GeolCarp_Vol58_No6_531

GEOLOGICA CARPATHICA, DECEMBER 2007, 58, 6, 531—540

www.geologicacarpathica.sk

Paleomagnetic properties of the ignimbrites from the famous

fossil footprints site, Ipolytarnóc (close to the Hungarian-Slovak

frontier) and their age assignment

EMŐ MÁRTON

, DIONÝZ VASS

, IGOR TÚNYI

, PÉTER MÁRTON

and TIBOR ZELENKA

Eötvös Loránd Geophysical Institute of Hungary, Palaeomagnetic Laboratory, Columbus ut. 17—23, H-1145 Budapest, Hungary;

paleo@elgi.hu

Geological Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava 45, Slovak Republic

Present address: Matičná 5, 831 03 Bratislava, Slovak Republic; dionyz.vass@zoznam.sk

Geophysical Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 28 Bratislava, Slovak Republic; geoftuny@savba.sk

Eötvös Loránd University, Geophysics Department, Pázmány Péter sétány 1/c, H-1117 Budapest, Hungary; martonp@ludens.elte.hu

University of Miskolc, Department of Geology, Egyetemváros, H-3515 Miskolc, Hungary; zelenka.tibor@freemail.hu

(Manuscript received September 10, 2006; accepted in revised form June 13, 2007)

Abstract: On geological grounds, the ignimbrites/tuffs of the Ipolytarnóc area were regarded as belonging to the
oldest of the three Miocene “tuff complexes” of the Pannonian Basin. From the paleomagnetic point of view, the three
complexes are significantly different in the area which comprises North Hungary and South Slovakia, since the oldest
is characterized by about 80

º, the middle by about 30º counterclockwise, while the youngest about 10º clockwise

rotation with respect to the present North. The significant differences in declinations are attributed to block rotations,
which affected the area in the time intervals of 18.5—17.5 Ma and 16—14.5 Ma. Earlier, a pilot study on three
ignimbrite sites from Ipolytarnóc indicated only 30

º of counterclockwise rotation, which suggested that the volcanism

was younger than assumed, while the underlying Eggenburgian sediments showed the expected large rotation.
Following up indications, we carried out a detailed paleomagnetic study at this locality on a large number of samples
from the terrestrial sequence which covers the Eggenburgian sandstone. These were the “footprint sandstone” and the
overlying unaltered, ignimbrites which represent three volcanic cycles separated by clastic sediments. Ignimbrites
from the surrounding area were also tested. The results obtained are of high quality, statistically well defined on the
site level and are highly consistent on the between-site level. The polarity is normal for the first two cycles and reversed
for the youngest. The rotation angle indicated is about 30

º. Thus, we conclude that the ignimbrites at the Ipolytarnóc

area are indeed younger than 17.5 Ma, so they belong to the “Middle Tuff Complex” of the Pannonian Basin.

Key words: Miocene, Northern Pannonian Basin, Ipolytarnóc, correlation, paleomagnetic marker horizon, ignimbrites.

Introduction

Ipolytarnóc, the famous site of fossil footprints of mam-
mals, birds and of subtropical-tropical plants is situated in
the Cserhát Upland which is dominated by elongated hills
and ridges built of Oligocene and Miocene sediments and
volcanics, and are topped by Pliocene-Pleistocene basalts.
The uplands belong geologically to the Buda (Hungarian)
Paleogene Basin, the Fi akovo-Pétervására Basin and the
Nógrád-Novohrad Basin. In those basins Miocene ignim-
brites and tuffs are widespread. Most of the ignimbrites
and tuffs, including those of the Ipolytarnóc area, are con-
sidered to represent the oldest Miocene “Tuff Complex”
of the Pannonian Basin.

