UNIVERSITY OF GOTHENBURG Department of Earth Sciences Geovetarcentrum/Earth Science Centre
Evaluation of and comparison
between petrographic and technical
properties of rock samples from the
supposed railway corridor between
Gothenburg and Jönköping, SW Sweden
Camilla Lindström
ISSN 1400-3821 B963 Master of Science (120 credits) thesis Göteborg 2017
Mailing address Address Telephone Telefax Geovetarcentrum Geovetarcentrum Geovetarcentrum 031-786 19 56 031-786 19 86 Göteborg University S 405 30 Göteborg Guldhedsgatan 5A S-405 30 Göteborg SWEDEN Table of Contents
1. Introduction ...... 6 1.1 Background ...... 6 1.2 Objectives ...... 7 2. Geological Setting ...... 7 2.1 The Western Segment ...... 8 2.2 The Mylonite zone ...... 8 2.3 The Eastern Segment...... 8 2.4 The Protogine zone ...... 8 2.5 The Transscandinavian Igneous Belt ...... 8 3. Crushed Rock Material ...... 9 3.1 Crushed Rock Material in Road and Railway Ballast ...... 9 3.2 Crushed Rock Material in Concrete ...... 9 4. Technical properties of rocks ...... 10 4.1 Grain Size and Grain Size Distribution ...... 11 4.2 Mineralogy ...... 11 4.3 Grain Boundaries ...... 12 4.4 Perimeter ...... 12 4.5 Foliation ...... 12 4.6 Micro Cracks ...... 12 4.7 Secondary Alterations ...... 13 4.8 Porosity ...... 13 5. Earlier Work ...... 13 6. Materials and Methods ...... 13 6.1 Technical Analysis ...... 14 6.1.1 Los Angeles Test ...... 14 6.1.2 Studded Tyre Test ...... 15 6.1.3 MicroDeval Test ...... 15 6.2 Micro Analysis ...... 15 6.2.1 Mineralogy ...... 15 6.2.2 Grading of Grain Boundaries ...... 15 6.2.3 Secondary Alterations ...... 15 6.3 Image Analysis ...... 16 6.3.1 Mineral Grain Size and Grain Size Distribution ...... 16 6.3.2 Perimeter Analysis ...... 18 7. Results ...... 18
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7.1 Technical Analysis ...... 18 7.2 Mineralogy ...... 24 7.3 Micro Analysis ...... 26 7.3.1 Grading of Grain Boundaries ...... 26 7.3.2 Altered Plagioclase ...... 28 7.4 Image Analysis ...... 29 7.4.1 Grain Size and Grain Size Distribution ...... 31 7.4.2 Perimeter ...... 32 7.4.3 Crystal Alignment ...... 33 8. Discussion ...... 33 8.1 Technical Analysis ...... 33 8.2 Mineralogy ...... 33 8.3 Micro Analysis ...... 34 8.3.1 Grading of Grain Boundaries ...... 34 8.3.2 Evaluation of Method ...... 34 8.3.3 Altered Plagioclase ...... 35 8.4 Image Analysis ...... 35 8.4.1 Grain Size and Grain Size Analysis ...... 35 8.4.2 Perimeter ...... 35 8.4.3 Crystal Alignment ...... 35 8.4.4 Evaluation of Method ...... 36 9. Conclusions ...... 37 10. Acknowledgments ...... 38 11. References ...... 39 12. Appendix ...... 42 12.1 Appendix A: General and technical data ...... 42 12.2 Appendix B: Grade of Intergrowth and Grade of Altered Plagioclase ...... 48 12.3 Appendix C: Mineralogy...... 51 12.4 Appendix D: Area and Perimeter ...... 54 12.5 Appendix E: Texture and Grain Size ...... 55
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Abstract
Natural gravel is considered a very important, and finite, resource given its significant role in various groundwater-related issues. Natural gravel has been used as ballast and aggregates for many decades, given its favourable properties such as well-rounded and well-sorted grains. As an alternative to natural gravel, it is possible to use larger quantities of crushed bedrock material instead. This does however place great demands on the bedrock's geological and technical characteristics. The strength and resistance of the bedrock is evaluated with the Los Angeles (resistance to fragmentation; LA) and Studded Tyre (resistance to abrasion; AN) tests, which will indicate whether the material is suitable enough to be used as construction material. The strength of a rock material is in many ways a product of its petrographic characteristics, such as mineralogy, grain size, grain boundary complexity, perimeter, microcracks and amount of alteration, amongst others. The rock samples analysed in this thesis originate from different lithotectonic units, why they are expected to show varying petrographic and technical properties.
The infrastructure in Sweden is intended to be extensively upgraded within the near future. The project “Götalandsbanan”, a railway for high-speed trains between Gothenburg and Stockholm, is intended to be a part of this upgrade. This construction does however place great demands on its surroundings, as large amounts of high quality crushed bedrock material will be needed for concrete aggregates and road- and railway constructions, preferably recovered in the vicinity of the locality where it will be used. The Swedish Geological Society is currently working on updating and expanding the geological data in the vicinity of the planned track profile between Gothenburg and Jönköping, why they have kindly contributed with sampled material and geological data from this area, enabling this thesis to be carried out.
A relatively large number of bedrock samples of predominantly granitic composition, together with corresponding technical data, have been analysed and evaluated in thin section with regards to their technical properties, mineralogy, grain boundary complexity, grain size and amount of altered plagioclase. This has been done by comparing the data at hand, i.e. the technical data with mineralogical data, and furthermore comparing the technical data with results from image analysis (grain size, perimeter, etc.), grading of grain boundary complexity and grading of amount of altered plagioclase. Image analysis has been carried out with image analysis software’s Adobe Photoshop CS6, ImageJ 1.50i and CSD Corrections 1.53.
The results of this thesis reveal that there is a correlation between the rocks LA value and its grain boundary complexity, were more interlocking and complex grain boundaries will strengthen the rock. The same correlation is seen between the rocks LA value and its total amount of altered plagioclase, where increased amounts of altered plagioclase seems to strengthen the rock as well. The AN value on the other hand seems to be more affected by the mineralogy of the rock, were increased amounts of mica and decreased amounts of feldspars most definitely lowers the rocks resistance to abrasion. No correlation between grain size, grain size distribution or perimeter and the rocks technical values was found, which might only reflect the fact that these properties of the rock samples were to alike in this case.
Regarding the different lithotectonic units, the most favourable (strength and resistance-wise) rock types were as expected found in the Transscandinavian Igneous Belt to the east, in comparison to the Western and Eastern Segments to the west.
Key Words: Rock quality, crushed bedrock material, quantitative petrographic analysis, image analysis, grain boundaries, perimeter, Los Angeles test, Studded tyre test
Supervisors: Johan Hogmalm, University of Gothenburg, and Thomas Eliasson, The Geological Society of Sweden
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Sammanfattning
Naturgrus anses vara en mycket viktig, och ändlig, naturtillgång med tanke på dess betydande roll i olika grundvattenrelaterade frågor. Naturgrus har använts som ballast och aggregat inom byggindustrin i många årtionden, mycket på grund av dess fördelaktiga egenskaper såsom välrundade och välsorterade korn. Som ett alternativ till naturgrus är det möjligt att använda sig av större mängder krossat berg istället. Detta ställer dock stora krav på berggrundens geologiska och tekniska egenskaper. Bergets styrka och beständighet kan utvärderas med hjälp av Los Angelestest (motstånd mot fragmentering; LA) och Kulkvarnstest (motstånd mot nötning; AN), tester som indikerar om materialet är lämpligt nog att användas som byggmaterial. Bergmaterialets styrka är i mångt och mycket ett resultat av dess petrografiska egenskaper såsom mineralogi, kornstorlek, typ av korngränser, perimeter, mikrosprickor och mängden omvandlad plagioklas, bland mycket annat. Bergproverna som analyserats i denna avhandling kommer från olika litotektoniska enheter, varför de kan förväntas uppvisa varierande egenskaper sinsemellan.
Infrastrukturen i Sverige står inför kraftiga uppgraderingar inom en snar framtid. Projektet ”Götalandsbanan” är en sträcka av en ny järnvägsförbindelse mellan Göteborg och Stockholm avsedd för höghastighetståg. En konstruktion som denna innebär dock högt ställda krav på sin omgivning, främst med tanke på att det kommer krävas stora mängder krossat berg av hög kvalitet till betongballast samt väg- och järnvägskonstruktioner, företrädesvis utvunnet i närheten av där materialet ska komma att användas. Sveriges Geologiska Undersökning (SGU) arbetar för närvarande med att uppdatera och utöka geologiska data i området avsett för den planerade spårprofilen mellan Göteborg och Jönköping, varför de vänligen bidragit med provtaget material och geologiska data från det berörda området, vilket möjliggjort detta projekt.
Ett relativt stort antal berggrundsprov av granitisk sammansättning, tillsammans med motsvarande tekniska data, har i tunnslips-form analyserats och utvärderats främst med avseende på tekniska egenskaper, mineralogi, typ av korngräns, kornstorlek och mängden av omvandlad plagioklas. Detta har gjorts genom att jämföra tillgängliga data, dvs tekniska värden, med provernas mineralogi, samt genom att jämföra de tekniska värdena med resultat från bildanalyser (kornstorlek, perimeter, etc.), gradering av korngränsernas komplexitet och gradering av mängden omvandlad plagioklas. Bildanalyserna har utförts med bilanalysprogrammen Adobe Photoshop CS6, ImageJ 1.50i and CSD Corrections 1.53.
Resultaten av ovan nämnda analyser visar att det finns ett samband mellan bergmaterialets LA-värde och komplexiteten av dess korngränser, där mer sammanväxta och komplexa korngränser ser ut att ge materialet en ökad styrka. Ett liknande samband verkar finnas mellan bergmaterialets LA-värde och andelen omvandlad plagioklas, där högre andel omvandlad plagioklas också verkar ha en tendens att stärka materialet. AN-värdet å andra sidan verkar vara mer påverkat av bergartens mineralogi, där ökad mängd glimmer och minskad mängd fältspater tydligt försämrar materialets motstånd mot nötning. Inget samband hittades mellan materialets tekniska egenskaper och dess kornstorlek, kornstorleksfördelning eller perimeter, något som möjligtvis endast återspeglar det faktum att dessa utvalda prover var alltför lika varandra för att påvisa något samband.
Vad gäller de olika litotektoniska enheterna så återfanns det bästa bergmaterialet (starkast och mest motståndskraftigt) som väntat i det Transskandinaviska bältet i öster, jämfört med det Västra och Östra Segmenten i väst.
Nyckelord: Bergkvalitet, krossat bergmaterial, kvantitativ petrografisk analys, bildanalys, korngränser, kornstorlek, perimeter, Los Angeles, Kulkvarn
Handledare: Johan Hogmalm, Göteborgs Universitet, och Thomas Eliasson, Sveriges Geologiska Undersökning
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1. Introduction for this purpose. However, the Swedish Parliament, in April 1999 (as well as in 1.1 Background November 2005), decided to establish 16 so- called "environmental quality objectives", As a result of a rapidly growing community which form the basis of the national with increasing demands for environmental environmental policy. These objectives include quality, accessibility and quality of life, an a vision stating that we, by year 2020, should extensive upgrading of Sweden's infrastructure be able to hand over a Swedish society to the is intended within the near future. This has led next generation in which the major to the project ”Götalandsbanan”, a railway for environmental problems have been solved. One high-speed trains between Gothenburg and of these environmental objectives is to reduce Stockholm, passing through smaller cities as the use of nature gravel, mainly due to its Borås, Jönköping and Linköping (Fig. 1). The significant role in various groundwater-related objective of the project is not only to issues, together with the fact that natural significantly shorten the travelling time gravel is not an endless resource. between these cities, but also, for example, "blurring" the boundaries between urban and As an alternative to natural gravel, it is rural areas, increasing economic integration possible to use larger quantities of crushed and achieve a better functioning labour market bedrock material (Fig. 2), preferably recovered along the current route (Om Projektet – in the vicinity of the locality where it will be Götalandsbanan, n.d.). This would eventually used, in order to dramatically reduce promote efficiency and growth while giving transportation of such large volumes of people greater opportunities to find a balance material. In order for the crushed material to between private life and work. be used as concrete aggregates or in road- and railway constructions, it must however meet The construction of Götalandsbanan does certain requirements, for example in terms of however place great demands on its the bedrock's geological and technical surroundings. Considering that the track is characteristics. Information on these features is mostly planned to be built as longitudinal not only required prior to the processing and concrete plate, called Slab track (i.e. ballast-free proportioning of concrete, but can also be used track), it is expected to require large amounts as a basis for the assessment of quarry of gravel, in particular for concrete aggregate. localities. The Geological Survey of Sweden is Ideally, one would prefer to use natural gravel currently working on updating and expanding the geological data in the vicinity of the planned track profile between Gothenburg and Jönköping, in order to create coherent information on bedrock, soil and groundwater in the area of concern (e.g. Bergström et al., 2015). The Geological Survey of Sweden has
Figure 1 Map of southern Sweden showing the approximate routes of planned railway for high- Figure 2 Graph displaying the amount of aggregate speed trains. The route called Götalandsbanan runs deliveries in Sweden 1984-2014 according to type from the city of Gothenburg in the west, through of material. Amounts are in million tonnes. The smaller cities such as Borås, Jönköping and graph reveals that the amount of natural gravel Linköping, to the city of Stockholm in east. The being used as aggregates for construction has concern of this thesis lies in the vicinity of the route steadily been reducing during the last few decades. between Gothenburg and Jönköping. Figure from Figure modified after Sveriges geologiska Stjärnered (2016). undersökning (2015a).
