Interrelated Orogenic Building and Subsequent Extension at the

VRIJE UNIVERSITEIT
Interrelated Orogenic Building and
Subsequent Extension at the Contact Between
the Dinarides and the Pannonian Basin
Evidence from low-temperature
thermochronology
ACADEMISCH PROEFSCHRIFT
ter verkrijging van de graad Doctor aan
de Vrije Universiteit Amsterdam,
op gezag van de rector magnificus
prof.dr. F.A. van der Duyn Schouten,
in het openbaar te verdedigen
ten overstaan van de promotiecommissie
van de Faculteit der Aard- en Levenswetenschappen
op maandag 15 september 2014 om 13.45 uur
in de aula van de universiteit,
De Boelelaan 1105
door
Uros Stojadinovic
geboren te Paracin, Servië
promotor:
copromotor:
prof.dr. P.A.M. Andriessen
dr. L.C. Matenco
The wreath's heavy, but the fruit is so sweet!
Without death there is no resurrection.
The Mountain Wreath
Petar II Petrović Njegoš
The research for this thesis was funded by the Netherlands Research
Centre for Integrated Solid Earth Science (ISES) and the VU University
Amsterdam. It was conducted at:
Departments of Isotope Geochemistry and Tectonics
Faculty of Earth and Life Sciences
VU University of Amsterdam
De Boelelaan 1085
1081 HV Amsterdam
The Netherlands
Members of the Reading Committee:
prof. dr. Vladica Cvetković
prof. dr. Giovanni Bertotti
dr. Ernst Wilingshofer
dr. Marinko Toljić
dr. Jurgen Foeken
Title: Interrelated Orogenic Building and Subsequent Extension at the
Contact Between the Dinarides and the Pannonian Basin, Evidence
from low-temperature thermochronology
Translated title: De samenhang tussen gebergtevorming en de
daaropvolgende extensie in de overgangszone tussen de Dinariden en
het
Pannoonse
Bekken,
afgeleid
uit
lage-temperatuurthermochronologie
Author: Uros Stojadinovic
Publisher: Copyright © 2014, U. Stojadinovic, Paraćin
Printed by: "M-graf" Trstenik, Kruševački put bb
Circulation: 100 copies
ISBN: 978-86-917901-0-3
Cover: Panoramic view of the Bukulja Mountains, photo by Uros
Stojadinovic
Contents
Acknowledgements .................................................................................. IX
Summary .................................................................................................. XIII
Samenvatting......................................................................................... XVII
Rezime ...................................................................................................... XXI
1 Introduction .............................................................................................. 1
1.1 Introduction ....................................................................................... 1
1.2 Thesis outline .................................................................................... 4
2 The evolution of the NE part of the Dinarides .................................... 7
2.1 The Dinarides: Regional overview of the geodynamics ............. 7
2.1.1 Main unites of the Dinarides .................................................. 13
2.1.2 The Fruška Gora, Cer, and Bukulja Mountains of the
NE Dinarides ..................................................................................... 18
2.2 Correlation of Mesozoic meta-sedimentary sequences
in the NE Dinarides .............................................................................. 22
2.3 Cretaceous−Paleogene syn-kinematic turbidites
(i.e. flysch) deposited along the NE Dinarides margin ................... 29
2.4 Oligocene−Miocene magmatism in the Cer and Bukulja
Mountains .............................................................................................. 36
2.5 Miocene−Quaternary sedimentation in the southeastern
Pannonian Basin ................................................................................... 40
3 Low-temperature thermochronology ................................................. 47
3.1 Introduction ..................................................................................... 47
3.2 Apatite (U-Th)/He thermochronology........................................ 48
3.3 Apatite and Zircon fission-track thermochronology ................. 53
3.4 Modeling of the time-Temperature histories .............................. 66
4 Miocene extensional exhumation in the NE Dinarides in the
context of Pannonian Basin formation: constraints from lowtemperature thermochronology ............................................................. 77
4.1 Introduction ..................................................................................... 77
4.2 Geological indications for existence of extensional
detachments in the NE Dinarides ...................................................... 80
4.3 Low-temperature thermochronology of NE Dinarides ............ 89
4.3.1 Cooling ages in the Fruška Gora Mountains ....................... 94
4.3.2 Cooling ages in the Cer Mountains ....................................... 98