In the Pannonian Basin three “Tuff Complexes” of Mi-

ocene age are distinguished (Hámor 1973; Póka et al.
1998): a “Lower Tuff Complex”, a “Middle Tuff Complex”
and an “Upper Tuff Complex” (Póka et al. 1998). All three
were paleomagnetically studied in northern Hungary
(Márton & Márton 1996; Márton & Pécskay 1998; Karát-
son et al. 2000; Póka et al. 2004) and in southern Slovakia
(Márton et al. 1996). It was shown that they differ from each

other significantly in declinations. The oldest exhibits
about 80

º, the middle about 30º counterclockwise rotation

and the youngest about 10

º clockwise rotation with respect

to the present North suggesting important tectonic rota-
tion events between the complexes. These events provide
paleomagnetic marker horizons. The ages of the rotations
are known from K/Ar isotope data obtained for the ignim-
brites of the Bükk Foreland (Márton & Pécskay 1998) to
be 18.5—17.5 Ma and 16—14.5 Ma, respectively.

From the Nógrád-Novohrad Basin a number of ignim-

britic sites belonging to the Gyulakeszi Tuff Formation
and related sedimentary localities were studied earlier and
most of them exhibited about 80

º counterclockwise rota-

tion (Márton & Márton 1996). However, three sites from
Ipolytarnóc yielded only about 30

º westerly declinations

(Márton & Márton 1996). It seemed that the ignimbrites of
Ipolytarnóc formed after the first Miocene rotation, but
this suggestion was met by the scepticism of several geol-
ogists who thought that the paleomagnetic results for the
Ipolytarnóc ignimbrites were “anomalies” due to local tec-
tonics or to an excursion of the geomagnetic field. In order
to decide if the Ipolytarnóc ignimbrites were really younger

532

E. MÁRTON, VASS, TÚNYI, P. MÁRTON and ZELENKA

than earlier thought, we collected a large number of sam-
ples from the Ipolytarnóc area. In this paper we shall
present results from the newly studied sites and interpret
them together with earlier published Miocene paleomag-
netic data from the Nógrád-Novohrad Basin (Fig. 1).

Geological background

In the Buda (Hungarian) Paleogene Basin, the Tertiary

formations are mostly marine sediments of Late Eocene—

Egerian age. In the Fi akovo-Pétervására Basin early
Eggenburgian marine sediments of the Pétervására (Báldi
1983) and/or Fi akovo Formation (Seneš 1965), compris-
ing cross-bedded sandstone with layers of felsic tuff
(Báldi 1986; Vass & Elečko (Eds.) 1992), have been de-
posited.

After the early Eggenburgian the area was uplifted and

eroded. Deposition was continental (Zagyvapálfalva –
Hámor 1973 and/or Bukovinka – Vass (Ed.) 1983, For-
mations) producing river sediments, partly intercalated,
partly coved by ignimbrites and tuffs. The continental

Fig. 1. Geological sketch map of the study area (after Lexa et al. 2000 simplified) with the paleomagnetic sampling sites/localities
numbered. Key to geology: 1 – Pliocene deposits undivided, 2 – motled clay, sand, gravel, Pontian, 3 – basalt volcanic rocks undivided,
b – diatreme, Pleistocene—Upper Miocene, 4 – clay, silt, sand, gravel, felsic tuff, Sarmatian, 5 – andesite volcanic rocks undivided,
Badenian—Sarmatian, 6 – siltstone, sandstone, Karpatian, 7 – clay, silt, sand, coal seams (Salgótarján Fm), Ottnangian, 8 – motled clay,
sand, gravel/conglomerate (Zagyvapálfalva and Bukovinka Fms), lower Ottnangian—upper Eggenburgian, 9 – rhyolite, rhyodacite tuff
and ignimbrite (Gyulakészi Fm and tuff layers in Bukovinka Fm), 10 – sand/sandstone, silt/siltstone, felsic tuff (Fi akovo and Pétervásara
Fms), Eggenburgian, 11 – silt/siltstone, sand/sandstone (Lučenec and Szécseny Schlier Fms), Egerian, 12 – sandstone, claystone,
marlstone (Buda Fm), Oligocene, 13 – pre-Cenozoic rocks of Veporic and Gemeric Units, 14 — faults, 15 – sampling sites.