6 therefore kindly contributed with sampled rocks technical quality by manually grading material and geological data, enabling this the amount of intergrowth between grains in thesis to be carried out. each thin section and comparing this with the LA and AN value of the sample, given that a The geological data from the Geological higher amount of interlocking grains has been Survey of Sweden consists, among other data, shown to improve a rocks technical properties of Los Angeles-value (LA) and Studded tyre (e.g. Höbeda, 1971; Höbeda, 1995; Åkesson et test values (AN) from samples collected along al., 2003; Göransson et al., 2004). the track profile between Gothenburg and Jönköping, values that display the technical This thesis also includes image analysis of a properties of the rock in terms of its resistance number of samples, mainly in order to try out to fragmentation (LA) and abrasion (AN). a tool in Adobe Photoshop CS6 which enables These mechanical properties vary due to quick and precise selection of individual differences in rock texture (grain size, grain minerals in a thin section photo acquired from boundaries, grain shape), structure (foliation) an optical microscope. The resulting image of and mineral composition. highlighted minerals has in turn be used for analysis of mean grain size, grain size 1.2 Objectives distribution (CSD), perimeter and to some extent fabric orientation, by using the image The aim and objective of this thesis is first and analysis software ImageJ 1.50i and CSD foremost to examine and evaluate a relatively Corrections 1.53. large amount of bedrock samples of predominantly granitic composition in thin By comparing the mentioned technical and section, together with corresponding technical microscopic characteristics of a rock, together data, in order to find and emphasize any with other given properties such as relations between different technical and minerology, one can hope to find reasons for petrological properties of a rock. Samples from and evidence to why two macroscopically alike rocks of granitic compositions are of interest rocks may display different technical not only because of their high occurrence in characteristics, as well as how two seemingly Sweden, but also because of the stability of different rock types can exhibit equal technical their mineral composition, often regardless of characteristics. deformation and/or metamorphism. 2. Geological Setting Given that the concerned samples originate from different lithotectonic units and zones, The geology of Sweden is mainly the result of they have supposedly been subject to various a number of orogenic events between 3.5 and types and amounts of geological processes in 1.5 Ga (Gaál & Gorbatschev, 1987), were the conjunction with tectonic activity in the area. Fennoscandian (Baltic) Shield grew by This is commonly evidenced by rocks accretion (Mohammad et al., 2011). The shield displaying different technical and petrological can be divided into three main domains; the properties depending on their lithotectonic Archean domain (north), the Svecofennian origin, whereupon this thesis attempts to point Province (east) and the Sveconorwegian out what one might be able to assume about a Province (south) (Fig. 3), the two latter being rocks quality simply by considering its tectonic of interest here. These domains have further history. been divided into different lithotectonic segments; the southernmost part of the In the construction industry today, you are Svecofennian Province consists of the constantly searching to find environmentally Transscandinavian Igneous Belt (TIB), while friendly as well as cost-effective methods the Sveconorwegian Province consists of, regarding searching for, evaluating and among other segments, the Eastern and extracting materials suitable for various types Western Segments (Fig. 3). These three of construction. The challenge often lies in the segments are separated by large deformation well-known fact that cost-effective and zones; the Mylonite zone separating the environmentally friendly methods are rarely Western Segment from the Eastern Segment, synonymous. With this in mind, this thesis and the Protogene Zone lying between the includes an attempt to prove and emphasize a Eastern Segment and the TIB (Fig. 3). simple, “quick and dirty” way to estimate a
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varying types of granitic and granodioritic gneiss (1700 Ma). The bedrock of the Eastern Segment has generally been subject to higher crustal depths and therefore higher temperatures and pressure compared to the Western Segment (Larson et al., 1986; Larson & Berglund, 1992). This is demonstrated by rock types with poor technical properties, with for example rounded grains and straight grain boundaries, together with high amounts of elongated minerals (Bergström et al., 2015). A problem when mapping the gneissic bedrock of the Eastern Segment, according to Bergström et al. (2015) is the heterogeneity of the bedrock, with a wide range of compositions even within the same outcrop. This results in an even more simplified bedrock map than usual, were only the most common composition is mapped. Figure 3 Map showing the major geological units of Bergström et al. (2015) also points out that the southern Sweden, modified after Hegardt et al. relatively flat dip (15-30 degrees towards the (2005). west) may result in a relatively thin superficial 2.1 The Western Segment layer being mapped over a large area, where the bedrock in reality is very heterogeneous. Within the concerned area of the railway route, the Western Segment (also known as the 2.4 The Protogine zone Idefjorden Terrane) is dominated by the Gothenburg suite (1600 Ma), with mostly The Protogine Zone (PZ) is a ~25 km wide and granodioritic and tonalitic rocks. These are steeply dipping deformation zone south of Lake often found to be gneissic and veined with Vättern that has been subject to high amounts characteristic features such as long, persistent of strain. The zone separates the high grade bands of augen gneiss, revealing that the Eastern Segment from the only slightly Gothenburg suite has been subject to generally metamorphosed TIB in a N-S trending high amounts of deformation (Bergström et al., direction (Larson et al., 1986; Johansson et al., 2015). The Western Segment also consists of 1993). In reality, the Protogine zone is a major the younger, generally less deformed Hisingen shear-zone system, its easternmost part being suite (ca 1560 Ma) and Kungsbacka suite (ca the Sveconorwegian Frontal Deformation 1320 Ma). Zone (SFDZ) which in turn is the eastern border of the Sveconorwegian orogeny 2.2 The Mylonite zone (Brander et al., 2012). The zone can therefore be considered to be a tectonometamorphic The Mylonite Zone (MZ), an arcuate, 400 km break, considering that the rocks to its west, in long, north-south trending ductile deformation the Eastern Segment, is heavily deformed by zone, is situated between the Eastern and Sveconorwegian and pre-Sveconorwegian Western Segment. The deformation zone is, in orogenic events, while the bedrock east of the summary, a result of Sveconorwegian zone comprises the nearly unaffected 1920- transpressional deformation, evidenced in the 1810 Ma rocks of the Svecokarelian orogen and northern and central parts of the zone 1810–1650 Ma plutons and volcanic rocks of (Mohammad et al., 2011). The bedrock within the TIB (e.g. Andréasson & Dallmeyer, 1995; the zone is heavily deformed and contains rock Söderlund et al., 2005; Möller et al., 2007). types from both the Western and Eastern Segment. 2.5 The Transscandinavian Igneous Belt
2.3 The Eastern Segment The Transscandinavian Igneous Belt, or TIB, stretches ~1500 km in a roughly N-S direction The Eastern Segment, within the concerned across the Scandinavian Peninsula, reaching area of the railway route, primarily consists of from the south-easternmost parts of Sweden all the way to north-western Norway (Högdahl et
8 al., 2004; Brander et al., 2012). It was formed material in their concrete with increasing effort mostly by the reworking of the juvenile (2100- in recent years. This does however place great 1870 Ma) Svecofennian crust with addition of demands on the knowledge of how the crushed mantle material in a continental-arc setting material interacts with other elements of the (Högdahl et al., 2004), why it is dominated by concrete, such as flowing agents and cement, granitoid, syenitoid and gabbroid plutons and and how to adapt the selection and quarrying associated volcanic rocks, all of whom are of bedrock and mixing of concrete agents in relatively undeformed (Brander et al., 2012). order to manufacture a final product with low maintenance needs and costs (Lagerblad et al., 3. Crushed Rock Material 2011).
The demands on the quality of rock material There are a number of differences between being used for road and railway construction natural gravel and crushed bedrock material. may be completely different depending on the The particles in the crushed rock material are area of use. In order to build sustainable more angular and have a rougher surface, while concrete constructions, roads and railways, the the natural gravel is more rounded and almost properties of the material must meet the polished (Göransson, 2011), given that it has demands of the construction being built. As been processed and worn by forces of nature mentioned, properties such as mineralogy, through time (Fig. 4-5). Furthermore, the grain size and grain boundaries may indicate weaker material of the natural gravel has been the mechanical behaviour of a rock material. In destroyed over time. Because of these order to utilize the resources in a cost effective differences, the amounts of concrete agents will and environmentally friendly manner, the area have to be assembled differently in order for of use of the rock material should be adapted according to the materials properties. Rock material with less desirable properties may be used in less sensitive constructions if possible, while the rock material with the highest quality can be used in the most sensitive constructions (Hellman, et al., 2011).
3.1 Crushed Rock Material in Road and Railway Ballast Figure 4 Scanning electron microscope (SEM) The requirements placed on rock materials image of thin sections with natural ballast (left) used for the construction of roads and railways versus crushed rock material (right). The natural varies somewhat, and largely depends on in gravel displays the characteristically more rounded which layer of the construction it is intended to grains, while the crushed rock material is flakier. The fraction is 0,5 – 1,0 mm. The fragments are be used. In general, rock materials used for built up by several mineral grains. Images from road construction is recommended to have low Lagerblad et al. (2011). Los Angeles (<25%) and studded tyre test (<4- 14%) values, a low to intermediate amount of mica minerals (<30%) as well as a low flakiness of particles (Geological Society of Sweden, 2016). For use in railroad constructions, the rock material should preferably have a low Los Angeles value (≤20% measured on fraction 31.5-50 mm), a low to intermediate amount of mica minerals (<10-25%), a low water absorption (<0.5%) as well as a low flakiness of Figure 5 Scanning electron microscope (SEM) particles (Geological Society of Sweden, 2016). image of thin sections with natural ballast (left) versus crushed rock material (right). The natural gravel displays the characteristically more rounded 3.2 Crushed Rock Material in Concrete grains, while the crushed rock material is flakier. The fraction is 0,125-0,25 mm. The fragments are The concrete industry has been attempting to predominantly individual minerals. Light coloured replace natural gravel with crushed rock flaky particles are most likely biotite. Images from Lagerblad et al. (2011)
9 the concrete to meet certain requirements, both aggregates will require more water and in liquid and solid form (Lagerblad et al., 2011). artificial floating agents when mixing concrete Concrete essentially consists of aggregates, in order to maintain the workability of the cement and water. The proportion of these liquid concrete, and therefore also more cement agents is usually determined depending on the to maintain the consistency, stability and area of application of the concrete, with respect hardening properties of the final product to the needs of workability, consistency, (Lagerblad et al., 2011). Adding more cement stability, hardening, air content and strength, and floating agents will not only be etc. (Lagerblad et al., 2011). Given that up to unsatisfying for the environment, but it is also 70% of the concrete can be made up of a very expensive solution. An amount of no aggregates, the quality of this material largely more than 7% mica minerals is therefore determines the properties of the concrete preferred in a rock material that is to be used (Bergkross i betong - Krossat berg ersätter as aggregates in concrete (Geological Survey naturgrus, Cementa, n.d.). Aggregates for of Sweden, 2016). concrete can be made up of most kinds of solid materials, as long as the material does not react The amount of mica in the crushed rock negatively with the cement. material from Swedish granites can vary from almost nothing at all, up to 20-30% in the filler Granitic bedrock material is usually favoured fractions. The most cost-effective is therefore in Sweden because of its low cost and local to choose a rock type with apparent low mica availability. The granitic composition seldom content if possible. If this is not an option, the reacts negatively with the cement, and the amount of free mica grains in crushed rock strength and durability of granitic aggregates material can be lowered by either washing or is rarely an issue as the weakest part of the wind sieving the material (Lagerblad et al., concrete will be the cement phase (Lagerblad 2011). This does however add yet another cost et al., 2011). Furthermore, the distribution of to the line of production. particle sizes from a crushed material is often more favourable than that of natural gravel. The conclusion of the above mentioned would While a crushed rock material will contain a be that if the input crushed rock material is of more even distribution from fine to large good quality with favourable properties, the particles, certain fractions of natural gravel has output concrete will be cost effective and of often been washed away, leaving so called equally good quality. Adequate information on particle gaps in the distribution of particle sizes the bedrock and its input characteristics is (Lagerblad et al., 2011). The more even and therefore required prior to any decisions continuous the particle distribution is, the regarding the construction of bedrock quarries, better the concrete will be compacted. mixing of concrete or anything in between the two. A problem with aggregates from crushed bedrock is however the flakiness of particles, 4. Technical properties of rocks especially in the so called filler fraction (0- 0,125mm). The shape of the larger particles can The technical properties of a rock that are usually be improved enough by using the right considered in this thesis are affected by a type of crushing process, resulting in more number of different factors. These factors are cubic particle shapes. However, the shape of all a product of the rock’s origin and tectonic smaller particles is to a larger extent history. By investigating the microstructural determined by the mineral type, which exhibits properties of the rock, one can roughly a predetermined crystal form (Lagerblad et al., estimate the rocks mechanical strength. Some 2011). Quist & Evertsson (2010) demonstrated of the most important and common factors to that particles or fragments finer than 0,25mm investigate for this purpose are the following: are harder to make cubic, revealing that this might be the critical size at which mineral Grain size and grain size distribution grains are becoming more common than rock Mineralogy fragments. Grain boundaries Mica minerals are the most troubling grains in Perimeter the filler fraction, given that they tend to form Foliation flaky minerals. A filler fraction with more flaky Micro cracks
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Secondary alterations on the rocks resistance to fragmentation and Porosity abrasion. Given that the major minerals of granitic rocks are feldspars, quartz, mica and Not all of these properties have been amphibole minerals, their properties are investigated here, but their principals and important for estimating the technical importance is still summarized below. The behaviour of the rock they constitute. technical properties of rocks are in one way or another affected by these properties, were the Feldspar crystals have very good cleavage, weakest property will act as the most limiting which will act to increase the brittleness and factor. lower the resistance to fragmentation of the rock. The feldspar minerals are however 4.1 Grain Size and Grain Size relatively hard, increasing its resistance to Distribution abrasion.
For magmatic granitoid rocks, and their Quartz crystals are hard, have low cleavage metamorphic equivalents, the grain size of the and are often anhedral. The hardness of the rock often has a large impact on its technical quartz crystals contributes to better resistance values. Rocks with a smaller mean grain size to fragmentation, the low cleavage prevents are known to correlate with better technical the mineral from easily breaking by qualities than do rocks with a larger mean fragmentation, while the anhedral grains are grain size (e.g. Åkesson et al, 2004; Göransson able to fill the space between other grains, et al., 2004; Hellman et al., 2011). A larger thereby lowering the porosity and grain size will enable cracks to propagate easier strengthening the rock (Johansson, 2011). and thereby weaken the rock, while a larger Quartz crystals have the ability to recrystallize number of smaller grains will make it more relatively easy, and at the same time form difficult for cracks to propagate. Another complex grain boundaries that contributes to disadvantage with very coarse grains is that the strength of the rock (Hellman et al., 2011). the cleavage planes of the minerals very well may affect the technical properties in a negative Mica minerals (biotite, muscovite and to some manner (Hellman et al., 2011). The grain size extent chlorite being relevant here) preferably distribution is also of great importance, where form flaky particles. Mica minerals are soft rocks with a larger grain size range is favoured minerals, giving them good resistance to over rocks with more homogenous grain size fragmentation but a not so good resistance to distributions. Rocks that consist of both coarse abrasion. In igneous rocks, the mica minerals and fine grains tend to have a positive effect on are often evenly dispersed and the mica content the resistance to fragmentation and wear therefore usually has less effect on the strength (Hellman et al., 2011). of the rock. In metamorphic rocks however, the mica minerals often form mica-rich bands were The grain size and grain size distribution have the particles are arranged parallel to each both been analysed in this thesis. A common other, creating a rock with anisotropic strength way to investigate these parameters has been properties (Johansson, 2011). The strength of by manually measuring the diameter of the rock in the direction parallel to the foliation individual grains along traverse lines that have will be the lowest, while the strength been traced on an image obtained from optical perpendicular to this foliation will be the microscopy (e.g. Åkesson et al., 2003; Hellman highest. et al., 2011; Lundgren, 2012). However, a new approach has been tried in this thesis, explained Furthermore, the amount of mica is known to further in Materials and Methods (Section 6). be enriched when the bedrock material is crushed (Miškovský, 2004; Loorents et al., 4.2 Mineralogy 2007; Johansson et al., 2008), which may cause the material to be unsuitable for road and/or The physical properties of minerals will affect rail way constructions due to its impaired the technical properties of the rock they build ability to manage freeze-thaw conditions up. The most primary mineral properties are (Arvidsson & Loorents, 2008) and the reduced crystal shape, density, cleavage and hardness, ability to pack the material (Höbeda & Bünsow, the two latter having the most significant effect 1974).
