GeolCarp_Vol63_No5_383

www.geologicacarpathica.sk

GEOLOGICA CARPATHICA

, OCTOBER 2012, 63, 5, 383—398

doi: 10.2478/v10096-012-0030-6

Vertical zonality of fractionated granite plutons reflected in

zircon chemistry: the Cínovec A-type versus the Beauvoir

S-type suite

KAREL BREITER

and RADEK ŠKODA

Institute of Geology AS CR, v.v.i., Rozvojová 269, CZ-165 00 Praha 6, Czech Republic; breiter@gli.cas.cz

Geological Institute, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic

(Manuscript received March 22, 2012; accepted in revised form June 13, 2012)

Abstract: We studied vertical changes in the chemical composition of zircon from two contrasting Variscan granite
systems. The Beauvoir system (Massif Central, France) composed of three successive intrusions (B1, B2, B3) represents
typical peraluminous S-type granite extremely enriched in P, F, Li, Rb, Cs, Be, Sn, Nb, Ta, and poor in Zr, Th, REE and Y.
The Cínovec system (Krušné hory Mts/Erzgebirge, Czech Republic/Germany) composed of two successive intrusions
(protolithionite granite, zinnwaldite granite) is only slightly peraluminous, P-poor, F, Li, Rb, Cs, U, Th, REE, Y, Sc, Sn,
W, Nb, Ta-rich granite, which may be classified as A-type. In both localities, the most fractionated intrusions are located
on the top of the system. Samples from borehole GPF-1 (Beauvoir) represent an 800 m long vertical section through the
entire granite stock, while CS-1 borehole (Cínovec) reached a depth of 1600 m. Chemical compositions of zircons from
both granite systems show distinct vertical zonality, but their shape and elemental speciation is highly contrasting. At
Beauvoir, zircon shows a remarkable increase in Hf-content from 2—4 wt. % HfO

( ~ 0.03 apfu Hf) in the deepest B3-unit

to 15—19 wt. % HfO

(up to 0.18 apfu Hf) in the uppermost B1-unit. The highest contents of F, P, and U were detected in

the intermediate unit B2 at a depth of 400—600 m. At Cínovec, Hf shows only moderate enrichment from ca. 2 wt. % HfO

in the deeper protolithionite granite to 5—10 wt. % HfO

in the uppermost part of the zinnwaldite granite. High contents of

Th (3—8 wt. % ThO

) are entirely bound in the uppermost section of the granite copula to a depth of 200 m, but below this

level the contents only sporadically exceed 1 wt. % ThO

. Concentrations of U, Y, HREE, Sc and Bi also reach their

highest values in the uppermost parts of the zinnwaldite granite, but their decrease downward is much gentler. Extreme
enrichment of outer zones of zircon crystals from some granites with Hf or high contents of Th, U, REE, Y, Nb and of some
other elements in zircons from other localities is not considered to be a specific phenomenon characterizing melts of A- or
S-type granite, but reflects a high degree of fractionation of systems rich in Na and F.

Key words: zircon, Cínovec, Beauvoir, trace elements analyses, S-type granite, A-type granite, fractionation.

Introduction

Zircon  is  almost  a  ubiquitous  and  relatively  stable  accessory
mineral  in  the  majority  of  types  of  granitoids.  Its  grains  that
show  no  obvious  metamictization  provide  information  about
the chemical composition of the melt, which the granite crys-
tallized from. In common I- and S-type granite, zircon belongs
among the first crystallizing minerals, although some slightly
Hf-enriched  grains  may  precipitate  during  the  final  stage  of
rock crystallization. Zircon is frequently embedded in biotite
and its crystallization results in the decrease of contents of not
only Zr (and Hf), but also of Th, Y and HREE in the melt. On
the contrary, in strongly fractionated peraluminous S-granites,
generally low in Zr, zircon is one of the late-crystallizing min-
erals. It is interstitial and strongly to extremely enriched with
U, P, F and with a number of “ore” elements (Nb, Ta, W, Bi).
In  the  A-type  granites,  zircon  crystallizes  during  the  whole
process  of  the  melt  differentiation,  so  that  in  relatively  less
differentiated intrusions the zircon crystallized as an early min-
eral, while in later highly differentiated  intrusions it may also
be filling interstices.

The contents of trace elements in zircon have been exten-

sively investigated since the early 1960s (summary in Görz

1974). However, only the routine use of electron probe mi-
cro-analysis  and  LA-ICP  MS  methods  during  the  last  20
years  has  produced  reliable  data  concerning  the  contents  of
many elements (Uher et al. 1998; Wang et al. 2000; Huang
et  al.  2002;  Rubatto  2002;  Hoskin  &  Schaltegger  2003;
Finch  &  Hanchar  2003;  Pettke  et  al.  2005;  Johan  &  Johan
2005; Breiter et al. 2006; Péréz-Soba et al. 2007; Grimes et
al.  2007;  Van  Lichtervelde  et  al.  2009).  So  far,  the  most
comprehensive study of the chemical composition of zircons
from  various  types  of  magmatic  rocks  obtained  using  the
ICP-MS  method  was  published  by  Belousova  et  al.  (2002).
The following average contents (medians) were established in
zircons from granites: ca. 0.1 wt. % P

, 0.25 wt. % Y, tens

ppm  of  LREE,  hundreds  ppm  of  HREE,  4 ppm  Nb,  2 ppm
Ta,  9 ppm  Pb,  368 ppm  Th  and  764 ppm  U.  Zircon  from
fractionated granites was found to be relatively rich in REE
(total  1.5—2 wt. %).  Metamict  zircon  can  be  LREE  enriched.
A  positive  Ce-anomaly  is  common.  Belousova  et  al.  (2002)
also report contents of 100—1000 ppm Nb and 10—100 ppm Ta
in zircon. The average Nb/Ta ratio in zircon is 3, whereas the
chondrite value is 17. The Th/U ratio in zircon usually corre-
sponds  to  0.1—1.0,  while  the  ratio  of  these  elements  in  the
Earth’s crust is equal to ca. 4. Contents of Th and U show a

384

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

positive correlation with Y and increase with increasing frac-
tionation of magmas from ultramafic rocks up to granites.
Belousova et al. (2002) consider high contents of P to be pri-
mary because phosphorus is compensated by the sum of
REE+Y as a consequence of xenotime substitution.

The majority of published analyses of zircons have been

obtained using the electron microprobe (see below). However,
only a few of the most abundant elements occurring in zircon
were analysed using this technique (in addition to Zr, Hf and
Si also U, Th, Y, some REE, Al and Ca). Complete analyses
for the 20 or more trace elements that contribute to the chem-
ical composition of individual zircon grains are still scarce
(Förster 2006; Breiter et al. 2006, 2009; Uher et al. 2009;
Förster et al. 2011).

The Zr/Hf ratio in chondrites is 37 (Hoskin & Schaltegger

2003), but this ratio in zircons varies considerably. There is a
general  rule  that  the  Zr/Hf  ratio  in  crystallizing  zircon  de-
creases with progressive fractionation of the melt. The con-
tent of Hf in zircon from rocks ranging from kimberlites to
common  granites  remains  almost  the  same  (0.8—1.7 wt. %)
and  increases  significantly  only  in  strongly  fractionated
granites (Belousova et al. 2002). The highest concentrations
of  Hf  in  zircon  were  found  in  pegmatites.  Černý  &  Siivola
(1980)  found  13.3—17.9 wt. %  HfO

(0.136—0.166 apfu Hf)

in  zircon  from  the  Tanco  pegmatite  in  Manitoba  (Canada).
Recently,  Van  Lichtervelde  et  al.  (2009)  reported  from  this
locality  late  zircon  with  up  to  38.9 wt. %  HfO

. Raimbault

(1998) reported 5.5—12.8 wt. % HfO

(0.055—0.116 apfu Hf)

and up to 11.67 wt. % P

(0.33 apfu P) in a zircon from the

Li-F pegmatite at Chedeville (France), while contents of UO

do not exceed 3 wt. % and those of ThO

are 0—11.9 wt. %.

Contents of Y and Sc are a few tenths of a percent. Contents of
REE are not given. Uher & Černý (1998) found in beryl-
columbite pegmatites fron Slovakia up to 22 wt. % HfO

Hafnon, the Hf-dominant member of the zircon group was
found in rare-metal pegmatite at Zambezia, Mozambique
(Correia Neves et al. 1974).

Wang et al. (2000) analysed zircons from granites of I- and

A-type in Laoshan, P.R.China. Zircons from the I-type gran-
ites are generally poor in trace elements (HfO

< 2 wt. %,

, ThO

, Y

< 1 wt. %), while zircons from the more

fractionated facies of A-type granites contain as much as
12.4 wt. % HfO

and 4.3 wt. % ThO

, but only small

amounts of UO

(< 0 .4 wt. %), Y

(< 1.4 wt. %) and P

(< 0 .75 wt. %). Contents of REE were not analyzed here ei-
ther. Wang et al. (1996) found an extremely high content of
Hf (up to 34.8 wt. % HfO

, 0.353 apfu Hf) in zircon from an

A-type granite at Suzhou, P.R.China. This zircon is U- and
Th-free, and Y-, P-poor (< 0 .5 wt. % Y

, < 1 wt. % P

Other elements were not reported. Huang et al. (2002) found
up to 22.0 wt. % HfO

in zircon from Yichun topaz-lepidolite

granite, P.R. China.

Uher et al. (1998) described a zircon rich in Hf and P, but

very poor in U, Th, Y and REE from the strongly peralumi-
nous Homolka muscovite granite of the South Bohemian
Pluton. Hoskin et al. (2000) analysed zircon from the zoned
I-type Boggy Plain pluton, Australia, and found 0.30—
3.98 wt. % HfO

. Péréz-Soba et al. (2007) were able to dis-

tinguish two types of zircon in Spanish peraluminous

granites: older prismatic crystals with low contents of trace
elements and high Zr/Hf ratio embedded mostly in biotite,
and younger, mostly interstitial zircon enriched with U, Th,
Y and REE and having a low Zr/Hf ratio.

Kempe et al. (2004) pointed out that extreme Hf-enrich-

ment is typical of zircons with patchy structure from P-poor
granites. This observation contradicts the results of analysis
of zircons from European Variscan rare-metal granites ob-
tained by us. The highest contents of Hf we found in zircons
from the peraluminous P-rich granites at Beauvoir (this
study) and at Argemela in Portugal (Breiter & Škoda 2010).