4.3.3 Cooling ages in the Bukulja Mountains.............................. 102
4.3.4 Specific cooling histories of Cer and Bukulja intrusions.. 105
4.4 The exhumation history in studied areas of the
NE Dinaridic margin ......................................................................... 108
4.4.1 The exhumation history of the Cer Mountains ................. 109
4.4.2 The exhumation history of the Bukulja Mountains .......... 111
4.4.3 The exhumation history of the Fruška Gora Mountains .. 115
4.5 The link between exhumation and processes associated
with the opening of the Pannonian Basin ....................................... 116
4.6 Conclusions ................................................................................... 120
5 Thermo-tectonic evolution of the NE Dinarides: inferences
from detrital thermochronology ........................................................... 123
5.1 Introduction ................................................................................... 123
5.2 Detrital thermochronology and interlinked tectonic and
sediment-forming processes in the NE Dinarides ......................... 126
5.3 Detrital thermochronology of NE Dinarides ............................ 134
5.3.1 Detrital thermochronology of Late
Cretaceous−Paleogene syn-kinematic sediments in the NE
Dinarides .......................................................................................... 134
5.3.2 Detrital thermochronology of Miocene sediments in
the Fruška Gora Mountains........................................................... 141
5.3.3 Detrital thermochronology of Miocene sediments in
the Bukulja and Cer Mountains .................................................... 146
5.4 Cretaceous−Eocene thermal histories of syn-kinematic
sediments deposited in the Sava Zone ............................................ 150
5.5 Miocene thermo-tectonic evolution of the Fruška Gora
Mountains ............................................................................................ 158
5.6 Syn-rift sedimentation as an effect of exhumation of
Bukulja and Cer Mountains core complexes .................................. 164
5.7 Conclusions ................................................................................... 167
6 Regional integration and conclusions............................................... 171
Appendices .............................................................................................. 183
Appendix A. Geological maps of the study areas with low-t
thermochronology ages of the analyzed samples .......................... 183
Appendix B. Low temperature thermochronology
analytical data ..................................................................................... 187
References ................................................................................................ 191
Acknowledgements
A friend once told me that doing a PhD is like a roller
coaster ride. Now, when the ride is over it is good time to
remember people that made it happen and others that I met
while it lasted.
Paul, first of all thank you for hiring me for this project.
Thank you for your help in the lab and with writing papers and
for being patient and tactful also during the times when I didn’t
completely deserve it. Liviu, thank you for showing me that
there is so much more in geology besides column descriptions.
Above all it is a quest for fundamental principles. Good luck
with your further quests across the Mediterranean. Marinko,
thank you for the ability to recognize the right moment. I will
always remember the discussions we had in the field and in the
office and the advices you and professor Marović gave me.
Knowing that he would be content with the things we done
makes me proud.
I would like to thank the members of the reading
committee: prof. dr. Vladica Cvetković, prof. dr. Giovanni
Bertotti, dr. Ernst Wilingshofer, dr. Marinko Toljić, and dr.
Jurgen Foeken, for the time spent reading this book and their
constructive comments.
IX
When I first came to A’dam I met people that helped me
a lot and made me feel welcomed. Marten, thank you for the
advices about living in Holland and at the VU and for
demonstrating personal integrity during all fieldworks, courses,
meetings, and conferences we visited together. Anne, my bff,
thank you for your company during the years spent at the VU
and for the great moments we had in the town. I wish to thank
my office mates during the early period Sandra and Elco.
Sandra, thanks for taking care of me, for all good advices, and
for amazing understanding of fission track methodology. Elco,
sharing office with you made me realize what it takes for young
scientist to become an outstanding one. I am equally grateful to
my office mates during the later stage of my work. Inge and
Catalin, thanks for everything and success with your research.
