GeolCarp_Vol53_No6_399

GEOLOGICA CARPATHICA, 53, 6, BRATISLAVA, DECEMBER 2002

399 — 410

OCHTINÁ ARAGONITE CAVE (WESTERN CARPATHIANS, SLOVAKIA):

MORPHOLOGY, MINERALOGY OF THE FILL AND GENESIS

PAVEL BOSÁK

, PAVEL BELLA

, VÁCLAV CÍLEK

, DEREK C. FORD

, HELENA HERCMAN

JAROSLAV KADLEC

, ARMSTRONG OSBORNE

and PETR PRUNER

Institute of Geology, Academy of Sciences of the Czech Republic, Rozvojová 135, 165 02 Praha 6-Lysolaje, Czech Republic;

bosak@gli.cas.cz, cilek@gli.cas.cz, kadlec@gli.cas.cz, pruner@gli.cas.cz

Slovak Caves Administration, Hodžova 11, 031 01 Liptovský Mikuláš, Slovak Republic; bella@ssj.sk

School of Geography and Geology, McMaster University, 1280, Main Street West, Hamilton, Ontario L8S 4K1, Canada;

dford@macmaster.ca

Institute of Geological Sciences, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland; hhercman@twarda.pan.pl

Faculty of Education, A35, University of Sydney, N.S.W. 2006, Australia; a.osborne@edfac.usyd.edu.au

(Manuscript received March 19, 2002; accepted in revised form October 3, 2002)

Abstract: Ochtiná Aragonite Cave is a 300 m long cryptokarstic cavity with simple linear sections linked to a geometri-
cally irregular spongework labyrinth. The metalimestones, partly metasomatically altered to ankerite and siderite, occur
as isolated lenses in insoluble rocks. Oxygen-enriched meteoric water seeping along the faults caused siderite/ankerite
weathering  and  transformation  to  ochres  that  were  later  removed  by  mechanical  erosion.  Corrosion  was  enhanced  by
sulphide  weathering  of  gangue  minerals  and  by  carbon  dioxide  released  from  decomposition  of  siderite/ankerite.  The
initial phreatic speleogens, older than 780 ka, were created by dissolution in density-derived convectional cellular circu-
lation conditions of very slow flow. Thermohaline convection cells operating in the flooded cave might also have influ-
enced its morphology. Later vadose corrosional events have altered the original form to a large extent. Water levels have
fluctuated many times during its history as the cave filled during wet periods and then slowly drained. Mn-rich loams
with Ni-bearing asbolane and birnessite were formed by microbial precipitation in the ponds remaining after the floods.
Allophane  was  produced  in  the  acidic  environment  of  sulphide  weathering.  La-Nd-phosphate  and  REE  enriched  Mn-
oxide precipitated on geochemical barriers in the asbolane layers. Ochres containing about 50 wt.% of water influence
the  cave  microclimate  and  the  precipitation  of  secondary  aragonite.  An  oldest  aragonite  generation  is  preserved  as
corroded  relics  in  ceiling  niches  truncated  by  corrosional  bevels.  Thermal  ionisation  mass  spectrometry  and  alpha
counting  U  series  dating  has  yielded  ages  of  about  500—450  and  138—121 ka,  indicating  that  there  have  been  several
episodes  of  deposition,  occurring  during  Quaternary  warm  periods  (Elsterian  1/2,  Eemian).  Spiral  and  acicular  forms
representing a second generation began to be deposited in Late Glacial (14 ka – Alleröd) times. The youngest aragonite,
frostwork, continues to be deposited today. Both of the younger generations have similar isotopic compositions, indicat-
ing that they originated in conditions very similar, or identical, to those found at present in the cave.

Key words: Slovenské rudohorie Mts, Ochtiná Aragonite Cave, cave morphology, speleogenesis, mineralogy, aragonite,
U series dating.

Introduction

Ochtiná Aragonite Cave (OAC) is unique among the 4,250
known caves in Slovakia, although with only 300 m of pas-
sages it is relatively small (Fig. 1B). The cave was discovered
in 1954 during the excavation of an adit (Kapusta Gallery) for
iron ore exploration. The mine workings also intersected oth-
er, smaller caves but none were so interesting or significant.
The cave was opened to the public in 1972 and in 1995 was
included in the UNESCO World Heritage List as a component
of the Caves of the Slovak and Aggtelek Karsts.

The cave is located in the NW shoulder of Hrádok Hill

(809 m a.s.l.)  in  the  Revúcka  vrchovina  Highlands,  a  part  of
the Slovenské rudohorie Mts, some 75 km west of the region-
al  capital,  Košice  (Fig.  1A).  Caves  there  are  developed  in
steeply dipping metalimestone lenses of variable size entirely
surrounded by phyllites of the Drnava Formation (Upper Sil-
urian  to  Lower  Devonian;  Gelnica  Group;  Bajaník  &
Vozárová, Eds.  1983; Ivanička et al. 1989). They were folded
and metamorphosed during the Variscan Orogeny.  Some of
the faults and fissures were rejuvenated during the formation
of  Alpine  nappes.  Portions  of  the  metalimestone  have  been

metasomatically altered to ankerites and siderites by Mg and
Fe-bearing  hydrothermal  solutions  (Mišík  1953)  ascending
particular  fissures  (Droppa  1957).  There  have  been  two  pro-
posals for the age of mineralization: (1) related to the Variscan
metamorphic front (e.g., Grecula, Ed. 1995), and  (2) a prod-
uct of hydrothermal activity associated with the emplacement
of  the  Gemericum  granites  (Andrusov  1958),  which  have
been  dated  to  96  Ma  (Kantor  in  Homza  et  al.  1970).  No
younger hydrothermal activity has been recognized in this re-
gion (Gaál 1996). The cave is structurally guided, with N-S,
W-E and SW-NE trends (Rajman et al. 1990; Gaál 1996; see
Fig. 1B). The cave lies between 636 (basal lake) and 647 m
a.s.l.  (Droppa  1957).  There  is  no  relationship  to  the  surface
hydrology  and  morphology,  as  the  metalimestone  lenses  are
isolated by nearly impermeable phyllites. Springs in the envi-
rons  of  the  cave  have  only  low  discharges  and    are  situated
some 20 to 100 m below (Bella et al. 2000).

About 15 other caves of the Ochtiná cryptokarst type have

been intercepted by the Kapusta Gallery (Gaál 1996) but they
are substantially smaller. Some are mazes, others are isolated
rooms or fissures. There are some aragonite speleothems simi-
lar to those in the OAC. These caves are not connected to the

400 BOSÁK et al.

OAC or each other. Other caves are found in the vicinity as
well, but they differ substantially from the Ochtiná cryp-
tokarst in form (Gaál 1998).

Previous work

Droppa (1957) compared the tube-like cave passages to the

erosion forms produced by typical flowing streams under-
ground. Aggressive corrosion by meteoric waters percolating
along tectonic fissures was the main agent in the development
of the cave. Eroded products from the chemical weathering of
the ankerites were deposited in the lower parts of cave, ob-
structing drainage outlets there.

Gaál & Ženiš (1986) argued that percolating meteoric wa-

ters  first  oxidized  the  ankerite  to  create  iron  hydroxides  –
ochres;  mechanical  erosion  of  the  ochres  then  produced  the
larger voids. The general shape of the cave thus is that of the
original  metasomatic  ankerite  bodies  in  the  limestone,  with
later  modifications  resulting  from  some  subsequent  dissolu-
tion of the limestone, partly under phreatic conditions.

