K/Ar DATING OF THE MIOCENE POTASH SALTS OF THE CARPATHIAN FOREDEEP 243
GEOLOGICA CARPATHICA, 54, 4, BRATISLAVA, AUGUST 2003
243249
K/Ar DATING OF THE MIOCENE POTASH SALTS
OF THE CARPATHIAN FOREDEEP (WEST UKRAINE): APPLICATION
TO DATING OF TECTONIC EVENTS
ARTUR WÓJTOWICZ
1,2
, SOFIYA P. HRYNIV
3/
, TADEUSZ MAREK PERYT
1
*, ANDRIY BUBNIAK
3
.
,
IHOR BUBNIAK
3
.
and PETRO M. BILONIZHKA
4
1
Polish Geological Institute, Rakowiecka 4, 00-975 Warszawa, Poland
2
Mass Spectrometry Laboratory, Institute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin,
Poland; wujek@tytan.umcs.lublin.pl
3
Institute of Geology and Geochemistry, National Academy of Sciences of Ukraine, Naukova 3a, 79053 Lviv, Ukraine;
/
igggk@ah.ipm.lviv.ua;
.
bubniak@franko.lviv.ua
4
Faculty of Geology, Lviv University, Hrushevskieho 4, 79005 Lviv, Ukraine
*Corresponding author: tperyt@pgi.waw.pl; Tel: +48-22-8495351; Fax: + 48-22-8495342
(Manuscript received April 16, 2002; accepted in revised form March 11, 2003)
Abstract: K/Ar dating of the potassium-magnesium sulphate minerals (langbeinite, polyhalite, and kainite) from Mi-
ocene evaporites of different stratigraphic formations and tectonic zones of the Carpathian Foredeep provides evidence
that they have recrystallized at roughly the same time, and thus the ages of those minerals differ from the age of the
hosting formations. The age of langbeinite from the Stebnyk mine (the host formation in Lower Miocene) indicates the
recrystallization in the Middle Miocene (13.6314.65 Ma), and the same age of langbeinite from the Kalush mine indi-
cates that the host formation (the age of which is uncertain) is older than the Tyras Suite (which belongs to the NN6
Zone). The recrystallization was a response to three major tectonic events which affected the area: (1) beginning of the
Carpathian nappe overthrusting in Ukraine (overthrust of the Outer Western Carpathians on the Carpathian Foredeep
and of the Boryslav-Pokuttya and Sambir Zones on the Bilche-Volytsa Zone) and the related overheating, dated at 13.6
14.6 Ma; (2) final stage of overthrusting, origin of faults transverse to the Carpathian overthrust (11.412.6 Ma); (3)
neotectonic movements and uplift (7.29.9 Ma). Thus, the evaporite minerals can be used to date the tectonic events in
the regions of complex geological structure.
Key words: Miocene, Carpathians, geochronology, evaporites, langbeinite, argon.
Introduction
Evaporite minerals often continue to act as open systems dur-
ing diagenesis and thus dating of evaporite deposits on the ba-
sis of ratios of radioactive elements and their daughter iso-
topes fails in some cases (Sonnenfeld 1984). The closure
temperature of the potassium-magnesium sulphate mineral
langbeinite is about 250 °C (Lippolt & Weigel 1988) and
thus this mineral is a potentially suitable K-Ar geochronome-
ter. K-Ar and
40
Ar/
39
Ar methods were successfully applied to
date the precipitation and recrystallization stages of Permian
langbeinites in the Zechstein of Germany (Pilot & Blank
1967; Lippolt et al. 1993) and the Salado Formation of New
Mexico, USA (Renne et al. 2001).
Deposits of potash salt in the Miocene of the Carpathian
Foredeep of Ukraine and Romania often contain langbeinite
(Vysotskiy et al. 1988; Stoica & Gherasie 1981). The K-Ar
dating of langbeinite from the Stebnyk mine (Ukraine) yield-
ed the following results: 14.1±0.5 Ma (1
σ
) (Halas et al.
1996), 15.28±0.11 and 15.31±0.30 Ma (Peryt et al. 1996),
and 11.5 Ma (Khrushchov & Zaydis 1978) although low K
content (7.85 %) in the last case suggests an impure langbein-
ite. The step-heating
40
Ar/
39
Ar laser dating on four langbeinite
single grains from the Stebnyk mine yielded very clustered
ages, including a high plateau age of 14.31±0.06 Ma (Léost et
al. 2001). The langbeinite from the Kalush mine yielded the
age of 13.5±0.1 Ma (Halas et al. 1996). The K-Ar dating of
polyhalite from Stebnyk gave the age of 5.7 Ma (Krushchov
& Zaydis 1978) and 12.38±0.1 Ma (Peryt et al. 1996) and
from Kalush 6.2±0.08 Ma (Peryt et al. 1996), 7.5 Ma
(Khrushchov & Zaydis 1978), and 10.5±0.1 Ma (Halas et al.
1996). In addition, 6 samples from clayey polyhalite gave
considerably older ages (22.961.3 Ma) (Halas et al. 1996;
Peryt et al. 1996), except for one sample (12.84±0.06 Ma),
because the disseminated clay material was considerably older
(Bilonizhka & Kostin 1977). The K-Ar dating of kainite from
Kalush yielded the age of 7.8±0.2 Ma (Halas et al. 1996).
