Acta Mirieralogica-Petrographica, Abstract Series 1, Szeged, 2003
ROCK-FORMING MINERALS OF BATTONYA AND CSONGRÁD UNIT GRANITOIDS
PÁL-MOLNÁR. E - BATKI, A. & KÓBOR, B.
Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P. O. Box 651, H-6701 Szeged, Hungary.
E-mail: palm@geo.u-szeged.hu
The crystalline mass of the Tisia Composite Terrane is characterised by granitoid ranges and anticline wings of middle and high grade metamorphites. This paper presents the results of a mineralogical analyses on the granitoid rocks originating from characteristic uplifts of the basement (Al- győ-Deszk-Ferencszállás-Makó - [ADFM] High and Pusz- taföldvár-Battonya - [PB] High) of the Békésia Terrane, Tisia Composite Terrane.
The granitoid samples of PB High are mainly of light grey, greenish grey colour. Most of them have a holocrystal- line, inequigranular texture, however, some samples are of equigranular texture. The colour of A D M F High granitoid rocks is mainly light grey, subordinately pale rose-colour.
Their texture is mostly holocrystalline, medium-grained inequigranular and equigranular. Based on the orientation of mica, in some places the studied rocks are characterised by a preferred orientation in terms of their texture. Concerning the mineral composition and texture of the rocks, significant differences cannot be detected, thus they can be considered of similar character (PÁL-MOLNÁR et al., 2002a, b). The major rock forming minerals are quartz, K-feldspar, plagio- clase feldspar and mica (biotite, muscovite). The usual size of minerals falls between 1-3 mm, however microcline por- phyroblasts of 2-3 cm are not rare either. Accessory compo- nents are apatite, zircon, monazite, less frequently garnet and titanite. Secondary components are chlorite, sericite, carbon- ate, epidote, limonite and opaque minerals.
Rock forming and accessory minerals were investigated with electron microprobe analysis. Representative results on the minerals are presented in Table 1.
i ' 1 ' m i n c r j i s t r i m e r i n i k ' l of B a l l o n v i - and ( Simple TíTC — r a n l i l i iTTT — r a r — r m - t n r T U Tm—
M taera bW(Kc aunen vili feldspar ¿panie mnaaulc
üli). U.3 ••7.1 ?5.S l í ? V.l * U 65.5 65.0 0.11 0.1 7
Till. 29» 3 01 2.H 3.1» 1.21 0.4 IS 0.06 0.02 0.02 Bd 2aO 1.45
A l.l), 17.4 17.2 16.» 16.4 31.1 14.5 l«.l 21.3 11.4 0.23 0.0» •ja,
.4.0 21.«
Fed- 17.6 It.l 2I1.4X 20.2 3.3 1.6 0.06 0.07 0 0.11 D d •ja,
.4.0 13.5
« • 0 0.21 0.3 11.5» 11.41 0.04 0.114 0.03 0.06 0.12 0.02 :<.o 21.0
M|0 ».5 1.1 .1.2 11 0.7 0.7 11.04 id 0.03 Id 'i.tl, 2.02
ClO «.It 0.12 0 II 0.05 nd 0 0.1? 2.5» 0.04 52.6 52.7 vd.O ».»<
Na,l> o.;? ! 150 0 22 0.14 0.30 0.3» 11.42 10 3 0.1» id 0.51 ruf). 1.11
K.fi ».24 7.33 ».00 •í.49 ».64 0.(1» 0.0« 15. »i 0.2Í • d
P.O. n .J • J Id »d id •d 40.6 41,1
Tnljl « 1» « H . . .. 43 U »4 >» M4< W . U V ) l »1 !1
CilbM ui 22 Oljrfcll O l » ! ! v * naypeis (. alioü lo 12 oxygens (. allot* lo
4 oiygens
s. 5.« 5 10 5 !6 j 5| »30 6.33 IM ;.»» 2.»» 0.03 001 ¡i O.034
Al !.U 3.15 3.05 3.02 5.17 5.41 1.02 1.10 1.00 0.02 0 ; i 0.064
Al™ 2.3» 2.22 2.44 2 42 1.001
Al" D.75 0.»2 OM 0 M .i 0.204
Ti 0.34 0 36 11.34 (I.J? 0.13 0.(15 1) 0 0 ?e 0.41»
Ft 2.24 2.1» 2.67 I.I3J ".31 0.1> 0 0 0 0 '1 0.030
V . 0.0' 0 04 0.01 O.IK. 0.01 0.01 0 0 0 0 sd 0.145
Ml 2.1« 2.03 l.«l 1 »4 0.15 0.14 0 0 ri 0.013
Cl 0.Ü3 0 02 0.02 0.01 0 0.04 0.12 0 4.70 4.61
\ a 11.07 0.05 0.07 0.04 0.01 0.10 0.97 0.17 0.01 0 01
K 1 SO 1.45 i i : 1 7» 1.47 1.63 0 0 0.»4 0.03
f 2.1? i,W
nd - nul detected element: F e O " - as l o l a l iron
The dominant mineral assemblages are feldspars and mi- cas. K-feldspar and microcline are abundant in the studied granites, and orthoclase is generally present as well. The often zoned plagioclase feldspars of A D M F High granitoids are albite-oligoclase in composition, the plagioclases of PB High granitoid rocks are albite-andesine (Fig. 1).
The biotites of PB and A D M F High granitoids are rich in Fe (Fig. 2). Besides, biotites can also be considered as petro- genetic indicators for early stage granite genesis, since their Mg content reflects the grade of magma fractionation (HECHT, 1993). Parallel to proceeding magma fractionation the Mg content of biotites decreases while the A1VI content remains constant, i.e. its value varies between 0.54 and 0.93.
Thus, based on the composition of biotites A D M F granites are more fractioned than PB granitoids (Fig. 3). According to the Mg vs Al101 ratio in biotites, the granites proved to be calc-alkaline.
Or
Fig.l. Feldspars from PB ( • ) and A D M F (Bjgranitoids.
h u b i n i c SiJcn^iInllile
— 2,6
< 2.4 2.2
• 1 * • 9 •
PHIo^oph: • Anniié
0.2 0.4 0 6 0
ft litt *M t) i
Fig. 2. All v VÍ. Fe/(Fe+Mg) ratio in Fig. 3. M g vs. Alv l of biotites from PB ( • ) and A D M F biotites from PB ( • ) and ( • ) granitoids. A D M F ( • ) granitoids.
Acknowledgements
The financial background of this work was ensured by the Hungarian National Science Found (OTKA) (Grant No.
F/029061) and the János Bolyai Research Grant.
References
HECHT, L. (1993). Münchener Geol Hefte, 10, 221.
PÁL-MOLNÁR, E., K O V Á C S , G. & BATKI, A. (2002a).
Acta Mineralogica-Petrographica, Szeged, 42: 21-31.
PÁL-MOLNÁR, E„ KOVÁCS, G. & BATKI, A. (2002b).
Acta Mineralogica-Petrographica, Szeged, 42: 51-58.
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