POSIVA OY

FI-27160 OLKILUOTO, FINLAND

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Jon Engström

Apri l 2012

Working Report 2012-18

Geological Mapping of Investigation TrenchOL-TK18 at the Olkiluoto Study Site,

Eurajoki, SW Finland

Apri l 2012

Working Reports contain information on work in progress

or pending completion.

Jon Engström

Geological Survey of F inland

Working Report 2012-18

Geological Mapping of Investigation TrenchOL-TK18 at the Olkiluoto Study Site,

Eurajoki, SW Finland

Base maps: ©National Land Survey, permission 41/MML/12

GEOLOGICAL MAPPING OF INVESTIGATION TRENCH OL-TK18 AT THE OLKILUOTO STUDY SITE, EURAJOKI, SW FINLAND

ABSTRACT Geological mapping of investigation trench OL-TK18 was carried out by the Geological Survey of Finland at the Olkiluoto study site, Eurajoki, as part of Posiva Oy’s site investigation programme for the development of an underground repository for nuclear waste. The E-W striking, ca. 55 m long trench is located in the central part of the Olkiluoto Island adjacent to investigation trenches OL-TK12 and OL-TK4. The trench was cleaned with a pressure washer and pressurized air. The rock types were determined macroscopically. The rock types in investigation trench OL-TK18 is of heterogeneous character, with a large variation in their composition. The rocks vary from tonalitic-granodioritic gneiss to diatexitic gneiss, with portions of K-feldspar porphyritic gneiss. Inclusions of mica gneiss and a well-preserved schollen migmatite is encountered. The trench ends in a feldspar-rich pegmatoid. The most dominant tectonic feature is D4 ductile deformation domain and associated S4 foliation. This domain and hence the S4 foliation is striking NE-SW with a moderate dip towards SE. Both ends of the trench are dominated by the earlier deformation phase, showing S3 foliation striking ENE-WSW and roughly dipping towards the S. The S3 foliation is associated with small-scaled granitic leucosome veining, while the S4 foliation have a schistose character and it is more sheared. D4 ductile deformation domain is also characterised by a sheared blastomylonitic rock having growth of roundish feldspar porphyroblasts and BT-schlierens indicating high alteration of the protolith. During the fracture mapping, all fractures intersecting the central thread were investigated and a total of 117 fractures were recorded. The average fracture frequency of the trench is 2.11 fractures/m. On the basis of fracture orientations one main set can be distinguished striking NE-SW (foliation parallel) with a moderate dip towards the SE. The median fracture trace length is 1.6 m and over half of the fractures exceed 1.5 m trace length, the longest measured fracture being 7.90 m. Fracture fillings include hematite, chlorite, biotite and muscovite. A few fracture surfaces also contain calcite, clay, pyrite, quartz, and illite. The thickness of the fillings varies between 0.1 – 60 mm and the average thickness is 1.7 mm. The trench contains two big faults, one with a distinct fault core of quartz, calcite and chlorite, and having a NW-SE strike and a moderate dip towards the NE. The other one is parallel to the D4 ductile deformation domain, having a NE-SW strike and a moderate dip to the SW, showing totally altered and sheared rock. A Q-classification for the investigation trench has been made for every mapping section and the quality varies from good to exceptionally good. The average Q-quality of the rocks is exceptionally good, indicating that no major brittle deformation zone intersects the trench. Keywords: Investigation trench, rock types, D4 ductile deformation domain, S3 and S4 foliation, fracturing, nuclear waste disposal, Olkiluoto.

EURAJOEN OLKILUODON TUTKIMUSKAIVANNON OL-TK18 GEOLOGINEN KARTOITUS

TIIVISTELMÄ Osana Olkiluodon sijoituspaikkatutkimuksia Geologian tutkimuskeskus teki Posiva Oy:n tilauksesta tutkimuskaivannon OL-TK18 geologisen kartoituksen kesäkuussa 2010. Tutkimuskaivanto OL-TK18 sijaitsee Olkiluodon tutkimusalueen keskiosassa, kaivantojen OL-TK12 ja OL-TK4 vieressä. Kaivanto on itä-länsi-suuntainen ja sen pituus on noin 55 m. Kartoitus tehtiin paineilmalla ja painepesurilla puhdistetulta kalliopinnalta. Pääkivilajit määritettiin makroskooppisesti kartoituksen yhteydessä. Kaivannossa ei ole selvää pääkivilajia, vaan se vaihtelee diateksiittisen gneissin, tonaliitti- granodioriittigneissin, K-maasälpäporfyyriin ja pegmatiittisen graniitin välillä. Kaivannosta löytyy myös hyvin säilynyt schollen-migmatiitti, jota aiemmin on havaittu vain ONKALOn tutkimustunnelista ja muutamilla yksittäisillä paljastumilla. Myös pari isompaa kiillegneissisulkeumaa havainnoitiin kartoituksen yhteydessä. Hallitsevin duktiili rakennepiirre on S4-liuskeisuus ja siihen liittyvä duktiili deformaatiovyöhyke, joka on hallitsevin piirre kaivannon keskiosassa. Tämä vyöhyke ja siihen yhdistyvä S4-liuskeisuus on koillis-lounas-suuntainen ja sen kaade on kohti kaakkoa. Kaivannon molemmissa päissä liuskeisuuden suunta muuttuu ja itäkoillis-länsilounas-suuntainen ja etelään kaatuva S3-liuskeisuus on hallitseva. S3-liuskeisuuden erityspiirteenä ovat graniittiset leukosomisuonet gneisseissä, kun taas S4-liuskeisuudessa on korkeampi hiertymisaste. Toisena erityspiirteenä ovat maasälpäporphyroblastit ja biotiitti-schlierenit jotka ovat tyypillisiä tunnusmerkkejä tästä viimeisestä duktiilideformaatiosta Olkiluodon tutkimusalueella. Kartoituksessa mitattiin kaikki raot, jotka leikkasivat kaivannon ylle pingotetun linjalangan. Rakojen kokonaismäärä oli 117 rakoa ja keskimääräinen rakotiheys 2,11 rakoa/m. Rakosuuntien perusteella yksi ryhmä hallitsee ja se on koillis-lounas-suuntainen ja kaade on kohti kaakkoa (liuskeisuuden suuntainen). Rakojen mediaani pituus on 1,6 m ja yli puolet raoista on yli 1,5 m pitkiä, pisin mitattu rako on 7,90 m. Rakotäytteitä ovat hematiitti, kloriitti, biotiitti ja muskoviitti. Muutamista raoista löytyy myös kalsiittia, savea, rikkikiisua, kvartsia ja illiittiä. Täytteiden paksuus vaihtelee 0,1 – 60 mm ja keskimääräinen paksuus on 1,7 mm. Tutkimuskaivannosta kartoitettiin kaksi isompaa haurasta siirrosta. Toinen niistä on luode-kaakko-suuntainen (kaade kohti koillista) ja toinen on duktiilin deformaatio-vyöhykkeen suuntainen, siis koillis-lounas-suuntainen. Ensimmäisessä siirroksessa on paksu kvartsitäyte, kun taas toisen siirroksen pinta on hiertynyt ja kivi on vahvasti muuttunut. Kaivannon jokaiselle paaluvälille arvioitiin Q-luokituksen mukainen kallio-laatu ja sen perusteella kaivannon kalliolaatu vaihtelee hyvästä poikkeuksellisen hyvään. Keskimääräinen Q-laatu on poikkeuksellisen hyvä, mikä tarkoittaa sitä, että isoja hauraita siirrosvyöhykkeitä ei kaivannosta havaittu. Avainsanat: Tutkimuskaivanto, kivilajit, D4 duktiili deformaatiovyöhyke, S3- ja S4- liuskeisuus, rakoilu, ydinjätteiden loppusijoitus, Olkiluoto.