Many thanks to my other fellow isotopes: Marlies,
Jurgen, Klaudia, Jan, Marlies, Fenny, Leah, Brett, Diana,
Ibrahim, Arnaud, Bad’r, Joaqium and all others. Jurgen, first
steps in the lab were much easier with your support,
confidence, and AC/DC. I want to thank Roel, Onno, Bas, and
John, all real professionals in their work, for their help during
the lab work. Tineke, although your help with fission track
preparation was irreplaceable, there were times when your
support as friend was helping me even more. I will not forget
this.
Good support and motivation I always found in
discussions with: Dimitrios, Ernst, Ioan, David, Stefan, Javier,
Mohamed, Karen, Maarten, Nico, and all other members of
professor Cloeting’s European school of tectonics.
I also need to mention some of the great people I met at
the VU and through the VU: Teresa, Matias, Silvia, Slavka,
Rasto, Andreas, Josepha, Brett, Emma, Jane, Ida, Alex, FransJan, Margriet, John, Martin, Kamil, Arjan, Martin, Wouter, and
many master and bachelor students.
Life in Holland would be much less interesting without
Vale and Sjoerd, my Amsterdam family. List of the things I need
to
thank
you
both
for
would
be
too long
for
the
acknowledgements. I also need to mention Eliene, Maarten,
Willem, Sofia, Jeroen, Douwe, Jelena, Rene…
During my studies in many different occasions I was
meeting Serbian colleagues in similar positions, sharing similar
hopes, motives, and problems. I am especially grateful to Erak
and Miloš, samurai of geology, for their support during these
years. Many thanks also to: Nikola, Dejan, Nevena, Milica, Zoja,
Ivanka, Ana, Josip, Miloš, Darko, and Milorad.
Through all these years, and especially in the final stage
I had good support from colleagues at University of Belgrade. I
am very grateful to professor Rundić, professor Knežević,
Nataša, Nevenka, and all other collaegues and students in
Belgrade.
Many thanks to my friends and family in Serbia,
especially to my sis Ana, the Keri family, and Natalija.
Summary
Low-temperature thermochronology in the Fruška Gora,
Cer, and Bukulja Mountains of Serbia is testifying a complex,
poly-phase thermo-tectonic evolution of the junction area
between the Dinarides and the Carpatho−Balkanides from the
end of Cretaceous times onwards. The north-eastern margin of
the Dinarides was affected by the Cretaceous–Paleogene
shortening related to collision between Adriatic- (i.e. Dinarides)
and European-(i.e. Tisza and Dacia) derived units, closing the
intervening ocean along what is commonly known as the Sava
suture zone. Zircon fission track thermochronology of samples
collected in syn-kinematic sediments of the Fruška Gora,
Bukulja and Cer Mountains of the NE Dinarides yields the
temporal constraints for the Europe–Adria collision, setting the
peak tectonic activity to Maastrichtian, at ~70 Ma, but must
have been prolonged in Early Paleogene times. The provenance
ages that were obtained point to a rapid exhumation of source
area that is most likely dominated by the Upper Cretaceous–
Paleogene intrusive and extrusive magmatism recorded in the
Banatitic‐Srednogorje Zone. Therefore, the main locus of the
latest Cretaceous–Paleogene exhumation was shifted from the
Dinarides margin and the Sava Zone of collision towards the
Carpathian units. Our study confirms the general position of the
Sava suture when compared with previous interpretations.
