districts in the
Fennoscandian Shield, where in particular the
Palaeoproterozoic assemblages are hosts to
many major mineral deposits of various types
(SGA Excursion Guidebook, 2013). All currently
active operating mines in Sweden are located
within the 2.0-1.8 Ga accretionary
Svecokarelian orogen (SGA Excursion
Guidebook, 2013).
Sweden has had an extensive mining and
mineral prospecting industry for centuries
where the most important types of ore
deposits include: volcanogenic massive
sulphide deposits; volcanic- and carbonate- or
skarn-hosted, replacement-type Zn-Pb-Ag-(Cu-
Au) sulphide and Fe oxide deposits, Cu-Au
deposits hosted by intrusive rock; and
orogenic gold deposits (SGA Excursion
Guidebook, 2013). Along with these well-
documented deposits, new types of deposits
are being explored, including Fe oxide-Cu-Au
deposits and REE, Li, Te deposits (SGA
Excursion Guidebook, 2013). No major or
economic mineral deposit has been found in
the Archean rocks in Sweden.
There are occurrences of other metals within
the borders of Sweden, including REE, Li, Mo,
Sn, W and U. In later years, a global interest
for rare earth element (REE) mineralisations
has surfaced which has ensued in rather
intense exploration for these metals also in
Sweden (SGA Excursion Guidebook, 2013).
Evidence of REE-bearing minerals have for
instance been found at numerous places in
Bergslagen, forming a line following an ore
belt hereby known as the “REE-line” (fig. 1).
2.1.2 Bergslagen The region of Bergslagen is located in the
south-western part of the Svecokarelian
orogen in the Fennoscandian Shield (fig. 1).
The rocks are of Palaeoproterozoic origin and
were formed and metamorphosed between
1.9 and 1.8 Ga. The rocks of the westernmost
part of the area were also affected by
deformation and metamorphism by a
Sveconorwegian tectonic overprint between
1.0 and 0.9 Ga (Stephens et al. 2009).The
region is rich in metallic mineral deposits with
three currently operating mines at base metal
sulphide deposits. These metallic mineral
deposits of Bergslagen can be found in the
hosting metamorphosed and hydrothermally
altered felsic volcanic rock and associated
skarn or crystalline carbonate rock (Stephens
et al. 2009).
Geijer & Magnusson (1944) mentioned two
types of rock that make up the bedrock of
Bergslagen; the supra-crustal so-called leptite
formation and contemporaneous and younger
granites. Mafic rocks and amphibolites occur
subordinately. In modern descriptions of
Bergslagen geology, the leptite formation
corresponds to Svecofennian felsic
metavolcanic rocks and the younger granite
correspond to granite-dioritoid-gabbroid
(GDG), granite-pegmatite (GP) and granite-
syenitoid-dioritoid-gabbroid (GSDG) intrusive
rock suites (Stephens et al. 2009). The volcanic
rocks were in places transformed into gneisses
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due to Svecokarelian metamorphism, but in
general they were only affected by
amphibolite, locally even greenschist, facies
conditions. The similarity in chemical
character between the older granites and
volcanic rocks indicates some sort of common
lineage according to Geijer & Magnusson
(1944).
Virtually all iron and sulphide ore deposits in
the Bergslagen region are found in, and were
largely formed at the same time or slightly
later than the supracrustal rocks (Geijer &
Magnusson 1944; Stephens et al. 2009). Iron
dominates the oxide deposits in the
Bergslagen region. They contain various
amounts of manganese in associated skarn
and crystalline carbonate rocks. There is also a
presence of iron sulphides and base metal
sulphides as well as rarities like uranium,
tungsten and rare earth elements (REE).
Manganese-poor skarn or crystalline
carbonate rock hosting iron oxide deposits are
the most common type of iron oxide
mineralisation in the region (Stephens et al.
2009).
The iron deposits in Bergslagen can be divided
into the following types: quartz-banded (BIF)
ores, skarn and lime ores and apatite-bearing
ores. Geijer & Magnusson (1944) interpreted
the banded iron formation as a product of
chemical sedimentation, where the material
probably surfaced onto the palaeoseafloor
through hot springs or similar forms of
emanations from the same magma masses
that fed surface eruptions. The skarn and lime
ores are formed from variably altered and
metamorphosed limestone.
The Bergslagen ore district contains several
thousands of Fe oxides and polymetallic base
metal sulphide deposits. There are three
deposits that are currently being mined in this
district: a Zn-Pb-Ag-(Cu-Au) sulphide deposits
at Garpenberg, a Zn-Pb-Ag sulphide deposit in
Zinkgruvan with subordinate Cu, and a Zn-Pb-
Ag sulphide at Lovisagruvan (SGA Excursion
Guidebook, 2013).
Bastnäs, located in the central of the REE-line
in Bergslagen, is one of best known REE-
bearing occurrences in Bergslagen. The
dominant country rock is an altered and
metamorphosed volcanic rock. The
surrounding area hosts numerous iron oxide
and base metal sulphide deposits (Andersson,
2004). The REE occurrences can be divided
into two subtypes according to Holtstam et al.
(2014): those enriched in light REEs (LREEs)
and Fe, and those enriched in heavy REEs
(HREEs), Y, Mg, Ca and F. The deposits in
Bastnäs are considered rich in LREE while the
district of Norberg further north is richer in
HREEs. Ferriallanite-(Ce), also known as
“cerine” or iron-rich “allanite”, and cerite-(Ce)
are the most common lanthanide mineral in
Bastnäs (Holtstam et al. 2003).
2.2 Local geology
2.2.1 Knutsbo Knutsbo is located just at the northern end of
the extensive lens of 80 km of supracrustal
rocks, known as the Nora-Riddarhyttan-
Norberg area, together forming the “REE-line”
(fig. 1). Intrusive rocks surround this region to
the east and intrusive and supracrustal rocks
in the west (Andersson, 2004).
As shown in figure 2, the bedrock at Knutsbo
consists of granitoid-dioritoid-gabbroid (GDG)
mafic intrusive rocks with GDG-type granite
and granodiorite to the south and GDG-type
granodiorite in the west. The mineralisations
at Knutsbo which host the REE-bearing
minerals, in turn, presumably occur as
supracrustal xenoliths in the GDG-rocks
(Persson, 1997)
Just like in the majority of Bergslagen rocks,
have the rocks around Knutsbo been affected
by amphibolite facies metamorphism.
Geophysical and topographic data indicate
several lineaments in the area, which could be
possible faults. The mineral lineations plunge
around 40 degrees north-east while tectonic
foliation strike around 290 degrees and dips
40 to 70 degrees north to north-northwest.
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There are occurrences of quartz rich iron oxide
deposits in the area, including banded iron
formation (BIF).
