Investigation of rock porosity and microfracturing with 14 C-PMMA method

Transkriptio

1 Working report 97-53e Investigation of rock porosity and microfracturing with 14 C-PMMA method Samples cored from the full-scale experimental deposition holes bored in the Research Tunnel at Olkiluoto Marja Siitari-Kauppi University of Helsinki Laboratory of Radiochemistry ~orma Autio Saanio & Riekkola Oy December 1997 POSIVA OY Mikonkatu 15 A, FIN HELSINKI. FINLAND Tel Fax

2 Working report 97-53e Investigation of rock porosity and microfracturing with 14 C-PMMA method Samples cored from the full-scale experimental deposition holes bored in the Research Tunnel at Olkiluoto Marja Siitari-Kauppi University of Helsinki Laboratory of Radiochemistry Jorma Autio Saanio & Riekkola Oy December 1997

3 UNIVERSITY OF HELSINKI LABORATORY OF RADIOCHEMISTRY Comissioned by: Posiva Oy Mikonkatu 15 A FIN , Helsinki, Finland Svensk Karnbranslehantering BOX 5864 S Stockholm Order: 9594/96/JPS Posiva Contact persons: Jukka-Pekka Salo, Posiva ''< Christer Svemar, SKB Marja Siitari-Kauppi, HYRL Jorma Autio, Saanio&Riekkola { INVESTIGATION OF ROCK POROSITY AND MICROFRACTURING WITH 14 C-PMMA METHOD. Samples cored from the full-scale experimental deposition holes bored in the Research Tunnel at Olkiluoto. Authors: fla1~ ~/a':fr FK Marja Siitari-Kauppi Research scientist??-~ TkL Jorma Autio Project manager Approved by: --r~af/~ TimoJaa~a Professor

4 Working reports contain information on work in progress or pending completion. The conclusions and viewpoints presented in the report are those of author(s) and do not necessarily coincide with those of Posiva.

5 INVESTIGATION OF ROCK POROSITY AND MICROFRACTURING WITH 14 C-PMMA METHOD - Samples cored from the full-scale experimental deposition holes bored in the Research Tunnel at Olkiluoto SUMMARY The porosity and microfracturing of samples taken from the full-scale experimental deposition holes at the Research Tunnel at Olkiluoto in Eurajoki were investigated by means of the 14 C-polymethylmethacrylate e 4 C-PMMA) method. The method involved impregnation of the rocks with 14 C-methylmethacrylate e 4 C-PMMA), irradiation polymerization, autoradiography and optical densitometry with digital image processing techniques. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS) were used to investigate in greater detail the pore apertures and minerals in porous regions. SEMIEDS measurements were made using 14 C-MMA-impregnated samples. This work is continuation of the work, which was started in The samples studied were of gneissic tonalite, homogeneous tonalite and pegmatite. According to the study the porosities of the undisturbed rock matrix ranged from 0.1 to 0.2 vol.% determined at depths of30 to 50 mm from the disturbed surface. For all the rock types studied, a clear increase in porosities was observed to a depth of about 10 mm from the wall surface. The porosity of homogeneous tonalite samples was clearly greater in the disturbed zone of 10 mm than in the undisturbed rock matrix. Several intragranular fractures were observed to a depth of 2 mm from the hole wall surface. There were also fractures parallel to the wall surface; the apertures ranged from a few to several Jlll1. Grain boundary porosity dominates in pegmatite samples. The measurement of total porosity in pegmatite obtained with the 14 C-PMMA method is an approximation, owing to the high heterogeneous structure of the matrix. A clear increase in porosity in pegmatite samples was observed to a depth of 12 mm from the disturbed surface. The first 3 to 5 mm from the surface wall were fractured, and the porosities were twice as high as in the undisturbed zone. Electron microscopic studies of the crushed zone revealed intrafractures transsecting the quartz and feldspar mineral grains. A clear increase in porosity was observed in gneissic tonalite samples to depths of 7-15 mm from the disturbed surface. Porous veins extending to depths of mm from the disturbed surface were detected in gneissic tonalite samples. Some of the samples included anomalous zones of porosity, the origin of which is not fully understood and requires further research. Keywords: porosity, microfracturing, 14 C-PMMA method, autoradiography, digital image analysis, SEMIEDS, excavation disturbance

6 KIVEN HUOKOISUUDEN JA MIKRORAKOILUN TUTKIMUS 14 C-PMMA MENETELMALLA - Olkiluodon tutkimustunnelista sijaitsevista tayden mittakaavan loppusijoitusrei'ista kairatut naytteet TIIVISTELMA Eurajoen Olkiluodossa StJattsevaan tutkimustunneliin on porattu kolme kokeellista tayden mittakaavan loppusijoitusreikaa. Reiat on porattu kiertomurskausmenetelmalla, joka aiheuttaa kiven pintaan hairion. Hairio ilmenee epatasaisuutena, lisaantyneena mikrorakoiluna ja huokoisuutena. Tassa tyossa tutkittiin porauksen aiheuttaman hairion syvyysulottuvuutta, mikrorakoilun maaraa ja huokoisuutta seka 14 C-PMMA menetelmalla etta elektronimikroskooppisesti hairiovyohykkeen geometrian ja ominaisuuksien arvioimiseksi. Tama tyo on jatkoa vuonna 1995 aloitetulle tutkimukselle. Aikaisemmin tutkittujen naytteiden tulokset varmistettiin mittaamalla uudet autoradiogrammit ja naytevalikoimaa laajennettiin tutkimalla gneissimaisen tonaliitin lisaksi myos homogeenista tonaliittia ja pegmatiittia. Tutkimustunnelien seinista kairatut naytteet impregnottnn 14 C leimatulla metyylimetakrylaatilla (MMA) vakuumikuivauksen jalkeen. Monomeeri polymeroitiin Co-60 sateilylahteen kentassa. Impregnoidut kivet sahattiin ja sahatut pinnat tutkittiin autoradiografisesti. Huokoisuusprofiilit ja huokoisuuden jakaumat maaritettiin autoradiogrammeista digitaalisen kuvienkasittelyn avulla. Hairiottoman vyohykkeen huokoisuus oli vol.%, joka mitattiin mm:n syvyydessa hairiopinnasta lukien. Kokonaishuokoisuuden huomattava nousu havaittiin keskimaarin 10 mm:n syvyyteen kaikki naytetyypit mukaanlukien. Homogeenisen tonaliitin huokoisuus kasvoi talla no in 10 mm:n vyohykkeella viisinkertaiseksi hairiottoman vyohykkeen huokoisuuteen verrattuna. Elektronimikroskopia tutkimuksissa havaittiin 0-2 mm:n vyohykkeella hairiopinnasta lukien mineraalikiteiden sisaista rakoilua. Rakoilu sisalsi hairiopinnan suuntaisia mikrorakoja, joiden avaumat olivat muutamia mikrometreja. Pegmatiitin huokoisuus koostuu mineraalien rajapintahuokoisuudesta seka hairiottomassa etta hairiintyneessa matriisissa. Kokonaishuokoisuuden mittaus 14 C-PMMA menetelmalla perustuu metyylimetakrylaatin jakautumiseen tasaisesti kivimatriisiin. Pegmatiitin huokoisuusmaaritys 14 C-PMMA menetelmalla on suuntaa-antava useiden mikrometrien avaumaisten mineraalirajapintahuokosten aiheuttamasta heterogeenisuudesta johtuen. Kokonaishuokoisuuden kasvu 0-5 mm:n syvyydella hairiopinnasta lukien oli kaksinkertainen. Elektronimikroskopia tarkastelussa kvartsi ja maasalpakiteiden sisaisia mikrorakoja havaittiin runsaasti 0-10 mm:n vyohykkeella hairiopinnasta lukien. Gneissimaisen tonaliitin huokoisuus on kohonnut 1-15 mm:n syvyyteen tunnelin seinaman pinnasta. Huokoiset vyohykkeet ulottuivat aina mm syvalle hairiopinnasta. Huokoisuusprofiilimaaritykset uusista tonaliittinaytteista olivat yhtapitavia aikaisempien maaritysten kanssa. Avainsanat: huokoisuus, mikrorakoilu, 14 C-PMMA menetelma, autoradiografia, digitaalinen kuvienkasittely, SEMIEDS, louhinnan aiheuttama hairio

7 TABLE OF CONTENTS PREFACE TIIVISTELMA SUMMARY 1 INTRODUCTION 2 SAMPLES 2.1 General Sawing of the samples before and after impregnation 3 INVESTIGATION OF SAMPLES WITH THE 14 C-PMMA METHOD 3.1 Properties of the 14 C-MMA tracer 3.2 Drying, impregnation with 14 C-MMA tracer 3.3 Autoradiography 3.4 Digital image analysis of auto radiographs Calculation of porosity Intensity and optical density Activity and optical density Porosity 4 ELECTRON MICROSCOPIC MEASUREMENTS 5 RESULTS OF THE 14 C-PMMA METHOD 5.1 Group Group Group

8 5.4 Group Group Group Group Group Group 11 6 RESULTS OF SCANNING ELECTRON MICROSCOPY 6.1 Structure of homogeneous tonalite Intact matrix Disturbed zone 6.2 Structure of granite pegmatite Intact matrix Disturbed zone 6.3 Structure of gneissic tonalite Intact matrix Disturbed zone 7 CONCLUSIONS AND DISCUSSION REFERENCES APPENDICES 52 54

9 PREFACE The work was carried out by Marja Siitari-Kauppi in co-operation with Jorma Autio at the Laboratory of Radiochemistry, Department of Chemistry, of the University of Helsinki. This study is one aspect of the characterisation of the full-scale experimental deposition holes bored in the Research Tunnel at Olkiluoto, which is being carried out by Posiva and SKB as a joint project. The work was commissioned by Jorma Autio of Saanio&Riekkola Oy, on behalf of Posiva and SKB. The contact persons were Jukka Pekka Salo at Posiva and Christer Svemar at SKB. Timo Kirkkomaki of Saanio&Riekkola Oy made the partition diagrams of the samples presented in the Appendices. Electron microscopic measurements were performed at the Department of Electron Microscopy, University of Helsinki.

