GeolCarp_Vol63_No6_441

www.geologicacarpathica.sk

GEOLOGICA CARPATHICA

, DECEMBER 2012, 63, 6, 441—452 doi: 10.2478/v10096-012-0034-2

Tectonothermal history of the basement rocks within the

NW Dinarides: new

Ar/

Ar ages and synthesis

SIBILA BOROJEVIĆ ŠOŠTARIĆ

, FRANZ NEUBAUER

, ROBERT HANDLER

and

LADISLAV A. PALINKAŠ

Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia;

sibila.borojevic-sostaric@rgn.hr

Department Geography and Geology, University of Salzburg, Hellbrunner Str. 34, A-5020 Salzburg, Austria

Faculty of Science, University of Zagreb, Horvatovac bb, HR-10000 Zagreb, Croatia

(Manuscript received February 16, 2012; accepted in revised form June 13, 2012)

Abstract: Very low-grade and low-grade metamorphosed basement rocks from distinct inliers of the Africa-derived
northwestern Dinarides (Medvednica Mts and Paleozoic Sana-Una Unit, respectively) have been studied with the multi-
grain step-heating

Ar/

Ar technique in order to compare and reveal their tectonothermal history.

Ar/

Ar ages from

detrital white mica of the very low-grade basement rocks of the Paleozoic Sana-Una Unit gave a Variscan age of
~ 335 Ma. The new age is in agreement with

Ar/

Ar ages from the very low-grade basement exposed at Petrova and

Trgovska Gora of the NW Dinarides. Within low-grade metamorphic basement rocks from the Medvednica Mts, we
found no Variscan ages. White mica from phyllitic basement rocks of the Medvednica Mts gives predominantly early
Alpine ages ranging between 135 and 122 Ma and younger Alpine ages of  ~ 80 Ma. The early Alpine ages of 135 and
122 Ma are interpreted as the date to the onset of ductile nappe stacking predating the formation of Gosau-type collapse
basins.  The  late  early  Alpine  event  of  ~ 80 Ma  can  be  traced  in  the  entire  Cretaceous-aged  orogen  of  the  Circum-
Pannonian  Region  and  is  synchronous  with  subsidence  of  the  Gosau-type  basins  and  opening  and  closure  of  the
neighbouring Sava-Vardar Zone.

Key words: Cretaceous overprint, Variscan, Dinarides, basement, nappe stacking.

Introduction

Geotectonic  models  of  the  southwestern  branch  of  the  Cir-
cum-Pannonian Region largely resulted in explanation of the
Early  to  Late  Cretaceous  orogeny  by  collision  of  continental
units  exposed  after  the  consumption  of  the  Maliac,  Meliata
and Vardar oceans throughout Jurassic, Cretaceous and Ceno-
zoic  times  (e.g.  Pamić  et  al.  1998;  Neugebauer  et  al.  2001;
Neubauer  2002;  Stampfli  et  al.  2002;  Schmid  et  al.  2008;
Ustaszewski  et  al.  2009  and  references  therein).  In  those
models, the Dinarides together with Apulia are predominantly
regarded as a stiff backbone without considering their inter-
nal deformation. The purpose of this study is to improve our
understanding  of  the  tectonothermal  evolution  of  the  base-
ment units within the NW Dinarides.

The Dinarides are a Mesozoic to Recent SW-vergent fold-

and-thrust belt that extends from the Southern Alps in the NW
to the Hellenides in the SE. The Paleozoic basement units of
the  Dinarides  can  generally  be  subdivided,  on  the  basis  of
their internal deformation and metamorphic state, into: i) low-
grade metamorphosed, and ii) very low-grade metamorphosed
units  (e.g.  Pamić  &  Jurković  2002  and  references  therein).
Low-grade metamorphosed basement units, such as the Drina-
Ivanjica, Jadar, Mid-Bosnian Schist Mts, Medvednica Mts re-
veal  widespread  Alpine  metamorphism  (based  on  K/Ar
mineral and whole rock ages; Milovanović 1984; Belak et al.
1995a,b; Palinkaš et al. 1996; Pamić et al. 2004; Judik et al.

2006),  whereas  very  low-grade  metamorphosed  Paleozoic
units  of  the  northwestern  Dinarides  (Petrova  and  Trgovska
Gora)  yielded  Variscan  ages  and  an  Early  Permian  overprint
(

Ar/

Ar ages; Borojević Šoštarić et al. 2009). What we can

extract from the above mentioned literature, is that low-grade
metamorphosed  units  underwent  a  single-stage  Alpine  meta-
morphism with an age range of 139—129 Ma, 121—95 Ma and
122—110 Ma  in  the  Drina-Ivanjica,  Mid-Bosnian  Schist  Mts
and Medvednica Mts, respectively. However, Tomljenović &
Csontos (2001) recognized several deformational stages in the
Medvednica  Mts.  Here,  we  performed  precise

Ar/

Ar dat-

ing in order to find an appropriate age relationship between, as
well as the timing of different stages of deformation.

We here report new

Ar/

Ar ages of the (i) low-grade

metamorphosed basement units of the Medvednica Mts (NW
Dinaride  junction,  i.e.  Zagorje  Mid-Transdanubian  Zone),
and  from  (ii)  the  very  low-grade  metamorphosed  Paleozoic
Sana-Una Unit (NW Dinarides) (Fig. 1). We use an approach
combining  microfabric  observations  with  the

Ar/

white  mica  dating.  These  new  ages  will  help  to  resolve  the
stepwise, long-lasting shortening and accretion history of the
Dinarides,  and  shed  new  light  on  the  distinction  between
Variscan and Alpine tectonothermal events in the low-grade
and  very  low-grade  metamorphosed  basement  units  of  the
Dinarides. In order to present general conclusions and models,
the  new  data  are  coupled  with  published

Ar/

Ar white

mica ages from Borojević Šoštarić et al. (2009).

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GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

Regional geological setting

The Dinarides are divided into a number of tectonic units,

which include external and internal sectors and are exposed
from the Adriatic Sea units towards the NE up to the adjoin-
ing Tisia Mega-tectonic Unit (the zonation follows those of
reviews by Pamić et al. 1998, and Dimitrijević 1982, 1997;
Fig. 1a,b). The Adriatic Carbonate Platform and its correla-
tives, together with the East Bosnian-Durmitor Zone consti-
tute  the  External  Dinarides,  while  the  Dinaric  Ophiolite
nappe and the Sava-Vardar Zone represent units of the Inter-
nal  Dinarides.  Equally,  the  Internal  and  External  Dinarides
contain  exposed  Paleozoic  basement  units  with  various  de-
grees  of  metamorphism,  mainly  up  to  greenschist,  in  some
cases up to epidote-amphibolite facies conditions (for over-
view see Pamić & Jurković 2002). The Paleozoic basement
units are composed of Ordovician to Carboniferous (Permian)
meta-sedimentary rocks (dominantly Carboniferous turbiditic
flysch  sandstones  and  shales  and  Permian  molasse-type  de-
posits) and meta-volcanics overlain by a mainly Triassic car-
bonate-clastic cover. The degree of metamorphism increases
from  the  northwest  towards  the  southeast.  Very  low-grade
metamorphism  is  found  in  the  northwestermost  part  of  the
Dinarides  (Petrova  and  Trgovska  Gora)  whereas  low-  and
medium-grade  metamorphism  is  established  in  the  central

and southeastern parts (Sana-Una, Drina-Ivanjica, Jadar,
Mid-Bosnian Schist Mts; Podubsky & Pamić 1967; Podubsky
1968; Majer et al. 1991).

Further to the north-west, between the Periadriatic-Balaton

and the Zagreb-Zemplín faults, heterogeneous units are jux-
taposed,  forming  the  NW  Dinaride  junction,  namely  the
Zagorje-Mid-Transdanubian  Zone  (ZMTZ,  according  to
Pamić  &  Tomljenović  1998)  or  the  Sava  Composite  Unit
(according to Haas et al. 2000). This complex zone comprises
deformed blocks of the Internal and External Dinarides and
of  South  Alpine  units,  and  can  be  traced  over  several  hun-
dred  km  from  the  NW  Dinarides  to  NE  Hungary  (Haas  &
Kovács 2001). The Medvednica Mts, as a part of ZMTZ, en-
closes  low-grade  and  high-pressure  Paleozoic  metamorphic
rocks (Belak & Tibljaš 1998).