3. Methods
3.1 Field trip
A fieldtrip guided by Per Nysten and Magnus
Ripa from SGU to the area of Knutsbo was
conducted during the 14th of April, where the
aim was to get a further understanding for the
region regarding rock types and other
geological features of importance for the
project. Four pits in the Knutsbo area were
visited where the samples previously collected
by the SGU had been taken. Strike and dip
were measured in areas displaying foliation
patterns (fig. 3) and a few new rock samples
were collected for further studies.
During the 21st and 22nd of April, a second
fieldtrip guided by Magnus Ripa (SGU) and
accompanied by Joakim Mansfeld (Stockholm
University) to the REE-line was conducted. The
aim was to get an overlook of the so called
REE-line in perspective of geology and
mineralogy. Previously mapped areas by the
SGU were visited. The outcrops displayed
certain foliations or other geological features
of interest. Places like Bastnäs were visited,
where evidence of mining is clearly shown. In
addition, Stora Malmkärra, Plåtängsgruvan,
Bojmossfältet and Östanmossa were visited.
3.2 Rock samples As mentioned in the introduction, a number of
rock samples collected by the SGU during a
national inventory of possible REE occurrences
in Sweden (the EU-financed EURare project).
Some of these samples were taken at Knutsbo
since this deposit was mentioned as
Fig. 2. Extract from the bedrock map of the Geological Survey of Sweden (Persson 1997). Green colour denotes GDG-type mafic intrusive rocks, brown colour denotes GDG-type granite to granodiorite, brown colour with green dots denotes GDG-type granodiorite. Brown colour with red dots denotes porphyritic textures. The view is c. 3.2 km wide, north is up.
Figure 3. Foliation patterns in the Knutsbo area.
7
potentially REE-bearing already by Geijer &
Magnusson (1944). Chemical analyses of the
samples revealed enrichment in particularly
light REEs (LREEs).
3.3 Thin sections studies A total of nine thin sections were produced
from samples collected by the SGU in the
Knutsbo region. These samples have been
studied in microscope, where they have been
viewed in magnifications from 2.5 to 40x. The
mineral assemblages in each sample have
been examined through parallel and crossed
polars to determine their characteristics, and
have been classified accordingly. Opaque
phases like ore minerals have been studied in
reflected light.
The nine thin sections derive from three
different areas within the Knutsbo region. Two
samples have been taken at Gruvhagen, three
samples at Mörkens and four samples at
Knutsbo. Out of these samples, four were
selected for further analysis with SEM to
detect the plausible site(s) of REEs.
3.4 SEM analysis A scanning electron microscope (SEM) was
used to determine the chemical composition
of selected minerals in the thin section
samples. A SEM is a type of electron
microscope that produces images of a sample
by scanning it with a focused beam of
electrons. The electrons interact with atoms in
the sample, producing various signals that
contain information about the surface
topography and composition of the sample.
The model used for SEM analysis was a FEI
Quanta FEG 650, where the samples were
scanned in low vacuum with a backscatter
detector. The additional software used for EDS
analysis was AZtec.
3.5 Calculations of data The results from the SEM analyses gave data
in form of weight percent (wt %). In order to
present this in an easily understandable way,
the data from each analysis were recalculated
to mineral compositions. The mole ratio was
calculated from the weight percent and
afterwards normalised according to the
amount of cations in the different minerals to
produce a more accurate result. There was
also a correction made for the sulphide, where
0.5 mole ratio of iron was removed for every
mole ratio of sulphide, giving a better end
result.
4. Results
4.1 Mineralogy
4.1.1 Gruvhagen The two thin sections from Gruvhagen are
both fibrous actinolite skarn, containing a
mineral assemblage of allanite, quartz,
actinolite and calcite. Both samples show
mainly a matrix of actinolite and quartz
crystals in ranging size (fig. 4) with some
elongated allanite crystals appearing
throughout. The remaining minerals are less
abundant and appear as minor crystals.
Both samples contain ore minerals which
show as opaque phases. Through studies in
reflected light, the samples demonstrate
presence of magnetite and hematite
throughout the thin section in minor amounts.
No sulphides are present.
No minerals in the samples from Gruvhagen
showed any significant potential for being
REE-bearing and have therefore been
excluded from SEM analysis.
Figure 4. Matrix of colourful actinolite in XPL (right) meeting with darker allanite and ore minerals (left).
8
4.1.2 Mörkens The three thin sections from Mörkens
differentiate from each other in terms of
mineral assemblages and compositions. All of
the samples show interesting characteristics
for potential REEs.
One sample from Mörkens is defined as
tremolite skarn, and contains allanite,
tremolite and quartz. Tremolite is the
abundant mineral with long and fairly large
crystals with varying sizes, while smaller
crystals of allanite and quartz occurs in a
lesser amounts. The opaque phases are ore
minerals like pyrite and some chalcopyrite.
A mineral we were unable to identify through
sheer observation occurs frequently, often
close to allanite crystals (fig. 5). It shows
similar characteristics as allanite but has
weakly brown-coloured pleochroism,
compared to allanite which has strong colours
of brown or red. Due to these observations it
is believed to have possible relations to REEs.
Another thin section sample from Mörkens is
defined as a copper-bearing quartz skarn. It
has a mineral assemblage of muscovite, quartz
and allanite. The sample consists of a mass of
quartz crystals in similar size, with muscovite
appearing throughout the sample as long
crystals in different sizes. The opaque phases
are ore minerals of chalcopyrite and possibly
iron, the latter which might occasionally
reacting to form magnetite.
The mineral allanite show similar
characteristics as in the other sample with
some weaker brown to grey pleochroistic
crystals (fig. 6). It appears abundantly in the
sample and is believed to have a relation with
REEs.
The last thin section from Mörkens in defined
as a copper-bearing amphibole skarn. It
contains minerals of amphiboles, tremolite
and quartz, along with an unknown mineral
showing the same characteristics of pale
brown pleochroism as in the previous samples
from the area. The mineral also appears as
pale brown in crossed polar, similar to the
mineral titanite and is believed to be REE-
bearing (fig. 7). The tremolite crystals are large
and abundant in the sample, their colours and
shape appearing somewhat distorted. Quartz
appear as small crystals within the matrix.
The opaque phases are mainly ore minerals of
converted pyrrhotite, shown by bird eye
Figure 7. Crystal with light to darker brown pleochroism and strong relief.
Figure 5. Mineral of pale brown pleochroism, occurring as small crystals throughout the sample.
Figure 6. Mineral appearing grey to colourless in PPL, with possible relation to REEs.
9
texture in reflected light. The sample also
contains some chalcopyrite, possibly related
to REEs.
4.1.3 Knutsbo Each of the four samples from Knutsbo differ
in mineralogy and opaque phases. One of the
samples has a matrix of quartz and biotite, the
latter often containing abundant haloes (fig.
