Working
Report
2004-66
Geological Mapping of Investigation
Trench OL-TK7 at the Olkiluoto Study Site,
Eurajoki, SW Finland
Seppo
Paulamäki
March 2005
POSIVA
OY
FI-27160 OLKILUOTO, FINLAND
Tel
+358-2-8372 31
Fax +358-2-8372 3709
Working
Report
2004-66
Geological Mapping of Investigation
Trench OL-TK7 at the Olkiluoto Study Site,
Eurajoki, SW Finland
Seppo
Paulamäki
Geological Survey of Finland
March 2005
Base maps: ©National Land Survey, permission 41/MYY/05
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.
ABSTRACT
Geological mapping of investigation trench OL-TK7 was carried out by the Geological
Survey of Finland at the Olkiluoto study site, Eurajoki, southwestern Finland, as part of
the site investigations of Posiva Oy for the final disposal of spent nuclear fuel. The
trench, ca. 300 metres in length and 1 to 3 metres in width, is situated in the
southeastern part of the of the study site. The rock types were determined
macroscopically from the bedrock surface, which was first cleaned by pressurised air
and then washed by pressure washer. For the mapping purposes the trench was divided
to 30 sections.
The migmatitic mica gneisses in the trench can be divided to two main types: 1) vein
migmatites, in which the amount of granite leucosome veins vary from ca. 10% to over
40%. The mesosome is fine- to medium-grained, biotite-rich mica gneiss with a weak,
mm-scale quartz-feldspar segregation banding. 2) Mica gneiss migmatites, which are
mostly (>70%) composed of coarse-grained granite leucosome, occurring as 0.5-15 cm
wide, more or less linear veins. The melanocratic part of the migmatite usually occurs as
narrow, several millimetres wide, biotite-rich schlieren (melanosome) between the
leucosome veins. In places, fine- to medium-grained mica gneiss with no or less than
10% of granite leucosome veins occur. Grey, medium- to coarse-grained, gneiss with
granitic composition occurs in the eastern part of the trench. At the eastern end of the
trench, the unweathered mica gneiss is overlain by ca. 2 metres of intensely weathered
migmatitic mica gneiss.
The foliation and associated granite leucosome veins usually strike ca. NE-SW and dip
gently to the southeast, the dip direction/dip maximum being 147/43°. The degree of
foliation usually varies from weak to medium, the degree of foliation being weakest in
the homogeneous mica gneisses and grey gneisses. It is folded by three successive
folding phases gently plunging to the NE- ENE/ SW-SSW, SSE and SE.
During fracture mapping a total of 200 fractures, equal to or longer than one metre,
were investigated. Strike and dip, rock type, trace length, type of fracture trace, form
(straight or curved), type (tight, open or filled), width and infilling, where present, were
recorded for each fracture. Most of the fractures strike ca. N-S, NNE-SSW and NE-SW.
In determining the fracture density (fractures/m) fractures cutting the median line of the
investigation trench were measured, the mean fracture density being 0.57 fractures/m.
The mean fracture trace length of all recorded fractures is 1.9 m, 33% of the fractures
being visible in their full length. Most of the measured fractures are either open or tight.
The aperture of the open fractures is usually some millimetres, and only few exceed 1
cm. Fractures with mineral infilling are sparse.
Key words: Investigation trenches, rock types, ductile deformation, fracturing, nuclear waste disposal,
Olkiluoto
TIIVISTELMÄ
Tutkimuskaivanto, jonka pituus on noin 300 m ja leveys 1-3 m, sijaitsee kairanreiän
KR4 ja KR8 välisessä maastossa. Kartoitus tehtiin paineilmalla puhdistetulta ja
painepesurilla pestyltä kalliopinnalta. Kartoitusta varten kaivanto jaettiin 30
suoraviivaiseen tutkimuslinjaan. Tutkimuslinjojen alku-ja päätepisteet on paikannettu
Posiva Oy:n toimesta. Havaintojen paikat tutkimuslinjoilla on määritetty kullekin
linjalle pingotetun linjalangan avulla mittaamalla sen horisontaalinen etäisyys linjan
alkupäästä ja langan korkeus havaintopisteen yläpuolella. Linjalankojen päätepisteiden
sijainnin perusteella voidaan sitten laskea havainnon paikka x-y-z-koordinaatistossa.
Tutkimuskaivannon pääkivilajina on migmatiittinen kiillegneissi, joka jakaantuu
kahteen eri tyyppiin. Suonimigmatiitissa vanhempi osa, paleosomi, on kiillegneissiä ja
siinä esiintyy karkearakeista graniittia kiillegneissin liuskeisuuden suuntaisina suonina,
joiden osuus kivestä on noin 10-40%. Kiillegneissimigmatiitissa graniittisuonien osuus
vaihtelee 50%:sta yli 90%:iin ja paleosomi esiintyy yleensä vain kapeina
biotiittirikkaina soiroina graniittisuonien välissä. Siellä täällä esiintyy kapeita osueita
homogeenista tai vain alle 10% graniittisuonia sisältävää kiillegneissiä. Migmatiittisessa
kiillegneississä on sulkeumina linssimäisiä, kehärakenteisia sulkeumia, jotka ovat
todennäköisesti Ca-rikkaiden kerrosten jäänteitä. Graniittikoostumuksellista, keskikarkearakeista, suuntautumatonta tai heikosti suuntautunutta harmaata gneissiä esiintyy
kaivannon itäpuolella.
Tutkimuskaivannon migmatiittisen kiillegneissin hallitseva rakennepiirre on liuskeisuus
niiden suuntaiset graniittisuonet. Liuskeisuuden/raitaisuuden suuntaus on noin
koillinen-lounas kaateen ollessa kaakkoon (maksimikaadesuuntal/kaade 147/43°).
Poimuakselit kaatuvat loivasti koilliseen-itäkoilliseen/lounaaseen-etelälounaaseen,
eteläkaakkoon ja kaakkoon.
Rakokartoituksessa tehtiin havaintoja 200 raosta (rakopituus ∃1 m). Kustakin raosta
havainnoitiin raon kaade ja kaateen suunta, kivilaji, pituus, jatkuvuus, muoto, laatu,
leveys ja rakotäyte. Suurin osa mitatuita raoista on suunnassa n. N-S, NNE-SSW ja
NE-SW. Rakotiheyksien mittauksessa laskettiin tutkimuskaivannon ylle pingotetun
langan määrittämää keskilinjaa leikkaavat raot. Rakotiheys tutkimuskaivannon linjoilla
vaihtelee välillä 0 – 1.34 rakoa/m, keskimääräinen rakotiheys on 0.57 rakoa/m.
Keskimääräinen rakopituus on 1,9 m, 33% raoista ollessa koko pituudeltaan näkyvissä.
Raot ovat enimmäkseen joko avoimia tai tiiviitä. Avoimien rakojen avaumat ovat
yleensä muutaman millimetrin luokkaa ja vain harvat raot ovat yli 1 cm leveitä.
Avainsanat: Tutkimuskaivannot, kivilajit, duktiili deformaatio, rakoilu, ydinjätteiden loppusijoitus,
Olkiluoto
1
CONTENTS
ABSTRACT
TIIVISTELMÄ
1
INTRODUCTION......................................................................................... 3
2
RESULTS OF INVESTIGATIONS .............................................................. 7
2.1
Lithology............................................................................................... 7
2.2
Ductile deformation ............................................................................ 30
2.3
Fracturing........................................................................................... 36
2.3.1 Fracture orientations ......................................................................... 36
2.3.2 Fracture densities ............................................................................. 39
2.3.4 Fracture characteristics ..................................................................... 43
3
SUMMARY AND DISCUSSION - GENERAL CORRELATIONS WITH
NEIGHBOURING TRENCHES, BOREHOLES AND CURRENT
BEDROCK MODEL .................................................................................. 47
4
REFERENCES.......................................................................................... 51
APPENDICES .................................................................................................. 53
2
3
1
INTRODUCTION
Investigation trench OL-TK7 is located in the southern part of the study site, between
boreholes KR4 and KR8 (Fig. 1-1). The length of the trench is about 300 m and the
width is 1 to 3 m. For the mapping purposes the trenches were divided to 30 sections.
The X-, Y- and Z-coordinates of the starting and end points of each section were
determined by Prismarit Co., under contract to Posiva Oy. The topography of the
bedrock surface in the investigation trench is shown in Figures 1-2 and 1-3. The
topography rises slowly from the beginning of the trench (z = 3.69 m above sea level)
until section P7 (z = 9.34 m), after which it quite rapidly falls to z = 5.12 m in section
P11. After that the topography again starts to rise, reaching the highest value of 14.38 m
in section P26. After section P26 the bedrock surface rapidly drops more than 6 m to z =
8.26 m in section P29, after which it slowly starts to rise again.
The mapping was performed using the standard operating procedures and guidelines of
the Geological Survey of Finland (GTK) for the bedrock mapping (KPK3-O1). The
rock types were determined macroscopically from the bedrock surface, which was first
cleaned by pressurised air and then washed by pressure washer (Fig. 1-3). Tectonic
investigations included measurements of foliation, lineation, fold axis and axial planes.
During the fracture mapping all the fractures appearing in the trenches were
investigated. Dip direction and dip, rock type, length, form (straight or curved), type
(tight, open or filled), width and infilling, where present, were recorded for each
fracture. A total of 200 fractures were investigated from the trench. Orientations of
structural elements are displayed using Schmidt equal-area, lower hemisphere
stereographic projection. In addition, orientation data are also presented using rose
diagrams. The stereograms and rose diagrams were drawn using the Norwegian
STEREO®-software. In all contoured stereograms presented in the present report, the
contouring method is angle of hemisphere, where the angle of contouring station and
the data points is measured. The unit for contour lines is percentage, where the result
from the calculation (divides?) the percentage each value represents (100/N) and
contour lines are made for each percentage. The resolution is 100, which will make 100
x 100 = 10 000 points. All contoured lines are drawn. The 5°declination has not been
added to the diagrams.
The location of each observation was determined by using a straight thread, which was
extended and tightened over each 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 measured.
The measured fractures and other tectonic features are listed in Excel-tables in
Appendices 1 – 2. The files were delivered to the TUTKA database of Posiva and the
original hand-written observations to Posiva's archive. The investigation trench was
photographed (stereophotographs) by Juhani Ojala, GTK. The detailed photographs
were taken by Seppo Paulamäki. The photographs were stored on CDs and delivered to
Posiva's archive.
4
Figure 1-1. Location of the investigation trenches at Olkiluoto.
16.000
14.000
12.000
10.000
8.000
6.000
4.000
2.000
0.000
P-5
P-4
P-3
P-2
P-1
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
P24
P25
P26
P27
P28
P29
P30
P31
Z (m)
OL-TK7
Coordinate points
Figure 1-2. Topography of the bedrock surface along investigation trench OL-TK7
based on the measurements of the starting points of each mapping section.
5
Z (m a.s.l.)
Topography of OL-TK7
16
14
12
10
8
6
4
2
0
P22
P7
P26
P16
P29
P-1
P11
0
50
100
150
200
250
300
Trench length (m)
Figure 1-3. Topography of the bedrock surface in investigation trench OL-TK7 based
on location of investigated fractures. The length of the trench is 295.30 m.
A
B
Figure 1-3. A) Washing of investigation trench OL-TK7. B) Photo mosaic showing the
cleaned and washed bedrock surface in the central part of investigation trench OL-TK7.
East is to the left in Figure B. The length of the trench section is ca. 62 m. Photographs
by Seppo Paulamäki (A) and Juhani Ojala (B), Geological Survey of Finland.
6
Table 1-1. X-, Y- and Z-coordinates of the starting points of the mapping sections in
OL-TK7.
SECTION
P-5
P-4
P-3
P-2
P-1
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
P24
P25
P26
P27
P28
P29
P30
P31
X -COORDINATE
(M)
Y-COORDINATE Z -COORDINATE
(M)
(M)
6792088.105
6792084.975
6792079.569
6792071.300
6792068.016
6792058.225
1525863.030
1525866.328
1525871.800
1525880.049
1525883.428
1525893.382
3.686
4.098
3.906
4.821
5.309
6.499
6792051.556
6792047.316
6792035.792
6792032.634
6792025.728
6792017.695
6792005.902
6792001.587
6791998.096
6791994.444
6791991.582
6791989.177
6791987.200
6791983.738
6791979.859
6791975.916
6791970.508
6791968.154
6791965.676
6791962.826
6791957.824
6791951.254
6791946.295
6791941.869
6791941.164
6791937.814
6791935.606
6791926.283
6791925.864
6791923.069
1525899.638
1525903.474
1525914.717
1525917.794
1525925.606
1525933.795
1525945.412
1525949.681
1525955.606
1525963.321
1525967.213
1525970.771
1525974.743
1525982.997
1525988.679
1525997.151
1526008.179
1526012.648
1526016.793
1526022.533
1526033.879
1526044.860
1526054.605
1526064.747
1526066.641
1526073.060
1526078.637
1526092.150
1526097.369
1526102.664
7.561
8.011
8.880
9.057
9.202
9.339
8.887
7.414
6.153
5.120
8.463
9.240
9.453
9.568
9.420
9.590
11.436
12.201
12.844
13.447
14.202
14.102
13.756
14.345
14.379
13.162
11.702
8.262
8.598
9.235
7
2
RESULTS OF INVESTIGATIONS
2.1
Lithology
The main rock types in investigation trench TK7 are mica gneisses, migmatitic mica
gneisses, granitic grey gneisses and coarse-grained to pegmatitic granites. The
distribution of the rock types in the trench is described in Table 2-1 and presented on a
map in Appendix 4. The rock determined as mica gneisses in the trench are
homogeneous or contain less than 10 % migmatizing granite leucosome veins (Fig. 2.11A). The mica gneisses are mica-rich, fine- or medium-grained, weakly foliated and
sometimes contain garnet porphyroblasts, visible to the naked eye. In section P28,
medium- to almost coarse-grained, unfoliated mica gneiss with mostly potassium
feldspar porphyroblasts or aggregates of potassium feldspar (0.5-5 cm in diameter)
occur in abundance. The largest individual potassium feldspar grain is 3 cm in diameter.
Large, reddish potassium feldspar grains are unaltered. Instead, smaller (1.5 cm in
diameter) feldspar grains are strongly altered to a white or very faintly greenish, soft
mineral. The alteration does not occur throughout the rock but only as small patches. In
places, a rim of the same white, soft mineral also surrounds the large reddish potassium
feldspar grains. It can be seen in places, how one potassium feldspar grain is totally
altered, while the adjacent grain is unaltered.
In the mapping of the migmatitic gneisses the terminology introduced in the Olkiluoto
baseline report (Posiva 2003) and in the most recent bedrock model (Vaittinen et al.
2003) has been used. On the basis of the migmatite structure of the drill core samples,
the migmatitic mica gneisses at Olkiluoto have been divided to three groups: vein
migmatites, dyke migmatites and mica gneiss migmatites. The leucosomes of the vein
migmatites show vein-like, more or less linear traces with some features similar to
large-scale augen structures. Planar, sheet-like leucosome dykes characterise the dyke
migmatites, while the migmatite structure of mica gneiss migmatites is more
asymmetric and irregular. The amount of leucosome varies from less than 10% to over
80%, with a mean of 30 - 40 %. Because these three migmatite types represent the end
members in an alteration series of migmatite structures, the naming of the different
kinds of migmatites turned out to be often quite difficult. The migmatitic rocks named
veined gneisses in the earlier trench reports TK1 and TK2 (Paulamäki 1995, 1996) are
comparable to mica gneiss migmatites of the present nomenclature, while the
migmatitic mica gneisses are vein migmatites.
The descriptive terminology of the migmatites used here is adopted from Mengel et al.
(2001). The leucosome is the leucocratic, lighter-coloured portion of the migmatite with
plutonic appearance. The mesosome is the darker-coloured, mesocratic part of the
migmatite, with metamorphic appearance (in this case mica gneiss), while the
melanosome is the biotite-rich stripes (schlieren) or narrow bands in the migmatite (2.11). The migmatitic mica gneisses in the trench can be divided to two main types. In the
beginning of the trench (sections P-4 – P-1) and occasionally in sections between P12
and P16, vein migmatites occur, in which the amount of leucosome veins varies from
ca. 10% to over 40% (Fig. 2.1-1B). The mesosome is fine- to medium-grained, biotiterich mica gneiss with a weak, mm-scale quartz-feldspar segregation banding. In the
foliation surfaces of the mica gneiss mesosome, pyrite, in places, occurs rather
8
abundantly. Very narrow kaolinite veins occur here and there in the beginning of the
trench. The reddish or pale-coloured, coarse-grained granite leucosome occur as
asymmetric and irregular veins parallel to the foliation of the mesosome. The main
migmatite type, designated here as mica gneiss migmatite, is mostly (>70%) composed
of coarse-grained granite leucosome, occurring as 0.5-15 cm wide, more or less linear
veins. The melanocratic part of the migmatite usually occurs as narrow, several
millimetres wide, biotite-rich schlieren (melanosome) between the leucosome veins
(Figs. 2.1-1C and 2.1-1D). In places, narrow discontinuous bands of biotite-rich mica
gneiss mesosome occur. The granite veins show a pinch-and-swell structure. In section
P3, the migmatite is cut by 20-40 cm wide porphyritic granite with potassium feldspar
phenocrysts, 0.5-2 cm in diameter. The contact between the granite and migmatite is
diffuse and the leucosome veins of the mica gneiss migmatite are bending towards the
contact (Fig. 2.1-E).
Lensoid skarn inclusions occasionally occur within the migmatitic mica gneisses (Fig.
