The Spatial Position of the East Vardar Ophiolite eGeophysical-Geological Model and Implications on Its Geodynamic Evolution.

[D. Petrović]

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Geološko inženjerstvo-Geofizika / Geological engineering-Geophysics

Centralni deo Balkanskog poluostrva je geotektonski veoma složen. Tetis je zatvoren tokom gornjeg mezozoika, a ofioliti na zapadu i ofioliti Vardarske zone predstavljaju ostatke nekadašnjih okeanskih prostora. Najistočniji deo Vardarske zone razlikuje se od svih ostalih ofiolita na Balkanskom poluostrvu i karakteriše se najizraženijim suprasubdukcijskim afinitetom. Istočna vardarska zona locirana je u centralom delu Srbije. Na severu se prostire do Apusena u Rumuniji, a na jugu obuhvata cetralni deo Makedonije i Peonias zonu u severnoj Grčkoj. Istočna vardarska zona se nalazi istočno od geotektonske jedinice Kopaonik i zapadno od Srpsko-makedonske mase. Mnoga istraživanja sprovedena na prostoru zapadnog i centralnog dela Vardarske zone dovela su do toga da su prostorni položaj i međusobni odnosi ovih ofiolita sa susednim jedinicama prilično dobro utvrđeni, međutim u dosadašnjim istraživanjim postoje brojna neslaganja oko položaja i vergence Istočne vardarske zone. Ova disertacija je imala zadatak da utvrdi prostorni položaj stenskih masa Istočne Vardarske zone, sa krajnjim ciljem da se iz dobijenih rezultata dođe do pouzdanije rekonstrukcije načina primarnog smeštanja ovih ofiolita. Prostorni položaj ofiolita Istočne vardarske zone utvrđen je na osnovu geofizičkih i geoloških podataka koji su dobijeni istraživanjem pojava ovih ofiolita u Srbiji, Makedoniji i Grčkoj. Primenjena metodologija obuhvatila je dalјinsku detekciju i strukturnu analizu, kao i gravimetrijska i geomagnetska istraživanja. Na osnovu dobijenih podataka kreirani su geofizičko-geološki modeli. Nad gravimetrijskim i geomagnetskim podacima sproveden je niz transformacija u cilju utvrđivanja položaja uzročnika anomalija. Budući da na izgled geomagnetske anomalije ne utiče samo položaj tela, već i remanetna magnetizacija, pored određivanja gustine i susceptibilnosti, sprovedena su laboratorijska određivanja intenziteta prirodne remanentne magnetizacije, inklinacije i deklinacije. Modelovanje je vršeno u programskom paketu Oasis Montaj/GM SYS, duž 7 profila postavljenih upravno na pružanje Istočne vardarske zone...

The central Balkan Peninsula has a very complex geotectonic fabric. The Tethys Ocean was closed during late Mesozoic leaving behind Dinaric (west) and the Vardar Zone (east), as important relicts of the former oceanic lithosphere. The easternmost ophiolite belt, known as the East Vardar Zone, differs from other Balkan ophiolites in displaying the most pronounced supra-subduction geochemical signatures. The East Vardar Zone is placed in central part of Serbia. In the north, it extends to the Apuseni Mts. in Romania, and in the south it continues through central parts of the FYR of Macedonia, and Peonias subzone towards North Greece. The East Vardar Zone is placed eastern of the continental Kopaonik Unit and western of the Serbo-Macedonian Massif. The true tectonic position of the East Vardar Zone ophiolites with respect to adjacent geotectonic units is still a matter of debate and this dissertation was aimed at addressing this problem. The spatial position of the East Vardar Zone ophiolites in Serbia, Macedonia and Greece was determined based on geophysical and geological data. The applied methodology included remote sensing and field observation data as well as gravity and geomagnetic data. Based on obtained data, 2D modeling of geomagnetic and gravity data was performed. Mathematical transformations were applied on gravity and geomagnetic data in order to determine the position of rocks masses that caused the anomalies. The pattern of geomagnetic anomalies depend not only form dip angle of the source of the anomaly, but of remanent magnetization, as well. Due to this reason laboratory measurements were done along determinations of density, susceptibility and remanent magnetization. Modeling was performed in software Oasis Montaj/GM SYS, along 7 sections that were placed perpendicular to the East Vardar Zone direction, and along three control sections. The sections were between 20 and 50 km long and their depth was between 2 and 4 km. The obtained results invariably suggest that the East Vardar Zone ophiolites are dipping to the east beneath the Serbo-Macedonian Massif. The inferred buried ophiolite bodies...

Istočna vardarska zona; ofioliti; 2D i pseudo 3D geofizičko-geološki model; geodinamička evolucija

East Vardar Zone; Ophiolite; 2D and pseudo 3D geophysical-geological models; Geodynamic evolution

552.3/550.34.01(497)(043.3) 552.3/.5:551.2/.3(497)(043.3)

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