ANNUAL REPORT OF THE GEOLOGICAL INSTITUTE OF HUNGARY, 1999 (2000)

MINERALOGICAL, PETROLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF CRYSTALLINE ROCKS OF THE ÜVEGHUTA BOREHOLES (MÓRÁGY HILLS, SOUTH HUNGARY)

GYÖRGY BUDA*, ZUÁRD PusKÁs**, KAMILLA GÁL-SÓLYMOS**, URS KLÖTZLI*** and BRIAN L. COUSENS****

*Department of Mineralogy, Eötvös L. University, H -1088 Budapest, Múzeum krt. 41A. **Department ofPetrology and Geochemistry, Eötvös L. University, H-1088 Budapest, Múzeum krt. 4/A. ***Laboratory for Geochronology, University of Vienna, Geocentrum, Department of Geology, Althanstrasse l4,A-1090 Vienna ****Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K IS 5B6 ~ ...

-..' Keywords: cataclasites, chromite, granites, Hungary, isotope, lamprophyre, microc1ine, microgranite, mylonites

Four types of crystalline rocks can be distinguished in the Üveghuta boreholes: 1. Microcline megacryst-bearing granitoids. 2. Amphibole-rich enc1aves. 3. Microgranites. 4. Pegmatites. In the Mórágy Hills these rock types can be found in outcrops as weIl. The amphibole-rich enc1aves are K-Mg-rich calc-alkaline vaugnerite-durbachite with lamprophyric character. The enc10sing granitoids have also K-Mg-rich calc-alkaline character. The two rock types are mineralogically and petrologically different, however, as a result of the interaction between the basic and acidic melts they show many geochemical similarities, e.g. normalised REE patterns and isotope ratios. Partial melts were formed in the collision zone oftwo continental crustal blocks during the Variscan orogeny (340-350 Ma). The more basic melts were formed as a result of partial fusion of a K-, Ba-, Rb-, Sr-rich upper mantle) wedge situated above an older subduc- tion zone, whereas the granitoid melts inc1ude both mantle and continental crustal contributions. The continental crust is presumed to .,.. be of Pan-African origin with Cadomian age (- 620 Ma). Peraluminous microgranitic melts of crustal origin intruded subsequently. Their volatile-rich fractions crystallised as pegmatites. The outer zones of microcline megacrysts with younger age, the widespread micro- cline replacement textures and the biotitisation of amphibole point to K-metasomatism. The crystalline massif has been subjected to vari- ous tectonic events causing frequent mylonitisation, catac1asis and hydrothermal mineralisation (carbonate, pyrite, chalcopyrite etc.).

1. Introduction 2. amphibole-rich enc1aves (syenite, monzonite, diorite), 3. microgranite, The Department of Mineralogy,and the Department of 4. pegmatite. Petrology and Geochemistry of the Eötvös Loránd These rock types also occur in outcrops and quarries University were requested by the Hungarian Geological where their geological settings can be studied better than Institute to carry out mineralogical-petrologicaland geo- on borehole samples (BUDAand PusKÁs 1997). The major- chemical investigationson the crystallinerocks of ten bore- ity of the samples are strongly sheared; mylonitisation and holes drilled in the Mórágy Hills, South Hungary. The aim catac1asis are common. The vein fillings are quartz, car- of the project, co-ordinated by the Institute, was to delin- bonate and small amount of sulphides. ~ eate the most favourablearea for disposal of low-and inter- mediate-levelradioactivewaste. 2.1. Microcline megacryst-bearing granitoiis -.%----- In this paper we described the mineralogy and petro- -~ logyof the main rock types, inc1udingthe alteration of min- This rock type is the dominant one in the borehole sam- erals as well as the deformation of rocks. Tectonic settings ples. The occurrences of white or pinkish microc1ines are have been identified based on major and trace element random. The rocks occurring in the near-surface, mylonitic compositions.Trace-elements,Sr,Nd and Pb isotope ratios zones or near to the microgranite dykes contain pinkish were used in order to determine the origin of melts these microc1ine. The white microc1ine-bearing granitoids usual- rocks crystallised from. Finally we outline the genesis of ly contain unaltered amphibole and . the crystalline rocks occurring in the investigatedarea. Microcline megacrysts are mostly euhedral, attaining sizes up to 5x3 cm. The white microc1ine, which also occurs in basic amphibole-rich enc1aves, has a slightly dis- 2. Mineralogy and petrology of the main rock types ordered structure (tjO = 0.86) compared with the pinkish microc1ine (tjO = 0.96 BUDAet al. 1999). Four main rock types havebeen distinguishedbased on lnc1usions of groundmass in microc1ine megacrysts are their textural characters, mineralogical and chemical com- common, inc1uding apatite, sphene, , amphibole, positions : biotite, quartz, plagioc1ase.These inc1usions are not deformed 1. microc1ine megacryst-bearing granitoids (quartz whereas the groundmass of the rock is strongly deformed monzonite, monzogranite), which suggests that the megacrysts crystallised before the