Previous geochronological studies of the basement

units

Various Paleozoic basement units of the northwestern Di-

narides  show  different  ages  of  metamorphism;  Variscan
(Carboniferous),  eo-Alpine  (Cretaceous)  or  Meso-Alpine
(Eocene). Previous K-Ar ages from Mid-Bosnian Schist Mts
show  two  age  groups,  namely  159—92 Ma  and  50—37 Ma

Fig. 1. a – Overview of the major tectonic units of the Alpine-Balkan-Carpathian-Dinaride orogen, with the location of the Medvednica
Mts and Sana-Una basement units (grey background), and the locations of Petrova and Trgovska Gora basement units (white background).
b – Simplified geological map of the Alpine-Carpathian-Dinaridic orogen with the positions of the investigated basement unit. Modified
after Pamić et al. (1998), Schmid et al. (1998), Willingshofer (2000) and Tomljenović (2002).

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GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

(Palinkaš  et  al.  1996;  Pamić  &  Jurković  2002;  Pamić  et  al.
2004). Low-grade metamorphic Paleozoic basement rocks of
the  Medvenica  Mts  show  ductile  deformation  and  an  Early
Cretaceous  metamorphic  overprint  dated  at  122  to  110 Ma
(Belak et al. 1995a,b; Judik et al. 2006).

Ar/

Ar dating of

the Paleozoic Lim Unit (East Bosnian-Durmitor Zone, an Up-
per  Carboniferous  molasse-type  foreland  basin,  Figs. 1, 2)
gave ages at 84—78 Ma and an overprint at ca. 52 Ma, essen-
tially showing that the older age group is younger than previ-
ously considered (Ilić et al. 2003). Ilić et al. (2005) reported
detrital white mica ages from the Upper Carboniferous mo-
lasse  of  the  Paleozoic  Lim  (East  Bosnian-Durmitor  Zone)
showing  the  dominance  of  a  Variscan  metamorphic  hinter-
land  during  the  post-Variscan  history.  Detrital  white  mica
from  Lower  Permian  sandstones  and  Carboniferous  shales
adjacent  to  siderite-polysulphide  veins  of  the  Petrova  Gora
Paleozoic  basement  shows  Variscan

Ar/

Ar plateau ages

at  342.9 ± 3.3 Ma  and  332.8 ± 3.1 Ma,  respectively,  and  are
overprinted  by  a  thermal  event  at  ca.  265.6 ± 6.2  to
274.2 ± 3.1 Ma  (Borojević  Šoštarić  et  al.  2009).  A  single
sample  of  fine-grained  sericite  within  the  tectonic  breccia
yielded a Late Cretaceous age (75.0 ± 0.8 Ma; Borojević Šoš-
tarić  et  al.  2009).  Detrital  white  mica  from  Devonian—Car-
boniferous flysch-like units of the Trgovska Gora Paleozoic
basement  shows  Variscan

Ar/

Ar ages, ranging from

353.8 ± 4.2 (?408.6 ± 3.8) to 313.5 ± 3.0 Ma. Two thermal
overprints are recorded; one at 298.0 ± 4.2 Ma which is inter-
preted as the maximum age of hydrothermal activity, and

one at 192.9 ± 7.2 Ma which is interpreted as a thermal re-
cord of Triassic advanced rifting/opening events (Borojević
Šoštarić et al. 2009).

Local geological setting

Medvednica Mts, Zagorje-Mid-Transdanubian Zone

In northwestern Croatia, the Zagorje-Mid-Transdanubian

Zone can be traced for about 120 km (Fig. 1a,b). The west-
ernmost  boundary  of  the  Zagorje-Mid-Transdanubian  Zone
terminates within Dinaridic units and the system of Sava and
Julian-Savinja  nappes.  Morphologically,  it  is  characterized
by a few isolated, around 1,000 m high mountains, including
the  Medvednica  Mts,  composed  of  pre-Neogene  tectono-
stratigraphic  units,  that  crop  out  within  the  Neogene  and
Quaternary fill of the Pannonian Basin.

The Medvednica Mts are situated in the northwestern part

of the Zagorje-Mid-Transdanubian Zone (ZMTZ), as a result
of  Cenozoic  extrusion  tectonics  (Pamić  &  Tomljenović
1998; Haas et al. 2000; Haas & Kovacs 2001; Tomljenović
& Csontos 2001; Tomljenović 2002). It comprises four main
tectonostratigraphic  units  (Fig. 2;  Tomljenović  2002):
(1) Paleozoic-Mesozoic  magmatic-sedimentary  complex
metamorphosed  during  the  Early  Cretaceous;  (2)  Jurassic
tectonized ophiolitic mélange; (3) a very low-grade Permian
to  Triassic  sequence  of  the  Žumberak-Medvednica  nappe

Fig. 2. Simplified tectonic map of the Medvednica Mts, showing sample localities and age of the

Ar/

Ar dating, modified after Tomljenović

(2002). Abbreviations: i.a. – integrated age, p.a. – plateau age, o – age of low-temperature overprint.

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composed mainly of carbonate platform facies and clastites,
and (4) Upper Cretaceous-Paleocene sedimentary sequences
(Tomljenović 2002). The post-tectonic Upper Cretaceous-
Paleogene sedimentary succession covering units (1) to (3) is
considered to be similar to the Gosau formations of the Austro-
alpine units in the Eastern Alps.

The Paleozoic-Mesozoic magmatic-sedimentary complex is

composed  of  siliciclastic  and  carbonate  rocks  (metagrey-
wackes,  quartz-muscovite  schists,  phyllites,  slates,  metacar-
bonates,  marbles)  interlayered  with  basic  lava,  tuffs  and
diabase sills. Biostratigraphic data, conodonts and graptolite
assemblages of the protolith sediments indicate a Silurian to
Late Triassic age (Đur anović 1968; Šikić et al. 1979; Sremac
& Mihajlović-Pavlović 1983). Meta-sediments are character-
ized by a syn-metamorphic foliation and lineation, generally
parallel  to  the  earlier  bedding,  penetrative  on  a  micro-  and
macro-scale  (Tomljenović  2002).  K/Ar  ages  obtained  from
six  muscovite  fractions  from  para-greenschists  and  ortho-
greenschists  gave  Early  Cretaceous  (122—110 Ma)  ages,
which  are  considered  to  represent  an  early  Alpine  (Creta-
ceous) metamorphic overprint (Belak et al. 1995a). Judik et
al.  (2004)  distinguished  a  high-temperature  (350—400 °C)
medium-pressure  (3—4 kbar)  metamorphic  event.  The  au-
thors  argue  that  the  present  tectonic  framework  of  the
Medvednica Mts can be explained by “transported metamor-
phism”, and suggest a polyphase deformation history.