8). Calcite is a less abundant component and
there are small occurrences of a mineral with
pale brown pleochroism, believed to be
related to REEs. The sample contains no
observed opaque phases.
Another sample from Knutsbo is defined as
quartz-banded hematite ore, seen clearly
across the thin section (fig. 9). It is abundant in
quartz along with some smaller crystals of
amphiboles like actinolite. Some possible
crystals of calcite were also observed but to a
smaller amount. The opaque phases are ore
minerals of mainly hematite, revealing some
twinning textures, along with some signs of
magnetite present in the sample.
One of the thin section samples from Knutsbo
is defined as actinolite-magnetite skarn with
pyrite. The sample has a mineral assemblage
of allanite and actinolite with large crystals of
allanite in the sample compared to the
surrounding matrix, some showing twinning
textures (fig. 10). The opaque phases are ore
minerals of pyrite along with magnetite.
Also in this sample the pale brown-coloured
pleochroistic mineral occurs, similar to that of
allanite but weaker in colour. This mineral or
the allanite itself is believed to be REE-
bearing.
The final sample from Knutsbo is defined as
quartz- and amphibole-mixed magnetite rock.
It contains minerals of quartz, amphiboles and
biotite as well as the unknown mineral
believed to be REE-bearing, appearing as pale
brown in parallel polars, much like in previous
samples. The opaque phases are ore minerals
of magnetite and hematite. No sulphides are
observed.
4.2 SEM analysis
Four thin section samples were selected for
SEM analysis, including one sample from
Knutsbo and three from Mörkens. The
minerals chosen for analysis were mainly the
crystals of lighter brown pleochroism seen in
several of the samples, as well as their closest
surroundings.
Figure 8. Biotite viewed in XPL, displaying haloes across the crystal.
Figure 10. Large crystals of what is believed to be allanite related, with brown to yellow pleochroism.
Figure 9. Quartz bands with hematite ore (opaque).
10
Through review and calculations of the SEM
results, several REEs were encountered in the
mineral assemblages in the analysed samples.
With the majority of the analyses done of the
samples from Mörkens, they reveal a variety
in REEs and their hosting mineral assemblages.
However, the mineral classifications are very
uncertain as the SEM data have been difficult
to interpret.
The samples from Mörkens revealed higher
amounts of REEs than that of Knutsbo. The
sample from Knutsbo mainly contains
tremolite-actinolite but also contains large
allanite crystals, generally poor in REEs, with
traces of for instance lanthanum (La), cerium
(Ce) and neodymium (Nd) in the allanite
crystals (tables 1 and 2).
As seen in tables 2 and 3, all three samples
from Mörkens contain dollaseite with REEs
like cerium (Ce), neodymium (Nd) and even
minor traces of praseodymium (Pr). One of
the samples from the Mörkens area contained
the mineral törnebohmite (table 4), slightly
richer in cerium (Ce) and lanthanum (La) while
another contain minerals of västmanlandite,
some being Fe-analogue and slightly richer in
iron (table 5).
Some of the more questionable results are the
presence of britholite-Y, rich in yttrium (Y) and
cerite, rich in cerium (Ce), both appearing in
the same sample (table 6). Talc was possibly
also encountered in one of the sample from
Mörkens. In addition, other possible REE-
minerals encountered in the samples could be
flourcerite, monazite, magnesiorowlandite,
and gadolinite but are all very uncertain
results and estimates (table 7).
Some of the opaque phases were also
analysed in the SEM, a majority being ore
minerals of pyrite. However, the results also
revealed presence of chalcopyrite and
pyrrhotite. The amount of REEs present in the
sulphides are low, only with some traces of
cerium (Ce) and lanthanum (La).
5. Discussion
5.1 Mineralogy The nine thin section samples previously
collected from the Knutsbo area show both
differences and similarities. They differ in their
overall appearance, the sizes of crystals, the
amount of minerals and their composition.
However, they share common mineralogy as
most of the samples contain allanite,
tremolite, quartz and actinolite. The opaque
phases in the samples are generally pyrite or
magnetite and hematite.
More importantly, almost all the samples
share an unidentifiable mineral with pale
brown pleochroism that appear as smaller
crystals in the samples. Both the samples from
Knutsbo and Mörkens show several examples
of this unknown mineral, however it seems to
be in insignificant amount or even be lacking
completely in the samples from Gruvhagen as
none more than allanite (REE-bearing) were
observed during microscopy.
As to why Gruvhagen is low on this mineral,
while Knutsbo and Mörkens have several
crystals of, is most likely a result of location as
to where the samples were collected.
Although in largely the same area, their
mineralogy and composition is slightly
different and the Gruvhagen samples may
have been collected from a generally REE-poor
location.
Since the unidentifiable mineral share
common characteristics with that of allanite,
like high relief and fairly strong, brown
pleochroism, it is believed to be related to
allanite in most of the thin sections. Although
still uncertain to say this is crystals of allanite,
since it contains a significant amount of REEs,
it can be considered to be one of REE-bearing
minerals in the samples.
As for the mineralogy itself, the observations
made are suggest metamorphism of
amphibolite facies, and possibly even
greenschist facies. With conditions of medium
11
Table 1. Recalculated data from SEM analyses of Knutsbo sample.
Weight%
Sample knut 3 knut 3 knut 3 knut 3 knut 3 knut 3
Mineral REE-poor allanite
REE-poor allanite
REE-poor allanite
REE-poor allanite
REE-poor allanite
REE-poor allanite
Analysis Spectrum 3
Spectrum 6 Spectrum 8 Spectrum 9 Spectrum 10
Spectrum 11
C 2,6 2,5 2,9 2,9 3,1 2,4
O 39,7 39,3 40,9 41,6 39,7 39,3
S 0,2
Si 16,5 17,4 17,7 17,8 17,2 17,3
Al 8,6 9,3 9,2 9,4 8,5 8,6
Fe 8,2 8 7,8 7,3 7,3 7,1
Mg 2,8 2,6 3 2,9 3,4 3,5
Ca 10 11,2 11,7 11,8 10,4 10,3
Na
K
Ti
Mn
P
Y
La 3,2 1,8 2,1 1,5 2,7 2,5
Ce 5,7 4,2 3,4 3,4 5,3 5,4
Pr 0,8 0,6
Nd 2,6 2,2 1,4 1,4 2,5 2,3
Sm 0,7 0,6
Eu
Gd
Tb
Co
Cu
Br
F
Mo
Ni
Total 100,1 100 100,1 100 100,1 99,9
12
Table 2. Recalculated data from SEM analyses of Knutsbo and Mörkens samples.