Zircons from peralkaline rocks contain in general less trace

elements. De Liz et al. (2009) described zircons from shosho-
nite association of the Lavras do Sul intrusive complex in Bra-
zil to contain on average 1.0—1.4 wt. % HfO

, 3—75 ppm Nb,

195—414 ppm Th, 400—800 ppm U and 700—2000 ppm Y.
Nardi et al. (2012) found zircons from several intrusions of
peralkaline granites of A-type near the tin-bearing deposit of
Pitinga in Brazil to contain on average 1.8—5.0 wt. % HfO

8—825 ppm Nb, 200—6649 ppm Th, 456—2975 ppm U and
2003—9211 ppm Y.

The chemistry of zircon from the Beauvoir granite was in-

vestigated by Wang et al. (1992). The published compositions
are as follows: 2.4—8.1 wt. % (one grain with 18 wt. %) HfO

up to 7.6 wt. %, ThO

max. 0.35 wt. % and PbO up to

0.55 wt. %. Elements such as P, Y and REE were not analysed.

Johan & Johan (2005) analysed the following 16 elements

in zircon from Cínovec: P, Si, Zr, Hf, Th, U, Pr, Sm, Dy, Er,
Yb, Y, Sc, Fe, Ca, and F and found significant differences in
the compositions of zircons from the zinnwaldite and pro-
tolithionite granites. Their interpretation is based on the idea
that the zinnwaldite granite is of metasomatic origin. This
view, however, is different from that of the majority of other
investigators (Breiter et al. 1999; Föster et al. 1999; Thomas
et al. 2005).

This paper on an example of two geologically well-docu-

mented  small  ore-bearing  granites  –  the  Beauvoir  and  the
Cínovec is intended to demonstrate the different behavior of
zircon  during  the  crystallization  of  fractionated  magma  of
S-  and  A-type  granites  and  to  show  differences  in  zircon
chemistry with depth and its relationship to an overall chem-
istry of the granite pluton.

Geology and samples

The late Variscan Cínovec granite lies on both sides of the

Czech-German border in the eastern sector of the Krušné
hory/Erzgebirge Mts. Here, the late Variscan tin-bearing gran-
ites form ca. 20 km long NW-SE- oriented belt intruded into
the Upper Proterozoic paragneisses and Upper Carboniferous
rhyolites. Only a few small exposures less than 1 km

in size,

in the form of small copulas (Cínovec, Altenberg) or vertical
stocks  (Krupka,  Sadisdorf),  are  exposed  on  the  surface.  The
pluton consists of two main types of granite: (i) the older me-
dium-  to  fine-grained  mostly  distinctly  porphyritic  biotite  to
protolithionite  granites  compose  the  majority  of  the  known
volume  of  the  pluton;  (ii)  the  younger  medium-  to  fine-
grained  not  porphyritic  albite-topaz-zinnwaldite  granites  ac-

385

ZIRCON CHEMISTRY IN FRACTIONATED GRANITE PLUTONS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

companied by Sn-W (Nb, Ta, Mo, Sc) mineralization of greisen
type form small separate intrusions. The spatial relationship be-
tween  the  two  types  of  granite  is  different:  the  younger  ore-
bearing  granites  can  form  stocks  or  stock-works  with  steep
contacts  which  intrude  in  older  granites  proved  by  numerous
boreholes and underground workings made at Krupka (Eisen-
reich  &  Breiter  1993),  or  intruded  in  the  form  of  tongue-like
bodies along the upper contact of older granites having formed
rather flat copulas in their roof (Cínovec and its surroundings).
Contacts of both types of granite are evidently intrusive.

The Cínovec granite copula exposure 1.4 0.3 km large was

studied to a depth of 1596 m by borehole CS-1 (Štemprok &
Šulcek 1969). An albite-topaz-zinnwaldite granite (hereinafter
“zinnwaldite granite”, ZiG) was proved to exist in several tex-
tural  varieties  to  a  depth  of  735 m,  while  an  albite-pro-
tolithionite granite (hereinafter “protolithionite granite”, PrG)
continues to greater depths (Fig. 1). A fractionation in situ can
be  observed  in  the  zinnwaldite  granite  showing  increasing
concentrations of volatile and lithophile elements upward. The
apical  part  of  the  copula  has  been  eroded,  but  a  facies  with
mica corresponding to lepidolite is preserved to a depth of ca.
80 m  below  the  present  surface  (Rub  et  al.  1998).  From  the
viewpoint  of  geochemistry,  the  Cínovec  pluton  represents

Fig. 1. Vertical zonality of granite
types in Cínovec from borehole CS-1
(modified according to Štemprok &
Šulcek 1969) with indication of posi-
tion of studied samples.

strongly fractionated A-type granites: it is only slightly peralu-
minous, enriched with F, Li, Rb, Zr, Th, HREE, Sc, Sn, W, Nb
and Ta, and depleted of P, Ti, Mg and Ca (Table 1). Common
accessory  minerals  comprise  fluorite,  topaz,  cassiterite,
columbite,  microlite,  pyrochlore,  Nb-rutile,  zircon,  thorite,
xenotime,  fluorides,  oxo-fluorides  and  carbonates  of  REE
(Cocherie  et  al.  1991;  Rub  et  al.  1998;  Breiter  et  al.  1999;
Förster et al. 1999; Johan & Johan 2005; Breiter 2011).

The Beauvoir granite forms a small body (< 0 .2 km

) at the

southern edge of the late Variscan Echassieres granite pluton
in the northern part of the Massif Central, France. Geochemi-
cally it is a highly specialized, strongly peraluminous (S-type),
rare metal-bearing granite enriched with P, F, Li, Rb, Nb, Ta,
Sn, and W, and depleted of Si, Fe, Ti, Mg, Sr, Y, REE etc.
(Cuney et al. 1992; Raimbault et al. 1995). The Beauvoir
granite is the latest intrusion in a peraluminous granitic com-
plex composed of three successively emplaced units: the hid-
den more or less hypothetical La Bosse granite, the Colettes
two-mica granite, and the Beauvoir topaz-lepidolite-albite
granite (Cuney & Autran 1987; Cuney et al. 1992). All gran-

Unit ZiG

ZiG

PrG

Depth (m)

60 559 749 1579

SiO

72.22

74.69

75.56

75.53

TiO

0.01

0.03

0.05

0.07

15.92

13.21

12.76

12.54

0.20

0.32

0.60

FeO

0.45

0.58

0.79

0.78

MnO

0.09

0.06

0.05

MgO

0.09

0.03

0.06

0.07

CaO

0.38

0.35

0.45

0.64

0.216 0.167

0.061

0.055

4.83

4.02

3.66

3.49

2.39

4.53

4.78

4.73

0.015 0.012

0.009

0.011

0.79

0.75

0.46

0.51

LOI

1.95

0.78

0.72

0.87

Total

99.55

99.54

99.73

99.98

1440

1900

1133

802

125

124

9.1

6.8

8.1

6.9

8.6

109

7.5

114

103

3.9

22.5

13.5

105

1.84

7.2

12.4

10.3

4.9

1.54

6.4

12.6

10.4

<0.02 <0.02

0.08

0.12

1.03

5.4

12.4

40.5

0.33

1.4

2.8

2.3

2.4

10.1

15.5

0.51

2.1

3.9

3.4

1.9

7.2

12.6

11.1

0.46

1.6

2.3

1.9

4.2

12.4

16.3

13.1

0.65

1.9

2.4

1.9

Table 1: Whole-rock chemical composition of granites from
Cínovec (major elements in wt. %, trace elements ppm).

386

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

ite types intruded into lower-Paleozoic micaschists. The
900 m deep borehole GPF-1 allowed study of the vertical evo-
lution of the Beauvoir granite over a section more than 700 m
long (Fig. 2). Three granitic units marked B1 to B3 were dis-
tinguished by Rossi et al. (1987) and Raimbault & Azencot
(1987). Later, a detailed geochemical study divided the
Beauvoir granite into two major units: B and B

’ (Raimbault

et al. 1995). The B-unit forms the upper part of the stock rep-
resenting geochemically more evolved, more fluid-enriched
part of the Beauvoir initial magma. The B

’-unit, smaller in

volume, represents a relatively less evolved and later em-
placed portion of the Beauvoir magma. Separation of the
B- and B

’-melts occurred at the early stage of evolution of the

granite system. Later, both melts in fact fractionated indepen-
dently. Thus, the upper B-unit can be divided into three sub-
units, from the uppermost ultimately fractionated B1-unit (at a
depth of 98—423 m), through the B2-unit (at a depth of ca.
423—571 m), to the B3-unit (in a depth of 765—790 m). Within
the lower B

’-unit, the relatively more fractionated B’2-unit

(at a depth of ca. 571—746 m), and less fractionated B

’3-unit

(at a depth of ca. 850—870 m) can be distinguished. All granite
units are built of quartz, K-feldspar, albite and Li-mica.
Chemical composition of the latter mineral ranges from lepi-
dolite (B1) to Li-enriched biotite (B

’3). Amblygonite and al-

kalifeldspars (Breiter et al. 2002) are the main hosts of
phosphorus. Common accessory minerals include apatite, to-
paz, cassiterite, minerals of the columbite group and zircon.
A number of other minerals were also identified (Raimbault

et al. 1995). Comprehensive whole-rock chemical data from
Beauvoir were published by Cuney & Raimbault (1991) and
Raimbault et al. (1995).

Altogether 15 samples from borehole CS-1 drilled at

Cínovec, representing mineralogical and chemical develop-
ment of the pluton to a depth of 1596 m, were collected and
analysed. A total of 10 samples from borehole GPF-1 drilled
at Beauvoir, representing all intrusive units defined by
Raimbault et al. (1995), except for the B3-unit, were collected
and analysed.

