GEOLOGICA CARPATHICA, JUNE 2005, 56, 3, 205221
www.geologicacarpathica.sk
Exotic orthogneiss pebbles from Paleocene flysch of the Dukla
Nappe (Outer Eastern Carpathians, Poland)
KRZYSZTOF B¥K
1
and ANNA WOLSKA
2
1
Institute of Geography, Cracow Pedagogical University, Podchor¹¿ych 2, 30-084 Kraków, Poland; sgbak@cyf-kr.edu.pl
2
Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Kraków, Poland;
wolska@ing.uj.edu.pl
(Manuscript received December 16, 2003; accepted in revised form September 29, 2004)
Abstract: Crystalline exotic pebbles have been found in the deep-water flysch of the Cisna Beds, in the Dukla Nappe,
Polish part of the Outer Western Carpathians. Most of them occur in a layer, which extends over a distance of at least
3 km within the SE limb of the ChryszczataWo³osañMa³a Rawka anticline. The dimensions of the pebbles vary be-
tween 2 and 18 cm (middle axis). The exotic pebbles consist of three types of granite derived orthogneisses: 1
medium-grained, medium-banded orthogneiss with alkali feldspar porphyroblasts showing structural features of foliated
granitic-gneiss, 2 medium-banded, medium-layered orthogneiss containing small microcline porphyroblasts and show-
ing structural features of foliated granitic-gneiss, and 3 strongly cataclastic granitic-gneiss with chess-board albite
porphyroblasts showing properties of partly mylonitized granite. The chemical composition of the orthogneisses indi-
cates that the protolith was represented by peraluminous, poorly-evolved, S-type granites exhibiting features of orogen-
related crustal granites. The discrimination shows that the protolith of the studied rocks evolved in active continental
margin or continental collision environments. The biostratigraphical data on deep-water agglutinated Foraminifera sug-
gest the position of the exotic-bearing layer in the lowermost part of the Rzehakina fissistomata Zone corresponding to
the lowermost Paleocene. Petrographic affinities between orthogneissic pebbles and mineral/rock fragments grains of
the Cisna-type sandstones show that they have the same provenance. These deposits were transported from the NE
extension of the Marmarosh massif, which had the character of a continental bearing source cordillera, formed mainly by
orthogneissic and granitic rocks.
Key words: Paleocene, Outer Carpathians, Dukla Nappe, provenance, stratigraphy, geochemistry, petrography,
orthogneissic pebbles.
Introduction
Crystalline exotic pebbles have been found within the thick
series of deep-water, Maastrichtian-Paleocene flysch deposits
of the Dukla Nappe in the Polish part of the Outer Eastern
Carpathians. These flysch series, called the Cisna Beds, be-
long to the northern part of the Dukla Nappe, outcropping in
the Bieszczady Mountains, close to the state boundary be-
tween Poland and Ukraine (Fig. 1).
The exotics from the Cisna Beds have not been described in
the Polish part of the Dukla Nappe, however, a single bed of
gravelstone with quartz, quartzite and phyllite pebbles was
noted in Slovakia (Medzilaborce area, Kamjan Mt; Koráb &
Ïurkoviè 1978).
The exotic rocks, presented here, have been found during
geological mapping by the first author (Ustrzyki Górne sheet
(1058) for the Detailed Geological Map of Poland, scale
1:50,000; Haczewski et al. submit.). They have been found
as loose pebbles in the channels of several left tributaries of
the Wo³osatka stream in the Bieszczady Mts, Poland. Their
abundant occurrences in several neighbouring, parallel
creeks suggest the same stratigraphic position of the exotic
occurrences.
The aim of this paper is to characterize the exotics and to
detect their provenance. Thus the petrographical characteris-
tics obtained for these pebbles are compared with the data
from the exotic-bearing layer and surrounding series, as well
as with data available in literature. The chemical characteris-
tics of the crystalline exotics and their radiometric age are
used to discriminate their protolith.
Geological setting
The described exotic rocks occur in the Dukla Nappe, which
belongs to the Fore-Magura group of nappes and is exposed at
the surface mainly in the Eastern Carpathians, within the Pol-
ish, Slovak and Ukrainian territories.
The studied area occurs to the south of the main overthrust
of the Dukla Nappe, in a zone to the south of Ustrzyki Górne
village, close to the state boundary with Ukraine (Fig. 1B).
The deposits are exposed within the Wo³osañChryszczata
Ma³a Rawka anticline, the northernmost tectonic unit of the
Dukla Nappe in its Polish part. The NE limb of this fold has
been strongly tectonized, contrary to the SW limb (partly in
the Ukrainian territory) which presents a continuous section
206 B¥K and WOLSKA
(Fig. 2A). The deposits in this limb include Upper Campanian
through middle Eocene deep-water flysch strata (Koszarski et
al. 1961; l¹czka 1971; B¹k 2004). The lithostratigraphic in-
ventory starts with the Upper Campanian-Maastrichtian
£upków Beds, and includes the Upper Maastrichtian-Pale-
ocene Cisna Beds, the Upper Paleocene Majdan Beds and the
uppermost Paleocene-Eocene Hieroglyphic Beds. The total
thickness of the Dukla sedimentary sequence reaches 2600 m
in the studied part of the Bieszczady Mts.
The described exotic rocks come from the outcrops of the
Cisna Beds, which are the thickest unit in this part of the Duk-
la Nappe (about 11001250 m).
The most characteristic feature of the Cisna Beds is the oc-
currence of grey (grey-brown on weathered surfaces), thick-
bedded (even more than 3 m), fine- to coarse-grained,
polymictic sandstones with calcareous-siliceous cement (so-
called Cisna-type sandstones). The thickness of the thick-bed-
ded sandstone packages reaches up to 50 m; it decreases up-
wards to a few meters in the uppermost part of the member.
Shales are a subordinate component in the Cisna Beds. Most
of them are dark grey, black, sandy, non-calcareous shales, oc-
curring in packages 1040 cm thick.
Fig. 1. Position of the studied area in relation to the main geologi-
cal units. A Outer Carpathians (O.C.) against the background of a
simplified geological map of the Alpine orogens and their foreland;
I.C. Inner Carpathians, C.F. Carpathian Foredeep. B
Dukla Nappe against the background of the eastern part of the Out-
er Carpathians.
The thick-bedded packages are intercalated with thin- to
medium-, rarely thick-bedded (up to 150 cm; mean 30
60 cm) sandstones, thin-bedded mudstones and sandy, non-
calcareous shales. The grey-yellow colour of weathered sur-
faces is a very characteristic feature of the sandstone and
mudstone beds. The sandstones are medium- to fine-grained,
have calcareous or calcareous-siliceous cement, with frequent
lamination of various types. The proportion of shales is higher
than in the thick-bedded packages, and it increases upwards.
The shales are non-calcareous, dark grey, brown, black, and
rarely green.
Calcareous spotty marls and calcareous mudstones, 47 cm
thick, so-called fucoid marls, occur in the upper part of the Ci-
sna Beds. Brown, ferrous coats cover the surface of the marls.
The marls occur in packages 4060 cm thick, together with
brown, non-calcareous shales.
Moreover, single beds (3050 cm thick on average) of grey-
green, fine-grained, muscovite-rich, siliceous sandstones oc-
cur in the upper part of the Cisna Beds. Abundant plant detri-
tus covers their upper surfaces.
Localities with exotic rocks
Most exotic pebbles have been found in the bedrock of five
parallel creeks (Fig. 2A), left tributaries of the Wo³osatka
stream, which cross the SE limb of the ChryszczataWo³osañ
Ma³a Rawka anticline. Most pebbles have been found in the
upper reaches of the creeks, along a straight line parallel to the
local structural grain. The exotic-bearing layer does not out-
crop there from beneath the thick alluvium in these sections of
the creeks. The supposed position of the exotic-bearing layer
is marked there by the occurrence of numerous crystalline
pebbles over small alluvial sections of the creeks (ca. 510
pebbles per 10 square meters). Additionally, no exotic pebbles
have been found in the higher parts of the creeks, where the
bedrock is exposed over a distance of at least 100200 m.
Several exotic pebbles and a block of sandstone with exotic
pebbles have been also found in other creeks, located west of
the Semenowa Mount. This area also lies within the SE limb
of the ChryszczataWo³osañMa³a Rawka anticline. The ex-
otic finds in individual creeks are not aligned; hence the posi-
tion of the supposed exotic-bearing layer has not been estab-
lished there.