533

PALEOMAGNETIC PROPERTIES OF THE IGNIMBRITES FROM THE IPOLYTARNÓC

sediments indicate either warm and humid or arid climate.
A famous example of the first is the post-lower Eggen-
burgian sequence of Ipolytarnóc protected area where the
sandstone deposited by rivers is famous for fossil animal
footprints and contains rich subtropical-tropical flora of
rain forest (Jablonszky 1914; Hably 1985). Although the
continental deposits at Ipolytarnóc are considered to be
equivalent to the Zagyvapálfalva Formation (Bartkó
1985), the sandstone with foot prints was distinguished
as a member – Ipolytarnóc “Beds” (Bartkó 1985, recte
Ipolytarnóc Member), and the overlying felsic ignimbrite/
tuff bodies and the tuffs were considered as equivalent of
the Gyulakeszi Rhyolite Tuff Formation (Bartkó l.c.). In
contrast to the Ipolytarnóc type deposits, the mottled clay
(free of fossil macroflora) deposited by rivers indicates an
arid climate.

The continental sediments of the Nógrád-Novohrad Ba-

sin are covered by lake deposits with marine intercalations
(Salgótarján Formation). The lower part of the Salgótarján
Formation is coal-bearing, the upper part consists of clay-
stone with tuffaceous intercalations, or tuff layers with ma-
rine pelitic intercalations containing nannoflora NN3—NN4
Zones pointing to the Ottnangian age of the Salgótarján
Formation (Lehotayová 1982; Vass 2002). The Salgótarján
Formation is followed by marine deposits which are
subdivided into two formations and in northern Hungary:
the lower Egyházasgerge Sandstone Formation and the
upper Garáb Schlier Formation (calcareous siltstone, Hámor
1973). In southern Slovakia the equivalent of the two
formations is the Modrý Kameň Formation (Vass (Ed.)
1983; Vass & Elečko (Eds.) 1992).

Badenian rocks are either intrusive bodies of andesite

(Karancs, Šiator, Halič Castle Hill) or andesite volcani-
clastics, lahars, tuffs, andesite epiclastic conglomerates
and sandstones. Inside the volcaniclastic sequence there
are lithotamnium limestone and calcareous mudstone rich
in marine fossils (Vinica and Lysec Formations).

The elongated hills and ridges of the Cerová vrchovina

Upland and of the Northern Cserhát Upland are topped by
basalts of the Cerová Formation (Vass & Kraus 1985) and/
or Salgó Basalt Formation (Jámbor in Gyalog 1996). The
basalt lava flows are underlain by gravels of Pliocene-
Pleistocene river channel lag.

Paleomagnetic sampling

NE of Ipolytarnóc village, in the natural conservation

area belonging to the Bükk National Park of Hungary,
there are excellent outcrops exposing Eggenburgian ma-
rine sandstone, which is covered discordantly by a se-
quence of subhorizontal sandstone with animal footprints
and plant remnants followed by three cycles of the ignim-
britic volcanism, separated by coarse-grained clastic de-
posits of non-volcanic material (Korpás 2003). The paleo-
magnetic samples for the present study were drilled from
the products of the ignimbritic volcanism, which were also
studied microscopically. Under the microscope, the ignim-
brites and tuffs were unaltered, since the zonation in the

plagioclase was clearly visible, sanidine identifiable, the
mafic minerals were fresh, the pumice glassy. Microscopic
analysis also revealed that there were differences in miner-
al composition between the ignimbrites of the different
cycles. The most important are summarized as follows.
The first cycle (thickness is about 15 m) starts with fine-
grained material deposited in water (biotite is the mafic
mineral) and continues with poorly welded ignimbrite (bi-
otite and green hornblende are the mafic minerals). The
volcaniclastics of the second cycle (about 25 m thick) are
biotite and pyroxene-bearing, and are obviously the prod-
ucts of a violent explosion (indicated by the presence of
glass shards). Glass shards are missing from the third cycle
(ignimbrite is about 40 m thick), and the mafic mineral is
exclusively biotite. This ignimbrite contains lithoclasts of
andesitic and rhyolitic composition.

