Mineralogy of spodumene pegmatites, Kaustinen, Western Finland Thair Al-Ani and Timo Ahtola

Transcription

1 Southern Finland Office M19/2323/2008/ Espoo Mineralogy of spodumene pegmatites, Kaustinen, Western Finland Thair Al-Ani and Timo Ahtola

2 GEOLOGICAL SURVEY OF FINLAND DOCUMENTATION PAGE Date / Rec. no. Authors Thair Al-Ani and Timo Ahtola Type of report Commissioned by GTK Title of report Mineralogy of spodumene Pegmatite, Kaustinen Western Finland Abstract More than 390 drill core samples were collected from three different zones in the Kaustinen area western Finland; Päiväneva, Leviäkangas and Syväjärvi have been examined mineralogical and geochemical in detail. The granitic pegmatite group (; ca Ga) in the Kaustinen bedrocks, occurs as sub parallel dike series cover an area of 500 km 2 dominated by mica schists and metavolcanic rocks of the Plaeoproterozoic Kaustinen Schist Belt. These pegmatite bodies are divisible into granitic pegmatite and spodumene-bearing pegmatite varieties that occur close together. The two types are mineralogically similar; both contain spodumene, albite, quartz, K-feldspar, mica (muscovite), and accessory minerals such as columbite-group minerals, apatite, tourmaline, beryl, Fe-oxide minerals and garnet. The spodumene pegmatites are dominated by spodumene more than 10%spodumene, as megacrysts (1 5 cm) with intergranular spodumene muscovite albite quartz. Spodumene pegmatite belongs to LCTtype (Li-Cs-Ta). The chemical composition of spodumene pegmatites is Na2O 4%, MgO 0.1%; Al2O3 16%, SiO2 75%, P2O5 0.3%; K2O 2.5%, CaO 0.3%, TiO2 0.01%, MnO 0.1%, Fe2O3 0.6%, Li2O 1.2%, Be 57ppm, Ce 8ppm, Nb 42ppm, Ta 34ppm, Th 1.6ppm, Y 5ppm, Li 5346ppm and Zr 20ppm. The spodumene pegmatites are clearly enriched in LiO2 and slightly in P2O5; clearly depleted in MgO and TiO2 and slightly depleted in Fe2O3, MnO, Na2O, K2O and CaO. This shift is due to the enriched in quartz and lithium aluminium silicates minerals and depletion of feldspar and tourmaline. The bulk mineral composition of the Kaustinen pegmatites were calculated and summarized in Table (11) to be : (Päiväneva pegmatite); quartz 34.54%, albite 35.1%, K-feldspar ~5%, spodumene 15.2%, muscovite ~10% and other minerals <1% and in Leviäkangas pegmatite; quartz 30.7%, albite 36.2%, K-feldspar ~5%, spodumene 14.1%, muscovite ~13.7% and other minerals <1%.The current Syväjärvi pegmatite bulk composition is different from the previous pegmatites in Leviäkangas and Päiväneva by volume of spodumene pegmatite but in mineral composition slightly same except more spodumene content as calculated to be : quartz 30.5%, albite 33.3%, K-feldspar ~5%, spodumene 17.1%, muscovite 13.6% and other minerals ~1%. Keywords: Kaustinen, Päiväneva, Leviäkangas and Syväjärvi pegmatites, spodumene, bulk composition, normative mineralogical calculation. Geographical area: Kaustinen Area; Päiväneva, Syväjärvi,, Matoneva, Leviäkangas and Heikinkangas Map sheet: 2323 Other information Report serial : M19 Total pages 45 Language English Price Confidentiality Archive code: M19/2323/2008/61 Unit and section Espoo, 211 Signature/name Thair Al-Ani Project code Signature/name Timo Ahtola

3 Contents Documentation page Kuvailulehti 1 INTRODUCTION General Geology of the area Background and previous studies Field work and laboratory methods 3 2 RESULTS AND RECOMMENDATIONS Geochemistry Geochemistry of separates minerals Whole rock geochemistry Mineralogy and petrography Composition of pegmatites Description of minerals Average composition of Kaustinen pegmatite Accessory minerals 21 3 CONCLUSION 24 4 REFERNCES 25 5 APPENDICES Chemical composition of whole rocks in Päiväneva pegmatite Chemical composition of whole rocks in Leviäkangas pegmatite Chemical composition of whole rocks in Syväjärvi pegmatite. 38

4 1 INTRODUCTION One of the main targets of industrial mineral survey at Geological Survey of Finland (GTK) are rare elements (Li, Ta, Nb, Be). From the beginning of 2003, the industrial mineral survey in the Southern Finland office has focused on the Kaustinen-Kälviä area in W-Finland. The objective has been to investigate Li (Ta, Nb, Be) resources and the potential of the area. The Kaustinen-Kälviä area is known for spodumene bearing pegmatites since 1960 s. There are relatively few outcrops in the area because it is covered by quaternary glacial sediments. Therefore all the samples which are considered in this study are drill core samples from four exploration targets of GTK; Päiväneva, Heikinkangas, Leviäkangas at Kaustinen and Syväjärvi at Kälviä (Fig. 1).This report summarizes the used laboratory methods and mineralogy of these spodumene pegmatites. 1 Figure 1. Locations of exploration targets in Kaustinen and Kälviä areas. 1.1 General Geology of the area The Kaustinen-Kälviä area REL (rare element) pegmatites are paleoproterozoic (ca Ga) and they crosscut the Svecofennian (ca Ga) supracrustal rocks in the western Finland (Alviola 1989). Their distribution roughly follows the metasedimentary dominated Pohjanmaa belt and their emplacement appears to follow the peak of the regional metamorphism at least 80 Ma (Mäkitie et al., 2001). Alviola et al. (2001) have shown that the different pegmatite types, classified according to Černý (1998), are located in different parts of the Pohjanmaa belt. Specific types of spodumene containing lithium pegmatites are known in Kruunupyy Ullava area of the Pohjanmaa belt. Because of limited data, Alviola et al. (2001) proposed tentatively that these