2.1-1E). The skarn proper in the centre of the inclusion is greenish, probably amphibole
bearing or brownish, in which case it is most likely pyroxene bearing. These are
regularly surrounded by a few centimetres wide rim of grey, quartz-feldspar-rich,
homogeneous mica gneiss. In Section P-2, there is a 50 x 25 cm skarn inclusion with
four rims. The outer rim consists of homogeneous mica gneiss, which is followed by a
greenish amphibole rim and a black biotite-rich rim. The centre of the inclusion consists
of potassium feldspar, which had not been encountered in the skarn inclusions before.
In sections P7 and P8, there is a quartz-feldspar-biotite rock, in which the feldspar
grains occur as porphyroblasts, 0.5-2.5 cm in diameter (in places 5 cm), surrounded by
biotite+quartz+feldspar (grain size 1-3 mm; Fig. 2.1-2A). In places, the rock is very
weakly foliated, otherwise the rock is unfoliated. The amount of feldspar grains can, in
places, be more than 70% of the total volume of the rock. Mica gneiss with abundant
potassium feldspar grains further occurs in sections P9 and P10, where it has turned
greenish in colour, probably due to alteration of the medium-grained feldspar grains to
mixture of epidote, chlorite, saussurite and sericite (Fig. 2.1-2B). These kinds of rocks
are named 'mica gneisses with K-feldspar porphyroblasts' in Appendix 4.
In sections P23-P27, medium- to coarse-grained, weakly oriented, homogeneous,
granitic grey gneiss (formerly granite gneisses, cf. Posiva (2003) occurs, which encloses
abundant migmatite fragments and a few small fragments of mica gneiss and skarn
(Figs. 2.1-2C and 2.1-2D). The grain size of the feldspars is 0.5-5 cm and they occur as
phenocrysts. Some of the grains are idiomorphic.
In Section P27, reddish or reddish grey, coarse-grained granite veins cut the mediumgrained granite. In places the coarse-grained granite brecciates the medium-grained
granite, giving rise to an agmatic structure (Fig. 2.1-2E). Both the medium-grained and
coarse-grained granites have, in places, abundant small cavities after some mineral,
which is totally eroded away. In sections P-5 and P-4, 35-40 cm wide pegmatite dykes
striking 330-335° cut the migmatitic mica gneisses. The dykes are very coarse-grained,
the grain size of potassium feldspar, quartz and biotite being several centimetres (Fig.
2.1-2F). In addition, pegmatite contains muscovite, calcite and greenish quartz. Also
quartz grains with brownish in colour (smoky quartz) occur.
9
Leucosome
Mesosome
A
B
Melanosome
Leucosome
C
D
E
F
Figure 2.1-1. A) Homogeneous, fine-grained mica gneiss. OL-TK7, section P-1. B) Vein
migmatite with alternating mica gneiss mesosome and veins of granite leucosome. OLTK7, section P-3. C) and D) Mica gneiss migmatite with abundant granite leucosome
and narrow biotite-rich melanosome schlieren. OL-TK7, sections P3 and P20. E)
Granite cutting the mica gneiss migmatite. OL-TK7, section P3, F) Lensoid skarn
inclusion within the mica gneiss migmatite. OL-TK7, section P5. The length of the plate
is 12 cm. Photographs by Seppo Paulamäki, Geological Survey of Finland.
10
A
B
C
D
E
F
Figure 2.1-2. A) Porphyroblastic (potassium feldspar) mica gneiss. OL-TK7, section
P7. B) Mica gneiss with unaltered (red) and altered (greenish) porphyroblasts. OLTK7, section P10. C) Granitic grey gneiss. OL-TK7, section P24. D) Granitic grey
gneiss with skarn and mica gneiss inclusions. OL-TK7, section P24. E) Reddish grey
medium-grained granite migmatized by coarse-grained granite. OL-TK7, section P27.
F) Vein migmatite cut by a pegmatite dyke. OL-TK7, section P-4. The length of the plate
is 12 cm. Photographs by Seppo Paulamäki, Geological Survey of Finland.
11
Regolith
In Sections P29 and P30, an about 2 m thick layer of strongly weathered vein migmatite
occurs directly on the unweathered mica gneiss (Fig. 2.1-3A). The degree of weathering
is so high that the rock can easily be crushed with a hammer or even with bare hands.
Those parts of the migmatite, which have fewer granite leucosome veins, are more
intensely weathered (Fig. 2.1-3B.). An almost completely weathered, ca. 1.5 m thick
part of the weathered part (regolith), which overlies the strongly weathered migmatite
has been excavated in the trench but it is still visible on the walls of the trench. The
lower, ca. 80 cm thick part of the regolith is composed of intensely weathered greenish,
clayey vein migmatite (Fig. 2.1-4A). In spite of very strong weathering, the structure of
the migmatite is still clearly observable. It is overlain by ca. 70 cm thick layer of
reddish granite or migmatite with abundant granite leucosome (Fig. 2.1-4A). The rock is
almost totally weathered to a small-grained gravel. The two layers are separated by ca.
15 cm thick layer of fine-grained sand, the lower 10 cm part being brownish grey and
the upper, slightly laminated, 5 cm part yellowish brown (Fig. 2.1-4B). The lower part
disappears towards the end of the trench, and the layer is mostly composed of yellowish
brown sand.
The regolith is overlain by a layer of sand, which, in turn, is overlain by a very dense
clayey till, which contains rounded rock fragments, 5 cm in diameter, and small, angular
rock chips (Fig. 2.1-4C).
A
B
Figure 2.1-3. A) Strongly weathered migmatite lying on the unweathered mica gneiss
(on the right). OL-TK7, sections P29 and P30. B) Detail picture of the weathered
migmatite in section P30. The length of the weathered section in A is ca. 8 m. The
length of the plate in B is 12 cm. Photographs by Juhani Ojala (A) and Seppo
Paulamäki (B), Geological Survey of Finland.
B
12
A
C
Figure 2.1-4. A) Layers of intensely weathered vein migmatite (lower) and granite
(upper) on the wall of trench section P30. B) Fine-grained sand separating the two
layers in A. C) Sand and fine-grained clayey till overlaying the weathered granite. OLTK7, section P29. The length of the plate is 12 cm. Photographs by Seppo Paulamäki,
Geological Survey of Finland.
B
Table 2.2-1. Description of rock types in investigation trench OL-TK7. MGN = mica gneiss, MGT = mica gneiss migmatite, VMGT = vein
migmatite, GGN = granitic grey gneiss, GRPG = granite pegmatite, GRGN = granite gneiss.
ROCK TYPE
VMGT
P-4
0-6.50
VMGT
6.50-6.95
GRPG
35 cm wide pegmatite dyke cutting the foliation and the leucosome veins in the direction
of 335°. The dyke is very coarse-grained with the grain size of potassium feldspar,
quartz and biotite being several centimetres. In addition, pegmatite contains muscovite
and calcite. Some of the quartz grains are greenish in colour.
6.95-7.70
MGN
0-11.68
VMGT
Homogeneous mica gneiss containing 0.1-0.3 cm wide pyrite veins and less than 0.1 cm
wide calcite and kaolinite veins.
Medium-grained, biotite-rich mica gneiss mesosome with a weak, mm-scale quartzfeldspar segregation banding. Two types of leucosome veins occur parallel to the weak
foliation of the mesosome: 1) coarse-grained, pale-coloured granite veins and 2) reddish,
coarse-grained granite veins. Pale-coloured, 2 cm wide veins are far more common than
the reddish veins. In spite of the colour difference, the veins seem to be coeval. The
colour difference is probably due to alteration of the feldspars. In addition to these veins,
5-15 cm wide granite pegmatite veins occur sparsely. The granite veins are in places
weakly boudined and isoclinally folded. In the foliation surfaces of the mica gneiss
P-3
DESCRIPTION
Vein migmatite with dark, fine- to medium-grained mica gneiss mesosome and reddish,
coarse-grained or medium-grained, pale-coloured granite leucosome as veins parallel to
the foliation of the mesosome. The amount of leucosome veins is ca. 50%. Until 2.2 m
the migmatite is strongly but chaotically folded. From 2.2 m on, the leucosome veins
occur rather linearly, although some tight to isoclinal, intrafolial folds occur. The mica
gneiss mesosome has, in places, a weak quartz-feldspar segregation banding. In the
beginning of the section there is a 40 cm wide pegmatite dyke in the direction of 330°.
Fine- to medium-grained, biotite-rich mica gneiss mesosome with a weak foliation and,
mm-scale quartz-feldspar segregation banding. The amount of coarse-grained, reddish
granite leucosome, occurring parallel to the foliation, is less than 20%.
13
SECTION POSITION (m)
P-5
0-4.55
mesosome, there is, in places, rather abundant pyrite. Here and there, throughout the
whole section, there are <0.1 cm wide kaolinite-filled fractures. In the beginning of the
section, calcite occurs in the foliation surface. In the NE part of the section, two skarn
inclusions occur with dimensions 30 x 16 cm and 85 x 25 cm. Both of the inclusion have
a greenish, most likely amphibole-bearing centre, surrounded by a grey, homogeneous
mica gneiss.
1.23-3.34
MGN
0-4.71
VMGT
P-1
0-2.05
VMGT
2.05-5.98
MGN
Fine- to medium-grained, biotite-rich, almost unfoliated, homogeneous mica gneiss, in
which no granite veins occur. In places, the biotite of the mica gneiss has altered to
chlorite.
14
P-2
Homogeneous mica gneiss, no granite leucosome veins. Because of the narrowness of
the trench, it cannot be said if it is an inclusion or not.
Medium-grained mica gneiss mesosome with two types of leucosome veins occurring
parallel to the weak foliation of the mesosome: 1) coarse-grained, 0.5-3 cm wide, palecoloured granite veins and 2) reddish, 5-15 cm granite pegmatite veins. The latter occur
only in the first metre of the section. Pale-coloured granite veins in places have a
greenish colour due to alteration of the feldspars. In spite of the colour difference, the
veins seem to be coeval, since the pale-coloured veins also contain reddish parts without
any contact. The colour difference is probably due to alteration of the feldspars. The
amount of leucosome is ca. 50%. At 2.30 m and 3.45 m, there are homogeneous mica
gneiss portions without any leucosome veins. At 1.70 m, abundant kaolinite occurs on
the foliation and fracture surfaces. At 1.20 m there is a 50 x 25 cm skarn inclusion with
four rims. The outer rim consists of homogeneous mica gneiss, which is followed by a
greenish amphibole rim and a black biotite-rich rim. The centre of the inclusions consists
of potassium feldspar.
Dark, fine- to medium-grained, biotite-rich mica gneiss mesosome with 1-4 cm wide,
pale-coloured, coarse-grained granite leucosome veins, constituting 20-30% of the total
volume of the rock. The leucosome veins are folded by a tight, chaotic folding.
MGN
Chloritized mica gneiss with small amount (ca. 10%) narrow, coarse-grained granite
leucosome veins parallel to the foliation.
8.00-10.42
GRPG, MGN
Section dominated by a granite pegmatite. In the beginning (until 9.80 m) the occurrence
of the granite pegmatite is rather chaotic, probably due to folding with a fold axis
plunging to the NE. The mica gneiss mesosome occurs as inclusions within the granite
pegmatite. After 9.80 m granite pegmatite leucosome occurs as 2-10 cm veins separated
by a mica gneiss mesosome. The veins are parallel to the foliation of the mesosome.
10.42-11.63
MGN
Fine-grained, slightly chloritized, clearly foliated, homogeneous mica gneiss.
11.63-12.47
VMGT
Migmatite with biotite-rich, fine- to medium-grained mica gneiss mesosome and coarsegrained granite leucosome, occurring as 1-5 cm wide veins parallel to the foliation of the
mica gneiss mesosome. The leucosome veins comprise ca. 40% of the total volume of
the rock.
12.47-14.02
GRPG
0-9.22
MGT
5-20 cm wide, reddish granite pegmatite veins separated by narrow, biotite-rich schlieren
(melanosome). The granite pegmatite veins are tightly folded, the fold axis gently
plunging to the NNE.
Migmatite, which is mostly (>90%) composed of coarse-grained granite leucosome. The
melanosome occurs as narrow, biotite-rich schlieren between the leucosome veins. Clear
veined structure with alternating bands of mica gneiss mesosome and granite leucosome
veins only occurs at end of the section. Here the granite veins are boudined or deformed
in to pinch-and swell structure. At 0.90 m 10-30 cm wide fine- to medium-grained,
homogeneous mica gneiss occur, which is isoclinally folded and re-folded by a more
open fold gently plunging to the ESE. Large-scale, open folding /wavelength ca. 2 m and
amplitude 0.5 m) occur at 7.80 m and 8.80 m, the fold axis gently plunging to the ENE
and NE, respectively.
15
P1
5.98-8.00
P2
P3
MGT
Migmatite, which is mostly (>90%) composed of coarse-grained granite leucosome. The
melanosome occurs as narrow, biotite-rich schlieren between the leucosome veins. The
granite veins show pinch-and-swell structure and isoclinal folding. At 0.5-1.5 m the
migmatite is slightly weathered and broken off along the melanosome schlierens. The
amount of leucosome increases after 2 m and the veining becomes more indistinct. At
the end of this section, there are two small inclusions of homogeneous mica gneiss in the
NE-part of the trench.
4.70-5.73
"GRGN"
0-16.13
MGT
"Granite gneiss", in which the feldspar usually occurs as porphyroblasts 0.3-1 cm in
diameter. In places grains with a diameter of 3-4 cm occur. The migmatitic veining can
be seen only vaguely. In places, mica gneiss occurs as small inclusions. In the SW-part
of the trench the "granite gneiss" seems to cut the mica gneiss migmatite.
Migmatite, which is mostly (>80%) composed of coarse-grained granite leucosome,
occurs as 0.5-15 cm wide leucosome veins. Between the veins there are narrow, biotiterich schlieren (melanosome) or narrow layers of mica gneiss (mesosome). The
leucosome veins are boudined or, more commonly, deformed to pinch-and swell
structure. In the beginning and at the end of the section (0-5.50 m and 15.50-16.13 m),
the amount of leucosome is >90% and the veining is rather unclear. After 5.50 m the
granitic veining is clear, although the amount of granite continues to be high (>80%).
The migmatite is slightly weathered. At 9.00 m in the NE-side of the trench there is a 1.5
x 1 m inclusion of grey, quartz-feldspar-rich, weakly segregated mica gneiss with
several brownish skarn inclusions. The mica gneiss with skarn inclusions is tightly to
isoclinally folded with possible weak axial plane foliation. These structural elements are
most likely remains of the deformation phases preceding the migmatite formation.
14.70
GR
The migmatite is cut by 20-40 cm wide porphyritic granite with potassium feldspar
phenocrysts, 0.5-2 cm in diameter. The strike of the granite is 120°. It may be associated
with a dextral, ductile faulting, since the granite leucosome veins are bending in the
diffuse contact of the granite. The granite does not continue through the trench but dies
out in the NW side of the trench ca. 80 cm from the central line.
16
0-4.70
P4
0-4.40
MGT
Migmatite, in which the amount of coarse-grained granite leucosome is ca. 90%. The
melanosome occurs as narrow (2-5 mm), biotite-rich schlieren between the leucosome
veins. At 0-3.50 m the granite leucosome veins are 2-10 cm wide but after 3.50 the width
of the veins is less than 1 cm. The granite veins show pinch-and-swell structure and are
in places clearly boudined, the rotated budins indicating dextral shearing conformable to
the foliation. At 3.20 m the migmatite is cut by 10 cm wide ductile, sinistral shear/fault
zone with an orientation 105/65°.
1.55
MGN
95 x 25 cm fine- to medium-grained, homogeneous mica gneiss inclusion.
3.70
P5
0-10.44
MGT
P6
MGT
80 x 6-16 cm skarn inclusion, which is surrounded by 7-8 cm wide rim of grey, finegrained, quartz-feldspar-rich, homogeneous mica gneiss.
Migmatite, in which the amount of coarse-grained granite leucosome is ≥ 90%. The
17
48 x 23 cm lensoid skarn inclusion, in which the probably amphibole-bearing centre is
surrounded by 1 cm wide brownish biotite rim. These are surrounded by 2-4 cm wide
rim of grey, quartz-feldspar-rich, homogeneous mica gneiss.
9.20
14.00
0-11.46
80 x 10 cm skarn inclusion, in which the 60 x 5 cm brownish (pyroxene-bearing?) skarn
proper is surrounded by grey, homogeneous mica gneiss.
Migmatite, in which the amount of coarse-grained granite leucosome is ca. 90%. The
melanocratic part of the migmatite usually occurs as narrow (2-5 mm), biotite-rich
schlieren (melanosome) between the leucosome veins. In places, however, narrow,
discontinuous bands of true mica gneiss mesosome occur, in which the mica gneiss is
grey-coloured, medium-grained and has a weak metamorphic quartz-feldspar banding.
The granite veins are clearly boudined or deformed to pinch-and-swell structure. At 6.10
m homogeneous, medium-grained, 4-40 cm wide mica gneiss band is isoclinally folded.
The mica gneiss has two garnet porphyroblasts 3-4 cm in diameter. Small portions of
"granite gneiss" with 0.2-1 cm feldspar phenocrysts occasionally occur, which clearly
cuts the migmatite. Within the "granite gneiss" there are narrow streaks of biotite.
P7
0-6.85
GRPG, MGT
6.85-13.90
"MGN"
Coarse-grained quartz-feldspar-biotite rock, in which the feldspar grains occur as
porphyroblasts, 1-2.5 cm in diameter (in places 5 cm), surrounded by
biotite+quartz+feldspar (grain size 1-3 mm) ("porphyroblastic mica gneiss"). In places
very weakly foliated, otherwise the rock is unfoliated.
13.90-16.58
"MGN"
As before but the grain size of feldspar becomes smaller (0.5-2 cm) and its amount
increases (>70%). The rock is slightly oriented but not foliated.
13.90-14.45
MGT
0-3.10
"MGN"
Portion of vein migmatite, most of which is located in the NNE-part of the trench. The
amount of medium- to coarse-grained granite leucosome is ca. 90%.