Paleomagnetic sampling was concentrated on the above

described fresh volcaniclastics in the natural conservation
area (Fig. 2) but similar ignimbrites were also collected
from several sites around the main section, both in Hunga-
ry and Slovakia. Some of the “satellite” sites, are correlat-
ed geologically to the second cycle of the main section
(Fig. 2), but a few are too distant for reliable geological
correlation, yet useful for checking the lateral extent of

Fig. 2. Sedimentary ignimbritic sequence at Ipolytarnóc Natural
Conservation Area (after Korpás 2003) with the numbered
paleomagnetic localities and sites from the section by Korpás
(2003) on the right side, and paleomagnetic sites related to the
2nd cycle based on geological and paleomagnetic considerations,
on the left side.

534

E. MÁRTON, VASS, TÚNYI, P. MÁRTON and ZELENKA

the “Ipolytarnóc type” of ignimbritic volcanism (sites 24,
25, 30, 31).

Laboratory measurements and results

The drill cores, oriented in the field with a magnetic

compass were cut into standard-size specimens in the lab-
oratory. Samples from two sites however, which were col-
lected as oriented hand samples, were drilled in the labora-
tory (sites 5 and 25), before cutting.

The measurements and demagnetizations were carried

out in two laboratories, in the Paleomagnetic Laboratory
of the Eötvös Loránd Geophysical Institute of Hungary
and in the Paleomagnetic Laboratory of the Geophysical
Institute of Slovak Academy of Sciences. In the first, JR-5A
and JR-4 magnetometers, KLY-2 Kappabridge, Schoen-
stedt AF and thermal demagnetizers and an AF demagne-
tizer built at the Technical University, Budapest, in the
second, MAVACS thermal demagnetization system, KLY-2
and JR-5 were used.

After measuring the natural remanent magnetization

(NRM) and susceptibility in the natural state, the samples
were subjected to either alternating field (AF), or less of-
ten, thermal demagnetization in increments. As Fig. 3
documents, the volcanic samples behaved on demagneti-
zation in a most regular manner, while the sediments ex-
hibited somewhat noisy behaviour.

Demagnetization curves were analysed for linear seg-

ments and locality/site mean paleomagnetic directions
were calculated from components defined by these seg-
ments (Table 1). Mean paleomagnetic directions are char-
acterized by excellent or good statistical parameters, espe-
cially in the ignimbrites deposited on land (Table 1). The
footprint sandstone and sites belonging to the first and
second ignimbritic cycles and those not correlated to the
“master” section of Fig. 2 have normal polarity. Some of
the latter (Lipovany, Mucin, Botos árok) are quite distant
(a few km) from the “master” section, thus, they are impor-
tant for demonstrating the consistency in space of the pa-
leomagnetic directions. The two sites representing the
third cycle have reversed polarity. The average declina-
tion calculated from all sites of Table 1 is around 330

(sites with reversed polarity are entered in the calculation
as normal polarity sites). All paleomagnetic site-mean di-
rections, except two (sites 17 and 33 drilled from blocks
which were probably not perfectly in situ) cluster so tight-
ly that graphical representation on a stereonet is not prac-
ticable.

Discussion and conclusions

The large number of good quality and consistent paleo-

magnetic data available now from the Ipolytarnóc area
(Table 1) represent three cycles of the ignimbritic volcan-

Fig. 3. Ipolytarnóc Natural Conservation Area. Typical demagnetization behaviour of the natural remanent magnetization for footprint
sandstone and volcanic material deposited in water and on dry land. Key: in Zijderveld diagrams, full/open circles: projection of the
NRM in the horizontal/vertical plane; in the others, dots: NRM – intensity, circles: susceptibility. R0 – initial susceptibility.