The first author collected dozens of exotic pebbles from the
described outcrops. Their dimensions vary between 2 and
18 cm (middle axis), 310 cm on average. The largest of the
exotic clasts, found in the Szczawianka creek measured
20 ×18 ×12 cm.
The exotic-bearing layer has not been found in situ but a
fragment of a sandstone bed (30×15×7 cm) with gneissic
clasts (Fig. 3.1), found as a loose block in the Semenowa
creek, has been accepted as a sample of this bed.
The exotic pebbles have various degrees of roundness, gen-
erally moderate to high. Their roundness is probably original,
as indicated by the pebbles in the mentioned fragment of the
sandstone bed with clasts (cf. Fig. 3.1).
Taking into account the dips of the beds, the stratigraphic
position of the supposed exotic-bearing layer occurs 550 m
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 207
Fig. 2. A Geological map of the Dukla Nappe in the Wo³osatka drainge basin (Bieszczady Mts, Poland) with suggested position of the
exotic-bearing layer (map after B¹k in Haczewski et al. submit.). B Lithological profile of the £upków Beds and the Cisna Beds in the
studied area, with suggested position of the exotic-bearing layer and position of micropaleontological samples. C Geological cross-sec-
tion along the Kañczowa stream with suggested position of the exotic-bearing layer.
above the base of the Cisna Beds (Fig. 2BC). The same posi-
tion in the parallel creeks may suggest that the layer represents
a continuous horizon, at least 3 km long within the southern
limb of the Wo³osañChryszczataMa³a Rawka anticline.
Methods of investigations
The JEOL 5410 electron microscope equipped with an ener-
gy spectrometer Voyager 3100 (NORAN) was used to micro-
probe chemical analyses of rock-forming minerals. The mea-
surements were carried out using a spot method. Samples
representing three types of gneissic pebbles (Szcz-1/99, Wo³-
13c/99 and Kañcz-12/98) were analysed in the Activation
Laboratories Ltd. in Canada by means of the following
geochemical methods: ICP (major elements), INAA (trace ele-
ments including REE) and XRF (Nb). The largest pebble
(Szcz-1c/98) was relaid to K/Ar isotope studies (for details see
Poprawa et al. 2004).
The foraminiferal samples were collected from exposures of
the uppermost part of the £upków Beds and a lower part of the
Cisna Beds, along several creeks in areas, where the exotic
pebbles have been found. For micropaleontological studies,
the samples were dried, weighed (most of them weighed 500
750 g) and disintegrated in a solution of sodium carbonate.
Then the material was washed through sieves with mesh diam-
eters of 0.63 mm. At least 300 foraminiferal tests were picked
from fraction 0.631.500 mm, or until all tests were removed
from the residue. The foraminiferal slides are housed in the In-
stitute of Geography, Cracow Pedagogical University (Collec-
tion No. 09Du).
Petrographic composition of exotics
All of the exotics are fragments of orthogneissic rocks. Po-
larizing microscope investigations and chemical microprobe
analyses of rock-forming minerals revealed the presence of
208 B¥K and WOLSKA
three types of orthogneisses, differing in colour, structural
properties (porphyroblasts sizes, thickness of layers) and min-
eral composition.
The first type represents a medium-grained, medium-band-
ed porphyroblast gneiss showing structural features of foliated
granitic-gneiss (samples: Szcz-1/99, Wo³-1/99 and Kañcz-11/
99). It is greyish in colour, though smaller pebbles are beige
coloured with creamy tint. The bands are usually 25 mm,
sporadically up to 2 cm thick (Fig. 3.2). The grey colouration
of bands is due to the presence of biotite. When the biotite is
altered, brownish stripes appear and these zones are beige or
creamy in colour (s. Wo³-1/99). The porphyroblasts are white-
Fig. 3. 1 Medium- to coarse-grained, non-calcareous sandstone (Cisna Beds) with orthogneiss pebbles (gn); white arrows mark the holes
after exotic pebbles; Semenowa stream. 2, 3 Orthogneiss pebbles from the Cisna Beds: 2 Po³oninka stream; 3 Kañcz-12/00, pol-
ished slab. 4 Myrmekite intergrowths in marginal part of alkali feldspar augen, Wo³-1/99, crossed nicols. 5 Strongly altered plagioclas-
es (albite or oligoclase) with poorly visible repeated lamellar twinning within alkali feldspar porhpyroblast, Szcz-1/99, crossed nicols. 6
Porphyroblast composed of chess-board albite (upper part) and asymmetrical fabric of S-C type, Kañcz-12/98, crossed nicols. 7 Porphy-
roblast of oligoclase showing repeated lamellar albite twinning and inclusions of light micas in central part, Kañcz-12/98, crossed nicols.
8 Porphyroblast of small microcline showing typical twinning of cross-hatched or tartan type twinning, Wo³-13c/99, crossed nicols.
9 Laminae consisting of pleochroic biotite flakes and crystals of quartz (mosaic and with undulatory extinction), Szcz-1/99, crossed
nicols. 10 Crystals of quartz (mosaic and with undulatory extinction), Kañcz-12/98, crossed nicols.
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 209
creamy and, in general, 38 mm and even up to 1.5 cm in size
(Fig. 3.3).
The porphyroblasts consist of alkali feldspars (Or
9385
Ab
711
)
containing about 1.5 wt. % BaO and showing poorly visible
perthite structures. Some alkali feldspars contain plate shaped
inclusions of plagioclase albite (An
39
) (s. Wo³-1/99) or
oligoclase (An
12
) (s. Szcz-1/99; Fig. 3.5). These plagioclase
crystals are strongly sericitized, displaying a greyish surface
and poorly visible repeated lamellar albite twinning. Only one
sample (Kañcz-11/99) contains a completely ordered variety
of alkali feldspar (microcline), showing repeated lamellar albi-
te and pericline twinning, well-known as typical cross-hatched
or tartan type twinning.
In all samples, where plagioclase (albiteoligoclase) is in
contact with alkali feldspar in marginal parts of porphyro-
blasts myrmekite form intergrowths (Fig. 3.4) as products of
release of silica (quartz) during replacement of potassium feld-
spar by plagioclases (Hatch et al. 1961). The evolved potassi-
um reacts with alumina and silica to form white mica (pheng-
ite), which occurs close to the feldspar porphyroblasts. Deer et
al. (1962) attributed the formation of myrmekite to the break-
down of plagioclases during metamorphism. However, its
common occurrence in the studied rock is more probably due
to strain (cf. Simpson 1985).
The quartz, occurring in the bands is represented by mosaic
type crystals and show undulatory extinction between crossed
polars. Apart from quartz crystals, bands contain perthitic al-
kali feldspars Or
8990
Ab
108
(consisting of host K-feldspar
with irregular albite inclusions of replacement type) and
strongly altered plagioclases (andesine-oligoclase An
3016
)
with repeated lamellar albite twinning. Biotite occurring in
bands (Fig. 3.9) is pleochroic, from α pale yellow to γ red
brownish (s. Szczaw-1/99) and chloritized to various degrees
(ss. Wo³-1/99 and Kañcz-11/99). The chemical composition of
well-preserved biotite is Fe-rich characterized by atomic ratio
Si/Al 2 :1 and Fe/Mg from 2.87 to 2.34. The MnO content is
0.5 wt. % and TiO
2
from 3.22 to 2.91 wt. %. Phengite is inter-
grown with biotite and chlorite. The Si/Al ratio in its tetrahe-
dral sites amounts to 3.893.66, whilst the Fe/Mg ratio in oc-
tahedral sites varies from 1.45 to 2.17. The content of TiO
2
is
low, ranging from 0.29 to 0.93 wt. %.
The second type is represented by medium-grained, medi-
um-banded orthogneiss containing small porphyroblasts and
showing structural features of foliated granitic-gneiss (s. Wo³-
13c/99). Megascopically, pale creamy quartz-feldspar bands
are 34 mm thick, whereas quartz bands of similar size are
dark grey. White porphyroblasts are up to 56 mm in size.
The investigations using optical and electron microscopes
have shown that the porphyroblasts consist of large alkali feld-
spar crystals showing highly ordered structure of microcline
type, characterized by typical twinning of cross-hatched or tar-
tan type, occurring sectorially in various parts of this mineral.
Moreover, these large crystals can be overgrown by fine-blastic
microcline. Some porphyroblasts can be aggregate in charac-
ter and consist of small microcline crystals (Fig. 3.8). Micro-
cline (Or
91
Ab
9
) contains up to 1.75 wt. % BaO.