Weight%
Sample knut 3 knut 3 knut 3 knut 3 mork 3 mork 3
Mineral Allanite Allanite Allanite Allanite Dollaseite Dollaseite
Analysis Spectrum 19
Spectrum 20
Spectrum 25
Spectrum 26
Spectrum 51
Spectrum 53
C 3 1,8 3,4 3 3,1 3,2
O 36,5 37,2 37,6 36,4 36,5 35,5
S 0,3 0,2 0,6 0,5
Si 14,6 15,9 14,9 14,6 15,8 15,7
Al 7,7 9,5 9,7 8 5,6 5,6
Fe 7,3 9,1 8,6 7,6 8,4 8,3
Mg 2,5 1,3 1,5 2,2 4,8 4,9
Ca 7,4 10,4 10 7,8 5,9 5,7
Na
K
Ti
Mn
P
Y
La 4,8 3,1 2,9 4,2 3,2 3,4
Ce 10,6 6,6 6,3 9,8 9,5 9,3
Pr 1,1 0,9 0,9 1,3 1,1 1,4
Nd 4,5 3,4 3,1 4,2 5,5 5,6
Sm 0,7 0,8 0,8 0,9
Eu
Gd
Tb
Co
Cu
Br
F
Mo
Ni
Total 100 99,9 100 100,1 100 100
13
Table 3. Recalculated data from SEM analyses of Mörkens samples.
Weight%
Sample mork 3 mork1 mork1 mork 2 mork3
Mineral Dollaseite Dollaseite Dollaseite Dollaseite Dollaseite
Analysis Spectrum 50 Spectrum 71 Spectrum 76 Spectrum 83 Spectrum 36
C 3,3 5,1 5 4,6 6,2
O 34,3 34,1 34,4 33,9 32,8
S 1,1 3,8
Si 14,8 15,4 15,7 16,4 13,2
Al 5,8 3,9 3,6 3,1 5
Fe 9,5 12,8 12,4 14,7 10,5
Mg 3,8 3,5 4 1,7 3,2
Ca 5,9 6,7 6,6 5,4 5,9
Na
K
Ti
Mn
P
Y
La 3,4 3,6 3,7 4,8 3,3
Ce 9,8 10 9,6 11,2 8,9
Pr 1,5 0,9 0,9 0,9 1,2
Nd 5,9 4 4,2 3 5,1
Sm 0,8 0,8
Eu
Gd
Tb
Co
Cu
Br
F
Mo
Ni 0,1
Total 99,9 100 100,1 99,8 99,9
14
Table 4. Recalculated data from SEM analyses of Mörkens samples.
Weight%
Sample mork2 mork2 mork2 mork2
Mineral Törnebohmite Törnebohmite Törnebohmite Törnebohmite
Analysis Spectrum 63 Spectrum 68 Spectrum 78 Spectrum 84
C 5 6,6 3,5 4
O 27,8 28,5 29,6 29,3
S 2,1 0,7 0,3
Si 11,9 12,4 13,6 12,7
Al 3,9 4,2 4,4 4,6
Fe 2,5 0,8
Mg 0,6 0,5 0,5 0,8
Ca
Na
K
Ti
Mn
P
Y 1,1
La 8,9 9 7,2 6,5
Ce 21,8 22,4 23,4 20,7
Pr 2,4 2,7 2,9 2,7
Nd 10,5 11 13,1 12,6
Sm 1,5 1,3 1,6 3,1
Eu
Gd 0,9 1,9
Tb
Co
Cu
Br
F
Mo
Ni
Total 99,8 100,1 100,1 100
15
Table 5. Recalculated data from SEM analyses of Mörkens samples.
Weight%
Sample mork 3 mork 2 mork3 mork3 mork2 mork2 mork2
Mineral
Västmanlandite
Västmanlandite
Västmanlandite
Västmanlandite
Västmanlandite
Västmanlandite
Västmanlandite
Analysis
Spectrum 52
Spectrum 80
Spectrum 28
Spectrum 43
Spectrum 64
Spectrum 65
Spectrum 81
C 3,6 3,6 2,7 4,2 5,5 6,4 3,2
O 32,1 32,7 32,2 31,6 30,5 31,4 30,8
S 1,1 0,2 1,4 2,4 3,5 1,1 0,5
Si 13,2 14,3 13,8 13,2 12,8 14,3 13,9
Al 5,1 5,5 4,9 4,7 4,4 4,5 5,2
Fe 4,6 8,6 4,7 5,1 6,8 3,8 2,2
Mg 3,3 0,9 3,3 3,1 1,8 1,9 1,8
Ca 3,6 4,9 3,8 3,7 2,6 2,7 2
Na
K
Ti
Mn
P
Y
La 5,2 5,4 5,3 4,4 6 6,2 5,8
Ce 15,2 14,1 15 14,2 15,3 16,3 18,2
Pr 2 1,6 1,9 2 1,9 2 2,8
Nd 9,2 6,9 9,4 9,2 7,9 8,2 10,3
Sm 1,1 1,1 1,4 1,6 1,2 1 2
Eu
Gd 1,3
Tb
Co
Cu 0,7 0,5
Br
F
Mo
Ni
Total 100 99,8 99,8 99,9 100,2 99,8 100
16
Table 5. Recalculated data from SEM analyses of Mörkens samples.
Weight%
Sample mork1 mork1 mork1 mork1 mork1
Mineral Britholite-Y? Britholite-Y? Britholite-Y? Cerite? Cerite?
Analysis Spectrum 60 Spectrum 61 Spectrum 59 Spectrum 72 Spectrum 74
C 4,1 5,2 4,2 6,9 8
O 37 38,7 43,2 28,6 28,4
S
Si 16,9 16 16,3 13,5 11,5
Al 0,8
Fe 0,4 0,6 3,6 1,1
Mg 1,2 1,3 4,8 4,1 5,3
Ca 11,1 10,7 9,4 3,8 3,3
Na
K
Ti
Mn
P
Y 18,8 18,3 15,2 2,5
La 1 3,2 9
Ce 1,9 1,6 0,5 12,4 18
Pr 2 1,6
Nd 1,6 1,5 1 11,9 9,8
Sm 0,8 3,8 1,6
Eu
Gd 2,1 2,6 1,7 2,8
Tb
Co
Cu
Br
F 2,4
Mo
Ni
Total 100,1 100 99,9 99,9 100
17
Table 7. Recalculated data from SEM analyses of Knutsbo and Mörkens samples.
Weight%
Sample mork3
mork3
mork1
knut 3 mork1 mork1 mork3
mork3
Mineral Fluorcerite?
Monazite?
Fluorcerite?
Altered allanite?
Magnesiorowlandite?
Dollaseite+tremolite?
Gadolinite?
Dollaseite+quartz?
