Introduction
The Brunovistulicum is the most important fluorite-bearing
geological unit on the eastern margin of the Bohemian Mas-
sif. To date, 24 mineralogical occurrences or subeconomic
fluorite accumulations are known from surface outcrops or
boreholes (Burkart 1953; Èeková 1975, 1978, 1985; Meli-
char & paèek 1995). On the basis of an overall paragenetic
analysis, the previous researchers (e.g. Bernard et al. 1981)
suggested that all the Brunovistulian fluorites belong to one,
late Variscan to Mesozoic fluorite-barite mineralization.
However, the mineralization was not investigated in greater
detail at the time because of its economic insignificance. Re-
cent detailed mineralogical and genetic study revealed four
different genetic types of fluorite mineralization within the
Brunovistulicum: (i) Variscan fluorite-chlorite; (ii) Variscan
(?) fluorite-epidote; (iii) Permian-Triassic fluorite-barite and
(iv) Cenozoic pure fluorite (Slobodník et al. 2000; Dolníèek
2001a,b; Dolníèek & Malý 2003; Dolníèek et al. 2003; Dol-
níèek, unpubl. data).
The main objective of this study is to provide more detailed
mineralogical and genetic information on the last and young-
est mentioned type of fluorite mineralization. A combination
of several modern research methods (fluid inclusions, stable
isotopes, trace elements) should make it possible to better (i)
understand the formation conditions of the mineralization and
(ii) compare Brunovistulian example with other young types
of fluorite mineralization within the Bohemian Massif and
elsewhere in the World.
GEOLOGICA CARPATHICA, APRIL 2005, 56, 2, 169177
www.geologicacarpathica.sk
Cenozoic fluorite mineralization from the Brunovistulicum,
southeastern margin of the Bohemian Massif
(Czech Republic)
ZDENÌK DOLNÍÈEK
Department of Geology, Faculty of Science, Palacký University, tø. Svobody 26, 771 46 Olomouc, Czech Republic;
dolnicek@prfnw.upol.cz
(Manuscript received February 24, 2004; accepted in revised form June 16, 2004)
Abstract: Anchimonomineralic fluorite vein mineralization was studied at six sites within the Proterozoic crystalline
basement of the Brunovistulicum. The mineral composition is very simple, represented mainly by fluorite, locally ac-
companied by quartz and calcite. Fluid inclusion study shows that the parent fluids were low-saline (04.3 wt. % NaCl
equiv.), low-temperature (homogenization temperatures 72183 °C) aqueous solutions. The REE data indicate strong
interaction of the fluids with host rocks. Stable isotope analyses reveal both variable oxygen isotope composition and an
apparent admixture of the oxidized organic carbon in the parent fluids. The formation conditions can be easily compared
with those characterizing the Neoidic (Tertiary-Quaternary) fluorite mineralization described from the North Bohemia
region. The source of the fluid can be found in formation waters of the southeastern margin of the Bohemian Massif
covered by the Carpathian Foredeep, Vienna Basin and Carpathian flysch nappes, which actually exhibit very similar
geochemical signatures to the fluorite-precipitating fluids.
Key words: Brunovistulicum, fluorite mineralization, fluid inclusions, stable isotopes, REE.
Geological setting
The Brunovistulicum (Dudek 1980) is the largest and oldest
crystalline complex situated on the easternmost margin of the
Bohemian Massif. The surface outcrops include the Brno mas-
sif, cores of the Svratka and Dyje Domes (Fig. 1) and small
occurrences in the surroundings of the city of Olomouc. A
great part is buried under the flysch nappes and foredeep of
the Western Carpathians. The unit is composed mainly of ig-
neous rocks. Relatively monotonous, calc-alkaline metalumi-
nous biotite to amphibole-biotite granodiorites prevail in the
eastern part of the Brno massif and in the Svratka and Dyje
Domes. The western part of the Brno massif is more complex,
involving also S-, I- and A-type granites. Both petrologically
different parts are separated by a metabasite zone, consisting
of metadiorites and metabasalts. All the rocks are crosscutt by
dikes of aplites, primitive pegmatites, rhyolites, porphyrites,
etc. (Mitrenga & Rejl 1993; Hanl & Melichar 1997). Relics
of the metamorphic mantle are most frequent in the western
part of the Brno massif (migmatites, paragneisses, calc-silicate
rocks, marbles, phyllites, mica schists). Radiometric dating
proved Neoproterozoic (580725 Ma) magmatic activity in
the Brunovistulicum (see Kalvoda et al. 2002 for references).
The crystalline complexes are covered by Paleozoic sedi-
ments. Cambrian to Devonian siliciclastics (quartzose con-
glomerates and sandstones) are followed by Devonian to Lower
Carboniferous limestones (Kalvoda et al. 2002).
The Brunovistulicum acted as a foreland massif for both the
Variscan and the Alpine fold belts (Kalvoda et al. 2002). The
170 DOLNÍÈEK
Fig. 1. Simplified geological map showing the setting of the studied localities.
reactivation during Variscan Orogeny caused mylonitization
and retrograde metamorphism under lower greenschist facies
conditions, especially in the western parts. The influence of
the Alpine Orogeny was much weaker, restricted probably
only to reactivation of older fault structures.
Methods
The studied samples of the hydrothermal mineralization
were collected in the field during the years 19922003 except
fluorite samples from Tetèice and Dyje localities, which were
provided by museum or private collectors. Thin sections for
conventional and cathodoluminescence (CL) microscopy were
prepared from the samples by J. Povolný (Institute of Geologi-
cal Sciences, Masaryk University, Brno). Fluid inclusions,
trace elements and isotopic composition of carbon and oxygen
were studied in selected typical samples.