10 1 INTRODUCTION Three holes with the size of deposition holes (depth 7.5 m and diameter 1.5 m), were bored in the Research Tunnel at Olkiluoto, Finland; Figure 1. A novel full-face boring technique was used, based on rotary crushing of rock and removal of crushed rock by vacuum flushing through the drill string /1/. The full-scale deposition holes were bored in the beginning of Extensive geoscientific characterisation preceded the boring, and was followed by an extensive characterisation programme /2-5/ that included studies focusing on the disturbance caused by excavation. In 1995 this disturbance was studied in laboratory, using 98 mm diameter core samples taken from different locations in the holes /6/. A novel 14 C polymethylmethacrylate e 4 C-PMMA) method /7-10/ and scanning electron microscopy were applied to evaluate the extent and nature of the disturbance. In addition, a novel helium gas diffusion method was employed to determine the diffusion coefficient and permeability of both disturbed and undisturbed rock /11 /. EXPERIMENTAL DEPOSITION HOLES WASTE -SILOS Figure 1. VLJ Repository and the Research Tunnel at Olkiluoto. 1

11 In 1996 complementary samples were taken from the deposition holes /12/, in order to obtain samples of carefully selected sections. The work presented in this report is a continuation of the investigations that were carried out in 1995, and is based on the use of the 14 C-PMMA method and analysis of the new samples taken in The 14 C-PMMA method makes it possible to study the spatial distribution of the pore space and the heterogeneities of rock matrices on submicrometric to centimetric scales. Subsequent autoradiography and digital image analysis enable features limited in size by the range of 14 C beta radiation to be measured. The porous zones detected with the 14 C-PMMA method were studied qualitatively in more detail by using scanning electron microscopy. The general objective of the work described in this report was to determine the properties of the excavation disturbed zone. Aspects studied included the determination of porosity, analysis of microfracturing and investigation of the structure of the zone. Other more specific objectives of the work were: - to improve and to test the accuracy and reliability of the earlier results; - to determine the disturbance in two other rock types - pegmatite and homogeneous tonalite- differing from the gneissic tonalite that was studied previously; - to obtain data on the effect of orientation of rock with respect to the disturbance; - to obtain more data on the effect of different thrusts used in boring on the extent of disturbance; and - to obtain data on the effect of gauge cutters with respect to the extent of disturbance. The results of the 14 C-PMMA study, which are presented in this report, are one part of a larger research entity which includes other studies focusing on the permeability, diffusion coefficient, porosity and structure of the disturbed zone. The present plans are that the summary of the findings of these studies, as well as analysis and conclusions with respect to the boring technique and cutter head design, will be reported later in a summary report. 2

12 2 SAMPLES 2.1 General Rock samples from different parts of the two deposition holes, and representing different operating boring parameters, were taken from the walls of full-scale deposition holes 2 and 3, bored in the Research Tunnel at Olkiluoto (Figure 1). The locations of the sampling sections of the experimental full-scale deposition holes, and the corresponding boring parameters, are presented in Reference 10 and 12. The cylindrical rock samples were 98 mm in diameter and 300 mm in length. The new samples collected from the two deposition holes were impregnated, and the samples were then treated as group 2 to group 11, each group representing different characteristics of rock type or different boring parameters. The samples were studied in eight groups. The first group, group 1, comprised samples A2, A3, Cl, C2, B3, B4, D2 and D4. The samples were impregnated in 1995 /6/. For the current work new autoradiographs were exposed using different exposure times. The porosity profiles were calculated to verify the earlier results and improve them. The second group, group 2, comprised samples B10, B11, D3, and D10. The rock type was gneissic tonalite as in group 1, and the samples were parallel to group 1. The third group, group 3, included samples B 1 and D9, which were also gneissic tonalite; here, the orientation of microfracturing was studied in comparison to the orientation of group 1. The fourth group, group 4, comprised samples L5 and L6 and represented pegmatite type rock. The fifth group, group 5, ws made up of samples L3 and L4, which represented homogeneous tonalite having a very fine-grained mineral composition. The sixth group, group 6, included samples L1 and L8. These gneissic tonalite samples served as a reference group for groups 4 and 5. The samples of groups 4, 5 and 6 were cored from deposition hole 3. 3

13 Group 7 comprised samples KK2, LL 1 and LL3 from deposition hole 2 and samples Wl, W2, Yl and Y2 from deposition hole 3. The boring parameters in these cases were varied. These samples were analysed in order to verify the earlier results. The same applies to group 8 which consisted of samples AAl, BB2, CCl and DD2 from deposition hole 2 and samples N2, N3, P2, P3, R2 and R3 from deposition hole 3. Results of groups 9 and 10 will be given elsewhere. Group 11 comprised two samples, C6 and C8, cored from deposition hole 3 and these samples were taken to study the affect of gauge cutters. In this research, samples for electron microscopic study were prepared from samples L6.1/B, L4.1/B and Ll.1/AB, following their 14 C-PMMA treatment. 2.2 Sawing of the samples before and after impregnation A schematic presentation of the sawing procedures used for each individual sample is shown in Appendices 1 to 8. The procedure for sample A2 is presented in Figure 2 as an example. ~ A2{) [)A!:/~: U) A2.1/A ----/---/ ~, '4. I.. A2.1/B / / [[\l A2.1/A I ~,..,. ' m.> A2.1/A II m' j. A213/A I L] A2.1/B I I ~ [\ A2.12/A I \j]a2.1/b 11 [Jj A2.12/A 11~ A2.11/A 11 [J A2.11/A I Figure 2. Partition diagram for sample A2 from deposition hole 2. 4

14 The dashed line in the diagrams (in Appendices 1-8) divides the procedure into partition of the samples before and after impregnation. The sawing after impregnation was done for autoradiography, scanning electron microscopy (SEM) and mineral composition characterisation with thin slice samples using polarisation microscopy. Groups 1, 4 and 5 were cut according to Figure 2, but the rest of the samples were cut into two after impregnation and the two profiles were studied (according to Appendix 2). The shaded sawed surfaces in the partition diagrams were exposed on autoradiographic film, and several autoradiographs were taken of the sawn surfaces. The code of a sawn rock piece is the same as that of the autoradiograph taken from the sawn surface. Each part of the sample is coded according to its proximity to the disturbed surface. For example, the first cut, which was made for a porosity profile, was along the axis of the cylindrical sample. The samples were then sawed parallel to the surface, which contained the disturbed zone at depths of 5 mm to 25 mm. The diamond saw used in the experiment was of the Eurocoup-Masonry type. The thickness of the blade was 1.8 mm and the diameter 350 mm. The speed of rotation was 2800 rpm and the loss of rock matrix 2.1 mm. 3 INVESTIGATION OF SAMPLES WITH 14 C-PMMA METHOD The 14 C-PMMA method involves impregnation of centimetric scale rock cores with 14 C labelled methylmethacrylate e 4 C-MMA) in a vacuum, irradiation polymerisation, autoradiography and optical densitometry with digital image processing techniques /6-10/. Impregnation with the labelled low-molecular-weight and low-viscosity monomer 14 C-MMA, which wets the silicate surfaces well and can be fixed by polymerisation, provides information on the accessible pore space in crystalline rock that cannot be obtained with other methods. 5

15 Total porosity is calculated by using 2D autoradiographs of the sawn rock surfaces. The geometry of porous regions is then visualised. The preconditions for applying this method are: (i) known local bulk density; (ii) presence of only two phases mineral and PMMA; and (iii) homogeneous distribution of pores and minerals below the limit of lateral resolution of autoradiography. Fissures and cracks with apertures larger than 20 J.!m were excluded from the quantitative measurements, at depths of 0 to 1 mm from the disturbed surface. 3.1 Properties of the 14 C-MMA tracer Methylmethacrylate (MMA) is a monomer with very low viscosity, P (20 C) /13/, while the viscosity of water is P (25 C) 114/. Because its contact angle on silicate surfaces is low, impregnation of bulk rock specimens is rapid and depends on existing pore apertures. The MMA molecule is small (mol.weight 100.1). It has nonelectrolytic properties and only low polarity, the polarity of the ester being considerably lower than that of water, and it behaves in the rock matrix like a non-sorbing tracer. The low f3 energy of the carbon-14 isotope, max 150 kev, is convenient for autoradiographic measurements. The monomer used was 14 C-labelled MMA with a specific activity of 2-5 mci/g and a total activity of 50 mci. Its radiochemical purity was >95 %. In this study the dilution of the tracer ranged between Bq/ml (SO ~Ci/ml) and Bq/ml (25 f.!ci/ml). The tracer activity used was determined after every impregnation with liquid scintillation counting (Rackbeta 280); the dilutions are presented in Table I. The calibration sources were prepared by diluting the 14 C-MMA with inactive MMA. The activities ranged from 462 Bq/ml (12.5 nci/ml) to Bq/ml (5 ~Ci/ml). 3.2 Drying, impregnation with 14 C-MMA and polymerisation of samples Samples were vacuum dried in a chamber for 8 to 14 days at a maximum temperature of 6

16 80 C. After drying they were cooled to 18 C. For 14 C-MMA impregnation, the tracer was put into a 50 ml reservoir and transferred under vacuum to the impregnation chamber. Slow transfer of the monomer ensures degassing of the monomer and infiltration of vapour only. The impregnation time ranged from 7 to 22 days. After impregnation the samples were irradiated with gamma rays from a Co-60 source, in order to polymerise the monomer in the rock matrix; the required dose was 50 kgy (5 Mrad). The samples were irradiated under water 14 C-MMA emulsion in polyethylene vials. 3.3 Autoradiography Irradiation of the rocks with Co-60 causes strong thermoluminescence of K-feldspar and other major rock-forming minerals, which exposes autoradiographic film. To avoid this, the thermoluminescence was released by heating samples to 120 C for 3 hours before sawing. Mylar foil with aluminium coating was placed on top of the film to shield it from the rest of the emissions. The heated samples were sawed into pieces as shown in Appendices The sawn rock surfaces were exposed on (3 film (Hyperfilm-(3max) or more sensitive Kodak BioMax MS autoradiographic film. Both films are high-performance autoradiographic films for 14 C and other low energy (3-emitting nuclides. The resolution of the (3 film is a few J.!m. The final resolution depends on the roughness of the sawn surface and the range of the 150 ke V beta particles in the rock matrix. As to the range, the rock samples used were infinite in thickness. The beta absorption correction is obtained from the ratio of the densities of rock and polymethylmethacrylate. With the tracer activity and the autoradiographic films employed here, the exposure times for samples ranged from 7 to 32 days. The impregnation and exposure times for each rock sample are listed in Table 1. 7