535

PALEOMAGNETIC PROPERTIES OF THE IGNIMBRITES FROM THE IPOLYTARNÓC

Table 1: Ipolytarnóc, “footprint sandstone” and overlaying ignimbrites (3 cycles) plus ignimbrites from outside of the protected area.
Paleomagnetic site-mean directions based on the results of principal component analysis (Kirschvink 1980). Key: n/no – number of
used/collected samples; D

º, Iº – declination, inclination before tilt correction; D

º, I

º — declination, inclination after tilt correction; k and

º – statistical parameters (Fisher 1953).

ism. They all show about 30

º counterclockwise declina-

tion deviation from the present North, with normal polari-
ty for the first two and reversed polarity for the third cycle.
The Ipolytarnóc “master” section sits on top of the earlier
studied glauconitic sandstone of Eggenburgian age which
yielded the expected rotation angle (Table 2, locality 2).
Thus, a difference of about 60

º in declination is observed

within the same section between the stratigraphically
well-dated marine glauconitic sandstone and the subhori-
zontal terrestrial sequence which follows it discordantly.
The difference in declination between them suggests that
the terrestrial sequence postdates the first Miocene rota-
tion event, so that it must be younger than 17.5 Ma. Other
explanations for the difference in declinations, like local
tectonics or anomalous behaviour of the magnetic field
can safely be excluded, as the first would have also in-
volved the glauconitic sandstone, the second, because of
the fairly long duration of the volcanism indicated by dif-
ferences in composition, in mode of explosion between
the cycles, for the time necessary for the deposition of sed-
iments separating the cycles and for the complete reversal
of the Earth’s magnetic field.

The above reasoning is valid if we regard the magneti-

zation of the footprint sandstone at the base of the terres-

Fig. 4. Comparison of overall-mean paleomagnetic directions
between Eggenburgian—lower Ottnangian sediments and
ignimbrites of the Nógrád-Novohrad Basin (A), lower ignimbrites
of the Bükk Foreland (B, all reversed polarities), upper
ignimbrites of the Bükk Foreland (C, all reversed polarities), and
ignimbrites (and footprint sandstone) from Ipolytarnóc and
related area (D). For data refer to Table 3.

539

PALEOMAGNETIC PROPERTIES OF THE IGNIMBRITES FROM THE IPOLYTARNÓC

ján Formation, yet exhibit much larger rotation than 30

º.

Therefore, we cannot exclude the possibility that the
boundary of the Zagyvapálfalva/Bukovinka and the Sal-
gótarján Formations is older than suggested by Fig. 5.

In the Ipolytarnóc area, the ignimbrites/tuffs belonging

to the first two cycles are of normal polarity (Table 1).

Thus, in Fig. 6 the normal polarity sites at Ipolytarnóc

and surroundings (Table 1) are placed in the time span of
17.2—17.5 Ma (Fig. 6). The third cycle with reversed polar-
ity is placed in the following reversed polarity interval,
thus correlated with the “Middle Tuff Complex” of the
Bükk Foreland (Fig. 4).

The age of the sandstone with footprints is not really

constrained paleomagnetically. On the assumption that its
remanence is primary, the position indicated in Fig. 6 is
valid. In the opposite case, the stratigraphic column of
Fig. 7 can be constructed, which has the advantage of
maintaining the co-evality of the flora assemblage from
the site NE of Lipovany and from the site of Ipolytarnóc,
both indicating subtropical—tropical rain forest climatic
conditions (Němejc 1967; Němejc & Knobloch 1973;
Hably 1985).

The age assignment suggested by Fig. 6, has conse-

quences for the degree of continuity of deposition as well
as for the paleoclimate.