The CL study was realized using the technique of hot lu-
minescence on a HC2-LM apparatus (Simon-Neuser, Bo-
chum, FRG) at the Institute of Geological Sciences, Masaryk
University, Brno under the guidance of J. Leichmann. The
polished thin sections were coated with graphite. Typical
working conditions include an accelerating voltage of 14 kV
and beam current approximately 10 µA/mm
2
.
Fluid inclusions (FI) were investigated by means of optical
microthermometry. Inclusions in quartz have been studied in
standard doubly polished wafers. Cleavage fragments were
used in the case of most calcites and fluorites. Discrimination
among the primary (P), primary-secondary (PS) and second-
ary (S) fluid inclusions was made in thin sections according to
criteria of Shepherd et al. (1985). Temperatures of phase tran-
sitions (homogenization temperatures Th; freezing temper-
atures Tf; eutectic temperatures Te; last ice crystal melt-
ing temperatures Tm) were measured at the Institute of
Mineralogy, Geochemistry and Natural Resources, Charles
University, Prague, using the Linkam THMSG 600 heating-
cooling stage. The stage was calibrated using phase transitions
of inorganic standards and synthetic fluid inclusions. Uncer-
tainty of the temperature estimate is ±0.1 °C. Salinity of the
trapped fluid was calculated from values Tm (ice) according to
Bodnar (1993).
Isotopic analyses of carbon and oxygen in calcites were
measured in laboratories of the Czech Geological Survey, Pra-
gue, using a Finnigan MAT 251 mass spectrometer (K. Malý,
I. Jaèková and J. Hladíková, analysts). Conversion of carbon-
ate to CO
2
was made by reaction with 100 % orthophosphoric
acid in the vacuum line. The results are conventionally ex-
pressed in delta (δ) notation as per mil () deviation from
commonly used standards (PDB, SMOW). Uncertainty is bet-
CENOZOIC FLUORITE MINERALIZATION FROM THE BRUNOVISTULICUM 171
ter than ±0.05 and ±0.1 for isotopic composition of carbon
and oxygen, respectively. Isotopic composition of the parent
fluid was calculated using published equations (ONeil et al.
1969; Friedman & ONeil 1977; Ohmoto & Goldhaber 1997).
When calculating the fluid δ
13
C value, equations for H
2
CO
3
and HCO
3
as dominating carbon species have been used for
temperatures above and below approx. 120140 °C (cf. Mat-
suhisa et al. 1985), respectively.
The analyses of trace elements were performed in the
ACME analytical laboratories, Vancouver, Canada. Calcite
and fluorites (samples weighing between 15 g) were hand-
picked under a binocular microscope. The separates were then
pulverized in the agate mortar. Aliquots for analyses of the
heavy metals were dissolved in hot (95 °C) aqua regia and the
analysis itself was performed using inductively coupled plas-
ma emission spectrometry method. Refractory metals and rare
earth elements (REE) were analysed by inductively coupled
plasma mass spectrometry in another sample aliquot, which
was decomposed using LiBO
2
fusion followed by leaching of
the cake in diluted (5%) HNO
3
. Reproducibility of the results
is within 510 % according to repeated analyses. REE concen-
trations were normalized to C1-chondrite using values given
by Anders & Grevesse (1989). Degrees of Ce and Eu anoma-
lies were calculated using the equations given by McLennan
(1989) and Monecke et al. (2002).
Fluorite mineralization
The anchimonomineralic fluorite mineralization has been
found at six sites within the Brno massif (Tetèice, Rakice,
Leskoun) and cores of the Svratka (Dolní Louèky, Kvìtnièka)
and Dyje Domes (Dyje locality; Fig. 1).
Tetèice. A 20 cm thick subvertical NESW vein crosscuts
fine-grained paragneisses and erlans belonging to the
metasedimentary mantle of the Brno massif. The oldest hydro-
thermal phase is quartz. It is accessoric, remarkable only in
thin section as fine grains coating the walls of the vein and en-
closed fragments of the wall rock. Botryoidal masses of zonal-
ly coloured, mainly violet fluorite exhibiting radial and con-
centric fabric are the dominating constituent. Coarse-grained
aggregates of green and violet fluorite and two generations of
calcite occur less frequently. Cores of violet fluorite crystals
show green cathodoluminescence colours, the rims are blue,
with detailed growth zonation. The irregular, corroded bound-
aries between individual growth zones are very interesting
(Fig. 2). Calcite I is coarse-grained white phase, dull orange in
CL microscope. Calcite II forms colourless corroded crystals
in the vugs, with light orange CL image. The paragenetic se-
quence is as follows: quartzgreen fluoritebotryoidal fluo-
ritecalcite Icalcite II.
Rakice. Fluorite mineralization cements strongly fractured
hydrothermally altered aplite-pegmatite dike striking WNW
ESE (Melichar & paèek 1995; Slobodník et al. 2000). The
fluorite veinlets showing the same direction as the pegmatite
dike steeply dip SSW. Three generations of fluorite have been
distinguished here. The oldest is grey-violet, very fine-grained
fluorite in thin veinlets. The coarse-grained colourless fluorite
is younger. Fluorite crystallization finished with violet to
blue-violet fluorite. Fluorite cubes up to 2.5 cm with zonal co-
louration are common in vein vugs. In the CL microscope,
fluorite shows blue luminescence and growth zonation. The
youngest phase is fine-grained quartz, often coating the fluorite
crystals. Moreover, chalcedony was occasionally recognized as
fillings of the remaining vugs. Quartz often forms thin lenticular
perimorphs after an unknown mineral, which was later totally
leached (barite?, calcite?). Calcite was identified by means of
CL microscopy as minute grains enclosed in fluorite.