However, it also demonstrates that its activity continued during
Paleogene times, much longer than previously assumed, at least
XIII
by
exhumation
at
the
resolution
of
fission-track
thermochronometers. Post-dating the Latest Cretaceous–Early
Paleogene event, the Middle to Late Eocene cooling and
exhumation ages obtained in this study are interpreted as a
result of one other tectonic event. These ages are coeval with the
Middle–Late Eocene phase of shortening that is widely
observed in the External Dinarides, extending as far west as the
Southern Alps. The novel observations demonstrate that the
Late Cretaceous–Paleocene thrusting continued during Eocene
times, when the Dinaric tectonic phase also significantly
affected the Internal Dinarides, including the contact with the
overlying European-derived units. Furthermore, we interpret
the emplacement of the Cer Mountains I-type pluton and other
genetically related late Paleogene granitoid bodies, as being
associated with the Dinaric tectonic phase. Since the collisional
processes between the Dinarides and the Carpatho−Balkanides
have reached their peak in the uppermost Cretaceous–Paleocene
times (starting with ~70 Ma), the Eocene (~40 Ma) contractional
episodes of the NE Dinarides are interpreted to denote the onset
of enhanced coupling between the two continental units in and
near the former subduction zone. Hence, this coupling is likely
the result of the continuing convergence between Adria/Africa
and Europe that was accommodated by the Alpine Tethys
subduction zone located more N-wards at the exterior of the
Alps and their prolongation in the Carpathians.
The present-day geometry of the junction area between
the Dinarides and the Carpatho−Balkanides is the result of a
Miocene extensional phase that has created the Pannonian
Basin, a classical example of a back-arc basin formed in response
to the retreat of a slab situated at the exterior of the Carpathians.
The low-temperature thermochronology has demonstrated that
the formation of the southeastern part of the Pannonian Basin
and its southern prolongation along the Morava river valley
was associated with coeval large-scale exhumation in the Fruška
Gora, Cer, and Bukulja Mountains of the NE Dinarides. These
findings disprove classical studies of the NE Dinaridic margin,
which assumed that following the Cretaceous–Eocene period of
orogenic build-up, the extension of the Pannonian Basin
resulted only in subsidence in the normal faults hanging-wall
and coeval deposition of up to 3–4 km of Miocene sediments.
This study demonstrates that rocks that were previously buried
to intermediate crustal depths by the subduction of the Sava
ocean and the following collision that took place between
European- and Adriatic‐derived units were subsequently
rapidly exhumed in the footwalls of large-scale extensional
detachments. This means that the extensional detachments
reactivated the inherited subduction/collision contact between
European
and
Adriatic
units.
Zircon
fission
track
thermochronology record in the Fruška Gora Mountains has
proven that the extension in the SE part of the Pannonian Basin
was ongoing already at the Oligocene−Miocene transition at ~24
Ma, earlier than at ~20 Ma that was the general interpreted
extensional onset age. The Pannonian extension along the NE
Dinarides margin has established an interlinked exhumationerosion-deposition system, which was active during the entire
late Early to early Late Miocene extensional period, with the
average exhumation exceeding the rate of 0.5 km/Ma. The
exhumation process was also associated with decompressional
melting and emplacement of the Bukulja Mountains S-type
pluton and other genetically related granitoid bodies, such as
the Polumir and the Cer Mountains S-type two-mica granite.
The Pannonian extension was characterized by a series of
parallel, top-to-E oriented, detachments that are presently
exposed in the Dinarides. The top-to-E extension cannot be
associated with an E-ward movement of the intervening
Carpathians units in this sector of the chain. The only other
possible genetic option is the roll-back of a Dinaridic slab, a
speculative hypothesis that would be compatible with the largescale extension that was recently quantified in this segment of
the orogenic chain.
Samenvatting
Het overgangsgebied tussen de Dinariden en CarpathoBalkaniden kent vanaf het einde van het Krijt een complexe
polyfase thermo-tectonische ontwikkeling. Dit blijkt uit lagetemperatuur-thermochronologie voor de Fruška Gora-, Cer- en
Bukulja-heuvels in Servië. De noordoostelijke rand van de
Dinariden ondervond gedurende het Krijt en Paleogeen
verkorting als gevolg van de convergentie van tektonische
blokken met een Adriatische (de Dinariden) en een Europese
affiniteit (Tisza en Dacia). Bij deze botsing werd een
tussenliggende oceaan gesloten en vormde zich een sutuur: de
Sava-zone.