Analysis Spectrum 42
Spectrum 44
Spectrum 57
Spectrum 24
Spectrum 62
Spectrum 73
Spectrum 27
Spectrum 40
C 10,7 3,6 8,1 6,4 2,3 8,2 6,6 12,6
O 21,2 27,8 26,2 42,8 26 38,3 29,8 37,3
S 5 1,4 0,3 4,2 1,3
Si 2,8 5,9 5,8 13,2 11,4 17,6 10,1 20,3
Al 0,8 7,3 2,9 2,7
Fe 3,9 2,3 14,2 0,5 8,6 8,6 6,8
Mg 1,3 2,4 2,3 5,3 2,3 5,6 1,1 2,3
Ca 0,6 1,5 1,1 4,8 2,4 7,3 0,4 4,5
Na
K
Ti
Mn
P 8,3
Y 2,3 1,3 3
La 9,5 5,7 15,8 1,3 9,7 2,1 1,8 1,9
Ce 20,4 20,6 24,4 3,2 23,6 6,1 9,6 6,5
Pr 2,9 3 2,8 0,8 2,1 0,8
Nd 12,3 14,4 8 1,3 13 2,5 14 2,9
Sm 2,4 2,3 2,6 4,9
Eu
Gd 0,8 1,3 3,8
Tb
Co
Cu
Br
F 6,1 5,5 0,8
Mo 0,5
Ni
Total 99,9 100 100 100,1 100 100 100 99,9
18
temperature and pressure, mafic and calc-
silicate mineral assemblages are common,
which is evident in the samples with minerals
like biotite, calcite, quartz and tremolite. The
high amount of allanite in the samples can be
considered an indication of REE presence in
the samples.
With most of the mineralogy in the samples
determined by observations through
microscopy, there is an uncertainty to be
considered. Although most mineral
assemblages can be determined through their
characteristics in parallel and crossed polars of
the microscope, some are harder to classify
only from this method. Some minerals might
have gone through reactions or contain more
information that requires further studies,
which therefore have not been detected
through the observations made of these
samples.
Also the classification of opaque phases
should be considered slightly uncertain as
they were only determined from observations
in reflected light in microscope. Even here,
some characteristics could have been missed
or even disregarded if irrelevant to the
project.
5.2 SEM results The SEM results are based on a backscatter
detector with low vacuum, which was chosen
due to absence of coal coating on the
samples. The four samples chosen for analyses
showed most potential for REE-bearing
mineralisations in microscopy and the
unidentifiable mineral were the main aim for
analysis, along with its surroundings.
As rather expected, REE mineralisations were
detected in several of the samples at variable
amounts, and most of them related to
minerals of the epidote family. The minerals
with pale brown pleochroism revealed REEs
like lanthanum (La) and cerium (Ce), and REE
mineralisations like törnebohmite and
västmanlandite were discovered in two of the
samples. Dollaseite was also detected in
several of the samples.
There are some rare mineralisations that have
possibly occurred in the samples but they are
very uncertain. These include britholite-Y,
yttrium, flourcerite, monazite,
magnesiorowlandite, and gadolinite. Many of
these mineralisations are very unusual and the
calculations of their chemical formulae are
very uncertain and can therefore be
considered more as guesses than actual
classifications.
As shown in the original data from the SEM
results, the samples contain coal. Since the
samples were not coal-coated, it could be a
result of inclusions of carbonate rocks or some
carbonates in the samples.
There are quite a few uncertainties regarding
the SEM analyses and their results. The
analyses of the different samples in general
suggest plenty of impurities and therefore
made it hard to calculate and determine the
compositions of the REE minerals. This issue
could be a result of the instrument itself, not
working correctly or having the wrong settings
adapted, the thin sections themselves could
have been soiled or simply the mineralisations
in the samples themselves have gone through
alteration.
It is not possible to determine where the error
lies for these impurities only from the data
collected, and the results should therefore be
reviewed with this in mind as they are rather
uncertain. SEM analyses are not the best
method of measuring REE in general, because
of their overall low contents close to detection
limits and their energy lines partially overlap.
The presented compositions of the REE-
bearing minerals are based of recalculations of
the values from the SEM analyses, normalised
to the mole ratio of the number of cations for
the different minerals. Quite a few
assumptions have been made during these
calculations, e.g. minor elements have been
excluded and all sulphide have been assumed
to be chalcopyrite or pyrite. This did not
change the results drastically but gave a better
end result for the somewhat inferior analyses.
19
5.3 Local geology As seen in figure 1, Knutsbo is not located
directly in the extensive lens of the REE-line,
but just at the northern end of it. Due to this,
it might not show all the same geological
features as that of the rest of the REE-line.
This can be considered by overviewing a
magnetic anomaly map of the region, where
Knutsbo might as well be a continuation of the
REE-line, only dislocated.
Although not a part of this work, figure 1 as
well as 2 show a possible fault stretching
between Knutsbo and the REE-line, which
could have displaced the bedrock of Knutsbo.
If that is the case, there should be similarities
between geology and mineralogy of that of
the REE-line, which is evident in some of the
result from this report.
The general mineral assemblages in the REE-
line resembles much of those in the Knutsbo
samples. The REE mineralisations are also
similar to those of the REE-line and a
connection between them seem apparent. It is
therefore reasonable to assume Knutsbo is
related to the REE-line, based on mineralogy
and REEs.
6. Conclusions The bedrock of Knutsbo consists of granitoid-
dioritoid-gabbroid (GDG) mafic intrusive rocks,
surrounded by GDG-type granite and
granodiorite to the south and GDG-type
granodiorite in the west. The rocks have been
affected by amphibolite facies metamorphism,
and there are occurrences, probably as
xenoliths, of iron oxide deposits in the area,
including banded iron formations (BIF).
The samples collected from the Knutsbo area
have a mineralogy mainly consisting of
allanite, tremolite, quartz and actinolite. There
is a presence of a pale brown-coloured
pleochroistic mineral that has proven to be
REE-bearing. The samples contain REEs like
lanthanum, cerium and neodymium, and
appear in mineralisations like dollaseite,
törnebohmite and västmanlandite. There is
traces of yttrium, monazite, gadolinite and
other rare mineralisations but their
classifications are very uncertain. Allanite is
abundant in the samples and also one of the
REE-bearing minerals.
Out of the nine thin sections that were
studied, the samples from Mörkens proved to
be richest in REEs, while REEs were generally
low in Gruvhagen. Results of the SEM analyses
can be found in appendix.
7. Acknowledgements First and foremost, I send my greatest
gratitude to my two supervisors during this
project. Joakim Mansfeld at Stockholm
University (SU) for good guidance and great
assistance in calculations and interpretation of
the results, and to Magnus Ripa at the
Geological Survey of Sweden (SGU) for good
supervision and very helpful guidance
throughout the project. Without their advice
and constructive feedback, this report would
not have been possible.
I would also like to thank the people at the
SGU for providing me with this project and the
material necessary in form of thin sections,
maps and literature. I thank the people
involved from that department, including Per
Nysten with his help with mineral
interpretations.
Lastly, I want to thank Marianne Ahlbom at SU
for assistance during the SEM analyses, as well
as Stockholm University and the Swedish
Museum of National History in Stockholm for
allowing me to use the SEM.
