GEOLOGICA CARPATHICA, 52, 3, BRATISLAVA, JUNE 2001
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE
KROSNO BEDS IN THE FORE-DUKLA ZONE (SILESIAN NAPPE,
OUTER CARPATHIANS), POLAND
, JACEK RUBINKIEWICZ
, MAŁGORZATA GARECKA
and BEATA DZIUBIŃSKA
Institute of Geography, Cracow Pedagogical University, Podchorążych 2, 30-084 Kraków, Poland
Institute of Geology, University of Warsaw, Żwirki i Wigury 93, 02-089 Warszawa, Poland
Polish Geological Institute, Carpathian Branch, Skrzatów 1, 31-560 Kraków, Poland
Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Kraków, Poland
(Manuscript received August 1, 2000; accepted in revised form March 15, 2001)
Abstract: A layer with exotic blocks has been found in the flysch of the Krosno Beds, in the Fore-Dukla Zone (the
southernmost part of the Silesian Nappe in the Bieszczady Mts, Polish Outer Carpathians). It has been traced over a
distance of 1 km near Wetlina (the Bieszczady Mts), in the southernmost exposed tectonic slice. The exotic blocks
include crystalline schist (quartz—chlorite—muscovite—orthoclase schist with tourmaline and garnet) and three types of
limestones: 1/ massive, sparitic, partly siliceous limestone, with numerous calcite veins; 2/ micritic limestone with rare
planktic (Globigerina-like) foraminiferal tests; 3/ bioclastic limestone with numerous tests of small and large foramini-
fers, coralline algae (Rhodophyta), bivalves, bryozoans and rare echinoid spines. The exotics are embedded in light- and
dark-grey argillaceous, partly sandy, calcareous matrix, together with a few small angular pebbles of grey mudstones and
very fine-grained sandstones, which resemble lithological types of the Krosno Beds. The described rocks are similar to
those found as exotic blocks in the Krosno Beds in neighbouring areas (Roztoki Dolne and Ustrzyki Górne) of the
Central Carpathian Depression (Silesian Nappe). Calcareous nannoplankton from the exotic-bearing layer and neighbouring
deposits show that they are not older than the NP24 Zone (late Kiscellian), below the isochronous marker horizon of the
Jasło Limestone. It may correspond to the Tenuitella munda Zone of Olszewska (1997, 1998), proposed for the Polish
part of the Central Paratethys. The source area of the layer with exotics (islands with narrow shelf margins), probably lay
to the south and south-east, was built mainly of crystalline rocks, and partly covered by various types of carbonate
Eocene-Oligocene rocks. The deeper parts of the island slopes were covered with Cretaceous-Paleogene sediments,
related to deep-water sedimentation in the marginal zone between the Dukla and Silesian subbasins. These deep-water
deposits have been partly eroded during the submarine mass movements descending to the Silesian Subbasin.
Key words: Outer Carpathians, Silesian Nappe, Fore-Dukla Zone, Oligocene, Krosno Beds, Foraminifera, calcareous
nannoplankton, dinocysts, exotic rocks.
The monotonous thick series of deep-water flysch deposits of
the Outer Carpathians includes rocks (as pebbles and blocks),
lithologically contrasting with their host sediments. In the Car-
pathians, they have been referred to as exotics (Świdziński
This paper presents the petrographic characteristics, strati-
graphic position and interpretation of the source area of a layer
with exotics which occurs in flysch deposits of the Krosno
Beds in the Fore-Dukla Zone (Silesian Nappe, Outer Car-
pathians) in the Polish part of the Bieszczady Mts. The exotics
in the Krosno Beds have not been described from this tectonic
unit; however, they have been documented from the Central
Carpathian Depression (Silesian Nappe), in the neighbouring
area. Numerous descriptions of exotic rocks come from the lo-
calities of Riszkania and Bukowiec (Vacek 1881; Wójcik
1905; Rogala 1932; Rogala & Weigner 1935; Gans & Hilter-
mann 1951; Krajewski 1952, 1955; Ślączka 1959, 1961). Mo-
chnacka & Tokarski (1972) found exotic blocks in the Krosno
Beds near Ustrzyki Górne (the Zakopaniec stream). Recently,
Haczewski and Bąk noted exotics at many localities in the
Bieszczady Mts, from the Opołonek Mt through the Połonina
Wetlińska Mt (Haczewski & Bąk 1999; Haczewski et al. sub-
The exotic rocks described here have been found in the
Fore-Dukla Zone during detailed mapping by J. Rubinkiewicz
and L. Mastella (Haczewski et al. submitted c).