" 232 Gy. BUDA, Z. PusKÁs, K. GÁL-SÓLYMOS, U. KLÖTZLI and B. L. COUSENS deformation. The most common twin law is Carlsbad but Apatite is a common accessory , occurring as cross-hatched twinned or untwinned megacrysts are also short, stubby prismatic crystals. observed. String perthite is common. Microc1ineoccurring Pyrite is disseminated throughout the granitoids, and is in ground mass has undulose extinction or shows cross- commonly altered to limonite. hatched twins and has disordered structure (~= 0.5), indi- Chalcopyrite occurs as an inc1usion in pyrite in a form cating crystallisation under the higher temperature and of droplet or rarely as a vein-filling. faster rate of cooling.Manyplagioc1asesare partly or entirely replaced by cross-hatchedmicroc1ines.These replacement 2.2. Amphibole-rich enclaves (diorite, monzonite, syenite) textures can be observed in amphibole-richenc1avesas weIl as in granitoids. The microc1ine megacryst-bearing granitoids contain Plagioclaseis very common. They are mostly zoned dark green, fine grained amphibole-rich enc1aves with few " with lamellar twinning and commonly altered to sericite. microcline and/or plagioc1ase megacrysts. The thickness of The core of the zoned crystals are enriched in biotite-inc1u- these enc1aves are variable between few cms and more than sions. Sometimesthey are strongly deformed and brecciat- 50 metres. The contact between enc1aves and host grani- -/ ed. The vein-fillingsare mostly quartz and epidote-zoisite. toids is not sharp, and the microc1ine megacrysts common- Microc1ine replacement is common. Compositions are ly have "grown" into the enc1aves. These amphibole-rich oligoc1aseto andesine (An28-3S)' enc1aves are slightly strained but porphyritic textures are Quartz forms knots, mostly deformed with undulose weIl preserved. extinction. Their mineralogical and chemical compositions are Biotiteis the most common mafic constituentwith tabul- highly variable. The total alkali content of enc1aves is usu- ar or lamellar shapes. It has reddish-brownand yellowish- ally higher (Na20+K2O -9 Wt%) than that of the enc1os- brown pleochroism in the pinkish microc1inemegacryst- ing granitoids suggesting that the basic and acidic melts bearing granitoids whereas the biotite in the white micro- coexisted. The higher temperature basic melt started to c1ine-bearing rock has greenish-brown, yellowish-brown crystallise at first (e.g. biotite) resulting in a deficiency in pleochroism indicating a slightlyhigher amount of Mg. alkalies which was equilibrated continuously from the SUf- Both are Mg-biotite(ca1c-alkalinetype). They are com- rounding alkali rich granitoid melt by K diffusion. monly strongly deformed with undulose extinction. They Plagioclase is an import ant constituent, commonly altered to chlorite in mylonitic zones. In microc1ine occurring as large porphyritic euhedral crystals. The crys- megacrysts the biotite is aligned parallel to the rim of tal are zoned from andesine (An41-43) cores through megacryst. These inc1usionsare not deformed. labradorite (And back to andesine rims (An36-3S)' This Amphiboleis not common. Mostlyit occurs in the white complex zonation also suggests the coexistence of acidic microc1inemegacryst-bearinggranitoid. It forms tabular or and basic melts before and during the crystallisation. prismatic euhedral crystals. Twins are common according Plagioc1ase crystals are saussuritised and sericitised, and to the (100) law. Rarely it forms knots. Alteration to chlo- microc1ine-replacement texture also occurs. Rarely crystals rite and ca1cite is also common. Compositions are Mg- are strained and exhibit undulose extinction. hornblende and actinolitic hornblende. Except for the euhedral megacrysts, microcline is main- Accessory : ly an anhedral groundmass phase, containing inc1usions of AIIaniteis euhedral and zoned. Metamictisation is com- plagioc1ase, amphibole, biotite and abundant acicular mon, with most crystals altered to REE-fluorcarbonates, apatite. They are either untwinned or have cross-hatched -~ c1ayand/or opaque minerals. It contains biotite, quartz, twins, and also OCcUfwith or without perthite exsolu- feldspar inc1usionssuggestinglate crystallisation. Epidote- tion. zoisite overgrowth is occasionally observed. Sometimes Quartz is rare and mostly forms knots in the grtmnd- ,.-;.-- crystals are fractured, and cracks are filled with quartz. mass. They are mylonitised with undulose extinction. The Amphibole is a very common mostly euhedral, prismatic high LREE content of the rock originates from abundant phase. Sometimes they are twinned according to the (100) allanite (BUDAand NAGY1995). law. Grains commonly have biotite inc1usions, but biotitisa- is common, euhedral, zoned and surrounded by tion can be observed too. Commonly it forms aggregates a in biotite and amphibole. Three typologi- according to SABATIER(1991) terrned pilites (amphibole caI types can be distinguished: tabular (S4-S9)' long pris- pseudomorphs after olivine). In these aggregates very fine- matic to stubby (S19-S24)and rare prismatic (S2S)genera- grained chromite can be found. Similar aggregates are com- tions with three V/Pb ages. The oldest one (S2S)has Ca- mon in the enc1aves called vaugnerite or durbachite in the domian age (6l9:t18 Ma) and the other two haveVariscan Variscan granitoids of Europe. Their compositions are Mg- ages (340:t8 Ma, and 350:t6 Ma). hornblende or actinolite. is rather common mainly in the white micro- Biotite is common, although its abundance is highly c1ine megacryst-bearing granitoids. They are mostly eu- variable in different enc1aves or different parts of a single hedral. They contain microcline and quartz inc1usionssug- enc1ave. Its composition is Mg-biotite (ca1c-alkaline type). gesting late crystallisation. CIinopyroxeneis not found in alI enc1aves.Mostly it occurs Mineralogical, petrological and geochemical characteristics of crystalline rocks of the Üveghuta boreholes (Mórágy Hills, South Hungary) 233