20
References Andersson, U. (2004). The Bastnäs-type REE-
mineralisations in north-western
Bergslagen, Sweden. The Geological
Survey of Sweden (SGU). Östervåla:
Elanders Tofters.
Geijer, P., & Magnusson, N. (1944). De
mellansvenska järnmalmernas
geologi. Stockholm: Kungl.
Boktryckeriet.
Holtstam, D., Andersson, U., & Mansfeld, J.
(2003). Ferriallanite-(Ce) from the
Bastnäs deposit, Västmanland,
Sweden. The Canadian Mineralogist,
41, 1233-1240.
Holtstam, D., Andersson, U., Broman, C., &
Mansfeld, J. (2014). Origin of REE
mineralisation in the Bastnäs-type Fe-
REE-(Cu-Mo-Bi-Au) deposits,
Bergslagen, Sweden. Mineralium
Deposita, 933-966.
Kampmann, T. (2015). structural framework
and constraints on the timing of
hydrothermal alteration and ore
formation at the Falun Zn.Pb-Cu-(Au-
Ag) sulphide deposit, Bergslagen,
Sweden. Licentiate thesis, Luleå
Technical University.
Persson, L. (1997). Berggrundskarta 12G
Avesta SO. Sveriges geologiska
undersökning Af 189.
SGA Excursion Guidebook. (2013). Bergslagen:
Geology of the volcanic- and
limestone-hosted base metal and iron
oxide deposits. Uppsala: 12th Biennial
SGA Meeting, Excursion Guidebook
SWE4.
Stephens, M., Ripa, M., Lundström, I., Persson,
L., Bergman, T., Ahl, M., Wahlgren,
C.H., Persson, P.O. & Wickström.
(2009). Synthesis of the bedrock
geology in the Bergslagen region,
Fennoscandian Shield, south-central
Sweden. The Geological Survey of
Sweden (SGU). Ba 58, 259 p.
21
Appendix
in Wt% Spectrum 2 Spectrum 3 Spectrum 4 Spectrum 5 Spectrum 6 Spectrum 7 Spectrum 8
S 41,3 0,2 38,7 24,8 0,1
Fe 36,6 8,2 35,1 23,8 8,0 11,9 7,8
C 8,7 2,6 9,2 11,9 2,5 4,4 2,9
O 7,9 39,7 10,5 8,8 39,3 42,7 40,9
Si 2,0 16,5 3,1 3,5 17,4 23,1 17,7
Ca 1,1 10,0 1,3 1,2 11,2 7,9 11,7
Al 0,9 8,6 0,6 9,3 0,9 9,2
Co 0,8
Mg 0,7 2,8 1,5 2,6 9,0 3,0
Ce 5,7 4,2 3,4
La 3,2 1,8 2,1
Nd 2,6 2,2 1,4
Cu 24,4
Br 1,5
Tb 0,1
Pr 0,8
Sm 0,7
Mn
Table 8. Result from SEM analysis of Knutsbo sample in wt%.
22
in Wt% Spectrum 9 Spectrum 10 Spectrum 11 Spectrum 12 Spectrum 19 Spectrum 20 Spectrum 21
S 26,2
Fe 7,3 7,3 7,1 6,2 7,3 9,1 24,6
C 2,9 3,1 2,4 2,4 3,0 1,8 6,7
O 41,6 39,7 39,3 43,7 36,5 37,2 8,4
Si 17,8 17,2 17,3 25,3 14,6 15,9 2,9
Ca 11,8 10,4 10,3 9,4 7,4 10,4 1,7
Al 9,4 8,5 8,6 1,4 7,7 9,5 1,7
Co
Mg 2,9 3,4 3,5 11,4 2,5 1,3 0,8
Ce 3,4 5,3 5,4 10,6 6,6 1,0
La 1,5 2,7 2,5 4,8 3,1
Nd 1,4 2,5 2,3 4,5 3,4
Cu 26
Br
Tb
Pr 0,6 1,1 0,9
Sm 0,6 0,7
Mn 0,2
Table 9. Result from SEM analysis of Knutsbo sample in wt%.
23
in Wt%
Spectrum 57
Spectrum 58
Spectrum 59
Spectrum 60
Spectrum 61
Spectrum 62
Spectrum 71
Spectrum 72
Spectrum 73
Spectrum 74
Spectrum 75
Spectrum 76
S 41,5
Fe 34,3 0,6 0,4 0,5 12,8 3,6 8,6 1,1 3,1 12,4
C 8,1 6,7 4,2 4,1 5,2 2,3 5,1 6,9 8,2 8,0 8,5 5,0
O 26,2 8,8 43,2 37,0 38,7 26,0 34,1 28,6 38,3 28,4 42,3 34,4
Si 5,8 3,4 16,3 16,9 16,0 11,4 15,4 13,5 17,6 11,5 24,8 15,7
Ca 1,1 1,2 9,4 11,1 10,7 2,4 6,7 3,8 7,3 3,3 8,9 6,6
Al 3,9 0,8 2,9 3,6
Co 2,1
Mg 2,3 1,9 4,8 1,2 1,3 2,3 3,5 4,1 5,6 5,3 12,4 4,0
Ce 24,4 0,5 1,9 1,6 23,6 10,0 12,4 6,1 18,0 9,6
La 15,8 1,0 9,7 3,6 3,2 2,1 9,0 3,7
Nd 8,0 1,0 1,6 1,5 13,0 4,0 11,9 2,5 9,8 4,2
Pr 2,8 0,9 2,0 0,8 1,6 0,9
Sm 0,8 2,6 3,8 1,6
Y 2,3 15,2 18,8 18,3 1,3 2,5
F 5,5 0,8 2,4
Mo 0,5
Dy 2,2 2,6 2,7
Gd 1,7 2,1 2,6 1,3 2,8
Er 1,4 1,4
Table 10. Result from SEM analysis of Mörkens sample in wt%.
24
in Wt% Spectrum 77 Spectrum 78 Spectrum 79 Spectrum 80 Spectrum 81 Spectrum 82 Spectrum 83 Spectrum 84
S 24,1 0,3 33,5 0,2 0,5 31,3
Fe 21,4 27,1 8,6 2,2 24,4 14,7
C 6,3 3,5 7,8 3,6 3,2 22,6 4,6 4,0
O 11,4 29,6 13,7 32,7 30,8 14,4 33,9 29,3
Si 4,7 13,6 4,0 14,3 13,9 3,9 16,4 12,7
Ca 0,1 0,1 4,9 2,0 5,4
Al 0,8 4,4 0,6 5,5 5,2 0,3 3,1 4,6
Mg 0,6 0,5 0,5 0,9 1,8 0,5 1,7 0,8
Ce 4,2 23,4 3,8 14,1 18,2 1,3 11,2 20,7
La 1,6 7,2 1,7 5,4 5,8 0,5 4,8 6,5
Nd 2,0 13,1 1,8 6,9 10,3 0,8 3,0 12,6
Pr 2,9 1,6 0,9 2,7
Sm 1,6 1,1 2,0 3,1
Cu 22,8 5,2
Gd 1,3 1,9
Ni 0,1
Y 1,1
Table 12. Result from SEM analysis of Mörkens sample in wt%.