The tectonized ophiolite mélange is a chaotic assemblage

composed of various ophiolite members, mainly basalt, gab-
bro, serpentinite and diabase, greywacke, radiolarite, and ex-
otic  limestone  fragments  within  a  silty-shaly  matrix  (Pamić
&  Tomljenović  1998;  Babić  et  al.  2002).  Radiolarite  bio-
stratigraphy provides Middle to Late Triassic and Middle Ju-
rassic ages (Halamić & Goričan 1995; Halamić et al. 1999).
The Lower to Middle Jurassic shaly-silty matrix of the mé-
lange originated in the subduction and/or accretion processes
related  to  the  closure  of  the  Meliata  and  Dinaridic  oceanic
basins between Middle Jurassic and Early Cretaceous times
(Babić  et  al.  2002).  Pamić  &  Pécskay  (1996)  reported  Late
Cretaceous  K/Ar  ages  of  94.3  and  85.4 Ma  from  basalt  and
diabase  from  the  northwestern  side  of  the  Medvednica
Mountains. The Upper Cretaceous-Paleocene flysch unit un-
comformably  overlies  both  the  Paleozoic-Mesozoic  meta-
morphic  complex  and  the  ophiolitic  mélange,  and  was
interpreted  by  previous  researchers  as  a  transgressive  shal-
low  water  to  basinal  sequence.  The  entire  succession  was
first  described  by  Gorjanović-Kramberger  (1908),  and  is
considered  to  be  similar  to  the  Gosau-type  basins  of  the
Austroalpine  domain  of  the  Eastern  Alps  and  Western  Car-
pathians  (e.g.  Faupl  et  al.  1987;  Willingshofer  et  al.  1999).
The  lower  portion  of  the  Medvednica  Mts  flysch  basin  is
composed of conglomerates, sandstones, siltites and laminated
shales  grading  into  semi-pelagic  Scaglia  type  micrite.  All
three  described  units  are  overthrusted  in  the  southwestern
part of the Medvednica Mts by the highest structural unit, the
Triassic  succession.  The  matrix  of  the  tectonized  ophiolite
mélange together with the Upper Cretaceous-Paleocene flysch
units  underwent  diagenesis  and  very  low-grade  metamor-
phism  at  temperatures  of  100—240 °C  based  on  vitrinite  re-
flection (Judik et al. 2008).

Paleozoic Sana-Una Unit, NW Dinarides

The Banovina-Kordun (Petrova Gora) and Paleozoic

Sana-Una (Trgovska Gora, Ljubija siderite body) Units rep-
resent  the  northwestern-most  part  of  the  Paleozoic  forma-
tions  of  the  south-vergent  Internal  Dinarides,  that  are
paleogeographically  related  to  Apulia  and  Africa.  The  final
incorporation into the present-day position took place during
the  Neogene,  after  polyphase  tectonic  evolution  that  lasted
from  Late  Jurassic/Early  Cretaceous  to  Eocene  times  (Jur-
ković  &  Pamić  2001).  The  lower  parts  of  these  units  are
composed  of  Lower—Middle  Carboniferous  flysch-type  sedi-
ments  (Fig. 3).  During  Late  Carboniferous—Early  Permian
times, shallowing of the sedimentary basin evolved into a dry
land-phase  followed  by  deposition  of  fine-  to  coarse-grained
quartz-sandstones  and  of  quartz-conglomerates.  The  onset  of
the  new  sedimentation  cycle  is  interpreted  as  a  possible
boundary  between  the  Variscan  and  post-Variscan  tectonic
and metallogenic events (Palinkaš et al. 2008). Formations of
the Paleozoic Banovina-Kordun Unit were interpreted as very
low-grade sedimentary sequences (Majer 1964) while the Pa-
leozoic  Sana-Una  Unit  were  metamorphosed  under  low-  and
very  low-grade  P-T  metamorphic  conditions  (Podubsky  &
Pamić 1967; Podubsky 1968).

The central part of the Paleozoic Sana-Una Unit, in the

Ljubija siderite open pit, consists of two sequences separated
by a pronounced tectonic and erosional discordance. An older,
Upper Devonian to Middle Carboniferous sequence is domi-
nated by a paleontologically well documented Carboniferous
flysch  composed  of  metasandstones,  metasiltstones,  dark
grey phyllite and metapelites with intercalations of limestones
and  metavolcanics  (Podubsky  &  Pamić  1967;  Podubsky
1968; Đur anović 1973; Jurić 1979). Recently, Grubić et al.
(2000) found remnants of trilobites and palynological mate-
rial within this sequence, which is interpreted to be Carbon-
iferous  in  age.  Underlying  Upper  Devonian  sequences  are
subordinate and consist mostly of limestone and sporadically
some coarse-grained quartz-sandstone (Jurić 1979). The De-
vonian  to  Carboniferous  sequence  contains  widespread  sid-
erite mineralizations. The overlying sequence, Late Permian
to  Triassic  in  age,  starts  with  clastic  sediments,  which  are
composed  of  quartzose  sandstones  and  conglomerates  and
continues  to  typical  cavernous  and  weathered  dolomites,
such as rauhwackes. Due to the lack of any organic remains,
a Late Permian age of these deposits was determined on the
basis  of  superposition  with  adjoining  Dinaric  Paleozoic
units. These deposits continue, without a break, into paleon-
tologically well defined lowermost Scythian clastic and car-
bonate shallow water formations.

Ar/

Ar analytical techniques

The preparation of the samples before and after irradiation,

Ar/

Ar analyses, and age calculations were carried out at

the ARGONAUT Laboratory of the Division General Geology
and  Geodynamics  at  the  University  of  Salzburg.  Mineral
concentrates  were  packed  in  aluminium-foil  and  loaded  in
quartz  vials.  For  calculation  of  the  J-values,  flux-monitors

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GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

were  placed  between  each  4—5  unknown  samples,  which
yielded a distance of ca. 5 mm between adjacent flux-moni-
tors.  The  sealed  quartz  vials  were  irradiated  in  the  MTA
KFKI reactor (Debrecen, Hungary) for 16 hours. Correction
factors  for  interfering  isotopes  were  calculated  from  10
analyses  of  two  Ca-glass  samples  and  22  analyses  of  two
pure    K-glass  samples,  and  are:

Ar/

(Ca)

= 0.00026025,

Ar/

(Ca)

=0.00065014, and

Ar/

(K)

=0.015466. Vari-

ations in the flux of neutrons were monitored with the
DRA 1 sanidine standard for which a

Ar/

Ar plateau age

of  25.03 ± 0.05 Ma  has  been  reported  (Wijbrans  et  al.  1995).
After  irradiation,  the  minerals  were  unpacked  from  the
quartz  vials  and  the  aluminium-foil  packets,  and  handpicked
into 1 mm diameter holes within one-way Al-sample holders.

Ar/

Ar analyses were carried out using a UHV Ar-ex-

traction line equipped with a combined MERCHANTEK

UV/IR laser ablation facility, and a VG-ISOTECH

NG3600 Mass Spectrometer. Stepwise heating analyses of
samples were performed using a defocused ( ~ 1 .5 mm dia-
meter) 25 W CO

-IR laser operating in Tem

mode at wave-

lengths between 10.57 and 10.63 µm. The laser is controlled
from  a  PC,  and  the  position  of  the  laser  on  the  sample  is
monitored through a double-vacuum window on the sample
chamber  via  a  video  camera  in  the  optical  axis  of  the  laser
beam  on  the  computer  screen.  Gas  clean-up  was  performed

using one hot and one cold
Zr-Al SAES getter. Gas ad-
mittance  and  pumping  of
the  mass  spectrometer  and
the  Ar-extraction  line  are
computer  controlled  using
pneumatic

valves.

The

NG3600  is  a  18 cm  radius
60°  extended  geometry  in-
strument,  equipped  with  a
bright Nier-type source op-
erated  at  4.5 kV.  Measure-
ment  was  performed  on  an
axial  electron  multiplier  in
static  mode.  Peak-jumping
and  stability  of  the  magnet
was  controlled  by  a  Hall-
probe.  For  each  increment
the intensities of

Ar,

Ar, and

Ar are

measured,

the

baseline

readings on mass 35.5 were
automatically

subtracted.

Intensities  of  the  peaks  are
back-extrapolated  over  16
measured  intensities  to  the
time  of  gas  admittance  ei-
ther  by  a  straight  line  or  a
curved  fit.  Intensities  are
corrected for system blanks,
background,

post-irradia-

tion decay of

Ar, and in-

terfering isotopes. Isotopic
ratios, ages and errors for

Fig. 3. Simplified tectonic map of the Paleozoic Sana-Una Unit showing sample locality for

Ar/

dating; modified after Grubić et al. (2000).

individual steps were calculated following suggestions by
McDougall & Harrison (1999) and using decay factors re-
ported by Steiger & Jäger (1977). Definition and calculation
of plateau ages were carried out using ISOPLOT/EX (Ludwig
2001, 2005).

