GEOLOGIJA 46/1, 75–81, Ljubljana 2003 doi:10.5474/geologija.2003.005

Lithostratigraphic column between and including highlights of the area characteristics (Southeastern & )

Mirza BA[AGI]1& Safet ^I^I]2

1 Mirza Ba{agi}, Faculty of Civil Engineering, University of – Geology Institute, S. Tomi}a 3, Sarajevo. 2 Safet ^i~i}, Earth Science Institute, Patriotske lige 30, Sarajevo. Keywords: litofacies, carbonated platform, structure, karst process

Abstract

The area between Nevesinje and Ljubinje in Eastern Herzegovina is a part the Dinaric massif, where Mesozoic carbonated platform is almost completely preserved. There are also Palaeogene sediments in the area structure, but they are considerably less preserved. However, they are an extraordinary indicator of the more important structures within and a solid base for reconstruction of tectonic occurrences during Neogene and Quaternary. The purpose of this paper is to provide more information on lithofacies and tectonic terrain structures, including particular karst characteristics. Causes for occurrence and possible development of karst process are issues that are also pointed out (considering the thickness of the carbonated sediments), as well as the directions and development volume of the process.

GEOGRAPHICAL POSITION GEOLOGICAL STRUCTURE

The studied area is located in Eastern Geologicaly part of Eastern Herzegovina Herzegovina, between Crvanj Mountain in consists of Mesozoic and Cenozoic struc- the north and in the south. tures. Previonsly explored rock massifs are This is the area with high mountains, pla- the product of sediment deposition. Con- teaus and karst fields. It is surrounded by tinual sedimentation lasted in this part of high mountains: Crvanj (highest point 1927 Tethys during Mesozoic, while in the Ceno- m) and Gata~ka Bjela{nica (highest point zoic, before the complete withdrawal of 1807 m) in the northeast; Vidu{a (highest the sea, there were some relatively short point 1419 m) in the east, and Vele‘ (highest periods of land and lacustrine environ- point 1969 m) and Snje‘nica in the west. ment. is in the south, with particular geomorphology and karst characteristics. The area encompasses approximately 1500 MESOZOIC (Mz) km2. Significant settlements are Nevesinje and Ljubinje. They are connected relatively During Mesozoic era, sedimentation con- well, by partly asphalt roads with , tinued through Triassic, Jurassic and Creta- and . ceous. 76 Mirza Ba{agi} & Safet ^i~i}

cherts and tuffa of the Ladinian stage (up- per middle Triassic stage). Thickness of the Anisian carbonate sediment is approxima- tely 250 m, and of discovered part of Ladini- an in anticline around 50 m.

Upper Triassic sediments (T3) are found on the western slopes of Crvanj mountain (Zimomor) and by Mo~ila. It is developed as bedded dolomite facies and its thickness be- ing up to 800 m. There are massive and thick bedded dolomites in the Zalomka anticline, that are mostly mixed with dolomite micri- tes and micrites, with rare occurrences of Megalodones. The thickness of this member is up to 400 m.

Jurassic sediments (J)

Liassic sediments (J1 – Lower Jurassic) are best represented in Duboki and streams, Zalomka river right tributaries. They consist of sheet and bedded limestone, mostly of allochemomicrite type. Cherts are frequent and dolomites are there, but rarely. The characteristic microfossil is Involutina liassica, especially for lower and middle Li- assic sediment. Vidalina martana occurs in the whole pillar transiting into Dogger (mid- dle Jurassic stage). There is an abundant Ammonites fauna within middle Liassic sta- ge (Domerian substage). The map of investigated area Liassic – Dogger sediments (J1,2 – Lower to Middle Jurrasic) consists of calcarenites and oolytic limestone, with rare occurrences of dolomites and chert nodules. Stephanoce- Triassic sediments (T) ras sp. is found here. There are also bedded There are three forms of Triassic sedi- biomicrites of Lower Dogger age. Characte- ments: ristic Dogger type is found in the upmost