In addition to the oxidation of siderite/ankerite, Rajman et

al.  (1990,  1993)  stressed  the  contribution  of  other  types  of
mineralization  to the development of the karst. Oxidation of
the  abundant  sulphide  minerals  in  the  surrounding  rocks
(chiefly pyrite) increased corrosional aggressivity of percolat-
ing  waters  by  producing  H

. Gaál (1996) also supposed

Fig. 1. Geomorphological map of the Ochtiná Aragonite Cave, showing typical cross-sections (after Bella 1998, modified) and the sediment
section in Oválna Passage. A – location map; B – plan: Corrosion-denudation forms: Planar speleogens: 1 – horizontal solutional ceil-
ings (Laugdecken); 2 – inclined planar walls of passages and halls descending to the floor (planes of repose, Facetten); 3 – inclined, more
or less planar walls of passages and halls with smaller corrosion convex and concave forms; Concave speleogens: 4 –  shallow oval irregu-
lar spoon-like depressions on roofs and walls; 5 – deeper distinct oval irregular depressions on roofs and walls; 6 –  distinct, mostly hori-
zontal  niches;  7 –  cupola-shaped  depressions  in  roofs;  8 –  shallow  elongated  channel-shaped  forms  in  roof;  9 –  horizontal  elongated
notches  on  walls;  10 –  blind  lateral  tube-like  holes;  11 –  rocky  windows  in  bedrock;  12 –  narrow  steep  corrosion  cavities  developed
along prominent fissures; 13 – horizontal shallow trough-like depressions; 14 – tubular karren; 15 – fissure karren on collapsed blocks;
16 – shallow drip-holes on collapsed blocks; Convex speleogens: 17 – large irregular bedrock protrusions in roofs; 18 – structurally-con-
trolled large elongated roof bedrock juts on roofs; 19 – less pronounced elongated roof bedrock juts on roofs controlled by bedding; 20 –
bedrock pendants; 21 – bedrock blades; 22 – elongate, indistinct and  irregular bedrock protrusions along walls; 23 –  elongated bedrock
protrusions  above  horizontal  corrosion  notches;  24 –  oval  bedrock  protrusions  in  floors;  Structural-tectonic  forms:  25 –  smooth  break-
down surfaces without corrosional relief; Depositional forms: 26 – sediment sequences; 27 – cones and banks of sediments at the foot of
walls; 28 – planar accumulation surface; 29 – piles of collapsed blocks;  Erosion forms: 30 – meandering channel on flat accumulation
surface; 31 – dripholes; Other: 32 – trail; 33 – lake;  C – cross-sections: 34 – planes of repose with thin cover of ochres; 35 – ochres;
36 – aragonite; 37 – stalagmite; 38 – trail; D – profile in Oválna Passage: black squares – position of paleomagnetic samples; magne-
tostratigraphic results (column on the right) =  black – normal polarised magnetozone, white – reverse polarised magnetozone; for expla-
nations of 1 to 5, see the text.

OCHTINÁ ARAGONITE CAVE 401

that limestone corrosion and ankerite oxidation and mechani-
cal washout were the main speleogenetic agents. He consid-
ered that during periods of higher rainfall the limestone lens-
es, hydrogeologically isolated by the phyllites, could become
temporarily flooded with water.

Despite the abundance of distinctive corrosion forms in the

cave,  little  has  been  written  about  their  genesis  and  the  hy-
draulic conditions under which they may have formed. Drop-
pa (1957) mentioned effects of hydrostatic pressure when the
open cavities were completely flooded. Gaál & Ženiš (1986)
and  Gaál  (1996,  1998)  argued  that  the  cave  formed  under
phreatic conditions. Bella (1997, 1998) was the first to recog-
nize  that  the  planar  solution  roofs  (bevels,  Laugdecken),
planes  of  repose  (facets,  Facetten)  and  longitudinal  wall
notches  are  particularly  important.  Cupola-shaped  depres-
sions in the roof originated by convective processes in the wa-
ter. He also recognized the dominant role of phreatic and stag-
nant  vadose  waters  in  the  cave  evolution  at  times  when  the
carbonate  lens  was  water-saturated  (cf.  Ford  &  Williams
1989, p. 294—308).

Due to the difficulty of explaining the origin of concave

corrosion  forms  and  the  development  of  passages  with  oval
cross-sections,  Choppy  (1994,  following  ideas  of  Nicod
1974), suggested that the OAC evolved as a result of hydro-
thermal  processes.  Gaál  (1996)  contended  that  hydrothermal
processes  during  the  Late  Cretaceous  time  operated  at  much
greater depths, however, and that the accelerated Tertiary and
Quaternary  meteoric  karst  corrosion  completely  overprinted
traces of any earlier hydrothermal activity. Results of detailed
geomorphological  research  do  not  support  a  hydrothermal
genesis  for  the  surviving  initial  forms  (Bella  1998).  Cílek  et
al.  (1998)  stressed  the  nothephreatic  origin  of  some  of  these
morphologies (cf. Jennings 1985). No hydrothermal minerals
have  been  detected  in  the  cave  and  the  aragonite  deposition
was not related to hydrothermal conditions (see Cílek & Šmej-
kal 1986; Rajman et al. 1990, 1993).

The presence of fresh, unweathered corrosion forms led

Droppa  (1957)  to  propose  that  the  caves  were  relatively
young,  with  speleogenesis  occurring  at  the  beginning  of  the
Holocene. Kubíny (1959) suggested that the caves originated
during  Quaternary  glaciations.  Weathering  of  the  ankerites
and successive exhumation and erosion of the ochres began in
the  Tertiary  and  has  been  active  ever  since  in  the  view  of
Homza et al. (1970), and Rajman et al. (1990). The first U se-
ries dating of samples of the aragonite (Ford, unpublished, cit-
ed in Rajman et al. 1990, 1993) gave two ages, one of 138—
121  and  the  other  of  14  ka  B.P.  that  rule  out  a  Holocene
origin.

Morphology

Detailed geomorphological mapping (Bella 1998), based on

previous maps (Ševčík & Kantor 1956, and Droppa 1957) has
defined the principal and smaller morphological forms (for lo-
cation and list of forms, see Fig. 1). The forms described here-
after are given non-genetic descriptive names owing to the
fact that some of them cannot be correlated with any com-
monly applied terms (e.g., those of Slabe 1995).

The cave consists of two genetically different types of voids

or  principal  speleogens:  (1)  high  and  narrow  linear  fissures
(e.g., from Vstupná Hall to Mramorová Hall; Fig. 1B), and (2)
a  labyrinth  of  passages  and  chambers  with  oval  cross-sec-
tions. Bedrock corrosion forms are the most abundant type of
speleogens.  Structural-tectonic  forms,  clastic  sedimentary
depositional  and  erosional  forms  are  less  frequent  (Fig.  1B).
The corrosional speleogens are products of the enlargement of
the caves, occurring on the floors, walls and roofs of all pas-
sages and chambers. They can be classified by their geometry
into: planar, concave, and convex types. The principal planar
speleogens  are  horizontal  solutional  ceilings  (Laugdecken
sensu  Kempe  et  al.  1975  or  bevels  sensu  Ford  &  Williams
1989)  and  inclined  planar  walls  descending  to  the  floors  of
passages and halls (planes of repose sensu Lange 1962, 1963;
Goodman 1964 or Facetten sensu Kempe et al. 1975; Figs. 1C
and  2.3).  The  predominant  concave  speleogens  are  pro-
nounced, more or less closed oval cupola-shaped depressions
in  roofs  (Fig.  2.1).  Horizontal  concave  notches  extending
along walls and convex bedrock prominences just above them
indicate positions of long-lasting paleo-water levels. In addi-
tion there are elongated shallow trough-like depressions and tu-
bular karren produced by flowing water for example in Vstupná
and Mramorová Halls.

Corrosion bevels are developed at three different levels

within the cave. The highest is preserved in Oválna Passage.
Lower bevels occur in Ježovitá Passage and Aragonitová
záhrada and 2 m below the roof in Oválna Passage. Near the
junction of Ježovitá Passage and Hlboký Hall, there is also a
bedrock pendant truncated by bevelling 0.4 m below the roof
level. The lowest bevels correspond with the low roof level in
Aragonitová záhrada near Hlboký Hall. This indicates that the
retention level of stagnant water in the cave has fallen over
time and/or oscillated substantially at different times.