Results

Petrography

Three samples were collected from the Paleozoic-Mesozo-

ic  magmatic-sedimentary  complex  of  the  Medvednica
Mountains.  Samples  CRO 11  and  CRO 12,  from  the
Bliznec  creek  valley,  come  from  the  southeastern  slope  of
the  Medvednica  Mts  (sample  locations  are  given  at  Fig. 2).
Sample CRO 11 represents a fine-grained metasandstone in-
tercalated  by  phyllite  layers,  whereas  sample  CRO 12  is  a
phyllite. The objects of the study were newly-formed meta-
morphic  muscovites.  Sample  SV-JAK  was  collected  from
the  Sv.  Jakob  Pb-Ag  epigenetic  deposit,  situated  on  the
southeastern slopes of the Medvednica Mts. The host rock is
a metacarbonate (dolostone) of undetermined age, represent-
ing a part of the Lower Cretaceous low-grade metamorphic
complex. Metacarbonates (dolostones) are distinctly foliated

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rocks, with foliation planes parallel to the original bedding.
The  epigenetic  ore  occurs  as  veinlets  and  lenses  of  galena
and  has  a  simple  paragenesis  of  galena,  sphalerite,  pyrite,
dolomite  and  quartz  (Šinkovec  et  al.  1988).  The  vein  halos
are composed mainly of sericite, which was the object of our
study.

Newly-grown metamorphic muscovite from three samples

of the Paleozoic-Mesozoic magmatic-sedimentary complex
of the Medvednica Mts have been separated. Sample loca-
tions are indicated in Fig. 2. Microfabrics of the dated rocks
are presented below.

From the central part of the Paleozoic Sana-Una Unit (Lju-

bija open pit; sample LJUB 1; Fig. 3), a sample of phyllite
from the Carboniferous flysch proximal to siderite mineral-
ization was collected. The selected sample is tectonically
disrupted by brittle microfaults, folded and characterized by
lamination and foliation.

Microfabrics

The microfabrics of the low-grade metamorphosed base-

ment rocks from the Medvednica Mts show the possible influ-
ence of a two-stage tectonothermal overprint. Representative
photo micrographs are shown in Fig. 4.

Sample CRO 11 from the Medvednica Mts is a fine-

grained  metasandstone  with  clasts  of  a  grain  size  of  up  to
0.1 mm  intercalated  by  phyllite  layers.  Clasts  comprise
mainly quartz and subordinate plagioclase, ore minerals and
tourmaline. No detrital white mica was observed in the thin
section.  The  matrix  contains  well-recrystallized  quartz  and
sericite (up to ca. 0.1 mm). The matrix as well as the clasts
are  affected  by  a  secondary  pressure  solution  foliation
(Fig. 4a).

Sample CRO 12 is a laminated, banded phyllite with gra-

phitic sericite layers and fine-grained quartz layers, which
also contains lenses with large, well-recrystallized quartz

and  calcite  (Fig. 4b).  The  sericite  of  the  sericite  layers  is
commonly between 0.02 to 0.06 mm in size and rarely con-
tains  larger  grains.  The  quartz  in  fine-grained  quartz  layers
has a grain size of 0.02 to 0.06 mm, and those of the recrys-
tallized quartz lenses 0.1 to 0.6 mm. These large grains have
straight  grain  boundaries  and  triple  junctions  due  to  perfect
recrystallization. Calcite within these quartz lenses is always
twinned.  The  foliation  made  up  of  sericite  is  parallel  to  the
bedding.  The  foliation  is  folded  into  microfolds,  and  a
crenulation cleavage generally affected the foliation, predomi-
nantly  those  defined  by  the  sericite  layers  (Fig. 4b).  Conse-
quently, sericite is often kinked and folded, which commonly
results  in  partial  opening  of  the  Ar  isotopic  system  (Villa
1998).  This  could  plausibly  explain  the  decrease  of  ages  in
low-laser energy steps (see below).

The phyllite sample from the Paleozoic Sana-Una Unit

(LJUB 1) consists of detrital quartz (10—20 vol. %) particles,
muscovite and secondary sericite, chlorite and coalified matter
of maximum 40 µm in size, within a microcrystalline sericitic
matrix.

Ar/

Ar dating results

The results of

Ar/

Ar dating are graphically displayed in

Figs. 5—6. Most samples are fine-grained, so the actual mea-
sured white mica grains are rather at the lower limit of the
given grain size.

Medvednica Mts

A fine-grained muscovite concentrate from metasandstone

(CRO 11) resulted in a slightly disturbed age pattern, which
yields an integrated age of ca. 135.1 ± 1.5 Ma of steps 4—8 to-
gether constituting 64.4 percent of

Ar released (Fig. 5a).

High-energy release steps show a decreasing age pattern
with an age of 121.3 ± 1.5 Ma.

Fig. 4. Representative and critical microfabrics of dated samples. The sample number is given on the figure. a – New grown muscovite
affected by pressure solution cleavage. Plane polarized light. b – Crenulation cleavage in a banded phyllite formed by affecting the metamor-
phic foliation during microfolding. Crossed polarizers. Legend: q – quartz, wm – white mica, sf – foliation, ss – bedding.

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A fine-grained muscovite concentrate from phyllite

(CRO 12) shows a staircase pattern, which allowed the cal-
culation of a plateau age of 126.5 ± 1.4 Ma, constituting ca.
61.6 percent of

Ar released (Fig. 5b). The first step shows a

significantly younger age of 81.0 ± 1.1 Ma.

A white mica concentrate from sericitic alteration (SV-JAK)

resulted in a slightly disturbed age pattern, which yielded a
plateau age of 122.5 ± 1.4 Ma, with steps 3—9 together com-
prising 78.5 percent of

Ar released (Fig. 5c).

Paleozoic Sana-Una Unit

A white mica concentrate from the phyllite, sample LJUB 1,

from the Paleozoic Sana-Una Unit yielded a plateau age of
335.1 ± 23.1 Ma comprising 96.8 percent of

Ar released

(Fig. 6a). The inverse isochrone plots show a slightly disturbed
initial

Ar/

Ar ratio of 322 ± 27, and an age of 327 ± 30 Ma,

together constituting 100 percent of

Ar released (Fig. 6b).

Fig. 5.

Ar/

Ar apparent age spectra of the metamorphic fine-

grained muscovite, ca. 10—20 grains for each sample, from: a – meta-
sandstone intercalated by phyllite layers, sample CRO 11; b – phyllite
(sample CRO 12), and c – metacarbonate, (sample SV-JAK) of the
Medvednica Mts. Laser energy increases from left to right. Vertical
width of bars represents 1 error. Steps used for calculation of pla-
teau ages are delineated by bar.

Fig. 6.

Ar/

Ar apparent age spectra and inverse isochrone of the

white mica (ca. 10—20 grains for each sample) from phyllite of the
Ljubija open pit (Paleozoic Sana-Una Unit). Laser energy increases
from left to right. Vertical width of bars represents 1 error. Steps
used for calculation of plateau ages are delineated by bar.

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Discussion

The new data from very low and low-grade metamorphosed

basement rocks of the northwestern Dinarides are used to con-
firm the existence and distribution of Variscan vs. Alpine tec-
tonothermal events of the investigated regions including rates
of erosion/uplift/cooling. The new set of

Ar/

Ar white mica

ages  from  Medvednica  and  Sana-Una  basement  rocks  com-
bined  with  microfabric  observations  reveal  an  Alpine  meta-
morphic  overprint  on  an  earlier  exclusively  main-stage
Variscan  tectonothermal  event.  The  data  from  this  study  are
combined  with  published  data  from  Borojević  Šoštarić  et  al.
(2009)  in  order  to  present  general  conclusions  and  models,
which are graphically presented in Fig. 7.