Biotite-rich, medium-grained mica gneiss with abundant potassium feldspar
porphyroblasts, 0.5-3 cm in diameter. In places, very vague granite leucosome veining.
The obscurity of the migmatitic structure may be due to the fact that only one gently
dipping foliation surface is visible.
3.10-6.07
MGN
Weakly chloritized, fine- to medium-grained mica gneiss, which, in places, contains
18
P8
leucosome occur as narrow veins, which show pinch-and-swell structure and are
isoclinally folded. The melanocratic part of the migmatite usually occurs as narrow,
biotite-rich schlieren (melanosome) between the leucosome veins. In places, narrow,
discontinuous bands of mica gneiss mesosome occur, in which the mica gneiss is fine- to
medium-grained, biotite-rich and has garnet porphyroblasts 0.5-1 cm in diameter.
Another type of mesosome is medium-grained and quartz-feldspar-rich. Exceptionally
wide (30 cm) granite leucosome vein with pinch-and-swell structure occur at 11.16 m.
Mixture of granite pegmatite and mica gneiss migmatite, The amount of granite
leucosome is >90%. Narrow, biotite-rich schlieren (melanosome) between the
leucosome veins. Skarn inclusions at 2.30 m and 3.90 m (40 x 15 cm). Potassium
feldspar grains or aggregates, 5 cm in diameter, around the mica gneiss inclusion at 3.84.2 m. 20 cm wide fine-grained mica gneiss inclusion at 5.50 m.
P9
0-4.10
MGT
4.10-6.00
MGT
The mesosome and part of the leucosome of the mica gneiss migmatite has turned
greenish in colour, probably due to alteration of the medium-grained feldspar grains to a
mixture of epidote, chlorite, saussurite and sericite. Most of the leucosome is unaltered.
The rock is homogeneous, unfoliated and is almost lacking in fractures.
6.00-7.00
MGN
0-7.70
MGN
Blackish or greenish, granoblastic, medium-grained, biotite-rich (70-80%) mica gneiss
with potassium feldspar porphyroblasts and occasional granite leucosome veins.
Compared to the previous section, the alteration decreases, smaller feldspar grains being
more altered than the larger reddish grains. Homogeneous, no clear foliation occurs.
Pale-coloured feldspar grains are more altered than the reddish feldspar grains.
The same rock as in the previous section. The alteration of the rock decreases towards
the end of the section.
7.70-8.53
MGN
The same kind of mica gneiss continues but the amount of biotite increases to 90-95%,
the rock being almost black in colour. Occasional (<10%) reddish, coarse-grained
granite leucosome veins. Skarn inclusion, 40 cm in diameter, at 0.30 m, surrounded by
10 cm wide rim of mica gneiss.
8.53-8.60
GRPG
Homogeneous, reddish granite pegmatite vein with the dip direction/dip of 130/30°.
19
P10
portion or discontinuous, narrow veins of granite pegmatite, as well as occasional
potassium feldspar grains. At the end of the section there is an 80 x 15 cm inclusion of
fine-grained, homogeneous mica gneiss, which has a strong greenish colouring due to
alteration of biotite in chlorite.
Reddish mica gneiss migmatite, in which the amount of coarse-grained granite
leucosome is >90%. The feldspar within the melanocratic bands of the migmatite has
altered to a greenish substance (probably a mixture of epidote, chlorite, saussurite and
sericite). At 0.90 m there is a strongly altered (chlorite, epidote, sericite), soft skarn
inclusion, surrounded by unaltered, fine-grained mica gneiss.
P11
P12
P13
NOT EXCAVATED DUE TO LARGE BLOCKS, WHICH COULD NOT BE
REMOVED.
Medium-grained, only weakly foliated, homogeneous mica gneiss with occasional 5-15
cm wide pale-coloured, coarse-grained granite leucosome veins, which in places contain
separate green minerals, unidentifiable with the naked eye. In the beginning of the
section a 15 cm wide granite vein is isoclinally folded and refolded by a tight folding
with fold axis very gently plunging to the W.
MGN
3.23-4.36
VMGT
0-0.30
MGT
0.30-2.05
MGN
Medium-grained mica gneiss with a weak quartz-feldspar segregation banding. Only
small amount (<10%) of coarse-grained granite leucosome veins parallel to the foliation.
Younger, 1-2 cm wide granite leucosome vein cuts the foliation in the direction of 050°.
2.05-3.68
VMGT
Vein migmatite, in which the amount of coarse-grained granite leucosome veins varies
50-80%. The mesosome is medium-grained mica gneiss with a weak quartz-feldspar
segregation banding. In places, the leucosome veins are boudined but more commonly
they show a pinch-and-swell structure. The veins are strongly folded. In places, narrow
(1 cm) shear zones occur conformably to the axial plane. Most of this vein migmatite
section is located in the NNE-side of the trench, the width of the migmatite being only
30 cm in the SSW-part.
Vein migmatite with a medium-grained mica gneiss mesosome with a weak foliation
and, mm-scale quartz-feldspar segregation banding. The amount of coarse-grained,
reddish granite leucosome, occurring parallel to the foliation, is ca. 40%.
Mica gneiss migmatite, in which the coarse-grained granite leucosome occurs as 0.5-5
cm wide veins parallel to the foliation of the mica gneiss mesosome. The mica gneiss
mesosome is medium-grained and shows weak quartz-feldspar segregation banding. The
granite leucosome comprises ca. 70% of the total volume of the migmatite.
20
0-3.23
P14
VMGT
Medium-grained mica gneiss mesosome with a weak quartz-feldspar segregation
banding. The coarse-grained granite leucosome veins occurring parallel to the foliation
of the mica gneiss comprise 40% of the total volume of the migmatite.
The migmatite of P13 continues. Medium-grained mica gneiss mesosome with a weak
quartz-feldspar segregation banding. The coarse-grained granite leucosome veins (0.5-6
cm wide) occur parallel to the foliation. The rock has been broken off along the foliation
surfaces.
0-1.82
VMGT
1.82-2.96
MGT
50 cm wide section of mica gneiss migmatite, in which the reddish, coarse-grained, 0.510 cm wide granite leucosome veins comprise more than 50% of the total volume of the
migmatite. The granite veins, in places, show a clear pinch-and-swell structure.
2.96-6.90
VMGT
Vein migmatite with a fine- to medium-grained mica gneiss mesosome and reddish,
coarse-grained granite leucosome comprising ca. 30-50% of the total volume of the rock.
The leucosome occurs as narrow veins parallel to the foliation of the mica gneiss. At
3.35 m there is a 20 cm wide, quite strongly weathered, intensely foliated zone in the
migmatite, which runs through the trench. The orientation of the zone is 080/25°.
6.90-8.84
MGT
Migmatite with a fine- to medium-grained, biotite-rich mica gneiss mesosome and
reddish, coarse-grained granite leucosome, occurring as a few millimetres to 5 cm wide
veins parallel to the foliation of the mica gneiss. The veins comprise ca 70% of the total
volume of the migmatite. The strike of the foliation and the granite veins is rather linear.
The granite veins show a weak pinch-and-swell structure. The veins are in places
isoclinally folded and re-folded by an open folding plunging to the NE. At 6.90-7.65 the
foliation is clearly seen due to weak weathering of the migmatite.
8.84-8.96
GRPG
Reddish, coarse-grained to pegmatitic granite/granite pegmatite.
21
3.68-4.43
P15
P16
GRPG
Reddish, coarse-grained to pegmatitic granite/granite pegmatite, which runs through the
trench parallel to the foliation of the mica gneiss migmatite (090/38°).
0.95-6.89
VMGT
0-4.59
VMGT
Vein migmatite with medium-grained, weakly foliated, rather homogeneous mica gneiss
mesosome (50-70%) and pale-coloured, coarse-grained granite leucosome (30-50%)
occurring as narrow, irregular, discontinuous veins parallel to the foliation or as small
patches. The veins, in places, have a weak pinch-and-swell structure. The veins show
isoclinal, intrafolial folding, which is refolded by tight to open folding, gently plunging
to the NE or ENE.
Fine-to medium-grained, biotite–rich mica gneiss mesosome with less than 20% of
narrow (0.5-5 cm), discontinuous, reddish, coarse-grained granite veins, occurring
parallel to the foliation of the mica gneiss mesosome.
4.59-9.35
MGT
0-12.42
MGT
A complex mixture of coarse-grained granite leucosome and mica gneiss mesosome, the
granite comprising >50% of the rock. Only in places does the granite leucosome occur
as clear veins paralleling the foliation of the mica gneiss mesosome. In the SSW-part of
the trench there is a 1.5 x 1.5 m portion of rather homogeneous mica gneiss with only a
few granite veins.
Migmatite, in which the amount of coarse-grained granite leucosome is >80%. The
melanocratic part of the migmatite usually occurs as narrow (2-5 mm), biotite-rich
schlieren (melanosome) between the leucosome veins. At 9.50-12.42 m, however,
narrow, discontinuous bands of true mica gneiss mesosome occur, in which the mica
gneiss is grey, medium-grained and has a weak metamorphic quartz-feldspar segregation
banding. From the beginning of the section until 7.50 m the veining is rather unclear,
because only one gentle foliation surface is visible. The migmatite is rather intensely
folded with three interpreted folding phases.
22
P17
0-0.95
0-5.12
MGT
P19
0.4.90
MGT
P20
0-6.38
MGT
P21
0-3.80
MGT
Migmatite, in which the amount of coarse-grained granite leucosome is > 80%. The
melanocratic part of the migmatite usually occurs as narrow, several millimetres wide,
biotite-rich schlieren (melanosome) between 0.5-3 cm wide, coarse-grained granite
leucosome veins. In places, discontinuous bands or relicts of biotite-rich mica gneiss
occur. The migmatite is intensely folded. Only at the end of the section, the veins strike
rather linearly and here the weak pinch-and swell structure of the veins is visible. The
surface of migmatite in the whole section is weakly weathered.
Migmatite, in which the amount of coarse-grained granite leucosome is > 80%. The
melanocratic part of the migmatite usually occurs as narrow, a few millimetres wide,
biotite-rich schlieren (melanosome) between a few centimetres wide, coarse-grained
granite leucosome veins. In places, a couple of discontinuous bands of biotite-rich mica
gneiss mesosome occur. The granite veins show a pinch-and-swell structure and smallscale rootless, isoclinal folds, which are refolded by tight folds gently plunging to the
SW. Two small (20 x 35 cm) skarn inclusions occur in the SSW-part of the trench. At
2.20 m and 4.80 m, two wide (20-40 cm) leucosome veins occur, the grain size of which
varies from medium-grained to pegmatitic. The surface of migmatite in the whole
section is weakly weathered.
The same kind of migmatite as in Section P19. Only one discontinuous, 5-20 cm wide
band of mica gneiss mesosome with a thin quartz-feldspar segregation banding. At 3.60,
120 x 45 cm portion of "granite gneiss", which deflects the foliation and the granite
veining. Ghost-like veining is visible within the "granite gneiss". Ca. 50 cm wide,
discontinuous granite pegmatite vein at 4.33 m parallel to the foliation. Tight, sinistral
folding, gently plunging to the NE, which, in one place, is accompanied by narrow (2
cm) shear zone. This tight folding is re-folded by more open folding, plunging to the SE.
The same migmatite as in Section P20 continues. In the first metre of the section the
strike of the foliation is almost perpendicular to the one in the previous section. The
foliation and the leucosome veins are folded by tight, dextral folding, gently plunging to
the NE and accompanied by shearing along the axial plane.
23
P18
P22
MGT
0-7.36
MGT
4.60
GR
7.36-10.55
The coarse-grained granite leucosome veins are wider than before and narrow, a few
millimetres wide, biotite-rich schlieren (melanosome) occur between the leucosome
veins. For instance, at 4.50 m a 50 cm wide coarse-grained to pegmatitic granite vein
occurs parallel to the foliation defined by the melanosome schlierens. The granite veins
show a clear pinch-and-swell structure. In places, portions of the same "granite gneiss"
as in the previous section, which here seems to cut the leucosome veins.
At 6.30-9.05 m, narrow bands of biotite-rich mica gneiss melanosome with a quartzfeldspar segregation banding occur, which is folded by tight, chevron-type folding,
gently plunging to the ENE. In places, narrow granite leucosome veins occur parallel to
the axial plane.
The melanocratic part of the migmatite usually occurs as narrow, a few millimetres
wide, biotite-rich schlieren (melanosome) between coarse-grained granite leucosome
veins. The veins are usually a few centimetres wide but in places wider, ca. 30 cm wide
veins occur. In places, the veins show a pinch-and-swell structure. At 6.00 m, in the
SSW-part of the trench, a few discontinuous bands of quartz-feldspar-rich mica gneiss
mesosome occur, the width of which ranges from a couple of centimetres up to 20 cm.
Medium- to coarse-grained granite vein with brownish mineral aggregates (about 0.5 cm
in diameter), which have eroded a little deeper than the surface of the rock.
Ductile shear zone parallel to the foliation. The structure of the migmatite with pinchand swell granite leucosome veins has been developed to narrow (about 1 cm) veins,
which in places show rotated megacrysts or budins. The potassium feldspar
porphyroclasts are common. In places, small fragments of the mica gneiss mesosome
occur, giving the rock a schollen migmatitic structure. The rotated budins, potassium
feldspar porphyroclasts and mica gneiss fragments indicate dextral sense of shearing. At
10.46 m the shearing is cut by a 0.5 cm wide quartz-feldspar vein with an orientation
085/67°.
24
3.80-12.45
P23
GGN
Grey gneiss with a granitic composition. The rock is coarse-grained and has narrow
biotite streaks and both small and large potassium feldspar porphyroblasts (or
porphyroclasts?). The contact between the above shear zone and the granitic grey gneiss
is diffuse, and it seems that the grey gneiss is somehow related to the shearing. The grey
gneiss, in places, contains fragments of vein migmatite, giving the rock a schollen
migmatitic structure. The strike of foliation within the fragments is perpendicular to the
one in the grey gneiss. At 10.55 m the rock is cut by ca. 1 mm wide biotite seam,
oriented 005/75°. It is possibly accompanied by a weak dextral faulting.
12.55-12.78
MGT
0-3.15
MGT
Strongly folded mica gneiss migmatite, which, on the basis of Section P23 and adjacent
investigation trench TK6, is part of a larger vein migmatite fragment within the granitic
grey gneiss.
Migmatite, in which the amount of coarse-grained granite leucosome is 70-90%. The
melanocratic part of the migmatite usually occurs as narrow, a few millimetres wide,
biotite-rich schlieren (melanosome). Abundant "rusty" spots after some unknown
mineral, which has eroded away. The migmatite is a large fragment within the granitic
grey gneiss.
2.00-2.10
GGN
Narrow portion of granitic grey gneiss within the vein migmatite, which comes from a
larger grey gneiss unit in the adjacent investigation trench TK6.
3.15-10.90
GGN
Medium- to coarse-grained, weakly oriented, homogeneous, granitic grey gneiss, which
encloses abundant vein migmatite fragments and a few small fragments of mica gneiss.
The grain size of the feldspars is 0.5-5 cm and they occur like phenocrysts. Some of the
grains are idiomorphic. In places, a ghost-like folding can be seen in the grey gneiss,
which, however, can be relict from a migmatite fragment. In the SSW-part of the trench,
the grey gneiss encloses rounded, banded mica gneiss inclusions, which show signs of
early foliation and folding. One of the inclusions has rotated in the shearing concordant
to the main foliation. Pegmatitic leucosome has accumulated at the boundary of the
inclusion (pressure shadows?).
25
10.55-12.55
MGT
Fragment of mica gneiss migmatite.
8.60-9.00
MGT
Fragment of mica gneiss migmatite.
10.00-10.50
MGT
0-2.00
MGT
Mica gneiss migmatite section, which widens towards the NNE-part of the trench and
continues outside the trench.
Folded mica gneiss migmatite, in which the amount of coarse-grained granite leucosome
is 80-90%. The melanocratic part of the migmatite usually occurs as narrow, a few
millimetres wide, biotite-rich schlieren (melanosome). This vein migmatite is a narrow
section within the grey gneiss. At 0.70 m a 15 x 20 cm skarn inclusion within the vein
migmatite.
2.00-11.10
GGN
Medium- to coarse-grained (feldspars 0.5-5 cm in diameter), weakly oriented,
homogeneous, granitic grey gneiss with a few inclusions of skarn and fine-grained mica
gneiss. A large (65 x 30 cm) skarn inclusion with coarse-grained quartz veins is located
at 6.80 m on the SSW-side of the trench.
P25
0-2.04
GGN, MGT
P26
0-4.50
GGN
Reddish grey, medium- to coarse-grained (feldspars 0.5-5 cm in diameter), almost
homogeneous granitic grey gneiss, which in the SSW-part of the trench is bounded by a
folded vein migmatite. The mica gneiss migmatite occupies the SSW-part of the section
and reaches the median line of the trench but does not continue through the trench. It
gradually changes to the grey gneiss.
Reddish grey, medium- to coarse-grained (feldspars 0.5-5 cm in diameter), slightly
oriented, almost homogeneous granitic grey gneiss, which in places has a weak veining
(biotite schlieren). A few deeply eroded skarn inclusions (<20 cm in diameter) and a
couple of mica gneiss inclusions.
4.50-6.00
MGT
P24
Reddish to grey, isoclinally folded mica gneiss migmatite, in which the amount of
coarse-grained granite leucosome is 60-80%. The migmatite has small (0.1-1.0 cm in
26
6.20-7.60
diameter) cavities after some mineral, which has totally eroded away. 70 x 20 cm mica
gneiss inclusion in the SSW-part of the trench, showing early foliation and folding.