The described exotic rocks occur in the Fore-Dukla Zone
(Świdziński 1953), which lies in the southern part of the Sile-
sian Nappe (Fig. 1). The Fore-Dukla Zone is a narrow tectonic
belt (a few km wide), extending from Bukowsko in the north-
west to the state boundary in the southeast. Its southern limit is
a steep (45—70
) overthrust of the Dukla Nappe (Świdziński
1953; Ślączka 1969; Ślączka 1971; Tokarski 1975; Rubink-
iewicz 1996). To the north, the Fore-Dukla Zone contacts with
the Central Carpathian Depression across a large reverse fault,
) dipping to NE (Opolski 1930; Koszarski et
160 BĄK et al.
al. 1960; Ślączka 1963; Tokarski 1975; Kuśmierek 1979; Mas-
tella 1995; Haczewski et al. submitted c).
The deposits of the Fore-Dukla Zone are tightly deformed
due to their low competence relative to the overlying thick-
bedded sandstone series. The thrust movements of the Dukla
Nappe over the Silesian Nappe produced complex deforma-
tions in that area. The marginal part of the Dukla Nappe is
formed by a series of rigid, thick-bedded sandstones (Cisna
Beds; Ślączka 1971) up to 1250 m thick in the study area
(Haczewski et al. submitted d). On the other side of the zone,
the south-western part of the Silesian Nappe (the Central Car-
pathian Depression) consists of a series, up to 2000 m thick,
with rigid, thick-bedded Otryt Sandstone (Haczewski et al.
Intense tectonic deformations (numerous folds, slices,
faults, thrusts) of the Fore-Dukla Zone make a stratigraphic re-
construction difficult. A general scheme for the stratigraphy of
the whole unit in the Bieszczady region was presented by
Kuśmierek (1979). The scheme presented below (Fig. 2) has
resulted from the mapping of the eastern part of the Fore-Duk-
la Zone in the Bieszczady Mts by Mastella & Rubinkiewicz
(Haczewski et al. submitted d). Within the studied area, the
Fore-Dukla Zone consists of a 1.2 km thick sequence of Paleo-
gene flysch deposits, including the Hieroglyphic Beds (up to
280 m), the Globigerina Marls (up to 20 m), the Menilite Beds
(up to 230 m), the Passage Beds (up to 300 m) and the Krosno
Beds (up to 320 m). The Krosno Beds in the Fore-Dukla Zone
include the lower division (thin-bedded sandstones with marl-
stones) and the middle division (with thick-bedded Otryt
The exotics-bearing layer was found in the Krosno Beds
(Fig. 2), which consist of marlstones with convolute and cross
laminated, thin-bedded sandstones, in a series up to 220 m
thick. They also include a smaller amount of black calcareous
and non-calcareous shales, often with hard mudstone aggre-
gates and rare thick-bedded (up to 1.5 m), medium- to coarse-
grained, polymictic Otryt-type sandstones and thick-bedded
(up to 0.5 m), medium grained, structureless sandstones. Sin-
gle beds of medium- to thick-bedded ferruginous dolomites
also occur in the section.
Localities with exotic blocks
The exotics have been found in two streams which flow
from the Dział Mt to the Wetlinka stream, near Wetlina village
(Fig. 3). The names used for these streams herein – Owczar-
nia and Osada – have been given for the purposes of this
work and are not used on published maps.
Fig. 2. Lithostratigraphical scheme of the Fore-Dukla Zone in the Pol-
ish part of the Bieszczady Mts (after Haczewski et al. submitted c).
Fig. 1. Regional setting of the study area in the context of Poland (A) and the Outer Carpathians (B).
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE KROSNO BEDS 161
Two exotic blocks have been found in the Owczarnia stream,
whose confluence with the Wetlinka stream lies 400 m down-
stream along the Wetlinka from the entrance on the road to the
Górna Wetlinka camping site (Fig. 3). The exotics occur about
170 m upstream from the mouth of a right affluent of the Owc-
zarnia stream, in the right bank, 0.5 m above the stream bed. A
thick bed (1.5 m) of the Otryt Sandstone occurs 40 m upstream
of the exotics.
The exotic block is a cobble (25
18 cm) of bioclastic
limestone with single bivalve shells, visible on weathered sur-
face, and a boulder (40
20 cm) of strongly fractured
sparitic limestone with thick calcite veins. These blocks seem
to be loose; however, the orientation of the longest axis of the
larger one corresponds with the strike (108
) of grey, calcare-
ous shales, showing a dip of 65
N. The samples taken from
these shales for micropaleontological analysis (left bank of the
stream; Fig. 4) included a mixed, that is allochthonous (shal-
low-water), and autochthonous (deep-water) foraminiferal as-
semblage. The shales seem to be the matrix of the exotics in
Several pebbles of the mudstone similar to those of the
Krosno Beds and small exotic blocks occur in the left bank of
Osada stream. This stream is the next one to the west of the
Owczarnia stream, also flowing from the Dział Mt (Fig. 3).
The mouth of this stream is located at Wetlina-Osada settle-
ment, about 80 m above the mouth of the Kimakowski stream,
which flows from the Połonina Wetlińska Mt. The exotic-
bearing layer occurs in the left bank of the stream, about 140
m upstream of the confluence with its longest right tributary
(Figs. 3, 4).