Leskoun. Only two pieces of calcite-fluorite mineralization
were found in blasted material in a large active quarry. The
mineralized veinlet, 1 mm thick, crosscuts relatively fresh and
undeformed coarse-grained biotitic granodiorite. The fluorite
is violet, the calcite white, both forming medium-grained ag-
gregates.
Dolní Louèky. Calcite-fluorite veins hosted by mylonitized
biotite granodiorite are occasionally found in the active quarry
(Dolníèek & Malý 2003). The veinlets are up to 5 mm thick.
They consist mainly of white-grey medium-grained calcite.
The fluorite forms blue-violet nests in calcite, up to 5 mm in
diameter. In a CL microscope, fluorite shows oscillatory zon-
ing in blue hues. In addition, a change of growing crystal mor-
phology was identified.
Kvìtnièka. Fluorite together with quartz cement brecciated
quartzites belonging to Devonian sedimentary cover of the
Brunovistulicum in the Svratka Dome. The fluorite is macro-
scopically very dark violet to black. In thin section, it is most-
ly light violet, with 23 darker growth zones near the crystal
rims. In the CL microscope, fluorite shows regular growth zo-
nation in blue hues and becomes deep violet, pleochroic and
anisotropic as a consequence of the interaction with electron
beam (Dolníèek 2001a). Superimposed quartz forms up to
5 mm euhedral crystals, in various colour varieties (amethyst,
smoky quartz, colourless quartz).
Dyje. The studied sample (leg. M. Slobodník) consists of
dominating coarse-grained colourless to white calcite, con-
taining small (max. 0.3 mm) violet fluorite crystals. The 1
2 cm thick vein crosscuts diorites.
Fig. 2. CL image of the blue luminescent fluorite from Tetèice
with distinct growth zonality and corroded boundaries among
growth zones. Calcite is white, fragments of wall rock are black.
Scale bar 1 mm.
172 DOLNÍÈEK
Fluid inclusions
Microthermometry of the fluid inclusions was applied to
fluorite, calcite and quartz from all the studied occurrences.
The measured data are summarized in Table 1 and graphically
presented in Fig. 3.
The studied fluorites contain numerous primary, pseudosec-
ondary and secondary FI. Primary FI are equant, three-dimen-
sional, randomly distributed, arranged along growth zones.
They are often negative-crystal shaped, creating either cubes
(Rakice), or tetrahedrons (Tetèice). PS and S FI are flat, ar-
ranged along healed microfractures. All the FI are two-phase
(L+V) with a constant liquid-vapour ratio around 0.95 except
for the sample from Leskoun, which contains liquid-only FI.
The microthermometrically measured P and PS FI reach 4
80 µm in diameter. Homogenization temperatures cover an in-
terval from 76 to 183 °C. FI totally freeze out at temperatures
between 29 and 46 °C but remain colourless. Unfortunate-
ly, eutectic melting as well as salt-hydrate melting could not
be typically observed due to metastable behaviour of the most
FI (total consumption of the vapour bubble by expanding ice
after freezing). The rare measurements of Te around 20 °C
Fig. 3. Presentation of the microthermometric data on the studied P and PS FI in fluorites. A histogram of the homogenization temper-
atures; B histogram of the last ice melting temperatures; C Th-salinity plot.
from Rakice indicate the presence of NaCl as the dominat-
ing salt. The last ice melted in the presence of vapour phase
within relatively narrow temperature interval between 0.0 and
2.6 °C, indicating low total fluid salinity between 0.0 and
4.3 wt. % NaCl equiv. (Bodnar 1993). A specific behaviour of
FI in fluorite from Tetèice (systematic increase of vapour bub-
ble diameter during continual heating above 0 °C) suggests
possible presence of a clathrate-forming gas (either CO
2
or
CH
4
). A more detailed examination is not possible due to
small sizes of gaseous bubbles. The general distribution of
measured data in the Th-salinity plot indicates mixing of dilut-
ed and cooler fluid with warmer and more saline fluid, howev-
er, very different trends characterize individual localities
(Fig. 3).
In most cases the associated minerals show FI parameters
very similar to those in fluorites. Markedly different are FI in
quartz from Kvìtnièka and those in calcites from Dyje and
Dolní Louèky (Table 1). Highly variable liquid-vapour ratios
in quartz from Kvìtnièka (consequently resulting in broadly
scattered homogenization temperatures) are evidently caused
by necking-down. FI in calcites from Dolní Louèky and Dyje
showed significantly higher salinities (up to 11.0 wt. % NaCl
CENOZOIC FLUORITE MINERALIZATION FROM THE BRUNOVISTULICUM 173
Table 1: Results of the fluid inclusion microthermometry (P and PS FI). Temperatures in °C. n.d. not determined.
Locality
Host mineral phase
FI nature
Th (°C)
Tf (°C)
Te (°C)
Tm (°C) Salinity (wt.%)
Tetèice
green fluorite
L+V
83/111
29/41
n.d.
0.0/0.3
0.0/0.5
white calcite I
L+V
48/73
30/43
22
0.0/0.3
0.0/0.5
colourless calcite II
L+V
41/49
23/25
n.d.
0.0
0.0
Rakice
colourless fluorite
L+V
116/142
39/45
20
0.1/1.8
0.2/3.1
violet fluorite
L+V
106/137
38/42
n.d.