Lower Triassic sediments (T1) are found parts of Dogger: Protopeneroplis striata. in the crest of Crvanj mountain range. Seis Thickness of Dogger in this part varies from Substage consists of sandstones and sandy 60 up to 300 m. limestone with interlayers of clay and marl- Upper Jurassic sediments (J3) are repre- stones where the following fossils are found: sented by light gray and bedded limestone Anodontophora fassaensis, Claraia claraia i with Nerineas. The following are found: Pti- Claraia aurita. These sediments are appro- gnatis carpathica, P. pseudobruntruntana ximately 200 m thick. Campil substage con- and Clypeina jurassica. Limestone thickness sists of marlstones, sandstones and limesto- of the Upper Jurassic sediments (including ne, with average thickness of 100 – 200 m. nerineas) is around 300 m. There are the following fossils found: Myop- horia costata, Turbo rectecostatus etc. Cretaceous sediments (K)

Middle Triassic sediments (T2) are repre- Lower Cretaceous sediments (K1) are fo- sented within both forms. Anisian (lower und in the syncline of Vele‘ mountain, the middle Triassic stage) is represented by gray southwestern part of Nevesinjsko polje, and and reddish limestone and dolomites, in the in Podvele‘je, from Hum (highest point 1025 western slopes of Crvanj mountain. Gradu- m) all the way behind Kokorina. It consists ally, they turn to sheet deposits of limestone, of two structures: Lithostratigraphic column between Nevesinje and Ljubinje including highlights ... 77

1 Older K1 structure, discovered in Luka- terrain, there are usually two levels: a) lo- 1,2 vica and Bjela{nica, consists of different wer parts (K2 ) consisting of well layered types of limestone with dolomites and dolo- organic – detrital, micro and cryptocristali- mite limestone. It is characterized by fine ne limestone and b) higher parts (K2,3) re- deposits of dark gray and brawn layers. The- presented by well layered various limesto- re are found: Campbelliella milesi, Tintine- ne that become massive in their final parts. psella lata, and Dascycladaceae: Clypeina The thickness of these carbonates is around jurassica, Pianella anmelata etc. The thic- 500 m. kness of the carbonate is around 300 m. 2 Younger K1 structure of the Lower Cre- taceous age takes up more terrain in the CENOZOIC (Kz) northwestern part of Nevesinjsko polje and southern parts of Vele‘. It comes up in the The sediments of Paleogene, Neogene and narrow parts of right bank of , on Quaternary belong to this era. the slopes of Hrgud. The most frequent structures are microsparites and limestone Paleogene (Pc) with paleodont shells, and in upper parts, Paleogene sediments are in the southwest layered dolomites and dolomite limestone of Nevesinjsko Polje (Biograd, Magunica, are noticeable. The thickness of this structu- ), northwest of Dabarsko Polje and re is 300 – 400 m. west of Ljubinje. There are four Paleogene representatives in this area:

Upper Cretaceous sediments (K2): These 1. Liburnian sediments (Pc, E) are repre- sediments have the most important part in sented by brown and dark gray deposited the terrain structure. They are characterized limestone. Limestone is often bituminous. by facies changes, vertical and side ones. They are discordant to Senonian carbonates Carbonated sediments of Upper Cretaceous and/or other representatives of Upper Cre- sediments, thick over 2500 m, are divided taceous sediments. Downthrown contact is into more stratigraphic units: characterized by the occurrence of bauxite.

1. Alb – Cenomanian (K1,2) sediments, bet- Their thickness is from a few up to 250 m. ween lower and upper Cretaceous age, are 2. Alveolina – nummulite limestone (E1,2) around Popovo Polje. They are developed in are concordant on top of Liburnian sedi- the dolomite and dolomite limestone facies. ments. These are light gray to white, laye- The thickness of these carbonates in this red, occasionally massive and compact lime- part of the terrain is around 400 m. stone. Their thickness varies from 100 – 1,2 2. Cenomanian – Turonian (K2 ) sedi- 200 m. ments are in the area of Snje‘nica, in the 3. Eocen flysch (E2,3) is located in the area Bregava canyon, area of Hrgud and Tre{ta- of Dabrica, Dabri~ko and Lukava~ko Polje. nica and outskirts of Dabarsko Polje. Lime- On the top of the older Cretaceous and Pa- stone and dolomites with chrondodite and leogene limestone there are conglomerates, rudites are on the top of Alb – Cenomanian brecciated limestone and large grain sand- carbonates, with gradual transition. The stone, that are thick up to few tens of me- thickness of these sediments is around ters. There is also bauxite on the downt- 500 m. hrown contact. Bauxites are of the economic 2,3 3. Turonian – Senonian (K2 ) sediments significance in the area of Dabrica. The thic- are around Hrgud, Udre‘nje and Snje‘nica. kness of flysch varies from 50 to 200 m.