The exotics found include: a rounded cobble (20
cm) of massive micritic limestone, a rounded boulder (35
15 cm) of crystalline schist, and a few angular fragments of
grey mudstone and very fine-grained sandstone (up to 5 cm in
size), which resemble the lithological types from the Krosno
Beds. These exotics are embedded in light-grey and dark-grey
marly, partly arenaceous matrix. The visible part of the exot-
ics-bearing layer is 70 cm thick. Four samples taken for mi-
cropaleontological studies (Fig. 4) include allochthonous,
shallow-water fauna, mainly small and large foraminifers,
Fig. 3. Detailed geological map of the Fore-Dukla Zone and the Dukla Nappe in vicinity of Wetlina (Bieszczady Mts) with location of the
exotics-bearing layer (after Haczewski et al. submitted c).
162 BĄK et al.
bryozoans, and juvenile gastropods and bivalves. The strike of
this layer (120
), which dips at 85
to SW, corresponds to the
strike of neighbouring strata.
The layer with exotics lies in the same stratigraphic position
at both described localities, distant by 1 km from each other. It
occurs in the southern limb of a syncline, near its hinge
(Fig. 3). The syncline belongs to the southernmost horse of the
Fore-Dukla duplex (Haczewski et al. submitted c).
Petrographic composition of exotics
The exotics found in two neighbouring streams include
crystalline schist and three types of limestones.
Macroscopically the rock represents grey-green, fine-
grained schist, with quartz-feldspar and mica laminae and
lenses and veins of quartz, up 1 cm thick.
Microscopically the rock was determined as quartz-chlorite-
muscovite-orthoclase schist with tourmaline and garnet (Fig.
5A—C). Orthoclase crystals are optically similar to quartz (Fig.
5A,C), but their indistinct fissility is diagnostic for orthoclase.
The high content of orthoclase in this rock was confirmed by
X-ray spectroscopy. Chlorite occurs as elongated grains, with
light-grey pleochroism (Fig. 5C) and low interference colours.
These crystals probably belong to orthochlorite from the pe-
nine-clinochlore-scheridonite series. Chlorite is here a second-
ary mineral, due to chloritization of biotite, whose occurence
in this rock is only accessory. Muscovite has been found as
single crystals and intergrown with chlorite (Fig. 5A—C). Short
columnar crystals of tourmaline (Fig. 5B), with distinct olive-
grey pleochroism and well visible striped structure, are fre-
quent. Carbonate minerals occur between the quartz-feldspar
and chlorite-muscovite laminae (Fig. 5C).
The concurrence of chlorite with the orthoclase-biotite-gar-
net assemblage suggests that the rock represents a product of
two types of metamorphism: progressive, medium-level and
Fig. 4. Detailed location of samples for micropaleontological stud-
ies; Owczarnia and Osada streams in vicinity of Wetlina (Bieszcza-
dy Mts.): 1 – grey, calcareous shales, 2 – light-grey and dark-grey
marly, partly arenaceous matrix of exotics-bearing layer, 3 – exotic
Fig. 5. Photomicrographs of crystalline schist; exotic block from
the Krosno Beds of the Fore-Dukla Zone (Silesian Nappe), Outer
Carpathians; Wetlina, Bieszczady Mts. A – fine-grained schist,
with quartz-feldspar and muscovite-chlorite-biotite laminae. En-
larged view in B – documents occurrence of garnet and calcite;
and in C – documents occurrence of tourmaline crystal.
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE KROSNO BEDS 163
Three types of limestone were found:
a/ Massive, sparitic, partly siliceous limestone, with numer-
ous calcite veins (Fig. 6A,B). Black, thin crusts of undeter-
mined oxides? are visible on some cracks. A poorly preserved
crinoide trochite has been found as the only biotic component
in a thin section.
b/ Massive, micritic limestone with rare planktonic (Globi-
gerina-like) foraminiferal tests (Fig. 6C,D). A thin lamina of
sandy material occurs in the marginal part of the exotic block.
Some of the foraminiferal tests (?Globigerina praebulloides
Blow) are pyritized. The limestone represents a pelagic type of
c/ Massive bioclastic limestone with numerous tests of
small and large foraminifers (Fig. 6D,F), fragments of coral-
line algae – Rhodophyta (Lithophylum spp.; Fig. 7H—J), bi-
valves (Fig. 7A), bryozoans (Fig. 7G) and echinoid spines
(Fig. 7B,C). Among the small foraminifers, planktic genera
such as Globigerina (Fig. 8A—D) and Subbotina (Fig. 8E,F),
and calcareous benthonic genera such as Cibicidoides (Fig.
8G,H), Saracenaria? (Fig. 8I), Lobatula (Fig. 8J), Valvulina
(Fig. 8K), Quingueloculina (Fig. 8L), Paratrochamminoides
(Fig. 8M) and Gyroidinoides (Fig. 8N) have been determined
in thin sections. Large foraminifers are represented by Opercu-
lina sp. (Fig. 7E), Heterostegina sp., Nummulites sp. and
Nummulites cf. fichteli (Michelotti) (Fig. 7D,F). Identification
of the last mentioned species in thin sections is very difficult.