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The mafic mineral amphibole commonly banding, realignment of micas and clays via exhibits a long, prismatic and sometimes even physical rotation of minerals, growth of platy fibrous mineral form. Fibrous minerals as such minerals, or alignment of tabular minerals, are known to increase the rocks flakiness and amongst other foliating mechanisms. The brittleness, in turn decreasing the strength of foliated planes of rocks will most likely give the rock (e.g. Brattli, 1992). High contents of rise to planes of weakness in the rock, causing amphibole are therefore expected to lower the it to easier fracture in this direction and strength of the rock. resulting in poor mechanical properties. This is not true for all foliated rocks however, as 4.3 Grain Boundaries certain metamorphic rocks have developed complex mineral grain boundaries with the The grain shape and grade of intergrowth ability to strengthen the rock instead (e.g., between adjacent grains in a rock will have a Persson & Göransson, 2005). Foliated rocks large impact on the rocks technical properties. with poor mechanical properties, on the other Rocks with more irregular grain shapes and a hand, are often found to inhibit straight grain higher grade of intergrowth between grains boundaries with 120° triple joints, a product of will be more resistant to stress than rocks with recrystallization during metamorphism less complex grain shapes and grain boundaries (Hellman et al., 2011). (e.g. Höbeda, 1971; Höbeda, 1995; Åkesson et al., 2003; Göransson et al., 2004). Straight The degree of foliation in a rock is commonly grain boundaries will allow cracks to easily measured using the Foliation index, FIX (e.g. propagate along the boundaries, instead of Åkesson et al., 2003; Hellman et al., 2011). This them having to propagate through minerals, has not been carried out in this thesis, but resulting in a more brittle rock with less consideration has been taken to whether or not resistance to fragmentation (Hellman et al., gneissic texture has been observed in the field 2011). when sampling was carried out, as gneissic texture is a type of foliation. Crystal alignment The grain boundaries of the samples in this results retrieved from the image analysis have thesis have been manually graded depending also been considered. on their amount of intergrowth. This grading has then been compared with other properties 4.6 Micro Cracks of the sample to find any possible correlations. Micro cracks are developed in a rock when it is 4.4 Perimeter deformed in brittle state, the deformation being caused by blasting, crushing, pressure By measuring the total perimeter of a sample, discharge, thermal contraction and/or tectonic one attains the total circumference of all objects movements in the crust (Kowallis & Wang, in the sample (Åkesson et al., 2003). This 1983; Hellman et al., 2011). These cracks may perimeter value is affected by grain size and have a large impact on the technical properties grain boundary complexity, were smaller grain of rocks, were especially the resistance to sizes and more complex grain boundaries fragmentation is known to be lowered by results in higher perimeter values, and vice higher amounts of micro cracks (Hellman et al., versa. A higher perimeter may indirectly 2011). correlate with more preferable technical properties in rocks, as particularly the LA- Micro cracks are generally intragranular or value is often greatly improved by smaller transgranular. Intragranular cracks are found grain size and interfingering or sutured grain inside the crystals, while transgranular cracks boundaries (Åkesson et al., 2003). propagate straight through crystals, affecting the entire lattice (Hellman et al., 2011). Micro 4.5 Foliation cracks may also occur along grain boundaries, given that cracks rather propagate along Foliation is a repetitive layering recognized in straight surfaces, such as straight grain metamorphic rocks, caused by shearing forces boundaries or cleavage planes, than bending its or differential pressure, typical for rocks that way through the lattice (Hellman et al., 2011). have been subject to orogenic events such as In feldspars and quartz, by far the most mountain formation. The foliation may be frequent minerals in the samples investigated represented by chemical or compositional in this thesis, the cracks are almost
12 predominantly intragranular. (Janssen et al., 4.8 Porosity 2001). The porosity refers to the void spaces in a Micro cracks are not investigated in this thesis, material, in this case in rocks. A higher but are still partly considered when evaluating porosity in a rock will lower its mechanical the results. quality. The porosity of crystalline bedrock in Sweden is however usually lower than 0,5% of 4.7 Secondary Alterations the volume of the rock, why it is commonly not considered a serious issue when investigating Certain minerals may be subject to secondary technical properties of these rocks (Höbeda, alterations by chemical and/or physical 1995; Mazurek et al., 1996). Neither is it processes, were the contemporary minerals are investigated or considered in this thesis. altered into new minerals by hydrothermal solutions in the Earth’s crust (Hellman et al., 5. Earlier Work 2011). Plagioclase that has been exposed to alteration, e.g. sericite or saussurite alteration, Due to the growing relevance of crushed is believed to make its host rock more resistant bedrock material in road and railway to brittle deformation (e.g. Åkesson et al., 2004; constructions, there is a relatively solid Hellman et al., 2011). Åkesson et al. (2004) foundation of information on the topic demonstrates that feldspars with sericite regarding comparisons between bedrocks alteration have less crack abundance, the technical characteristics and its texture, reason being that sericitized feldspar grains structure, mineral composition, and so on. exhibit more flexible properties than do an Lindqvist & Åkesson (2001) carried out a brief unaltered feldspar grain. It has however also literature review regarding the field of image been indicated that an overly aggressive analysis applied to the technical analysis of sericite alteration will weaken the rock geological materials, with the intention to give (Göransson et al., 2004). an introduction to the available literature in that area of scientific research. Weathering of rocks may be considered secondary alterations as well, a process that Michael Denis Higgins recognized that there weakens the rocks strength properties. was an entire ocean of widespread information Weathering is however a very slow process, on image analysis available, and decided to and most parts of the Swedish granitic bedrock compile it all in an entire book on the topic of has only been weathered a few millimetres quantitative textural measurements in since the latest ice sheet eroded and polished petrology (Higgins, 2006). The book not only the landforms throughout northern Europe. discusses aspects of petrological theory, it also The amount of weathered bedrock in crushed develops the methodological basis of bedrock material is therefore often negligible quantitative textural measurements, evaluates (Lagerblad et al., 2008). Problems with available software for analysis, and indicates weathering may however appear more were mistakes and errors may occur during the prevalent on a local scale, for example in the analysis process. vicinity of road cuts, tunnels and larger deformation zones, why caution must be taken Johansson (2011) carried out an extensive in such areas. literature review with regards to the correlation between the petrographic and The degree of alteration was determined for mechanical properties of bedrock, where the each thin section through a microscope by most important conclusions of the various simply grading the amount and extent of properties of bedrock have been summarized. altered plagioclase grains from 1 to 5, were a grade 1 corresponds to no or very small 6. Materials and Methods amounts of alteration, and a grade 5 corresponds to very high amounts of alteration. The material used and analysed in this thesis The degree of alteration has then been has exclusively been received from the compared with the technical properties of the Geological Survey of Sweden, as mentioned. corresponding rock samples. The material consists of thin sections from sampling sites along the potential track profile
13 of the Götalandsbanan, including a number of Merely a petrographic analysis is not sufficient additional samples east-northeast of Jönköping enough to conclusively evaluate a rocks (Fig. 6). Furthermore, the Geological Society suitability for use in constructional purposes. of Sweden provided technical and Petrographic results should rather be seen as mineralogical data for each site of sampling as basic information from which you decide if and well. what kind of further analysis, tests and controls should be carried out. The analysis of thin sections and image capturing from the same thin sections has 6.1 Technical Analysis mostly been carried out at the Geological Society of Sweden in Gothenburg, but partly The technical properties of a rock may initially also at the Department of Earth Sciences, decide whether it is suitable for use as University of Gothenburg. aggregates for road and railway construction, in terms of quality and sustainability. These All thin sections were reviewed briefly in a properties are routinely investigated by microscope, whereupon the grain boundaries standardized methods in order to were graded depending on the degree of quantitatively evaluate the characteristics of intergrowth. A number of samples were chosen different materials. The methods considered in for further analysis of grain size, grain size this thesis are described below. All values from distribution, perimeter and grain orientation. the technical analysis described below and used The results were then compared with in this thesis were, as mentioned, provided by corresponding technical properties and the Geological Society of Sweden. mineralogical composition of each sample, and furthermore compared more accurately with 6.1.1 Los Angeles Test single samples that exhibit similar properties. The Los Angeles value (LA) indicates a rocks In a statistical analysis, expected results resistance to fragmentation. The test is carried largely depend on the choice and number of out according to the Swedish standard method input samples. The samples that were analysed SS-EN 1097-2 (Svensk Standard, 1997a). In in this project are of granitic or closely granitic brief words, a bedrock sample is crushed, sieved composition, given that this is the most and weighed, after which 5000 g of a fixed common composition in the concerned area. fraction of the sample together with 11 steel The precision of the results partly depends on balls (diameter 45-49 mm) is added to a Los how homogeneous/heterogeneous the bedrock Angeles mill. The mill rotates the material 30 is in the sampling area, and in part also depends min (500 rotations) and the resulting material on how homogeneous/heterogeneous the thin is sieved for 10 min and weighed again. On this section from the sampling area is, given that basis the Los Angeles vale for the sample can only a small window if the thin section was be determined. Higher values correspond to analysed in terms of grain size, grain size poor technical values, and vice versa. distribution, perimeter and grain orientation.
Figure 6 Map showing the location of all 116 samples of granitoid compositions. The city of Gothenburg is located in the west and the city of Jönköping in the east.
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6.1.2 Studded Tyre Test Society of Sweden, by point counting a minimum of 500 minerals of every sample. The The studded tyre test value (AN) reveals a rocks results are presented in percent of each mineral resistance to wear by abrasion from studded type of the sample. This modal composition has tyres. The test is carried out according to the been used to determine the rock type based on Swedish standard method SS-EN 1097-9 the Streckeisen (1967) classification for (Svensk Standard, 2004a). In brief words, a igneous rocks. bedrock sample is crushed in two steps by a rotational jaw crusher followed by a smaller 6.2.2 Grading of Grain Boundaries jaw breaker, after which the sample is sieved and the different fractions are weighed. The All 116 thin sections were analysed through sample is then placed in a ball mill, together microscope in order to determine the general with steel balls (7000 g) and two litres of water, amount of intergrowth between individual and the ball mill spins the material 5400 grains in every sample. The observations were revolutions (c. 1 hour). The steel balls are based on the amount of intergrowth and magnetically removed, the sample is sieved, interlocking between the grains, how apparent dried in an oven and finally weighed in the grain boundaries were and if the grain different fractions, after which the studded tyre boundaries were straight/smooth or irregular. test value can be calculated. Higher values Depending on the character of these features, correspond to poor technical values, and vice each sample was assigned a grade from 1-5, versa. with joints every 0.5 grade, according to Figure 7. 6.1.3 MicroDeval Test 6.2.3 Secondary Alterations The MicroDeval (MDe) test measures a rocks resistance to abrasion. The test is carried out All 116 thin sections were analysed through according to the Swedish standard method SS- microscope in order to determine the general EN 1097-1 (Svensk Standard, 1997b). In brief amount of altered plagioclase in each rock words, the process of crushing, sieving and sample. Each sample was assigned a grade of 1- weighing is carried out as for the studded tyre test. The sample (500 g) is placed in a mill together with steel balls (5000 g) and water (c. 2,5 l) and rotated 12 000 revolutions (c. two hours), after which the steel balls are removed and the sample is sieved, dried and weighed in different fractions. The microDeval test value can then be established. Higher values correspond to poor technical values, and vice versa.
6.2 Micro Analysis
As mentioned, all thin sections used for micro analysis were sampled and provided by the Geological Society of Sweden. A total of 116 thin sections have been analysed, all of whom were sampled in the vicinity of the proposed railway corridor of the Götalandsbanan (Fig. 6) at different periods of time during the past few decades. In order to avoid bias, the technical properties of the samples where not known nor at hand while analysing the grain boundaries.
6.2.1 Mineralogy Figure 7 Scale for determining the grade of The mineralogical composition of all but three intergrowth of grain boundaries. Figure modified from Hellman et al. (2011). samples was determined by the Geological
15
5, were a grade 1 corresponds to no or very data manually. Automatic image analysis will small amounts of alteration, and a grade 5 not be subject to the same amount of operator corresponds to very high amounts of alteration. bias, but on the other hand often requires a The grade was decided with regards to the larger amount of time to set up. The analysis amount of altered plagioclase, according to itself will however be much less time both total volume of the whole sample and the consuming, especially if there is a large number extent of the alteration in individual of similar samples being analysed. A general plagioclase grains. problem with data being automatically processed is that the quality of the results will 6.3 Image Analysis be lowered the more times a computer accounts for the interpretations. Image analysis is a technique used in many fields of science in order to obtain quantitative 6.3.1 Mineral Grain Size and Grain Size information by measuring the features in an Distribution image (Mainwaring & Petruk, 1989). Applications are known from scientific fields The mineral grain size and grain size such as medicine, biology, physical metallurgy, distribution has been determined for 25 remote sensing, military detection, food samples. Most of these samples were selected sciences and earth sciences. In all these fields, for specific comparative purposes, but a it has been recognised that it is possible to number of samples were chosen on a more obtain information on several different random basis in order to attain a larger volume parameters by measuring a computerised of data for general comparison. Samples with image, such as size, shape, number of objects or very complex grain boundaries were not able grey-scale value. to be chosen for this purpose, nor were samples with porphyritic texture, due to the nature of In this study, the analysed images are obtained the method presented below. from optical microscopy, which despite its long history still is considered a cost-effective method for quantitative textural analysis, and is probably one of the most commonly used methods as well. This is partly due to the wide range of optical properties displayed by minerals in thin section investigated through optical microscopes. This makes it relatively easy to distinguish individual crystals and different mineral types, unlike for example the also commonly used images from a scanning electron microscope with backscattered detector (SEM/BSE), were the thin section is investigated in grey scale depending on the minerals atomic weight. This makes it difficult to separate mineral grains of the same composition when positioned next to each other (Fig. 8).
The quality and range of data possible to obtain depends largely on the resolution of the image. This is however not considered a serious issue Figure 8 SEM/BSE (a and c) and binary (b and d) today, as there are a large number of cheap images used for perimeter analysis by Åkesson et al. alternatives of cameras and camera lenses for (2003). Image a and c have been treated with a obtaining images of sufficient resolution. number of image enhancing operations in order to detect the biotite (image a and b) and K-feldspar (image c and d) phases for measuring their Manual image analysis methods generally perimeter value. Note that the boundaries between yield high-quality data directly, but on the single mineral grains cannot be detected if adjacent other hand requires a large amount of time and grains are of the same phase. Images from Åkesson judgement. There is also a higher risk of et al. (2003) operator bias when collecting and interpreting
16
A B C
D E
Figure 9 Microscopic images from sample TEN140014. A) Crossed polarized image. B) Plane polarized image. C) Crossed polarized image with a first order retardation plate inserted. D) All grains have been traced and highlighted. E) All grains intersecting the boundary of the image have been removed.
For each of the 25 samples, a representative of the selection. Minerals that intersect the part of the thin section was photographed border of the image were not considered, while through an optical microscope. Images were broken and altered grains were traced taken of the sample in crossed polarized (Fig. according to their original form, as far as 9A) and plane polarized (Fig. 9B) light. For a possible. When all visible grains have been number of samples, an image was taken with a highlighted, the resulting image will look like first order retardation plate inserted under in Figures 9D and 9E. crossed polarized light (Fig. 9C) as well. These images were then stacked on top of each other, An image like Figure 9E can be used to analyse but in different layers, in the image processing the size, distribution, perimeter and orientation software Adobe Photoshop CS6. Minor of the grains in an image processing program. adjustments were made to the images, e.g. The open source program ImageJ 1.50i was regarding contrast and colour, in order to used for this purpose. Given the nature of the increase the probability to detect and highlight image used for analysis, the image does not the grain boundaries correctly. Working with require any major adjustments in order for the a copy of the crossed polarized image as base, software to analyse it. The procedures carried the mineral grains were selected one by one out after adding the images to the ImageJ using the Adobe Photoshop tool Quick Selection program are summarized in Table 1. Tool. By using this tool, the boundaries of a mineral grain are automatically traced simply In order to obtain 3D data from the 2D data by clicking in the middle of the grain. Minor provided from ImageJ calculations, the adjustments of the selection made by the tool program CSD Corrections 1.53 (Higgins, are required for more complex grains, 2000) has been used to perform the necessary adjustments that are easily made by simply stereological conversion. In order for the decreasing or increasing the selection with the calculations to work out properly, the general same tool. By stacking the different types of crystal shape has to be estimated for each images of the sample taken from the sample. This has been done by plotting the 2D microscope on top of each other in different data into the spreadsheet CSDSlice (version 5), layers, one can use them alternatively in order created and explained in detail by Morgan & to more accurately identify the grain Jerram (2006), and was kindly provided by the boundaries when they are somewhat unclear. authors. The CSDSlice spreadsheet contains a large amount of crystal shape measurements. Here, every traced grain was highlighted in red Hence, by entering our 2D data to the and a black border was assigned to the outline spreadsheet, it will be compared to the data in
17 the CSDSlice database, and a best-fit overall 20 crystal shape will be proposed. 18 The 2D data from ImageJ, together with the 16 best-fit crystal shape from CSDSlice, is then entered into the 3D conversion program CSD 14 Corrections. When the calculations have been 12 made, a macro connecting ImageJ to CSD Corrections will alert if any crystals are too 10
small to be measured reliably. The crystal sizes MDe(%) 8 are divided into different bins, the number of 6 bins chosen prior to calculations. The number of crystals in each bin should not be less than 4 three (Higgins, 2006) for statistical matters. 2 y = 0,7116x - 0,9298 R² = 0,8674 6.3.2 Perimeter Analysis 0 0 10 20 30 The perimeter was measured in the same AN (%) samples as the grain size distribution was Figure 10 MicroDeval value (%) compared to measured, given that the software ImageJ Studded Tire Test value (%) of 77 samples. As (section 6.3.1) is able to attain perimeter values expected, the values show a good positive from the image as well. The total perimeter correlation. value attained directly from the measurement Table 1 Procedures carried out prior to analysing was normalized against the total area of images in ImageJ 1.50i. measured grains, as the total area of grains Binary image The program requires an image differ somewhat from sample to sample. and threshold that contains fields with given values in order to recognize and 7. Results measure different features of the image. This was obtained 7.1 Technical Analysis here by adjusting the image type to an 8-bit binary image and then using the threshold All data from technical analysis has been tool to obtain an image with compiled in Appendix A. only two colours (e.g. black and white), or more accurately two As expected, due to the similar nature of both values. test types, the values from the microDeval and Set The following features were studded tyre tests show an evident correlation measurements measured: Area, Centroid, (Fig. 10). This correlation between technical Perimeter and Fit Ellipse. methods can be applicable when only one value Set scale The scale of the image must be is known for a certain material. As stated by set correctly. Göransson et al. (2008), the unknown value can Analyse Prior to analysing the particles then be estimated if necessary. The correlation particles of the image, a number of of the 77 samples in this study, where MDE = conditions can be set. The 0.71 x AN – 0.93 (R2 = 0.87), can successfully following are of interest here: be compared with correlations made by Stenlid Size of particles: determines the (2000; MDE = 0.86 × AN – 2.71 (R2 = 0.95)), minimum and maximum area of Göransson et al. (2008; MDE = 0.89 × AN – 2.50 the particles wished to be (R2 = 0.89)), Bergström et al. (2008; MDE = measured (here: 0,0001- 0.77 × AN – 1.51 (R2 = 0.97) and Lundgren Infinity). (2012; MDE = 0.62 × AN + 0.55 (R2 = 0.96), all Exclude on edges: in order to not showing a distinct positive correlation. measure the “empty” area along the edge of the image. Show Outlines: the program will The comparison between Los Angeles and produce an image showing the Studded Tire Test values for a total of 112 outlines of every measured samples are shown in Figure 11. The samples grain.