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TABLE OF CONTENTS ABSTRACT TIIVISTELMÄ 1 INTRODUCTION .................................................................................................... 2 2 RESULTS OF INVESTIGATIONS .......................................................................... 5

2.1 Lithology ........................................................................................................ 5 2.2 Ductile deformation ....................................................................................... 9

2.2.1 High-grade ductile shear zone Intersection (HGI) ........................... 12 2.3 Brittle deformation ....................................................................................... 13

2.3.1 Fracture orientation data ................................................................. 13 2.3.2 Fracture frequencies ....................................................................... 16 2.3.3 Fracture characteristics ................................................................... 17

2.4 Rock mass quality (Q-classification) ........................................................... 21 3 SUMMARY ........................................................................................................... 22 REFERENCES ............................................................................................................. 23 APPENDICES ............................................................................................................... 24

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1 INTRODUCTION

Investigation trench OL-TK18 is located in the central part of the Olkiluoto study site adjacent to the investigation trenches OL-TK12 and OL-TK4 (Fig. 1-1). The trench has an E-W direction with a total length of 55.4 m and a width from 1 to 3 m. The trench was divided into 10 mapping sections (P1-P10) for the mapping purpose. The bedrock is close to the quaternary surface throughout the trench and the deepest parts are only a few meters deep. The purpose of the trench was to locate a brittle deformation zone OL-BFZ045 at surface, which was detected in the ONKALO research tunnel at chainage PL3333-3350, but also to investigate a geophysical mise-à-la-masse survey signature (Fig. 1-2). During the mapping every bolt (P1-P10) were given a detailed coordinate, thus x-, y-, and z-coordinates, giving starting and end points for every section. The location of each observation was determined by using a straight thread, which was extended and tightened over each mapping section, and measuring the horizontal distance from the starting point of the section to the observation point as well as the vertical distance from the thread to the observation point. Knowing the coordinates of the starting and end point of the section, the location of the observation point in the x-y-z coordinate system can be calculated. The rock types were determined macroscopically from the bedrock surface, which was cleaned with pressured air and water. The general mapping was performed using the standard operating procedures and guidelines of the Geological Survey of Finland (GTK) for the bedrock mapping (GTK Guide for bedrock mapping KPK3-O1). The structural investigations, however, were carried out using Posiva’s standard form for the ONKALO tunnel mapping, which was slightly modified for the investigation trench purpose. Investigations of the ductile deformation included measurements of foliation (deformation phase, type and intensity), lineation (slickenside), fold axis and axial planes. During the fracture mapping, all the fractures intersecting the central thread were investigated and in addition all fractures over 1 m in trace length were investigated from the whole trench area. Dip direction and dip, spacing (if more than one fracture had the same direction), length, filling (thickness), aperture, type (ends, joins or continues), undulation and rock type were determined for each fracture. A determination for the Jr (a value indicating roughness of joint surface) and Ja (a value indicating the degree of alteration or clay filling in the joint) values of the Q-system were also carried out for each fracture. A total of 94 fractures and fracture clusters were investigated. To obtain an accurate amount of fractures, all fractures in fracture clusters were added to the total tally, and this resulted in a total of 117 fractures for the trench. The measured fractures and other tectonic features are listed in Excel-tables in Appendix 2. The files were delivered to the POTTI database of Posiva and the original hand-written observations to Posiva’s archive. Orientations of structural elements are displayed using Fisher equal-area, lower hemisphere stereographic projection. The 5 declination has been added to the stereographic projections, but not to the original data gathered in Appendix 2. The investigation trench was also documented with digital photographs (Fig. 1-3). The photographs were stored into Posiva’s archive.

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Figure 1-1. Map illustrating the location of all investigation trenches at the Olkiluoto Island. OL-TK18 is highlighted by a red circle.

Figure 1-2. Map illustrating the location of the mise-à-la-masse survey (violet circles) and possible ground surface projection of a brittle zone (OL-BFZ045) detected at chainage PL3333-3350 in the ONKALO access tunnel (orange lines, location modelled using ground magnetic data).

OL-TK18

0 250 500 750 1 000125Meters

4

Figure 1-3. General photo of the investigation trench OL-TK18. A view from mapping section P8 towards the west.

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2 RESULTS OF INVESTIGATIONS

2.1 Lithology

The rock types in the investigation trench OL-TK18 are of heterogeneous character, with a variation from tonalitic-granodioritic gneiss (TGG) to diatexitic gneiss (DGN), with portions of K-feldspar porphyritic gneiss (KFP). Inclusions of mica gneiss (MGN), quartz gneiss and skarn are also present throughout the trench. A few coarse-grained pegmatitic granite dykes (PGR) are also encountered. The trench ends in a feldspar-rich leucosomatic pegmatoid (PGR). The rock types are presented on a map in Appendix 1. Posiva’s practice of naming rocks, which has been used in this study, is introduced in Mattila (2006). The rock types are described in the summary report of the petrology of Olkiluoto (Kärki & Paulamäki 2006). The gneisses of Olkiluoto commonly have a migmatitic appearance and therefore the descriptive terminology (Wimmenauer & Bryhni 2002) of migmatites is useful. The leucosome is the leucocratic, lighter-coloured portion of the migmatite with plutonic appearance and the melanosome is the darkest part of the migmatite. The melanosome is here referred to the biotite rich stripes (schlieren) or narrow bands in the migmatite. The mesosome is the mesocratic, intermediately coloured, part of the migmatite with metamorphic appearance (in this case mostly mica gneiss). On the basis of the migmatite structure, the migmatitic gneisses at Olkiluoto can be divided to three groups: veined gneisses, stromatic gneisses and diatexitic gneisses. (Kärki & Paulamäki 2006). The leucosome of the veined gneiss shows vein like, more or less linear traces with some features similar to large-scale augen structures. Planar sheet-like leucosome dykes characterise the stromatic gneisses, whereas the migmatite structure of the diatexitic gneisses is more asymmetric and irregular. The leucosome amount varies from 10 % to over 80 %, the average amount being 20-40 % (Kärki & Paulamäki 2006). The western end of the trench is composed of DGN that consists of TGG paleosome and PGR leucosome (as veins and dykes) (Fig. 2.1-1A). The TGG is medium-grained and probably has a psammitic origin. In the middle of section P2 a pegmatoid with KFP signature prevails, containing clear pegmatitic groundmass and abundant in feldspar porphyroblasts. The rock contains biotite schlieren as melanosome and totally lacks paleosome (Fig. 2.1-1B). The section ends in a MGN inclusion which is approximately 3 m wide and 6 m long. The KFP pegmatoid gradually turns into a schollen-type migmatite in section P4, where the groundmass is a KFP pegmatoid containing BT-schlieren melanosome. The rock contains abundantly angular pieces (20-30 cm long) of MGN/skarn inclusions, which give the schollen character to the rock (Fig. 2.1-1C). The rock type changes gradually into a DGN with TGG paleosome and pegmatitic leucosome in the end of section P4. The DGN rock with TGG paleosome prevails from section P5 into the middle of section P7. The rock is unaltered and the leucosome content is 30-40 %. The veins are ambiguous and irregular in orientation but they are generally quite wide, the width is mostly 20-40 cm, the widest patches are up to 70 cm (Fig. 2.1-2A). After this the rock

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turns into homogenous tonalitic to granodioritic gneiss (TGG) containing small garnets and cordierite porphyroblasts together with a few patches/veins of pegmatite (Fig. 2.1-2B). This rock type ends in the middle of section P8 where a KFP pegmatoid is encountered. The contact between the TGG and the KFP is sheared, altered and densely fractured parallel with to the foliation plane. This rock contains clear pegmatitic groundmass and is abundant in feldspar porphyroblasts, but also some BT-schlieren melanosome is present. The rock is similar to the rock seen in section P3. Section P9 contains a large (ca. 0.75 m wide and 10 m long) MGN inclusion which is rich in mica and densely fractured (Fig. 2.1-2C). The end of the trench (eastern part) is composed of a feldspar-rich pegmatoid which is classified as PGR (see Mattila 2006) even though it’s not a typical pegmatitic granite occurring in Olkiluoto. The rock type has a granitic/granodioritic composition, but it contains feldspar porphyroblasts, which is characteristic of KFP type rocks (Fig. 2.1-2D). These porphyroblasts are generally 2-3 cm wide and 4-6 cm long and contain BT-schlieren in between. The pegmatoid/leucosome material composes approximately 80-90 % of the total rock volume and the rest of the rock contains BT-schlieren melanosome, but occasionally there are significantly more BT-schlieren as seen in Fig. 2.1-2D. This dominating character of the originally granitic/granodioritic composition of the rock is illustrated on a photo in the next chapter, which describes the late ductile deformation (D4) altering and deforming the protolith (Fig. 2.2-4).