in amphibole as relict cores after the uralitisation. Its com- Biotite is very rare, altered mostly to chlorite, and position is ferrodiopside W048-50En36-39Fsll-16' strained with undulose extinction. Its composition is Fe- Accessory minerals: biotite (peraluminous-type). Titanite is a very common mostly euhedral in form but anhedral shapes are also observed. 2.4. Pegmatoids Acicular apatite is also common. The acicular form indicates fast rate of cooling, and a magmatic origin. Pegmatoids occur as dikes or pods. Commonly they Zircon is arare, euhedral phase, commonly with a occur together with microgranite. It has graphic texture. pleochroic halo in amphibole as well as in biotite. The structure of microcline is highly ordered (~ = 0.92) Allanite is euhedral but mosdy they are metamictic, with indicating a lower temperature of crystallisation than the ~ :' quartz inc1usions and epidote-zoisite overgrowths on the rim. microc1ine megacrysts in granitoids. Chromite grains are very small (1-30 flm). They are euhedral or have rounded shapes and occur mosdy in ;. amphibole aggregates. They are chromium-, iron- and Zn- 3. Alteration and deformation rich (Table 1, Plate L 100xCr/(Cr+Al) = 89) and 100xMg/ (Mg+Fe2+) = 0.9). Alteration of primary crystallised minerals is wide- Table 1 spread: most pyroxeneis altered to green amphibole. Due Chromite composition from ampibole-rich enclaves to K-metasomatism,plagioc1aseis replaced by microc1ine Wt% Cation numbers based on and amphibolebybiotite.Later biotitealteredto chloriteand 32 oxigene amphibole to chlorite plus carbonates. The sodic plagio- Si02 - Si - Ti02 0.48 Al 1.340 c1aseis partly altered to sericite and ca1cicto saussurite. Allanite is altered to REE-fluorcarbonates and c1aymin- Al203 3.88 Cr 11.126 Cr203 47.99 Fe'+ 3.313 erals due to metamictisation and hydrothermal alteration. FeO 27.97 Ti 0.105 Deformation:Strain and catac1asticeffects are common in the whole crystalline complex. Initially, grinding and 15.01 15.884 Fe203* rolling out processes forrned mylonite with different grain- MnO 2.78 Mg 0.065 sizes.The mylonitewas later brecciated and cemented with ZnO 2.19 Fe'+ 6.858 fine-grained carbonate and quartz. Subsequendy the brec- MgO 0.15 Mn 0.690 ciated mylonite was cross-cut by fractures that filled with CaO 0.08 Zn 0.474 calcite showing secondary twin lamellae and quartz with Total 100.53 Ca 0.025 undulose extinction. During the most recent deformation 8.112 event, a younger crack systems forrned which was filled 100 Mg/(Mg + Fe'+) = 0.93 with ca1citeand quartz which exhibit no strain effect. IDO Cr/(Cr + Al) = 89.25 * Fe" ca1culation after DRooP (1987). 4. Rock c1assification and plate-tectonic settings Pyrite is usually partly altered to limonite, and rarely based on the major-element chemistry contains droplets of chalcopyrite. ~ Galena is very rare, fine-grained (1-2 flm), and mostly it Monzogranite (adamellite), quartz monzonite, mon- zonite, syenite, quartz syenite have been distinguished /' occurs in K-feldspar. / based on cationic ca1culationsfrom major element data by ..... Theseamphibole-richenc1avesare slightlystrainedbut ~-'" porphyritic textures are well preserved. DEBONand LE FORT(1983). The prevailing rock types of the enc1aves are monzonite, syenite and microc1ine 2.3. Microgranite megacryst-bearinggranitoids that are c1assifiedas quartz monzonite and monzogranite based on CIPW norm calcu- Microgranite dikes vary in size from a few centimetres lations (Figure 1, A). Some enc1aveshave dioritic modal to 10 metres in width (observed in Kismórágy quarry). compositions. They are fine-grained,equigranular,and pinkish in colour. Twomajor groups can be distinguishedaccording to the Sometimes the original texture is obliterated by strong degree of Al-saturation: 1. enc1avesas well as the white mylonitisation.The mylonitised dikes show catac1astictex- microcline megacryst-bearinggranitoids are metaluminous ture as well, with common carbonate and quartz vein-fill- (Al/Ca+Na+K<1, Figure 1, B). 2. pinkish microc1ine ings. megacryst-bearinggranitoids and microgranites are slightly Plagioclaseis common, sometimes replaced by cross- peraluminous (Al/Ca+Na+K>1, Figure 1, B). Both groups hatched microcline.They are mosdystrained and onlylarger are mainly I-type(Al/Ca+Na+Ca<1.1,Table2, Figure 1,C) Carlsbad-twinnedcrystals are not deformed. except some microgranite which has S-type characters, Quartz is fine grained, forming aggregates with undu- such as the presence of muscovite and garnet. The rock- lose extinction. series is ca1c-alkalinewith Mg-(Figure 1,D) and K-enrich- 234 Gy. BUDA, Z. PusKÁs, K. GÁL-SÓLYMOS, U. KLÖTZLI and B. L. COUSENS

Q 3JI Pe- quartzollle %.3r-"""", 2.6 M 2.2 z.o AlNKI.8 1.6 . tonallle lA . \ \' \ 1.1 mtn: anoedlorill>\ 1.0 "".~..:':l- "u,"'\u..... U m~odionl\dió~ U -omudiórit diórillO '" OA 1.0 2.0 A p 0.5 1.5 AlCNK A B

FeOt

AlCNKI ---- .. .

Calc-AIIIIIllite o 40 50 60 70 30 Na20+~O MgO SIO. C D Na20 1500 t--- 3-1IIppo_"""""""'-2-~~- 1000 4-50""""- 5-__""'- 6-_-"'- -... 1500 lU

1000 -,

500

o o 500 1000 1500 %000 %500 3000 KtO CaO Rt E F

Figure 1. Major element composition of amphibole-rich encIaves, granitoids and microgranites

. = amphibole-rich enc1aves,'" ~ microc1ine megacryst-bearing granitoids, . = microgranites, A/NK = Al/Na+K; A/CNK = Al/Ca+Na+K 1. ábra. Az amfibolgazdag zárványok, ganitoidok és mikrogránitok foelem-összetétele

. = amfibolgazdag zárványok, ... ~ mikroklin megakrislályokat tartalmazó granitoidok, . = mikrogránitok II íJ t) ') "