However, some characteristic features of this taxon, observed
in our material such as: the curved shape of both sides of the
test in axial section, the small size of the whole test and the
proloculus seem to be sufficient for its identification. The first
appearance of Nummulites fichteli has been described from the
Oligocene (Schaub 1981). Thus the occurrence of this species
in the exotic limestone block may indicate an Oligocene age of
Microfossils from the matrix
Six samples taken from shales in which the exotics occur
(Fig. 4) and one sample taken from neighbouring calcareous
marlstones of the Krosno Beds have been analysed for Fora-
minifera, calcareous nannoplankton and dinocysts.
The foraminiferal assemblage includes autochthonous, pyri-
tized Foraminifera, typical of the Krosno Beds in the Bieszc-
zady Mts area (Bąk 1999) and allochthonous non-pyritized,
well diversified forms with dominance of shallow-water cal-
The autochthonous benthonic Foraminifera are represented
by agglutinated forms such as Rhabdammina sp., Bathysiphon
sp., Spirorutilus carinatus (d’Orbigny), Haplophragmoides ex
gr. suborbicularis (Grzybowski), Glomospira charoides
(Jones et Parker), Gyroidina? constans (Reiser), and calcare-
ous forms belonging to Uvigerina multistriata Hantken, Prae-
globobulimina pupoides (d’Orbigny), Virgulinella chalkophila
(Hagn), Virgulinella karagiensis Mikhailova, Guttulina prob-
lema Cushman et Ozava, Praebulimina sp. and Chilostomella
oviformis (Sherborn et Chapman). Planktic Foraminifera of
the autochthonous assemblage, also pyritized, include Globi-
gerina praebulloides Blow, Tenuitella liverovskae (Bykova),
Tenuitellinata angustiumbilicata (Bolli), Tenuitella? brevispi-
ra (Subbotina), Tenuitella munda (Jenkins), Globigerina post-
cretacea Mjatljuk, Globigerina ciperroensis Bolli, Globigeri-
anguliofficinalis Blow, Beella rohiensis (Popescu et Brotea),
Bolliella navazuelensis (Molina) and Paragloborotalia nana
Calcareous non-pyritized benthic Foraminifera of the rede-
(d’Orbigny), Reticulophragmium acutidorsatum (Hantken),
Valvulina haeringensis (Gümbel), Elfidiella? dolfusi (Cush-
man), Asterigerinoides guerichi (Franke), Discorbis alteconi-
cus Pokorny, Cibicidoides lopjanicus (Mjatliuk), Cibicidoides
amphistylensis (Andreae), Cibicidoides eocenus (Gümbel),
Lobatula carinata Terquem, Hanzawaia sp., Gyroidinoides
mamillatus Andreae, Cribroporella pteromphalia (Guembel),
?Neoponides schreibersi (d’Orbigny), Planularia kubinyii
(Hantken), Planularia costata (Hantken), Hemirobulina hant-
keni (Bandy), Astacolus sp., Dentalina cf. communis (Reuss),
Dentalina sp., Stilostomella cf. emaciata (Reuss), Stilostomel-
la kressenbergensis (Guembel), Lenticulina inornata
(d’Orbigny), Bulimina alsatica Cushman et Parker, Quiquelo-
culina hauerina d’Orbigny, Cribroparella pteromphalia
(Guembel), Biapertorbis cf. alteconicus Pokorny, Heterolepa
costata Franzeman, and Uvigerina sp.
Single specimens of large Foraminifera have also been
found. They include typical Eocene forms, such as Nummu-
lites fabianii (Prever), Operculina alpina (Douvile) and Het-
erostegina depressa (d’Orbigny), and the Oligocene species
Nummulites vascus Joly et Leymerie. Similar assemblages of
large Foraminifera from the Krosno deposits were described
by Cizancourt (1933) from exotic material at Bukowiec
(Bieszczady Mts), and by Bieda (1938, 1963) from Seletyn
(Bukowina; Romanian Carpathians) and Baligród (Bieszczady
Mts; also from exotic rocks).
Redeposited, non-pyritized planktonic Foraminifera, also
occur. Some are typical of Late Eocene Turborotalia ex gr.
cerroazulensis (Cole), Turborotalia centralis (Cushman et
Bermudez) and Globigerina eocaena (Guembel), as well as
Late Eocene-Early Oligocene forms (cf. Popescu et al.