The Miocene Carpathian foreland basin has been strongly
affected by the overthrusting Carpathians, which resulted in
deformation of the molasse sequence (Vyalov 1965), and
hence the stratigraphic position of potash evaporites, especial-
ly those occurring in the Kalush mine, is subject to controver-
sies (e.g., Vyalov 1965; Korenevskiy et al. 1977; Gurzhiy
1969; Dzhinoridze 1980; Khrushchov 1980; Koriñ 1994). In
addition, due to the diagenetic-metamorphic processes, which
affected the potash evaporites in the Carpathian Foredeep in
244 WÓJTOWICZ et al.
response to the Carpathian nappe overthrusting (Dzhinoridze
1980), those ages may indicate the time of (re)crystallization
of langbeinite, which can be different from the age of the
langbeinite-bearing formations (cf. Léost et al. 2001).
Except for langbeinite, nine other evaporite minerals that
occur in the Miocene of the Ukrainian part of the Carpathian
Foredeep contain potassium and thus can be used for K-Ar ra-
diometric dating. We have studied samples of compound po-
tassium sulphates: langbeinite, kainite, polyhalite, leonite,
syngenite, and picromerite. Chlorides (sylvite and carnallite)
have not been studied due to a methodological reason (too
high chlorine content).
Geological setting
The Carpathian Foredeep Basin was formed in the early Mi-
ocene northeast of the overthrusting Carpathian nappes. It is
filled with Miocene deposits more than 3000 m thick in the
area adjacent to the Carpathians (Vyalov et al. 1981; Kruglov
et al. 1988). In the Ukrainian part of the foredeep, three tec-
tonic zones are distinguished: outer (Bilche-Volytsa), central
(Sambir Nappe thrusted over the foreland) and inner (Bo-
ryslav-Pokuttya Nappe, thrusted over the Sambir Nappe and
the underlying foreland). The Stebnyk potash deposit is locat-
ed in the latter zone, near the front of the overthrusted Car-
pathian nappes, and the Kalush potash deposit is located in
the Sambir Nappe (Fig. 1).
Because of such a geological location, the stratigraphic sec-
tion is likely to be repeated. The potash deposit in the Stebnyk
mine is part of the Vorotyshcha Suite
1
(Fig. 2). The suite
is composed of three members: lower salt-bearing, middle ter-
rigenous and upper salt-bearing ones, with a total thickness of
more than 2000 m (Petryczenko et al. 1994). New data on pot-
ash layers (Koriñ 1994) in the Stebnyk mine showed that upper
and lower salt-bearing members belong to the same suite,
and the terrigenous member separating them is an olistostrome.
The real total thickness of deposits is thus 100125 m, and the
occurrence of multiple potash layers and the great visible
thickness of the suite are the result of intensive overthrust
tectonics (Koriñ 1994; Peryt & Kovalevich 1997). This inter-
pretation assumes that there is only one potash horizon in the
middle part of the suite. Above and below this horizon, rela-
tively thick salt breccias and massive rock salts are present.
The most common minerals of the potash horizon are kainite
and langbeinite. Chlorides (sylvite and carnallite) are usually
noticed in the underlying salt breccias. The mineralogical com-
position of different parts of potash deposits varies consider-
ably (Kovalevich 1978), but the bulk chemical composition is
constant. There is a relation of mineral composition of potash
layers and the intensity of tectonic deformations (Koriñ 1994).
In the most strained parts the langbeinite prevails, and in the
slightly strained the kainite does. In the fault zones, trans-
versal to the Carpathian overthrust direction, where the potash
salt beds disappear, red polyhalite-bearing rocks occur. Poly-
halite beds (515 cm thick) are present at the base and the top
of the potash complex and they are described as polyhalite-an-
hydrite beds. The Vorotyshcha Suite is of Eggenburgian age
(Korenevskiy et al. 1977; Andreyeva-Grigorovich et al. 1997)
(Fig. 2).
The lithostratigraphic and chronostratigraphic position of
the evaporite deposits in the Kalush mine is subject to contro-
versies. The potash-bearing sequence consists of interbedded
salt claystones, breccias, potash and rock salt, gypsum and an-
hydrite, up to 500 m thick (Petryczenko et al. 1994). These de-
posits have been regarded as belonging to the upper member of
the Stebnyk Suite (Korenevskiy et al. 1977; Glushko 1968)
of Ottnangian (Klimov 1968) or Badenian age (Khrushchov
1980), Balych Suite of Karpatian age (cf. Blagovidov et al.
1977), Dombrovo Suite (Dzhinoridze 1973) and Kalush
Beds that are counterparts of the Badenian Tyras Suite
(Dzhinoridze 1980). The Badenian age is supported by the
study of calcareous nannoplankton assemblages suggesting
that the evaporites in the Kalush deposit belong to the NN6
Zone (Andreyeva-Grigorovich et al. 1999), similar to the Bad-
enian evaporites of Poland (D. Peryt 1997, 1999).
The present structure of the Kalush deposit is complex, but it
seems that during sedimentation in a saline basin only two
beds of potash salts were formed: the lower chloride and upper
sulphate (Dzhinoridze 1973; Griniw 1994). The major rock-
forming minerals of the potash deposits are halite, langbeinite,
and kainite. Kieserite, polyhalite, anhydrite, sylvite, and car-
nallite are present in smaller quantities. The potash salts form a
langbeinite-kainite genetic row (Khodkova 1971).
Langbeinite is considered to be syndepositional (Lobanova
1956) or early diagenetic (Valyashko 1962; Khodkova 1968),
and kainite syndepositional (Lobanova 1956), syndepositional
and early diagenetic (Valyashko 1962), or secondary (Khodko-
va 1968). Study of fluid inclusions in tetrahedral crystals of
Fig. 1. The Carpathian Foredeep in Ukraine and the location of
the Stebnyk and Kalush mines.
1
Instead of formation, the term suite is applied, which is more consistent with its poorly defined and complex stratigraphy.