5 2 pegmatites may belong to the albite spodumene subtype of LCT (Li, Cs, Ta) family (see Černý & Ercit 2005). 1.2 Background and previous studies The occurrence of spodumene and associated columbite-group minerals in the Kaustinen area of western Finland has been known since 1960 (Lonka 1971), but until recently, there has been limited exploration of this pegmatite, whereas detail mineralogical and geochemical studies are limited and only few of RE-pegmatite have been studied in detail to those of Alviola (1989), Lonka (1971) and Alviola et al. (2001). However, extensive drilling and stripping of the area have exposed a large amount of pegmatite, whereas drilling has provided access to the deeper portions and complete sections through the pegmatite bodies. This work deals with detail mineralogical and geochemical studies on the spodumene, albite, quartz and associated Ta-Nb oxide minerals and work to date indicates that this pegmatite has potential to produce good-quality of theses minerals. Li-rich pegmatites of the studied area are referred to as late-stage or highly evolved granitic rocks, and albite-spodumene pegmatites are a sub-class known to be among the most evolved. Spodumene (LiAlSi2O6) is the most abundant Li mineral in pegmatites and is considered to be primary when formed during the pegmatite period of crystallization. Spodumene formally known as lithium-aluminium pyroxene, it s often used as a source of Li for the ceramics market, and also keenly sought by mineral collectors. Spodumene is the most abundant Li mineral in pegmatites and is considered to be primary when formed during the pegmatitic period of crystallization. A second generation of spodumene that crystallized during a later pneumatolytic period of mineralization is also known. Primary spodumene is found in a variety of occurrences: (l) as phenocrystsi n poorly zoned pegmatites, ( 2) as a constituent of one or more zones, principally intermediate zones and cores, (3) rarely, as constituents in replacement units, and (4) as fillings in vugs (Heinrich, 1975; London and Burt, 1982). In cores it has been found as giant crystals (eg.9, 2 m thick and 13 m long at the Etta mine, South Dakota). Spodumene is commonly associated with quartz, feldspar, micas, and minor accessory minerals such as beryl in granitic pegmatites. Spodumene can have high Fe3+ contents, since its pyroxene structure can accommodate up to 1.6 wt% of Fe2O3 (Heinrich, 1975). The substitution of small amounts of Fe 3+ for Al 3+ markedly increases the stability of spodumene (Appleman and Stewart, 1968). Secondary spodumene produced by the breakdown of petalite is relatively pure and less content of Fe (Černy and Ferguson, 1972). TANCO is one of the three major suppliers of high grade spodumene concentrates to the world market. To meet the requirements of a wide range of industries and applications, the following grades of Spodumene concentrates are present in Table 1.

6 Table 1. TANCO s standard grade spodumene. Grade 7.25% Grade -200 Mesh 6.8% Grade Spodulite Li 2 O % % 6.8% min. 5.00% min. Na 2 O 0.35% max. 0.30% max. 0.45% max. 0.75% max. K 2 O 0.30% max. 0.60% max. 0.40% max. 0.75% max. Fe 2 O % 0.15% max. 0.08% max. 0.10% max. Al 2 O % min. 25.0% min. 23.0% min. 20.0% type MnO % max. 0.06% max. 0.04% max. 0.05% max. P 2 O % max. 0.40% max. 0.27% max. 0.05% max. Note: Tantalum Mining Corporation (Tanco) in Canada. Lithium products spodumene high-grade concentrate: 7.25% grade, -200 meshes, 6.8% Li2O grade for glassmaker s grade concentrate, and Spodulite concentrate Field work and laboratory methods The material for this study is from diamond drilling and detailed sampling of all complex pegmatites dikes. GTK s recent drilling program covered more than 70 drill holes with a total length more than 11 km. The cores penetrated pegmatite was subdivided for chemical analysis into sections of 3m in length or less. The following table summarizes drill core locations, length and provides details description of the drilling cores lithology. The geochemical study of the Kaustinen pegmatite dikes was developed into two stages: the geochemistry of separated minerals from drilling core samples and whole-rock geochemistry of drill-core material. The geochemical characteristics with the mineralogy of theses pegmatites allow us to classify pegmatite bodies as element or minerals pegmatites, according to content of Li or spodumene mineral. To determine the major- and trace-element chemistry of spodumene, muscovite, albite, K- feldspar and quartz, mineral separates were produced. This involved repeatedly cleaning mineral samples by ultrasonically rinsing in distilled water, followed by crushing in Mn-steel and grinding by carbon steel container before leaching and in some cases by magnetic separation. Wholerock samples of pegmatite, granite, and host-rock schists were also analyzed. The geochemical analysis were submitted and completed in the Labtium laboratory in Espoo. Many Labtium s methods have been used for analysis of elements. Major elements were determined on fused beads (LiBO 2 flux), and Cr, Ni, Cu, S, Sc, Zn, V, Sr, Ga, As, Rb, Sn, Sb, Ba, Pb, Bi, Mo and Zr on pressed pellets by XRF. X-ray fluorescence (XRF) analysis. The limit of determination will depend on the sample matrix, and will thus be able to vary depending on a sample of reasons are given. If the samples contain fluoride, carbon, boron, lithium or beryllium, a coupled plasma mass spectrometry (ICP-MS) and instrumental epithermal neutron activation analysis (IENAA) will need the information to their volumes. REE, Nb, Nd,, Be, Ce, Sc, Ta, Th and Ga were analysed by using ICP-MS technology after dissolution of the sample powder in mixed acids (HF, HC1, HNO3, HCIO4) in Teflon containers. The samples contained Li and F has been analyzed by using ICP-AES-technology. Loss on ignition (LOI) was determined gravimetrically at 1000 C, and total carbon was analysed using a Lecco carbon analyzer. Laboratory investigations consisted of petrographic study of the pegmatites and country rocks by using light petrographic microscope to study more than 80 thin sections of selected samples, XRD (Siemens Diffract Meter D5000) and Scanning Electron Microscopy (SEM).