Quartz bands are characterized by mosaic crystals and crys-
tals exhibiting undulatory extinction. Apart from quartz, they
contain small plagioclase crystals (An
35
andesine) showing
repeated lamellar twinning. Small white mica flakes occur in
their central parts. The process of K-feldspathization of pla-
gioclases is also recorded (irregular, replacement type per-
thites including K-feldspar). Some alkali feldspar (Or
93
Ab
6
)
crystals occurring in matrix consist of host K-feldspar. The
feldspars contain replacement type inclusions which show the
composition of pure albite (Ab
97
An
2
Or
1
). In the groundmass,
small nests occur, filled with fine-blastic microcline, showing
characteristic twinning of cross-hatched or tartan type. Bi-
otite is usually decolourized and altered into hydrobiotite or
completely transformed into iron-rich chlorite (showing Fe/
Mg ratio about 2.8). White mica (phengite) occurs close to
large microcline augen. The atomic Si/Al ratio in tetrahedral
sites amounts to ca. 5.32, whilst the Fe/Mg atomic ratio in oc-
tahedral sites varies from 0.9 to 1.00.
The third type is represented by strongly cataclastic granit-
ic-gneiss showing properties of partly mylonitized granite (s.
Kañcz-12/98). Megascopically, grey bands are 25 mm (up to
8 mm) thick, and marked by parallel distribution of white
mica. Pale grey porphyroblasts, 310 mm in size, are com-
posed of feldspars.
The porphyroblasts consist of chess-board albite (An
8
) con-
taining up to 5 wt. % K
2
O (Fig. 3.6). The bands consist of
quartz with mosaic crystals and crystals with undulatory ex-
tinction (Fig. 3.10). There are also crystals of rather well pre-
served oligoclases (An
1517
) showing no zonality, displaying
repeated lamellar, albite twinning and containing numerous
inclusions of white micas in their central parts (Fig. 3.7). The
crystals of host oligoclases contain irregular spotty replace-
ment perthites of K-feldspar and quartz veinlets. Asymmetri-
cal fabric of S-C type is observed (Fig. 3.6). Phengite is char-
acterized by atomic Si/Al ratio in tetrahedral sites from 3.87 to
3.67 and atomic Fe/Mg ratio in octahedral sites amounting to
3.05. The content of TiO
2
is constant (1.101.15 wt. %) whilst
that of MnO does not exceed 0.07 wt. %. Phengite is inter-
grown with strongly altered biotite (hydrobiotite) and chlorite.
This mineral is pleochroic from pale yellow (α) to intense
green (γ) and distinctly enriched in iron.
Geochemical characteristics of exotics
Three types of orthogneissic pebbles distinguished on the
basis of structural and petrographic investigations were analy-
sed for major, trace and REE elements (Table 1). The first and
third distinguished types of orthogneisses (medium-grained
orthogneiss, with alkali feldspars porphyroblasts and granitic-
gneiss with chess-board albite porphyroblasts, respectively)
exhibit similar contents of major elements; only the contents
of MgO, CaO and Na
2
O display small differences. The second
type of orthogneiss (medium-grained orthogneiss with small
microcline porphyroblasts) differs from other types by higher
content of SiO
2
, lower contents of Al
2
O
3
, TiO
2
, Fe
2
O
3
, MgO
and a low Na
2
O/K
2
O ratio.
The proportions of [(Al+Fe+Ti/3)K] versus [(Al+Fe+Ti/
3)Na] (after Moine & de La Roche 1968) allowed us to de-
fine a kind of protolith of the studied types of gneisses as the
orthogneisses (Fig. 4A) the granite and rhyolite field in the
diagram. Another plutonic rock classification diagram ex-
210 B¥K and WOLSKA
pressing the balance between R1 [4Si11(Na+K)2(Fe+Ti)]
and R2 [6Ca+2Mg+Al] parameters (de La Roche et al. 1980)
shows the position of studied rocks in the fields of granodior-
ite, monzogranite and syenogranite (Fig. 4B). These geochem-
ical differences of granitoid protolith between the orthogneiss-
es are connected with the above mentioned different amounts
of SiO
2
, alkalis and Na
2
O/K
2
O ratio.
Taking into consideration the molar proportions of A/NK
and A/CK, the protolith granitoids had a peraluminous charac-
ter (Maniar & Piccoli 1989; Fig. 5A).
The calculated molar [Al/(Na+K+Ca/2)] parameter, whose
values exceed 1.05 for all types of the studied orthogneisses
(1.54, 1.24 and 1.37 for the first, second and third type of
gneiss, respectively), indicates an S-type granitic protolith
(Pitcher 1982). A similar suggestion may be expressed if dis-
crimination indexes, such as prevalence of Na
2
O over K
2
O (cf.
Hovorka & Petrík 1992), low iron content versus SiO
2
(cf.
Broska & Uher 2001), low Rb content versus Sr (Fig. 5B), and
low Y content versus high SiO
2
content (Fig. 5C) are taken
into account. The indexes resemble those, calculated for S-
type West-Carpathian granites (Petrík et al. 1994; Broska &
Uher 2001), however, their values are transitional to the in-
dexes of I-type granites (Fig. 5BD). The S-type West-Car-
pathian granites, the most abundant type in this region, repre-
sent peraluminous biotite two-mica granites to granodiorites
(for summary of their petrography and chemistry see Bros-
ka & Uher 2001).
Chondrite-normalized trace and REE element data show
positive (+) anomalies for Ba, K, Sr, Hf and Y, and negative ()
anomalies for Rb, Nb, Nd, Sm and Ti (Fig. 6). These samples
exhibit enrichment in more mobile LIL (large ion lithophile)
(Ba, K, Sr) and less mobile HFS (high field strength) (Hf, Y)
elements, as well as, impoverishment in LIL (Rb) and HFS
Table 1: Chemical composition of three types of orthogneissic pebbles: first type Szcz-1/99, second type Wo³-13c/99, third type
Kañcz-12/98. Chromium, molybdenum, tantalum, tin, vanadium, uranium, terbium, wolfram are present below their respective limits (Cr,
Ta<1, Sn, Mo, V<5, U, Tb<0.5, W<3).
Major elements (wt. %)
Type of
orthogneiss
SAMPLE
SiO
2
TiO
2
Al
2
O
3
Fe
2
O
3
MnO
MgO
CaO
Na
2
O
K
2
O
P
2
O
5
LOI Total
First type
Szcz-1/99
74.10
0.155
14.60
1.56
0.022
0.35
2.01
4.10
1.96
0.07
1.05 99.99
Second type
Wo³-13c/99
77.17
0.026
13.07
0.39
0.002
0.04
1.10
3.47
3.49
0.03
0.73 99.51
Third type
Kañcz-12/98
71.94
0.136
14.91
1.45
0.016
0.53
1.15
4.96
1.51
0.07
1.50 98.17
Trace elements (ppm)
Type of
orthogneiss
SAMPLE
Ag
Ba
Be
Cd
Co
Cs
Cu
Ga
Hf
Nb
Ni
First type
Szcz-1/99
1.4
683
2
0.7
1.0
0.0
4
18
2.5
10
3
Second type
Wo³-13c/99
2.0
2553
2
0.3
0.0
1.4
9
13
0.7
2
2
Third type
Kañcz-12/98
1.3
747
2
0.0
1.0
0.9
4
19
2.3
10
4
Trace elements (ppm)
Type of
orthogneiss
SAMPLE
Pb
Rb
S (wt.
%)
Sc
Sr
Th
U
Y
Zn
Zr
First type
Szcz-1/99
14
60
0.000
2.1
468
5.2
0
5
48
106
Second type
Wo³-13c/99
14
84
0.008
0.2
368
1.4
0
0
15
23
Third type
Kañcz-12/98
8
43
0.005
2.4
345
5.3
0.8
4
39
94
REE (ppm)
Type of
orthogneiss
SAMPLE
La
Ce
Nd
Sm
Eu
Yb
Lu
First type
Szcz-1/99
27.3
45
15
2.5
0.7
0.5
0.08
Second type
Wo³-13c/99
4.8
10
0
0.5
0.5
0.0
0.00
Third type
Kañcz-12/98
14.7
27
9
1.8
0.4
0.6
0.08
Fig. 4. The position of the granitic protolith on the petrological dia-
grams for gneissic exotics. A Proportions of [(Al+Fe+Ti/3)K]
vs. [(Al+Fe+Ti/3)Na]; diagram after Moine & de La Roche (1968).