Fig. 7a presents the Carboniferous development of the

basement units of the northwestern Dinarides. The main pro-
cess  during  the  Carboniferous  within  Variscan  Europe  was
the  closure  of  the  Paleotethys  due  to  the  progressing  colli-
sion  between  Gondwana  and  Laurussia  (e.g.  Pamić  &  Jur-
ković 2002). This process led to the exhumation and surface
uplift  of  medium-grade  metamorphic  units  and  subsequent
erosion of the Variscan orogen. The synorogenic flysch and
succeeding  molasse  deposits  filled  newly  formed  foreland
basins, Carboniferous in age. New white mica

Ar/

Ar age

data from the Sana-Una flysch-type units ( ~ 330 Ma) corre-
spond  to  obtained  ages  from  the  flysch-type  units  of  the
Petrova  and  Trgovska  Gora  regions  (354  to  314 Ma;
Borojević  Šoštarić  et  al.  2009).  Similar  ages  of  the  detrital
white mica to the stratigraphic age of their host sediments in-
dicate  rapid  cooling  and  exhumation  of  the  adjacent
Variscides during the formation of foreland basins. Such old
ages  are  common  within  the  Tisia  Unit  (Dallmeyer  et  al.
1996),  within  the  uppermost  nappes  of  the  Eastern  Alps
(Wiesinger  et  al.  2006),  and  are  widespread  within  the
Variscan units of the Dinarides (Ilić et al. 2005).

Fig. 7b presents the late Variscan tectonothermal event,

which, within the Dinarides, developed into a rift during Early
Permian  times.  Recorded  tectonothermal  overprint  ranging
from  298 Ma  to  265 Ma,  was  synchronous  with  the  forma-
tion  of  widespread  siderite-barite-polysulphide  deposits
(Palinkaš et al. 2008; Borojević Šoštarić et al. 2009; Strmić
Palinkaš  et  al.  2009)  and  the  formation  of  the  Dinaride
evaporites.  The  Permian  event  could  be  related  to  ongoing
Alpine  rifting  similar  to  that  in  the  Southalpine  and  Aus-
troalpine  basement  units  of  the  Alps  (e.g.  Neubauer  et  al.
2000; Schuster et al. 2001).

Fig. 7c shows the Early Cretaceous low-grade metamor-

phism, recorded in the Medvednica Mts. The basement of the
Medvednica  Mts  shows  a  two-stage  evolution.  The  main
stage, an early Alpine metamorphic overprint between 135 Ma
and 122 Ma, is interpreted as the stage of nappe stacking pre-
dating the formation of Gosau collapse basins. The age range
(135 Ma to 122 Ma) recorded in the Medvednica Mts indicates
very  slow  regional  cooling/exhumation  postdating  the  main
regional nappe stacking. A similar age range of 139—129 Ma
was obtained in the Drina-Ivanjica Unit (Milovanović 1984),
while  ranges  of  121—95 Ma  and  123—116 Ma  were  reported
for the rocks of the Mid-Bosnian Schist Mts (Palinkaš et al.
1996; Pamić et al. 2004) and Medvednica Mts (Belak et al.

Fig. 7. Simplified tectonic models for the tectonic evolution of
northwestern Dinarides.

1995a; Judik et al. 2006), respectively. This gives evidence
for the Early Cretaceous onset of ductile nappe stacking in
the entire Cretaceous-aged orogen of the Circum-Pannonian
Region.

Fig. 7d shows a younger, Late Cretaceous overprint

( ~ 80 Ma) contemporaneous with the subsidence of Gosau-

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GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

type basins and the opening and closure in the neighbouring
Sava-Vardar Zone (Neubauer et al. 1995, 2000; Dallmeyer et
al.  1996;  Schuster  &  Frank  1999;  Schuster  et  al.  2001;
Schmid  et  al.  2008;  Ustaszewski  et  al.  2008).  Due  to  a
younger  overprint  (ca.  80 Ma),  the  age  group  135—122 Ma
from the Medvenica Mts is older than the hitherto available
K-Ar white mica ages. The obtained age data of the overprint
is similar to the Late Cretaceous age (75 Ma) from the fault
zone  of  the  Petrova  Gora  region  (Borojević  Šoštarić  et  al.
2009). Most likely, these units attained a similar geotectonical
setting during the Late Cretaceous.

The new data also shows remarkable age similarities of the

NW Internal Dinarides to the Eastern Alps. The similarities in-
clude all four critical time levels shown in this study: the same
age as the main-stage Variscan overprint of the Austroalpine
Quartzphyllite units of the Eastern Alps (Neubauer et al. 1999
and references therein), the age of Permian overprint (Schuster
et al. 2001), the Early Cretaceous age of a low-grade tectono-
thermal overprint in some Quartzphyllite units (Dallmeyer et
al. 1998; Wiesinger et al. 2006), and the Late Cretaceous de-
formation contemporaneous with the subsidence of Gosau-
type basins (Neubauer et al. 1995, 2000; Dallmeyer et al.
1996; Schuster & Frank 1999; Schuster et al. 2001).

Cretaceous tectonic restoration

Various reconstructions of the Cretaceous and Cenozoic de-

formation in the Circum-Pannonian Region have been dis-

cussed by, for example, Auboin et al. (1970), Burchfiel (1980),
Csontos  et  al.  (1992),  Dercourt  et  al.  (1993),  Robertson  &
Karamata (1994), Csontos (1995), Channell & Kozur (1997),
Stampfli & Mosar (1999), Willingshofer (2000), Neugebauer
et  al.  (2001),  Ziegler  &  Stampfli  (2001),  Neubauer  (2002),
Stampfli et al. (2002) and Schmid et al. (2008). None of them
appears  to  have  solved  all  the  problems,  so  that  many  open
questions remain. Fig. 8 shows a tectonic reconstruction of the
Cretaceous  configuration  that  is  based  mainly  on  paleomag-
netic  data  from  Upper  Cretaceous  units  collected  by  Neuge-
bauer  et  al.  (2001)  and  Stampfli  et  al.  (2002).  However,  the
reconstruction is considerably different from those models due
to the shift of the Adriatic microplate to the East based on the
restoration of the 400 km displacement along the Periadriatic
fault.  The  reconstruction  shows  that  the  Upper  Cretaceous
units  can  be  divided  into:  (1)  the  ALCAPA  (ALpine-CAr-
pathian-PAnnonian)  block  comprising  the  Austroalpine  units
in  the  Eastern  Alps  and  Inner  Western  Carpathians,  (2)  the
Tisia block extending from Moslavačka Gora in Croatia to
the  Apuseni  Mountains,  (3)  the  Dacia  block,  which  in-
cludes the Eastern und Southern Carpathians and the Balkan,
(4) the Rhodope block and (5) the South-Alpine Dinaric block
(see Figs. 1, 2). These blocks were strongly deformed during
Cenozoic  time,  mainly  around  their  margins.  Additionally,
they were also partially rotated during their invasion into the
future  Alpine-Carpathian  realm.  The  Tisia  block  records  a
50—90°  clockwise  rotation  mostly  during  the  Middle  Mio-
cene (Rosu et al. 2004). A simple solution suggests that the

Fig. 8. Late Cretaceous tectonic reconstruction of the Circum-Pannonian Region also showing orogen polarity (modified after Neubauer
2002). Black arrows show sense of overall displacement during nappe stacking (Late—Early Cretaceous). Open arrows show sense of normal
fault motion during extension (Late Cretaceous).