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Figure 2.1-1. A) Diatexitic gneiss with TGG paleosome. OL-TK18, mapping section P1. B) KFP pegmatoid with pegmatitic groundmass and abundant in feldspar porphyroblasts. OL-TK18, mapping section P3. C) KFP/Scholllen migmatite with typically angular MGN/skarn inclusions. OL-TK18, mapping section P4. The length of the plate is 16 cm and the measuring stick is 4 m long. Photos by Jon Engström, Geological Survey of Finland.

A B

C

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Figure 2.1-2. A) Diatexitic gneiss with TGG paleosome and PGR neosome. OL-TK18, section P5. B) Tonalitic granodioritic gneiss with cordierite porphyroblasts. OL-TK18, mapping section P8. C) Large MGN inclusion located in a KFP pegmatoid. OL-TK18, mapping section P9. D) KFP pegmatoid with BT-schlieren melanosome and feldspar porphyroblasts. OL-TK18, mapping section P10. The length of the plate is 16 cm and the measuring stick is 4 m long. Photos by Jon Engström, Geological Survey of Finland.

A B

D C

TGG

PGR

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2.2 Ductile deformation

In the course of Proterozoic tectonic evolution, the metamorphic, mainly supracrustal rocks at Olkiluoto has been subjected to a polyphase ductile deformation. Relicts of lithological layering and a weak foliation created by the first phase of deformation (D1) represent the oldest observed structural elements detected. Second phase (D2) is the most dominant in its entirety and it caused strong migmatitisation associated with intense folding and thrust related ductile shearing. During third deformation phase (D3), the deformed migmatites were again folded and sheared and subareas dominated by D3 structural elements were formed simultaneously with pegmatite-like dykes or migrated leucosomes which intruded mainly parallel to the D3 shear zones and S3 axial surfaces. Subsequently, all earlier structural elements were again re-deformed in fourth deformation phase (D4), which produced close to open folds and small-scaled ductile shear structures (Aaltonen et al. 2010). Based on the occurrence, type and intensity of the products of different deformation phases, Olkiluoto site can be divided into three tectonic sub-domains which are well observable, e.g. on the basis of magnetic map (Aaltonen et al. 2010). These “tectonic units” are bordered by deformation zones in which shear-related structures are important elements. One of these is the E-W striking Selkänummi Deformation Zone (SDZ), a strongly deformed domain in which ductile shear structures are significant elements. Southern border of this zone defines also the southern border of the northern tectonic unit (NTU). In the southern part of the study site, an E-W striking ductile shear zone (Liikla Shear Zone, LSZ) defines the northern border of the southern tectonic unit (STU) and the domain between those is designated as central tectonic unit (CTU). This unit is divided by the NE – SW striking Flutanperä Deformation Zone (FDZ), characterized by D3 deformation phase and by two intensively deformed D4 zones (Aaltonen et al. 2010). The investigation trench is located directly north of FDZ in an area with prevailing D3 deformation, but signs of the D4 deformation are also evident. The observations of the ductile deformation are gathered in Appendix 2. As stated earlier, the rocks of the investigation trench have experienced a multiphase ductile deformation and it is situated in an area were the latest ductile deformation phase, D4 prevails (Fig. 2.2-1). The rocks in the trench have a very heterogeneous character which occasionally shows a distinct foliation, while it at other places is absent. The oldest tectonic feature is the D2 leucosome veining visible in the beginning of the trench (Fig. 2.1-1A), but the oldest foliation seen in the trench is the S3 foliation and associated smaller-scaled granitic leucosome veining. The D3 deformation is the dominant ductile deformation phase in the middle of the Olkiluoto Island and structural elements of the subsequent fourth deformation phase, in many ways resemble the products created by this phase (Aaltonen et al. 2010).

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Figure 2.2-1. Distribution of poles to foliation S3 and S4 in investigation trench OL-TK18 (Fisher equal area, lower hemisphere projection). The main part of the trench is dominated by a domain of D4 ductile deformation, whereas the elements of the earlier deformation phase D3 are situated in both ends of the trench, giving an approximate width of 30 m for the D4 ductile domain (Appendix 1). In Figure 2.2-2 it is evident that the foliation S3 is more ENE-WSW orientated direction whereas the S4 foliation has a NE-SW strike. In addition to this difference in orientation, the different structural signature of these two deformation types is evident in the investigation trench. The S3 foliation is defined by smaller scaled granitic leucosome veining (Fig. 2.2-3A), while the S4 is a sheared, schistose type of foliation, including BT-schlieren and showing a blastomylonitic character (Fig. 2.2-3B). This blastomylonitic type of rock shows growth of roundish feldspar porphyroblasts which is typically associated with D4 fault rocks on the Olkiluoto Island (Aaltonen et al. 2010). Other ductile deformational features (e.g. folding and shear bands) were not encountered in the trench.

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Figure 2.2-2. Foliation sets for the two different deformation phases S3 and S4 in OL-TK18 (Fisher equal area, lower hemisphere projection).

Figure 2.2-3. A) Diatexitic gneiss with small-scale leucosome veining and associated S3 foliation. OL-TK18, section P2. B) KFP pegmatoid with blastomylonitic sheared typical D4 deformed rock and associated S4 schistose type foliation. OL-TK18, mapping section P8. The length of the plate is 16 cm. Photos by Jon Engström, Geological Survey of Finland.

B A

S4

S3

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2.2.1 High-grade ductile shear zone Intersection (HGI)

The middle part of the trench (see Appendix 1) is dominated by a D4 ductile domain or a high-grade ductile shear zone intersection in accordance with the classification developed by Milnes et al. 2007. The width of the zone is approximately 30 m wide (Appendix 1) beginning at mapping section P2 and ending (Fig. 2.2-4) in the beginning of section P10. The zone is characterised mainly by a sheared blastomylonitic rock having growth of roundish feldspar porphyroblasts and BT-schlieren melanosome indicating high alteration of the protolith. These BT-schlierens are together with the S4 schistosity strongly foliated and thus give the orientation for the D4 ductile deformation zone (Fig. 2-2-3B). Although both ends of the zone have typical D4 character, the center part of the zone is different exhibiting a schollen type migmatite (Fig. 2.1-1C) and less sheared rocks such as DGN (Fig. 2.1-2A) and TGG (Fig. 2.1-2B).

Figure 2.2-4. Photo showing the eastern border of the D4 ductile deformation domain, the border of the zone is showing the typical transposition between the D3 and D4 ductile deformation. The measuring stick (white bar) is 4 m long and the picture is approximately orientated with top towards north. Photo by Jon Engström, Geological Survey of Finland.