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Figure 11 Los Angeles values (%) 50 compared to Studded Tire Test values 40 (%) of 112 samples. The symbols PZ representing the samples are given 30 different shapes and colors depending on TIB which lithotectonic unit or zone they
LA (%) LA 20 ES belong to. The concerned units and zones are the Protogene Zone (PZ), the 10 WS Transscandinavian Igneous Belt (TIB), 0 MZ the Eastern Segment (ES), the Western 0 5 10 15 20 25 30 Segment (WS) and the Mylonite Zone
AN (%) (MZ). are categorized in different colors and symbols road- and railway constructions. Figure 11 depending on which lithotectonic unit or zone demonstrates that the rocks in the TIB are they belong to, given the diverse properties more likely to have more favourable (low observed between these geological areas. The values) technical properties. The two samples concerned units and zones are the Protogene from the Mylonite zone seem to have a Zone (PZ), the Transscandinavian Igneous tendency towards the lower values as well. Belt (TIB), the Eastern Segment (ES), the Samples from the Protogine zone together Western Segment (WS) and the Mylonite with the Eastern and Western segments rarely Zone (MZ), all present on the geological map give LA-values below 20, and only a few in Figure 3. samples have AN values lower than 10. Above these values, the samples seem to be more or The Los Angeles and Studded Tyre Test less widespread. values show a good positive correlation overall, with lower values being equal to more A more detailed, but still simplified, map of the favourable technical properties, enabling use of geology in the concerned area can be seen in this material in more demanding concrete-, Figure 12, with the evident boundaries of the
Figure 12 Geologic map of the area surrounding the planned railway corridor between the cities of Gothenburg (west) and Jönköping (east) with locations of 169 sampling sites. The samples are of different rock types, in contrary to the exclusively granitoid rock samples analysed in more detail in this study, in order to obtain an overview of the technical properties of all rocks in the area.
19 different lithotectonic units (Fig. 3). When In Figure 15, the samples have been divided comparing this geological map with the maps into rock types, according to Streckeisen in Figures 13 and 14, where the Los Angeles (1967). To make it easier to evaluate the and Studded Tyre Test values from the technical values displayed by each rock type, analysed rock samples have been interpolated the rock types from Figure 15 have all been respectively, it is made obvious once again that divided into separate figures (Figs. 16 – 25). the technical properties of the bedrock are more favourable in and near the TIB compared The 31 rock samples of monzogranitic to the rocks in the Eastern and Western composition (Fig. 16) are widely dispersed, Segments. One should however bear in mind with both high and low values of LA and AN. that these maps are greatly simplified, given The correlation between the two values is very the scattered distribution of samples and evident here as well. The 23 gneissic variation of rock types in the area. The values monzogranitic rock samples (Fig. 17) are interpolated farther away from the sampling confined to LA values higher than 20% and AN sites are subject to significant uncertainties values higher than 10%. The values appear with increased distance to sampling sites. The almost to be divided into two clusters, one maps do however provide a general picture of group with higher values and one group with the technical properties of the concerned lower values when compared to each other. corridor and its surroundings.
Figure 13 Map with interpolated (IDW) Los Angeles values from a total of 169 rock samples in the vicinity of the planned railway corridor.
Figure 14 Map with interpolated (IDW) Studded Tyre Test values from a total of 169 rock samples in the vicinity of the planned railway corridor.
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The 11 syenogranitic rock samples (Fig. 18) Four rock samples were of tonalitic are relatively spread out, displaying composition (Fig. 22). The AN values of these intermediate values of both LA and AN, with rocks were found to be generally high, with the the characteristic correlation between the two lowest value at 15.4% and the highest at 25%. values being fairly evident. One rock sample The LA values on the other hand are low to differs from the others with its very high values intermediate values (15.5 – 29.4%). Two of both LA (46.2%) and AN (26.5%). The six additional rock samples of tonalitic gneiss (Fig. syenogranitic gneiss samples (Fig. 19) are not 23) showed generally higher values of both LA very unlike the non-gneissic syenogranites, but and AN values (28.2-35.5%; 18.5-21.8%). Three do in comparison have overall slightly higher rock samples are of quartz dioritic or quartz values. gabbroic compositions (Fig. 24). All three samples have similar LA values (14.9-21.4%), The 13 granodioritic rock samples (Fig. 20) and their AN values range from 11.6% to 18.7%. display varying technical properties, ranging Another three rock samples have quartz from low to high values of both LA and AN. The monzodioritic compositions (Fig. 24), and have correlation between the two values is evident fairly low and similar LA and AN values (13.8- here. The four rock samples of granodioritic 18.9%; 8.6-13.1%). Eight quartz monzonite gneiss (Fig. 21) however, show higher and rock samples where recognized (Fig. 25), and more consistent properties, with LA values of they all plot in a more or less straight line when 26.8-35.9%, and AN values of 13.2-19.85%. comparing LA and AN values. The LA values range from 15.9% all the way up to 37.5%, and the AN values lie between 7.2% and 20.4%
50 Granodiorite 45 Granodioritic Gneiss 40 Quartz Diorite / Quartz Gabbro 35 30 Quartz Monzodiorite 25 Quartz Monzonite
LA (%) LA 20 Monzogranite 15 Monzogranitic Gneiss 10 Syenogranite 5 Syenogranitic Gneiss 0 Tonalite 0 5 10 15 20 25 30 Tonalitic Gneiss AN (%)
Figure 15 Los Angeles values (%) compared to Studded Tyre Test values (%) of 108 samples. The samples have been divided into corresponding rock type, according to Streckeisen (1967).
Monzogranite Monzogranitic Gneiss
50 50 40 40 30 30
20 20
LA (%) LA (%) LA 10 10 0 0 0 10 20 30 0 10 20 30
AN (%) AN (%)
Figure 16 Los Angeles values (%) compared to Figure 17 Los Angeles values (%) compared to Studded Tyre Test values (%) for 31 samples of Studded Tyre Test values (%) for 23 samples of monzogranitic composition. monzogranitic gneiss.
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Syenogranite Syenogranitic Gneiss
50 50 40 40 30 30
20 20
LA (%) LA (%) LA 10 10 0 0 0 10 20 30 0 10 20 30
AN (%) AN (%)
Figure 18 Los Angeles values (%) compared to Figure 19 Los Angeles values (%) compared to Studded Tyre Test values (%) for 11 samples of Studded Tyre Test values (%) for 6 samples of syenogranitic composition. syenogranitic gneiss.
Granodiorite Granodioritic Gneiss
50 50 40 40 30 30
20 20
LA (%) LA LA (%) LA 10 10 0 0 0 10 20 30 0 10 20 30
AN (%) AN (%)
Figure 20 Los Angeles values (%) compared to Figure 21 Los Angeles values (%) compared to Studded Tyre Test values (%) for 13 granodioritic Studded Tyre Test values (%) for 4 samples of samples. granodioritic gneiss.
Tonalite Tonalitic Gneiss
50 50 40 40 30 30
20 20
LA (%) LA (%) LA 10 10 0 0 0 10 20 30 0 10 20 30
AN (%) AN (%)
Figure 22 Los Angeles values (%) compared to Figure 23 Los Angeles values (%) compared to Studded Tyre Test values (%) for 4 samples of Studded Tyre Test values (%) for 2 samples of tonalitic composition. tonalitic gneiss.
22
Quartz Diorite / Quartz Gabbro Quartz Monzodiorite Quartz Monzonite 50 50 40 40 30 30
20 20
LA (%) LA LA (%) LA 10 10 0 0 0 10 20 30 0 10 20 30
AN (%) AN (%)
Figure 24 Los Angeles values (%) compared to Figure 25 Los Angeles values (%) compared to Studded Tyre Test values (%) for 3 samples of quartz Studded Tyre Test values (%) for 8 samples of quartz dioritic/gabbroic composition and 3 samples of monzonitic composition. quartz monzodioritic composition.
Granitoid rock types with gneissic texture are Regarding the AN values, only two gneissic common in south-western Sweden, and the samples plot below 10%, the rest being non- texture is likely to impact on the technical gneissic samples, and on the other side of the properties of the rocks associated with it. spectra only two non-gneissic samples plot Therefore, the Geological Society of Sweden above 20% while the rest are gneissic rock have indicated whenever the sampled rock type samples. is of gneissic origin. Using these field observations, the rock samples were divided Certain properties of minerals can sometimes into non-gneissic and gneissic, and their be estimated simply by considering if they are technical properties were compared (Fig. 26). light or heavy, why the technical values of a The result shows a clear trend with most of the rock may be demonstrated by comparing the non-gneissic rock samples inheriting low or ratio of LA and AN values with the density of intermediate technical values, while the the rock (Fig. 27). Light minerals, such as gneissic rock samples almost exclusively have quartz and feldspars, tend to have lower intermediate and high technical values. When fracture energies which enables them to crack considering the LA value, only two non- more easily (Lindqvist et al., 2007; Tavares & gneissic rock samples plot above 30%, the rest das Neves, 2008). A rock containing large above this value being gneissic rock samples. amounts of light minerals will therefore behave
Non-Gneissic Gneissic 3,5
50 3 45 2,5 40
35 N 2 30
25 LA/A 1,5
LA (%) LA 20 1 15 10 0,5 5 0 0 0 10 20 30 2,6 2,65 2,7 2,75 2,8 2,85 3 AN (%) Density (g/cm )
Figure 26 Los Angeles values (%) compared to Figure 27 The LA/AN ratio of 112 samples Studded Tyre Test values (%) of 112 samples. The compared to their density. High contents of heavy samples have been divided into non-gneissic and minerals seem to lower the LA/AN ratio, and vice gneissic rocks, based on observations made by the versa. Geological Survey of Sweden during sampling.
23 in a more brittle manner, hence increasing the 7.2 Mineralogy LA value of the rock. The same minerals are however known to have a high resistance to The mineralogy of a rock may have a large abrasion because of their hardness, and will impact on its technical values. The influence of therefore show low AN values. This single mineral types on the LA and AN values combination will result in a higher LA/AN of the rock samples in this study are evidenced ratio. High-density minerals such as biotite and in Figures 28-41. All mineralogical data is amphiboles on the other hand have high compiled in Appendix C. fracture energies, and are therefore more likely to have lower LA values (Lindqvist et al., 2007; The influence of quartz on the technical values Tavares & das Neves, 2008). The same (Figs. 28-29) is not obvious in the samples of minerals are however less resistant to abrasion, this study. A weak positive correlation can and will therefore cause the rock to have higher however be seen between the quartz content AN values. and LA value (Fig. 28). Plagioclase does not seem to have an evident effect on its own on the The above mentioned correlations between rocks technical values (Figs. 30-31). The high and low-density minerals and their rocks amount of alkali feldspar in a rock shows no technical values are evident in Figure 27, correlation with the LA values in the samples where all the rock samples LA and AN ratio are of this study (Fig. 32), but does however show compared with the density of the sampled rock, a weak negative correlation with the AN values resulting in a negative correlation. (Fig. 33). When combining the amounts of plagioclase and alkali feldspar and comparing this value with the technical values (Figs. 34- 35), there is still no correlation with the LA
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 20 40 60 0 20 40 60 Quartz (%) Quartz (%)
Figure 28 The Los Angeles value (%) of 110 rock Figure 29 The Studded Tyre Test value (%) of 113 samples compared to their amount of quartz (%). rock samples compared to their amount of quartz (%).
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 20 40 60 0 20 40 60 Plagioclase Total (%) Plagioclase Total (%)
Figure 30 The Los Angeles value (%) of 110 rock Figure 31 The Studded Tyre Test value (%) of 113 samples compared to their amount of plagioclase (%). rock samples compared to their amount of plagioclase (%).
24 value (Fig. 34) but there is on the other hand The total amount of mica (biotite, muscovite an obvious negative correlation with the AN and chlorite) in the rock samples does not affect value (Fig. 35). the LA value in an evident way (Fig. 38), but it does however have an obvious impact on the When combining the amount of quartz, AN value (Fig. 39), which is lowered with plagioclase and alkali feldspar, no correlation lowered amount of mica in the sample. can be seen with the LA value (Fig. 36), but a Amphibole content does not seem to affect the negative correlation can be seen with the AN technical properties of the rock samples of this values of the samples (Fig. 37). study (Figs. 40-41).
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 20 40 60 0 20 40 60 Alkali Feldspar (%) Alkali Feldspar (%)
Figure 32 The Los Angeles value (%) of 106 rock Figure 33 The Studded Tyre Test value (%) of 110 samples compared to their amount of alkali feldspar rock samples compared to their amount of alkali (%). feldspar (%).
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 20 40 60 80 100 0 20 40 60 80 100 Feldspar Total (%) Feldspar Total (%)
Figure 34 The Los Angeles value (%) of 110 rock Figure 35 The Studded Tyre Test value (%) of 113 samples compared to their total amount of feldspar rock samples compared to their total amount of (%). feldspar (%).
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 20 40 60 80 100 0 20 40 60 80 100 QAP (%) QAP (%)
Figure 36 The Los Angeles value (%) of 110 rock Figure 37 The Studded Tyre Test value (%) of 113 samples compared to their amount of quartz (Q), rock samples compared to their amount of quartz alkali feldspar (A) and plagioclase (P; %). (Q), alkali feldspar (A) and plagioclase (P; %).
25
50 30 40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 10 20 30 0 10 20 30 Mica Total (%) Mica Total (%)
Figure 38 The Los Angeles value (%) of 108 rock Figure 39 The Studded Tyre Test value (%) of 111 samples compared to their total amount of biotite, rock samples compared to their total amount of muscovite and chlorite (%). biotite, muscovite and chlorite (%).
50 30
40 25 20 30
(%) 15 N
20 A LA (%) LA 10 10 5 0 0 0 10 20 30 40 50 0 10 20 30 40 50 Amphibole (%) Amphibole (%)
Figure 40 The Los Angeles value (%) of 30 rock Figure 41 The Studded Tyre Test value (%) of 31 samples compared to their amount of amphibole (%). rock samples compared to their amount of amphibole (%).
7.3 Micro Analysis compared to the LA values of the rock samples. There is an obvious negative correlation 7.3.1 Grading of Grain Boundaries between the two properties, where a high amount of intergrowth between the grains seems to correlate with lower LA values, and All data from grading of grain boundaries is vice versa. A correlation can also be observed compiled in Appendix B. between the grade of intergrowth and the AN
value of the rock samples (Fig. 44), but this is The grade of intergrowth between adjacent not as evident. grains has been determined for 116 rock samples. The observations were predominantly When comparing the grade of intergrowth built on the amount of intergrowth and between gneissic and non-gneissic rock interlocking between the grains, how apparent samples, it is evident that the gneissic rocks the grain boundaries were and if the grain have a higher tendency to have less boundaries were straight/smooth or irregular. interlocking grain boundaries (Fig. 45), with Figure 42 illustrates the type of grain no samples graded higher than 3.0. The grain boundaries that can be assigned certain grades boundaries of the non-gneissic rocks show of intergrowth, with examples from the current more variation, with both high and low grades study. The difference between i.e. grade 1.5 and of intergrowth, although they seem to trend 2.0 may not be obvious at this scale, but the towards the intermediate grades. This trend difference between i.e. grade 1.5 and grades reflects the recrystallization of minerals that higher than 3.5 is be more evident. occurs during metamorphic processes,
therefore causing gneissic rocks to have lower The results are summarized in Figures 43 and resistance to fragmentation (LA). 44. In Figure 43, the grade of intergrowth is
26
Figure 42 Examples of grain boundaries and their grade of intergrowth from samples analysed in this thesis. Los Angeles value and Studded Tyre Test values are also included for each sample.