5 '";:,' i:! cs- qs u.~ ~j\ 1 6L1'~ ,-...8' "'"'" ~ cs- Qq [ Arophibo1e-richeAves ,) Microcline roegacryst-bearinggranitoids Microgranites ;:," 1 2 3 'r 4 5 6 7 8 9' 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 !:>.. ~ SiOl 51.60 48.30 49.40 51.90 50.30 49.70 55.60 60.70 60.90 61.20 60.30 62.00 67.00 61.90 62.00 62.20 62.60 59.50 60.10 66.70 76.20 74.00 75.60 a ~ TiOl 1.25 1.53 1.49 1.16 1.25 1.32 1.23 0.89 0.91 0.85 0.92 0.93 0.82 0.50 0.81 0.81 0.84 0.81 0.87 0.94 0.53 0.05 0.18 0.04 '" 21 AlzÜ3 13.30 16.80 16.80 12.10 16.50 16.70 18.00 10.90 16.60 16.60 16.60 16.50 16.30 14.80 16.40 16.30 16.10 16.30 16.40 16.60 15.00 12.90 14.00 13.00 [ FelO3 1.55 1.39 1.54 1.20 1.64 2.33 2.17 1.27 1.04 1.14 1.13 1.23 0.36 0.87 0.26 0.61 1.17 1.28 1.13 0.99 0.95 0.39 0.89 0.41 ~ FeO 4.70 6.00 5.80 5.00 4.49 4.56 4.88 4.20 3.50 3.20 3.50 3.60 4.14 1.98 4.14 3.88 3.32 3.04 3.50 3.50 1.90 0.09 0.10 0.10 " i:! MnO 0.13 0.11 0.11 0.12 0.09 0.10 0.11 0.09 0.05 0.06 0.06 0.07 0.07 0.04 0.06 0.07 0.07 0.06 0.07 0.06 0.05 0.01 0.01 0.03 " 1i>' MgO 7.32 6.89 6.56 9.40 5.81 6.91 5.26 10.20 3.05 2.98 3.31 3.18 2.77 1.71 2.71 2.68 2.88 2.78 3.07 2.67 1.79 0.12 0.10 0.02 ~. CaO 5.91 6.73 6.59 5.45 5.84 5.94 6.87 8.15 3.53 3.17 3.26 3.63 3.35 2.06 3.76 3.90 3.82 3.40 3.86 3.51 2.76 1.04 0.62 0.62 ~. ~ NalO 0.55 2.77 2.84 0.84 3.15 3.13 2.68 1.64 3.13 3.10 3.25 3.33 3.10 3.12 3.11 3.26 3.19 3.26 3.33 3.04 3.06 3.89 3.24 4.01 " 8.50 4.78 4.81 8.07 5.18 4.29 5.15 4.39 4.8 4.93 4.51 4.26 4.17 5.34 3.74 4.30 4.26 4.04 4.32 4.58 4.57 4.26 5.64 4.45 ~ KlO ~ 0.33 0.30 0.19 0.02 0.05 -0.01 :::: PlOS 0.79 0.89 0.88 0.76 0.78 0.80 0.93 0.96 0.33 0.31 0.33 0.34 0.33 0.21 0.33 0.29 0.35 0.30 S. 2.10 1.60 1.50 1.20 1.86 2.25 2.02 1.60 0.90 1.50 1.40 0.90 1.61 1.28 1.32 1.14 1.22 1.58 1.50 1.60 1.60 0.44 0.70 0.40 '" HlO. 21 0.20 0.20 0.30 0.10 0.02 0.24 0.16 0.20 0.10 0.20 0.20 0.20 0.10 0.17 0.10 0.02 0.06 0.10 0.20 0.20 0.10 0.08 0.10 0.10 " HlO- i:; COl 1.15 n.d. n.d. n.d. 0.27 0.18 0.23 n.d. n.d. n.d. n.d. n.d. 0.18 0.02 0.31 0.15 0.08 0.14 n.d. n.d. n.d. 0.22 n.d. n.d. ~ Total 99.05 97.99 98.62 98.20 98.78 99.05 99.38 100.09 98.65 98.94 99.67 98.47 99.30 99.10 98.95 99.40 99.56 99.69 98.08 98.09 99.20 99.70 99.63 98.77 '"SO c;::: A/CNK 0.64 I 0.76 I 0.77 0.60 0.77 I 0.81 I 0.80 0.49 I 0.99 I 1.02 1.03 0.99 I 1.04 I 1.01 1.03 I 0.95 I 0.96 1.02 0.96 I 1.02 I 1.00 1.00 I 1.11 I 1.04 ~:=: A/NK 1.32 I 1.73 I 1.70 1.20 1.53 I 1.71 I 1.80 1.46 I 1.60 I 1.59 1.62 1.64 I 1.70 I 1.36 1.79 I 1.63 I 1.63 1.67 1.62 I 1.67 I 1.50 1.17 I 1.22 I 1.14 ~ <::r- a

~ ~ ;;; ~~ch enclqves:1 Dh-1, 48.?I; 2 Dh-1, 84 ro; 3:=Dh-1, 86 n(f;JJlh 1, 118-119~ ~ 1!.h-3, 205.8 ro ; 6 = D.h-23, 107.1 ro; 7 ~ Dh-.~3, 212.2 ro; 8 ~ MÓJ,.ágy:Microcline megacryst-~earing granitoids: 9 = ;:,- a ~ 10 ~ Uh-1, 56 ro; 11 ~ Uh-1, 142/Bro; 12 ~ Uh-1, 158 ro; 13 = Uh-22, 105.3 ro; 14 ~ Uh-23, 80.3 ro; 15 = Uh-23, 174.7 ro; 16 ~ Uh-23, 220.25 ro; 17 ~ Uh-23, 241.6 ro; 18 ~ Uh-23, 300.4 ro; 19 ~ ~ Erdösroecske; 20 ~ Kisroórágy; 21 ~ Mórágy. Microgranite: 22 = Üh-23, 245.8 ro; 23 ~ Kisroórágy; 24 ~ Erdösroecske. co Remarks: e.g. Üh-1, 118 ro etc. ~ Üveghuta boreho1e sarop1es. ~a. X-rayjluorescence analysis (FeO, Hp', Hp- by classical techniques): 1,2, 3,4, 8, 9, 11, 12, 19,20,21,23,24 by XRAL Laboratories, Canada. Classical wet techniques: 5, 6, 7, 13, 14, 15, 16, 17, 18,22 by Geol. lust. of i:! Hungary. n.d. = deterroined ~. t:!; ,[;;: :=:~ SO ;:,~ ~ "'-~ to.> VIUJ tV Table3 W cr-- Trace element analyses of enclaves and granitoids of Mecsek Mts