K/Ar DATING OF THE MIOCENE POTASH SALTS OF THE CARPATHIAN FOREDEEP 245
langbeinite from the Stebnyk and Kalush mines indicated that
the inclusions originated at the temperature from 56 to 77 °C
(70 °C on average; Kovalevich 1982). This, together with the
paragenesis of langbeinite crystals and transparent, coarse
crystalline halite suggests that the langbeinite originated as a
result of recrystallization of primary minerals at increased
temperature and pressure (Kovalevich 1982). It seems that the
primary deposited minerals were halite, epsomite, sylvine,
hexahydrite, and carnallite. Subsequently, in hot brines with
temperature >55 °C langbeinite, kieserite, polyhalite, kainite
and some other minerals have formed (Kovalevich 1978). Lat-
er, due to the increased temperature and pressure, dehydration
and transformation of metastable minerals into stable ones oc-
curred (Kovalevich 1978).
Material and methods
In the Miocene potash formations of the Carpathian Fore-
deep, langbeinite occurs in the form of langbeinite rock which
contains small admixtures of halite, polyhalite and clay mate-
rial (Lobanova 1956). When langbeinite is replaced by kain-
ite, kainite-langbeinite rock is formed, and sylvite and
kieserite are practically lacking. In the composite kainite-
langbeinite rock also kieserite, sylvine, halite and insoluble
residue are the main constituents, exceeding 10 vol. %. This
rock exhibits characteristic breccia-type texture.
Kainite rock is the most common potash rock in the Ukrai-
nian part of the Carpathian Foredeep. Kainite may fill the
veins in the salt-bearing breccias and potash deposits. Leonite
fills the veins in kainite-bearing rock. Polyhalite occurs in
several lithological types: polyhalite-anhydrite beds (a few to
30 cm thick that occur in the salt-bearing breccias, usually a
few tens of centimeters from the potash bed) (Griniw 1994)
and red polyhalite rock (occurring within potash bed). Pi-
cromerite and syngenite are minerals of the weathering zone
and occur in the lower part of the caprock.
The samples of potash salts were crushed and sieved. The
fraction of 0.30.5 mm was divided for analysis of potassium
content by the XRF method and for the radiogenic argon con-
tent by means of the static-vacuum mass spectrometry. The
determination of the potassium content was made in the Cen-
tral Chemical Laboratory, Polish Geological Institute on the
Philips PW 2400 spectrometer. The standard error (1
σ
) was
0.5 %. The determination of the radiogenic argon content was
made in the Mass Spectrometry Laboratory, Institute of Phys-
Fig. 2. Chronostratigraphy (after Rögl 1996; Vakarcs et al. 1998; Steininger & Wessely 2000) and lithostratigraphy (after Petryczenko et
al. 1994) of the Miocene in the Ukrainian part of the Carpathian Foredeep.
246 WÓJTOWICZ et al.
ics, Lublin University, using the internal spike method (see
e.g., Dalrymple & Lanphere 1969) and the modified MS-10
spectrometer. The backing of the line was performed over-
night at the temperature of 100 °C. Aliquots of about 50 mg
were melted in the double-vacuum crucible of the argon ex-
traction-purification line (see Staudacher et al. 1978) and
spiked with pure argon-38 (
38
Ar/
36
Ar>100000;
38
Ar/
40
Ar>
10000) produced by the Institute for Inorganic and Physical
Chemistry, University of Bern. The content of atmospheric ar-
gon was determined by measurement of the argon-36 peak in
the mass spectrum. The mass discrimination of the mass spec-
trometer is not determined, but because we use international
standards (as for example MMhb-1 see Samson & Alex-
ander, Jr. 1987) to calibrate the amount of the spike, the mass
discrimination errors are eliminated.
In the case of kainite, which contains chlorine in its struc-
ture, the H
35
Cl
+
ions can possibly interfere with argon-36. The
following test was made to check such a possibility. Peak
mass 36 was recorded repeatedly after gas admission into the
mass spectrometer chamber. At the beginning of measure-
ments the peak 36 was high due to presence of H
35
Cl
+
ions.
However over about 30 minutes its value was reduced to a
constant level by the action of the sorption pump which
cleaned argon from reactive gases. Therefore, the results of
the argon determination in kainite samples are reliable in spite
of the relatively high chlorine content.
The purity of analysed samples was verified by the immer-
sion method. The samples containing more than 1 % of clastic
material were disregarded. The maximum concentration of ra-
diogenic argon from clay minerals in salts samples was calcu-
lated after Bilonizhka & Kostin (1977). Assuming 1 % of
clastic material in the sample, 3 % K in this material, and its
age of 200 Ma one may obtain 8 pmol/g of radiogenic argon.
It gives an apparent increase of age of 0.40 Ma for a salt sam-
ple containing 15 % K.
Results and interpretation
Langbeinite. Most (11) analysed samples gave ages within
the range of 13.615.9 Ma, and only 2 samples taken from the
kainite-langbeinite rock gave younger ages (Table 1). There
are no essential differences between the Stebnyk and Kalush
deposits, although the data for three samples from Stebnyk
(including two samples studied earlier Peryt et al. 1996)
are older than 15 Ma.
The principle of mineral succession in an evaporite basin
indicates that langbeinite forms during early diagenesis by re-
actions of sylvite and hexahydrite or kainite and hexahydrite
precipitated from brine (Valyashko 1962). Accordingly, early
diagenetic langbeinite from Kalush and Stebnyk should give
different ages as the Stebnyk potash rocks are older than the
Kalush potash deposits (despite the controversies related to
the stratigraphic position of the Kalush rocks). This is not the
case and thus it is possible that langbeinite is diagenetic in ori-
gin and was transformed under the influence of strong ther-
modynamic factors related to the tectonic evolution of the
area (Dzhinoridze 1980). At that time, in addition to recrystal-
lization, langbeinite has formed de novo. During the thrusting
and related folding of evaporite deposits, buried brines have
migrated into the axial part of the forming anticlines because
of smaller pressure there, and the langbeinite crystallized (Ko-
riñ 1994). The transformation was induced by the compres-
sional overthrust tectonics, which dominated in the northern
and eastern part of the Carpathians front during the Middle
Miocene (Kováè et al. 1998) and resulted in the telescopic
shortening of the Carpathian nappes and the shift of the thrust
belt by 2030 km towards the NE (Oszczypko 1997). Those
tectonic events have been accompanied by increase in temper-
ature and pressure.