7 4 Electron microprobe analyses of phosphate minerals (as apatite in most instances) and other minerals were performed by the wavelength dispersive technique using a Cameca SX100 instrument at the Geological Survey of Finland (GTK) in Espoo. Analyses were determined using an accelerating voltage of 15 kv. Probe current and beam diameter used were 20 na and 1-5 micrometers respectively. Analytical results were corrected using the PAP on-line correction programme (Pouchou & Pichoir, 1986). There are two stages involved in calculating the mineral composition of the Kaustinen pegmatite. The initial stage of this process has been estimated by examining the drill core, photograph observations, and microscopic studies of fine grained assemblages. The final stage includes the normative mineralogical calculation for individual minerals such as quartz, albite, K-feldspar, apatite, anorthite and other trace minerals were estimate by using GCDkit 2.3 software program (after Vojtech Janousek, 2008). Spodumene content calculated according to the question: (Spodumene =13.3 x Li2O %) 2 RESULTS AND RECOMMENDATIONS 2.1 Geochemistry Geochemistry of separates minerals The result analyses of spodumene, muscovite, albite, K-feldspar and quartz for 28 specimens are given in Table (2). The studied spodumene samples contain extremely low contents of trace elements ranging from ( % Na2O), ( % Fe2O3), ( %CaO), ( % MgO), ( % MnO) and ( % K2O). According to chemical formula; spodumene theoretically contains 8.04% Li 2 O. However, because of incorporation of small amounts of Na, K, Ca, Mn, Fe and Mg into structure, spodumene generally contain between 4 and 7 wt% Li 2 O. The studied spodumene grade between 69.3 to 91.4, with average (85.2%) and Li content ( % Li2O) with average of 6.4% were favourable (Table 2), but it was deemed that the Fe content ( % Fe2O3). The comparing of the studied spodumene to market standards is acceptable as seen in Table (1). According to Černy (1991) high Fe content is typical for primary spodumene, whereas moderate Fe content is in secondary spodumene and hydrothermal spodumene is mostly low in Fe content and other alkali elements. This suggested that the Kaustinen spodumene is considered to be primary in origin, which is formed during the pegmatite period of crystallization and developed from granitic pegmatite of albite-spodumene type. The studied spodumene is commonly associated with albite and quartz and occurred as phenocrysts in poorly zoned albite-spodumene pegmatites. The average content of Na2O, K2O and Li2O were compared separately for the selected minerals as quartz, spodumene, muscovite, albite and K-feldspar (Table 1). Note that the Li 2 O content of the muscovite and albite is too low (0.15 and 0.20% respectively) and the K2O content is more in the K-feldspar and muscovite (15.9 and 9.7% respectively), while the Na2O content is more in albite (~12%). This pointed that lithium in Kaustinen pegmatite come mainly/or wholly from spodumene mineral. The SiO2 and Al2O3 content were computed from the selected minerals data in (Table 3), using typical analysis of 5 essential minerals of the pegmatite, as follows: Oxide% Quartz Spodumene Muscovite Albite K-feldspar SiO2 100% 65,7% 45,0% 67,6% 63,34 Al2O3 25,6% 36,0% 19,2% 18,06