Zirkoon-splijtingssporen-thermochronologie
van
monsters verzameld in de syn-kinematische sedimenten van de
Fruška Gora-, Cer- en Bukulja-heuvels (Interne Dinariden)
leveren het tijdskader voor de botsing tussen Europa en Adria:
de tektonische activiteit piekte rond 70 Ma, in het Maastrichtien
(Laat-Krijt), maar duurde voort tot in het Vroeg-Paleogeen. De
verkregen data wijst op een snelle exhumatie van het
brongebied, dat hoogstwaarschijnlijk gedomineerd werd door
intrusief en extrusief magmatisme in de Banatiten-Srednogorje
Zone. De zone waar exhumatie plaatsvond verplaatste zich
gedurende het Laat-Krijt en Paleoceen van de noordoostelijke
rand van de Dinariden en de Sava-zone richting de eenheden
met een Karpaten-affiniteit. Alhoewel de studie eerdere
interpretaties van de positie van de Sava-zone bevestigt, wordt
ook aangetoond dat de zone veel langer actief bleef dan eerder
XVII
gedacht; exhumatie op de resolutie van de splijtingssporenthermochronometers vond plaats tot in het Paleogeen. De in
deze studie gevonden Midden–Laat-Eocene afkoelings- en
exhumatieouderdommen worden geïnterpreteerd als een aparte
tektonische
fase.
Deze
ouderdommen
kunnen
worden
gecorreleerd aan de Midden–Laat-Eocene verkortingsfase die
plaatsvond in de externe zone van de Dinariden en zelfs tot in
de Zuid-Alpen. Hieruit concluderen wij dat de Laat-Krijt–
Paleocene verkortings- en accretiefase in de Externe Zone van
de Dinariden voortduurde tot in het Eoceen, gelijktijdig met de
Dinarische tektonische fase in de interne zone van de Dinariden
en de bovengelegen eenheden met een Europese affiniteit.
Bovendien kunnen we het I-type intrusief in de Cer-heuvels en
overige Laat-Paleogene granitoïden koppelen aan deze Eocene
fase van verkorting. Aangezien de piek van continentale collisie
tussen de Dinariden en de Carpatho-Balkaniden plaatshad
tijdens het Laat-Krijt–Paleoceen (vanaf ~70 Ma), beschouwen we
de Eocene (~40 Ma) verkorting in de noordoostelijke Dinariden
het gevolg van de sterkere wordende koppeling tussen de twee
continentale eenheden in en nabij de inactief geworden
subductiezone. Deze sterkere koppeling is vermoedelijk het
gevolg van de voortdurende convergentie tussen Adria/Afrika
en Europa die verder noordwaarts, aan de buitenrand van de
Karpaten
en
Alpen,
geaccommodeerd
subductiezone van de Alpiene Tethys.
werd
langs
de
In het overgangsgebied tussen de Dinariden en de
Carpatho-Balkaniden bevindt zich tegenwoordig het Pannoonse
Bekken, een klassiek voorbeeld van een back-arc bekken. Het
werd gevormd werd tijdens de Miocene extensie die het gevolg
was van het terugrollen van een subducerende plaat aan de
buitenrand
van
de
Karpaten.
De
lage-temperatuur-
thermochronologie toont aan dat de vorming van het
zuidoostelijke en zuidelijke deel van het Pannoonse Bekken in
de
Noordoostelijke
Dinariden
ook
gepaard
ging
met
grootschalige Miocene exhumatie in de Fruška Gora-, Cer-, and
Bukulja-heuvels.