P27
GGN, MGT
0-1.50
GGN
1.50-6.00
GR
0-0.75
GR
0.75-2.85
MGT
Grey, slightly reddish, medium- to coarse-grained (feldspars 0.5-5 cm in diameter),
almost homogeneous granitic grey gneiss. In the NNE-part of the section the grey gneiss
changes to the mica gneiss migmatite. The foliation and the veining of the migmatite are
deflected by a large (170 x 70 cm), grey, fine-grained mica gneiss inclusion, which
shows early foliation and folding. The mica gneiss has garnet porphyroblasts.
Reddish grey, medium- to coarse-grained granitic grey gneiss, with potassium feldspar
phenocrysts, 1-3 cm in diameter. 4-16 cm wide medium-grained granite veins in the
direction of 035° cut the grey gneiss. In the NNE part of the section 3-5 cm wide granite
pegmatite veins cut the grey gneiss in the same direction. At 1.1 m in the NNE-side of
the section, the grey gneiss encloses a medium-grained mica gneiss inclusion (30 x 10
cm).
Reddish or reddish grey, medium-grained granite is cut by coarse-grained granite veins.
In places the coarse-grained granite brecciates the medium-grained granite, giving rise to
an agmatic structure. At 1.50 m on the SSW-side of the trench, the coarse-grained
granite veins are tightly folded, the fold axis plunging to the S. At 3.35-5.40 m, both the
medium-grained and coarse-grained granites have abundant small cavities after some
mineral, which is totally eroded away. The NNE-side of the section is composed of a
complex mixture of granitic grey gneiss, medium-grained granite cutting it and coarsegrained granite, which cuts both of them. The SSW-side of the section is composed of
the vein migmatite, which, in places, is clearly cut by the medium-grained granite
described above.
Reddish or reddish grey, medium-grained granite is cut by coarse-grained granite veins
(same as in the previous section).
Mica gneiss migmatite, in which the 0.5-2 cm wide, coarse-grained granite leucosome
veins amount to ca. 40% of the total volume of the rock. The migmatite is tightly folded
27
P28
6.00-7.35
with narrow shear zones concordantly to the axial plane (125/85°). The fold axis plunges
gently to the SW. At 1.30 and 2.50 m (SSW-side), 60 x 30 cm portions of the same
medium-grained granite as in the beginning of the section. The coarse-grained granite
veins, cutting the granite, have the same folding as the migmatite.
MGN
Medium- to almost coarse-grained, unfoliated mica gneiss with mostly potassium
feldspar porphyroblasts or aggregates of potassium feldspar (0.5-5 cm in diameter) in
abundance. The largest individual potassium feldspar grain is 3 cm in diameter. Large,
reddish potassium feldspar grains are unaltered. Instead, smaller (1.5 cm in diameter)
plagioclase and potassium feldspar grains are strongly altered to white or very faintly
greenish, soft minerals (illite and kaolinite?). The alteration does not occur throughout
the rock but only as small patches. In places, a rim of the same white, soft mineral
surrounds the large reddish potassium feldspar grains also. It can be seen in places how
one potassium feldspar grain is totally altered, while the adjacent grain is unaltered.
Small patches of reddish granite pegmatite occur occasionally. In places, weak vein
migmatite structure is visible but it is never continuous. These places give an impression
that the visible mica gneiss is only a gentle foliation surface and that the rock in reality is
an ordinary migmatite.
13.35-16.77
MGN
0-0.70
VMGT
Medium-grained, unfoliated mica gneiss with some potassium feldspar porphyroblasts
(0.5-5 cm in diameter) and, in places, narrow, discontinuous, coarse-grained granite
leucosome veins. The rock is unaltered. At the end of the section, there are 2-8 cm wide,
gently dipping (20°ESE), coarse-grained granite leucosome veins.
Vein migmatite with mica gneiss mesosome alternating with 0.5-2 cm wide coarsegrained granite leucosome veins, which comprise ca. 40% of the total volume of the
rock.
0.70-3.10
MGN
Medium-grained, unfoliated mica gneiss with some potassium feldspar porphyroblasts
(0.5-5 cm in diameter).
28
P29
2.85-13.35
P30
VMGT
Strongly weathered vein migmatite lying directly on the rather homogeneous
unweathered mica gneiss. The leucosome veins constitute more than 50% of the total
volume of the migmatite. The rock is still quite compact but it can easily be crushed with
a hammer.
The same kind of strongly weathered vein migmatite as before. The rock is still quite
compact but can easily be crushed with a hammer.
0-1.90
VMGT
1.90-4.80
VMGT
The migmatite is much more weathered than before and it can be crushed just by hand.
The amount of the granite leucosome veins is only ca. 15-20%, which explains the
higher degree of weathering (biotite-rich mica gneiss mesosome weathers more easily
than the granite veins). In spite of the very intense weathering, the structure of the rock
is still clearly visible. Due to strong weathering, the rock is strongly cleaved along the
foliation surfaces.
4.80-6.02
VMGT
The weathering is still strong but weaker than previously due to higher amount of the
leucosome veins, which comprise 40-50% of total volume of the migmatite. The rock is
still quite compact but it can easily be crushed with a hammer. The width of the granite
veins is usually a few centimetres but at 4.82 m there is a 35 cm wide granite pegmatite
vein parallel to the foliation. Ca. 50 cm thick layer of fine sand overlies the weathered
rock. This sand is overlain by a fine-grained, very compact clayey till, which contains
rounded rock fragments and angular mineral grains.
29
3.10-5.24
30
2.2
Ductile deformation
The observations of the ductile deformation are presented in Appendix 1. The rock
types of the investigation trench show a polyphase ductile deformation. The earliest
deformational features can be seen in some mica gneiss and skarn inclusions within the
migmatite, which have a fine banding and biotite schistosity (S1), and which are
isoclinally folded (F2A) (Fig. 2.2-2A). The new foliation, axial planar to the folding
(S2A), can be separated from the S1 in fold hinges, elsewhere they are subparallel. These
early deformation events were followed by development of a foliation S2B and intense
production of granitic leucosome veins parallel to the foliation, which more or less
destroyed the early structures. The foliation S2B includes here schistosity, metamorphic
quartz-feldspar segregation banding, as well as the orientation of the biotite-rich
melanosome schlierens (Fig. 2.2-2B). The foliation usually strikes to ca. NE-SW and
dips gently to the southeast, the mean dip direction/dip angle being 147/43° (Fig. 2.2-1).
In sections P12-P16, the foliation has a more northerly strike, the mean dip direction/dip
angle being 103/36°. In sections P23-P28, there are three foliation maxima: 100/23°,
125/54° and 140/81°. The last maximum comes from the measurements in the granitic
grey gneiss. The degree of foliation, using the Finnish engineering geological
classification (Korhonen et al. 1974, Gardemeister et al. 1976), usually varies from
weak to medium, the degree of foliation being weakest in the homogeneous mica
gneisses and grey gneisses. Only in narrow sections is the mica gneiss strongly foliated.
During the later stages of the D2 deformation, the migmatites were intensely extended,
as indicated by the granite leucosome veins and more competent mica gneiss mesosome
layers showing boudinage or pinch-and-swell structures (Fig. 2.2-2B). The veins are
occasionally isoclinally folded (F2C).
147/43°
1%
2%
3%
4%
5%
6%
7%
8%
9%
10 %
11 %
12 %
N=106
A)
Lower hemisphere - OL-TK7: Foliation
K=100.00
Sigma=1.060
Lower hemisphere - OL-TK7: Foliation
Peak=11.68
N=106
B)
Figure 2.2-1. Distribution of poles to foliation S2B in investigation trench OL-TK7
(Schmidt equal area, lower hemisphere projection). A) Contoured stereogram, B) pole
strereogram.
31
S1
S2B
A
F2A
B
Figure 2.2-2. Skarn inclusions with S1 foliation folded by isoclinal F2A fold. Ol-TK7,
section P3 B). S2B foliation defined by biotite melanosome. Granite veins showing a
weak boudinage and pinch-and-swell structure are parallel to the foliation. The length
of the plate is 12 cm. Photographs by Seppo Paulamäki, Geological Survey of Finland.
In the next deformation phase, D3, the mica gneiss and the granite leucosome veins with
isoclinal F2 folds were refolded by F3 folding (Fig. 2.2-4A). In investigation trench
TK7, the F3-folds occur as small-scale, tight, and in places chevron-type folds with the
fold axis gently (15 – 45°) plunging to the NE-ENE or SW-SSW (Figs. 2.2-3 and 2.24A-C). In places, narrow granite veins and a weak dextral shearing/faulting occur
parallel to the axial planes, dipping to the SE (Fig. 2.2-4D). In places, the F3-folds are
refolded by more open folds, plunging to ca. SSE or SE (Fig. 2.2-4E). On the basis of
structural interpretation by Paulamäki & Koistinen (1991) these folds may correspond
to the deformation phases D4 and D5, respectively.
F3
2.2 %
4.3 %
6.5 %
8.7 %
10.9 %
13.0 %
F3
N=46
A)
Lower hemisphere - OL-TK7: Fold axis
K=100.00
Sigma=1.000
Lower hemisphere - OL-TK7: Fold axis
Peak=6.40
N=46
B)
Figure 2.2-3. Distribution of fold axis in investigation trench OL-TK7. Schmidt equal
area, lower hemisphere projection. A) contoured stereogram, B) plot stereogram. A
plunge of 90° plots at the centre and 0° at the outer perimeter.
32
F2
F3
A
B
D3 shear
C
D
F5?
F3
E
Figure 2.2-4. A) Isoclinal F2 folding refolded by F3. OL-TK7, section P17. B) Tight F3
folds. OL-TK7, section P13. C) Tight, partly chevron-type F3 folds. OL-TK7, section
P21. D) D3 shear cutting the S2B foliation and leucosome veins. OL-TK7, section P21.
E) F3 folding refolded by F5 plunging to the SE. OL-TK7, section P17. The length of the
plate is 12 cm. Photographs by Seppo Paulamäki, Geological Survey of Finland.
33
Shear zone (structure R24)
About a 5 m wide ductile shear zone parallel to the foliation occurs in Section P22. The
structure of the migmatite with boudinage and/or pinch-and swell granite leucosome
veins has developed into narrow (about 1 cm) veins, which in places show rotated
budins (fragments of boudined granite leucosome veins). The potassium feldspar
porphyroclasts are common. In places, small fragments of the mica gneiss mesosome
occur, giving the rock a schollen migmatitic structure. The rotated budins, potassium
feldspar porphyroclasts and mica gneiss fragments indicate sinistral sense of shear.
The shearing is similar to the shear zones in investigation trenches TK1 and TK5, which
belong to the same shear zone (structure R24 in the bedrock model by Vaittinen et al.
2003). However, the shear zone in TK7 is not weathered or fractured as in TK1 and
TK5 and it is located in a different place than expected on the basis of these trenches.
To find out if these shear zones in three adjacent investigation trenches do indeed
belong to the same shear zone, the area between the trenches and outcropping parts of
the zone in the vicinity of trenches TK1 and TK7 were excavated and cleaned. The
investigations showed that the same shear zone R24 occurs in all three trenches, and
that the zone is folded, which explains its different position in TK7 (Fig. 2.2-5 and 2.26).
Fig. 2.2-7 shows some detailed photos of the shear zone. The shearing is strongest in the
southern part of the zone, where a clear mylonitic foliation occurs (Figs. 2.2-7A and
2.2-7B). Within the foliation there are larger and potassium feldspar grains or
porphyroclasts. The grain size within the shear zone is clearly reduced compared to the
migmatite protholith. The sense of shear is sinistral. The shearing is less pronounced,
but still evident, in the middle of the zone in investigation trenches TK1 and TK5 (Figs.
2.2-7D and 2.2-7D). The characteristic feature to this part of the shear zone is the slight
weathering and fracturing of part of the zone. The weathered and fractured zone within
the shear zone is at its widest in investigation trench TK5, where it is ca 3.5 m wide.
The zone dies out towards TK7 and does not occur in TK7 anymore. Also to the SW of
TK1 the zone becomes narrower and narrower and probably dies out ca. 15 m from
TK1. The shear zone is at least 15 m wide in the area northeast of trench TK7. Also in
this part of the shear zone shearing is conspicuous, although the rock is not as mylonitic
as in the southern part of the zone (Figs. 2.2-7E and 2.2-7F). The granite neosome veins
occur as strongly extended narrow streaks and the strong penetrative foliation deflects
around potassium feldspar porphyroclasts or megacrysts representing survivors from
destruction of less ductile granite leucosome veins. Asymmetric megacryst structures
indicate sinistral sense of shear (Fig. 2.2-7F)
The shear zone is interpreted as being a D2 shear zone, which is folded by a large scale
F3 fold with an almost E-W axial plane, which can be seen in the ground survey
magnetic map. The shape of the shear zone also indicates younger folding plunging to
the SE, which can be seen in the migmatites near the shear zone.
34
Not exposed
Fig. 2.2-6C
Fig. 2.2-6B
OL-TK7
Fig. 2.2-6A
OL-TK5
OL-TK6
Not exposed
OL-KR8
OL-TK1
Figure 2.2-5. Shear zone R24 in the area of investigation trenches TK1 (Paulamäki
1995), TK5, TK6 (Paulamäki & Aaltonen 2004) and TK7. Deep blue = mica gneiss,
blue = migmatitic mica gneiss, orange = grey gneiss, red = granite pegmatite.
A
B
C
Figure 2.2-6. A) Shear zone to the SW of TK1 and TK5. The view is towards NE.
B) Shear zone between TK5 and TK7. The view is towards ENE. C) Shear zone to the
NE of TK7. The view is towards NE. Photographs by Seppo Paulamäki, Geological
Survey of Finland.
35
A
B
C
D
E
F
FE
Figure 2.2-7. A) Sheared vein migmatite in the S part of the shear zone with a strong
mylonitic foliation. B) Sheared vein migmatite in the S part of the shear zone showing
sinistral sense of shear. C) and D) Weathered mica gneiss migmatite in the shear zone
in TK5. E) Sheared vein migmatite in the NE part of the shear zone. F) Sheared vein
migmatite in the NE part of the shear zone with a potassium feldspar megacrysts
showing sinistral sense of shear. The length of the plate is 12 cm. Photographs by Seppo
Paulamäki, Geological Survey of Finland.
36
2.3
Fracturing
The results of fracture investigations are shown in Appendix 2. The first five columns
show the position of the fracture in relation to the central thread and the x-y-zcoordinates calculated on the basis of this data. They are followed by the dip direction
and dip of the fracture, the rock type, fracture trace length, type of fracture trace (Are
one or both ends visible?), fracture form (straight - curved - winding), character (open
or tight, filled), aperture (if open), possible fracture filling mineral and other remarks.
2.3.1
Fracture orientations
The distribution of all fracture orientations and distribution of fracture orientations by
rock types in investigation trench OL-TK7 are shown in Figs. 2.3-1 and 2.3-2,
respectively, as Schmidt equal area, lower hemisphere projection and rose diagram. The
main sets of the fracture orientations are shown in Table 2.3-1. The five fracture sets
presented in the Table cover 67.5% of all measured fractures. The remaining fractures,
which are not included in the Table 2.3-1 but are shown in Fig. 2.3-1, are mainly evenly
distributed between dip directions 105° and 180°, i.e., between and in the range of
fracture sets I and II. However, from the fractures with dip direction 070-180°, fracture
sets I and II cover 71.9%. The most common fracture set (I) represents fractures, which
strike parallel to the foliation and have the same dip angle as the foliation.
Fig. 2.3-2 and Appendix 3 suggest that there may be some differences in the fracture
orientations between the rock types and in different parts of the trench. However, no
definitive conclusions can be made due to the rather small number of fractures. The
mica gneisses seem to favour fracture set IV, migmatitic mica gneisses fracture set I and
the grey gneisses fracture set V. Absence of set I in the mica gneisses is most likely due
to weak foliation in these rock types. Appendix 3 shows the distribution of fracture
orientations along the trench in four different trench sections, which are mainly
compiled on the basis of the main rock types. The most striking difference in the
fracture orientations is in trench sections P12-P16, which are mainly composed of the
vein migmatite. In these trench sections, fractures dipping steeply to the NW or WNW
are abundant but fracture sets II and IV, which are common in other parts of the trench,
are poorly represented. The foliation has a more northerly strike in this part of the trench
than elsewhere in the trench, which in the fracture orientations are reflected by fractures
gently dipping to the ESE. The same strike of foliation and related fracturing can also
be seen in sections P23-P28.
Table 2.3-1. Distribution of main fracture orientations in investigation trench OL-TK7.
Fracture set
Fracture strikes (maxima Dip direction/dip (maxima
and orientation range)
and orientation range)
I
II
III
IV
V
064° (050-082°)
355° (340-015°)
75-108°
352° (342-356°)
020-034°
154°/35° (140-172°/25-50°)
085°/85° (070-105°/65-90°)
345-018°/65-85°
262°/82° (252-266°/75-90°)
290-304°/70-85°
Percentage from all
measured fractures
(N = 200)
23.5%
21.0%
9.5%
9.0%
4.5%
37
1%
2%
3%
4%
5%
6%
N=200
Lower hemisphere - OL-TK7: All fractures
K=100.00
Sigma=2.000
A)
Lower hemisphere - OL-TK7: All fractures
Peak=6.22
N=200
B)
Lower hemisphere - OL-TK7: All fractures
N=200
C)
Figure 2.3-1. Distribution of poles to fractures in investigation trench OL-TK7,
(N = 200). A) Contoured stereogram and B) pole stereogram (Schmidt equal area,
lower hemisphere projection), C) rose diagram, where the strikes of the fractures are
presented regardless of the dip of the fracture (scale of ring in the rose diagram is 5%).
Approximate trench trend is marked with a dashed line.