S4

S3

D4 Ductile domain D3 Ductile domain

Border zone between D3 and D4

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2.3 Brittle deformation

During the fracture mapping, all fractures that intersect the central thread were measured. In addition, fractures with a length of more than 1 m were measured from the entire area of the trench. The results of fracture investigations are shown in Appendix 2. The first six columns show the position of the fracture in relation to the central thread and the calculated x-y-z-coordinates. They are followed by the dip direction and dip, number of fractures, fracture space, fracture length, Jr, Ja, fracture filling and width, aperture, fracture ends, undulation, rock type, water leakage and kinematics. A total of 84 joints and 10 faults were investigated in the trench. Occasionally these joints and faults appear clustered together (thus one observation may represent as many as 6 joints/faults), and these clusters were investigated together, giving total amount of joints/faults to be 117. From this point forward in the report, the joints and the faults will be referred as fractures, regardless of if they show movement or not.

2.3.1 Fracture orientation data

The distribution of all fracture orientations in investigation trench OL-TK18 is shown in Fig. 2.3-1 as Fisher equal area, lower hemisphere projection.

Figure 2.3-1. Distribution of poles to fractures in OL-TK18 (Fisher equal area, lower hemisphere projection).

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On the basis of orientations of all measured fractures one main set can be distinguished (Fig. 2.3-2). This set covers 32 % of all measured fractures, and it strikes NE-SW with a moderate dip towards the SE (Set 1). The occurrence of this fracture set is explained by the D4 ductile deformation domain that is natural environment for the development of these fractures, following the foliation of the domain. Two other less distinct sets can also be extracted from the stereographic plot. They show a more vertical dip, one trending NW-SE with a sub-vertical dip towards NE (Set 2) and another trending NE-SW with a vertical dip (Set 3) (Fig. 2.3-2). The fracturing resembles the characteristic fracturing for diatexitic gneisses; this rock type occurs mainly in areas where the D3 and D4 ductile deformation is prevailing, mostly encountered in the SE part of the Olkiluoto site (Aaltonen et al. 2010).

Figure 2.3-2. Contour plot visualizing the main fractures set in OL-TK18 (Fisher equal area, lower hemisphere projection). There are no noticeable differences between fault and joint orientations in the trench. In fact almost all faults are in the same direction as the S4 foliation parallel joints (Fig 2.3-3). Only two faults have a different orientation one E-W orientated with sub-vertical dip towards the south and one striking NW-SE with moderate dip towards the NE. This latter fault is a big fault with a distinct, up to 6 cm thick, fault core of quartz, calcite and chlorite. On the side of the fault there is an alteration zone showing microbreccia (Fig. 2.3-4A). Another big fault is encountered in the middle of the D4 ductile deformation domain sub-parallel with the foliation, having a NE-SW strike and a moderate dip to the SW. The width of the fault is approximately 50 cm, showing totally altered and sheared rock (Fig. 2.3-4B). On the fault surface illite and other clays, which could not be indentified, were also observed.

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Figure 2.3-3. Pole plot visualizing all faults in OL-TK18 (Fisher equal area, lower hemisphere projection).

Figure 2.3-4. A) Photo showing the major fault in mapping section P2 with a thick (6 cm) fault core of quartz. The long side of the compass is ca 11 cm long and the picture is approximately orientated with top towards north. B) Photo showing the major fault in mapping section P4 with an ambiguous fault core of sheared and altered rock, with some clay. The long side of the compass is ca 11 cm long and the picture is approximately orientated with top towards south-east. Photos by Jon Engström, Geological Survey of Finland.

B A

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The majority of all the fractures show no indications of fault movement and although 20 faults were found in the trench only three had striations that could be measured. All these measurements are plunging moderately towards ESE (Fig. 2.3-5). All these measurements are from faults striking NE-SW and dipping to the SE, located in the large MGN inclusion in section P9 (Fig. 2.2-4).

Figure 2.3-5. Corrected fault-slip data from all faults with visible movement within TK-18, shown as an Anglier-plot (equal-area, lower hemisphere projection).

2.3.2 Fracture frequencies

The fracture frequencies of the investigation trench in each mapping section are presented in Fig. 2.3-6. 94 fractures were investigated in detail from the trench. As stated above a few of these measurements were fracture clusters and to get the total amount of fracturing these were added to total tally. This gives a total of 117 fractures, which has been used as basis for determining the fracture frequency (fractures/m). Accordingly, the average fracture frequency for the 55.43 m long trench is 2.11 fractures/m. The significantly more frequent fracturing observed in section P9 compared to the rest of the trench is due to a the large MGN inclusion intersecting the trench, as these inclusions typical have a higher fracture frequency and the same trend has also been observed in the ONKALO research facility.

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OL-TK18 Fracture frequency

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

P1 P2 P3 P4 P5 P6 P7 P8 P9 P10

Section

Frac

ture

s/m

Figure 2.3-6. Fracture frequencies of the bedrock in sections P1-P10 of OL-TK18.

2.3.3 Fracture characteristics

Fracture lengths were measured from 117 fractures, including fracture clusters. The fracture length in fracture clusters was specified as an estimated average length of all fractures in the cluster. The width of the mapped area was commonly less than 2.5 m and this restriction have affected the lengths recorded for the fractures. The fracture length distribution is compiled and shown in the histogram in Fig. 2.3-7. 7.7 % of all fractures are less than 0.5 m in length, 37.6 % are 0.5-1.5 m in length and 54.7 % of the fractures are longer than 1.5 m. The median fracture trace length is 1.60 m and the longest measured fracture is 7.90 m.

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Histogram, OL-TK18

0

2

4

6

8

10

12

14

16

0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.9MoreBin

Freq

uenc

y

0.00 %

20.00 %

40.00 %

60.00 %

80.00 %

100.00 %

120.00 %

Frequency Cumulative %

Figure 2.3-7. Fracture length distribution as histogram for the bedrock investigation trench OL-TK18. Approximately half (54.8 %) of the investigated fractures contained no identifiable mineral fracture fillings, which can be explained by the surface proximity and that some of the fillings probably have been washed away during the excavation of the trench. Mineral fillings observed on fracture surfaces are mostly hematite, but also chlorite biotite and muscovite is found. Less common are calcite, pyrite, clay and quartz (Fig. 2.3-8). The thicknesses of the fillings vary between 0.1-60 mm, the average thickness being 1.66 mm and the median thickness 0.30 mm. The distribution of the fracture filling thickness is shown in Fig. 2.3-9. The aperture of the open fractures varies from 0.1-45 cm, commonly being between 1-2 centimeters. All fractures were classified applying the Q-classification scheme (Barton 1974; Grimstad & Barton 1993) and the description of the various Q-parameters is found in Appendix 3. This scheme is described in detailed in the next chapter but the fracture profile describing the surface and the shape of the fracture is illustrated in Fig. 2.3-10. Slightly more than half of all fractures are undulating or stepped, where the undulation varies between 2-25 cm/m and mostly being 2-5 cm/m. The fractures mainly have rough surfaces (62.4 %), some smooth and slickenside fractures are also present in even amount (Fig. 2.3-10). Only a few stepped fractures were observed in the trench, whereas water-conducting fractures were absent.

19

Fracture filling distribution, OL-TK18

47

19

13 13

2 2 1 1 10

5

10

15

20

25

30

35

40

45

50

Hematite Chlorite Biotite Muscovite Calcite Pyrite Clay Illite Quartz

Num

ber

of fr

actu

res

Figure 2.3-8. The distribution of fracture fillings in OL-TK18.

Fracture filling thickness, OL-TK18

63

41

11

2

0

10

20

30

40

50

60

70

No filling 0.1-0.5 >0.5-1 >1-60

Filling thickness (mm)

Num

ber o

f fra

ctur

es

Figure 2.3-9. The distribution of fracture filling thickness in OL-TK18.