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ALCAPA and Tisia blocks invaded the Carpathian arc during
Cenozoic times, the Tisia block pushing at its front the west-
ern  sectors  of  the  Dacia  block.  The  Moesian  platform  seem-
ingly represents an indenter that is interpreted to have moved
westwards during Late Cretaceous and Paleogene times due to
the opening of the West Black Sea oceanic basin. The essen-
tial  result  of  this  restoration  is  that  the  ALCAPA,  Tisia  and
Dacia blocks together formed an E—W-trending, straight oro-
gen  during  the  critical  time  at  ~80 Ma  when  most  of  the  so-
called Banatite magmatism (e.g. Neubauer et al. 2003), which
is also preserved in the Tisia microplate adjacent to NW Di-
narides  (Pamić  et  al.  2002),  occurred  (Fig. 8).  This  view  is
also supported by paleomagnetic data from Upper Cretaceous
Banatites,  which  call  for  post-Cretaceous  bending  and  oro-
cline formation of the Banatite belt during its invasion into the
Carpathian arc (Patrascu et al. 1992, 1994). It is reasonable to
assume that the Cretaceous orogen separated a northern, South
Penninic  oceanic  tract  from  the  still  open  Tethys/Vardar
ocean  in  the  south.  The  South  Alpine-Dinaric  belt  was  con-
nected  to  the  southern  ALCAPA  block  when  an  open  ocean
was closed in a scissor-like manner due to the convergence of
the  Dinarides  towards  the  ALCAPA  Tisia-Dacia-Rhodope
continent. During the Late Cretaceous convergence, both the
Medvednica  Mts  and  Petrova  Gora  region  behaved  as  rigid
blocks. Slow regional cooling/exhumation of the Medvednica
Mts  throughout  Cretaceous  time  resulted  in  transition  from
ductile  deformation  stage  dated  at  135  to  122 Ma  to  brittle
stage  dated  at  ~ 80 Ma  whereas  the  Petrova  Gora  region  un-
derwent  only  brittle  deformation  stage,  where  new-grown
muscovite from the fault zone was dated at 75 Ma (Borojević
Šoštarić et al. 2009). This is synchronous with the formation
of  the  Late  Carboniferous  to  Paleocene  Gosau-type  foredeep
basin  along  the  present  day  northward  margins  of  the  meta-
morphic  complex  of  the  Medvednica  Mts.  The  deepening  of
the Medvednica Mts foredeep basin, indicated by change in li-
thology  from  Santonian/Campanian  fluvial-lacustrine  envi-
ronment  to  Paleocene  turbiditic  flysch  and  hemipelagic
sediments (Tomljenović 1995), is a common characteristic of
the Late Cretaceous Gosau type basins of the Eastern Alps and
Apuseni Mts (sensu Dallmeyer et al. 1996) related to contem-
poraneous  exhumation  of  the  metamorphic  core  complexes.
Both  processes  are  a  result  of  ongoing  Cretaceous  conver-
gence  (subduction/collision)  of  the  Dinarides—Helenides  and
the ALCAPA Tisia-Dacia-Rhodope block.

In summary, reconstructions indicate open oceanic tracts,

both to the north and south of the Upper Cretaceous orogenic
belt.  This  belt  was  attached  to  the  Moesian  platform  in  the
east, and to the Adriatic microplate in the west. This leaves
open the question as to which geodynamic process occurred
within this belt during the Late Cretaceous. Was there con-
tinuous  subduction  or  collision  along  segments  that  are  at-
tached  to  continental  blocks  (Moesia/Europe)  in  the  east,
and the Adriatic block in the west? Orogenic polarity of the
closure  and  nappe  stacking  was,  respectively,  to  the  N  and
NW  rotating  units  back  into  their  present-day  position  (e.g.
Ratschbacher  et  al.  1989,  1993;  Schmid  et  al.  1998,  2008
and  references  in  these  papers;  Fig. 8).  On  the  other  hand,
the figure shows that the Cretaceous-aged orogen could rep-
resent  a  double-vergent  continent-continent  collisional  oro-

gen.  Its  initial  vergency  is  towards  the  Adriatic  microplate
during the Late Jurassic emplacement of the Dinaric ophio-
lite  nappe;  subsequently,  a  double-vergent  orogenic  wedge
formed  during  the  Early  Cretaceous,  but  finally  collapsed
during the Late Cretaceous.

Conclusions

The very low-grade metamorphosed basement rocks from

the Paleozoic Sana-Una Unit show the main-stage Variscan
tectonothermal  event,  synchronous  with  the  Petrova  and
Trgovska Gora region (354 to 314 Ma; Borojević Šoštarić et
al.  2009).  Low-grade  metamorphosed  basement  rocks  from
the Medvednica Mts show two stages of Alpine tectonother-
mal  events  and  no  evidence  of  Variscan  tectonism:  (i)  The
main  stage  of  early  Alpine  overprint  between  135  and
122 Ma,  interpreted  as  the  onset  of  ductile  nappe  stacking,
predates  the  formation  of  Gosau  collapse  basins.  The  age
gradient  indicates  very  slow  regional  cooling/exhumation
postdating  the  main  regional  nappe  stacking.  Similar  ages
can  be  traced  in  the  entire  Cretaceous-aged  orogen  of  the
Circum-Pannonian Region namely the Tisia Unit, uppermost
nappes of the Eastern Alps and Variscan units of the Dinar-
ides. (ii) A later, early Alpine event at  ~ 80 Ma found in the
area  of  the  Medvednica  Mts  is  contemporaneous  with  the
subsidence  of  Gosau-type  basins  and  the  opening  and  clo-
sure in the neighbouring Sava—Vardar Zone.

Acknowledgments:  This  paper  was  supported  by  Projects
119-0982709-1175  and  098-0982934-2742  of  the  Ministry
of  Science,  Republic  of  Croatia.  We  acknowledge  the  sup-
port of the University of Salzburg for allowing visits of SBŠ
to the ARGONAUT Laboratory. The Authors are very grate-
ful to Stefan Schmid, Vladica Cvetković and an anonymous
reviewer for their comments and suggestions. Final English
polishing was done by Isabella Merschdorf.

References

Auboin J., Blanchet R., Cadet J.P., Celet P., Charvet J., Chorowicz

J., Cousin J. & Rampnoux J. 1970: Essai sur la géologie des
Dinarides. Bull. Soc. Geol. France 7, 12, 1060—1095.

Babić L., Hochuli P.A. & Zupanič J. 2002: The Jurassic ophiolitic

mélange in the NE Dinarides: dating, internal structure and
geotectonic implications. Eclogae Geol. Helv. 95, 263—275.

Belak M. & Tibljaš D. 1998: Discovery of blueschists in the Medved-

nica mountain (Northern Croatia) and their significance for the
interpretation of the geotectonic evolution of the area. Geol.
Croatica 51, 27—32.

Belak M., Pamić J., Kolar-Jurkovšek T., Pécskay Z. & Karan D.

1995a: Alpine regional metamorphic complex of the Mt.
Medvednica. Proc. 1

Croat. Geol. Congr. Opatija, Zagreb,

567—570 (in Croatian with English summary).

Belak M., Jamičić D., Crnko J. & Sremac J. 1995b: Low-metamor-

phic rocks from the lower part of Bliznec creek. In: Šikić K.
(Ed.): Geological guide of Mts. Medvednica. Naftaplin, Zagreb,
97—102 (in Croatian).

Borojević Šoštarić S., Palinkaš A.L., Strmić Palinkaš S., Bermenec

V., Neubauer F., Spangenberg J. & Prochaska W. 2009: Origin

451

TECTONOTHERMAL HISTORY OF THE BASEMENT ROCKS

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

of siderite mineralisation in Petrova and Trgovska Gora Mts.,
NW Dinarides. Miner. Petrology 97, 111—128.

Burchfiel B.C. 1980: Eastern European alpine system and the Car-

pathian orocline as an example of collision tectonics. Tectono-
physics 63, 31—61.

Channell J.E.T. & Kozur H. 1997: How many oceans? Meliata, Var-

dar, and Pindos oceans in Mesozoic Alpine paleogeography.
Geology 25, 183—186.

Csontos L. 1995: Tertiary tectonic evolution of the Intra-Carpathian

area: a review. Acta Vulcanol. 7, 1—13.

Csontos L., Nagymaroshi A., Horvath F. & Kovac M. 1992: Tertiary

evolution of the Intra-Carpathian arc: a model. Tectonophysics
208, 221—241.

Dallmeyer R.D., Neubauer F., Handler R., Fritz H., Müller W.,

Pana D. & Putiš M. 1996: Tectonothermal evolution of the in-
ternal Alps and Carpathians: Evidence from

Ar/

Ar mineral

and whole rock data. Eclogae Geol. Helv. 89, 203—227.

Dallmeyer R.D., Handler R., Neubauer F. & Fritz H. 1998: Sequence

of thrusting within a thick-skinned tectonic wedge: Evidence
from

Ar/

Ar ages from the Austroalpine nappe complex of

the Eastern Alps. J. Geol. 106, 71—86.

Dercourt J., Ricou L.E. & Vrielinck B. 1993: Atlas Tethys, paleoen-

vironmental maps. Gauthier-Vilars, Paris, 1—307.