Flat surfaces (smooth joint planes without any corrosional

relief) produced by breakdown along structural discontinuities
(Mramorová Hall) represent structural-tectonic forms.  Depo-
sitional forms (sediment sequences, piles of collapsed blocks,
etc.) developed when clastic sediments were deposited or re-
moved from the caves: for example horizontal accumulations
with  desiccation  cracks,  deposited  by  periodic  floods;  cones
of  infiltration  sediments  from  percolating  water  (Vstupná
Hall).  Small  depressions  (small  meandering  channels,  drip-
holes) resulting from the erosion of clayey sediments by flow-
ing and dripping water in Vstupná Hall represent clastic ero-
sional speleogens, which are less important in the cave.

Mineralogy

Methods

Twenty three samples of ochres, clays, broken aragonite

speleothems and neomorphic aragonite were collected in the
cave. Twelve typical samples were studied by SEM and anal-
ysed on 60 points by EDAX (LINK connected to a JEOL-
JXA-50A Microprobe). A total of 34 X-ray diffraction analy-
ses were made (Philips Diffractometer PW 3710, radiation
CuK

). Powder produced for the X-ray work was also analy-

OCHTINÁ ARAGONITE CAVE 403

Sample/

Oxide

Ochre Asbolane Allophane

Muscovite La-Nd-

bearing

phosphate

SiO

4.31

23.88 51.14 57.67 14.09

TiO

0.05 nd 0.19 0.40 nd

2.48

24.24 41.16 33.45 13.71

/FeO*

84.01

*2.14 1.29 0.75 *5.94

0.16

1.03 0.08 0.11 1.04

0.27

0.10 0.20 11.86 0.20

CaO

0.57

1.22 3.29 0.08 4.01

MgO

1.80

13.28 2.27 1.91 2.37

MnO

6.34

29.65 0.37 0.23 27.80

BaO

nd nd nd

1.40

NiO 3.94

3.94 nd nd

2.87

0.52

0.52 nd nd

5.46

nd nd nd

12.21

nd nd nd

8.91

nd — not determined

lar forms (several

m) “floating” in fine-grained ochre. The

moisture content of the ochres distinctly influences the hu-
midity of the air analysed in the cave, as the ochres function
as a humidity buffer, able to adsorb and release water vapour.

The ochres contain irregular laminae of birnessite

[(Na,Ca)Mn

·3H

O]. In addition to clastic quartz, the

ochres also contain clay minerals (muscovite 2M

, illite, prob-

able chlorite and 1.48 nm smectite) that were deposited on the
rock surface in flooded cave conditions. Some of the ochres
contain elevated concentrations of P

(0.3 to 1.0 %; cf. Ta-

ble 1).

Asbolane

Black Mn ochres occur as an admixture in the Fe ochres

and other cave fills. They are derived from the ankeritic meta-
somatites,  which  contain  about  2  %  MnO.  The  sequence  in
Oválna  Passage  (Fig.  2.4)  is  composed  of  very  fine-grained
massive brown clay (a mixture of goethite and clay minerals)
and includes a layer about 300 mm thick that is composed of
several  bands  of  Mn  ochres  with  abundant  intercalations  of
white allophane and redeposited Fe ochres. Asbolane is abun-
dant here as soft, black, earthy material with a clayey appear-
ance. Bulk samples and various grain-size fractions were anal-
ysed.  There  were  problems  of  exact  identification  due  to
structural  disordering,  the  almost  amorphous  nature  of  the
mineral  that  may  represent  a  mixture  of  semi-amorphous
phases. However a comparison with PDF-2 (Powder Difrac-
tion File, CD Rom of JCPDS-ICDD, 1996; Fig. 3) points to
asbolane  as  the  closest  mineral.  Submicron-sized  plates  of
muscovite  2M

remained in the sample even after extended

sedimentation, masking other diffuse diffraction lines.

Asbolane comprise about 30 to 40 % of the black fills. It is

usually accompanied by muscovite, and also by quartz, goet-
hite,  allophane,  birnessite,  apatite,  anatase  and,  more  rarely,
by  rutile  and  authigenic  La-Nd-bearing  phosphate  (Fig.  4a).
Nickel content can reach 3.94 % (Table 1), while only traces
of Co (less than 0.1 %) appeared. The magnesium content is
relatively  stable  but  can  be  locally  increased  (2.4  to  nearly

10 %). Similar variability was detected in P, Ba (0.4 to 1.4 %)
and the rare earth elements (REE).

Sometimes the asbolane consists of microscopic globules of

Mn-oxide covered by fine Mn-fossilized organic filaments,
indicating the microbial conversion of Mn

to Mn

. The as-

bolane layers probably result from bacterial precipitation in
shallow residual pools left after the cave was suddenly
drained (see also Andrejchuk & Klimchouk 2001).

Birnessite

Birnessite occurs as a soft black substance. It cannot be dis-

tinguished optically from the asbolane. Birnessite was identi-
fied both in Fe ochres (as fine darker coloured and irregular

Fig. 4. DTA/TG curves of asbolane (a) and allophane (b) from the
Oválna Passage (velocity of heat 10

C.min

—1

, air 10 ml.min

—1

sensitivity DTA 10

V/10mV).

Table 1: Representative chemical analyses of selected minerals.

Fig. 3. X-ray diffraction spectrum of the asbolane layer. A – as-
bolane, Q – quartz, M – muscovite, AP – apatite, G – goethite.

404 BOSÁK et al.

bands) and in the asbolane layers where it is probably a prod-
uct of maturation of asbolane.

Allophane

Allophane was found only in the asbolane deposits, as sepa-

rate white, fine-grained earthy layers 30 to 80 mm thick disin-
tegrating into cubes, or as admixtures within the asbolane.
Allophane was identified by chemical analyses, X-ray diffrac-
tion and particularly by DTA and TG analyses (Fig. 4b).

Allophane is an uncommon mineral in karst caves (Hill &

Forti 1997, p. 179—181), but nevertheless, is relatively abun-
dant in speleothems growing in abandoned mines. It has also
been  found  in  pseudokarst  fissure  caves  (Cílek,  Langrová  &
Melka 1998). Allophane commonly forms in the acidic envi-
ronment  produced  by  weathering  of  sulphides  in  the  sur-
rounding  rocks.  Its  occurrence  in  limestones  that  are  usually
associated with high pH may therefore appear somewhat surpris-
ing.  However,  its  presence  is  a  strong  indication  that  sulphide
weathering played a role during speleogenesis of the cave.

Kaolinite group mineral (halloysite)

A mineral of the kaolinite group, structurally similar to hal-

loysite, occurs as an indistinct admixture in the allophane. It
was detected by X-ray diffraction. We presume that it formed
either by maturation of the allophane or that the allophane was
formed by the transformation of weathering products contain-
ing minerals of the kaolinite group.

Anatase

Authigenic cryptocrystalline anatase forms amoeba-like

patches  of  cement  in  small  fragments  of  brown  ferruginous
clayey siltstones/sandstones. The fragments represent relics of
kaolinitization products washed down into the cave. Anatase
was  detected  by  chemical  analyses  and  on  the  basis  of  mor-
phological  comparison  with  samples  from  the  Czech  Karst
(Cílek & Bednářová 1993).

Apatite

Authigenic apatite forms irregular thin laminae, less than

1 mm thick, and irregular amoeba-like impregnations in the
asbolane profiles. It was detected by chemical analysis and X-
ray diffraction. Migration of Ca-phosphate requires an acidic
environment. Phosphates, other than those derived from gua-
no, precipitate in limestone from relatively acidic surficial P-
enriched solutions, which have been leached from soil and
weathering profiles.

Accessory minerals

Muscovite 2M

is a very common accessory mineral, detect-

ed in samples by X-ray diffraction, then separated and chemi-
cally analysed. The typical chemical analysis is given in Table
1. Muscovite occurs as very fine-grained plates. It is probably
derived from phyllites. Quartz occurs as angular and corroded
silt-sized grains. Acicular rutile was found in some places as-
sociated with anatase cement.

