RESULTS OF MONITORING RADIOACTIVITY IN UPPER BARAĆ CAVE
Report for 2017
Radiation Protection Unit
Head of Unit: dr.sc. Gordana Marović
Head of Affairs: dr.sc. Tomislav Bituh
Associates: Mak Avdić, mag. ing. kem. tehn., Jasminka Senčar, Marko Šoštarić, dipl.ing.
The testing conducted on the site of the cave structure of Barać Caves, in Upper Barać Cave in 2017, showed the presence of elevated concentrations of radon activity, and thus also the expected measurement results for ionising radiation. The values of concentration of radon activity are within the parameters recorded for other caves in Croatia and worldwide, and in such amounts do not pose a hazard to the health of employees and visitors. The discovered seasonal fluctuations of radon concentrations are commonplace due to the environmental conditions in the cave and outside it. For a more detailed analysis and a more reliable assessment of the exposure of cave employees, more frequent measurements on several locations in the cave would be necessary. The exposure of people and locations to ionising radiation should, in the near future, be incorporated in the new ordinance on monitoring radioactivity in the environment, and it will demand the systematic monitoring of sites such as Barać Caves.
MICROCLIMATIC FEATURES OF BARAĆ CAVES IN THE PERIOD 2014-2016
Report drafted by:
Izv.prof.dr.sc. Neven Bočić
Izv.prof.dr.sc. Nenad Buzjak
CONCLUSION AND RECOMMENDATIONS
After the completion of research, and on the basis of available data, the following conclusions can be made:
– the average air temperature at the measuring stations in Upper Barać Cave and Lower Barać Cave is as follows:
– the average measured relative humidity at the measuring stations in Upper Barać Cave and Lower Barać Cave is almost 100% (rounded to two decimal places);
– the stated average values and the air temperature and relative humidity curve indicate that these are typical cave conditions with, generally speaking, slight oscillations that largely depend on seasonal variations in external values, and less on diurnal variations;
– certain specificities in relation to the values of internal and external air temperatures have been discovered and merit further research.
On the basis of the presented data and conclusions, the following is proposed:
– establishing a denser network of measuring stations
– ensuring the technical conditions for permanent monitoring with the shortest interruptions in data sequences possible;
– establishing monitoring with a higher reading density (e.g. 15 min) in the part of Upper Barać Cave that is opened to tourists for certain periods, in order to monitor the possible effect of visitors on the microclimate;
– in addition to spatial distribution, allowing for the monitoring of the vertical distribution of air temperature;
– in addition to the monitoring of temperature and air humidity, it is also necessary to measure other parameters such as air flow and the content of
CO2 in the air in the cave;
– including other forms of monitoring the environment (monitoring of water, soil and sediments).
PALEONTOLOGICAL DETERMINATION OF THE FOSSILISED REMAINS FROM UPPER BARAĆ CAVE
Zagreb, March 2014
Author: dr. sc. Kazimir Miculinić
SHORT OVERVIEW OF ANALYSIS RESULTS
The following families have been determined in the material: cave bear (Ursus spelaeus), cave lion (Panthera spelaea), leopard (Panthera pardus), cave hyena (Crocuta crocuta), wolf (Canis lupus), fox / Arctic fox (Vulpes vulpes/Alopex lagopus), wild cat (Felis silvestris), European pine marten (Martes martes), European badger (Meles meles), European hare / mountain hare (Lepus europaeus/lepus timidus), rhinoceros (Rhinocerotidae), horse (Equus caballus), aurochs/bison (Bos primigenius/Bison priscus), Alpine ibex/chamois (Capra ibex/Rupicapra rupicapra), red deer (Cervus elaphus), European roe deer (Capreolus capreolus), wild boar (Sus scrofa) and micromammals (Micromammalia), birds (Aves) and frogs (Anura).
The most represented species is the extinct cave bear. As an animal that appears at Pleistocene localities much more seldom than the cave bear, the cave lion finds are very interesting because their number exceeds the numbers found at most other cave lion localities in Croatia, while the well-preservedness of the skeletal elements allows for further metric and morphological processing and insight into the appearance of these big cats that used to inhabit the area of Rakovica. The wolf remains are very interesting as they indicate that wolves used to actively use Upper Barać Cave during the Pleistocene. The number of the finds allows for better morphometric analysis, as well as for a partial reconstruction of the skeletons of these animals. The osteological and odontological differences between the fox and the Arctic fox are very small, which is why only the mandible has been with certainty defined as belonging to a fox, while the rest of elements have been determined as fox / Arctic fox. Other beasts that have been discovered are the wild cat, European badger, as well as a single bone of a young leopard.