Concerning the first, we have to calculate with a consid-

erable hiatus (missing Bukovinka/Zagyvapálfalva and
Salgótarján Formations) in the Ipolytarnóc area (Fig. 6).
This is surprising, because the mentioned formations do
occur in the vicinity, on the Slovak side at Lipovany and
at Čakanovce villages. The paleoclimatic implication is
that the rain forest vegetation is of Ottnangian age and is
most probably younger than the Salgótarján Formation
characterized by luxurious swamp vegetation indicative
of a cooler, but still humid climate.

Finally, it has to be mentioned that a recently published

paper of Pálfy et al. (2007), which was accessible on-line a
few days after the revised version of this paper was submit-
ted, contains new radiometric data concerning the numeri-
cal age of the ignimbrite formation at Ipolytarnóc, which
is 17.42 ± 0.04 Ma (crystal zircon U-Pb age). Thus, the re-
sults of two independent methods – the paleomagnetic
and the radiometric – are in perfect agreement, both sug-
gesting that the Ipolytarnóc felsic ignimbrites are of late
Ottnangian age.

Acknowledgment: We thank Imre Szarvas for field guid-
ance, Doc. M. Bielik, Dr. M. Jelenska and M. Lantos for re-
vising the manuscript. Our special thanks are due to József
Duska (director of the Bükk National Park), and Imre Szar-
vas, who is in charge of the Ipolytarnóc area, for permis-
sion to drill in the protected area and for accommodation
on the spot. The work was financially supported by the
Hungarian Scientific Research Fund (OTKA) Project
No. T043773, by Grant Agency VEGA Project Nos. 4042,
Agency for Science and Research, Project No. 51-011305,
APVT-51002804 and 6045/26 and a joint project of the
Academies of Sciences of Slovakia and Hungary.

References

Báldi T. 1983: Oligocene and Lower Miocene formations of Hun-

gary. Akadémia Kiadó, Budapest, 1—293 (in Hungarian).

Báldi T. 1986: Mid-Tertiary stratigraphy and paleogeographic evo-

lution of Hungary. Akadémia Kiadó, Budapest, 1—196.

Bartkó L. 1985: Geology of Ipolytarnóc. Geol. Hung., Ser. Pale-

ont. 44, 49—71.

Fisher R. 1953: Dispersion on a sphere. Proc. Roy. Soc. London,

Ser. A. 217, 295—305.

Gyalog L. 1996: Key to the geological maps and short description of

the stratigraphic units. MÁFI Alkalmi kiadványa 187, 1—171
(in Hungarian).

Gradstein F.M., Ogg J.G. & Smith A.G. 2004: A geological time

scale 2004. Cambridge University Press, 1—500.

Hably L. 1985: Early Miocene plant fossils from Ipolytarnóc, North-

ern Hungary. Geol. Hung., Ser. Paleont. 44—46, 75—255.

Hámor G. 1973: Relationship between the type of sedimentation and

tectonization in epirogenic areas. Földt. Közl. 103, 245—240
(in Hungarian).

Jablonszky J. 1914: Flora Mediterranean in age at Tarnóc. Földt.

Int. Évkönyve. 22, 4, 227—274 (in Hungarian).

Karátson D., Márton E., Harangi Sz., Józsa S., Balogh K., Pécskay

Z., Kovácsvölgyi S., Szakmány Gy. & Dulai A. 2000: Volca-
nic evolution and stratigraphy of the Miocene Börzsöny
Mountains, Hungary: An integrated study. Geol. Carpathica
51, 325—343.

Kirschvink J.L. 1980: The least-squares line and plane and the anal-

ysis of paleomagnetic data. Geophys. J. Roy. Astron. Soc. 62,
699—718.

Korpás L. 2003: New sedimentological model of the Ipolytarnóc

sandstone. Chronology of the volcanic event and reconstruc-
tion of the eruption centre. Magyar Karszt és Barlangkutató
Társulat, 1—42 (in Hungarian).

Laurent L., Hilgen F., Shackleton N.J., Laskar J. & Wilson D. 2004:

The Neogene period. In: Gradstein F.M., Ogg J.G. & Smith
A.B. (Eds.): A geologic time scale. Cambridge University
Press, Cambridge, 409—440.