38
2%
4%
6%
8%
10 %
12 %
14 %
16 %
N=31
Lower hemisphere - OL-TK7: Fractures in the mica gneiss
K=100.00
Sigma=0.310
Peak=16.62
Lower hemisphere - OL-TK7: Fractures in the mica gneiss
Lower hemisphere - OL-TK7: Fractures in the mica gneiss
N=31
N=31
A)
1%
2%
3%
4%
5%
6%
7%
8%
9%
Lower hemisphere - OL-TK7: Fractures in the migmatitic mica gneisses
N=111
K=100.00
Sigma=1.110
Peak=9.13
Lower hemisphere - OL-TK7: Fractures in the migmatitic mica gneisses
N=111
Lower hemisphere - OL-TK7: Fractures in the migmatitic mica gneisses
N=111
B)
1%
2%
3%
4%
5%
6%
7%
8%
N=46
Lower hemisphere - OL-TK7: Fractures in the grey gneiss
K=100.00
Sigma=0.460
Peak=7.92
Lower hemisphere - OL-TK7: Fractures in the grey gneiss
Lower hemisphere - OL-TK7: Fractures in the grey gneiss
N=46
N=46
C)
Figure 2.3-2. Distribution of poles to fracturing by rock types in investigation trench
OL-TK7. A) Mica gneisses, B) migmatitic mica gneisses and C) granitic grey gneisses.
Contoured stereograms, pole stereograms (Schmidt equal area, lower hemisphere
projection) and rose diagrams, where the strikes of the fractures are presented
regardless of the dip of the fracture (scale of ring in the rose diagram is 5%).
Approximate trench trend is marked with a dashed line.
39
2.3.2
Fracture densities
Table 2.3-2 and Fig. 2.3-3 presents the fracture densities of investigation trench TK7 in
each section. All the fractures equal to or longer than one metre cutting the median line
of the trench were recorded. A total of 167 fractures were recorded at the length of
290.48 m. Accordingly, the mean fracture density is 0.57 fractures/m. The fractures
cutting the median line of the trench cover 83.5% of all measured fractures.
In terms of Finnish engineering geological rock classification (Korhonen, et al. 1974,
Gardemeister et al. 1976), no fracture zones (>10 fractures/m) occur in the trench.
However, in sections P-1, P1, P8, P17, P24 and P28, narrow zones of abundant
fracturing (i.e. more abundant than in the immediate surroundings) occur (Table 2.3-2,
Figs. 2.3-4 and 2.3-5). In section P-1 the fracturing is restricted to a narrow mica gneiss
unit within the mica gneiss migmatite (Fig. 2.3-4A). The fractures dip steeply to the
west. In Section P1 all the fractures (4 fractures/1.3 m) dip steely to the WSW. In
section P8 (Fig. 2.3-4B) the fractures also dip steeply but the dip is to the E. The
fractures are partly filled with calcite.
In section P17 there is a narrow (0.50 m) fractured zone with four tight fractures
steeply dipping to the WSW. In the fractured zone in section P24 (Fig. 2.3-4C), the
fractures (6 fractures/1.6 m) dip steeply to the E or ESE. They are long and have
apertures of several centimetres, indicating that they may have also vertical
continuation. In the fractured zone in section P28 (Fig. 2-3-4D), the fractures (6
fractures/1.7 m) are tight and steeply dipping to the E.
One single fracture, which may have a vertical extent, occurs in section 17. This
vertical, NNW striking fracture can be followed more than 20 m to adjacent
investigation trenches TK1 and TK5. In TK7 the surface aperture of the fracture is 20
cm but deeper it can be seen that the aperture is not as wide but the fracture is in fact
composed of four adjacent, closely spaced fractures with apertures of just a few
millimetres. Another long and open fracture occurs ca. 10 m SW of investigation trench
TK1. However, it was not found or recognised in nearby borehole KR26.
Section P12 is ca. 0.5 m lower than adjacent section P13 as if it had dropped down. It is
thereby possible that there is a (sub)horizontal fracture beneath P12 and possibly also
P11, which was not excavated due to large blocks. The gently SE dipping rock surface
in sections P9 and P10 with almost no fractures probably represents the surface of this
fracture.
40
Table 2.3-2. The mean fracture densities along the investigation trench TK7 in
Olkiluoto. MGN = mica gneiss, MGT = mica gneiss migmatite, VMGT = vein
migmatite, GGN = grey gneiss, GR = granite, FZ = fractured zone.
Section
Rock type
Section
length (m)
P-5
P-4
P-3
P-2
P-1
VMGT
VMGT
VMGT
VMGT
VMGT,
MGN
MGT
MGT
MGT
MGT
MGT, MGN
MGT
MGT, MGN
MGN
MGN
MGM
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
P24
P25
P26
P27
P28
P29
P30
P-5 –
P30
4.55
7.69
11.68
4.70
13.96
Number
of
fractures
0
3
0
0
8
Fracture
density
(pcs/m)
0.00
0.39
0.00
0.00
0.57
9.14
5.72
16.10
4.41
10.43
11.47
16.55
6.07
6.88
8.54
7
1
2
5
8
7
12
8
0
0
0.76
0.17
0.12
1.14
0.77
0.61
0.72
1.32
0
0
MGN,
VMGT
VMGT,
MGT
VMGT,
MGT
VMGT
MGT
MGT, MGT
MGT
MGT
MGT
MGT
MGT, GGN
4.30
5
1.15
4.44
5
1.13
8.95
9
1.00
6.88
9.34
12.28
5.05
4.83
6.41
12.40
12.80
5
4
11
7
7
2
5
13
0.73
0.43
0.89
1.34
1.43
0.31
0.40
1.02
GGN, MGT
GGN
GGN
GGN, MGN
GR
MGN
MGN,
VMGT
VGMT
10.93
11.07
2.02
7.24
6.00
16.42
5.24
7
10
1
6
3
6
0
0.64
0.90
0.49
0.83
0.50
0.36
0
5.99
0
0
290.48
167
0.57
Remarks
No fractures in the section.
No fractures in the section.
No fractures in the section.
FZ in mica gneiss, 5 fractures/2.8 m.
FZ, 4 fractures /1.3 m.
Section 3.50-5.65 covered with ice.
Fracturing parallel to the foliation.
Section 4.90-5.40 covered with ice.
FZ, 5 fractures/1.63 m
4.80-6.10 m covered with mud.
5.10-7.70 m covered with mud.
Not excavated!
FZ, 4 fractures/0.52 m.
FZ, 4 fractures/0.3 m
Incl. 5 m wide shear zone with no
fractures.
FZ, 6 fractures/1.6 m.
FZ, 6 fractures/1.7 m.
3.10-5.24 m strongly weathered
(regolith).
The whole section is very strongly
weathered (regolith).
41
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
P-5
P-4
P-3
P-2
P-1
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
P24
P25
P26
P27
P28
P29
P30
Fractures/m
Fracture densities
Section number
Figure 2.3-3. Distribution of fracture densities in investigation trench OL-TK7. The
fracture density is smallest, where the bedrock surface is at lowest.
42
A
B
Figure 2.3-4. N-S striking narrow fractured zones in the mica gneiss in sections P-1 (A)
and in section P8 (B). Olkiluoto, investigation trench OL-TK7. The length of the plate
is 12 cm. Photographs by Seppo Paulamäki, Geological Survey of Finland.
A
B
Figure 2.3-5. Ca. N-S striking fractured zones in the grey gneiss in section P24 (A) and
in the mica gneiss in section P28 (B). The length of the plate is 12 cm. Photographs by
Seppo Paulamäki, Geological Survey of Finland.
43
2.3.4
Fracture characteristics
The distribution of the fracture trace lengths is shown in Fig. 2.3-6. All fractures with a
trace length equal to or longer than 1 m were measured with an accuracy of 0.5 m. The
mean fracture trace length of all recorded fractures is 1.9 m, 33% of the fractures being
visible in their full length (mean fracture length 1.5 m). Fractures with one fracture end
covered constitute 37.5% of all fractures, the mean length being 1.65 m. Fractures with
both ends under soil cover (29.5%) have the mean length of 2.75 m, the longest fracture
being more than 22 m long. There is no connection between the fracture trace length
and the fracture orientation but both short and long fractures occur in the same main
fracture set presented in Table 2.3-1. In most cases the fracture trace length is not
dependent on the rock type. However, in the mica gneiss and skarn inclusion there are
often short fractures, which are solely restricted to the inclusion (Fig. 2.3-7).
Number of fractures
Distribution of fracture trace lengths
100
90
80
70
60
50
40
30
20
10
0
93
65
29
6
1
2
3
4
1
0
1
0
0
5
6
7
8
9
0
2
10 >10
Fracture trace length (m)
Figure 2.3-6. The fracture trace lengths measured in investigation trench OL-TK7. The
value of 1 m includes the range from 1.0 - 1.5 m, 2 m 1.5-2.5 etc.
44
A
B
Figure 2.3-7. A) Long (>4 m), ca. N-S striking, open fractures in section P24 in
investigation trench OL-TK7. B) Short, open fractures, restricted to mica gneiss
inclusion, Section P5. The length of the plate is 12 cm. Photographs by Seppo
Paulamäki, Geological Survey of Finland
Most of the measured fractures are either open (54.6%) or tight (37.2%). The aperture
of the open fractures is usually some millimetres, and only few exceed 1 cm (Fig. 2.38). The fractures with widest aperture are most likely to have been opened by frost.
Fractures with mineral infilling are sparse (3.1%). Fracture fillings include calcite,
chlorite, pyrite and clay minerals (Fig. 2.3-9). The measured fractures are either
undulating (48.2%) or linear (40.2%), some of the fractures being slightly curved
(11.6%).
Number of fractures
Aperture of open fractures
50
45
40
35
30
25
20
15
10
5
0
47
22
12
11
2
0.1
0.2
0.3
0.4
1
0.5
0.6
3
0.7
Aperture (cm)
Figure 2.3-8. Aperture of open fractures.
6
0
0
0.8
0.9
2
1
>1
45
calcite
pyrite
A
B
Figure 2.3-9. Calcite and pyrite (B) on the surface of minor fractures. OL-TK7, section
P-3. The length of the plate is 12 cm. Photographs by Seppo Paulamäki, Geological
Survey of Finland.
No clear brittle faults, i.e., fractures, along which the markers (veins, dykes, other
fractures etc.) have moved past each other, have been observed. However, some
fractures show signs, which may indicate a faulting component (Fig. 2.3-10) but the
interpretations are uncertain.
B
Figure 2.3-10. N-S striking fracture with a possible sinistral brittle fault. OL-TK7,
section P24. The length of the plate is 12 cm. Photographs by Seppo Paulamäki,
Geological Survey of Finland.
46
47
3
SUMMARY AND DISCUSSION - GENERAL CORRELATIONS WITH
NEIGHBOURING TRENCHES, BOREHOLES AND CURRENT
BEDROCK MODEL
Investigation trench OL-TK7 is located in the southern part of the study site, between
boreholes KR4 and KR8. The rock types were determined macroscopically from the
bedrock surface, which was first cleaned by pressurised air and then washed by pressure
washer. Tectonic investigations included measurements of foliation, lineation, fold axis,
axial planes and fractures.
The main rock types in investigation trench TK7 are mica gneisses, migmatitic mica
gneisses, granitic grey gneisses and coarse-grained to pegmatitic granites. The
migmatitic mica gneisses in the trench can be divided into two main types: 1) vein
migmatites, in which the amount of granite leucosome veins varies from ca. 10% to
over 40%. The mesosome is fine- to medium-grained, biotite-rich mica gneiss with a
weak, mm-scale quartz-feldspar segregation banding, and 2) mica gneiss migmatites,
which are mostly (>70%) composed of coarse-grained granite leucosome, occurring as
0.5-15 cm wide, more or less linear veins. The melanocratic part of the migmatite
usually occurs as narrow, a few millimetre wide, biotite-rich schlieren (melanosome)
between the leucosome veins. Lensoid, amphibole or pyroxene-bearing skarn inclusions
occasionally occur within the vein migmatite. In places, fine- to medium-grained mica
gneiss with less than 10% of granite leucosome veins occurs. Grey, medium- to coarsegrained, gneiss with granitic composition and having migmatite inclusions occur in the
eastern part of the trench.
Investigation trench TK7 causes minor adjustments to the current lithological map
presented in the bedrock model by Vaittinen et al. (2003). On the basis of the
lithological map, the granite pegmatite unit PG24 of the bedrock model, located north of
borehole KR4 and determined on the basis of outcrop observations, should occupy most
of the first part of the trench. Since only narrow sections of granite pegmatite occur in
the beginning of the trench, the granite pegmatite unit does not extend as far to the SW
as predicted in the lithological map. Minor correction to the extent and shape of grey
gneiss unit GGN4 should also be made.
In borehole KR4, which runs across the trench under section P-1 at the depth of ca. 200
m, the main rock type is migmatitic mica gneiss similar to the one in the trench. Just as
in the trench between sections P-5 and P1, several narrow intersections of fine-grained
mica gneiss occur in the drill core sample (see Lindberg & Paananen 1990).
The strong weathering observed in investigation trench TK4 in sections P66-P69 and
P72-P74 (Paulamäki 2004) less than 50 m from TK7, does not continue to TK7. In the
eastern end of the trench, in sections P29 and P30, the unweathered mica gneiss is
overlain by ca. 2 metres of strongly weathered migmatitic mica gneiss and almost
completely weathered regolith. This weathering may have a large aerial extent since
both in boreholes KR22B and KR23B, located ca. 245 m and 150 m NE and E of the
eastern end of the trench, respectively, the core sample is strongly to completely
48
weathered from the surface to a depth of ca. 25 m (see Niinimäki 2002a, 2002b).
Furthermore, in borehole KR23, the drill core is slightly to strongly weathered to a
depth of ca. 56 m (Niinimäki 2002b). Since the foliation in the weathering profile dips
gently (20-35°) to E or ESE, it is possible that the weathering in the trench may
correspond to the weathering in the boreholes. The weathering in the trench seems to
have a limited extent to the S or SSW, since the drill core sample from borehole KR8,
located less than 40 m SSW from the weathering in the trench, is unweathered or only
slightly weathered (Rautio 1995).
The rock types of the investigation trench reveal a polyphase ductile deformation. The
earliest deformational features can be seen in some mica gneiss and skarn inclusions
within the migmatite, which have a fine banding and biotite schistosity (S1), and which
are isoclinally folded (F2A). These early deformation events were followed by the
development of a foliation S2B and intense production of granitic leucosome veins
parallel to the foliation, which more or less destroyed the early structures. The foliation
usually strikes ca. NE-SW and dips gently to the southeast. The migmatites were
intensely extended, as indicated by the granite leucosome veins and more competent
mica gneiss mesosome layers showing boudinage or pinch-and-swell structures. In later
deformation phases the migmatites were folded by three successive folding phases. The
main folding phase (F3) occurs as tight, and in places chevron-type, folds with a fold
axis gently (15 – 45°) plunging to the NE-ENE or SW-SSW. In places, narrow granite
veins and a weak dextral shearing/faulting occur parallel to the axial planes, dipping to
the SE.
During fracture mapping a total of 200 fractures, equal to or longer than one metre,
were investigated. Strike and dip, rock type, trace length, type fracture trace, form
(straight or curved), type (tight, open or filled), width and infilling, where present, were
recorded for each fracture. Most of the fractures strike ca. N-S, NNE-SSW and NE-SW.
In determining the fracture density (fractures/m) fractures cutting the median line of the
investigation trench were measured, the mean fracture density being 0.57 fractures/m.
The mean fracture trace length of all recorded fractures is 1.9 m, 33% of the fractures
being visible in their full length. Most of the measured fractures are either open or tight.
The aperture of the open fractures is usually some millimetres, and only few exceed 1
cm. Fractures with mineral infilling are sparse. In Table 3-1, the main characteristics of
the fractures in TK 7 are compared with the fracture characteristics in six other trenches
mapped so far at Olkiluoto.
No fracture zones (fracture density >10 fractures/m) occur in the trench. However, in
sections P-1, P1, P8, P17, P24 and P28, narrow zones of abundant fracturing (i.e. more
abundant than in the near surroundings) occur.
49
Table 3-1. Main characteristics of the fractures in investigation trenches TK1-TK7
(Paulamäki 1995, 1996, 2004; Lindberg & Paulamäki 2003; Paulamäki & Aaltonen
2004). N = both ends of fracture are visible, O = one of the ends is covered, P = both
ends are covered.
Trench
Trench
length
(m)
TK1
TK2
TK3
TK4
TK5
TK6
TK7
406
405
580
780
35
45
290
1)
Total
Average
number
fracture
of
density
fractures (fractures/m)1)
417
368
614
656
116
133
200
0.77
1.06
1.12
0.98
1.41
1.02
0.57
Mean
fracture
trace
length
(m)
2.2
1.9
2.1
1.4
2.2
2.1
1.9
Type of fracture Fracture character
trace
N
O
P Tigh Open Filled
%
%
%
t
%
%
%
46.2 39.7 14.1 67.3 31.3 1.4
31.4 40.4 28.2 39.6 58.5 1.9
29.8 19.2 51.0 61.9 37.4 0.7
27.6 41.9 30.4 35.1 59.1 5.8
55.2 33.6 11.2 34.5 65.5
67.0 24.0 9.0 46.6 53.4
33.0 37.5 29.5 37.2 59.7 3.1
Includes the fractures cutting the median line of trench
In Appendix 3, the contoured stereograms of investigation trenches TK5 and TK6 are
presented together with corresponding stereograms from TK7, sections P17-P22 and
P23-P28, respectively. Although the trenches are very close to each other and run
almost parallel, there are certain differences in the distribution of fracture orientations.
For instant, the NNW-SSE striking fracturing, which is the main fracture set in TK5, is
rather weak in TK7/P16-P22. In TK6, the NW-SE striking fracturing is very
pronounced, while in TK7 such fractures are much more rare. The most obvious
explanation for the differences is that trenches TK5 and TK6 are twice as wide as TK7.