Dimitrijević M.D. 1982: Dinarides: An outline of the tectonics.

Earth Evol. Sci. Berlin 2, 1, 4—23.

Dimitrijević M.D. 1997: Geology of Yugoslavia. Geol. Surv. GEMI-

NI, Belgrade, 1—187.

Đur anović Ž. 1968: Conodonten des unteren Devons des Gebirges

Medvednica (Zagrebačka gora). Geol. Vjes. 21, 93—102 (in
Croatian with German summary).

Đur anović Ž. 1973: Conodonten des Unterdevons und Unterkar-

bons westlich von Dvor na Uni (Kroatien—Jugoslawien). Geol.
Vjes. 25, 29—45 (in Croatian with German summary).

Faupl P., Pober E. & Wagreich M. 1987: Facies development of the

Gosau Group of the eastern parts of the Northern Calcareous
Alps during Cretaceous and Paleogene. In: Flügel H.W. &
Faupl P. (Eds.): Geodynamics of the Eastern Alps. Deucticke,
Wien, 142—155.

Gorjanović-Kramberger D. 1908: Geological map and explanatory

notes scheet Zagreb (Zona 22, COL. XIV). Naklada Kr. Ze-
maljske Vlade, 1—75 (in Croatian).

Grubić A., Protić L., Filipović I. & Jovanović D. 2000: New data on

the Paleozoic of the Sana-Una Area. Proceedings of the Inter-
national Symposium of the Dinarides and the Vardar Zone.
The Acad. Sci. Arts of the Republic of Srpska, Banja Luka – Sa-
rajevo 1, 49—54.

Haas J. & Kovacs S. 2001: The Dinaridic-Alpine connection – as

seen from Hungary. Acta Geol. Hung. 44, 345—362.

Haas J., Mioč P., Pamić J., Tomljenović B., Árkai P., Berczi-Makk

A., Koroknai B., Kovacs S. & Felganhauer E. 2000: Complex
structural pattern of the Alpine-Dinaric-Pannonian triple junc-
tion. Int. J. Earth Sci. (Geol. Rundsch.) 89, 377—389.

Halamić J. & Goričan Š. 1995: Triassic radiolarites from Mts.

Kalnik and Medvednica (Northwestern Croatia). Geol. Croatica
48, 2, 129—146.

Halamić J., Goričan G., Slovenec D. & Kolar-Jurkovšek T. 1999:

Middle Jurassic Radiolarite-Clastic Succession from the
Medvednica Mt. (NW Croatia). Geol. Croatica 52, 1, 29—57.

Ilić A., Neubauer F. & Handler R. 2003: Cretaceous collision and

Tertiary oblique convergence in Central Dinarides. Geophys.
Res. Abstracts, 5—0056.

Ilić A., Neubauer F. & Handler R. 2005: Late Paleozoic-Mesozoic

tectonics of Dinarides revisited: implications from

Ar/

dating of detrital white micas. Geology 33, 3, 233—236.

Judik K., Árkai P., Horváth P., Dobosi G., Tibljaš D., Dražen

B.,

Tomljenović B. & Pamić J. 2004: Diagenesis and low-temper-

ature metamorphism of Mt. Medvednica, Croatia: mineral as-
semblages and phyllosilicate characteristics. Acta Geol. Hung.
47, 2, 151—176.

Judik K., Balogh K., Tibljaš D. & Árkai P. 2006: New age data on

the low-temperature regional metamorphism of Mt. Medvednica
(Croatia). Acta Geol. Hung. 49, 3, 207—221.

Judik K., Rantitsch G., Rainer T.M., Árkai P. & Tomljenović B.

2008: Alpine metamorphism of organic matter in metasedimen-
tary rocks from Mt. Medvednica (Croatia). Swiss. J. Geosci.
101, 605—616.

Jurić M. 1979: Geology of the Sana-Una Paleozoic within north-

western Bosnia. Unpubl. PhD Thesis, University of Sarajevo,
Sarajevo, 1—175 (in Croatian).

Jurković I. & Pamić J. 2001: Geodynamics and metallogeny of

Variscan complexes of the Dinarides and South Tisia as related
to plate tectonics. Nafta, Zagreb 52, 9, 267—284.

Ludwig K.R. 2001: Using Isoplot/Ex, Version 2.01: a geochrono-

logical toolkit for Microsoft Excel. Berkeley Geochronology
Center, Spec. Publ. 1a, Berkeley, 1—47.

Ludwig K.R. 2005: Isoplot/EX rev. 3.32: A geochronological tool-

kit for Microsoft Excel. Berkeley Geochronology Center, Spec.
Publ. 4, Berkeley, USG Open File Repository.

Majer V. 1964: Petrography of Paleozoic sediments from the north-

eastern part of Trgovska gora Mts. Geol. Vjes. 17, 79—92 (in
Croatian with German summary).

Majer V., Lugović B. & Trubelja F. 1991: Metamorphism of the

Bosnian Schist Mountains (Preliminary investigation). Rad.
Akad. Nauka Umjet BiH, Sarajevo 13, 141—158 (in Croatian
with German summary).

McDougall I. & Harrison M.T. 1999: Geochronology and thermo-

chronology by the

Ar/

Ar Method. Oxford University Press

Sec. Ed., Oxford, 1—269.

Milovanović D. 1984: Petrology of low-metamophic rocks from the

central part of the Drina-Ivanjica Paleozoic. Glasnik Prir.
Muzeja, Belgrade A39, 13—139 (in Serbian with English sum-
mary).

Neubauer F. 2002: Contrasting Late Cretaceous to Neogene ore

provinces  in  the  Alpine-Balkan-Carpathian-Dinaride  collision
belt.  In:  Blundell  D.J.,  Neubauer  F.  &  von  Quadt  A.  (Eds.):
The  timing  and  location  of  major  ore  deposits  in  an  evolving
orogen. Geol. Soc. London, Spec. Publ. 206, 81—102.

Neubauer F., Dallmeyer R.D., Dunkl I. & Schirnik D. 1995: Late Cre-

taceous exhumation of the metamorphic Gleinalm dome, Eastern
Alps: kinematics, cooling history and sedimentary response in a
sinistral wrench corridor. Tectonophysics 242, 79—89.

Neubauer F., Hoinkes G., Sassi F.P., Handler R., Höck V., Koller F.

& Frank W. 1999: Pre-Alpine metamorphism of the Eastern
Alps. Schweiz. Mineral. Petrogr. Mitt. 79, 1, 41—62.

Neubauer F., Genser J. & Handler R. 2000: The Eastern Alps: result

of a two-stage collision process. Mitt. Österr. Geol. Gesell. 92,
117—134.

Neubauer F., Heinrich C.A. & GEODE ABCD Working Group

2003:  Late  Cretaceous  and  Tertiary  geodynamics  and  ore  de-
posit evolution of the Alpine-Balkan-Carpathian-Dinaride oro-
gen. In: Eliopoulos D.G. et al. (Eds.): Mineral exploration and
sustainable development. Proceedings of the Seventh Biennial
Society  for  Geology  Applied  to  Mineral  Deposits  Meeting  on
Mineral  Exploration  and  Sustainable  Development,  Athens,
Greece. Millpress Science Publishers, Rotterdam, 1133—1136.
August 24—28, 2003.

Neugebauer J., Greiner B. & Appel E. 2001: Kinematics of Alpine-

West Carpathian orogen and palaeogeographic implications. J.
Geol. Soc. London 158, 97—110.

Palinkaš L., Majer V., Balogh K., Bermanec V. & Jurković I. 1996:

Geochronometry and thermochronometry of the metamor-
phism in the Inner Dinarides, Mid-Bosnian Schist Mts. IGCP

452

BOROJEVIĆ ŠOŠTARIĆ, NEUBAUER, HANDLER and PALINKAŠ

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2012, 63, 6, 441—452

No. 356, Plate tectonic aspects of the Alpine metallogeny.
Poster Session, 2, 53.

Palinkaš L., Borojević Šoštarić S. & Strmić Palinkaš S. 2008: Metal-

logeny of the North-Western and Central Dinarides and Southern
Tisia. Ore Geol. Rev. 34, 501—520.