Polyhalite. Polyhalite from the red polyhalite rock (6 sam-
ples) gave the age of 8.314.7 Ma, and four of the analyses
fall into the interval between 11.412.6 Ma (Table 1). Poly-
halite from polyhalite-anhydrite beds shows slightly younger
ages (5.712.3 Ma) (9 samples). The younger ages are related
to thicker beds characterized by zoned occurrence of polyhali-
te and anhydrite, what indicates formation in several stages.
Kainite. The ages for kainite are within the 7.29.9 Ma in-
terval (11 samples; Table 1). One result published earlier
(Halas et al. 1996) falls within this range (7.8 Ma). The ages
for 2 kainite samples from the vein fillings in clay or salt brec-
cia are younger than one could expect (4.43 and 6.14 Ma).
Except for one sample (No. 79), all other kainite samples were
taken from the Kalush deposit. The results indicate that all
samples represent secondary kainite. However, its origin was
influenced by buried brines. This is supported by the bromine
content typical of kainite originating during the process of
seawater evaporation (Bilonizhka 1964). The kainite is clearly
younger than langbeinite, owing to instability of kainite struc-
ture (Bilonizhka 2001). Accordingly, the changes of PT con-
ditions, which occurred 710 Ma ago, resulted in the recrys-
tallization of kainite, but did not influence the langbeinite.
Leonite, picromerite, and syngenite. Two samples of leo-
nite taken from veins gave low ages (3.64 and 2.95 Ma). Very
young ages of picromerite and syngenite were expected and
confirmed by radiometric dating (Table 1).
Discussion
The Early Miocene Eggenburgian age of the Vorotyshcha
Suite hosting the Stebnyk evaporites is supported by the mi-
cropaleontological data (Andreyeva-Grigorovich et al. 1997).
The langbeinite from Stebnyk shows the ages significantly
younger than the Early Miocene, which clearly indicates re-
crystallization in the Middle Miocene (cf. Léost et al. 2001).
The clustered data on langbeinite in Stebnyk (as well as in
Kalush) indicate that the temperature of ca. 70
o
C derived
from fluid inclusions (Kovalevich 1982) had a regional char-
acter and afterwards these conditions did not occur; otherwise
langbeinite would recrystallize.
The chronostratigraphic correlation of the Miocene in the
Central Paratethys with the Mediterranean stages and biozo-
nations is uncertain (Berger 1992). This especially pertains to
the NN6. Recent correlations suggest the age of the NN5/NN6
boundary at 13.6 Ma (Rögl 1996; Vakarcs et al. 1998; Stein-
inger & Wessely 2000). The Badenian evaporites in Poland
(D. Peryt 1997, 1999) and Romania (Mãrunþeanu 1999) occur
K/Ar DATING OF THE MIOCENE POTASH SALTS OF THE CARPATHIAN FOREDEEP 247
in the NN6 Zone, close to the NN5/NN6 boundary, so the
much older ages of the Kalush langbeinites are puzzling.
There are two possible explanations. The first possibility is
that the strata hosting the Kalush potash evaporites are of
Badenian age, and thus the Badenian evaporites in the Car-
pathian Foredeep are older than recently assumed. The second
possibility is that the strata hosting the Kalush potash evapor-
ites are older than Badenian.
The assumption that the Kalush potash deposits are of Bad-
enian age is in contrast to what is known about a relatively
low concentration of brines during the precipitation of Bade-
nian halite in the entire Carpathian Foredeep Basin (Ko-
renevskiy et al. 1977; Galamay 1997). The only exception is
the occurrence of potash salts in one borehole in the Roma-
nian part of the Carpathian Foredeep Basin in the upper salt-
bearing formation the counterpart of the Tyras Suite
(Stoica & Gherasie 1981).
Accordingly, geochemical arguments and radiometric data
suggest the third evaporite formation represented by the
Kalush potash salts in the Carpathian Foredeep. This forma-
tion is older than the Tyras and younger than the Vorotyshcha
formations. Although the age of that formation remains uncer-
tain, it is possible that the Kalush deposit can represent Karpa-
tian evaporites that occur in Carpathian Foredeep basin in ad-
dition to the Eggenburgian and Badenian evaporites.
The K/Ar dating of the Miocene potash salts of the Car-
pathian Foredeep in the West Ukraine provides information
on the timing of tectonic processes in the Outer Ukrainian
Carpathians and their foredeep. The accretionary wedge of the
Ukrainian Carpathians and their foredeep is the result of the
thrusting during Tertiary tectonic events. Three main phases
of the thrusting were recognized in the Ukrainian Carpathian
region (Sãndulescu 1988). The first Carpathian thrusting oc-
curred during the earliest MioceneEgerianEggenburgian
Table 1: Characteristics of samples and results of radiometric dating. K kainite rock, KL kainite-langbeinite rock, L langbeinite
rock, P polymineral kainite-langbeinite rock.