They are concordantly laid on top of chron- 4. Promina conglomerates (E3, Ol1) are in dodite carbonates in the thick structure of the area of Nevesinjsko and Dabarsko Polje. layered limestone, of white and light gray They are lying concordantly on the older color. Their thickness is around 450 m. flysch. Conglomerates have the characteri- 3 4. Senonian (K2 ) carbonated sediments stics of molasses and synorogenic deposit are located south of Lukavi~ko and - that would be in accordance with Pyrenean sko Polje, and take up more terrain in the tectogenesis. On this basis, the Upper Eocen surroundings of Ljubinje. They are layered and Lower Eocen age of this thick (some on the Turonian sediments, with gradual places even up to 800 m) carbonated com- transition. In the Senonian stage of this plex has been determined. 78 Mirza Ba{agi} & Safet ^i~i}

GEOLOGICAL MAP BETWEEN NEVESINJSKO AND LJUBINJE POLJE – EASTERN HERZEGOVINA

Quaternary: alluvial, proluvial, and colluvial deposits Upper Miocene: clay, sandstone, lignite, marl and limestone Paleocene-Eocene: Liburnian limestone, flych and Promina conglomerate Upper Cretaceous (Senonian): limestone and marl Upper Cretaceous (Turonian): limestone, marl and dolomite Upper Cretaceous (Cenomanian-Turonian): limestone and dolomite Upper Cretaceous (inseparabled): limestone, dolomite and marl Lower Cretaceus (Barremian-Aptian): limestone, dolomite, marl Lower Cretaceous: limestone, dolomite, breccia Lower Cretaceous (inseparabled): limestone, dolomite, marl Upper Jurassic (inseperabled): limestone, dolomite, dolomite limestone Lower to Middle Jurassic: limestone, interbedded dolomite, chert and sandstone Upper Triassic: limestone and dolomite

Front of overthrust

Reverse and normal ---faults Lithostratigraphic column between Nevesinje and Ljubinje including highlights ... 79