Analytical methods employed

In order to study zircon grains in relation to rock-forming

minerals polished thin sections were made from all collected
samples.  Back-scattered  electron  (BSE)  images  were  taken
prior  to  analysis  to  study  the  internal  zoning  of  individual
mineral grains and their relative position to rock-forming min-
erals. Zircon and associated minerals such as monazite, xeno-
time, thorite, and other similar mineral phases were analysed
using the identical set-up and included all of the chemical ele-
ments identified in at least one of the above-mentioned miner-
als. Elemental abundances of W, P, As, Nb, Ta, Si, Ti, Zr, Hf,
Th, U, Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb, Al, Sc, Bi, Mn,
Fe, Ca, Pb, S, and F in oxide minerals were determined using
a CAMECA SX100 electron microprobe (Masaryk University
and Czech Geological Survey, Brno) equipped with five WD
spectrometers. Minerals were analysed at an accelerating volt-
age and beam current of 15 keV and 40 nA, respectively, and
with  a  beam  diameter  ranging  from  1  to  5 µm.  The  following
standards were used: U – metallic U, Pb – PbSe, Th – ThO

P – fluorapatite, Y – YAG, La – LaB

, Ce – CeAl

, Pr –

PrF

, Nd – NdF

, Sm – SmF

, Gd – GdF

, Dy – DyP

Er – YErAG, Yb – YbP

, Al – almandine, Si, Ca,

Fe – andradite, Mn – rhodonite, W – scheelite, S – barite,
F – topaz, As – InAs, Nb – columbite, Ta – CrTa

Ti – titanite, Zr – zircon, and Sc – ScVO

. Empirical for-

mulae of zircon were calculated on the basis of 4 atoms of ox-
ygen in a formula unit (4 O apfu).

Contents of major elements in whole rock samples from

Cínovec were established using the standard methods of wet
chemistry at the Laboratory of the Czech Geological Survey,
Praha, while the trace elements were analysed in the ACME
Laboratory, Vancouver, Canada using the ICP-MS method.

Results

Position of zircon crystals in granite and its internal structure

In Cínovec, zircon in the zinnwaldite granite forms tiny iso-

metric crystals 10—50 µm in size (Fig. 3). They are enclosed in
quartz and feldspars, but some of the grains that crystallized
later occupy the interstices between the other minerals. Some
crystals contain µm-sized inclusions of quartz and feldspars
and numerous tiny cavities. Most of the crystals are not zoned
in the BSE image. The internal composition is patchy with do-
mains enriched in Hf, Y and Th. In the few zoned grains, the

Fig. 2. Geological cross-section of the Beauvoir granite stock along
the borehole GPF-1 Eschassieres (modified according to Raimbault
et al. 1995) with indication of position of studied samples.

390

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

Table 2: Representative electron-microprobe analyses (wt. %) and structural formula (apfu) of zircon from Cínovec (ZiG, PrG) and Beauvoir
(B1, B2, B

’2, B3).

0.0 = below detection limit.

Unit ZiG

ZiG ZiG ZiG

PrG

PrG B1 B1 B2 B2 B´2 B´2 B3 B3

Depth (m)

24 97 413 559 860 988 1580 107 228 396 522 600 657 858 858

Sample

4672 4683 4687 4688 4802 4692 4693 3059B 3061 3062 3063 3066 3067 3069 3069

0.00 0.01 0.01 0.03 0.02 0.01 0.01 0.04 0.03 0.02 0.33 0.04 0.04 0.01 0.02

2.48 2.72 0.44 1.10 0.61 0.38 0.22 0.29 5.97 0.30 7.35 0.21 4.50 0.02 1.95

0.76 0.33 1.09 1.30 0.17 0.20 0.07 0.56 0.22 0.20 0.06 0.09 0.07 0.11 0.29

SiO

23.26 24.04 25.46 24.76 29.95 29.76 30.65 30.60 23.31 31.15 19.11 29.92 20.93 32.02 26.49

0.60 0.57 0.83 0.75 0.22 0.16 0.13 0.02 1.41 0.04 1.23 0.10 2.64 0.02 0.67

0.03 0.47 0.64 0.67 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00

0.84 0.89 0.45 0.39 0.01 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.22 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

TiO

0.02 0.02 0.03 0.03 0.02 0.01 0.00 0.02 0.05 0.00 0.00 0.00 0.05 0.00 0.02

ZrO

39.54 40.98 44.24 45.12 54.30 59.84 61.25 48.16 53.37 60.29 46.75 57.93 51.74 62.94 55.32

HfO

10.27 3.53 2.01 3.18 2.42 2.80 1.74 19.15 4.82 6.78 2.15 2.66 2.69 4.39 2.84

ThO

2.19 1.86 1.63 0.51 0.14 0.23 0.27 0.34 0.06 0.03 0.07 0.00 0.01 0.03 0.03

3.46 2.19 7.00 1.35 3.37 0.54 1.03 0.12 0.74 0.14 9.69 4.62 4.25 0.17 2.11

1.27 0.86 0.30 0.80 0.08 0.04 0.01 0.00 0.04 0.00 0.02 0.02 0.06 0.01 0.03

3.27 4.41 2.67 3.89 1.08 1.07 0.33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03

0.20 0.37 0.34 0.52 0.05 0.02 0.02 0.00 0.03 0.00 0.00 0.00 0.00 0.02 0.00

0.00 0.06 0.02 0.00 0.02 0.10 0.00 0.00 0.00 0.00 0.07 0.00 0.00 0.00 0.00

0.00 0.05 0.03 0.07 0.04 0.01 0.00 0.05 0.00 0.03 0.03 0.00 0.00 0.00 0.06

0.11 0.13 0.00 0.01 0.02 0.02 0.00 0.00 0.03 0.00 0.00 0.00 0.02 0.00 0.00

0.22 0.25 0.02 0.11 0.00 0.00 0.01 0.00 0.00 0.02 0.00 0.00 0.02 0.00 0.00

0.76 1.48 0.34 0.89 0.21 0.22 0.13 0.02 0.19 0.00 0.16 0.04 0.17 0.03 0.21

0.72 1.41 0.64 0.92 0.26 0.20 0.05 0.18 0.03 0.03 0.02 0.02 0.00 0.05 0.01

1.47 4.46 1.99 2.97 0.86 0.32 0.15 0.00 0.00 0.06 0.00 0.00 0.02 0.04 0.00

0.09 0.46 0.06 0.93 0.11 0.05 0.10 0.07 0.05 0.01 0.09 0.06 0.10 0.10 0.01

MnO

0.08 0.09 0.14 0.80 0.25 0.16 0.33 0.01 0.74 0.07 0.57 0.06 0.45 0.02 0.98

FeO

1.19 0.19 0.50 1.13 0.38 1.12 0.23 0.04 0.45 0.00 0.30 0.06 0.28 0.05 1.52

CaO

1.18 0.87 1.73 1.93 0.61 0.44 0.48 0.05 2.36 0.12 2.83 0.10 2.27 0.02 0.59

MgO

0.00 0.01 0.01 0.00 0.03 0.01 0.01 0.00 0.14 0.02 0.17 0.01 0.30 0.00 0.03

PbO

0.00 0.00 0.04 0.02 0.01 0.03 0.10 0.00 0.01 0.02 0.00 0.21 0.02 0.03 0.04

2.39 2.09 0.50 0.66 0.33 0.16 0.09 0.00 0.97 0.00 1.09 0.31 1.97 0.00 0.85

Total

96.37 95.09 93.17

94.87 95.60 97.91 97.41 99.75 95.04 99.35 92.02 96.43 92.60 100.07 94.12

0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.009 0.001 0.001 0.000 0.000

0.076 0.084 0.014 0.033 0.017 0.010 0.006 0.008 0.167 0.008 0.222 0.006 0.134 0.001 0.056

0.014 0.006 0.021 0.024 0.003 0.003 0.001 0.010 0.004 0.003 0.001 0.002 0.001 0.002 0.005

0.845 0.873 0.925 0.877 0.993 0.959 0.981 1.011 0.769 0.986 0.681 0.988 0.735 0.997 0.896

0.026 0.024 0.036 0.031 0.009 0.006 0.005 0.001 0.055 0.001 0.052 0.004 0.109 0.001 0.027

B-site

0.961 0.987 0.996 0.966 1.022 0.978 0.993 1.031 0.996 0.998 0.965 1.001 0.980 1.001 0.984

0.000 0.004 0.006 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.014 0.015 0.007 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.001

0.701 0.726 0.784 0.780 0.878 0.940 0.956 0.776 0.858 0.931 0.813 0.933 0.886 0.956 0.913

0.107 0.037 0.021 0.032 0.023 0.026 0.016 0.181 0.045 0.061 0.022 0.025 0.027 0.039 0.027

0.018 0.015 0.013 0.004 0.001 0.002 0.002 0.003 0.000 0.000 0.001 0.000 0.000 0.000 0.000

0.028 0.018 0.057 0.011 0.025 0.004 0.007 0.001 0.005 0.001 0.077 0.034 0.033 0.001 0.016

0.040 0.027 0.010 0.025 0.002 0.001 0.000 0.000 0.001 0.000 0.001 0.001 0.002 0.000 0.001

0.063 0.085 0.052 0.073 0.019 0.018 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.003 0.005 0.005 0.007 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000

0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001

0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.003 0.003 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.009 0.017 0.004 0.010 0.002 0.002 0.001 0.000 0.002 0.000 0.002 0.000 0.002 0.000 0.002

0.008 0.016 0.007 0.010 0.003 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.016 0.049 0.022 0.032 0.009 0.003 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000

0.001 0.004 0.001 0.008 0.001 0.000 0.001 0.001 0.000 0.000 0.001 0.001 0.001 0.001 0.000

0.002 0.003 0.004 0.024 0.007 0.004 0.009 0.000 0.021 0.002 0.017 0.002 0.013 0.001 0.028

0.036 0.006 0.015 0.034 0.011 0.030 0.006 0.001 0.012 0.000 0.009 0.002 0.008 0.001 0.043

0.046 0.034 0.067 0.073 0.021 0.015 0.016 0.002 0.083 0.004 0.108 0.003 0.085 0.001 0.021

0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.000 0.007 0.001 0.009 0.000 0.016 0.000 0.001

0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.000 0.000 0.000

A-site

1.096 1.071 1.077 1.138 1.004 1.048 1.023 0.968 1.035 1.001 1.061 1.003 1.074 1.000 1.054

0.274 0.240 0.058 0.074 0.034 0.016 0.009 0.000 0.101 0.000 0.123 0.032 0.219 0.000 0.091

Zr/Hf at. 6.6

19.8

37.6

24.2

38.4

36.5

60.1

4.3

18.9

15.2

37.2

32.9

24.5

33.3

Zr/Hf wt. 4.4

13.3

25.2

16.3

25.7

24.5

40.3

2.9

12.7

10.2

24.9

22.0

16.4

22.3

391

ZIRCON CHEMISTRY IN FRACTIONATED GRANITE PLUTONS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

740—800 m, while at the Beauvoir locality the highest values
were detected in B2 and B

’2 units at a depth of 550—650 m.