Sample
number
Location
Host rock
Sample description
K
[%]
%
40
Ar
rad
40
Ar
rad
±
1ó
[pmol/g]
Age
±
1ó
[Ma]
Langbeinite
2048
Stebnyk
L
rouge, coarse crystalline
18.46
85.6
446.6±2.7
13.90±0.11
543
Stebnyk
L
rouge with light grey shade, coarse crystalline
18.36
86.3
466.2±2.6
14.59±0.11
143
Stebnyk, Bed 16
L
rouge, coarse crystalline
18.41
85.0
457.6±2.7
14.28±0.11
S1
Stebnyk
claystone
tetrahedron
19.13
82.7
467.3±3.2
14.03±0.12
SN
Stebnyk
P
rouge
18.62
91.7
516.7±1.4
15.93±0.09
SN2
Stebnyk
P
rouge
18.39
90.4
465.1±1.7
14.53±0.09
156
Kalush Dombrowo quarry
L
rouge, coarse crystalline
18.34
85.3
467.7±2.6
14.65±0.11
22
Kalush, New Holyn Mine
L
rouge with light grey shade, coarse crystalline
16.95
80.0
418.1±3.6
14.17±0.14
K1
Kalush Dombrowo quarry
L
rouge, coarse crystalline
18.75
87.3
444.9±2.4
13.63±0.10
1114
Kalush Dombrowo quarry
L
rouge, coarse crystalline
19.20
90.2
468.7±1.9
14.02±0.09
AR
Kalush Dombrowo quarry
L
rouge, coarse crystalline
18.78
85.6
454.1±2.4
13.89±0.10
LL
Kalush Dombrowo quarry
KL
light rouge
17.92
76.8
299.4±2.7
9.61±0.10
K2
Kalush Dombrowo quarry
KL
rouge with light grey shade
19.09
74.6
193.4±1.7
5.83±0.06
Kainite
79
Stebnyk, Bed Zygmunt, cross-cut 88/3
vein in salt breccia
dark with rouge shade, fibrous veins
17.38
53.1
133.8±2.3
4.43±0.08
14
Kalush Dombrowo quarry
P
honey yellow, grainy-fibrous, lamina
14.52
64.7
186.5±2.6
7.39±0.11
10-D
Kalush Dombrowo quarry
KL
yellow, fine crystalline
14.19
74.6
218.9±2.5
8.87±0.11
2024
Kalush, Holyn Mine, East Field
KL
grey-yellow, fine crystalline
14.10
66.6
175.7±2.3
7.22±0.10
240
Kalush, Central Field
K
fine crystalline, light grey
12.98
62.7
164.7±2.6
7.30±0.12
2210
Kalush, Dombrowo quarry, level +205
claystone and rock salt
honey yellow from lenses
12.84
39.7
173.8±3.0
7.79±0.14
2209
Kalush, Dombrowo quarry, level +205
P
honey yellow, pseudomorphs after langbeinite
12.84
24.2
163.9±4.4
7.35±0.20
2192
Kalush, Holyn Mine, level+140, bed LK-1/2
fissure in claystone above K
yellow
11.25
58.1
120.0±2.1
6.14±0.11
D1
Kalush Dombrowo quarry
K
yellow
15.16
78.1
252.5±2.3
9.58±0.10
D2
Kalush Dombrowo quarry
K
yellow
13.33
74.6
221.1±2.6
9.54±0.12
D3
Kalush Dombrowo quarry
K
yellow
14.00
59.5
181.9±2.8
7.48±0.12
D4
Kalush Dombrowo quarry
K
yellow
14.46
79.1
248.8±2.2
9.90±0.10
D5
Kalush Dombrowo quarry
K
yellow
10.80
65.7
170.8±2.5
9.10±0.14
Leonite
170
Stebnyk
salt breccia
yellow, fine crystalline, vein
20.02
54.1
126.6±2.0
3.64±0.06
R1
Stebnyk, Mine 1, Bed 15, level 2
fissure (a few cm wide) in salt breccia
leonite vein with epsomite
19.55
53.8
100.0±1.6
2.95±0.05
Picromerite
PK1
Kalush Dombrowo quarry
caprock
crystal
19.85
1.3
1.3±1.6
0.04±0.05
Syngenite
SY1
Kalush Dombrowo quarry
caprock
crystal
24.02
1.9
2.8±2.1
0.07±0.05
Polyhalite
2201
Stebnyk, Bed 15, level 2 (+183 m)
12.47
59.9
123.5±2.1
5.70±0.10
2202
Stebnyk, Bed 13, level 2 (+180 m)
12.57
61.0
149.5±2.3
6.85±0.11
A-1
Stebnyk
13.09
82.8
280.5±2.3
12.30±0.12
2237
Rossilna, borehole 943 [Vorotyshcha Suite]
12.52
69.5
239.6±3.0
11.01±0.15
2208
Kalush, level +205 m
12.46
58.7
183.8±3.1
8.49±0.15
2144
Kalush, level +90 m
10.86
66.1
171.0±2.5
9.06±0.14
2145
Kalush, Bed K-3, level +90 m
12.43
64.2
258.8±3.9
11.96±0.19
2220
Kalush, Bed LK-4
12.70
68.2
227.1±3.1
10.28±0.15
2079
Kalush, Bed LK-3
salt breccia
polyhalite-anhydrite bed
12.62
57.5
191.5±3.1
8.73±0.15
2204
Stebnyk, Bed 13, level 2 (+180 m)
11.01
57.1
158.7±2.8
8.29±0.15
2206
Stebnyk, Bed 13, level 2 (+180 m)