17 The samples of group 1 were impregnated in 1995 /6/. The new samples taken in 1996 were impregnated with 14 CMMA in five stages, using the impregnation times shown in Table 1. Table 1. Codes and locations of rock samples, densities of rock types, the 14 C MMA tracer activities that were used (I), impregnation times (11) and exposure times of autoradiographs (Ill). l) Kodak Biomax film was used otherwise Hyperfilm-f3max. sample hole Q (g/cm 2 ) I (Ci/ml) II (d) Ill (d) group 1 group 2 group 3 group 4 group 5 group 6 group 7 group 8 group 11 A /18 A Cl 3 14 C B B4 2 7 D2 3 7 D4 3 7 BlO /32 B /25 D /32 D /32 Bl /32 D ) /25 LS /25 L ) /25 L L Ll /30 L KK LL LL W W Yl Y AAl BB CCl DD N N P P ) R R C CS

18 3.4 Digital image analysis of auto radiographs Calculation of porosity Interpretation of the results is based on digital image analysis of autoradiographs. Digital image analysis starts from dividing the autoradiograph into area units called pixels. In this work, 300 dpi resolution was used in the quantitative analysis; this means a pixel size of about 85x85!J.m. Basically all the intensities of the subdomains were converted into corresponding optical densities, which in turn were converted into activities with the help of the calibration curves measured for each exposure. Finally, the activities were converted into respective porosities. In principle, the interpretation is based on studying the abundance of tracer in each subdomain Intensity and optical density Since the response of the image source (video camera or table scanner) and the amplifier of the digital image analysator are linear, the digitised grey levels of the film can be handled as intensities. Intensity here means the light intensity coming through the autoradiographic film. Optical densities, which according to Lambert & Beer's law are concentration proportional, are derived from the intensities: (1) where D is the optical density, I 0 is the intensity of the background and I is the intensity of the sample. It can be seen that as the intensity decreases (i.e. the film dark ens), the optical density increases. 9

19 3.4.3 Activity and optical density A conversation function is needed to relate the optical densities (grey levels) measured to corresponding activities. 14 C-PMMA standards (tracer diluted with inactive MMA) having specific activities between 462 and Bq/ml have been used to establish the calibration function. The following calibration curve was used: where Dmax is the maximum optical density, k is a fitting parameter, and A is the specific activity. Solving A from the Eq. (2) gives: (2) (3) Porosity The local porosity 8 of the sample was simply obtained from the abundance of the tracer (assuming constant tracer concentration in the PMMA, the higher the abundance of the tracer, the higher the local porosity): 8 = (3(A I A 0 ) (4) where A 0 is the specific activity of the tracer used to impregnate the rock matrix, and (3 is the (3-absorption correction factor. The absorption of (3 radiation in a substance depends roughly linearly on the density of the substance. Therefore factor (3 can be approximated from: (5) where Qs is the density of the sample and Qo is the density of pure PMMA (1.18 g/cm 3 ). In the interpretation the sample is assumed to consist of rock materal and pores (containing PMMA), and therefore Q 8 can be expressed as: (6) 10

20 where Qr is the density of mineral grains. In the practice of bulk measurements the average density of the rock sample is used. Using Eqs.(S) and (6) in Eq.(4), the porosity and the activity relationship can be solved: & 8 = Qo A 1+(&-1)~ Ao Qo Ao where A is the specific activity of individual pixel and A 0 is the specific activity of the tracer. The porosity of each individual pixel n from the autoradiogram is calculated according to equations (3) and (7). The porosity histogram gives the relative frequency of regions of individual porosities. The total porosity is obtained from the porosity distribution by taking the weighted average: (7) LAreanEn n Etot = LArean (8) n where Arean is the area of pixel n, and 8 0 is the local porosity of pixel n. The intensities of autoradiograms are digitised with a CCD camera or a table scanner. The maximum optical resolution of the scanner is 600 dpi, but in this work the resolution for the scanning was usually 300 dpi. The amount of tracer in the sample, and the volumetric porosity, can thus be derived from the blackening of the film caused by the radiation emitted from the plane surface of the rock section. If the pore sizes are well below the resolution of the autoradiography, the major fraction of the beta radiation emitted is attenuated by silicate. The tracer can thus be considered diluted by silicate. For the 14 C-PMMA method to be used, the bulk density must be known; there must be only two phases (mineral and PMMA), and pores and minerals must be homogeneously distributed below the limit of the lateral resolution of the autoradiography. Fissures or cracks with apertures of 20 f..!m or more are not comparable with calibration sources. 11

21 The porosity profiles were measured from the autoradiographs taken from the surfaces of sawn rock samples. Each profile contains seven to fifteen measurements where the thickness of digitally scanned sector is 7 to 14 mm. The autoradiograph of sample DD2.1/A is shown in Figure 3, and the seven porosity profiles that were measured are shown in Figure 4 for an example. The total porosity profile of each sample is the arithmetic average of the sectors measured. Figure 3. Autoradiograph of rock sample DD2.1/A cored from deposition hole /A <>- sector ,..._ sector 2 ~ tr-sector 3 f Sector sector 5 0 c. --<>- sector t--sector Figure 4. Porosity profiles taken from autoradiograph of sample DD2.1/A. 12

22 4 ELECTRON MICROSCOPIC MEASUREMENTS Scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS) were performed in order both to study the pore apertures of porous regions in greater detail and to detect the corresponding minerals. The regions for SEM/EDS measurements were selected from 14 C-PMMA autoradiographs. Local porosities are measured with the 14 C-PMMA method, which yields an approximation of 2D images of centimetric-scale rock surfaces calculated from the intensities of the autoradiographs. The porous regions comprise pores and fissures with a wide aperture range. The apertures of pores and fissures in and around the minerals were determined. The samples selected for SEM/EDS determinations were B 11 from group 2, which is a genissic tonalite, and D9 from group 3; also a gneissic tonalite. The samples from group 4 were L5 and L6: these represent the pegmatite samples. The samples from group 5 were L3 and L4, representing homogeneous tonalite. The last samples for SEM/EDS determinations were L1 and L8, which were gneissic tonalite. The sawing schemes for SEM/EDS, and also for thin slice samples, are illustrated in partition diagrams in Appendices 2 to 8. The SEM results of samples L6, L4 and L1 are presented in this work; the SEM analysis of samples B11, D9, L5, L3 and L8 will be presented elsewhere. The thin slices and the SEM rock samples will be exposed on autoradiographic film afterwards. Electron microscopic analysis of polished rock sections (polished with m diamond paste) was performed using a Zeiss DSM 962 electron microscope and the Link ISIS program with a UTW Si(Li) detector operated in the backscattered electron image (BSE) mode. The main minerals were determined with energy dispersive X-ray microanalysis (EDS). The samples were carbon coated. Magnifications of up to fold were used to reveal apertures down to a size of 500 nm. The range of aperture measurements is limited, since according to our experience, SEM examination of the polished surfaces of dense granitic rock samples does not reveal apertures exceeding 1 1-1m in diameter, unless the matrix is altered or weathered. The contrast between the pore space and solid rock is enhanced by the MMA impregnant. 13

23 , ~ RESULTS OF THE 14 C-PMMA METHOD 5.1 Group 1 The partition diagrams and autoradiographs and earlier porosity profiles of samples A2 and A3 from deposition hole 2, and of samples Cl and C2 from deposition hole 3, were presented in previous report /6/. The new porosity profiles of samples A2 and A3 are presented in Figure 5 and the porosity profiles of samples C 1 and C2 in Figure 6. The new exposure times for the autoradiographs used in this analysis were 18 days ~ 0.25 f ~ ~--~--~+-~~~ distance (mm} Figure 5. Porosity profiles of samples A2 and A3 from deposition hole 2. Comparison of the results with those presented in /6/, reveals that the porosity profiles of samples A2 and A3 differ from the earlier ones. The porosity of the undisturbed matrix in sample A2 was 0.1 %. The zone of increased porosity (porosity greater than 0.1 %) extended to a depth of 17 mm from the disturbed surface. The porosity of the undisturbed zone in sample A3 was 0.05%; this was lower than that measured previously, but still within error limits. A porosity higher than 0.05% was detected to a depth of about 12 mm from the disturbed surface. The objective of the 14

24 different measurements was to determine the porosity profiles using the same comparable exposure time for all samples and a scanning procedure that was more accurate than the one used previously /6/ ~ 0.25 f j-+=c1l ~ ~ r ~ distance (mm} Figure 6. Porosity profiles of samples Cl and C2 from deposition hole 3. The porosity profiles of samples Cl and C2, determined earlier, were similar to the results measured here except for the highest porosities of sample Cl, detected at depths of 0 to 3 mm from the disturbed surface. The autoradiograph exposed from the rock surface were scanned in several slices in order to prevent errors stemming from the roughness of the surface. In addition, next to the disturbed surface, a few fissures, having apertures assumed to be tens of!-!m, were excluded from the quantitative measurement in this work at depths of 0 to 1 mm. The existing fissures increased the real porosity at the crushed zone. The porosity of the undisturbed rock was 0.1 %. The zone of increased porosity was about 13 mm in sample C 1 and about 18 mm in sample C2. The porous veins extended to depths of 20 to 25 mm from the disturbed surface in samples Cl and C2. The partition diagrams and earlier autoradiographs of samples B3 and B4 from deposition hole 2, and of samples D2 and D4 from deposition hole 3, are presented in /6/. The new porosity profiles of samples B3 and B4 are presented in Figure 7 and those of samples D2 and B3 are presented in Figure 8. 15