8 5 Table 2. Chemical composition of pure mineral separates (spodumene, muscovite albite, K-feldspar and quartz) from studied pegmatites. Mineral Sample No. SiO2% Al2O3% Li2O% Na2O% Fe2O3% CaO% MgO% MnO% K2O% Rb2O% Total Spodumene% Spodumene R2/1981/ ,9 26,1 6,8 0,19 0,70 0,051 0,10 0,104 0,157 0,003 99,13 91,0 R3/1981/ ,7 26,4 6,7 0,16 0,53 0,018 0,08 0,118 0,101 0,001 98,77 89,0 R4/1981/ ,4 26,7 6,9 0,35 0,41 0, ,122 0,020 0,001 98,88 91,4 R3/1965/ ,7 23,2 5,2 1,24 0,40 0,061 0,033 0,092 0,605 0,025 99,55 69,3 Average 65,68 25,60 6,39 0,48 0,51 0,04 0,07 0,11 0,22 0,01 99,08 85,2 Muscovite R3/1981/ ,36 36,11 0,17 0,30 1,17 0,01 0,00 0,02 9,69 0,001 92,84 2,32 R6/1981/ ,59 36,74 0,16 0,51 1,25 0,00 0,00 0,05 9,88 0,001 94,18 2,17 R3/1965/ ,71 35,80 0,11 0,44 1,04 0,00 0,00 0,05 9,62 0,003 91,78 1,44 R422/43,90/ 45,28 36,19 0,12 0,49 1,23 0,02 0,02 0,07 9,92 0,005 93,35 1,60 R422/43,90/ 44,38 35,15 0,19 0,82 1,35 0,03 0,01 0,10 9,48 0,008 91,51 2,5 Average 45,06 36,00 0,15 0,51 1,21 0,01 0,01 0,06 9,72 0,00 92,73 2,01 Albite R406/2008/ ,41 18,87 1,11 12,05 0,02 0,05 0,00 0,00 0,10 99,61 14,8 R406/2008/ ,71 19,63 0,05 12,14 0,00 0,07 0,01 0,00 0,09 99,69 0,67 R406/2008/ ,95 19,07 0,02 12,04 0,00 0,04 0,01 0,00 0,05 99,19 0,27 R428/2008/ ,52 19,32 0,01 12,12 0,00 0,10 0,00 0,00 0,08 99,15 0,19 R428/2008/ ,83 18,91 0,01 11,93 0,00 0,04 0,00 0,01 0,09 97,82 0,19 R429/2008/ ,63 19,35 0,01 12,18 0,02 0,03 0,00 0,02 0,17 100,42 0,20 Average 67,67 19,19 0,20 12,08 0,01 0,05 0,00 0,01 0,10 99,31 2,72 K-feldspar R422/43,90/ 63,25 18,04 0,24 0,00 0,00 0,00 0,02 15,96 97,51 R422/43,90/ 63,57 18,37 0,53 0,00 0,00 0,01 0,00 15,67 98,16 R422/43,90/ 63,27 17,99 0,21 0,01 0,00 0,00 0,00 16,02 97,50 R422/43,90/ 63,85 18,19 0,36 0,01 0,00 0,00 0,00 15,80 98,21 R422/43,90/ 63,19 17,94 0,27 0,02 0,00 0,00 0,00 16,06 97,49 R422/43,90/ 63,57 18,06 0,21 0,00 0,01 0,00 0,00 15,94 97,79 R422/43,90/ 62,71 17,83 0,33 0,00 0,00 0,00 0,00 15,42 96,30 R422/43,90/ 63,43 18,13 0,30 0,02 0,01 0,01 0,01 16,04 97,95 R422/43,90/ 63,27 18,01 0,36 0,02 0,00 0,00 0,00 15,81 97,48 Average 63,34 18,06 0,31 0,01 0,00 0,00 0,00 15,86 97,60 Quartz R419/ ,36 0,07 0,00 0,00 0,00 0,01 0,00 0,00 0,00 98,44 R419/ ,81 0,04 0,00 0,00 0,00 0,00 0,00 0,02 0,00 98,88 R422/43,90/around spodumene 99,67 0,04 0,00 0,01 0,02 0,00 0,00 0,00 0,00 99,74 R422/43,90/around spodumene 98,78 0,03 0,00 0,01 0,00 0,01 0,00 0,02 0,04 98,89 Average 98,91 0,04 0,00 0,01 0,00 0,00 0,00 0,01 0,01 98,99