50 30 45 25 40 35 20 30
25 (%) 15
N A LA (%) LA 20 10 15 10 5 5 0 0 1,0 2,0 3,0 4,0 5,0 1,0 2,0 3,0 4,0 5,0 Grade of Intergrowth Grade of Intergrowth
Figure 43 The Los Angeles value (%) compared to Figure 44 The Studded Tyre Test value (%) the grade of intergrowth between grains of 112 compared to the grade of intergrowth between rock samples. grains of 116 rock samples.
Gneissic Non-Gneissic
30
20
10
0 1,5 2 2,5 3 3,5 4 4,5 Number ofSamples Number Grade of Intergrowth
Figure 45 Comparison between the grade of intergrowth between grains in gneissic versus non-gneissic rock types for 116 rock samples.
27
A B Figure 46 Microscope images from thin sections with widely different amounts of altered plagioclase. A and B) Plane polarized (A) and crossed polarized (B) images from rock sample TEN140014. Plagioclase crystals are nearly unaffected by alteration. The amount of plagioclase alteration equals grade 1. The LA value of the sample is 46.29% and the AN value C D is 14.77%. C and D) Plane polarized (C) and crossed polarized (D) images from rock sample TEN082013. Plagioclase crystals are abundant and severely affected by alteration. The amount of plagioclase alteration equals grade 5. The LA value of the sample is 13.8% and the AN value is 8.6%.
7.3.2 Altered Plagioclase 50 All data from grading the amount of altered plagioclase is compiled in Appendix B. 40
30 Figures 46A-D show examples of rock samples with a grade 1 (Fig. 46A-B) and grade 5 (Fig. LA (%) LA 20 46C-D) amount of altered plagioclase. 10 The comparison between the amount of altered 0 plagioclase compared to the LA value of 112 0 1 2 3 4 5 rock samples is shown in Figure 47. The Altered Plagioclase results indicate that low amounts of altered plagioclase correlate with higher LA values, Figure 47 The amount of altered plagioclase (grade and vice versa. The trend is somewhat more 1-5) compared to the Los Angeles value (%) of 112 evident when comparing samples with grade 1, rock samples. Grade 1 corresponds to no or low amounts of altered plagioclase, while grade 5 4 and 5 regarding amounts of altered corresponds to high amounts of altered plagioclase. plagioclase, apart from two grade 1 samples with lower LA values than expected and one 30 grade 4 sample with higher LA value than expected. Grade 2 and 3 samples are somewhat 25 more continuously spread out with regards to 20
their LA values. (%) 15 N
A When comparing the amount of altered 10 plagioclase compared to the AN value of the 5 rock samples (Fig. 48) a correlation does exist, 0 but is far less evident. The grade 1 samples 0 1 2 3 4 5 show intermediate AN values, while grade 2, 3 Altered Plagioclase and 4 samples show larger variation in terms of the AN value. Grade 5 samples inherit low and Figure 48 The amount of altered plagioclase (grade more similar AN values. 1-5) compared to the Studded Tyre Test value (%) of 112 rock samples. Grade 1 corresponds to no or low amounts of altered plagioclase, while grade 5
corresponds to high amounts of altered plagioclase.
28
7.4 Image Analysis regression is calculated from the ln (population density) (mm-4) versus size (mm). The mean All data from the image analysis is compiled in grain size is retrieved from this graph as well. Appendix D and E. Figure 52 shows a histogram displaying the population density (number of grains) versus Figure 49 contains a map showing the position size (mm), a complementary grain size of the 25 samples that were subject to image distribution result. This has not been used in analysis in this study. The map also displays the analysis, but can be used to get a better the different lithotectonic units present in the understanding of the grain size distribution. area. In Figure 53, a rose diagram displays the Examples of images used in and created from alignment of the grains in the measured analysis in ImageJ 1.50i are shown in Figure 50 sample, i.e. the foliation of the sample. The (from sample MGO035025A). Examples of the scale to the left in the figure indicates number graphic results obtained from the of grains. measurements of the mentioned images in CSD Corrections 1.53 are shown in Figures 51-53. Table 2 demonstrates the results obtained for Figure 51 is the basis for the grain size and the measurements of sample MGO035025A grain size distribution results, were a linear that gave rise to the graphs and the rose diagram in Figures 51-53
Figure 49 Map showing the lithotectonic units of the area surrounding the planned railway corridor, and the positions of all samples that have been subject to image analysis.
29
A D
B
C
Figure 50 Microscopic images of thin section MGO035025A. A common scale for figures A-C is found in the bottom right corner of Figure A. A) Crossed polarized image. B) Resulting image from digitalization of grains. C) Binary image created in ImageJ 1.50i prior to measurement. D) Resulting image from measurements of grain size in ImageJ 1.50i.
Figure 53 Rose diagram displaying the alignment of grains in the sample measured. Scale indicates number of grains.
Table 2 Results obtained from CSD Corrections 1.53 for sample Figure 51 A linear regression Figure 52 A histogram displaying MGO035025A.
curve with ln(population the population density (number of density) (mm-4) versus grain grains) versus grain size (mm). Regression Slope -2,84 size (mm). The grain size and Mean Grain Size 0,4266 grain size distribution results Alignment Factor 0,36 are retrieved from this graph.
30
7.4.1 Grain Size and Grain Size however. Figures 57 and 58 display the mean Distribution grain size values obtained from the measurements, compared to the technical The LA value versus the grade of intergrowth properties of the rock samples as well. The between grains in the 25 rock samples subject same division into granitic gneiss and granites to image analysis are shown in Figure 54, as mentioned has been made here as well. No demonstrating that the complexity of grain boundaries does not have a definitive effect on the LA value in this case. 50 40 The measured grain size distributions of the 25 rock samples are displayed in Figures 55 30 20 and 56, where the results have been compared (%) LA to the LA and AN values, respectively. The 10 more negative the regression slope value is, the 0 smaller the grain size distribution. The rock 0 1 2 3 4 5 samples have been divided into granitic gneiss Grade of Intergrowth and granites. There seems to be no obvious correlation between the grain size distribution Figure 54 The Los Angeles value (%) versus the and the technical properties of the samples grade of intergrowth between grains in the 25 rock samples that have been subject to image analysis.
Granitic gneiss (ES) Granite Granitic Gneiss Granite
50 30 40 25 20 30 (%) 15
20 N A LA (%) LA 10 10 5 0 0 -5 -4 -3 -2 -1 0 -5 -4 -3 -2 -1 0 Regression Slope Regression Slope
Figure 55 The Los Angeles value (%) versus the Figure 56 The Los Angeles value (%) versus the grain size distribution (regression slope) of 24 rock grain size distribution (regression slope) of 25 rock samples. The more negative the regression slope samples. The more negative the regression slope value, the smaller the grain size distribution. value, the smaller the grain size distribution.
Granitic Gneiss Granite Granitic Gneiss Granite
50 30 40 25 20 30 (%) 15
20 N A LA (%) LA 10 10 5 0 0 0 0,2 0,4 0,6 0,8 1 0 0,2 0,4 0,6 0,8 1 Mean Grain Size (mm) Mean Grain Size (mm)
Figure 57 The Los Angeles value (%) versus the Figure 58 The Los Angeles value (%) versus the grain size distribution (regression slope) of 24 rock grain size distribution (regression slope) of 25 rock samples. The more negative the regression slope samples. The more negative the regression slope value, the smaller the grain size distribution. value, the smaller the grain size distribution.
31 evident correlation seems to exist between the 7.4.2 Perimeter mean grain size and the technical properties either. The mean grain size of the rock samples The results from the perimeter analysis in is however quite similar, with all but three comparison with the technical values of the samples within the range of 0.2-0.5 mm. rock samples are displayed in Figures 60 and 61. The rock samples have been divided into A correlation of grain size and technical granitic gneiss and granites. All samples plot properties that does seem to exist however can be seen in Figure 59, where the LA and AN Non-Porphyritic Weakly Porphyritic Porphyritic values are compared to each other and the rock 50 samples have been categorised according to the 40 absence or presence of porphyritic texture. The 30
texture has been observed in the field by the 20 LA (%) LA Geological Survey of Sweden in the process of 10 collecting the rock samples, or during the 0 study of thin sections through microscope. The 0 10 20 30 results show that the rock samples that are AN (%) porphyritic, or even weakly so, seem to be more likely to obtain lower technical values, while Figure 59 The Los Angeles value (%) compared to technical values of the non-porphyritic rocks the Studded Tyre Test value (%) of 112 rock samples, divided into non-porphyritic, weakly are more widespread. porphyritic and porphyritic.
Granitic Gneiss Granite Granitic Gneiss Granite
50 30 40 25 20 30 (%) 15
20 N A LA (%) LA 10 10 5 0 0 0 5 10 15 20 25 0 5 10 15 20 25 Perimeter (mm/mm2) Perimeter (mm/mm2)
Figure 60 The Los Angeles value (%) compared to Figure 61 The Studded Tyre Test value (%) the perimeter (mm/mm2) of 24 rock samples. A compared to the perimeter (mm/mm2) of 25 rock higher perimeter value equals a smaller grain size samples. A higher perimeter value equals a smaller and/or more complex grain boundaries. grain size and/or more complex grain boundaries.
Gneiss (ES) Granite Gneiss (ES) Granite
50 30 40 25 20 30 15
20 LA (%) LA AN (%) AN 10 10 5 0 0 0 0,2 0,4 0,6 0,8 1 0 0,2 0,4 0,6 0,8 1 Alignment Factor Alignment Factor
Figure 62 The Los Angeles value (%) compared to Figure 63 The Studded Tyre Test value (%) the alignment factor of the grains in 24 rock compared to the alignment factor of the grains in samples. A higher alignment factor corresponds to 25 rock samples. A higher alignment factor a more foliated fabric. corresponds to a more foliated fabric.
32 within a perimeter value of c. 12-20 mm/mm2. Streckeisen (1967), there seems to be no clear The perimeter of the samples does not seem to correlations between solely the rock type and correlate with the technical values. the technical properties. The granites (Figs. 16-19) and granodiorites (Figs. 20-21) all plot 7.4.3 Crystal Alignment in a widespread manner. One might argue that the quartz diorites/gabbros (Fig. 24), quartz The alignment of crystals in a rock reveals the monzodiorites (Fig. 24) and quartz monzonites (Fig. 25) all display exclusively low technical amount of foliation present in the rock. The values compared to the rest of the rock types, results from measurements of the crystal while the tonalities (Figs. 22-23) tend to show alignment in 25 rock samples are shown in higher technical values, but there are however Figures 62 and 63, where it is compared to the very few samples of these rock types in this technical values of corresponding rock study, making their results somewhat samples. The rock samples have been divided uncertain. As mentioned, it is however clear that the gneissic equivalents of the granites into granitic gneiss and granites. Alignment (Figs. 17 and 19), granodiorites (Fig. 21) and factor 0 corresponds to a massive texture, while tonalities (Fig. 23) all seem to exhibit less a value of 1 corresponds to a perfectly foliated favourable technical values. rock. All but one sample have an alignment factor less than 0.4. No evident correlation was With the above-mentioned differences between found between the degree of crystal alignment the lithotectonic units and gneissic vs non- and the technical properties of the rock gneissic rock types, it is made clear that the rocks of the TIB are far more likely to be samples. suitable for use as concrete aggregates and/or in road- and railway constructions, given their
8. Discussion stronger and more predictable technical values.
8.1 Technical Analysis 8.2 Mineralogy
When comparing the technical properties of In general, the results reveal that the the rock samples in this study with their mineralogy of a rock first and foremost affects original location (Figs 13, 14 and 15), it is the rocks resistance to abrasion rather than the evident that the more favourable properties are resistance to fragmentation. The only mineral found in the rocks belonging to the TIB. The that shows the opposite relation in this study is properties of the rocks derived from the the amount of quartz (Figs. 28-29). Although Eastern and Western segments, as well as the weak, there is a correlation between the Protogine and Mylonite zones, tend to be more amount of quartz and the LA value, where a unpredictable, and their resistance to higher amount of quartz correlates to reduced fragmentation and abrasion is more likely to be resistance to fragmentation. Quartz, given its lower than for the TIB rocks. This is most hardness and low cleavage, is normally known likely due to the fact that the rocks in the TIB to have a good resistance to fragmentation, but are more or less undeformed, while the rocks of the crystals may in this case be affected by the the Eastern and Western segments, the stress and strain that acted upon the rocks Mylonite zone and the Protogine zone were all during the orogenic events in the area. This subject to high amounts of stress and strain may have led to an increased amount of during a number of orogenic events. A large intragranular cracks and sub-grain formation, amount of the rocks in the deformed areas features that will weaken the crystal lattice. No exhibit gneissic texture, which evidently correlation was found between the amount of lowers the rocks resistance to both quartz and the rocks resistance to fragmentation and abrasion (Fig. 26). This is fragmentation however, indicating that the most likely due the fact that deformation will hardness of the quartz crystals still applies. cause minerals to recrystallize and increase the frequency of micro cracks in the rock, causing The effect of feldspars on a rocks technical it to break more easily. properties is more evident when combining the amount of plagioclase and alkali feldspar (Figs. When comparing the technical properties 34-35), rather than comparing them separately between different rock types, according to (Figs. 30-31 and 32-33). The rocks resistance
33 to fragmentation shows no correlation with the to fragmentation compared with rocks that amount of feldspars (Fig. 34), while the rocks exhibit less complex grain boundaries. It is also resistance to abrasion on the other hand shows made clear that rocks with observed gneissic a very strong correlation (Fig. 35). A higher texture will have predominantly less complex amount of feldspar correlates with better grain boundaries (Fig. 45), which could partly resistance to abrasion, and vice versa. These explain why gneissic rocks exhibit less results coincide well with the fact that the favourable technical properties (Fig. 26). Only feldspar crystals are relatively hard, and are one gneissic rock sample was obtained from therefore expected to have a high resistance to within the TIB, were gneissic rocks are abrasion. Feldspar crystals are however likely uncommon given the TIBs low grade of to have a highly developed cleavage and may deformation. This explains to a great extent exhibit high amounts of intragranular cracks, why the technical properties of the rock types properties that will lower the resistance to in the TIB are profoundly more favourable fragmentation. This seems not to be the case than those of the Eastern and Western for the rock samples of this study however, Segments (Fig. 11), reinforcing the fact that the given that the resistance to fragmentation is tectonic history of a rock may reveal its not lowered with increased amounts of technical properties prior to analysis. feldspar. 8.3.2 Evaluation of Method When combining the amounts of quartz and feldspar in the rock samples, it is evident that The results obtained in this study from the the rocks resistance to abrasion favours a grading of grain boundaries shows that it is higher total amount of these minerals (Fig. 37). possible to obtain quantitative data reflecting As mentioned, quartz and feldspars are hard this property, which can then be successfully minerals, and will naturally resist abrasion used to evaluate a rocks technical properties, in more easily. this case especially the rocks resistance to fragmentation and in a lesser degree the rocks The amount of mica (biotite, muscovite and resistance to abrasion. The results also show chlorite) has an evident effect on the rocks that the method may be an effective way to resistance to abrasion in the samples studied distinguish between rocks that have i.e. a grade here, with lower amounts of mica correlating 1.5 and 4 of intergrowth, but will likely not be with a better resistance to abrasion (Fig. 39). useful when comparing rocks with i.e. a grade The softness of the mica minerals is most likely 2 and 2.5 of intergrowth. As seen in Figure 43, the cause for this. The content of mica minerals rock samples with a 2 or 2.5 grade of seems not to have an evident effect on the intergrowth show great variation when it rocks’ resistance to fragmentation however. comes to LA values. Perhaps other properties The amount of mica in the rock samples varies of the rock are more dominating here, such as throughout the investigated area. Around 40 microcracks, making it hard to draw any rock samples (out of a total 112) have a mica- conclusions from these parts of the results. content lower than 7%, as required for use as This coincides with the fact that this method concrete aggregate. should be used as a tool for obtaining “the big picture” of the concerned area and perhaps not Regarding the amount of amphibole in the rock for detailed studies. samples, it does not seem to affect the properties of the rock in this case (Figs. 40-41), There is however an uncertainty of how most likely due to the low amounts present in compatible the method is when it comes to the considered rock samples. comparing the results with other studies. The grade of intergrowth in the rock samples was 8.3 Micro Analysis decided based on the model from Hellman et al. (2006) in Figure 7, but is to some extent also 8.3.1 Grading of Grain Boundaries based on individual interpretations, why the results may turn out somewhat different if The grade of intergrowth between adjacent carried out by another individual. grains in a rock shows a clear correlation with Furthermore, the grading is most likely a the Los Angeles value of the same rock (Fig. comparison between the samples concluded in 43), where rocks with more complex grain this study, and hence the results are not boundaries are likely to have better resistance adapted to any global scale of grain boundary
34 intergrowth. The results from this study may 8.4 Image Analysis therefore not be compatible with a similar study carried out in a completely different area. 8.4.1 Grain Size and Grain Size Analysis
Considering the positive outcome of the The grain size and grain size distribution of the results, the method should be considered when samples were initially expected to show a searching for simple and cost-effective methods correlation with the technical properties of the for analysing and evaluating rock properties in rock samples. This correlation does not appear a general manner, as results can be obtained to exist, however. The samples do however from a large amount of rock samples in a short show very similar results in terms of grain size period of time. distribution (Figs. 55-56) and mean grain size (Figs. 57-58), which might prevent a possible 8.3.3 Altered Plagioclase correlation from being made visible. It is also possible that the influence of the grain size and Altered plagioclase crystals are known to affect grain size distribution is insignificant in this the strength of rocks, either weakening them area, and that other properties affect the because of overly aggressive alteration technical properties to a much greater extent. (Göransson et al., 2004), or strengthening This is however less likely true, given that them due to the more flexible properties rocks with porphyritic texture in the area tends obtained from alteration (e.g. Åkesson et al., to increase the resistance to fragmentation and 2004; Hellman et al., 2011). Particularly the abrasion (Fig. 59), while rocks with non- resistance to fragmentation has been found to porphyritic texture are more unpredictable. be affected by this. The results obtained in this This has however not been determined study, considering the amount of altered numerically in this study, and is only based on plagioclase in a total of 112 samples, complies observations done during sampling in the field with the results obtained by Åkesson et al. and during microscope analysis. (2004) and Hellman et al. (2011), indicating that an increased amount of altered plagioclase 8.4.2 Perimeter does in fact seem to increase the rocks resistance to fragmentation (Fig. 47). A weak No correlation was found between the correlation can also be seen between increased perimeter of the rock samples and their amount of altered plagioclase and increased technical properties (Figs. 60-61). The resistance to abrasion (Fig. 48). perimeter results were however also very similar for all samples, with values roughly These results indicate that this method for between 12 and 20 mm/mm2. Åkesson et al. briefly determining the amount of altered (2001) found a correlation between the plagioclase in a large number of rock samples perimeter and technical properties, but did on may be successfully used as a cost-effective way the other hand have perimeter values of up to to estimate the rocks’ resistance to 50 mm/mm2. The lower perimeter values (<20 fragmentation at an initial stage of mm/mm2) of Åkesson et al. (2001) did not investigation. show an equally strong, or even absent, correlation, why there is reason to believe that There are however disadvantages of this the perimeter of the samples in this present method as well, and they are nearly identical to study are simply too similar to reveal a possible those found for the method of grading the correlation. amount of intergrowth between adjacent grains. The method is based on individual 8.4.3 Crystal Alignment interpretations, why the results may turn out somewhat different if carried out by another The results from the crystal alignment analysis individual. Furthermore, the grading is most shows that all samples but one plot below 0.4 likely a comparison between the samples on the 0-1 scale, revealing that they are concluded in this study, and hence the results considered more massive than foliated. It is are not adapted to any global scale regarding therefore not surprising that there is no the amount of altered plagioclase. The results obvious correlation between the foliation of the from this study may therefore not be samples and their technical properties (Figs. compatible with a similar study carried out in a 62-63). completely different area.