B R1R2 diagram (after de La Roche et al. 1980): R1 = 4Si
11(Na+K)2(Fe+Ti), R2 = 6Ca+2Mg+Al (Ab = albite, An
50
= pla-
gioclase An
50
, Or = orthoclase).
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 211
(Nb, Ti) elements. A little different course of curve for the sec-
ond type of orthogneiss is observed, when compared with the
other two curves. It is expressed in deficiency of Nb, La, Ce,
Sm and Ti.
Foraminiferal assemblages in the vicinity of the
exotic-bearing layer
Stratigraphic data on the position of the Cisna Beds are
known from the western part of the Dukla Nappe within Pol-
ish territory. Blaicher (in l¹czka 1971) and Olszewska (1980)
determined the age of these deposits on the basis of Foramin-
ifera as the Late CampanianEarly? Paleocene. They suggest-
ed a diachronism of their lower boundary. Paleontological
data (based also on Foraminifera), obtained by the present au-
thor from the Bieszczady Mts have confirmed the suggested
age of the Cisna Beds (B¹k 2004). However, the lower bound-
ary could not be precisely determined (Upper Campanian?
Maastrichtian?), because of the lack of taxa diagnostic of age.
Eight samples taken for biostratigraphical study of micro-
fauna from the non-calcareous shales in the lower and middle
Fig. 6. Chondrite normalized spider diagram (after Tompson 1982)
for orthogneissic exotics.
Fig. 5. The position of the granitic protolith for the studied orthogneissic exotics within the discrimination diagrams for granites. A The A/
NK (molar) vs. A/CNK (molar) (after Maniar & Piccoli 1989). B Sr vs. Rb plot including data for various types of the Variscan West-Car-
pathian granitic rocks (after Broska & Uher 2001). C Y vs. SiO
2
plot including data for various types of the Variscan West-Carpathian granit-
ic rocks (after Broska & Uher 2001). D RbBaSr ternary discrimination diagram including data for various types of the Variscan West-Car-
pathian granitic rocks (after Broska & Uher 2001). 1 poorly evolved granites, 2 mildly evolved granites, 3 highly evolved granites.
parts of the Cisna Beds include mainly deep-water agglutinat-
ed Foraminifera (DWAF) (Fig. 7) and undeterminable radi-
olarian moulds. The DWAF assemblage is poorly to moder-
ately-diversified (Fishers alpha index: 3.19.1) including
212 B¥K and WOLSKA
siliceous-walled forms with several species of limited strati-
graphical significance. The lower part of the Cisna Beds, close
to the contact with the £upków Beds, probably represents the
upper part of Caudammina gigantea Zone (Maastrichtian?
Fig. 7. Species distribution chart of deep-water agglutinated Fora-
minifera in the Cisna Beds and £upków Beds, around the inferred
exotic-bearing layer (black star); the Bieszczady Mountains, Poland.
R.f. Rzehakina fissistomata Zone.
sensu Geroch & Nowak 1984), as the occurrences of R. epigo-
na, R. minima and hormosinids show (Fig. 8.1). First occur-
rences of R. varians (Glaessner) (Fig. 8.3) and Spiroplectam-
mina spectabilis (Grzybowski) (Fig. 8.4), which most
probably fall within the Middle-Upper Maastrichtian, have not
been noted in the sediments from the presented sections.
However, they have been found in the lower part of the Cisna
Beds, a few kilometers to the north from the studied area (B¹k
2004).
The suggested position of the exotic-bearing layer is close
to the position of the micropaleontological sample Szcz-7/96,
which was taken from the grey, non-calcareous shales, 10 m
above the inferred position of this layer (Fig. 2B). These
shales include Rzehakina fissistomata (Grzybowski)
(Fig. 8.6,7), a Paleocene species (Morgiel & Olszewska 1981;
Geroch & Nowak 1984; Olszewska 1997; B¹k, 2004) for
which this sample is its first occurrence in this section (Fig. 5).
Higher up in the section (s. Wo³-7/96; Fig. 2B), other Pale-
ocene species have been found, Annectina grzybowskii (Jur-
kiewicz) (Fig. 8.5) and Conotrochammina whangaia Finlay
(Fig. 8.8, 8.9), together with a well-diversified DWAF assem-
blage (Fig. 7).
Discussion
Petrography
The mineralogical composition and structural properties of
the granitic protolith was strongly modified. Relics of primary
magmatic minerals in orthogneissic pebbles studied are not
observed. The rocks studied display structural diversification
(S-C fabric), different thickness of quartz, quartz-feldspar, mi-
caceous layers and variable size of porphyroblasts. Micro-
probe analyses have revealed the differences in the chemical
composition of feldspars forming porphyroblasts (alkali- and
K-feldspars) and differences in matrix (alkali-, K-feldspars,
Na-Ca plagioclases). The effects of metasomatic processes
(Na-, K-feldspathization) are observed (replacement perthite)
in feldspars, both in porphyroblasts and matrix. Biotite flakes
are altered in various degrees (chloritization process). Pheng-
ite occurs in micaceous layers and is always overgrown by bi-
otite and chlorite. Phengitic muscovite is stable up to >750 °C
and >7 GPa (Catlos & Sorensen 2003). The presence of
phengite in the orthogneissic exotics may indicate even the
high-pressure metamorphism in terranes of subduction zone
slab (Ferraris et al. 2000). However, the recognition of meta-
morphic facies is here difficult, due to a lack of typical meta-
morphic mineral assemblages. It is possible that the orthog-
neisses underwent greenschist facies metamorphism. The
orthogneisses from Seward Peninsula, Alaska (Evans &
Patrick 1987) are an example of such rocks with similar min-
eral composition recording such facies conditions.
Geochemistry
The chemical composition of the first and third type of or-
thogneisses shows that they could originate from the same
granitic protolith. The differences in chemical composition of
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 213
Fig. 8. Paleocene deep-water agglutinated Foraminifera in the vicinity of the exotic-bearing layer, the Dukla Nappe, Polish Outer Car-
pathians, Bieszczady Mountains: 1 Hormosina excelsa (Dyl¹¿anka); Wo³-11/98. 2 Kalamopsis grzybowskii (Dyl¹¿anka); Wo³-11/98.
3 Remesella varians (Glaessner); Wo³-7/96. 4 Spiroplectammina spectabilis (Grzybowski); Wo³-7/96. 5 Annectina grzybowskii
(Jurkiewicz); Szcz-6/96. 6, 7 Rzehakina fissistomata (Grzybowski); Wo³-11/98. 8, 9 Conotrochammina whangaia Finlay; Wo³-7/96.
Scale bar = 100 µm.
the second type of orthogneiss in relation to the two other
types could be most probably due to weathering and transport
of pebbles from one side, and/or to the effects of earlier pro-
cesses, which took place in the granitic protolith (e.g. feldspa-
thization and albitization). First of these factors is here probably
the most important, because the second type of orthogneiss was
recognized from the small pebble (8 ×5 ×4 cm), two times
smaller than the other studied pebbles. Consequently, it may
represent only a fragment of a larger body of banded orthog-
neisses, which disintegrated during the weathering and trans-
port processes. Thus we can observe only the quartz and
quartz-feldspar bands, the most resistant fragments of the orig-
inal orthogneissic body, and their chemical composition could
not be representative for the original rocks. However, on the
other hand, the earlier metamorphic processes, such as felds-
pathization and albitization could be responsible for changes
of chemical composition of the original granitic protolith.
During recrystallization and formation of orthogneissic struc-
ture, under conditions of high-pressure metamorphism, meta-
somatic processes could operate. Na-metasomatism is sug-
gested on the basis of irregular albite inclusions (replacement
perthite type) occurring in the matrix of host K-feldspar crys-
tals (s. Szcz-1/99; Wo³-13c/99). These inclusions and addi-
tionally, chess-board albite porphyroblasts are also found in
other types of orthogneisses (s. Kañcz-12/98). K-metasoma-
tism is related to the observed formation of spotty replacement
perthites of K-feldspar in the matrix of host oligoclases (s.
Kañcz-12/98).
Geotectonic position of granitic protolith
Various concentrations of trace elements, such as Rb, Y
(and its analogue Yb) and Nb (and its analogue Ta) may help
in discrimination of granites from different tectonic settings
(Pearce et al. 1984). The discrimination diagrams for the stud-
ied protolith granitoids, based on NbY, RbYNb and Rb
YbTa variations, show that they could represent volcanic-arc
or syn-collisional granites (Fig. 9). Other chemical data used
for discrimination, such as proportions of Al
2
O
3
versus SiO
2
and proportions of (FeO
T
+MgO) versus CaO (Maniar & Pic-
coli 1989) may confirm this suggestion. The studied rocks are
classified on such discrimination diagrams as island arc, conti-
nental arc or continental collision granitoids (Fig. 10). Taking
into consideration their degree of differentiation, they can be
classified as poorly-evolved granites sensu Broska & Uher
(2001; see Fig. 5D).