Thorium

: it is one of the elements for which the concents

differ most in the two plutons studied (Fig. 6). In the upper
part of zinnwaldite granite in Cínovec, to a depth of 200 m,
Th-content in zircon commonly reach 1—5 wt. % (max.
8 wt. %) but in deeper parts of the pluton fluctuate only
around 0.5 wt. % ThO

. Contents of Th in the Beauvoir plu-

ton are almost always lower than 0.05 wt. % ThO

, and only

in B1 unit sporadically exceed 0.1 wt. % ThO

Yttrium

: it is another element behaving differently at both

localities (Fig. 6). At Cínovec the contents of Y

in zir-

cons  are  generally  high,  fluctuating  in  zinnwaldite  granite
mostly  between  0.3—5 wt. %,  in  the  upper  part  of  pro-
tolithionite granite, they range mostly between 0.2—3 wt. %,
whereas  in  its  deeper  section  only  0.1—1 wt. %  Y

(but

here the zircon is associated with xenotime). Conversely,
contents of Y in zircon from Beauvoir are negligible (only
sporadically exceed 0.05 wt. % Y

HREE

: due to the dimensions of its crystal lattice, zircon

is able to absorb the heavy REE in particular (Figs. 6, 8). The
most abundant elements are Yb and Dy, the former element
correlates well with Y and its distribution at both localities is
similar as that of Y as far as attains its absolute contents (up
to 5 wt. % Yb

at Cínovec) and also regarding differences

in its vertical distribution. Dy at Cínovec behaves like Yb,
but its contents are ca. 3 times lower than those of Yb (max.
1.7 wt. % Dy

). Dy at Beauvoir compared to Y is markedly

enriched reaching 0.3 wt. % Dy

at a depth interval of

400—650 m (units B2 and B

’2). Anomalous enrichment of Dy

in relation to other REE is well demonstrated in the Dy/Yb
ratio the values of which range between 0.1 and 0.9 at
Cínovec, but between 4 and 9 at the above mentioned depth
interval in borehole GPF1. It is to be pointed out, that chon-
dritic Dy/Yb ratio is 1.15.

LREE

: contents of light REE in zircon are commonly low

(Fig. 8), usually near the detection limits of the microprobe.
When comparing both localities studied, the LREE-contents
are slightly higher in Cínovec (0.2—0.7 wt. % Ce

and

0.1—0.20 wt. % Nd

Scandium

: it is another element exhibiting significantly

higher concentrations in zircon from Cínovec (Fig. 6). The
contents of Sc

reach 0.6—1.5 wt. % in the upper 100 m

thick  section  of  lepidolite  and  zinnwaldite  granite,  but  its
contents  decrease  randomly  with  depth.  Contents  of  Sc  in
protolithionite granite at Cínovec and in all types of granite
at  Beauvoir  are  markedly  lower,  mostly  not  exceeding
0.1 wt. % Sc

Bismuth

: it is a characteristic trace element occurring in a

number  of  European  Variscan  tin-bearing  granites.  While
some  zircons  from  the  upper  section  of  zinnwaldite  granite
(from  a  depth  of  50—100 m)  at  Cínovec  contain  as  much  as
1.0—1.2 wt. % Bi

, zircons from Beauvoir usually contain

only around 0.05—0.10 wt. % Bi

, (Fig. 6).

Phosphorus

: it is a common minor element incorporated in

zircon (Fig. 7). At Cínovec, contents up to 4 wt. % P

were

detected in the upper 200 m of the granite copula. However,
with increasing depth the concentration of P only rarely ex-
ceeds 1 wt. % P

. Although the Beauvoir granite system is

strongly P-enriched, zircons from the uppermost B1 unit in
Beauvoir contain only 0.5—1 wt. % P

; higher contents up

to 8 wt. % P

were found only scarcely. In the deeper units

B2 and B

’2 at a depth interval of 500—700 m the contents of

5—8 wt. % P

were often found more frequently.

Arsenic

: it is only rarely analysed in zircon, although it is

likely to be a relatively common minor or trace element
bound in this mineral. Arsenic at Cínovec appears to be more
abundant when its contents of 0.2—1.0 (max. 1.6) wt. %
As

were detected to a depth of 1000 m, but at greater

depths its concentration again decreases to 0.1 wt. % As

(Fig. 7). Zircons from the Beauvoir locality contain mostly
0.1—0.2 wt. % As

and close to the upper granite contact

as much as 0.8 wt. % As

Fluorine

: it is a substantial component of fractionated gran-

ite  magmas  and  at  the  end  of  crystallization  it  enters  crystal
lattice of numerous silicates where it replaces oxygen or OH
radical.  High  contents  of  fluorine  in  zircons  from  Cínovec
were  established  to  a  depth  of  ca. 200 m  (1.0—2.5 wt. %  F,
Fig. 7),  and  then  gradually  decrease  to  0.0—0.2 wt. %  F  at  a
depth of 1600 m. At the Beauvoir locality the highest concen-
trations of F in zircon, similar to phosphorus, were detected in
lower  sections  of  borehole  GPF-1  with  a  maximum  of
1.5 wt. % F at a depth interval of 500—700 m. Zircons in the
uppermost  section  of  the  borehole  contain  surprisingly  only
0.0—0.8 wt. % F.

Niobium, tantalum and tungsten

: these elements form in

granites  individual  minerals  such  as  columbite/tantalite  and
wolframite  but  they  also  enter  the  crystal  lattice  of  zircon.
Tungsten  and  niobium  were  commonly  detected  in  zircons
from Cínovec to a depth of ca. 800 m (up to 1 wt. % WO

and

1.3 wt. % Nb

). Tantalum was found only rarely in contents

of 0.1—0.4 wt. % Ta

. Contents of all three elements at

depths  below  800 m  are  below  their  detection  limits.  Their
concentrations at the Beauvoir locality are markedly lower: Ta
and  W  always  below  their  detection  limits,  Nb  was  detected
only  in  one  sample  from  a  depth  of  573 m  (top  of  the  B

’2

unit) showing a content of 0.1—0.8 wt. % Nb

Titanium

: its contents at both localities are low and its

distribution similar: 0.0—0.06 (up to 0.1) wt. % TiO

and

tends to decrease with depth.

Lead

: contents of this element at both localities are low,

mostly below the detection limit, only rarely exceeding
0.1 wt. % PbO with no signs of any vertical zoning. No cor-
relation exists between U and Pb or between (Th + U) and Pb
either. If all lead in zircon is considered to be of radiogenic
origin then a substantial part of it in the studied zircons must
have been leached out.

Sulphur

: was detected in measurable amount only in zir-

cons from the uppermost section of the Cínovec granite copula
to a maximum depth of 80 m (0.5—4 wt. % SO

Aluminum

: contents of Al at Cínovec range between 0.0

and 1.2 wt. % Al

and tend to decrease gently with depth.

At Beauvoir the highest concentrations (1—3 wt. % Al

)

were found at a depth interval of 500—700 m. Its contents
both upward and downward are slightly lower (Fig. 7).

Iron, manganese, calcium and magnesium

: iron in zircons

from both localities shows contents of 0—1.5 wt. % FeO re-
gardless of the depth which the samples were collected from.

392

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

Manganese was found to be more abundant at the Beauvoir locality (up to
1.5 wt. % MnO) relative to the Cínovec locality (max. 0.8 wt. % MnO).
The highest contents of this element were detected in zircons from medi-
um depths of 400—800 m. Calcium is also more abundant at Beauvoir (up
to 3 wt. % CaO) than in zircons from Cínovec (max. 2 wt. % CaO). The
highest concentrations of Ca, similar to Mn, were detected in zircons from
medium depths. On the contrary, the contents of Mg differ significantly:
while at Cínovec they do not exceed 0.07 wt. % MgO, at Beauvoir they at-
tain 0.5 wt. % MgO in the middle section of borehole GPF-1. Divalent ele-
ments Ca, Mg, Fe and Mn, due to their ionic radii, are unsuitable to enter
the crystal lattice of zircon. Elevated Ca-, Fe-, Mn- and Mg- contents were
found mainly in metamict areas of analysed zircon grains, we suppose that
these elements were incorporated in zircon after its metamictization.

Associated U, Th, Y, REE-minerals

Xenotime-(Y) was found to be the major host for Y and HREE in the

granites from Cínovec. In the zinnwaldite granite, this mineral is abun-
dant. It forms homogeneous subhedral crystals with a maximum size of
10 µm. Whenever this mineral is in direct contact with zircon, xenotime-(Y)
is always younger. Thin coatings of xenotime-(Y) enveloping whole zir-
con  grains  were  observed  in  deeper  parts  of  the  zinnwaldite  granite.
A  substantial  proportion  of  Y  and  HREE  is  located  in  the  primary  mag-
matic  fluorite.  Thorite  is  rather  sporadic  in  the  zinnwaldite  granite,  but
secondary  minerals  of  the  bastnäsite  group  containing  Th,  U  and  REE
are abundant and mostly occur in contact with fluorite.

Thorite and xenotime-(Y) are relatively abundant accessories in the

Cínovec protolithionite granite, occurring together with zircon as inclu-
sions in mica, but monazite-(Ce) is rare. Zircon was not found in direct
contact with these minerals so it is difficult or impossible to establish
their relative age of crystallization in relation to zircon. Neither uraninite
nor coffinite was identified at the Cínovec locality. Uranium at Cínovec,
apart from zircon, is bound in minerals of the bastnäsite group, which
crystallized at the later stages of granite evolution.

Separate REE, Y and Th minerals were not found in either of the types

of granite at Beauvoir because contents of these elements are generally
low (Cuney et al. 1992; Raimbault et al. 1995). Rossi et al. (1987) de-
scribed only scarce uraninite in some samples from a depth exceeding
475 m (deeper part of unit B2, and units B3, B

’2, B’3).

Discussion

Aluminum and divalent elements in zircon, metamictization and hydra-
tion, low totals of analyses

The position of Al, Ca, Fe, Mn and Mg in the zircon structure can be

explained in two ways: (i) by primary incorporation of these elements in
the lattice sites to compensate the substitution of Nb, Ta, and W for Zr
and/or substitution of P and As for Si, (ii) through secondary entry of
these elements into metamictized parts of zircon crystal lattice in the fluids
responsible for alteration.