35
8.4.4 Evaluation of Method determined at the same time, which has not been done in this thesis however. Different The method used in this thesis for mineral types can be assigned different colours digitalisation of mineral grains in a microscope when digitalising the grains in the image, after image from a thin section comes with both which the image processing program ImageJ advantages and disadvantages, the same as for 1.50i can distinguish between the different many other methods concerning image phases. The results can then additionally be analysis. First and foremost, the method is very used for analysing the impact of the specific simple as well as relatively time efficient and area of each mineral phase, their nucleation cost-effective, considering that analysis of one rates, the amount of monominerallic single image with digitalised grains can aggregates, or simply for comparing the produce a large amount of data concerning volume of each mineral phase instead of the many different properties of the rock sample. modal amounts used frequently today. The method requires no more than a basic background in geology, mineralogy or similar There are however a number of downsides to in order carry out the simplest analysis steps the method as well. A disadvantage of the like identification of mineral grain boundaries. method when used in this thesis was the fact The steps carried out in the image processing that the digitalisation of mineral grains was software’s (Photoshop CS6, ImageJ 1.50i and only applicable on images from rock samples CSD Correction 1.53) are simple as well, with less complex grain boundaries and low considering that the image with digitalized amounts of alteration. Complex grain grains require a very low amount of processing boundaries and alteration makes it difficult, if prior to analysis (Table 1). This in turn yields not impossible, to distinguish grain boundaries better regulated results, given that the more and the results would therefore be far more the data is interpreted or manipulated by a uncertain. Unfortunately, only rocks from the computer, the less reliable the results may be Eastern and Western Segments where able to considered. be analysed in this study because of this, as the rocks from the TIB were too complex in their Microscopy is not only an established and well- texture to be able to be analysed. Neither were known method for analysing rock samples, but porphyritic rock types possible to analyse, it is also one of the most cost-effective methods. given that they consist of large amounts of very By using images from a microscope, the small grains gathered in aggregate bands, pictures will have a very good resolution as making it impossible, or at the least extremely well, increasing the possibility to distinguish time consuming, to distinguish between every the grain boundaries and very small grain single grain. The problem with complex rock sizes. In combination with the “Quick textures are however not exclusive for this selection” tool used in Photoshop CS6 for method, but is rather an issue for nearly all tracing minerals both precisely and efficiently, types of image analysis methods. the accuracy of the results is considered very high. For samples with larger grain sizes, Another issue when digitalising mineral grains several images can be taken at the highest was to distinguish between grain boundaries magnification, and then be stitched together in and cleavage plains in certain grains, mostly in order to analyse a larger area but still contain mica minerals. Quartz grains displayed the high resolution. In order to enhance the subgrain formation in many samples as well, precision of the method even more, SEM/BSE adding additional uncertainty to the analysis. images may be used in combination with microscope images, as the SEM/BSE images The precision of the “Quick Selection” tool in may yield very clear grain boundaries. The Photoshop CS6 for tracing mineral grains is as downside with these images are however the mentioned relatively high in comparison with fact that the grain boundaries of minerals other methods, but a problem does arise when within the same phase that lay adjacent each it comes to tracing the outlines of very small or other are not visible. The method will also be very flaky minerals. If these minerals were to more time consuming and costly if SEM/BSE be traced as accurately as the larger, less images are to be used. complex minerals, the method would be far more time consuming, as the size of the tool Another advantage with the method is that the range would have to be repeatedly adjusted mineralogical composition of the sample can be according to mineral size during the
36 digitalisation process. This can perhaps be recrystallization of minerals that takes considered negligible regarding the very small place during metamorphic events. grains, but in terms of flaky minerals being traced and digitalised as more rounded, this Quantitative results of mean grain size could have a considerable effect on for example and grain size distribution, as well as the the perimeter results depending on the amount alignment of mineral grains, show no of flaky minerals in the sample. correlation with the technical properties of the rock samples analysed. This is Furthermore, the conversion of 2D data however suspected to be caused by the obtained from measurements in ImageJ 1.50i similarity of the analysed samples, into 3D data in CSD Corrections 1.53 involves preventing any correlation from being the mathematical assumptions of stereology. made visible. Although not Stereological conversions are of complex quantitatively determined, observations nature, and a large number of equations have made in the field and during microscope been used through time for the same purpose. analysis regarding the presence of In this case, Higgins (2000) has used and porphyritic texture reveal that modified the Saltikov method in the program porphyritic rocks tend to exhibit more CSD Corrections 1.53. This conversion adds a favourable technical properties than computerized interpretation into the result, non-porphyritic rocks are likely to do. why the results may vary to a certain degree depending on the input variables selected in the Considering the non-existing program prior to conversion of data. correlation between grain size, grain size distribution and alignment of grains 9. Conclusions compared to the technical properties, there is also a suspicion that micro- The most obvious conclusions made from this cracks could have a strong influence on thesis are summarized below. the material on this scale.
As expected, the technical properties of The mineralogy of the rock samples in the TIB rocks are more favourable for this study corresponds to the technical use in concrete-, road- and railway properties as expected, the most evident constructions than rocks of the Eastern being that increased amounts of and Western Segments. This can be feldspars correlates with better attributed to the apparent difference in resistance to abrasion, while increased tectonic history of the areas, were the amounts of mica lowers the rocks rocks of TIB are relatively undeformed, resistance to abrasion. Quartz was while the rocks of the Eastern and shown to be the only mineral affecting Western Segments have been subject to the resistance to fragmentation, as there large amounts of stress and strain due to is a very weak but evident correlation a number of orogenic events. between high amounts of quartz and better resistance to fragmentation. The above mentioned tectonic history of the area has led to an increased amount The grade of intergrowth between of gneissic rocks in the Eastern and adjacent grains showed a strong Wstern Segment. By observations made correlation to the technical properties of in the field during sampling regarding the rock samples in this study, gneissic or non-gneissic texture, it has particularly with their resistance to been made visible that rocks with fragmentation. More complex grain gneissic texture are more likely to boundaries will give more favourable correspond with less favourable technical properties. technical properties. By grading the amount of intergrowth between adjacent The results from the grading of grain grains, it has also been determined that boundaries imply that the method can be gneissic rocks display less complex grain used in an early stage of analysis, and is boundaries, most likely due to the a cost-effective way to retrieve basic information on a large number of rock
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samples. The method is preferably used rock more resistant to brittle to distinguish between and estimate the deformation (e.g. Åkesson et al., 2004; technical properties of rock samples with Hellman et al., 2011). Åkesson et al. significantly low or high grade of (2004) demonstrates that feldspars with intergrowth, i.e. 1.5 and 4 on the scale of sericite alteration have less crack 1-5, and not between samples with a abundance, the reason being that more similar grade of intergrowth (i.e. 2 sericitized feldspar grains exhibit more and 2.5). flexible properties than do an unaltered feldspar grain. The image analysis method used in this thesis, were mineral grains were 10. Acknowledgments digitalised with the “Quick Selection” tool in Photoshop CS6 and analysed in I would like to thank my supervisor Johan ImageJ 1.50i and CSD Corrections 1.53, Hogmalm for contributing with ideas and is considered to be both cost-effective knowledge in order to design this project, as and time-efficient. The method can well as for the help and input along the way and produce a large amount of data on several different parameters from one for critically reviewing the results of the thesis. single measurement. A disadvantage of Thanks also to my co-supervisor Thomas the method is that too complex, heavily Eliasson at the Geological Society of Sweden, altered or porphyritic rock samples are for contributing with the initial idea of the not able to be analysed as time project, as well as extensive supervision, advise efficiently, nor with good enough and input throughout the whole project. Many precision. thanks also to the Geological Society of
Sweden for providing the material on which Higher amounts of altered plagioclase correlates with a higher LA value, which this thesis was based on, and for providing a coincides with results obtained by workspace for the microscopic analysis. Last Åkesson et al. (2004) and Hellman et al. but not least, thanks the Department of Earth (2011). Plagioclase that has been Sciences at the University of Gothenburg for exposed to alteration, e.g. sericite making this project possible. alteration, is believed to make its host
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11. References Göransson, M. (2011). Ersättningsmaterial för naturgrus. Sveriges geologiska Andréasson, P. G., & Dallmeyer, R. D. (1995). undersökning, 10, 32. Tectonothermal evolution of high‐alumina rocks within the Protogine Zone, southern Göransson, M., Bergström, U., Shomali, H., Sweden. Journal of Metamorphic Claeson D. & Hellström, F., 2008: Geology, 13(4), 461-474. Beskrivning till berg-kvalitetskartan delar av Kungsbacka och Varbergs kommuner. Arvidsson, H., & Loorents, K. J. (2008). Sveriges geologiska undersökning K 96, 37 pp. Inverkan av köld och vatten på glimmerhaltiga bärlager. VTI, Statens väg- Göransson, M., Persson, L., & Wahlgren, C. H. och transportforskningsinstitut, 2-2008. (2004). The variation of bedrock quality with increasing ductile Bergkross i betong - Krossat berg ersätter deformation. Bulletin of Engineering Geology naturgrus, Cementa (n.d.). Retrieved from and the Environment, 63(4), 337-344. http://www.cementa.se/sv/system/files_force/ assets/document/d7/bf/bergkrossibetong.pdf?d Hegardt, E. A., Cornell, D., Claesson, L., ownload=1, 2016-07-05. Simakov, S., Stein, H., & Hannah, J. (2005). Eclogites in the central part of the Bergström, U., Eliasson, T., Engdahl, M., Sveconorwegian Eastern Segment of the Jelinek, C., Lindh, Å., Lundqvist, L., Lång, Baltic Shield: support for an extensive L-O., Persson, L., Persson, T., & Pile, O. eclogite terrane. GFF, 127(3), 221-232. (2015). Geologiska data mellan Göteborg och Jönköping del I: Göteborg-Borås. The Hellman, F., Åkesson, U., & Eliasson, T. Geological Survey of Sweden, SGU-rapport (2011). Kvantitativ petrografisk analys av 2015:18. bergmaterial: en metodbeskrivning. VTI rapport 714. Bergström, U., Göransson, M. & Shomali, H. (2008) Beskrivning till bergkvalitetskartan Higgins, M. D. (2000). Measurement of crystal Partille och Lerums kommuner. Sveriges size distributions. American geologiska under-sökning K 94, 33 pp. Mineralogist, 85(9), 1105-1116.
Brander, L., Appelquist, K., Cornell, D., & Higgins, M. D. (2006). Quantitative textural Andersson, U. B. (2012). Igneous and measurements in igneous and metamorphic metamorphic geochronologic evolution of petrology. Cambridge University Press. granitoids in the central Eastern Segment, southern Sweden. International Geology Höbeda, P. (1971). Bergmaterial till Review, 54(5), 509-546. vägbyggnad. Statens väginstitut, Stockholm. Specialrapport 84. 1–126. Brattli, B. (1992). The influence of geological factors on the mechanical properties of basic Höbeda P. (1995). FAS Asfaltsbok. Kapitel: igneous rocks used as road surface Stenmaterial. Published by Föreningen för aggregates. Engineering Geology, 33(1), 31- Asfaltsbeläggningar i Sverige. 85–110. 44. Höbeda, P. & Bünsow, L. (1974). Inverkan av Gaál, G., & Gorbatschev, R. (1987). An outline glimmer på packnings- och of the Precambrian evolution of the Baltic bärighetsegenskaperna hos berggrus. VTI Shield. Precambrian Research, 35, 15-52. rapport 55. Statens väg och trafikinstitut, Stockholm. 1–29. Geological Survey of Sweden (2016). Produkt: Ballast (Visningstjänst). Retrieved 2016-11- Högdahl, K., Andersson, U. B., & Eklund, O. 08, from http://resource.sgu.se/data/service (Eds.). (2004). The Transscandinavian /wms/130/ballast. Igneous Belt (TIB) in Sweden: a review of its character and evolution (Vol. 37). Geological survey of Finland.
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Janssen, C., Wagner, F., Zang, A., & Dresen, G. Loorents, K. J., Johansson, E., & Arvidsson, H. (2001). Fracture process zone in granite: a (2007). Free mica grains in crushed rock microstructural analysis. International aggregates. Bulletin of Engineering Geology Journal of Earth Sciences, 90(1), 46-59. and the Environment, 66(4), 441-447.