The partial melting of the crust material during the colli-
sional conditions may also be evidenced on the basis of nega-
tive Nb and Ti anomalies, as well as distinct enrichment in Ba,
K, Sr, Hf and Y on the chondrite-normalized diagram (Rollin-
son 1993). However, these data should be discussed carefully,
because the same anomalies may be an effect of hydrothermal
214 B¥K and WOLSKA
or metasomatic activity in the protolith of granitic rocks and of
later metamorphic processes (e.g. albitization resulted in Nb
negative anomaly; Rollinson 1993).
So, in conclusion, the presented petrographical and
geochemical data, related to typology of protolith granites and
their geotectonic setting, represent features, typical of the per-
Fig. 9. A Nb vs. Y diagram (after Pearce et al. 1984). B Rb
vs. (Y+Nb) diagram (after Pearce et al. 1984). C Rb vs. (Yb+Ta)
diagram (after Pearce et al. 1984). syn-COLG syn-collisional
granites, WPG within-plate granites, VAG volcanic-arc gran-
ites, ORG ocean-ridge granites. For explanations of gneiss sym-
bols see Fig. 5.
aluminous, poorly-evolved, S-type granites, widely known
from the Western Carpathians (see summary in Cambel et al.
1985; Broska & Uher 1991; Uher & Gregor 1992; Uher et al.
1994; Petrík & Broska 1994; Petrík et al. 1994; Broska &
Uher 2001). According to their mineralogical and geochemi-
cal characteristics, Broska & Uher (2001) suggested that this
type of granite group exhibits features of orogen-related crust-
al granites, connected with collisional and extensional regime
during and after collision with various contribution from the
mantle especially in the post-collisional tectonics. They were
formed in the Western Carpathians during the meso-Variscan,
Early Carboniferous period (with culmination at about
350 Ma; Cambel et al. 1990).
Age of orthogneissic exotics
Recently, isotope study of orthogneissic-exotic pebble
(Szcz-1c/99) has been carried out on separated mineral phase
using the K/Ar method. The age of white micas from this peb-
Fig. 10. A Al
2
O
3
vs. SiO
2
diagram (after Maniar & Piccoli 1989).
B (FeO
T
+MgO) vs. CaO diagram (after Maniar & Piccoli 1989).
IAG island-arc granitoids, CAG continental-arc granitoids,
CCG continental collision granitoids, POG post-orogenic
granitoids. For explanations of orthogneiss symbols see Fig. 5.
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 215
ble, representing the first type of orthogneiss was calculated as
304.9±11.4 Ma (for details see Poprawa et al. 2004). The
obtained Late Carboniferous date, which represents a meta-
morphic event in the rocks, may suggest that the protolith
granites may have intruded earlier, during the main Variscan
magmatism event in the Carpathians, around 350340 Ma
(Burchart et al. 1987; Cambel et al. 1990; Petrík et al. 1994;
Petrík & Kohút 1997; Petrík 2000; Poller et al. 2000; Puti et
al. 2003).
Stratigraphic position of exotic-bearing layer
The biostratigraphy of the MiddleUpper Campanian,
Maastrichtian and Paleocene of deep-water sediments in the
Carpathians renders some problems. Planktonic species, usu-
ally poorly preserved, occur as single redeposited specimens,
or they are absent. On the other hand, abundant deep-water ag-
glutinated Foraminifera (DWAF), which are in many cases the
only microfossils in the sediments, include long-ranging
forms. Practically, all of them may occur in both the upper-
most Cretaceous and Paleocene sediments. Only two long-
ranging taxa may be used to distinguish the Upper Cretaceous
from Paleogene sediments: Caudammina gigantea (Geroch)
typical of the CampanianMaastrichtian (Geroch & Nowak
1984) and Rzehakina fissistomata (Grzybowski), which oc-
curs over the whole Paleocene section. Unfortunately, both
taxa are found as single specimens, being especially rare near
their last appearance data (e.g. C. gigantea is extremely rare in
the Upper Maastrichtian). Several DWAF taxa appeared pro-
gressively during CampanianMaastrichtian times. It concerns
such species as Hormosina excelsa (Dyl¹¿anka), Hormosina
velascoensis (Cushman), Rzehakina minima Cushman et
Renz, which have FADs in the Campanian, and Rzehakina
epigona (Rzehak), Remesella varians (Glaessner), Glomospi-
ra diffundens (Cushman et Renz) and Spiroplectammina spec-
tabilis (Grzybowski) which appear progressively in the Maas-
trichtian. However, a precise correlation of their FADs is not
established yet (for details see B¹k 2000, 2004).
Such progressive appearance of these DWAF species took
place within the lower part of the Cisna Beds, below the exot-
ic-bearing layer. This shows at least the Maastrichtian age of
this part of the Cisna Beds.
The paleontological data, obtained from the shales, near to
the inferred position of the exotic-bearing layer, and from the
overlying sediments show that this layer was laid down close
to the Cretaceous/Tertiary (K/T) boundary, most probably
during the earliest Paleocene, as indicated by the first appear-
ance of R. fissistomata, noted in the Carpathians just above the
K/T boundary (Bubík et al. 1999).
Source rocks of the exotic-bearing layer and the
Cisna Beds
In order to identify the provenance of the studied pebbles,
and also to evaluate the possibility that the orthogneissic rocks
were the source rocks for the siliciclastic material of the flysch
series of the Cisna Beds, the analytical data from the pebbles
have been compared with the petrographic composition of the
Cisna-type sandstones. This comparison is based on our stud-
ies in various localities of the Bieszczady Mountains (Fig. 11;
Table 2), and on additional petrographic data, related to occur-
rences of the Cisna Beds in both the Polish (l¹czka 1971) and
Slovak parts (Koráb & Ïurkoviè 1978) of the Dukla Nappe.
Quartz
Feldspars
Other minerals
Rock fragments
Samples
M
osa
ic
cry
st
al
Cr
ys
tal
w
ith
u
nd
ul
ato
ry
ex
tin
ctio
n
Cr
ys
tal
w
ith
n
or
m
al
ex
tin
ctio
n
C
orro
de
d
cryst
al
M
yrm
ek
ite
Pl
agio
clas
e
w
ith
rep
eated
lam
ellar
tw
in
in
g
M
icro
clin
e
Pe
rt
ite
-or
th
oc
la
se
St
ro
ng
ly
alt
ered
feld
sp
ar
Bio
tit
e
Calcite
Ch
lo
ri
te
Mu
sc
ov
ite
Gl
au
co
ni
te
Fe
rr
ous
oxi
de
s
an
d
hy
dr
ooxi
de
s
To
ur
m
alin
e
Ru
tile
Zi
rc
on
G
arn
et
s
G
nei
sses a
nd
g
ra
ni
tic
-g
ne
iss
Crys
tallin
e
sc
hi
st
s
Crys
tallin
e
garn
et
-b
earin
g
sc
hi
st
s
Ph
yllites
Si
lic
eo
us
r
oc
ks
Clayey
sh
ales
Si
de
ri
te
s?
Vo
lcan
ic
ro
ck
s
Sa
nd
st
one
s
and
m
ud
st
one
s
Ce
m
en
t
Kañcz-11/99
38.4 12.1 6.3 0.5 2.4 4.8 5.1 3.4
0.5 0.5
2.7 1.7 1.2 0.2
20.2
Semen-lewy-17/1/99 36.2 13.1 7.9 0.1 3.6 0.7 2.4 7.0 0.1
0.3 0.3 1.5 0.1 0.1
1.4 1.8 3.1 0.4
0.1 19.8
Szyp-wierzch-4/1/98 34.3 9.3 6.3 1.1 0.2 2.3 0.8 4.9 11.5 0.5 1.1 1.1 0.2 1.1
2.9 2.5 1.0 0.5 0.2 0.3 17.9
Chresty-1/99
36.5 6.8 3.5 0.6 2.2 4.0 5.5 0.8
0.8 1.2
10.5 8.1 3.3 1.4 0.7 1.3 2.4 10.4
Wlk. Semen-2/99/a 18.0 2.6 1.6
0.2 0.3 6.3 1.0 0.1
0.1 2.0
51.3 5.2 0.4 0.7 1.6 1.1 0.7 6.8
Wo³-13b/98
28.9 10.0 9.1 1.0 2.3 1.2 8.8 5.5 1.0 0.2 0.7 0.6 2.9
9.2 8.2 0.1 0.5
9.8
Wo³osate-3/98/c
26.9 7.7 7.6
0.2
3.5 1.0 0.1 2.3 0.1 3.7 0.1 0.1 0.4 16.3 16.1 0.1 3.5 0.6
0.1 9.6
Table 2: Petrographic composition of the fine-grained conglomerate of the Cisna Beds, Bieszczady Mountains, Poland. Total content
calculated as 100 %.