Geisler et al. (2002, 2003) and Schmidt et al. (2006) demonstrated that

there is significant removal of Si, Zr, U, Th, Pb and uptake of Al, Mg and
Ca due to the interaction of chloride-bearing fluids with metamict zircon.
This means that the present chemical composition of porous metamictized

Fig. 7. Vertical distribution of selected chemical elements in zircon: P, As, F, Al.

393

ZIRCON CHEMISTRY IN FRACTIONATED GRANITE PLUTONS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

cores in zircons may be quite different from those produced by
crystallization from the initial magma. Moreover, the reaction
of zircon with fluids accelerates the restoration (annealing) of
the  lattice  structure  in  amorphized  domains  (Geisler  et  al.
2003).  Nevertheless,  rational  evaluation  of  the  primary  and
secondary contents of Al, Ca, Fe, Mn and Mg remains prob-
lematic.  For  instance,  Geisler  &  Schneider  (2000)  consider
contents of CaO exceeding 2 wt. % to be strongly indicative for
post- metamictization chemical changes in zircon. Ca-enriched
zircons from Cínovec usually show to high occupancy of the
A-site  (Table  2),  which  is  a  strong  argument  for  late,  post-
metamict input of Ca. Nyman et al. (1984) and Crichton et al.
(2005)  found  similarities  in  structures  of  CaSO

, CePO

and

ZrSiO

and proposed so-called clinoanhydrite substitution

(Ca

+ S

REE

+ P

) as a possible way to incorporate

Ca into monazite lattice. In Cínovec, occasionally 1—4 wt. %
SO

was found, but there is no correlation between Ca and S.

So, in the case of the studied zircons, existence of the
(Ca

+ S

+ S i

)-substitution is unlikely. On the other

hand, the Al bound in tetrahedral position according to berlin-
ite substitution (Al

+ P

+ S i

) is believed to by pri-

mary magmatic (Breiter et al. 2006).

Analytical totals for zircon obtained using EMPA are of-

ten significantly lower than 100 wt. %. The deficit in the
analyses is commonly interpreted as being due to the OH ion
in the mineral structure or to molecular H

O in the amor-

phous domains of the metamict zircon structure. This is only
partly true because a substantial part of the missing matter
may be accounted for other elements that were not analysed.
For instance, As, Bi, Nb and Ta, that are analysed only spo-
radically, may constitute as much as a several wt. % of zir-
con. The direct determination of the water content in zircon
is rare but analyses do exist. For instance, Nasdala et al.
(2009) found up to 8.8 wt. % H

O in Archaean zircon from

Jack Hills, Australia. Caruba & Baumer (1985) synthetised
zircon with as much as 0.8 apfu (OH,F)

replacing the (SiO

)

group in the structure of the mineral. These authors predict
that hydration takes place only in tetrahedral sites (SiO

)

without affecting the occupancy of the Zr position.

Remarkable contents of As (Breiter et al. 2009; Förster et

al. 2011) and Bi (Breiter et al. 2006, 2009) reported recently
from granitic zircons from Krušné Hory/Erzgebirge are sup-
posed to be a product of high-temperature hydrothermal
overprinting taking place shortly after granite crystallization,
and so prior to metamictization.

High contents of fluorine in many zircon grains from

Beauvoir and Cínovec correlate with enhanced content of U,
thus with grade of metamictization. Contents > 0 .5 wt. % F in
Beauvoir and > 1 .5 wt. % F in Cínovec were found mainly in
zircons with > 2 wt. % UO

. On the other hand, there is no

correlation between F and Hf: the Hf-enriched rims of zircon
crystals  crystallizing  from  residual  F-rich  melt  are  actually
poor in F. In that case, strong enrichment of F in some zircons
should be interpreted as results of reaction of late F-enriched
fluids  with  U-rich  parts  (dominantly  cores)  of  some  zircon
grains.  Enrichments  of  W,  Nb,  Ta  and  Sc  in  zircons  from
Cínovec correlated well with enrichment of F. Thus, entry of
all these elements in the zircon structure may also be better ex-
plained  via  reaction  of  zircon  with  high-temperature  F-  and

metal-rich  fluids  after  granite  solidification.  All  fractionated
granites in the Erzgebirge intruded at a very shallow subvolca-
nic  level  and  were  fast  cooled  after  intrusion  (Jarchovský  &
Pavlů  1991;  Seltmann  &  Schilka  1991;  Breiter  et  al.  1999,
2005). Thus, the question of whether the short-lived high-tem-
perature hydrothermal fluids reacted with still fully-ordered or
already metamictized zircons, remains unresolved.

Taken together, high contents of Hf, U, Th, Y and REE in

studied  zircons  are  probably  primary  magmatic  and  mirror
high  grade  of  fractionation  of  evolved  granitic  melt,  while
unusually high contents of F, As, W, Nb, Ta, Ca, Fe and Mg
resulted  from  later  hydrothermal  overprint.  In  the  case  of
phosphorus  and  alumina,  P  in  xenotime  substitution  and
P + Al  in  berlinite  substitution  are  primary  magmatic  in  ori-
gin. The additional P in pretulite and ximengite substitution
(Breiter et al. 2006) and the additional Al are very probably
of secondary hydrothermal origin.

Comparison between the studied zircons and whole-rock
chemical composition

The differences in the geochemical character of the granites

from Beauvoir and Cínovec enables conclusions to be drawn
about which features of the chemistry of the zircons inves-
tigated are governed by the type of granite magma involved
(S- or A-type) and which resulted because of the high degree
of fractionation of residual melt regardless of the magma type.

Strongly fractionated rare metal-bearing granites and peg-

matites are in general enriched with F, Li, Rb, Sn, W, Nb and
Ta,  but  differ  markedly  in  contents  of  Zr,  Th,  REE  and  Y.
The A-type granites are Zr, Th, REE, Y-rich, while granites
of  S-type  are  poor  in  these  elements.  Similarly,  pegmatites
are classified as LCT-type (strongly peraluminous, enriched
with  Li,  Cs,  Ta,  Rb,  P,  Ga,  etc.)  and  NYF-type  (enriched
with  Nb,  Y,  F,  REE,  Sc,  Zr,  U,  Th,    etc.,  Černý  &  Ercit
2005). Zircon from fractionated and F-rich granites was of-
ten found to contain high concentrations of minor and trace
elements.  A  high  content  of  complex-forming  fluorine  in
particular,  and  also  high  concentrations  of  sodium  in  the
magma are reported to enable the entry of “exotic” elements
into  the  crystal  lattice  of  zircon  (Kempe  et  al.  2004).  Al-
though many authors (cf. Raimbault et al. (1995) and refer-
ences therein) pointed out the high activity of F-rich fluids in
Beauvoir, the zircons from Beauvoir are nearly pure stoichio-
metric  (Zr,Hf)SiO

. In contrast, at Cínovec, zircon absorbed

not  only  “common”  minor  and  trace  elements  such  as  Y,
HREE, U and Th, from the melt, but also contains significant
amounts of “exotic” elements like W, Nb, Ta, Sc, Bi, As. For
example, the content of W in granites from Beauvoir is about
40 ppm,  while  in  Cínovec  the  content  is  about  20 ppm.  Zir-
cons  from  Cínovec  generally  contain  0.5—1.0 wt. %  WO

while zircons from Beauvoir are W-free. The content of Nb
in granites from both localities is similar, ca. 100—150 ppm,
but zircon from Cínovec contains about 0.5 (up to 2) wt. %
Nb

, whereas zircon from Beauvoir is Nb-free. Entry of

elements like Sc, Bi, Nb, Ta, and W into the structure of zir-
con from Cínovec are thought not to be due to the specific
type of melt (A-type vs. S-type), while zircons from some
fractionated S-type granites from the Erzgebirge are also Nb,

394

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

Ta,  W,  Bi,  Sc-enriched  (cf.  Breiter  et  al.  2006).  Concentra-
tions  of  Ta  in  zircon  crystallizing  from  Li-rich  pegmatite
melt  may  be  occasionally  as  high  as  4.7 wt. %  Ta

(Van

Lichtervelde et al. 2009); contents of Nb are usually much
lower (Van Lichtervelde et al. 2011).

High contents of Th, Y and HREE in zircon from Cínovec

and  very  low  contents  of  all  these  elements  in  zircon  from
Beauvoir correlate well with concentrations of these elements
in  all  granite  varieties  from  both  localities  (10—60 ppm  Th,
7—114 ppm  Y  and  4—16 ppm  Yb  in  Cínovec,  < 1  ppm  Th,
< 10 ppm Y, < 0 .05 ppm Yb in Beauvoir).

At Beauvoir, high contents of U, P and F in zircons from the

interval 500 to 700 m deep do not correlate with the chemical
composition of the whole-rock. Contents of F in granite at a
depth of about 520 m decrease from 2.0 to 1.6 wt. %, while
contents of P

below the depth of 550 m decrease from 1.3

to 0.8 wt. %. Contents of U are stable at around 15 ppm. En-
richment of zircon with U, P and F is believed to have resulted
from intensive mineral-fluid reactions taking place in the B2
and B

’2 granite units in the interval from 500 to 700 m deep

(compare  also  Raimbault  et  al.  1995).  It  is  also  worth  men-
tioning that high contents of U are found in the cores of zircon
crystals  from  both  Beauvoir  and  Cínovec,  while  their  outer
zones and rims are poor in uranium. Consequently, uranium is
thought  to  have  entered  the  zircon  structure  particularly  at
higher temperature at the beginning of its crystallization. Dur-
ing  the  final  stages  of  crystallization  uranium  preferentially
entered the minerals of the bastnäsite group crystallizing from
water-saturated melt or aqueous fluids.

The content of any trace element in crystallizing mineral is

theoretically determined by its concentration in the melt and
by partition coefficient Kd

mineral/melt

for the given trace ele-

ment. Partition coefficients Kd

mineral/melt

for zircon were es-

tablished experimentally (Thomas et al. 2002; Luo & Ayers
2009)  or  by  comparison  of  their  contents  in  zircon  and  in
bulk rock (de Liz et al. 2009; Nardi et al. 2012), zircon and
surrounding glass (Sano et al. 2002) or zircon and surround-
ing leucosome  (Bea  et  al.  1994).  However,  results  obtained
and  referred  by  the  above-mentioned  authors  differ  signifi-
cantly (Table 3). The reason for such large differences in the
determination of Kd lie only partly in analytical inaccuracies
when establishing low contents of the given trace elements.
Different composition of the parent rock melt is considered
to play a fundamental role in distribution of trace elements in
zircon, specifically its peraluminity or otherwise its peralka-
linity, the content of water, fluorine and other fluxing agents.