Johansson, Å., Meier, M., Oberli, F., & Lundgren, L. (2012). Variation in rock quality Wikman, H. (1993). The early evolution of between metamorphic domains in the lower the Southwest Swedish Gneiss Province: levels of the Eastern Segment, geochronological and isotopic evidence Sveconorwegian Province. Dissertations in from southernmost Sweden. Precambrian Geology at Lund University, no 324. Research, 64(1), 361-388. Mainwaring, P. R., & Petruk, W. (1989). Johansson, E. (2011). Technological properties Introduction to image analysis in the Earth of rock aggregates. Luleå: Luleå Tekniska and mineral science. Image Analysis in Earth Universitet. (Doctoral Thesis / Luleå Sciences. Mineralogical Association of Canada, University of Technology). Short Course Handbook, 16, 1-5.
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Om Projektet - Götalandsbanan. (n.d.). Svensk Standard (2004a): SS-EN 1097-9. Retrieved October 03, 2016, from http://xn-- Ballast – Mekaniska och fysikaliska gtalandsbanan- egenskaper – Del 9: Bestämning av imb.nu/omprojektet.4.252ae5fb14a14b7e8 motstånd mot nötning av dubb-däck bbe5c1.html. (Nordiska kulkvarnsmetoden). Swedish Standards Institute, Sweden. Persson, L., & Göransson, M. (2005). Mechanical quality of bedrock with Söderlund, U., Isachsen, C. E., Bylund, G., increasing ductile deformation. Engineering Heaman, L. M., Patchett, P. J., Vervoort, J. geology, 81(1), 42-53. D., & Andersson, U. B. (2005). U–Pb baddeleyite ages and Hf, Nd isotope Quist, J., & Evertsson, C. M. (2010). chemistry constraining repeated mafic Application of discrete element method for magmatism in the Fennoscandian Shield simulating feeding conditions and size from 1.6 to 0.9 Ga. Contributions to reduction in cone crushers. In XXV Mineralogy and Petrology, 150(2), 174-194. International Mineral Processing Congress (IMPC) 2010 Proceedings/Brisbane, QLD, Tavares, L. M., & das Neves, P. B. (2008). Australia/6-10 September 2010 (pp. 3337- Microstructure of quarry rocks and 3347). relationships to particle breakage and crushing. International Journal of Mineral Stenlid, L., 2000: Utvärdering av micro- Processing, 87(1), 28-41. Devalmetoden. Slutrapport SBUF projekt nr 5002. Skanska Sverige AB, Vägtekniskt Åkesson, U., Hansson, J., & Stigh, J. (2004). Centrum Nord, Bålsta, 16 pp. Characterisation of microcracks in the Bohus granite, western Sweden, caused by Stjärnered, P-O. (2016). Här ska tågen stanna. uniaxial cyclic loading. Engineering SVT Nyheter Väst, retrieved 2016-09-12 from Geology, 72(1), 131-142. http://www.svt.se/nyheter/lokalt/vast/ha r-stannar-de-nya-tagen. Åkesson, U., Lindqvist, J., Göransson, M., & Stigh, J. (2001). Relationship between Streckeisen, A. (1967). Classification and texture and mechanical properties of nomenclature of igneous rocks. Neues granites, central Sweden, by use of image- Jahrbuch für Mineralogie, Abhandlungen 107, analysing techniques. Bulletin of Engineering 144-240. Geology and the Environment, 60(4), 277-284.
Sveriges geologiska undersökning, 2015a: Åkesson, U., Stigh, J., Lindqvist, J. E., & Grus, sand och krossberg 2014. Periodiska Göransson, M. (2003). The influence of publikationer 2015:2, 31 s. foliation on the fragility of granitic rocks, image analysis and quantitative Svensk Standard (1997a): SS-EN 1097-2. microscopy. Engineering Geology, 68(3), 275- Ballast – Mekaniska och fysikaliska 288. egenskaper – Del 2: Bestämning av motstånd mot sönderdelning. Swedish Standards Institute, Sweden.
Svensk Standard (1997b): SS-EN 1097-1. Ballast – Mekaniska och fysikaliska egenskaper – Del 1: Bestämning av nötningsmotstånd (Micro-Deval). Swedish Standards Institute, Sweden.
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12. Appendix
12.1 Appendix A: General and technical data
Tectonic Sample ID N-S E-W Rock Type (QAP) Gneissic Porphyritic Unit * MGO035002B 6389234 325179 Quartz Diorite WS MGO035004A 6395487 326491 Monzogranite WS Yes MGO035005A 6393555 328550 Syenogranite WS MGO035006A 6392540 327682 Tonalite WS Yes MGO035013A 6394752 350308 Tonalite WS MGO035014A 6396010 335631 Monzogranite WS MGO035016A 6396295 342178 Monzogranite WS Yes MGO035018A 6391557 333629 Monzogranite WS MGO035025A 6401488 342003 Monzogranite WS MGO035031A 6389494 339883 Granodiorite WS MGO035036A 6397892 334366 Monzogranite WS Yes MGO035037A 6396108 352450 Monzogranite ES MGO035039A 6396605 361771 Granodiorite ES MGO035044A 6397587 358420 Quartz Monzonite ES MGO035046A 6390050 356492 Granodiorite ES MGO035050A 6391007 331586 Granodiorite WS MGO035070A 6400582 344891 Granodiorite WS MGO035071A 6390465 345516 Granodiorite WS MGO035071B 6390465 345516 Granodiorite WS MGO035072A 6394756 339224 Granodiorite WS MGO035073A 6402360 333671 WS MGO035080A 6397438 366059 Monzogranite WS MGO035081A 6400444 373256 Monzogranite Yes WS MGO035082A 6404464 387787 Syenogranite WS MGO045025A 6398925 333293 Syenogranite WS MGO045026A 6390590 350606 Syenogranite MZ Yes MGO045031A 6404351 393563 Syenogranite Yes ES MGO045033A 6391491 384232 Syenogranite Yes ES MGO045034A 6392494 383161 Monzogranite Yes ES MGO045038A 6394508 358236 Monzogranite ES MGO045041A 6391649 359824 Granodiorite Yes ES MGO045046A 6389794 323168 WS MGO045048A 6399531 352307 Tonalite ES MGO045051A 6393684 382249 Monzogranite Yes ES MGO045055A 6390103 379356 Syenogranite Yes ES MGO045056A 6405441 387946 Monzogranite Yes ES Yes MGO045057A 6400350 382457 Syenogranite Yes ES MGO045059A 6401444 380419 Monzogranite Yes ES MGO045060A 6402642 378162 Syenogranite Yes ES
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Tectonic Sample ID N-S E-W Rock Type (QAP) Gneissic Porphyritic Unit * MGO045064A 6407515 376359 Syenogranite Yes ES MGO045065A 6403260 373237 Monzogranite Yes ES MGO045069A 6405270 379986 Monzogranite Yes ES MGO045070A 6398782 375290 Tonalite Yes ES MGO045071A 6395414 368809 Tonalite Yes ES MGO045082A 6395250 353219 Syenogranite ES MGO045083A 6398201 360280 Granodiorite ES MGO045084A 6400892 365350 Monzogranite Yes ES MGO045085A 6402486 365272 Quartz Syenite Yes ES MGO045085B 6402486 365272 Granodiorite Yes ES MGO045087A 6393214 368116 Granodiorite Yes ES MGO045092A 6394291 348479 Monzogranite WS Yes MGO045094A 6393220 348336 Tonalite MZ Yes MGO055025A 6389515 352837 Monzogranite ES MGO055026A 6390028 352607 Syenogranite ES MGO055074A 6393796 348014 MZ Weakly MGO082001 6394234 460070 Monzogranite TIB TEN062001 6409163 444006 Monzogranite PZ Yes TEN062002 6399176 445339 Monzogranite PZ Weakly TEN062003 6406058 436615 Monzogranite PZ Weakly TEN062004 6402027 435860 Monzogranite PZ TEN062005 6409227 447621 Quartz Monzodiorite TIB Yes TEN062006 6408897 444138 Syenogranite PZ Yes TEN062007 6404132 448201 Syenogranite PZ Yes TEN062008 6404018 448233 Syenogranite PZ Yes TEN062010 6407154 464592 Quartz Monzonite TIB TEN062011 6401870 466056 Monzogranite TIB TEN062012 6402164 433914 Monzogranite PZ Weakly TEN072001 6401061 429018 Monzogranite Yes WS TEN072002 6398954 429591 Monzogranite Yes WS TEN072003 6401511 447122 Monzogranite PZ Yes TEN072004 6405529 467933 Monzogranite TIB TEN072005 6404126 472773 Monzogranite TIB Yes TEN072007 6407963 472046 Monzogranite TIB TEN072009 6406544 460674 Granodiorite TIB TEN072010 6403328 456563 Monzogranite TIB TEN072011 6398540 455422 Quartz Monzonite PZ Yes TEN072012 6389580 456237 Monzogranite PZ Yes TEN072013 6402772 463459 Monzogranite TIB Weakly TEN072014 6406148 462634 Quartz Monzonite TIB TEN072018 6394775 452718 Monzogranite PZ TEN072021 6397521 466246 Granodiorite TIB Weakly TEN072025 6410510 460905 Quartz Gabbro TIB
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Tectonic Sample ID N-S E-W Rock Type (QAP) Gneissic Porphyritic Unit * TEN072026 6413594 449331 Granodiorite TIB TEN072027 6411243 466436 Quartz Monzonite TIB TEN072028 6397539 461371 Quartz Monzodiorite TIB TEN082002 6415987 470463 Quartz Monzonite TIB Yes TEN082004 6392295 449383 Monzogranite TIB Yes TEN082007 6412550 457859 Quartz Diorite TIB Weakly TEN082008 6413693 463096 Quartz Monzonite TIB Yes TEN082009 6416857 463309 Quartz Monzonite TIB TEN082010 6415718 468721 Monzonite TIB TEN082011 6415008 468104 Monzonite TIB TEN082012 6412800 472747 Monzogranite TIB TEN082013 6393341 467506 Quartz Monzodiorite TIB TEN082016 6384836 455288 Syenogranite PZ Yes TEN082017 6383153 457666 Monzogranite TIB Yes TEN082018 6386820 451295 Monzogranite Yes PZ TEN082020 6396164 439396 Monzogranite Yes PZ TEN082021 6393435 434304 Monzogranite Yes PZ Yes TEN082024 6425942 463544 Granodiorite TIB TEN082025 6425983 463492 Monzogranite TIB TEN082026 6421612 460340 Monzogranite TIB Yes TEN082029 6421526 466381 Monzogranite TIB TEN082030 6425482 469947 Syenogranite TIB Yes TEN140001 6402481 404551 Monzogranite Yes ES TEN140002 6410678 416386 Monzogranite Yes ES TEN140004 6402867 402299 Monzogranite Yes ES TEN140005 6397378 398583 Quartz Monzonite Yes ES TEN140006 6400769 393880 Monzogranite Yes ES TEN140007 6396265 394112 Monzogranite Yes ES TEN140009 6403374 399540 Monzogranite Yes ES TEN140010 6402764 406254 Quartz Monzodiorite Yes ES TEN140011 6409901 399122 Granodiorite Yes ES TEN140012 6409607 397173 Monzogranite Yes ES TEN140013 6409587 397088 Monzogranite Yes ES TEN140014 6408816 404122 Monzogranite Yes ES
* ES = Eastern Segment; WS = Western Segment; PZ = Protogine Zone; MZ = Mylonite Zone; TIB = Transscandinavian Igneous Belt
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Density Studded Tyre Test Los Angeles MicroDeval Sample ID (g/cm3) (%) (%) (%) MGO035002B 2,66 12,7 21,4 MGO035004A 2,69 18,5 29,4 MGO035005A 2,64 12,6 31,7 9 MGO035006A 2,81 25 29,4 MGO035013A 2,81 15,4 19,8 MGO035014A 2,71 17,6 28,3 MGO035016A 2,67 13,4 26,2 10 MGO035018A 2,76 21,8 26,7 MGO035025A 2,64 14,2 28,7 8 MGO035031A 2,74 22,6 33,5 MGO035036A 2,69 18,5 29,8 MGO035037A 2,68 17,5 30,7 MGO035039A 2,66 16,3 44,1 MGO035044A 2,76 20,4 37,5 MGO035046A 2,69 22,3 42,1 MGO035050A 2,74 13,6 22,3 MGO035070A 2,71 16,6 24,9 MGO035071A 2,75 20,8 28,5 17 MGO035071B 2,73 18,9 28 13 MGO035072A 2,78 22,2 37,6 MGO035073A 2,67 18,1 33,5 MGO035080A 2,69 20,3 44,8 14 MGO035081A 2,63 12,2 28,2 7 MGO035082A 2,64 16,7 39 MGO045025A 2,71 26,5 46,2 MGO045026A 2,68 11,2 22 7,3 MGO045031A 2,63 11,4 30,4 7,6 MGO045033A 2,64 16,3 37,1 8,6 MGO045034A 2,72 20,8 40,2 13,2 MGO045038A 2,71 19,2 31,5 12,4 MGO045041A 2,72 17,3 29,6 11,7 MGO045046A 2,63 13,4 25,9 7 MGO045048A 2,76 15,8 25,1 MGO045051A 2,69 16,4 35 10,2 MGO045055A 2,63 15,1 36,9 15,1 MGO045056A 2,7 12,8 23,3 MGO045057A 2,69 13,3 25,6 MGO045059A 2,74 13,1 21,3 MGO045060A 2,64 11,7 23 MGO045064A 2,65 13,9 33,4 MGO045065A 2,74 21,1 31,5 MGO045069A 2,63 10,6 26,7 MGO045070A 2,83 21,8 35,5