20

Fracture Profile Distribution, OL-TK18

9

13

32

11 10

36

0 1

5

0

5

10

15

20

25

30

35

40

PSL PSM PRO USL USM URO SSL SSM SRO

P=Planar, U=Undalating, S=Stepped and SL=SLickenside, SM=SMooth, RO=ROugh

Num

ber o

f fra

ctur

es

Figure 2.3-10. The fracture profile distribution observed in OL-TK18.

21

2.4 Rock mass quality (Q-classification)

The Q-classification scheme was used in order to determine the rock mass quality in the trench. The description of the various Q-parameters is found in Appendix 3. The rock quality designation (RQD) is defined on the basis of visual estimation of the total amount of fracturing. The joint set numbers (Jn) have been defined from stereo projections. Roughness (Jr) and alteration (Ja) numbers (median values) were calculated for each section. Joint water reduction number (Jw) is estimated visually for each section and stress reduction factor (SRF) was given 1 for all sections due to surface proximity. Q-value is calculated using the following equation (Barton 1974; Grimstad & Barton 1993):

SRFJ

JJ

JRQDQ w

a

r

n

**

The Q-classification for the investigation trench OL-TK18 has been made for every mapping section (1.97-7.4 m long) and the results are listed in Table 2.5-1. The Q-quality varies from good to extremely good. The average Q-quality of the rocks is extremely good, thus the trench is absent in major brittle deformation zones which would have affected the Q-quality. Table 2.4-1. Q-parameters and Q-quality for each section in investigation trench OL-TK18.

Section Section Length RQD Jn Jr Ja Jw SRF Q-value Rock type Q-quality

P1 5.9 100 1 1.5 1 1 1 150.0 DGN Extremely Good P2 7.34 98 2 1.5 1 1 1 73.5 DGN/KFP/MGN Very Good P3 4.06 100 1 1.5 2 1 1 75.0 MGN/KFP Very Good P4 7.4 100 1 1.5 2 1 1 75.0 KFP/DGN Very Good P5 5.63 100 1 3 1 1 1 300.0 DGN Extremely Good P6 1.97 100 1 1.5 1 1 1 150.0 DGN Extremely Good P7 4.57 100 1 3 1 1 1 300.0 DGN/TGG Extremely Good P8 6.75 97 2 3 2 1 1 72.8 TGG/KFP Very Good P9 5.11 97 2 1.5 2 1 1 36.4 KFP/MGN/PGR Good P10 6.7 100 1 1.5 1 1 1 150.0 PGR Extremely Good

22

3 SUMMARY

Investigation trench OL-TK18 is located in the central part of the Olkiluoto study site adjacent to investigation trench OL-TK12 and OL-TK4. The trench has an E-W direction with a total length of 55.4 m and a width from 1 to 3 m. The rock types in investigation trench OL-TK18 is of heterogeneous character, with a large variation in their composition. The rocks vary from tonalitic granodioritic gneiss (TGG) to diatexitic gneiss (DGN), with portions of K-feldspar porphyritic gneiss (KFP). Inclusions of mica gneiss (MGN), quartz gneiss and skarn are encountered throughout the trench. A few coarse-grained pegmatitic granite dykes (PGR) are also present in the middle of the trench. The trench ends in a feldspar-rich pegmatoid (PGR). The rocks in the investigation trench have been subjected to a multiphase ductile deformation and the trench is situated in an area were the latest ductile deformation phase, D4 prevails. The central part of the trench is dominated by this D4 ductile deformation domain whereas the elements of the earlier deformation phase D3 prevail in both ends of the trench. The deformation phase D3 has a more ENE-WSW orientated direction whereas the D4 is striking NE-SW. In addition to this difference in orientation, the different structural signature of these two deformation types is observed, the S3 foliation is defined by smaller scaled granitic leucosome veining whereas the S4 foliation is more sheared and have a schistose character. The D4 ductile deformation domain is also characterised by a sheared blastomylonitic rock having growth of roundish feldspar porphyroblasts and it contains BT-schlieren indicating high alteration of the protolith. These BT-schlieren are strongly foliated and together with the S4 schistosity it gives the orientation for the D4 ductile zone. On the basis of orientations of all measured joints and faults one main set can be distinguished, striking NE-SW with a moderate dip towards the SE. The occurrence of this fracture set is explained by the D4 ductile deformation domain that is a natural zone of weakness for the development of these fractures in the same direction. There are no noticeable differences between fault and joint orientations in the trench, almost all faults are follows the foliation parallel joints of the D4 ductile deformation domain. Two major faults were identified from the trench, one with a distinct fault core of quartz, calcite and chlorite, and having a NW-SE strike and a moderate dip towards NE. The other one is parallel to the D4 ductile deformation domain, having a NE-SW strike and a moderate dip to SW, showing totally altered and deformed rock due to shearing. Mineral fillings observed on fracture surfaces are mostly hematite, but also chlorite biotite and muscovite is found. The average Q-quality of the rocks is extremely good, since the trench is absent in major brittle deformation zones which would have affected the Q-quality. The trench was instigated to investigate a geophysical mise-à-la-masse survey signature and also try to locate a brittle deformation zone OLBFZ045 at surface, which was detected in the ONKALO research tunnel at chainage PL3333-3350. Although no major brittle deformation zones were detected, the trench gave valuable information about the latest ductile deformation phase (D4) and characteristics of that phase.

23

REFERENCES

Aaltonen, I. (ed.), Lahti, M., Engström, J., Mattila, J., Paananen, M., Paulamäki, S., Gehör, S., Kärki, A., Ahokas, T., Torvela, T. & Front, K. 2010. Geological Model of the Olkiluoto Site, Version 2.0. Working report 2010-70. Posiva Oy, Eurajoki. 580 p. Barton, N. Lien & R. Lunde, J. 1974. Engineering classification of rock masses for the design of tunnel support. Rock Mechanics, Vol 6, No 4, p. 189–236. Grimstad, E. & Barton, N. 1993. Updating of the Q-system for NMT. Proc. of the International Symposium on Sprayed Concrete. Fagernes, Norway. Kompen, E. Opsahl, Berg. Norwegian Concrete Association, p. 46–66. Kärki, A. & Paulamäki, S. 2006. Petrology of Olkiluoto. Posiva 2006-02, Eurajoki, Finland: Posiva Oy. Mattila, J. 2006. A system of Nomenclature for Rocks in Olkiluoto. Posiva 2006-32, Eurajoki, Finland: Posiva Oy. Milnes A. G., Aaltonen, I., Ahokas, T., Front, K., Gehör, S., Kemppainen, K., Kärki, A., Mattila, J., Paananen, M., Paulamäki, S. & Wikström, L. 2007. Geological Data Acquisition for Site Characterisation at Olkiluoto: a Framework for the Phase of Underground Investigations. Working report 2007-32. Posiva Oy, Eurajoki 133 p. Wimmenauer, W. & Bryhni, I. 2002. Towards a unified nomenclature of metamorphic petrology: Migmatites and related rocks. A proposal on behalf of the IUGS Subcommission on the Systematic of Metamorphic Rocks. Web-version 31.07.2002. www.bgs.ac.uk/SCMR/docs/paper_7/scmr_paper_07.pdf.

24

APPENDICES

Appendix 1: Geological map of investigation trench TK-18 Appendix 2: Observations of all measured structures in investigation trench TK-18 Appendix 3: Q-classification scheme

App

endi

x 1

App

endi

x 2:

Mea

sure

men

ts a

nd o

bser

vatio

ns o

f all

map

ping

dat

a in

OL-

TK18

. Se

e en

d of

tabl

e fo

r exp

lana

tion

of a

bbre

viat

ions

.