Dit
bewijst het
ongelijk van
klassieke
interpretaties van de noordoostelijke Dinariden, waarin er
vanuit werd gegaan dat de extensie in het Pannoonse bekken
alleen zorgde voor daling en de afzetting van 3–4 km
sedimenten boven de bovengelegen blokken van afschuivende
breuken. Deze studie toont echter aan dat gesteenten die tijdens
de subductie van de Sava-oceaan en de daaropvolgende
continentbotsing tot op diepten van omstreeks 10 km in de korst
begraven waren vervolgens snel geëxhumeerd werden als
onderdeel van de onder de grootschalige ontkoppelingsniveaus
gelegen blokken. Dit impliceert dat de oudere subductie- en
botsingscontacten tussen de Europese en Adriatische eenheden
gereactiveerd
werden
als
ontkoppelingsniveau.
splijtingssporen-thermochronologie laat
ook zien
Zirkoondat
de
extensie in het zuidoostelijke deel van het Pannoonse bekken al
rond 24 Ma gaande was, vroeger dan de eerder aangenomen 20
Ma. De Pannoonse extensie langs de noordoostelijke rand van
de Dinariden zorgde voor het ontstaan van een gekoppeld
exhumatie-erosie-afzettingssysteem. Dit systeem was actief
tijdens de gehele extensiefase, die duurde van het eind van het
Vroeg-Mioceen tot in het begin van het Laat-Mioceen en
resulteerde in exhumatie met snelheden van meer dan 0.5 km
per miljoen jaar. Deze exhumatie ging samen met decompressief
smelten en het intruderen van het S-type Bukulja-intrusief en
geassocieerde granitoïden zoals de Polumir and Cer S-type
twee-glimmergraniet.
De
Pannoonse
extensiefase
werd
gekarakteriseerd door een groep van parallelle top-oost gerichte
ontkoppelingsniveaus, die tegenwoordig ontsloten zijn in de
Dinariden. Aangezien de top-oost extensie in dit gedeelte van
de gebergteketen niet verklaard kan worden door een
oostwaartse verplaatsing van de tussenliggende eenheden van
de Karpaten, is de enige mogelijke verklaring het terugrollen
van de Dinaridische subducerende plaat. Deze speculatieve
hypothese zou de recent aangetoonde grootschalige extensie in
dit gedeelte van de gebergteketen verklaren.
Rezime
Niskotemperaturna termohronološka istraživanja na
prostorima Fruške gore, Cera i Bukulje, koji pripadaju
severoistočnom obodu unutrašnjih Dinarida, pružaju dokaze o
složenoj, višefaznoj termo-tektonskoj evoluciji spojnog područja
Dinarida i Karpato-balkanida od kredne periode nadalje.
Severoistočni obod Dinarida pretrpeo je značajna tektonska
skraćenja kao posledicu kolizije između adrijskih (Dinaridi) i
evropskih (Tisa i Dakija) kontinentalnih jedinica, pri čemu je
samo područje kontakta poznato kao “Sava sutura“. “Fissiontrack“ termohronologija na cirkonima iz flišnih sedimenata
Fruške gore, Bukulje i Cera definiše vreme kolizije evropskih i
adrijskih jedinica, markirajući mastrihtski kat (~70 Ma) kao
vreme najveće tektonske aktivnosti. Dobijeni podaci o starosti
takođe ukazuju na ubrzanu ekshumaciju izvorišnih područja
sedimenata, koja su najverovatnije predstavljena gornjekrednopaleogenim
intruzivnim
i
ekstruzivnim
magmatitima
Banatitsko-srednjegorske zone. Na osnovu toga se može
zaključiti da je glavno područje gornjekredne ekshumacije
pomereno od dinarske margine i Sava suture ka jedinicama
Karpato-balkanida. Ova studija, u skladu sa prethodnim
tumačenjima,
potvrđuje
generalnu
poziciju
Sava
suture.
