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Query: "author" (Rok Brajkovič) .

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1.
Hydrogeological characterization of karst springs of the white (Proteus anguinus anguinus) and black olm (Proteus anguinus parkelj) habitat in Bela krajina (SE Slovenia)
Katja Koren, Rok Brajkovič, 2023, original scientific article

Abstract: The springs west of Črnomelj, in SE Slovenia, are the habitat of the black (Proteus anguinus parkelj) and the white olm (Proteus anguinus anguinus). Some of these springs are also the only known habitat in the world of endemic species of black olm. A steady decline in olm populations has been observed in this area over the past decades. Owing to the rapid runoff and groundwater flow high-resolution monitoring is essential in providing better insight into the hydrogeological characterization of the catchment area of springs. Specific factors and critical parameters of water behind said olm degradation have not yet been defined. Because the olm’s environment is largely aquatic, one potential critical parameter could be the higher water temperatures (>12 °C) or higher nitrate concentration (>9.2mg/l). The six-month observation of the springs (July – December 2021) point to water temperature as a potential critical parameter since the water temperature of the springs exceeded 12 °C in months July and August. Nitrate concentrations could also be a second critical parameter in the degradation of the olm’s habitat. Maximum nitrate concentrations above 9.2mg/l throughout much of the observation period (except for Dobličica spring). Due to less agricultural activity in December in the spring catchment area and a higher dilution rate due to reduced evapotranspiration and increased effective precipitation during this time of the year, the nitrate concentrations are decreased. The results of the measured parameters of groundwater could show the hydrogeological connection between the Otovski and Pački breg springs and between Šotor, Jamnice and Dobličica. The Obršec spring has an independent catchment area. A detailed estimation of the springs catchment area is possible due to a detailed geologic map. It is necessary to determine the origin of the nitrate (nitrate isotope analysis), to quantify the threshold values of the critical parameters, to define precisely all the causes of the olm deterioration, and to make proposals for appropriate measures to limit or even stop the decline of the olm population.
Keywords: hydrogeology, olm, ecology, nitrate, monitoring
Published in DiRROS: 16.01.2024; Views: 143; Downloads: 48
.pdf Full text (13,65 MB)

2.
Geochemical and mineralogical approaches in unraveling paleoweathering, provenance, and tectonic setting of the clastic sedimentary succession (Western Central Paratethys)
Kristina Ivančič, Rok Brajkovič, Mirijam Vrabec, 2024, original scientific article

Abstract: Pronounced tectonic and paleogeographic changes were detected in the Alpine–Pannonian region during the Miocene at the interface between the Alps, the Dinarides, and the Pannonian Basin. To understand the major tectonic, paleogeographic, and paleoclimatic changes during this period, geochemical and mineralogical investigations were carried out on the fine-grained clastic sedimentary rocks in the Tunjice Hills. The paleoweathering indicates a cold and/or arid to a warm and humid period. The paleoclimate and the regional climatic conditions correspond well with the Middle Miocene Climatic Optimum. The mineral composition shows an abundance of quartz and calcite. Quartz is associated with detrital origin from volcanic and metamorphic rocks of the Eastern and Southern Alps and with authigenic processes in sediments. Calcite is related to authigenic origin formed in shallow marine environments and to detrital provenance from the Southern Alps. Not all discriminant functions based on major oxides provided adequate results in determining the tectonic setting. The source rocks were subjected to oceanic island arc and collision. Moreover, sedimentation was influenced by both active and passive margin settings. The former is related to the Alpine collision, which continued from the Cenozoic onward, and the latter is connected to the processes associated with the formation of the Pannonian Basin System, which began in the late Early Miocene.
Keywords: Central Paratethys, provenance, tectonic setting, paleoweathering, Miocene, Tunjice Hills
Published in DiRROS: 15.01.2024; Views: 124; Downloads: 44
.pdf Full text (13,59 MB)

3.
Mid-Cretaceous calcarenite in stone products from the Roman colony of Emona, Regio X (modern Ljubljana, Slovenia)
Rok Brajkovič, Bojan Djurić, David Gerčar, Blanka Cvetko Tešović, Boštjan Rožič, Luka Gale, 2022, original scientific article