216 B¥K and WOLSKA
Structural features, textural features and mineralogy of the
Cisna-type sandstones
Detrital grains in the sandstones vary in the degree of round-
ing. According to Pettijohns (1975) classification, they are
subrounded, rounded and well rounded. Their contacts are
straight-line, but convex-concave are also observed. The size
of grains is diversified, mineral grains range from 0.2 to
2.1 mm, whereas rock fragments from 0.9 to 2.5 mm. In
some samples, the sandy grain size is accompanied by gravel-
ly grain size, represented by mineral and rock fragments, 3.5
7.0 mm in size. In the sample Wlk. Semen-2/99/a, the size of
detrital grains and rock fragments exceeds 2.0 mm and the
volume of gravelly grain size is higher than 50 %.
Quartz is dominant among detrital minerals, forming com-
monly mosaic crystals and crystals exhibiting undulatory ex-
tinction (Fig. 12.8). The present study has confirmed
l¹czkas opinion (1971) that the majority of detrital feldspar
grains are strongly altered. Their content is significant and
amounts to 11.6 vol. %, whilst that of unaltered feldspars, rep-
resented mainly by orthoclase perthite (Fig. 12.3) and less
common microcline (Fig. 12.7), showing typical-twinning
cross-hatched or tartan type and repeated lamellar-twinning
plagioclases (Fig. 12.6) is distinctly lower. The fragments of
Fig. 11. Petrographic composition of the Cisna-type sandstones from the studied area; northern part of the Dukla Nappe, Bieszczady
Mountains, Poland.
myrmekite (Fig. 12.5) and phyllosilicates occur in subordinate
amounts, while white mica is more common than biotite. Bi-
otite is more easily altered, showing different stages of chlori-
tization. Small chlorite flakes and glauconite aggregates are
also observed. Opaque minerals are represented mainly by an-
hydrous and hydrated iron oxides.
The sandstones also contain heavy minerals, including gar-
nets, zircon, tourmaline and rutile (Table 2). The amount of
garnets is the highest. Though these minerals are not resistant
to chemical weathering, they are well preserved during trans-
port and mechanical disintegration. This conclusion is consis-
tent with the data reported by other authors (l¹czka 1971;
Koráb & Ïurkoviè 1978; Winkler & l¹czka 1992, 1994) for
heavy minerals of the Cisna Beds. All these authors described
the population dominated by garnet and very stable minerals
(zircon, tourmaline and rutile) (up to 95 % in frequency), with
accessory of brookite, anatase, titanite, apatite and epidote.
Rock-fragment grains are the other significant component
of the Cisna-type sandstones. They are represented by crystal-
line rocks (Fig. 11, Table 2) showing medium degree of re-
gional metamorphism mainly orthogneisses and schists (in
s. Wo³-13b/98 also garnet-bearing schist). The content of
crystalline rocks is variable. It is the highest in sandstones
containing gravelly grain size (18.632.4 vol. %) and in con-
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 217
glomerates (s. Wlk. Semen-2/99/a: 56.8 vol. %). Fragments of
phyllites and siliceous, ferruginous, clayey and effusive (vol-
canic) rocks are less common. Some thick-bedded layers (not
studied here) may also contain sedimentary clasts (mainly
non-calcareous shales).
The Cisna-type sandstones contain predominantly contact-
porous and basal cement. In some samples, matrix-type ce-
ment also occurs, where the main detrital quartz and less com-
mon feldspars are much smaller in size. The content of cement
is diversified, as documented by planimetric analyses (Ta-
Fig. 12. 1 Gravelstone of the Cisna Beds with abundant white pebbles of orthogneiss fragments (gn) and dark grey quartz (q), Wo³-3/98,
polished slab. 28 Micrographs of grains from sandstones of the Cisna Beds which derive from decomposition of orthogneisses: 2
Crystalline rocks fragments; A orthogneiss grain, B phyllite grain, Wo³osate-3/98/c, crossed nicols. 3 Grain of perthitic orthoclase,
Wo³-13b/98, crossed nicols. 4 Plagioclase grain, Kañcz-11/99, crossed nicols. 5 Fragment of myrmekite, Semen-lewy-17/1/99,
crossed nicols. 6 Plagioclase grain showing repeated lamellar albite twinning, Semen-lewy-17/1/99, crossed nicols. 7 Fragment of or-
thogneiss (microcline and mosaic quartz crystalloblasts), Kañcz-11/99, crossed nicols. 8 Mosaic quartz grain, Semen-lewy-17/1/99,
crossed nicols.
ble 2). In sandstones lacking the gravelly grains (pebbles), it
varies from 10 to 20 vol. % and does not exceed 10 vol. % in
sandstones containing some admixture of gravelly material. In
conglomerates, the content of cement is distinctly low (ca.
6.8 vol. %). The majority of clastic rocks contain clayey-fer-
ruginous cement, but locally it is calcareous, corroding detrital
feldspar grains. This phenomenon may be related to the pres-
ence of secretional forms calcite veinlets and nests.
In the classification FQR and MQF+R diagrams (for
details, see Fig. 13A,B) showing the petrographical and struc-
218 B¥K and WOLSKA
tural features, the Cisna-type sandstones containing pebbles of
orthogneissic rocks are plotting in similar fields to those of
sandstones examined by l¹czka (1971) from the western part
of the Dukla Nappe.
In the FQL and FQ
m
L
t
diagrams showing the prove-
nances of material (Dickinson & Suczek 1979), the studied
Cisna-type sandstones are plotted in the field of continental
block provenances (Fig. 13C,D).
Cisna-type sandstones versus orthogneissic exotics
Detailed petrographic studies of sandstones and conglomer-
ates from the series containing orthogneissic pebbles have
confirmed that the continental crust rocks consisting of or-
thogneisses and granitic-gneisses were the source material for
the Cisna-type sandstones.
The following data indicate that orthogneisses were the
dominant rocks of the source area for the Cisna-type sand-
Fig. 13. A, B Mineral-petrographic composition of sandstones in the Dukla Beds including data from literature (l¹czka 1971; Koráb &
Ïurkoviè 1978): A Content of quartz, feldspars and rock fragments calculated as 100 %. B Content of quartz, feldspars together with
rock fragments and matrix calculated as 100 %. C, D Ternary discrimination diagrams of the coarse-grained sandstones of the Cisna
Beds, related to different tectonic provenances (after Dickinson & Suczek 1979). 1 Kañcz-11/99, 2 Semen-lewy-17/1/99, 3
Szyp-wierz-4/1/98.
stones: 1 prevalence of clasts of mosaic quartz (up to
39 vol. %), 2 considerable content of crystals of quartz ex-
hibiting undulatory extinction, 3 myrmekite fragments, 4
microcline clasts showing typical twinning cross-hatched or
tartan type, 5 alkali feldspar clasts displaying perthite
structures, 6 plagioclase clasts containing light mica inclu-
sions in central parts, 7 occurrence of flakes of white mica
and sporadically strongly altered flakes of biotite (hydrobi-
otite), 8 occurrence of small fragments of gneisses (quartz
+feldspars, quartz+plagioclase, quartz+K-feldspar+ plagio-
clase, K-feldspar+plagioclase) and larger fragments of or-
thogneisses in gravelly grain size in sandstone and conglomer-
ate samples.
The occurrence of granitic rocks as the source rocks of the Ci-
sna-type sandstones is here documented by various mineral as-
semblages, found in the studied samples. They include quartz+
feldspars (alkali feldspar+K-feldspar+plagioclases)+white
mica (phengite)+biotite (chlorite).
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 219
Fig. 14. A Directions of paleotransport in the Cisna Beds near the inferred exotic-bearing layer; Wo³osatka drainge basin, Bieszczady
Mountains, Poland. B Directions of material transport in the £upków and Cisna Beds (CampanianPaleocene) and position of the source
area (after Ksi¹¿kiewicz 1962; l¹czka 1971; supplemented).
