Field trip to the Dinarides, Serbia

August 23rd to 29th 2013

The first excursion day, Saturday August 24th

The summer field trip to Serbia began as we met up in the Hotel Royal in central Belgrade on the afternoon of Friday 23rd of August.

Following our arrival, the group became acquainted (or re-acquainted, as the case may be) over some beers in the hotel bar before heading out with Anta who showed us the area around the hotel before bringing us to a nearby restaurant where we had our first taste of Serbian food: delicious, but very rich and with a heavy emphasis on grilled meats. Not a place for vegetarians!

Our field trip began in earnest the next morning as we met up with our guide, Professor Nenad Banjac from the University of Belgrade. As soon as everybody was present on the minibus at around 9 am we headed out from Belgrade to make our way towards the Dinarides in the western part of the country.

flysch near Ljig
Ljig Flysch

Our first stop was near the village of Moravel, where we observed an outcrop of bivalve-rich Urgonian limestone dating from the lower Cretaceous. It was explained that this was part of a big block of the flysch associated with the closure of the Tethys Ocean. The Professor explained to us that the area at the time consisted of shallow seas and isolated islands - an interesting result of which were the dwarf dinosaurs of Romania (sadly, no dinosaurs – dwarf or otherwise – were spotted on this field trip).

Our group leaders also took time at this point to go over the area's quite complicated geological setting and explained that the ophiolite here is the largest in continental Europe.

After being given time to examine the outcrop and take a few photos, the group then made its way back to the minibus and we continued on to our next stop, the Ljig Flysch. The rocks there are Santonian to Maastrichtian in age, and the formation represents proximal sedimentation. Interesting features such as Bouma sequences and micro-conglomerates are present as infill channels. Flute marks were used to show us the flow direction, and bioturbation was also present, giving us another method to determine which way was up. Overall it was a great place to see textbook examples in real life, though unfortunately the outcrop was on the edge of a busy road so we had to take extra care not to get hit by oncoming traffic as we examined it. Luckily everyone in the group survived this stop.

Struganik Quarry
Struganik Quarry

The next stop then was at Struganik Quarry.

Here the rocks date from the Maastrichtian to the Palaeogene and represent one of the most tectonically complex areas due to its proximity to a contact between different blocks.

The limestone beds in the quarry itself are almost horizontal with only a small slope of a few degrees, and they represent a deep marine environment deposited on a continental slope. The presence of pyroclastic material in certain layers indicates periods of volcanic activity in the zone.

Cast of a Paleodictyon
Cast of a Paleodictyon

Here the rocks date from the Maastrichtian to the Palaeogene and represent one of the most tectonically complex areas due to its proximity to a contact between different blocks.

The limestone beds in the quarry itself are almost horizontal with only a small slope of a few degrees, and they represent a deep marine environment deposited on a continental slope. The presence of pyroclastic material in certain layers indicates periods of volcanic activity in the zone.

Other geological features such as neptunian dykes and styolites were also present here, again giving excellent textbook examples in real life.

trace fossils
Traces of burrows

The stop was also the closest the group came to identifying anything dinosaur-related, with a possible footprint identified at the base of the quarry – however, the lack of accompanying prints and the badly eroded nature of the depression meant we could not identify it with any certainty and thus the trip would officially remain a dinosaur-free expedition.

Once everyone got back on the minibus we then headed off to the Petnica Science Centre, our final stop before lunch. The Petnica Science Centre is a non-governmental educational institution where young students who show advanced interest or ability in science can go to take more in-depth courses and further their education. Our group visited their library and we were given an interesting talk about what the institution does, and we were given an opportunity to ask questions.

sculptures in a cave near Petnica
Sculptures in the cave

Upon leaving the centre we made our way on foot down to a nearby cave.

The cave itself formed as a fault line allowed water in and karstified the limestone, and it is somewhat famous in the area as reputedly being a vampire lair. Faces were sculpted into its walls, adding to the cave's charm.

cave near Petnica
Cave beside the restaurant

The restaurant where we had lunch was located just at the entrance, and the cave's cooler air was a welcome relief from the rather hot weather we had experienced so far.

Once we had finished our lunch we set back out for the minibus and on to our final stop of the day. This was at Maljen-Divzibare, where massive ophiolites and ophiolite mélange were exposed at the side of road – thankfully not nearly as busy as the one at stop 2.

serpentinite
Serpentinite

We were able to observe serpentine and peridotite and had a discussion about the difference between the two.

The outcrop was a mélange and thus featured different lithologies, including pillow lavas.

The emplacement of the mélange dated from the Mid to Upper-Jurassic. The ophiolite formed by obduction onto the continental crust when the ocean was closed by southeastward subduction.