On the basis of the small number of hare remains, it was not possible to determine whether they belonged to the European hare or perhaps to the mountain hare, which also inhabited this area during the Pleistocene.
The remains of red deer are the most numerous herbivore remains in the material, while the European roe deer, and Alpine ibex or chamois appear in a significantly smaller number of specimens. An unspecified species of rhinoceros has been determined on the basis of a single bone, as has the aurochs or bison specimen which was collected at a different location in the cave than the others – in Barać Avenue.
A smaller number of finds have been determined as birds or amphibians (frogs).
PREVIOUS RESEARCH AND PROPOSAL FOR FUTURE WORK
The history of the paleontological research of Upper Barać Cave dates back to the 19th century, which is when cave bear finds were described (Kišpatić 1885). This work also gives a brief description of the first excavations in the cave, which were performed in 1877. Poljak (1914) and Malez (1955, 1962) established the need for systematic paleontological excavations in the cave, which were later conducted (Malez 1978), together with archaeological excavations (Mihelić & Balen 2004). In spite of the large number of excavations through a long period of time, it was only in 2013 that, owing to the selection of a good location inside the cave, the exceptional value of the paleontological finds was able to be determined, together with their great potential for further research. The fossilised remains from Upper Barać Cave are very interesting from a paleontological point of view, and in addition to scientific purposes they can also be used for exhibition and educational purposes. The performed anatomical and taxonomic analysis represents the basis for all further work.
A large number of skeletal elements have been during analysis, but the majority still remains fragmented. In addition to the 6274 specimens defined in the materials, more than 30,000 fragments still remain. These fragments have been initially examined and, were possible, glued together with certain other specimens. However, it is necessary to systematically review and sort these fragments and attempt to connect them with certain other specimens. In this manner, it will be possible to obtain bones that are as complete as possible, which is important both for further paleontological processing and for educational presentations and exhibitions. In addition, a large number of non-united bones of the head have been determined, and which also need to be connected to form integrated specimens.
It is necessary to perform systematic paleontological processing with an emphasis on the morphometric analysis of the bones and teeth of all families. Morphodynamic analysis of the tooth of the cave bear (Rabeder 1983, 1999) and analysis of the metapodium (Withalm 2001) may be used to determine to which of the new families in the new and increasingly-accepted taxonomic classification of cave bears could the bears from Upper Barać Cave belong. In addition, morphometric analysis of the interesting remains of the cave lion and wolf will allow for comparisons with other European populations to be drawn.
The method of absolute dating of radioactive carbon (14C) could be used to determine the age of the finds and the locality, which would allow for a more faithful reconstruction of the events in Upper Barać Cave, as well as for a reconstruction of its paleoenvironment.
The brief excavations conducted in the cave have yielded exceptional results and demonstrated the potential of further research. Due to the brevity of the research, the small test probe was not dug up to the bedrock or sterile layer. In addition to continuing work in the probe and the possibility of its expansion, the possibility of accessing new areas that have remained inaccessible since the Pleistocene due to the sedimentation of limestone debris is also very intriguing. Although it is likely that very few people had accessed the area where the probe is located, surface findings, mostly between the limestone debris, show new fractures, i.e. they have been fragmented by the passage of people. Entering new spaces and digging up the sediment would allow for intact surface findings that date back to the Pleistocene.
The fossilised materials covered in this report already allow for the opportunity for creating a better presentation of the Upper Barać Caves to tourists. If work on the materials were to be continued, and if further excavations were performed and the materials were appropriately presented, the Public Institution of Barać Caves could enrich their offer with paleontological finds and thus attract more visitors off season.