Amphibole-richenclaves Microcline megacryst-bearinggranitoids Microgranites I 2 3 4 5 6 A 7 8 9 lO II 12 A 13 14 A Ba 3220 1840 1770 3150 1920 2180 2346.67 1410 1170 933 1070 1290 858 1072.67 50 645 347.50 Rb 258 225 228 270 321 331 272.17 188 198 211 224 199 169 197.33 329 257 293.00 Sr 347 620 585 344 455 470 470.17 528 456 418 385 354 384 374.33 22 193 107.50 Y 40 32 44 32 35 35 36.33 23 28 24 27 26 24 25.67 49 25 37.00 Zr 447 383 387 335 160 145 309.50 308 335 324 306 344 227 292.33 82 145 113.50 Nb 22 17 18 16 12 14 16.50 12 17 16 21 22 17 20.00 29 28 28.50 Th 48 19 21 45 22 22 29.50 20 28 28 19.6 17.4 27.9 21.63 18.5 41.1 29.80 Q \:;o Ga n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 21 21 18 20.00 18 18 18.00 C Zn n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 155 317 296 256.00 397 253 325.00 ffi: Ni n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 50 50 208 102.67 275 129 202.00 ~ '"ti Cr n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 68.9 63.6 55.6 62.70 8.1 18.5 13.30 C Hf n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 13.6 16.8 9 13.13 31.7 13.1 22.40 ~. Cs n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 12.5 18 3.1 11.20 16.9 19 17.95 .'" ~ Sc n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 13.7 12.8 8.29 11.60 3.51 2.38 2.95 Q Ta n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 1 4.6 0.8 2.13 3.5 1.3 2.40 e-;J>. V, Co n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 33.2 33.1 43.2 36.50 85.4 62.9 74.15 o' U n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 7.7 4.6 5.4 5.90 15.5 2.3 8.90 ~ ° La 73.4 60.9 60.2 68.5 47.9 47.4 59.72 59.1 85.4 64.9 60.8 66.5 49.5 58.93 5.2 32.2 18.70 y' Ce 154 121 125 140 103 103 124.33 110 154 118 118 119 93 110.00 19 71 45.00 ~ Pr n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. ~ Nd 71 57 63 65 56 55 61.17 44 56 45 81 82 40 67.67 65 3 34.00 o< tj Sm 14.3 11.4 13.4 13 13.1 12.9 13.02 7.73 9.56 8.1 8.49 9.39 6.49 8.12 2.77 4.69 3.73 t:: 1" Eu 2.31 2.18 2.37 1.69 2.73 2.97 2.38 1.7 1.57 1.49 2.2 1.22 0.89 1.44 0.31 1 0.66 i:j P. Gd n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. \:;o Tb 1.3 1.2 1.5 1 0.8 0.8 1.10 0.9 1 1 2.5 1.1 1.9 1.83 2.5 2.2 2.35 ~ 5.5* 5.8* 7.5* 4.7* 4.5* 4.5* 5.42* 4.4* 6.2* 4.7* n.d. n.d. n.d. 5.10* n.d. n.d. 4.20* (j Dy ° Ho n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. C Er n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. ~'" Tm n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. yb 2.59 2.27 2.64 2.01 1.41 1.45 2.06 1.71 1.92 1.36 1.65 1.91 1.78 1.78 6.13 1.48 3.81 Lu 0.38 0.32 0.36 0.29 0.2 0.21 0.29 0.22 0.25 0.19 0.01 0.01 0.01 0.01 0.01 0.01 0.01 l:REE 319.3 256.3 268.5 291.5 225.1 223.7 264.06 225.4 309.7 240 274.65 281.1 193.6 249.78 100.9 115.6 108.25 LREE 73.8 66.6 58.66 87.3 92.4 89.9 75.5 78.6 96.7 93.1 65.0 92.1 51.5 77.4 10.6 30.3 20.5 HREE

Amphibole-rich enclaves: I ~ Üh-I, 48 m; 2 ~ Üh-I, 84 m; 3 ~ Üh-I, 86 m; 4 ~ Üh-I, 1I8-1I9 m; 5 = Üh-3, 91.6 m; 6 = Üh-3, 96.3 m. Microcline megacryst-bearing granitoids: 7 ~ Üh-I, 54 m; 8 ~ Üh-I, 142/B. m; 9 ~ Üh-I, 158 m; 10 ~ Erdosmecske; II ~ Kismórágy; 12 ~ Mórágy. Microgranite: 13 = Erdosmecske;14 = Kismórágy. A = average, n.d. ~ not determined, * = not counted in SREE. Remarks: e.g. Üh-I, 1I8 m etc.: bore- hole samples. Neutron activation and X-ray fluorescence analysis (XRAL Laboratories, Canada).

'1 '. Mineralogical, petrological and geochemical characteristics of crystalline rocks of the Üveghuta boreholes (Mórágy Hills, South Hungary) 237

400 400

.. ~ :c 1: '1:1 '1:1 : 100 100 .CI .CI~ U V ... ~ V iS. .. e iS. o:e ~ lJ) 10 10 7 7 La Pr Eu Tb Ho Tm Lu La Pr Eu Tb Ho Tm La ~ ce Nd Sm Gd Dy Er Th Ce Nd Sm Gd Dy Er Yb A ~ B

200 400

.. 100 ~ :c 1: '1:1 1 100 1'1 Q Q .CI .CI V U eJ ~ .. iS. iS. e.. ..e lJ) 10 fl) 10

5 5 La pr Eu Tb Ho Tm Lu La pr Eu Tb Ho Tm La Ce Nd Sm Gd Dy Er Th Ce Nd Sm Gd Dy Er Yb c D

2000 1000

1000 'Syn-COLG

100 100 .CI .CI ~ Z

10 10

- VAG ORG ORC 1 1 1 10 100 1000000 1 10 100 1000000 .. Y+Nb Y E F

Figure 2. Chondrite normalized REE patterns of granitoids and enclaves

A = Amphibole-rich enc1aves, B = Microc1ine megacryst-bearing granitoids, C = Microgranites, D = Summary of the three rock-types, E-F: . = amphi- bole-rich enclaves, ... = microc1in megacryst-bearing granitoids,. = microgranite. ORG = Oceanic Ridge Granites, VAG = Volcanic Arc Granites, SYN- COLG = Syncollision Granites, WPG = Within Plate Granites

2. ábra. Granitoidok és zárványok kondritra normált RFF eloszlása

A = amfibolgazdag zárványok, B = mikroklin megakristályokat tartalmazó granitoidok, C = mikrogránitok, D = A három kozettipus RFF eloszlásának összefoglalóábrája,E-F: . = amfibolgazdagzárványok,... = mikroklinmegakristályokattartalmazó granitoidok, . = mikrogránitok. ORG = Óceánközepi granitoidok, VAG = Vulkáni szigetiv granitoidjai, SYN-COLG = Szinkolliziós granitoidok, WPG = Lemezközepi granitoidok 238 Gy. BUDA, Z. PusKÁs, K. GÁL-SÓLYMOS, U. KLÖTZLI and B. L. COUSENS

