GEOLO[KI ANALI BALKANSKOGA POLUOSTRVA 66 (2004–2005) 17–20 BEOGRAD, decembar 2005 ANNALES GÉOLOGIQUES DE LA PÉNINSULE BALKANIQUE BELGRADE, December 2005

Spatial distribution of geological resources in northwestern ( block terrane) and its relation to tectonic structures

IVAN FILIPOVI]

Abstract. This work presents new information about the interconnection between diverse geological resources and tectonic structures framing the Jadar block terrane. Deep fault zones are found to have been principal bear- ers of geothermal, thermomineral and metallic ore resources. Increased bitumen and hydrocarbon concentrations in pre-Tertiary deposits, which may be potential oil/gas zones, are also associated with these areas. Key words: Boundary deep fault zones, geological resources, northwestern Serbia.

Apstrakt. U radu su prikazana nova saznawa o me|usobnoj povezanosti raznovrsnog spektra geolo{kih resursa i tektonskih struktura koje uokviruju Jadarski blok teran. Konstatovano je da su dubinske razlomne zone glavni nosioci geotermalnog, termomineralnog i metali~nog potencijala, kao i da su za wih u pretercijarnim sedimentima, vezane pove}ane koncentracije bitumena i ugqovodonika pa, u odre|enim prostorima, mogu biti potencijalne naftno-gasne zone. Kqu~ne re~i: grani~ne dubinske razlomne zone, geolo{ki resursi, geotermalni i naftno-gasni potencijali, severozapadna Srbija.

Introduction vant characteristics given in the generally accepted def- inition of a terrane (KEPPIE & DALLAMEYER, 1990). It New geodynamic ideas on the plate tectonics and is an exotic block of the Earth’s crust which, like the terranes initiated among national geologists enable fun- Bükkium terrane in Hungary, is highly correlative with damentally different interpretations of the spatial distri- the Dinaride-South Alpine belt. bution of geological resources in northwestern Serbia It differs only in its present geological environment. (FILIPOVI] et al., 1996). First knowledge about the The major characteristics of the Jadar block terrane, interconnection of deep boundary fault structures and which derived from Gondwana, are the following: 1. La- diverse geological resources was based on a long sur- te Variscan molasse with fusulinids; 2. Middle Permian face oil-geological study of pre-Tertiary formations in evaporites; 3. Upper Permian limestones bearing Cauca- western Serbia (A[ANIN et al., 1998). Consistent surface sian-Indo-Armenian brachiopods; 4. Extinction of the sampling and organo-geochemical analyses indicated abundant Upper Permian organic life at the Permi- that pre-Tertiary rocks occur as country rocks only in an/Triassic boundary; 5. Ooids in the Lower Triassic; and the zones of deep boundary faults along which differ- 6. Intracontinental rifting magmatism in the Ladinian. ent geotectonic units are converging. An illustrative Marked features of the geotectonic units adjacent to example is the Jadar block terrane. In this paper, its the Jadar block terrane are the following: 1. Cambri- relevant characteristics are described in order to explain the interrelation of different geological resources and an/Ordovician metamorphic rocks: 2. Lower Carbonife- boundary tectonic structures with particular reference to rous pre-flysch deposits; 3. A long regressive stage in potential energy resources in some areas. the late Paleozoic; 4. Lower Triassic red continental beds; and 5. Jurassic ophiolite complexes. The above major characteristics of the Jadar block ter- Major characteristics of the Jadar block rane and the geotectonic units adjacent to the terrane terrane and the boundary tectonic structures suggest the followings: all formations characterizing the Jadar block terrane are lacking in the surrounding areas, The Jadar tectono-stratigraphic unit all the rele- and, vice versa, not a single mentioned characteristic of

“Gemini” Geological Institute, Karadjordjeva 48, 11000 Belgrade, Serbia & Montenegro. E-mail: [email protected] 18 IVAN FILIPOVI] the Vardar Zone or the -Ivanjica element is recog- 2. The southwestern boundary consists of a long, very nized in the Jadar terrane. The boundaries of the Jadar narrow belt of a ophiolite melange that can be traced terrane, which were proved in the uncovered profiles to from the Boranja granodiorite massif to Jagodnja, to the be tectonic, are based on the mentioned pattern model. southwestern slopes of the Sokolska Planina Mt., to Ti-