25 ~ f Q distance (mm) Figure 7. Porosity profiles of samples B3 and B4 from deposition hole 2 Sample B3 was 10 mm thick and sample B4 was 15 mm thick. In both samples the lowest porosities, indicating undisturbed rock, were 0.2%, which was higher than the previously measured lowest porosity of 0.15%. The exposure times used were 10 days in the earlier experiments, but 15 and 18 days in this work. The different shape of the profiles can be observed at depths of 0 to 4 mm from the disturbed surface; this difference could be due to artefacts in the first autoradiographs /6/. Several fissures parallel to the disturbed surface, at depths of 0 to 1 mm from the disturbed surface, were observed in sample B4. A few of them were excluded of the quantitative analyse. The thickness of the fissured zone in both samples seems penetrate through the sample, indicating that the sample lengths were too short to enable determination of the maximum extent of disturbance. Owing to the short sample length the increase of porosity in the undisturbed zone was studied with reference samples from group 2, where the sample lengths were about 40 mm. 16

26 ! 0.4 ; l' Q distance (mm) Figure 8. Porosity profiles of samples D2 and D4 from deposition hole 3. The results for samples D2 and D4 were similar to those for samples B3 and B4. The thicknesses of samples D2 and D4 were 17 mm. The porosity of the undisturbed sample was 0.2%. The highest detected porosities ranged from 0.6 to 0.8% at depths of 0 to 2 mm from the disturbed surface. The values are lower than those detected previously, owing to the more accurate measurement method used in this work. The porosity profiles of D2 and D4 indicate that the thickness of the fissured zone extendes to a depth of at least 17 mm from the disturbed surface, the increased porosity zone extending to a depth of 10 mm. Because of the short sample length, the increase in porosity in the undisturbed zone was studied also with reference samples from group 2, where the sample lengths were about 50 mm. 5.2 Group 2 The partition diagrams and the autoradiographs of samples B 10 and B 11 from deposition hole 2 and of samples D3 and D10 from deposition hole 3, are presented in Appendix 1. The photograph of rock surface B11.1/A and the corresponding autoradiograph are shown in Figure 9. The porosity profiles of samples B10 and B11 17

27 are presented in Figure 10, and those of samples D3 and D10 are presented in Figure 12. Figure 9. Photograph of rock surface B 11.1 I A from deposition hole 2 and corresponding autoradiograph. Sample width is 98 mm. Samples B 10 and B 11 were analogous to samples B3 and B4 from deposition hole 2. Sample B 10 was 41 mm thick and sample B 11 was 46 mm thick. The possible increase in porosity owing to the overly short sample length was thus avoided using thicker samples than those from B3 and B4. The porosity of the undisturbed surface was 0.1 %, i.e. lower than the porosity of the assumed undisturbed zone in samples B3 and B4. The depth of the zone of increased porosity in sample B 10 extended to a depth of 15 mm from the disturbed surface. This zone contains crushed and fractured parts of the disturbance. The crushed zone extended to a depth of 5 mm from the wall surface. The micro fracturing extended to a depth of 23 mm from the disturbed surface, which was 18

28 observed qualitatively from the autoradiographs. The porous veins were perpendicular to the disturbed surface. The porosity in the crushed zone at depths from 0 to 5 mm from the disturbed surface was found to be six to three times as high as the porosity in undisturbed rock. Results similar to those for sample B 10 were observed for sample B 11, although the orientation of the porous veins in B 11 was different from that in sample B 10. The zones of porosity inclined at an angle of 45 up from the deposition hole wall in sample B11, and extended to a depth of about 18 mm from the disturbed surface. The thickness of the zone of increased porosity extended to 15 mm from the disturbed surface. The highest porosities in samples B 10 and B 11 at depths from 0 to 5 mm from the disturbed surface were in agreement with the results for samples B3 and B ~ 0.4 ~ 0.3 Cl) a distance (mm) Figure 10. Porosity profiles of samples B 10 and B 11 from deposition hole 2. The porosity profiles of samples A2, A3, B1(group 3), B3, B4, B10 and B11 are presented in Figure 11. The increase in porosity at depths of 0 to 10 mm from the disturbed surface was found to be similar for samples B3, B4, B 10 and B 11, B3, B4, B 10 and B 11 showed greater effect of disturbance than A2 and A3. The porosities of undisturbed matrices were similar in almost all samples. 19

29 "0' ~ ~ u; Q A2 ---A3 83 ~ _._ distance (mm) Figure 11. Porosity profiles of samples A2, A3, B1 (group 3), B3, B4, B10 and B11 from deposition hole 2. Samples D3 and D10 were analogous to samples D2 and D4 from deposition hole 3. Samples D3 and D10 were 40 mm thick. The porosity of undisturbed sample was 0.05% in sample D3 and 0.1% in sample D10. The porosities of undisturbed rock were found to be lower than the porosities of samples D2 and D4. The pronounced increase in porosity was observed from the disturbed surface to a depth of 7 mm in sample D3 and to a depth of 10 mm in sample D10. The positive gradient in the porosity profile of sample D 10 at depths of 0 to 2 mm from the disturbed surface is due to an experimental error which occurred during sample handling. The tracer was able to evaporate from the open pores that were nearest to the surface, before water+:mj\1a emulsion surrounded the sample prior to irradiation. The porous veins perpendicular to the disturbed surface extended to a depth of 20 mm in sample D3 and to a depth of 15 mm in sample D10. The porous veins inclined at an angle of 45 down from the deposition hole wall in sample D3 and up in sample D10. The density of micro :fissures parallel to the disturbed surface was high in both samples, and the results agree with those for samples D2 and D4 from group 1. The highest porosities observed in samples D3 and D10 were lower than the porosities in samples D2 and D4. 20

30 ~ ;: u; ~ 0 Q r=+=d3l ~ distance (mm) Figure 12. Porosity profiles of samples D3 and D 10 from deposition hole 3. The porosity profiles of Cl, C2, D2, D3, D4, D9 (group 3) and DlO are presented in Figure 13. The porosities of samples D2 and D4 were higher at depths of 5 to 15 mm from the disturbed surface than the porosities of samples D3 and DlO. The porosity was found to be higher in DlO sample than in C samples at depths of 0 to 5 mm from the disturbed surface. The porosity profile of sample D3 was similar to the porosity profile of samples Cl and C2. The porosities of undisturbed matrices were similar in all the samples Cl,C2 and D3, D9, DlO. 0.5 ~ :; 0.4 "iii e Q C1 ---C2 ~ 02 --M _._09 -f distance (mm) Figure 13. Porosity profiles ofsamples Cl, C2, D2, D3, D4, D9 (group 3) anddlo from deposition hole 3 21

31 5.3 Group 3 The partition diagrams and the autoradiographs of samples B 1 from deposition hole 2 and D9 from deposition hole 3 are presented in Appendix 2. The photograph of rock surface D9.1/A and the corresponding autoradiograph are shown in Figure 14. The porosity profiles of samples B1 and D9 are presented in Figure 15. Figure 14. Photograph of rock surface D9.1/A from deposition hole 3 and corresponding autoradiograph. Sample width is 98 mm. Group 3 comprised two samples; B1 from deposition hole 2, and D9 from deposition hole 3. Sample B 1 was 40 mm thick and sample D9 was 43 mm thick. The porosity of undisturbed sample was 0.1 %, being slightly smaller in sample B 1. These samples were investigated to obtain complementary information of the effect of orientation on disturbance. The increased porosity in samples B 1 and D9 extended to a depth of 10 mm from the disturbed surface. Microfissures parallel to the disturbed surface were 22

32 observed to a depth of 2 mm from the disturbed surface. A few porous veins inclined at an angle of 45 up from the deposition hole wall in sample D9. The density of porous veins in sample B 1 was minor compared to that of sample D ~ ~ 0.3 e 0 Q. 0.2 FBfl ~ 0.1 'o ~----~----r-----r---~~--~ ~----~ < ; distance (mm) Figure 15. Porosity profiles of sample B1 from deposition hole 2 and sample D9 from deposition hole Group 4 The partition diagrams and the autoradiographs of samples L5 and L6 from deposition hole 3 are presented in Appendix 3. The photograph of rock surface L5.1/B and the corresponding autoradiograph are shown in Figure 16. The porosity profiles of samples L5 and L6 are presented in Figure

33 Figure 16. Photograph of rock surface L5.1/B from deposition hole 3 and corresponding autoradiograph. Sample width is 98 mm. Samples LS and L6 cored from the deposition hole 3 represent pegmatitic rock type. The main minerals are potassium feldspar, plagioclase and quartz. The grain size of the matrix is larger than in samples of other groups representing gneissic tonalite and homogeneous tonalite. Grain boundary porosity is dominant in pegmatite samples. The requirements for total porosity measurement which is based on the facts that the pore apertures are far below the range of beta particles having 150 kev energy and that the tracer is homogeneously diluted into the rock pores, are not met. Thus the quantitative porosity measurement here is more or less suggestive. Samples LS and L6 were 40 mm thick. The quantitative measurement for the porosity profiles, Figure 17, was done from the autoradiographs of polished SEM samples. The width of the slice scanning the profile was about 2 mm. A zone of clearly increased porosity was observed to a depth of about 12 mm from the disturbed surface in sample 24

34 LS. In sample L6, a zone of increased porosity - a crushed and fractured zone - was observed to a depth of 5 mm from the disturbed surface. The porosity of the undisturbed sample was about 0.2%, but large quartz grains showed porosities below 0.05%. These quartz grains can be classified as a nonporous matrix according to measurement with the 14 C-PMMA method. One sample, L5.3, was sawed from a depth of 151 mm from the disturbed surface and was then impregnated so that the porosity of the undisturbed pegmatite matrix could be determined. The grain boundary porosity was also determined for sample L5.3. The total porosity was 0.2%, but porosities of 0.2 to 0.5% were found inside mineral grains, too. The sample surfaces shall be grinded and new autoradiographs are made later to ensure that the darker zones seen in Figure 16 are not artefacts caused for example by improper cooling during sawing ~ ~ c;; a.. 0 c. 0.2 ~ ~ distance (mm) Figure 17. Porosity profiles of samples L5 and L6 from deposition hole 3. 25