Rb/30 granite differs entirely from the previous two rock types, having a characteristicnegativeEu-anomaly,relativeenrich- ment in HREE and depletion of REE indicatinga more dif- ferentiated character (Table 1,Figure 2, C) compare with enc1avesas weilas with granitoids. In Rb-Y+Nb and Nb-Y discrimination diagrams the trace element compositions plot (PEARCEet al. 1984)in the tieid ofVolcanic Arc Granites (VAG)as weilas in the tieid , of Within Plate Granites (WPG, Figure2, E, F). The post- , , collisional granites have the broadest range of sources, e.g. ...., having either subduction-like mantie sources with geo- " t>O ..' chemical characters similar to the vo1canicarc granites, or " Ill. intraplate-likesources having the characteristics of within O plate granites. In addition there are interactions between the mantie-derivedmelts and crustal meits (PEARCE,1996). In order to better determine the proper tectonic settings of " \/ Hf these rocks Rb- Hf-Ta compositions were plotted discrimi- nation diagram of HARRISet al. (1986), where they plot in Figure 3. Rb- IIf-Ta trianguIar plot of Variscan granitoids the late or post-collision ca1c-alkalinetieid (Figure 3). in the Mórágy Hills Primary magmas were derived from a mantie source but underwent extensivecrustal contamination (Figure 3) and o = amphibole-rich enclaves, = microcline megacryst-bearing grani- toids (Erdosmecske, Kismórágy etc.), . = Microgranite (Erdos!TIecske, in this diagram they can be distinguished from VAG and Kismórágy). Group II: "Syncollision" peraluminous intrusions, Group Ill: WPG. Ba (2300 g/t), Rb (272 g/t), Cr (1100g/t, BUDAet al. Late or postcollision calc-alkaline intrusions (HARRIs et al., 1986) 1999) are enriched in amphibole-bearing enc1aves,e.g. microcline-rich(K2O = 8-8.5 Wt%) syenitic enc1avescon- 3. ábra. A mórágyi-hegységi variszknszi granitoidok tain the highest Ba concentration (3200 g/t), and Cr- Rb-lIf- Ta megoszlása enrichment can be found in the chromite-bearing amphi- o = amfibolgazdag ásványok, = mikroklin megakristályokat tartalmazó bole-rich enc1aves.Similar enrichment of compatible and

granitoidok(Erdosmecske,Kismórágystb.),. ~ mikrogránitok (Erdos- incompatible elements (Figure 4, A) has been described mecske, Kismórágy). II.: SzínkoIlíziós peralumínium-jellegü intúziók. Ill.: from lamprophyre-derived mafic enc1aves (vaugnerite- Késo v. posztkoIlíziós mészalkáli intrúziók (HARRIs et al. 1986) series, e.g. durbachite) and from hosting granitoids occur- ring in Variscan collision zone (SABATIER1991). Mantie and upper crust normalised trace-element dis- ment (KINa>1, Figure 1, E). Total alkali contents do not tribution patterns of host granite and enc1avesare verysimi- correlate with silica content, suggestingthat alkali enrich- lar (Figure 4, B, C). Ba, Rb, Sr etc.are enriched compared ment is due to post-crystallisationmetasomatism.According to the mantie (I-type granitoids). The trace element distri- to multicationic parameters 2(Fe+Ti), R2 = 6Ca+2Mg+Al bution pattern of microgranites indicates a weil differenti- (OELAROCHEet al. 1980) these rocks belong to the high- ated magma with crustal source (Figure 4, D, E). potassic calc-alkaline group and forrned from melts that originated partiy from uplifted mantle and partly from meited continental crust (BATCHELORand BowoEN 1980, 6. Radiogenic isotope composition Figure 1,F) in the continent-continentcollision-zone. Rb-Sr and Sm-Nd isotope analyseswereperforrned on 5. Trace element composition whole rock samples at the Laboratory for Geochronology, University of Vienna and Pb isotope ratios in K-feldspar Total rare earth element (LREE) contents of the amphi- megacryst mineral separates were determined at Carleton bole-rich enc1aves(264 g/t) are very similar to the hosting University,Ottawa. microcline megacryst-bearinggranitoids (254 g/t, Table3). The absence of negativeEu-anomalyin the enc1avesis due 6.1. Rb-Sr and Sm-Nd isotopes to the plagioc1ase.The chondrite-normalised REE patterns are very similar for both rock types (LLREE/LHREE ratio Isotope analyses have been carried out in order to deter- is 76 in enc1avesand 77 in granitoids) too. LREE enrich- mine the origin of granitoids and their amphibole-bearing ment (Figure2,A, B, D) is due to the common occurrences enc1aves. Initial Sr isotope ratios (Sr(i» and ENdvalues were of allanitein each rock type. The very similar REE-patterns calculated assuming a c1osed-system behaviour for parent indicate REE equilibration which means the enc1avesat and daughter isotopes and a crystallisation age of 340 Ma. least partiaIly crystallised together with the hosting grani- Sr(i) as weil as Nd values are very similar in both rock types toid melt. The chondrite-normalised REE pattern of micro- (Table4): Mineralogical, petrological and geochemical characteristicsof crystalline rocks of the Üveghuta boreholes (Mórágy Hills, South Hungary) 239

3000

-!1000 1:1 ol ~

lEi ol r.fJ 10

10 5 CI !Ib V Nb Sr zr Th ce Ni Ta cs Rb U Nb Sr Zr Tb Cr NI Ta S.ThPbUCe y zn BaTbPbUCe V ZI! A B

20 '

10 ...., E u .. ci.8. ~ c.. Ei ol r.fJ

0.3 Cs ab U Nb Sr zr Tb Cr NI Ta BaTbPbUCe V ZU c

20 10 ...., ..::1 U

Figure 4. Spider diagrams of amphibole-rich enclaves, granitoids and microgranites

A-C: amphibole-rich enc1aves (verticallines) and microcline-bearing granitoids (horizontallines). D-E: microgranites

4. ábra. Amfibolgazdag zárványok, granitoidok és mikrogránitok köpenyre, alsó- és felso kéregre normált nyomelemeloszlása

A-C: amfibolgazdag zárványok (fúggoleges vonalak) és mikroklin megakristályokat tartalmazó ganitoidok (vizszintes vonalak). D-E: mikrogránitok

- Gy. BUDA, Z. PusKÁs, K. GÁL-SÓLYMOS, U. KLÖTZLI and B. L. COUSENS 240 ,Ai;-'/~v,t,.., ~ ;.1 Ar ~ ~. w'1 , (j~ 1. ..A~ ti'"