11.51
72.0
245.6±3.2
12.27±0.17
72
Stebnyk, Bed 11, level 4
12.70
71.1
262.8±3.2
11.89±0.16
20
Stebnyk, Bed 19
12.52
81.9
275.2±2.5
12.63±0.13
2188
Kalush, Bed LK-3, level +90 m
13.09
87.1
334.3±2.2
14.67±0.12
2179
Kalush, Bed LK-1/2, level +140 m
potash rock
red polyhalite rock
12.58
68.0
249.3±3.3
11.39±0.16
248 WÓJTOWICZ et al.
(cf. Andreyeva-Grigorovich et al. 1997). This tectonic event
corresponds to an old Styrian phase (Sãndulescu 1988). In
turn, the young Styrian phase appears to be roughly con-
temporaneous with the Badenian evaporites (Sãndulescu
1988). The last phase (Moldavian phase of Sãndulescu
1988) is expressed the best. The detailed structural investiga-
tions deciphered relative ages of the folding, thrusting and
jointing (Zuchiewicz et al. 1997; Bubniak et al. 2001), and the
K/Ar dating combined with the mineralogical-geochemical
investigations provides a possibility to date more precisely the
tectonic events in the Ukrainian Carpathian accretionary
wedge and adjoining areas.
Langbeinite is dated at ca. 13.614.6 Ma. The increase in
temperature necessary for the langbeinite crystallization can
be connected with the processes of thrusting (Dzhinoridze
1980; cf. Turcotte & Schubert 1973; Graham & England
1976). Dispersion of ages obtained from the langbeinite could
be the result of the thrusting process during the young Styrian
phase.
Red polyhalite rock (ca. 11.412.6 Ma) is connected with
transverse faults and joints, the origin of which was attributed
to the Moldavian phase. These SW-NE striking faults are
younger than the thrust structures (Dzhinoridze 1980). The
formation of kainite happened in the time span ca. 7.29.9 Ma
during the final neotectonic structural stage. This stage began
after deposition of the Lower Sarmatian sediments and uplift
of the territory. Tectonic geomorphology studies demonstrate
that the region is still neotectonically active (Bubniak &
Zuchiewicz 2001).
Conclusions
K/Ar dating of the potassium-magnesium sulphate minerals
from Miocene evaporites of different stratigraphic formations
and tectonic zones of the Carpathian Foredeep provides evi-
dence that they have recrystallized at roughly the same time.
Consequently, the age of these minerals differs from that of
the hosting formations. The age of langbeinite from the Steb-
nyk mine (13.6314.65 Ma) hosted in the Lower Miocene
Eggenburgian deposits indicates recrystallization in the Mid-
dle Miocene. The same age of langbeinite from the Kalush
mine indicates that the host formation, the age of which is un-
certain, is older than the Tyras Suite, which belongs to the
NN6 Zone.
This recrystallization was a response to three major tectonic
events, which affected the area. The age difference between
langbeinite and polyhalite from red polyhalite rock indicates 2
Ma duration of the overthrust of the Carpathians and the Bo-
ryslav-Pokuttya Nappe on the Sambir Nappe, and the time of
formation of transverse faults about 1 Ma. The younger tec-
tonic events are fixed by the age of kainite and polyhalite
from polyhalite-anhydrite beds. Evaporite minerals can thus
be used to date the tectonic events in regions of complex geo-
logic structure.
Acknowledgments: This work was supported by the State
Committee for Scientific Research (Grants 6 PO4D 067 18
and 6 PO4D 009 11 to TMP). We thank B. Baranenko, V.A.
Buchynskiy, L.M. Mitil, S.S. Koriñ, and S.I. Trachuk for
making possible and helping in the field research in the Steb-
nyk and Kalush mines, and S. Halas, V.M. Kovalevych and
O.Y. Petrychenko for discussions and comments. The first
draft of the paper was read and criticized by G. Feraud, V. Hu-
rai, J. Krá¾ and N. Oszczypko; we are grateful for their con-
structive suggestions.
References
Andreyeva-Grigorovich A.S., Kulchytsky Y.O., Gruzman A.D.,
Lozynyak P.Y., Petrashkevich M.I., Portnyagina L.O., Ivanina
A.V., Smirnov S.E., Trofimovich N.A., Savitskaya N.A. & Sh-
vareva N.J. 1997: Regional stratigraphic scheme of Neogene
formations of the Central Paratethys in the Ukraine. Geol. Car-
pathica 48, 123136.
Andreyeva-Grigorovich A.S., Oszczypko N., l¹czka A., Sav-
itskaya N.A. & Trofimovich N.A. 1999: The age of the Mi-
ocene salt deposits in the Wieliczka, Bochnia and Kalush areas
(Polish and Ukrainian Carpathian Foredeep). Biul. Pañstw.
Inst. Geol. 387, 8586.
Berger J.-P. 1992: Correlative chart of the European Oligocene and
Miocene: Application to the Swiss Molasse Basin. Eclogae
Geol. Helv. 85, 573609.
Bilonizhka P.M. 1964: About bromine concentration in kainite from
potassium salt deposits of the Carpathian Foredeep. Mineral.
Sbornik Lvovsk.Univ. 18, 210213 (in Russian).
Bilonizhka P.M. 2001: Phase transformations of kainite during heat-
ing and their geological significance. Visnyk Lvivsk. Univ. Ser.
Geol. 15, 7782 (in Ukrainian).
Bilonizhka P.M. & Kostin V.A. 1977: Origin of hydromicas from
the salt deposits of the Carpathian Foredeep (based on their ab-
solute ages). In: Kytik V.I. (Ed.): Geology and geochemistry
of salt-bearing formations of Ukraine. Naukova Dumka, Kiev,
53-65 (in Russian).
Blagovidov V.V., Klimov M.A. & Kuznetsov V.G. 1977: Structure
and conditions of origin of Neogene salt deposits in USSR. In:
Yanshin A.L. & Zharkov M.A. (Eds.): Problems of saltaccu-
mulation. Nauka, Novosibirsk, 243257 (in Russian).