La-Nd-bearing phosphate

Detailed sampling of the asbolane layer revealed places

with increased P content in the form of apatite (X-ray identifi-
cation). In other places the P content was slightly greater than
Ca content. Nevertheless, high La (La

up to 12.21 %) and

Nd contents (Nd

up to 8.91 %) occurred in similar posi-

tions repeatedly. The La-Nd-bearing phases are very fine-
grained (tens of

m) and cannot be macroscopically distin-

guished within the black asbolane. The chemical composition
of the phosphate-asbolane layer with high REE and Ba con-
tents is listed in Table 1.

The REE regularly occur in association with high P concen-

trations. In some places the REE concentration is higher than
the P contents, so the relationship between REE and Mn ox-
ides has to be taken into account. A number of REE released
by weathering (presumably of volcanics) can migrate effi-
ciently within carbonate sequences. They form authigenic
minerals only with difficulty, but they can be fixed in finely
dispersed phosphate or in Mn oxides.

Aragonite

Aragonite speleothems are the outstanding feature of this

cave. According to Rajman et al. (1990, 1993), aragonite spe-
leothems have been traditionally classified according to their
morphology into: kidney-shaped, acicular and spiral (i.e. flos
ferri) forms. Cílek et al. (1998) identified three generations of
aragonite speleothems according to their age and/or relation-
ship to the speleogens.

The oldest aragonite generation (AI) occurs as massive,

whitish milky-coloured, kidney-shaped forms and irregularly
corroded relics with polyhedral appearance, rarely more than
300 mm thick (Fig. 2.2). The aragonite is highly and irregular-
ly  recrystallized  and  corroded.  Fine-grained  parts  are  still
composed of aragonite (radial-fibrous aggregates), with some
calcite (blocky mosaic). Recrystallized patches consist of cal-
cite,  with  some  aragonite,  mica  and  quartz  (X-ray  analysis).
Fine  box-work  structures  or  very  fine  dogtooth-like  crystals
cover  walls  of  corrosion  voids.  Some  voids  are  filled  with
milky-white  finely  radial-fibrous  aggregates  of  aragonite  or
by mica-rich sediment (X-ray detection). Long duration phos-
phorescence (up to 5 s.) after illumination by UV-lamp differ-
entiates the oldest generation from the younger one. Plane so-
lution roofs (bevels) commonly truncate the oldest aragonite.

The second generation of aragonite (AII) occurs as long

needles and helictites, so-called acicular and spiral forms, up
to several hundred millimetres long (Fig. 2.5) growing on the
metalimestone walls and roofs, and along fissures. It displays
fluorescence, but no phosphorescence in UV-light. The arago-
nite  needles  are  sometimes  associated  with  globular  opal.
Crystal  faces  do  not  display  any  corrosion,  even  under  high
magnification  (

30 to 500). Microscope and field observa-

tions indicate that this generation of aragonite has been grow-
ing continually up to the present time, explaining its bright
white colour and fresh appearance.

The youngest aragonite generation (AIII) has not previously

been detected due to its tiny size (Fig. 2.6). It occurs as fine
fan-like forms with diameter of 2 to 4 mm (sometimes more)
and as miniature helictites with lengths not exceeding 40 mm.

OCHTINÁ ARAGONITE CAVE 405

The helictites usually grow from centres of radial aggregates.
These  forms  –  “frostwork”  –  grow  on  soil  and  Fe  ochres,
typically  in  Hlboký  Hall  above  the  lake.  Here,  aggregates
cover thin coatings of loam and ochre deposited from stagnant
water. There was inhomogeneous glowing, with greenish and
bluish points and phosphorescence of 1 to 2 seconds duration
appeared  when  the  aragonite  was  illuminated  by  the  UV-
lamp.

U series ages of speleothems

Samples of aragonite and calcite were collected by Štefan

Roda sen. in 1989 or 1990, and by Pavel Bosák and Pavel
Bella in 1997, 1999 and 2000 in Oválna Passage and Hlboký
Hall. The location of Roda’s samples was marked by red
crosses on the map in Rajman et al. (1990).

Methods

Samples of aragonite and calcite have been dated in two

laboratories  –  at  McMaster  University,  Hamilton,  Canada
(Ford)  and  at  the  Institute  of  Geological  Sciences,  Polish
Academy of Sciences, Warsaw, Poland (Hercman). Two ap-
plications  of  the

230

Th/

234

U method (Ivanovich & Harmon,

Eds.  1992)  were  adopted,  the  first  using  the  older  standard
means of estimating the ratio of the two isotopes by counting
radioactive  disintegrations  (alpha  particles)  by  spectroscopy;
the second using the modern method of direct isotope count-
ing  in  a  mass  spectrometer  (TIMS  –  thermal  ionisation
mass spectrometry; Li et al. 1989). Results are summarized
in Table 2.

Results

Ford dated two of Roda’s samples in 1990 (90/Och1 and

90/Och2). All samples had a high uranium content (as is typi-
cal in aragonite) and negligible amounts of detrital thorium,
and thus yielded precise and unambiguous ages. Results were
partly published by Rajman et al. (1993).

Sample 90/Och2 was a portion of aragonite flowstone (AI/

2) broken during trail construction. It was 20 mm in thickness,
clean and opaque white, with a coconut meat texture. For al-
pha dating it was cut into three slices of ~7 mm thickness each
(samples  Och2A,  Och2B  and  Och2C),  representing  the  top,
middle and base of the deposit respectively. All three analyses
yielded  U  contents  of  8—10  ppm.  Thorium  was  lost  from
Och2C  during  the  extraction,  with  the  result  that  no  date
could  be  obtained.  Sample  Och2B  from  the  middle  third  of
the flowstone gave an age of 138,000±7,000 years BP, where
±7,000 is the one standard deviation statistical counting error.
Sample Och2A from the top one third of the flowstone gave
an age of 121,000±6,500 years.

If sample Och2 grew at a constant rate between Och2B and

Och2A,  then  the  accumulation  rate  was  ~0.41  mm/1,000
years.  If  it  is  further  assumed  that  all  of  the  deposit  grew  at
this  constant  rate,  then  its  growth  commenced  about  162  ka
ago and ceased at approximately 115 ka ago.

Sample 90/Och1 consisted of three broken aragonite spiral

helictites (AII “needles” or “whiskers”), all measuring about
60 mm in length and tapering from ~3 mm external diameter
at the base to ~2 mm at the tip. They contained central canals
for water flow but the tips were sealed. The needles appear to
be extending by fluid permeating out and precipitating in the
region of the tips and it was supposed that the latter were

Table 2: Uranium series dating.

Method

Sample

Lab. No

U conc.

[ppm]

234

238

230

Th/

234

230

Th/

232

Age
[ka]

Remarks

JOA 1

W142

3.553

±0.049 1.056±0.008 1.388±0.024

216

leaching?

JOA 2

W152

0.650

±0.020 1.086±0.044 1.246±0.030

23 U

leaching?

JOA 3

W158

6.157

±0.089

1.132

±0.009

0.823

±0.019

1140

+10

177

-9

01/Och2 W270

1.755

±0.047 1.002±0.028 1.017±0.036

432 >350

Calcite

01/Och1 W269

5.505

±0.112 1.064±0.017 1.093±0.030

780 >350

Aragonite

90/Och1 -

* 13.5±0.5

90/Och2A -

* 121±6.5

90/Och2B -

* 138±7.0

α-s

ros

copy

90/Och2C -

Lost

95/Och1A -

* 13.3±0.068

95/Och1B -

01/Och1A

aragonite

- 5.5

0.9934

1.046

±0.003

63000

Age cannot be calculated

01/Och1B

aragonite

- 5.6

0.9975

1.057

±0.003

49000

Age cannot be calculated

01/Och2A

calcite

0.76

1.0268

0.9938

7065

+69

449

-42

01/Och2B

calcite

- 0.67

0.9999

1.0101

±0.007

7064

Age cannot be calculated

02/Och2

+267

505

-71

N.B. Error margins quoted are two standard deviations for TIMS data and one standard deviation for alpha-spectroscopy.
* Data not available (lost when laboratory moved).

406 BOSÁK et al.

modern. The observed sealing of the tips might possibly be a
consequence of the artificial opening of the cave changing the
microclimate.