Consequently, more fractures parallel or sub-parallel to the trench orientation can be
observed in TK5 and TK6.
Comparing the fracture orientations in the trench and in borehole KR23, located ca. 150
east of the trench and having the same orientation as the trench, it can be noticed that
the fractures in the drill core are mostly close to horizontal or gently (about 40°) dipping
to the SE (see Niinimäki 2002b). In the trench, the horizontal or sub-horizontal fractures
are sparse, most likely due to observation geometry. However, the fractures gently
dipping to the SE are well also represented in the trench (fracture set I). On the other
hand, N-S striking, sub-vertical fractures, which are common in the trench (fracture sets
II and IV), are almost absent in the drill core.
Structure R24 is the only fracture zone of the current bedrock model of Olkiluoto by
Vaittinen et al. (2003), which is supposed to be found in trench TK7. In the bedrock
model, structure R24 connects the fractured shear zones in trench TK1 and boreholes
R22 and R9, at 45.0 - 67.5 m and 146.4 - 151.1 m, respectively. The structure is
modelled as a liner zone with a dip direction/dip angle changing from 139/63º at TK1 to
139/33º at KR9. On the basis of investigations in TK7 and its surroundings, the
assumption of R24 being a linear and continuous fracture zone should be abandoned. In
the area of investigation trenches TK1, TK5 and TK7, the structure is a strongly folded
50
shear zone, the dip direction/dip angle varying from 084/50° to 158/60°. The fracturing
in trenches TK1 (Paulamäki 1995) and TK5 (Paulamäki & Aaltonen 2004) follows the
shear zone and it is related to weathered parts of the zone. The fractured zone is at its
widest in TK5, where it is ca. 3.5 m wide but it quite sharply dies out so that no
fracturing occurs in TK7 at about 15 m from TK5. The total length of the fractured zone
is only about 30 m. In TK7 and in the area NE of it, R24 continues solely as a shear
zone, at least 15 m in width, in which hardly any fractures occur. Consequently, it
seems likely that the fracturing in trenches TK1 and TK5 cannot be connected to the
fractured drill core section in boreholes KR22 and KR9. However, the shearing
observed both in the trenches and the boreholes are similar and can be parts of the same
shear zone.
On the basis of correlation between the trenches and the nearest boreholes KR23, KR26
and KR28, it is evident that the weathering and related fracturing observed in trenches
TK1 and TK5 is restricted to the very surface of the bedrock. Structure R24 should
intersect boreholes KR23, KR26 and KR28 at the depths of ca. 220 m, 12 m and 34 m,
respectively, but at those depths no fracturing or weathering occurs, which could be
connected to R24.
51
4
REFERENCES
Gardemeister, R., Johansson, S., Korhonen, P., Patrikainen, P., Tuisku, T. & Vähäsarja,
P. 1976. Application of the Finnish engineering geological classification (in Finnish).
Espoo, Finland: Technical Research Centre of Finland, Geotechnical laboratory,
Research note 25, 38 p.
Korhonen, K-H., Gardemeister, R., Jääskeläinen, H., Niini, H. & Vähäsarja, P. 1974.
Engineering geological bedrock classification (in Finnish). Espoo, Finland: Technical
Research Centre of Finland, Geotechnical laboratory, Research note 78, 78 p.
Lindberg, A. & Paananen, M. 1991. Petrography, lithogeochemistry and petrophysics of
rock samples from Olkiluoto study site, Eurajoki, western Finland. Helsinki, Finland:
Teollisuuden Voima Oy. Working Report 90-10, 65 p.
Lindberg, A. & Paulamäki, S. 2003. Geological mapping of the investigation trench
OL-TK3 at the Olkiluoto study site, Eurajoki, SW Finland. Posiva Oy, Working report
2003-40, 75 p.
Mengel, K., Richter, M. & Johannes, W. 2001. Leucosome-forming small-scale
geochemical processes in the metapelitic migmatites of the Turku area, Finland. Lithos
56, pp. 47-73.
Niinimäki, R. 2002a. Core drilling of deep borehole OL-KR22 at Olkiluoto in Eurajoki
2002. Helsinki, Finland: Posiva Oy. Working Report 2002-59, 198 p.
Niinimäki, R. 2002b. Core drilling of deep borehole OL-KR23 at Olkiluoto in Eurajoki
2002. Helsinki, Finland: Posiva Oy. Working Report 2002-60, 137 p.
Paulamäki, S. 1995. Geological bedrock and fracture mapping of the investigation
trench TK1 at the Olkiluoto study site, Eurajoki, western Finland (in Finnish with an
English abstract). Helsinki, Teollisuuden Voima Oy/Site investigation project, Work
Report PATU-95-81, 24 p.
Paulamäki, S. 1996. Geological bedrock and fracture mapping of the investigation
trench TK2 at the Olkiluoto study site, Eurajoki, western Finland (in Finnish with an
English abstract. Helsinki, Posiva Oy, Work Report PATU-96-61, 30 p.
Paulamäki, S. 2004. Geological mapping of the investigation trench OL-TK4 at the
Olkiluoto study site, Eurajoki, SW Finland. Posiva Oy, Working report 2004-XX, 101
p.
Paulamäki, S. & Koistinen, T.J. 1991. Interpretation of the geological structures of the
Olkiluoto area, Eurajoki, western Finland (in Finnish with an English abstract).
Helsinki, Finland: Teollisuuden Voima Oy/Site investigations, Work Report 91-62,
34 p.
52
Paulamäki, S. & Aaltonen, I. 2004. Geological mapping of the investigation trenches
OL-TK5 and OL-TK6 at the Olkiluoto study site, Eurajoki, SW Finland. Posiva Oy,
Working report 2004-XX, 43 p.
Posiva Oy 2003. Baseline Conditions at Olkiluoto. Eurajoki, Finland: Posiva Oy, Posiva
report 2003-2, 121 p.
Rautio, T. 1995. Core drilling of deep borehole OL-KR8 at Olkiluoto in Eurajoki.
Helsinki, Finland: Teollisuuden Voima Oy. Working Report PATU-95-22, 24 p.
Vaittinen, T., Ahokas, H., Heikkinen, E., Hellä, P., Nummela, J., Saksa, P., Tammisto,
E., Paulamäki, S., Paananen, M., Front, K. & Kärki, A. 2003. Bedrock model of the
Olkiluoto site, version 2003/1. Eurajoki, Finland: Posiva Oy, Work report 2003-43.
53
APPENDICES
Appendix 1: Observations of ductile deformation (foliation, fold axis, axial planes,
lineations)
Appendix 2: Fracture measurements
Appendix 3. Fracture orientations in the investigation trench TK7
Appendix 4: Bedrock of the investigation trench 1:850
Appendix 1: Measurements and observations of ductile deformation (foliation, fold axis, axial planes, lineations) in investigation trench TK7.
See end of table for explanation of abbreviations.
SECTION
SECTION P-5
SECTION P-4
SECTION P-3
SECTION P-2
SECTION P-1
SECTION P1
SECTION P2
X (M)
6792088,105
6792085,489
6792084,975
6792084,659
6792083,429
6792080,828
6792079,774
6792079,569
6792076,85
6792075,923
6792074,988
6792071,64
6792071,3
6792069,572
6792068,059
6792068,059
6792068,016
6792066,242
6792063,121
6792061,144
6792060,709
6792060,653
6792059,531
6792058,225
6792057,933
6792057,933
6792056,511
6792056,511
6792056,511
6792055,417
6792055,162
6792055,162
6792052,536
6792052,536
6792051,807
6792051,807
6792051,556
6792051,17
6792050,332
6792047,997
Y (M)
1525863,03
1525865,786
1525866,328
1525866,648
1525867,893
1525870,525
1525871,592
1525871,8
1525874,512
1525875,437
1525876,369
1525879,71
1525880,049
1525881,827
1525883,384
1525883,384
1525883,428
1525885,232
1525888,404
1525890,415
1525890,857
1525890,914
1525892,054
1525893,382
1525893,656
1525893,656
1525894,99
1525894,99
1525894,99
1525896,016
1525896,255
1525896,255
1525898,718
1525898,718
1525899,403
1525899,403
1525899,638
1525899,987
1525900,745
1525902,858
Z (M)
3,686
3,970
4,098
3,957
3,973
3,871
3,893
3,906
3,697
3,799
3,913
4,633
4,821
4,878
5,303
5,303
5,309
4,705
4,804
5,214
5,197
5,204
5,480
6,499
6,475
6,475
6,622
6,622
6,622
6,826
6,897
6,897
7,345
7,345
7,501
7,501
7,561
7,582
7,631
7,909
ROCK
TYPE
STRUCTURAL
ELEMENT
DIP
DIRECTION
(°)
DIP (°)
REMARKS
VMGT
S
115
40
MGT
MGT
MGT
MGT
S
S
S
S
167
143
132
140
35
35
45
40
MGT
MGT
MGT
MGT
S
S
S
S
110
100
115
124
48
45
45
50
MGT
MGT
MGT
S
S
FA
100
115
18
40
80
MGN
MGT
MGT
MGT
MGT
MGT
S
S
S
FA
S
S
60
130
114
55
100
109
40
30
45
30 F3
40
18
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
S
L
FA
AP
FA
S
FA
AP
S
FA
S
FA
65
120
160
70
99
125
215
125
160
115
125
160
45
15
40
30
35
52
45
55
35
42
55
25
VMGT
VMGT
VMGT
S
S
S
161
144
158
52
47
35
TIGHT
TIGHT TO ISOCLINAL
OPEN, REFOLDS FA = 160/40
TIGHT TO ISOCLINAL
OPEN, WAVELENGTH C. 2 M AND AMPLITUDE C. 50 CM
OPEN, WAVELENGTH C. 2 M AND AMPLITUDE C. 50 CM
Appendix 1 (54)
SECTION
SECTION P3
SECTION P4
SECTION P5
SECTION P6
X (M)
Y (M)
Z (M)
ROCK
TYPE
STRUCTURAL
ELEMENT
VMGT
FA
70
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
S
S
S
S
S
S
FA
140
130
131
147
160
146
65
43
55
25
50
45
55
VMGT
VMGT
VMGT
VMGT
VMGT
S
S
FP
S
S
145
155
105
164
165
38
36
65 DEXTRAL SHEAR/FAULT ZONE, 10 CM
30
35
VMGT
VMGT
VMGT
VMGT
VMGT
S
S
S
FA
S
170
155
163
75
170
48
25
54
55 ISOCLINAL, F2? DISTANCE BETWEEN THE FOLD LIMBS IS C. 45 CM.
32
VMGT
VMGT
9,220 VMGT
9,185 VMGT
S
FA
S
FA
174
290
191
35
9,267
9,257
9,273
9,290
9,339
9,054
8,989
7,414
6,482
8,463
8,379
8,379
8,444
8,461
VMGT
VMGT
VMGT
VMGT
S
FA
S
S
190
190
145
148
10
15 TIGHT, DEXTRAL FOLDING ON THE SW-SIDE
18
22 TIGHT, F3. 1CM WIDE SHEARS PARALLEL TO THE AXIAL PLANE.
REFOLDS ISOCLINAL FOLDING.
35
15 TIGHT
40
35
VMGT
VMGT
S
FA
75
265
70
40
VMGT
S
180
60
MGN
MGN
MGN
MGN
FA
AP
S
S
268
185
43
65
15
70
55
38
6792047,997
6792047,316
6792045,527
6792042,52
6792041,518
6792039,192
6792037,224
6792036,758
1525902,858
1525903,474
1525905,22
1525908,153
1525909,13
1525911,4
1525913,32
1525913,774
7,909
8,011
8,016
8,183
8,198
8,464
8,702
8,757
6792035,792
6792035,291
6792034,216
6792033,5
6792033,249
6792032,855
6792032,634
6792032,435
6792030,779
6792028,594
6792028,329
6792025,978
6792025,728
6792025,063
1525914,717
1525915,206
1525916,252
1525916,95
1525917,194
1525917,578
1525917,794
1525918,019
1525919,892
1525922,364
1525922,664
1525925,324
1525925,606
1525926,284
8,880
8,808
8,958
8,988
9,013
9,035
9,057
8,961
8,866
9,002
9,047
9,187
9,202
9,133
6792022,927 1525928,461
6792022,612 1525928,783
6792020,721
6792019,601
6792019,215
6792018,235
SECTION P7
6792017,695
6792015,487
6792013,777
SECTION P9
6792001,587
6791999,506
SECTION P12 6791991,582
6791991,47
6791991,47
6791990,742
6791989,762
1525930,71
1525931,852
1525932,245
1525933,244
1525933,795
1525935,97
1525937,655
1525949,681
1525953,213
1525967,213
1525967,379
1525967,379
1525968,456
1525969,906
DIP
DIRECTION
(°)
DIP (°)
REMARKS
ISOCLINAL, F2?
ISOCLINAL, F2?
Appendix 1 (55)
SECTION
X (M)
Y (M)
SECTION P13 6791989,177 1525970,771
6791988,821 1525971,487
6791988,353 1525972,427
6791987,898
1525973,34
Z (M)
ROCK
TYPE
9,240
9,248 VMGT
9,149 MGN
9,338 VMGT
STRUCTURAL
ELEMENT
DIP (°)
6791987,261
6791987,2
6791986,968
6791986,709
6791986,221
6791986,055
6791986,055
6791985,904
6791985,73
6791985,266
6791984,841
6791984,492
6791984,454
1525974,621
1525974,743
1525975,296
1525975,914
1525977,076
1525977,473
1525977,473
1525977,832
1525978,247
1525979,354
1525980,368
1525981,198
1525981,29
9,446
9,453
9,261
9,009
9,116
8,901
8,901
8,886
9,102
8,927
8,541
9,023
9,084
MGT
S
115
MGT
MGT
VMGT
VMGT
VMGT
MGT
MGT
MGT
MGT
VMGT
VMGT
S
S
FA
S
S
S
AP
FA
S
S
FA
120
100
225
90
115
80
78
55
135
125
60
40
30
30
30
35
25
20
35
35
26
45
6791984,222
6791983,893
SECTION P15 6791983,738
6791983,129
6791982,622
1525981,844
1525982,628
1525982,997
1525983,889
1525984,632
9,332
9,483
9,568
9,345
9,265
VMGT
VMGT
S
S
102
105
35
35
MGT
MGT
MGT
S
S
FA
90
85
55
9,475 MGT
9,484 MGT
S
FA
69
74
MGT
S
92
MGN
VMGT
VMGT
S
S
S
160
146
125
35
45
75
VMGT
VMGT
VMGT
VMGT
VMGT
VMGT
S
S
S
FA
FA
AP
150
60
77
145
205
115
45
25
50
25 ISOCLINAL
35 TIGTH, REFOLDS THE ISOCLINAL FOLDING WITH FA = 145/25.
82
6791981,821 1525985,805
6791981,539 1525986,218
6791980,051
SECTION P16 6791979,859
6791979,205
6791977,285
6791976,293
SECTION P17 6791975,916
6791975,696
6791974,419
6791972,526
1525988,398
1525988,679
1525990,084
1525994,209
1525996,34
1525997,151
1525997,6
1526000,204
1526004,064
9,267
9,420
9,078
7,861
8,774
9,590
9,435
9,321
10,527
58
60
35
REMARKS
54
42
45 TIGHT, F3. 1CM WIDE SHEARS PARALLEL TO THE AXIAL PLANE.
REFOLDS ISOCLINAL FOLDING.
45
SECTION P14
S
S
FA
DIP
DIRECTION
(°)
RATHER TIGHT, SINISTRAL, F3
SSW-SIDE
NNE-SIDE
20 CM WIDE STRONGLY FOLIATED, WEATHERED ZONE
ISOCLINAL
SINISTRAL, F3. REFOLDS ISOCLINAL FOLDING WITH AP = 078/20
OPEN, F3. REFOLDS ISOCLINAL FOLDING WITH FA PARALLEL TO THE
TREND OF THE FOLIATION
38
45
50 LARGE OPEN FOLD COMPRISING WHOLE OF THE SSW-SIDE OF THE
TRENCH.
47
25 TIGHT TO OPEN FOLDING, WAVELENGTH C. 40 CM AND AMPLITUDE C.
30 CM. REFOLDS TIGHT TO ISOCLINAL FOLDING WITH FA PARALLEL
TO THE R´TREND OF THE FOLIATION (FA = 020/-).