1998), such as Subbotina linaperta (Finlay), Subbotina tapu-
riensis Blow et Banner and Subbotina praeturritilina (Blow
Two assemblages of calcareous nannoplankton have been
found in the matrix of the layer with exotics. The first repre-
sents redeposited nannoplankton in which the youngest forms
belong to Cyclicargolithus floridanus (Roth et Hay in Hay et
al.) Bukry, Dictyococcites bisectus (Hay, Mohler et Wade)
Bukry et Percival and Reticulofenestra cf. umbilica (Levin)
Martini et Ritzkowski. This assemblage occurs in the matrix
of the studied layer in the Osada stream (samples: Osada-6/99
& Osada-8/99), showing that it is not older than the NP16
164 BĄK et al.
Fig. 6. Photomicrographs of limestones from exotic blocks; exotic blocks from the Krosno Beds of the Fore-Dukla Zone (Silesian
Nappe), Outer Carpathians; Wetlina, Bieszczady Mts. A, B – Massive, sparitic, partly siliceous limestone, with calcite vein; Owczarnia
stream-2/99. C, D – Massive, micritic limestone with rare planktic (Globigerina-like) foraminiferal tests; Osada stream-9b/99; E, F –
Massive, bioclastic limestone with numerous tests of small and large Foraminifera, fragments of coralline algae (Rhodophyta) and rare
bivalves and bryozoans; Owczarnia stream-1/99. Scale bar – 0.1 mm (for A, B) and 0.5 mm (for C—F).
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE KROSNO BEDS 165
Fig. 7. Microfossils from bioclastic limestone; exotic block from the Krosno Beds of the Fore-Dukla Zone (Silesian Nappe), Outer Car-
pathians; Wetlina, Bieszczady Mts; sample Owczarnia stream-2/99: A – fragment of juvenile bivalve test; B, C – echinoid spine; D, F
– Nummulites cf. fichteli Michelotti; E – Operculina sp.; G – fragment of bryozoan colony (Hornera? sp.); H—J – fragment of coral-
line algae (Rhodophyta: Litophyllum sp.). Scale bar – 0.5 mm (for A) and 0.1 mm (for B—J).
166 BĄK et al.
Fig. 8. Small Foraminifera from bioclastic limestone; exotic block from Krosno Beds of the Fore-Dukla Zone (Silesian Nappe), Outer
Carpathians; Wetlina, Bieszczady Mts; Owczarnia stream-2/99: A—C – Globigerina sp.; D – Globigerina sp. cf. G. eocaena Guembel;
E – Subbotina sp.; F – Subbotina sp. cf. S. pseudovenezuelana (Blow et Banner); G, H – Cibicidoides? sp.; I – Saracenaria? sp.; J
– Lobatula sp. cf. Lobatula lobatula (Terquem); K – Valvulina sp.; L – Quinqueloculina sp.; M – Paratrochamminoides sp.; N –
Gyroidinoides sp. Scale bar – 0.1 mm.
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE KROSNO BEDS 167
Zone (middle Eocene; Perch-Nielsen 1985). The following
have also been determined: Braarudosphaera cf. bigelowii
(Gran et Braarud) Deflandre, Coccolithus pelagicus (Wallich)
Schiller, Discoaster barbadiensis Tan, Ericsonia formosa (Ka-
mptner) Haq, Pontosphaera cf. multipora (Kamptner) Roth,
Sphenolithus moriformis (Bronnimann et Stradner) Bramlette
et Wilcoxon, Tribrachiatus orthostylus Shamraî, Zygrha-
blithus bijugatus (Deflandre in Deflandre et Fert) Deflandre.
The second assemblage includes younger calcareous nanno-
plankton. The youngest species with FAD in the NP24 Zone
(late early Oligocene through early late Oligocene; Perch-
Nielsen 1985; Berggren et al. 1995) is Helicosphaera recta
Haq. This assemblage occurs in the marly shales, which seem
to be the matrix of the exotic blocks (samples: Owczarnia-1/99
& Owczarnia-3/99). Other calcareous nannoplankton of this
assemblage is represented by Coccolithus pelagicus (Wallich)
Schiller, Cyclicargolithus floridanus (Roth et Hay in Hay et
al.) Bukry, Dictyococcites bisectus (Hay, Mohler et Wade)
Bukry et Percival, Ericsonia subdisticha (Roth et Hay in Hay
et al.) Roth in Baumann et Roth, Helicosphaera perch-nielse-
niae Haq, Pontosphaera cf. latelliptica and Reticulofenestra
cf. umbilica (Levin) Martini et Ritzkowski.
Two assemblages characterize the dinocysts from the layer
with exotics (Gedl 2000). The first of them occurs in the sam-
ple Osada-7/99 including only redeposited, Late Paleocene—
Early Eocene dinocysts: Cordosphaeridium sp., Glaphyrocys-
ta intricata (Eaton) Stover et Evitt, Homotryblium sp.,
Hystrichokolpoma cincatum Klumpp, Impagidinum sp., Lan-
ternosphaeridium? sp., Oligosphaeridium spp., Spiniferites
ramosus (Ehrenberg) Mantell, Thalassiphora pelagica (Eisen-
ack) Eisenack et Gocht, and Wetzeliella unicaudalis Caro.