& W Locality Rocktype Rb* Sr* 87Rbj86Sr87Srj86Sr Sm* Nd* I47Smj'44Nd I43Ndj'44Nd Sr(i) Nd(i) ENd Üh-l, amphibole- 258.0 378.2 1.976 0.71798 13.9 85.4 0.0981 0.512157 0.70842 0.511939 -5.1 48 m rich enc1ave Üh-l, amphibole- 229.9 649.4 1.025 0.71324 13.3 74.1 0.1082 0.512171 0.70828 0.511930 -5.3 84m rich enc1ave Üh-l, amphibole- 228.0 601.8 1.096 0.71365 14.3 74.8 0.1151 0.512189 0.70835 0.511933 -5.2 86m rich enc1ave \ Üh-l, amphibole- 270.6 384.0 2.041 0.71815 13.3 80.7 0.0996 0.512143 0.70827 0.511921 -5.4 "54m Ifich enclav", ,Qh-l, 188.0 552.7 0.984 0.71389 8.1 50.5 0.0972 0.512165 0.70913 0.511949 -4.9 , 118m './I@d'gra tOl Üh-l, 200.0 561.1 1.032 0.71402 9.0 57.2 0.0955 0.512151 0.70903 0.511939 -5.1 56m granitoid Üh-l, ':ft granitoid 198.0 459.1 1.248 0.71451 9.3 60.9 0.0923 0.512150 0.70847 0.511945 -5.0 142/Bm Üh-l, 211.0 433.1 1.410 0.71528 8.9 50.4 0.1064 0.512162 0.70846 0.511925 -5.4 158m granitoid CHUR 0.1967 0.512638 0.512200

* in ppm. i ~ inital isotopic ratio at 340 Ma, CHUR = Chondritic Uniform Reservoir

- Average isotope parameters of amphibole-rich enclaves: enclaves and host granitoids are strikingly similar, like their Sr(i) = 0.7083, ENd= -5.3. REE patterns, suggesting that equilibrium existed between - Average isotope parameters of granitoids: Sr(i) = the enclaves and granitoids and consequently the enclaves 0.7087, ENd= -5.1 are not restites or xenoliths. Sr(i) as weH as ENdvalues indicate mixing of melts origi- nated from upper mantle and continental crust which is 6.2. Pb isotopes characteristic for I-type calc-alkaline granitoids (McCuLLocH and CHAPPELL1982; Figure 5). Sm/Nd ratio (0.16-0.17) in Pb isotope ratios (Table 5) in K-feldspar indicate a model age between 350-380 Ma (STACEYand KRAMERS "Srt"Sr(I) 1975),and mixingofmelts from mantle and crustal sources (Figure6). The core of the zoned microcline megacryst has a larger mantle component compared with the rim of the same megacryst. It suggests that the overgrowth of the K- feldspar is probably due to a later K-metasomaticevent and

Table5 Lead isot, . ti f K-feld ,J -4 Samp1e 208Pbj204Pb 207Pbj204Pb 206Pbj204Pb Cndt8I 1. Üh-2, 159.1 m 38.127 15.602 18.107 .. 2. Üh-2, 318.0 m 38.173 15.616 18.119 "itf= 3. Üh-3, 130.1 m 38.128 15.601 18.102 4. Üh-3, 174.9 m 38.130 15.601 18.116 .jO jO 100 IjO 200 5. Üh-3, 201.0 m 38.179 15.617 18.117 ss. 6. Üh-23, 205 m 38.110 15.590 18.114 Figure 5. Initia] Nd and Sr isotopic composition 7. Üh-23, 234.5 m CC) 38.077 15.579 18.102 ofVariscan (340 Ma) granitoids and amphibole-rich enclaves 8. Üh-23, 234.5 m CR) 38.211 15.625 18.161 occurring in Mecsek Mts (in McCuLLOcH and CHAPPEL1982 plot) 9. Üh-23, 257.0 m 38.155 15.606 18.110 10. VE 5900/14 m 38.408 15.633 18.406 D.= granitoid ~ amphibole-rich enclave 1- 7. - Microcline megacrysts from granitoid from borehole samples of 5. ábra. A Mecsek hegységi variszkuszi (340 M év) granitoidok Üveghuta (Mecsek Mts), 8. - Core (C) of the microcline megacryst from granitoid from borehole samples of Üveghuta (Mecsek Mts), 9. - Rim (R) és amfibolgazdag zárványok iniciális Nd- és Sr-izotóp összetétele of the same microcline megacryst from granitoid from borehole samples (MCCULLOCHés CHAPPEL1982 nyomán) készült of Üveghuta, 10.- Orthoclase from granite (VE ~ VelenceMts) Remarks: e.g. Üh-3, 130.1 m = Üveghuta borehole samples and depth in D.= granitoid, = amfibolgazdag zárvány metre. Mineralogical, petrological and geochemical characteristics of crystalline rocks of the Üveghuta boreholes (Mórágy Hills, South Hungary) 241

0.8

15,6

18.5

15.7 OAGa

upper crust, DZ. Ip

15.6 .o p.. (!; "l... .o Variscan K-felspar data from r-p.. 1'i 15.5 O Vitrac et al. (1981): V = Vosges,IP = Iber.Peninsula O Br = Brittany, WMC = Westem Massif Central, SEMC = SE-Massjf Central, py = Pyrénées

Variscan Schwarzwald K-feldspars data from B.Kober et al. (1985). ISA . Mecsek Mts.,K feldspars . VelenceMts., K feldspars Core ofmegacryst (Mecsek Mts.) ec ~ Rím of megacryst (MecsekMts.) 15.3 a' I 17.5 18.0 "" - 18.5 a. 19.0 266pbfG4pb

Figure 6. Lead isotope ratios of K-feldspar, occurring in Variscan granitoids of Mecsek and Velence Mts

oz = after OOE and ZARTMAN1979; SK = after STACEYand KRAMERS1975

6. ábra. A Mecsek és velencei-hegységi granitoidok K-földpátjainak Pb-izotóp arányai

oz = OOE és ZARTMAN 1979, SK = STACEY és KRAMERS 1975

that this potassium was derived mainly from the crust. We 7. Conc1usions compare these Pb isotope data with Pb isotope ratios in K- feldspar of 8-type granitoids of Velence Mts in Figure 6. Four rock types have been distinguished in the bore- The model age of orthoc1ase in Velence granitoids is 280 hole samples of Üveghuta: amphibole-rich enc1aves (syen- Ma. and these feldspars inc1ude more crustal Pb, consistent ite, monzonite, diorite), host microc1ine megacryst-bearing with the conc1usions of previous work (BUDAet al. 1999). granitoid (quartz monzonite, monzogranite), microgranite 242 Gy. BUDA, Z. PusKÁs, K. GÁL-SÖLYMOS, U. KLÖTZLI and B. L. COUSENS