0.0/0.5
0.0/0.9
Leskoun
fluorite, calcite
L
n.d.
n.d.
n.d.
n.d.
Kvìtnièka
dark violet fluorite
L+V
118/165
41/46
28 ?
0.8/2.6
1.4/4.3
colourless quartz
L, L+V
110/>300
35/42
20
0.1/1.6
0.2/2.7
Dolní Louèky
white calcite
L+V
142/177
49/55
50
1.6/7.4
2.7/11.0
light blue-violet fluorite
L+V
183
45
n.d.
1.4/2.2
2.4/3.7
Dyje
white calcite
L+V
111/147
42/47
n.d.
1.5/6.1
2.6/9.3
equiv.) and lower Te (ca. 50 °C), indicating the presence of
CaCl
2
and/or MgCl
2
in addition to NaCl.
Stable isotopes
The isotopic composition of carbon and oxygen was deter-
mined in calcites from Tetèice, Leskoun, Dyje and Dolní
Louèky. The results are listed together with the calculated
δ
18
O and δ
13
C values of the parent fluids in Table 2.
The δ
18
O values of calcites vary between 7.5 and 16.6
PDB. The calculated fluid δ
18
O values are variable. Negative
values (0.2 to 8.1 SMOW; Tetèice and Leskoun) are
characteristic of meteoric waters, whereas the higher positive
values (+1.1 to +5.2 SMOW; Dolní Louèky and Dyje) could
indicate either a contribution of metamorphic and/or magmatic
waters to hydrothermal system, or reflect a stronger fluid-rock
interaction at elevated temperatures (Sheppard 1986).
The δ
13
C values in calcite range between 6.7 and 14.1
PDB. Calculated δ
13
C values (H
2
CO
3
for Dolní Louèky and
Dyje and HCO
3
for Tetèice and Leskoun) of the parent fluid
vary between 6.4 and 18.7 PDB. Enriched values (down
to approximately 8 PDB) may be interpreted as (i) carbon
derived from a deep-seated source; (ii) average homogenized
carbon of the Earths crust (Hoefs 1997); (iii) carbon derived
from local igneous rocks or (iv) recycled carbon of older hy-
drothermal mineralizations with a similar carbon isotopic
composition (Dolníèek & Malý 2003). More negative fluid
δ
13
C values (below approx. 8 PDB) indicate an admixture
of carbon derived from organic matter (δ
13
C typically between
-20 and 35 PDB; Hoefs 1997).
Trace elements
Contents of 44 trace elements were determined in selected
fluorites, calcite and host rocks. The mineral separates show
higher concentrations only at Ba, Sr, Y and REE (Table 3).
Other elements, including alkali, refractory, precious and
heavy metals are mostly below detection limits (ranging from
0.01 to 5 ppm) or only slightly above them. Low concentra-
tions of Rb, Ga and Zr reveal negligible contamination of Ca-
minerals by host silicate rocks.
The total REE content in hydrothermal minerals can be clas-
sified as medium to high (46400 ppm). Chondrite-normal-
ized REE distribution patterns are variable (Fig. 4): a strong
LREE enrichment is typical of Tetèice and especially of Dolní
Louèky localities, whereas samples from Rakice and espe-
cially from Kvìtnièka are more balanced in terms of their
LREE/HREE ratio. It is noteworthy that the REE distributions
in hydrothermal minerals correspond well to abundances in lo-
cal country rocks (Fig. 4), except for Ce and Eu, which are
sensitive to redox variations.
Calcite from Dolní Louèky displays weak positive Eu
anomaly. A pronounced positive Eu anomaly is typical for flu-
orite samples from Rakice whereas fluorites from Tetèice and
Kvìtnièka show no anomalies. Moreover, violet fluorite from
Rakice exhibits weak positive Ce anomaly. Positive Ce and
Eu anomalies most probably reflect an increase in oxygen
fugacity during fluid migration and mineral precipitation (Lee
et al. 2003). Local mixing of the ascending hot saline hydro-
thermal fluid with descending oxidized meteoric waters at
depositional site might explain both REE and fluid inclusion
(Fig. 3c) behaviour.
Table 2: Carbon and oxygen isotopic composition of the studied calcites and calculated δ
18
O and δ
13
C values of the parent fluids. Tem-
peratures in °C.
Calcite
Fluid
Locality
Mineral
@
13
C (PDB)
@
18
O (PDB)
@
18
O (SMOW)
T (°C)
@
18
O (SMOW)
@
13
C (PDB)
Tetèice
calcite I
7.1
15.0
+15.5
48/73
4.3/8.1
9.6/10.6
calcite I
6.7
14.1
+16.4
48/73
3.4/7.2
9.2/10.2
calcite II
9.9
7.5
+23.2
41/49
0.2/1.6
13.3/13.8
Leskoun
calcite
14.1
10.4
+20.3
30/50
2.9/6.6
17.5/18.7
Dolní Louèky
calcite
6.4
16.6
+13.8
142/177
+1.1/+3.5
6.4/7.7
Dyje
calcite
10.3
12.9
+17.6
111/147
+2.1/+5.2
7.5/9.3
174 DOLNÍÈEK
Discussion
The mineral assemblage of the studied occurrences (domi-
nating fluorite, lack of barite and sulphides) is similar to the
Neoidic fluorite mineralization described from Northern Bo-
hemia (Teplice, Jílové near Dìèín). This youngest type of flu-
orite vein mineralization in the Bohemian Massif is character-
ized by (i) dominating fluorite with subordinate quartz, calcite
or barite; (ii) occurrence in the geographically restricted area
of the southeastern slope of the Kruné hory Mountains; (iii)
Tertiary to Quaternary age of the mineralizing processes based
on geological criteria; (iv) low saline (mostly up to 3 wt. %
NaCl equiv. with one excursion up to 18 wt. % NaCl equiv.),
low temperature (60155 °C), low δ
18
O (1 to 10
SMOW) Na-Cl-HCO
3
fluids derived mainly from local mete-
Table 3: Trace element abundances in fluorites and calcite (all
values in ppm except Au in ppb). n.d. not determined.