25
in Wt%
Spectrum 27
Spectrum 28
Spectrum 29
Spectrum 30
Spectrum 31
Spectrum 32
Spectrum 33
Spectrum 34
Spectrum 35
Spectrum 36
Spectrum 37
Spectrum 38
S 4,2 1,4 39,2 20,8 37,7 3,6 30,5 17,9 27,4 3,8 1,4 0,9
Fe 8,6 4,7 34,1 21,0 32,0 2,9 26,8 20,0 24,9 10,5 4,1 10,8
C 6,6 2,7 14,2 34,4 19,0 20,9 24,9 31,8 27,8 6,2 4,0 2,3
O 29,8 32,2 9,6 17,1 8,4 38,5 13,6 25,2 14,2 32,8 42,1 42,5
Si 10,1 13,8 1,5 2,7 1,3 21,2 1,5 2,2 2,2 13,2 25,1 25,3
Ca 0,4 3,8 0,8 1,1 0,5 3,7 0,7 0,8 1,0 5,9 8,8 8,7
Al 4,9 0,5 0,6 0,2 0,3 0,3 5,0 0,4
Mg 1,1 3,3 0,7 1,3 0,5 2,0 0,7 1,0 1,1 3,2 12,6 9,6
Ce 9,6 15,0 0,5 0,6 8,9
La 1,8 5,3 3,3
Nd 14,0 9,4 5,1
Pr 2,1 1,9 1,2
Sm 4,9 1,4 0,8
Gd 3,8
K 0,1 0,1 0,2 0,2 0,2
Y 3,0
Na 0,1 0,2
F 1,4
Co 0,4 0,6 0,4 0,6 1,0
Table 13. Result from SEM analysis of Mörkens sample in wt%.
26
in Wt% Spectrum 39 Spectrum 40 Spectrum 41 Spectrum 42 Spectrum 43 Spectrum 44 Spectrum 45 Spectrum 46 Spectrum 47
S 0,6 1,3 2,7 5,0 2,4 1,4 41,2 5,2 4,6
Fe 2,8 6,8 3,1 3,9 5,1 2,3 34,7 6,6 6,3
C 2,6 12,6 15,5 10,7 4,2 3,6 15,5 7,4 8,2
O 45,5 37,3 44,7 21,2 31,6 27,8 6,1 39,4 39,1
Si 28,1 20,3 29,5 2,8 13,2 5,9 1,3 21,5 21,2
Ca 0,8 4,5 0,2 0,6 3,7 1,5 0,3 7,7 7,4
Al 2,7 0,3 4,7 0,8 0,6
Mg 17,2 2,3 0,7 1,3 3,1 2,4 0,4 11,1 11,1
Ce 6,5 0,9 20,4 14,2 20,6
La 1,9 9,5 4,4 5,7
Nd 2,9 1,4 12,3 9,2 14,4
Pr 0,8 2,9 2,0 3,0
Sm 0,5 2,4 1,6 2,3
Gd 0,5 0,5
K 0,8
Y 0,1
Na 0,3
F 2,4 6,1 1,1 1,2
Co 8,3
Table 14. Result from SEM analysis of Mörkens sample in wt%.
27
in Wt% Spectrum 48 Spectrum 49 Spectrum 50 Spectrum 51 Spectrum 52 Spectrum 53 Spectrum 54 Spectrum 55 Spectrum 56
S 3,4 2,3 1,1 0,6 1,1 0,5 1,3 30,7 1,2
Fe 5,6 10,1 9,5 8,4 4,6 8,3 3,3 29,1 4,5
C 10,0 5,9 3,3 3,1 3,6 3,2 3,6 8,8 3,3
O 40,2 40,7 34,3 36,5 32,1 35,5 45,2 20,6 41,6
Si 21,5 23,4 14,8 15,8 13,2 15,7 26,9 4,6 24,6
Ca 7,7 8,6 5,9 5,9 3,6 5,7 0,7 2,4 8,2
Al 0,5 5,8 5,6 5,1 5,6 0,3 0,7 0,7
Mg 11,0 9,1 3,8 4,8 3,3 4,9 16,6 2,8 12,5
Ce 9,8 9,5 15,2 9,3 8,2
La 3,4 3,2 5,2 3,4
Nd 5,9 5,5 9,2 5,6
Pr 1,5 1,1 2,0 1,4
Sm 0,8 1,1 0,9
Gd 0,7 0,6
K 0,3
Y 0,2
Na 2,2 1,6
F
Co
Table 15. Result from SEM analysis of Mörkens sample in wt%.