ARCHAEOLOGICAL RESEARCH OF BARAĆ CAVES
Krešimir Raguž, graduate archaeologist and Romanist
SHORT OVERVIEW OF RESULTS
Barać Caves are a renowned archaeological locality that, among others, attracted natural scientists such as Hirtz, Kišpatić and Malez. Out of the incidental finds from this locality, some that merit special mention are, for example, the bronze bracelet from Upper Barać Cave that is kept in the Archaeological Museum in Zagreb, which was gifted to the Archaeology Department of the National Museum by dr. Anton Culek in 1912. With its typological characteristics, this object corresponds to the Early Iron Era, most likely the 8th or 7th century BC. At the turn of the 21st century, a human skull was also found, together with many pottery fragments. It has also been confirmed that Upper Barać Cave is home to many human remains, out of which the incidental find of the remains of a hapless German soldier who met his demise near the end of World War Two or just after it particularly distinguishes itself.
However, the first archaeological research of the caves was conducted more than a century later. In 2004, while the caves were being renovated for the purpose of opening them to tourists, a team of experts from the Archaeological Museum in Zagreb (Sanjin Mihelić, Jacqueline Balen, Ivan Radman Livaja) conducted the first preliminary research in line with the advice provided by the speleologist Hrvoje Cvitanović and the archaeologist Krešimir Raguž.
The objects found during these protective excavations mostly consist of pottery fragments, together with a few pieces of metal or stone, which are irrelevant from the perspective of archaeological attribution. The pottery appears to have been intended for everyday use, and the craftsmanship is mostly rough and sloppy. It dates back either to prehistoric times, i.e. the Late Bronze Age or Early Iron Age, or to a more recent period, most likely mediaeval or post-mediaeval, largely made on a potter’s wheel. Preliminary analysis of the prehistoric pottery fragments also indicates dating between the Late Bronze Age and Early Iron Age, though a broader timeframe also cannot be excluded. Surface finds also include the fragment of an iron spear, which is today kept at the museum in Karlovac. This object most likely dates to a more recent period, possibly the Middle Ages.
The first protective excavations of Upper Barać Cave have confirmed its status as an interesting archaeological site with great potential for further research. Superficial inspection of the cave is enough to reach the conclusion that it was used as a dwelling place (at least temporarily) during the past three millennia. Probe research has not shown any large-scale interventions in the cave sediment (excluding, naturally, those that were part of the recent restorations), however, since the probes covered only a very small part of the surface, it is presumed that new research would be able to discover such interventions, if they existed. The stratigraphy of the cave and the well-preservedness of the bones of the Pleistocene fauna from the deeper layers indicate conditions that are favourable for preservation, which means that thorough research could yield traces of human habitation of the cave – naturally, providing that such traces existed at all.
In the early 2000s, Upper Barać Cave began to attract the attention of researchers, the speleologist Hrvoje Cvitanović and the archaeologist Krešimir Raguž, who included it in the fortified cave project of the caving club ˝Ursus spelaeus˝ from Karlovac and the Ministry of Culture of the Republic of Croatia, as this cave is one of about a hundred in Croatia in which the people built and adapted fortifications and in which they hid from the Ottomans (there are also dozens in other countries such as Bosnia and Herzegovina, Slovenia, Serbia, Montenegro, Greece, Lebanon…). These jewels of defensive and traditional architecture remained forgotten until recently, and were only known to a few select locals. During this project, all finds and find documentation were precisely documented, as were the fortifications in Upper Barać Cave themselves (the same was done for the other fortified caves included in the project), and the cave was included in the list of caves for archaeological excavations. In cooperation with the Ministry of Culture, the University of Zagreb and the University of Wyoming (USA), systematic research of this locality commenced in 2013, involving the participation of: Krešimir Raguž, Hrvoje Cvitanović, Kazimir Miculinić, Nataša Cvitanović, Iva Perković with her colleague Boris Olujić from the History Department of the Faculty of Humanities and Social Sciences of the University of Zagreb, James Ahern from University of Wyoming (USA), Rory Becker from Eastern Oregon University (USA) and their Croatian and American students.
One of the tasks of this research was to determine the nature of the locality (i.e. whether Upper Barać Cave was used as a place of residence, or perhaps as a ritual site, graveyard, etc.).
The second task was to, by using state-of-the-art methods, gather finds and data and systematically process them in order to make comprehensive multi-year research plans.