The basal 15 mm of one needle were analysed by the alpha

method in 1990 (sample 90/Och1), yielding the remarkable U
content of 15 ppm and an age of 13,600±500 years (one stan-
dard deviation). As a check, a second needle was analysed by
mass spectrometry in 1995. The basal 15 mm of growth con-
tained 18 ppm U and yielded an age of 13,300±68 years (two
standard deviation error; 95/Och1B). No age could be derived
for the top 15 mm (sample Och1A, 16 ppm U) because it had
insufficient thorium; this implies that it is both very clean (no
detrital contamination problems) and young, supporting the
assumption that the very tip is modern. From these measure-
ments we establish that the needle grew ~52.5 mm in 13.3 ka,
giving a mean extension rate of about 4 mm per 1 ka.

Two pieces of the AI generation truncated by bevels from

the junction of the Oválna Passage and Hlboký Hall (samples
JOA 1 and JOA 2) were corroded and partially recrystallized
to calcite. Measurements were done with alpha spectroscopy
(OCTET PC, EG & G ORTEC; by Hercman in 1999). Both
analyses yielded low uranium contents (0.6 and 3 ppm) and a

230

Th/

234

U ratio significantly higher than 1 (about 1.4). The

high ratio, unusual in the nature, suggests that there was pref-
erential leaching of uranium from the samples during recrys-
tallization and/or corrosion, rendering the computed age unre-
liable.  Alpha  spectrometric  data  from  similar  eroded  old
aragonite and calcite flowstone of the AI generation that were
found  as  fragments  within  the  cave.  Data  of  Hercman  from
early  2001  indicated  age  both  of  calcite  and  aragonite  over
350  ka.  Therefore,  TIMS  U  series  analyses  were  made  by
Ford in 2001 on another part of the same samples. The miner-
alogy  was  confirmed  by  X-ray  diffraction.  The  extractions
were carried out in a clean room with laminar flow hoods, and
two analyses were made of each sample.

The two analyses of calcite (01/Och2A and 01/Och2B) are

very similar. The U content is satisfactory for calcite (most
speleothems have between 0.05 and 1.0 ppm). The sample is
clean (

230

Th/

232

Th >>20). In the second analysis the

230

Th/

234

U ratio just exceeded 1.0000, possibly from detritus. But it

is very similar to the first analysis in all other respects. This
can be taken as confirmation that the age estimate of approxi-
mately 450 ka is acceptable, which was confirmed by repeat-
ed analysis (02/Och2).

Two analyses of aragonite (01/Och1A and 01/Och1B) show

that the sample is very clean and has the high U content typi-
cal of aragonite. The

230

Th/

234

U ratio is just in secular equi-

librium, so that an age cannot be obtained by this method.

234

238

U on the other hand is not in equilibrium, implying

that the sample is certainly younger than 1,250,000 years. It is
probably a little older than the calcite sample.

Paleomagnetism

A clastic sediment section well exposed on the northern

side  of  the  Oválna  Passage  is  about  0.7  m  high  (Fig.  1D).
From  the  top,  it  is  composed  of  the  following  layers:  1  –
white  flowstone  with  stalagmite;  2  –  clay,  reddish  brown,
with  greyish  black  schlieren  enriched  in  Mn-compounds,

massive, laminated in places, disintegrated into irregular poly-
hedral fragments (samples OCH 1 and OCH 2); 3 – alterna-
tion  of  reddish  brown  clay  (thickness  max.  1.5  cm;  samples
OCH 3 and OCH 4) with layers blackened by Mn-rich miner-
als  (thickness  from  4  to  6  cm),  and  white  bands  with  allo-
phane  crystals  (thickness  of  1  to  5  cm;  Fig.  2.4);  4  –  clay,
reddish  brown,  massive,  disintegrates  into  irregular  polyhe-
dral fragments (sample OCH 5).

The flowstone, about 1—2 cm thick (layer No. 1 on Fig. 1D)

was dated by the U series alpha counting method (Hercman).
The U content (about 6 ppm) was similar to aragonite samples
(see above). The content of detrital Th was negligible. The
analysis gave an age of 177,000+10,000/—9,000 at one stan-
dard deviation.

Methods

Samples were demagnetized by the alternating field proce-

dures up to 1,000 Oe with a Schonstedt GSD-1 machine. The
remanent magnetisation J

was measured on a JR-5 spinner

magnetometer (Jelínek 1966). Values of volume magnetic
susceptibility k

were measured on a kappa-bridge KLY-2

(Jelínek 1973). Separation of the respective remanent magne-
tization components was carried out by multi-component
analysis (Kirschvink 1980).

Results

The magnetic properties, both J

and k

values, of samples

from layer No. 2 are distinctly different from those of layers
Nos. 3 to 5 (Table 3). Sample OCH 1 (layer No. 2) displays
normal remanent magnetization. All underlying samples are
magnetically reversed (Fig. 1D). Pruner et al. (2000) correlat-
ed this polarity change with the Brunhes/Matuyama reversal
of 780 ka B.P., because the speleothem date of 177 ka estab-
lishes that it must be older than any of the short-lived reverse
magnetic excursions within Matuyama chron (cf. Zhu & Tschu,
Eds. 2001).

Discussion

At several places in the cave it can be clearly seen that the

voids were filled by ochres, which were later removed. Pas-
sages that are partly filled at present have an oval shape. They
were formed either before the ochres were produced by anker-
ite oxidation or before the eroded ochre residuum was depos-
ited in water-filled passages.

Sample No.

[pT]

[10

–6

SI]

Polarity

OCH 1

30,375

714

Normal

OCH 2

35,651

1,999

Reverse

OCH 3

11,879

347

Reverse

OCH 4

283

176

Reverse

OCH 5

1,715

161

Reverse

Mean value

15,981

679

Standard deviation

16,285

771

Table 3: Principal magnetic properties of samples.

OCHTINÁ ARAGONITE CAVE 407

The first subsurface cavities were formed by corrosion of

the  limestone  and  oxidation  of  the  ankerite.  These  cavities
were  flooded  by  meteoric  water  infiltrating  along  the  major
fault line in Vstupná and Mramorová Halls and also along the
lesser  fissures  in  Hlboký  Hall  and  Sieň  mliečnej  cesty  Hall.
Continuous and dominantly horizontal cavities formed along
parallel fissures. Irregular corrosion features developed on the
bedrock surfaces, these were considerably enlarged and modi-
fied by later corrosional events. The only original forms still
preserved  are  irregular  niches  and  cupolas  found  above  the
younger  corrosion  bevels.  The  source  of  the  carbon  dioxide
for intensive corrosion can be found in the ankerite weather-
ing with an end product of goethite, that is by a process simi-
lar to that described by Kempe (1998) from Harz (Germany)
for  alteration  of  siderite  to  limonite,  according  to  following
equations:

2FeCO

+ 2CO

+ 2H

O = 2Fe(HCO

)

, then (Eq. 1)

2Fe(HCO

)

+ 1/2O

+ H

O = 2Fe(OH)

+ 4CO

or (Eq. 2)

4FeCO

+ O

+ H

O = 2Fe

·nH

O + 4CO

(Eq. 3)

where 2Fe

·nH

O is limonite.

The frequent presence of pyrite in the metalimestones and

of allophane, a typical product of acid decomposition of clay
minerals, suggests that the corrosion might have been en-
hanced by sulphide weathering and oxidation to H

. Howev-

er, the absence of any gypsum replacing limestone or of native
sulphur in the cave indicates this effect was probably minor.

In the OAC, the origin of the niches and cupolas was linked

by some authors (Nicod 1974; Choppy 1994) with hydrother-
mal processes. However, both forms can originate from con-
vection  induced  by  gravitational  settling  of  water  enriched
with solute ions, without any hydrothermal influence (cf. Curl
1966;  Cordingley  1991;  Klimchouk  1997a).  The  density  of
water in the phreatic zone of a karst system will increase as it
dissolves the enclosing rock. During continual or periodic in-
filtration of “fresh” water into a water-saturated environment,
a density gradient forms. This can generate convection cells in
the water body, which may produce corrosion forms in the en-
closing  limestone.  The  effect  is  essentially  limited  to  condi-
tions of static or very slow water movement. In rapidly mov-
ing water this effect will be negligible.