The Jadar terrane is bounded by deep fault zones and sovik and Bobija. This repeatedly reduced ophiolite com- tectonic melanges with which diverse geological resour- plex is at present a typical tectonic melange which was ces are associated: geothermal and thermomineral waters, produced during the Jadar block sliding. According to metallic ores (Pb-Zn, As, Au, Cu, Sb), country rocks ]IRI] (1996), it is the large fault zone of having oil-bearing properties and epicenters of registered which “could have been formed by faulting and differ- earthquakes (Fig. 1). Tectonic structures - deep seated ential block movements, including rock crushing and faults and tectonic melanges – are geologically well mixing over the entire fault zone”. The western part of marked and exposed for direct observation in the south- the Azbukovica Zone is described by RADOI^I] (1977) ern half of the Jadar tectono-stratigraphic unit. Unlike as “a chaotic formation of Rujevac and Veliki Majdan” these, the boundary faults are covered by thick Neogene in which rocks of diverse geological ages were “mecha- deposits in the northern half of the unit, as inferred from nically” mixed (Paleozoic, Triassic, Jurassic, and epochs drilling data. Thus, the drilled Triassic limestone aquifers of the Cretaceous from the Malm/Neocomian conclusive belong to the Jadar terrane, and the drilled ophiolite, with the Lower Senonian). The most instructive profiles north of the Sava, to the Vardar Zone. The major char- of the melange were formed in the Rujevac area, which acteristics of the boundary structures are the following: show the crushed groundmass of dominantly basic rocks 1. The western boundary of the Jadar block terrane is that include clasts and blocks of various sizes, diverse marked by the thermomineral springs of Banja Kovilja~a lithology and stratigraphy. Associated with the tectonic and Radaljska Banja. Further to the SSE, the Boranja melange of Azbukovica are the deposits of Rujevac (Sb- granodiorite intrusion and contact-metamorphic aureoles Pb-Zn-As), Postenje and Tisovik (Pb), Eri}i and Skakav- are obviously associated with the boundary fault zone. ci (Cu), and Crvena Stena (Sb). Spatial distribution of geological resources in northwestern Serbia 19

3. The southern boundary runs along the northern tered earthquakes (8° MCS, , 1905; 8° MCS, slopes of the Medvednik, Jablanik and Povlen Mts., the Mionica, 1998; 9° MCS, Lazarevac, 1992). Zabava, Kr~marska and Pa{tri} valleys to Vrujci spa. This boundary is marked also by an ophiolite melange, with which the Rebelj and Krsti} copper deposits, the Conclusion Vujinova~a and Brezovica antimony deposits, the Vrujci thermomineral springs, and country rock near Po}uta and Based on this new research data, it can be conclud- Podbukovo are associated. The ophiolite complex is ed that most of the geological resources of northwest- much wider than the Azbukovica belt, and is character- ern Serbia are associated with the faults bounding the ized by the presence of a tectonic melange only in the Jadar block terrane, which explains the distribution pat- contact zone with the Jadar block, which refutes the tern of the geological resources (thermal and ther- statement that the melange is of sedimentary derivation momineral waters and metallic ores) and oil-bearing (DIMITRIJEVI] & DIMITRIJEVI], 1973). The information of rocks. It also enables the location of new deposits. particular importance concerning the tectonic melange is Economic concentrations of hydrocarbons may be (1) A Lower Permian dkm/size block containing fusuli- expected only in deep depressions under impermeable nids at Podbukovo and (2) the epicenter of a recent rocks, bounded by fluid-permeable deep-seated faults. earthquake in the Krm~ar-Pa{tri} area. Further eastwards, Resources of this kind can be expected to be found in the boundary fault trace is indicated by the thermo- the Ka~er depression and in the Neogene valleys of the mineral springs of and by numerous occurrences of , Ma~va, and Semberija. oil-source country rock. The extreme eastern boundary is The hydrothermal resources in Ma~va and Posavo- marked by Bukulja granitoid, and the northwestern by are the largest in the southern part of the antimony minerals at Trbu{nica and Devonian/Carboni- Pannonian basin. According to this model, the existing ferous rocks of oil-bearing properties in Kru{evica. reserves may increase toward the boundary faults. More- 4. The deep seated boundary faults in the northern over, thermomineral water may also be expected, and half of the terrane are marked by thermal springs at even oil deposits, in some tectonic structures. Posavo-Tamnava, Ma~va, and Semberija in the Jadar block, near the boundary faults which separate this tectono-stratigraphic unit from the Vardar Zone. References