9 2.1.2 Whole rock geochemistry 6 Representative 390 samples of studied pegmatite groups were collected for geochemical analysis from 60 drill holes. The chemical analyses of studied samples were acquired on 0.5 to 4 m long lengths of drill core. Two classes of pegmatites are distinguished here. They are based on differences in mineral assemblages, geochemical signature or a combination of these aspects. The first concept deals with geological location, leading to division of granitic pegmatites into two classes (spodumene pegmatite and granitic pegmatite); most of granitic pegmatite is possible to subdivide into subclasses with fundamentally different geochemical and mineralogical characteristics. The second approach is petrogenetic, developed for pegmatite bodies of a particular types with an increasing degree of fractionation from granitic pegmatite (as whole pegmatite rocks) to spodumene pegmatite (contains >10% spodumene or >0.7 wt% Li2O). The chemical analysis data of spodumene pegmatites in studied locations are presented in Tables 3, 4, 5 and 6 for Heikinkangas, Päiväneva, Leviäkangas and Syväjärvi spodumene pegmatites respectively The geochemical data of all whole rock samples were showed in appendixes 1, 2 and 3 for Päiväneva, Leviäkangas and Syväjärvi granitic pegmatites respectively. The bulk mineralogy, chemical composition in terms of main rock-forming constituents, and the rare elements concentrations are quite similar in all spodumene pegmatite (Table 7). These geochemical data are characterized by high SiO2 and low TiO2, CaO, MgO and Fe2O3 except that in Päiväneva pegmatites, which are characterized by enriched in iron content (Fe2O3 content between % with average ~2.6%) comparing to Leviäkangas and Syväjärvi pegmatites (Fe2O3 content %). The bulk chemical composition of the Kaustinen granitic pegmatite is: Na2O 5%, MgO 0.4%; Al2O3 15.8%, SiO2 73.2%, P2O5 0.3%; K2O 3.1%, CaO 0.6%, TiO2 0.1%, MnO 0.1%, Fe2O3 1.2%, Li2O 0.2%, Be 73ppm, Ce 22ppm, Nb 43ppm, Ta 40ppm, Th 2ppm, Y 9ppm, Li 1010ppm and Zr 50ppm, whereas the chemical composition of spodumene pegmatites is Na2O 4%, MgO 0.1%; Al2O3 16%, SiO2 75%, P2O5 0.3%; K2O 2.5%, CaO 0.3%, TiO2 0.01%, MnO 0.1%, Fe2O3 0.6%, Li2O 1.2%, Be 57ppm, Ce 8ppm, Nb 42ppm, Ta 34ppm, Th 1.6ppm, Y 5ppm, Li 5346ppm and Zr 20ppm. The current calculated bulk chemical composition of granitic pegmatite is different from the mean calculated of spodumene pegmatite in Kaustinen area as seen in Figure (2) The spodumene pegmatites are enriched in LiO2, Al2O3, SiO2 and P2O5 and slightly depleted in Fe2O3, MnO, MgO, TiO, Na2O, K2O and CaO. This shift is due to the enriched in quartz and lithium aluminium silicates minerals of the studied spodumene pegmatites. In Päiväneva - Heikinkangas pegmatites; 150 pegmatite samples were analysed for geochemical study. Only twenty-six samples were classified as spodumene pegmatite according to enriched lithium, the content of Li2O between wt % with an average of 1.1 wt% and the average spodumene content was 15.2%. The other 124 samples were classified as granitic or whole rock pegmatite according to low content of lithium (average content 0.14 wt% Li2O), but at the same time these pegmatite samples were enriched in albite and quartz. In Leviäkangas pegmatite about half of the analyses samples classified as spodumene pegmatite, that contain spodumene between ( %) with average 16.7% other 46 samples classified as whole rocks or granitic pegmatites, which are contain spodumene between ( ) with average 3.3%.

10 In Syväjärvi most pegmatite samples (104 samples) classified as spodumene pegmatite, characterized by high content of spodumene (>10% spodumene) ranging between % with average 16.5%. Other 45 samples of pegmatite (< 10% spodumene) classified as granitic pegmatite, contain spodumene between percent with average 4.2% granitic pegmatite samples spodumene pegmatite samples Weight% Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Li2O Spod Figure 2. Bar chart illustrated the chemical compositional differences between the granitic pegmatite and spodumene pegmatite intrusions in studied areas. Table 3. Chemical composition of spodumene pegmatite from Heikinkangas in Kaustinen area. Oxides % Minor elemnts (ppm) Sample Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Li2O Be Ce Nb Ta Th U Y Li Zr R398/ < <10 <10 < R438/ R438/ R438/ < R438/ R438/ R438/

11 Table 4. Chemical composition of spodumene pegmatite from Päiväneva in Kaustinen area. 8 Oxides % Minor elemnts (ppm) Sample Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Li2O Be Ce Nb Ta Th U Y Li Zr R392/ < <10 <10 < R392/ < <10 <10 < R393/ < <10 <10 < R393/ < <10 <10 < R393/ < <10 <10 < R405/ < <10 <10 < R405/ < <10 <10 < R406/ < <10,0 < R406/ < < <10 <10 < R406/ < <10 <10 < R408/ < <10 < R408/ <10 < R408/ < < <10 < R408/ < < <10 < R408/ < < <10 < R408/ < < <10 < R408/ < < <10 < R408/ <10 < R408/ < < <10 < R427/ Min Max Avareage Table 5. Chemical composition of spodumene pegmatite from Leviäkangas pegmatite in Kaustinen area Samples Oxides% Minor elements (ppm) Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Be Ce Nb Ta Th U Y Zr Li 65R2/ < < R2/ < < R4/ < < R4/ < < R4/ < < R450/ R450/ < R453/ R454/ < R455/ < R455/ R455/ < R455/ < R455/ < R455/ < R456/ < R456/ R456/ R457/ < R457/ < R473/ < < R473/ < < R473/ < Min Max Average

12 Table 6. Chemical composition of spodumene pegmatite from Syväjärvi pegmatite in Kaustinen area Sample Oxides % Minor elemnts (ppm) Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Li2O Be Ce Nb Ta Th U Y Li Zr Na2O/K2O R439/ R439/ R440/ R440 / R441/ R441/ < R441/ R441/ < R441/ R441/ < R441/ R441/ < R441/ R441/ R441/ R442/ R442/ R442/ R442/ R442/ < R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ < R442/ R442/ R442/ R442/ < R442/ R442/ R442/ R442/ < R442/

13 Table 6 (continued) Sample Oxides % Minor elemnts (ppm) Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 Li2O Be Ce Nb Ta Th U Y Li Zr R443/ R443/ R443/ < R443/ R443/ R443/ R443/ R443/ < R443/ R443/ < R443/ R443/ R443/ R443/ R443/ R458/ R459/ R459/ <10 R459/ < R460/ <10 R462/ <10 R462/ <10 R462/ <10 R462/ <10 R462/ R462/ <10 R462/ <10 R462/ <10 R462/ <10 R462/ R462/ R462/ <10 R462/ <10 &462/ <10 R462/ <10 R462/ <10 R462/ <10 R463/ < Max Min Average