Convection is a differential process, the dissolution produc-

ing roof cupola- and tube-like depressions in roofs that are be-
low  the  waterline,  horizontal  ceilings  (bevels)  or  corrosion
notches in the walls at the waterline, and inclined planar walls
beneath  it.  Convection  circulation  and  solution  cannot  only
modify morphological forms but it can also influence the en-
tire  pattern  of  such  cave  systems  during  their  initial  phases
where the waters are predominantly static or semi-static. This
feature is particularly common where there is artesian speleo-
genesis (Klimchouk 1997b).

The OAC is developed in an isolated lens of metalimestone

surrounded  by  non-karst  rocks.  Such  lenses  readily  fill  with
water during floods and drain only slowly afterwards through
poorly permeable phyllites. Corrosion notches along the walls
are  produced  in  acidic  stagnant  water  conditions  and  where
roofs dip down they will eventually be planed off as bevels at
the waterline. Stagnant water still forms a lake in the deepest
part  of  Hlboký  Hall.  Chemical  analysis  of  the  modern  lake

water  shows  that  it  is  highly  undersaturated  with  respect  to
both calcite and aragonite (Bella et al. 2000). The difference
of  elevation  between  the  highest  bevel  in  the  cave  and  the
present lake level is 12 m. Nearly horizontal bedding favoured
bevelling in Ježovitá Passage and Aragonitová záhrada, while
corrosional  ledges  that  have  developed  in  steeply  dipping
beds indicate the corrosional origin of the bevels. Notches and
bevels  commonly  intersect  the  older  speleothems,  such  as
those discussed above.

Planes of repose (Lange 1962, 1963; Goodman 1964) are

found in many parts of the cave (Fig. 2.3). These are the in-
clined  bedrock  surfaces  developed  in  the  lower  portions  of
cavern  walls.  They  also  formed  during  periods  of  very  slow
water circulation when accumulated insolubles blocked solu-
tion enlargement at the base of a wall in a flooded section of
cave.  In  passages  where  bevels  are  developed,  planes  of  re-
pose are similar to Facetten (sensu Kempe et al. 1975).

Iron ochres were formed by the weathering of ankerite/sid-

erite metasomatites. The ochres are composed principally of
goethite and a variety of autochthonous minerals deposited in
flooded cave conditions or by the dripping water. The ochres
contain on average 50 % water. They cover a substantial area
of the cave and act as an important humidity buffer stabilizing
the microclimate. The natural humidity, not affected by visi-
tors, is extremely stable (99 % in average, Klaučo et al. 1998).

Black Mn-bearing loams contain Ni-bearing asbolane and

birnessite,  which  developed  from  asbolane.  Mn-oxides  were
most  probably  formed  by  microbial  precipitation  at  the  bot-
tom of water bodies, as recently described by Andrejchuk &
Klimchouk (2001), that is just after the cave was drained and
fresh  air  entered  it.  Beds  of  allophane  occur  within  the  as-
bolane layers (Fig. 2.4).  Because it forms in a low pH envi-
ronment,  allophane  is  not  a  common  mineral  in  karst  caves.
We suggest that the allophane could have formed in the acidic
conditions  produced  by  weathering  of  sulphide  minerals.  A
kaolinite  group  mineral  similar  to  halloysite  was  formed  by
maturation of allophane. The asbolane layer formed an impor-
tant  geochemical  barrier,  which  caused  the  concentration  of
the REE, the growth of La-Nd-bearing phosphate and eventu-
ally the formation of the REE-enriched Mn oxide. Due to vari-
ations in local permeability and the diversity of sources, apa-
tite has formed only in some parts of the karst fills. In other
places the possible effect of phosphate molecular sieving led
to  formation  of  REE-bearing  phosphates.  The  excess  of  the
REE concentration became bound to Mn oxide.

The allogenic minerals, which have entered the cave are ex-

tremely fine-grained and partly weathered and abraded. They
indicate that the cave was poorly connected with the surface,
allowing only slow infiltration through narrow or choked fis-
sures, rather than direct, open communication with flowing
streams. Features of the quartz grains indicate that they have
derived from dissolution of the local limestones rather than
being transported from greater distances.

Two principal factors caused deposition of aragonite in the

OAC: (1) high concentrations of Mg, Fe and Mn ions in the
karst solutions, and (2) a closed and deeply-seated, partly
flooded cave environment with a high proportion of the walls
covered by moist Fe ochres.

The ochres act as a humidity exchanger between the walls

and the cave atmosphere. Ochtiná aragonite occurs most fre-

408 BOSÁK et al.

quently on substrates with water rising by capillary action or
with very slowly percolating water on moist sediments, which
slowly release water vapour into the cave atmosphere. A simi-
lar situation is also observed in Zbrašovské Aragonite Caves
(Czech Republic; V. Cílek unpubl.).

The isotopic composition of carbon in the aragonite, ex-

pressed the customary

C values, varies between —7.4 and

—6.0 ‰ (PDB). Oxygen isotopic composition (

O) was

found to fall within the range between —7.0 and —6.3 ‰
(PDB). The C and O isotopes thus are within the range typical
for isotopically equilibrated cave carbonates formed under the
slow, equilibrium release of CO

from solution. The graph in

Figure 5 compares aragonites from Ochtiná Cave with calcites
and aragonites from Starý hrad Cave (Nízke Tatry Mts., Slo-
vakia; Cílek & Šmejkal 1986). Ochtiná aragonites plot within
the field of the lowest values of the calcite spelothems from
Starý hrad Cave, but distinctly away from the Starý hrad ara-
gonites, indicating different depositional conditions. While
aragonite from the well-ventilated Starý hrad Cave shows in-
fluence of kinetic CO

escape from the solution, and of aque-

ous evaporation, the Ochtiná aragonite, from a closed envi-
ronment, shows an isotopic composition in the field typical
for usual “equilibrium-type” cave carbonates.

Rapid kinematic processes and evaporation can be excluded

from any role in the deposition of the aragonite. The slow iso-
topic re-equilibration of HCO

within the thin film on cave

walls and growing crystals with CO

in cave air could take

place, too. The measured data are not in isotopic equilibrium
with the CO

of the outside air. In poorly ventilated caves,

concentrations are often substantially higher than in the

external atmosphere, while the isotopic composition of that
CO

is substantially lower than outside. The genesis of the

aragonite in the OAC cannot be completely explained until
data from direct measurement of CO

concentrations and car-

bon isotopic composition, as well as in parent solutions are
available. Nevertheless, the isotopic data show one important
result – the aragonite of the AIII generation has an identical
isotopic composition that is nearly identical to as the acicular
aragonite AII (see Fig. 5) – both types thus were deposited
under similar conditions.

The AI generation of speleothems are preserved as corroded

relics truncated by bevels (Fig. 2.2). The aragonite in them is
partly recrystallized to calcite. There were at least two sepa-
rate periods of the growth (AI/1 and AI/2). TIMS U series
ages for recrystallized calcite of the older sample (AI/1) indi-
cate an age of about 450 ka. TIMS U series ages for the arago-
nite cannot be calculated as they are at the limit of the method.

234

238

U on the other hand is not in equilibrium, implying

that the sample is certainly younger than 1.25 Ma. It is proba-
bly a little older than the calcite sample and perhaps related to
a warm episode of Elsterian 1/2.

The aragonite in the younger recrystallized speleothems

(AI/2) yielded U series dates indicating an Eemian age (138-
121 ka). The pre-recrystallization age may be greater. The AII
generation, of spiral and acicular aggregates (Fig. 2.5), began
to be deposited during Late Glacial (Alleröd, 14 ka). Growth
has continued to the present day. The AIII generation, of fine
acicular aggregates of aragonite and miniature helictites, is
also actively growing (Fig. 2.6). The AII and AIII generations
have similar isotopic compositions, indicating that they origi-

nated in conditions very similar, or identical, to those found at
present in the cave.