ID

Structural Element

Dis

tanc

e fr

om b

olt

Nor

thin

g (m

) E

astin

g (m

)

Elevation (m)

Ori

enta

tion

Number of fractures

Fracture spacing (m)

Fracture length (m)

Displacement (cm)

Jr

Ja

Frac

ture

filli

ng

Aperture (cm)

Frac

ture

end

s

Undulation (cm/m)

Rock type

Foliation Type

Foliation intensity

Kin

emat

ic in

dica

tors

Remarks

Horizontal (m)

Vertical (cm)

Dip

Dip /Dir

No.

Profile

minerals + oxidation

width (mm)

End 1

to

End 2

to

F_Dip

F_Dir

Sens

e

of

Mov

e-m

ent

Uncertainty

P1_

1 JO

0.

57

0 67

9256

7.07

9 15

2578

3.66

1 8.

617

80

305

1

5.00

1.5

PR

O

1

P

J

PG

R

P1

_2

JO

3.30

17

67

9256

6.55

1 15

2578

6.30

9 8.

044

65

300

1

1.02

1.5

PRO

1

P

P

MG

N

P1

_3

JO

5.30

18

67

9256

6.16

4 15

2578

8.24

9 7.

739

40

170

1

5.50

3 U

RO

1

Y

2P

1 J

6

PG

R

P1

_4

JO

0 23

67

9256

8.85

6 15

2578

3.44

1 8.

471

75

190

1

3.70

3 U

RO

1

Y

2P

1 J

10

TG

G

N-s

ide

P1_5

JO

1.

50

43

6792

570.

037

1525

785.

189

8.05

0 65

15

1

2.

50

3

UR

O

1

J

Y

2P1

5 TG

G

N-s

ide

P1_6

JO

1.

40

10

6792

568.

585

1525

784.

798

8.39

4 75

20

2

0.4

1.40

1.5

PRO

1

Y

4

P

TGG

N

-sid

e P1

_7

JO

0 16

67

9256

6.31

6 15

2578

2.93

4 8.

541

70

20

1

1.22

1.5

PRO

1

P

J

P

GR

S

-sid

e P2

_1

FAU

LT

0.14

1

6792

566.

039

1525

788.

962

7.80

0 60

60

1

6.

00

0.

5 PS

L 2

KV, C

C, K

L 60

J

J

P

GR

M

easu

red

P2_

2 FO

L 1.

3 25

67

9256

5.95

5 15

2579

0.10

6 7.

385

55

170

1

D

GN

B

AN

1

S3

P2_

3 JO

1.

6 20

67

9256

5.93

3 15

2579

0.40

1 7.

390

60

315

1

3.50

1.5

PR

O

1

J

J

D

GN

M

easu

red

P2_

4 JO

1.

75

30

6792

565.

922

1525

790.

549

7.26

7 85

28

0 1

0.

90

1.

5 P

RO

1

Y

3

P

DG

N

P

2_5

FOL

3.4

52

6792

565.

803

1525

792.

176

6.79

8 50

13

0 1

KFP

S

CH

1

S4

P2_6

JO

3.

92

54

6792

565.

766

1525

792.

689

6.70

0 50

15

0 1

2.

60

2

USM

2

HE,

KL

0.3

J

J

4

KFP

M

easu

red

P2_7

JO

5.

15

57

6792

565.

677

1525

793.

901

6.48

4 15

13

0 1

1.

60

2

USM

1

HE

0.

3

Y

8 Y

3P

1 3

KFP

P2_

8 JO

5.

4 52

67

9256

5.65

9 15

2579

4.14

8 6.

496

80

320

1

1.20

2 U

SM

1

HE

0.

3

J

Y

3P1

3 M

GN

P2_

9 JO

5.

7 46

67

9256

5.63

7 15

2579

4.44

4 6.

511

75

10

1

0.40

1.5

PR

O

1

P

P

M

GN

P2_1

0 JO

5.

75

51

6792

565.

633

1525

794.

493

6.45

4 80

32

0 1

1.

50

1

PSM

1

HE

0.

3

J

Y

3P1

M

GN

P2_1

1 JO

5.

96

41

6792

565.

618

1525

794.

700

6.52

2 75

65

1

0.

40

1

PSM

1

HE

0.

3

Y

10

P

MG

N

P2

_12

JO

6 38

67

9256

5.61

5 15

2579

4.73

9 6.

546

25

146

3 0.

10

1.60

2 U

SM

1 H

E

0.1

J

Y

3P

1 2

MG

N

P2

_13

JO

7 18

67

9256

5.54

3 15

2579

5.72

5 6.

595

28

150

1

2.30

2 U

SM

1 H

E

0.1

J

Y

3P

1 2

MG

N

P2

_14

JO

7.18

10

67

9256

5.53

0 15

2579

5.90

3 6.

648

55

270

2 0.

05

1.06

1 PS

M

1

J

P

MG

N

P

2_15

JO

0

0 67

9256

7.80

4 15

2578

8.95

3 7.

831

85

40

1

3.00

7

4 S

RO

1

Y

1

P

DG

N

N-s

ide

P2_

16

JO

0 0

6792

567.

246

1525

788.

912

7.83

1 70

26

5 3

0.7

1.27

1 P

SM

1

HE

0.

2

P

P

D

GN

N

-sid

e P

3_1

FAU

LT

0.23

1

6792

565.

481

1525

796.

291

6.68

7 36

14

3 1

6.

05

1.

5 U

SL

2 H

E, K

L 0.

5

P

J

7

MG

N

P

3_2

JO

0.63

2

6792

565.

416

1525

796.

684

6.63

3 87

23

1

1.

50

1

PS

M

2 H

E, K

L 0.

2

J

Y

10

M

GN

P3_

3 JO

0.

72

2 67

9256

5.40

1 15

2579

6.77

2 6.

623

50

165

1

0.45

3 U

RO

1

0.5

P

P

2 M

GN

P3_

4 JO

1.

40

8 67

9256

5.29

1 15

2579

7.43

9 6.

487

68

290

1

1.41

1.5

PR

O

1

0.

1 P

P

KFP

P3_5

JO

2

7 67

9256

5.19

3 15

2579

8.02

7 6.

430

60

290

1

1.20

3 U

RO

2

HE,

KL

0.5

P

P

2

KFP

P3_6

JO

2.

38

7 67

9256

5.13

2 15

2579

8.39

9 6.

388

37

294

1

0.70

3 U

RO

2

HE,

KL

0.2

P

P

2

KFP

P3_7

JO

2.

65

10

6792

565.

088

1525

798.

664

6.32

7 80

27

5 1

0.

31

1.

5 PR

O

2 H

E, K

L 0.

2

P

P

K

FP

P

3_8

JO

2.9

8 67

9256

5.04

7 15

2579

8.90

9 6.

320

72

131

1

0.51

1.5

PR

O

2 H

E

0.2

P

P

KFP

P3_9

JO

3.

05

11

6792

565.

023

1525

799.

056

6.27

3 70

80

1

0.

70

1.

5 PR

O

2 H

E, K

L 0.

2

P

P

K

FP

P3

_10

JO

0 -1

0 67

9256

4.74

8 15

2579

5.93

9 6.

823

40

174

1

1.30

2 U

SM

2 BT

, KL

0.4

P

J

5 KF

P

S-si

de

P4_1

FA

ULT

4.

70

100

6792

563.

939

1525

804.

664

5.42

9 40

14

9 1

5.

30

1.

5 U

SL

5 IL

, SV

10

45

J

J

6

KFP

M

easu

red

P4_

2 JO

5.

20

148

6792

563.

841

1525

805.

154

4.96

6 83

84

1

1.

80

1.

5 P

RO

2

HE

0.