Temperature and pressure are also believed to affect the par-
tition  coefficient.  Moreover,  the  relative  older  zircons  (or
their cores) crystallized from parental melt, while their rims
and  the  late,  interstitial  zircons  in  the  whole  crystallized
from  residual  melt;  nevertheless  the  chemical  composition
(trace-element  content)  of  parental  and  residual  melt  differ
substantially.  In  such  complex  cases,  the  determination  of
real  Kd

zircon/melt

is impossible. Therefore, we at least deter-

mined  empirical enrichment factors (hereafter Ef) of zircon/
whole  rock  for  elements  of  which  concentrations  in  zircon
from Cínovec and Beauvoir could be established with suffi-
cient  accuracy  (Table 3).  Contents  of  Y,  HREE  and  Th  in
whole-rock samples of granites from Cínovec correlate well
with  the  content  of  Zr  which  indicates  that  the  Th/Zr,  Y/Zr
and HREE/Zr ratios in the melt were stable during the major
part  of  fractionation.  In  spite  of  this,  the  enrichment  factor
for all the above-mentioned elements and also for Ce and Nb
was  found  to  be  higher  in  more  differentiated  zinnwaldite
granite  than  in  protolithionite  granite.  The  Ef  values  deter-
mined  by  us  are  also  higher  than  the  Kd  established  by  the
above-mentioned authors in less differentiated granites.

As emerges from the comparison of Kd and Ef shown in Ta-

ble 3, both coefficients for all the studied elements in slightly
to strongly peraluminous rocks are higher than those in alka-
line rocks. In this context the occurrence of solid solutions zir-
con-xenotime and zircon-thorite found at some localities in
the Krušné hory/Erzgebirge area (Förster 2006; Breiter et al.
2009; Förster et al. 2011) indicates that zircon under specific
conditions of fractionated melts rich in water and F is able to
absorb by order of magnitude higher contents of Th, U, Y,
HREE, than would correspond to Kd coefficients established
in granitoids of “common” composition. In the case of enrich-
ment of some zircons in Nb, Ta, Sc and Bi, the ratio between
the primary magmatic and secondary fluid-induced portion of
particular element remain unresolved.

Based on the above-mentioned analyses and consider-

ations the zircons from strongly differentiated granites and
pegmatites can be divided into two basic types:

1. zircons strongly enriched with Hf ( > 10 wt. % HfO

(particularly  in  rims),  and  poor  in  all  other  HFS-elements.
This type was reported from some Europen Variscan strongly
peraluminous  granites  (Beauvoir  and  Argemela/Portugal
(Breiter  &  Škoda  2010)),  LCT  pegmatites  (Tanco/Canada
(Van Lichtervelde et al. 2009), Chedeville/France (Raimbault
1998)), but also from some A-type granites (Suzhou, China
(Wang et al. 1996));

Source

Remark

Ce Dy Yb Y Nb U Th

Bea et al. 1994

peraluminous leucosome

2.04

38.8

278

71.4

354

22.1

Sano et al. 2002

melt of dacite glass

0.36

45.9

277

Thomas et al. 2002 melt inclusions in zircon from tonalite 0.43–2.06

12.4–73

14–97

2.4–191

204–312

Luo & Ayres 2009 melt of peralkaline rhyolite

0.14–3.3

11–83

6.8–66

2.1–32

2–18

de Liz et al. 2009

shoshonitic rocks

1.6–3.0

29–64

150–544

54–114

0.2–3.6

71–168

14–19

Nardi et al. 2012

peralkaline A-type granites

1.5

307

106

2.1

168

this work

Cínovec protolithionite granite

1–10

49–147

118–914

43–158

<10

192–742

32–106

this work

Cínovec zinnwaldite granite

9–144

140–3451 595–6212 106–2694

13–66

307–2807 63–1412

this

work Beauvoir

270–1760

210–650

Table 3: Partition coefficient Kd

zircon/melt

from laboratory experiments (Sano et al. 2002; Thomas et al. 2002; Luo & Ayres 2009) and natural

granitoids (Bea et al. 1994; de Liz et al. 2009; Nardi et al. 2012) and empirical enrichment factors Ef

zircon/whole rock

calculated in this work.

395

ZIRCON CHEMISTRY IN FRACTIONATED GRANITE PLUTONS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

2. zircons moderately enriched with Hf ( < 10 wt. % HfO

as  well  as  moderately  to  strongly  enriched  with  Th,  Y,
HREE,  (Nb,  Sc,  Ta,  Bi).  This  type  is  typical  of  the  Krušné
hory/Erzgebirge  area:  A-type  granites  at  Cínovec  (Förster
2006) and Hora Svaté Kateřiny (Breiter et al. 2009), S-type
granites at Podlesí (Breiter et al. 2007). A similar type of zir-
con, but with lower absolute contents of Th, Y and REE, was
also  described  from  peralkaline  A-type  granites  in  Eastern
China  (Wang  et  al.  2000;  Xie  et  al.  2005),  peraluminous
granites  from  Spain  (Pérez-Soba  et  al.  2007),  granites  and
pegmatites from Japan (Hoshino et al. 2010) and leucogran-
ites from Slovakia (Uher & Ondrejka 2009).

Consequently, it is evident that high contents of minor ele-

ments in zircon are not determined only by their concentra-
tions in the melt or by the type of melt as such or even by the
degree of its peraluminity and or alkalinity, and the degree of
melt fractionation, but other phenomena or parameters of the
crystallizing system seem to play a decisive role in this case.
For instance, the concentration of Li (up to 1 wt. % Li

O in

rocks  with  HFSE-poor  zircon  and  only  0.1—0.2 wt. %.  in
granites  with  HFSE-rich  zircon)  may  play  some  role  or  the
pressure  can  also  affect  the  process  of  crystallization.  All
granites  in  the  Krušné  hory/Erzgebirge  area  containing
HFSE-rich zircons are of subvolcanic nature and underwent
explosive  degasation  and  resurgent  boiling  followed  by  in-
tensive F-rich fluid percolation (Breiter et al. 2005).

Some authors (e.g. Kempe et al. 2000; Pettke et al. 2005;

Uher et al. 2009) argued for post-magmatic origin of the
HFSE- and- REE-enriched late zircons or rims of zoned zir-
con crystals. But in case of zircon from the Cínovec borehole
(this study) and similar A-type granites from the Krušné
hory/Erzgebirge Mts (Breiter et al. 2009; Förster et al. 2011),
during the fluid-related processes zircons are enriched in As,
P, and F, while released REEs form secondary minerals like
chernovite and bastnäsite.

Fractionation of HREE

Zircon preferentially concentrates HREE. Experiments car-

ried out by Hanchar et al. (2001) showed that zircon crystals
doped with REE + P displayed an increase of approximately
1000-fold in contents of REE from La through Lu as a result
of shrinking ionic radii. Of the LREE, zircon tends to selec-
tively accumulate Ce

, which often results in a distinct posi-

tive Ce anomaly. Negative Eu anomalies are typical of zircon
from slightly to strongly peraluminous granites (cf. summary
in Hoskin & Schaltegger 2003), but absent in zircon from sub-
alkaline and shoshonitic rock (de Liz et al. 2009); relative con-
centration of Eu in zircon mimic those in the whole rock.

The distribution of HREE at Cínovec is homogeneous.

HREE are more abundant than LREE and there is a distinct
positive  Ce-anomaly  (Fig. 8).  Granites  from  Cínovec  are
characteristic  of  a  distinct  “tetrad  effect”  in  chondrite-nor-
malized distribution of REE (Cocherie et al. 1991). Imprint
or transfer of tetrad effect from a melt into zircon has been
interpreted  as  a  proof  of  late  crystallization  of  this  mineral
after separation of fluid phase from F-rich melt (Nardi et al.
2012).  However,  because  of  the  applied  analytical  method
only contents of even-numbered elements (more abundant in

Fig. 8. Chondrite-normalized distribution of REE in zircons from
Cínovec (normalized according to McDonough & Sun 1995).

396

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

nature) were established in zircon, it would be inappropriate
to comment the above-mentioned phenomenon.

Contents of REE in zircon from Beauvoir are very low,

usually near or below the detection limit of the microprobe.

Phosphorus in the zircon crystal lattice

Kimura & Hironaka (1936) first described zircon enriched

with P and Y, and Hata (1938) explained this as the result of
zircon-xenotime miscibility. Hanchar et al. (2001) experi-
mentally confirmed the tendency for zircon to accommodate
Y and REE in its lattice dominantly by the xenotime substi-
tution (YPO

ZrSiO

). This may explain the P-enrichment

in zircons from the generally P-poor, but Y, REE-enriched
A-type granites. In peraluminous P-rich and Y, HREE-poor
granites, the high P-contents can be explained by the berlin-
ite substitution Al + P

Si + Si (Breiter et al. 2006). In special

cases of Sc-enriched zircons, pretulite-type substitution
(Sc + P

Zr + Si) also plays a role (Breiter et al. 2006).

Among the zircons studied, the Beauvoir zircons are Y-free

and follow the berlinite substitution with P predominant over
Al,  particularly  in  the  B2  and  B´2  units.  Zircons  from
Cínovec generally follow the xenotime substitution with sig-
nificant  predominance  of  Y + REE  over  P  (Fig. 9).  Surpris-
ingly, the excess of Y + REE is greater in the deeper part of
the pluton relative to the upper section that was rich in fluo-
rine and fluids. The occurrence of trivalent elements in zir-
con from the uppermost part of the cupola must be explained
by another type of substitution. One possibility is the substi-
tution  (Y,REE) + (Nb,Ta)   Zr + Zr  (Van  Lichtervelde  et  al.
2011) or perhaps even the incorporation of lithium or other
small ions in interstitial positions apart from the main lattice
sites. Lithium is abundant in fractionated granites and its ion,
due to its small size, can enter a number of minerals not only
in the principal lattice sites but also in their interstices. Lithi-
um cannot be analysed using the electron probe so that data
on  its  content  and  distribution  in  mineral  structures  is  spo-
radic. Ushikubo et al. (2008) found as much as 259 ppm Li
in  zircons  from  granitoids,  and  suggested  that  the  coupled
substitution  (Y,  REE) + Li

interstitial

Zr was responsible for

accommodation of trivalent ions in zircon crystal lattice.