Conclusions

The modern morphology of the cave reflects a comparative-

ly complex evolution under particular lithological and hydro-
geological conditions within an isolated lens of karst rock sur-
rounded  by  insoluble  rocks.  Such  lenses  can  become  filled
with water, often with artesian confinement and have little or
no  relationship  to  development  of  the  surface  hydrological
system and morphology. Primary phreatic subsurface cavities
were formed by the corrosion of the limestone and oxidation/
erosion of the ankerite. Elongated, chiefly horizontal cavities
formed  along  parallel  fissures.  Irregular  corrosion  forms  de-
veloped on the bedrock surfaces. The niches and cupolas are
relics  of  phreatic  speleogens  created  by  convection  induced
by gravitational, density-derived circulation of water in a re-
gime of very slow flow. Hydrothermal effects are not neces-
sary. The abundant pyrite together with a common allophane
indicates  the  carbonic  acid  corrosion  was  most  probably  en-
hanced  by  sulphide  weathering  producing  diluted  brines.
Thermohaline convection cells operating in the flooded cave
might also have influenced the wall morphology.

Younger corrosional events under vadose conditions

changed the original forms to a large extent. The intensity of
corrosion was enhanced by carbon dioxide released by anker-

Fig. 5. The isotopic composition of calcite and aragonites from the
well ventilated Starý hrad Cave in the Nízke Tatry Mts compared
with the closed deeper system of Ochtiná Aragonite Cave. Very
slow evaporation and isotopic equilibrium fractionation is proposed
for the samples from Ochtiná (AII and AIII aragonite generations).

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

O (‰, PDB)

C (‰, PDB)

Starý Hrad Cave - calcite
Starý Hrad Cave - aragonite
Starý Hrad Cave - calcite and aragonite (mixture)
Ochtinská Cave - aragonite

–

OCHTINÁ ARAGONITE CAVE 409

ite  weathering  in  the  oxidizing  meteoric  waters.  The  water-
level fluctuations were repeated several times as indicated by
several levels of flat roofs (bevels), wall niches and planes of
repose.  Bevels  form  by  corrosion  in  stagnant  water  condi-
tions. Roof planation was influenced both by limestone bed-
ding  and  by  the  duration  and  intensity  of  water  convection.
Bevels  intersected  older  speleothems.  Corrosion  notches
along the walls indicate that the levels of stagnant water were
stable for long periods, representing significant phases of cave
enlargement. Planes of repose also indicate slow water circu-
lation following floods; accumulated insolubles blocked solu-
tion enlargement at the base of a cave wall.

Water-level oscillations and water flow have to be very

slow, as indicated by the fact that the sediment section studied
in Oválna Passage survived several submergences. Neverthe-
less, the velocity of flow during the early phases of the cave
evolution had to be sufficient to transport the clastic products
of the ankerite disintegration into lower levels of the cave.

Dating this sequence of processes is a complicated and

risky task. We can assert that the cave started to form before
0.78 Ma according to the paleomagnetic data from the oldest
dated cave fill in Oválna Passage (Table 4). The roof of that
passage is the highest preserved bevel to have developed un-
der the succeeding vadose conditions. We may tentatively
link the formation of this highest bevel with the oldest sedi-
mentary fill. Therefore, vadose conditions probably were es-

tablished 0.78 Ma. The phreatic phase of cave development
has to be older (Late Tertiary/Pleistocene), but it cannot be
dated properly. It appears that the age of cave origin is close
to that suggested by Kubíny (1959) and Homza et al. (1970).
The sequence of cave development summarized in Table 4 is
based primarily on the U series dating of flowstones and ara-
gonite/calcite speleothems.

Acknowledgements: The authors wish to express their thanks
especially  to  Dipl.-Ing.  Jozef  Hlaváč,  Director  of  the  Slovak
Caves  Administration  in  Liptovský  Mikuláš  and  Mr.  Ján
Ujházy, Head of the Ochtiná Aragonite Cave for permission
to  conduct  research  and  to  take  samples  during  a  period  of
1996 to 2001. We acknowledge the contribution of: Dr. Karel
Melka and Mr. Jiří Dobrovolný (X-ray analyses and interpre-
tations),  Dipl-Ing.  Anna  Langrová  (microprobe  analyses;  all
from  Laboratory  of  Physical  Methods,  Institute  of  Geology,
AS  CR  Prague),  Dr.  Daniela  Venhodová  (production  and
evaluation  of  palaeomagnetic  data;  Department  of  Palaeo-
magnetism,  Insitute  of  Geology  AS  CR  Prague),  Dr.  Karel
Žák (stable isotopic analyses; Czech Geological Survey, De-
partment  of  Geochemistry,  Prague),  and  Dr.  Jana  Ederová
(DTA-GTA  analyses,  University  of  Chemical  Technology,
Prague). The research was carried out under the Agreement on
Scientific  Co-operation  between  the  Slovak  Caves  Adminis-
tration and the Institute of Geology AS CR. Costs were cov-

Age (ka)

Process

Water regime

Notes

Late Cretaceous

Hydrothermal activity

Thermal

Initial speleogenesis

Phreatic

Late Tertiary
Pleistocene

Cave enlargement

Epiphreatic, vadose

>780

<780

Corrosion, bevels and
deposition of sediments
(Oválna Passage)

Highstand

Lowstand

Asbolane as a product of sulphide
weathering by oxidising waters

Glacial?

Erosion/redepositon of cave
fill, possible bevels

Fluctuations

Periods of water highstands not excluded,
CO

released from ankerite

decomposition in oxidising waters

500

450

Speleothems, the oldest
generation AI/1

Lowstand

Calcite recrystallized from aragonite
prevails and is somewhat younger than
aragonite (ca. 50 ka)

Glacial?

Corrosion, bevels, cut of rocky
pendants, erosion/redeposition
of cave fill

Highstand and fluctuations

released from ankerite

decomposition in oxidising waters

177

Flowstone on sedimentary
profile

Lowstand

Glacial? Corrosion,

bevels,

erosion/redeposition of cave
fill

Highstand

released from ankerite

decomposition in oxidising waters

(162 calculated age)
138
121
(115 calculated age)

Aragonite speleothems, the
oldest generation AI/2

Lowstand

Only partly recrystallized to calcite

Glacial? Corrosion,

bevels,

erosion/redeposition of cave
fill
Corrosion, protrusions

Highstand

Fluctuations

Corrosional vugs in 138 –121 ka old
speleothems contain mica and quartz

14

0

Aragonite growth, AII
generation
Aragonite growth, the AIII
generation

Lowstand

Water level oscillations not excluded,
max. ca. 8 m

Table 4: Succession of processes during origin of Ochtiná Aragonite Cave.

410 BOSÁK et al.

ered from sources of the Caves Administration (Task B. of the
Main Activity Plan in 1998), Plan of Scientific Activity No.
Z 03-013-912 of the Institute of Geology AS CR, and Grant
No. A3013201 of the Grant Agency of AS CR. U series anal-
yses by Ford at McMaster University were supported by a
grant in aid of research from the National Scientific and Engi-
neering Research Council of Canada. We appreciate numerous
critical comments of Michał Gradziński, Tadeusz Peryt, and
Karel Žák.

References

Andrejchuk V.N. & Klimchouk A.B. 2001: Geomicrobiology and redox

geochemistry of the karstified Miocene gypsum aquifer, Western
Ukraine: The study from Zolushka Cave. Geomicrobiology Jour-
nal 18, 275—295.

Andrusov D. 1958: The geology of Czechoslovak Carpathians. Part I.

Publ. House Slovak Academy of Sciences, Bratislava, 1—304 (in
Slovak).

Bajaník Š. & Vozárová A. (Eds.) 1983: Explanations to the geological

map of the Slovenské rudohorie Mts. – eastern part. Geological
Institute D. Štúr, Bratislava, 1—223 (in Slovak).

Bella P. 1995: Principles and theoreticaly-metodical aspects of classifi-

cation of cave morphological types. Slovenský kras 33, 3—15 (in
Slovak, English summary).

Bella P. 1997: The views to the genesis of the Ochtiná Aragonite Cave.

