edinstvene najdbe otolitov v šentjerneju

Cases from Slovenia

Is it Always Possible to Preserve Geological Natural Heritage?

In many places it is hard, impossible or even irrational to protect the geological natural heritage. Such cases, which could not be protected due to many different factors, are very frequent, also in Slovenia. In the paper two of them from the field of palaeontology are presented.

Figure 1.  Locations of represented fossil gastropods.
1- Soteska near Moravce, location of Melongena semseyiana; 2 - locations of Pereiraea gervaisi in surrounding of Šentjernej in Lower Carniola.

At the end of 18th century, as in most countries in Europe it was a high mining activity in Slovenia. They were searching for different ores, above all energetics as oil, gas and coal. At that time a coal research shaft was sunk by Soteska near Moravce (Fig. 1). In Egerian-Eggenburgian (Upper Oligocene - Lower Miocene) beds coal was found, but the beds was too thin for exploitation and the shaft was abandoned. During sinking a rich micro and macrofauna was discovered. Among macrofauna recordings are the very interesting and relatively large and rich ornamented gastropod Melongena semseyiana (Erdös, 1900) (Fig. 2a-b). Specimens of gastropod M. semseyiana are very rare and could be found only in the Paratethys: in Hungary, Croatia and Slovenia (Fig. 3). The material which was dug out of the shaft was deposited into a nearby mine dam where it is still possible to find specimens of M. semseyiana. Today the specimens can be found only in the secondary place. The primary location is left in the depth of the shaft which has been filled in. Access to the natural beds with M. semseyiana is completely impossible. That is why the preservation of the primary location as well as the preservation of the mine dam, is impossible and unreasonable. In recent years both locations are overgrown by bushes and the nature protects them by itself.

Figure 2.  Melongena semseyiana (Erdös, 1900).a - dorsal side, natural size; b - the same specimen from upper side, natural size. Photo: M. Grm

The second case is from Lower Carniola. The hills on the southern end of Krško valley consist of Middle Miocene (Badenian) and sandy marls rich in different fossils. Among them are the most prominent and easily distinguishable gastropod Pereiraea gervaisi (Vézian, 1856) (Fig. 4a-b). The only known locality of P. gervaisi in Slovenia is in the vicinity of Šentjernej (Fig. 1). In Europe the localities with Pereiraea gervaisi are sparse, but they are found both in the Mediterranean Tethys (Spain, Portugal, Algeria, Italy, France?) and in Paratethys (Hungary, Croatia, Austria?) (Fig. 3). The uniqueness of P. gervaisi is seen in the different ornamentation of the last whorl, which is a rarity among gastropods, as well as the fact that in the Mediterranean Tethys it is only found in the Lower Miocene and in the Paratethys it was not expanded earlier than the Middle Miocene.

The landscape of the Pereiraea gervaisi locality is consisted by numerous private vineyards. About 20 years ago, when winegrowers prepared terrain for new vineyards they ploughed soil very deep. After rain the vineyards surfaces was full of pereiraeas and other fossils. The majority of pereiraeas shells were collected by fossil collectors, house owners, winegrowers and palaeontologists. Today only the fragments of shells can be found.

Figure 3. Geographical distribution of gastropods Melongena semseyiana (A - C) and Pereiraea gervaisi (1 - 9) in Europe and North Africa.
1-Spain, 2-Portugal, 3- Algeria, 4-Italy, 5-France(?), 6-Slovenia, 7-Croatia, 8-Hungary, 9-Austria(?); A-Hungary, B-Slovenia, C-Croatia.

The area near Šentjernej was protected by community act in 1992 and every collection of pereiraeas shells is forbidden. The problem is that the mentioned act was published in the community official gazette only and the majority of people is not even acquainted with it. At the same time some information tables should be set up in localities which would point up locals and visitors to this Slovenian palaeontological sight. A lot would be missed since the information desk is a project of the Regional Survey for Natural Heritage as late as in year 2000.

Figure 4. Pereiraea gervaisi (Vézian, 1856) from locality near Šentjernej in Lower Carniola.
 a - ventral side, natural size; b - the same specimens from upper side, natural size. Photo: M. Grm

Despite the protection act and warning boards the protection and preservation of the natural geologic heritage in Lower Carniola will not be effective, because of the unconsciousness of the citizens, the private land ownership and fieldwork in the vineyards. Hoeing, which can not be forbidden, results in continuously destroying of shells of rare fossil species. Like in the first case, the nature itself will provide the best preservation. The majority of known locations of P. gervaisi are now entirely cultivated and build up, which makes deliberate fossils destruction impossible. If someone wishes to obtain samples for research purposes, it is always possible to dig up adequate probes.

Vasja Mikuž & Aleksander Horvat
University of Ljubljana
Department of Geology
1000 Ljubljana, Aškerceva 2
Slovenia

Vsebina teh strani je last Občine Šentjernej ali podjetij oz. posameznikov, kjer je to navedeno.
Spletna stran je zaščitena kot avtorsko delo. Vse pravice so pridržane.

Prepovedano je kopiranje ali drugačno presnemavanje vsebine in njena javna

raba brez predhodnega pisnega dovoljenja nosilcev ekskluzivne pravice.

Copyrigh(c) 2003: Občina Šentjernej & Edvard Bogataj