Conclusions

The main results of the present study can be summarized

as follows:

The chemistry of zircons from the highly fractionated

S-type  and  A-type  granites  at  Beauvoir  and  Cínovec  differ
significantly  from  one  another.  Zircons  from  the  A-type
granite  at  Cínovec  are  markedly  enriched  with  Th,  Y,  REE
and Sc, while zircons from the S-type granite at Beauvoir are
more enriched with P and Hf;

A distinct vertical zoning of zircon compositions was

found in both granites with a tendency for the content of Hf
to increase at higher levels of the crystallizing system more
enriched with fluids;

High contents of uranium at both localities were always

detected in the cores of zircon crystals, while their rims are
enriched with Hf;

Enrichments of F and U in zircons at Cínovec correlate with

the  concentration  of  these  elements  in  the  parent  rock  and  in-
crease systematically upwards in the granite body. At Beauvoir,
these elements are mostly concentrated in the middle part of the
profile and show no correlation with their contents in the parent
rock. The chemistry of zircons at Beauvoir correlates more with
the  initial  vertical  division  of  the  system  into  B1,  B2  and  B3
units  (Cuney  et  al.  1992)  rather  than  the  classification  into  B
and B

’units later proposed by Raimbault et al. (1995);

Zircons from highly differentiated granites can generally

be divided into two chemical types: (i) zircons strongly en-
riched with Hf ( > 10 wt. % HfO

, particularly in rims), and

poor in all other HFS-elements. These zircons are typical of
peraluminous strongly Li-enriched granites and LCT pegma-
tites, but also of some A-type granites; (ii) zircon moderately
enriched with Hf ( < 10 wt. % HfO

), as well as moderately

to strongly enriched with Th, Y, HREE, (Nb, Sc, Ta, Bi).
These zircons are characteristic of moderately Li-enriched

Fig. 9. Crystallochemical relations in zircon: a) correlation between P
and Y: zircon from the uppermost 100 m interval in Cínovec follows
xenotime-(Y) substitution (Y+P Z r+Si) with only small deficiency
of Y, while in zircon from the Cínovec deeper part yttrium markedly
prevails and is probably compensated byh Nb and Ta (Y+Nb Zr+Zr)
or by Li (Y + Li Zr). Zircon from Beauvoir is Y-free and phosphorus
enters the lattice mainly acc. to berlinite substitution (Al + P Si + Si);
b) taking into account all trivalent elements, there is clear deficiency
of P in all samples from Cínovec, and still overabundance of P in
Beauvoir.

397

ZIRCON CHEMISTRY IN FRACTIONATED GRANITE PLUTONS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

and strongly F-enriched subvolanic granites of both S- and
A-types of the Krušné hory/Erzgebirge area, but occasionally
were found in evolved S- and A-type granites and granitic
pegmatites worldwide.

High contents of minor elements in zircon are not directly

determined by their concentrations in the melt, but by combi-
nation  of  enrichment  of  the  melt  with  water,  Al,  F,  Na  and
Li,  and  the  pressure.  High  degree  of  peraluminity  and  high
content  of  Li  seem  to  be  favourable  phenomena  facilitating
crystallization of zircon rich in Hf, whereas subvolcanic con-
ditions  of  the  intrusion  linked  with  explosive  degasation  and
secondary boiling support the crystallization of zircon high in
Th, U, Y, REE, Nb and W. Influence of late- to post-magmatic
fluid-driven zircon alteration also play a role.

Acknowledgments: It is a very pleasant duty for the authors
to  thank  Louis  Raimbault  for  providing  the  samples  from
borehole  GPF1  drilled  at  Beauvoir.  Thanks  are  also  due  to
Zuzana  Korbelová  and  Vlasta  Böhmová  (Laboratories  of  the
Geological Institute AS CR Praha) for technical assistance in
producing the excellent EBS photomicrographs used to illus-
trate our paper. Constructive reviews by J. Leichmann (Brno)
and  P.  Uher  (Bratislava)  helped  to  improve  the  manuscript
significantly.  L.V.S.  Nardi  (Porto  Alegre),  I.  Broska  (Bra-
tislava) and J.F. Molina (Granada) are thanked for comments
on the older version of the manuscript. This study was made
possible thanks to the Czech Science Foundation – Projects
P210/10/1105 and P210/10/1309, and also to the Czech IGCP
Committee.

References

Bea F., Pereira M.D. & Stroh A. 1994: Mineral leucosome trace-ele-

ment partitioning in a peraluminous migmatite (a laser ablation-
ICP-MS study). Chem. Geol. 117, 291—312.

Belousova E.A., Griffin W.L., O’Reilly S.Y. & Fisher N.I. 2002: Ig-

neous zircon: trace element composition as an indicator of
source rock type. Contr. Mineral. Petrology 143, 602—622.

Breiter K. 2011: Nearly contemporaneous evolution of the A- and

S-type fractionated granites in the Krušné hory/Erzgebirge
Mts., Central Europe. Lithos, in print.

Breiter K., Förster H.-J. & Seltmann R. 1999: Variscan silicic mag-

matism and related tin-tungsten mineralization in the Erzgebirge-
Slavkovský les metallogenic province. Mineralium Depos. 34,
505—521.

Breiter K., Čopjaková R. & Škoda R. 2009: The involvement of F,

-, and As in the alteration of Zr-Th-REE-bearing accessory

minerals in a the Hora Svaté Kateřiny A-type granite, Czech Re-
public. Canad. Mineralogist 47, 1375—1398.

Breiter K., Förster H.-J. & Škoda R. 2006: Extreme P-, Bi-, Nb-, Sc-,

U- and F-rich zircon from fractionated perphosphorus granites:
The peraluminous Podlesí granite system, Czech Republic.
Lithos 88, 15—34.

Breiter K., Frýda J. & Leichmann J. 2002: Phosphorus and rubidium

in alkali feldspars: case studies and possible genetic interpreta-
tion. Bull. Czech Geol. Surv. 77, 93—104.

Breiter K., Müller A., Leichmann J. & Gabašová A. 2005: Textural

and chemical evolution of a fractionated granitic system: the
Podlesí stock, Czech Republic. Lithos 80, 323—345.

Breiter K. & Škoda R. 2010: Zircon from extremely fractionated West-

European Variscan peraluminous granites. Geoscience Research
Reports for 2009, 194—198; Czech Geol. Surv., Praha (in Czech).

Caruba R. & Baumer A. 1985: An experimental study of hydroxyl

groups and water in synthetic and natural zircons: a model of
the metamict state. Amer. Mineralogist 70, 1224—1231.

Cocherie A., Johan V., Rossi Ph. & Štemprok M. 1991: Trace-element

variation and lanthanide tetrad effect studied in an Variscan lithium
granite: case of the Cínovec granite (Czechoslovakia). In: Pagel
M. & Leroy J.L. (Eds.): Source, transport and deposition of met-
als. Proceedings of SGA Anniversary Meeting, 745—749.

Correia Neves J.M., Lopes Nunes J.E. & Sahama T.G. 1974: High

hafnian members of the zircon-hafnon series from the granite
pegmatites of Zambézia, Mozambique. Contr. Mineral. Petrology
48, 73—80.

Cuney M. & Autran A. 1987: Objectifs généraux du project GPF

Échassiéres no 1 et résultats essentiels acquis par le forage de
900 m sur le granite albitique á topaze-lépidolite de Beauvoir.
Géol. France 2—3, 7—24.

Cuney M., Marignac Ch. & Weisbrod A. 1992: The Beauvoir topaz-

lepidolite albite granite (Massif Central, France): the dissemi-
nated magmatic Sn-Li-ta-Nb-Be mineralization. Economic Geol.
87, 1766—1794.

Cuney M. & Raimbault L. 1991: Variscan rare metal granites and as-

sociated mineralizations from the North French Massif Central.
25 years SGA anniversary meeting, Guide book of the field trip.
CREGU, Vandoeuvre Cédex, 1—75.

Černý P. & Ercit T.S. 2005: The classification of granitic pegmatites

revisited. Canad. Mineralogist 43, 2005—2026.

Černý P. & Siivola J. 1980: The Tanco pegmatite at Bernic lake, Manito-

ba. XII. Hafnian zircon. Canad. Mineralogist 18, 313—321.

De Liz J.D., Nardi L.V.S., de Lima E.F. & Jarvis K. 2009: The trace-ele-

ment record in zircon from the Lavras Do Sul shoshonitic associa-
tion, southernmost Brazil. Canad. Mineralogist 47, 833—846.

Eisenreich M. & Breiter K. 1993: Krupka, deposit of Sn-W-Mo ores in

the eastern Krušné hory Mts. Bull. Czech Geol. Surv. 68, 15—22.

Finch R.J. & Hanchar J.M. 2003: Structure and chemistry of zircon

and zircon group minerals. In: Hanchar J.M. & Hoskin P.W.O.
(Eds.): Zircon. Rev. Mineral. Geochem. 53, 1—26.

Förster H.J. 2006: Composition and origin of intermediate solid solu-

tions in the system thorite-xenotime-zircon-coffinite. Lithos 88,
35—55.

Förster H.J., Ondrejka M. & Uher P. 2011: Mineralogical responses to

subsolidus alteration of granitic rocks by oxidizing As-bearing flu-
ids: REE arsenates and As-rich silicates from the Zinnwald granite,
eastern Erzgebirge, Germany. Canad. Mineralogist 49, 913—930.

Förster H.J., Trumbull R.B. & Gottesmann B. 1999: Late-collisional

granites in the Variscan Erzgebirge, Germany. J. Petrology 40,
1613—1645.

Geisler T., Pidgeon R.T., van Bronswijk W. & Kurtz R. 2002: Transport

of uranium, thorium, and lead in metamict zircon under low-tem-
perature hydrothermal conditions. Chem. Geol. 191, 141—154.

Geisler T., Pidgeon R.T., Kurtz R., van Bronswijk W. & Schleicher

H. 2003: Experimental hydrothermal alteration of partially
metamict zircon. Amer. Mineralogist 88, 1496—1513.

Geisler T. & Schleicher H. 2000: Improved U-Th-total Pb dating of zir-

cons by eklectron microprobe using a simple new background
modelling procedure and Ca as a chemical criterion of fluid-in-
duced U-Th-pb discordance in zircon. Chem. Geol. 163, 269—285.