46
Appendix 1 (56)
SECTION
X (M)
Y (M)
Z (M)
ROCK
TYPE
STRUCTURAL
ELEMENT
SECTION P20 6791965,676 1526016,793
6791965,365
1526017,42
6791965,254 1526017,644
VMGT
11,338 VMGT
VMGT
VMGT
11,436
11,638 VMGT
11,638 VMGT
11,828 VMGT
11,828 VMGT
11,933 VMGT
11,933 VMGT
12,048 VMGT
12,173 VMGT
12,201
12,361 VMGT
12,471 VMGT
12,640 VMGT
12,750 VMGT
12,750 VMGT
VMGT
12,844
12,890 VMGT
12,913 VMGT
6791965,254
6791965,254
6791964,831
6791964,831
6791964,831
6791964,609
6791963,141
SECTION P21 6791962,826
6791962,523
6791962,523
1526017,644
1526017,644
1526018,495
1526018,495
1526018,495
1526018,943
1526021,898
1526022,533
1526023,219
1526023,219
12,913 VMGT
12,913 VMGT
13,003 VMGT
13,003 VMGT
13,003 VMGT
13,060 VMGT
13,350 VMGT
13,447
13,463 VMGT
13,463 VMGT
AP
FA
FA
AP
FA
S
S
140
120
60
150
120
147
159
S
FA
40
55
6791961,898 1526024,638
6791959,296 1526030,539
13,557 VMGT
13,910 VMGT
S
FA
150
62
13,919 VMGT
13,999 VMGT
14,178 VMGT
14,202
FA
FA
FA
80
63
68
6791970,765 1526007,656
SECTION P18 6791970,508
6791969,856
6791969,856
6791969,18
6791969,18
6791968,947
6791968,947
6791968,411
6791968,178
SECTION P19 6791968,154
6791967,538
6791966,999
6791966,384
6791965,999
6791965,999
6791959,236
6791959,034
6791957,985
SECTION P22 6791957,824
1526008,179
1526009,418
1526009,418
1526010,701
1526010,701
1526011,143
1526011,143
1526012,16
1526012,603
1526012,648
1526013,678
1526014,579
1526015,609
1526016,253
1526016,253
1526030,677
1526031,134
1526033,513
1526033,879
FA
S
L
FA
DIP
DIP (°)
DIRECTION
(°)
160
90
130
130
REMARKS
30 OPEN, REFOLDS FA = 205/35 AND AP = 115/82.
75
10 OCCASIONALLY ON THE SW-SIDE.
10 OPEN, REFOLDS TIGHT FOLDING WITH FA = 205/-.
FA
AP
FA
AP
FA
AP
S
S
195
105
200
110
210
130
140
125
40 TIGHT
80
45 TIGHT
80
30 TIGHT
65
45
53
S
S
S
FA
AP
FA
140
142
144
200
110
90
60
50
70
35 TIGHT
85
38 TIGHT, YOUNGER THAN FA = 200/35
S
FA
145
50
50
35 TIGHT, SINISTRAL. 2 CM WIDE SHEAR ZONE 150/70
SEMICONCORDANTLY TO THE AXIAL PLANE.
65
40 MORE OPEN, REFOLDS FA = 050/35.
35 TIGHT
55
25 MORE OPEN, REFOLDS FA = 060/35.
45
74
30
30 TIGHT, DEXTRAL. 1 CM WIDE SHEAR ZONE 150/35° CONCORDANTLY
TO THE AXIAL PLANE.
35
40 TIGHT, CHEVRON-TYPE FOLDING WITH OCCASIONAL NARROW GRVEINS PARALLEL TO THE AXIAL PLANE.
55 TIGHT
40 TIGHT
35 TIGHT
Appendix 1 (57)
SECTION
X (M)
Y (M)
6791956,951 1526035,338
6791956,633
1526035,87
6791955,709 1526037,415
Z (M)
ROCK
TYPE
6791936,599 1526076,128
SECTION P28 6791935,606 1526078,637
6791934,641 1526080,036
14,159 VMGT
14,084 VMGT
13,940 VMGT
VMGT
14,081 VMGT
14,073 VMGT
14,098 VMGT
14,108 VMGT
14,104 VMGT
14,102
13,956 VMGT
13,451 VMGT
VMGT
13,245 GGN
13,685 GGN
13,722 GGN
13,756
13,246 VMGT
13,056 VMGT
14,259 GGN
14,345
14,335 GGN
GGN
GGN
14,379
13,445 GGN
13,191 VMGT
13,162
GR
12,009 VMGT
11,702
11,146 VMGT
6791934,47
6791930,495
6791926,111
SECTION P29 6791926,283
6791926,243
6791926,211
6791925,967
6791925,883
11,063
8,986
8,169
8,262
8,114
8,040
8,355
8,578
6791953,152
6791952,613
6791952,305
6791951,663
6791951,355
SECTION P23 6791951,254
6791951,163
6791949,957
1526041,688
1526042,589
1526043,104
1526044,177
1526044,691
1526044,86
1526045,038
1526047,409
6791948,714
6791947,286
6791946,673
SECTION P24 6791946,295
6791945,695
6791945,615
6791942,215
SECTION P25 6791941,869
6791941,66
1526049,851
1526052,658
1526053,862
1526054,605
1526055,98
1526056,163
1526063,954
1526064,747
1526065,309
SECTION P26 6791941,164 1526066,641
6791939,776 1526069,301
6791938,527 1526071,694
SECTION P27 6791937,814
1526073,06
1526080,283
1526086,045
1526092,399
1526092,15
1526092,648
1526093,047
1526096,087
1526097,134
STRUCTURAL
ELEMENT
DIP
DIRECTION
(°)
DIP (°)
REMARKS
FA
S
S
FA
S
S
S
S
FA
90
160
155
155
136
110
105
115
45
45
45
48
50
70
65
55
40
40
TIGHT, SINISTRAL
S
FA
FA
FA
S
S
135
65
40
80
130
140
65
60
25
30
55
80
S
S
S
140
150
150
75
60
90
S
FA
FA
140
55
60
85
25
30
S
S
142
130
63
80
FA
S
180
144
55 TIGHT
18
FA
210
VMGT
MGN
MGN
S
S
S
195
84
115
15 TIGHT FOLDING WITH NARROW SHEAR ZONES 125/85°
CONCORDANTLY TO THE AXIAL PLANE.
60
20
20
MGT
MGT
VMGT
VMGT
S
S
S
S
125
152
91
90
50
35
17 STRONGLY WEATHERED
25 STRONGLY WEATHERED
RATHER OPEN. REFOLDS TIGHT FOLDING (F3).
WITHIN THE SHEAR ZONE
WITHIN THE SHEAR ZONE
WITHIN THE SHEAR ZONE
WITHIN THE SHEAR ZONE
TIGHT, F3
Appendix 1 (58)
SECTION
X (M)
Y (M)
SECTION P30 6791925,864 1526097,369
6791924,674 1526099,624
6791924,253
1526100,42
6791923,647
1526101,57
6791923,427 1526101,985
Z (M)
8,598
8,869
8,965
9,103
9,153
ROCK
TYPE
STRUCTURAL
ELEMENT
VMGT
VMGT
VMGT
VMGT
S
S
S
S
DIP
DIRECTION
(°)
112
120
118
110
DIP (°)
REMARKS
22
46
30
35
VERY STRONGLY WEATHERED AND FOLIATED
VERY STRONGLY WEATHERED AND FOLIATED
VERY STRONGLY WEATHERED AND FOLIATED
STRONGLY WEATHERED
ABBREVIATIONS:
MGN = MICA GNEISS, MGT = MICA GNEISS MIGMATITE, VMGT = VEIN MIGMATITE, GGN = GREY GNEISS, GR = GRANITE/GRANITE PEGMATITE
S = FOLIATION, FA = FOLD AXIS, AP = AXIAL PLANE, FP = FAULT PLANE, L = LINEATION
Appendix 1 (59)
Appendix 2: Fracture measurements and observations in investigation trench TK7. See end of table for explanation of abbreviations.
SECTION
LENGTH (M)
POSITION (M) POSITION
(CM)
X (M)
Y (M)
Z (M)
DIP DIRECTION DIP
4,546834504 SECTION P-5
6792088,105
1525863,03
3,686
7,692049142 SECTION P-4
0,8
1,53
2,61
11,67999837 SECTION P-3
6792084,975
6792084,413
6792083,9
6792083,141
6792079,569
1525866,328
1525866,897
1525867,416
1525868,185
1525871,8
4,098
3,878
3,720
3,753
3,906
6792071,3
1525880,049
4,821
ROCK TYPE TRACE
TYPE OF
LENGTH FRACTURE
(M)
TRACE
SHAPE
CHARACTER APERTURE
(CM)
INFILLING
REMARKS
NO FRACTURES
20
34
28
60
68
260
70 VMGT
70 VMGT
30 VMGT
1O
2P
1P
S
M
M
TI
OP
OP
0,2
0,1
OPENED BY FROST
NO FRACTURES
4,711931345 SECTION P-2
NO FRACTURES
13,96229913 SECTION P-1
0,34
3,7
4,35
5,18
5,63
5,8
6,5
8,93
10,5
13,48
9,14401974 SECTION P1
0,27
5,56
5,7
6,01
6,01
7,65
8,2
5,717735216 SECTION P2
5,5
16,09992624 SECTION P3
12,3
15,02
4,409182805 SECTION P4
0,7
1,05
2
2,47
2,97
10,42689695 SECTION P5
0,39
3,17
5,66
5,95
6,57
7,05
7,28
7,28
9,75
10,1
11,47121659 SECTION P6
0,83
2,74
7,65
8,72
9,56
10,3
10,56
16,55383756 SECTION P7
0,18
3,48
14
91
35
59
63
6792068,016
6792067,778
6792065,421
6792064,966
6792064,384
6792064,068
1525883,428
1525883,67
1525886,066
1525886,529
1525887,121
1525887,442
5,309
5,198
4,714
5,330
5,160
5,159
100
82
6792063,458
6792061,754
1525888,062
1525889,794
4,863
5,250
6792058,563
6792058,225
12 6792058,028
7
6792054,17
5 6792054,068
3 6792053,842
3 6792053,842
7 6792052,646
5 6792052,245
6792051,556
2 6792047,477
6792047,316
23 6792038,512
8 6792036,565
6792035,792
10 6792035,291
6
6792035,04
3
6792034,36
3 6792034,023
4 6792033,665
6792032,634
17 6792032,376
23 6792030,534
19 6792028,885
19 6792028,693
6792028,283
8 6792027,965
6792027,812
19 6792027,812
1525893,038
1525893,382
1525893,567
1525897,186
1525897,282
1525897,494
1525897,494
1525898,616
1525898,992
1525899,638
1525903,328
1525903,474
1525912,063
1525913,963
1525914,717
1525915,206
1525915,45
1525916,113
1525916,441
1525916,79
1525917,794
1525918,086
1525920,169
1525922,035
1525922,252
1525922,716
1525923,076
1525923,248
1525923,248
6,388
6,499
6,410
7,075
7,111
7,167
7,167
7,317
7,401
7,561
7,974
8,011
8,445
8,742
8,880
8,808
8,862
8,930
8,949
8,959
9,057
8,892
8,871
8,946
8,950
9,148
9,075
9,158
8,968
1525925,099
1525925,361
1525925,606
1525926,199
1525927,562
1525931,067
1525931,831
1525932,431
1525932,959
1525933,145
1525933,795
1525933,921
1525936,237
9,123
9,187
9,202
9,092
9,145
9,233
9,246
9,246
9,255
9,278
9,339
9,294
8,994
7
7
1
12
9
6
6
7
7
5
4
25
6792026,176
6792025,945
6792025,728
6792025,147
6792023,809
6792020,371
6792019,622
6792019,033
6792018,515
6792018,333
6792017,695
6792017,567
6792015,216
255
265
266
266
265
30
300
171
60
75
50
77
77
77
80
60
85
70
85
20
VMGT
MGN
MGN
MGN
MGN
MGN
VMGT
GR
MGN
GR
1
1,5
2
3
1,5
2,5
1
2
1
1
N
P
O
O
O
P
O
P
O
O
K
S
S
S
S
S
S
M
S
M
TI
TI
FI
OP
OP
OP
OP
OP
TI
TI
150
256
252
255
255
160
160
35
87
85
75
87
35
30
MGT
MGT
MGT
MGT
MGT
MGT
MGT
1
1,4
1,2
1,2
2
1,5
1,5
O
O
O
O
O
N
N
M
S
K
S
S
M
M
TI
OP
OP
TI
OP
OP
OP
1N
M
TI
85
75 GRGN
0,1 CALS
0,5
0,5
0,3
0,2
0.2-1
ENDS UP TO FRACTURE 30/60
ENDS UP TO FRACTURE 30/61
SW-SIDE
OPENED BY FROST
0,1
0,1
ENDS UP TO FRACTURE 256/87
0,1
0,1
0,1
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
180
202
35 MGT
40 MGT
4,5 N
6,5 N
M
S
OP
OP
0,1
0,2
STRONGLY UNDULATING
145
130
155
150
150
38
35
35
40
15
1,5
1,5
1,5
2
1
O
O
O
O
O
M
M
M
S
S
OP
OP
OP
OP
TI
0,1
0,1
0,1
0,2
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
APPR. PARALLEL TO THE FOLIATION
APPR. PARALLEL TO THE FOLIATION
170
156
140
310
10
83
91
140
45 MGT
25 MGT
55 MGT
40 MGT
75 MGN
75 MGN
75 MGN
65 MGT
1O
1O
1,5 O
2P
0,8 N
1N
1N
1O
M
M
M
M
S
S
S
S
OP
OP-TI
TI
OP
OP
OP
OP
OP
0,1
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
170
85
35 MGT
75 MGT
2O
1N
M
M
OP
OP
150
200
265
105
155
150
150
76
10
80
60
35
35
35
P
P
P
O
P
P
O
S
M
M
M
M
M
M
TI
OP
TI
OP
OP
OP
OP
94
255
65 GR
82 MGT
1N
2,5 P
K
S
OP
OP
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
1,5
2,5
1,5
1,5
2
2
1,5
0.1-0.4
0,1
0.1-0.5
0.5-2
1
0,1
NE-SIDE
OPENED BY FROST
OPENED BY FROST, NE-SIDE
PARALLEL TO THE FOLIATION, IN
VMGT/MGN CONTACT
0.1-0.5
0,1
0,4
0,1
0,1
0,1
0,1
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
0,2
0,4
Appendix 2 (60)
SECTION
LENGTH (M)
3,48
25 6792015,216 1525936,237
8,994
170
POSITION (M) POSITION X (M)
Y (M)
Z (M)
DIP DIRECTION DIP
(CM)
3,61
8,38
9,36
11,16
11,16
12
12,9
13,35
13,95
16,08
16,1
16,33
6,069891761 SECTION P8
0,47
0,84
2,37
3,47
3,55
3,55
3,85
4
6,876969245 SECTION P9
5
8,535709051 SECTION P10
18
20
24
31
31
31
31
6792015,123
6792011,725
6792011,027
6792009,745
6792009,745
6792009,146
6792008,505
1525936,328
1525939,676
1525940,364
1525941,627
1525941,627
1525942,216
1525942,848
9,060
8,910
8,843
8,724
8,724
8,701
8,677
17
6792007,757
1525943,585
8,788
2
6792006,061
6792005,902
6792005,568
6792005,305
6792004,217
6792003,435
6792003,378
6792003,378
6792003,165
6792003,058
6792001,587
1525945,255
1525945,412
1525945,743
1525946,003
1525947,079
1525947,852
1525947,909
1525947,909
1525948,12
1525948,225
1525949,681
8,873
8,887
8,733
8,683
8,232
7,645
7,546
7,546
7,383
7,316
7,414
6791998,096
1525955,606
6,153
6791994,444
1525963,321
5,120
4
0
8
40
48
48
57
60
O
TYPE OF
FRACTURE
TRACE
O
P
N
P
O
O
P
P
P
O
O
O
S
SHAPE
TI
CHARACTER APERTURE
(CM)
164
290
5
190
162
182
95
184
93
5
260
103
85 GR
1,5
ROCK TYPE TRACE
LENGTH
(M)
88 GR
1,5
70 "MGN"
2,5
67 "MGN"
0,9
65 "MGN"
3
65 "MGN"
1,5
82 "MGN"
1
70 "MGN"
2
65 "MGN"
1
60 MGT
2,5
67 MGT
1
80 MGT
1
75 MGT
1,5
M
M, K
M
S
S
S
M
S
K
M
S
M
TI
TI
TI
TI
TI
TI
270
80
325
90
75
85
89
105
68
82
65
75
75
85
65
65
O
N
O
O
O
P
P
P
S
S
K
S
S
S
K
S
TI-FI
TI-FI
TI
TI
TI
TI
TI-FI
TI-FI
160
35 MGN
1P
S
TI
MGN
MGN
MGN
MGN
MGN
MGN
MGN
MGN
1,5
1,25
1
1
1
1,5
1,5
1,5
TI
OP
TI
INFILLING
ENDS UP TO FRCTURE 255/82
REMARKS
ENDS UP TO FRCTURE 255/82
EN ECHELON (5 FRACTURES)
UNDULATING FRACTURE SURFACE
ENDS UP TO FRACTURE 190/65
RIGTH-SIDE JUMPING
COVERED WITH WATER
SW-SIDE, COVERED BY WATER
COVERED WITH WATER
NE-SIDE
SW-SIDE
0.1-0.2
0,1 FSP
0,1 FSP
ENDS UP TO FRACTURE 85/85
0,1 CALS+CLAY MIN.
0,1 CALS+CLAY MIN.
SW-SIDE
NO FRACTURES!