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Density Studded Tyre Test Los Angeles MicroDeval Sample ID (g/cm3) (%) (%) (%) MGO045071A 2,76 18,5 28,2 MGO045082A 2,63 10,9 27,6 MGO045083A 2,7 17,8 40,4 MGO045084A 2,64 14 36,4 MGO045085A 2,74 20,2 32,6 MGO045085B 2,65 13,2 35,9 MGO045087A 2,77 18,1 26,8 MGO045092A 2,71 16,9 20,7 MGO045094A 2,82 16,5 15,5 MGO055025A 2,69 20,9 MGO055026A 2,62 10,8 33,5 MGO055074A 2,82 16,2 MGO082001 2,64 8,3 18,8 5,2 TEN062001 2,72 16,7 11,3 TEN062002 2,64 10 24,2 5,6 TEN062003 2,63 18,7 38,5 11,6 TEN062004 2,62 12,5 40 7,9 TEN062005 2,77 9,9 18,9 6,3 TEN062006 2,62 11,6 25,6 6,4 TEN062007 2,62 8,3 23 5,1 TEN062008 2,67 10,8 20,7 6,7 TEN062010 2,72 13,9 28,9 7,4 TEN062011 2,65 7,6 17,1 5 TEN062012 2,64 15 29,7 8,9 TEN072001 2,76 16,5 39,5 10,7 TEN072002 2,65 17,7 43,3 11,2 TEN072003 2,69 14 22 8,9 TEN072004 2,63 11,1 26 6,3 TEN072005 2,75 12,4 21,4 7,7 TEN072007 2,65 13,9 25,9 8,4 TEN072009 2,68 6,6 15,5 4,1 TEN072010 2,73 9,9 17,8 7,3 TEN072011 2,73 11,5 20,1 7,4 TEN072012 2,7 11,7 21,2 7,4 TEN072013 2,74 9,5 18,1 5,5 TEN072014 2,68 12,2 25,8 6,6 TEN072018 2,65 8,9 22 4,9 TEN072021 2,7 10,1 21 5,8 TEN072025 2,81 17,5 18,7 13,9 TEN072026 2,66 8,2 19,4 5,5 TEN072027 2,67 7,9 17 5,6 TEN072028 2,81 13,1 18,8 8,1 TEN082002 2,68 7,2 18 4,2
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Density Studded Tyre Test Los Angeles MicroDeval Sample ID (g/cm3) (%) (%) (%) TEN082004 2,65 10,4 25,8 6,8 TEN082007 2,81 11,6 14,9 9,2 TEN082008 2,68 7,8 15,9 4,6 TEN082009 2,66 9 20,3 5 TEN082010 2,7 9,8 21,9 5,7 TEN082011 2,69 12,7 7 TEN082012 2,65 8,8 22,5 4,7 TEN082013 2,8 8,6 13,8 6 TEN082016 2,64 15,7 22,1 9,7 TEN082017 2,7 6,9 16,7 4,5 TEN082018 2,64 10,2 28,4 6,9 TEN082020 2,71 16,8 36,7 11,2 TEN082021 2,67 16,8 32,3 12,2 TEN082024 2,71 7,9 16,9 4,9 TEN082025 2,66 6,1 14,8 3,5 TEN082026 2,67 10,8 26,4 6,4 TEN082029 2,66 8,3 18,1 5,3 TEN082030 2,64 7,3 19,3 4,4 TEN140001 2,63 11,11 31,73 6,63 TEN140002 2,61 13,57 44,54 8,67 TEN140004 2,62 13,5 39 8,12 TEN140005 2,63 12,38 34,46 7,56 TEN140006 2,68 10,49 24,42 6,31 TEN140007 2,67 15,37 42,41 10,02 TEN140009 2,64 14,22 45,69 9,11 TEN140010 2,68 14,34 32,28 9,91 TEN140011 2,74 19,85 31,92 13,2 TEN140012 2,7 18,39 35,89 10,7 TEN140013 2,63 15,25 34,97 8,34 TEN140014 2,62 14,77 46,29 8
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12.2 Appendix B: Grade of Intergrowth and Grade of Altered Plagioclase
Grade of Grade of Altered Sample ID Intergrowth (1-5) Plagioclase (1-5) MGO035002B 3,0 2 MGO035004A 3,0 2 MGO035005A 2,5 1 MGO035006A 3,0 2 MGO035013A 3,5 1 MGO035014A 3,0 2 MGO035016A 2,0 2 MGO035018A 3,0 3 MGO035025A 2,0 3 MGO035031A 2,5 2 MGO035036A 2,5 3 MGO035037A 2,5 2 MGO035039A 1,5 2 MGO035044A 2,0 3 MGO035046A 2,0 2 MGO035050A 3,0 3 MGO035070A 3,0 3 MGO035071A 2,5 3 MGO035071B 2,5 3 MGO035072A 2,5 2 MGO035073A 2,0 2 MGO035080A 2,5 2 MGO035081A 3,0 3 MGO035082A 2,5 1 MGO045025A 2,5 2 MGO045026A 2,5 3 MGO045031A 2,0 2 MGO045033A 2,0 2 MGO045034A 2,5 3 MGO045038A 3,0 4 MGO045041A 2,0 2 MGO045046A 2,5 2 MGO045048A 3,0 2 MGO045051A 2,0 2 MGO045055A 1,5 2 MGO045056A 3,0 3 MGO045057A 2,0 2 MGO045059A 2,0 2 MGO045060A 2,0 1 MGO045064A 2,5 2 MGO045065A 3,0 3
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Grade of Grade of Altered Sample ID Intergrowth (1-5) Plagioclase (1-5) MGO045069A 3,0 2 MGO045070A 2,0 3 MGO045071A 2,5 3 MGO045082A 3,0 2 MGO045083A 1,5 2 MGO045084A 1,5 1 MGO045085A 2,0 2 MGO045085B 1,5 2 MGO045087A 2,5 2 MGO045092A 3,0 3 MGO045094A 4,0 3 MGO055025A 1,5 3 MGO055026A 2,5 3 MGO055074A 3,0 4 MGO082001 4,0 5 TEN062001 2,5 4 TEN062002 2,5 3 TEN062003 2,0 2 TEN062004 2,5 1 TEN062005 3,5 4 TEN062006 3,0 4 TEN062007 3,0 3 TEN062008 4,0 4 TEN062010 3,0 3 TEN062011 3,0 4 TEN062012 2,0 2 TEN072001 1,5 1 TEN072002 2,0 1 TEN072003 3,0 2 TEN072004 3,5 3 TEN072005 3,5 4 TEN072007 3,5 4 TEN072009 4,5 5 TEN072010 3,0 5 TEN072011 4,0 5 TEN072012 3,5 5 TEN072013 3,5 5 TEN072014 3,0 3 TEN072018 3,5 5 TEN072021 3,0 4 TEN072025 3,5 4 TEN072026 3,0 5 TEN072027 4,0 4
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Grade of Grade of Altered Sample ID Intergrowth (1-5) Plagioclase (1-5) TEN072028 3,0 4 TEN082002 3,5 4 TEN082004 2,5 2 TEN082007 4,0 4 TEN082008 3,0 4 TEN082009 3,5 5 TEN082010 3,5 4 TEN082011 3,0 2 TEN082012 4,0 4 TEN082013 4,0 5 TEN082016 2,5 2 TEN082017 3,0 5 TEN082018 2,0 2 TEN082020 2,0 2 TEN082021 2,0 2 TEN082024 4,0 3 TEN082025 4,0 4 TEN082026 2,0 3 TEN082029 3,0 4 TEN082030 2,5 2 TEN140001 2,0 1 TEN140002 2,0 1 TEN140004 2,0 1 TEN140005 2,5 2 TEN140006 2,5 3 TEN140007 2,5 1 TEN140009 1,5 1 TEN140010 3,0 2 TEN140011 2,5 2 TEN140012 2,5 2 TEN140013 2,5 2 TEN140014 1,5 1
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12.3 Appendix C: Mineralogy
Note: Includes only the minerals that are of interest for this thesis, other minerals have been left out from this Appendix.
Quartz Alkali Feldspar Plagioclase Biotite Chlorite Muscovite Amphibole Sample ID (%) (%) (%) (%) (%) (%) (%) MGO035002B 8,2 33,1 7,6 45,8 MGO035004A 31,2 28,8 30,8 6,2 1,6 MGO035005A 36,7 36 17 9,3 MGO035006A 36 33,6 22 0,6 2,2 MGO035013A 23 40 19,1 0,6 9,1 MGO035014A 28,7 20 33,9 14,6 0,2 0,6 MGO035016A 34,5 26 28,8 6,5 0,2 MGO035018A 27,3 18,7 30,9 15,1 4,8 0,2 MGO035025A 20,8 33,6 34,4 2,2 8 MGO035031A 30 17 35,2 12,6 0,4 MGO035036A 31,6 25,8 32,6 6,4 1,4 2 MGO035037A 29,8 20,8 41,4 5,6 0,2 MGO035039A 27 15,8 47,4 9,4 MGO035044A 8,2 24,4 45,8 8,2 0,4 0,2 12,2 MGO035046A 32 13 42 7,8 0,2 4 MGO035050A 28,2 9 39,6 10,8 1,6 4,6 MGO035070A 30,5 12,8 37,4 16,1 0,4 MGO035071A 27,4 10,6 35,8 17,6 MGO035071B 28,6 13,6 39,4 12 MGO035072A 29,6 7,7 39,4 16,3 3 MGO035073A MGO035080A 26,1 24,7 42,2 5,8 0,4 MGO035081A 39,8 21,2 33,1 4,2 MGO035082A 34,2 41,1 19,2 1,4 s MGO045025A 32,3 32,7 10,8 16,8 1,3 MGO045026A 39,9 27,7 14,2 8,6 2,4 MGO045031A 48,5 29,4 14,8 6 0,3 MGO045033A 33,6 41,5 15,5 6 0,8 MGO045034A 26,2 33 20,2 16,3 2,2 s MGO045038A 18,5 25,9 29,7 1,8 13,5 8 MGO045041A 34,3 4,1 26,9 14,9 2,9 15,4 MGO045046A MGO045048A 29,2 3,8 36 14,9 2,8 10,8 MGO045051A 41,9 18,4 22,5 12,2 0,3 3,4 MGO045055A 36,8 42,3 13,1 4,6 s MGO045056A 29,3 27,8 15,5 11,5 3,9 8,4 MGO045057A 39,8 26,7 13,2 10,5 1,8 5,1 MGO045059A 38,7 16,1 21,2 13,9 0,6 6,4 MGO045060A 38,3 36,6 16,9 5,9 0,3
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Quartz Alkali Feldspar Plagioclase Biotite Chlorite Muscovite Amphibole Sample ID (%) (%) (%) (%) (%) (%) (%) MGO045064A 23,1 42 16,1 10,9 1,7 1 MGO045065A 29,9 17,5 22,1 23,4 0,6 4,9 MGO045069A 40,3 23 22,4 7,4 1,8 0,4 MGO045070A 11,6 1,4 37,2 7,2 7,2 30,1 MGO045071A 20,3 1,5 41 17,5 6,2 11,8 MGO045082A 39,5 37,2 10,9 4,4 0,6 MGO045083A 25,5 9,9 37,8 7,3 5,6 11,3 MGO045084A 33,7 28,1 27,9 8,9 MGO045085A 15,4 54,8 16 7,3 2,3 MGO045085B 34,4 7 30 13 7,2 6,8 MGO045087A 31,9 6,4 32 17,3 2,4 8,6 MGO045092A 38,3 13,9 16,4 17,6 9,4 MGO045094A 25,9 4,2 23,5 13,4 8 15,1 MGO055025A 25,4 25 33,8 10 0,8 3 MGO055026A 42 40,2 16,8 0,4 MGO055074A MGO082001 32,6 30,8 33 1,4 0,6 TEN062001 19,6 25,8 29,4 8,1 9,7 TEN062002 34,7 32,1 25,6 3,7 1,4 TEN062003 35,7 33,2 21,2 4,3 1,9 TEN062004 34,2 36,6 25,3 1 1,6 TEN062005 6,2 22,9 55 12,2 1,1 TEN062006 32,4 50,5 13 2,8 TEN062007 38,5 36,6 17,4 0,2 s 5 TEN062008 27,9 38,8 20,6 5,2 4,1 TEN062010 10,2 35,4 32,1 3,6 17,5 TEN062011 24,5 41,3 28 4,8 TEN062012 42 30,7 22 2,8 0,3 0,1 TEN072001 26,5 27,2 34,6 8,2 1 TEN072002 22,8 34,2 33,8 2,6 4,4 TEN072003 28,4 24,2 24 6,2 11,6 TEN072004 34,8 40 21,2 3,2 x TEN072005 19,8 30,6 32,6 11,8 x 2,4 TEN072007 25,6 29,6 34,6 7,8 x TEN072009 23,2 12,4 55,8 7,4 x TEN072010 27 21,4 32,4 14,2 x 2 TEN072011 15,8 25,2 47 7 1,6 2,2 TEN072012 18,8 24 48,2 5,4 0,4 TEN072013 23,8 26,2 31,2 8 x 8,2 TEN072014 8 49,8 33,8 2,2 5,2 TEN072018 32 22,4 36 5,2 x 2,2 TEN072021 25,8 14,2 48,6 9 x TEN072025 12,2 54,6 x 7,6 7,2 7,4
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Quartz Alkali Feldspar Plagioclase Biotite Chlorite Muscovite Amphibole Sample ID (%) (%) (%) (%) (%) (%) (%) TEN072026 37,8 18,8 37,6 4,4 0,4 TEN072027 8,6 42,8 35,2 9,8 x x TEN072028 14,8 14,4 50,2 8,4 10,6 TEN082002 12,14 33,14 39,14 5 + 8,57 TEN082004 30 42,71 23,14 3 TEN082007 12,01 2,95 51,7 15,35 9,28 TEN082008 14,42 46,42 24,28 5,42 4,85 TEN082009 16,28 37,28 39,57 4,57 + 0,57 TEN082010 3,42 32,85 51,71 7,28 0,42 1,57 TEN082011 0,2 39,8 50,2 6,6 1,6 TEN082012 27,4 36,6 30,8 1,6 + 0,2 TEN082013 12,4 13,6 48,8 6,2 + 0,2 15,2 TEN082016 36,4 28,4 15,4 1,4 13 TEN082017 26,2 22,4 41,4 5,6 1,2 TEN082018 26,4 31,6 33,6 5,6 0,4 TEN082020 17,2 21,4 36,8 15,2 5 TEN082021 37,6 26,4 24 7,6 0,4 TEN082024 19,54 18,95 45,04 7,62 0,23 3,09 TEN082025 26,78 28,1 37,46 4,74 TEN082026 26,62 35,76 27,8 3,31 0,13 2,78 0,13 TEN082029 22,63 43,02 26,44 0,78 0,26 3,42 TEN082030 34,3 45,8 13,7 TEN140001 19,1 30,6 42,5 3,1 s 1,3 TEN140002 27,4 26,3 43,9 0,8 0,2 TEN140004 21,8 29,9 42,9 3,8 s TEN140005 11 37 44,6 4,8 0,3 s TEN140006 23,4 24,1 43,3 5,7 0,6 0,5 TEN140007 25,3 32,5 31,7 5,6 s 0,1 2,9 TEN140009 23,7 24,8 40,5 7,9 0,2 TEN140010 10,8 21,5 47,9 9,6 0,1 7,4 TEN140011 16,3 12,7 44,9 9 s 15,4 TEN140012 19,9 27,2 38,8 6,6 0,4 0,2 4,4 TEN140013 30,5 32,1 31,6 5,5 0,1 TEN140014 33,6 33,5 29,6 0,4 s
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12.4 Appendix D: Area and Perimeter
Total Area Perimeter Perimeter/Area Number of Grains Sample ID (mm2) (mm) (mm/mm2) Measured MGO035005A 28,3477904 505,865 17,84495345 698 MGO035014A 26,0773902 442,475 16,9677639 518 MGO035025A 29,1716268 561,958 19,26385538 646 MGO035037A 28,3739688 431,302 15,2006229 463 MGO035039A 29,0437459 441,033 15,18512803 484 MGO035073A 28,78194 525,438 18,25582292 646 MGO035080A 29,2143332 461,002 15,77999391 488 MGO035082A 31,8846661 523,014 16,40330805 625 MGO045025A 29,3106853 569,11 19,41646857 725 MGO045034A 27,4020931 402,466 14,68741817 385 MGO045046A 30,4588297 428,857 14,07989093 424 MGO045055A 27,907023 354,822 12,71443393 310 MGO045059A 29,5770569 492,854 16,66338884 639 MGO045060A 28,5308982 442,009 15,49229179 485 MGO055025A 29,7030977 448,493 15,09919957 485 MGO055026A 28,4445408 390,855 13,74094955 365 TEN140001 28,8295588 500,798 17,37099078 594 TEN140002 28,8427404 403,29 13,98237457 426 TEN140004 27,2458083 395,803 14,52711535 393 TEN140006 30,0549182 376,903 12,54047665 353 TEN140007 29,0559077 508,16 17,48904234 549 TEN140009 28,1592101 470,135 16,69560326 509 TEN140012 27,8759639 342,278 12,2786068 314 TEN140013 27,2148216 381,187 14,00659558 384 TEN140014 28,4637767 372,162 13,07493394 337
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12.5 Appendix E: Texture and Grain Size
Regression Mean Grain Size Sample ID Alignment Factor Slope (mm) MGO035005A 0,25 -2,46 0,4235 MGO035014A 0,33 -0,986 0,801 MGO035025A 0,36 -2,84 0,4266 MGO035037A 0,61 -1,02 0,8324 MGO035039A 0,32 -3,52 0,26 MGO035073A 0,32 -3,44 0,3311 MGO035080A 0,39 -2,01 0,5505 MGO035082A 0,15 -4,48 0,211 MGO045025A 0,22 -4,06 0,296 MGO045034A 0,3 -3,06 0,3844 MGO045046A 0,23 -3,49 0,3251 MGO045055A 0,11 -3,43 0,2691 MGO045059A 0,19 -4,29 0,2523 MGO045060A 0,21 -2,22 0,479 MGO055025A 0,17 -2,81 0,3278 MGO055026A 0,26 -3,64 0,2768 TEN140001 0,14 -3,97 0,2667 TEN140002 0,28 -2,66 0,363 TEN140004 0,16 -4,11 0,1905 TEN140006 0,36 -4,62 0,2318 TEN140007 0,14 -3,33 0,333 TEN140009 0,27 -4,72 0,2425 TEN140012 0,2 -3,27 0,2614 TEN140013 0,22 -3,36 0,2979 TEN140014 0,06 -3,02 0,3621 0=massive; 1=perfectly foliated
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