Bubniak I., Bubniak A., Kilyn I. & Popp I. 2001: Structural-sedi-
mentological studies of Dobrotiv deposits of the Carpathian
Foredeep (Nadvirna area). Pratsi naukovoho tovarystva imeni
Shevchenka, Geolohichnyi zbirnyk 5, 8493 (in Ukrainian).
Bubniak A. & Zuchiewicz W. 2001: Morphotectonic properties of the
Ukrainian Carpathian Foredeep. In: A. Ádám, L. Szarka & J.
Szendrõi (Eds.): PANCARDI 2001. II. Abstracts, Sopron, CP-4.
Dalrymple G.B. & Lanphere M.N. 1969: Potassium-argon dating,
principles, techniques and applications to geochronology. W.H.
Freeman & Co., San Franscisco, 1251.
Dzhinoridze N.M. 1973: Tertiary potassium basins. In: V.I.
Raievskiy & M.P. Fiveg (Eds.): Deposits of potassium salts in
the USSR. Nedra, Leningrad, 183234 (in Russian).
Dzhinoridze N.M. 1980: Carpathian potassium-bearing region. In:
Dzhinoridze N.M., Gemp S.D., Gorbov A.F. Rayevskiy V.I.
(Eds.): Principles of distribution and exploration criteria for
potassium salts in the USSR. Izdatelstvo Mecniereba, Tbili-
si, 73159 (in Russian).
Galamay A.R. 1997: Origin of the middle Miocene Badenian salts in
the Carpathian region. Przegl. Geol. 45, 10121017 (in Polish).
Glushko V.V. 1968: Tectonics and oil- and gas-bearing of the Car-
pathian and adjacent deeps. Nedra, Moskva, 1264 (in Russian).
Graham C.M. & England P.C. 1976: Thermal regimes and regional
metamorphism in the vicinity of overthrust fault: an example
of shear heating and metamorphic zonation from southern Cal-
ifornia. Earth Planet. Sci. Lett. 31, 142152.
Griniw S.P. 1994: Composition and lithostratigraphic correlation of
K/Ar DATING OF THE MIOCENE POTASH SALTS OF THE CARPATHIAN FOREDEEP 249
salts of the Kalush-Holyn deposit (Miocene, Ukrainian Fore-
Carpathians). Przegl. Geol. 42, 748750 (in Polish)
Gurzhiy D.V. 1969: Lithology of the Forecarpathian molasses.
Naukova Dumka, Kiev, 1201 (in Russian).
Halas S., Wójtowicz A. & Peryt T.M. 1996: K/Ar dates of some Mi-
ocene potash salts from Carpathian Foredeep. Acta Geol. Hun-
garica 39, Suppl. (Isotope Workshop III), 6467.
Khodkova S.V. 1968: Langbeinite of the Forecarpathian and its
parageneses. Litologiya i poleznye iskopaemye 9, 7385 (in
Russian).
Khodkova S.P. 1971: Minerals and rocks of the Stebnik potassium
salt deposit. In: A.E. Khodkov (Ed.): Materials on hydrogeolo-
gy and geological role of subsurface waters. Leningradskiy
Universitet, Leningrad, 8291 (in Russian).
Khrushchov D.P. 1980: Lithology and geochemistry of halogenic
formations of the Carpathian Foredeep. Naukova Dumka, Kiev,
1313 (in Russian).
Khrushchov D.P. & Zaydis P.P. 1978: Determination of absolute
age of rocks and minerals of salt-bearing formations. In:
Tkachyk L.G. (Eds.): Sedimentary rocks and ores. Naukova
Dumka, Kiev, 221227 (in Russian).
Klimov M.A. 1968: Forecarpathian potassium-bearing basin and
perspectives of increase of potassium resources potential in
Ukraine. Geologichnyy Zhurnal 28, 2, 5660 (in Ukrainian).
Korenevskiy S.M., Zakharova V.M. & Shamakhov V.A. 1977: Mi-
ocene halogenic formations of the Carpathian Foredeeps. Ne-
dra, Leningrad, 1248 (in Russian).
Koriñ S.S. 1994: Geology of the Miocene salt-bearing formations of
the Ukrainian Fore-Carpathians. Przegl. Geol. 42, 744747 (in
Polish).
Kováè M., Nagymarosy A., Oszczypko N., Csontos L., l¹czka A.,
Mãrunþeanu M., Matenco L. & Márton E. 1998: Palinspastic
reconstruction of the Carpathian-Pannonian region during the
Miocene. In: M. Rakús (Ed.): Geodynamic development of
the Western Carpathians. Dionýz túr Publishers, Bratislava,
189217.
Kovalevich V.M. 1978: Physico-chemical conditions of salt forma-
tion in the Stebnik potassium deposit. Naukova Dumka, Kiev,
1100 (in Russian).
Kovalevich V.M. 1982: Genesis of langbeinite in potassium salts of
the Carpathian Foredeep based on study of inclusions of miner-
al-forming solutions. In: Kityk V.I. (Ed.): Geology and
geochemistry of non-metallic mineral resources. Naukova
Dumka, Kiev, 3241 (in Russian).
Kruglov S.S., Tsypko A.K., Arsiriy Y.A., Vitenko V.A., Vishnyak-
ov I.B., Kiriluk V.I., Polukhtovich B.M., Popadyuk I.V., Sa-
marskiy A.D., Sivoronov A.A., Sollogub V.B. & Chekunov
A.V. 1988: Tectonics of Ukraine. Nedra, Moskva, 1254 (in
Russian).
Léost I., Féraud G., Blanc-Valleron M.M. & Rouchy J.M. 2001:
First absolute dating of Miocene langbeinite evaporites by
40
Ar/
39
Ar laser stop-heating: [K
2
Mg
2
(SO
4
)
3
] Stebnyk mine
(Carpathian Foredeep Basin). Geophysical Research Letters
28, 43474350.