The final stop on our first day was thus concluded just as rain was starting to fall (this was to become a theme throughout the trip), and we then made our way to our hotel for the night. There we enjoyed yet another large and delicious Serbian dinner, and our group grew even larger as additional members joined up with us.

Emmanuel Kavanagh

rudist
Rudist bivalves at the Titan quarry

Sunday, 25th August

A visit was arranged to the Titan cement works, one of many locations exploiting Cretaceous deposits in Serbia. We were unable to go inside the massive quarry on safety reasons, but were met outside the perimeter fence by a senior employee, a friend of Nenad.

The quarry produces 500,000 tonnes of limestone per year from an Upper Cretaceous limestone reef, which contains mudstones and marl lenses. A selection of fossils taken from the quarry was available for us to examine, which included good large specimens of rudist bivalves, brachiopods and corals.

ductile deformation
Multiphase deformation in Carboniferous deposits near Kosjeric

Our next stop was to look at Drina Palaeozoic schists near Tmusa where a single complex represents these formations. Quartzitic sandstone is the dominant rock type, and it alternates with slates and lenses of crystalline limestone. The whole complex has been metamorphosed to greenschist facies. The outcrop we examined is Carboniferous in age based on micro-organisms, but lower parts of the complex have been dated as Cambrian to Lower Ordovician. In the outcrop, we could see the results of three phases of ductile deformation in multiphase folds. The oldest phase is Variscan, which can be seen in thin section only. The second phase is refolding of these early folds. The final phase is interpreted as resulting from a Miocene granite intrusion.

church of Saint George at Seča Reka
The wooded church of Saint George

A stop at the church at Seca Reka was an interesting break from the rocks of the Kosjeric area. The wooden church of St George was first built in the 15th century. Its present appearance is from 1812, during the time of the first Serbian uprising against the Ottoman Turks.

The resident priest gave us a short talk on the history and use of the church which has a number of monuments around its wall that were erected in memory of local soldiers who died in the Balkan Wars in 1912-13.

Roadside exposure of the Palaeozoic Kovilje conglomerates
Roadside exposure of the Palaeozoic Kovilje conglomerates

A tricky roadside stop followed to view the Kovilje conglomerates which represent locally extensive Palaeozoic rocks seen at outcrop at several places. These sandstones contain well-rounded pebbles of sandstone and schist. The whole series is metamorphosed into a gneiss with lenses or strips of quartz and muscovite that are folded.

Another roadside outcrop followed near the Slivoviza River, where a boundary between Triassic limestone and Jurassic peridotite, lherzolite and harzburgite can be seen.

This ophiolite has been dated at 160 Ma., and is thought to part of the closure of an ocean. There is an argument amongst geologist that there is evidence for the existence and closure of three oceans. More evidence needs to be collected for a conclusive model to be established.

Closer view of the Kovilje conglomerates
Closer view of the Kovilje conglomerates
peridotites at the Slivoviza River
The peridotites at the Slivoviza River
near the source of the river Vrelo
Explorers upstream in the River Vrelo

We drove through a mountainous Mokra Gora National Park with great scenery including views of Bosnia across the River Drina. We stopped for a late lunch near the River Vrelo, which at 365 metres long is one of the shortest rivers in the world. Brave members of the group explored the source of this river and returned to tell their stories.

We then went to the hotel for the night at Mokra Gora village. Nenad had arranged a visit to see modern culture at the Drvengrad complex, a cultural-tourist built by the Serbian film director Emir Kusturica. The hotel for the night was located in the local railway station which now forms part of the tourist attraction.

Cretaceous transgression at the Tusto brdo outcrop
The beginning of the Cretaceous transgression at the Tusto brdo outcrop

Monday, 26th August

The Tusto brdo outcrop near Mokra Gora was the first stop of the day, where easily accessible roadside exposures record the beginning of a large-scale transgression in Albian and Cenomonian periods. Parasequences containing sandstone and limestone were seen with some graptolites and syn-sedimentary structures.

bear hunters' hut on Zlatibor Mountain
A hunters’ refuge near the place of the impromptu lecture. No bears here today

Our next stop was high up on Zlatibor Mountain in the Sargan-Mokra Gora Nature Park which had extensive wooded views and a car park, where the group was given a high level presentation on the competing theories currently being considered for the evolution of the western Serbia. It was given by our attending PhD student who outlined the research she was doing at a Swiss university.

In summary there are two theories, one of which involves the existence and closure of three oceans based on a study of ophiolites, all of which are older than the Upper Cretaceous; the other invokes two subduction zones with Cenozoic deformation and strike-slip movement to the north east.

The talk was very interesting and detailed but there is much work to be done if the true evolution of the Dinarides is to be known.