The second assemblage includes younger forms with Cali-
godinium amiculum Drugg, Cleistosphaeridium sp., Cor-
dosphaeridium cantharellum (Brosius) Gocht, Cribroperidini-
um sp., Chiropteridium sp., Deflandrea spp., Glaphyrocysta
pastielsii (Deflandre et Cookson) Stover et Evitt, Glaphyro-
cysta? sp., Homotryblium pallidum Davey et Williams, Ho-
motryblium vallum, Homotryblium sp., Pentadinium lopho-
phorum (Benedek) Benedek et al., Reticulatosphaera
actinocoronata, Spiniferites pseudofurcatus (Klumpp) Sar-
jeant, Spiniferites ramosus (Ehrenberg) Mantell, Systemato-
phora placacantha (Deflandre et Cookson) Davey and Thalas-
siphora pelagica (Eisenack) Eisenack et Gocht.
The occurrence of Chiropteridium sp. and Caligodinium
amiculum Drugg as well as the type of palinofacies suggest an
age for the matrix not older than Kiscellian (see Andreyeva-
Grigorovich & Gruzman 1994).
Age of the exotics-bearing layer
The youngest assemblage of calcareous nannoplankton sug-
gests that the exotics-bearing layer is not older than the NP24
Zone (late Kiscellian in the Central Paratethys; Rögl 1998). It
is probably older than the coccolith Jasło Limestone chrono-
horizon (see Koszarski & Żytko 1959, 1961; Jucha & Kotlarc-
zyk 1961; Haczewski 1989), as suggests the lack of Cyclicar-
golithus abisectus (Müller). The first occurrence of C. abisec-
tus was noted just below the Jasło Limestone in the area with a
similar type of sequence in the Krosno Beds (Baligród Syn-
cline – M. Garecka, unpublished data).
Planktic Foraminifera confirm the late Kiscellian age of the
Krosno Beds in which the exotics-bearing layer has been
found. The youngest taxa in this assemblage are Tenuitella
munda and Globigerina ciperroensis, for which the first oc-
currences were noted near the Early/Late Kiscellian boundary
(Popescu et al. 1998). The autochthonous planktic assemblage
may correspond to the Tenuitella munda Zone, proposed for
the Polish part of the Central Paratethys by Olszewska (1997,
An additional confirmation of the Oligocene age is the as-
semblage of dinocysts. The occurrence of Hiropteridium sp.
and Caligodinium amiculum Drugg suggests the age of the ex-
otics-bearing layer not older than Kiscellian.
Comparison with other exotic occurrences
in the Krosno Beds (Bieszczady Mts)
Exotics have been described from a few localities in the
southern part of the Silesian Nappe (Central Carpathian De-
pression), within its Polish part.
Scattered exotic blocks were found in the Krosno Beds near
Ustrzyki Górne, in the Zakopaniec stream (about 15 km SE
from Wetlina) by A.K. Tokarski (Mochnacka & Tokarski
1972) (Fig. 9). There occur steel-grey coloured, chlorite-mus-
covite schist with garnet crystals, locally “saturated” with sili-
ca, and crossed by veins of white quartz, a few cm thick. Ac-
cording to Tokarski (1975), the exotics occur within the upper
division of the Krosno Beds, about 250 m above the top of the
youngest package of the Otryt Sandstone belonging to the
middle division of the Krosno Beds. This position was recent-
ly reinterpreted by G. Haczewski (Haczewski et al. submitted
c,d) as near the top of the middle division of the Krosno Beds.
The basis for this reinterpretation was the different criterion to
define the upper boundary of the middle division of the Kros-
no Beds (top of the last thick-bedded Otryt-type sandstones).
The exotic blocks are loose, and the matrix of the exotic layer
has not been found at this locality. Thus the precise strati-
graphic correlation is impossible, though the exotic crystalline
schist from this place is similar to that at Wetlina.
Another occurrence of exotics in the Krosno Beds has been
described from Roztoki Dolne south of Baligród (about 26 km
to NW from Wetlina) (Ślączka 1959) (Fig. 1). These exotics
occur in a few layers 1—70 m thick, visible over a distance of 8
km (Ślączka 1959, 1963; Malata et al. in print). The most
abundant are crystalline rocks (0.5—2 m of diameter), classi-
fied as: phyllites, albite and albite-calcite gneiss-phyllites, gar-
net phyllites, phyllitic epidote-albite amphibolites and quartz-
ites (Ślączka & Wieser 1962). Moreover, rounded blocks of
Eocene bioclastic limestone (up to 0.5 m in diameter), con-
glomerate boulders (up to 2 m in diameter) and platy frag-
ments of dark shales, green marls and shales (up to 1.5 m long)
have been found there. Unstratified grey, calcareous, siltstones
form the matrix of the exotics. Lenses of thick-bedded, coarse-
grained sandstones are another component of the matrix. The
shales, mudstones and sandstones include bivalves, echinoids,
168 BĄK et al.
bryozoans and large Foraminifera, including Nummulites vas-
cus Joly et Leymerie. The age of the matrix has been deter-
mined as Oligocene (Bieda 1963). The exotics-bearing layer at
Roztoki Dolne occurs in the upper division of the Krosno
Beds, about 180—200 m above a thick package of the Otryt
Sandstone (Ślączka 1959; Malata et al. in print). However, it
should be stressed that the thick-bedded sandstones (Otryt
Sandstone?) also occur within the series with exotics and im-
mediately above them (Ślączka 1963).