2

P

J

DG

N

P

4_3

JO

5.40

10

3 67

9256

3.80

2 15

2580

5.35

0 5.

423

64

155

1

5.50

3 U

RO

1

2 J

J

10

D

GN

M

easu

red

P4_

4 JO

6.

70

34

6792

563.

548

1525

806.

624

6.15

7 46

75

1

2.

60

3

UR

O

2 C

C, H

E

0.3

2 Y

5

Y

5 5

DG

N

P

4_5

JO

7.00

55

67

9256

3.48

9 15

2580

6.91

8 5.

958

72

314

1

3.21

1.5

PR

O

1

2

Y

3 J

DG

N

P4

_6

FAU

LT

0.4

30

6792

565.

661

1525

800.

625

5.98

3 75

17

0 1

1.

20

1.

5 U

SL

3 H

E, K

L 0.

6

P

P

3 K

FP

N-s

ide

P5_

1 FO

L 0

0 67

9256

3.41

2 15

2580

7.30

5 6.

521

50

128

1

D

GN

B

AN

1

S4

P5_

2 JO

0.

85

23

6792

563.

573

1525

808.

122

6.46

3 76

31

5 1

1.

24

1.

5 P

RO

1

HE

0.

2

P

P

D

GN

P5_

3 JO

3.

49

55

6792

564.

072

1525

810.

658

6.67

9 56

26

3 1

0.

91

1.

5 P

RO

1

2.5

Y

5 Y

4

D

GN

P5_

4 JO

3.

83

40

6792

564.

137

1525

810.

985

6.89

8 83

14

4 1

5.

48

3

UR

O

1

3.

5 J

J

15

D

GN

M

easu

red

P5_

5 JO

4.

05

41

6792

564.

178

1525

811.

196

6.93

3 73

28

1

7.

90

1.

5 P

RO

1

HE

0.

2 1.

5 J

J

DG

N

Mea

sure

d P5

_6

JO

4.71

6

6792

564.

303

1525

811.

830

7.41

6 88

23

2 1

0.

99

2 4

SRO

1

Y

4

Y

5

TGG

P5_7

JO

1.

03

31

6792

564.

196

1525

808.

179

6.42

0 74

34

8 1

2.

15

2 4

SRO

2

HE,

KL

0.3

J

P

D

GN

N

-sid

e

P5_

8 JO

3.

88

9 67

9256

3.61

6 15

2581

1.13

7 7.

218

87

29

1

3.95

1.5

PR

O

1 H

E

0.2

P

J

D

GN

M

easu

red

/S-s

ide

P5_

9 JO

5.

03

0 67

9256

2.89

2 15

2581

2.42

7 7.

541

25

4 1

1.

90

3

UR

O

1

P

Y

2P

7 5

DG

N

S-s

ide

P5_1

0 JO

5.

03

0 67

9256

2.30

3 15

2581

2.54

3 7.

541

28

112

1

1.30

3 U

RO

1

Y

9

Y

2P7

4 D

GN

S

-sid

e P

6_1

JO

0.79

3

6792

564.

140

1525

813.

420

7.74

1 16

16

0 1

0.

39

3

UR

O

1

Y

3 P

2 TG

G

P

6_2

JO

0.89

3

6792

564.

097

1525

813.

510

7.75

5 76

23

8 1

0.

68

1.

5 P

RO

1

P

P

DG

N

P

6_3

JO

0.93

3

6792

564.

080

1525

813.

545

7.76

1 71

29

5 1

2.

07

3

UR

O

1

J

P

2

TGG

P6_4

JO

1.

00

3 67

9256

4.05

0 15

2581

3.60

8 7.

770

40

219

1

0.09

1.5

PRO

1

Y

3

P

TGG

P6_

5 JO

1.

63

0 67

9256

3.78

1 15

2581

4.17

1 7.

887

84

69

1

0.79

1.5

PR

O

1

P

P

D

GN

P7_

1 JO

0.

38

7 67

9256

3.61

4 15

2581

4.85

8 7.

831

88

58

1

0.24

1.5

PR

O

1

P

P

M

GN

P7_

2 JO

0.

50

11

6792

563.

607

1525

814.

977

7.78

0 70

14

4 1

7.

10

3

UR

O

1

J

J

5 D

GN

M

easu

red

P7_

3 JO

0.

83

14

6792

563.

589

1525

815.

306

7.72

2 85

12

4 1

1.

92

3

UR

O

1

P

P

2 TG

G

P

7_4

JO

0.90

18

67

9256

3.58

6 15

2581

5.37

5 7.

675

40

126

1

3.01

3 U

RO

1

P

J

4 TG

G

P7

_5

JO

3.52

87

67

9256

3.44

5 15

2581

7.98

1 6.

757

25

123

1

3.02

2 U

SM

1 H

E

0.5

J

J

10

TG

G

Mea

sure

d P7

_6

JO

3.99

59

67

9256

3.41

9 15

2581

8.44

9 6.

996

84

264

1

3.54

3 U

RO

1

J

J

6

TGG

M

easu

red

P7_7

JO

4.

00

57

6792

563.

419

1525

818.

459

7.01

5 62

14

4 1

2.

78

3

UR

O

1

Y

2 Y

5

5 TG

G

P7

_8

JO

0.40

12

67

9256

3.41

3 15

2581

4.86

7 7.

779

87

34

1

1.54

1

4 SR

O

1

Y

2 Y

5P

5

TGG

S-

side

P8

_1

JO

0.45

13

67

9256

3.34

3 15

2581

9.47

1 7.

355

86

294

1

5.55

3 U

RO

1

HE

0.

2

J

J

6 TG

G

Mea

sure

d P8

_2

JO

1.10

16

67

9256

3.27

9 15

2582

0.11

4 7.

253

80

290

1

3.90

3 U

RO

1

Y

1

Y

1 4

TGG

P8_

3 JO

1.

25

15

6792

563.

264

1525

820.

262

7.24

6 68

20

3 1

1.

52

3

UR

O

1

P

P

25

TGG

P8_4

JO

2.

23

11

6792

563.

167

1525

821.

231

7.17

7 85

24

2 1

0.

63

1.

5 PR

O

1

P

P

TG

G

P

8_5

FOL

3.42

21

67

9256

3.04

8 15

2582

2.40

8 6.

945

45

119

1

K

FP

SC

H

1

S

4 P8

_6

FAU

LT

3.55

38

67

9256

3.03

6 15

2582

2.53

6 6.

761

34

120

5 0.

05

4.91

1.5

USL

3

HE,

KL

0.5

J

J

KFP

M

easu

red

P8_7

FA

ULT

4.

20

40

6792

562.

971

1525

823.

179

6.66

8 35

10

9 2

0.1

3.01

1.5

USL

4

HE,

KL,

SK

, MU

0.

6

J

J

KF

P

P8

_8

JO

5.35

29

67

9256

2.85

7 15

2582

4.31

6 6.

651

45

124

1

3.30

3 U

RO

2

HE,

KL

0.3

J

Y

7

5 K

FP

P8

_9

JO

6.20

18

67

9256

2.77

2 15

2582

5.15

7 6.

666

48

143

1

0.76

3 U

RO

1

Y

Y

2

KFP

P8_1

0 JO

6.

50

10

6792

562.

743

1525

825.

453

6.71

3 59

15

3 1

2.

40

3

UR

O

4 BT

1

P

P

5

KFP

P8_

11

FOL

5.40

21

67

9256

2.85

2 15

2582

4.36

6 6.

725

43

140

1

K

FP

SC

H

1

S

4 P

8_12

FO

L 6.

75

0 67

9256

2.71

8 15

2582

5.70

1 6.