Neogene (Ng) Palaeogene sediments, and various folded This is where lake sediments of Nevesinj- structures. sko Polje are. Limnic series starts with basal Within Outer Dinarides, in the High Karst conglomerates with interlayers of clay. Fol- Overthrust area there are larger structures lowing are the marls with three layers of of facies: coal, 60 cm, 4 m and 1 m thick. The total • Syncline structure of Vele‘ Mountain thickness of marly hanging wall with layers where there are carbonates of lower cretace- of coal is 80 – 100 m. They are probably of ous sediments, and the bottom is consisted Miocene age, synchronic with upper Mioce- of Upper Cretaceous and Palaeogene sedi- ne sediments in in the east and Mo- ments. star valley in the west. • Isoclinally folded complex Biograd – Snje‘nica – Hrgud, that encompasses the ter- Quaternary (Q) rain between Nevesinjsko and Dabarsko Po- These are the youngest sediments in Ne- lje, and vesinjsko Polje and in other parts of this • Tectonic unit Vidu{a – Bjela{nica, that area. They are represented by Moraine struc- is of a very complicated form. There are tures (slopes of Vele‘ Mountain), limnogla- structures of Upper and Lower Cretaceous cial sediments (Piska~i), proluvial and allu- sediments, then carbonates and clastics of vial covers that are larger in the valley of Paleogene in its lithofacies content. (Pc, E). Zalomka River, and swamp sediments in the In-depth built of this terrain is consisted fields, and, finally, talus structures in the of a few large blocks that are divided by outskirts of fields. deep reverse faults. Along them are Cretace- ous carbonates over the Eocen flysch and/or Promina conglomerates. There are parts of TECTONICS anticlines of Lastva and Sitnica in southe- astern part, syncline of @ukovica – Gradina, From the structural-tectonics point of Budo{i – Mosko (northwestern part) and Pu- view, the area belongs mostly to the tectonic stipuhe – Ljubinje. West of Ljubinje is isola- unit of Outer Dinarides, namely the High ted unit of Hrasno. Karst Overthrust. In the northern part it goes into Middle Dinarides, the zone of Pa- leozoic slate and Mesozoic limestone. How- ever, the area completely belongs to tectonic KARST CHARACTERISTICS category of Dinarides that, in the territory of , have the form of Morphology and the surface appearance total fold, with characteristics of mega- of the studied area have typical karst char- overhrust, folded and moved towards north- acteristics. High mountain reefs dominate in east. This is the paradigmatic consequence the area (above 1500 m). Mountain ranges of the Earth crust dynamics, showed in the are characterized by dominant tectonic (Di- Alpide orogenic cycle, due to the collision narides) lines. They consist of carbonate la- and underthrust of African plate under the yers and are marked by bilaterally laid high Euro-Asian continent. and steep escarpments towards lower val- Middle Dinarides encompass large struc- leys or fields. tural unit in this area, namely: Karst plateaus are formed between mo- • Anticline Crvanj, and untain reefs. They are very characteristic • Anticline of Zalomska river geomorphologic element for this area. They Between these two anticlines and Neve- are formed in the tectonically predisposed sinjsko Polje is the border between Outer terrains, and shaped by the processes of cor- and Middle Dinarides. In the northwest, rosion and erosion of the karst, effects of the border goes towards Veliko Ruji{te (k. other exogenetic factors, among which the 1765 m), where over Porim i Prigradac it river erosion and lake abrasion possibly ha- goes down to riverbed. In the so- ve played the major role. South of Nevesinj- utheast, the border between these two me- sko Polje, characteristic morphostructures ga-structures is characterized by reverse are structurally erosive plateau Biograd – faults with overthrust of Cretaceous onto Udre‘nje, then Trusina (without mountain 80 Mirza Ba{agi} & Safet ^i~i} reef), and parts of Hrgud and Sitnica, where • Outflow of water from these fields is we can find destructed karst plateaus. exclusively underground, which makes them Karst fields are paleodepressions betwe- closed karst fields. en high mountain massifs, or morphostruc- Of all karst forms, we often see karst val- tures of sinking in the areas of longitudinal leys, wide 0,5 – 1,0 km. They are smaller faults of regional importance. The attached than karst fields and larger than sinkholes. geological map shows three larger karst fi- Dry karst river valleys are extraordinarily elds: characteristic form in this karst. They are • Nevesinjsko Polje encompasses the area especially well developed in the valleys of of 190 km2. It belongs to the category of the Bregava and Zalomka rivers. largest karst fields in Eastern Herzegovina. Among karst micro-forms in this area, It is located in the area of reverse faults, there are: lapies, gorges, sinkholes, natural between the highest mountains in the regi- ceilings, holes, caves etc. developed depen- on: Vele‘ (Botin, 1969 m) and Crvanj (Zimo- ding on the lythofacies content, structure mor, 1921 m). The height of the field bottom and influence of the other, mainly exogene- ranges from 800 – 850 m. tic factors. • Dabarsko Polje is located in the zone of Hydrographical network of this area has deep faults, on the northwest – southeast all the characteristics of the “developed line. It is formed between Snje‘nica and Tru- karst”. It id underdeveloped and it has net- sina mountains that form its southeastern worked, dendritic look. outskirt, and Hrgud and Sitnica mountains, The major streaus in the area are Bregava in the southwest. It is around 20 km long and Zalomka. Both are tributaries to Neret- around and wide 3 km the most. It encom- va River. Bregava is above ground flowing passes the area of around 40 km2. into Nereretva near ^apljina, while Zalom- • Ljubinjsko Polje is the smallest of these ka is an underground tributary (Vrelo Bu- three fields. It encompasses the area of only ne). Aside from those, more important (shor- 9 km2. It is located in the area of reverse ter) karst river flows are Du{ila in fault that formed the overthrust of the Up- Nevesinjsko Polje, Opa~ica and Vrijeka in per Cretaceous sediments on the Paleogene Dabarsko Polje and Bukov potok in Lju- and Lower Cretaceous sediments. The bot- binjsko Polje. They have formed their own tom of the field is on the 400 – 410 m. underground paths, directed towards Neret- Common characteristics of these fields va or Bregava, and partly towards Trebi{- are: njica. • They are stairs-like, from north to so- River flows are mainly occasional. Only uth; Vrijeka River in Dabarsko Polje is a perma- • The height difference between Nevesinj- nent river flow. Bregava and Zalomka are a sko and Dabarsko Polje is almost 500 m, and combination of permanent and occasional between Dabarsko Polje and Lubinje 70 – flow. They dry when they get to larger abys- 80 m; ses or in the extraordinary dry periods. • They are formed during tectogenetic The characteristics of this area are wells processes in the area of regional faults of and springs in the outskirts of crast field Dinarides range; and in the river valleys. Their capacity vari- • They are modeled by the effect of exo- es in the wide range, depending on the in- genetic factors, where phases of lakes and tensity of rainfall. The extreme examples fluvial erosion, alongside with dominant and are the springs of Bregava that have the long term karst processes, had the most im- minimum of 2 m3/s, and maximum over 1000 portant role; m3/s. • On the northern outskirts are springs and wells, and on the south side are abysses, where sometimes the streams are formed CONCLUSION with oscillations in the flow; • Fields are flooded periodically, while in Karstification process in the Eastern Her- Nevesinjsko Polje, the water accumulations zegovina, aside from the one on the surface, are formed in the northern and southern is going on in the deep parts of carbonate part; complex. According to the karst forms and Lithostratigraphic column between Nevesinje and Ljubinje including highlights ... 81 occurrences, the process is developed in the ^i~i}, S., 2002: Geolo{ki sastav i tektonika Bosne i Hrecegovine. 1–350, Earth Science Insti- depths from – 200 up to + 1900 m. Carbonate tute, Sarajevo. massive – platform in this area is over ^i~i}, S., 2002: Geolo{ka karta Bosne i Her- 5.000 m thick. Aside from that, tectogenetic cegovine, R 1:300.000, Earth Science Institute, Sa- processes of folding, faulting and horizontal rajevo. Gakovi}, M., 1986: Stratigrafija lijasa Za- movements have brought to the smaller lomke i Gacka u Hercegovini kao osnova biostra- blocks of measured in km. We should bear in tigrafske podele donje jure u Dinaridima. 1–143, mind the significant increase in carbonate Geol. gl., Posebna izdanja, knj. XXI, Sarajevo. Katzer, F., 1921: Die Fossilen Kohlen Bosni- sediment thickness in the overhrust area. ens und der Herzegovina. Zweite Band, 1–271, This makes the possibility of exact determi- Sarajevo. nation of status and future development of Moji~evi}, M., Tomi}, B., Dimitrov, P. & An- drija{evi}, M. 1973: Dubinski geolo{ki profil kroz the whole karst process even more compli- Dinaride (od Cavtata do Fru{ke gore). Geol. gl., cated. However, it is certain that this pro- 61–106, Sarajevo. cess is strong (longitudinal, and in depth), Moji~evi}, M. & Lau{evi}, M. 1973: Osnovna geolo{ka karta 1:100000, Tuma~ lista NEVESI- that is has been repeated (with different in- NJE, Savezni geolo{ki zavod, Beograd. tensity), but it is permanent, and it is shown Moji~evi}, M., 1975: Geolo{ki sastav i tekton- as typical “Dinaric karst”. ski odnosi terena izme|u Sarajeva i Nevesinja, –138, Geol. gl., Posebna izdanja, knj. XIV, Sarajevo. Moji~evi}, M. & Tomi}, B. 1982: Osnovna geolo{ka karta 1:100000, Tuma~ lista KALINO- References VIK, Institut za geolo{ka istra‘ivanja (1981.), Sa- vezni geolo{ki zavod, Beograd. 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