Provenance of orthogneissic exotics
The exposures with exotics in the Dukla Nappe do not pro-
vide direct information about the location of the source area
for the orthogneissic exotics. Petrographic affinities between
orthogneissic pebbles and mineral/rock fragments grains of
the Cisna-type sandstones unequivocally show on the same
provenance of them. Thus we suggest that these deposits were
transported from south-east, like the material of the Cisna-type
sandstones. The directions of material transport, measured
from hieroglyphs in the studied area are fairly stable, from
100º to 160º
(Fig. 14A). Comparison of the petrographic com-
position of the Dukla-type sandstones, textural features of the
sandstones (e.g. ratio of grains versus matrix) and contents of
coarse-grain material between the western and eastern parts of
the Dukla Nappe (l¹czka 1971; Koráb & Ïurkoviè 1978) are
additional factors which point to the location of the source
area south-east of the studied area.
The paleogeography of the Dukla Basin during the Senon-
ian and Paleocene was presented by Ksi¹¿kiewicz (1962),
l¹czka (1971), Danysh (1973) and Koráb & Ïurkoviè
(1978). According to these authors, the turbidites of the Cisna
Beds were derived from a cordillera, located to the SE
(Fig. 14B). Sedimentological and petrographical data, present-
ed by l¹czka (1959) from the Bystre Scale (Upper Creta-
ceous-Paleocene Istebna Beds of the Silesian Basin) show that
the Dukla Basin was restricted to the north by the south-east-
ern extension of the Silesian cordillera. On the other hand,
Danysh (1973) suggested an occurrence of the so-called Cen-
tral Cordillera within the south-eastern part of the Dukla Ba-
sin. It was the source area for thick-bedded, coarse-grained
turbidites of the Upper Berezny Beds (equivalent of the Cisna
Beds in Ukrainian territory). Most probably, an extension of
this cordillera, which is recently regarded as the NE part of the
Marmarosh massif (Hamor et al. 1989; Poprawa et al. 2002)
could be the source area of the Cisna Beds in the Polish part of
the Dukla Basin. The foraminiferal assemblages (Saccammi-
na-Bathysiphon biofacies; B¹k 2004) show on deep-water
sedimentation, below the calcium compensation depth during
the MaastrichtianPaleocene in the Dukla Basin. According to
l¹czka (1971) and Leko et al. (1960), the thickness distribu-
tion of the Cisna Beds, which gradually disappear in the more
inner folds of the Dukla Nappe, show that the axis of maxi-
mum deposition was near the northern margin of the Dukla
Basin.
Conclusions
1 The layer with exotics may be a useful correlation hori-
zon on a regional scale in the CampanianPaleocene monoto-
nous flysch series of the Dukla Nappe. The exotics from the
Dukla Nappe probably occur in a layer, which extends over a
distance of at least 3 km. This layer occurs in the southern
limb of the northernmost anticline of the Dukla Nappe, within
the thick series of thick-bedded and coarse-grained sandstones
of the Cisna Beds, 550 m above their lower boundary.
2 The exotic pebbles include three types of granite de-
rived orthogneisses: 1 medium-banded orthogneiss with al-
kali feldspar porphyroblasts showing structural features of fo-
liated granitic-gneiss, 2 medium-banded orthogneiss
containing small microcline porphyroblasts and showing
structural features of foliated granitic-gneiss, and 3 strong-
ly cataclastic granitic-gneiss with chess-board albite porphy-
roblasts showing properties of partly mylonitized granite. The
petrographic composition of the orthogneisses shows that the
protolith of the orthogneisses points to granites metamor-
phosed under conditions of greenschist facies.
220 B¥K and WOLSKA
3 The chemical composition of the exotic pebbles con-
firms that they represent orthogneisses, which point to peralu-
minous, poorly-evolved, S-type granites, widely known from
the Variscan crystalline basement of the Western Carpathians.
According to their mineralogical and geochemical characteris-
tics, they exhibit features of orogen-related crustal granites.
The discrimination diagrams, based upon major elements and
trace elements show that the protolith rocks could represent
active continental margin or continental collision (syn-colli-
sional) granites.
4 The Late Carboniferous age date of white micas from
the orthogneissic pebble (first type of orthogneiss; K/Ar meth-
od: 304.9±11.4 Ma; Poprawa et al. 2004) is related to the
metamorphism event of the rocks. It may suggest that the pro-
tolith granites may have intruded during the main Variscan
magmatism event in the Carpathians, coinciding with interval
350340 Ma.
5 The biostratigraphical data on deep-water agglutinated
Foraminifera suggest the position of the exotic-bearing layer
in the lowermost Paleocene, close to the K/T boundary.
6 Petrographic affinities between orthogneissic pebbles
and mineral/rock fragments grains of the Cisna-type sand-
stones show the same provenance for them. These deposits
were transported from the northeast extension of the Marma-
rosh massif. During the Maastrichtian and Paleocene, the mas-
sif had the character of continental source bearing cordillera,
formed mainly of orthogneissic and granitic rocks.
Acknowledgments: Thanks are due to Prof. G. Haczewski
(Cracow Pedagogical University) for his discussion during the
mapping of the study area and for improving the English text
of the manuscript, and Prof. W. Narêbski (Museum of the
Earth, Polish Academy of Sciences, Warsaw) for critical read-
ing of the geochemical part of this paper. Thanks are extended
to the Directors of the Bieszczady National Park for the per-
mission to carry out the fieldwork. The authors are indebted to
Jadwiga Faber M.Sc. (Scanning Microscope Laboratory of the
Institute of Zoology, Jagiellonian University) for scanning
electron micrographs and chemical microprobe analyses.
Many thanks are also due reviewers of the manuscript: Prof.
N. Oszczypko, Dr. L. vábenická, Dr. O. Krejèí, Dr. I. Petrík
and two anonymous persons for constructive comments.
References
B¹k K. 2000: Biostratigraphy of deep-water agglutinated Foramin-
ifera in Scaglia Rossa-type deposits of the Pieniny Klippen
Belt, Carpathians, Poland. In: Hart M.B., Kaminski M.A. &
Smart C. (Eds.): Proceedings of the Fifth International Work-
shop on Agglutinated Foraminifera, Plymouth, England, Sep-
tember 1219. 1997. Grzybowski Found. Spec. Publ. 7, 1540.
B¹k K. 2004: Upper Cretaceous-Palaeogene foraminiferal biofacies
in the deep-water flysch environment; a case study from the
Eastern Carpathians. In: Kaminski M.A. & Bubík M. (Eds.):
Proceedings of the Sixth International Workshop on Aggluti-
nated Foraminifera. Grzybowski Found. Spec. Publ. 8, 156.
Broska I. & Uher P. 1991: Regional typology of zircon and their re-
lationships to allanite-monazite antagonism (on example of
Hercynian granitoids of the Western Carpathians). Geol. Car-
pathica 42, 271277.
Broska I. & Uher P. 2001: Whole-rock chemistry and genetic typol-
ogy of the West-Carpathian Variscan granites. Geol. Carpathi-
ca 52, 7990.
Bubík M., B¹k M. & vábenická L. 1999: Biostratigraphy of the
Maastrichtian to Paleocene distal flysch sediments of the Raèa
Unit in the Uzgruò section (Magura group of nappes, Czech
Republic). Geol. Carpathica 50, 3348.
Burchart J., Cambel B. & Král J. 1987: Isochron reassessment of
K-Ar dating from the West Carpathian crystalline complex.
Geol. Zbor. Geol. Carpath. 41, 131170.
Cambel C., Petrík I. & Vilinoviè V. 1985: Variscan granitoids of the
Western Carpathians in the light of geochemical-petrochemical
study. Geol. Zbor. Geol. Carpath. 36, 204218.
Cambel C., Král J. & Burchart J. 1990: Isotopic geochronology of the
West Carpathian crystalline complex with catalogue of data.
Veda, Bratislava, 1183 (in Slovak with English summary).
Catlos E.J. & Sorensen S.S. 2003: Phengite-based chronology of K-
and Ba-rich fluid flow in two paleosubduction zone. Science
299, 9295.
Danysh W.W. 1973: Geology of the western part of the Ukrainian
Carpathians. Naukova dumka, Kijev, 1116 (in Russian).
Deer W.A., Howie R.A. & Zussman J. 1962: Rock-forming miner-
als; part 5. Longmans, Green and Co Ltd., London, 1435.
de La Roche H., Leterrier J., Grande Claude P. & Marchal M. 1980:
A classification of volcanic and plutonic rocks using R1-R2 di-
agrams and major element analyses its relationships and
current nomenclature. Chem. Geol. 29, 183210.