In 2013, 4 sites within the cave itself were researched: two probes in the first cave (Guana hall). In this part, probe S1 discovered an open campfire site right behind the wall which was preliminarily, according to stratigraphic relations, carefully dated to the Middle Ages or the New Era, while analysis C-14 confirmed such dating to the second half of the 17th or to the 18th century. The other probe yielded no finds of greater importance, with the exception of several pottery fragments from approximately the similar period.
A lot of human remains were discovered in the rear part of the cave that is not open to tourists. Knowledge of these remains already existed, but on this occasion they were precisely recorded, and systematic archaeological excavation commenced (in probe S3). With the use of the C-14 method, the human remains were dated approximately to the period between the second half of the 15th century and the end of the 16th century. The same applies to Barać Avenue, the second rear tunnel behind the collapsed ceiling where, in addition to human remains, prehistoric pottery which can roughly be dated to the Late Bronze Era or Early Iron Era was discovered at the very end of the tunnel.
The analysis of human remains and folk tales confirmed that this was a case of the tragic destinies of the Croats of this region – a mass grave from the era of Ottoman invasions.
In the central part of the cave, i.e. the Dragon’s Throat, an exceptional number of valuable paleontological finds was discovered. To begin with, let us note only a few of the most important ones: numerous finds of Pleistocene animals, i.e. the cave lion, cave bear, Pleistocene wolf, hairy rhinoceros… as well as the exceptional find of one part of a wooden bow (the only one of its kind in Croatia and an iron spur, which are currently undergoing restoration at the Archaeological Museum in Zagreb owing to the efforts of the museum’s management board. The analysis of the human remains was entrusted to James Ahern from the University of Wyoming (USA).
Therefore, in 2013, systematic research of the entire cave commenced with the use of the ˝Paleolithic˝ method – in which each find or fragment, whether pottery, bone or something else, was drawn separately. Geophysical research was also conducted, as was paleontological research.
In 2015, the second international Croatian-American campaign (caving club ˝Ursus spelaeus˝ from Karlovac, Ministry of Culture of the Republic of Croatia, University of Wyoming and University of Zagreb) of systematic research was conducted under the leadership of archaeologists Krešimir Raguž, Rick Weathermon (University of Wyoming, USA) and Iva Perković, paleontologist Kazimir Miculinić, speleologists Hrvoje Cvitanović and Nataša Cvitanović and geologists Neven Šuica. The campaign built upon the research and, in addition to previous analyses on this locality, also introduced the analysis of stable isotopes, which can be used to determine the spatial origin and movement and diet of the inhabitants that met their untimely demise in Upper Barać Cave.
In June and August 2017, the third Croatian-American campaign (caving club ˝Ursus spelaeus˝ from Karlovac, Ministry of Culture of the Republic of Croatia, University of Wyoming and University of Zagreb, with the help of the Public Institution for the Management of Protected Natural Values on the Territory of the Municipality of Rakovica) of systematic research was conducted under the leadership of archaeologists Krešimir Raguž, Rick Weathermon (University of Wyoming, USA) and Iva Perković, paleontologist Kazimir Miculinić, speleologists Hrvoje Cvitanović and Nataša Cvitanović and geologist Neven Šuica. As part of this campaign, field classes for American students were held within the scope of the Croatian-American field school in which 7 students and one doctoral student participated. The campaign built upon existing research, in addition to previous analyses on this locality, also introduced the analysis of stable isotopes, which can be used to determine the spatial origin and movement and diet of the inhabitants that met their untimely demise in Upper Barać Cave. After many years of research and spatial analysis of the remains, it seems likely that a hypothesis on the deaths of a greater number of people inside the cave can be made. Was this due to a tragedy caused by the lighting of a fire, as the finds in the front part of the cave suggest? Were these people locals (analysis of radioactive isotopes), and were they related by blood (DNA analyses)? This is yet to be shown by future research and analysis.
As the research conducted so far has shown that the folk legends that tell the tale someone called Barać who defeated an burly Ottoman soldier in front of Barać Caves are not just ˝smoke without fire˝ and represent an important piece of information for historical analysis, it is the hope of researchers that modern methods can be used to shed as much light as possible both on scientific data and the Ottoman tyranny that the Croats suffered during their gruelling and bloody history.