green colourless violet dark violet
white
Mineral
fluorite fluorite
fluorite
fluorite
calcite
Locality Tetèice Rakice Rakice Kvìtnièka D. Louèky
Cs
0.1
0.2
0.1
0.2
< 0.1
Rb
1.0
1.6
2.2
1.0
< 0.5
Ba
172
28
12
n.d.
22
Sr
73
68
63
175
1 000
Co
< 0.5
< 0.5
< 0.5
1.9
< 0.5
Mo
< 1
< 1
1
< 1
0.1
Sn
< 1
< 1
< 1
< 1
< 1
Ga
6.5
3.7
2.5
< 0.5
1.5
Cu
< 1
< 1
< 1
< 1
11
Pb
< 3
< 3
< 3
< 3
11
Zn
1
4
< 1
< 1
26
Ni
< 1
< 1
< 1
< 1
2.3
As
< 2
< 2
< 2
2
< 0.5
Cd
< 0.2
< 0.2
< 0.2
< 0.2
0.1
Sb
< 0.5
< 0.5
< 0.5
< 0.5
0.1
Bi
0.5
< 0.5
0.8
< 0.5
0.1
Ag
n.d.
n.d.
n.d.
< 0.5
< 0.1
Au
n.d.
n.d.
n.d.
n.d.
2.3
Hg
n.d.
n.d.
n.d.
n.d.
< 0.01
Tl
n.d.
n.d.
n.d.
n.d.
< 0.1
Se
n.d.
n.d.
n.d.
n.d.
< 0.5
Th
0.1 0.1
0.1
0.2
< 0.1
U
< 0.1 < 0.1
< 0.1
< 0.1
1
V
< 5
< 5
< 5
7
< 5
W
< 1
< 1
< 1
< 1
< 1
Ta
< 0.1 < 0.1
0.1
< 0.1
< 0.1
Nb
< 0.5 < 0.5
< 0.5
0.5
< 0.5
Hf
< 0.5 < 0.5
< 0.5
< 0.5
< 0.5
Zr
3.0 1.9
1.2
4.6
< 0.5
Y
140
96
33
115
86
La
44
4
7
8
79
Ce
104
11.7
13.5
19.8
164
Pr
12.6 1.3
1.6
3.2
18.6
Nd
51
6.5
7.1
15.5
71
Sm
11.4 3.0
2.2
5.3
16.9
Eu
4.5 1.8
1.4
1.9
6.5
Gd
14
6.1
3.3
7.8
15
Tb
2.2 1.3
0.57
1.2
2.4
Dy
13.6 9.5
4.0
9.2
12.3
Ho
2.8 2.0
0.81
2.0
2.1
Er
6.9 5.3
2.2
4.8
6.1
Tm
0.83 0.76
0.30
0.66
0.87
Yb
4.8 4.6
1.8
3.2
5.1
Lu
0.62 0.55
0.22
0.46
0.71
5 REE
273
58
46
83
400
Ce/Ce*
1.06 1.21
0.96
0.93
1.02
Eu/Eu*
1.08 1.27
1.61
0.89
1.23
La
N
/Yb
N
6.4 0.6
2.8
1.7
10.8
Tb
N
/La
N
0.3 2.1
0.5
1.0
0.2
oric waters; (v) supply of Ca, Sr, Ba, F
and SO
4
necessary
for fluorite and barite precipitation from the adjacent crystal-
line and Cretaceous sedimentary rocks; (vi) fluid circulation
driven by tectonic activity and heat flow related to Tertiary
volcanism in the Èeské støedohoøí Mountains (Èadek et al.
1964, 1981; ák et al. 1990).
Most genetic characteristics of the studied Brunovistulian
fluorites (i.e. fluid inclusion and partly also stable isotope
data) are comparable with the Neoidic Bohemian examples,
too. Two additional coincidences arise after more detailed ex-
amination of the existing data. Firstly, Èadek et al. (1981)
pointed to a significant role of increasing fugacity of CO
2
al-
lowing for fluorite precipitation from the diluted fluids. In
these terms paragenetic sequence and growth zonality of fluo-
rite from Tetèice can be easily explained. Here, the presence
of minor CO
2
cannot be excluded in the fluid inclusions. Cor-
roded boundaries between individual growth zones in a fluo-
rite crystal can be interpreted as a consequence of changing
CO
2
concentration in the fluid. After penetration of the actual
portion of the CO
2
-bearing fluid to the depositional site, fluo-
rite precipitates. However the CO
2
is soon lost, either by the
fluid degassing or by a reaction with the host rock. Finally,
fluorite crystallization terminates and it may be even dissolved
by the same fluid if enough CO
2
is released. Repeating pulses
of the same fluid under the same physicochemical and hydro-
logic conditions gave rise to the observed texture. The end of
the fluorite crystalization may be characterized by a more pro-
nounced decrease of CO
2
resulting in an increase of alkalinity
and onset of calcite precipitation (Rimstidt 1997). Secondly,
an intense interaction of the parent fluid with host rocks is in-
dicated by the trace element abundances. The REE distribu-
tions in hydrothermal minerals are very similar to that in the
local country rocks, indicating a supply of REE (and at least a
certain part of the geochemically similar Ca) from the host
rocks.