35 5.5 Group 5 The partition diagrams and the autoradiographs of samples L3 and L4 from deposition hole 3 are presented in Appendix 4. The photograph of rock surface L3.1/B and the corresponding autoradiograph are shown in Figure 18. The porosity profiles of samples L3 and L4 are presented in Figure 19. Figure 18. Photograph of rock surface L3.1/B from deposition hole 3 and corresponding autoradiograph. Width of sample is 98 mm. Samples L3 and L4 represent the homogeneous tonalite rock type. Compared to the gneissic tonalite samples (groups 1 to 3) the grain size of minerals in samples L3 and L4 was small (~ 0.5 mm). Sample L3 was 40 mm thick and sample L4 was 42 mm thick. The autoradiographs showed an even porosity distribution in the undisturbed section. The porosity of the undisturbed sample was 0.05%. No porous veins of any kind were observed of any kind in the autoradiographs. The increased porosity zones did not show 26

36 any orientation. In both samples L3 and L4, a pronounced increase in porosity was observed to a depth of about 15 mm from the disturbed surface. The positive porosity gradient and apex in the porosity profile of sample L3 at depths of 0 to 2 mm from the disturbed surface were the consequence of an experimental error during sample handling, as was earlier stated for sample D10. After impregnation and before irradiation, the sample was able to dry; and methylmethacrylate thus evaporated from pores and fissures, at depths of 0 to 2 mm ~ ~ 0.15 e 0 c. 0.1 I=+=L3l ~ distance {mm) Figure 19. Porosity profiles of samples L3 and L4 from deposition hole Group 6 The partition diagrams and the autoradiographs of samples L1 and L8 from deposition hole 3 are presented in Appendix 5. The photograph of rock surface L1.1/B and the corresponding autoradiograph are shown in Figure 20. The porosity profiles of samples L 1 and L8 are presented in Figure

37 Figure 20. Photograph of rock surface Ll.1/B from deposition hole 3 and corresponding autoradiograph. Sample width is 98 mm. Group 6 was the reference group for groups 4 and 5, and represented gneissic tonalite. The samples were fine grained, as were the homogeneous tonalites of group 5. Sample L1 was 41 mm thick and sample L8 was 40 mm thick. The porosity of the undisturbed matrix in both samples was 0.05%. A pronounced increase in porosity was observed to a depth of 7 mm from the disturbed surface in sample L1, and to a depth of 10 mm in sample L8. A few porous veins were observed to depths of 10 to 15 mm from the disturbed surface in both samples; these veins were directed perpendicular to the disturbed surface. The crushed zone extended to 2 mm from the disturbed surface and qualitative inspection revealed short microfissures parallel to the wall surface. The grain boundaries were observed more clearly in samples L1 and L8 than in samples of 28

38 homogeneous tonalite (group 5). The porosity was found to be more evenly distributed in autoradiographs of samples Ll and L8 than in other samples of gneissic tonalite ~ 0.3 ~ c FTil ~ r r ~------~ distance (mm) Figure 21. Porosity profiles of samples Ll and L8 from deposition hole Group 7 The partition diagrams and the autoradiographs of samples KK2, LLl and LL3 from deposition hole 2 are presented in Appendix 6. The partition diagrams and the autoradiographs of samples Wl, W2, Yl and Y2 from deposition hole 3 are presented in Appendix 7. The porosity profile of sample LL3 is presented in Figure 22. The porosity profiles of samples Wl and W2 are presented in Figure 23. The porosity profiles of samples Yl and Y2 are presented in Figure 24. The samples of group 7 were a reference the samples of group 1. The samples of group 7 represented the gneissic tonalite rock type. Sample LLl was 40 mm thick and samples LL3 and KK2 were 51 mm thick. The autoradiographs of samples LLl and KK2 showed anomalious dark zones at depths of 5-10 mm from the disturbed surface. The result shall be verified by grinding the surface and making a new autoradiograph to ensure that the result is not caused by a contamination of rock surfaces as a result of inproper cooling during sawing of the rock surfaces for autoradiography. Quantitative analysis shall be performed for samples LLl and KK2 29

39 after the results have been verified. The porosity profile of LL3 is illustrated in Fig. 22. The porosity of the undisturbed matrix in sample LL3 was 0.2%. The porosity of the undisturbed matrix was measured also for samples LL3 and KK2, was found to be 0.2%. ~ ~ u; 0.3 J-+-LL3 J a distance (mm) Figure 23. The porosity profile of samples LL3 from deposition hole 2. A pronounced increase in porosity was observed to a depth of 5 mm in sample LL3. A few porous veins were found in samples LLl and LL3, and the veins extended to depths of 15 and 10 mm from the disturbed surface. These veins inclined at an angle of 45 up from the deposition hole wall in sample LLl and down in sample LL3. In sample KK2 increased porosity was found to a depth of 10 mm and a few porous veins extended to a depth of 15 mm from the disturbed surface. Samples Yl and Wl were 35 mm thick and samples Y2 and W2 were 51 mm thick. The results of these samples were similar for all but of sample Wl. In sample Wl, the porosity at the crushed zone was greater than that in samples Yl, Y2 and W2. The porosity of undisturbed rock matrix was 0.1% in all these samples. A pronounced increase in porosity was observed to depths of 5 to 7 mm froin the disturbed surface. The porous veins studied qualitatively from the autoradiographs extended to depths of 20 and 25 mm from the disturbed surface. The veins were perpendicular to the deposition hole wall in samples Wl and Yl, and inclined at an angle of 45 down from the deposition hole wall in samples W2 and Y2. Microfissures parallel to the wall were 30

40 found in all these samples. These fissures extended to depths of 1 to 3 mm from the disturbed surface ~ ~ ~ 0.2 a FVfl ~ ~----~------~----~ distance (mm} Figure 23. The porosity profiles of samples Y1 and Y2 from deposition hole ~ 0.4 ~ u; a. 0.2 FWfl ~ distance {mm} Figure 24. The porosity profiles of samples W1 and W2 from deposition hole Group 8 The partition diagrams and the autoradiographs of samples AA1, BB2, CC1 and DD2 from deposition hole 2 are presented in Appendix 8. The partition diagrams and the autoradiographs of samples N2, N3, P2, P3, R2 and R3 from deposition hole 3 are 31

41 presented in Appendix 9. The porosity profiles of samples AA1 and BB2 are presented in Figure 25. The porosity profiles of samples CC1 and DD2 are presented in Figure 26. The porosity profiles of samples N2 and N3 are presented in Figure 27. The porosity profile of sample P2 and P3 are presented in Figure 28. The porosity profiles of samples R2 and R3 are presented in Figure '#. ; 0.4 c;; 0 ' Q. 0.2 FAA1l ~ distance (mm) Figure 25. The porosity profiles of samples AA1 and BB2 from deposition hole 2. The porosity of the undisturbed matrix in samples AA1 and BB2 was 0.2%. The rock type was gneissic tonalite. A few microfissures were observed in sample AA1; these microfissures were parallel to the wall and occurred at depths of 1 to 5 mm from the disturbed surface. An increased porosity was measured to a depth of 20 mm from the disturbed surface. Qualitative inspection revealed a pronounced increase in porosity up to depths 15 to 20 mm from the disturbed surface. A few porous veins were observed parallel to the disturbed surface, to a depth of 10 mm from the disturbed surface. The increased porosity in sample BB2 extended to a depth of 13 mm from the disturbed surface. The crushed porosity zone extended to a depth of 3 mm from the wall. The porosity measured was twice as high as the porosity of the undisturbed matrix. A few porous veins trending perpendicular to the wall were observed in sample BB2. In samples CC1 and DD2 the porosity of undisturbed matrix was 0.2%. The crushed porosity zone extended to depths of 1 to 2 mm from the disturbed surface. A few 32

42 microfissures parallel to the wall were found in both samples. A pronounced increase in porosity was observed to a depth of 1Z mm from the disturbed surface in the sample CC1, and to a depth of 16 mm from the disturbed surface in the sample DDZ ~ i' O r ~----~ ~~---r--~ distance (mm) Figure Z6. The porosity profiles of samples CC1 and DDZ from deposition hole Z. Samples N3, R3 and P3 were homogeneous tonalite and NZ, PZ and RZ were gneissic tonalite cored from deposition hole 3. In sample N3 the porosity of the undisturbed matrix was 0.1 %. It was 0.15% in samples NZ and R3 and O.Z% in sample RZ. In samples PZ and P3 the porosity of undisturbed matrix was 0.05%. The crushed porosity zone extended to a depth of 3 mm from the wall in sample NZ, but only to a depth of 1 mm from the disturbed surface in sample N3. The pronounced increase in porosity extended to a depth of 15 mm in sample NZ and to a depth of 18 mm from the disturbed surface in sample N3. Visual inspection of autoradiographs revealed a few microfissures parallel to the wall in sample NZ; these microfissures caused the increased porosity in the zone 0 to 5 mm from the disturbed surface. 33

43 ~ f '- 0 c. 0.2 FN2l ~ distance (mm) Figure 27. The porosity profiles of samples N2 and N3 from deposition hole 3. Sample P2 was 50 mm thick and P3 46 mm thick. In sample P2 the crushed porosity zone extended to a depth of 1 mm. A few microfissures parallel to the wall were observed to a depth of 3 mm from the disturbed surface. A pronounced increase in porosity extended to a depth of 20 mm in sample P2 and to a depth of 15 mm in sample P3. Grain boundary porosity was found in sample P2, but not in sample P3. The porous zone was homogeneous, having small porous spots in the autoradiograph of sample P ~ 0.25 ~ u; '- & ~ ~ distance (mm) Figure 29. The porosity profiles samples P2 and P3 from deposition hole 3. 34