Dickinson W.R. & Suczek C.A. 1979: Plate tectonics and sandstone
compositions. Bull. Amer. Assoc. Petrol. Geol. 63, 21642182.
Evans B.W. & Patrick B.E. 1987: Phengite (3T) in high-pressure
metamorphosed granitic orthogneisses, Seward Peninsula,
Alaska. Canad. Mineralogist 25, 141158.
Ferraris C., Chopin C. & Wessicken R. 2000: Nano- to micro-scale
decompression products in ultra high-pressure phengite: HR-
TEM and AEM study, and some petrological implications.
Amer. Mineralogist 85, 11951201.
Geroch S. & Nowak W. 1984: Proposal of zonation for the Late Ti-
thonianLate Eocene, based upon arenaceous Foraminifera
from the Outer Carpathians, Poland. In: Oertli H.J. (Ed.):
Benthos 83: 2nd International Symposium on Benthic Fora-
minifera (Pau, April 1115, 1983). Elf-Aquitane, ESO REP and
TOTAL CFP, Pau & Bordeoux, 225239.
Haczewski G., B¹k K., Kukulak J., Mastella L. & Rubinkiewicz J.
(submitted to print): Ustrzyki Górne Sheet (1068) of Detailed
Geological Map of Poland, scale 1:50,000. Pañstw. Inst. Geol.,
Warszawa.
Hamor G., Steininger F.F., Kojundgieva E., Cicha I., Vass D., Bar-
thelt D., Halmai J., Boccaletti M., Gelati R., Moratti G., Slacz-
ka A., Marinescu F., Berger J.P., Babak E.V., Goncharova I.A.,
Ilvina L.B., Nevesskaja L.A., Paramanova N.P., Popov S.V.,
Eremija M. & Marinovich D. 1989: Neogene Palaeogeographic
Atlas of Central and Eastern Europe, scale 1:3,000,000. Maps
17. Geol. Inst. Hung. (MÁFI), Budapest.
Hatch F.H., Wells A.K. & Wells M.K. 1961: Petrology of the igne-
ous rocks. 12
th
edition. Thomas Murby & Co, London, 1515.
Hovorka D. & Petrík I. 1992: Variscan granitic bodies of the West-
ern Carpathians the backbone of the mountain chain. In:
Vozár J. (Ed.): The Palaeozoic geodynamic domains of the
Western Carpathians, Eastern Alps and Dinarides. Spec. Vol.
IGCP 276, Bratislava, 5766.
Koráb T. & Ïurkoviè T. 1978: Geology of Dukla Unit (East-Slova-
kian Flysch). Geol. Ústav D. túra, Bratislava, 1144.
Koszarski L., l¹czka A. & ¯ytko K. 1961: Stratigraphy and palaeo-
geography of the Dukla Nappe in the Bieszczady Mts. Kwart.
Geol. 5, 551578 (in Polish).
Ksi¹¿kiewicz M. 1962: Geological Atlas of Poland. Cretaceous and
EXOTIC ORTHOGNEISS PEBBLES FROM PALEOCENE FLYSCH OF THE DUKLA NAPPE 221
Paleogene stratigraphy and facies in the Polish Central Car-
pathians. Inst. Geol., Warszawa (in Polish, English summary).
Leko B., Nemèok J. & Koráb T. 1960: Flysch of the Uská hornati-
na Mts. Geol. Práce, Spr. 19, 6585 (in Slovak).
Maniar P.D. & Piccoli P.M. 1989: Tectonic discrimination of grani-
toids. Geol. Soc. Amer. Bull. 101, 635643.
Moine B. & de La Roche H. 1968: Nouvelle approche du problème
de lorigine des amphibolites, à partir de leur composition
chimique. C. R. Acad. Sci. 267, 2084.
Morgiel J. & Olszewska B. 1981: Biostratigraphy of the Polish Ex-
ternal Carpathians based on agglutinated foraminifera. Micro-
paleontology 27, 130.
Olszewska B. 1980: Foraminiferal stratigraphy of Upper Cretaceous
and Palaeogene sediments of the central part of the Dukla Unit.
Biul. Inst. Geol. (Warszawa) 326, 59107 (in Polish, English
summary).
Olszewska B. 1997: Foraminiferal biostratigraphy of the Polish Out-
er Carpathians: a record of basin geohistory. Ann. Soc. Geol.
Poloniae 67, 325336.
Pearce J.A., Harris N.B.W. & Tindle A.G. 1984: Trace element dis-
crimination diagrams for the tectonic interpretation of granitic
rocks. J. Petrology 25, 956983.
Petrík I. 2000: Multiple sources of the West-Carpathian granitoids: A
review of Rb/Sr and Sm/Nd data. Geol. Carpathica 51, 145158.
Petrík I. & Broska I. 1994: Petrology of two granite types from the
Tribec Mountains, Western Carpathians: an example of allanite
(+magnetite) versus monazite dichotomy. Geol. J. 29, 5978.
Petrík I. & Kohút M. 1997: The evolution of granitoid magmatism
during the Hercynian orogen in the Western Carpathians. In:
Grecula P., Hovorka D. & Puti M. (Eds.): Geological evolu-
tion of the Western Carpathians. Miner. Slovaca Monograph
235252.
Petrík I., Broska I. & Uher P. 1994: Evolution of the West Car-
pathian granite magmatism: source rock, geotectonic setting
and relation to the Variscan structure. Geol Carpathica 45,
283291.
Pitcher W.S. 1982: Granite type and tectonic environment. In: Hsu
K.J. (Ed.): Mountain Building Processes. Acad. Press, London,
1940.
Pettijohn F.J. 1975: Sedimentary rocks. Harper & Row Publishers,
New York, 1628.
Poller U., Broska I., Finger F., Uher P. & Janák M. 2000: Early
Variscan in the Western Carpathians: U/Pb zircon data from
granitoids and orthogneisses of the Tatra Mountains (Slovakia).
Int. J. Earth Sci. 89, 336349.
Poprawa P., Malata T. & Oszczypko N. 2002: Tectonic evolution of
the Polish part of Outer Carpathians sedimentary basins con-
strains from subsidence analysis. Przegl. Geol. 50, 10921108.
Poprawa T., Malata T., Pécskay Z., Bana M., Skulich J., Paszkowski
M. & Kusiak M. 2004: Geochronology of crystalline basement
of the Western Outer Carpathians sediment source areas pre-
liminary data. Mineral. Soc. Pol. Spec. Pap. 22, 329332.
Puti M., Kotov A.B., Petrík I., Korikovsky S.P., Madarás J., Salnik-
ova S.P., Yakovleva S.Z., Berezhnaya N.G., Plotkina Y.V., Ko-
vach V.P., Lupták B. & Majdán M. 2003: Early- vs. late
orogenic granitoids relatioships in the Variscan basement of the
Western Carpathians. Geol. Carpathica 54, 163174.
Rollinson H. 1993: Using geochemical data: evaluation, presenta-
tion, interpretation. Longman Group UK Ltd., London, 1352.
Simpson C.A. 1985: Deformation of granitic rocks across the brittle-
ductile transition. J. Struct. Geol. 7, 503511.
l¹czka A. 1959: Stratigraphy of the Bystre Scale Middle Car-
pathians. Biul. Inst. Geol. 131, 203286 (in Polish, English
summary).
l¹czka A. 1971: The geology of the Dukla unit Polish Flysch
Carpathians. Prace Inst. Geol. 63, 1167 (in Polish, English
summary).
Tompson R.N. 1982: British Tertiary volcanic province. Scott. J.
Geol. 18, 49107.
Uher P. & Gregor T. 1992: The Turèok granite a product of pos-
torogenic magmatism of A-type. Miner. Slovaca 24, 301304
(in Slovak, English summary).
Uher P., Marschalko R., Martiny E., Pukelová ¼., Streko V., To-
man B. & Walzel E. 1994: Geochemical characterization of
granitic rock pebbles from Cretaceous to Paleogene flysch of
the Pieniny Klippen Belt. Geol. Carpathica 45, 171183.
Winkler W. & l¹czka A. 1992: Sediment dispersal and provenance
in the Silesian, Dukla and Magura flysch nappes (Outer Car-
pathians, Poland). Geol. Rdsch. 81, 371382.
Winkler W. & l¹czka A. 1994: A Late Cretaceous to Paleogene
geodynamic model for the Western Carpathians in Poland.
Geol. Carpathica 45, 7182.