The source of the parent fluid may be found in the formation
waters, which have been actually drilled during prospection
and exploitation of hydrocarbons on the southeastern margin
of the Bohemian Massif buried by Carpathian Foredeep, Vien-
na Basin and Carpathian flysch nappes (Michalíèek 1978;
Koláøová 1981). These fluids show Na-Cl-HCO
3
composi-
tion, total dissolved salts in the range of 652 g/l (i.e. 0.6
5.0 wt. % NaCl or NaHCO
3
according to Dykyj et al. 1953),
and δ
18
O values ranging between +4.6 and 10.0 SMOW
(Buzek & Michalíèek 1997). Such an interpretation can also
be supported by the occurrence of
13
C-depleted calcites within
fluorite veins (possible due to a HCO
3
supply derived from
decomposition of hydrocarbons). Moreover, the fluorite REE
patterns corresponding to abundances in host rocks may serve
as an indirect evidence too, because the hydrocarbon-bearing
fluids show very low REE contents in this region (Dolníèek &
Slobodník, unpubl. data), therefore, their REE budget may be
easily overprinted by local suitable REE source.
Furthermore, a post-Mesozoic age of the fluorite mineral-
ization is also indicated by the lack of tectonic deformation of
the vein fill. Alpine thrusting-related shearing, deformation
and recrystallization have widely influenced the Mesozoic flu-
orite-barite veins occupying the NWSE trending steep faults
in this area (Dolníèek, unpubl. data). In addition, the results of
2
CENOZOIC FLUORITE MINERALIZATION FROM THE BRUNOVISTULICUM 175
Fig. 4. Chondrite-normalized REE patterns of hydrothermal minerals and associated host rocks. Host rock data are partly original data of
the author and J. Leichmann, and partly taken from literature (Hanl & Melichar 1997; Leichmann et al. 1999).
nic rocks (e.g. ák et al. 1990; Hill et al. 2000), rarely to acid-
ic plutonic-volcanic complexes (Cunningham et al. 1998).
The second group includes non-volcanic regions, where main-
ly tectonic processes, sediment compaction, and dissolution of
fluorine-bearing phases are believed to be responsible for the
fluorite crystalization. Some Austrian fluorites (e.g. Götzinger
& Seemann 1990; Götzinger 1993), and most probably also
the described Brunovistulian mineralization are the typical ex-
amples.
Conclusions
1. The origin of the anchimonomineralic fluorite vein min-
eralization hosted by Cadomian granitoids of the Brno massif
and Svratka and Dyje Domes on the southeastern margin of
the Bohemian Massif has been studied. The mineralization
consists mainly of fluorite locally accompanied by calcite and/
or quartz. A typical feature is the lack of sulphidic minerals
and barite within the fluorite veins. The parent fluids were low
temperature, low-saline aqueous solutions with variable oxy-
gen isotope composition. Carbon isotopes in calcites indicate
local involvement of carbon derived from oxidized organic
matter. REE data indicate strong interaction of the fluorite-
forming fluids with the host rocks as well as variable redox
parameters. Hydrothermal alteration led to leaching of rare
paleomagnetic dating of the most important hydrothermal flu-
orite-bearing event at Rakice are also in agreement with the
proposed Cenozoic timing. Approximately 90 % of the rema-
nent magnetization intensity of the hydrothermally altered
host rocks is bound to a compound whose orientation refers to
a Tertiary age (Dolníèek & Chadima 2004).
Although layers of the acidic vitric tuffs and tuffites are
known to occur within the Tertiary sedimentary fill of the Car-
pathian Foredeep and Vienna Basin (Krystek 1959; Zádrapa
1988), their source is believed to be in the volcanic areas be-
longing to the Inner or Central Western Carpathians. No other
indications of Cenozoic volcanic activity are reported in a
wider region. Therefore, a fluid migration mechanism not re-
lated to the Tertiary volcanism must have been involved in the
formation of the Cenozoic Brunovistulian fluorites. Most
probably, mainly tectonically driven fluid migration related to
the latest stages of the Alpine Orogeny may have taken place
on the eastern margin of the Bohemian Massif. Especially the
most frequent NWSE trending regional faults (Fig. 1) could
act as important pathways allowing influx of the Carpathian
fluids into the Brunovistulian foreland.
Cenozoic fluorite mineralizations originating from low-tem-
perature, low-saline fluids are uncommon worldwide. Howev-
er, on the basis of their geological setting, two subtypes could
be distinguished. The first one comprises mineralizations spa-
tially and genetically related to young basic riftogenic volca-
176 DOLNÍÈEK
earths, calcium, and probably also fluorine from the grani-
toids, allowing the precipitation of fluorite under suitable con-
ditions.
2. The mineral composition as well as formation conditions
of the studied Brunovistulian fluorites are comparable with
those of Cenozoic fluorite mineralizations in Northern Bohe-
mia and elsewhere in the world.
3. Formation waters within Carpathian Foredeep and Vien-
na Basin, immediately neighbouring and covering the studied
area, may have been the source of the parent fluid on the east-
ern margin of the Bohemian Massif.
4. Due to a common lack of Cenozoic volcanic activity in
the studied area, a tectonically driven fluid flow during the fi-
nal stages of the Alpine Orogeny in the Western Carpathians
may be responsible for formation of the Cenozoic Brunovistu-
lian fluorites.