Pamić J. & Jurković I. 2002: Paleozoic tectonostratigraphic units of

the northwest and central Dinarides and the adjoining South
Tisia. Int. J. Earth Sci. 91, 538—554.

Pamić J. & Pécskay Z. 1996: Geological and K/Ar ages of Tertiary

volcanic formations from the southern part of the Panonian Ba-
sin in Croatia – based on surface and subsurface data. Nafta,
Zagreb 47, 195—202.

Pamić J. & Tomljenović B. 1998: Basic geological data from the

Croatian part of the Zagorje-Mid-Transdanubian Zone. Acta
Geol. Hung. 41, 4, 389—400.

Pamić J., Gušić I. & Jelaska V. 1998: Geodynamic evolution of the

Central Dinarides. Tectonophysics 297, 251—268.

Pamić J., Tomljenović B. & Balen D. 2002: Geodynamic and petro-

genetic evolution of Alpine ophiolites from the central and
NW Dinarides: an overview. Lithos 65, 113—142.

Pamić J., Balogh K., Hrvatović H., Balen D., Jurković I. & Palinkaš

L. 2004: K-Ar and Ar-Ar dating of the Palaeozoic metamor-
phic complex from the Mid-Bosnian Schist Mts., Central Di-
narides, Bosna and Hercegovina. Miner. Petrology 82, 65—79.

Patrascu S., Bleahu M., Panaiotu C. & Panaiotu C.E. 1992: The pa-

leomagnetism of the upper Cretaceous magmatic rocks in the
Banat area of the South Carpathians: tectonic implications.
Tectonophysics 213, 341—352.

Patrascu S., Panaiotu C., Seclaman M. & Panaiotu C.E. 1994: Timing

of rotational motion of Apuseni Mountains (Romania): paleo-
magnetic data from Tertiary magmatic rocks. Tectonophysics
233, 163—176.

Podubsky V. 1968: Lithology of Paleozoic formations from NW

Bosnia. Geol. Glas., Sarajevo 12, 73—91 (in Croatian).

Podubsky V. & Pamić J. 1967: Volcanic rocks in the Sana Paleozoic

(NW Bosnia) and their position in columnar section. Rad
JAZU, Zagreb, 45—54.

Ratschbacher L., Frisch W., Neubauer F., Schmid S.M. & Neuge-

bauer J. 1989: Extension in compressional orogenic belts: The
eastern Alps. Geology 17, 404—407.

Ratschbacher L., Linzer G.H., Moser F., Strusievicz R.O., Bedelean

H., Har N. & Mogos P.A. 1993: Cretaceous to Miocene thrust-
ing and wrenching along the central South Carpathians due to a
corner effect during collision and orocline formation. Tectonics
12, 855—873.

Robertson A.H.F. & Karamata S. 1994: The role of subduction-ac-

cretion process in the tectonic evolution of the Mesozoic
Tethys in Serbia. Tectonophysics 234, 73—94.

Rosu E., Seghedi I., Downes H., Alderton D.H.M., Szakács A., Péc-

skay Z., Panaiotu C., Panaiotu C.E. & Nedelcu L. 2004: Exten-
sion-related Miocene calc-alkaline magmatism in the Apuseni
Mountains, Romania: Origin of magmas. Schweiz. Mineral.
Petrogr. Mitt. 84, 153—172.

Schmid S.M., Berza T., Diaconescu N., Fügenschuh B., Schönborn O.

& Kissling E. 1998: Orogen-parallel extension in the Southern
Carpathians. Tectonophysics 15, 1036—1064.

Schmid S.M., Bernoulli D., Fügenschuh B., Matenco L., Schefer S.,

Schuster R., Tischler M. & Ustaszewski K. 2008: The Alpine-
Carpathian-Dinaridic orogenic system: correlation and evolu-
tion of tectonic units. Swiss J. Geosci. 101, 139—183.

Schuster R. & Frank W. 1999: Metamorphic evolution of the Austro-

alpine units east of the Tauern Window: indications for Jurassic
strike slip tectonics. Mitt. Gesell. Geol. Bergbaustud. Österr.
42, 37—58.

Schuster R., Scharbert S., Abart R. & Frank W. 2001: Permo-Triassic

extension and related HAT/LP metamorphism in the Austro-
alpine—Southalpine realm. Mitt. Gesell. Geol. Bergbaustud.
Österr. 45, 111—141.

Sremac J. & Mihajlović-Pavlović M. 1983: Graptolites from Mt.

Medvednica. Rad JAZU, Zagreb 404, 19, 65—68 (in Croatian).

Stampfli G.M. & Mosar J. 1999: The making and becoming of

Apulia. Mem. Sci. Geol., Padova 51, 141—154.

Stampfli G.M., Borel G.D., Marchant R. & Mosar J. 2002: Western

Alps geological constraints on western Tethyan reconstruc-
tions. J. Virtual Explorer 8, 77—106.

Steiger R.H. & Jäger E. 1977: Subcommission on geochronology:

Convention on the use of decay constants in geo-and cosmo-
chronology. Earth Planet. Sci. Lett. 36, 359—362.

Strmić Palinkaš S., Spangenberg J.E. & Palinkaš L. 2009: Organic

and inorganic geochemistry of Ljubija siderite deposits, NW
Bosnia and Herzegovina. Min. Deposita 44, 893—913.

Šikić K., Basch O. & Šimunić A. 1979: Explanatory notes for the

geological map 1 : 100,000, sheet Zagreb. Geol. Surv., Belgrade,
1—81 (in Croatian with English summary).

Šinkovec B., Palinkaš L. & Durn G. 1988: Ore deposits from

Medvednica Mts. Geol. Vjes., Zagreb 41, 395—405 (in Croatian
with English summary).

Tomljenović B. 2002: Structural characteristics of the Mt. Medved-

nica and the Samoborsko gorje Mt (in Croatian). Unpubl. PhD
Thesis, University of Zagreb, Zagreb, 1—208.

Tomljenović B. & Csontos L. 2001: Neogene-Quaternary structures

in the border zone between Alps, Dinarides and Pannonian Ba-
sin (Hrvatsko zagorje and Karlovac Basin, Croatia). Int. J.
Earth Sci. (Geol. Rundsch.) 90, 560—578.

Ustaszewski K., Schmid S.M., Lugović B., Schuster R., Schaltegger

U., Bernoulli D., Hottinger L., Kounov A., Fügenschuh B. &
Schefer S. 2009: Late Cretaceous intra-oceanic magmatism in
the internal Dinarides (northern Bosnia and Herzegovina): Im-
plications for the collision of the Adriatic and European plates.
Lithos 108, 1—4, 106—125.

Villa I. 1998: Isotopic closure. Terra Nova 10, 42—47.
Wiesinger M., Neubauer F. & Handler R. 2006: Exhumation of the

Saualpe eclogite unit, Eastern Alps: constraints from

Ar/

ages. Miner. Petrology 88, 149—180.

Wijbrans J.R., Pringle M.S., Koopers A.A.P. & Schveers R. 1995:

Argon geochronology of small samples using the Vulkaan argon
laserprobe. Proc. Kon. Ned. Akad. Wetensch 98, 2, 185—218.

Willingshofer E. 2000: Extension in collisional orogenic belts: the

Late Cretaceous evolution of the Alps and Carpathians. Un-
publ. PhD Thesis, Vrije University, Vrije, 1—146.

Willingshofer E., Neubauer F. & Cloetingh S. 1999: Significance of

Gosau basins for the upper Cretaceous geodynamic history of
the Alpine—Carpathian belt. Phys. Chem. Earth Part A: Solid
Earth Geodes. 24, 687—695.

Ziegler P.A. & Stampfli G.M. 2001: Late Paleozoic Early Mesozoic

plate boundary reorganisation: collapse of the Variscan orogen
and opening of Neotethys. In: Cassinis R. (Ed.): The continen-
tal Permian of the Southern Alps and Sardinia (Italy) regional
reports and general correlations. Ann. Museo Civico Science
Naturali, Brescia 25, 17—34.