14 11 Table 7. Summarize the average chemical composition of spodumene pegmatite and surrounding whole rocks in studied pegmatites. Location Päiväneva peg Vintturi peg Ruohojärvi peg Oxudes% Wh.Rx Sp.peg Wh.Rx Sp.peg Wh.Rx Sp.peg Na2O MgO Al2O SiO P2O K2O CaO TiO MnO Fe2O Li2O Spod Minor elements (ppm) Be Ce Nb Ta Th U Y Li Zr Total samples Sample Mineralogy and petrography Composition of pegmatites Mineral compositions of the studied pegmatite were taken from drill cores examinations, optical petrographic study and normative mineralogy calculation. Detailed thin-section descriptions were done for more than 80 core samples from spodumene pegmatite dikes and hosted rocks. The normative mineralogical calculation for quartz, albite, K-feldspar, apatite, anorthite and other trace minerals were estimate by using GCDkit 2.3 software program (after Vojtech Janousek, 2008). Kesler (1961) pointed that 97.6 wt% of the Li2O in whole rocks was present in spodumene, which had an average Li 2 O content of 7.46 wt% as compared to the theoretical 8.04 wt%. Also the experimental data of Li content calculations by Cerny et. al, (1985) indicate that about 2.1 wt% Li2O equivalents to wt% spodumene, this represents the maximum possible accumulation of spodumene in some studied pegmatites. Based on the average composition of the Kaustinen spodumene in this study the spodumene content calculated from the whole-rock chemical analysis according to the formula: Spodumene =13.3 x Li2O% Mineralized Li-pegmatites at Kaustinen and surrounding areas are composed mainly of albite, quartz, spodumene, potassium feldspar and muscovite with occasional apatite, accessory graphite and Ta-Nb oxides. The normative mineralogical composition of studied spodumene pegmatites is given in Figure (3) and Tables (8, 9 and 10). The average content of spodumene in the studied

15 12 pegmatites is up to 15 %, and the content of spodumene in Päiväneva, Leviäkangas and Syväjärvi pegmatites are 15.2%, 14.1 % and 16.5% respectively. The distributions lithium contents for the Kaustinen pegmatites vary and each location has distinct distribution pattern (Fig. 3). The Päiväneva pegmatite has a unimodal pattern with inconsiderable amount of spodumene pegmatite samples (16% spodumene) and one exceptional rich sample. The Leviäkangas pegmatite shows asymmetrical unimodal pattern with high variance. Most of Leviäkangas samples contain <15% of spodumene. The Syväjärvi pegmatite has a symmetrical pattern and a considerable amount of spodumene pegmatite, more than 50% of studied samples contain >20% spodumene. The estimation of proportional volumes of spodumene pegmatite in Syväjärvi is more than other types. Päiväneva pegmatite is slightly poorer in lithium (pegmatite) comparing to Syväjärvi and Leviäkangas pegmatites Description of minerals Spodumene Powder X-ray diffraction analyses of the spodumene specimen from Leviäkangas pegmatite (Fig 4) showed high peak intensities in 2.921Å, 2.793Å and 4.205Å, which are typical quartz peaks and are likely related to the presence of silica in solid solution with spodumene. Colourless to light green primary spodumene occurs as elongate or bladed and stubby crystals exclusively in the intermediate and core zones (Fig 5). Anhedral xenocrysts of spodumene are present in the border or wall zones of some pegmatites. Spodumene forms lath-shaped crystals up to 7cm long, although it is commonly around 5 cm long. Spodumene is commonly found as similarly coarse phenocrysts, sub parallel grains or smaller penetrating grains (Figs. 5 b, c and d). The megacrysts of spodumene are euhedral and free of macroscopic inclusions, but along their margins, subhedral quartz may occur (Figs. 6 a, b, c). Spodumene is rarely altered or replaced by albite or muscovite. Less commonly, spodumene occurs as intergrowth with blocky K-feldspar or massive albite ± quartz ± mica (lepidolite, or rarely, muscovite). Plagioclase The average content of albite in the studied pegmatites is about 35%. Albite occurs homogenously in most studied pegmatites. Albite is the dominant feldspar in the Kaustinen pegmatites. Albite occurs in two major textural varieties: white to cream colored crystals with cleavelandite habit and white to slightly greyish fine- to medium-grained crystals. Cleavelandite, ranging from 0.5 to 5 cm in grain size, is the major constituent in coarse-grained, particularly spodumene-free pegmatite dikes (Fig 5). Here the albite plates are intergrown with quartz, K-feldspar and, in some places, muscovite. This variety is also found with calcite occurring as fracture fillings (Fig 7f). Fine- to medium-grained (1 to 5 mm) albite is ubiquitous across the dikes, occurring with equal amounts of quartz and muscovite in the aplitic layers and pods of the pegmatites. The albite is almost pure NaAlSi3O8; the analyzed specimens of albite (Table 2) contain traces of Ca (0.05 wt. % CaO), Li (0.2wt%Li2O), Fe (0.01wt% Fe2O3) and K (0.10wt%K2O).