Acknowledgments: I. Jaèková, J. Hladíková and K. Malý
(Czech Geological Survey, Prague) are gratefully acknowl-
edged for the isotope analyses. J. Zachariá (Charles Universi-
ty, Prague) and J. Leichmann (Masaryk University, Brno) are
thanked for access to heating-freezing stage and CL micro-
scope, respectively. S. Houzar (Moravian Museum, Brno) and
M. Slobodník (Masaryk University, Brno) provided samples
today hardly accessible in the field. Valuable comments by
Profs. B. Fojt, M. Novák, M. Slobodník and J. Zimák as well
as those by three journal reviewers (Profs. V. Hurai, M. Slo-
bodník and dr. P. Uher) helped to improve the initial draft of
the manuscript.
References
Anders E. & Grevesse N. 1989: Abundances of the elements: Mete-
oritic and solar. Geochim. Cosmochim. Acta 53, 197214.
Bernard J.H., Èech F., Dávidová ., Dudek A., Fediuk F., Hovorka
D., Kettner R., Kodìra M., Kopecký L., Nìmec D., Padìra K.,
Petránek J., Sekanina J., Stanìk J. & ímová M. 1981: Mineral-
ogy of the Czechoslovakia, 2
nd
edition. Academia, Praha, 1
615 (in Czech).
Bodnar R.J. 1993: Revised equation and table for determining the
freezing point depression of H
2
O-NaCl solutions. Geochim.
Cosmochim. Acta 57, 683684.
Burkart E. 1953: Mährens Minerale und ihre Literatur. Nakl. ÈSAV,
Praha, 11006.
Buzek F. & Michalíèek M. 1997: Origin of the formation waters of
S-E parts of the Bohemian Massif and Vienna Basin. Appl.
Geoch. 12, 333343.
Cunningham C.G., Rasmussen J.D., Stevens T.A., Rye R.O., Row-
ley P.D., Romberger S.B. & Selverstone J. 1998: Hydrothermal
uranium deposits containing molybdenum and fluorite in the
Marysvale volcanic field, west-central Utah. Mineralium De-
pos. 33, 477494.
Èadek J., Beneová Z., Buzek F., Fengl M., Hladíková J., Jansa J.,
Legierski J., Majer V., Mikovská J., Novák F., Reichmann F.,
mejkal V., Vavøín I. & Veselý J. 1981: Genetic conditions of
origin of the fluorite deposits. MS Czech Geol. Surv., Prague,
171 (in Czech).
Èadek J., Kaèura J. & Malkovský M. 1964: Occurrence of the fluorite
in the surroundings of the Teplice Spa in the Bohemia and its
genesis. Sbor. Geol. Vìd, Lo. Geol. Mineral. 3, 741 (in Czech).
Èeková L. 1975: Hydrothermal mineralization in the Brno massif.
Scripta Fac. Sci. Nat. UJEP Brunensis, Geol. 1, 5, 3542 (in
Czech).
Èeková L. 1978: Metalogenetic characteristics of some geological
units at the eastern margin of the Bohemian massif. Folia Fak.
Sci. Nat. Univ. Purk. brun., Geol. 19, 5101 (in Czech).
Èeková L. 1985: Metalogenesis of the crystalline complexes at the
SE margin of the Bohemian massif. MS J.E. Purkynì Universi-
ty, Brno, 1125 (in Czech).
Dolníèek Z. 2001a: Mineralogy of the barite veins from Kvìtnice
Hill near Tinov. Acta Mus. Moraviae, Sci. Geol. 86, 5973 (in
Czech).
Dolníèek Z. 2001b: Origin of the neoidic fluorite mineralization in
the Brno massif, Czech Republic: Cathodoluminescence, REE,
fluid inclusion and stable isotope study. Mitt. Österr. Mineral.
Gesell. 146, 6768.
Dolníèek Z. & Chadima M. 2004: Palaeomagnetic evidence for
Neoidic age of the fluorite mineralization from Rakice (Brno
massif). In: Rojkoviè I. (Ed.): Mineralogy of the Western Car-
pathians and Bohemian Massif 2004. Komenský University,
Bratislava, 2124 (in Czech).
Dolníèek Z., Chadima M. & Pruner P. 2003: Age determination of
the barite veins from Tinov using the palaeomagnetic method.
In: Zimák J. (Ed.): Mineralogy of the Bohemian Massif and
Western Carpathians 2003. Palacký University, Olomouc, 49
(in Czech).
Dolníèek Z. & Malý K. 2003: Mineralogy and genesis of the epither-
mal veins from the quarry in Dolní Louèky near Tinov. Acta
Mus. Moraviae, Sci. Geol. 88, 149166 (in Czech).
Dudek A. 1980: The crystalline basement block of the Outer Car-
pathians in Moravia: Bruno-Vistulicum. Rozpr. Ès. Akad. Vìd,
Ø. mat. pøír. Vìd 90, 180.
Dykyj J., Hemala M., Roubal M. & Vlasáková L. 1953: The physi-
co-chemical tables, part 1. SNTL, Prague, 1680 (in Czech).
Friedman I. & ONeil J.R. 1977: Compilation of stable isotope frac-
tionation factors of geochemical interest. U.S. Geol. Surv. Prof.
Pap. 440-KK, 149.
Götzinger M.A. 1993: Three different types of fluorite mineraliza-
tions, characterized by geological setting and fluid inclusions,
in weakly metamorphosed sedimentary rocks in the Alps, Aus-
tria. Final Meeting of IGCP Project No. 291 Metamorphic flu-
ids and mineral deposits, Prague, July 1213, 1993, 2122.