(monzogranite) and pegmatite. These rock types also occur tallised as microgranite dykes cross-cutting the main crys- in the outcrops of Mórágy Hills. talline massif. Replacement textures are widespread due to The K- Mg-calc-alkaline amphibole-rich chromite-bearing K-metasomatism originated írom these volatile enr~ched enc1aves have calc-alkaline lamprophyric characters similar melts.- The crystalline massif was subsequently strained to vaugnerites and durbachites (ROCK1991) described in the (mylonitisation, catac1asisetc.) and effected by hydrother- Variscan collision belt of Europe. The hosting granitoids mal alteration. have also K-Mg-rich calc-alkaline characters. The observed REE and isotopic equilibrium between host granitoids and enc1aves suggests common sources and simultaneous crys- 8. Acknowledgement tallisation of these rock types. The basic component origi- nated from partially fused upper mantle wed ee' . We are indebted to Zoltán Balla and Géza Chikán vo at es an a, b, Sr due to older subduction p-vp-nt>:. (GeologicalInstitute of Hungary) for permissionto sample This higher temperature basic melt, preserved as enc1aves, the cores for investigation. This research is a part of the intruded into the continental crust causing its partial melt- program entitled: "Correlation of Variscan granitoids ing and formation of the mlcroclme-bearing granitoiás. occurring in Central Europe" financed by Hungarian Later on the continental crust again partially melted National Science Foundation (OTKA No. 023762) and producing a peraluminous Si-rich melt which was crys- Ministry of Education (OM 0181).

References

BATCHELOR,R. A., and BOWDEN,P., 1985: Petrogenetic interpre- - Geological Society Special Publications 19, pp. 67-81. tation of granitoid rock-series using mu1ticationic parameters. KOBER,R, and LIPPOLT,H. J., 1985: Pre-Hercynian mantle lead - Chemical Geology 48 (1-4), pp. 43-55. transfer to basement rocks as indicated by lead isotopes of the BUDA, Gy., and NAGY, G., 1995: Some REE-bearing accessory Schwarzwald crystalline, SW-Germany. n. Lead isotope evolution minera1s in two types of Variscan granitoids, Hungary. - of the European Hercynides. - Contributions to Mineralogy Geologica Carpathica 42 (2), pp. 67-78. and Petrology 90 (2-3), pp. 172-178. BUDA,GY., and PusKÁs, Z., 1997: Crystalline rocks of the Üveg- MCCULLOCH,M. T., and CHAPPELL,R W, 1982: Nd isotopic huta-1 boreho1e (Az Üveghuta-1 fúrás kristályos kozetei). - A characteristics of S- and I-type granites. - Earth and Planetary Magyar Állami Földtani Intézet Évi Jelentése 1996/[1, pp. 78-98. Science Letters 58 (1), pp. 51-64. BUDA,Gy., LOVAS,GY., KLÖTZLI,u., and COUSENS,B. L., 1999: PEARCE,J. A., 1996: Sources and settings of granitic rocks. - Variscan granitoids of the Mórágy Hills (South Hungary). - Episodes 19 (4), pp. 120-125. Beitrage zur European Journal of Mineralogy lJ (2), pp. 21- 34. PEARCE,J. A., HARRIs,N. B. W, and TlNDLE,A. G., 1984: Trace DELAROCHE,H., LETERRIER,I., GRANDCLAUDE,P. ANDMARCHAL, element discrimination diagrams for the tectonic interpretation M., 1980: A c1assification of vo1canic and p1utonic rocks of granitic rocks. - Journal of Petrology 25 (4), pp. 956-983. using R1-R2 diagrams and major element ana1yses - is re1a- ROCK, N. M. S., 1991: Lamprophyres. - Blackie, Glasgow and tionships with current nomenc1ature. - Chemical Geology 29 London, 285 p. (3-4), pp. 183-210. SABATIER,H., 1991: Vaugnerites: Special lamprophyre-derived DEBON,E, and LE FORT,P., 1983: A chemica1-minera10gica1 c1as- mafic enc1aves in some Hercynian granites from Western and sification of common p1utonic rocks and associations. - Central Europe. In: DIDIER, J., and BARBARIN,R, (editors): Transactions of Royal Society of Edinburgh Earth Science 73 Enc1aves and granite petrology. - Development in Petrology 13, (3), pp. 135-149. Elsevier, pp. 63-81. DOE, R R., and ZARTMAN,R. E., 1979: P1umbotectonics 1. The STACEY,J. S., and KRAMERS,J. D., 1975: Approximation ofterres- Phanerozoic. In: BARNES,H. L., (editor): Geochemistry of triallead isotope evolution by a two-stage model. - Earth and Hydrothermal Ore Deposits. - Wiley, New York, pp. 22-70. Planetary Science Letter 26 (2), pp. 207-221. HARRIS, N. R W, PEARCE,J. A., and TINDLE, A. G., 1986: VITRAC,A. M., ALBAREDE,E, and ALLCGRE,C. J., 1981: Lead iso- Geodynamica1 characteristics of collision-zone magmatism. tope composition of Hercynian granitic K-fe1dspars constrain In: GOWARD, M. P., RIES, A. c., (editors): Collision Tectonics. continenta1 genesis. - Nature 291 (5815), pp. 460-464.

Plate I - 1.tábla

1. Chromite grains in amphibole in basic enc1aves (Borehole ÜH-22). - Kromit szemcsék amfibolban, visszaszórt elektronkép IN, 200 2. BEI of the same chromite grains. - Kromit szemcsék, visszaszórt elektronkép 3. BEI and x-ray map of CrKC

L Mineralogical, petrological and geochemical characteristicsof crystalline rocks of the Üveghuta boreholes (Mórágy Hills, South Hungary) 243

1.

2.

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3.