28
Weight% oxides
Sample knut 3 knut 3 knut 3 knut 3 knut 3 knut 3 knut 3 knut 3 knut 3 knut 3
Mineral REE-poor allanite REE-poor allanite REE-poor allanite REE-poor allanite REE-poor allanite REE-poor allanite Allanite Allanite Allanite Allanite
SiO2 35,29903818 37,22444026 37,86624096 38,08017452 36,79657313 37,0105067 31,2343005 34,0154368 31,8761011 31,2343005
TiO2
Al2O3 16,24939046 17,57201527 17,38306887 17,76096167 16,06044406 16,24939046 14,5488729 17,9499081 18,3278009 15,1157121
FeO** 10,54926638 10,2919672 10,03466802 9,391420071 9,391420071 9,134120891 9,39142007 11,7071127 11,0638647 9,77736884
MnO
MgO 4,643169662 4,311514686 4,974824638 4,80899715 5,63813459 5,803962078 4,1456872 2,15575734 2,48741232 3,64820473
CaO 13,99206446 15,67111219 16,37071542 16,51063606 14,55174704 14,41182639 10,3541277 14,551747 13,9920645 10,9138103
Na2O
K2O
P2O5
NiO
Y2O3
La2O3 3,2 1,8 2,1 1,5 2,7 2,5 4,8 3,1 2,9 4,2
Ce2O3 6,676299459 4,919378549 3,982354063 3,982354063 6,207787216 6,324915277 12,4155744 7,73045201 7,37906782 11,4785499
Pr2O3 0,936254383 0,702190787 1,28734978 1,05328618 1,05328618 1,52141337
Nd2O3 3,032591436 2,566038908 1,63293385 1,63293385 2,915953304 2,68267704 5,24871595 3,96569649 3,6157821 4,89880155
Sm2O3 0,811722965 0,695762542 0,81172297 0,92768339 0,92768339
Eu2O3
Gd2O3
Tb2O3
CoO
CuO
MoO2
F
Table 16. Calculated oxide values for Knutsbo sample, in wt%
29
Weight% oxides
Sample mork 3 mork 3 mork 3 mork1 mork1 mork 2 mork3
Mineral Dollaseite Dollaseite Dollaseite Dollaseite Dollaseite Dollaseite Dollaseite
SiO2 33,8015032 33,5875697 31,6621676 32,94577 33,58757 35,0851 28,23923
TiO2
Al2O3 10,5809984 10,5809984 10,9588912 7,36891 6,80207 5,857338 9,44732
FeO** 10,8065656 10,677916 12,2217111 16,46715 15,95255 18,91149 13,50821
MnO
MgO 7,95971942 8,12554691 6,30144454 5,803962 6,6331 2,819067 5,30648
CaO 8,25531803 7,97547674 8,25531803 9,374683 9,234763 7,555715 8,255318
Na2O
K2O
P2O5
NiO 0,127259
Y2O3
La2O3 3,2 3,4 3,4 3,6 3,7 4,8 3,3
Ce2O3 11,1271658 10,8929096 11,4785499 11,71281 11,24429 13,11834 10,4244
Pr2O3 1,28734978 1,63844517 1,75547697 1,053286 1,053286 1,053286 1,404382
Nd2O3 6,41509727 6,5317354 6,8816498 4,665525 4,898802 3,499144 5,948545
Sm2O3 1,04364381 0,92768339 0,927683
Eu2O3
Gd2O3
Tb2O3
CoO
CuO
MoO2
F
Table 17. Calculated oxide values for Mörkens samples, in wt%
30
Weight% oxides
Sample mork 3 mork 2 mork3 mork3 mork2 mork2 mork2 mork2 mork2 mork2 mork2
Mineral Västmanlandite
Västmanlandite
Västmanlandite
Västmanlandite
Törnebohmite
Törnebohmite
Törnebohmite
Törnebohmite
Västmanlandite
Västmanlandite
Västmanlandite
SiO2 28,23923 30,5925 29,52283 28,23923 25,45809 26,52776 29,09496 27,16956 27,3835 30,5925 29,73677
TiO2
Al2O3 9,636266 10,39205 9,258374 8,880481 7,36891 7,935749 8,313642 8,691534 8,313642 8,502588 9,825213
FeO** 5,917881 11,06386 6,046531 6,561129 3,21624 1,029197 8,748172 4,888684 2,830291
MnO
MgO 5,472307 1,492447 5,472307 5,140652 0,994965 0,829137 0,829137 1,32662 2,984895 3,150722 2,984895
CaO 5,037143 6,856112 5,316984 5,177064 3,637937 3,777857 2,798413
Na2O
K2O
P2O5
NiO
Y2O3 1,396932
La2O3 5,2 5,4 5,3 4,4 8,9 9 7,2 6,5 6 6,2 5,8
Ce2O3 17,80347 16,51506 17,56921 16,63218 25,53392 26,23669 27,40797 24,24551 17,92059 19,09187 21,31731
Pr2O3 2,340636 1,872509 2,223604 2,340636 2,808763 3,159859 3,393922 3,159859 2,223604 2,340636 3,27689
Nd2O3 10,73071 8,048031 10,96398 10,73071 12,247 12,83019 15,2796 14,6964 9,214412 9,564327 12,01373
Sm2O3 1,275565 1,275565 1,623446 1,855367 1,739406 1,507486 1,855367 3,594773 1,391525 1,159604 2,319208
Eu2O3
Gd2O3 1,037354 2,189969 1,4984
Tb2O3
CoO
CuO 0,876244 0,625888
MoO2
F
Table 18. Calculated oxide values for Mörkens samples, in wt%
31
Weight% oxides
Sample mork1 mork1 mork1 mork1 mork1
Mineral Britholite-Y? Britholite-Y? Britholite-Y? Cerite? Cerite?
SiO2 36,15477244 34,22937036 34,87117105 28,88103124 24,60235994
TiO2
Al2O3 1,511571206
FeO** 0,51459836 0,77189754 4,631385241 1,41514549
MnO
MgO 1,989929855 2,155757343 7,959719421 6,798927006 8,788856861
CaO 15,53119155 14,97150897 13,15254059 5,316984494 4,617381271
Na2O
K2O
P2O5
NiO
Y2O3 23,87484342 23,23987418 19,30306489 3,1748462
La2O3 1 3,2 9
Ce2O3 2,225433153 1,874048971 0,585640303 14,52387952 21,08305092
Pr2O3 2,340635957 1,872508765
Nd2O3 1,866210115 1,749571982 1,166381322 13,87993773 11,43053695
Sm2O3 0,927683389 4,406496098 1,855366778
Eu2O3
Gd2O3 2,420492481 2,996800215 1,959446294 3,227323308
Tb2O3
CoO
CuO
MoO2
F 2,4
Table 19. Calculated oxide values for Mörkens samples, in wt%
32
Weight% oxides
Sample mork3 mork3 mork1 knut 3 mork1 mork1 mork3 mork3
Mineral Fluorcerite? Monazite? Fluorcerite? Altered allanite? Maggnesiorowlandite? Dollaseite+tremolite? Gadolinite? Dollaseite+quartz?
SiO2 5,99013981 12,6220803 12,4081468 28,23923 24,38843 37,6523074 21,60729 43,4285136
TiO2
Al2O3 1,51157121 13,79309 5,47944562 5,10155282
FeO** 5,01733401 2,95894057 18,26824 0,643248 11,0638647 11,0638647 8,74817212
MnO
MgO 2,15575734 3,97985971 3,81403222 8,788857 3,814032 9,28633932 1,82410237 3,81403222
CaO 0,83952387 2,09880967 1,53912709 6,716191 3,358095 10,2142071 0,55968258 6,29642901
Na2O
K2O
P2O5 19,018351
NiO
Y2O3 2,9208585 1,65092 3,80981544
La2O3 9,5 5,7 15,8 1,3 9,7 2,1 1,8 1,9
Ce2O3 23,8941244 24,1283805 28,5792468 3,748098 27,64222 7,1448117 11,2442938 7,61332394
Pr2O3 3,39392214 3,51095394 3,27689 0,93625438 2,45766775 0,93625438
Nd2O3 14,3464903 16,795891 9,33105057 1,516296 15,16296 2,9159533 16,3293385 3,38250583
Sm2O3 2,78305017 2,66708974 3,014971 5,68206076
Eu2O3
Gd2O3 0,92209237 1,4984 4,37993878
Tb2O3
CoO
CuO
MoO2 0,66673031
F 6,1 5,5 0,8
Table 20. Calculated oxide values for Mörkens samples, in wt%
2016 - Karolina Mattsson - BSc - Geology 15hpKarolina Report