16 (a) Frequency spodumene% Li2O % (b) Frequency spodumene% Li2O% (C) Frequency spodumene% Li2O% Figure 3. Distribution of Li2O and spodumene (weight percent) in studied pegmatites (a) 27 samples from Päiväneva, (b) 42 samples from Leviäkangas and (c) 113 samples from Syväjärvi pegmatites.

17 14 Figure 4. XRD pattern of spodumene specimen from Leviäkangas pegmatite. Quartz The average content of quartz in the studied pegmatites is about 32% distribute as 33% in Heikinkangas, 34.8% in Päiväneva, 31% in Leviäkangas and 30.5% in Syväjärvi pegmatites (Table 12). Quartz varies considerably in its habit and colour within the pegmatite. Rarely is it subhedral form with short prismatic grains diameter 0.5-4cm (Figs 5.); it may be intergrowth with albite (Fig. 7d) or K-feldspar (Fig. 7c). The most common occurrence of quartz is anhedral and generally greys in colour. The chemical analyses of selected quartz grains show that the quartz occurs as pure mineral and contains more than 98 SiO2% (Table 2). Rare occurrences of vein quartz are noted, in particular where it cross-cuts spodumene near the contact or marginal zone (Fig. 7d). K-feldspar The average content of K-feldspar in studied pegmatites was about 5% (Table 12). The chemical analyses of the K-feldspar concentrated reveal a range from Or97Ab3An0 to Or98Ab2An0 (Table 2); the low Ab content corresponds to the minimum Na2O value of 0.3 wt. %. The high orthoclase and low Na and Ca contents are an indication of sub solidus equilibration. The concentrations of Ca, Mg, Mn, Fe, Sr, P, Rb and Ba are nil or negligible. K-feldspar is usually perthitic microcline and grey, white or sometimes pinkish in colour. The grain size and the abundance of K-feldspar increase from inner zone to border as 3cm to 5 cm respectively. Elongate anhedral K-feldspar forms, on average, 1-cm-wide stringer-like crystals

18 aligned parallel to each other, and generally alternating with rod-shaped spodumene laths. In many dikes, these two types of mineral are oriented perpendicular to the contact between the pegmatite and the wall rock. 15 Anhedral K-feldspar is fine-grained, and normally occurs in the wall zone of the pegmatite bodies. Euhedral cryptoperthite crystals are restricted to calcite filled fractures and pockets (Fig 7e), which are relatively rare features in the Kaustinen pegmatites. Muscovite The average contents of muscovite for studied pegmatites are 11.8% (Table 12) and are highest content in Leviäkangas 13.66% and Syväjärvi 13.63%. Muscovite is close to uniform composition, with minor Fe ( 1.2 wt. % Fe2O3), Na ( 0.5 wt. % Na2O), and Li (0.15% Li2O) contents as illustrated in Table (2). CaO, MgO, and MnO, contents from below detection limit to 0.01, 0.01, and 0.06 wt. %, respectively. Muscovite of the studied pegmatites is colourless to silver or green colours. The colourless to silver variety muscovite occurs in the wall and aplitic zones of many studied pegmatites dikes, where it forms masses of medium- to coarse-grained crystals with grain size more than 5cm in some samples (Fig. 5). Muscovite occurs as books or scaly aggregates, generally associated with spodumene, quartz, and feldspar. In some cases, coarse-grained purple mica forms coneshaped aggregates with a botryoidally ball-peen habit. The coarse-grained muscovites up to 4 cm in diameter are subhedral to anhedral and have ragged margins (Fig 5). Fine-grained crystals of colourless to silver colour mica occur in the border zone of some dikes, associated with similarly fine-grained quartz and albite (Fig 7) Average composition of Kaustinen pegmatite Bulk mineral composition of the Kaustinen pegmatites were calculated by using the mineral compositions, mineral densities (Table 12) and the volumes of individual spodumene pegmatite. The bulk mineral composition of the Päiväneva pegmatite is 34.54% quartz, 35.1% albite, ~5% K-feldspar, 15.2% spodumene, ~10% muscovite and <1% other minerals. The mineral composition of Leviäkangas pegmatite is quartz 30.7%, albite 36.2%, K-feldspar ~5%, spodumene 14.1%, muscovite ~13.7% and other minerals <1%.The Syväjärvi pegmatite composition is different from the composition of Leviäkangas and Päiväneva pegmatites by volume of spodumene pegmatite but in mineral composition slightly same except more spodumene content as calculated to be: quartz 30.5%, albite 33.3%, K-feldspar ~5%, spodumene 17.1%, muscovite 13.6% and other minerals ~1%.

19 16 Table 8. Normative minerals percentages (wt %) and accessory minerals in Heikinkangas spodumene pegmatite. Sample Mineral Composition of sp-pegmatite Total Qz Mus K-Fes Alb An Hy Mt Hm Ap Sp R398/ R438/ R438/ R438/ R438/ R438/ R438/ Max Min Average Table 9. Normative minerals percentages (wt %) and accessory minerals in Päiväneva spodumene pegmatite. Sample Mineral Composition of sp-pegmatite Total Qz Mus K-Fes Alb An Hy Mt Hm Ap Sp R392/ R392/ R393/ R393/ R393/ R405/ R405/ R406/ R406/ R406/ R408/ R408/ R408/ R408/ R408/ R408/ R408/ R408/ R408/ R427/ Max Min Average