44 Sample R2 was 49 mm thick. A crushed porosity zone was observed in sample R2. Microfissures parallel to the disturbed surface extended to a depth of 3 mm from the wall. As measured from the porosity profile a pronounced effect of disturbance was observed to a depth of S mm from the disturbed surface; this was verified by visual inspection. A few porous trace lines were found trending perpendicular to the wall and extending to a depth of 15 mm from the disturbed surface. Sample R3 was 33 mm thick. Grain boundary porosity was not found in sample R3, nor were there porous veins perpendicular to the wall. One possible reason for this is the fine-grained mineral texture of sample R3. A crushed porosity zone was found to a depth of 1 mm from the disturbed surface. A pronounced increase in porosity extended to a depth of 10 mm from the wall ~ 0.4 ~ "iii e a. r=+=r3l ~ distance (mm) Figure 30. The porosity profiles of samples R3 and R2 from deposition hole Group 11 The partition diagrams and the autoradiographs of samples C6 and CS from deposition hole 3 are presented in Appendix 10. The porosity profiles of samples C6 and CS are presented in Figure 31. The autoradiographs of sample C6 showed anomalious dark 35

45 zones. Despite that the quantitative analyses were performed and the result shall be verified later by repeating the test ~ u; l: &. 0.2 FC8l ~ distance (mm) Figure 31. The porosity profiles of samples C6 and C8 from deposition hole 3. Sample C6 was 55 mm thick and sample C8 was 50 mm thick. The porosities of the undisturbed rock matrix was 0.1% in samples C6 and C8. An increased porosity was observed to a depth of 22 mm from the disturbed surface in sample C6 and to a depth of 18 mm from the wall surface in sample C8. A few microfissures existed parallel to the disturbed surface; in both samples they extended to a depth of 2 mm from the surface. A few porous veins inclined at an angle of 45 down from the deposition hole wall and extended to a depth of 20 mm from the disturbed surface in sample C6. In sample C8, some microfissures were observed parallel to the disturbed surface extending to a depth of 3 mm, but porous veins were not observed. 36

46 6 RESULTS OF SCANNING ELECTRON MICROSCOPY 6.1 Structure of homogeneous tonalite Intact matrix Sample L4.1/B was sawn following autoradiography according to the partition scheme illustrated in Appendix 4, to obtain an SEM sample. The sample was 43 mm long and 20 mm wide. The SEM sample included the intact rock matrix as well as the matrix nearest to the disturbed surface. The grain size of the mineral crystals in homogeneous tonalite was 0.5 to 2.0 mm. The autoradiograph of surface L4.1/B/SEM is shown in Figure 32. The structure of the intact homogeneous tonalite sample was analysed at depths of 35 to 40 mm from the disturbed surface. The corresponding backscattered electron (BSE) images, performed using 500-fold magnification, are presented in Figures 33, 34 and 35. Quartz, plagioclase and biotite mineral grains were analysed in more detail. Figure 32. Autoradiograph of SEM sample L4.1/B. Sample width is 43 mm. 37

47 Figure 33. BSE image of sample L4.1/B at a depth of 35 mm from disturbed surface. Quartz grain. Magnification 500x Figure 34. BSE image of sample L4.1/B at a depth of 38 mm from disturbed surface. Plagioclase grain. Magnification 500x. A few intragranular fissures and pores were observed in plagioclase grains, in sample L4 at a depth of 38 mm from the disturbed surface. The apertures of intragranular fissures were smaller than the fissures observed in quartz grains. Grain boundaries were not visible when employing 500-fold magnifications. Biotite lamellaes were not open at depths of 35 to 40 mm, but a few fissures cutting biotite grains parallel to the orientation 38

48 of lamellae structure were observed. In summary, some intrafissures were detected in all minerals, although the grain boundaries were not fractured. Figure 35. BSE image of sample L4.1/B at a depth of 35 mm from disturbed surface. Biotite grain. Magnification 500x Disturbed zone The minerals quartz, plagioclase and biotite were studied at depths of 1 to 5 mm from the disturbed surface, and the results were compared to those for the corresponding minerals in the intact zone. A very many intragranular and transgranular fissures were observed at depths of 1 to 2 mm from the disturbed surface in all mineral grains (Figure x). Fissures having apertures of 10 to 20 ~m were observed mainly in plagioclase grains. A few fissures having apertures about 1 ~m were detected in quartz grains. A quartz grain at a depth of 2 mm from the disturbed surface is shown in Figure 37, where intragranular fissuration is increased compared to that in the intact zone. Magnifications of 500x were used, and the range of the pore apertures, in micrometers, could be seen easily. 39

49 Figure 36. BSE image of sample L4.1/B at a depth of 1 mm from disturbed surface. Magnification 1 OOx. Figure 37. BSE image of sample L4.1/B at a depth of 1 mm from disturbed surface. A quartz grain. Magnification 200x. The grain boundaries were opened at depths from 0 to 2 mm between mineral grains. A fractured grain boundary between quartz and biotite grain is clearly seen in Figure 38. In biotite grains, lamellaes were not clearly opened, but intergranular porosity between quartz and biotite grains was increased and a few intragranular fractures transsecting 40

50 biotite grains were detected. Intragranular microfissures were found in plagioclase grains at a depth of 3 mm from the disturbed surface (Figure 39). Figure 38. BSE image of sample L4.1/B at a depth of 1 mm from disturbed surface. Biotite grain. Magnification SOOx. Figure 39. BSE image of sample L4.1/B at a depth of 3 mm from disturbed surface. Plagioclase grain. Magnification SOOx. The three minerals, namely quartz, plagioclase and biotite, were also studied at a depth of 5 mm from the disturbed zone. The grain boundaries of mineral crystals were opened, 41

51 and apertures of grain boundaries of several micrometers wide were observed in all minerals. Quartz grains were fractured and intracrystalline fissuration was increased. The apertures of fissures were found to be in the range of a few micrometers. 6.2 Structure of granite pegmatite Intact matrix The sample L6.1/B was sawn following autoradiography, according to the partition scheme illustrated in Appendix 3, to obtain an SEM sample. The sample was 40 mm long and 25 mm wide. The SEM sample included the intact rock matrix as well as the matrix nearest to the disturbed surface. The autoradiograph of surface L6.1/B/SEM is shown in Figure 40. Figure 40. Autoradiograph of SEM sample L4.1/B. Sample width is 40 mm. The grain size of granite pegmatite varied from 2 to 10 mm. The main minerals were quartz, plagioclase and potassium feldspar. The structure of the intact granite pegmatite was analysed at a depth of 35 mm from the disturbed surface; the corresponding backscattered electron (BSE) images are presented in Figures 41 and 42. The magnifications employed were 200-fold and 500-fold, and the images shown are for plagioclase and quartz minerals. 42

52 Figure 41. BSE image of sample L6.1/B at a depth of 35 mm from disturbed surface. Quartz and plagioclase grains. Magnification 200x Grain boundary porosity was dominant in this rock type, as had been also observed in the autoradiographs. The intact rock could not be distinguished from the disturbed zone. The grainboundaries between different minerals could already be detected SEM with 50-fold to loo-fold magnifications at depths of 20 to 35 mm from the disturbed surface. A few quartz grains were fractured at the depth of 25 mm from the disturbed surface; see Figure 43. A few intracrystalline fissures were observed in both quartz and plagioclase mineral grains. At a depth of 30 mm from the disturbed surface, grain boundary fractures were usually observed between the mineral grains, not inside the grains. Figure 42. BSE image of sample L6.1/B at a depth of 35 mm from disturbed surface. Plagioclase grain. Magnification SOOx. 43

53 Figure 43. BSE image of sample L6.1/B at a depth of 35 mm from disturbed surface. Quartz grain. Magnification 50x Disturbed zone The autoradiograph of the surface L6.1/B revealed a clear increase in intragranular porosity adjacent to the disturbed surface. The minerals studied- quartz, plagioclase and potassium feldspar - were analysed at depths of 1 to 8 mm from the disturbed surface. Very many intracrystalline fissures were observed at a depth of 0 to 2 mm from the disturbed surface. Fissures having apertures of about 10 ~m were observed mainly in plagioclase and potassium feldspar grains (Figures 44 and 45). The mineral grains were observed to be crushed to a depth of 0.5 mm from the wall surface. The fractures were transsecting the plagioclase grains. 44

54 Figure 44. BSE image of sample L6.1/B at a depth of 1 mm from disturbed surface. Plagioclase and potassium feldspar grains. Magnification 1 OOx. Fgure 45. BSE image of sample L6.1/B at a depth of 0.5 mm from disturbed surface. Plagioclase and quartz grains. Magnification 1 OOx. The mineral grains were fractured close to the disturbed zone, to a depth of 2 mm. Frequent intrafissures were observed transsecting plagioclase and potassium feldspar grains at depths of 2 to about 10 mm from the disturbed surface. The fractured albite grain at a depth of 5 mm from the disturbed surface is shown in Figure 46. Compared to 45

55 depths of 20 to 30 mm from the disturbed surface an increase in intrafissuration of mineral grains was observed. Figure 46. BSE image of sample L6.1/B at a depth of 5 mm from disturbed surface. Albite grain. Magnification SOOx. 6.3 Structure of gneissic tonalite Intact matrix Sample Ll.l/B was sawn following autoradiography, according to the partition scheme illustrated in Appendix 4, to obtain an SEM sample representing group 5. The sample was 40 mm long and 19 mm wide. The autoradiograph of surface Ll.l/B/SEM is shown in Figure 47. A microfissure was observed in the autoradiograph of the SEM perpendicular to the disturbed surface; it had an aperture of several micrometers. The fissure ran through the sample in a plane. The SEM sample included the intact rock matrix as well as the matrix nearest to the disturbed surface. The BSE images of the intact gneissic tonalite sample Ll are presented in Figures 48, 49 and 50. The magnification employed was 500-fold, and the images show quartz, plagioclase, biotite and apatite minerals at depths of 30 and 32 mm from the disturbed surface. 46