4,831015214 SECTION P11
NOT OPENED
4,294576696 SECTION P12
1,56
2,04
3,3
3,66
3,53
4,436813384 SECTION P13
0,3
0,7
0,9
1,15
1,78
2,9
3,65
3,4
8,950640201 SECTION P14
1,68
1,8
1,86
2,45
2,6
3,86
4,58
6,85
8,48
6,8798085 SECTION P15
0,95
1,4
2,94
5,45
5,8
6,62
9,344625889 SECTION P16
4,2
34
67
59
64
61
5
2
3
6791991,582
6791990,708
6791990,44
6791989,734
6791989,532
6791989,605
6791989,177
6791989,043
6791988,865
6791988,776
1525967,213
1525968,505
1525968,903
1525969,947
1525970,245
1525970,138
1525970,771
1525971,04
1525971,398
1525971,577
8,463
8,405
8,162
8,470
8,485
8,492
9,240
9,204
9,254
9,253
21
6791988,384
1525972,365
9,115
2
6791987,551
1525974,039
9,395
6791987,2
6791986,55
6791986,504
6791986,481
6791986,252
6791986,194
6791985,707
6791985,429
6791984,551
6791983,92
6791983,738
6791983,202
6791982,949
6791982,08
6791980,665
1525974,743
1525976,292
1525976,403
1525976,458
1525977,002
1525977,141
1525978,303
1525978,967
1525981,06
1525982,563
1525982,997
1525983,782
1525984,153
1525985,425
1525987,498
9,453
8,895
8,846
8,917
9,104
9,066
9,063
8,992
8,441
9,432
9,568
9,248
9,268
9,315
9,051
58
63
56
38
42
44
52
110
13
30
27
19
40
13
160
6791980,005
6791979,859
6791978,087
1525988,464
1525988,679
1525992,487
9,296
9,420
7,896
300
154
64
100
330
80
55
60
58
80
135
235
300
195
30 MGT
65 VMGT
60 VMGT
75
VMGT
42 VMGT
65 VMGT
45 VMGT
60
185
105
MGN
MGN
MGN+VMGT
VMGT
VMGT
1
1
1,5
3
1
N
N
N
P
S
S
M
S
TI
TI
TI
OP
0,6 N
1,5 N
1,5 O
1N
M
M
M
S
OP
OP
TI
OP
0,2
0,1
1,5 N
2N
0,6 N
M
M
M
OP
OP
OP
0,1
0,2
0,2
SOIL
ENDS UP TO FRACTURE 100/60
210
50 VMGT
1,5 N
M
OP
300
290
287
316
320
350
355
120
100
74
70
75
80
80
85
85
30
40
1,5
2
2
1
1,5
3
3
1,5
1,5
O
P
P
O
O
O
O
P
O
S
S
S
S
K
M
M
M
M
TI-OP
TI
TI
TI
TI-OP
OP
OP
OP
TI
85
180
75
100
14
1O
3O
3P
1,5 O
1,5 N
S
M
M
M
S
OP
OP
OP
OP
OP
345
32 VMGT
25 VMGT
50 VMGT
20 VMGT
78
VMGT
58 VMGT
3P
M
OP
90
35 VMGT
2P
S
OP
VMGT
VMGT
MGT
MGT
MGT
VMGT
VMGT
VMGT
VMGT
ENDS UP TO FRACTURE 100/58
0.5-1
0,1
0,5
ENDS UP TO FRACTURE 195/75
NNE-SIDE, ENDS UP TO FRACTURE
235/65
PARALLEL TO THE FOLIATION
SSW-SIDE
BETWEEN FRACTURES 185/65 AND
210/50
NNE-SIDE
0.1-0.2
0,3
OPENED BY FROST
OPENED BY FROST
OPENED BY FROST
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
0,1
0,3
0,2
PARALLEL TO THE FOLIATION
0,1
NNE-SIDE, ENDS UP TO FRACTURE
345/58
0.5-1
0.5-2
PARALLEL TO THE FOLIATION
0,1
Appendix 2 (61)
SECTION
LENGTH (M)
5,45
170 6791977,559
1525993,62
7,819
296
POSITION (M) POSITION X (M)
Y (M)
Z (M)
DIP DIRECTION DIP
(CM)
8,45
9
9,09
12,28264011 SECTION P17
1,93
2,63
2,65
3,03
3,15
4,35
4,78
6,6
8,5
10,4
10,82
11,03
5,051066917 SECTION P18
0,27
1,55
3,86
4,95
4,829234826 SECTION P19
1,35
2,04
2,62
3,09
3,56
6,40859579 SECTION P20
0,6
1,5
12,39966612 SECTION P21
5,6
7,4
9,01
11,1
11,58
11,83
12,79637687 SECTION P22
0,31
1,81
2,75
2,7
2,75
4,5
4,7
5,18
5,32
5,56
5,84
6,75
6,98
7,49
10,7
11,71
10,93419892 SECTION P23
2,2
3,2
3,54
4,15
5,75
6,25
74
52
52
6791976,293
6791976,061
6791976,023
6791975,916
6791975,066
6791974,758
6791974,749
6791974,582
6791974,529
6791974,001
6791973,811
6791973,01
6791972,173
6791971,337
1525996,34
1525996,839
1525996,92
1525997,151
1525998,884
1525999,512
1525999,53
1525999,871
1525999,979
1526001,057
1526001,443
1526003,077
1526004,783
1526006,489
8,834
9,064
9,065
9,590
9,260
9,235
9,228
9,215
9,253
9,444
9,558
9,722
10,407
10,953
6791971,06
6791970,508
3 6791970,382
10 6791969,786
10 6791968,709
10 6791968,201
6791968,154
5 6791967,461
1526007,054
1526008,179
1526008,418
1526009,55
1526011,594
1526012,559
1526012,648
1526013,807
11,128
11,436
11,447
11,571
11,921
12,086
12,201
12,331
6791967,107
6791966,81
6791966,568
6791966,327
6791965,676
6791965,409
6791965,009
6791962,826
6791960,567
6791959,841
6791959,191
6791958,348
1526014,399
1526014,897
1526015,3
1526015,704
1526016,793
1526017,33
1526018,137
1526022,533
1526027,657
1526029,304
1526030,777
1526032,69
12,403
12,460
12,592
12,655
12,844
12,880
12,935
13,447
13,648
13,748
13,906
14,103
10
7
40
6791958,054
6791957,824
6791957,665
6791956,895
6791956,412
1526033,358
1526033,879
1526034,145
1526035,432
1526036,239
14,137
14,202
14,100
14,118
13,781
40
49
50
17
15
23
18
15
20
11
6791956,412
6791955,514
6791955,411
6791955,164
6791955,093
6791954,969
6791954,826
6791954,358
6791954,24
6791953,978
1526036,239
1526037,741
1526037,912
1526038,324
1526038,444
1526038,65
1526038,89
1526039,671
1526039,869
1526040,306
13,781
13,677
13,665
13,992
14,010
13,929
13,976
13,999
13,947
14,033
55
52
6791951,254
6791950,256
6791949,803
1526044,86
1526046,821
1526047,712
14,102
13,482
13,481
62
75
76
83
81
80
75
86
46
20
12
7
9
2
2
2
5
14
15
9
2
3
81
80
6791948,646
6791948,419
1526049,985
1526050,43
13,110
13,104
130
220
95
75 MGT
1,5
ROCK TYPE TRACE
LENGTH
(M)
70 MGT
1,5
75 MGT
2
73 MGT
2,5
P
TYPE OF
FRACTURE
TRACE
O
N
P
M
M
S
TI
OP
OP
90
265
257
248
249
345
345
265
252
5
12
110
75
85
85
62
75
70
70
85
90
62
65
30
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
2,5
1
2,5
1,5
3
1
4
3
22
2
2
1
P
N
N
O
P
O
O
P
P
N
O
O
S
S
S
S
S
S
S
K
M
M
M
M
TI-OP
TI
TI
TI
TI
TI-OP
TI-OP
OP
OP
OP
OP
OP
117
130
165
126
55
50
75
55
MGT
MGT
MGT
MGT
2
1,5
1,5
1,5
O
P
O
P
M
M
M
M
TI
OP
OP
OP
0,2
0,5
4 SOIL
130
68 MGT
1,5 P
M
OP
0,2
140
86
82
145
80
63
75
68
1,5
2
2
2
M
M
S
M
OP
OP
OP
TI
180
130
45 MGT
28 MGT
1,5 O
2P
K, M
M
OP
OP
145
125
103
100
180
155
45
70
58
65
50
35
2
2
2,5
3
1,5
0,8
P
P
P
P
N
N
M
M
K
M
M
M
TI-OP
OP
OP
OP
TI
TI
155
160
148
185
2,5 O
3P
2O
1,5 N
M
M
M
M
TI-OP
TI
OP
TI
205
160
155
143
140
165
150
69
165
357
190
220
55 MGT
42 MGT
58 MGT
75
MGT
70 MGT
60 MGT
75 MGT
70 MGT
65 MGT
60 MGT
43 MGT
78 MGT
72 MGT
55 MGT
75 GGN
75 GGN
1
3
2
1,5
1
1
1
3
2
1,5
1,5
1
N
P
P
O
N
N
N
P
O
O
N
O
M
S
M
M
M
M
M
S
K, M
K, M
M
S, M
TI
OP
OP
OP
OP
OP
OP
OP
TI
OP
TI
TI
140
75
115
42
120
110
55
70
50
80
60
25
2
1
1
2
1
5
P
P
O
N
O
O
M
M
K
S
K
M
OP
OP
OP
OP
OP
OP
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
MGT
GGN
GGN
GGN
GGN
GGN
P
P
P
P
S
SHAPE
CHARACTER APERTURE
(CM)
INFILLING
REMARKS
ENDS UP TO FRACTURE 220/75
ENDS UP TO FRACTURE 95/73
0,1
0,2
0,1
0,5
0,5
0,2
4 PARALLEL FRACTURES/20 CM
0,3
0.1-0.2
NNE-SIDE
0,1
PARALLEL TO THE FOLIATION
4 FRACTURES/30 CM
PARALLEL TO THE FOLIATION
2 FRACTURES/5 CM PARALLEL TO
THE FOLIATION
PARALLEL TO THE FOLIATION
0,1
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
PARALLEL TO THE FOLIATION
0,5
0,1
PARTLY 2 FRACTURES/3 CM
NNE-SIDE
0,5 SOIL
SSW-SIDE, ENDS UP TO FRACTURE
148/58
0,2
COVERED BY ICE
COVERED BY ICE
0.1-0.5
0,3
0,1
0,5
ENDS UP TO FRACTURE 69/78
ENDS UP TO FRACTURE 69/79
0.5-3
0,1
SSW-SIDE
SSW-SIDE
0,1
0,2
0,2
0,2
1.0-15.0
NNE-SIDE
SSW-SIDE
SOIL
STRONGLY UNDULATING
Appendix 2 (62)
6,25
SECTION
LENGTH (M)
30
POSITION (M) POSITION
(CM)
X (M)
Y (M)
Z (M)
DIP DIRECTION DIP
6,9
8,47
9,08
9,08
9,55
9,58
9,8
11,06569654 SECTION P24
0,68
0,92
1,35
2,1
4,25
4,3
4,5
4,5
5,5
5,9
6,13
6,3
6791947,413
6791947,136
1526052,409
1526052,952
13,414
13,715
6
6791946,909
1526053,398
13,739
30
6791946,295
6791946,023
1526054,605
1526055,228
13,756
13,492
110
135
6791945,455
6791944,595
1526056,53
1526058,5
12,768
12,632
130
6791944,495
1526058,729
12,696
150
72
67
6791944,095
6791943,935
6791943,843
1526059,646
1526060,013
1526060,223
12,549
13,350
13,412
9,24
9,55
9,55
10,3
10,37
10,68
10,75
2,020955467 SECTION P25
0,21
7,240584299 SECTION P26
2,99
3,13
4,58
4,72
5,65
7,25
6
6,25
5,998182475 SECTION P27
0,53
1,07
2,04
4,59
16,417049 SECTION P28
3,64
4,21
4,21
4,8
5,15
5,35
3,5
3
6791942,147
1526064,109
14,278
2
6791941,995
6791941,869
6791941,796
6791941,164
6791939,781
6791939,716
6791939,045
6791938,98
6791938,55
6791937,81
1526064,458
1526064,747
1526064,944
1526066,641
1526069,292
1526069,416
1526070,701
1526070,825
1526071,65
1526073,068
14,308
14,345
14,339
14,379
13,406
13,413
13,419
13,396
13,099
12,920
1
47
44
19
19
33
24
12
36
12
50
67
67
70
59
60
6791937,814
1526073,06
13,162
6791937,42
6791937,063
6791936,124
6791935,606
6791933,539
6791933,215
6791933,215
6791932,88
6791932,681
6791932,568
1526074,055
1526074,957
1526077,328
1526078,637
1526081,633
1526082,102
1526082,102
1526082,588
1526082,876
1526083,041
12,782
12,305
11,925
11,702
10,439
10,150
10,150
9,996
10,033
9,981
2N
S
OP
0,1
ROCK TYPE TRACE
TYPE OF
LENGTH FRACTURE
(M)
TRACE
75 GGN
2N
SHAPE
CHARACTER APERTURE
(CM)
K
OP
0,5
122
110
70
195
125
135
65
30
50
80
45
87
P
N
N
N
O
N
M
M
K
S
M
S
OP
TI-OP
TI
OP
TI
OP
0,1
0,1
125
180
42 GGN
60 GGN
2N
1,5 N
M
M
TI
TI
18
315
100
160
230
85 GGN
15 GGN
80 GGN
35 GGN
85 GGN
1N
2O
2N
1,5 N
1,5 N
S
M
K
M
S
TI
OP
OP
TI
TI
170
110
95
85
100
85 GGN
60 GGN
75 GGN
75 GGN
85 GGN
1N
3P
12 P
2O
1,3 N
S
S
S
S
S
TI
OP
OP
OP
TI
85
90
5
85 GGN
85 GGN
80 GGN
1O
1O
1N
S
S
M
TI
TI
TI
S
S
K
K, M
TI
OP
OP
OP
15
42
10
70 GGN
18
115
290
90
80
75
77
87
GGN
GGN
GGN
GGN
GGN
GGN
GGN
GGN
GGN
GGN
3,5
1,5
0,9
3
2
1
1
4
1
3,5
N
P
N
P
265
85 GGN
3N
K
TI
145
140
120
128
358
162
172
165
50 GGN
20 GGN
55 GGN
50 GGN
70 GGN
75 GGN
78 MGN+GGN
90 MGN
4O
1,5 N
1N
3O
1,5 N
1,5 N
1,5 O
1N
M
M
S
M
K
S
K
S
TI
TI
TI
TI-OP
OP
TI
OP
OP
162
195
348
304
87
28
80
79
"GGN"
"GGN"
"GGN"
"GGN"
2
2
1,3
1,5
O
N
N
N
S
M
S
S
TI
OP
TI-OP
TI
72
110
77
155
70
80
8
78
75
75
30
75
72
60
MGN
MGN
MGN
MGN
MGN
MGN
MGN
4
2
2,5
1
4,5
2,5
1
P
O
O
N
P
N
N
M
S
M
K, M
M
M
S
OP
FI-OP
TI
TI
TI
TI
TI
INFILLING
SSW-SIDE, BETWEEN FRACTURES
110/25 AND 122/65
REMARKS
SSW-SIDE, ENDS UP TO FRACTURE
110/25
0,1
NNE-SIDE
SSW-SIDE
0,2
SSW-SIDE
NNE-SIDE, ENDS UP TO FRACTURE
125/42
NNE-SIDE
0,1
0,3
3.0-8.0
0.1-3.0
SOIL
SSW-SIDE
2 FRACTURES/20 CM BETWEEN
FRACTURES 100/80 AND 110/60
SSW-SIDE, 4 FRACTURES/65 CM
PARTLY 60 CM HIGH SIDE
>1 M HIGH SIDE
0,1
SSW-SIDE, ENDS UP TO FRACTURE
85/75
NNE-SIDE
NNE-SIDE
NNE-SIDE, ENDS UP TO FRACTURE
90/87
NNE-SIDE
0.1-0.5
0,1
0,2
NNE-SIDE
0,2
0,5
0,1
0,1
NNE-SIDE
NNE-SIDE, RESTRICTED TO AN MICA
GNEISS INCLUSION
NNE-SIDE
1
0.5-1
OPENED BY FROST
0,1
0.1-0.5
GREEN CLAY MIN.
NO FRACTURES
NO FRACTURES
Appendix 2 (63)
SECTION
LENGTH (M)
POSITION (M) POSITION
(CM)
X (M)
Y (M)
Z (M)
DIP DIRECTION DIP
5,235792395 SECTION P29
6791926,283
1526092,15
8,262
5,987407619 SECTION P30
6791925,864
1526097,369
8,598
SECTION P31
6791923,069
1526102,664
9,235
ROCK TYPE TRACE
TYPE OF
LENGTH FRACTURE
(M)
TRACE
SHAPE
CHARACTER APERTURE
(CM)
INFILLING
REMARKS
ABBREVIATIONS:
MGN = MICA GNEISS, MGT = MICA GNEISS MIGMATITE, VMGT = VEIN MIGMATITE, GGN = GREY GNEISS, GR = GRANITE, "MGN" = MICA GNEISS WITH ABUNDANT K-FELDSPAR PORPHYROBLASTS
N = BOTH ENDS VISIBLE, O = ONE OF THE ENDS COVERED, P = BOTH ENDS COVERED
N = BOTH ENDS VISIBLE, O = ONE OF THE ENDS COVERED, P = BOTH ENDS COVERED
S = LINEAR FRACTURE, K = CURVED FRACTURE, M = UNDULATING FRACTURE
TI = TIGHT FRACTURE, AV = OPEN FRACTURE
NNE-SIDE = FRACTURE IS LOCATED ON THE NNE SIDE OF THE TRENCH COMPARED TO THE CENTRAL THREAD
SSW-SIDE = FRACTURE IS LOCATED ON THE SSW SIDE OF THE TRENCH COMPARED TO THE CENTRAL THREAD
Appendix 2 (64)
1%
2%
3%
4%
5%
6%
7%
8%
9%
10 %
11 %
12 %
1%
N=69
Lower hemisphere - OL-TK7: Fractures in sections P-5_P8
K=100.00
Sigma=0.690
Peak=12.77
2%
3%
4%
5%
6%
7%
65
1%
N=45
Lower hemisphere - OL-TK7: Fractures in P17-P22
K=100.00
Sigma=0.450
2%
Peak=6.96
3%
4%
5%
6%
7%
1%
2%
N=53
3%
Lower hemisphere - OL-TK7: Fractures in P23-P28
K=100.00
Sigma=0.530
Peak=7.72
4%
5%
6%
7%
8%
9%
N=33
Lower hemisphere - OL-TK7: Fractures in P12-P16
K=100.00
Sigma=0.330
Peak=9.35
1%
2%
3%
4%
5%
6%
7%
8%
1%
2%
3%
5%
6%
7%
N=116
8%
9%
Peak=8.54
10 %
11 %
12 %
N=133
Lower hemisphere - OL-TK6: Fractures
K=100.00
Sigma=1.330
Peak=12.09
Appendix 3
4%
Lower hemisphere - OL-TK5: All fractures
K=100.00
Sigma=1.160