Lehotayová R. 1982: Miocene nannoplankton zones in West Car-

pathians. Západ. Karpaty, Ser. Paleont. 8, 91—110.

Lexa J., Bezák V., Elečko M., Mello J., Polák M., Potfaj M. &

Vozár J. (Eds.) 2000: Geological map of Western Carpathians
and adjacent areas 1: 500,000. Geol. Surv. Slovak Rep., Bra-
tislava.

Márton E. & Márton P. 1996: Large scale rotations in North Hun-

gary during the Neogene as indicated by palaeomagnetic data.
In: Morris A. & Tarling D.H. (Eds.): Palaeomagnetism and
tectonics of the Mediterranean Region. Geol. Soc. London,
Spec. Publ. 105, 153—173.

Márton E. & Pécskay Z. 1998: Correlation and dating of the Mi-

ocene ignimbritic volcanics in the Bükk foreland, Hungary:
complex evaluation of paleomagnetic and K/Ar isotope data.
Acta Geol. Hung. 41, 467—476.

Márton E., Vass D. & Túnyi I. 1996: Rotation of the South Slovak

Paleogene and Lower Miocene rocks indicated by paleomag-
netic data. Geol. Carpathica 47, 31—41.

Nemějc F. 1967: Paleofloristical studies in the Neogene of Slovakia.

Sborník Národního muzea 23, 1—32 (in Czech).

Nemějc F. & Knobloch E. 1973: Die Makroflora der Salgótajáner

Schichten Grupp (Die Flora aus Lipovany). In: Papp A., Rögl
F. & Seneš J. (Eds.): Chronostratigraphie und Neostratotypen.
Miocän der Zentralen Paratethys. Bd. III: M

-Ottnangien.

Vydavate stvo Slov. Akadémie vied, Bratislava, 694—759.

Pálfy J., Mundil R., Renne P.R., Bernor R.L., Kordos L. & Gasparik

M. 2007: U—Pb and

Ar/

Ar dating of the Miocene fossil

540

E. MÁRTON, VASS, TÚNYI, P. MÁRTON and ZELENKA

track site at Ipolytarnóc (Hungary) and its implication. Earth
Planet. Sci. Lett. 258, 160—174.

Póka T., Zelenka T., Szakács A., Seghedi I., Nagy G. & Simonits

A. 1998: Petrology and geochemistry of the Miocene acidic
explosive volcanism of the Bükk Foreland, Pannonian Basin,
Hungary. Acta Geol. Hung. 41, 437—466.

Póka T., Zelenka T., Seghedi I., Pécskay Z. & Márton E. 2004: Mi-

ocene volcanism of the Cserhát Mts. (N. Hungary): Integrated
volcano-tectonic, geochronologic and pertochemical study.
Acta Geol. Hung. 47, 221—246.

Seneš J. 1965: Paleogene of Little Danubian Lowland and South-

ern Slovakia (Buda Development). In: Andrusov D. 1965
(Ed.): Geologie der Tschechoslowakischen Karpathen. Vol. 3.

Vydavate stvo Slov. Akadémie vied, Bratislava, 298—322 (in
Slovak).

Vass D. (Ed.) 1983: Explanations to the geological map of Ipe ská

kotlina Depression and Krupinská planina Plain, 1: 50,000.
GÚDŠ, Bratislava, 1—126 (in Slovak).

Vass D. 2002: Lithostratigraphy of Western Carpathians: Neogene

and Buda Paleogene. ŠGÚDŠ, Bratislava, 1—202.

Vass D. & Elečko M. (Eds.) 1992: Explanations to the geological

map of Lučenská kotlina Depression and Cerová vrchovina
Upland, 1: 50,000. GÚDŠ, Bratislava, 1—196 (in Slovak).

Vass D. & Kraus I. 1985: Double age of basalts in the Southern

Slovakia and their relation to Poltár beds. Miner. Slovaca 17,
435—440 (in Slovak).