Međutim, takođe pokazuje da se tektonska aktivnost na ovom
prostoru nastavila tokom čitavog paleogena, mnogo duže u
odnosu na ranije pretpostavke. Eocenska faza ekshumacije sledi
kredno-paleogenu fazu i predstavlja rezultat drugih tektonskih
XXI
događanja. Dobijene eocenske starosti istovremene su sa fazom
tektonskog skraćenja koja je dobro definisana u jedinicama
spoljašnjih Dinarida (“Dinarska faza”). Naša istraživanja
ukazuju na to da se kredno-paleogena kompresija nastavila i
kroz eocen, te da je Dinarska tektonska faza imala značajan
uticaj i na jedinice unutrašnjih Dinarida, uključujući i sam
kontakt sa jedicama evropskog afiniteta. Osim toga, utiskivanje
I-tipa granitoida Cera kao i drugih genetski srodnih poznopaleogenih granitoida, interpretira se kao povezano sa
Dinarskom tektonskom fazom. Budući da su kolizioni procesi
između Dinarida i Karpato-balkanida dostigli svoj maksimum
na granici krede i paleocena (~70 Ma), eocenske kontrakcione
epizode (~40 Ma) u severoistočnim Dinaridima interpretirane su
kao rezultat pojačane kompresije između kontinentalnih
jedinica u blizini nekadašnje zone kolizije. Ova kompresija
predstavlja rezultat kontinuirane konvergencije između jedinica
adrijskog/afričkog i evropskog afiniteta, koja je kompenzovana
zonom subdukcije Alpskog Tetisa lociranom severnije, u
spoljašnjem delu Alpa i njihovom produženju u Karpatima.
Današnja geometrija spojnog područja Dinarida i
Karpato-balkanida
predstavlja
rezultat
miocenske
faze
ekstenzije zaslužne za stvaranje Panonskog basena, koji
predstavlja tipičan primer “back-arc” basena nastalog kao
rezultat uzmicanja ploče locirane u spoljašnjem delu Karpata.
Niskotemperaturna termohronologija ukazuje na to da je
formiranje jugoistočnog dela Panonskog basena i njegovog
južnog produženja duž doline Morave bilo povezano sa
istovremenom ekshumacijom velikih razmera na područjima
Fruške gore, Cera i Bukulje. Ovi zaključci opovrgavaju klasične
interpretacije evolucije obodnih delova unutrašnjih Dinarida
prema kojima nakon kredno-eocenskog perioda stvaranja
orogena, ekstenzija Panonskog basena rezultirala isključivo
subsidencijom u povlatnim blokovima normalnih raseda i
istovremenom depozicijom miocenskih sedimenata debljine do
3–4 km. Ova studija dokazuje da su stene pohranjene do
srednjih dubina zemljine kore (~10 km) tokom kolizije između
jedinica evropskog i adrijskog afiniteta u kasnijem periodu bile
ubrzano ekshumirane iz podinskih blokova ekstenzionih
detačment raseda velikih razmera. To znači da su ekstenzioni
detačment
rasedi
ponovo
aktivirali
nasleđene
kontakte
evropskih i adrijskih jedinica. Fission track termohronologija na
cirkonima iz uzoraka sa Fruške Gore ukazuje na to da se
ekstenzija u jugoistočnim delovima Panonskog basena odvijala
već na granici oligocena i miocena (~24 Ma), znatno ranije od
~20 Ma koji se generalno interpretiraju kao vreme početka
ekstenzije.
Panonska
ekstenzija
uspostavila
je
duž
severoistočnog oboda Dinarida jedan međusobno povezani
ekshumaciono-eroziono-depozicioni sistem koji je bio aktivan
tokom čitavog miocena, pri čemu je iznos ekshumacije tokom
čitavog perioda prevazilazio iznos od 0.5 km/Ma. Proces
ekshumacije je takođe povezan sa utiskivanjem S-tip granita
Bukulje i drugih genetski srodnih granitoida, kao što su Polumir
i S-tip granit Cera. Panonska ekstenzija odlikovala se
formiranjem serije paralelnih detačment raseda, po kojima se
ekstenzija odvijala u pravcu istoka i koji su danas prisutni u
Dinaridima. Ekstenzija u pravcu istoka ne može biti povezana
sa istočnim pomeranjem karpatskih jedinica u ovom delu
orogena. Jedina alternativna genetska opcija bi bilo uzmicanje
dinarske ploče. Ova spekulativna hipoteza odgovarala bi
ekstenziji
velikih
razmera
koja
je
dokumentovana u ovom delu orogena.
tokom
ove
studije

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