20 17 Table 10. Normative minerals percentages (wt %) and accessory minerals in spodumene pegmatite of Leviäkangas. Sample Mineral composition of Sp-pegmatite Qz Ab K-Fel Mus Hy Mt Hm Ap Spo Sum 65R2/ R2/ R4/ R4/ R4/ R450/ R450/ R453/ R454/ R455/ R455/ R455/ R455/ R455/ R455/ R456/ R456/ R456/ R457/ R457/ R473/ R473/ R473/ Max Min Average

21 Table 11. Normative minerals percentages (wt %) and accessory mineral associations in Syväjärvi spodumene pegmatite. Sample Mineral composition of Sp-pegmatite Qz Mus Fels Ab Spo An Hy Mt Hm Ap Sum R439/ R439/ R440/ R440 / R441/ R441/ R441/ R441/ R441/ R441/ R441/ R441/ R441/ R441/ R441/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/ R442/

22 19 Table 11 (continue) Sample Mineral composition of Sp-pegmatite Qz Mus Fels Ab Spo An Hy Mt Hm Ap Sum R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R443/ R458/ R459/ R459/ R459/ R460/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ R462/ &462/ R462/ R462/ R462/ R463/ Min Max Average

23 20 Table 12. Summarized the mineral composition of Kaustinen pegmatites. Minerals Mineral composition Heikinkangas Päiväneva Leviäkangas Syväjärvi Average Quartz (Qz) Muscovite(Mus) K-Feldspar(K-Fel) Albite(Ab) Spodumene(Spo) Anorthite(An) Hypersthene(Hy) magnatite(mt) Hematite(Hm) Apatite(Ap) a b c d Figure 5. Drill core showing coarse grain albite-quartz-feldspar rich pegmatites. (b) Drill core of spodumene pegmatite. (c &d) Close up of spodumene pegmatite rich in muscovite Note the drilling core R475 of Leviäkangas pegmatite.

24 2.2.4 Accessory minerals 21 Accessory mineral phases include apatite, tourmaline, garnet, beryl, chlorite, Ta Nb oxides, carbonate, amblygonite, cassiterite, sphalerite, zircon, epidote, clay and variety of phosphate phases (e.g., montebrasite and crandallite). The composition and distribution of Ta-Nb oxides were currently studied in a separated report (Al-Ani et al, 2008). Only some of the minerals are discussed here. Apatite is the most abundant phosphate in the Kaustinen pegmatites, occurring as euhedral to anhedral, microcrystalline (mm size) grains within a variety of settings: (1) intergrown with bladed albite (Fig 6a, c, e), (2) disseminated in K-feldspar (Fig.6b), (3) euhedral composited uniform apatite (AP) grain (Fig 6d), and (4) along fractures or voids in perthitic K-feldspar - albite (Fig.6f). The chemical composition of the primary apatite (Table 13) shows that apatite occurs mainly as Fluor apatite with ~4% F in most studied grains. Electronmicroprobe analyses show highly variable Mn contents of the apatite ranges from approximately 0.1 to 3.7 wt% MnO. In general, the green crystals show the lowest Mn contents, and the purple variety is highest in Mn. The average content of Fe in the studied apatite grains was 0.23% Fe2O3. The concentrations of Mg, Na, K, Cr, Sr, Ni, Cl, V and Ba are below detection limit or negligible. Garnet is rare and occurs as multicentimetric subhedral to euhedral, orange-red to reddish brown grains within albite-rich zones with or without secondary muscovite (Fig. 8d in upper right). The few garnet grains observed contain considerable subgrain development related to deformation. In some cases, the garnet overgrows tourmaline, but is in turn replaced by muscovite. Galena occurs as minute inclusions and as discrete grains within feldspar grains. Sphalerite forms anhedral blebs associated with albite and K-feldspar. Pyrrhotite and pyrite are associated with schorl and garnet along the pegmatite host-rock contact. Minerals of the columbite group (columbite-tantalite) occur as disseminated crystals, largely in the albite-spodumene pegmatite, but also in the wall and intermediate zones of the studied pegmatite. Subhedral to euhedral, blocky to tabular crystals (less than 1 mm to 5 cm long) generally are intergrown with albite (rarely with tourmaline), and interstitial to the K-feldspar and quartz (Al-Ani et al, 2008). Table 13. Electronic-microprobe data for apatite mineral phases in the Syväjärvi pegmatite. Sample / grain SiO2 TiO2 Al2O3 Cr2O3 V2O3 FeO MnO MgO CaO Na2O K2O SrO BaO NiO P2O5 F Cl Total Mineral R443_62,15-64,15/rae Apatite (green) R443_62,15-64,15/rae Apatite (green) R443_62,15-64,15/rae17b Apatite R443_62,15-64,15/rae17b Apatite R443_62,15-64,15/rae18b Apatite R443_62,15-64,15/rae20b Apatite R443_62,15-64,15/rae20b Apatite

25 Figure 6. Electron-microprobe images showing mineralogical features of sample R443 ( ) from Syväjärvi pegmatite, (a, c, e)euhedral to subhedral apatite (Ap) in albite(alb), some grains have a ragged margin owing to subsequent alteration and may contain a variety of micro-inclusions, (b) intergrowth with K-fels, (d) Apatite (Ap) grain of uniform composition may contain an euhedral form (f) Perthitic K-fels (dark areas are albite) characterized by pitted texture, with apatite filling fractures or voids along intervening perthitic areas. 22