56 Figure 47. Autoradiograph of SEM sample L4.1/B. Sample width is 40 mm. No intragranular fissures were visible in the quartz grains. A few intragranular fissures were observed transsecting the plagioclase grains. The grain boundaries were not visible between quartz and plagioclase grains when magnifications of 500 to 1000-fold were used. Figure 48. BSE image of sample L6.1/B at a depth of 30 mm from disturbed surface.. Quartz and plagioclase grains. Magnification SOOx. 47

57 Figure 49. BSE image of sample L6.1/B at a depth of 30 mm from disturbed surface. Biotite grain. Magnification SOOx. The lamellaes of biotite grains were not open, but a few intrafissures perpendicular to the direction of the lamellaes were detected. Fissures transsecting all the main minerals were not found at depths of 30 to 32 mm from the disturbed surface. The BSE image of apatite grain is presented in Figure 49. The image is at a depth of 32 mm from the disturbed surface. The grain is surrounded by biotite. Magnification of 500-fold does not reveal any fissuration of the apatite grain. Figure 50. BSE image of sample L6.1/B at a depth of 30 mm from disturbed surface. Apatite grain. Magnification SOOx. 48

58 6.3.2 Disturbed zone An increased porosity zone was observed to a depth of 12 mm from the disturbed surface. Frequent fractures were observed to a depth of 2 mm from and parallel to the wall surface as seen in the BSE image at a depth of 0.5 mm shown in Figure 51. the magnification employed was 200-fold and the image shows plagioclase, quartz, biotite and apatite grains. Figure 51. BSE image of sample L1.1/B at a depth of 0.5 mm from disturbed surface. Plagioclase, quartz and biotite grains. Magnification 200x. Intrafissures having apertures of several micrometers were observed transsecting plagioclase, biotite and quartz grains. The grain boundaries between the minerals were opened, having apertures of a few micrometers. A fractured biotite grain is illustrated in Figure 52. The image is at a depth of 2 mm from the wall surface and the magnification is 1000-fold. The lamellae structure of biotite was not observed to be opened. A few horizontal fractures were observed at depths of about 1 to 3 mm from the disturbed surface; these fractures transsected all three mineral grains examined (Figure 53). 49

59 Figure 52. BSE image of sample Ll.1/B at a depth of 2 mm from disturbed surface. Biotite grain. Magnification 1 OOOx. Figure 53. BSE image of sample Ll.1/B at a depth of 2 mm from disturbed surface. Biotite, plagioclase and quartz grains. Magnification 1 OOx. A few apatite grains were observed; these were fractured at depths of 1 to 2 mm from the disturbed surface (Figure 54). Various intrafissures transsecting the grains were observed, and there was a clear difference compared to the apatite grains in the intact rock zone. The apertures of fractures in apatite grains were about 10 f.!m or less. 50

60 Figure 54. BSE image of sample Ll.l/B at a depth of 1 mm from disturbed surface. Apatite grain. Magnification 500x. 7 CONCLUSIONS AND DISCUSSION The zone caused by rotary crushing was studied in laboratory with 14 C-PMMA method using samples taken from the full-scale deposition holes. Undisturbed and disturbed rock matrix of gneissic tonalite, homogeneous tonalite and pegmatite samples was studied and differences in porosity profiles were recorded with the 14 C-PMMA method. The porosities of the undisturbed rock matrix ranged from 0.1 to 0.2%. In all rock types studied, a clear increase in porosities was observed at depths of 0 to 10 mm from the disturbed surface. In all rock types, several intragranular fractures were observed at depths of 0 to 2 mm from the disturbed surface. Fractures also existed parallel to the wall surface, and the apertures ranged from a few to several micrometers. Electron microscopic studies revealed intrafractures transsecting quartz and feldspar mineral grains the crushed zone. 51

61 According to the result grain boundary porosity dominates in pegmatite samples. The pore apertures detected were several micrometers in size and the spatial porosity distribution was heterogeneous. The requirement for total porosity measurement, which relies on the facts that the pore apertures are far below the range of beta particle having 150 kev energy and that the tracer is homogeneously diluted into the rock pores, was therefore not fulfilled. The porosity values measured, although, on a typical range for pegmatite, cannot be taken for granted and more or less illustrate the difference in the disturbed texture and extent of disturbed zone. The autoradiographs of samples LL1 and KK2 showed anomalious dark zones at depths of S-1 0 mm from the disturbed surface. The feature has great significance if caused by the boring and therefore it shall be studied in more detail to exclude the possible artefacts. The result shall be verified by grinding the surface and making a new autoradiograph to ensure that the result is not a contamination of rock surfaces as a result of inproper cooling during sawing of the rock surfaces for autoradiography. REFERENCES 1. Autio, J., Kirkkomaki, T Boring of full scale deposition holes using a novel dry blind boring method, POSIVA SKB 2. Hautojarvi, A., Vieno, T., Autio, J., Johansson, E., Ohberg, A.& Salo, J.-P Characterization and tracer tests in the full-scale deposition holes in the TVO Research Tunnel. Geoval' 94, Paris, October Autio,J. & Salo, J.-P Boring of the full-scale deposition holes in the TVOresearch tunnel. In. Backblom, G. (ed.), Aspo Hard Rock Laboratory International Workshop on the Use of Tunnel Boring Machines for Deep repositories, Aspo, June 13-14, Stockholm, Swedish Nuclear Fuel and Waste management Co (SKB), International Cooperation Report Autio, J., Aikas, K. and Kirkkomaki, T Coring and Description of Samples from the Full Scale Erperimental Deposition Holes at TVO/Research Tunnel, Nuclear Waste Commission of Finnish Power Companies, Work Report Teka SKB 52

62 5. Hautojarvi, A., Ilvonen, M., Vieno, T., Viitanen, P Hydraulic and Tracer Experiments in the TVO Research Tunnel Helsinki, Nuclear Waste Commission of Finnish Power Companies, Report YJT Siitari-Kauppi, M Investigation of Porosity and Microfracturing in a Disturbed Zone with the 14 CPMMA Method Based on Samples from Full-Scale Experimental Deposition Holes of the TVO Research Tunnel, Nuclear Waste Commission of Finnish Power Companies, Report YJT & Arbets Rapport AR D Hellmuth, K.H., Siitari-Kauppi, M. and Lindberg, A Study of Porosity and Migration Pathways in Crystalline Rock by Impregnation with 14 C polymethylmethacrylate. Journal of Contaminant Hydrology, 13: Hellmuth, K.H., Lukkarinen, S. and Siitari-Kauppi, M Rock Matrix Studies with Carbon-14-Pol ymethy lmethacry late (PMMA); Method Development and Applications. Isotopenpraxis Environ. Health Stud., 30: Siitari-Kauppi, M., Lukkarinen, S. and Lindberg, A Study of Rock Porosity by Impregnation with Carbon-14-Methylmethacrylate, Nuclear Waste Commission of Finnish Power Companies, Report YJT Rasilainen, K., Hellmuth, K-H., Kivekas, L., Melamed, A., Ruskeeniemi, T., Siitari Kauppi, M., Timonen, J. & Valkiainen, M An Interlaboratory Comparison of Methods for Measuring Rock Matrix Porosity. Espoo: VTT Energy, VTTRN Autio, J., Characterization of the excavation disturbance caused by boring of the experimental full scale deposition holes in the Research Tunnel at Olkiluoto. Report Posiva-96-09, Posiva Oy, Helsinki and similar report in SKB 's (Svensk Karnbranslehantering AB) report series 12. Autio, J., Aikas, K. and Kirkkomaki, T Coring and description of the samples from the full scale experimental deposition holes and from the walls of the research tunnel at Olkiluoto, Work Report TEKA-96-0Se. SKB 13. Daniels, F. and Alberty, R. A Physical Chemistry, Third Edition, John Wiley & Sons, Inc. New York, p 384 (767). 14. Leonard, E. C Vinyl and Diene Monomers, Part 1, A series of Monographs on the Chemistry, Physics, and Technology of High Polymeric Substances, Vol. XXIV, p

63 APPENDICES Appendix 1. Partition diagrams of samples B 10 and B 11 from deposition hole 2 and D3 and DlO from deposition hole 3. Group 2. la. Autoradiographs of rock surfaces BlO.l/A and BlO.l/B lb. Autoradiographs of rock surfaces B 11.1/ A and B 11.1/B lc. Autoradiographs of rock surfaces D3.1/A and D3.1/B ld. Autoradiographs of rock surfaces DlO.l/A and DlO.l/B Appendix 2. Partition diagrams of samples B 1 from deposition hole 2 and D9 from deposition hole 3. Group 3. 2A. Autoradiographs of rock surfaces Bl.l/A and Bl.l/B 2B. Autoradiographs of rock surfaces D9.1/A and D9.1/B Appendix 3. Partition diagrams of samples LS and L6 from deposition hole 3. Group 4. 3A. Autoradiographs of rock surfaces LS.l/B and LS.l/A I 3B. Autoradiographs of rock surfaces L6.1/B and L6.1/ A I Appendix 4. Partition diagrams of samples L3 and L4 from deposition hole 3. Group 5. 4A. Autoradiographs of rock surfaces L3.1/B and L3.1/A I 4B. Autoradiographs of rock surfaces L4.1/B and L4.1/A I Appendix 5. Partition diagrams of samples Ll and L8 from deposition hole 3. Group 6. SA. Autoradiographs of rock surfaces Ll.l/A and Ll.l/B SB. Autoradiographs of rock surfaces L8.1/ A and L8.1/B Appendix 6. Partition diagrams of samples KK2, LLl and LL3 from deposition hole 2. Group 7. 6A. Autoradiographs of rock surfaces KK2.1/A and KK2.1/B 6B. Autoradiographs of rock surfaces LLLl/A, LLl.l/B, LL3.1/A and LL3.1/B 54