Lippolt H.J., Hautmann S. & Pilot J. 1993:
40
Ar/
39
Ar-dating of Zech-
stein potash salts: New constraints on the numerical age of the
latest Permian and the P-Tr boundary. Terra Abstr. 7, 591.
Lippolt H.J. & Weigel E. 1988:
4
He diffusion in
40
Ar-retentive min-
erals. Geochim. Cosmochim. Acta 52, 14491458.
Lobanova V.V. 1956: Questions of petrography of potassium depos-
its of the eastern Forecarpathians. Trudy Vsesoyuznogo institu-
ta galurgii 32, 164214 (in Russian).
Mãrunþeanu M. 1999: Litho- and biostratigraphy (calcareous nanno-
plankton) of the Miocene deposits from the Outer Moldavides.
Geol. Carpathica 50, 313324.
Oszczypko N. 1997: The Early Miocene Carpathian peripheral fore-
land basin (Western Carpathians, Poland). Przegl. Geol. 45,
10541066.
Peryt D. 1997: Calcareous nannoplankton stratigraphy of the Mid-
dle Miocene in the Gliwice area (Upper Silesia, Poland). Bull.
Pol. Acad. Sci., Earth Sci. 45, 119131.
Peryt D. 1999: Calcareous nannoplankton assemblages of the Bade-
nian evaporites in the Carpathian Foredeep. Biul. Pañstw. Inst.
Geol. 387, 158161.
Peryt T.M., Halas S. & Koryñ S.S. 1996: Stratigraphic position of
the Miocene potassium salts of the Carpathian Foredeep. In: III
Ogólnopolska Sesja Naukowa Datowanie minera³ów i ska³.
UMCS, Lublin, 5556 (in Polish).
Peryt T.M. & Kovalevich V.M. 1997: Association of redeposited
salt breccias and potash evaporites in the Lower Miocene of
Stebnyk (Carpathian Foredeep, West Ukraine). J. Sed. Res. 67,
913922.
Petryczenko O.I., Panow G.M., Peryt T.M., Srebrodolski B.I.,
Pobere¿ski A.W. & Kowalewicz W.M. 1994: Outline of geology
of the Miocene evaporite formations of the Ukrainian part of the
Carpathian Foredeep. Przegl. Geol. 42, 734737 (in Polish).
Pilot J. & Blank P. 1967: K-Ar Bestimmungen von Salzgestein des
Zechstein. Z. Angew. Geol. 13, 661662.
Renne P.R., Sharp W.D., Montañez I.P., Becker T.A. & Zieren-
berg R.A. 2001:
40
Ar/
39
Ar dating of Late Permian evaporites,
southeastern New Mexico, USA. Earth Planet. Sci. Lett. 193,
539547.
Rögl F. 1996: Stratigraphic correlation of the Paratethys Oli-
gocene and Miocene. Mitt. Gesell. Geol. Bergbaustud. Ös-
terr. 41, 6573.
Samson S.D. & Alexander Jr. E.C. 1987: Calibration of interlabora-
tory
40
Ar-
39
Ar dating standard MMhb-1. Chem. Geol., Isotope
Geosci. Sect. 66, 2734.
Sãndulescu M. 1988: Cenozoic tectonic history of the Carpathians,
AAPG Memoir 45, 1725.
Sonnenfeld P. 1984: Brines and evaporites. Academic Press, Orlan-
do, 1613.
Staudacher T., Jessberger E.K., Dörflinger D. & Kiko J. 1978: A re-
fined ultrahigh-vacuum furnace for rare gases analysis. J.
Phys. E: Sci. Instrum. 11, 781784.
Steininger F.F. & Wessely G. 2000: From the Tethyan Ocean to the
Paratethys Sea: Oligocene to Neogene stratigraphy, paleogeog-
raphy and paleobiogeography of the circum-Mediterranean re-
gion and the Oligocene to Neogene basin evolution in Austria.
Mitt. Österr. Geol. Gesell. 92, 95116.
Stoica C. & Gherasie I. 1981: Sarea ºi sarurile de potasiu ºi magne-
ziu din România. Editura Tehnica, Bucureºti, 1248.
Turcotte D.L. & Schubert G. 1973: Frictional heating of the de-
scending lithosphere. Jour. Geophys. Research 78, 58765886.
Vakarcs G., Hardenbol J., Abreu V.S., Vail P.R., Várnai P. & Tari
G. 1998: Oligocene-Middle Miocene depositional sequences of
the Central Paratethys and their correlation with regional stag-
es. SEPM Special Publication 60, 209231.
Valyashko M.G. 1962: Geochemical principles of origin of potassi-
um salt deposits. Izd. Moskovskogo Universiteta, Moskva, 1
396 (in Russian).
Vyalov O.S. 1965: Stratigraphy of Neogene molasses of the Car-
pathian Foredeep. Naukova Dumka, Kiev, 1192 (in Russian).
Vyalov O.S., Havura S.P., Danysh V.V., Leshchukh P.I., Ponomari-
ova L.D., Romaniv A.M., Tsarnenko P.N. & Tsizh I.T. 1981:
History of geologic development of the Ukrainian Carpathians
Karpat. Naukova Dumka, Kiev, 1180 (in Russian).
Vysotskiy E.A., Garetskiy R.G. & Kislik V.Z. 1988: Potassium basins
of the world. Nauka i Tekhnika, Minsk, 1387 (in Russian).
Zuchiewicz W., Bubniak I.M. & Rauch M. 1997: Jointing in the
Skiba (Skole) Unit, Ukrainian Carpathians. Przegl. Geol. 45,
408413 (in Polish).