Aragonit 2, 13—14 (in Slovak).

Bella P. 1998: Morphological and genetic features of the Ochtiná Arago-

nite Cave. Aragonit 3, 3—7 (in Slovak, English summary).

Bella P., Zelinka J., Peško P. & Gažík P. 2000: Natural phenomena and

protection of the Ochtina Aragonite Cave (Slovakia). In: L. Song
(Ed.): Show Caves Protection and Restoration. Proceedings of In-
ternational Symposium, Yaolin-Tonglu, China, 22—36.

Choppy J. 1994: La première karstification. Synthèse spéléologique et

karstique. Les facteurs géographiques 3. Spéléo-Club de Paris,
Club Alpin Français, 1—70.

Cílek V. & Bednářová J. 1993: Silcretes in the Bohemian Karst. Český

kras (Beroun) 18, 4—13 (in Czech, English summary).

Cílek V., Bosák P., Melka K., Žák K., Langrová A. & Osborne A. 1998:

Mineralogical investigations in the Ochtiná Aragonite Cave. Ara-
gonit 3, 7—12 (in Czech, English summary).

Cílek V., Langrová A. & Melka K. 1998: Pseudokarst phosphate-allo-

phane speleothems from ice caves of the Podyjí National Park.
Speleo (Praha) 26, 20—27 (in Czech, English summary).

Cílek V. & Šmejkal V. 1986: The origin of aragonite in caves. The

study of stable isotopes. Československý kras 37, 7—13 (in Czech,
English summary).

Cordingley N. J. 1991: Water stratification in active phreatic passages.

Cave Science 18, 3, 159.

Curl R.L. 1966: Cave conduit enlargement by natural convention. Cave

Notes 8, 1, 4—8.

Droppa A. 1957: Ochtiná Aragonite Cave. Geografický časopis 9, 3,

169—184 (in Slovak, Russian and German summary).

Ford D.C. & Williams P.W. 1989: Karst geomorphology and hydrolo-

gy. Unwin Hyman, London—Boston—Sydney—Wellington, 1—601.

Gaál . 1996: Exploration and protection of aragonite caves in sur-

roundings of the Hrádok Hill. In: P. Bella (Ed.): Sprístupnené jas-
kyne – výskum, ochrana a využívanie jaskýň. Zborník referátov,
Liptovský Mikuláš, 130—133 (in Slovak, English summary).

Gaál . 1998: Karst phenomena in the surroundings of the Hrádok Hill

and their relation to the Ochtiná Aragonite Cave. In: P. Bella (Ed.):
Výskum, využívanie a ochrana jaskýň. Zborník referátov, Lip-
tovský Mikuláš, 44—52 (in Slovak, English summary).

Gaál . & Ženiš P. 1986: Karst of the Revúcka Highland. Slovenský

kras 24, 27—60 (in Slovak, Russian summary).

Goodman L. R. 1964: Planes of repose in Höllern, Germany. Cave

Notes 6, 3, 17—19.

Grecula P. (Ed.) 1995: Mineral deposits of the Slovak Ore Mountains.

Volume 1. Geocomplex, Bratislava, 1—834.

Hill C. & Forti P. 1997: Cave minerals of the world. Second edition.

National Speleological Society, Huntsville, 1—463.

Homza Š., Rajman L. & Roda Š. 1970: Origin and evolution of karst

phenomenon of the Ochtiná Aragonite Cave. Slovenský kras 8,
21—68 (in Slovak, English abstract, German summary).

Ivanička J., Snopko L, Smopková P. & Vozárová A. 1989: Gelnica

Group – Lower Unit of Spiško-gemerské rudohorie Mts. (Early
Paleozoic, West Carpathians). Geol. Zbor. Geol. Carpath. 40, 4,
483—501.

Ivanovich M. & Harmon R.S. (Eds.), 1992: Uranium Series Disequilib-

rium. Applications to Environmental Problems. 2

Ed. Claren-

don, Oxford, 1—910.

Jelínek V. 1966: A high sensitivity spinner magnetometer. Studia Geo-

physica et Geodetica 10, 58—78.

Jelínek V. 1973: Precision A.C. bridge set for measuring magnetic sus-

ceptibility and its anisotropy. Studia Geophysica et Geodetica 17,
36—48.

Jennings J.N. 1985: Karst geomorphology. Basil Blackwell, Oxford,

1—293.

Kempe S. 1998: Siderite weathering, a rare source of CO

for cave gen-

esis: the Eisenstein Stollen System and adjacent caves in the Iberg,
Harz Mountains, Germany (abs.). Journal Cave Karst Stud. 60, 3,
188.

Kempe S., Brandt A., Seeger M. & Vladi F. 1975: “Facetten” and

“Laugdecken”, the typical morphological elements of caves devel-
oped in standing water. Annales de Spéleologie 30, 4, 705—708.

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

of palaeomagnetic data. Geophysical Journal of the Royal Astro-
nomical Society, Oxford, 62, 699—718.

Klaučo S., Filová J. & Zelinka J. 1998: The influence of visitor atten-

dance  on  speleoclimate  of  the  Ochtinská  Aragonite  Cave.  In:  P.
Bella (Ed.): Výskum využívanie a ochrana jaskýň. Zborník referá-
tov z  vedeckej konferencie, Liptovský Mikuláš, 75—85 (in Slovak,
English  summary).

Klimchouk A. 1997a: Artesian speleogenetic setting. Proceedings 12

International Congress of Speleology, La Chaux-de-Fonds, 1,
157—160.

Klimchouk A. 1997b: Speleogenetic effects of water density differenc-

es. Proceedings 12

International Congress of Speleology 1,

161—164. La Chaux-de-Fonds.

Kubíny D. 1959: Aragonite cave in Slovakia. Ochrana prírody 14, 1,

17—18 (in Slovak).

Lange A. 1962: Water level planes in caves. Cave Notes 4, 2, 12—16.
Lange A. 1963: Planes of repose in caves. Cave Notes 5, 6, 41—48.
Li W.-X., Lundberg J., Dickin A.P., Ford D.C., Schwarcz H.P., McNutt

R. & Williams D. 1989: High-precision mass-spectrometric urani-
um-series dating of cave deposits and implications for paleocli-
matic studies. Nature 339, 534—536.

Mišík M. 1953: Geology of the area between Jelšava and Štítnik. Geol.

Sbor. Slov. Akad. Vied 4, 3-4, 557—587 (in Slovak).

Nicod J. 1974: Les régions karstiques de Slovaquie et de Hongrie septen-

trionale. Bulletin Société de Géographie, N.S. 82, 12, 14, 11—25.

Pruner P., Bosák P., Kadlec J., Venhodová, D. & Bella, P. 2000: Paleo-

magnetic research of sedimentary fill of selected Slovak caves. In:
P.  Bella  (Ed.):  Výskum  využívanie  a  ochrana  jaskýň.  Zborník
referátov  z 2.  vedeckej  konferencie,  Liptovský  Mikuláš,  13—25  (in
Czech, English  summary).

Rajman L., Roda Š. jr., Roda Š. sen. & Ščuka J. 1990: Physico-chemical

investigation of the karst phenomenon of the Ochtiná Aragonite
Cave. Final Report. MS, Slovenské múzeum ochrany prírody a jas-
kyniarstva, Archive, Liptovský Mikuláš, 1—46 (in Slovak).

Rajman L., Roda Š. jr., Roda Š. sen. & Ščuka J. 1993: Untersuchungen

über die Genese der Aragonithöhle von Ochtiná (Slowakei). Die
Höhle 44, 1, 1—8.

Slabe T. 1995: Cave rocky relief and its speleogenetical significance.

Zbirka ZRC, Ljubljana, 10, 1—128.

Ševčík R. & Kantor J. 1956: Aragonite cave in the Hrádok Hill near Jel-

šava. Geol. Práce, Zpr. 7, 161—170 (in Slovak).

Zhu R.X., Tschu K.K. (Eds.) 2001: Studies in paleomagnetism and rever-

sals of geomagnetic field in China. Sciences Press, Beijing 1—168.