Görz H. 1974: Microprobe studies of inclusions and compilation of

minor and trace elements in zircon from literature. Chemie der
Erde 33, 326—357.

Grimes C.B., John B.E., Kelemen P.B., Mazdab F.K., Wooden J.L.,

Cheadle M.J., Hanghoj K. & Schwartz J.J. 2007: Trace element
chemistry of zircon from oceanic crust: a method for distin-
guishing detrital zircon provenance. Geology 35, 643—646.

Hanchar J.M., Finch R.J., Hoskin P.W.O., Watson E.B., Cherniak

D.J. & Mariano A.N. 2001: Rare earth elements in synthetic zir-
cons: Part 1. Synthesis, and rare earth element and phosphorus
doping. Amer. Mineralogist 86, 667—680.

398

BREITER and ŠKODA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 5, 383—398

Hata S. 1938: Xenotime and a variety of zircon from Iisaka. Sci. Pap.

Inst. Physical and Chemical Research, Tokyo 34, 619—622.

Hoshino M., Kimata M., Nishida N., Shimizu M. & Akasaka T.

2010: Crystal chemistry of zircon from granitic rocks, Japan:
genetic implications of HREE, U and Th enrichment. Neu. Jb.
Miner. Abh. 187, 167—188.

Hoskin P.W.O. & Schaltegger U. 2003: The composition of zircon

and igneous and metamorphic petrogenesis. In: Hanchar J.M.
& Hoskin P.W.O. (Eds.): Zircon. Rev. Mineral. Geochem. 53,
27—62.

Hoskin P.W.O., Kinny P.D., Wyborn D. & Chappell B.W. 2000:

Identifying accessory mineral saturation during differentiation
in granitoid magmas: an integrated approach. J. Petrology 41,
1365—1396.

Huang X., Wang R.C., Chen X.M., Hu H. & Liu C.S. 2002: Vertical

variations in the mineralogy of the Yichun topaz-lepidolite
granite, Jiangxi province, Southern China. Canad. Mineralogist
40, 1047—1068.

Jarchovský T. & Pavlů D. 1991: Albite-topaz microgranite from

Horní Slavkov (Slavkovský les Mts.) NW Bohemia. Bull. Czech
Geol. Surv. 66, 13—22.

Johan Z. & Johan V. 2005: Accessory minerals of the Cínovec (Zin-

nwald) granite cupola, Czech Republic: indicators of petroge-
netic evolution. Miner. Petrology 83, 113—150.

McDonough W.F. & Sun S. 1995: The composition of the Earth.

Chem. Geol. 120, 223—253.

Kempe U., Gruner T., Renno A.D., Wolf D. & Rene M. 2004: Dis-

cussion on Wang et al. (2000) “Chemistry of Hf-rich zircons
from the Laoshan I- and A-type granites, Eastern China”. Mine-
ralogical Mag. 64, 867—877; 68, 669—675.

Kimura K. & Hironaka Y. 1936: Chemical investigations of Japanese

minerals containing rarer elements, XXIII: Yamagutilite, a phos-
phorus-bearing variety of zircon, found at Yamaguli village, Na-
gano prefecture. J. Chem. Soc. Japan 57, 1195—1199 (in Japanese).

Luo Y. & Ayers J.C. 2009: Experimental measurements of zircon/

melt trace-element partition coefficients. Geochim. Cosmochim.
Acta 73, 3656—3679.

Nardi L.V.S., Formoso M.L.L., Jarvis K., Oliveira L., Bastos Neto

A.C. & Fontana E. 2012: REE, Y, Nb, U, and Th contents and tet-
rad effect in zircon from a magmatic-hydrothermal F-rich system
of Sn-rare metal-cryolite mineralized granites from the Pitinga
Mine, Amazonia, Brazil. J. South Amer. Earth Sci. 33, 34—42.

Nasdala L., Kronz A., Wirth R., Váczi T., Pérez-Soba C., Willner A.

& Kennedy A.K. 2009: The phenomenon of deficient electron
microprobe totals in radiation-damaged and altered zircon.
Geochim. Cosmochim. Acta 73, 1637—1650.

Pérez-Soba C., Villaseca C., Gonzáles del Tánago J. & Nasdala L.

2007: The composition of zircon in the peraluminous Hercynian
granites of the Spanish central system batholith. Canad.
Mineralogist 45, 509—527.

Pettke T., Audétat A., Schaltegger U. & Heinrich Ch.A. 2005: Mag-

matic to hydrothermal crystallization in the W-Sn mineralized
Mole Granite (NSW, Australia). Part II: Evolving zircon and
thorite trace element chemistry. Chem. Geol. 220, 191—213.

Raimbault L. 1998: Composition of complex lepidolite-type granitic

pegmatites and of constituent columbite-tantalite, Ch

deville,

Massif Central, France. Canad. Mineralogist 36, 563—583.

Raimbault L. & Azencott C. 1987: Géochemie des éléments majeurs et

traces du granite á métaux rares de Beauvoir. Géol. France 2—3,
189—198.

Raimbault L., Cuney M., Azencott C., Duthou J.L. & Joron J.L.

1995: Geochemical evidence for a multistage magmatic genesis
of Ta-Sn-Li mineralization in the granite at Beauvoir, French
Massif Central. Econ. Geol. 90, 548—596.

Rossi Ph., Autran A., Azencott C., Burnol L., Cuney M., Johan V.,

Kosakevitch A., Ohnensteter D., Monier G., Piantone P., Raim-
bault L. & Viallefond L. 1987: Logs pétrographique et géochem-

ique du granite de Beauvoir dans le sondage Échassieres 1:
minéralogie et géochemie comparées. Géol. France 2—3, 111—136.

Rub A.K., Štemprok M. & Rub M.G. 1998: Tantalum mineralization

in the apical part of the Cínovec (Zinnwald) granite stock. Mine-
ral. Petrology 63, 199—222.

Rubatto D. 2002: Zircon trace element geochemistry: partitioning

with garnet and the link between U-Pb ages and metamorphism.
Chem. Geol. 184, 123—138.

Sano Y., Terada K. & Fukuoka T. 2002: High mass resolution ion

probe analysis of rare earth elements in silicate glass, apatite and
zircon: lack of matrix dependency. Chem. Geol. 184, 217—230.

Schmidt C., Rickers K., Wirth R., Nasdala L. & Hanchar J.M. 2006:

Low-temperature Zr mobility: an in situ synchrotron-radiation
XRF study of the effect of radiation damage in zircon on the ele-
ment release in H

O + HCl ± SiO

fluids. Amer. Mineralogist 91,

1211—1215.

Seltmann R. & Schilka W. 1991: Metallogenic aspects of breccia-related

tin granites in the eastern Erzgebirge. Z. Geol. Wiss. 19, 485—490.

Štemprok M. & Šulcek Z. 1969: Geochemical profile through an ore-

bearing lithium granite. Econ. Geol. 64, 392—404.

Thomas J.B., Bodnar R.J., Shimizu N. & Sinha A.K. 2002: Determi-

nation of zircon/melt trace element partition coefficients from
SIMS analysis of melt inclusions in zircon. Geochim. Cosmo-
chim. Acta 66, 2887—2901.

Thomas R., Förster H.-J., Rickers K. & Webster J.D. 2005: Forma-

tion of extremely F-rich hydrous melt fractions and hydrothermal
fluids during differentiation of highly evolved tin-granite mag-
mas. A melt/fluid-inclusion study. Contr. Mineral. Petrology
148, 582—601.

Uher P., Breiter K., Klečka M. & Pivec E. 1998: Zircon in highly

evolved Hercynian Homolka granite, Moldanubian zone, Czech
Republic: indicator of magma source and petrogenesis. Geol.
Carpathica 49, 151—160.

Uher P. & Černý P. 1998: Zircon in Hercynian granitic pegmatites of the

Western Carpathians, Slovakia. Geol. Carpathica 49, 261—270.

Uher P. & Ondrejka M. 2009: P-Al-Th-REE-rich zircon and cheralite-

like phase in aplititic-pegmatitic granophyre from the Dubová,
Horné Trávniky near Modra (Malé Karpaty Mountains, SW Slo-
vakia). Bull. Mineral.-Petrolog. Odd. Nár. Muz. 17, 81—86.

Uher P., Ondrejka M. & Konečný P. 2009: Magmatic and post-mag-

matic Y-REE-Th phosphate, silicate and Nb-Ta-Y-REE oxide min-
erals in A-type metagranite: an example from the Turčok massif,
the Western Carpathians, Slovakia. Mineral. Mag. 73, 1009—1025.

Ushikubo T., Kita N.T., Cavosie A.J., Wilde S.A., Rudnick R.L. &

Valley J.W. 2008: Lithium in Jack Hills zircons: evidence for
extensive weathering of Earth’s crust. Earth Planet. Sci. Lett.
272, 666—676.

Van Lichretvelde M., Holtz F., Dziony W., Ludwig T. & Meyer H.-P.

2011: Incorporation mechanism of Ta and Nb in zircon and impli-
cations for pegmatitic systems. Amer. Mineralogist 96, 1079—1089.

Van Lichtervelde M., Melcher F. & Wirth R. 2009: Magmatic vs. hy-

drothermal origins for zircon associated with tantalum mineral-
ization in the Tanco pegmatite, Manitoba, Canada. Amer.
Mineralogist 94, 439—450.

Wang R.C., Fontan F., Xu S.J., Chen X.M. & Monchoux P. 1996:

Hafnian zircon from the apical part of the Suzhou granite, China.
Canad. Mineralogist 34, 1001—1010.

Wang R.C., Fontan F. & Monchoux P. 1992: Minéraux disséminés

comme indicateurs du caract

re pegmatitique du granite de

Beauvoir, massif d’Echassi

res, Allier, France. Canad. Mineralo-

gist 30, 763—770.

Wang R.C., Zhao G.T., Lu J.J., Chen X.M., Xu S.J. & Wang D.Z.

2000: Chemistry of Hf-rich zircons from the Laoshan I- and
A-type granites, Eastern China. Mineral. Mag. 64, 867—877.

Xie L., Wang R., Chen X., Qui J. & Wang D. 2005: Th-rich zircon

from peralkaline A-type granite: mineralogical features and pet-
rological implications. Chinese Sci. Bull. 50, 809—817.