64 Appendix 7. Partition diagrams of samples Wl,W2,Yl and Y2 from deposition hole 3. Group 7. 7 A. Autoradiographs of rock surfaces Wl.l/ A, Wl.l/B, W2.1/ A andw2.1/b 7B. Autoradiographs of rock surfaces Yl.l/A, Yl.l/B, Y2.1/A and Y2.1/B Appendix 8. Partition diagrams of samples AAl, BB2, CCl and DD2 from deposition hole 2. Group 8. 8A. Autoradiographs of rock surfaces AAl.l/A, AAl.l/B, BB2.1/A and BB2.1/B 8B. Autoradiographs of rock surfaces CCl.l/A, CCl.l/B, DD2.1/A and DD2.1/B Appendix 9. Partition diagrams of samples N2,N2,P2,P3,R2 and R3 from deposition hole 3. Group 8. 9A. Autoradiographs of rock surfaces N2.1/A, N2.1/B, N3.1/A and N3.1/B 9B. Autoradiographs of rock surfaces P2.1/A, P2.1/B, P3.1/A and P3.1/B 9C. Autoradiographs of rock surfaces R2.1/A, R2.1/B, R3.1/A and R3.1/B Appendix 10. Partition diagrams of samples C6 and C8 from deposition hole3. Group 11. loa. Autoradiographs of rock surfaces C6.1/A, C6.1/B C8.1/A and C8.1/B 55

65 APPENDIX 1 Group 2 INSIN66RITOIMISTO J"'\ SAANIO & RIEKKOLA ov..1 EO (]) 42 mm 8/0.1 ED CD 45 mm /8 /~ DJ\ lv 810.7/ A G 811.1/8 [TI a, ~, / I ~ 811.1/A [] ID_ /8 11/SEM+ / ~ THIN SLICE [] ~ i i 27mm INSIN66RITOIMISTO J"'\ SAANIO & RIEKKOLA ov..1 ED (]) 40 mm 03.1 EO (]) 40 mm 0/ /8 / ~ / ~ [] 03.//:10.1/ 8 UTI / A

66 APPENDIX la Group 2 Autoradiographs of rock surfaces BlO.l/A and BlO.l/B. Sample width is 98 mm.

67 APPENDIX lb Group 2 Autoradiographs of rock surfaces Bll.l/A and Bll.l/B. Sample width is 98 mm.

68 APPENDIX lc Group 2 Autoradiographs of rock surfaces D3.1/A and D3.1/B. Sample width is 98 mm.

69 APPENDIX ld Group 2 Autoradiographs of rock surfaces DlO.l/A and DlO.l/B. Sample width is 98 mm.

70 APPENDIX2 Group 3 INSINOORITOIMISTO ~ SAANIO & RIEKKOLA OY" mm /A INSINOCRITOIMISTO ~ SAANIO & RIEKKOLA ov mm 09.1/8 ED CB /\ m- / LSJ /A / ~ DJ 09.1/A/SEM+ THIN SLICE,, k 1 27 mm

71 APPENDIX2A Group 3 Autoradiographs of rock surfaces Bl.l/A and Bl.l/B. Sample width is 98 mm.

72 APPENDIX2B Group 3 Autoradiographs of rock surfaces Bl.l/A and Bl.l/B. Sample width is 98 mm.

73 APPENDIX3 Group 4 INSJN66RITOIMISTO ~ SAANIO & RIEKKOLA ov -I LS./3/ A 11 LS./2/ A 11 INSJN06RJTOIMISTO ~ SAANIO & RIEKKOLA ov -I ED 40 mm Cill 6.1 L6.1/ A I ~ []~6.1/A I []] l 6.1/B ~ c::d / LJJ..--- ~6.1/B/SEM+ THIN SLICE I / \3] CID 6.1/A 11 ~'' \ ~n1l ( 6) I> ~. ( r('jl/ 6.14/A If ~ 6.11/A 11 (4) (3) (2) L6.13/ A 11 L6.12/ A 11

74 APPENDIX3A Group 4 Autoradiographs of rock surfaces LS.l/B and LS.l/A I. Sample width of LS.l/B is 98 mm.

75 APPENDIX3B Group 4 Autoradiographs of rock surfaces L6.1/B and L6.1/A I. Sample width of L6.1/B is 98 mm.

76 APPENDIX4 Group 5 INSINOORITOIMISTO ""' SAANIO & RIEKKOLA ov...i 40 mm ED CU l3.1 []' 13.1/B / ~ I n 13.1/A / 13.1/B/SEM + []) THIN SLICE / Jl. ~----- o:ij 13.1/ A 11,)J1l ~ (6} / \ (I} l3.14/ A 11 {5} {4} {3} {2} l3.13/ A 11 l3. 12/ A 11 l3.11/ A 11 l3.1/a I INSINOORITOIMISTO SAANIO & RIEKKOLA ov...i ""' ED (]) mm /8 /,. LJ) --_ [D- L4.1/A r:==?l ~ ~ l4.1/a I \_\j / ~ D I E3J L4.1/B/SEM +,. THIN SLICE UID14.1/A 11 [J~\ -----~ {6} /. {1} 14.14/A 11 ~ 14.11/A 11 (4} (3} {2} l4.13/ A 11 l4.12/ A 11

77 APPENDIX4A Group 5 Autoradiographs of rock surfaces L3.1/B and L3.1/A I. Sample width of L3.1/B is 98 mm.

78 APPENDIX4B Group 5 Autoradiographs of rock surfaces L4.1/B and L4.1/A I. Sample width of L4.1/B is 98 mm.

79 APPENDIXS Group 6 INSINOORITOIMISTO...n SAANIO & RIEKKOLA ov mm ED W ll.1 ll.l/8 I CD--- ~ ~ ~~-~/sem + 1 THIN SLICE t:id u.j/a...n ED w LB./ INSINOORITOIMISTO SAANIO & RIEKKOLA ov-...1 LB.l/8 40 mm /~ LB. I/ A 0~ LB. I/ A/SEM + THIN SLICE [] /~ :--o \ ~

80 APPENDIX SA Group 6 Autoradiographs of rock surfaces Ll.l/A and Ll.l/B. Sample width is 98 mm.

81 APPENDIX SB Group 6 Autoradiographs of rock surfaces L8.1/A and L8.1/B. Sample width is 98 mm.

82 APPENDIX6 Group 7 INSIN06RITOIMISTO ""' SAANIO & RIEKKOLA ay...1 E1) (]) 51 mm KK2.1 ED (]) 44 mm lll.l / ~ KK2.1/B (IT! ll/.1/8 / KK2.1/A lll.l/a INSINOORITOIMISTO ""' SAANIO & RIEKKOLA ay...1 ED (]) 50 mm ll31 ll3.1/b ([]/ ~ D) LL3.//A

83 APPENDIX6A Group 7 Autoradiographs of rock surfaces KK2.1/A and KK2.1/B. Sample width is 98 mm.

84 APPENDIX6B Autoradiographs of rock surfaces LLl.l/A, LL2.1/B, LL3.1/A and LL3.1/B. Sample width is 98 mm.

85 APPENDIX 7 Group 7 Jll\ INSIN66RITOIMISTO SAANIO & RIEKKOLA oy -I ED m WI.I (0 l I' W/ mm (ill / ~ 35 mm Wl.ll ED W2.1 (])I I I I I I \ W2.1/8 49 mm W2.1/8 / ~ Wl.ll/8 Wl.ll/A INSIN66RITOIMISTO Jll\ SAANIO ED & RIEKKOLA oy m -I (0 Y/. / ~ Y/.1 11 mm 34 mm ~ I' 12 (ill Y/. 11 EO Y2.7 COl I I. I ([TI: I 51 mm Y2.1/A / ~ Yl.ll/8 Yl.ll/ A

86 APPENDIX 7A Group 7 Autoradiographs of rock surfaces Wll.l/A, Wll.l/B, W2.1/A and W2.1/B. Sample width is 98 mm.

87 APPENDIX 7B Group 7 Autoradiographs of rock surfaces Yll.l/A, Yll.l/B, Y2.1/A and Y2.1/B. Sample width is 98 mm.

88 APPENDIX8 Group 8...JII\ SAANIO & RIEKKOLA ov...1 EO l ~ 50 mm (] AA/./ INSIN66RITOIMISTO EO CB ~ I' 42 mm / ~.. AAT.l/8 AAl.l/A Il ( /8 / ~ ~ 882.1/A...JII\ INSIN66RITOIMISTO SAANIO & RIEKKOLA ov...1 EO (] CC/.1 51 mm EO CB I ~ 50 mm / ~ CCT.l/8 CCl.l/A (f7l/ ~ ~ 002.1/8 DD2.1/A

89 APPENDIX BA Group 8 Autoradiographs of rock surfaces AAl.l/A, AAl.l/B, BB2.1/A and BB2.1/B. Sample width is 98 mm.

90 APPENDIX BB Autoradiographs of rock surfaces CCl.l/A, CCl.l/B, DD2.1/A and DD2.1/B. Sample width is 98 mm.

91 APPENDIX9 Group 8 INSINOORITOIMISTO,n SAANIO & RIEKKOLA ov...1 ED 'I '1' 50 mm (] N2./ / ~ ED 50 mm (] N3.1 / ~ N2.1/8 INSINOORITOIMISTO,n SAANIO & RIEKKOLA ov...1 ED (] 50 mm P2.1 /~ P2.1/8 N2.1/A P2.1/A N3.1/ 8..n INSINOORITOIMISTO SAANIO & RIEKKOLA oy...i ED CD P mm /~ CJI P3J/ 8 P3.1/ A N3.1/A..n INSIN00RITOIMISTO SAANIO & RIEKKOLA ov...1 ED (] 49 mm R2.1 / ~ R2.1/8 R2.1/A 'I ED CD R3.1 1 / \ 13 mm 35 mm [) R3.12 (ill R3.ll / ~ """ R3.11/8 R3.11/A

92 APPENDIX9A Group 8 Autoradiographs of rock surfaces N2.1/A, N2.1/B, N3.1/A and N3.1/B. Sample width is 98mm.