A[ANIN, P., FILIPOVI], I., JOVANOVI], D., JOVAN^I]EVI], D. & Discussion VITOROVI], D., 1998. Results of geological and organic – geochemical investigations of western Serbia, [umadija The purpose of this work was is to develop a model and Kosmet. Vesnik Zavoda za geolo{ka i geofizi~ka istra- of the geological resource distribution pattern of NW `ivanja, Serija A, 48: 277–295. Serbia. The model is based on the following relevant ]IRI], B., 1966. Geology of Serbia: Composition and devel- information: opment of the Earth’s crust. “Geokarta”, 1–273, Beograd 1. The Jadar block terrane is a segment of the (in Serbian). Earth’s crust which is highly correlative with the Dina- DIMITRIJEVI], M.D., 1995. Geology of Yugoslavia. Geoinsti- ride-South Alpine belt, and extremely different from tut, 1–205, Beograd. the adjacent geotectonic units. FILIPOVI], I., 1996. Geological characteristics and potentiali- 2. The tectonic structures bounding the Jadar block ty of geological resources in the Kolubara, Ma~va and Po- are deep fault zones which allowed migration and for- drinje regions. Geolo{ki zavod “Gemini”, 1–21, Beograd. mation of diverse geological resources. FILIPOVI], I., 2000: Paleozoic of the Jadar block terrane (NW 3. Surface geological explorations for petroleum in Serbia). Proceeding of the International Symposium of western Serbia revealed that rocks of oil-bearing proper- Geology and Metallogeny of the Dinarides and the Var- ties occur only in the boundary fault zones. In the tec- dar Zone, 66–68, Banja Luka–Serbian Sarajevo. tonic structures bounding the Jadar block terrane these FILIPOVI], I., JOVANOVI], D., SUDAR, M., PELIKAN, P., KO- rocks are found in Devonian/Carboniferous clastics, Up- VACS, S., LESS, G. & HIPS, K., 2003. Comparation of the per Permian limestones, and Cretaceous/Paleogene flysch. Variscan – Early Alpine evolution of the Jadar Block (NW 4. There are many examples in the literature of the Serbia) and “Bükkum” (NE Hungary) terranes: Some pale- spatial interconnection of thermomineral aquifers, ore ogeographic implications. Slovak Geological Magazine, 9 deposits, and oil fields, particularly among recent se- (1): 23–40. ismogenetic faults. Some of the examples are locations KEPPIE, J. D., & DALLMEYR, R.D., 1990. Introduction to ter- on the southern and eastern margins of the Jadar rane and the tectonic map of pre-Mesozoic terranes in tectono-stratigraphic unit, where the mentioned geolog- Circum – Atlantic Planerozoic orogens. IGCP Meeting, ical resources were found or were epicenters of regis- Abstract, 223, Göttingen. 20 IVAN FILIPOVI]

RADOI^I], R., 1997. On the Rujevac – Veliki Majdan chaot- ferima trijaskih kre~waka pripadaju Jadarskom ic formation (Western Serbia). Vesnik Zavoda za geolo{ka teranu, a bu{otine sa ofiolitima, severno od Sa- i geofizi~ka istra`ivanja, Serija A, 47: 53–61. ve, Vardarskoj zoni. Na temequ novih nau~nih saznawa evidentno je da je najve}i broj geolo{kih resursa severozapadne Rezime Srbije vezan za grani~ne razlome u obodnim de- lovima Jadarskog blok terana. Time ne samo da su O prostornom razme{taju geolo{kih sagledane prostorne zakonitosti u pogledu razme- resursa u severozapadnoj Srbiji (Jadar {taja geolo{kih resursa (termalne i termominer- blok teran) i wihov odnos sa tektonskim alne vode i metali~ne sirovine) i mati~nih stena strukturama za naftu, ve} su istovremeno i stvorene mogu}no- sti za otkrivawe novih sirovinskih potencijala. Jadarski teran oivi~en je dubinskim razlomnim Tu se prevashodno misli na slede}e: zonama i tektonskim melan`ima za koje je vezan Ekonomski zna~ajne koncentracije ugqovodonika raznovrstan spektar geolo{kih rasursa: geoter- mogu}e je o~ekivati samo u dubokim depresijama sa malne i termomineralne vode, metali~ne sirovine impermeabilnim pokrovima i sa fluidno provod- (Pb-Zn, As, Au, Cu i Sb), stene sa mati~nim svoj- nim dubinskim grani~nim razlomima. Takve poten- stvima za naftu i epicentri dogo|enih zemqotre- cijale mogla bi predstavqati Ka~erska depresija i sa (sl. 1). Tektonske strukture – dubinski razlomi neogeni baseni Kolubare, Ma~ve i Semberije. i tektonski melan`i u ju`noj polovini Jadarske Hidrotermalna nalazi{ta u Ma~vi i Posavo- tektonostratigrafske jedinice jasno su geolo{ki tamnavi su najzna~ajnija u ju`nom delu Panonskog izra`ene i znatnim delom dostupne direktnim te- basena. Me|utim, prema na{em modelu ne samo da renskim promatrawima. Me|utim, u severnoj polo- se postoje}e rezerve mogu bitno uve}ati ve}, idu}i vini ove jedinice grani~ni razlomi su pokriveni ka grani~nim razlomima, treba o~ekivati i termo- debelim neogenim naslagama, pa su oni izvu~eni na mineralnu vodu, a u odre|enim tektonskim struk- osnovu rezultata bu{ewa. Tako bu{otine sa akvi- turama u le`i{tima nafte.