Abstract: Over the course of studying stone products from theRoman colony of Emona (Regio X), stratigraphicallyundefined calcarenite that was used to make simplesepulchral and architectural stone products wasdetected. The calcarenite used is late Aptian to earlyCenomanian in age. The corresponding facies werefound in the Lower Flyschoid Formation outcroppingnear the town of Medvode, within the local radius ofEmona. The Roman quarry was likely located in thisarea near the Sava River. According to the collecteddata, the quarry was in operation mainly in the 1stcentury.
Keywords: Cretaceous, microfacies, quarry production, Regio X, Roman time, stone products
Published in DiRROS: 17.08.2022; Views: 630; Downloads: 429
.pdf Full text (25,02 MB)
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4.
Multi-method study of the Roman quarry at Podpeč sedimentary succession and stone products
Rok Brajkovič, Luka Gale, Bojan Djurić, 2022, original scientific article

Abstract: The paper presents a multi-method characterisation of the Roman quarry of the middle Lower Jurassic (Pliensbachian) limestone situated in the village of Podpeč, south of Ljubljana, and examples of the placement of stone products made from micritic, fine-grained, and oolithic facies into the known extent of the quarry. 23 m of the rock succession from the ancient quarry was exposed at the northern tip of the St. Ana Hill by archaeological trenching. Petrological, micropaleontological, mineralogical, geochemical, and isotopic analyses of carbon, oxygen, and strontium were performed in order to characterise the rocks exploited in the quarry. Additionally, a new detailed geological map of the wider Podpeč area was prepared, which defines in detail the lithostratigraphic units in the area.
Keywords: Lower Jurassic, Podbukovje Formation, provenance, facies, foraminifera, geochemistry, Emona, geoarchaeology
Published in DiRROS: 27.07.2022; Views: 713; Downloads: 251
.pdf Full text (6,47 MB)

5.
Kamnolom apnenca v Podpeči pri Ljubljani in njegovi izdelki
Bojan Djurić, Luka Gale, Rok Brajkovič, 2022, original scientific article

Abstract: Kamnolom v naselju Podpeč pri Ljubljani velja za glavni kamnolom rimske kolonije Emone (Ljubljana). Obstoj antič-nega kamnoloma v Podpeči je bil do sedaj utemeljen le na podlagi makroskopske podobnosti med Členom litiotidnega apnenca, ki izdanja v Podpeči, in z njim povezanimi rimskimi spomeniki, odkritimi v Ljubljani. V okviru pričujočega dela smo skušali poiskati oprijemljive arheološke in geoarheološke dokaze za njegov obstoj. V skrajno severnem delu kamnoloma smo izvedli arheološko sondiranje, hkrati pa natančno določili sestavo apnenca na tem območju in v 288 izdelkih iz antične Emone. Sondiranje severno od modernega kamnoloma je odkrilo dobro ohranjene sledove rimsko-dobne kamnoseške dejavnosti. Hkrati je litološka analiza spomenikov iz Emone razkrila, da je kar 182 (ali 64 odstotkov) analiziranih spomenikov izdelanih iz apnenca, litološko identičnega različkom, ki izdanjajo v Podpeči. Ti različki se prostorsko grupirajo severno od modernega kamnoloma. Pri tem sicer ostaja odprto vprašanje pripadnosti nekaterih različkov apnenca v izdelkih, ki so brez diagnostičnih komponent in bi lahko pripadali tudi nekoliko starejšemu Členu krkinega apnenca. Rekonstrukcijo obsega starega kamnoloma omogoča primerjava faciesov izvornih litostratigrafskih enot in izdelkov, pa tudi historična analiza zgodnjih kartografskih in katastrskih dokumentov. Analiza najzgodnejših izdelkov je omogočila hipotezo o prihodu kamnosekov iz kamnoloma v Nabrežini.
Keywords: Slovenija, Podpeč, Emona, rimska doba, litiotidni apnenec, mikrofaciesna analiza, rimski in novoveški kamnolom, izdelki
Published in DiRROS: 21.07.2022; Views: 638; Downloads: 526
.pdf Full text (28,23 MB)

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