785

35

118

1

K

FP

SC

H

1

S

4 P8

_13

JO

5.72

20

67

9256

2.98

9 15

2582

4.69

9 6.

699

51

149

1

3.02

0.

5 3

UR

O

1 H

E

0.2

J

Y

8

8 K

FP

N-s

ide

P8_1

4 JO

4.

60

40

6792

562.

752

1525

823.

557

6.62

4 81

20

3 1

2.

30

0.5

3 U

RO

1

Y

7

Y

4

KFP

S

-sid

e P8

_15

JO

6.15

18

67

9256

2.67

8 15

2582

5.09

7 6.

672

60

68

1

1.40

3 U

RO

1

Y

10

J

10

K

FP

S-s

ide

P9_

1 JO

0.

86

7 67

9256

2.86

6 15

2582

6.55

5 6.

744

89

342

1

1.44

8

4 S

RO

1

P

P

MG

N

P

9_2

JO

1.40

12

67

9256

2.96

0 15

2582

7.08

7 6.

712

74

355

1

0.56

2

3 S

SM

1

P

P

MG

N

P

9_3

FAU

LT

1.46

10

67

9256

2.97

0 15

2582

7.14

6 6.

734

47

130

1

5.00

1.5

US

L 2

HE

, BT,

MU

0.

3

J

J

2 M

GN

50

12

5

P9_

4 FA

ULT

2.

20

27

6792

563.

098

1525

827.

874

6.59

0 33

13

0 1

3.

60

1

PS

L 2

BT,

MU

0.

3

P

P

M

GN

P9_

5 JO

2.

30

15

6792

563.

116

1525

827.

973

6.71

3 25

11

9 1

3.

40

2

US

M

2 B

T, M

U

0.2

P

J

2 M

GN

P9_

6 FO

L 2.

31

15

6792

563.

118

1525

827.

983

6.71

4 25

11

9 1

MG

N

SC

H

2

S

4 P

9_7

LIN

2.

31

13

6792

563.

118

1525

827.

983

6.73

4 20

89

1

MG

N

P

9_8

JO

2.65

24

67

9256

3.17

7 15

2582

8.31

7 6.

635

74

56

5 0.

6 0.

95

1.

5 P

SM

1

P

P

MG

N

P9

_9

FAU

LT

3.40

42

67

9256

3.30

7 15

2582

9.05

5 6.

481

26

130

1

3.80

1 PS

L 2

HE,

BT,

MU

0.

4

J

J

M

GN

20

10

6 H

WD

V

P9_

10

FAU

LT

3.8

36

6792

563.

376

1525

829.

449

6.55

5 34

14

1 6

0.02

3.

02

1

PS

L 3

HE

, BT,

MU

0.

7

P

P

M

GN

25

12

0

P9_

11

JO

4.35

34

67

9256

3.47

1 15

2582

9.99

0 6.

594

35

124

1

4.20

3 U

RO

2

HE

, MU

0.

5 3

J

J

3 P

GR

P9_

12

JO

4.8

30

6792

563.

549

1525

830.

433

6.65

0 27

11

6 1

2.

70

3

UR

O

1

1.

5 J

Y

11

7

PG

R

P

9_13

JO

0.

4 9

6792

563.

111

1525

826.

045

6.70

8 40

14

0 1

1.

60

3

UR

O

3 B

T 0.

6

P

Y

10

P8

2 K

FP

N-s

ide

P10

_1

JO

0.85

36

67

9256

3.62

6 15

2583

1.60

5 6.

585

45

125

1

3.41

3 U

RO

1

1 Y

3

Y

3 2

PG

R

P

10_2

JO

1.

45

34

6792

563.

640

1525

832.

204

6.59

4 88

12

8 1

1.

30

3

UR

O

1

0.

1 Y

1

Y

3 5

PG

R

P

10_3

JO

1.

60

20

6792

563.

643

1525

832.

354

6.73

1 75

13

2 1

5.

86

1.

5 P

RO

1

HE

0.

2 1

J

J

P

GR

M

easu

red

P10_

4 FO

L 3.

00

5 67

9256

3.67

6 15

2583

3.75

4 6.

855

50

168

1

P

GR

B

AN

1

S3

P10

_5

JO

5.00

12

67

9256

3.72

2 15

2583

5.75

3 6.

748

74

143

1

2.60

1.5

PR

O

1

0.

5 P

J

P

GR

P10_

6 JO

5.

25

15

6792

563.

728

1525

836.

003

6.71

3 30

60

1

2.

92

3

UR

O

1

Y

10

J

7 P

GR

P10

_7

JO

5.55

5

6792

563.

735

1525

836.

303

6.80

8 13

11

1 2

0.06

0.

25

1.

5 P

RO

1

P

P

PG

R

P1

0_8

JO

6.30

10

67

9256

3.75

2 15

2583

7.05

2 6.

744

89

143

1

1.30

3 U

RO

1

0.1

P

P

4 P

GR

P10_

9 JO

6.

54

12

6792

563.

758

1525

837.

292

6.72

0 32

12

0 1

1.

11

3

UR

O

1

P

P

2 P

GR

P10_

10

JO

1.40

46

67

9256

4.43

8 15

2583

2.13

6 6.

475

82

142

1

2.32

3 U

RO

1

J

P

3 P

GR

N

-sid

e P1

0_11

JO

4.

20

3 67

9256

4.80

3 15

2583

4.92

8 6.

853

62

125

2 0.

53

1.50

1.5

PRO

1

P

P

PG

R

N-s

ide

P10_

12

JO

1.40

0

6792

562.

139

1525

832.

189

6.93

5 89

130

2 0.

3 1.

20

1.

5 PR

O

1

P

P

P

GR

S

-sid

e P1

0_13

JO

6.

13

5 67

9256

3.87

8 15

2583

6.87

9 6.

797

6523

51

1.

12

1.

5 PR

O

1

Y

7 Y

P

GR

N

-sid

e A

bbre

viat

ions

: R

ock

type

s: M

GN

= M

ica

gnei

ss, D

GN

= D

iate

xitic

gne

iss,

PGR

= P

egm

atiti

c gr

anite

, TG

G =

Ton

aliti

c gr

anod

iorit

ic g

neis

s, K

FP =

Fel

dspa

r por

phyr

itc S

truct

ural

ele

men

t: JO

= Jo

int,

FOL

= Fo

liatio

n J r

(Joi

nt r

ough

ness

): P

= P

lana

r, U

= U

ndul

ated

, S =

Ste

pped

, SM

= S

moo

th, R

O =

Rou

gh, S

L =

Slic

kens

ided

, Fol

iatio

n T

ype:

BA

N =

Ban

ded,

SC

H =

Sch

isto

se

Min

eral

abb

reva

tions

: KL

= C

hlor

ite, B

T =

Bio

tite,

KA

= K

aolin

ite, S

V =

Cla

y, H

E =

Hem

atite

, CC

= C

alci

te, S

K =

Pyr

ite, I

L =

Illite

, KV

= Q

uartz

, MU

= M

usco

vite

Fr

actu

re e

nds:

P =

vis

ible

, J =

hid

den,

Y =

join

s Kin

emat

ic in

dica

tors

, Sen

se o

f mov

emen

t: H

WD

= H

angi

ng w

all d

own

O

ther

: W =

wes

t, E

= ea

st, S

= so

uth,

N =

nor

th. N

-Sid

e/S-

Side

= o

bser

vatio

ns o

utsi

de o

f the

cen

tral t

hrea

d. M

easu

red

= Fr

actu

res w

hich

hav

e be

en m

easu

red

with

a la

ser t

achy

met

er to

get

exa

ct c

oord

inat

es.

28

Appendix 3. Description of RQD (1), Jn (2), Jr (3), Ja (4), Jw (5) and SRF (6) (Grimstad & Barton 1993).