The lithological types of described exotics in the Fore-Duk-
la Zone are similar to some rocks from Roztoki Dolne. The
crystalline schist from the Owczarnia stream may correspond
to the “garnet phyllite”, determined by T. Wieser (Ślączka &
Wieser 1962). Moreover, the assemblage of large Foraminifera
in the massive bioclastic limestone (Osada stream) is similar
to that from the bioclastic limestone, described by Bieda
Other occurrences of exotic blocks in the Krosno Beds in
the front of the Dukla Nappe are known, in Poland, from the
ranges between the Opołonek Mt through the Połonina
Wetlińska Mt. Some of the localities with exotics, such as
Bukowiec, the Litmirz and Negrylów streams, and Riszkania
(all of them located 22—27 km SE from Wetlina) (Fig. 9) have
been studied mainly in relation to abundant macrofauna,
which occur in the redeposited bioclastic limestone blocks and
in the matrix of exotic layer (Wójcik 1905; Rogala 1932; Cin-
zancourt 1933; Rogala & Weigner 1935; Krach & Liszka
1961; Danysh 1966). According to Ślączka (1961), the exot-
ics-bearing layer from these localities (representing a single
horizon) occurs in a similar stratigraphic position as at Roztoki
Dolne, that is within the upper division of the Krosno Beds.
This view was revised during the detailed mapping of this area
(Haczewski & Bąk 1999; Haczewski et al. submitted a,b). The
exotics-bearing layer occurs significantly lower in this area –
Fore-Dukla Zone against a background of the main tectonic elements of the Eastern Carpathians (after Żytko 1999; simpli-
fied); emphasized the location of recent position of the Maramuresh Massif and Rakhiv-Ceahlau Nappe – the area with rocks similar to
the studied exotics: 1 – Maramureh Massif and their post-Austrian covers, 2 – Rakhiv-Ceahlau Nappe; B – Bitla tectonic unit, Ch (G)
– Chornogora Nappe (Goverla), Ch (S) – Chornogora Nappe (Skupovna), FD – Fore-Dukla Zone, K – Krasnoshora Subunit, M –
Magura Nappe, PKB – Pieniny Klippen Belt, S – Silesian Nappe, S + SS – Silesian Nappe (northern part) and Sub-Silesian Nappe, SV
– Svidovets tectonic subunit.
Exotic occurrences (stars) in the most southern part of the Silesian Nappe and the Bitla tectonic unit,
the Bieszczady Mts (boundaries of the Fore-Dukla Zone after Haczewski et al. (submitted a,c); overthrusts in the Bitla tectonic unit after
Glushko et al. (1999); exotic localities – see in the text).
EXOTICS-BEARING LAYER IN THE OLIGOCENE FLYSCH OF THE KROSNO BEDS 169
Fig. 10. Trial of correlation of the exotics-bearing layers in the south-western part of the Silesian Nappe and the Fore-Dukla Zone, the
about 200 m above the base of the middle division of the Kros-
no Beds. Thus it could not be correlated with the exotic-bear-
ing strata at Roztoki Dolne and Ustrzyki Górne.
Recently, G. Haczewski (Haczewski et al. submitted c,d)
found exotics on the south-western slopes of the Połonina
Wetlińska Mt and the Połonina Caryńska Mt (2—7 km from our
localities) and traced them to the localities near Ustrzyki
Górne. The lithological spectrum of the exotic rocks seems to
be similar to those from Roztoki Dolne, Ustrzyki Górne and
The exotic rocks (within olistostromes and as isolated olis-
toliths) occur also in the Ukrainian Carpathians, immediately
in front of the Dukla overthrust (Fig. 9; Shakin et al. 1976).
The Oligocene Krosno Beds include, among others, blocks of
dark-grey “glassy” sandstones, related to the Lower Creta-
ceous Shipot Beds, and grey-green and variegated shales
(Danysh 1973; Smirnov 1975). The latter lithological type
may correspond to the Eocene Hieroglyphic Beds. The Krosno
Beds are represented there by medium-bedded flysch. The
stratigraphic position of the exotics within the Krosno Beds is
Source area of the exotics
The exposures of the exotics-bearing layer in the Fore-Duk-
la Zone do not provide unequivocal clues on the location of
the source area for this material. We speculate that these de-
posits were transported from south and south-east, like the ma-
terial of the Otryt Sandstone. All known exotic findings in the
Bieszczady Mts are related to the occurrence of thick-bedded,
middle- to coarse-grained, polymictic sandstones (the Otryt
Sandstone). Single layers of such sandstone (1.5 thick) also
occur just above the described layer with exotics. The petro-
graphic composition of the grains in the Otryt-type sandstones
resembles the composition of the exotic blocks. The grains in
the Otryt Sandstone include fragments of crystalline schists,
other crystalline rocks (with quartz, alkaline feldspar, plagio-
clase, muscovite, biotite), quartzite and limestone (Haczewski
et al. submitted b).