A stop at Stopica Cave was next, on the northeastern side of Zlatibor Mountain, which was formed in Triassic limestone more than 100 metres thick.

Although the cave has 5 levels, only one is open to visitors and has several features such as the large opening, openings in the ceiling and pools and basins. The Trnava stream flows through the cave to fill the pools.

Klisura quarry
View of the Klisura quarry, where Red Siogojno is removed.
Red Siogojno
Details in the Red Siogojno after wetting

A stop at Klisura quarry was next; here, fossiliferous red limestone of Middle Triassic age are removed in blocks which are sawn out by wire cutting. The rock, known as ‘Red Sirogojno’ is used for architectural purposes as it contains ammonites and other molluscs. The quarry was not working but many blocks could be seen. Wetting the smooth faces of the blocks brought out the decorative structures and fossils.

Nenad had reserved a late lunch for us at the Restoran Zavicaj, where we had many courses of traditional Serbian food. Afterwards we walked to the Old Village of Sirogojno, which is an open-air museum that presents the cultural heritage of the region with traditional buildings and facilities depicting the way of life in earlier times.

Phillip Robinson, OUGS Yorkshire branch

Olistholite within a melange
Olistholite within a melange (basalt and chert) on a rainy day

Tuesday, 27 August

On this day, as we left the Hotel Panorama, it was wet, so all our field stops were taken as views from the bus. It became a travelling day as we headed back to Belgrad with some tourist stops en route.

We had stayed near Nova Varos in the southern part of Serbian Alps, the furthest south we would travel on our trip. This area, including adjacent regions in Montenegro and Bosnia, is a Muslim enclave but also has many Orthodox Christian Churches.

Our first roadside stop was to view a limestone olistolith of Triassic age which displayed all the elements of reef limestone. It is the largest olistolith in Serbia being several hundred of metres long and is interpreted as having slumped into the ocean trench.

Our next and final roadside stop was to view bedded limestones that were deformed into tight folds. The outcrop changed into massive cherts and diabase volcanics all of which were deposited into the ocean trench.

Mileseva Monastery
Mileseva Monastery

Out first tourist stop of the day: The high point in this region is Mt Zlatar and on it’s slopes is the Monastery of Mileseva. Founded in 1234, it is dedicated to St Sava. Although the church has suffered damage over the years, the 13th century frescos are now preserved and free to view. Most famous is the White Angel, which appears as an emblem in many places in the region and has also been adopted as an emblem by the United Nations. The frescos are simply amazing considering their age and give a flavour of how highly decorated the interiors of churches must have been at the time.

engine at a railway museum
Where does this little train head to?

As we headed north, the Professor took us to see a Railway Museum where some of the preserved engines had been used by the Royal Family. In addition to the engines, there was a replica ticket office, restored to 1940’s. The Professor found a kindred spirit in at least one of our members who discussed technical details about the engines on display with great enthusiasm.

Wednesday, 28 August

On our final day with the Professor, he treated us to another day with a mix of (a little) geology and some sightseeing.

We saw the previous headquarter of the Army which had been bombed in 1999 by the UN, when Kosovo was struggling for independence from Serbia. To date the damage has not been repaired. (This was the only example we saw of any war damage.) We also saw several of the international embassies including the American and the French. The previous USA embassy was a building with windows entirely shuttered with a barricaded access road. The new one on the outskirts of town is behind high walls and was completely inaccessible from the road.

We stopped to visit St Sava’s Cathedral. This a huge, newly constructed building in the centre of Belgrad that dominates the skyline of the city. It is the largest Orthodox church in the world and one of the ten largest churches of any denomination. It is clad in white marble and granite but the interior murals are not yet finished. It can accommodate up to 10,000 believers at one time.

outdoor theatre in an abandoned quarry
Theatre quarry

We visited an abandoned outdoor theatre, sited in an old quarry. This was our geology for the day. The outcrops visible were deposited during a huge transgressive event in Albian times. Oolites the size of peas could be seen – pisaliths.

We also viewed Urgonian limestone with slickensides and fault brecchia.

Returning to sightseeing, we visited 2 memorials. The first, in Belgrad, was to 1st World War German soldiers. The German nation purchased a small area of land to erect this, so that the memorial could be placed on German soil.

View over the Danube
View over the Danube from the Citadel

Driving slightly out of town to Avala, a hilltop park overlooking the city, we climbed up the steps to enjoy the view from the top of the Monument to the Unknown Soldier.

Returning to the centre of Belgrad, we walked around the Citadel. This is a huge public space sited within the old fortifications of the city, overlooking the River Sava near its confluence with the Danube. We were told that a small house opposite the Citadel was where the final talks had broken down the evening before WW1 was declared.

 

Jane Hiscott, OUGS Severnside Branch (Branch Organiser)

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