Götzinger M.A. & Seemann R. 1990: Exkursion E3: Fluoritvorkom-
men Vorderkrimml, Pinzgau, Salzburg. Mitt. Österr. Mineral.
Gesell. 135, 119128.
Hanl P. & Melichar R. 1997: The Brno massif: A section through
the active continental margin or a composed terrane? Krystalin-
ikum 23, 3358.
Hill G.T., Campbell A.R. & Kyle Ph.R. 2000: Geochemistry of
southwestern New Mexico fluorite occurrences: implications
for precious metals exploration in the fluorite-bearing systems.
J. Geoch. Explor. 68, 120.
Hoefs J. 1997: Stable isotope geochemistry. 4
th
edition. Springer
Verlag, Berlin-New York, 1201.
Kalvoda J., Melichar R., Bábek O. & Leichmann J. 2002: Late Prot-
erozoicPaleozoic tectonostratigraphic development and paleo-
geography of Brunovistulian terrane and comparison with other
terranes at the SE margin of Baltica-Laurussia. J. Czech Geol.
Soc. 47, 81102.
Koláøová M. 1981: Hydrogeological criteria of the prospection for
hydrocarbons in the Carpathian Foredeep and Flysch Belt in
the Czechoslovak part of the West Carpathians. Sbor. Geol.
Vìd, Lo. Geol. Mineral. 22, 89157 (in Czech).
Krystek I. 1959: Petrography of the tuffitic rocks from the Vienna
basin. Geol. Práce, Zoit 54, 127144 (in Czech).
Lee S.-G., Lee D.-H., Kim Y., Chae B.-G., Kim W.-Y. & Woo N.-
Ch. 2003: Rare earth elements as indicators of groundwater en-
CENOZOIC FLUORITE MINERALIZATION FROM THE BRUNOVISTULICUM 177
vironment changes in a fractured rock system: evidence from
fracture-filling calcite. Appl. Geoch. 18, 135143.
Leichmann J., Novák M. & Sulovský P. 1999: Peraluminous whole-
rock chemistry versus peralkaline mineralogy of highly frac-
tionated garnet-bearing granites from the Brno Batholith. Ber.
Dtsch. Mineral. Gesell. 11, 1144.
Matsuhisa Y., Morishita Y. & Sato T. 1985: Oxygen and carbon iso-
tope variations in gold-bearing hydrothermal veins in the Kush-
ikino mining area, southern Kyushu, Japan. Econ. Geol. 80,
283293.
McLennan S.M. 1989: Rare earth elements in sedimentary rocks: in-
fluence of provenance and sedimentary processes. Rev. in Min-
eralogy 21, 169200.
Melichar R. & paèek P. 1995: New fluorite locality in the vicinity
of Rakice SSW of Brno and the significance of fluorite miner-
alization for the Brno massif tectonics. Geol. Výzk. Mor. Slez.
v r. 1994, 2, 98100 (in Czech).
Michalíèek M. 1978: Hydrogeochemical study of the southern part
of the Carpathian Foredeep and the Outer Carpathians in Mora-
via for oil and gas prospection purposes. Sbor. Geol. Vìd, Lo.
Geol. Mineral. 19, 3587 (in Czech).
Mitrenga P. & Rejl L. 1993: The Brno massif. In: Pøichystal A., Ob-
stová V. & Suk M. (Eds.): Geology of the Moravia and Silesia.
Moravian Museum and Masaryk University, Brno, 913 (in
Czech).
Monecke T., Kempe U., Monecke J., Sala M. & Wolf D. 2002: Tet-
rad effect in rare earth element distribution patterns: A method
of quantification with application to rock and mineral samples
from granite-related rare metal deposits. Geochim. Cosmochim.
Acta 66, 11851196.
Ohmoto H. & Goldhaber M. B. 1997: Sulfur and carbon isotopes. In:
Barnes H.L. (Ed.): Geochemistry of hydrothermal ore deposits.
3
rd
edition. J. Wiley & Sons, New York, 517611.
ONeil J.R., Clayton R.N. & Mayeda T.K. 1969: Oxygen isotope
fractionation in divalent metal carbonates. J. Chem. Phys. 51 ,
55475558.
Rimstidt J.D. 1997: Gangue mineral transport and deposition. In:
Barnes H.L. (Ed.): Geochemistry of hydrothermal ore deposits.
3
rd
edition. J. Wiley & Sons, New York, 487515.
Shepherd T.J., Rankin A.H. & Alderton D.H.M. 1985: A practical
guide to fluid inclusion studies. Blackie, Glasgow and London,
1240.
Sheppard S.M.F. 1986: Characterization and isotopic variations in
natural waters. Rev. in Mineralogy 16, 165183.
Slobodník M., Dolníèek Z. & Leichmann J. 2000: Genetic aspects of
the fluorite mineralization from Rakice in the Brno massif.
Geol. Výzk. Mor. Slez. v r. 1999, 7, 132134 (in Czech).
Zádrapa M. 1988: Presence of the volcanoclastic sediments within
the Carpathian Formation in the area of dánice elevation.
Zemní Plyn Nafta 33, 323331 (in Czech).
ák K., Èadek J., Dobe P., mejkal V., Reichmann F., Vokurka K.
& Sandstat J.S. 1990: Vein barite mineralization of the Bohe-
mian massif: sulfur, oxygen and strontium isotopes and fluid
inclusion characteristics and their genetic implications. In: Do-
be P. & Poole F.G. (Eds.): Proceedings of the symposium on
barite and barite deposits. Czech Geol. Surv., Prague, 3549.