On the basis of the composition of the Otryt-type sandstones
and the exotics, we suggest that the source area of the exotics-
bearing layer was composed of crystalline rocks and partly of
Eocene-Oligocene limestones. The latter lithological types
originate from two types of environment (based on the exotic
rocks): inner shelf (bioclastic limestone with numerous and di-
versified macro- and microfossils) and outer shelf-upper
bathyal zone (micritic limestone with planktic Foraminifera).
The Foraminifera from the exotic matrix also represent vari-
ous environments. Some of them are shallow-water taxa
from inner shelf (e.g. Nummulites vascus Joly et Leymerie,
Quiqueloculina hauerina d’Orbigny), others belong to outer
shelf and bathyal assemblages (e.g. Spirorutilus carinatus
(d’Orbigny), Haplophragmoides ex gr. suborbicularis (Grzy-
bowski), Glomospira charoides (Jones et Parker), Uvigerina
(d’Orbigny), Virgulinella chalkophila (Hagn), V. karagiensis
Mikhailova, Guttulina problema Cushman et Ozava, Prae-
bulimina sp. and Chilostomella oviformis (Sherborn et Chap-
A similar source area for the exotic rocks from Roztoki Dol-
ne was proposed by Ślączka & Wieser (1962) and Ślączka
(1963). According to these authors, the submarine slumps with
exotic rocks descended from the north-western extension of
the Marmaros or Rachów massifs, which formed small islands
between the Dukla and Silesian subbasins.
170 BĄK et al.
The composition of the exotic material from the Ukrainian
part of the Fore-Dukla Zone (the Tikhyy stream – a left tribu-
tary of the Uzh river; Smirnov 1975), may additionally suggest
submarine erosion of older lithostratigraphic units (Shipot
Beds, Hieroglyphic Beds) during the dense gravitational flows
from the shelf area.
The reduction in the thickness of the Krosno Beds (Tokarski
1975) in the Fore-Dukla Zone, scarcity of paleontological data
from this area and from the south-western margin of the Cen-
tral Carpathians Depression (Silesian Nappe), and the likely
diachronism of facies, make a precise correlation of the Kros-
no Beds difficult and, in consequence, also the correlation of
the described exotic layer with other exotic localities. It seems
that the exotics at Roztoki Dolne and Ustrzyki Górne may be
in a similar stratigraphic position, that is near the boundary be-
tween the middle and upper divisions of the Krosno Beds (Fig.
10). The lack of thick packages of the Otryt Sandstone in the
southernmost tectonic slice of the Fore-Dukla Zone, precludes
the determination of the position of the exotic-bearing layer
with respect to the boundary between the middle and upper di-
visions of the Krosno Beds.
The fossils in the exotic layer and the host strata in the
Fore Dukla Zone, indicate their position not older than the
NP24 Zone (late Kiscellian), below the Jasło Limestone, cor-
responding to the Tenuitella munda Zone sensu Olszewska
(1997, 1998). The lack of similar data from other exotic lo-
calities precludes a precise biostratigraphic correlation be-
tween these localities. It seems likely that these localities
represent several independent gravity flows and submarine
slumps of similar age.
Paleotransport direction of the exotic material are suggested
here on the basis of the paleocurrent directions in the Otryt
Sandstone, whose grains are similar in petrographic composi-
tion to the exotics. The paleotransport is from the south and
south-east. The source area (islands with narrow shelf mar-
gins) was composed of crystalline schists, covered partly with
various types of carbonate Eocene-Oligocene rocks. Deeper
parts of the island slopes could be covered with Cretaceous-
Paleogene sediments, related to deep-water sedimentation on a
submarine elevation between the Dukla and Silesian subba-
sins. These deep-water deposits have been included in the sub-
marine mass movements descending to the Silesian Subbasin.
Acknowledgments: Thanks are due to P. Gedl (Polish Acade-
my of Sciences, Kraków) who examined dinocysts. Special
thanks go to M. Bąk (Jagiellonian University, Kraków) for dis-
cussion during the mapping of the study area, and to G. Hac-
zewski (Cracow Pedagogical University) for valuable com-
ments, and for improving the English of the manuscript. L.
Mastella (University of Warsaw), A. Ślączka (Jagiellonian
University, Kraków), A. S. Andreyeva-Grigorovich (Come-
nius University, Bratislava) and J. Soták (Slovak Academy of
Sciences, Banská Bystrica) are gratefully acknowledged for
reviewing of the manuscript. The authors also thank the Direc-
tors of the Bieszczady National Park and other members of the
Park staff for help during the field work. Grant BS-03/G/00 (to
K. Bąk) supported this contribution.
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